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  Subjects -> ENGINEERING (Total: 2279 journals)
    - CHEMICAL ENGINEERING (191 journals)
    - CIVIL ENGINEERING (185 journals)
    - ELECTRICAL ENGINEERING (101 journals)
    - ENGINEERING (1203 journals)
    - ENGINEERING MECHANICS AND MATERIALS (390 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (65 journals)
    - MECHANICAL ENGINEERING (89 journals)

ENGINEERING (1203 journals)                  1 2 3 4 5 6 7 | 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: 222)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
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: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 4)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 5)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
Advances in Artificial Neural Systems     Open Access   (Followers: 4)
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: 10)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 20)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 24)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
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: 12)
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: 37)
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: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 9)
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 Network Science     Open Access  
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
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: 7)
Arid Zone Journal of Engineering, Technology and Environment     Open Access  
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
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: 8)
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: 8)
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: 4)
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: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 3)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
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     Hybrid Journal   (Followers: 14)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 41)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 7)
Case Studies in Thermal Engineering     Open Access   (Followers: 3)
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: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 4)
Coatings     Open Access   (Followers: 3)
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: 25)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 256)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 181)
Composites Part B : Engineering     Hybrid Journal   (Followers: 227)
Composites Science and Technology     Hybrid Journal   (Followers: 169)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 13)
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: 28)
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: 10)
Computing and Visualization in Science     Hybrid Journal   (Followers: 5)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 29)
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: 8)
Control Engineering Practice     Hybrid Journal   (Followers: 41)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 25)
CT&F Ciencia, Tecnologia y Futuro     Open Access  

        1 2 3 4 5 6 7 | Last

Journal Cover Applied Sciences
  [SJR: 0.178]   [H-I: 9]   [2 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Online) 2076-3417
   Published by MDPI Homepage  [151 journals]
  • Applied Sciences, Vol. 7, Pages 476: Severity Prediction of Traffic
           Accidents with Recurrent Neural Networks

    • Authors: Maher Sameen, Biswajeet Pradhan
      First page: 476
      Abstract: In this paper, a deep learning model using a Recurrent Neural Network (RNN) was developed and employed to predict the injury severity of traffic accidents based on 1130 accident records that have occurred on the North-South Expressway (NSE), Malaysia over a six-year period from 2009 to 2015. Compared to traditional Neural Networks (NNs), the RNN method is more effective for sequential data, and is expected to capture temporal correlations among the traffic accident records. Several network architectures and configurations were tested through a systematic grid search to determine an optimal network for predicting the injury severity of traffic accidents. The selected network architecture comprised of a Long-Short Term Memory (LSTM) layer, two fully-connected (dense) layers and a Softmax layer. Next, to avoid over-fitting, the dropout technique with a probability of 0.3 was applied. Further, the network was trained with a Stochastic Gradient Descent (SGD) algorithm (learning rate = 0.01) in the Tensorflow framework. A sensitivity analysis of the RNN model was further conducted to determine these factors’ impact on injury severity outcomes. Also, the proposed RNN model was compared with Multilayer Perceptron (MLP) and Bayesian Logistic Regression (BLR) models to understand its advantages and limitations. The results of the comparative analyses showed that the RNN model outperformed the MLP and BLR models. The validation accuracy of the RNN model was 71.77%, whereas the MLP and BLR models achieved 65.48% and 58.30% respectively. The findings of this study indicate that the RNN model, in deep learning frameworks, can be a promising tool for predicting the injury severity of traffic accidents.
      PubDate: 2017-06-08
      DOI: 10.3390/app7060476
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 509: Passive Vibration Control of a
           Semi-Submersible Floating Offshore Wind Turbine

    • Authors: Chao Li, Tongyi Zhuang, Shengtao Zhou, Yiqing Xiao, Gang Hu
      First page: 509
      Abstract: Floating offshore wind turbines have the potential to commercially convert the vast wind resource in deep-water area. Compared with fixed-bottom wind turbines, motions of the floating foundation complicate vibrations and loads of the wind turbine in offshore environment. To alleviate the responses of the wind turbine, this study investigates the use of fore–aft tuned mass damper (TMD) in nacelle/tower for passive control of a semi-submersible offshore wind turbine. A simplified structural model, considering the degree-of-freedom of platform pitch and surge, tower tilt and TMD translation, is proposed in the light of motion features of semi-submersible platform. After identifying ten unknown parameters, the correctness of the deterministic model is validated by pitch free decay responses. The mass, stiffness and damping of TMD are optimized using both method of exhaustion and genetic algorithm to avoid local minimum. Six optimized TMD devices are evaluated under three kinds of realistic environment conditions. The control effectiveness is assessed by the extreme and fatigue response reduction ratios. It is found that the high stiffness TMDs that directly dissipate the energy of tower oscillation exhibit an overall stable performance. Similar to the spar-type foundation, the TMDs in the nacelle/tower are capable of extending the service life of floating wind turbines.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060509
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 512: Direct-Current Forced Interruption
           and Breaking Performance of Spiral-Type Contacts in Aero Applications

    • Authors: Wenlei Huo, Jianwen Wu, Bowen Jia, Mingxuan Chen, Suliang Ma, Liying Zhu
      First page: 512
      Abstract: This paper analyses the transient characteristics and breaking performance of direct-current (DC) forced-interruption vacuum interrupters in 270 V power-supply systems. Three stages are identified in forced interruption: the DC-arcing stage, current-commutation stage, and voltage-recovery stage. During the current-commutation stage, the reverse peak-current coefficient k, which is a key design factor, is used to calculate the rate of current at zero-crossing (di/dt). MATLAB/Simulink simulation models are established to obtain the transient characteristics influenced by the forced-commutation branch parameters and the coefficient k. To study the breaking performance of spiral-type contacts, experiments are conducted for different contact materials and arcing times for currents less than 3.5 kA. During the DC-arcing stage, a locally intensive burning arc is observed in the CuW80 contact; however, it is not observed in the CuCr50 contact. On examining the re-ignition interruption results of the CuW80 contact, the intensive burning arc is found to be positioned within a possible re-ignition region. When the arcing time is longer than 1 ms, the intensive burning arc occurs and affects the breaking performance of the spiral-type contacts. If the DC-arcing stage is prolonged, the total arcing energy increases, which leads to a lower breaking capacity.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060512
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 513: Equivalence between Fuzzy PID
           Controllers and Conventional PID Controllers

    • Authors: Chun-Tang Chao, Nana Sutarna, Juing-Shian Chiou, Chi-Jo Wang
      First page: 513
      Abstract: This paper proposes the equivalence between fuzzy Proportional-Integral-Derivative (PID) controllers and conventional PID controllers. A well-designed conventional PID controller, with the help of the proposed method, can be rapidly transformed to an equivalent fuzzy logic controller (FLC) by observing and defining the operating ranges of the input/output of the controller. Furthermore, the knowledge base of the proposed equivalent fuzzy PID controller is represented as a cube fuzzy associative memory (FAM), instead of a combination of PD-type and PI-type FLCs in most research. Simulation results show the feasibility of the proposed technique, both in continuous and discrete time. Since the design techniques of conventional linear PID controllers have matured, they can act as preliminary expert knowledge for nonlinear FLCs designs. Based on the proposed equivalence relationship, the designer can further tune the membership functions of fuzzy variables in the control rules to exhibit the nonlinearity of a FLC and yield more satisfactory system responses in an efficient way.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060513
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 517: An Automatic Measurement Method for
           Absolute Depth of Objects in Two Monocular Images Based on SIFT Feature

    • Authors: Lixin He, Jing Yang, Bin Kong, Can Wang
      First page: 517
      Abstract: Recovering depth information of objects from two-dimensional images is one of the very important and basic problems in the field of computer vision. In view of the shortcomings of existing methods of depth estimation, a novel approach based on SIFT (the Scale Invariant Feature Transform) is presented in this paper. The approach can estimate the depths of objects in two images which are captured by an un-calibrated ordinary monocular camera. In this approach, above all, the first image is captured. All of the camera parameters remain unchanged, and the second image is acquired after moving the camera a distance d along the optical axis. Then image segmentation and SIFT feature extraction are implemented on the two images separately, and objects in the images are matched. Lastly, an object’s depth can be computed by the lengths of a pair of straight line segments. In order to ensure that the most appropriate pair of straight line segments are chosen, and also reduce computation, convex hull theory and knowledge of triangle similarity are employed. The experimental results show our approach is effective and practical.
      PubDate: 2017-05-25
      DOI: 10.3390/app7060517
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 526: Stereoscopic Image Super-Resolution
           Method with View Incorporation and Convolutional Neural Networks

    • Authors: Zhiyong Pan, Gangyi Jiang, Hao Jiang, Mei Yu, Fen Chen, Qingbo Zhang
      First page: 526
      Abstract: Super-resolution (SR) plays an important role in the processing and display of mixed-resolution (MR) stereoscopic images. Therefore, a stereoscopic image SR method based on view incorporation and convolutional neural networks (CNN) is proposed. For a given MR stereoscopic image, the left view of which is observed in full resolution, while the right view is viewed in low resolution, the SR method is implemented in two stages. In the first stage, a view difference image is defined to represent the correlation between views. It is estimated by using the full-resolution left view and the interpolated right view as input to the modified CNN. Accordingly, a high-precision view difference image is obtained. In the second stage, to incorporate the estimated right view in the first stage, a global reconstruction constraint is presented to make the estimated right view consistent with the low-resolution right view in terms of the MR stereoscopic image observation model. Experimental results demonstrated that, compared with the SR convolutional neural network (SRCNN) method and depth map based SR method, the proposed method improved the reconstructed right view quality by 0.54 dB and 1.14 dB, respectively, in the Peak Signal to Noise Ratio (PSNR), and subjective evaluation also implied that the proposed method produced better reconstructed stereoscopic images.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060526
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 538: Investigation on Eddy Current Sensor
           in Tension Measurement at a Resonant Frequency

    • Authors: Chengzhu Xiu, Liang Ren, Hongnan Li
      First page: 538
      Abstract: For resolving deficiencies of conventional tension measurement methods, this paper proposes a novel eddy current sensor with a single-coil structure based on the inverse magnetostrictive effect. An inductor–resistor–capacitor (LRC) model of eddy current sensor, which considers more parameters than the traditional inductor–resistor (LR) model, was established. The eddy current sensor was operated by a swept frequency signal that ranged from 0.1 MHz to 1.6 MHz, encompassing the sensor resonant frequency. At the resonant frequency, the data of impedance magnitude and phase were extracted and linear relations between the impedance parameters and the external tension were ascertained. The experimental results show that the resonant frequency and impedance magnitude of eddy current sensor will decrease linearly with the increase of the external tension, which is consistent with the theoretical model. In addition, to improve sensor performance, the sleeve structure was designed to reduce the loss of magnetic field. Both finite element simulations and experimental results demonstrate that the sleeve structure provides a higher permeability path to the magnetic field lines than the non-sleeve structure and effectively improves sensor sensitivity and correlation coefficient.
      PubDate: 2017-05-24
      DOI: 10.3390/app7060538
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 543: DegoViz: An Interactive Visualization
           

    • Authors: Somyung Oh, Junghyeon Ha, Kyungwon Lee, Sejong Oh
      First page: 543
      Abstract: Microarray is a general scheme to identify differentially expressed genes for a target concept and can be used for biology. The output is presented utilizing a heatmap that biologists analyze in related terms of gene ontology to determine the characteristics of differentially expressed genes. In this paper, we propose an integrated visualization tool for a heatmap and gene ontology graph. Most of the previous methods used were static and none of them were combined. The proposed visualization tool integrates these and provides users with an interactive management ability. Users can easily identify and confirm related terms of gene ontology for given differentially expressed genes. Further, the proposed tool visualizes the connections between genes on the heatmap and gene ontology graph. Therefore, the proposed tool can be used for precision healthcare.
      PubDate: 2017-05-25
      DOI: 10.3390/app7060543
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 544: Split-And-Delay Unit for FEL
           Interferometry in the XUV Spectral Range

    • Authors: Sergey Usenko, Andreas Przystawik, Leslie Lazzarino, Markus Jakob, Florian Jacobs, Christoph Becker, Christian Haunhorst, Detlef Kip, Tim Laarmann
      First page: 544
      Abstract: In this work we present a reflective split-and-delay unit (SDU) developed for interferometric time-resolved experiments utilizing an (extreme ultraviolet) XUV pump–XUV probe scheme with focused free-electron laser beams. The developed SDU overcomes limitations for phase-resolved measurements inherent to conventional two-element split mirrors by a special design using two reflective lamellar gratings. The gratings produce a high-contrast interference signal controlled by the grating displacement in every diffraction order. The orders are separated in the focal plane of the focusing optics, which enables one to avoid phase averaging by spatially selective detection of a single interference state of the two light fields. Interferometry requires a precise relative phase control of the light fields, which presents a challenge at short wavelengths. In our setup the phase delay is determined by an in-vacuum white light interferometer (WLI) that monitors the surface profile of the SDU in real time and thus measures the delay for each laser shot. The precision of the WLI is 1 nm as determined by optical laser interferometry. In the presented experimental geometry it corresponds to a time delay accuracy of 3 as, which enables phase-resolved XUV pump–XUV probe experiments at free-electron laser (FEL) repetition rates up to 60 Hz.
      PubDate: 2017-05-25
      DOI: 10.3390/app7060544
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 545: Effects of Three Different Additives
           and Two Different Bulk Densities on Maize Silage Characteristics,
           Temperature Profiles, CO2 and O2–Dynamics in Small Scale Silos during
           Aerobic Exposure

    • Authors: Kerstin Jungbluth, Manfred Trimborn, Gerd-Christian Maack, Wolfgang Büscher, Menghua Li, Hong Cheng, Qiang Cheng, Yurui Sun
      First page: 545
      Abstract: Silage quality and aerobic stability are sometimes insufficient. If management requirements are not met, or to improve silage quality, additives are often used. The objective of this study is to investigate the effects of different factors on silage during aerobic conditions. Whole-crop forage maize was harvested and 24 buckets (65 L) were filled and assigned to one of four treatment groups: (1) control (no treatment); (2) chemical additive (sodium benzoate, potassium sorbate, sodium acetate); (3) a mixed biological inoculant containing Lactobacillus buchneri, L. plantarum, and Pediococcus acidilacti; and (4) a mixed biological inoculant containing L. buchneri, L. plantarum, and L. rhamnosus. An untreated variation was also ensiled. Two different densities were adjusted during ensiling. After opening, the temperature was measured for seven days and O2 and CO2 concentrations were analysed. The findings show that the chemical additive very effectively prevented silage from reheating and deteriorating. Aerobic reheating of silage was also successfully inhibited through biological additives and high density.
      PubDate: 2017-05-25
      DOI: 10.3390/app7060545
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 546: Control of the Polymorphism of
           Calcium Carbonate Produced by Self-Healing in the Cracked Part of
           Cementitious Materials

    • Authors: Heesup Choi, Hyeonggil Choi, Masumi Inoue, Risa Sengoku
      First page: 546
      Abstract: Cracking is an inherent development in reinforced concrete structures and can lead to serious damages during their service period. The repeated occurrence of such damages can enlarge the cracks, thereby allowing other deteriorating elements such as CO2 and Cl− to further infiltrate the concrete, which can seriously compromise the concrete structure. This study focuses on the type of calcium carbonate (CaCO3) crystals generated by the self-healing phenomenon. Owing to polymorphism, CaCO3 has three types of crystal forms—calcite, vaterite, and aragonite—whose formation can be controlled by the temperature and pH. Vaterite has the highest density among these crystals, and it is expected to be capable of self-healing. Therefore, experiments were conducted to establish the conditions required to promote the generation of vaterite. A saturated Ca(OH)2 solution with CO2 nanobubbles (CN) was employed for effective self-healing. The temperature was controlled at 20, 40, and 60 °C, and the pH was controlled at 9.0, 10.5, and 12.0. The results showed that the self-healing of cracks occurred both on the surface and internally, and the main product of the self-healing phenomenon was vaterite in CaCO3 crystals at a pH of 9.0 and a temperature of 40 °C. Furthermore, the addition of a saturated Ca(OH)2 solution with CO2 nanobubbles (CN) resulted in the most effective self-healing of the surface and internal cracks.
      PubDate: 2017-05-25
      DOI: 10.3390/app7060546
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 547: Modular and Offsite Construction of
           Piping: Current Barriers and Route

    • Authors: Xiaodan Li, Zhongfu Li, Guangdong Wu
      First page: 547
      Abstract: To investigate current practices and identify challenges of piping prefabrication, this paper conducts a comprehensive survey to mechanical, electrical, and plumbing (MEP) contractors. This paper is performed in three main steps. First, the current state of piping prefabrication, the attitude of MEP contractors to piping prefabrication, and the challenges of piping prefabrication are identified through a comprehensive data collection process that included semi-structured interviews, case studies, site visits, and questionnaires. The second step included suggesting a pattern and roadway of piping prefabrication. The results showed that: (1) The attitudes to feasibility of piping prefabrication differ in piping systems, piping connector modes, and types of project; and (2) building information modelling (BIM) promotes the adoption of piping prefabrication. Integrated project delivery (IPD), and distributor’s early involvement into projects have significant effects on the successful implementation of piping prefabrication. (3) The main barriers and challenges were identified including the low level of standardization of design, lack of preferential policy, economies of scale, low-skilled workers, as well as the availability of fittings and valves. In the final step, a four-phase route of piping prefabrication is suggested for MEP contractors to expand the prefabrication capacity incrementally. The main contributions of this paper include: (1) This paper proposes a route for MEP contractors to improve their piping construction through the Modular and offsite construction (MOC) method. (2) This paper finds that the level of feasibility of piping prefabrication differs in piping systems, connection modes, and types of project. Challenges and barriers of piping prefabrication are firstly identified.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060547
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 548: Bioimaging Using Full Field and
           Contact EUV and SXR Microscopes with Nanometer Spatial Resolution

    • Authors: Przemysław Wachulak, Alfio Torrisi, Mesfin Ayele, Joanna Czwartos, Andrzej Bartnik, Łukasz Węgrzyński, Tomasz Fok, Tomáš Parkman, Šárka Salačová, Jana Turňová, Michal Odstrčil, Henryk Fiedorowicz
      First page: 548
      Abstract: We present our recent results, related to nanoscale imaging in the extreme ultraviolet (EUV) and soft X-ray (SXR) spectral ranges and demonstrate three novel imaging systems recently developed for the purpose of obtaining high spatial resolution images of nanoscale objects with the EUV and SXR radiations. All the systems are based on laser-plasma EUV and SXR sources, employing a double stream gas puff target. The EUV and SXR full field microscopes—operating at 13.8 nm and 2.88 nm wavelengths, respectively—are currently capable of imaging nanostructures with a sub-50 nm spatial resolution with relatively short (seconds) exposure times. The third system is a SXR contact microscope, operating in the “water-window” spectral range (2.3–4.4 nm wavelength), to produce an imprint of the internal structure of the investigated object in a thin surface layer of SXR light sensitive poly(methyl methacrylate) photoresist. The development of such compact imaging systems is essential to the new research related to biological science, material science, and nanotechnology applications in the near future. Applications of all the microscopes for studies of biological samples including carcinoma cells, diatoms, and neurons are presented. Details about the sources, the microscopes, as well as the imaging results for various objects will be shown and discussed.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060548
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 549: Effect of Load Transfer Section to
           Toughness for Steel Fiber-Reinforced Concrete

    • Authors: Yoon-Jung Han, Sang-Keun Oh, Byoungil Kim
      First page: 549
      Abstract: This study analyzed the correlation between the load transfer properties and the overall toughness in the flexural behavior of steel fiber-reinforced concrete after concrete matrix cracking. Beam specimens with identical aspect ratios were made with three different types of steel fiber, each of which had different properties, and were used for the flexural test. The load displacement graph from the test was divided into sections by behavioral properties, and the regression model by mix was analyzed to extract the correlation between the load transfer section (concrete-fiber) and the overall toughness. The analysis results showed three types of load displacement curve based on the fiber type and fiber content, and confirmed that the load reduction section towards fiber after concrete cracking and the slope and area of the load reascension section had a huge impact on the overall toughness. The regression model of the whole toughness (Tb) was then acquired by proposing the resulting correlation as the load transfer factor (LTF).
      PubDate: 2017-05-26
      DOI: 10.3390/app7060549
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 550: Pore Characteristics and Their
           Effects on the Material Properties of Foamed Concrete Evaluated Using
           Micro-CT Images and Numerical Approaches

    • Authors: Sang-Yeop Chung, Christian Lehmann, Mohamed Abd Elrahman, Dietmar Stephan
      First page: 550
      Abstract: Foamed concrete contains numerous pores inside the material, and these pores are a significant factor determining the material characteristics. In particular, the pore distribution characteristics of foamed concrete significantly affect its thermal and mechanical properties. Therefore, an appropriate investigation is necessary for a more detailed understanding of foamed concrete. Here, a set of foamed concrete samples with different densities is used in order to investigate the density effects on the pore characteristics, as well as the physical properties of the materials. The pore distribution characteristics of these samples are investigated using an X-ray micro-computed tomography (micro-CT) imaging technique with probabilistic and quantitative methods. Using these methods, the anisotropy, the pore circularity factor and the relative density of cell thickness are examined. The thermal (thermal conductivity) and mechanical (directional modulus and strength) properties of each foamed specimen are computed using numerical simulations and compared with experimental results. From the obtained results, the effects of the pore sizes and shapes on the local and global properties of the foamed concrete are examined for developing advanced foamed concrete with lower thermal conductivity by minimizing the strength reduction.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060550
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 551: The Aerodynamic Analysis of a
           Rotating Wind Turbine by Viscous-Coupled 3D Panel Method

    • Authors: Bryan Nelson, Jen-Shiang Kouh
      First page: 551
      Abstract: In addition to the many typical failure mechanisms that afflict wind turbines, units in Taiwan are also susceptible to catastrophic failure from typhoon-induced extreme loads. A key component of the strategy to prevent such failures is a fast, accurate aerodynamic analysis tool through which a fuller understanding of aerodynamic loads acting on the units may be derived. To this end, a viscous-coupled 3D panel method is herewith proposed, which introduces a novel approach to simulating the severe flow separation so prevalent around wind turbine rotors. The validity of the current method’s results was assessed by code-to-code comparison with RANS data for a commercial 2 MW wind turbine rotor. Along the outboard and inboard regions of the rotor, pressure distributions predicted by the current method showed excellent agreement with the RANS data, while pressure data along the midspan region were slightly more conservative. The power curve predicted by the current method was also more conservative than that predicted by the RANS solver, but correlated very well with that provided by the turbine manufacturer. Taking into account the high degree of comparability with the more sophisticated RANS solver, the excellent agreement with the official data, and the considerably reduced computational expense, the author believes the proposed method could be a powerful standalone tool for the design and analysis of wind turbine blades, or could be applied to the emerging field of wind farm layout design by providing accurate body force input to actuator line rotors within full Navier-Stokes models of multi-unit wind farms.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060551
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 552: Effects of Temperature Variations
           during Sintering of Metal Ceramic Tooth Prostheses Investigated
           Non-Destructively with Optical Coherence Tomography

    • Authors: Cosmin Sinescu, Adrian Bradu, Virgil-Florin Duma, Florin Topala, Meda Negrutiu, Adrian Podoleanu
      First page: 552
      Abstract: Calibration loss of ovens used in sintering metal ceramic prostheses leads to stress and cracks in the material of the prostheses fabricated, and ultimately to failure of the dental treatment. Periodic calibration may not be sufficient to prevent such consequences. Evaluation methods based on firing supplemental control samples are subjective, time-consuming, and rely entirely on the technician’s skills. The aim of this study was to propose an alternative procedure for such evaluations. Fifty prostheses were sintered in a ceramic oven at a temperature lower, equal to or larger than the temperature prescribed by the manufacturer. A non-destructive imaging method, swept source (SS) optical coherence tomography (OCT) was used to evaluate comparatively the internal structure of prostheses so fabricated. A quantitative assessment procedure is proposed, based on en-face OCT images acquired at similar depths inside the samples. Differences in granulation and reflectivity depending on the oven temperature are used to establish rules-of-thumb on judging the correct calibration of the oven. OCT evaluations made on a regular basis allow an easy and objective monitoring of correct settings in the sintering process. This method can serve rapid identification of the need to recalibrate the oven and avoid producing prostheses with defects.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060552
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 553: Modeling of Heat Transfer and
           Oscillating Flow in the Regenerator of a Pulse Tube Cryocooler Operating
           at 50 Hz

    • Authors: Xiufang Liu, Chen Chen, Qian Huang, Shubei Wang, Yu Hou, Liang Chen
      First page: 553
      Abstract: The regenerator of the pulse tube refrigerator (PTR) operates with oscillating pressure and mass flow, so a proper description of the heat transfer characteristics of the oscillating flow in the regenerator is crucial. In this paper, a one-dimensional model based on Lagrangian representation is developed to simulate the oscillating flow in the regenerator of the PTR. The continuity equation, momentum equation and energy equation are solved iteratively using the SIMPLER algorithm. The Darcy-Brinkman-Forchheimer model is used in the momentum equation, and a thermal non-equilibrium model is implemented in the energy equation. Lagrangian representation is employed to describe the thermodynamics of fluid parcels while the Eulerian representation (control volume method) is adopted for the energy equation of the solid matrix. The boundary conditions are set as the periodic flow of the sine function. The thermodynamic parameters of the gas parcels are obtained, which reveal the critical processes of the heat transfer in the regenerator under oscillating flow. The performance of the regenerator with different geometries is evaluated based on the numerical results. The present study provides insight for better understanding the physical process in the regenerator of the PTR, and the proposed model serves as a useful tool for the design and optimization of the cryogenic regenerator.
      PubDate: 2017-06-05
      DOI: 10.3390/app7060553
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 554: Optimal Design of an Air-to-Air Heat
           Exchanger with Cross-Corrugated Triangular Ducts by Using a Particle Swarm
           Optimization Algorithm

    • Authors: Caihang Liang, Xiaoman Tong, Tengyue Lei, Zhenxing Li, Guoshan Wu
      First page: 554
      Abstract: Air-to-air heat exchangers with cross-corrugated triangular ducts are widely used in various industrial fields to recover waste heat. The geometric parameters of the heat exchangers greatly affect the performance and total annual cost of these systems. In this study, the effectiveness-number of transfer units (ε-NTU) method was utilized to develop the thermal mathematical model, which was verified by comparing it with previous research. The configuration parameters of the heat exchanger were optimized in this study. The particle swarm optimization (PSO) algorithm was applied using both single and multi-objective algorithm. The colburn factor (j factor), friction factor (f factor), and comprehensive thermal hydraulic performance index (JF factor) were considered as objective functions to be optimized using a single objective and multi-objective algorithm. Then, the entropy generation rate and total annual cost were optimized by using a multi-objective PSO algorithm. In addition, to identify the influential geometric parameters, a global sensitivity analysis was performed. The sensitivity analysis showed that the apex angle θ, channel height H, and heat exchanger height Lh influenced the performance and annual total cost of these systems.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060554
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 555: Construction of Nonblocking
           Wavelength/Space Switches with AWGs and WSSes

    • Authors: Bey-Chi Lin, Chin-Tau Lea
      First page: 555
      Abstract: In this paper, we how to use two technologies, AWG (arrayed-waveguide grating) and WSS (wavelength selective switches), to design nonblocking wavelength/space optical cross connects. An AWG is a passive device and can route multiple wavelengths simultaneously. However, to apply AWGs, there are several issues to consider, including the wavelength conversion range, crosstalk, and switch size constraint. We show a decomposition technique for designing an AWG-based nonblocking wavelength/space switch. The decomposition is carried out in a transformed space network. The new technique is simpler in concept and more flexible in setting switch sizes. We also study another class of wavelength/space switches that are based on WSSes and compare the two approaches in terms of the scalability, switch size constraint, and number of WCs (wavelength converters) required.
      PubDate: 2017-05-26
      DOI: 10.3390/app7060555
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 556: Ultrafast Optical Signal Processing
           with Bragg Structures

    • Authors: Yikun Liu, Shenhe Fu, Boris Malomed, Iam Khoo, Jianying Zhou
      First page: 556
      Abstract: The phase, amplitude, speed, and polarization, in addition to many other properties of light, can be modulated by photonic Bragg structures. In conjunction with nonlinearity and quantum effects, a variety of ensuing micro- or nano-photonic applications can be realized. This paper reviews various optical phenomena in several exemplary 1D Bragg gratings. Important examples are resonantly absorbing photonic structures, chirped Bragg grating, and cholesteric liquid crystals; their unique operation capabilities and key issues are considered in detail. These Bragg structures are expected to be used in wide-spread applications involving light field modulations, especially in the rapidly advancing field of ultrafast optical signal processing.
      PubDate: 2017-05-27
      DOI: 10.3390/app7060556
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 557: Energy-Efficient Caching for Mobile
           Edge Computing in 5G Networks

    • Authors: Zhaohui Luo, Minghui LiWang, Zhijian Lin, Lianfen Huang, Xiaojiang Du, Mohsen Guizani
      First page: 557
      Abstract: Mobile Edge Computing (MEC), which is considered a promising and emerging paradigm to provide caching capabilities in proximity to mobile devices in 5G networks, enables fast, popular content delivery of delay-sensitive applications at the backhaul capacity of limited mobile networks. Most existing studies focus on cache allocation, mechanism design and coding design for caching. However, grid power supply with fixed power uninterruptedly in support of a MEC server (MECS) is costly and even infeasible, especially when the load changes dynamically over time. In this paper, we investigate the energy consumption of the MECS problem in cellular networks. Given the average download latency constraints, we take the MECS’s energy consumption, backhaul capacities and content popularity distributions into account and formulate a joint optimization framework to minimize the energy consumption of the system. As a complicated joint optimization problem, we apply a genetic algorithm to solve it. Simulation results show that the proposed solution can effectively determine the near-optimal caching placement to obtain better performance in terms of energy efficiency gains compared with conventional caching placement strategies. In particular, it is shown that the proposed scheme can significantly reduce the joint cost when backhaul capacity is low.
      PubDate: 2017-05-27
      DOI: 10.3390/app7060557
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 558: Low Frequency Interactive
           Auralization Based on a Plane Wave Expansion

    • Authors: Diego Gómez, Jeremy Astley, Filippo Fazi
      First page: 558
      Abstract: This paper addresses the problem of interactive auralization of enclosures based on a finite superposition of plane waves. For this, room acoustic simulations are performed using the Finite Element (FE) method. From the FE solution, a virtual microphone array is created and an inverse method is implemented to estimate the complex amplitudes of the plane waves. The effects of Tikhonov regularization are also considered in the formulation of the inverse problem, which leads to a more efficient solution in terms of the energy used to reconstruct the acoustic field. Based on this sound field representation, translation and rotation operators are derived enabling the listener to move within the enclosure and listen to the changes in the acoustic field. An implementation of an auralization system based on the proposed methodology is presented. The results suggest that the plane wave expansion is a suitable approach to synthesize sound fields. Its advantage lies in the possibility that it offers to implement several sound reproduction techniques for auralization applications. Furthermore, features such as translation and rotation of the acoustic field make it convenient for interactive acoustic renderings.
      PubDate: 2017-05-27
      DOI: 10.3390/app7060558
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 559: Rogue Wave Modes for the Coupled
           Nonlinear Schrödinger System with Three Components: A Computational Study
           

    • Authors: Hiu Ning Chan, Kwok Wing Chow
      First page: 559
      Abstract: The system of “integrable” coupled nonlinear Schrödinger equations (Manakov system) with three components in the defocusing regime is considered. Rogue wave solutions exist for a restricted range of group velocity mismatch, and the existence condition correlates precisely with the onset of baseband modulation instability. This assertion is further elucidated numerically by evidence based on the generation of rogue waves by a single mode disturbance with a small frequency. This same computational approach can be adopted to study coupled nonlinear Schrödinger equations for the “non‐integrable” regime, where the coefficients of self‐phase modulation and cross‐phase modulation are different from each other. Starting with a wavy disturbance of a finite frequency corresponding to the large modulation instability growth rate, a breather can be generated. The breather can be symmetric or asymmetric depending on the magnitude of the growth rate. Under the presence of a third mode, rogue wave can exist under a larger group velocity mismatch between the components as compared to the two‐component system. Furthermore, the nonlinear coupling can enhance the maximum amplitude of the rogue wave modes and bright four‐petal configuration can be observed.
      PubDate: 2017-05-29
      DOI: 10.3390/app7060559
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 560: Evaluation of a Novel Controlled
           Cutting Fluid Impinging Supply System When Machining Titanium Alloys

    • Authors: Salah Gariani, Islam Shyha, Fawad Inam, Dehong Huo
      First page: 560
      Abstract: Following a comprehensive review on titanium machining and methods of cutting fluid application, this paper presents a new Controlled cutting fluid impinging supply system (Cut‐list) developed to deliver an accurate amount of cutting fluid into the machining zone via wellpositioned coherent nozzles based on the calculation of the heat generated. The performance of the new system was evaluated against a conventional flood cutting fluid supply system during step shoulder milling of Ti‐6Al‐4V using vegetable oil‐based cutting fluid. The comparison was performed at different cutting speeds and feed rates. Comparison measures/indicators were cutting force, workpiece temperature, tool flank wear, burr formation and average surface roughness (Ra). The new system provided significant reductions in cutting fluid consumption of up to 42%. Additionally, reductions in cutting force, tool flank wear and burr height of 16.41%, 46.77%, and 31.70% were recorded, respectively. Smaller Ra values were also found with the use of the new system.
      PubDate: 2017-05-29
      DOI: 10.3390/app7060560
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 561: Waveguiding Light into Silicon
           Oxycarbide

    • Authors: Faisal Memon, Francesco Morichetti, Andrea Melloni
      First page: 561
      Abstract: In this work, we demonstrate the fabrication of single mode optical waveguides in silicon oxycarbide (SiOC) with a high refractive index n = 1.578 on silica (SiO2), exhibiting an index contrast of Δn = 8.2%. Silicon oxycarbide layers were deposited by reactive RF magnetron sputtering of a SiC target in a controlled process of argon and oxygen gases. The optical properties of SiOC film were measured with spectroscopic ellipsometry in the near-infrared range and the acquired refractive indices of the film exhibit anisotropy on the order of 10−2. The structure of the SiOC films is investigated with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The channel waveguides in SiOC are buried in SiO2 (n = 1.444) and defined with UV photolithography and reactive ion etching techniques. Propagation losses of about 4 dB/cm for both TE and TM polarizations at telecommunication wavelength 1550 nm are estimated with cut-back technique. Results indicate the potential of silicon oxycarbide for guided wave applications.
      PubDate: 2017-05-30
      DOI: 10.3390/app7060561
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 562: Damage Assessment Using Information
           Entropy of Individual Acoustic Emission Waveforms during Cyclic Fatigue
           Loading

    • Authors: Christine Sauerbrunn, Ali Kahirdeh, Huisung Yun, Mohammad Modarres
      First page: 562
      Abstract: Information entropy measured from acoustic emission (AE) waveforms is shown to be an indicator of fatigue damage in a high-strength aluminum alloy. Three methods of measuring the AE information entropy, regarded as a direct measure of microstructural disorder, are proposed and compared with traditional damage-related AE features. Several tension–tension fatigue experiments were performed with dogbone samples of aluminum 7075-T6, a commonly used material in aerospace structures. Unlike previous studies in which fatigue damage is measured based on visible crack growth, this work investigated fatigue damage both prior to and after crack initiation through the use of instantaneous elastic modulus degradation. Results show that one of the three entropy measurement methods appears to better assess the damage than the traditional AE features, whereas the other two entropies have unique trends that can differentiate between small and large cracks.
      PubDate: 2017-05-30
      DOI: 10.3390/app7060562
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 563: Prediction of Maximum Story Drift of
           MDOF Structures under Simulated Wind Loads Using Artificial Neural
           Networks

    • Authors: Omar Payán-Serrano, Edén Bojórquez, Juan Bojórquez, Robespierre Chávez, Alfredo Reyes-Salazar, Manuel Barraza, Arturo López-Barraza, Héctor Rodríguez-Lozoya, Edgar Corona
      First page: 563
      Abstract: The aim of this paper is to investigate the prediction of maximum story drift of Multi-Degree of Freedom (MDOF) structures subjected to dynamics wind load using Artificial Neural Networks (ANNs) through the combination of several structural and turbulent wind parameters. The maximum story drift of 1600 MDOF structures under 16 simulated wind conditions are computed with the purpose of generating the data set for the networks training with the Levenberg–Marquardt method. The Shinozuka and Newmark methods are used to simulate the turbulent wind and dynamic response, respectively. In order to optimize the computational time required for the dynamic analyses, an array format based on the Shinozuka method is presented to perform the parallel computing. Finally, it is observed that the already trained ANNs allow for predicting adequately the maximum story drift with a correlation close to 99%.
      PubDate: 2017-05-30
      DOI: 10.3390/app7060563
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 564: Scheduling of Crude Oil Operations in
           Refinery without Sufficient Charging Tanks Using Petri Nets

    • Authors: Yan An, NaiQi Wu, Chi Hon, ZhiWu Li
      First page: 564
      Abstract: A short-term schedule for crude oil operations in a refinery should define and sequence the activities in detail. Each activity involves both discrete-event and continuous variables. The combinatorial nature of the scheduling problem makes it difficult to solve. For such a scheduling problem, charging tanks are a type of critical resources. If the number of charging tanks is not sufficient, the scheduling problem is further complicated. This work conducts a study on the scheduling problem of crude oil operations without sufficient charging tanks. In this case, to make a refinery able to operate, a charging tank has to be in simultaneous charging and feeding to a distiller for some time, called simultaneously-charging-and-feeding (SCF) mode, leading to disturbance to the oil distillation in distillers. A hybrid Petri net model is developed to describe the behavior of the system. Then, a scheduling method is proposed to find a schedule such that the SCF mode is minimally used. It is computationally efficient. An industrial case study is given to demonstrate the obtained results.
      PubDate: 2017-05-30
      DOI: 10.3390/app7060564
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 565: Detection of Eccentricity Faults in
           Five-Phase Ferrite-PM Assisted Synchronous Reluctance Machines

    • Authors: Carlos López-Torres, Jordi-Roger Riba, Antonio Garcia, Luís Romeral
      First page: 565
      Abstract: Air gap eccentricity faults in five-phase ferrite-assisted synchronous reluctance motors (fPMa-SynRMs) tend to distort the magnetic flux in the air gap, which in turn affects the spectral content of both the stator currents and the ZSVC (zero-sequence voltage component). However, there is a lack of research dealing with the topic of fault diagnosis in multi-phase PMa-SynRMs, and in particular, those focused on detecting eccentricity faults. An analysis of the spectral components of the line currents and the ZSVC allows the development of fault diagnosis algorithms to detect eccentricity faults. The effect of the operating conditions is also analyzed, since this paper shows that it has a non-negligible impact on the effectivity and sensitivity of the diagnosis based on an analysis of the stator currents and the ZSVC. To this end, different operating conditions are analyzed. The paper also evaluates the influence of the operating conditions on the harmonic content of the line currents and the ZSVC, and determines the most suitable operating conditions to enhance the sensitivity of the analyzed methods. Finally, fault indicators employed to detect eccentricity faults, which are based on the spectral content of the stator currents and the ZSVC, are derived and their performance is assessed. The approach presented in this work may be useful for developing fault diagnosis strategies based on the acquisition and subsequent analysis and interpretation of the spectral content of the line currents and the ZSVC.
      PubDate: 2017-05-31
      DOI: 10.3390/app7060565
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 566: Analyzing the Characteristics of Soil
           Moisture Using GLDAS Data: A Case Study in Eastern China

    • Authors: Jingze Cai, Yuanzhi Zhang, Yu Li, X. Liang, Tingchen Jiang
      First page: 566
      Abstract: In this paper, we use GLDAS (Global Land Data Assimilation System) to analyze the effects of air temperature and precipitation on the characteristics of soil moisture in the eastern region of China from 1961 to 2011. We find that the temperature and precipitation in different seasons have different degrees of influence on the characteristics of soil moisture in each layer. The results show that over the last 50 years, the soil moisture in eastern China has a tendency to dry out, especially between the late 1970s to the early 1980s. The change of soil moisture with the depth of soil layer has similar inter-annual and seasonal patterns. Soil moisture in different depths (0–200 cm) positively correlates with the air temperatures of spring, summer and autumn, but negatively correlates with the air temperature in winter at 0–10 cm, 40–100 cm and 100–200 cm. Similarly, soil moisture is positively related to the precipitation in spring, summer and autumn, and the opposite is true in winter. The results also show that precipitation has a significant effect on the shallow soil moisture (0–10 cm), while air temperature most affects the deep soil moisture (100–200 cm).
      PubDate: 2017-05-31
      DOI: 10.3390/app7060566
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 567: A New Framework of Human Interaction
           Recognition Based on Multiple Stage Probability Fusion

    • Authors: Xiaofei Ji, Changhui Wang, Zhaojie Ju
      First page: 567
      Abstract: Visual-based human interactive behavior recognition is a challenging research topic in computer vision. There exist some important problems in the current interaction recognition algorithms, such as very complex feature representation and inaccurate feature extraction induced by wrong human body segmentation. In order to solve these problems, a novel human interaction recognition method based on multiple stage probability fusion is proposed in this paper. According to the human body’s contact in interaction as a cut-off point, the process of the interaction can be divided into three stages: start stage, execution stage and end stage. Two persons’ motions are respectively extracted and recognizes in the start stage and the finish stage when there is no contact between those persons. The two persons’ motion is extracted as a whole and recognized in the execution stage. In the recognition process, the final recognition results are obtained by the weighted fusing these probabilities in different stages. The proposed method not only simplifies the extraction and representation of features, but also avoids the wrong feature extraction caused by occlusion. Experiment results on the UT-interaction dataset demonstrated that the proposed method results in a better performance than other recent interaction recognition methods.
      PubDate: 2017-06-01
      DOI: 10.3390/app7060567
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 568: Measuring the Reflection Matrix of a
           Rough Surface

    • Authors: Kenneth Burgi, Michael Marciniak, Mark Oxley, Stephen Nauyoks
      First page: 568
      Abstract: Phase modulation methods for imaging around corners with reflectively scattered light required illumination of the occluded scene with a light source either in the scene or with direct line of sight to the scene. The RM (reflection matrix) allows control and refocusing of light after reflection, which could provide a means of illuminating an occluded scene without access or line of sight. Two optical arrangements, one focal-plane, the other an imaging system, were used to measure the RM of five different rough-surface reflectors. Intensity enhancement values of up to 24 were achieved. Surface roughness, correlation length, and slope were examined for their effect on enhancement. Diffraction-based simulations were used to corroborate experimental results.
      PubDate: 2017-05-31
      DOI: 10.3390/app7060568
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 569: Infrared Small Moving Target
           Detection via Saliency Histogram and Geometrical Invariability

    • Authors: Minjie Wan, Kan Ren, Guohua Gu, Xiaomin Zhang, Weixian Qian, Qian Chen, Shuai Yu
      First page: 569
      Abstract: In order to detect both bright and dark small moving targets effectively in infrared (IR) video sequences, a saliency histogram and geometrical invariability based method is presented in this paper. First, a saliency map that roughly highlights the salient regions of the original image is obtained by tuning its amplitude spectrum in the frequency domain. Then, a saliency histogram is constructed by means of averaging the accumulated saliency value of each gray level in the map, through which bins corresponding to bright target and dark target are assigned with large values in the histogram. Next, single-frame detection of candidate targets is accomplished by a binarized segmentation using an adaptive threshold, and their centroid coordinates with sub-pixel accuracy are calculated through a connected components labeling method as well as a gray-weighted criterion. Finally, considering the motion characteristics in consecutive frames, an inter-frame false alarm suppression method based on geometrical invariability is developed to improve the precision rate further. Quantitative analyses demonstrate the detecting precision of this proposed approach can be up to 97% and Receiver Operating Characteristic (ROC) curves further verify our method outperforms other state-of-the-arts methods in both detection rate and false alarm rate.
      PubDate: 2017-06-01
      DOI: 10.3390/app7060569
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 570: Influence of Road Excitation and
           Steering Wheel Input on Vehicle System Dynamic Responses

    • Authors: Zhen-Feng Wang, Ming-Ming Dong, Liang Gu, Jagat-Jyoti Rath, Ye-Chen Qin, Bin Bai
      First page: 570
      Abstract: Considering the importance of increasing driving safety, the study of safety is a popular and critical topic of research in the vehicle industry. Vehicle roll behavior with sudden steering input is a main source of untripped rollover. However, previous research has seldom considered road excitation and its coupled effect on vehicle lateral response when focusing on lateral and vertical dynamics. To address this issue, a novel method was used to evaluate effects of varying road level and steering wheel input on vehicle roll behavior. Then, a 9 degree of freedom (9-DOF) full-car roll nonlinear model including vertical and lateral dynamics was developed to study vehicle roll dynamics with or without of road excitation. Based on a 6-DOF half-car roll model and 9-DOF full-car nonlinear model, relationship between three-dimensional (3-D) road excitation and various steering wheel inputs on vehicle roll performance was studied. Finally, an E-Class (SUV) level car model in CARSIM® was used, as a benchmark, with and without road input conditions. Both half-car and full-car models were analyzed under steering wheel inputs of 5°, 10° and 15°. Simulation results showed that the half-car model considering road input was found to have a maximum accuracy of 65%. Whereas, the full-car model had a minimum accuracy of 85%, which was significantly higher compared to the half-car model under the same scenario.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060570
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 571: Studies on Seismic Performance of
           Precast Concrete Columns with Grouted Splice Sleeve

    • Authors: Zheng Lu, Zixin Wang, Jianbao Li, Biao Huang
      First page: 571
      Abstract: In order to validate the seismic performance of precast concrete members with steel sleeve connections, pseudo-static tests on four prefabricated columns with vertical grouted splice sleeve connections and on a control group of two cast-in-situ columns have been conducted. The test results indicated that the failure modes of the prefabricated columns and of the cast-in-situ columns are basically identical but differences exist in their crack distribution. The cast-in-situ columns mainly crack horizontally at the bottom of the column, whereas the prefabricated columns have horizontal cracks above the sleeves, and then form diagonal cracks downwards and develop many wider cracks within the range of height of 300 mm at the bottom of the column. The hysteresis curves of the prefabricated columns are plump, which demonstrates that prefabricated columns have satisfactory energy-dissipating capacity. Moreover, the stiffness degradation of the prefabricated specimens is slower than that of the cast-in-situ specimens. The ultimate displacement angle of the prefabricated columns is up to 1/104–1/54, which satisfies the requirements of the inter-story drift ratio during major earthquakes. Finally, some recommendations on practical seismic design pertinent to the precast concrete members with grouted splice sleeves are proposed.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060571
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 572: The Use of the Surface Roughness
           Value to Quantify the Extent of Supercritical CO2 Involved Geochemical
           Reaction at a CO2 Sequestration Site

    • Authors: Jinyoung Park, Kyoungbae Baek, Minhee Lee, Chul-Woo Chung, Sookyun Wang
      First page: 572
      Abstract: Changes in the physical properties of the supercritical CO2 (scCO2) reservoir rock is one of the most important factors in controlling the storage safety at a scCO2 sequestration site. According to recent studies, it is probable that geochemical reactions influence changes in the rock properties after a CO2 injection in the subsurface, but quantitative data that reveal the interrelationship of the factors involved and the parameters needed to evaluate the extent of scCO2-rock-groundwater reactions have not yet been presented. In this study, the potential for employing the surface roughness value (SRRMS) to quantify the extent of the scCO2 involved reaction was evaluated by lab-scale experiments. For a total of 150 days of a simulation of the scCO2-sandstone-groundwater reaction at 100 bar and 50 °C, the trends in changes in the physical rock properties, pH change, and cation concentration change followed similar logarithmic patterns that were significantly correlated with the logarithmic increase in the SRRMS value. These findings suggest that changes in surface roughness can quantify the extent of the geochemical weathering process and can be used to evaluate leakage safety due to the progressive changes in rock properties at scCO2 storage sites.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060572
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 573: Multi-Objective Optimization of
           Voltage-Stability Based on Congestion Management for Integrating Wind
           Power into the Electricity Market

    • Authors: Jin-Woo Choi, Mun-Kyeom Kim
      First page: 573
      Abstract: This paper proposes voltage-stability based on congestion management (CM) for electricity market environments and considers the incorporation of wind farms into systems as well. A probabilistic voltage-stability constrained optimal power flow (P-VSCOPF) is formulated to maximize both social welfare and voltage stability. To reflect the probabilistic influence of CM in the presence of wind farms on voltage stability, Monte Carlo simulations (MCS) are used to analyze both the system load and the wind speed from their probability distribution functions. A multi-objective particle-swarm optimization (MOPSO) algorithm is implemented to solve the P-VSCOPF problem. A contingency analysis based on the voltage stability index (VSI) for line outages is employed to find the vulnerable line of congestion in power systems. The congestion distribution factor (CDF) is also used to find the optimal location of a wind farm in CM. The optimal pricing expression, which is obtained, with respect to preserving voltage stability, by calculating both the locational marginal prices (LMPs) and the nodal congestion prices (NCPs), is demonstrated in terms of congestion solutions. Simultaneously, the voltage stability margin (VSM) is considered within the CM framework. The proposed approach is implemented on a modified IEEE 24-bus system, and the results obtained are compared with the results of other optimal power flow methods.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060573
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 574: Synergistically-Enhanced Thermal
           Conductivity of Shape-Stabilized Phase Change Materials by Expanded
           Graphite and Carbon Nanotube

    • Authors: Zhang-Peng Liu, Rui Yang
      First page: 574
      Abstract: The thermal conductivity of expanded graphite plate (EGP) and/or multi-wall carbon nanotube (MWCNT)-filled, shape-stabilized, phase change material (SSPCM), based on paraffin, high-density polyethylene (HDPE), and styrene-butadiene-styrene copolymer (SBS), was investigated. The results demonstrated that both EGP and MWCNT increased the thermal conductivity of the SSPCM. EGP showed a greater thermal conductivity improvement than MWCNT. The conductivity of EGP-filled SSPCM reached 0.574 W/mK at 9 wt %, while that of MWCNT was just 0.372 W/mK at the same loading. Furthermore a series of EGP/MWCNT hybrid fillers were prepared and introduced into the SSPCM, and a synergistic effect was observed between the two fillers. When the EGP/MWCNT ratio was 8:2, the most significant thermal conductivity enhancement to the SSPCM was obtained. The thermal conductivity was 0.674 W/mK, 288% that of the SSPCM and 117% that of 9 wt % EGP-filled SSPCM. The SEM photos showed that a bridging of two-dimensional (2D) planar EGP by flexible one-dimensional (1D) MWCNT was constructed. The so-formed EGP-MWCNT network favored heat transfer along it and led to a decreased thermal interface resistance due to the increased EGP-MWCNT junctions.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060574
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 575: Bionic Walking Foot and Mechanical
           Performance on Soil

    • Authors: Ying Wang, Jianqiao Li, Xiujuan Li, Han Huang, Feng Qiu
      First page: 575
      Abstract: The surface structure of the Chinese mitten crab dactylopodite was investigated. The results indicated that the Chinese mitten crab dactylopodite has grooves with variable section structure on the surface of dactylopodite for achieving good traveling behavior on soft terrain. Surface structure plays a key role in the walking performance of the leg mechanism. Based on the bionics coupling theory, three bionic walking feet with different section shapes, including circular (Bio 1), circular with grooves (Bio 2), hexagon (Bio 3) and a cylinder foot used for comparison on the aluminum alloy, were designed and fabricated successfully. Meanwhile, comparative experiments on intrusion, extraction and propulsion for walking feet were conducted on different soil. Experimental results show that a bionic walking foot reduced the energy consumption of insertion and extraction, which topped out to 93.95% and 92.78% of cylinder foot, and Bio 2 behaves better. Propulsion is closely correlated with intrusion depth; therefore, compared with cylinder foot, the sinkage of a bionic walking foot helps to achieve a larger propulsion force with the same pressure. Furthermore, the proper depth in balancing the sinkage and propulsion was discussed, which enables us to optimize the structure and performance of a walking foot.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060575
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 576: Dual Functionalized Freestanding TiO2
           Nanotube Arrays Coated with Ag Nanoparticles and Carbon Materials for
           Dye-Sensitized Solar Cells

    • Authors: Ho-Sub Kim, Myeung-Hwan Chun, Jung Suh, Bong-Hyun Jun, Won-Yeop Rho
      First page: 576
      Abstract: Highly ordered, freestanding TiO2 nanotube arrays (TiO2 NTAs) were prepared using an electrochemical method. The barrier layer was etched to open the bottom of each array, aptly named “open-ended TiO2 NTAs”. These arrays were coated with silver nanoparticles (Ag NPs) and/or carbon materials to enhance electron generation and transport. The energy conversion efficiency of the resulting dye-sensitized solar cells (DSSCs) with open-ended freestanding TiO2 NTAs, when coated with Ag NPs, increased from 5.32% to 6.14% (by 15%) due to plasmonic interactions. Meanwhile, coating the open-ended freestanding TiO2 NTAs with carbon materials increased the energy conversion efficiency from 5.32% to 6.07% (by 14%), due to π-π conjugation. When the Ag NPs and carbon materials were simultaneously applied to the open-ended freestanding TiO2 NTAs, the energy conversion efficiency increased from 5.32% to 6.91%—an enhancement of 30%, due to the additive effects of plasmonics and π-π conjugation.
      PubDate: 2017-06-02
      DOI: 10.3390/app7060576
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 577: Special Issue on Advancing
           Grid-Connected Renewable Generation Systems

    • Authors: Frede Blaabjerg, Yongheng Yang
      First page: 577
      Abstract: n/a
      PubDate: 2017-06-03
      DOI: 10.3390/app7060577
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 578: Computational Fluid Dynamics Analysis
           of Cold Plasma Plume Mixing with Blood Using Level Set Method Coupled with
           Heat Transfer

    • Authors: Mehrdad Shahmohammadi Beni, Kwan Ngok Yu
      First page: 578
      Abstract: Cold plasmas were proposed for treatment of leukemia. In the present work, conceptual designs of mixing chambers that increased the contact between the two fluids (plasma and blood) through addition of obstacles within rectangular-block-shaped chambers were proposed and the dynamic mixing between the plasma and blood were studied using the level set method coupled with heat transfer. Enhancement of mixing between blood and plasma in the presence of obstacles was demonstrated. Continuous tracking of fluid mixing with determination of temperature distributions was enabled by the present model, which would be a useful tool for future development of cold plasma devices for treatment of blood-related diseases such as leukemia.
      PubDate: 2017-06-03
      DOI: 10.3390/app7060578
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 579: Impact of the Fused Deposition (FDM)
           Printing Process on Polylactic Acid (PLA) Chemistry and Structure

    • Authors: Michael Arthur Cuiffo, Jeffrey Snyder, Alicia M. Elliott, Nicholas Romero, Sandhiya Kannan, Gary P. Halada
      First page: 579
      Abstract: Polylactic acid (PLA) is an organic polymer commonly used in fused deposition (FDM) printing and biomedical scaffolding that is biocompatible and immunologically inert. However, variations in source material quality and chemistry make it necessary to characterize the filament and determine potential changes in chemistry occurring as a result of the FDM process. We used several spectroscopic techniques, including laser confocal microscopy, Fourier transform infrared (FTIR) spectroscopy and photoacousitc FTIR spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) in order to characterize both the bulk and surface chemistry of the source material and printed samples. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were used to characterize morphology, cold crystallinity, and the glass transition and melting temperatures following printing. Analysis revealed calcium carbonate-based additives which were reacted with organic ligands and potentially trace metal impurities, both before and following printing. These additives became concentrated in voids in the printed structure. This finding is important for biomedical applications as carbonate will impact subsequent cell growth on printed tissue scaffolds. Results of chemical analysis also provided evidence of the hygroscopic nature of the source material and oxidation of the printed surface, and SEM imaging revealed micro- and submicron-scale roughness that will also impact potential applications.
      PubDate: 2017-06-04
      DOI: 10.3390/app7060579
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 580: A Polarization-Dependent
           Frequency-Selective Metamaterial Absorber with Multiple Absorption Peaks

    • Authors: Guangsheng Deng, Tianyu Xia, Yong Fang, Jun Yang, Zhiping Yin
      First page: 580
      Abstract: A polarization-dependent, frequency-selective metamaterial (MM) absorber based on a single-layer patterned resonant structure intended for F frequency band is proposed. The design, fabrication, and measurement for the proposed absorber are presented. The absorber’s absorption properties at resonant frequencies have unique characteristics of a single-band, dual-band, or triple-band absorption for different polarization of the incident wave. The calculated surface current distributions and power loss distribution provide further understanding of physical mechanism of resonance absorption. Moreover, a high absorption for a wide range of TE-polarized oblique incidence was achieved. Hence, the MM structure realized on a highly flexible polyimide film, makingthe absorber suitable for conformal geometry applications. The proposed absorber has great potential in the development of polarization detectors and polarizers.
      PubDate: 2017-06-04
      DOI: 10.3390/app7060580
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 581: Cycling Segments Multimodal Analysis
           and Classification Using Neural Networks

    • Authors: Aleš Procházka, Saeed Vaseghi, Hana Charvátová, Ondřej Ťupa, Oldřich Vyšata
      First page: 581
      Abstract: This paper presents methodology for the processing of GPS and heart rate signals acquired during long-term physical activities. The data analysed include geo-positioning and heart rate multichannel signals recorded for 272.2 h of cycling across the Andes mountains over a 5694-km long expedition. The proposed computational methods include multimodal data de-noising, visualization, and analysis in order to determine specific biomedical features. The results include the correspondence between the heart rate and slope for downhill and uphill cycling and the mean heart rate evolution on flat segments: a regression coefficient of - 0 . 014 bpm/h related to time and 6 . 3 bpm/km related to altitude. The classification accuracy of selected cycling features by neural networks, support vector machine, and k-nearest neighbours methods is between 91.3% and 98.6%. The proposed methods allow the analysis of data during physical activities, enabling an efficient human–machine interaction.
      PubDate: 2017-06-04
      DOI: 10.3390/app7060581
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 582: Solution Strategies for Linear
           Inverse Problems in Spatial Audio Signal Processing

    • Authors: Mingsian Bai, Chun Chung, Po-Chen Wu, Yi-Hao Chiang, Chun-May Yang
      First page: 582
      Abstract: The aim of this study was to compare algorithms for solving inverse problems generally encountered in spatial audio signal processing. Tikhonov regularization is typically utilized to solve overdetermined linear systems in which the regularization parameter is selected by the golden section search (GSS) algorithm. For underdetermined problems with sparse solutions, several iterative compressive sampling (CS) methods are suggested as alternatives to traditional convex optimization (CVX) methods that are computationally expensive. The focal underdetermined system solver (FOCUSS), the steepest descent (SD) method, Newton’s (NT) method, and the conjugate gradient (CG) method were developed to solve CS problems more efficiently in this study. These algorithms were compared in terms of problems, including source localization and separation, noise source identification, and analysis and synthesis of sound fields, by using a uniform linear array (ULA), a uniform circular array (UCA), and a random array. The derived results are discussed herein and guidelines for the application of these algorithms are summarized.
      PubDate: 2017-06-05
      DOI: 10.3390/app7060582
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 583: A Study on Evaluation and Application
           of Snowmelt Performance of Anti-Icing Asphalt Pavement

    • Authors: Mulian Zheng, Shujuan Wu, Chongtao Wang, Yifeng Li, Zonghui Ma, Lei Peng
      First page: 583
      Abstract: This paper presents a quantitative estimation of anti-icing asphalt mixture snow-melting performance and provides the application guidance for the mixture under study. The regression model of snowmelt quality evolution was established and experimentally verified for different values of snowfall intensity, temperature and blending content of anti-icing filler. The deicing performance of anti-icing asphalt mixtures was evaluated via the impact load tests. The results obtained indicate that the application temperatures of the anti-icing asphalt mixture should exceed −10 °C for moderate or light snow conditions and exceed 0 °C for heavy or blizzard snow conditions. A linear dependence between the snowmelt quality of anti-icing asphalt mixture and time is observed for all tested values of snowfall intensity and temperature. On the other hand, under the same snowfall intensity conditions, a two- to threefold increase of the melting rate with temperature is observed. The available records for the last 30 years in different regions under study concerning variation ranges of three meteorological factors (namely, the extremely minimum temperature, snowfall intensity and the coldest month’s average temperature), the most suitable temperature for application of anti-icing asphalt pavement was identified for each particular region.
      PubDate: 2017-06-05
      DOI: 10.3390/app7060583
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 584: Measurement of the X-ray Spectrum of
           a Free Electron Laser with a Wide-Range High-Resolution Single-Shot
           Spectrometer

    • Authors: Yuichi Inubushi, Ichiro Inoue, Jangwoo Kim, Akihiko Nishihara, Satoshi Matsuyama, Hirokatsu Yumoto, Takahisa Koyama, Kensuke Tono, Haruhiko Ohashi, Kazuto Yamauchi, Makina Yabashi
      First page: 584
      Abstract: We developed a single-shot X-ray spectrometer for wide-range high-resolution measurements of Self-Amplified Spontaneous Emission (SASE) X-ray Free Electron Laser (XFEL) pulses. The spectrometer consists of a multi-layer elliptical mirror for producing a large divergence of 22 mrad around 9070 eV and a silicon (553) analyzer crystal. We achieved a wide energy range of 55 eV with a fine spectral resolution of 80 meV, which enabled the observation of a whole SASE-XFEL spectrum with fully-resolved spike structures. We found that a SASE-XFEL pulse has around 60 longitudinal modes with a pulse duration of 7.7 ± 1.1 fs.
      PubDate: 2017-06-06
      DOI: 10.3390/app7060584
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 585: Effect of Different Gradings of
           Lightweight Aggregates on the Properties of Concrete

    • Authors: Sang-Yeop Chung, Mohamed Abd Elrahman, Dietmar Stephan
      First page: 585
      Abstract: Lightweight aggregate concrete is a material with very low density and good thermal insulation, and several types of lightweight aggregates have been used for lightweight concrete. Since the characteristics of lightweight aggregates strongly affect the properties of lightweight concrete, a proper consideration for the use of lightweight aggregate is very important for development of lightweight materials. In particular, the sizes and spatial distributions of lightweight aggregates can influence the material responses of lightweight concrete, such as compressive strength and thermal conductivity. In this study, different types of gradings of lightweight aggregates are adopted to investigate the effect of gradings on the material properties. Liaver ® , an expanded glass granulate, is used as a lightweight aggregate for the specimens. Virtual models of the lightweight specimens with different gradings are numerically generated, and both mechanical and thermal properties are evaluated using experimental and numerical approaches for more detailed investigation. The obtained results can be utilized to suggest an optimal grading that satisfies both the mechanical and thermal properties of lightweight concrete specimen.
      PubDate: 2017-06-07
      DOI: 10.3390/app7060585
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 586: Computational Vibroacoustics in Low-
           and Medium- Frequency Bands: Damping, ROM, and UQ Modeling

    • Authors: Roger Ohayon, Christian Soize
      First page: 586
      Abstract: Within the framework of the state-of-the-art, this paper presents a summary of some common research works carried out by the authors concerning computational methods for the prediction of the responses in the frequency domain of general linear dissipative vibroacoustics (structural-acoustic) systems for liquid and gas in the low-frequency (LF) and medium-frequency (MF) domains, including uncertainty quantification (UQ) that plays an important role in the MF domain. The system under consideration consists of a deformable dissipative structure, coupled with an internal dissipative acoustic fluid including a wall acoustic impedance, and surrounded by an infinite acoustic fluid. The system is submitted to given internal and external acoustic sources and to prescribed mechanical forces. An efficient reduced-order computational model (ROM) is constructed using a finite element discretization (FEM) for the structure and the internal acoustic fluid. The external acoustic fluid is treated using a symmetric boundary element method (BEM) in the frequency domain. All the required modeling aspects required for the analysis in the MF domain have been introduced, in particular the frequency-dependent damping phenomena and model uncertainties. An industrial application to a complex computational vibroacoustic model of an automobile is presented.
      PubDate: 2017-06-07
      DOI: 10.3390/app7060586
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 587: Photon Propagation through Linearly
           Active Dimers

    • Authors: José Huerta Morales, Blas Rodríguez-Lara
      First page: 587
      Abstract: We provide an analytic propagator for non-Hermitian dimers showing linear gain or losses in the quantum regime. In particular, we focus on experimentally feasible realizations of the PT -symmetric dimer and provide their mean photon number and second order two-point correlation. We study the propagation of vacuum, single photon spatially-separable, and two-photon spatially-entangled states. We show that each configuration produces a particular signature that might signal their possible uses as photon switches, semi-classical intensity-tunable sources, or spatially entangled sources to mention a few possible applications.
      PubDate: 2017-06-07
      DOI: 10.3390/app7060587
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 588: Stochastic Model Predictive Control
           for Urban Traffic Networks

    • Authors: Bao-Lin Ye, Weimin Wu, Huimin Gao, Yixia Lu, Qianqian Cao, Lijun Zhu
      First page: 588
      Abstract: This paper proposes a stochastic model predictive control (MPC) framework for traffic signal coordination and control in urban traffic networks. One of the important features of the proposed stochastic MPC model is that uncertain traffic demands and stochastic disturbances are taken into account. Aiming to effectively model the uncertainties and avoid queue spillback in traffic networks, we develop a stochastic expected value model with chance constraints for the objective function of the stochastic MPC model. The objective function is defined to minimize the queue length and the oscillation of green time between any two control steps. Furthermore, by embedding the stochastic simulation and neural networks into a genetic algorithm, we propose a hybrid intelligent algorithm to solve the stochastic MPC model. Finally, numerical results by means of simulation on a road network are presented, which illustrate the performance of the proposed approach.
      PubDate: 2017-06-07
      DOI: 10.3390/app7060588
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 589: Thermal Management of Concentrated
           Multi-Junction Solar Cells with Graphene-Enhanced Thermal Interface
           Materials

    • Authors: Mohammed Saadah, Edward Hernandez, Alexander Balandin
      First page: 589
      Abstract: We report results of experimental investigation of temperature rise in concentrated multi-junction photovoltaic solar cells with graphene-enhanced thermal interface materials. Graphene and few-layer graphene fillers, produced by a scalable environmentally-friendly liquid-phase exfoliation technique, were incorporated into conventional thermal interface materials. Graphene-enhanced thermal interface materials have been applied between a solar cell and heat sink to improve heat dissipation. The performance of the multi-junction solar cells has been tested using an industry-standard solar simulator under a light concentration of up to 2000 suns. It was found that the application of graphene-enhanced thermal interface materials allows one to reduce the solar cell temperature and increase the open-circuit voltage. We demonstrated that the use of graphene helps in recovering a significant amount of the power loss due to solar cell overheating. The obtained results are important for the development of new technologies for thermal management of concentrated photovoltaic solar cells.
      PubDate: 2017-06-07
      DOI: 10.3390/app7060589
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 590: Developing Computational Fluid
           Dynamics (CFD) Models to Evaluate Available Energy in Exhaust Systems of
           Diesel Light-Duty Vehicles

    • Authors: Pablo Fernández-Yáñez, Octavio Armas, Arántzazu Gómez, Antonio Gil
      First page: 590
      Abstract: Around a third of the energy input in an automotive engine is wasted through the exhaust system. Since numerous technologies to harvest energy from exhaust gases are accessible, it is of great interest to find time- and cost-efficient methods to evaluate available thermal energy under different engine conditions. Computational fluid dynamics (CFD) is becoming a very valuable tool for numerical predictions of exhaust flows. In this work, a methodology to build a simple three-dimensional (3D) model of the exhaust system of automotive internal combustion engines (ICE) was developed. Experimental data of exhaust gas in the most used part of the engine map in passenger diesel vehicles were employed as input for calculations. Sensitivity analyses of different numeric schemes have been conducted in order to attain accurate results. The model built allows for obtaining details on temperature and pressure fields along the exhaust system, and for complementing the experimental results for a better understanding of the flow phenomena and heat transfer through the system for further energy recovery devices.
      PubDate: 2017-06-08
      DOI: 10.3390/app7060590
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 591: Systematic Design Method and
           Experimental Validation of a 2-DOF Compliant Parallel Mechanism with
           Excellent Input and Output Decoupling Performances

    • Authors: Yao Jiang, Tiemin Li, Liping Wang, Feifan Chen
      First page: 591
      Abstract: The output and input coupling characteristics of the compliant parallel mechanism (CPM) bring difficulty in the motion control and challenge its high performance and operational safety. This paper presents a systematic design method for a 2-degrees-of-freedom (DOFs) CPM with excellent decoupling performance. A symmetric kinematic structure can guarantee a CPM with a complete output decoupling characteristic; input coupling is reduced by resorting to a flexure-based decoupler. This work discusses the stiffness design requirement of the decoupler and proposes a compound flexure hinge as its basic structure. Analytical methods have been derived to assess the mechanical performances of the CPM in terms of input and output stiffness, motion stroke, input coupling degree, and natural frequency. The CPM’s geometric parameters were optimized to minimize the input coupling while ensuring key performance indicators at the same time. The optimized CPM’s performances were then evaluated by using a finite element analysis. Finally, a prototype was constructed and experimental validations were carried out to test the performance of the CPM and verify the effectiveness of the design method. The design procedure proposed in this paper is systematic and can be extended to design the CPMs with other types of motion.
      PubDate: 2017-06-08
      DOI: 10.3390/app7060591
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 592: Photon Beam Transport and Scientific
           Instruments at the European XFEL

    • Authors: Thomas Tschentscher, Christian Bressler, Jan Grünert, Anders Madsen, Adrian Mancuso, Michael Meyer, Andreas Scherz, Harald Sinn, Ulf Zastrau
      First page: 592
      Abstract: European XFEL is a free-electron laser (FEL) user facility providing soft and hard X-ray FEL radiation to initially six scientific instruments. Starting user operation in fall 2017 European XFEL will provide new research opportunities to users from science domains as diverse as physics, chemistry, geo- and planetary sciences, materials sciences or biology. The unique feature of European XFEL is the provision of high average brilliance in the soft and hard X-ray regime, combined with the pulse properties of FEL radiation of extreme peak intensities, femtosecond pulse duration and high degree of coherence. The high average brilliance is achieved through acceleration of up to 27,000 electron bunches per second by the super-conducting electron accelerator. Enabling the usage of this high average brilliance in user experiments is one of the major instrumentation drivers for European XFEL. The radiation generated by three FEL sources is distributed via long beam transport systems to the experiment hall where the scientific instruments are located side-by-side. The X-ray beam transport systems have been optimized to maintain the unique features of the FEL radiation which will be monitored using build-in photon diagnostics. The six scientific instruments are optimized for specific applications using soft or hard X-ray techniques and include integrated lasers, dedicated sample environment, large area high frame rate detector(s) and computing systems capable of processing large quantities of data.
      PubDate: 2017-06-09
      DOI: 10.3390/app7060592
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 593: Shake Table Test for the Collapse
           Investigation of a Typical Multi-Story Reinforced Concrete Frame Structure
           in the Meizoseismal Area

    • Authors: Weixiao Xu, Weisong Yang, Chunwei Zhang, Dehu Yu
      First page: 593
      Abstract: According to statistics from past earthquakes, it is observed that multi-story reinforced concrete (RC) frames represent a large proportion of the structural failures or collapses in seismic events. Hence, research on seismic collapse mechanisms and risks of RC frame structures subjected to extreme earthquakes is of foremost importance. Both experimental and numerical studies have been substantially carried out in this field. In order to represent an actual process of structural damage in an actual seismic event and provide a calibration test for numerical studies, a shake table collapse test of a typical multi-story RC frame structural model, which is scaled from a nearly collapsed building in the 2010 Ms 7.1 Yushu earthquake in China, was performed. Both the test and earthquake field investigation indicate that severe damage mainly occurred at the column ends. As dual structural systems, i.e., systems combining frames and additional members that mainly carry seismic loading, could be a better way to solve the unexpected damage mechanism of RC frames, a practical stiffness iteration design method based on the nonlinear static analysis to obtain the optimal stiffness demanding of the lateral load-resisting members in each story is proposed. This approach aims to control the structural deformation pattern along the height. The outcome of this study provides some intrinsic understanding of the inherent collapse mechanisms of similar RC frames during strong earthquakes. It also offers a practical design method to improve the seismic collapse resistance of RC frames.
      PubDate: 2017-06-08
      DOI: 10.3390/app7060593
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 594: Zwitterionic Polymer P(AM-DMC-AMPS)
           as a Low-Molecular-Weight Encapsulator in Deepwater Drilling Fluid

    • Authors: Xin Zhao, Zhengsong Qiu, Yongjun Zhang, Hanyi Zhong, Weian Huang, Zhichuan Tang
      First page: 594
      Abstract: In deepwater oil and gas drilling, the high-molecular-weight encapsulator aggravates the thickening of the drilling fluid at low temperatures. Therefore, it is hard to manage the downhole pressure, and drilling fluid loss occurs. In this paper, a zwitterionic polymer P(AM-DMC-AMPS) which was the terpolymer of acrylamide, methacrylatoethyl trimethyl ammonium chloride, and 2-acrylamido-2-methylpropane sulfonic acid, was developed as a low-molecular-weight encapsulator. It was characterized by Fourier transform infrared spectrum analysis, nuclear magnetic resonance, and gel permeation chromatography. Moreover, the low-temperature rheology, shale inhibition and filtration properties of water-based drilling fluids (WBDFs) containing different encapsulators were experimentally investigated and compared. The results showed that the molecular weight of P(AM-DMC-AMPS) was about 260,000, much lower than that of the conventional encapsulators. In the deepwater drilling temperature range 4–75 °C, WBDF containing P(AM-DMC-AMPS) had lower and more stable rheological property because of its short molecular chains. The high shale recovery rate and low swelling rate indicated its strong shale inhibition performance, owing to its adsorption on the clay surface and the wrapping effect through both hydrogen bonding and electrostatic interaction. It also improved the filtration property of WBDF, and was compatible with other WBDF components. This product is expected to simultaneously realize the good encapsulation performance and low-temperature rheological property for deepwater drilling fluid.
      PubDate: 2017-06-08
      DOI: 10.3390/app7060594
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 595: Scattering Characteristics of X-, C-
           and L-Band PolSAR Data Examined for the Tundra Environment of the
           Tuktoyaktuk Peninsula, Canada

    • Authors: Tobias Banks, Andreas Schmitt, Thomas Jagdhuber
      First page: 595
      Abstract: In this study, polarimetric Synthetic Aperture Radar (PolSAR) data at X-, C- and L-Bands, acquired by the satellites: TerraSAR-X (2011), Radarsat-2 (2011), ALOS (2010) and ALOS-2 (2016), were used to characterize the tundra land cover of a test site located close to the town of Tuktoyaktuk, NWT, Canada. Using available in situ ground data collected in 2010 and 2012, we investigate PolSAR scattering characteristics of common tundra land cover classes at X-, C- and L-Bands. Several decomposition features of quad-, co-, and cross-polarized data were compared, the correlation between them was investigated, and the class separability offered by their different feature spaces was analyzed. Certain PolSAR features at each wavelength were sensitive to the land cover and exhibited distinct scattering characteristics. Use of shorter wavelength imagery (X and C) was beneficial for the characterization of wetland and tundra vegetation, while L-Band data highlighted differences of the bare ground classes better. The Kennaugh Matrix decomposition applied in this study provided a unified framework to store, process, and analyze all data consistently, and the matrix offered a favorable feature space for class separation. Of all elements of the quad-polarized Kennaugh Matrix, the intensity based elements K0, K1, K2, K3 and K4 were found to be most valuable for class discrimination. These elements contributed to better class separation as indicated by an increase of the separability metrics squared Jefferys Matusita Distance and Transformed Divergence. The increase in separability was up to 57% for Radarsat-2 and up to 18% for ALOS-2 data.
      PubDate: 2017-06-08
      DOI: 10.3390/app7060595
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 596: IoT-Based Information System for
           Healthcare Application: Design Methodology Approach

    • Authors: Damian Dziak, Bartosz Jachimczyk, Wlodek Kulesza
      First page: 596
      Abstract: Over the last few decades, life expectancy has increased significantly. However, elderly people who live on their own often need assistance due to mobility difficulties, symptoms of dementia or other health problems. In such cases, an autonomous supporting system may be helpful. This paper proposes the Internet of Things (IoT)-based information system for indoor and outdoor use. Since the conducted survey of related works indicated a lack of methodological approaches to the design process, therefore a Design Methodology (DM), which approaches the design target from the perspective of the stakeholders, contracting authorities and potential users, is introduced. The implemented solution applies the three-axial accelerometer and magnetometer, Pedestrian Dead Reckoning (PDR), thresholding and the decision trees algorithm. Such an architecture enables the localization of a monitored person within four room-zones with accuracy; furthermore, it identifies falls and the activities of lying, standing, sitting and walking. Based on the identified activities, the system classifies current activities as normal, suspicious or dangerous, which is used to notify the healthcare staff about possible problems. The real-life scenarios validated the high robustness of the proposed solution. Moreover, the test results satisfied both stakeholders and future users and ensured further cooperation with the project.
      PubDate: 2017-06-08
      DOI: 10.3390/app7060596
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 597: Research on the Robustness of
           Interdependent Networks under Localized Attack

    • Authors: Junde Wang, Songyang Lao, Yirun Ruan, Liang Bai, Lvlin Hou
      First page: 597
      Abstract: Critical infrastructures (CI) are the cornerstone of modern society, and they are connected with each other through material, energy, or information. The robustness of interdependent CI systems under attack has been a hot topic in recent years, but previous studies mainly focused on malicious attacks or random failure. To analyze the impact of some natural disasters whose destructive force is mainly related to distance with respect to interdependent CI systems, we present a new localized attack mode considering destructive force decays with distance, and carry out simulations on several interdependent networks constructed by artificial and real world networks. Furthermore, this article analyzes the influence of coupling strength and coupling pattern on the robustness of interdependent system. The results show that dependency links between networks decrease the robustness of interdependence networks, but the robustness under failure probability degradation is not vulnerable like that under malicious attack or random failure. In addition, the coupling preference has little effect on the robustness of interdependent networks under the new localized attack strategy; when the average degree of subnetworks is large, the same conclusion can be obtained for the coupling strength.
      PubDate: 2017-06-09
      DOI: 10.3390/app7060597
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 598: Performance Analysis of a Forecasting
           Relocation Model for One-Way Carsharing

    • Authors: Ganjar Alfian, Jongtae Rhee, Muhammad Ijaz, Muhammad Syafrudin, Norma Fitriyani
      First page: 598
      Abstract: A carsharing service can be seen as a transport alternative between private and public transport that enables a group of people to share vehicles based at certain stations. The advanced carsharing service, one-way carsharing, enables customers to return the car to another station. However, one-way implementation generates an imbalanced distribution of cars in each station. Thus, this paper proposes forecasting relocation to solve car distribution imbalances for one-way carsharing services. A discrete event simulation model was developed to help evaluate the proposed model performance. A real case dataset was used to find the best simulation result. The results provide a clear insight into the impact of forecasting relocation on high system utilization and the reservation acceptance ratio compared to traditional relocation methods.
      PubDate: 2017-06-09
      DOI: 10.3390/app7060598
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 599: Bridge Expansion Joint in Road
           Transition Curve: Effects Assessment on Heavy Vehicles

    • Authors: Paola Di Mascio, Giuseppe Loprencipe, Laura Moretti, Lorenzo Puzzo, Pablo Zoccali
      First page: 599
      Abstract: Properly-designed road surfaces provide a durable surface on which traffic can pass smoothly and safely. In fact, the main causes that determine the structural decay of the pavement and its parts are the traffic loads. These repeated actions can create undesirable unevennesses on the road surface, which induce vertical accelerations on vehicles, up to hindering contact between pavement and tire, with dangerous consequences on traffic safety. The dynamic actions transmitted by the vehicles depend on these irregularities: often, a bridge expansion joint (BEJ), introducing a necessary discontinuity between different materials, determines from the beginning a geometric irregularity in the running surface. Besides, some structural conditions could emphasize the problem (e.g., local cracking due to the settlement of the subgrade near the abutment or the discontinuity of stiffness due to the presence of different materials). When the BEJ is located in a transition curve, an inevitable vertical irregularity between road and joint can reach values of some centimeters, with serious consequences for the road safety. This paper deals with the analysis of a case study of a BEJ. Several test surveys were performed in order to fully characterize the effects on both vehicles and pavement. The three-dimensional representation of the pavement surface and the acceleration measurements on a heavy test vehicle were performed to analyze the joint behavior under traffic. Finally, a finite element model was implemented to evaluate the stress contribution on vehicle components induced by the vertical irregularities.
      PubDate: 2017-06-09
      DOI: 10.3390/app7060599
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 600: Endoscopic Laser-Based 3D Imaging for
           Functional Voice Diagnostics

    • Authors: Marion Semmler, Stefan Kniesburges, Jonas Parchent, Bernhard Jakubaß, Maik Zimmermann, Christopher Bohr, Anne Schützenberger, Michael Döllinger
      First page: 600
      Abstract: Recently, we reported on the in vivo application of a miniaturized measuring device for 3D visualization of the superior vocal fold vibrations from high-speed recordings in combination with a laser projection unit (LPU). As a long-term vision for this proof of principle, we strive to integrate the further developed laserendoscopy as a diagnostic method in daily clinical routine. The new LPU mainly comprises a Nd:YAG laser source (532 nm/CW/2 ω ) and a diffractive optical element (DOE) generating a regular laser grid (31 × 31 laser points) that is projected on the vocal folds. By means of stereo triangulation, the 3D coordinates of the laser points are reconstructed from the endoscopic high-speed footage. The new design of the laserendoscope constitutes a compromise between robust image processing and laser safety regulations. The algorithms for calibration and analysis are now optimized with respect to their overall duration and the number of required interactions, which is objectively assessed using binary classifiers. The sensitivity and specificity of the calibration procedure are increased by 40.1% and 22.3%, which is statistically significant. The overall duration for the laser point detection is reduced by 41.9%. The suggested semi-automatic reconstruction software represents an important stepping-stone towards potential real time processing and a comprehensive, objective diagnostic tool of evidence-based medicine.
      PubDate: 2017-06-09
      DOI: 10.3390/app7060600
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 601: A Statistical Model Updating Method
           of Beam Structures with Random Parameters under Static Load

    • Authors: Zhifeng Wu, Bin Huang, Yejun Li, Wuchuan Pu
      First page: 601
      Abstract: This paper presents a new statistical model updating method of beam structures with random parameters under static load. The new updating method considers structural parameters and measurement errors to be random. To reduce the unmeasured degrees of freedom in the finite element model, a static condensation technique is used in this method. A statistical model updating equation with respect to element updated factors is established afterwards. The element updated factors are expanded as random multivariate power series. Using a high-order perturbation technique, the statistical model updating equation can be solved to obtain the coefficients of the power series expansions of the element updated factors. The results of two numerical examples show that for the solution of the statistical model updating equation, the accuracy of the proposed method agrees with that of the Monte Carlo simulation method very well. The static responses obtained by the updated finite element model coincide with the measured results very well. Finally, a series of static load tests of the concrete beam are conducted to testify the effectiveness of the proposed method.
      PubDate: 2017-06-09
      DOI: 10.3390/app7060601
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 602: A Multi-Year Study on Rice
           Morphological Parameter Estimation with X-Band Polsar Data

    • Authors: Onur Yuzugullu, Esra Erten, Irena Hajnsek
      First page: 602
      Abstract: Rice fields have been monitored with spaceborne Synthetic Aperture Radar (SAR) systems for decades. SAR is an essential source of data and allows for the estimation of plant properties such as canopy height, leaf area index, phenological phase, and yield. However, the information on detailed plant morphology in meter-scale resolution is necessary for the development of better management practices. This letter presents the results of the procedure that estimates the stalk height, leaf length and leaf width of rice fields from a copolar X-band TerraSAR-X time series data based on a priori phenological phase. The methodology includes a computationally efficient stochastic inversion algorithm of a metamodel that mimics a radiative transfer theory-driven electromagnetic scattering (EM) model. The EM model and its metamodel are employed to simulate the backscattering intensities from flooded rice fields based on their simplified physical structures. The results of the inversion procedure are found to be accurate for cultivation seasons from 2013 to 2015 with root mean square errors less than 13.5 cm for stalk height, 7 cm for leaf length, and 4 mm for leaf width parameters. The results of this research provided new perspectives on the use of EM models and computationally efficient metamodels for agriculture management practices.
      PubDate: 2017-06-09
      DOI: 10.3390/app7060602
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 603: A New Life for Cross-Linked Plastic
           Waste as Aggregates and Binder Modifier for Asphalt Mixtures

    • Authors: Liliana Costa, Joana Peralta, Joel Oliveira, Hugo Silva
      First page: 603
      Abstract: Every year, millions of tons of plastic waste, with potential to be reused, are wasted in landfills. Based on a literature review and in a local market analysis, cross-linked polyethylene (PEX) waste arose as the material with the greatest potential to be tested for incorporation in asphalt mixtures due to the difficulty in its recycling and the lack of solutions for its reuse. Thus, in the present work, mixtures produced with and without PEX were tested in order to compare their performance, aiming at understanding if this waste could successfully be used as an alternative material for this type of application. Thus, water sensitivity, rutting resistance, stiffness modulus and fatigue cracking resistance tests were carried out on asphalt mixtures with up to 5% PEX. Based on the results obtained, it can be concluded that the incorporation of PEX in asphalt mixtures is a viable solution for paving works, especially when high service temperatures are expected. It also decreases the density of the mixture, which can be attractive to lighten structures. Thus, this technology contributes to give new life to cross-linked polyethylene plastic waste.
      PubDate: 2017-06-10
      DOI: 10.3390/app7060603
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 604: Status of the SACLA Facility

    • Authors: Makina Yabashi, Hitoshi Tanaka, Kensuke Tono, Tetsuya Ishikawa
      First page: 604
      Abstract: This article reports the current status of SACLA, SPring-8 Angstrom Compact free electron LAser, which has been producing stable X-ray Free Electron Laser (XFEL) light since 2012. A unique injector system and a short-period in-vacuum undulator enable the generation of ultra-short coherent X-ray pulses with a wavelength shorter than 0.1 nm. Continuous development of accelerator technologies has steadily improved XFEL performance, not only for normal operations but also for fast switching operation of the two beamlines. After upgrading the broadband spontaneous-radiation beamline to produce soft X-ray FEL with a dedicated electron beam driver, it is now possible to operate three FEL beamlines simultaneously. Beamline/end-station instruments and data acquisition/analyzation systems have also been upgraded to allow advanced experiments. These efforts have led to the production of novel results and will offer exciting new opportunities for users from many fields of science.
      PubDate: 2017-06-10
      DOI: 10.3390/app7060604
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 605: Effect of Seasonal Temperature on the
           Performance and on the Microbial Community of a Novel AWFR for
           Decentralized Domestic Wastewater Pretreatment

    • Authors: Juanhong Li, Xiwu Lu
      First page: 605
      Abstract: Due to environmental burden and human health risks in developing countries, the treatment of decentralized domestic wastewater has been a matter of great concern in recent years. A novel pilot-scale three-stage anaerobic wool-felt filter reactor (AWFR) was designed to treat real decentralized domestic wastewater at seasonal temperature variations of 8 to 35 °C for 364 days. The results showed that the average chemical oxygen demand (COD) removal efficiencies of AWFR in summer and winter were 76 ± 7.2% and 52 ± 5.9% at one day and three days Hydraulic Retention Time (HRT), respectively. COD mass balance analysis demonstrated that even though COD removal was lower in winter, approximately 43.5% of influent COD was still converted to methane. High-throughput MiSeq sequencing analyses indicated that Methanosaeta, Methanobacterium, and Methanolinea were the predominant methanogens, whereas the genus Bacillus probably played important roles in fermentation processes throughout the whole operation period. The performance and microbial community composition study suggested the application potential of the AWFR system for the pretreatment of decentralized domestic wastewater.
      PubDate: 2017-06-11
      DOI: 10.3390/app7060605
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 606: Effects of Nozzle Configuration on
           Rock Erosion Under a Supercritical Carbon Dioxide Jet at Various Pressures
           and Temperatures

    • Authors: Man Huang, Yong Kang, Xiaochuan Wang, Yi Hu, Deng Li, Can Cai, Feng Chen
      First page: 606
      Abstract: The supercritical carbon dioxide (SC-CO2) jet offers many advantages over water jets in the field of oil and gas exploration and development. To take better advantage of the SC-CO2 jet, effects of nozzle configuration on rock erosion characteristics were experimentally investigated with respect to the erosion volume. A convergent nozzle and two Laval nozzles, as well as artificial cores were employed in the experiments. It was found that the Laval nozzle can enhance rock erosion ability, which largely depends on the pressure and temperature conditions. The enhancement increases with rising inlet pressure. Compared with the convergent nozzle, the Laval-1 nozzle maximally enhances the erosion volume by 10%, 21.2% and 30.3% at inlet pressures of 30, 40 and 50 MPa, respectively; while the Laval-2 nozzle maximally increases the erosion volume by 32.5%, 49.2% and 60%. Moreover, the enhancement decreases with increasing ambient pressure under constant inlet pressure or constant pressure drop. The growth of fluid temperature above the critical value can increase the enhancement. In addition, the jet from the Laval-2 nozzle with a smooth inner profile always has a greater erosion ability than that from the Laval-1 nozzle.
      PubDate: 2017-06-12
      DOI: 10.3390/app7060606
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 607: Status of the SXFEL Facility

    • Authors: Zhentang Zhao, Dong Wang, Qiang Gu, Lixin Yin, Ming Gu, Yongbin Leng, Bo Liu
      First page: 607
      Abstract: The Shanghai soft X-ray Free-Electron Laser facility (SXFEL) is being developed in two steps; the SXFEL test facility (SXFEL-TF), and the SXFEL user facility (SXFEL-UF). The SXFEL-TF is a critical development step towards the construction a soft X-ray FEL user facility in China, and is under commissioning at the Shanghai Synchrotron Radiation Facility (SSRF) campus. The test facility is going to generate 8.8 nm FEL radiation using an 840 MeV electron linac passing through the two-stage cascaded HGHG-HGHG or EEHG-HGHG (high-gain harmonic generation, echo-enabled harmonic generation) scheme. The construction of the SXFEL-TF started at the end of 2014. Its accelerator tunnel and klystron gallery were ready for equipment installation in April 2016, and the installation of the SXFEL-TF linac and radiator undulators were completed by the end of 2016. In the meantime, the SXFEL-UF, with a designated wavelength in the water window region, began construction in November 2016. This was based on upgrading the linac energy to 1.5 GeV, and the building of a second undulator line and five experimental end-stations. Construction status and the future plans of the SXFEL are reported in this paper.
      PubDate: 2017-06-12
      DOI: 10.3390/app7060607
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 608: The Influences of Assisting Gas Type
           and Process Parameters on the Fiber Laser Microprofiling of Thin CoCr
           Tubes for Vascular Stents

    • Authors: Lei Liu, Dongbo Li, Yifei Tong, Yufu Zhu
      First page: 608
      Abstract: Cobalt chromium (CoCr) alloy tubes have been widely used in manufacturing of vascular stents, due to their excellent bio-mechanical properties, especially their high strength. In recent years, fiber lasers have been used in the micro-machining of vascular stents, given their better cutting quality than neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers. A comparison study of CoCr fiber laser cutting with oxygen and argon is presented, and the differences, such as surface topography, chemical composition, and kerfs geometry, between the oxygen cuts and argon cuts are studied. Three types of topographies are obtained for the oxygen cuts, and the underlying reason for the different topographies are discussed. The influences of key parameters including power, repetition rate, pulse width, and cutting speed on the cutting quality are analyzed. The present research can also provide an optimization guideline for the micro-profiling of CoCr vascular stents.
      PubDate: 2017-06-12
      DOI: 10.3390/app7060608
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 609: Kinetics Study of Gas Pollutant
           Adsorption and Thermal Desorption on Silica Gel

    • Authors: Rong A, Meng Liu, Liping Pang, Dongsheng Yang, Jun Wang, Yue Zhou
      First page: 609
      Abstract: Silica gel is a typical porous desiccant material. Its adsorption performance for gaseous air pollutants was investigated to determine its potential contribution to reducing such pollutants. Three gaseous air pollutants, toluene, carbon dioxide, and methane, were investigated in this paper. A thermogravimetric analyzer was used to obtain the equilibrium adsorption capacity of gases on single silica gel particles. The silica gel adsorption capacity for toluene is much higher than that for carbon dioxide and methane. To understand gas pollutant thermal desorption from silica gel, the thermogravimetric analysis of toluene desorption was conducted with 609 ppm toluene vapor at 313 K, 323 K, and 333 K. The overall regeneration rate of silica gel was strongly dependent on temperature and the enthalpy of desorption. The gas pollutant adsorption performance and thermal desorption on silica gel material may be used to estimate the operating and design parameters for gas pollutant adsorption by desiccant wheels.
      PubDate: 2017-06-12
      DOI: 10.3390/app7060609
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 610: Vibro-Acoustic Numerical Analysis for
           the Chain Cover of a Car Engine

    • Authors: Enrico Armentani, Raffaele Sepe, Antonio Parente, Mauro Pirelli
      First page: 610
      Abstract: In this work, a vibro-acoustic numerical and experimental analysis was carried out for the chain cover of a low powered four-cylinder four-stroke diesel engine, belonging to the FPT (FCA Power Train) family called SDE (Small Diesel Engine). By applying a methodology used in the acoustic optimization of new FPT engine components, firstly a finite element model (FEM) of the engine was defined, then a vibration analysis was performed for the whole engine (modal analysis), and finally a forced response analysis was developed for the only chain cover (separated from the overall engine). The boundary conditions applied to the chain cover were the accelerations experimentally measured by accelerometers located at the points of connection among chain cover, head cover, and crankcase. Subsequently, a boundary element (BE) model of the only chain cover was realized to determine the chain cover noise emission, starting from the previously calculated structural vibrations. The numerical vibro-acoustic outcomes were compared with those experimentally observed, obtaining a good correlation. All the information thus obtained allowed the identification of those critical areas, in terms of noise generation, in which to undertake necessary improvements.
      PubDate: 2017-06-12
      DOI: 10.3390/app7060610
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 611: Application of Finite Layer Method in
           Pavement Structural Analysis

    • Authors: Pengfei Liu, Qinyan Xing, Yiyi Dong, Dawei Wang, Markus Oeser, Si Yuan
      First page: 611
      Abstract: The finite element (FE) method has been widely used in predicting the structural responses of asphalt pavements. However, the three-dimensional (3D) modeling in general-purpose FE software systems such as ABAQUS requires extensive computations and is relatively time-consuming. To address this issue, a specific computational code EasyFEM was developed based on the finite layer method (FLM) for analyzing structural responses of asphalt pavements under a static load. Basically, it is a 3D FE code that requires only a one-dimensional (1D) mesh by incorporating analytical methods and using Fourier series in the other two dimensions, which can significantly reduce the computational time and required resources due to the easy implementation of parallel computing technology. Moreover, a newly-developed Element Energy Projection (EEP) method for super-convergent calculations was implemented in EasyFEM to improve the accuracy of solutions for strains and stresses over the whole pavement model. The accuracy of the program is verified by comparing it with results from BISAR and ABAQUS for a typical asphalt pavement structure. The results show that the predicted responses from ABAQUS and EasyFEM are in good agreement with each other. The EasyFEM with the EEP post-processing technique converges faster compared with the results derived from ordinary EasyFEM applications, which proves that the EEP technique can improve the accuracy of strains and stresses from EasyFEM. In summary, the EasyFEM has a potential to provide a flexible and robust platform for the numerical simulation of asphalt pavements and can easily be post-processed with the EEP technique to enhance its advantages.
      PubDate: 2017-06-13
      DOI: 10.3390/app7060611
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 612: Composite Kernel Method for PolSAR
           Image Classification Based on Polarimetric-Spatial Information

    • Authors: Xianyuan Wang, Zongjie Cao, Yao Ding, Jilan Feng
      First page: 612
      Abstract: The composite kernel feature fusion proposed in this paper attempts to solve the problem of classifying polarimetric synthetic aperture radar (PolSAR) images. Here, PolSAR images take into account both polarimetric and spatial information. Various polarimetric signatures are collected to form the polarimetric feature space, and the morphological profile (MP) is used for capturing spatial information and constructing the spatial feature space. The main idea is that the composite kernel method encodes diverse information within a new kernel matrix and tunes the contribution of different types of features. A support vector machine (SVM) is used as the classifier for PolSAR images. The proposed approach is tested on a Flevoland PolSAR data set and a San Francisco Bay data set, which are in fine quad-pol mode. For the Flevoland PolSAR data set, the overall accuracy and kappa coefficient of the proposed method, compared with the traditional method, increased from 95.7% to 96.1% and from 0.920 to 0.942, respectively. For the San Francisco Bay data set, the overall accuracy and kappa coefficient of the proposed method increased from 92.6% to 94.4% and from 0.879 to 0.909, respectively. Experimental results verify the benefits of using both polarimetric and spatial information via composite kernel feature fusion for the classification of PolSAR images.
      PubDate: 2017-06-13
      DOI: 10.3390/app7060612
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 613: Energy Regeneration Hydraulic System
           via a Relief Valve with Energy Regeneration Unit

    • Authors: Tianliang Lin, Qiang Chen, Haoling Ren, Yi Zhao, Cheng Miao, Shengjie Fu, Qihuai Chen
      First page: 613
      Abstract: Relief valves are widely used in industrial machinery. Due to the outlet of the relief valve being connected to the tank, the pressure drop of the relief valve is frequently equal to the inlet pressure. Accordingly, the energy loss of the relief valve is very high in some cases and this will worsen with an increase in the rated pressure of the hydraulic system. In order to overcome the disadvantage of overflow energy loss in a relief valve, a hydraulic energy regeneration unit (HERU) is connected to the outlet of the relief valve to decrease the pressure drop between the inlet and outlet of the relief valve. The overflow loss, which is characterized by the pressure drop, can be reduced accordingly. The approach is to convert the overflow energy loss in hydraulic form and allow for release when needed. The configuration and working principle of the relief valve with HERU is introduced in this present study. The mathematical model is established to obtain the factors influencing the stability of the relief valve. The working pressure of the hydraulic accumulator (HA) is explored. Furthermore, the control process of the operating state of the HA is scheduled to decide whether to regenerate the energy via the HERU. The software AMESim is utilized to analyze the performance and characteristics of the relief valve with HERU. Following this, the test rig is built and used to verify the effectiveness of the proposed relief valve with HERU. The experimental results show that the relief valve with the HERU connected to its outlet can still achieve better pressure-regulating characteristics. The energy regeneration efficiency saved by the HA is up to 83.6%, with a higher pre-charge pressure of the HA. This indicates that the proposed structure of the relief valve with HERU can achieve a better performance and higher regeneration efficiency.
      PubDate: 2017-06-13
      DOI: 10.3390/app7060613
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 614: Terawatt-Isolated Attosecond X-ray
           Pulse Using a Tapered X-ray Free Electron Laser

    • Authors: Sandeep Kumar, Alexandra Landsman, Dong Kim
      First page: 614
      Abstract: High power attosecond (as) X-ray pulses are in great demand for ultrafast dynamics and high resolution microscopy. We numerically demonstrate the generation of a ~230 attosecond, 1.5 terawatt (TW) pulse at a photon energy of 1 keV, and a 115 attosecond, 1.2 TW pulse at a photon energy of 12.4 keV, using the realistic electron beam parameters such as those of Korean X-ray free electron laser (XFEL) in a tapered undulator configuration. To compensate the energy loss of the electron beam and maximize its radiation power, a tapering is introduced in the downstream section of the undulator. It is found that the tapering helps in not only amplifying a target radiation pulse but also suppressing the growth of satellite radiation pulses. Tapering allows one to achieve a terawatt-attosecond pulse only with a 60 m long undulator. Such an attosecond X-ray pulse is inherently synchronized to a driving optical laser pulse; hence, it is well suited for the pump-probe experiments for studying the electron dynamics in atoms, molecules, and solids on the attosecond time-scale. For the realization of these experiments, a high level of synchronization up to attosecond precision between optical laser and X-ray pulse is demanded, which can be possible by using an interferometric feedback loop.
      PubDate: 2017-06-13
      DOI: 10.3390/app7060614
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 615: Non-Pulse-Leakage 100-kHz Level, High
           Beam Quality Industrial Grade Nd:YVO4 Picosecond Amplifier

    • Authors: Zhenao Bai, Zhenxu Bai, Zhijun Kang, Fuqiang Lian, Weiran Lin, Zhongwei Fan
      First page: 615
      Abstract: A non-pulse-leakage optical fiber pumped 100-kHz level high beam quality Nd:YVO4 picosecond amplifier has been developed. An 80 MHz, 11.5 ps mode-locked picosecond laser is used as the seed with single pulse energy of 1 nJ. By harnessing the double β-BaB2O4 (BBO) crystal Pockels cells in both the pulse picker and regenerative amplifier, the seed pulse leakage of the output is suppressed effectively with an adjustable repetition rate from 200 to 500 kHz. Through one stage traveling-wave amplifier, a maximum output power of 24.5 W is generated corresponding to the injected regenerative amplified power of 9.73 W at 500 kHz. The output pulse duration is 16.9 ps, and the beam quality factor M2 is measured to be 1.25 with near-field roundness higher than 99% at the full output power.
      PubDate: 2017-06-14
      DOI: 10.3390/app7060615
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 616: Smartphones as a Light Measurement
           Tool: Case of Study

    • Authors: Jose-Maria Gutierrez-Martinez, Ana Castillo-Martinez, Jose-Amelio Medina-Merodio, Juan Aguado-Delgado, Jose-Javier Martinez-Herraiz
      First page: 616
      Abstract: In recent years, smartphones have become the main computing tool for most of the population, making them an ideal tool in many areas. Most of these smartphones are equipped with cutting-edge hardware on their digital cameras, sensors and processors. For this reason, this paper discusses the possibility of using smartphones as an accessible and accurate tool, focusing on the measurement of light, which is an element that has a high impact on human behavior, which promotes conformance and safety, or alters human physiology when it is inappropriate. To carry out this study, three different ways to measure light through smartphones have been checked: the ambient light sensor, the digital camera and an external Bluetooth luxmeter connected with the smartphone. As a result, the accuracy of these methods has been compared to check if they can be used as accurate measurement tools.
      PubDate: 2017-06-14
      DOI: 10.3390/app7060616
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 617: Synthesis and Biophysical Insights
           into the Binding of a Potent Anti-Proliferative Non-symmetric Bis-isatin
           Derivative with Bovine Serum Albumin: Spectroscopic and Molecular Docking
           Approaches

    • Authors: Ali Abdelhameed, Ahmed Bakheit, Mostafa Mohamed, Wagdy Eldehna, Hatem Abdel-Aziz, Mohamed Attia
      First page: 617
      Abstract: As part of the research endeavors to combat cancer, a non-symmetric bis-isatin derivative (compound 3) was synthesized and showed a significant anti-proliferative potency. The current study provides a comprehensive characterization of the interaction of compound 3 with the drug-transporting protein bovine serum albumin (BSA) via the use of spectroscopic tools along with molecular docking studies. Fluorescence spectral measurements showed that the BSA intrinsic fluorescence can be significantly quenched by the addition of compound 3 and the formation of a non-fluorescent complex. Further measurements revealed a static type of quenching with Stern–Volmer and Linweaver–Burk constants of 105. The thermodynamic parameters of the binding were calculated to be ΔS° 105.09 ± 5.32 with ΔH° of −0.72 ± 0.71 and negative ΔG° values. In addition, synchronous fluorescence and 3D fluorescence spectroscopy suggested that compound 3 did not induce conformational changes in BSA. Site competition experiments revealed that compound 3 competes with warfarin within the BSA binding domain (Sudlow site I). This was further confirmed by the molecular docking results showing a binding energy of −25.93 kJ/mol for compound 3-BSA. Hence, the observed results in the present study assumed that the compound 3-BSA binding is spontaneous, involving electrostatic forces and hydrogen bonding.
      PubDate: 2017-06-14
      DOI: 10.3390/app7060617
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 618: Iridescent Perfect Absorption in
           Critically-Coupled Acoustic Metamaterials Using the Transfer Matrix Method
           

    • Authors: Noé Jiménez, Jean-Philippe Groby, Vincent Pagneux, Vicent Romero-García
      First page: 618
      Abstract: The absorption performance of a locally-reacting acoustic metamaterial under oblique incidence is studied. The metamaterial is composed of a slotted panel, each slit being loaded by an array of Helmholtz resonators. The system is analytically studied using the transfer matrix method, accounting for the viscothermal losses both in the resonator elements and in the slits, allowing the representation of the reflection coefficient in the complex frequency plane. We show that by tuning the geometry of the metamaterial, perfect absorption peaks can be obtained on demand at selected frequencies and different angles of incidence. When tilting the incidence angle, the peaks of perfect absorption are shifted in frequency, producing an acoustic iridescence effect similar to the optic iridescence achieved by incomplete band gap. Effectively, we show that in this kind of locally-reacting metamaterial, perfect and omnidirectional absorption for a given frequency is impossible to achieve because the metamaterial impedance does not depend on the incidence angle (i.e., the impedance is a locally reacting one). The system is interpreted in the complex frequency plane by analysing the trajectories of the zeros of the reflection coefficient. We show that the trajectories of the zeros do not overlap under oblique incidence, preventing the observation of perfect and omnidirectional absorption in locally reacting metamaterials. Moreover, we show that for any locally resonant material, the absorption in diffuse field takes a maximal value of 0.951, which is achieved by a material showing perfect absorption for an incidence angle of 50.34 degrees.
      PubDate: 2017-06-14
      DOI: 10.3390/app7060618
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 619: Simulation Investigation on
           Combustion Characteristics in a Four-Point Lean Direct Injection Combustor
           with Hydrogen/Air

    • Authors: Jianzhong Li, Li Yuan, Hukam Mongia
      First page: 619
      Abstract: To investigate the combustion characteristics in multi-point lean direct injection (LDI) combustors with hydrogen/air, two swirl–venturi 2 × 2 array four-point LDI combustors were designed. The four-point LDI combustor consists of injector assembly, swirl–venturi array and combustion chamber. The injector, swirler and venturi together govern the rapid mixing of hydrogen and air to form the mixture for combustion. Using clockwise swirlers and anticlockwise swirlers, the co-swirling and count-swirling swirler arrays LDI combustors were achieved. Using Reynolds-Averaged Navier–Stokes (RANS) code for steady-state reacting flow computations, the four-point LDI combustors with hydrogen/air were simulated with an 11 species and 23 lumped reaction steps H2/Air reaction mechanism. The axial velocity, turbulence kinetic energy, total pressure drop coefficient, outlet temperature, mass fraction of OH and emission of pollutant NO of four-point LDI combustors, with different equivalence ratios, are here presented and discussed. As the equivalence ratios increased, the total pressure drop coefficient became higher because of increasing heat loss. Increasing equivalence ratios also corresponded with the rise in outlet temperature of the four-point LDI combustors, as well as an increase in the emission index of NO EINO in the four-point LDI combustors. Along the axial distance, the EINO always increased and was at maximum at the exit of the dump. Along the chamber, the EINO gradually increased, maximizing at the exit of chamber. The total temperature of four-point LDI combustors with different equivalence ratios was identical to the theoretical equilibrium temperature. The EINO was an exponential function of the equivalence ratio.
      PubDate: 2017-06-14
      DOI: 10.3390/app7060619
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 620: Experimental Investigations of
           Composite Adsorbent 13X/CaCl2 on an Adsorption Cooling System

    • Authors: Huizhong Zhao, Shaolong Jia, Junfeng Cheng, Xianghu Tang, Min Zhang, Haoxin Yan, Wenting Ai
      First page: 620
      Abstract: A new experimental device which tests the adsorption performance of the 13X/CaCl2 composite adsorbent under vacuum conditions was established. In this device, heat transfer characteristics in the adsorbent bed have a great influence on the adsorbent performance, the temperature of the bottom outside bed is very close to the temperature of the bottom inside bed and the temperature difference between them at the end of heating and cooling are 5.66 °C and 0.303 °C, respectively. The following conclusions could be drawn: the equilibrium water uptake of composite adsorbent CA10X (zeolite 13X impregnated with 10 wt % CaCl2 solution) was increased 5.7% compared with that of 13X, and the water uptake was 0.37 g/g. The composite adsorbent CA10X has a better performance in the adsorption refrigeration system.
      PubDate: 2017-06-14
      DOI: 10.3390/app7060620
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 621: Application of Matched-Filter
           Concepts to Unbiased Selection of Data in Pump-Probe Experiments with Free
           Electron Lasers

    • Authors: Carlo Callegari, Tsukasa Takanashi, Hironobu Fukuzawa, Koji Motomura, Denys Iablonskyi, Yoshiaki Kumagai, Subhendu Mondal, Tetsuya Tachibana, Kiyonobu Nagaya, Toshiyuki Nishiyama, Kenji Matsunami, Per Johnsson, Paolo Piseri, Giuseppe Sansone, Antoine Dubrouil, Maurizio Reduzzi, Paolo Carpeggiani, Caterina Vozzi, Michele Devetta, Davide Faccialà, Francesca Calegari, Mattea Castrovilli, Marcello Coreno, Michele Alagia, Bernd Schütte, Nora Berrah, Oksana Plekan, Paola Finetti, Eugenio Ferrari, Kevin Prince, Kiyoshi Ueda
      First page: 621
      Abstract: Pump-probe experiments are commonly used at Free Electron Lasers (FEL) to elucidate the femtosecond dynamics of atoms, molecules, clusters, liquids and solids. Maximizing the signal-to-noise ratio of the measurements is often a primary need of the experiment, and the aggregation of repeated, rapid, scans of the pump-probe delay is preferable to a single long-lasting scan. The limited availability of beamtime makes it impractical to repeat measurements indiscriminately, and the large, rapid flow of single-shot data that need to be processed and aggregated into a dataset, makes it difficult to assess the quality of a measurement in real time. In post-analysis it is then necessary to devise unbiased criteria to select or reject datasets, and to assign the weight with which they enter the analysis. One such case was the measurement of the lifetime of Intermolecular Coulombic Decay in the weakly-bound neon dimer. We report on the method we used to accomplish this goal for the pump-probe delay scans that constitute the core of the measurement; namely we report on the use of simple auto- and cross-correlation techniques based on the general concept of “matched filter”. We are able to unambiguously assess the signal-to-noise ratio (SNR) of each scan, which then becomes the weight with which a scan enters the average of multiple scans. We also observe a clear gap in the values of SNR, and we discard all the scans below a SNR of 0.45. We are able to generate an average delay scan profile, suitable for further analysis: in our previous work we used it for comparison with theory. Here we argue that the method is sufficiently simple and devoid of human action to be applicable not only in post-analysis, but also for the real-time assessment of the quality of a dataset.
      PubDate: 2017-06-16
      DOI: 10.3390/app7060621
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 622: ANN Sizing Procedure for the
           Day-Ahead Output Power Forecast of a PV Plant

    • Authors: Francesco Grimaccia, Sonia Leva, Marco Mussetta, Emanuele Ogliari
      First page: 622
      Abstract: Since the beginning of this century, the share of renewables in Europe’s total power capacity has almost doubled, becoming the largest source of its electricity production. In 2015 alone, photovoltaic (PV) energy generation rose with a rate of more than 5%; nowadays, Germany, Italy, and Spain account together for almost 70% of total European PV generation. In this context, the so-called day-ahead electricity market represents a key trading platform, where prices and exchanged hourly quantities of energy are defined 24 h in advance. Thus, PV power forecasting in an open energy market can greatly benefit from machine learning techniques. In this study, the authors propose a general procedure to set up the main parameters of hybrid artificial neural networks (ANNs) in terms of the number of neurons, layout, and multiple trials. Numerical simulations on real PV plant data are performed, to assess the effectiveness of the proposed methodology on the basis of statistical indexes, and to optimize the forecasting network performance.
      PubDate: 2017-06-15
      DOI: 10.3390/app7060622
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 623: Combined CFD-Stochastic Analysis of
           an Active Fluidic Injection System for Jet Noise Reduction

    • Authors: Mattia Barbarino, Mario Ilsami, Raffaele Tuccillo, Luigi Federico
      First page: 623
      Abstract: In the framework of DANTE project (Development of Aero-Vibroacoustics Numerical and Technical Expertise), funded under the Italian Aerospace Research Program (PRORA), the prediction and reduction of noise from subsonic jets through the reconstruction of turbulent fields from Reynolds Averaged Navier Stokes (RANS) calculations are addressed. This approach, known as Stochastic Noise Generation and Radiation (SNGR), reconstructs the turbulent velocity fluctuations by RANS fields and calculates the source terms of Vortex Sound acoustic analogy. In the first part of this work, numerical and experimental jet-noise test cases have been reproduced by means RANS simulations and with different turbulence models in order to validate the approach for its subsequent use as a design tool. The noise spectra, predicted with SNGR, are in good agreement with both the experimental data and the results of Large-Eddy Simulations (LES). In the last part of this work, an active fluid injection technique, based on extractions from turbine and injections of high-pressure gas into the main stream of exhausts, has been proposed and finally assessed with the aim of reducing the jet-noise through the mixing and breaking of the turbulent eddies. Some tests have been carried out in order to set the best design parameters in terms of mass flow rate and injection velocity and to design the system functionalities. The SNGR method is, therefore, suitable to be used for the early design phase of jet-noise reduction technologies and a right combination of the fluid injection design parameters allows for a reduction of the jet-noise to 3.5 dB, as compared to the baseline case without injections.
      PubDate: 2017-06-16
      DOI: 10.3390/app7060623
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 624: Efficiency Evaluation of Operation
           Analysis Systems Based on Dynamic Data Envelope Analysis Models from a Big
           Data Perspective

    • Authors: Yixin Sun, Xiaobao Yu, Zhongfu Tan, Xiaofei Xu, Qingyou Yan
      First page: 624
      Abstract: The operating environment of power grid enterprises is complex with a range of monitoring indicators. To grasp the overall operational status in time and find the key affecting factors, Balanced Scorecard Card (BSC), Interpretive Structural Model (ISM), Principal component analysis (PCA) should be applied. This paper proposed several grid enterprise operators and monitoring indicator systems (which include achievement indicators and driver indicators), and applied PCA for verification and evaluation. The achievement indicators mainly reflected the effectiveness of business operations, which included corporate value, social value, customer value, and so on. Driver indicators mainly reflected the core resources and operations process management of business operations, which have a direct impact on the achievement indicators. The driver and achievement indicators were used as input and output indicators for the provinces to assess the efficiency of operations, and appropriate measures were proposed for improvement. The results showed that the dynamic data envelopment analysis (DEA) model could reflect the time lag of the grid enterprises operating investment and income much better than the other two methods, and the static changes compared to assess efficiency had an average around 4%.
      PubDate: 2017-06-16
      DOI: 10.3390/app7060624
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 625: Large Earthquake Magnitude Prediction
           in Chile with Imbalanced Classifiers and Ensemble Learning

    • Authors: Manuel Fernández-Gómez, Gualberto Asencio-Cortés, Alicia Troncoso, Francisco Martínez-Álvarez
      First page: 625
      Abstract: This work presents a novel methodology to predict large magnitude earthquakes with horizon of prediction of five days. For the first time, imbalanced classification techniques are applied in this field by attempting to deal with the infrequent occurrence of such events. So far, classical classifiers were not able to properly mine these kind of datasets and, for this reason, most of the methods reported in the literature were only focused on moderate magnitude prediction. As an additional step, outputs from different algorithms are combined by applying ensemble learning. Since false positives are quite undesirable in this field, due to the social impact that they might cause, ensembles have been designed in order to reduce these situations. The methodology has been tested on different cities of Chile, showing very promising results in terms of accuracy.
      PubDate: 2017-06-16
      DOI: 10.3390/app7060625
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 626: A Wireless Sensor Network Using GNSS
           Receivers for a Short-Term Assessment of the Modal Properties of the
           Neckartal Bridge

    • Authors: Timo Kumberg, Sascha Schneid, Leonhard Reindl
      First page: 626
      Abstract: In this article, we present a novel structural health monitoring system based on a wireless sensor network for GNSS (global navigation satellite system) receivers. The GNSS network presented here consists of three GNSS rover stations and one base station that are deployed at the Neckartal bridge on the Autobahn A81 in southwest Germany. The newly-developed GNSS sensor nodes support satellite data logging up to a sampling rate of 20 Hz. Due to the ultra-low-power consumption achieved by the wake-up receiver during inactive periods, the nodes offer a lifetime from 20 to almost 200 days, without energy harvesting and depending on the satellite data logging period. By performing differential post-processing, precise positioning information in the millimeter range could be achieved. Using the GNSS sensors, we determined resonant frequencies at 0.33 Hz and 1.31 Hz, mainly in the lateral direction of the bridge. To verify the GNSS results, we placed an accelerometer on the bridge. The frequencies detected by the acceleration sensor correspond well to the frequencies found by the GNSS sensors, although the accelerometer measured further higher frequencies as it is probably more sensitive to small amplitudes.
      PubDate: 2017-06-16
      DOI: 10.3390/app7060626
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 627: Spatial Audio for Soundscape Design:
           Recording and Reproduction

    • Authors: Joo Hong, Jianjun He, Bhan Lam, Rishabh Gupta, Woon-Seng Gan
      First page: 627
      Abstract: With the advancement of spatial audio technologies, in both recording and reproduction, we are seeing more applications that incorporate 3D sound to create an immersive aural experience. Soundscape design and evaluation for urban planning can now tap into the extensive spatial audio tools for sound capture and 3D sound rendering over headphones and speaker arrays. In this paper, we outline a list of available state-of-the-art spatial audio recording techniques and devices, spatial audio physical and perceptual reproduction techniques, emerging spatial audio techniques for virtual and augmented reality, followed by a discussion on the degree of perceptual accuracy of recording and reproduction techniques in representing the acoustic environment.
      PubDate: 2017-06-16
      DOI: 10.3390/app7060627
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 628: Entropy Analysis for Damage
           Quantification of Hysteretic Dampers Used as Seismic Protection of
           Buildings

    • Authors: Elisabet Suarez, Andrés Roldán, Antolino Gallego, Amadeo Benavent-Climent
      First page: 628
      Abstract: Relative wavelet energy entropy (RWEE) is proposed to detect and quantify damage to hysteretic dampers used for the passive seismic control of building structures. Hysteretic dampers have the role of dissipating most of the energy input of an earthquake. Minor or moderate earthquakes do not exhaust the energy dissipation capacity of the dampers, yet they damage them. For this reason, continuous or periodic damper-health evaluation is required to decide if they need to be replaced. Such evaluation calls for the application of efficient structural health monitoring techniques (SHM). This paper focuses on the well-known vibration technique, which is applied to a particular type of hysteretic damper called Web Plastifying Damper (WPD), patented by the University of Granada. Vibration signals, properly recorded by piezoelectric sensors attached around the damaged area of the dampers, are decomposed by means of wavelet packet analysis. Then, the relative wavelet energy entropy of these decompositions is used to calculate the proposed index. Validation of RWEE for this particular application involved dampers installed in two different specimens of reinforced concrete structures subjected to earthquake sequences of increasing intensity. When compared with a well-established mechanical energy-based damage index, results demonstrate that RWEE is a successful and low-cost technique for reliable in-situ monitoring of dampers.
      PubDate: 2017-06-17
      DOI: 10.3390/app7060628
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 629: Experimental Study and Numerical
           Simulation of a Laminated Reinforced Concrete Shear Wall with a Vertical
           Seam

    • Authors: Jianbao Li, Yan Wang, Zheng Lu, Junzuo Li
      First page: 629
      Abstract: In this paper, 12 laminated reinforced concrete shear walls are designed for cyclic loading tests. Seismic performance of laminated reinforced concrete shear walls with vertical seams are evaluated by the failure mode, deformability, hysteresis curve, stiffness degradation, and energy dissipation capacity. In addition, two different construction measures and construction techniques are designed to study their influence on the wall behavior, which provides a reference for the construction of laminated reinforced concrete shear walls. The numerical simulation of the specimen is carried out with ABAQUS, which is in good agreement with the experimental results. These results provide a technical basis for the design, application, and construction of the laminated reinforced concrete shear wall structure.
      PubDate: 2017-06-17
      DOI: 10.3390/app7060629
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 630: Comparative Study of Stator
           Configurations of a Permanent Magnet Linear Oscillating Actuator for
           Orbital Friction Vibration Actuator

    • Authors: Jianhui Hu, Meng Zhao, Jibin Zou, Yong Li
      First page: 630
      Abstract: A PM orbital friction vibration actuator (OFVA) which composes four linear oscillating actuators (LOA) is proposed in this paper. This paper presents the design, analysis, and experimental validation of stator configuration of a permanent magnet LOA to improve its thrust force characteristics. First, the magnetized topology and the coil configuration are interpreted. The optimization design goal of the LOA was established and the end effects of the actuator are illustrated. The influences of stator design parameters on the performance of LOA were investigated and the optimal parameters have been identified with reference to the thrust force density and thrust force ripple. Results showed that a quasi‐Halbach magnetized E‐cored LOA with obtrapezoid teeth has the best electromagnetic performances of all the LOAs examined here. Finally, the predicted thrust force characteristics were validated by measurements on a prototype actuator.
      PubDate: 2017-06-17
      DOI: 10.3390/app7060630
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 631: Demonstration of High-Speed Optical
           Transmission at 2 µm in Titanium Dioxide Waveguides

    • Authors: Manon Lamy, Christophe Finot, Julien Fatome, Juan Arocas, Jean-Claude Weeber, Kamal Hammani
      First page: 631
      Abstract: We demonstrate the transmission of a 10-Gbit/s optical data signal in the 2 µm waveband into titanium dioxide waveguides. Error-free transmissions have been experimentally achieved taking advantage of a 23-dB insertion loss fiber-to-fiber grating-based injection test-bed platform.
      PubDate: 2017-06-17
      DOI: 10.3390/app7060631
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 632: Supercritical Transesterification of
           Waste Vegetable Oil: Characteristic Comparison of Ethanol and Methanol as
           Solvents

    • Authors: Sujeeta Karki, Nawaraj Sanjel, Jeeban Poudel, Ja Hyung Choi, Sea Cheon Oh
      First page: 632
      Abstract: Transesterification of waste vegetable oil is one of the promising partial substitutes for fossil fuels. The degradation characteristics of waste vegetable oil using supercritical alcohols (ethanol and methanol) have been studied in this research. The elementary target was to conduct comparative analysis of the effect of supercritical methanol and supercritical ethanol as solvents on the transesterification along with the analysis of product obtained in terms of carbon number. The experiments were carried out at transesterification temperatures of 250, 270 and 290 °C, retention time of 0 to 60 min at an interval of 15 min and oil to alcohol molar ratios of 1:6, 1:12 and 1:18 for both alcohols. The conversion increased with increase in transesterification temperature and retention time. At 290 °C, almost 99% conversion was achieved for 60-min holding time for both alcohols. Increase in conversion of waste vegetable oil was observed as the molar ratio increased. Supercritical transesterification resulted into ester yield higher than 95% with non-ester composition and glycerol collectively less than 5%.
      PubDate: 2017-06-17
      DOI: 10.3390/app7060632
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 633: Experimental Investigation on the
           Effects of DBD Plasma on the Film Cooling Effectiveness of a 30-Degree
           Slot

    • Authors: Ye Kim, Gi Kim, Youhwan Shin, Jae Kwak
      First page: 633
      Abstract: The effects of dielectric barrier discharge (DBD) plasma on the film cooling effectiveness of a 30-degree slot was experimentally investigated in a low-speed wind tunnel. The pressure sensitive paint (PSP) technique was used to measure the film cooling effectiveness, and two blowing ratios (0.5 and 1.0) were tested. A sinusoidal waveform with a 1-kHz frequency was supplied to the exposed electrode. Two input voltages (6 and 7 kV) and two exposed electrode locations were considered. The results showed that the film cooling effectiveness of the slot was higher for the blowing ratio of the 1.0 case than that for the blowing ratio of the 0.5 case regardless of plasma operation. The higher input voltage case (7 kV) showed higher film cooling effectiveness than the lower input voltage case (6 kV). The improvement in film cooling effectiveness facilitated by the DBD plasma was more significant when the coolant had less momentum. The maximum improvement of the area averaged film cooling effectiveness was 2.3% for the case with the exposed electrode located at the slot exit and a blowing ratio of 0.5.
      PubDate: 2017-06-19
      DOI: 10.3390/app7060633
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 634: Optimized Design of Thermoelectric
           Energy Harvesting Systems for Waste Heat Recovery from Exhaust Pipes

    • Authors: Marco Nesarajah, Georg Frey
      First page: 634
      Abstract: With the increasing interest in energy efficiency and resource protection, waste heat recovery processes have gained importance. Thereby, one possibility is the conversion of the heat energy into electrical energy by thermoelectric generators. Here, a thermoelectric energy harvesting system is developed to convert the waste heat from exhaust pipes, which are very often used to transport the heat, e.g., in automobiles, in industrial facilities or in heating systems. That is why a mockup of a heating is built-up, and the developed energy harvesting system is attached. To build-up this system, a model-based development process is used. The setup of the developed energy harvesting system is very flexible to test different variants and an optimized system can be found in order to increase the energy yield for concrete application examples. A corresponding simulation model is also presented, based on previously developed libraries in Modelica®/Dymola®. In the end, it can be shown—with measurement and simulation results—that a thermoelectric energy harvesting system on the exhaust pipe of a heating system delivers extra energy and thus delivers a contribution for a more efficient usage of the inserted primary energy carrier.
      PubDate: 2017-06-19
      DOI: 10.3390/app7060634
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 635: Soliton Content of Fiber-Optic Light
           Pulses

    • Authors: Fedor Mitschke, Christoph Mahnke, Alexander Hause
      First page: 635
      Abstract: This is a review of fiber-optic soliton propagation and of methods to determine the soliton content in a pulse, group of pulses or a similar structure. Of central importance is the nonlinear Schrödinger equation, an integrable equation that possesses soliton solutions, among others. Several extensions and generalizations of this equation are customary to better approximate real-world systems, but this comes at the expense of losing integrability. Depending on the experimental situation under discussion, a variety of pulse shapes or pulse groups can arise. In each case, the structure will contain one or several solitons plus small amplitude radiation. Direct scattering transform, also known as nonlinear Fourier transform, serves to quantify the soliton content in a given pulse structure, but it relies on integrability. Soliton radiation beat analysis does not suffer from this restriction, but has other limitations. The relative advantages and disadvantages of the methods are compared.
      PubDate: 2017-06-19
      DOI: 10.3390/app7060635
      Issue No: Vol. 7, No. 6 (2017)
       
 
 
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