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  Subjects -> ENGINEERING (Total: 2266 journals)
    - CHEMICAL ENGINEERING (190 journals)
    - CIVIL ENGINEERING (183 journals)
    - ELECTRICAL ENGINEERING (99 journals)
    - ENGINEERING (1195 journals)
    - ENGINEERING MECHANICS AND MATERIALS (391 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (64 journals)
    - MECHANICAL ENGINEERING (89 journals)

ENGINEERING (1195 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Full-text available via subscription   (Followers: 5)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 216)
Acta Geotechnica     Hybrid Journal   (Followers: 6)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 1)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 10)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 4)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 5)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 6)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
Advances in Artificial Neural Systems     Open Access   (Followers: 3)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 9)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 13)
Advances in Polymer Science     Hybrid Journal   (Followers: 40)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 35)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 1)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 4)
AIChE Journal     Hybrid Journal   (Followers: 29)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access  
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 5)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 6)
Applied Clay Science     Hybrid Journal   (Followers: 4)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3)
Applied Nanoscience     Open Access   (Followers: 7)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 4)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 8)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 2)
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 7)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 7)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 3)
Batteries     Open Access   (Followers: 3)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 23)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 3)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 9)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 16)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 31)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 1)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 3)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Full-text available via subscription   (Followers: 13)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 40)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 7)
Case Studies in Thermal Engineering     Open Access   (Followers: 4)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 5)
CEAS Space Journal     Hybrid Journal  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 4)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 4)
Coatings     Open Access   (Followers: 2)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 23)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 252)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 177)
Composites Part B : Engineering     Hybrid Journal   (Followers: 223)
Composites Science and Technology     Hybrid Journal   (Followers: 164)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 12)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 17)
Computers & Geosciences     Hybrid Journal   (Followers: 25)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 8)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 25)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 7)
Control Engineering Practice     Hybrid Journal   (Followers: 40)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 24)
CT&F Ciencia, Tecnologia y Futuro     Open Access  
CTheory     Open Access  
Current Applied Physics     Full-text available via subscription   (Followers: 4)

        1 2 3 4 5 6 | Last

Journal Cover Applied Sciences
  [SJR: 0.178]   [H-I: 9]   [3 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Online) 2076-3417
   Published by MDPI Homepage  [148 journals]
  • Applied Sciences, Vol. 7, Pages 312: An Encoder-Decoder Based Convolution
           Neural Network (CNN) for Future Advanced Driver Assistance System (ADAS)

    • Authors: Robail Yasrab, Naijie Gu, Xiaoci Zhang
      First page: 312
      Abstract: We propose a practical Convolution Neural Network (CNN) model termed the CNN for Semantic Segmentation for driver Assistance system (CSSA). It is a novel semantic segmentation model for probabilistic pixel-wise segmentation, which is able to predict pixel-wise class labels of a given input image. Recently, scene understanding has turned out to be one of the emerging areas of research, and pixel-wise semantic segmentation is a key tool for visual scene understanding. Among future intelligent systems, the Advanced Driver Assistance System (ADAS) is one of the most favorite research topic. The CSSA is a road scene understanding CNN that could be a useful constituent of the ADAS toolkit. The proposed CNN network is an encoder-decoder model, which is built on convolutional encoder layers adopted from the Visual Geometry Group’s VGG-16 net, whereas the decoder is inspired by segmentation network (SegNet). The proposed architecture mitigates the limitations of the existing methods based on state-of-the-art encoder-decoder design. The encoder performs convolution, while the decoder is responsible for deconvolution and un-pooling/up-sampling to predict pixel-wise class labels. The key idea is to apply the up-sampling decoder network, which maps the low-resolution encoder feature maps. This architecture substantially reduces the number of trainable parameters and reuses the encoder’s pooling indices to up-sample to map pixel-wise classification and segmentation. We have experimented with different activation functions, pooling methods, dropout units and architectures to design an efficient CNN architecture. The proposed network offers a significant improvement in performance in segmentation results while reducing the number of trainable parameters. Moreover, there is a considerable improvement in performance in comparison to the benchmark results over PASCAL VOC-12 and the CamVid.
      PubDate: 2017-03-23
      DOI: 10.3390/app7040312
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 314: Seismic Damage Evaluation of
           Concrete-Encased Steel Frame-Reinforced Concrete Core Tube Buildings Based
           on Dynamic Characteristics

    • Authors: Lei Zeng, Yunfeng Xiao, Yiguang Chen, Siqian Jin, Wei Xie, Xianjie Li
      First page: 314
      Abstract: To evaluate damage state and residual resistance of concrete-encased steel frame-reinforced concrete core tube buildings under earthquake actions, a criterion of damage assessment based on dynamic characteristics is proposed in this paper. Dynamic characterization experiments were conducted on a 10-story and 1/5 scaled building model using velocity sensors on each floor, and natural frequencies were obtained based on the measured data. Modal analysis was carried out using a nonlinear finite element program, and the simulation results of the dynamic characteristics agreed well with experimental ones. Then, the damage processes under different seismic wave inputs were revealed based on finite element analysis, and the max story drift angle was chosen to reflect the damage state and to quantify the degree of damage. A criterion of seismic damage assessment is proposed based on the relationship between the quantitative damage value and the dynamic characteristics, in which the higher order modes were considered. Moreover, influencing factors, including earthquake intensity and structural stiffness ratio, were analyzed, and the results indicated that the proposed damage index based on dynamic characteristics can account for the higher-order modes and provides an innovative approach to evaluate the seismic damage.
      PubDate: 2017-03-23
      DOI: 10.3390/app7040314
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 315: Zero-Voltage Ride-Through Capability
           of Single-Phase Grid-Connected Photovoltaic Systems

    • Authors: Zhen Zhang, Yongheng Yang, Ruiqing Ma, Frede Blaabjerg
      First page: 315
      Abstract: Distributed renewable energy systems play an increasing role in today’s energy paradigm. Thus, intensive research activities have been centered on improving the performance of renewable energy systems, including photovoltaic (PV) systems, which should be of multiple-functionality. That is, the PV systems should be more intelligent in the consideration of grid stability, reliability, and fault protection. Therefore, in this paper, the performance of single-phase grid-connected PV systems under an extreme grid fault (i.e., when the grid voltage dips to zero) is explored. It has been revealed that combining a fast and accurate synchronization mechanism with appropriate control strategies for the zero-voltage ride-through (ZVRT) operation is mandatory. Accordingly, the representative synchronization techniques (i.e., the phase-locked loop (PLL) methods) in the ZVRT operation are compared in terms of detection precision and dynamic response. It shows that the second-order generalized integrator (SOGI-PLL) is a promising solution for single-phase systems in the case of fault ride-through. A control strategy by modifying the SOGI-PLL scheme is then introduced to single-phase grid-connected PV systems for ZVRT operation. Simulations are performed to verify the discussions. The results have demonstrated that the proposed method can help single-phase PV systems to temporarily ride through zero-voltage faults with good dynamics.
      PubDate: 2017-03-24
      DOI: 10.3390/app7040315
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 316: Fall Detection for Elderly from
           Partially Observed Depth-Map Video Sequences Based on View-Invariant Human
           Activity Representation

    • Authors: Rami Alazrai, Mohammad Momani, Mohammad Daoud
      First page: 316
      Abstract: This paper presents a new approach for fall detection from partially-observed depth-map video sequences. The proposed approach utilizes the 3D skeletal joint positions obtained from the Microsoft Kinect sensor to build a view-invariant descriptor for human activity representation, called the motion-pose geometric descriptor (MPGD). Furthermore, we have developed a histogram-based representation (HBR) based on the MPGD to construct a length-independent representation of the observed video subsequences. Using the constructed HBR, we formulate the fall detection problem as a posterior-maximization problem in which the posteriori probability for each observed video subsequence is estimated using a multi-class SVM (support vector machine) classifier. Then, we combine the computed posteriori probabilities from all of the observed subsequences to obtain an overall class posteriori probability of the entire partially-observed depth-map video sequence. To evaluate the performance of the proposed approach, we have utilized the Kinect sensor to record a dataset of depth-map video sequences that simulates four fall-related activities of elderly people, including: walking, sitting, falling form standing and falling from sitting. Then, using the collected dataset, we have developed three evaluation scenarios based on the number of unobserved video subsequences in the testing videos, including: fully-observed video sequence scenario, single unobserved video subsequence of random lengths scenarios and two unobserved video subsequences of random lengths scenarios. Experimental results show that the proposed approach achieved an average recognition accuracy of 93 . 6 % , 77 . 6 % and 65 . 1 % , in recognizing the activities during the first, second and third evaluation scenario, respectively. These results demonstrate the feasibility of the proposed approach to detect falls from partially-observed videos.
      PubDate: 2017-03-24
      DOI: 10.3390/app7040316
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 317: Sensing Performance of a Vibrotactile
           Glove for Deaf-Blind People

    • Authors: Albano Carrera, Alonso Alonso, Ramón de la Rosa, Evaristo Abril
      First page: 317
      Abstract: This paper presents a glove designed to assess the viability of communication between a deaf-blind user and his/her interlocutor through a vibrotactile device. This glove is part of the TactileCom system, where communication is bidirectional through a wireless link, so no contact is required between the interlocutors. Responsiveness is higher than with letter by letter wording. The learning of a small set of concepts is simpler and the amount learned can be increased at the user’s convenience. The number of stimulated fingers, the keying frequencies and finger response were studied. Message identification rate was 97% for deaf-blind individuals and 81% for control subjects. Identification by single-finger stimulation was better than by multiple-finger stimulation. The interface proved suitable for communication with deaf-blind individuals and can also be used in other conditions, such as multilingual or noisy environments.
      PubDate: 2017-03-24
      DOI: 10.3390/app7040317
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 318: Investigation of Interactive
           Strategies Used in Undertaking Collaborative Tasks

    • Authors: Kan Lo, Tao Zeng, Yaoping Hu
      First page: 318
      Abstract: Collaborative virtual environments (CVEs) present ways for human users to work together on a task. Research efforts of CVEs have mainly focused on the factors that affect the task performance of the users, such as awareness, communication, and presence. Furthermore, the users involved normally have the same task experience or knowledge background. In this paper, we examined the effect of interactive strategies for human/human interaction, which involves human users with different levels of expertise. Within a CVE for an expert and a novice, we deployed three interactive strategies—Tele-Operation, Tele-Assistance3, and Tele-Assistance7—to give the three degrees of autonomy to the novice. Focusing on the performance of the novice, our findings revealed that each interactive strategy has a different effect on the task performance of the novice. These findings could aid in choosing an optimal interactive strategy for performing a collaborative task between an expert and a novice.
      PubDate: 2017-03-24
      DOI: 10.3390/app7040318
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 319: Analyses of the Effect of Cycle Inlet
           Temperature on the Precooler and Plant Efficiency of the Simple and
           Intercooled Helium Gas Turbine Cycles for Generation IV Nuclear Power
           Plants

    • Authors: Arnold Gad-Briggs, Theoklis Nikolaidis, Pericles Pilidis
      First page: 319
      Abstract: Nuclear Power Plant (NPP) precooler coolant temperature is critical to performance because it impacts the work required to increase the coolant pressure. Variation of the coolant temperature results in varied precooler hot gas temperatures, which are cooled before re-entry. For recirculation, the heat sink (usually sea water), could exit the precooler at unfavourable temperatures and impact the re-entering coolant, if not recirculated properly at the source. The study objective is to analyse the effects of coolant inlet temperature on the heat sink and cycle efficiency. The cycles are Simple Cycle Recuperated (SCR), Intercooler Cycle Recuperated (ICR), and Intercooled Cycle without Recuperation (IC). Results show that the co-current precooler provides favourable outlet heat sink temperatures but compromises compactness. For a similar technology level, the counter-current precooler yields excessive heat sink outlet temperatures due to a compact, robust, and efficient heat transfer design, but could be detrimental to precooler integrity due to corrosion, including the cycle performance, if not recirculated back into the sea effectively. For the counter-current, the ICR has the best heat sink average temperature ratio of 1.4; the SCR has 2.7 and IC has 3.3. The analyses aid the development of Gas Cooled Fast Reactors (GFRs) and Very High Temperature Reactors (VHTRs), where helium is used as the coolant.
      PubDate: 2017-03-24
      DOI: 10.3390/app7040319
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 320: A Study on the Optimal Actuation
           Structure Design of a Direct Needle-Driven Piezo Injector for a CRDi
           Engine

    • Authors: Sangik Han, Juhwan Kim, Jinwook Lee
      First page: 320
      Abstract: Recently, the high-pressure fuel injection performance of common-rail direct injection (CRDi) engines has become more important, due to the need to improve the multi-injection strategy. A multiple injection strategy provides better emission and fuel economy characteristics than a normal single injection scheme. The CRDi engine performance changes with the type of high-pressure electro-mechanical injector that is used and its injection response in a multi-injection scheme. In this study, a direct needle-driven piezo injector (DPI) was investigated, to optimize its actuation components, including the plate length, number of springs, and the elasticity of the spring between the injector needle and the piezo stack. Three prototype DPIs were proposed by this research. They were classified as Type 1, 2, and 3, depending on whether the injector needle was hydraulic or mechanical. Then, the optimal prototype was determined by conducting four evaluation experiments analyzing the maximum injection pressure, injection rate, spray visualization, and real engine combustion application. As a result, it was found that the Type 3 DPI prototype, with several pan-springs and plates, had the highest injection pressure, a steady injection rate, and the fastest spray speed. It also demonstrated the most effective emission reduction for a two-stage rapid spray injection in a single-cylinder CRDi engine. The Type 3 DPI displays an increased elasticity from its hydraulic needle that provides a synergy effect for improving DPI actuation.
      PubDate: 2017-03-24
      DOI: 10.3390/app7040320
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 321: Optimization of Subcritical Water
           Extraction of Resveratrol from Grape Seeds by Response Surface Methodology
           

    • Authors: Yajie Tian, Yingsa Wang, Yunyun Ma, Pengbo Zhu, Jing He, Jiandu Lei
      First page: 321
      Abstract: The subcritical water extraction (SWE) is a high-efficiency and environment-friendly extraction method. The extraction of resveratrol (RES) of grape seeds obtained from the wine production process was proposed using subcritical water extraction (SWE). The effects of different extraction process parameters on RES yield were investigated by single factors. Extraction optimization was conducted using response surface methodology (RSM). Extraction temperature was proven to be the most significant factor influencing RES yield. The optimal conditions was as follows: extraction pressure of 1.02 MPa, temperature of 152.32 °C, time of 24.89 min, and a solid/solvent ratio of 1:15 g/mL. Under these optimal conditions, the predicted extraction RES yield was 6.90 μg/g and the recoveries was up to 91.98%. Compared to other previous studies, this method required less pollution and less treatment time to extract RES from grape seeds. From these results, added economic value to this agroindustrial residue is proposed using environmentally friendly extraction techniques.
      PubDate: 2017-03-24
      DOI: 10.3390/app7040321
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 322: The Application of Supercritical
           Carbon Dioxide and Ethanol for the Extraction of Phenolic Compounds from
           Chokeberry Pomace

    • Authors: Łukasz Woźniak, Krystian Marszałek, Sylwia Skąpska, Renata Jędrzejczak
      First page: 322
      Abstract: Chokeberry (Aronia melanocarpa (Michx.) Elliot) is a fruit with exceptionally high levels of phenolic compounds which are accumulated mainly in the peel; hence, the majority remains in the leftovers after juice production. Extraction with the use of carbon dioxide in supercritical conditions was used to isolate phenolic compounds from the pomace. The effect of the process parameters (temperature; pressure; and the addition of ethanol) on the extraction yields and properties of the extracts was investigated. The anthocyanin and total phenolic compound content, as well as the scavenging activity against five selected radicals, were evaluated. The best results were acquired for 35 °C, 10 MPa, and 80% m/m ethanol addition, the yield of phenolic compounds was 1.52 g per 100 g of pomace. The amount of extracted phenolics and the antioxidative attributes of the extracts were highly correlated. The impact of supercritical carbon dioxide density on the amount of recovered compounds was confirmed. The use of supercritical CO2 led to a significant reduction in the volume of organic solvent required for extraction.
      PubDate: 2017-03-25
      DOI: 10.3390/app7040322
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 323: Integrated Design of Hybrid
           Interstory-Interbuilding Multi-Actuation Schemes for Vibration Control of
           Adjacent Buildings under Seismic Excitations

    • Authors: Francisco Palacios-Quiñonero, Josep Rubió-Massegú, Josep Rossell, Hamid Karimi
      First page: 323
      Abstract: The design of vibration control systems for the seismic protection of closely adjacent buildings is a complex and challenging problem. In this paper, we consider distributed multi-actuation schemes that combine interbuilding linking elements and interstory actuation devices. Using an advanced static output-feedback H ∞ approach, active and passive vibration control systems are designed for a multi-story two-building structure equipped with a selected set of linked and unlinked actuation schemes. To validate the effectiveness of the obtained controllers, the corresponding frequency responses are investigated and a proper set of numerical simulations is conducted using the full scale North–South El Centro 1940 seismic record as ground acceleration disturbance. The observed results indicate that using combined interstory-interbuilding multi-actuation schemes is an effective means of mitigating the vibrational response of the individual buildings and, simultaneously, reducing the risk of interbuilding pounding. These results also point out that passive control systems with high-performance characteristics can be designed using damping elements.
      PubDate: 2017-03-25
      DOI: 10.3390/app7040323
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 324: Empirical Mode Decomposition of
           Ultrasound Imagingfor Gain-Independent Measurement on Tissue Echogenicity:
           A Feasibility Study

    • Authors: Zhuhuang Zhou, Weiwei Wu, Shuicai Wu, Kebin Jia, Po-Hsiang Tsui
      First page: 324
      Abstract: Empirical mode decomposition (EMD) is an adaptive method for decomposing a signal into intrinsic mode functions (IMFs).This study explored using EMD of ultrasound imaging for gain-independent measurements on tissue echogenicity. The IMF-based echogenicity ratio (IER) was proposed using the first (C1) and second IMFs (C2) of ultrasound radiofrequency data. Experiments on lipid phantoms were conducted to investigate the practical performance of IER. Phantoms with lipid concentrations 0%–30% (n = 36) were scanned using a clinical ultrasound scanner to acquire the radiofrequency data under different gains (12–33 dB) for EMD and IER calculations. Experiments on a tissue-mimicking phantom were further performed using the same ultrasound system and data acquisition procedure to investigate the effect of ultrasound frequency on the IER at5–8 MHz.Experimental results showed that the IER measured under 33-dB gain decreased from 6.65 ± 0.23 to 3.97 ± 0.10 when the lipid concentrations were increased from 0% to 30%. When 12-dB gain was used, the IER decreased from 6.21 ± 0.29 to 3.39 ± 0.07. However, whenincreasing the frequency, the IER had a mean decreasing rate of −8.67% per MHz, which was lower than those of the C1 and C2 intensities.The proposed IER may allow gain-independent measurement on tissue echogenicity.
      PubDate: 2017-03-25
      DOI: 10.3390/app7040324
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 325: A Substrate-Reclamation Technology
           for GaN-Based Lighting-Emitting Diodes Wafer

    • Authors: Shih-Yung Huang, Po-Jung Lin
      First page: 325
      Abstract: This study reports on the use of a substrate-reclamation technology for a gallium nitride (GaN)-based lighting-emitting diode (LED) wafer. There are many ways to reclaim sapphire substrates of scrap LED wafers. Compared with a common substrate-reclamation method based on chemical mechanical polishing, this research technology exhibits simple process procedures, without impairing the surface morphology and thickness of the sapphire substrate, as well as the capability of an almost unlimited reclamation cycle. The optical performances of LEDs on non-reclaimed and reclaimed substrates were consistent for 28.37 and 27.69 mcd, respectively.
      PubDate: 2017-03-27
      DOI: 10.3390/app7040325
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 326: An Improvement of a Fuzzy
           Logic-Controlled Maximum Power Point Tracking Algorithm for Photovoltic
           Applications

    • Authors: Woonki Na, Pengyuan Chen, Jonghoon Kim
      First page: 326
      Abstract: This paper presents an improved maximum power point tracking (MPPT) algorithm using a fuzzy logic controller (FLC) in order to extract potential maximum power from photovoltaic cells. The objectives of the proposed algorithm are to improve the tracking speed, and to simultaneously solve the inherent drawbacks such as slow tracking in the conventional perturb and observe (P and O) algorithm. The performances of the conventional P and O algorithm and the proposed algorithm are compared by using MATLAB/Simulink in terms of the tracking speed and steady-state oscillations. Additionally, both algorithms were experimentally validated through a digital signal processor (DSP)-based controlled-boost DC-DC converter. The experimental results show that the proposed algorithm performs with a shorter tracking time, smaller output power oscillation, and higher efficiency, compared with the conventional P and O algorithm.
      PubDate: 2017-03-29
      DOI: 10.3390/app7040326
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 327: The Experimental Study of the
           Temperature Effect on the Interfacial Properties of Fully Grouted Rock
           Bolt

    • Authors: Fuhai Li, Xiaojuan Quan, Yi Jia, Bo Wang, Guibin Zhang, Siyin Chen
      First page: 327
      Abstract: This study analyzes the phenomenon of performance deterioration in fully grouted rock bolts in tunnels with a dry, hot environment and high geothermal activity with a focus on temperature effects on interfacial bond performance. Three groups of fully grouted rock bolt specimens were designed based on similar mechanical principles. They were produced and maintained at 20 °C, 35 °C, and 50 °C. Through the indoor gradual loading tensile test of specimens, variations of axial force and shear stress between the rock bolt and mortar adhesive interface were obtained under different environmental temperatures. Distribution of the axial force and shear stress on the anchorage section were found under different tensile forces. Results showed that, with an increase in specimen environmental temperature, maximum shear stress of the rock bolt section became smaller, while shear stress distribution along the rock bolt segment became more uniform. In addition, the axial force value at the same position along the pull end was greater, while axial stress along the anchorage’s length decayed faster. With an increase in tensile force under different temperatures, the axial force and maximum shear stress of rock bolt specimens along the anchorage section has a corresponding increase.
      PubDate: 2017-03-27
      DOI: 10.3390/app7040327
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 328: Simulation Analysis and Experiment of
           Variable-Displacement Asymmetric Axial Piston Pump

    • Authors: Youshan Gao, Jie Cheng, Jiahai Huang, Long Quan
      First page: 328
      Abstract: The variable displacement pump control system has greater energy-saving advantages and application prospects than the valve control system. However, the variable displacement pump control of differential cylinder is not concurrent with the existing technologies. The asymmetric pump-controlled cylinder is, therefore, used to balance the unequal volume flow through a single rod cylinder in closed-circuit system. This is considered to be an effective method. Nevertheless, the asymmetric axial piston pump (AAPP) is a constant displacement pump. In this study, variable-displacement asymmetric axial piston pump (VAPP) is investigated according to the same principle used in investigating AAPP. This study, therefore, aims at investigating the characteristics of VAPP. The variable-displacement output of VAPP is implemented by controlling the swash plate angle with angle feedback control circuit, which is composed of a servo proportional valve and an angular displacement sensor. The angular displacement sensor is connected to the swash plate. The simulation model of VAPP, which is set up through the ITI-SimulationX simulation platform, is used to predict VAPP’s characteristics. The purpose of implementing the experiment is to verify the theoretical results. Both the simulation and the experiment results demonstrated that the swash plate angle is controlled by a variable mechanism; when the swash plate angle increases, the flow of Port B and Port T increases while the response speed of Port B and Port T also accelerates. When the swash plate angle is constant, the flow of Port B and Port T increases along with the increase of pump speed, although the pressure-response speed of Port B is faster than that of Port T. Consequently, the flow pulsation of Port B and Port T tends to decrease gradually along with the increase of pump speed. When the pressure loaded on Port B equals to that of Port T, the flow ripple cycle of Port B is longer than that of Port T, whereas the peak flow of Port B is higher than that of Port T. Since the flow ripple of Port T is bigger than that of Port B, Port T should be connected to the low pressure sides or the oil tank so that it does not affect VAPP’s performance. Further, to avoid the backflow of VAPP from Port T to Port B, Port T cannot be loaded alone, and the loading pressure of Port T also cannot exceed that of Port B.
      PubDate: 2017-03-27
      DOI: 10.3390/app7040328
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 329: Collision Avoidance for Cooperative
           UAVs with Rolling Optimization Algorithm Based on Predictive State Space

    • Authors: Tianyuan Yu, Jun Tang, Liang Bai, Songyang Lao
      First page: 329
      Abstract: Unmanned Aerial Vehicles (UAVs) have recently received notable attention because of their wide range of applications in urban civilian use and in warfare. With air traffic densities increasing, it is more and more important for UAVs to be able to predict and avoid collisions. The main goal of this research effort is to adjust real-time trajectories for cooperative UAVs to avoid collisions in three-dimensional airspace. To explore potential collisions, predictive state space is utilized to present the waypoints of UAVs in the upcoming situations, which makes the proposed method generate the initial collision-free trajectories satisfying the necessary constraints in a short time. Further, a rolling optimization algorithm (ROA) can improve the initial waypoints, minimizing its total distance. Several scenarios are illustrated to verify the proposed algorithm, and the results show that our algorithm can generate initial collision-free trajectories more efficiently than other methods in the common airspace.
      PubDate: 2017-03-28
      DOI: 10.3390/app7040329
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 330: Large-Scale Permanent Slide Imaging
           and Image Analysis for Diatom Morphometrics

    • Authors: Michael Kloster, Oliver Esper, Gerhard Kauer, Bánk Beszteri
      First page: 330
      Abstract: Light microscopy analysis of diatom frustules is widely used in basic and applied research, notably taxonomy, morphometrics, water quality monitoring and paleo-environmental studies. Although there is a need for automation in these applications, various developments in image processing and analysis methodology supporting these tasks have not become widespread in diatom-based analyses. We have addressed this issue by combining our automated diatom image analysis software SHERPA with a commercial slide-scanning microscope. The resulting workflow enables mass-analyses of a broad range of morphometric features from individual frustules mounted on permanent slides. Extensive automation and internal quality control of the results helps to minimize user intervention, but care was taken to allow the user to stay in control of the most critical steps (exact segmentation of valve outlines and selection of objects of interest) using interactive functions for reviewing and revising results. In this contribution, we describe our workflow and give an overview of factors critical for success, ranging from preparation and mounting through slide scanning and autofocus finding to final morphometric data extraction. To demonstrate the usability of our methods we finally provide an example application by analysing Fragilariopsis kerguelensis valves originating from a sediment core, which substantially extends the size range reported in the literature.
      PubDate: 2017-03-28
      DOI: 10.3390/app7040330
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 331: Simulation of Permanent Deformation
           in High-Modulus Asphalt Pavement with Sloped and Horizontally Curved
           Alignment

    • Authors: Mulian Zheng, Lili Han, Chongtao Wang, Zhanlei Xu, Hongyin Li, Qinglei Ma
      First page: 331
      Abstract: This study aims to evaluate the permanent deformation of high-modulus asphalt pavement in special road using viscoelastic theory. Based on the creep test, the Prony series representation of Burgers model parameters for different asphalt mixtures were obtained and used in the deformation simulation of a high-modulus asphalt pavement situated in a horizontally curved ramp. The orthogonal design method was used to show the effect of different factors on the deformation. Results reveal that rutting in curved ramp was greater than in straightaway. Further, evident upheaval was found on the downhill pavement surface and outer pavement parts of the curve due to longitudinal friction force and sideway force. In addition, the upper and middle asphalt courses in such road seemed more crucial to pavement anti-rutting performance, since inclusion of shear force changed pavement deformation characteristic and the potential rutting area tended to move up. Finally, a preliminary equation to predict rutting in sloped and curved road with widely accepted pavement structure in China was proposed.
      PubDate: 2017-03-28
      DOI: 10.3390/app7040331
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 332: An Independent Internal Cooling
           System for Promoting Heat Dissipation during Dry Cutting with Numerical
           and Experimental Verification

    • Authors: Bin Yao, Weifang Sun, Binqiang Chen, Xiaojin Yu, Yuchao He, Wei Feng, Shuyang Wang
      First page: 332
      Abstract: The cooling system has emerged as an effective way to alleviate the excessive heat generation during dry cutting processes. In this paper, we investigated a novel type of internal cooling system, independent of additional mechanical accessories, as a promising cooling alternative. The proposed system is devised as connected internal fluid channels of a-“V” shape created according to the geometric shape of the tool-holder. Enabling quantitative evaluation of the effectiveness of the proposed system, a new numerical approach is established. Within the approach, heat transfer equations are deduced according to thermodynamics; parameters of the equations are specified via analytical modeling. As a result, cutting temperatures can be estimated with high precision according to the outlet temperature. Moreover, a cutting experiment was carried out to verify the effectiveness of the proposed numerical approach. Tool-chip interface temperatures were measured using an infrared thermal imager. Smooth measurements with suppressed noises are derived based on a new adaptive mean filter originated by empirical mode decomposition (EMD). The experimental results demonstrate the proposed system can reduce the temperature substantially (almost 30% at the measuring point) and the results are highly consistent with those of numerical simulation. The proposed cooling system is a prospective enhancement for development of smart cutting tools.
      PubDate: 2017-03-28
      DOI: 10.3390/app7040332
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 333: Target Tracking Based on a
           Nonsingular Fast Terminal Sliding Mode Guidance Law by Fixed-Wing UAV

    • Authors: Kun Wu, Zhihao Cai, Jiang Zhao, Yingxun Wang
      First page: 333
      Abstract: This paper proposes a modified nonsingular fast terminal sliding mode (NFTSM) guidance law to solve the problem of ground moving target tracking for fixed-wing unmanned aerial vehicle (UAV) in a planar environment. Firstly, the loitering algorithm is analysed, which can steer the UAV to follow and circle around a ground moving target with the desired distance by heading angle control. Secondly, the effects of different parameters on the convergence time of sliding manifold is presented which is helpful for the designing of sliding manifold. Singularity can be avoided by using a modified saturation function which is obtained through a small range around the null point. Moreover, the NFTSM sliding manifold is used in the loitering algorithm. By using the Lyapunov theory, the finite-time convergence of the proposed method has been proved in the the reaching phase and the sliding phase. In order to verify the approach’s feasibility and benefits, numerical simulations are performed by using a moving target with three different motion states in comparison with the conventional sliding model control method. Simulation results indicate that, under the proposed NFTSM guidance law, the UAV can reach the desired distance in a short time.
      PubDate: 2017-03-29
      DOI: 10.3390/app7040333
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 334: Fouling in Membrane Distillation,
           Osmotic Distillation and Osmotic Membrane Distillation

    • Authors: Mourad Laqbaqbi, Julio Sanmartino, Mohamed Khayet, Carmen García-Payo, Mehdi Chaouch
      First page: 334
      Abstract: Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD), osmotic distillation (OD) and osmotic membrane distillation (OMD) use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED), membrane capacitive deionization (MCD), reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), microfiltration (MF), etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling), fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.
      PubDate: 2017-03-29
      DOI: 10.3390/app7040334
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 335: Piecewise-Linear Frequency Shifting
           Algorithm for Frequency Resolution Enhancement in Digital Hearing Aids

    • Authors: Qingyun Wang, Ruiyu Liang, Susanto Rahardja, Liye Zhao, Cairong Zou, Li Zhao
      First page: 335
      Abstract: In human hearing, frequency resolution is a term used to determine how well the ear can separate and distinguish two sounds that are close in frequency. This capability of breaking speech sounds into various frequency components plays a key role in processing and understanding speech information. In this paper, a piecewise-linear frequency shifting algorithm for digital hearing aids is proposed. The algorithm specifically aims at improving the frequency resolution capability. In the first step, frequency discrimination thresholds are processed by a computer testing software. Then, the input signal is parsed through the proposed piecewise-linear frequency shifting algorithm, which comprises of linearly stretching and compressing the frequency content at different frequency ranges. Experimental results showed that by using the proposed frequency shifting algorithm, the separation of formant tracks was increased in the stretching region and slightly squeezed in the adjacent compression region. Subjective assessment on six hearing-impaired persons with V-shaped audiograms demonstrated that nearly a 10% improvement of speech discrimination score was achieved for monosyllabic word lists tested in a quiet acoustic setting. In addition, the speech reception threshold was also improved by 2~8 dB when disyllabic word listswere tested in a noisy acoustic scenario.
      PubDate: 2017-03-29
      DOI: 10.3390/app7040335
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 336: Perception-Driven Obstacle-Aided
           Locomotion for Snake Robots: The State of the Art, Challenges and
           Possibilities †

    • Authors: Filippo Sanfilippo, Jon Azpiazu, Giancarlo Marafioti, Aksel Transeth, yvind Stavdahl, Pål Liljebäck
      First page: 336
      Abstract: In nature, snakes can gracefully traverse a wide range of different and complex environments. Snake robots that can mimic this behaviour could be fitted with sensors and transport tools to hazardous or confined areas that other robots and humans are unable to access. In order to carry out such tasks, snake robots must have a high degree of awareness of their surroundings (i.e., perception-driven locomotion) and be capable of efficient obstacle exploitation (i.e., obstacle-aided locomotion) to gain propulsion. These aspects are pivotal in order to realise the large variety of possible snake robot applications in real-life operations such as fire-fighting, industrial inspection, search-and-rescue, and more. In this paper, we survey and discuss the state of the art, challenges, and possibilities of perception-driven obstacle-aided locomotion for snake robots. To this end, different levels of autonomy are identified for snake robots and categorised into environmental complexity, mission complexity, and external system independence. From this perspective, we present a step-wise approach on how to increment snake robot abilities within guidance, navigation, and control in order to target the different levels of autonomy. Pertinent to snake robots, we focus on current strategies for snake robot locomotion in the presence of obstacles. Moreover, we put obstacle-aided locomotion into the context of perception and mapping. Finally, we present an overview of relevant key technologies and methods within environment perception, mapping, and representation that constitute important aspects of perception-driven obstacle-aided locomotion.
      PubDate: 2017-03-29
      DOI: 10.3390/app7040336
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 337: Reel-to-Reel Atmospheric Pressure
           Dielectric Barrier Discharge (DBD) Plasma Treatment of Polypropylene Films
           

    • Authors: Lukas Seidelmann, James Bradley, Marina Ratova, Jonathan Hewitt, Jamie Moffat, Peter Kelly
      First page: 337
      Abstract: Atmospheric pressure plasma treatment of the surface of a polypropylene film can significantly increase its surface energy and, thereby improve the printability of the film. A laboratory-scale dielectric barrier discharge (DBD) system has therefore been developed, which simulates the electrode configuration and reel-to-reel web transport mechanism used in a typical industrial-scale system. By treating the polypropylene in a nitrogen discharge, we have shown that the water contact angle could be reduced by as much as 40° compared to the untreated film, corresponding to an increase in surface energy of 14 mNm−1. Ink pull-off tests showed that the DBD plasma treatment resulted in excellent adhesion of solvent-based inks to the polypropylene film.
      PubDate: 2017-03-29
      DOI: 10.3390/app7040337
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 338: Fatigue Life Estimation of
           Medium-Carbon Steel with Different Surface Roughness

    • Authors: Changyou Li, Weibing Dai, Fei Duan, Yimin Zhang, David He
      First page: 338
      Abstract: Medium-carbon steel is commonly used for the rail, wire ropes, tire cord, cold heading, forging steels, cold finished steel bars, machinable steel and so on. Its fatigue behavior analysis and fatigue life estimation play an important role in the machinery industry. In this paper, the estimation of fatigue life of medium-carbon steel with different surface roughness using established S-N and P-S-N curves is presented. To estimate the fatigue life, the effect of the average surface roughness on the fatigue life of medium-carbon steel has been investigated using 75 fatigue tests in three groups with average surface roughness (Ra): 0.4 μm, 0.8 μm, and 1.6 μm, respectively. S-N curves and P-S-N curves have been established based on the fatigue tests. The fatigue life of medium-carbon steel is then estimated based on Tanaka-Mura crack initiation life model, the crack propagation life model using Paris law, and material constants of the S-N curves. Six more fatigue tests have been conducted to validate the presented fatigue life estimation formulation. The experimental results have shown that the presented model could estimate well the mean fatigue life of medium-carbon steel with different surface roughness.
      PubDate: 2017-03-29
      DOI: 10.3390/app7040338
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 339: Acoustic Emission and Modal Frequency
           Variation in Concrete Specimens under Four-Point Bending

    • Authors: Giuseppe Lacidogna, Gianfranco Piana, Alberto Carpinteri
      First page: 339
      Abstract: The Acoustic Emission (AE) and Dynamic Identification (DI) techniques were applied simultaneously, in an original way, to examine the stress dependent damage progress in pre-notched concrete beams tested in four-point bending. The damage mechanisms were characterized by analyzing the AE signals registered during the tests, conducted by increasing the specimen’s vertical deflection. In particular, the dominant fracture mode was identified, and correlations between dissipated and emitted energies were investigated. Moreover, variations in the natural bending frequencies, produced by the crack advancement under loading, were detected and put in relation with the cumulated AE energy. Two different types of piezoelectric (PZT) sensors, operating in well distinct frequency ranges, were used to measure AE and modal signals. This study may be of interest with an outlook on possible correlations between a multi-parameter structural monitoring and the solution of inverse problems by numerical models.
      PubDate: 2017-03-30
      DOI: 10.3390/app7040339
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 340: Pulse Propagation Models with Bands
           of Forbidden Frequencies or Forbidden Wavenumbers: A Consequence of
           Abandoning the Slowly Varying Envelope Approximation and Taking into
           Account Higher-Order Dispersion

    • Authors: Jorge Fujioka, Alfredo Gómez-Rodríguez, Áurea Espinosa-Cerón
      First page: 340
      Abstract: We study linear and nonlinear pulse propagation models whose linear dispersion relations present bands of forbidden frequencies or forbidden wavenumbers. These bands are due to the interplay between higher-order dispersion and one of the terms (a second-order derivative with respect to the propagation direction) which appears when we abandon the slowly varying envelope approximation. We show that as a consequence of these forbidden bands, narrow pulses radiate in a novel and peculiar way. We also show that the nonlinear equations studied in this paper have exact soliton-like solutions of different forms, some of them being embedded solitons. The solutions obtained (of the linear as well as the nonlinear equations) are interesting since several arguments suggest that the Cauchy problems for these equations are ill-posed, and therefore the specification of the initial conditions is a delicate issue. It is also shown that some of these equations are related to elliptic curves, thus suggesting that these equations might be related to other fields where these curves appear, such as the theory of modular forms and Weierstrass ℘ functions, or the design of cryptographic protocols.
      PubDate: 2017-03-30
      DOI: 10.3390/app7040340
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 341: Guided Self-Accelerating Airy
           Beams—A Mini-Review

    • Authors: Yiqi Zhang, Hua Zhong, Milivoj Belić, Yanpeng Zhang
      First page: 341
      Abstract: Owing to their nondiffracting, self-accelerating, and self-healing properties, Airy beams of different nature have become a subject of immense interest in the past decade. Their interesting properties have opened doors to many diverse applications. Consequently, the questions of how to properly design the spatial manipulation of Airy beams or how to implement them in different setups have become important and timely in the development of various optical devices. Here, based on our previous work, we present a short review on the spatial control of Airy beams, including the interactions of Airy beams in nonlinear media, beam propagation in harmonic potential, and the dynamics of abruptly autofocusing Airy beams in the presence of a dynamic linear potential. We demonstrate that, under the guidance of nonlinearity and an external potential, the trajectory, acceleration, structure, and even the basic properties of Airy beams can be adjusted to suit specific needs. We describe other fascinating phenomena observed with Airy beams, such as self-Fourier transformation, periodic inversion of Airy beams, and the appearance of spatial solitons in the presence of nonlinearity. These results have promoted the development of Airy beams, and have been utilized in various applications, including particle manipulation, self-trapping, and electronic matter waves.
      PubDate: 2017-03-30
      DOI: 10.3390/app7040341
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 342: Design and Implementation of a Shape
           Shifting Rolling–Crawling–Wall-Climbing Robot

    • Authors: Takeru Yanagida, Rajesh Elara Mohan, Thejus Pathmakumar, Karthikeyan Elangovan, Masami Iwase
      First page: 342
      Abstract: Designing an urban reconnaissance robot is highly challenging work given the nature of the terrain in which these robots are required to operate. In this work, we attempt to extend the locomotion capabilities of these robots beyond what is currently feasible. The design and unique features of our bio-inspired reconfigurable robot, called Scorpio, with rolling, crawling, and wall-climbing locomotion abilities are presented in this paper. The design of the Scorpio platform is inspired by Cebrennus rechenbergi, a rare spider species that has rolling, crawling and wall-climbing locomotion attributes. This work also presents the kinematic and dynamic model of Scorpio. The mechanical design and system architecture are introduced in detail, followed by a detailed description on the locomotion modes. The conducted experiments validated the proposed approach and the ability of the Scorpio platform to synthesise crawling, rolling and wall-climbing behaviours. Future work is envisioned for using these robots as active, unattended, mobile ground sensors in urban reconnaissance missions. The accompanying video demonstrates the shape shifting locomotion capabilities of the Scorpio robot.
      PubDate: 2017-03-30
      DOI: 10.3390/app7040342
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 343: Using Thermal Shock to Inhibit
           Biofilm Formation in the Treated Sewage Source Heat Pump Systems

    • Authors: Siyuan Chang, Jinchun Chen, Lin Shi
      First page: 343
      Abstract: Treated sewage source heat pump systems can reuse the waste energy in the treated sewage. However, biofilms in the heat exchangers decrease the system efficiency. This work investigates the feasibility of thermal shock at accessible temperatures in heat exchangers for biofilm inhibition. Bacillus subtilis biofilms were formed on coupons and in a miniaturized plate heat exchanger. Thermal shocks at different temperatures (50–80 °C) for different exposure times (1–60 min) were used to treat the biofilms. The results showed that thermal shock had a significant bactericidal and biofilm inhibition effect, and the effect was enhanced as the temperature and the exposure time increased. Data fitting of the biomass showed that temperature had a more significant influence on the biofilm inhibition effect than exposure time. The results of the heat exchanging experiments showed that high temperature thermal shock could significantly mitigate the heat transfer deterioration caused by the biofilms, indicating that thermal shock could be used as a viable biofilm inhibition approach for heat exchangers.
      PubDate: 2017-03-30
      DOI: 10.3390/app7040343
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 344: Experimental Investigation of a Base
           Isolation System Incorporating MR Dampers with the High-Order Single Step
           Control Algorithm

    • Authors: Weiqing Fu, Chunwei Zhang, Li Sun, Mohsen Askari, Bijan Samali, Kwok Chung, Pezhman Sharafi
      First page: 344
      Abstract: The conventional isolation structure with rubber bearings exhibits large deformation characteristics when subjected to infrequent earthquakes, which may lead to failure of the isolation layer. Although passive dampers can be used to reduce the layer displacement, the layer deformation and superstructure acceleration responses will increase in cases of fortification earthquakes or frequently occurring earthquakes. In addition to secondary damages and loss of life, such excessive displacement results in damages to the facilities in the structure. In order to overcome these shortcomings, this paper presents a structural vibration control system where the base isolation system is composed of rubber bearings with magnetorheological (MR) damper and are regulated using the innovative control strategy. The high-order single-step algorithm with continuity and switch control strategies are applied to the control system. Shaking table test results under various earthquake conditions indicate that the proposed isolation method, compared with passive isolation technique, can effectively suppress earthquake responses for acceleration of superstructure and deformation within the isolation layer. As a result, this structural control method exhibits excellent performance, such as fast computation, generic real-time control, acceleration reduction and high seismic energy dissipation etc. The relative merits of the continuity and switch control strategies are also compared and discussed.
      PubDate: 2017-03-30
      DOI: 10.3390/app7040344
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 345: Pet Fiber Reinforced Wet-Mix
           Shotcrete with Walnut Shell as Replaced Aggregate

    • Authors: Weimin Cheng, Guoming Liu, Lianjun Chen
      First page: 345
      Abstract: In the rapidly developing modern society, many raw materials, such as crushed limestone and river sand, which are limited, are consumed by the concrete industry. Naturally, the usage of waste materials in concrete have become an interesting research area in recent years, which is used to reduce the negative influence of concrete on the environment. Hence, this paper presents the development of a sustainable lightweight wet-mix shotcrete by replacing natural coarse gravel with a kind of byproduct, nut shell (walnut). Fibers made from dumped polyethylene terephthalate (PET) bottles were mixed in the composite to improve the properties of the lightweight wet-mix shotcrete. The initial evaluation of the fresh concrete mixed with different volume fraction of walnut shell was carried out in terms of its performance capacities of mechanical properties (i.e., tensile and compressive strength), pumpability and shootability (i.e., slump, pressure drop per meter and rebound rate) and the results were compared with plain concrete. With increase of walnut shell, compressive and splitting tensile strength of casting concrete decreased, while slump and pressure drop reduced slightly. Additionally, appropriate dosage of walnut shell can improve the shootability of fresh concrete with low rebound rate and larger build-up thickness. In the second series tests, polypropylene (PP) fiber and multi-dimension fiber were also mixed in composite for comparative analysis. After mixing fibers, the splitting tensile strength had obtained marked improvement with slight reduction of compressive strength, along with acceptable fluctuation in terms of pumpability and shootability. Furthermore, relation of density and compressive strength, relation of rebound and density, build-up thickness and relation of compressive and splitting tensile strength were discussed. This study found wet-mix shotcrete incorporating PET fiber with walnut shell of about 35% coarse aggregate replacement could be used for roadway support as lightweight shotcrete per requirements of mine support.
      PubDate: 2017-03-31
      DOI: 10.3390/app7040345
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 346: Numerical Control Machine Tool Fault
           Diagnosis Using Hybrid Stationary Subspace Analysis and Least Squares
           Support Vector Machine with a Single Sensor

    • Authors: Chen Gao, Wei Xue, Yan Ren, Yuqing Zhou
      First page: 346
      Abstract: Tool fault diagnosis in numerical control (NC) machines plays a significant role in ensuring manufacturing quality. However, current methods of tool fault diagnosis lack accuracy. Therefore, in the present paper, a fault diagnosis method was proposed based on stationary subspace analysis (SSA) and least squares support vector machine (LS-SVM) using only a single sensor. First, SSA was used to extract stationary and non-stationary sources from multi-dimensional signals without the need for independency and without prior information of the source signals, after the dimensionality of the vibration signal observed by a single sensor was expanded by phase space reconstruction technique. Subsequently, 10 dimensionless parameters in the time-frequency domain for non-stationary sources were calculated to generate samples to train the LS-SVM. Finally, the measured vibration signals from tools of an unknown state and their non-stationary sources were separated by SSA to serve as test samples for the trained SVM. The experimental validation demonstrated that the proposed method has better diagnosis accuracy than three previous methods based on LS-SVM alone, Principal component analysis and LS-SVM or on SSA and Linear discriminant analysis.
      PubDate: 2017-03-31
      DOI: 10.3390/app7040346
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 347: Tangible User Interface and Mu Rhythm
           Suppression: The Effect of User Interface on the Brain Activity in Its
           Operator and Observer

    • Authors: Kazuo Isoda, Kana Sueyoshi, Ryo Miyamoto, Yuki Nishimura, Yuki Ikeda, Ichiro Hisanaga, Stéphanie Orlic, Yeon-kyu Kim, Shigekazu Higuchi
      First page: 347
      Abstract: The intuitiveness of tangible user interface (TUI) is not only for its operator. It is quite possible that this type of user interface (UI) can also have an effect on the experience and learning of observers who are just watching the operator using it. To understand the possible effect of TUI, the present study focused on the mu rhythm suppression in the sensorimotor area reflecting execution and observation of action, and investigated the brain activity both in its operator and observer. In the observer experiment, the effect of TUI on its observers was demonstrated through the brain activity. Although the effect of the grasping action itself was uncertain, the unpredictability of the result of the action seemed to have some effect on the mirror neuron system (MNS)-related brain activity. In the operator experiment, in spite of the same grasping action, the brain activity was activated in the sensorimotor area when UI functions were included (TUI). Such activation of the brain activity was not found with a graphical user interface (GUI) that has UI functions without grasping action. These results suggest that the MNS-related brain activity is involved in the effect of TUI, indicating the possibility of UI evaluation based on brain activity.
      PubDate: 2017-03-31
      DOI: 10.3390/app7040347
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 348: Improved Gender Recognition during
           Stepping Activity for Rehab Application Using the Combinatorial Fusion
           Approach of EMG and HRV

    • Authors: Nor Rosli, Mohd Rahman, Malarvili Balakrishnan, Takashi Komeda, Saiful Mazlan, Hairi Zamzuri
      First page: 348
      Abstract: Gender recognition is trivial for a physiotherapist, but it is considered a challenge for computers. The electromyography (EMG) and heart rate variability (HRV) were utilized in this work for gender recognition during exercise using a stepper. The relevant features were extracted and selected. The selected features were then fused to automatically predict gender recognition. However, the feature selection for gender classification became a challenge to ensure better accuracy. Thus, in this paper, a feature selection approach based on both the performance and the diversity between the two features from the rank-score characteristic (RSC) function in a combinatorial fusion approach (CFA) (Hsu et al.) was employed. Then, the features from the selected feature sets were fused using a CFA. The results were then compared with other fusion techniques such as naive bayes (NB), decision tree (J48), k-nearest neighbor (KNN) and support vector machine (SVM). Besides, the results were also compared with previous researches in gender recognition. The experimental results showed that the CFA was efficient and effective for feature selection. The fusion method was also able to improve the accuracy of the gender recognition rate. The CFA provides much better gender classification results which is 94.51% compared to Barani’s work (90.34%), Nazarloo’s work (92.50%), and other classifiers.
      PubDate: 2017-03-31
      DOI: 10.3390/app7040348
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 349: Effects of Mindfulness Meditation on
           Conscious and Non-Conscious Components of the Mind

    • Authors: Anastasia Fabbro, Cristiano Crescentini, Alessio Matiz, Andrea Clarici, Franco Fabbro
      First page: 349
      Abstract: The aim of the present review is to investigate previous studies concerning the effects of meditation and dispositional mindfulness on conscious and implicit or non-conscious attitudes. First we present a brief perspective on conscious and non-conscious states of mind. Then we introduce the fundamental bases of mindfulness meditation. Third we review studies on dispositional mindfulness and meditation that employed either direct or indirect measures to assess explicit and implicit attitudes. Finally, we briefly present how meditation has been associated with the psychotherapeutic practice of psychoanalysis and, hence, as a therapeutic technique to access the unconscious. Until now, few studies have investigated the impact of meditation on non-conscious states of mind and personality; nevertheless, both scientific studies involving implicit measures and reflections from psychotherapy have underlined the importance of meditation in promoting psychological well-being, leading to de-automatization of automatic patterns of responding and to higher levels of self-awareness.
      PubDate: 2017-04-01
      DOI: 10.3390/app7040349
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 350: Electric Turbocharging for Energy
           Regeneration and Increased Efficiency at Real Driving Conditions

    • Authors: Pavlos Dimitriou, Richard Burke, Qingning Zhang, Colin Copeland, Harald Stoffels
      First page: 350
      Abstract: Modern downsized internal combustion engines benefit from high-efficiency turbocharging systems for increasing their volumetric efficiency. However, despite the efficiency increase, turbochargers often lack fast transient response due to the nature of the energy exchange with the engine, which deteriorates the vehicle’s drivability. An electrically-assisted turbocharger can be used for improving the transient response without any parasitic losses to the engine while providing energy recovery for increasing overall system efficiency. The present study provides a detailed numerical investigation on the potential of e-turbocharging to control load and if possible replace the wastegate valve. A parametric study of the optimum compressor/turbine sizing and wastegate area was performed for maximum torque, fast response time and energy regeneration across the real driving conditions speed/load area of the engine. The results showed that the implementation of a motor-generator could contribute to reducing the response time of the engine by up to 90% while improving its thermal efficiency and generating up to 6.6 kWh of energy. Suppressing the wastegate can only be achieved when a larger turbine is implemented, which as a result deteriorates the engine’s response and leads to energy provision demands at low engine speeds.
      PubDate: 2017-04-01
      DOI: 10.3390/app7040350
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 351: Scan-Less Line Field Optical
           Coherence Tomography, with Automatic Image Segmentation, as a Measurement
           Tool for Automotive Coatings

    • Authors: Samuel Lawman, Bryan Williams, Jinke Zhang, Yao-Chun Shen, Yalin Zheng
      First page: 351
      Abstract: The measurement of the thicknesses of layers is important for the quality assurance of industrial coating systems. Current measurement techniques only provide a limited amount of information. Here, we show that spectral domain Line Field (LF) Optical Coherence Tomography (OCT) is able to return to the user a cross sectional B-Scan image in a single shot with no mechanical moving parts. To reliably extract layer thicknesses from such images of automotive paint systems, we present an automatic graph search image segmentation algorithm. To show that the algorithm works independently of the OCT device, the measurements are repeated with a separate time domain Full Field (FF) OCT system. This gives matching mean thickness values within the standard deviations of the measured thicknesses across each B-Scan image. The combination of an LF-OCT with graph search segmentation is potentially a powerful technique for the quality assurance of non-opaque industrial coating layers.
      PubDate: 2017-04-01
      DOI: 10.3390/app7040351
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 352: Thermal Optimization of Horizontal
           Tubes with Tilted Rectangular Fins under Free Convection for the Cooling
           of Electronic Devices

    • Authors: Jong Lee, Hyun Kim, Dong-Kwon Kim
      First page: 352
      Abstract: In the present work, the horizontal tubes with tilted rectangular fins under free convection are experimentally investigated for the cooling of electronic devices. The temperature differences of horizontal tubes with tilted rectangular fins are measured for several heat inputs, tilt angles, and numbers of fins. Using the measurement results, a correlation for the prediction of the Nusselt number is suggested. This correlation is suitable for the situation for Rayleigh numbers of 200,000–1,100,000, tilt angles of 0°–90°, and numbers of fins of 9–36. On the basis of the correlation, the cooling performances are presented for various numbers of fins and thicknesses of fins, and the value of the optimal cooling performance is found. Finally, the optimal cooling performances of tubes with tilted rectangular fins and conventional radial rectangular fins are compared. The comparison results show that the optimal cooling performance of the tube with tilted fins is 6% greater than that of the tube with radial rectangular fins.
      PubDate: 2017-04-02
      DOI: 10.3390/app7040352
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 353: Algorithm and Implementation of
           Distributed ESN Using Spark Framework and Parallel PSO

    • Authors: Kehe Wu, Yayun Zhu, Quan Li, Guolong Han
      First page: 353
      Abstract: The echo state network (ESN) employs a huge reservoir with sparsely and randomly connected internal nodes and only trains the output weights, which avoids the suboptimal problem, exploding and vanishing gradients, high complexity and other disadvantages faced by traditional recurrent neural network (RNN) training. In light of the outstanding adaption to nonlinear dynamical systems, ESN has been applied into a wide range of applications. However, in the era of Big Data, with an enormous amount of data being generated continuously every day, the data are often distributed and stored in real applications, and thus the centralized ESN training process is prone to being technologically unsuitable. In order to achieve the requirement of Big Data applications in the real world, in this study we propose an algorithm and its implementation for distributed ESN training. The mentioned algorithm is based on the parallel particle swarm optimization (P-PSO) technique and the implementation uses Spark, a famous large-scale data processing framework. Four extremely large-scale datasets, including artificial benchmarks, real-world data and image data, are adopted to verify our framework on a stretchable platform. Experimental results indicate that the proposed work is accurate in the era of Big Data, regarding speed, accuracy and generalization capabilities.
      PubDate: 2017-04-02
      DOI: 10.3390/app7040353
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 354: A Wideband High-Voltage Power
           Amplifier Post-Linearizer for Medical Ultrasound Transducers

    • Authors: Hojong Choi, Changhan Yoon, Jung-Yeol Yeom
      First page: 354
      Abstract: The medical ultrasound transducer is a principal component in ultrasound systems, as it significantly influences system performance. The high-voltage power amplifier (HVPA) is the key ultrasound transmitter component and interfaces with the medical ultrasound transducer. Therefore, the performance of the HVPA critically affects the echo signal quality of the ultrasound transducer. As they are inherently non-linear devices, harmonic distortion of echo signals generated by the ultrasound transducers would critically deteriorate the echo signal quality in ultrasound systems. The primary aim of this research is to integrate a novel post-linearizer into the HVPA to suppress harmonic distortion in medical ultrasound transducers. Moreover, this study is based on the assumption that linearizing the HVPA could reduce the harmonic distortion components of the echo signals. The developed HVPA with post-linearizer was tested in an ultrasound microscopy system in order to demonstrate the harmonic suppression capability on the echo signal generated by the ultrasound transducer. When 10 MHz, 5-cycle, 26 dBm input power was sent to the HVPA with and without the post-linearizer circuits, the measured second-, third-, fourth- and fifth- harmonic distortions of a 10 MHz transducer with the post-linearizer (−13.11 dB, −10.81 dB, −16.33 dB, and −22.78 dB) were suppressed to a greater degree than those of the same transducer without the post-linearizer (−4.58 dB, −8.87 dB, −10.51 dB, and −15.31 dB).. Therefore, we conclude that the addition of the post-linearizer to the HVPA is a potentially useful electronic technique for improving echo signal quality in medical ultrasound transducers.
      PubDate: 2017-04-04
      DOI: 10.3390/app7040354
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 355: Self-Organized Nanoscale Roughness
           Engineering for Broadband Light Trapping in Thin Film Solar Cells

    • Authors: Carlo Mennucci, Christian Martella, Lucia V. Mercaldo, Iurie Usatii, Paola Delli Veneri, Francesco Buatier de Mongeot
      First page: 355
      Abstract: We present a self-organized method based on defocused ion beam sputtering for nanostructuring glass substrates which feature antireflective and light trapping effects. By irradiating the substrate, capped with a thin gold (Au) film, a self-organized Au nanowire stencil mask is firstly created. The morphology of the mask is then transferred to the glass surface by further irradiating the substrate, finally producing high aspect ratio, uniaxial ripple-like nanostructures whose morphological parameters can be tailored by varying the ion fluence. The effect of a Ti adhesion layer, interposed between glass and Au with the role of inhibiting nanowire dewetting, has also been investigated in order to achieve an improved morphological tunability of the templates. Morphological and optical characterization have been carried out, revealing remarkable light trapping performance for the largest ion fluences. The photon harvesting capability of the nanostructured glass has been tested for different preparation conditions by fabricating thin film amorphous Si solar cells. The comparison of devices grown on textured and flat substrates reveals a relative increase of the short circuit current up to 25%. However, a detrimental impact on the electrical performance is observed with the rougher morphologies endowed with steep v-shaped grooves. We finally demonstrate that post-growth ion beam restructuring of the glass template represents a viable approach toward improved electrical performance.
      PubDate: 2017-04-04
      DOI: 10.3390/app7040355
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 356: A New High-Efficiency Double-Stator
           Split-Pole Permanent-Magnet Vernier Machine with Flux-Focusing Topology

    • Authors: Zhengwen Dai, Jiangui Li, Lin Zou, Junhua Wang, Ruiren Luo
      First page: 356
      Abstract: Permanent-magnet vernier machines (PMVMs) have attracted much attention for their high efficiency and output torque in low-speed application. However, the conventional PMVM suffers from the problems of low power factor and high cogging torque. In this paper, a double-stator flux-focusing split-pole permanent-magnet vernier machine (SP-PMVM) with low cogging torque and high power factor has been proposed. The split-pole topology in the vernier motor has been used mainly to modulate the magnetic flux in this paper, although the stator teeth are used for this purpose in some cases. The newly-proposed SP-PMVM topology is characterized by reduced flux leakage through using a flux-focusing topology and staggering approximately half of the pitch angularly between the inner stator and outer stator. Firstly, the vernier principle of the proposed SP-PMVM has been investigated by analytical methods. Secondly, a 12-slot-stator and 22-pole-pair-rotor SP-PMVM has been optimized with the goal of maximum average steady-state torque and the minimum cogging torque and ripple. Thirdly, the overall performance of the newly-proposed SP-PMVM has been analyzed as compared with the conventional PMVM. The results verify that the SP-PMVM can provide higher power factor, higher output torque and lower cogging torque than that of the conventional PMVM in low-speed application.
      PubDate: 2017-04-04
      DOI: 10.3390/app7040356
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 357: Increasing the Performance of Vacuum
           Membrane Distillation Using Micro-Structured Hydrophobic Aluminum Hollow
           Fiber Membranes

    • Authors: Chia-Chieh Ko, Chien-Hua Chen, Yi-Rui Chen, Yu-Hsun Wu, Soon-Chien Lu, Fa-Chun Hu, Chia-Ling Li, Kuo-Lun Tung
      First page: 357
      Abstract: This study develops a micro-structured hydrophobic alumina hollow fiber with a high permeate flux of 60 Lm−2h−1 and salt rejection over 99.9% in a vacuum membrane distillation process. The fiber is fabricated by phase inversion and sintering, and then modified with fluoroalkylsilanes to render it hydrophobic. The influence of the sintering temperature and feeding temperature in membrane distillation (MD) on the characteristics of the fiber and MD performance are investigated. The vacuum membrane distillation uses 3.5 wt % NaCl aqueous solution at 70 °C at 0.03 bar. The permeate flux of 60 Lm−2h−1 is the highest, compared with reported data and is higher than that for polymeric hollow fiber membranes.
      PubDate: 2017-04-04
      DOI: 10.3390/app7040357
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 358: Multiple Sensors Based Hand Motion
           Recognition Using Adaptive Directed Acyclic Graph

    • Authors: Yaxu Xue, Zhaojie Ju, Kui Xiang, Jing Chen, Honghai Liu
      First page: 358
      Abstract: The use of human hand motions as an effective way to interact with computers/robots, robot manipulation learning and prosthetic hand control is being researched in-depth. This paper proposes a novel and effective multiple sensor based hand motion capture and recognition system. Ten common predefined object grasp and manipulation tasks demonstrated by different subjects are recorded from both the human hand and object points of view. Three types of sensors, including electromyography, data glove and FingerTPS are applied to simultaneously capture the EMG signals, the finger angle trajectories, and the contact force. Recognising different grasp and manipulation tasks based on the combined signals is investigated by using an adaptive directed acyclic graph algorithm, and results of comparative experiments show the proposed system with a higher recognition rate compared with individual sensing technology, as well as other algorithms. The proposed framework contains abundant information from multimodal human hand motions with the multiple sensor techniques, and it is potentially applicable to applications in prosthetic hand control and artificial systems performing autonomous dexterous manipulation.
      PubDate: 2017-04-05
      DOI: 10.3390/app7040358
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 359: Mode Coupling Properties of the
           Plasmonic Dimers Composed of Graphene Nanodisks

    • Authors: Houbo Chen, Weibin Qiu, Pingping Qiu, Junbo Ren, Zhili Lin, Jia-Xian Wang, Qiang Kan, Jiao-Qing Pan
      First page: 359
      Abstract: The electromagnetic properties of the plasmonic dimer composed of coupled graphene nanodisks are numerically investigated in this paper. The results demonstrate that the degeneracy of the plasmonic modes of the dimer is lifted when the coupling is introduced. The evolution of the plasmonic mode, with the variation of inter-disk distance and the chemical potential of one of the nanodisks, is studied. The proposed structure might find broad areas of application including light–matter interaction, optical switching, directional emission of the plasmonic emitter, etc.
      PubDate: 2017-04-05
      DOI: 10.3390/app7040359
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 360: Performance Analysis of a Fluidic
           Axial Oscillation Tool for Friction Reduction with the Absence of a
           Throttling Plate

    • Authors: Xinxin Zhang, Jianming Peng, He Liu, Dongyu Wu
      First page: 360
      Abstract: An axial oscillation tool is proved to be effective in solving problems associated with high friction and torque in the sliding drilling of a complex well. The fluidic axial oscillation tool, based on an output-fed bistable fluidic oscillator, is a type of axial oscillation tool which has become increasingly popular in recent years. The aim of this paper is to analyze the dynamic flow behavior of a fluidic axial oscillation tool with the absence of a throttling plate in order to evaluate its overall performance. In particular, the differences between the original design with a throttling plate and the current default design are profoundly analyzed, and an improvement is expected to be recorded for the latter. A commercial computational fluid dynamics code, Fluent, was used to predict the pressure drop and oscillation frequency of a fluidic axial oscillation tool. The results of the numerical simulations agree well with corresponding experimental results. A sufficient pressure pulse amplitude with a low pressure drop is desired in this study. Therefore, a relative pulse amplitude of pressure drop and displacement are introduced in our study. A comparison analysis between the two designs with and without a throttling plate indicates that when the supply flow rate is relatively low or higher than a certain value, the fluidic axial oscillation tool with a throttling plate exhibits a better performance; otherwise, the fluidic axial oscillation tool without a throttling plate seems to be a preferred alternative. In most of the operating circumstances in terms of the supply flow rate and pressure drop, the fluidic axial oscillation tool performs better than the original design.
      PubDate: 2017-04-05
      DOI: 10.3390/app7040360
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 361: A Simplified Method to Estimate
           Sc-CO2 Extraction of Bioactive Compounds from Different Matrices: Chili
           Pepper vs. Tomato By-Products

    • Authors: Francesca Venturi, Chiara Sanmartin, Isabella Taglieri, Gianpaolo Andrich, Angela Zinnai
      First page: 361
      Abstract: In the last few decades, the search for bioactive compounds or “target molecules” from natural sources or their by-products has become the most important application of the supercritical fluid extraction (SFE) process. In this context, the present research had two main objectives: (i) to verify the effectiveness of a two-step SFE process (namely, a preliminary Sc-CO2 extraction of carotenoids followed by the recovery of polyphenols by ethanol coupled with Sc-CO2) in order to obtain bioactive extracts from two widespread different matrices (chili pepper and tomato by-products), and (ii) to test the validity of the mathematical model proposed to describe the kinetics of SFE of carotenoids from different matrices, the knowledge of which is required also for the definition of the role played in the extraction process by the characteristics of the sample matrix. On the basis of the results obtained, it was possible to introduce a simplified kinetic model that was able to describe the time evolution of the extraction of bioactive compounds (mainly carotenoids and phenols) from different substrates. In particular, while both chili pepper and tomato were confirmed to be good sources of bioactive antioxidant compounds, the extraction process from chili pepper was faster than from tomato under identical operating conditions.
      PubDate: 2017-04-05
      DOI: 10.3390/app7040361
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 362: Experimental Damage Identification of
           a Model Reticulated Shell

    • Authors: Jing Xu, Jiajia Hao, Hongnan Li, Minzhang Luo, Wen Guo, Weijie Li
      First page: 362
      Abstract: The damage identification of a reticulated shell is a challenging task, facing various difficulties, such as the large number of degrees of freedom (DOFs), the phenomenon of modal localization and transition, and low modeling accuracy. Based on structural vibration responses, the damage identification of a reticulated shell was studied. At first, the auto-regressive (AR) time series model was established based on the acceleration responses of the reticulated shell. According to the changes in the coefficients of the AR model between the damaged conditions and the undamaged condition, the damage of the reticulated shell can be detected. In addition, the damage sensitive factors were determined based on the coefficients of the AR model. With the damage sensitive factors as the inputs and the damage positions as the outputs, back-propagation neural networks (BPNNs) were then established and were trained using the Levenberg–Marquardt algorithm (L–M algorithm). The locations of the damages can be predicted by the back-propagation neural networks. At last, according to the experimental scheme of single-point excitation and multi-point responses, the impact experiments on a K6 shell model with a scale of 1/10 were conducted. The experimental results verified the efficiency of the proposed damage identification method based on the AR time series model and back-propagation neural networks. The proposed damage identification method can ensure the safety of the practical engineering to some extent.
      PubDate: 2017-04-06
      DOI: 10.3390/app7040362
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 363: Predictive Modelling and Analysis of
           Process Parameters on Material Removal Characteristics in Abrasive Belt
           Grinding Process

    • Authors: Vigneashwara Pandiyan, Wahyu Caesarendra, Tegoeh Tjahjowidodo, Gunasekaran Praveen
      First page: 363
      Abstract: The surface finishing and stock removal of complicated geometries is the principal objective for grinding with compliant abrasive tools. To understand and achieve optimum material removal in a tertiary finishing process such as Abrasive Belt Grinding, it is essential to look in more detail at the process parameters/variables that affect the stock removal rate. The process variables involved in a belt grinding process include the grit and abrasive type of grinding belt, belt speed, contact wheel hardness, serration, and grinding force. Changing these process variables will affect the performance of the process. The literature survey on belt grinding shows certain limited understanding of material removal on the process variables. Experimental trials were conducted based on the Taguchi Method to evaluate the influence of individual and interactive process variables. Analysis of variance (ANOVA) was employed to investigate the belt grinding characteristics on material removal. This research work describes a systematic approach to optimise process parameters to achieve the desired stock removal in a compliant Abrasive Belt Grinding process. Experimental study showed that the removed material from a surface due to the belt grinding process has a non-linear relationship with the process variables. In this paper, the Adaptive Neuro-Fuzzy Inference System (ANFIS) model is used to determine material removal. Compared with the experimental results, the model accurately predicts the stock removal. With further verification of the empirical model, a better understanding of the grinding parameters involved in material removal, particularly the influence of the individual process variables and their interaction, can be obtained.
      PubDate: 2017-04-06
      DOI: 10.3390/app7040363
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 364: Spectral Domain Optical Coherence
           Tomography for Non-Destructive Testing of Protection Coatings on Metal
           Substrates

    • Authors: Marcel Lenz, Cristian Mazzon, Christopher Dillmann, Nils Gerhardt, Hubert Welp, Michael Prange, Martin Hofmann
      First page: 364
      Abstract: In this paper we demonstrate that optical coherence tomography (OCT) is a powerful tool for the non-destructive investigation of transparent coatings on metal substrates. We show that OCT provides additional information which the common practice electrical impedance spectroscopy (EIS) cannot supply. First, coating layer thicknesses were measured and compared with reference measurements using a magnetic inductive (MI) measurement technique. After this validation of the OCT measurements, a customized sectioned sample was created to test the possibility to measure coating thicknesses with underlying corrosion, which cannot be analyzed accurately by MI or EIS measurements. Finally, we demonstrate the benefit of OCT on a standard sample. The OCT measurements provide the correct coating layer thickness with high lateral resolution and even enable metal and corrosion layers to be distinguished from each other.
      PubDate: 2017-04-06
      DOI: 10.3390/app7040364
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 365: Vehicle Loads for Assessing the
           Required Load Capacity Considering the Traffic Environment

    • Authors: Sang-Hyo Kim, Won-Ho Heo, Dong-woo You, Jae-Gu Choi
      First page: 365
      Abstract: The effects of traffic loads on existing bridges are quite different from those of design live loads because of the various traffic environments. However, the bridge maintenance and safety assessment of in-service bridges maintain the design load capacity without considering the current traffic environment. The real traffic conditions on existing bridges may require a load capacity that is considerably different from the design. Therefore, the required load capacity of an existing highway bridge should be determined according to the extreme load effects that the bridge will experience from the actual traffic environment during its remaining service life for more rational maintenance of the infrastructure. A simulation process was developed to determine evaluation vehicle loads for bridge safety assessment based on the extreme load effects that may occur during the remaining service life. Realistic probabilistic traffic models were used to reflect the actual traffic environment. The presented model was used to analyze the extreme load effect on pre-stressed concrete (PSC) and steel box girder bridges, which are typical bridge types. The traffic environmental conditions included the traffic volume (2000–40,000), the proportion of heavy vehicles (15–45%), and the consecutive vehicle traveling patterns. The spans of the sample bridges were 30 m (PSC bridge) and 45 or 60 m (steel box girder bridge). In the results, the extreme load effects tended to increase with either the traffic volume or proportion of heavy vehicles. The evaluation vehicle loads for bridge safety assessment may be adjusted with the traffic conditions, such as the traffic volume, the proportion of heavy vehicles, and the consecutive vehicle traveling patterns.
      PubDate: 2017-04-06
      DOI: 10.3390/app7040365
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 366: Efficient Real-Time Lossless EMG Data
           

    • Authors: Gyoun-Yon Cho, Gyoun-Yon Lee, Tae-Ro Lee
      First page: 366
      Abstract: An estimated 15 million babies are born prematurely every year worldwide, and suffer from disabilities. Appropriate care of these pre-term babies immediately after birth through telemedicine monitoring is vital. However, problems associated with a limited bandwidth and network overload due to the excessive size of the electromyography (EMG) signal impede the practical application of such medical information systems. Therefore, this research proposes an EMG uterine monitoring transmission solution (EUMTS), a lossless efficient real-time EMG transmission solution that solves such problems through efficient EMG data lossless compression. EMG data samples obtained from the Physionet PhysioBank database were used. Solution performance comparisons were conducted using Lempel-Ziv Welch (LZW) and Huffman methods, in addition to related researches. The LZW and Huffman methods showed CRs of 1.87 and 1.90, respectively, compared to 3.61 for the proposed algorithm. This was relatively high compared to related researches, even when considering that those researches were lossy whereas the proposed research was lossless. The results also showed that the proposed algorithm contributes to a reduction in battery consumption by reducing the wake-up time by 1470.6 ms. Therefore, EUMTS will contribute to providing an efficient wireless transmission environment for the prediction of pre-term delivery, enabling immediate interventions by medical professionals. Another novel point of EUMTS is that it is a lossless algorithm, which will prevent any misjudgement by clinicians because the data will not be distorted. Pre-term babies may receive point-of-care immediately after birth, preventing exposure to the development of disabilities.
      PubDate: 2017-04-06
      DOI: 10.3390/app7040366
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 367: A Novel Dual–Parallelogram Passive
           Rocking Vibration Isolator: A Theoretical Investigation and Experiment

    • Authors: Shuai Wang, Peng Gao, Ying Hu, Bing Li
      First page: 367
      Abstract: Vibration isolators with quasi-zero stiffness (QZS) perform well for low- or ultra-low-frequency vibration isolation. This paper proposes a novel dual-parallelogram passive rocking vibration isolator with QZS that could effectively attenuate in-plane disturbances with low-frequency vibration. First, a kinematic model of the proposed vibration isolator was established and four linear spring configuration schemes were developed to implement the QZS. Next, an optimal scheme with good high-static-low-dynamic stiffness (HSLDS) performance was obtained through comparison and analysis, and used as a focus for the QZS model. Subsequently, a dynamic model-based Lagrangian equation that considered the spring stiffness and damping and the influence of the payload gravity center on the vibration isolation system was developed, and an average approach was used to analyze the vibration transmissibility. Finally, the prototype and test system were constructed. A comparison of the simulation and experimental results showed that this novel passive rocking vibration isolator could bolster a heavy payload. Experimentally, the vibration amplitude decreased by 53% and 86% under harmonic disturbances of 0.08 Hz and 0.35 Hz, respectively, suggesting the great practical applicability of this presented vibration isolator.
      PubDate: 2017-04-07
      DOI: 10.3390/app7040367
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 368: Analysis of Dual- and Full-Circular
           Polarimetric SAR Modes for Rice Phenology Monitoring: An Experimental
           Investigation through Ground-Based Measurements

    • Authors: Yuta Izumi, Sevket Demirci, Mohd bin Baharuddin, Tomoro Watanabe, Josaphat Sumantyo
      First page: 368
      Abstract: Circularly polarized synthetic aperture radar (CP-SAR) is known to be insensitive to polarization mismatch losses caused by the Faraday rotation effect and antenna misalignment. Additionally, the dual-circular polarimetric (DCP) mode has proven to have more polarimetric information than that of the corresponding mode of linear polarization, i.e., the dual-linear polarimetric (DLP) mode. Owing to these benefits, this paper investigates the feasibility of CP-SAR for rice monitoring. A ground-based CP-radar system was exploited, and C-band anechoic chamber data of a self-cultivated Japanese rice paddy were acquired from germination to ripening stages. Temporal variations of polarimetric observables derived from full-circular polarimetric (FCP) and DCP as well as synthetically generated DLP data are analyzed and assessed with regard to their effectiveness in phenology retrieval. Among different observations, the H / α ¯ plane and triangle plots obtained by three scattering components (surface, double-bounce, and volume scattering) for both the FCP and DCP modes are confirmed to have reasonable capability in discriminating the relevant intervals of rice growth.
      PubDate: 2017-04-07
      DOI: 10.3390/app7040368
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 369: Heat Transfer Investigation of the
           Unsteady Thin Film Flow of Williamson Fluid Past an Inclined and
           Oscillating Moving Plate

    • Authors: Taza Gul, Abdul Khan, Saeed Islam, Aisha Alqahtani, Ilyas Khan, Ali Alshomrani, Abdullah Alzahrani, Muradullah
      First page: 369
      Abstract: This investigation aims at analyzing the thin film flow passed over an inclined moving plate. The differential type non-Newtonian fluid of Williamson has been used as a base fluid in its unsteady state. The physical configuration of the oscillatory flow pattern has been demonstrated and especial attention has been paid to the oscillatory phenomena. The shear stresses have been combined with the energy equation. The uniform magnetic field has been applied perpendicularly to the flow field. The principal equations for fluid motion and temperature profiles have been modeled and simplified in the form of non-linear partial differential equations. The non-linear differential equations have been solved with the help of a powerful analytical technique known as Optimal Homotopy Asymptotic Method (OHAM). This method contains unknown convergence controlling parameters C 1 , C 2 , C 3 , ... which results in more efficient and fast convergence as compared to other analytical techniques. The OHAM results have been verified by using a second method known as Adomian Decomposition Method (ADM). The closed agreement of these two methods and the fast convergence of OHAM has been shown graphically and numerically. The comparison of the present work and published work has also been equated graphically and tabulated with absolute error. Moreover, the effect of important physical parameters like magnetic parameter M , gravitational parameter m , Oscillating parameter ω , Eckert number E c and Williamson number W e have also been derived and discussed in this article.
      PubDate: 2017-04-07
      DOI: 10.3390/app7040369
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 370: Resilient Modulus Characterization of
           Compacted Cohesive Subgrade Soil

    • Authors: Wojciech Sas, Andrzej Głuchowski, Katarzyna Gabryś, Emil Soból, Alojzy Szymański
      First page: 370
      Abstract: Soil investigations concerning cyclic loading focus on the evaluation, in particular, of design parameters, such as elastic modulus, Poisson’s ratio, or resilient modulus. Structures subjected to repeated loading are vulnerable to high deformations, especially when subgrade soils are composed of cohesive, fully-saturated soils. Such subgrade soils in the eastern part of Europe have a glacial genesis and are a mix of sand, silt, and clay fractions. The characteristic of, e.g., Young modulus variation and resilient modulus from repeated loading tests, is presented. Based on performed resonant column and cyclic triaxial tests, an analytical model is proposed. The model takes into consideration actual values of effective stress p′, as well as loading characteristics and the position of the effective stress path. This approach results in better characterization of pavement or industrial foundation systems based on the subgrade soil in undrained conditions. The recoverable strains characterized by the resilient modulus Mr value in the first cycle of loading was between 44 MPa and 59 MPa for confining pressure σ’3 equal to 45 kPa, and between 48 MPa and 78 MPa for σ’3 equal to 90 kPa. During cyclic loading, cohesive soil, at first, degrades. When pore pressure reaches equilibrium, the resilient modulus value starts to increase. The above-described phenomena indicate that, after the plastic deformation caused by excessive load and excess pore water pressure dissipation, the soil becomes resilient.
      PubDate: 2017-04-07
      DOI: 10.3390/app7040370
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 371: Development of Auto-Seeding System
           Using Image Processing Technology in the Sapphire Crystal Growth Process
           via the Kyropoulos Method

    • Authors: Churl Kim, Sung Kim, Jung Ahn
      First page: 371
      Abstract: The Kyropoulos (Ky) and Czochralski (Cz) methods of crystal growth are used for large-diameter single crystals. The seeding process in these methods must induce initial crystallization by initiating contact between the seed crystals and the surface of the melted material. In the Ky and Cz methods, the seeding process lays the foundation for ingot growth during the entire growth process. When any defect occurs in this process, it is likely to spread to the entire ingot. In this paper, a vision system was constructed for auto seeding and for observing the surface of the melt in the Ky method. An algorithm was developed to detect the time when the internal convection of the melt is stabilized by observing the shape of the spoke pattern on the melt material surface. Then, the vision system and algorithm were applied to the growth furnace, and the possibility of process automation was examined for sapphire growth. To confirm that the convection of the melt was stabilized, the position of the island (i.e., the center of a spoke pattern) was detected using the vision system and image processing. When the observed coordinates for the center of the island were compared with the coordinates detected from the image processing algorithm, there was an average error of 1.87 mm (based on an image with 1024 × 768 pixels).
      PubDate: 2017-04-07
      DOI: 10.3390/app7040371
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 372: Grain Size in Aluminum Alloy 6061
           under Hot Ring Compression Test and after T6 Temper

    • Authors: Kuang-Jau Fann, Chun-Chi Chen
      First page: 372
      Abstract: Peripheral coarse grain during and after hot forming is often a major inconvenience for manufacturing aluminum alloy parts. Not only is the strength reduced, but the subsequent surface treatments are also hard to realize. The literature has shown that peripheral coarse grain is very likely induced by the previous process, such as extrusion. To investigate if peripheral coarse grain could be caused solely by hot forming, this study removed the billet surface layers. This eliminates the effect from the previous processes preparing the billets and forms ring specimens for executing ring compression test. The ring compression test can reveal the friction circumstance of the specimen to the die surface and create versatile deformation in the specimens to simulate forging situations, thereby providing multifaceted conditions to develop diverse grain size in specimen, particularly on its surface. The experiments were designed and analyzed under the Taguchi method, with consideration for factors such as working temperature, speed and amount of compression, and lubricant. Under each experiment, no peripheral coarse grains were found in the specimen, which were peeled and compressed, and even the average grain size after compression test is larger than that of the received billet. No peripheral coarse grains were found in the subsequent T6 temper either, which could, however, refine the grains.
      PubDate: 2017-04-08
      DOI: 10.3390/app7040372
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 373: Influence of Welding Parameters on
           the Weld Pool Dimensions and Shape in a TIG Configuration

    • Authors: Marine Stadler, Pierre Freton, Jean-Jacques Gonzalez
      First page: 373
      Abstract: The weld pool shape created by the plasma arc interaction on a workpiece depends on many geometrical and physical parameters and on the operating conditions. Theoretical models are developed in such a way as to predict and to characterize the material. However, these models first need to be validated. Experimental results are hence proposed with parametric studies. Nevertheless, the interaction time is often short and the weld pool shape evolution not presented. In this work, the experimental setup and the diagnostic methods characterizing the workpiece are presented. The weld pool shape was evaluated versus time according to several parameters such as the current intensity value, the distance between the two electrodes, the cathode tip angle or the plasma gas nature. The results show that the depth-to-width ratio alone is not enough to compare the impact of the parameters. The analysis points out the great influence of the current intensity on the increase of the width and depth compared to the influence of the value of the cathode tip angle. The rise of the arc length leads to an increase of the power through a higher arc voltage; nevertheless, for distances of three and five millimeters and a characteristic time of the welding process of one second, this parameter has a weak influence on the energy transferred. The use of helium leads to a bigger volume of the weld pool due to an increase of width and depth.
      PubDate: 2017-04-08
      DOI: 10.3390/app7040373
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 374: Objective Evaluation Techniques for
           Pairwise Panning-Based Stereo Upmix Algorithms for Spatial Audio

    • Authors: Martin Mieth, Udo Zölzer
      First page: 374
      Abstract: Techniques for generating multichannel audio from stereo audio signals are supposed to enhance and extend the listening experience of the listener. To assess the quality of such upmix algorithms, subjective evaluations have been carried out. In this paper, we propose an objective evaluation test for stereo-to-multichannel upmix algorithms. Based on defined objective criteria and special test signals, an objective comparative evaluation is enabled in order to obtain a quantifiable measure for the quality of stereo-to-multichannel upmix algorithms. Therefore, the basic functional principle of the evaluation test is demonstrated, and it is illustrated how possible results can be visualized. In addition, the proposed issues are introduced for the optimization of upmix algorithms and also for the clarification and illustration of the impacts and influences of different modes and parameters.
      PubDate: 2017-04-10
      DOI: 10.3390/app7040374
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 375: On the Link between Diesel Spray
           Asymmetry and Off-Axis Needle Displacement

    • Authors: Giancarlo Chiatti, Ornella Chiavola, Pierluigi Frezzolini, Fulvio Palmieri
      First page: 375
      Abstract: Cutting edge experiments and thorough investigations have pointed out that radial components affect the needle lift of diesel nozzles. So far, the effects of such needle “off-axis” have been investigated within the nozzle and immediately downstream from the hole outlet. Here, the focus has been extended to the spray ambient, far outside a multi-hole VCO (Valve Covered Orifice) nozzle. A reference off-axis configuration of the needle has been defined and used to investigate its effects on the spray, in terms of hole-to-hole differences. Indeed, the spray alterations due to the needle position have been addressed for those factors, such as the velocity-coefficient CV and the area-coefficient CA, able to describe the nozzle flow behavior under needle off-axis. The investigation has been based on 3D-CFD (three-dimensional computational fluid dynamics) campaigns. The modeling of diesel nozzle flow has been interfaced to the Eulerian–Eulerian near-nozzle spray simulation, initializing the break-up model on the basis of the transient flow conditions at each hole outlet section. The dense spray simulation has been on-line coupled to the Eulerian–Lagrangian modeling of the dilute spray region. Quantitative results on each fuel spray have been provided (in terms of penetration and Sauter Mean Diameter). The range of variability within the spray characteristics are expected to vary has been found and reported, providing reference information for lumped parameter models and other related investigations.
      PubDate: 2017-04-11
      DOI: 10.3390/app7040375
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 376: A Comparative Study on the Laser
           Welding of Ti6Al4V Alloy Sheets in Flat and Horizontal Positions

    • Authors: Baohua Chang, Zhang Yuan, Haitao Pu, Haigang Li, Hao Cheng, Dong Du, Jiguo Shan
      First page: 376
      Abstract: Laser welding has been increasingly utilized to manufacture a variety of components thanks to its high quality and speed. For components with complex shapes, the welding position needs be continuously adjusted during laser welding, which makes it necessary to know the effects of the welding position on the quality of the laser welds. In this paper, the weld quality under two (flat and horizontal) welding positions were studied comparatively in the laser welding of Ti6Al4V titanium alloy, in terms of weld profiles, process porosity, and static tensile strengths. Results show that the flat welding position led to better weld profiles, less process porosity than that of the horizontal welding position, which resulted from the different actions of gravity on the molten weld metals and the different escape routes for pores under different welding positions. Although undercuts showed no association with the fracture positions and tensile strengths of the welds, too much porosity in horizontal laser welds led to significant decreases in the strengths and specific elongations of welds. Higher laser powers and travel speeds were recommended, for both flat and horizontal welding positions, to reduce weld porosity and improve mechanical properties.
      PubDate: 2017-04-10
      DOI: 10.3390/app7040376
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 377: The Chemical Behaviors of Nitrogen
           Dioxide Absorption in Sulfite Solution

    • Authors: Ye Sun, Xiaowei Hong, Tianle Zhu, Xiaoyan Guo, Deyuan Xie
      First page: 377
      Abstract: The simultaneous removal of nitrogen oxides (NOx) and sulfur dioxide (SO2) by absorption is considered to be one of the most promising technologies for flue gas treatment, and sulfite is the main component of the absorption solution. To understand the chemical behaviors of the NO2 absorption in sulfite solution, the absorption time dependences of concentrations of nitrogen and sulfur compositions in both gas phase and liquid phases were investigated by flue gas analyzer, Ion chromatography (IC), Gas chromatography (GC), and Fourier transform infrared spectrometry (FTIR) methods using a bubbling reactor. The mass equilibrium of the N and S compositions were also studied. The results indicate that sulfite concentration plays a vital role in NO2 absorption. The main absorption products are NO3− and NO2−, and NO2− can be converted into NO3− in the presence of oxygen. Besides, about 4% to 9% by-products of S compositions are formed, and 4% to 11% by-products of N compositions such as NO, N2, N2O5, N2O, and HNO3 in the gas phase were detected in the emissions from the bubbling reactor. On the basis of N and S compositions, a possible pathway of NO2 absorption in sulfite solution was proposed.
      PubDate: 2017-04-12
      DOI: 10.3390/app7040377
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 378: Study of the Effect of Time-Based
           Rate Demand Response Programs on Stochastic Day-Ahead Energy and Reserve
           Scheduling in Islanded Residential Microgrids

    • Authors: Mostafa Vahedipour-Dahraie, Hamid Najafi, Amjad Anvari-Moghaddam, Josep Guerrero
      First page: 378
      Abstract: In recent deregulated power systems, demand response (DR) has become one of the most cost-effective and efficient solutions for smoothing the load profile when the system is under stress. By participating in DR programs, customers are able to change their energy consumption habits in response to energy price changes and get incentives in return. In this paper, we study the effect of various time-based rate (TBR) programs on the stochastic day-ahead energy and reserve scheduling in residential islanded microgrids (MGs). An effective approach is presented to schedule both energy and reserve in presence of renewable energy resources (RESs) and electric vehicles (EVs). An economic model of responsive load is also proposed on the basis of elasticity factor to model the behavior of customers participating in various DR programs. A two-stage stochastic programming model is developed accordingly to minimize the expected cost of MG under different TBR programs. To verify the effectiveness and applicability of the proposed approach, a number of simulations are performed under different scenarios using real data; and the impact of TBR-DR actions on energy and reserve scheduling are studied and compared subsequently.
      PubDate: 2017-04-11
      DOI: 10.3390/app7040378
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 379: Wavefront Shaping by a Small-Aperture
           Deformable Mirror in the Front Stage for High-Power Laser Systems

    • Authors: Sensen Li, Luoxian Zhou, Can Cui, Kai Wang, Xiusheng Yan, Yirui Wang, Lei Ding, Yulei Wang, Zhiwei Lu
      First page: 379
      Abstract: We demonstrate a method for wavefront distribution compensation with a low-cost small-aperture deformable mirror in the front stage of a complex high-power solid-state laser system. Meanwhile, an iterative algorithm for improving wavefront quality is indicated. Using this method, the wavefront compensation was studied in our single-shot high-power laser system that operated with and without the main amplifiers, respectively. The wavefront was compensated effectively, showing the near-flopped-shape output with the peak-to-valley value of 0.29 λ and root meam square (RMS) of 0.06 λ at 1053 nm.
      PubDate: 2017-04-11
      DOI: 10.3390/app7040379
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 380: Performance of Nanostructures within
           InGaN-Based Multiquantum-Well Light-Emitting Devices

    • Authors: Ya-Fen Wu, Jiunn-Chyi Lee
      First page: 380
      Abstract: We introduced multiquantum-barrier (MQB) nanostructures into the barrier layers of InGaN/GaN multiquantum-well (MQW) heterostructures to improve the operation characteristics of the light-emitting devices. The electroluminescence (EL) spectra were examined over a broad range of temperatures for the samples. We observed inhibited carrier leakage for the sample with the MQB nanostructures. Greater inhomogeneity of nanocrystallite size and a stronger localization effect were also observed for the sample. To interpret this phenomenon, high-resolution X-ray diffraction curves were measured and analyzed using the Warren–Averbach model. External quantum efficiency as a function of temperature was also evaluated. The calculation results correspond with the inference the EL measurements provided. We determined that the performance of the light-emitting devices is enhanced by the MQB nanostructures within InGaN/GaN MQWs.
      PubDate: 2017-04-11
      DOI: 10.3390/app7040380
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 381: Helicopter Blade-Vortex Interaction
           Airload and Noise Prediction Using Coupling CFD/VWM Method

    • Authors: Yinyu Zhao, Yongjie Shi, Guohua Xu
      First page: 381
      Abstract: As a high resolution airload with accurate rotor wake is pivotal for rotor BVI (Blade-vortex interaction) analysis, a hybrid method with combined Navier-Stokes equation, viscous wake model, and FW-H (Ffowcs Williams-Hawkings) equation is developed for BVI airload and noise in this paper. A comparison with the CFD (Computational Fluid Dynamics)/FW-H method for the AH-1/OLS (Operational Load Survey) rotor demonstrates its capability for favorable accuracy and high computation efficiency. This paper further discusses the mechanisms for the impacts of four flight parameters (i.e., tip-path-plane angle, thrust coefficient, tip Mach number, advance ratio) on BVI noise. Under the BVI condition, several BVI events concurrently occur on the rotor disk. Each interaction has a distinct radiation direction which depends on the interaction azimuth, and its noise intensity is highly associated with the characteristic parameters (e.g., miss-distance, interaction angle, vortex strength). The BVI noise is dominated by the interactions at 30–90° in azimuth on the advancing side, of which the wake angle range is from 180° to 540°. Furthermore, the tip-path-plane angle, thrust coefficient, and tip Mach number change the noise intensity mainly via miss-distance, interaction angle, and vortex strength, but for different advance ratios, the noise intensity and propagation direction are more dependent on the interaction angle and interaction azimuth.
      PubDate: 2017-04-11
      DOI: 10.3390/app7040381
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 382: Flow Measurement by Lateral Resonant
           Doppler Optical Coherence Tomography in the Spectral Domain

    • Authors: Julia Walther, Edmund Koch
      First page: 382
      Abstract: In spectral domain optical coherence tomography (SD-OCT), any transverse motion component of a detected obliquely moving sample results in a nonlinear relationship between the Doppler phase shift and the axial sample velocity restricting phase-resolved Doppler OCT (PR-DOCT). The size of the deviation from the linear relation depends on the amount of the transverse velocity component, given by the Doppler angle, and the height of the absolute sample velocity. Especially for very small Doppler angles between the horizontal and flow direction, and high flow velocities, the detected Doppler phase shift approaches a limiting value, making an unambiguous measurement of the axial sample velocity by PR-DOCT impossible. To circumvent this limitation, we propose a new method for resonant Doppler flow quantification in spectral domain OCT, where the scanner movement velocity is matched with the transverse velocity component of the sample motion similar to a tracking shot, where the camera is moved with respect to the sample. Consequently, the influence of the transverse velocity component of the tracked moving particles on the Doppler phase shift is negligible and the linear relation between the phase shift and the axial velocity component can be considered for flow velocity calculations. The proposed method is verified using flow phantoms on the basis of 1% Intralipid solution and diluted human blood.
      PubDate: 2017-04-11
      DOI: 10.3390/app7040382
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 383: Solar Explosive Evaporation Growth of
           ZnO Nanostructures

    • Authors: Arsenii Ievtushenko, Vasily Tkach, Victor Strelchuk, Larisa Petrosian, Oleksander Kolomys, Oleksander Kutsay, Viktor Garashchenko, Olena Olifan, Sergiy Korichev, Georgii Lashkarev, Volodymyr Khranovskyy
      First page: 383
      Abstract: For the first time, we present a novel method of explosive evaporation (MEE) for the deposition of ZnO nanostructures using concentrated solar radiation for precursor evaporation. Zinc acetylacetonate powder and a mixture of ZnO with graphite powders are used as precursors for the deposition of ZnO nanostructures. ZnO nanostructures are deposited on Au/Si, Ag/Si, and unpolished Si substrates by MEE. The scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, Raman scattering, photoluminescence, and Fourier transformed infrared spectroscopy are used for sample characterization. We demonstrate that the changing of precursors and the substrate types allows ZnO nanostructures to be grown with diverse morphologies: hexagons, spheres, and needles. The properties of ZnO nanostructures deposited on unpolished, coated by Ag and Au silicon substrates are discussed. MME using concentrated solar radiation is promising method for applications in the semiconductor industry as an economically efficient environmentally-friendly method for the growth of nanostructures.
      PubDate: 2017-04-12
      DOI: 10.3390/app7040383
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 384: Cable Force Health Monitoring of
           Tongwamen Bridge Based on Fiber Bragg Grating

    • Authors: Dongtao Hu, Yongxing Guo, Xianfeng Chen, Congrui Zhang
      First page: 384
      Abstract: A normal cable force state of a suspension bridge is extremely vital to bridge safety. For cable force monitoring of already completed suspension bridges, it is not suitable to conduct direct parameter measurements by modifying the anchor cable structure of the bridge. Instead, using an indirect measurement would not destroy the bridge’s original structure and also meet engineering requirements. In this paper, a fiber Bragg grating (FBG) vibration sensor was developed for online monitoring of the cable vibration characteristics of Tongwamen bridge. The monitored vibration frequency was converted into cable force according to the theory of string vibration, so as to achieve an indirect measurement of bridge cable force. On both north and south sides of the bridge, FBG vibration sensors were mounted symmetrically on 8 of 19 cables for distributed measurement. The forces of two cables were found to be abnormal, which was considered worthy of attention and close inspection. This result is of great significance for the structural monitoring and safe operation of Tongwamen bridge.
      PubDate: 2017-04-12
      DOI: 10.3390/app7040384
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 385: Tunable-Q Wavelet Transform Based
           Multiscale Entropy Measure for Automated Classification of Epileptic EEG
           Signals

    • Authors: Abhijit Bhattacharyya, Ram Pachori, Abhay Upadhyay, U. Acharya
      First page: 385
      Abstract: This paper analyzes the underlying complexity and non-linearity of electroencephalogram (EEG) signals by computing a novel multi-scale entropy measure for the classification of seizure, seizure-free and normal EEG signals. The quality factor (Q) based multi-scale entropy measure is proposed to compute the entropy of the EEG signal in different frequency-bands of interest. The Q -based entropy (QEn) is computed by decomposing the signal with the tunable-Q wavelet transform (TQWT) into the number of sub-bands and estimating K-nearest neighbor (K-NN) entropies from various sub-bands cumulatively. The optimal selection of Q and the redundancy parameter (R) of TQWT showed better robustness for entropy computation in the presence of high- and low-frequency components. The extracted features are fed to the support vector machine (SVM) classifier with the wrapper-based feature selection method. The proposed method has achieved accuracy of 100% in classifying normal (eyes-open and eyes-closed) and seizure EEG signals, 99.5% in classifying seizure-free EEG signals (from the hippocampal formation of the opposite hemisphere of the brain) from seizure EEG signals and 98% in classifying seizure-free EEG signals (from the epileptogenic zone) from seizure EEG signals, respectively, using the SVM classifier. We have also achieved classification accuracies of 99% and 98.6% in classifying seizure versus non-seizure EEG signals and the individual three classes, namely normal, seizure-free and seizure EEG signals, respectively. The performance measure of the proposed multi-scale entropy has been found to be comparable with the existing state of the art epileptic EEG signals classification methods studied using the same database.
      PubDate: 2017-04-12
      DOI: 10.3390/app7040385
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 386: A Free Interface Model for
           Static/Flowing Dynamics in Thin-Layer Flows of Granular Materials with
           Yield: Simple Shear Simulations and Comparison with Experiments

    • Authors: Christelle Lusso, François Bouchut, Alexandre Ern, Anne Mangeney
      First page: 386
      Abstract: Flows of dense granular materials comprise regions where the material is flowing, and regions where it is static. Describing the dynamics of the interface between these two regions is a key issue to understanding the erosion and deposition processes in natural environments. A free interface simplified model for non-averaged thin-layer flows of granular materials has been previously proposed by the authors. It is a coordinate-decoupled (separated variables) version of a model derived by asymptotic expansion from an incompressible viscoplastic model with Drucker-Prager yield stress. The free interface model describes the evolution of the velocity profile as well as the position of the transition between static and flowing material. It is formulated using the coordinate Z in the direction normal to the topography and contains a source term that represents the opposite of the net force acting on the flow, including gravity, pressure gradient, and internal friction. In this paper we introduce two numerical methods to deal with the particular formulation of this model with a free interface. They are used to evaluate the respective role of yield and viscosity for the case of a constant source term, which corresponds to simple shear viscoplastic flows. Both the analytical solution of the inviscid model and the numerical solution of the viscous model (with a constant viscosity or the variable viscosity of the μ ( I ) rheology) are compared with experimental data. Although the model does not describe variations in the flow direction, it reproduces the essential features of granular flow experiments over an inclined static layer of grains, including the stopping time and the erosion of the initial static bed, which is shown to be closely related to the viscosity for the simple shear case.
      PubDate: 2017-04-12
      DOI: 10.3390/app7040386
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 387: Mechanically Strong CaSiO3 Scaffolds
           Incorporating B2O3-ZnO Liquid Phase

    • Authors: Cijun Shuai, Songlin Duan, Dan Gao, Ping Wu, Chengde Gao, Youwen Yang, Long Liu, Fulai Yuan, Sheng Yang, Pei Feng
      First page: 387
      Abstract: Calcium silicate (CaSiO3) scaffolds were reinforced by introducing liquid phase. The liquid phase was made of B2O3 and ZnO. The fracture toughness and compressive strength increased by 48% and 141%, respectively, compared with those of the scaffolds without the liquid phase. This was attributed to the enhanced densification, the elongated grains pull-out and the cracks bridging. In addition, because of its increasing mechanical properties, the fracture model of the cleavage fracture was more beneficial than the intergranular fracture. The mechanical properties of the scaffolds with the liquid phase could be steadily maintained and then they decreased slowly when immersed in simulated body fluid (SBF). Meanwhile, the hydroxyapatite (HAp) generated on their surfaces. In addition, the scaffolds possessed favorable biocompatibility and could promote cell proliferation. These results demonstrated that the scaffolds with B2O3-ZnO liquid phase are a promising substitute for bone repair applications.
      PubDate: 2017-04-13
      DOI: 10.3390/app7040387
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 388: Stability and Dynamics of Dark-Bright
           Soliton Bound States Away from the Integrable Limit

    • Authors: Garyfallia Katsimiga, Jan Stockhofe, Panagiotis Kevrekidis, Peter Schmelcher
      First page: 388
      Abstract: The existence, stability, and dynamics of bound pairs of symbiotic matter waves in the form of dark-bright soliton pairs in two-component mixtures of atomic Bose–Einstein condensates is investigated. Motivated by the tunability of the atomic interactions in recent experiments, we explore in detail the impact that changes in the interaction strengths have on these bound pairs by considering significant deviations from the integrable limit. It is found that dark-bright soliton pairs exist as stable configurations in a wide parametric window spanning both the miscible and the immiscible regime of interactions. Outside this parameter interval, two unstable regions are identified and are associated with a supercritical and a subcritical pitchfork bifurcation, respectively. Dynamical manifestation of these instabilities gives rise to a redistribution of the bright density between the dark solitons, and also to symmetry-broken stationary states that are mass imbalanced (asymmetric) with respect to their bright soliton counterpart. The long-time dynamics of both the stable and the unstable balanced and imbalanced dark-bright soliton pairs is analyzed.
      PubDate: 2017-04-13
      DOI: 10.3390/app7040388
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 389: Study of the Preparation and
           Dielectric Property of PP/SMA/PVDF Blend Material

    • Authors: Zixuan Chen, Jianzhong Pei, Rui Li
      First page: 389
      Abstract: Polypropylene (PP) and polyvinylidene fluoride (PVDF) polymer materials have been widely used because PP has excellent piezoelectricity and PVDF has a robust tensile strength. However, few studies have been reported about PP/PVDF blends, and the main issue has proven to be the interfacial compatibility of blends. This research investigated the microstructure of blends to characterize their compatibility. X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis showed the poor interactions between PP and PVDF interface, and thus this study adopted styrene maleic anhydride (SMA) copolymer as compatibilizer to modify the properties of blends. The XRD and SEM investigations showed an enhancement in the interactions between PP and PVDF after the addition of SMA. The dielectric properties of PP/SMA/PVDF blends showed a significant increase when PP content was 40%–60% and the dielectric constant (ε) was up to 13; meanwhile, the dielectric loss (tanδ) of PP/SMA/PVDF was lower than PP/PVDF blends.
      PubDate: 2017-04-13
      DOI: 10.3390/app7040389
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 390: Adaptive Feature Extraction of Motor
           Imagery EEG with Optimal Wavelet Packets and SE-Isomap

    • Authors: Ming-ai Li, Wei Zhu, Hai-na Liu, Jin-fu Yang
      First page: 390
      Abstract: Motor imagery EEG (MI-EEG), which reflects one’s active movement intention, has attracted increasing attention in rehabilitation therapy, and accurate and fast feature extraction is the key problem to successful applications. Based on wavelet packet decomposition (WPD) and SE-isomap, an adaptive feature extraction method is proposed in this paper. The MI-EEG is preprocessed to determine a more effective time interval through average power spectrum analysis. WPD is then applied to the selected segment of MI-EEG, and the subject-based optimal wavelet packets (OWPs) with top mean variance difference are obtained autonomously. The OWP coefficients are further used to calculate the time-frequency features statistically and acquire the nonlinear manifold structure features, as well as the explicit nonlinear mapping, through SE-isomap. The hybrid features are obtained in a serial fusion way and evaluated by a k-nearest neighbor (KNN) classifier. The extensive experiments are conducted on a publicly available dataset, and the experiment results of 10-fold cross-validation show that the proposed method yields relatively higher classification accuracy and computation efficiency simultaneously compared with the commonly-used linear and nonlinear approaches.
      PubDate: 2017-04-14
      DOI: 10.3390/app7040390
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 391: Hierarchical Wavelet-Aided Neural
           Intelligent Identification of Structural Damage in Noisy Conditions

    • Authors: Mao-Sen Cao, Yu-Juan Ding, Wei-Xin Ren, Quan Wang, Minvydas Ragulskis, Zhi-Chun Ding
      First page: 391
      Abstract: A sophisticated hierarchical neural network model for intelligent assessment of structural damage is constructed by the synergetic action of auto-associative neural networks (AANNs) and Levenberg-Marquardt neural networks (LMNNs). With the model, AANNs aided by the wavelet packet transform are firstly employed to extract damage features from measured dynamic responses and LMNNs are then utilized to undertake damage pattern recognition. The synergetic functions endow the model with a unique mechanism of intelligent damage identification in structures. The model is applied for the identification of damage in a three-span continuous bridge, with particular emphasis on noise interference. The results show that the AANNs can produce a low-dimensional space of damage features, from which LMNNs can recognize both the location and the severity of structural damage with great accuracy and strong robustness against noise. The proposed model holds promise for developing viable intelligent damage identification technology for actual engineering structures.
      PubDate: 2017-04-14
      DOI: 10.3390/app7040391
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 392: Excitation of Surface Waves Due to
           Thermocapillary Effects on a Stably Stratified Fluid Layer

    • Authors: William Zimmerman, Julia Rees
      First page: 392
      Abstract: In chemical engineering applications, the operation of condensers and evaporators can be made more efficient by exploiting the transport properties of interfacial waves excited on the interface between a hot vapor overlying a colder liquid. Linear theory for the onset of instabilities due to heating a thin layer from above is computed for the Marangoni–Bénard problem. Symbolic computation in the long wave asymptotic limit shows three stationary, non-growing modes. Intersection of two decaying branches occurs at a crossover long wavelength; two other modes co-exist at the crossover point—propagating modes on nascent, shorter wavelength branches. The dispersion relation is then mapped numerically by Newton continuation methods. A neutral stability method is used to map the space of critical stability for a physically meaningful range of capillary, Prandtl, and Galileo numbers. The existence of a cut-off wavenumber for the long wave instability was verified. It was found that the effect of applying a no-slip lower boundary condition was to render all long waves stationary. This has the implication that any propagating modes, if they exist, must occur at finite wavelengths. The computation of 8000 different parameter sets shows that the group velocity always lies within 1 2 to 2 3 of the longwave phase velocity.
      PubDate: 2017-04-13
      DOI: 10.3390/app7040392
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 393: Modeling and Dynamics of a MDOF
           Isolation System

    • Authors: Youshuo Song, Xiuting Sun
      First page: 393
      Abstract: This study analyzes the modeling and dynamics of a novel passive multi-degree-of-freedom (MDOF) vibration isolation platform which can achieve a significant isolation effect. Symmetrical scissor-like structures (SLSs) are utilized in the proposed MDOF isolation platform as the supporting and isolation elastic components. Based on the mathematical modeling and theoretical analysis of the MDOF vibration isolation system with SLSs, the effects of structural parameters and joint friction on the stiffness and damping properties are investigated. It is shown that due to geometric relations within the SLSs, the natural frequencies can be reduced via adjusting structural parameters of the SLS for different direction vibration isolation. Theoretical and experimental results show that the SLS isolation platform can achieve much better loading capacity and vibration isolation performance simultaneously by only using linear passive components because of the MDOF adjustable stiffness property. Therefore, with low cost and energy consumption, the proposed novel isolation platform can improve the vibration suppression in various engineering practices.
      PubDate: 2017-04-14
      DOI: 10.3390/app7040393
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 394: An Improved Radio Resource Management
           with Carrier Aggregation in LTE Advanced

    • Authors: Hasibur Chayon, Kaharudin Dimyati, Harikrishnan Ramiah, Ahmed Reza
      First page: 394
      Abstract: Long term evolution-advanced (LTE-A) system introduces carrier aggregation (CA) technique to improve the user throughput by aggregating multiple component carriers (CCs). Previous research works related to downlink radio resource allocation with carrier aggregation have not considered the delay factor and the error probability. Therefore, the previous methods are unable to provide better quality of service (QoS) compared to the LTE-A standard. This paper considers the radio resource management problem by zooming into the head of line delay, probability of packet loss, and the delay threshold for different types of data. In doing this, several constraints are imposed following the specifications of LTE-A system. Hence, an improved method is developed in this study to enhance the system throughput and to maintain the computational complexity. Extensive simulations were carried out with other well-known methods to verify the overall performance of the proposed method. The result obtained indicates that the proposed method outperforms the previous methods in the measurement of average user throughput, average cell throughput, fairness index, and spectral efficiency.
      PubDate: 2017-04-14
      DOI: 10.3390/app7040394
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 395: Parametric Sensitivity Analysis on
           the Buffeting Control of a Long-Span Triple-Tower Suspension Bridge with
           MTMD

    • Authors: Tianyou Tao, Hao Wang, Chengyuan Yao, Xuhui He
      First page: 395
      Abstract: The long-span triple-tower suspension bridge is a brand-new type of structural form with typical wind-sensitive features. Inevitable wind-induced vibrations will heavily influence the driving comfort during strong winds and shorten the fatigue life of the bridge structure, which highlights the demand for the mitigation of wind-induced vibrations of long-span bridges. In this study, a parametric analysis is performed to investigate the control effect of multiple tuned mass dampers (MTMD) on the buffeting responses of a long-span triple-tower suspension bridge. Taking Taizhou Bridge as an example, the buffeting analysis is conducted via the finite-element-based approach. A step-updating framework is presented to guide the parametric analysis and determine the preferred values of the mechanical parameters of the MTMD. Specifically, four parameters—including the number of TMDs, the mass ratio, the damping ratio, and the frequency bandwidth ratio—are included in the parametric analysis. The robustness of the MTMD is also evaluated by changing another parameter called the frequency ratio. It is found that the performance of the MTMD is sensitive to the variation of the four parameters and the robustness can be adjusted by increasing the frequency bandwidth ratio. Utilizing the MTMD with reasonable mechanical parameters, the buffeting responses of the long-span triple-tower suspension bridge under strong winds can be effectively mitigated.
      PubDate: 2017-04-14
      DOI: 10.3390/app7040395
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 396: Oxidation Products of Ester-Based
           Oils with and without Antioxidants Identified by Stable Isotope Labelling
           and Mass Spectrometry

    • Authors: Marcella Frauscher, Charlotte Besser, Günter Allmaier, Nicole Dörr
      First page: 396
      Abstract: As lubricants with a high thermo-oxidative stability such as synthetic esters are gaining more importance in the lubricant market, a detailed knowledge regarding their oxidative degradation behaviour is of high importance. In order to reveal their degradation products and processes, a novel approach combining artificial alteration, isotope labelling based on oxidation with 16O2 and 18O2, and mass spectrometry (MS), was applied to a bis(2-ethylhexyl) adipate base oil. The degradation products such as 2-ethylhexanol and its monoesters with short-chain fatty acids pinpointed the C–O ester bond as the site prone to oxidative attack, allowing the collection of information about the oxidation mechanisms. Furthermore, the influence of the antioxidant (AO) 4,4′-methylene-bis(2,6-di-tert-butylphenol) as an additive on the oxidation behaviour and resulting products was studied: blends containing AO showed a remarkably higher resistance against oxidation. However, similar degradation products were obtained after AO depletion and without AO. AO cleavage occurred at the carbon atom that bridges the phenols to give 2,6-di-tert-butyl-p-benzoquinone and 3,5-di-tert-butyl-4-hydroxybenzoic acid. By applying the isotope labelling approach, sites of preferential oxidative cleavage and hence differentiation of the origin of oxygen atoms—either from the atmosphere or from base oil components—can be unambiguously related in oxygen-containing base oils, as well as in blends with additives.
      PubDate: 2017-04-16
      DOI: 10.3390/app7040396
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 397: Study of the Diffusion of
           Rejuvenators and Its Effect on Aged Bitumen Binder

    • Authors: Yue Xiao, Chao Li, Miao Wan, Xinxing Zhou, Yefei Wang, Shaopeng Wu
      First page: 397
      Abstract: Aged asphalt mixture is heavily involved in pavement maintenance and renewed construction because of the development of recycling techniques. The aged bitumen binder has partially lost its viscous behavior. Rejuvenators are therefore designed and used in this recycling procedure to enhance the behavior of such aged reclaimed bitumen. However, tests have not yet been clearly specified to understand the diffusion characteristics of rejuvenators in aged bitumen. In this research, molecular dynamic simulation is proposed and conducted with Materials Studio software to study the diffusion behavior of rejuvenators in aged bitumen at the molecular level. Two rejuvenators, named R-1 and R-2, were included. The difference between these two rejuvenators is their chemical composition of C=O. The diffusion coefficient is determined by studying the molecular movement. Results illustrate that the proposed models can be used to study the diffusion of rejuvenators in aged bitumen sufficiently. In the meantime, a dynamic shear rheometer (DSR) is used to evaluate the recovery influence on aged bitumen resulting from rejuvenators. The experimental results strengthen the model simulations and indicate that the aging index of bitumen has a significant influence on the rejuvenating effect. Research results indicate that rejuvenators have a sufficient rejuvenating effect on the long-term aged bitumen and a limited effect on short-term aged bitumen.
      PubDate: 2017-04-14
      DOI: 10.3390/app7040397
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 398: Bi-Level Programming Approach for the
           Optimal Allocation of Energy Storage Systems in Distribution Networks

    • Authors: Nian Shi, Yi Luo
      First page: 398
      Abstract: Low-CO2-emission wind generation can alleviate the world energy crisis, but intermittent wind generation influences the reliability of power systems. Energy storage might smooth the wind power fluctuations and effectively improve system reliability. The contribution of energy storage to system reliability cannot be comprehensively assessed by the installed capacity of energy storage. The primary goal of this paper is to investigate the impact of the installed location and capacity of energy storage on power system reliability. Based on a bi-level programming approach, this paper presents a bi-level energy storage programming configuration model for energy storage capacity and location configuration. For upper-level optimization, a depth search method is utilized to obtain the optimal installed location of energy storage. For the lower-level optimization, the optimal capacity of energy storage is solved to meet the system reliability requirements. The influence of the contribution of energy storage location to system reliability is analyzed. The proposed model and method are demonstrated using the RBTS-Bus6 System and Nanao (NA) island distribution system in China. The results show the effectiveness and practicability of the proposed model and method.
      PubDate: 2017-04-14
      DOI: 10.3390/app7040398
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 399: FMS Scheduling under Availability
           Constraint with Supervisor Based on Timed Petri Nets

    • Authors: Mohamed Kammoun, Wajih Ezzeddine, Nidhal Rezg, Zied Achour
      First page: 399
      Abstract: This paper proposes an optimal solution to large-scale Flexible Manufacturing System (FMS) scheduling problems under availability constraints based on Timed Petri Nets (TPNs). First a decomposition method of TPNs is proposed, then a mathematical model is derived based on their properties. The mathematical model is built to determine the optimal firing sequence of TPN transitions to minimize the total manufacturing time. The resulting firing sequence of TPN transitions is used to generate the manufacturing system supervisor operated by TPN and digital controllers. Several numerical examples and comparative studies are provided in this paper in order to prove the new approach’s efficiency.
      PubDate: 2017-04-15
      DOI: 10.3390/app7040399
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 400: Rare Ellagic Acid Sulphate
           Derivatives from the Rhizome of Geum rivale L.—Structure, Cytotoxicity,
           and Validated HPLC-PDA Assay

    • Authors: Aleksandra Owczarek, Marek Różalski, Urszula Krajewska, Monika Olszewska
      First page: 400
      Abstract: Two rare sulphate ellagic acid derivatives were isolated from the rhizome of Geum rivale L. in three simple steps. Their structures were identified by comprehensive NMR studies (1H NMR, 13C NMR, 1H-1H COSY, HMBC, HSQC) as 3,3′-dimethoxy-4-sulphoxyellagic acid potassium salt (1) and 3,3′,4′-trimethoxy-4-sulphoxyellagic acid potassium salt (2). Subsequently, a new precise (RSD < 2.6%), accurate (recoveries in the range of 96.5–98.7%), and sensitive (LODs in the range of 0.15–0.16 μg/mL) HPLC-PDA procedure was developed for the simultaneous quantification of compounds 1 and 2 in plant material. The rhizome of G. rivale proved to be a good source of both compounds, with the content of 2.94 ± 0.03 and 5.45 ± 0.03 mg/g dw respectively, whereas at most, trace amounts were detected in related plant materials (aerial parts of G. rivale, rhizome and aerial parts of G. urbanum). The cytotoxicity of isolated compounds tested on human leukaemia (promyelocytic HL-60 and lymphoblastic NALM-6) and melanoma (WM 115) cell lines with IC50 values in the range of 306.4–473.8 μM was demonstrated to be lower than that of ellagic acid (IC50 = 62.3–300.6 μM).
      PubDate: 2017-04-15
      DOI: 10.3390/app7040400
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 401: Using Text Mining Techniques to
           Identify Research Trends: A Case Study of Design Research

    • Authors: Binling Nie, Shouqian Sun
      First page: 401
      Abstract: The research goal of this paper is to identify major academic branches and to detect research trends in design research using text mining techniques. In this paper, the information about scientific literature in design research isprocessed. A combination of clustering and bibliometric analysis led to shaping four academic branches and summarizing each academic branch. Then, research trends and the evolution for each academic branch are explored. We perform a two-dimensional text mining approach, including bibliometric and network analysis, in order to detect trends of major academic branches. Specifically, the bibliometric characterization aims to assess design research area outputs, while the network analysis intends to reveal research trends in each academic branch of design research and the evolution of core research themes.
      PubDate: 2017-04-15
      DOI: 10.3390/app7040401
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 402: Hydrophobic Ceramic Membranes for
           Water Desalination

    • Authors: Joanna Kujawa, Sophie Cerneaux, Wojciech Kujawski, Katarzyna Knozowska
      First page: 402
      Abstract: Hydrophilic ceramic membranes (tubular and planar) made of TiO2 and Al2O3 were efficiently modified with non-fluorinated hydrophobic grafting molecules. As a result of condensation reaction between hydroxyl groups on the membrane and reactive groups of modifiers, the hydrophobic surfaces were obtained. Ceramic materials were chemically modified using three various non-fluorinated grafting agents. In the present work, the influence of grafting time and type of grafting molecule on the modification efficiency was evaluated. The changes of physicochemical properties of obtained hydrophobic surfaces were determined by measuring the contact angle (CA), roughness (RMS), and surface free energy (SFE). The modified surfaces were characterized by contact angle in the range of 111–132°. Moreover, hydrophobic tubular membranes were utilized in air-gap membrane distillation to desalination of sodium chloride aqueous solutions. The observed permeate fluxes were in the range of 0.7–4.8 kg·m−2·h−1 for tests with pure water. The values of permeate fluxes for membranes in contact with NaCl solutions were smaller, within the range of 0.4–2.8 kg·m−2·h−1. The retention of NaCl in AGMD process using hydrophobized ceramic membranes was close to unity for all investigated membranes.
      PubDate: 2017-04-15
      DOI: 10.3390/app7040402
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 403: A Three-Dimensional Resonant
           Triggering Probe for Micro-CMM

    • Authors: Qiangxian Huang, Chen Chen, Kui Wu, Liansheng Zhang, Ruijun Li, Kuang-Chao Fan
      First page: 403
      Abstract: To achieve true 3D nano-measurement with sub-nanometer resolution and very low touch force through a micro/nano coordinate measuring machine, a new 3D resonant trigger probe based on a quartz tuning fork is proposed. In this trigger probe, a quartz tuning fork with a microsphere tip vibrates at its resonant frequency, and is used as the sensing element. The resonance parameters of this quartz tuning fork (e.g., vibrating amplitude and resonant frequency) are extremely sensitive to external 3D microforces. The distinguished feature of this probe is its ability to interact with the sample surface in the actual three directions. The microsphere tip of the probe interacts with the sample surface in tapping mode in the Z direction, whereas it interacts in friction mode in the X and Y directions. The dynamic contact mechanism of the probe is based on interfacial force theory, and mechanical models of the interactions between the microsphere tip and sample surface in the X, Y, and Z directions are constructed and simulated. The experiment shows that the probe has sub-nanometer resolution in 3D directions and triggers repeatability of approximately 40 nm in each direction. Theoretical analysis and experimental results verify that this 3D resonant trigger probe can be used for true 3D profile measurement.
      PubDate: 2017-04-15
      DOI: 10.3390/app7040403
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 404: The Brownian and Thermophoretic
           Analysis of the Non-Newtonian Williamson Fluid Flow of Thin Film in a
           Porous Space over an Unstable Stretching Surface

    • Authors: Liaqat Ali, Saeed Islam, Taza Gul, Ilyas Khan, L. Dennis, Waris Khan, Aurangzeb Khan
      First page: 404
      Abstract: This paper explores Liquid Film Flow of Williamson Fluid over an Unstable Stretching Surface in a Porous Space . The Brownian motion and Thermophoresis effect of the liquid film flow on a stretching sheet have been observed. This research include, to focus on the variation in the thickness of the liquid film in a porous space. The self-similarity variables have been applied to convert the modelled equations into a set of non-linear coupled differential equations. These non-linear differential equations have been treated through an analytical technique known as Homotopy Analysis Method (HAM). The effect of physical non-dimensional parameters like, Eckert Number, Prandtl Number, Porosity Parameter, Brownian Motion Parameter, Unsteadiness Parameter, Schmidt Number, Thermophoresis Parameter, Dimensionless Film Thickness, and Williamson Fluid Constant on the liquid film size are investigated and conferred in this endeavor. The obtained results through HAM are authenticated, from its comparison with numerical (ND-Solve Method). The graphical comparison of these two methods is elaborated. The numerical comparison with absolute errors are also been shown in the tables. The physical and numerical results using h curves for the residuals of the velocity, temperature and concentration profiles are obtained
      PubDate: 2017-04-18
      DOI: 10.3390/app7040404
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 405: Modeling Analysis on Propagation of
           Structure-Borne Vibration Caused by an Indoor Distribution Transformer in
           a Building and Its Control Method

    • Authors: Junhua Wang, Yi Xu, Kaibin Liang, Qisheng Liu, Jiangui Li, Kaipei Liu
      First page: 405
      Abstract: With the increase of urban population and electricity demand, in order to provide sufficient power to residents, distribution transformers are getting closer to residential buildings, and are even directly placed on the first floor or the basement of buildings due to space limitations. The vibration and noise with low frequency of mainly 50–250 Hz generated by the distribution transformers spread to rooms through beams, bricks, walls and other building structures, which inevitably damages the living environment. In this paper, through focusing on the frame of buildings, simulation models of the indoor distribution transformer vibrating in the structure field are built, including a two-layer model and a six-layer model. This paper simulates and analyzes the vibration response of the structural system, studies the propagation laws of the structure-borne sound caused by the transformer and quantitatively analyzes the attenuation characteristics of the vibration. Finally the prevention method of the structure-borne noise, called vibration isolation, is introduced and analyzed by the field test to evaluate the noise reduction effect.
      PubDate: 2017-04-17
      DOI: 10.3390/app7040405
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 406: Learning-Based Optimal Desired
           Compensation Adaptive Robust Control for a Flexure-Based Micro-Motion
           Manipulator

    • Authors: Shi Jia, Yao Jiang, Tiemin Li, Yunsong Du
      First page: 406
      Abstract: Flexure-based micro-motion mechanisms activated by piezoelectric actuators have a wide range of applications in modern precision industry, due to their inherent merits. However, system performance is negatively affected by model uncertainty, disturbance and uncertain nonlinearity, such as the cross-coupling effect and the hysteresis of the actuator. This paper presents an integrated learning-based optimal desired compensation adaptive robust control (LODCARC) methodology for a flexure-based parallel micro-motion manipulator. The proposed LODCARC optimizes the reference trajectory used in the desired compensation adaptive robust control (DCARC) by iterative learning control (ILC), which can greatly compensate for the effect of repetitive disturbance and uncertainty. The proposed control approach was tested on the flexure-based micro-motion manipulator, with the comparative results of high-speed tracking experiments verifying that the proposed LODCARC controller can achieve excellent tracking and contouring performances with parametric adaption and disturbance robustness. Furthermore, the iterative reference optimization can effectively accommodate the effects of unmodeled repetitive uncertainty from the micro-motion system. This study provides a practical and effective technique for the flexure-based micro-motion manipulator to achieve high-precision motion.
      PubDate: 2017-04-17
      DOI: 10.3390/app7040406
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 407: Self-Referenced Spectral
           Interferometry for Femtosecond Pulse Characterization

    • Authors: Xiong Shen, Peng Wang, Jun Liu, Takayoshi Kobayashi, Ruxin Li
      First page: 407
      Abstract: Since its introduction in 2010, self-referenced spectral interferometry (SRSI) has turned out to be an analytical, sensitive, accurate, and fast method for characterizing the temporal profile of femtosecond pulses. We review the underlying principle and the recent progress in the field of SRSI. We present our experimental work on this method, including the development of self-diffraction (SD) effect-based SRSI (SD-SRSI) and transient-grating (TG) effect-based SRSI (TG-SRSI). Three experiments based on TG-SRSI were performed: (1) We built a simple TG-SRSI device and used it to characterize a sub-10 fs pulse with a center wavelength of 1.8 μm. (2) On the basis of the TG effect, we successfully combined SRSI and frequency-resolved optical gating (FROG) into a single device. The device has a broad range of application, because it has the advantages of both SRSI and FROG methods. (3) Weak sub-nanojoule pulses from an oscillator were successfully characterized using the TG-SRSI device, the optical setup of which is smaller than the palm of a hand, making it convenient for use in many applications, including sensor monitoring the pulse profile of laser systems. In addition, the SRSI method was extended for single-shot characterization of the temporal contrast of ultraintense and ultrashort laser pulses.
      PubDate: 2017-04-18
      DOI: 10.3390/app7040407
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 408: Nobel Symposium on Free Electron
           Laser Research

    • Authors: Mats Larsson
      First page: 408
      Abstract: This meeting report describes the Nobel Symposium on Free Electron Laser Research, which was organized in Sigtuna, Sweden, 14–18 June 2015.
      PubDate: 2017-04-18
      DOI: 10.3390/app7040408
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 409: Viscosity Prediction of Different
           Ethylene Glycol/Water Based Nanofluids Using a RBF Neural Network

    • Authors: Ningbo Zhao, Zhiming Li
      First page: 409
      Abstract: In this study, a radial basis function (RBF) neural network with three-layer feed forward architecture was developed to effectively predict the viscosity ratio of different ethylene glycol/water based nanofluids. A total of 216 experimental data involving CuO, TiO2, SiO2, and SiC nanoparticles were collected from the published literature to train and test the RBF neural network. The parameters including temperature, nanoparticle properties (size, volume fraction, and density), and viscosity of the base fluid were selected as the input variables of the RBF neural network. The investigations demonstrated that the viscosity ratio predicted by the RBF neural network agreed well with the experimental data. The root mean squared error (RMSE), mean absolute percentage error (MAPE), sum of squared error (SSE), and statistical coefficient of multiple determination (R2) were respectively 0.04615, 2.12738%, 0.46007, and 0.99925 for the total samples when the Spread was 0.3. In addition, the RBF neural network had a better ability for predicting the viscosity ratio of nanofluids than the typical Batchelor model and Chen model, and the prediction performance of RBF neural networks were affected by the size of the data set.
      PubDate: 2017-04-18
      DOI: 10.3390/app7040409
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 410: Performance Improvement of High
           Efficiency Mono-Crystalline Silicon Solar Cells by Modifying Rear-Side
           Morphology

    • Authors: Chung-Yuan Kung, Chih-Hsiang Yang, Chun-Wei Huang, Shui-Yang Lien, Wen-Zhang Zhu, Hai-Jun Lin, Xiao-Ying Zhang
      First page: 410
      Abstract: In this work, aluminum oxide films with excellent passivation effects were prepared on the rear-side surface of passivated emitter and rear cells (PERCs) using a self-developed spatial atomic layer deposition system. Various rear-side surface morphologies were obtained through different etching treatments. We compared the PERCs with standard etching treatment and further polishing processes on rear-side surfaces. Experimental results show that compared with the unpolished cell, the polished cell attained superior electrical performance, particularly in open-circuit voltage (Voc) and short-circuit current density (Jsc), because of the more effective rear-side surface passivation and reabsorption of long-wavelength light. The improvement in Voc and Jsc raised the conversion efficiency to 19.27%. This study verifies that despite polished cells requiring complex processes, the polishing treatment displays application potential for achieving high efficiency in the solar industry.
      PubDate: 2017-04-18
      DOI: 10.3390/app7040410
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 412: Simplified Swarm Optimization-Based
           Function Module Detection in Protein–Protein Interaction Networks

    • Authors: Xianghan Zheng, Lingting Wu, Shaozhen Ye, Riqing Chen
      First page: 412
      Abstract: Proteomics research has become one of the most important topics in the field of life science and natural science. At present, research on protein–protein interaction networks (PPIN) mainly focuses on detecting protein complexes or function modules. However, existing approaches are either ineffective or incomplete. In this paper, we investigate detection mechanisms of functional modules in PPIN, including open database, existing detection algorithms, and recent solutions. After that, we describe the proposed approach based on the simplified swarm optimization (SSO) algorithm and the knowledge of Gene Ontology (GO). The proposed solution implements the SSO algorithm for clustering proteins with similar function, and imports biological gene ontology knowledge for further identifying function complexes and improving detection accuracy. Furthermore, we use four different categories of species datasets for experiment: fruitfly, mouse, scere, and human. The testing and analysis result show that the proposed solution is feasible, efficient, and could achieve a higher accuracy of prediction than existing approaches.
      PubDate: 2017-04-19
      DOI: 10.3390/app7040412
      Issue No: Vol. 7, No. 4 (2017)
       
  • Applied Sciences, Vol. 7, Pages 440: Fatigue Assessment of Explosive Bolts
           Considering Vibration of Fixtures

    • Authors: Lixu Wang, Yang Zhao, Tieqiang Gang, Lijie Chen, Hongyu Tian
      First page: 440
      Abstract: In order to comprehensively evaluate the safety and reliability of a missile, this paper gives a process of how to perform fatigue assessment for release devices—such as explosive bolts—considering road roughness during its carrying on different classes of roads. Firstly, displacement power spectral density (PSD) function is used to fit models of road surfaces of Class A, C, and E. Taking the surface models as simulations, multi-body dynamics analyses with code ADAMS are performed to obtain acceleration responses of different points on the missile. Loading these accelerations, the corresponding stress distribution of explosive bolts is achieved with FEM code ABAQUS. These loads are counted by rainflow method. Finally, constant life curves with different survival rates are employed to get the S-N curves at different stress ratios and stress concentration coefficients, and fatigue lives of explosive bolts are assessed based on the stress-life method. Afterward, the effect of pretension force on the vibration load is obtained. This paper provides a fatigue evaluation procedure for release devices, which is helpful to raise the reliability of release devices for both design and service procedures.
      PubDate: 2017-04-03
      DOI: 10.3390/app7040440
      Issue No: Vol. 7, No. 4 (2017)
       
 
 
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