for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> ENGINEERING (Total: 2284 journals)
    - CHEMICAL ENGINEERING (192 journals)
    - CIVIL ENGINEERING (184 journals)
    - ELECTRICAL ENGINEERING (102 journals)
    - ENGINEERING (1208 journals)
    - ENGINEERING MECHANICS AND MATERIALS (389 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (65 journals)
    - MECHANICAL ENGINEERING (89 journals)

ENGINEERING (1208 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     Hybrid Journal   (Followers: 6)
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: 229)
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: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
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: 15)
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: 21)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
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: 41)
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   (Followers: 2)
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: 4)
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: 4)
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: 8)
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: 5)
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: 26)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 254)
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: 184)
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: 30)
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: 42)
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 644: Lévy Statistics and the Glassy
           Behavior of Light in Random Fiber Lasers

    • Authors: Cid Araújo, Anderson Gomes, Ernesto Raposo
      First page: 644
      Abstract: The interest in random fiber lasers (RFLs), first demonstrated one decade ago, is still growing and their basic characteristics have been studied by several authors. RFLs are open systems that present instabilities in the intensity fluctuations due to the energy exchange among their non-orthogonal quasi-modes. In this work, we present a review of the recent investigations on the output characteristics of a continuous-wave erbium-doped RFL, with an emphasis on the statistical behavior of the emitted intensity fluctuations. A progression from the Gaussian to Lévy and back to the Gaussian statistical regime was observed by increasing the excitation laser power from below to above the RFL threshold. By analyzing the RFL output intensity fluctuations, the probability density function of emission intensities was determined, and its correspondence with the experimental results was identified, enabling a clear demonstration of the analogy between the RFL phenomenon and the spin-glass phase transition in disordered magnetic systems. A replica-symmetry-breaking phase above the RFL threshold was characterized and the glassy behavior of the emitted light was established. We also discuss perspectives for future investigations on RFL systems.
      PubDate: 2017-06-22
      DOI: 10.3390/app7070644
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 645: Modulational Instability in Linearly
           Coupled Asymmetric Dual-Core Fibers

    • Authors: Arjunan Govindarajan, Boris Malomed, Arumugam Mahalingam, Ambikapathy Uthayakumar
      First page: 645
      Abstract: We investigate modulational instability (MI) in asymmetric dual-core nonlinear directional couplers incorporating the effects of the differences in effective mode areas and group velocity dispersions, as well as phase- and group-velocity mismatches. Using coupled-mode equations for this system, we identify MI conditions from the linearization with respect to small perturbations. First, we compare the MI spectra of the asymmetric system and its symmetric counterpart in the case of the anomalous group-velocity dispersion (GVD). In particular, it is demonstrated that the increase of the inter-core linear-coupling coefficient leads to a reduction of the MI gain spectrum in the asymmetric coupler. The analysis is extended for the asymmetric system in the normal-GVD regime, where the coupling induces and controls the MI, as well as for the system with opposite GVD signs in the two cores. Following the analytical consideration of the MI, numerical simulations are carried out to explore nonlinear development of the MI, revealing the generation of periodic chains of localized peaks with growing amplitudes, which may transform into arrays of solitons.
      PubDate: 2017-06-22
      DOI: 10.3390/app7070645
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 646: Algorithm for Reconstruction of 3D
           Images of Nanorice Particles from Diffraction Patterns of Two Particles in
           Independent Random Orientations with an X-ray Laser

    • Authors: Sung Kim, Sandi Wibowo, Dilano Saldin
      First page: 646
      Abstract: The method of angular correlations recovers quantities from diffraction patterns of randomly oriented particles, as expected to be measured with an X-ray free electron laser (XFEL), proportional to quadratic functions of the spherical harmonic expansion coefficients of the diffraction volume of a single particle. We have previously shown that it is possible to reconstruct a randomly oriented icosahedral or helical virus from the average over all measured diffraction patterns of such correlations. We point out in this paper that a structure of even simpler particles of 50 Å or so in diameter and consisting of heavier atomic elements (to enhance scattering) that has been used as a test case for reconstructions from XFEL diffraction patterns can also be solved by this technique. Even though there has been earlier work on similar objects (prolate spheroids), one advantage of the present technique is its potential to also work with diffraction patterns not only due to single particles as has been suggested on the basis on nonoverlapping delta functions of angular scattering. Accordingly, we calculated from the diffraction patterns the angular momentum expansions of the pair correlations and triple correlations for general particle images and reconstructed those images in the standard way. Although the images looked pretty much the same, it is not totally clear to us that the angular correlations are exactly the same as different numbers of particles due to the possibility of constructive or destructive interference between the scattered waves from different particles. It is of course known that, for a large number of particles contributing to a diffraction parttern, the correlations converge to that of a single particle. It could be that the lack of perfect agreement between the images reconstructed with one and two particles is due to uncancelling constructive and destructive conditions that are not found in the case of solution scattering.
      PubDate: 2017-06-23
      DOI: 10.3390/app7070646
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 647: An Evaluation of the Efficiency of
           Compartmented Alginate Fibres Encapsulating a Rejuvenator as an Asphalt
           Pavement Healing System

    • Authors: Amir Tabaković, Luke Schuyffel, Aleksandar Karač, Erik Schlangen
      First page: 647
      Abstract: This paper explores the potential methods for evaluating a healing system for asphalt pavements. The healing system under investigation involves compartmented calcium-alginate fibres encapsulating an asphalt binder healing agent (rejuvenator). This system presents a novel method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are used to distribute the rejuvenator throughout the pavement mixture, thereby overcoming some of the problems associated with alternate asphalt pavement healing methods, i.e., spherical capsules and hollow fibres. The asphalt healing efficiency methods to be evaluated in this paper include: (i) standard test methods for asphalt pavements, such as the Indirect Tensile Strength test and the 4 Point Bending Fatigue test; and (ii) alternative fracture tests such as the Semi Circular Bend test. The study employs fracture theory in order to evaluate the efficiency of the damage repair. The research findings demonstrate that including compartmented calcium-alginate fibres encapsulating a rejuvenator into an asphalt pavement mix does not significantly improve the healing properties of the asphalt pavement. Nevertheless, the findings indicate that, with further enhancement, compartmented calcium alginate fibres may present a promising new approach for the development of self-healing asphalt pavement systems. Additionally, the test results indicate that the 4 point bend fatigue test is the most suitable test for evaluating the performance of self healing asphalt pavements.
      PubDate: 2017-06-23
      DOI: 10.3390/app7070647
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 648: Non-Destructive Study of the
           Microstructural Effects of Sodium and Magnesium Sulphate Attack on Mortars
           Containing Silica Fume Using Impedance Spectroscopy

    • Authors: Mark Williams, José Ortega, Isidro Sánchez, Marta Cabeza, Miguel Climent
      First page: 648
      Abstract: The microstructural effects of exposure to a 15% magnesium sulphate, 15% sodium sulphate, and mixed solutions were observed in mortars with and without silica fume, using the non-destructive impedance spectroscopy technique. The non-destructive “Wenner” resistivity test and the classical mercury intrusion porosimetry were used as contrast techniques. The compressive strength of the mortars was also studied. In view of the results obtained, impedance spectroscopy was the most sensitive technique for detecting changes in the porous network of the studied mortars. The addition of silica fume results in a more refined microstructure and a higher compressive strength in mortars exposed to aggressive sulphate solutions.
      PubDate: 2017-06-23
      DOI: 10.3390/app7070648
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 649: Remaining Useful Life Prediction of
           Hybrid Ceramic Bearings Using an Integrated Deep Learning and Particle
           Filter Approach

    • Authors: Jason Deutsch, Miao He, David He
      First page: 649
      Abstract: Bearings are one of the most critical components in many industrial machines. Predicting remaining useful life (RUL) of bearings has been an important task for condition-based maintenance of industrial machines. One critical challenge for performing such tasks in the era of the Internet of Things and Industrial 4.0, is to automatically process massive amounts of data and accurately predict the RUL of bearings. This paper addresses the limitations of traditional data-driven prognostics, and presents a new method that integrates a deep belief network and a particle filter for RUL prediction of hybrid ceramic bearings. Real data collected from hybrid ceramic bearing run-to-failure tests were used to test and validate the integrated method. The performance of the integrated method was also compared with deep belief network and particle filter-based approaches. The validation and comparison results showed that RUL prediction performance using the integrated method was promising.
      PubDate: 2017-06-23
      DOI: 10.3390/app7070649
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 650: Effects of Fine Particles on Thermal
           Conductivity of Mixed Silica Sands

    • Authors: Jaehun Ahn, Jongwon Jung
      First page: 650
      Abstract: The physical properties of granular materials (such as hydraulic, strength, and thermal properties) are largely dependent on their density (or porosity) and particle size distribution. In infrastructure design, the thermal properties of soils are now more important than in the past. However, our understanding of the thermal properties of mixed granular materials is still poor. In this study, the thermal conductivity of silica sands with different porosities and particle sizes was experimentally investigated, based on ASTM D5334-14. The thermal conductivity of granular materials is presented as a function of the porosity and proportion of fine particles. The thermal conductivity tends to be low when the porosity is high and the proportion of fine particles is low (and vice versa). When the fine particles are small enough to fill the pore body of the larger particles, the coordination number increases; thus, the thermal conductivity increases when the proportion of fine particles is high. Therefore, both the porosity and particle size distribution should be carefully considered when the thermal conductivity of mixed silica sand is evaluated.
      PubDate: 2017-06-23
      DOI: 10.3390/app7070650
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 651: Early Diagnosis of Dementia from
           Clinical Data by Machine Learning Techniques

    • Authors: Aram So, Danial Hooshyar, Kun Park, Heui Lim
      First page: 651
      Abstract: Dementia is the most prevalent degenerative disease in seniors in which progression can be prevented or delayed by early diagnosis. In this study, we proposed a two-layer model inspired by the method used in dementia support centers for the early diagnosis of dementia and using machine learning techniques. Data were collected from patients who received dementia screening from 2008 to 2013 at the Gangbuk-Gu center for dementia in the Republic of Korea. The data consisted of the patient’s gender, age, education, the Mini-Mental State Examination in the Korean version of the CERAD Assessment Packet (MMSE-KC) for dementia screening test, and the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD-K) for the dementia precise test. In the proposed model, MMSE-KC data are initially classified into normal and abnormal. In the second stage, CERAD-K data are used to classify dementia and mild cognitive impairment. The performance of each algorithm is compared with that of Naive Bayes, Bayes Network, Begging, Logistic Regression, Random Forest, Support Vector Machine (SVM) and Multilayer Perceptron (MLP) using Precision, Recall and F-measure. Comparing the F-measure values of normal, mild cognitive impairment (MCI), and dementia, the MLP was the highest in the F-measure values of normal with 0.97, while the SVM appear to be the highest in MCI and dementia with 0.739. Using the proposed early diagnosis model for dementia reduces the time and economic burden and can help simplify the diagnosis method for dementia.
      PubDate: 2017-06-23
      DOI: 10.3390/app7070651
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 652: Fractal Prediction of Grouting Volume
           for Treating Karst Caverns along a Shield Tunneling Alignment

    • Authors: Wen-Chieh Cheng, Qing-Long Cui, Jack Shen, Arul Arulrajah, Da-Jun Yuan
      First page: 652
      Abstract: Karst geology is common in China, and buried karst formations are widely distributed in Guangdong province. In the process of shield tunneling, the abundant water resources present in karst caverns could lead to the potential for high water ingress, and a subsequent in situ stress change-induced stratum collapse. The development and distribution of karst caverns should therefore be identified and investigated prior to shield tunnel construction. Grouting is an efficient measure to stabilize karst caverns. The total volume of karst caverns along the shield tunneling alignment, and its relationship with the required volume of grouts, should be evaluated in the preliminary design phase. Conventionally, the total volume of karst caverns is empirically estimated based on limited geological drilling hole data; however, accurate results are rarely obtained. This study investigates the hydrogeology and engineering geology of Guangzhou, the capital of Guangdong province, and determines the fractal characteristics of the karst caverns along the tunnel section of Guangzhou metro line no. 9. The karst grouting coefficients (VR) were found to vary from 0.11 in the case of inadequate drilling holes to 1.1 in the case where adequate drilling holes are provided. A grouting design guideline was furthermore developed in this study for future projects in karst areas.
      PubDate: 2017-06-25
      DOI: 10.3390/app7070652
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 653: State-Population Narrowing Effect in
           Two-Photon Absorption for Intense Hard X-ray Pulses

    • Authors: Krzysztof Tyrała, Klaudia Wojtaszek, Marek Pajek, Yves Kayser, Christopher Milne, Jacinto Sá, Jakub Szlachetko
      First page: 653
      Abstract: We report on studies of state-populations during the two-photon absorption process using intense X-ray pulses. The calculations were performed in a time-dependent manner using a simple three-level model expressed by coupled rate equations. We show that the proposed approach describes well the measured rates of X-rays excited in the one-photon and two-photon absorption processes, and allows detailed investigation of the state population dynamics during the course of the incident X-ray pulse. Finally, we demonstrate that the nonlinear interaction of X-ray pulses with atoms leads to a time-narrowing of state populations. This narrowing-effect is attributed to a quadratic incidence X-ray intensity dependence characteristic for nonlinear interactions of photons with matter.
      PubDate: 2017-06-24
      DOI: 10.3390/app7070653
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 654: Virtual Inertia: Current Trends and
           Future Directions

    • Authors: Ujjwol Tamrakar, Dipesh Shrestha, Manisha Maharjan, Bishnu Bhattarai, Timothy Hansen, Reinaldo Tonkoski
      First page: 654
      Abstract: The modern power system is progressing from a synchronous machine-based system towards an inverter-dominated system, with large-scale penetration of renewable energy sources (RESs) like wind and photovoltaics. RES units today represent a major share of the generation, and the traditional approach of integrating them as grid following units can lead to frequency instability. Many researchers have pointed towards using inverters with virtual inertia control algorithms so that they appear as synchronous generators to the grid, maintaining and enhancing system stability. This paper presents a literature review of the current state-of-the-art of virtual inertia implementation techniques, and explores potential research directions and challenges. The major virtual inertia topologies are compared and classified. Through literature review and simulations of some selected topologies it has been shown that similar inertial response can be achieved by relating the parameters of these topologies through time constants and inertia constants, although the exact frequency dynamics may vary slightly. The suitability of a topology depends on system control architecture and desired level of detail in replication of the dynamics of synchronous generators. A discussion on the challenges and research directions points out several research needs, especially for systems level integration of virtual inertia systems.
      PubDate: 2017-06-26
      DOI: 10.3390/app7070654
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 655: Modified Godard Timing Recovery for
           Non Integer Oversampling Receivers

    • Authors: Arne Josten, Benedikt Baeuerle, Edwin Dornbierer, Jonathan Boesser, David Hillerkuss, Juerg Leuthold
      First page: 655
      Abstract: A timing recovery algorithm is introduced that operates with less than two samples per symbol and provides an enormous complexity reduction. The complexity reduction is due to a synergy with the already existing Fourier transforms in a coherent receiver, an avoidance of terms that are dominated by noise, and a complete elimination of multiplications. A simulation and an experiment with a single carrier modulation format show that the inherent timing jitter is, despite of the significant complexity reduction, comparable with the state of the art, and in particular outperforms the Godard algorithm for low roll-off factors. In addition, it is one of the few algorithms that operates with less than two samples per symbol in the frequency domain, and thus enables the lowest complexity in a receiver.
      PubDate: 2017-06-24
      DOI: 10.3390/app7070655
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 656: Higher‐Order Interactions in
           Quantum Optomechanics: Revisiting Theoretical Foundations

    • Authors: Sina Khorasani
      First page: 656
      Abstract: The theory of quantum optomechanics is reconstructed from first principles by finding a Lagrangian from light’s equation of motion and then proceeding to the Hamiltonian. The nonlinear terms, including the quadratic and higher‐order interactions, do not vanish under any possible choice of canonical parameters, and lead to coupling of momentum and field. The existence of quadratic mechanical parametric interaction is then demonstrated rigorously, which has been so far assumed phenomenologically in previous studies. Corrections to the quadratic terms are particularly significant when the mechanical frequency is of the same order or larger than the electromagnetic frequency. Further discussions on the squeezing as well as relativistic corrections are presented.
      PubDate: 2017-06-24
      DOI: 10.3390/app7070656
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 657: Laser and Electron Beam Additive
           Manufacturing Methods of Fabricating Titanium Bone Implants

    • Authors: Bartłomiej Wysocki, Piotr Maj, Ryszard Sitek, Joseph Buhagiar, Krzysztof Kurzydłowski, Wojciech Święszkowski
      First page: 657
      Abstract: Additive Manufacturing (AM) methods are generally used to produce an early sample or near net-shape elements based on three-dimensional geometrical modules. To date, publications on AM of metal implants have mainly focused on knee and hip replacements or bone scaffolds for tissue engineering. The direct fabrication of metallic implants can be achieved by methods, such as Selective Laser Melting (SLM) or Electron Beam Melting (EBM). This work compares the SLM and EBM methods used in the fabrication of titanium bone implants by analyzing the microstructure, mechanical properties and cytotoxicity. The SLM process was conducted in an environmental chamber using 0.4–0.6 vol % of oxygen to enhance the mechanical properties of a Ti-6Al-4V alloy. SLM processed material had high anisotropy of mechanical properties and superior UTS (1246–1421 MPa) when compared to the EBM (972–976 MPa) and the wrought material (933–942 MPa). The microstructure and phase composition depended on the used fabrication method. The AM methods caused the formation of long epitaxial grains of the prior β phase. The equilibrium phases (α + β) and non-equilibrium α’ martensite was obtained after EBM and SLM, respectively. Although it was found that the heat transfer that occurs during the layer by layer generation of the component caused aluminum content deviations, neither methods generated any cytotoxic effects. Furthermore, in contrast to SLM, the EBM fabricated material met the ASTMF136 standard for surgical implant applications.
      PubDate: 2017-06-26
      DOI: 10.3390/app7070657
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 658: Characteristics of GMAW Narrow Gap
           Welding on the Armor Steel of Combat Vehicles

    • Authors: Jae-Seong Kim, Hui-Jun Yi
      First page: 658
      Abstract: The primary purpose of this investigation was to study the characteristics of the armor steel weldment of combat vehicles by using GMAW narrow gap welding (NGW). The results showed that the mechanical properties and residual stress distribution of NGW weldment were improved, compared with conventional X-groove weldment. Additionally, ballistic tests according to MIL-HDBK-1941 were carried out to verify the ballistic ability of NGW weldment and the result showed that the NGW process was qualified for welding the armor steel of combat vehicle.
      PubDate: 2017-06-27
      DOI: 10.3390/app7070658
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 659: A Single Gyroscope Can Be Used to
           Accurately Determine Peak Eversion Velocity during Locomotion at Different
           Speeds and in Various Shoes

    • Authors: Christian Mitschke, Matthias Öhmichen, Thomas Milani
      First page: 659
      Abstract: Gyroscopes have been used in previous studies to measure the peak angular velocity of the shoe or foot in the frontal plane (evVel). However, it is not clear whether different test conditions (footwear hardness or locomotion speed) can influence the accuracy of evVel. The purpose of the present study was to compare the accuracy of gyroscopes and electrogoniometers when measuring evVel and the time until evVel (t_evVel) in 12 different conditions using a single axis gyroscope attached to the heel cap. Twenty-four recreational runners were instructed to walk and run on a 15-m indoor track at four locomotion speeds (1.5, 2.5, and 3.5 m/s, and individual running speed) and in three footwear conditions (low to high hardness). The gyroscope data and electrogoniometer data were sampled at a rate of 1000 Hz. Comparisons between both measurement devices showed small mean differences up to 49.8 ± 46.9 deg/s for evVel and up to 5.3 ± 3.5 ms for t_evVel. Furthermore, strong relationships between gyroscope and electrogoniometer data were found for evVel as well as for t_evVel for all conditions. It can be concluded that gyroscopes can be used to accurately determine evVel and t_evVel under a variety of conditions.
      PubDate: 2017-06-27
      DOI: 10.3390/app7070659
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 660: Differentiating Authentic Adenophorae
           Radix from Its Adulterants in Commercially-Processed Samples Using
           Multiplexed ITS Sequence-Based SCAR Markers

    • Authors: Byeong Moon, Wook Kim, Kyeong Han, Sungyu Yang, Youngmin Kang, Inkyu Park, Renzhe Piao
      First page: 660
      Abstract: Determining the precise botanical origin of a traditional herbal medicine is important for basic quality control. In both the Chinese and Korean herbal pharmacopoeia, authentic Adenophorae Radix is defined as the roots of Adenophora stricta and Adenophora triphylla. However, the roots of Codonopsis lanceolata, Codonopsis pilosula, and Glehnia littoralis are frequently distributed as Adenophorae Radix in Korean herbal markets. Unfortunately, correctly identifying dried roots is difficult using conventional methods because the roots of those species are morphologically similar. Therefore, we developed DNA-based markers for the identification of authentic Adenophorae Radix and its common adulterants in commercially-processed samples. To develop a reliable method to discriminate between Adenophorae Radix and its adulterants, we sequenced the nuclear ribosomal DNA internal transcribed spacers (nrDNA-ITS) and designed sequence-characterized amplified region (SCAR) primers specific to the authentic and adulterant species. Using these primers, we developed SCAR markers for each species and established a multiplex-PCR method that can authenticate the four herbal medicines in a single PCR reaction. Furthermore, we confirmed that commercially-processed herbal medicines, which often have degraded DNA, could be assessed with our method. Therefore, our method is a reliable genetic tool to protect against adulteration and to standardize the quality of Adenophorae Radix.
      PubDate: 2017-06-27
      DOI: 10.3390/app7070660
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 661: Double-Sided Terahertz Imaging of
           Multilayered Glass Fiber-Reinforced Polymer

    • Authors: Przemyslaw Lopato
      First page: 661
      Abstract: Polymer matrix composites (PMC) play important roles in modern industry. Increasing the number of such structures in aerospace, construction, and automotive applications enforces continuous monitoring of their condition. Nondestructive inspection of layered composite materials is much more complicated process than evaluation of homogenous, (mostly metallic) structures. Several nondestructive methods are utilized in this case (ultrasonics, shearography, tap testing, acoustic emission, digital radiography, infrared imaging) but none of them gives full description of evaluated structures. Thus, further development of NDT techniques should be studied. A pulsed terahertz method seems to be a good candidate for layered PMC inspection. It is based on picosecond electromagnetic pulses interacting with the evaluated structure. Differences of dielectric parameters enables detection of a particular layer in a layered material. In the case of multilayered structures, only layers close to surface can be detected. The response of deeper ones is averaged because of multiple reflections. In this paper a novel inspection procedure with a data processing algorithm is introduced. It is based on a double-sided measurement, acquired signal deconvolution, and data combining. In order to verify the application of the algorithm stress-subjected glass fiber-reinforced polymer (GFRP) was evaluated. The obtained results enabled detection and detailed analysis of delaminations introduced by stress treatment and proved the applicability of the proposed algorithm.
      PubDate: 2017-06-27
      DOI: 10.3390/app7070661
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 662: Measurement of the Resonant
           Magneto-Optical Kerr Effect Using a Free Electron Laser

    • Authors: Shingo Yamamoto, Iwao Matsuda
      First page: 662
      Abstract: We present a new experimental magneto-optical system that uses soft X-rays and describe its extension to time-resolved measurements using a free electron laser (FEL). In measurements of the magneto-optical Kerr effect (MOKE), we tune the photon energy to the material absorption edge and thus induce the resonance effect required for the resonant MOKE (RMOKE). The method has the characteristics of element specificity, large Kerr rotation angle values when compared with the conventional MOKE using visible light, feasibility for M-edge, as well as L-edge measurements for 3d transition metals, the use of the linearly-polarized light and the capability for tracing magnetization dynamics in the subpicosecond timescale by the use of the FEL. The time-resolved (TR)-RMOKE with polarization analysis using FEL is compared with various experimental techniques for tracing magnetization dynamics. The method described here is promising for use in femtomagnetism research and for the development of ultrafast spintronics.
      PubDate: 2017-06-27
      DOI: 10.3390/app7070662
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 663: Analysis of Land Cover Classification
           Using Multi-Wavelength LiDAR System

    • Authors: Tee-Ann Teo, Hsien-Ming Wu
      First page: 663
      Abstract: The airborne multi-wavelength light detection and ranging (LiDAR) system measures different wavelengths simultaneously and usually includes two or more active channels in infrared and green to acquire both topographic and hydrographic information. The reflected multi-wavelength energy can also be used to identify different land covers based on physical properties of materials. This study explored the benefits of multi-wavelength LiDAR in object-based land cover classification, focusing on three major issues: (1) the evaluation of single- and multi-wavelength LiDARs for land cover classification; (2) the performance of spectral and geometrical features extracted from multi-wavelength LiDAR; and (3) the comparison of the vegetation index derived from active multi-wavelength LiDAR and passive multispectral images. The three-wavelength test data were acquired by Optech Titan in green, near-infrared, and mid-infrared channels, and the reference data were acquired from Worldview-3 image. The experimental results show that the multi-wavelength LiDAR provided higher accuracy than single-wavelength LiDAR in land cover classification, with an overall accuracy improvement rate about 4–14 percentage points. The spectral features performed better compared to geometrical features for grass, road, and bare soil classes, and the overall accuracy improvement is about 29 percentage points. The results also demonstrated the vegetation indices from Worldview-3 and Optech Titan have similar characteristics, with correlations reaching 0.68 to 0.89. Overall, the multi-wavelength LiDAR system improves the accuracy of land cover classification because this system provides more spectral information than traditional single-wavelength LiDAR.
      PubDate: 2017-06-28
      DOI: 10.3390/app7070663
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 664: Investigation of Depth and Injection
           Pressure Effects on Breakdown Pressure and Fracture Permeability of Shale
           Reservoirs: An Experimental Study

    • Authors: Wanniarachchillage Wanniarachchi, Ranjith Gamage, Mandadige Perera, Tharaka Rathnaweera, Mingzhong Gao, Eswaran Padmanabhan
      First page: 664
      Abstract: The aim of this study was to identify the influence of reservoir depth on reservoir rock mass breakdown pressure and the influence of reservoir depth and injecting fluid pressure on the flow ability of reservoirs before and after the hydraulic fracturing process. A series of fracturing tests was conducted under a range of confining pressures (1, 3, 5 and 7 MPa) to simulate various depths. In addition, permeability tests were conducted on intact and fractured samples under 1 and 7 MPa confining pressures to determine the flow characteristic variations upon fracturing of the reservoir, depending on the reservoir depth and injecting fluid pressure. N2 permeability was tested under a series of confining pressures (5, 10, 15, 20 and 25 MPa) and injection pressures (1–10 MPa). According to the results, shale reservoir flow ability for gas movement may reduce with increasing injection pressure and reservoir depth, due to the Klinkenberg phenomenon and pore structure shrinkage, respectively. The breakdown pressure of the reservoir rock linearly increases with increasing reservoir depth (confining pressure). Interestingly, 81% permeability reduction was observed in the fractured rock mass due to high (25 MPa) confinement, which shows the importance of proppants in the fracturing process.
      PubDate: 2017-06-28
      DOI: 10.3390/app7070664
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 665: Barriers and Chemistry in a Bottle:
           Mechanisms in Today’s Oxygen Barriers for Tomorrow’s Materials

    • Authors: Youri Michiels, Peter Puyvelde, Bert Sels
      First page: 665
      Abstract: The stability of many organic compounds is challenged by oxidation reactions with molecular oxygen from the air in accordance with thermodynamics. Whereas glass or metal containers may protect such products, these packaging types also offer severe disadvantages over plastics. Large-scale packaging, especially for food and beverage industries, has shifted towards polymeric materials with passive and active oxygen barrier technologies over the last decades. Even though patent literature is flooded with innovative barrier systems, the mechanisms behind them are rarely reported. In a world where packaging requirements regarding recyclability and safety are continuously getting stricter, accompanied by the appearance of emerging applications for plastic oxygen barriers (such as organic semi-conductors), research towards new materials seems inevitable. To this cause, proper in-depth knowledge of the existing solutions is a prerequisite. This review therefore attempts to go deep into the problems at hand and explain the chemistry behind the existing solution strategies and finally discusses perspectives suggesting new applications such as organic light-emitting diodes (OLEDs) and solar cells.
      PubDate: 2017-06-28
      DOI: 10.3390/app7070665
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 666: Auditory Distance Control Using a
           Variable-Directivity Loudspeaker

    • Authors: Florian Wendt, Franz Zotter, Matthias Frank, Robert Höldrich
      First page: 666
      Abstract: The directivity of a sound source in a room influences the D/R ratio and thus the auditory distance. This study proposes various third-order beampattern pattern designs for a precise control of the D/R ratio. A comprehensive experimental study is conducted to investigate the hereby achieved effect on the auditory distance. Our first experiment auralizes the directivity variations using a virtual directional sound source in a virtual room using playback by a 24-channel loudspeaker ring. The experiment moreover shows the influence of room, source-listener distance, signal, and additional single-channel reverberation on the auditory distance. We verify the practical applicability of all the proposed beampattern pattern designs in a second experiment using a variable-directivity sound source in a real room. Predictions of experimental results are made with high accuracy, using room acoustical measures that typically predict the apparent source width.
      PubDate: 2017-06-29
      DOI: 10.3390/app7070666
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 667: Impact of Cryogenic Condition and
           Drill Diameter on Drilling Performance of CFRP

    • Authors: Gültekin Basmaci, A. Yoruk, Ugur Koklu, Sezer Morkavuk
      First page: 667
      Abstract: Machining of carbon fiber-reinforced polymer (CFRP) is a rather hard task due to the inhomogeneity and anisotropy of this material. Several defects occur in the material when CFRP is machined and machining quality deteriorates owing to these material properties. In recent years, liquid nitrogen has been considered an environmentally safe, clean, and non-toxic coolant used to cut various materials in order to enhance machinability and prevent damage during machining. In this study, a new, eco-friendly cryogenic machining technique called dipped cryogenic machining was applied for the drilling of CFRP. This experimental study investigated the effect of feed rate and drill diameter on the thrust force, delamination factor, surface quality and drill wear. Machined surfaces were analyzed in detail using a scanning electron microscope and atomic force microscope. Results indicated that the drilling of CFRP with the dipped cryogenic machining approach greatly improved machinability by reducing the surface roughness of the drilled parts and tool wear. However, it increased the thrust force and delamination factor.
      PubDate: 2017-06-29
      DOI: 10.3390/app7070667
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 668: Adaptive Neuro-Fuzzy Inference System
           Model Based on the Width and Depth of the Defect in an Eddy Current Signal
           

    • Authors: Moneer Faraj, Fahmi Samsuri, Ahmed Abdalla, Damhuji Rifai, Kharudin Ali
      First page: 668
      Abstract: Non-destructive evaluation (NDE) plays an important role in many industrial fields, such as detecting cracking in steam generator tubing in nuclear power plants and aircraft. This paper investigates on the effect of the depth of the defect, width of the defect, and the type of the material on the eddy current signal which is modeled by an adaptive neuro-fuzzy inference system (ANFIS). A total of 60 samples of artificial defects are located 20 mm parallel to the length of the block in each of the three types of material. A weld probe was used to inspect the block. The ANFIS model has three neurons in the input layer and one neuron in the output layer as the eddy current signal. The used design of experiments (DOE) software indicates that the model equations, which contain only linear and two-factor interaction terms, were developed to predict the percentage signal. This signal was validated through the use of the unseen data. The predicted results on the depth and width of defect significantly influenced the percentage of the signal (p < 0.0001) at the 95% confidence level. The ANFIS model proves that the deviation of the eddy current testing measurement was influenced by the width and depth of the defect less than the conductivity of the materials.
      PubDate: 2017-06-29
      DOI: 10.3390/app7070668
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 669: Sampietrini Stone Pavements: Distress
           Analysis Using Pavement Condition Index Method

    • Authors: Pablo Zoccali, Giuseppe Loprencipe, Andrea Galoni
      First page: 669
      Abstract: In several Italian cities, it is possible to find historical pavements such as the Sampietrini pavements, which are mainly located in the center of the city of Rome. The Sampietrini pavement is a particular road surface paved in natural stone with irregular sharp elements that are assembled by hand with the evident not plan effect. Because of their peculiarities, they are not suitable for streets where high speed is allowed. In many cases, high vibration and noise levels due to road traffic traveling on Sampietrini pavements are caused by inadequate maintenance, which is also affected by the absence of specific evaluation criteria regarding surface conditions and performances of Sampietrini pavements. It is not possible, in fact, to adopt common approaches developed to be used for flexible and rigid pavements, because they present completely different features and distresses. In this paper, to overpass this problem, a new evaluation criterion based on Pavement Condition Index (PCI) method established for block pavements is proposed. Furthermore, to fully characterize this kind of pavements, other analyses, i.e., International Roughness Index (IRI) and comfort level evaluation based on ISO 2631 standard, were also carried out. The results showed a good correlation between PCI and IRI approaches (R2 = 0.82), also highlighting that new or reconstructed Sampietrini pavements present not negligible roughness level. This aspect was also confirmed estimating the comfort level perceived by users traveling at several speeds (≤50 km/h). Finally, speed related threshold values to be adopted for PCI and IRI methods are proposed. The proposed method can be implemented by pavement managers in a PMS ad hoc for stone block paving and thus, it can be integrated with other equivalents methods of visual inspection based on PCI.
      PubDate: 2017-06-29
      DOI: 10.3390/app7070669
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 670: Ambient Light Rejection Using a Novel
           Average Voltage Tracking in Visible Light Communication System

    • Authors: Quan Pham, Vega Rachim, Jinyoung An, Wan-Young Chung
      First page: 670
      Abstract: The quality of a received signal is one of the most important factors to be considered when designing a receiver for visible light communication (VLC) systems. Therefore, it is necessary to evaluate the robustness of the VLC receiver circuit in low-signal-to-noise ratio (SNR) communication. The SNR is the quantity characterized by the ratio of the signal power to the noise power of the received signal. The noise generates an offset voltage and distorts the desired signal waveform. Thus, a low SNR makes it difficult to retrieve the data. Among the sources of noise, ambient light has the most negative impact on the VLC data signal. Therefore, the novel receiver proposed by us acts as an ambient light rejection circuit. As our average-voltage tracking circuit is insensitive to the sunlight and indoor fluorescent light, our design could be a solution to enhance the performance of low-SNR VLC systems. Several experiments are conducted using light of same intensity, but with different distances and semi-angles. Experimental results demonstrate that robust interference rejection is possible to send an error-free communication with an On-Off Keying modulation base on microcontroller up to 1 Mbps at an SNR of −2.7 dB.
      PubDate: 2017-06-29
      DOI: 10.3390/app7070670
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 671: Probing Physics in Vacuum Using an
           X-ray Free-Electron Laser, a High-Power Laser, and a High-Field Magnet

    • Authors: Toshiaki Inada, Takayuki Yamazaki, Tomohiro Yamaji, Yudai Seino, Xing Fan, Shusei Kamioka, Toshio Namba, Shoji Asai
      First page: 671
      Abstract: A nonlinear interaction between photons is observed in a process that involves charge sources. To observe this process in a vacuum, there are a growing number of theoretical and experimental studies. This process may contain exotic contribution from new physics beyond the Standard Model of particle physics, and is probed by experiments using a high-power laser or a high-field magnet, and more recently using an X-ray free-electron laser (XFEL). Here, we review the present status of our experiments testing various vacuum processes. We describe four experiments with a focus on those using an XFEL: (i) photon–photon scattering in the X-ray region, (ii) laser-induced birefringence and diffraction of X rays, (iii) vacuum birefringence induced by a high-field magnet, and (iv) a dedicated search for axion-like particles using the magnet and X rays.
      PubDate: 2017-06-29
      DOI: 10.3390/app7070671
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 672: Numerical Calculation of the
           Performance of a Thermoacoustic System with Engine and Cooler Stacks in a
           Looped Tube

    • Authors: Irna Farikhah, Yuki Ueda
      First page: 672
      Abstract: The performance of a thermoacoustic system that is composed of a looped tube, an engine stack, a cooler stack, and four heat exchangers, is numerically investigated. Each stack has narrow flow channels, is sandwiched by two heat exchangers, and is located in the looped tube. In order to provide a design guide, the performance of the system is numerically calculated by changing the following three parameters: the radius of the flow channels in the engine stack, the radius of the flow channels in the cooler stack, and the relative position of the cooler stack. It was found that when the three parameters are optimized, the efficiency of the engine stack reaches 75% of Carnot’s efficiency and the coefficient of the performance (COP) of the cooler stack is 53% of Carnot’s COP, whereas 33% of the acoustic power generated by the engine stack is utilized in the cooler stack.
      PubDate: 2017-06-30
      DOI: 10.3390/app7070672
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 673: Numerical Predictions of Early Stage
           Turbulence in Oscillatory Flow across Parallel-Plate Heat Exchangers of a
           Thermoacoustic System

    • Authors: Fatimah Mohd Saat, Artur Jaworski
      First page: 673
      Abstract: This work focuses on the predictions of turbulent transition in oscillatory flow subjected to temperature gradients, which often occurs within heat exchangers of thermoacoustic devices. A two-dimensional computational fluid dynamics (CFD) model was developed in ANSYS FLUENT and validated using the earlier experimental data. Four drive ratios (defined as maximum pressure amplitude to mean pressure) were investigated: 0.30%, 0.45%, 0.65% and 0.83%. It has been found that the introduction of the turbulence model at a drive ratio as low as 0.45% improves the predictions of flow structure compared to experiments, which indicates that turbulent transition may occur at much smaller flow amplitudes than previously thought. In the current investigation, the critical Reynolds number based on the thickness of Stokes’ layer falls in the range between 70 and 100. The models tested included four variants of the RANS (Reynolds-Averaged Navier–Stokes) equations: k-ε, k-ω, shear-stress-transport (SST)-k-ω and transition-SST, the laminar model being used as a reference. Discussions are based on velocity profiles, vorticity plots, viscous dissipation and the resulting heat transfer and their comparison with experimental results. The SST-k-ω turbulence model and, in some cases, transition-SST provide the best fit of the velocity profile between numerical and experimental data (the value of the introduced metric measuring the deviation of the CFD velocity profiles from experiment is up to 43% lower than for the laminar model) and also give the best match in terms of calculated heat flux. The viscous dissipation also increases with an increase of the drive ratio. The results suggest that turbulence should be considered when designing thermoacoustic devices even in low-amplitude regimes in order to improve the performance predictions of thermoacoustic systems.
      PubDate: 2017-06-30
      DOI: 10.3390/app7070673
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 674: Toward Defect Engineering Strategies
           to Optimize Energy and Electronic Materials

    • Authors: Efstratia Sgourou, Yerasimos Panayiotatos, Ruslan Vovk, Alexander Chroneos
      First page: 674
      Abstract: The technological requirement to optimize materials for energy and electronic materials has led to the use of defect engineering strategies. These strategies take advantage of the impact of composition, disorder, structure, and mechanical strain on the material properties. In the present review, we highlight key strategies presently employed or considered to tune the properties of energy and electronic materials. We consider examples from electronic materials (silicon and germanium), photocatalysis (titanium oxide), solid oxide fuel cells (cerium oxide), and nuclear materials (nanocomposites).
      PubDate: 2017-06-30
      DOI: 10.3390/app7070674
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 675: Synergetic of PALSAR-2 and
           Sentinel-1A SAR Polarimetry for Retrieving Aboveground Biomass in
           Dipterocarp Forest of Malaysia

    • Authors: Hamdan Omar, Muhamad Misman, Abd Kassim
      First page: 675
      Abstract: Space borne synthetic aperture radar (SAR) data have become one of the primary sources for aboveground biomass (AGB) estimation of forests. However, studies have indicated that limitations occur when a single sensor system is employed, especially in tropical forests. Hence, there is potential for improving estimates if two or more different sensor systems are used. Studies on integrating multiple sensor systems for estimation of AGB over Malaysia’s tropical forests are scarce. This study investigated the use of PALSAR-2 L-band and Sentinel-1A C-band SAR polarizations to estimates the AGB over 5.25 million ha of the lowland, hill, and upper hill forests in Peninsular Malaysia. Polarized images, i.e., HH–HV from PALSAR-2 and VV–VH from Sentinel-1A have been utilized to produce several variables for predictions of the AGB. Simple linear and multiple linear regression analysis was performed to identify the best predictor. The study concluded that although limitations exist in the estimates, the combination of all polarizations from both PALSAR-2 and Sentiel-1A SAR data able to increase the accuracy and reduced the root means square error (RMSE) up to 14 Mg ha−1 compared to the estimation resulted from single polarization. A spatially distributed map of AGB reported the total AGB within the study area was about 1.82 trillion Mg of the year 2016.
      PubDate: 2017-06-30
      DOI: 10.3390/app7070675
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 676: Risk Analysis of a Two-Level Supply
           Chain Subject to Misplaced Inventory

    • Authors: Lijing Zhu, Chulung Lee
      First page: 676
      Abstract: Misplaced inventory is prevalent in retail stores and may lead to the overall poor performance of the supply chain. We explore the impact of misplaced inventory on a two-level supply chain, which consists of a risk-neutral supplier and a risk-averse retailer. The supplier decides the wholesale price to maximize her profit, whereas the retailer decides the order quantity to maximize his utility. Under the Conditional Value-at-Risk (CVaR) criterion, we formulate the problem as a Stackelberg game model and obtain the equilibrium solutions in three cases: (i) information asymmetry about inventory errors exists; (ii) the retailer shares information about inventory errors with the supplier; and (iii) in order to reduce misplaced inventory, the supply chain deploys Radio-Frequency Identification (RFID) technology. The benefits of information sharing and RFID implementation are explored. A revenue and cost sharing contract is proposed to coordinate the supply chain and to allocate the cost savings from RFID implementation among supply chain participants. Finally, we provide managerial insights for risk-averse decision makers that are considering investing in the RFID technology.
      PubDate: 2017-06-30
      DOI: 10.3390/app7070676
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 677: The Vertical Dynamic Properties of
           Flexible Footbridges under Bipedal Crowd Induced Excitation

    • Authors: Yan-an Gao, Juan Wang, Min Liu
      First page: 677
      Abstract: The excessive vibration of footbridges caused by walking pedestrians has generated great public concern in recent years. However, it has not been explored how crowd size quantitatively influences structural dynamic properties, including human dynamic properties. This paper provides an alternative method for understanding how crowds excite the excessive sway motion of a large-span structure when walking on it. In this study, pedestrians are modeled by a walking dynamic bipedal system. The crowd-structure system is established based on the bipedal model, for which the dynamic properties from pedestrians are considered. The vertical dynamic property equations of structure are calculated under crowd-induced vibration, based on the assumption of a uniformly distributed crowd. Through the proposed framework, the changes of frequency and damping of structure induced by walking pedestrians are studied. The increase of the crowd size can reduce structural frequency, but increase its damping. The impact tendency of crowd size on structural dynamic properties is consistent with measured results. This research provides insight as to how crowd size quantitatively influences the change of structural dynamic properties.
      PubDate: 2017-07-01
      DOI: 10.3390/app7070677
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 678: Effects of Tooth Breakage Size and
           Rotational Speed on the Vibration Response of a Planetary Gearbox

    • Authors: Wenguang Yang, Dongxiang Jiang, Te Han
      First page: 678
      Abstract: A nonlinear dynamic model for a planetary gearbox with tooth breakage fault is built based on an improved rigid multibody model, and the effects of tooth breakage size and rotational speed on the vibration response of the planetary gearbox are investigated numerically and experimentally. A time-varying mesh stiffness model of planetary gears with tooth breakage fault is established. Dynamic simulations of a healthy planetary gear and seven fault gears with different breakage sizes under several rotational speeds are carried out. Experiments for healthy, half tooth breakage fault and whole tooth breakage fault planetary gears under several rotational speeds are performed. Amplitude analysis, spectrum analysis and envelope spectrum analysis are applied on the numerical and experimental vibration signals. The dynamic model is validated by experiment. The analysis results reveal the resonance and modulation characteristics in the vibration response, and the law of the vibration changes with breakage size and rotational speed.
      PubDate: 2017-07-01
      DOI: 10.3390/app7070678
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 679: Numerical Investigation of
           Heat-Insulating Layers in a Cold Region Tunnel, Taking into Account
           Airflow and Heat Transfer

    • Authors: Qixiang Yan, Binjia Li, Yanyang Zhang, Jian Yan, Chuan Zhang
      First page: 679
      Abstract: In cold regions, heat-insulating layers play a crucial role in frost prevention in tunnels. This paper presents a numerical study on the anti-freezing behavior of a cold region tunnel (the Dege tunnel) with heat-insulating layers. A numerical model based on the temperature field coupling theory is firstly proposed and validated using field test data of the Dege tunnel. Subsequently, a comprehensive parametric study is carried out to investigate the influences of heat-insulating layers on the temperature characteristics of airflows inside the tunnel, the surrounding rock, and the tunnel lining. Furthermore, a numerical investigation based on the proposed numerical model is carried out to propose reasonable design parameters of heat-insulating layers for different velocities of mechanical ventilation, and different heat-insulating materials for cold region tunnels. The numerical results show that using the heat-insulating layer can effectively reduce the heat transfer between the surrounding rock and the airflow inside the tunnel. It is also found that the design parameters for the heat-insulating layer are greatly affected by the tunnel ventilation conditions and heat-insulating materials.
      PubDate: 2017-07-01
      DOI: 10.3390/app7070679
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 680: Robust Co-Optimization to Energy and
           Reserve Joint Dispatch Considering Wind Power Generation and Zonal Reserve
           Constraints in Real-Time Electricity Markets

    • Authors: Chunlai Li, Jingyang Yun, Tao Ding, Fan Liu, Yuntao Ju, Shun Yuan
      First page: 680
      Abstract: This paper proposes an energy and reserve joint dispatch model based on a robust optimization approach in real-time electricity markets, considering wind power generation uncertainties as well as zonal reserve constraints under both normal and N-1 contingency conditions. In the proposed model, the operating reserves are classified as regulating reserve and spinning reserve according to the response performance. More specifically, the regulating reserve is usually utilized to reduce the gap due to forecasting errors, while the spinning reserve is commonly adopted to enhance the ability for N-1 contingencies. Since the transmission bottlenecks may inhibit the deliverability of reserve, the zonal placement of spinning reserve is considered in this paper to improve the reserve deliverability under the contingencies. Numerical results on the IEEE 118-bus test system show the effectiveness of the proposed model.
      PubDate: 2017-07-01
      DOI: 10.3390/app7070680
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 681: Observing Femtosecond Fragmentation
           Using Ultrafast X-ray-Induced Auger Spectra

    • Authors: Thomas Wolf, Fabian Holzmeier, Isabella Wagner, Nora Berrah, Christoph Bostedt, John Bozek, Phil Bucksbaum, Ryan Coffee, James Cryan, Joe Farrell, Raimund Feifel, Todd Martinez, Brian McFarland, Melanie Mucke, Saikat Nandi, Francesco Tarantelli, Ingo Fischer, Markus Gühr
      First page: 681
      Abstract: Molecules often fragment after photoionization in the gas phase. Usually, this process can only be investigated spectroscopically as long as there exists electron correlation between the photofragments. Important parameters, like their kinetic energy after separation, cannot be investigated. We are reporting on a femtosecond time-resolved Auger electron spectroscopy study concerning the photofragmentation dynamics of thymine. We observe the appearance of clearly distinguishable signatures from thymine′s neutral photofragment isocyanic acid. Furthermore, we observe a time-dependent shift of its spectrum, which we can attribute to the influence of the charged fragment on the Auger electron. This allows us to map our time-dependent dataset onto the fragmentation coordinate. The time dependence of the shift supports efficient transformation of the excess energy gained from photoionization into kinetic energy of the fragments. Our method is broadly applicable to the investigation of photofragmentation processes.
      PubDate: 2017-07-01
      DOI: 10.3390/app7070681
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 682: Computer Color Matching and Levelness
           of PEG-Based Reverse Micellar Decamethyl cyclopentasiloxane (D5)
           Solvent-Assisted Reactive Dyeing on Cotton Fiber

    • Authors: Alan Tang, Yan Wang, Chang Lee, Chi-Wai Kan
      First page: 682
      Abstract: The color matching and levelness of cotton fabrics dyed with reactive dye, in a non-aqueous environmentally-friendly medium of decamethylcyclopentasiloxane (D5), was investigated using the non-ionic surfactant reverse-micellar approach comprised of poly(ethylene glycol)-based surfactant. The calibration dyeing databases for both conventional water-based dyeing and D5-assisted reverse micellar dyeing were established, along with the dyeing of standard samples with predetermined concentrations. Computer color matching (CCM) was conducted by using different color difference formulae for both dyeing methods. Experimental results reveal that the measured concentrations were nearly the same as the expected concentrations for both methods. This indicates that the D5-assisted non-ionic reverse micellar dyeing approach can achieve color matching as good as the conventional dyeing system. The levelness of the dyed samples was measured according to the relative unlevelness indices (RUI), and the results reveal that the samples dyed by the D5 reverse micellar dyeing system can achieve good to excellent levelness comparable to that of the conventional dyeing system.
      PubDate: 2017-07-02
      DOI: 10.3390/app7070682
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 683: Data Mining Approaches for Landslide
           Susceptibility Mapping in Umyeonsan, Seoul, South Korea

    • Authors: Sunmin Lee, Moung-Jin Lee, Hyung-Sup Jung
      First page: 683
      Abstract: The application of data mining models has become increasingly popular in recent years in assessments of a variety of natural hazards such as landslides and floods. Data mining techniques are useful for understanding the relationships between events and their influencing variables. Because landslides are influenced by a combination of factors including geomorphological and meteorological factors, data mining techniques are helpful in elucidating the mechanisms by which these complex factors affect landslide events. In this study, spatial data mining approaches based on data on landslide locations in the geographic information system environment were investigated. The topographical factors of slope, aspect, curvature, topographic wetness index, stream power index, slope length factor, standardized height, valley depth, and downslope distance gradient were determined using topographical maps. Additional soil and forest variables using information obtained from national soil and forest maps were also investigated. A total of 17 variables affecting the frequency of landslide occurrence were selected to construct a spatial database, and support vector machine (SVM) and artificial neural network (ANN) models were applied to predict landslide susceptibility from the selected factors. In the SVM model, linear, polynomial, radial base function, and sigmoid kernels were applied in sequence; the model yielded 72.41%, 72.83%, 77.17% and 72.79% accuracy, respectively. The ANN model yielded a validity accuracy of 78.41%. The results of this study are useful in guiding effective strategies for the prevention and management of landslides in urban areas.
      PubDate: 2017-07-02
      DOI: 10.3390/app7070683
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 684: Robustness Analysis of the Collective
           Nonlinear Dynamics of a Periodic Coupled Pendulums Chain

    • Authors: Khaoula Chikhaoui, Diala Bitar, Najib Kacem, Noureddine Bouhaddi
      First page: 684
      Abstract: Perfect structural periodicity is disturbed in presence of imperfections. The present paper is based on a realistic modeling of imperfections, using uncertainties, to investigate the robustness of the collective nonlinear dynamics of a periodic coupled pendulums chain. A generic discrete analytical model combining multiple scales method and standing-wave decomposition is proposed. To propagate uncertainties through the established model, the generalized Polynomial Chaos Expansion is used and compared to the Latin Hypercube Sampling method. Effects of uncertainties are investigated on the stability and nonlinearity of two and three coupled pendulums chains. Results prove the satisfying approximation given by the generalized Polynomial Chaos Expansion for a significantly reduced computational time, with respect to the Latin Hypercube Sampling method. Dispersion analysis of the frequency responses show that the nonlinear aspect of the structure is strengthened, the multistability domain is wider, more stable branches are obtained and thus multimode solutions are enhanced. More fine analysis is allowed by the quantification of the variability of the attractors’ contributions in the basins of attraction. Results demonstrate benefits of presence of imperfections in such periodic structure. In practice, imperfections can be functionalized to generate energy localization suitable for several engineering applications such as vibration energy harvesting.
      PubDate: 2017-07-03
      DOI: 10.3390/app7070684
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 685: A 3D Human Skeletonization Algorithm
           for a Single Monocular Camera Based on Spatial–Temporal Discrete Shadow
           Integration

    • Authors: Jie Hou, Baolong Guo, Wangpeng He, Jinfu Wu
      First page: 685
      Abstract: Three-dimensional (3D) human skeleton extraction is a powerful tool for activity acquirement and analyses, spawning a variety of applications on somatosensory control, virtual reality and many prospering fields. However, the 3D human skeletonization relies heavily on RGB-Depth (RGB-D) cameras, expensive wearable sensors and specific lightening conditions, resulting in great limitation of its outdoor applications. This paper presents a novel 3D human skeleton extraction method designed for the monocular camera large scale outdoor scenarios. The proposed algorithm aggregates spatial–temporal discrete joint positions extracted from human shadow on the ground. Firstly, the projected silhouette information is recovered from human shadow on the ground for each frame, followed by the extraction of two-dimensional (2D) joint projected positions. Then extracted 2D joint positions are categorized into different sets according to activity silhouette categories. Finally, spatial–temporal integration of same-category 2D joint positions is carried out to generate 3D human skeletons. The proposed method proves accurate and efficient in outdoor human skeletonization application based on several comparisons with the traditional RGB-D method. Finally, the application of the proposed method to RGB-D skeletonization enhancement is discussed.
      PubDate: 2017-07-03
      DOI: 10.3390/app7070685
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 686: Bonded-Particle Model with Nonlinear
           Elastic Tensile Stiffness for Rock-Like Materials

    • Authors: Yiping Ouyang, Qi Yang, Xinquan Chen
      First page: 686
      Abstract: The bonded-particle model (BPM) is a very efficient numerical method in dealing with initiation and propagation of cracks in rocks and can model the fracture processes and most of macro parameters of rocks well. However, typical discrete element method (DEM) underestimates the ratio of the uniaxial compressive strength to the tensile strength (UCS/TS). In this paper, a new DEM method with a nonlinear elastic tensile model embedded in BPM is proposed, which is named as nonlinear elastic tensile bonded particle model (NET-BPM). The relationships between micro parameters in NET-BPM and macro parameters of specimens are investigated by simulating uniaxial compression tests and direct tension tests. The results show that both the shape coefficient of the nonlinear elastic model and the bond width coefficient are important in predicting the value of UCS/TS, whose value ranging from 5 to 45 was obtained in our simulations. It is shown that the NET-BPM model is able to reproduce the nonlinear behavior of hard rocks such as Lac du Bonnet (LDB) granite and the quartzite under tension and the ratio of compressive Young’s modulus to tensile Young’s modulus higher than 1.0. Furthermore, the stress-strain curves in the simulations of LDB granite and the quartzite with NET-BPM model are in good agreement with the experimental results. NET-BPM is proved to be a very suitable method for modelling the deformation and fracture of rock-like materials.
      PubDate: 2017-07-04
      DOI: 10.3390/app7070686
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 687: Can OCT Angiography Be Made a
           Quantitative Blood Measurement Tool'

    • Authors: Jun Zhu, Conrad Merkle, Marcel Bernucci, Shau Chong, Vivek Srinivasan
      First page: 687
      Abstract: Optical Coherence Tomography Angiography (OCTA) refers to a powerful class of OCT scanning protocols and algorithms that selectively enhance the imaging of blood vessel lumens, based mainly on the motion and scattering of red blood cells (RBCs). Though OCTA is widely used in clinical and basic science applications for visualization of perfused blood vessels, OCTA is still primarily a qualitative tool. However, more quantitative hemodynamic information would better delineate disease mechanisms, and potentially improve the sensitivity for detecting early stages of disease. Here, we take a broader view of OCTA in the context of microvascular hemodynamics and light scattering. Paying particular attention to the unique challenges presented by capillaries versus larger supplying and draining vessels, we critically assess opportunities and challenges in making OCTA a quantitative tool.
      PubDate: 2017-07-04
      DOI: 10.3390/app7070687
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 688: Frequency Regulation of Power Systems
           with Self-Triggered Control under the Consideration of Communication Costs
           

    • Authors: Zhiqin Zhu, Jian Sun, Guanqiu Qi, Yi Chai, Yinong Chen
      First page: 688
      Abstract: In control systems of power grids, conveying observations to controllers and obtaining control outputs depend greatly on communication and computation resources. Particularly for large-scale systems, the costs of computation and communication (cyber costs) should not be neglected. This paper proposes a self-triggered frequency control system for a power grid to reduce communication costs. An equation for obtaining the triggering time is derived, and an approximation method is proposed to reduce the computation cost of triggering time. In addition, the communication cost of frequency triggering is measured quantitatively and proportionally. The defined cost function considers both physical cost (electricity transmission cost) and communication cost (control signal transmission cost). The upper bound of cost is estimated. According to the estimated upper bound of cost, parameters of the controller are investigated by using the proposed optimization algorithm to guarantee the high performance of the system. Finally, the proposed self-triggered power system is simulated to verify its efficiency and effectiveness.
      PubDate: 2017-07-04
      DOI: 10.3390/app7070688
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 689: Switched 4-to-1 Transimpedance
           Combining Amplifier for Receiver Front-End Circuit of Static Unitary
           Detector-Based LADAR System

    • Authors: Eun-Gyu Lee, Jae-Eun Lee, Bang Jung, Bongki Mheen, Choul-Young Kim
      First page: 689
      Abstract: Laser detection and ranging (LADAR) systems are commonly used to acquire real-time three-dimensional (3D) images using the time-of-flight of a short laser pulse. A static unitary detector (STUD)-based LADAR system is a simple method for obtaining real-time high-resolution 3D images. In this study, a switched 4-to-1 transimpedance combining amplifier (TCA) is implemented as a receiver front-end readout integrated circuit for the STUD-based LADAR system. The 4-to-1 TCA is fabricated using a standard 0.18 μm complementary metal-oxide-semiconductor (CMOS) technology, and it consists of four independent current buffers, a two-stage signal combiner, a balun, and an output buffer in one single integrated chip. In addition, there is a switch on each input current path to expand the region of interest with multiple photodetectors. The core of the TCA occupies an area of 92 μm × 68 μm, and the die size including I/O pads is 1000 μm × 840 μm. The power consumption of the fabricated chip is 17.8 mW for a supplied voltage of 1.8 V and a transimpedance gain of 67.5 dBΩ. The simulated bandwidth is 353 MHz in the presence of a 1 pF photodiode parasitic capacitance for each photosensitive cell.
      PubDate: 2017-07-04
      DOI: 10.3390/app7070689
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 690: Discrimination of Aortic and
           Pulmonary Components from the Second Heart Sound Using Respiratory
           Modulation and Measurement of Respiratory Split

    • Authors: Hong Tang, Huaming Chen, Ting Li
      First page: 690
      Abstract: The second heart sound consists of aortic and pulmonary components. Analysis on the changes of the second heart sound waveform in respiration shows that the aortic component has little variation and the delay of the pulmonary component is modulated by respiration. This paper proposes a novel model to discriminate the aortic and pulmonary components using respiratory modulation. It is found that the aortic component could be simply extracted by averaging the second heart sounds over respiratory phase, and the pulmonary component could be extracted by subtraction. Hence, the split is measured by the timing difference of the two components. To validate the measurement, the method is applied to simulated second heart sounds with known varying splits. The simulation results show that the aortic and pulmonary components can be successfully extracted and the measured splits are close to the predefined splits. The method is further evaluated by data collected from 12 healthy subjects. Experimental results show that the respiratory split can be accurately measured. The minimum split generally occurs at the end of expiration and the split value is about 20 ms. Meanwhile, the maximum split is about 50 ms at the end of inspiration. Both the trend of split varying with respect to respiratory phase and the numerical range of split varying are comparable to the results disclosed by previous physiologists. The proposed method is compared to the two previous well known methods. The most attractive advantage of the proposed method is much less complexity. This method has potential applications in monitoring heart hemodynamic response to respiration.
      PubDate: 2017-07-04
      DOI: 10.3390/app7070690
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 691: Emotion-Based Classification and
           Indexing for Wallpaper and Textile

    • Authors: Yuan-Yuan Su, Hung-Min Sun
      First page: 691
      Abstract: This study, based on human emotions and visual impression, develops a novel framework of classification and indexing for wallpaper and textiles. This method allows users to obtain a number of similar images that can be corresponded to a specific emotion by indexing through a reference image or an emotional keyword. In addition, a predefined color–emotion model is applied to deal with the transference between emotions and colors in the paper. Besides color and emotion, the other significant feature for indexing is texture. Therefore, two features—the main colors (the representative colors) and the foreground complexity of a color image—are adopted in the method. The foreground complexity (a pattern complexity) is also called the texture of the pattern in an image. Another contribution of this study is the new algorithms of Touch Four Sides (TFS) and Touch Up Sides (TUS), which can aid in extracting an accurate background and foreground for color images. The potential applications of this study can support non-professionals in finding suitable color-combinations based on emotions for many applications with the transference between emotions and colors, and to imitate the professional operation of the color matching such as interior design, product design, advertising design, image retrieval and other relative applications.
      PubDate: 2017-07-05
      DOI: 10.3390/app7070691
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 692: Inoculation with Glomus mosseae
           Improves the Growth and Salvianolic Acid B Accumulation of Continuously
           Cropped Salvia miltiorrhiza

    • Authors: Meilan Chen, Guang Yang, Dahui Liu, Minhui Li, Hongyan Qiu, Lanping Guo, Luqi Huang, Zhi Chao
      First page: 692
      Abstract: Salvia miltiorrhiza (S. miltiorrhiza) Bunge is one of the most economically important medicinal crops in China. In traditional Chinese medicine, its root is used as an important ingredient in formulas for treatment of atherosclerosis-related disorders. The continuous cropping of S. miltiorrhiza increases the proportion of dried seedlings and decreases the biomass of the shoots and roots and the contents of active components. In this study, three field experiments were conducted to investigate the effects of Glomus mosseae (G. mosseae) inoculation on the growth and contents of active ingredients and nutrients in continuously cropped S. miltiorrhiza. The results showed that inoculation with G. mosseae increased the shoot biomass of S. miltiorrhiza by 48.1% and the root biomass by 39.2%, and decreased the dried seedling rate by nearly 75%. Inoculation with G. mosseae also increased the salvianolic acid B concentration by 21.9% in the shoots and 9.2% in the roots of S. miltiorrhiza, and also significantly increased Mn concentration in the roots and shoots (by 65.1% and 93.4%, respectively) and Fe concentration in the roots (by 75%). The accumulation of salvianolic acid B, Mn, and Fe in G. mosseae inoculated S. miltiorrhiza may be a mechanism that imparts tolerance to continuous cropping. Inoculation of S. miltiorrhiza with G. mosseae can serve as an effective approach of biocontrol to improve the performance of continuously cropped S. miltiorrhiza.
      PubDate: 2017-07-05
      DOI: 10.3390/app7070692
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 693: Economic Analysis for Collapse Hazard
           Areas

    • Authors: Bo-Young Heo, Won-Ho Heo
      First page: 693
      Abstract: In order to improve the quality assurance of collapse hazard zone projects, the economic effect of these projects in hazardous areas was analyzed. Ten areas were selected for the analysis to consider historical disaster records, and their effects were analyzed using a benefit/cost (B/C) analysis. The benefit was estimated using the human and material losses in the damage hazard zones and the cost was assumed with the total project cost. Analysis results indicate the B/C ratio is larger than 1 in the difference range, depending on factors such as analysis period and discount rates. According to the analysis results, the average B/C of the ten projects is 3.5. The project implies that a disaster management project in hazardous areas will yield positive investment effects. The results of this study can be applied for improving the ways investment priorities for collapse hazard zones are determined.
      PubDate: 2017-07-05
      DOI: 10.3390/app7070693
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 694: Mechanical and Permeability
           Characteristics of Latex-Modified Fiber-Reinforced Roller-Compacted
           Rapid-Hardening-Cement Concrete for Pavement Repair

    • Authors: Seung-Kee Lee, Myong-Jin Jeon, Sang-Sun Cha, Chan-Gi Park
      First page: 694
      Abstract: This study evaluated the effects of reinforcement fibers on the mechanical characteristics, chloride ion penetration properties and abrasion resistance of roller-compacted latex-modified fiber-reinforced rapid-hardening-cement concrete (RCLMFRRHCC) for use in the emergency repair of concrete pavements. The reinforcement fibers tested included macro synthetic fibers (a structural fiber) as well as PVA (polyvinyl alcohol) and natural Jute fibers (non-structural fibers). In the experiment, compressive strength, flexural strength, splitting tensile strength, chloride ion penetrating properties, abrasion resistance tests and impact resistance tests were performed. Test results were compared with traffic open standards of concrete for concrete pavement emergency repair. RCLMFRRHCC satisfied all traffic open standards for concrete emergency repair. Mixes with reinforcement fibers showed superior results to the mix without, in terms of compressive strength, flexural strength, splitting tensile strength, chloride ion penetration resistance, abrasion resistance and impact resistance. With regard to the reinforcement fibers, the compressive strength, flexural strength, splitting tensile strength, and impact resistance of the mix with macro synthetic fiber showed improved results as a structural fiber compared to mixes containing natural jute and PVA fibers, namely the non-structural fibers. However, using the reinforcement fiber type had little effect on chloride ion penetration resistance or abrasion resistance. Thus, the addition of reinforcement fibers was effective in improving the performance of RCLMFRRHCC. The use of macro synthetic fibers improved the mechanical characteristics of concrete.
      PubDate: 2017-07-05
      DOI: 10.3390/app7070694
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 695: Design of 4 × 1 Power Beam Combiner
           Based on MultiCore Photonic Crystal Fiber

    • Authors: Dror Malka, Eyal Cohen, Zeev Zalevsky
      First page: 695
      Abstract: A novel concept of 4 × 1 power beam combiner based on multicore photonic crystal fiber is described. The light coupling obtained by integrating small air-holes in the multicore photonic crystal fiber (PCF) structure allows light coupling between coherent laser sources to the central core. The beam propagation method (BPM) and coupled mode theory were used for analyzing the proposed device. Simulation results show that four coherent fiber laser sources of 1 µm in a multicore PCF structure can be combined into one source after 2.6 mm light propagation, with a power efficiency of 99.6% and bandwidth of 220 nm. In addition, a higher 8 × 1 ratio combiner was demonstrated, based on the proposed device. Thus, the device can be very useful to combine beams.
      PubDate: 2017-07-05
      DOI: 10.3390/app7070695
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 696: IoT and iTV for Interconnection,
           Monitoring, and Automation of Common Areas of Residents

    • Authors: Héctor Sánchez, Carlos González-Contreras, J. Agudo, Miguel Macías
      First page: 696
      Abstract: Internet and, in particular, computer networks have become a key issue in our daily lives, due to the birth of wireless technologies. Internet of Things (IoT) aims to integrate sensors and actuators in daily objects, maximizing miniaturization and minimizing the economic cost of these hardware components. The purpose is to connect these components to the Internet through wireless and fixed networks, and thereby produce information in real time which is then stored for later processing. On the other hand, Interactive TV (iTV) combines traditional TV with interactivity similar to that of the Internet and the personal computer. The evolution of TV technology has brought computing power to this device, offering services apart from the traditional ones, making it a device capable of running applications and maximizing its networking potential. This work presents a framework that includes and integrates a wireless sensor network, an IoT platform, and a real interactive TV application. It covers the deployment and communication of the wireless sensor network through the interoperability of data, to final consumption, through a real interactive television application. It has been tested within a residential community to provide real-time information, in order to improve the quality of life of its inhabitants. In addition, it incorporates the possibility of analyzing this information to establish processes with the objective of reducing energy consumption, thus improving sustainability and contributing to the efficient use of existing resources. The proposed framework serves as the basis for any deployment of similar characteristics.
      PubDate: 2017-07-06
      DOI: 10.3390/app7070696
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 697: Experimental Study on the Physical
           Simulation of Water Invasion in Carbonate Gas Reservoirs

    • Authors: Feifei Fang, Weijun Shen, Shusheng Gao, Huaxun Liu, Qingfu Wang, Yang Li
      First page: 697
      Abstract: Water invasion in carbonate gas reservoirs often results in excessive water production, which limits the economic life of gas wells. This is influenced by reservoir properties and production parameters, such as aquifer, fracture, permeability and production rate. In this study, seven full diameter core samples with dissolved pores and fractures were designed and an experimental system of water invasion in gas reservoirs with edge and bottom aquifers was established to simulate the process of water invasion. Then the effects of the related reservoir properties and production parameters were investigated. The results show that the edge and bottom aquifers supply the energy for gas reservoirs with dissolved pores, which delays the decline of bottom-hole pressure. The high water aquifer defers the decline of water invasion in the early stage while the big gas production rate accelerates water influx in gas reservoirs. The existence of fractures increases the discharge area of gas reservoirs and the small water influx can result in a substantial decline in recovery factor. With the increase of permeability, gas production rate has less influence on recovery factor. These results can provide insights into a better understanding of water invasion and the effects of reservoir properties and production parameters so as to optimize the production in carbonate gas reservoirs.
      PubDate: 2017-07-07
      DOI: 10.3390/app7070697
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 698: Preparation of Titania on Stainless
           Steel by the Spray-ILGAR Technique as Active Photocatalyst under UV Light
           Irradiation for the Decomposition of Acetaldehyde

    • Authors: Sheela Chandren, Kamarulafizam Ismail, Hadi Nur, Bunsho Ohtani
      First page: 698
      Abstract: One of the methods used to produce buffer layers for thin film solar cells is the Spray ion layer gas reaction (SPRAY-ILGAR). This method has exhibited astonishing efficiencies in the fabrication of homogenous compact metal chalcogenide films. The same approach can be applied in the preparation of photocatalyst on a substrate, in order to acquire a homogeneous and durable layer. In this work, the Spray-ILGAR technique has been utilized in the preparation of titania photocatalysts on stainless steel, which was carried out at Helmholtz-Zentrum Berlin for Materials and Energy, in Berlin, Germany. The characterizations and photocatalytic testing of the synthesized materials were then done at the Institute of Catalysis, Hokkaido University. The scanning electron microscopy (SEM) analysis showed that the titania was dispersed uniformly on top of the stainless steel, with a very durable and strong attachment. It was also found that the concentration of the titania on stainless steel can be easily varied by changing the concentration of the titania-precursor solution. Higher concentrations will result in a more compact and dense layer, while lowering the concentration of the precursor solution produces a less dense layer of TiO2. Apart from that, different temperatures did not change the distribution of the samples much. The photocatalytic activity of the synthesized materials was determined in terms of the photocatalytic decomposition of acetaldehyde under ultra violet (UV) light irradiation. The photocatalytic testing results proved that the samples can completely degrade acetaldehyde under UV irradiation. The heating temperature played a crucial role, as the sample prepared by with heating temperature of 550 °C, concentration of titania-precursor of 6.83 mM and a spraying time of 12 min showed the best results, requiring only 35 min to fully degrade 500 ppm of acetaldehyde.
      PubDate: 2017-07-06
      DOI: 10.3390/app7070698
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 699: An Energy Demodulation Based Fiber
           Optic Sensing System for Landslide Early-Warning

    • Authors: Xing Wang, Bin Shi, Guangqing Wei, Shenen Chen
      First page: 699
      Abstract: To help reduce the impact of geo-hazards, an innovative landslide early-warning technology based on an energy demodulation-based fiber optic sensing (FOS-LW for short) technology, is introduced in this paper. FOS-LW measures the energy change in a sensing fiber at the segment of micro-bending, which can be caused by landslide movements, and automatically raises an alarm as soon as the measured signal intensity in the fiber reaches a pre-set threshold. Based on the sensing of micro-bending losses in the fiber optics, a two-event sensing algorithm has been developed for the landslide early-warning. The feasibility of the FOS-LW technology is verified through laboratory simulation and field tests. The result shows that FOS-LW has some unique features—such as the graded alarm, real-time responses, remote monitoring, low cost and passive optical network—and can be applied in the early-warning of landslides.
      PubDate: 2017-07-07
      DOI: 10.3390/app7070699
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 700: Integrated Optical Content
           Addressable Memories (CAM) and Optical Random Access Memories (RAM) for
           Ultra-Fast Address Look-Up Operations

    • Authors: Christos Vagionas, Pavlos Maniotis, Stelios Pitris, Amalia Miliou, Nikos Pleros
      First page: 700
      Abstract: Electronic Content Addressable Memories (CAM) implement Address Look-Up (AL) table functionalities of network routers; however, they typically operate in the MHz regime, turning AL into a critical network bottleneck. In this communication, we demonstrate the first steps towards developing optical CAM alternatives to enable a re-engineering of AL memories. Firstly, we report on the photonic integration of Semiconductor Optical Amplifier-Mach Zehnder Interferometer (SOA-MZI)-based optical Flip-Flop and Random Access Memories on a monolithic InP platform, capable of storing the binary prefix-address data-bits and the outgoing port information for next hop routing, respectively. Subsequently the first optical Binary CAM cell (B-CAM) is experimentally demonstrated, comprising an InP Flip-Flop and a SOA-MZI Exclusive OR (XOR) gate for fast search operations through an XOR-based bit comparison, yielding an error-free 10 Gb/s operation. This is later extended via physical layer simulations in an optical Ternary-CAM (T-CAM) cell and a 4-bit Matchline (ML) configuration, supporting a third state of the “logical X” value towards wildcard bits of network subnet masks. The proposed functional CAM and Random Access Memories (RAM) sub-circuits may facilitate light-based Address Look-Up tables supporting search operations at 10 Gb/s and beyond, paving the way towards minimizing the disparity with the frantic optical transmission linerates, and fast re-configurability through multiple simultaneous Wavelength Division Multiplexed (WDM) memory access requests.
      PubDate: 2017-07-07
      DOI: 10.3390/app7070700
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 701: Investigation of Catalytic Effects
           and Compositional Variations in Desorption Characteristics of
           LiNH2-nanoMgH2

    • Authors: Sesha Srinivasan, Dervis Demirocak, Yogi Goswami, Elias Stefanakos
      First page: 701
      Abstract: LiNH2 and a pre-processed nanoMgH2 with 1:1 and 2:1 molar ratios were mechano-chemically milled in a high-energy planetary ball mill under inert atmosphere, and at room temperature and atmospheric pressure. Based on the thermogravimetric analysis (TGA) experiments, 2LiNH2-nanoMgH2 demonstrated superior desorption characteristics when compared to the LiNH2-nanoMgH2. The TGA studies also revealed that doping 2LiNH2-nanoMgH2 base material with 2 wt. % nanoNi catalyst enhances the sorption kinetics at lower temperatures. Additional investigation of different catalysts showed improved reaction kinetics (weight percentage of H2 released per minute) of the order TiF3 > nanoNi > nanoTi > nanoCo > nanoFe > multiwall carbon nanotube (MWCNT), and reduction in the on-set decomposition temperatures of the order nanoCo > TiF3 > nanoTi > nanoFe > nanoNi > MWCNT for the base material 2LiNH2-nanoMgH2. Pristine and catalyst-doped 2LiNH2-nanoMgH2 samples were further probed by X-ray diffraction, Fourier transform infrared spectroscopy, transmission and scanning electron microscopies, thermal programmed desorption and pressure-composition-temperature measurements to better understand the improved performance of the catalyst-doped samples, and the results are discussed.
      PubDate: 2017-07-07
      DOI: 10.3390/app7070701
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 702: Evaluation of Aging Resistance of
           Graphene Oxide Modified Asphalt

    • Authors: Shaopeng Wu, Zhijie Zhao, Yuanyuan Li, Ling Pang, Serji Amirkhanian, Martin Riara
      First page: 702
      Abstract: Graphene oxide (GO) has a unique layered structure with excellent gas and liquid blocking properties. It is widely used in many areas, such as gas sensors, carbon-based electronics, impermeable membranes, and polymeric composite materials. In order to evaluate whether GO (1% and 3% by weight of asphalt) can improve the aging resistance performance of the asphalt, 80/100 penetration grade asphalt (90 A) and styrene–butadiene–styrene modified asphalt (SBS MA) were used to prepare the GO modified asphalt by the melt blending method. The surface morphology of the GO was analyzed by scanning electron microscope (SEM). The UV aging test was conducted to simulate the aging during the service period. After UV aging test, the physical performances of GO-modified asphalts were tested, and the IC=O and IS=O increments were tested by Fourier transform infrared spectroscopy (FTIR) to evaluate the aging resistance performance of the GO modified asphalt. In addition, the rheological properties of GO modified asphalts were studied using a dynamic shear rheometer (DSR). The SEM analysis indicated that the GO exhibits many shared edges, and no agglomeration phenomenon was found. With respect to the physical performance test, the FTIR and the DSR results show that GO can improve the UV aging resistance performance of 90 A and SBS MA. In addition, the analysis indicated that the improvement effect of 3% GO is better than the 1% GO. The testing on the rheological properties of the modified asphalt indicated that the GO can also improve the thermo-oxidative aging resistance performance of asphalt.
      PubDate: 2017-07-07
      DOI: 10.3390/app7070702
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 703: An Improved Distribution Policy with
           a Maintenance Aspect for an Urban Logistic Problem

    • Authors: Nadia Ndhaief, Olivier Bistorin, Nidhal Rezg
      First page: 703
      Abstract: In this paper, we present an improved distribution plan supporting an urban distribution center (UDC) to solve the last mile problem of urban freight. This is motivated by the need of UDCs to satisfy daily demand in time under a high service level in allocated urban areas. Moreover, these demands could not be satisfied in individual cases because the delivery rate can be less than daily demand and/or affected by random failure or maintenance actions of vehicles. The scope of our work is to focus on a UDC, which needs to satisfy demands in a finite horizon. To that end, we consider a distribution policy on two sequential plans, a distribution plan correlated to a maintenance plan using a subcontracting strategy with several potential urban distribution centers (UDCs) and performing preventive maintenance to ensure deliveries for their allocated urban area. The choice of subcontractor will depend on distance, environmental and availability criteria. In doing so, we define a mathematical model for searching the best distribution and maintenance plans using a subcontracting strategy. Moreover, we consider delay for the next periods with an expensive penalty. Finally, we present a numerical example illustrating the benefits of our approach.
      PubDate: 2017-07-07
      DOI: 10.3390/app7070703
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 704: Creation of Optimal Frequency for
           Electrostatic Force Microscopy Using Direct Digital Synthesizer

    • Authors: Seunghyun Moon, Mingyu Kang, Jung-Hwan Kim, Kyeo-Reh Park, ChaeHo Shin
      First page: 704
      Abstract: Electrostatic force microscopy (EFM) is a useful technique when measuring the surface electric potential of a substrate regardless of its topography. Here, we have developed a frequency detection method for alternating current (AC) bias in EFM. Instead of an internal lock-in amplifier (LIA) for EFM that only detects ωe and 2ωe, we have used other LIAs that can amplify the amplitude of specific frequency by direct digital synthesizer (DDS), that finds the optimal frequency of surface charge images. In order to confirm the performance of the proposed methods, the electrical properties of lead zirconate titanate (PZT) and triglycine sulfate (TGS) samples were measured. In addition, we compared the performances of the frequency-detection method and the conventional EFM method. Ultimately, enhanced images could be achieved using the frequency-detection method. The optimal modulated frequency-shift for force–gradient measurements was found to be 2 kHz. Additionally, we have shown that it is possible to use a hard cantilever (K = 42 N/m, 330 kHz). Therefore, we expect that this technique can be applied to measure the electrical properties of bio-molecular films.
      PubDate: 2017-07-08
      DOI: 10.3390/app7070704
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 705: Collinear FAST CARS for Chemical
           Mapping of Gases

    • Authors: Anton Shutov, Dmitry Pestov, Narangerel Altangerel, Zhenhuan Yi, Xi Wang, Alexei Sokolov, Marlan Scully
      First page: 705
      Abstract: We examine the concentration dependence of the Coherent Anti-Stokes Raman Scattering (CARS) signal obtained for gas mixtures at various conditions using the Femtosecond Adaptive Spectroscopic Technique (FAST). We use the CARS signal of the Q-branch vibrational oscillation of molecular oxygen (1556 cm−1) to confirm the quadratic dependence of the coherent signal on the number of molecules in a test volume. In addition, we demonstrate multi-shot FAST CARS imaging of a gas flow in free space by raster-scanning the area of interest.
      PubDate: 2017-07-08
      DOI: 10.3390/app7070705
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 706: A Si-αTCP Scaffold for Biomedical
           Applications: An Experimental Study Using the Rabbit Tibia Model

    • Authors: Piedad De Aza, Miguel Rodríguez, Sergio Gehrke, José Maté-Sánchez de Val, Jose Calvo-Guirado
      First page: 706
      Abstract: We herein hypothesize that bioceramics with an appropriate architecture made of Si-αtricalcium phosphate (Si-αTCP) meet the biocompatibility and biological safety requirements for bone grafting applications. Polyurethane sponges were used as templates, soaked with ceramic slurry at different ratios and sintered at 1400 °C for 3 h at heating and cooling rates of 5 °C/min. Four critical size defects of 6 mm Ø were created in 15 NZ tibias. Three working times were established as 15, 30 and 60 days. A highly porous Si-αTCP scaffold with micro and macropores and pore interconnectivity was produced by the polymer replication method. Considerably more bone formation took place in the pores and the periphery of the implant for the Si-αTCP scaffolds than for the control group. The ceramic scaffold (68.32% ± 1.21) generated higher bone-to-implant contact (BIC) percentage values (higher quality, closer contact) than the control group, according to the histomorphometric analysis, and defect closure was significant compared with the control group. The highest percentages of BIC and bone formation were found after 60 days of implantation. These results suggest that the Si-αTCP scaffold is advantageous for initial bone regeneration.
      PubDate: 2017-07-08
      DOI: 10.3390/app7070706
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 707: Vibration Control Design for a Plate
           

    • Authors: Chih-Jer Lin, Chun-Ying Lee, Ying Liu
      First page: 707
      Abstract: This study presents vibration control using actively tunable vibration absorbers (ATVA) to suppress vibration of a thin plate. The ATVA is made of a sandwich hollow structure embedded with electrorheological fluid (ERF). ERF is considered to be one of the most important smart fluids and it is suitable to be embedded in a smart structure due to its controllable rheological property. ERF’s apparent viscosity can be controlled in response to the electric field and the change is reversible in 10 microseconds. Therefore, the physical properties of the ERF-embedded smart structure, such as the stiffness and damping coefficient, can be changed in response to the applied electric field. A mathematical model is difficult to be obtained to describe the exact characteristics of the ERF embedded ATVA because of the nonlinearity of ERF’s viscosity. Therefore, a fuzzy modeling and experimental validations of ERF-based ATVA from stationary random vibrations of thin plates are presented in this study. Because Type-2 fuzzy sets generalize Type-1 fuzzy sets so that more modeling uncertainties can be handled, a semi-active vibration controller is proposed based on Type-2 fuzzy sets. To investigate the different performances by using different types of fuzzy controllers, the experimental measurements employing both type-1 fuzzy and interval type-2 fuzzy controllers are implemented by the Compact RIO embedded system. The fuzzy modeling framework and solution methods presented in this work can be used for design, performance analysis, and optimization of ATVA from varying harmonic vibration of thin plates.
      PubDate: 2017-07-08
      DOI: 10.3390/app7070707
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 708: Potential Model Overfitting in
           Predicting Soil Carbon Content by Visible and Near-Infrared Spectroscopy

    • Authors: Lizardo Reyna, Francis Dube, Juan A. Barrera, Erick Zagal
      First page: 708
      Abstract: Soil spectroscopy is known as a rapid and cost-effective method for predicting soil properties from spectral data. The objective of this work was to build a statistical model to predict soil carbon content from spectral data by partial least squares regression using a limited number of soil samples. Soil samples were collected from two soil orders (Andisol and Ultisol), where the dominant land cover is native Nothofagus forest. Total carbon was analyzed in the laboratory and samples were scanned using a spectroradiometer. We found evidence that the reflectance was influenced by soil carbon content, which is consistent with the literature. However, the reflectance was not useful for building an appropriate regression model. Thus, we report here intriguing results obtained in the calibration process that can be confusing and misinterpreted. For instance, using the Savitzky–Golay filter for pre-processing spectral data, we obtained R2 = 0.82 and root-mean-squared error (RMSE) = 0.61% in model calibration. However, despite these values being comparable with those of other similar studies, in the cross-validation procedure, the data showed an unusual behavior that leads to the conclusion that the model overfits the data. This indicates that the model should not be used on unobserved data.
      PubDate: 2017-07-08
      DOI: 10.3390/app7070708
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 709: Transmission Power Determination
           Based on Power Amplifier Operations in Large-Scale MIMO-OFDM Systems

    • Authors: Byung Lee, Youngok Kim
      First page: 709
      Abstract: This paper presents a method to determine transmission power based on power amplifier (PA) operations in order to improve the energy efficiency (EE) of a large-scale (LS) Multiple Input Multiple Output (MIMO)-OFDM system, which is a multi-carrier multiple antenna system with a large amount of transmitter (TX) antennas. Regarding the EE improvement, we propose two kinds of PA operation schemes: increasing the effective TX power (ITXP) and reducing the PA power consumption (RPC) assuming that a reduction of peak-to-average power ratio is applied in the appropriate manner. Closed-form expressions of relative EE are derived for both schemes, and the relative EE of the ITXP scheme is shown to depend on the precoding method that is applied to reduce the inter-user interference, while that of the RPC scheme is independent of the precoding method. The relative EE difference between the ITXP and the RPC schemes is also shown to rely on the occupation ratio of the PA power consumption over the total power consumption. Thus, the EE can remarkably improve by selecting the appropriate scheme based on the circumstances. The results of a simulation also validate the derived closed-form expression of the relative EE.
      PubDate: 2017-07-09
      DOI: 10.3390/app7070709
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 710: Fabricating High-Quality 3D-Printed
           Alloys for Dental Applications

    • Authors: Min-Ho Hong, Bong Min, Tea-Yub Kwon
      First page: 710
      Abstract: Metal additive manufacturing (AM), especially selective laser melting (SLM), has been receiving particular attention because metallic functional structures with complicated configurations can be effectively fabricated using the technique. However, there still exist some future challenges for the fabrication of high-quality SLM products for dental applications. First, the surface quality of SLM products should be further improved by standardizing the laser process parameters or by appropriately post-treating the surface. Second, it should be guaranteed that dental SLM restorations have good dimensional accuracy and, in particular, a good marginal fit. Third, a definitive standard regarding building and scanning strategies, which affect the anisotropy, should be established to optimize the mechanical properties and fatigue resistance of SLM dental structures. Fourth, the SLM substructure’s bonding and support to veneering ceramic should be further studied to facilitate the use of esthetic dental restorations. Finally, the biocompatibility of SLM dental alloys should be carefully examined and improved to minimize the potential release of toxic metal ions from the alloys. Future research of SLM should focus on solving the above challenges, as well as on fabricating dental structures with “controlled” porosity.
      PubDate: 2017-07-10
      DOI: 10.3390/app7070710
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 711: Experimental Study of Vibration
           Isolation Characteristics of a Geometric Anti-Spring Isolator

    • Authors: Lixun Yan, Xinglong Gong
      First page: 711
      Abstract: In order to realize low-frequency vibration isolation, a novel geometric anti-spring isolator consisting of several cantilever blade springs are developed in this paper. The optimal design parameters of the geometric anti-spring isolator for different nonlinear geometric parameters are theoretically obtained. The transmissibility characteristic of the geometric anti-spring isolator is investigated through mathematical simulation. A geometric anti-spring isolator with a nonlinear geometric parameter of 0.92 is designed and its vibration isolation performance and nonlinearity characteristic is experimentally studied. The experiment results show that the designed isolator has good low-frequency vibration isolation performance, of which the initial isolation frequency is less than 3.6 Hz when the load weight is 21 kg. The jump phenomena of the response of the isolator under linear frequency sweep excitation are observed, and this result demonstrates that the geometric anti-spring isolator has a complex nonlinearity characteristics with the increment of excitation amplitude. This research work provides a theoretical and experimental basis for the application of the nonlinear geometric anti-spring low-frequency passive vibration isolation technology in engineering practice.
      PubDate: 2017-07-10
      DOI: 10.3390/app7070711
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 712: Simulating the Effects of the
           Airborne Lidar Scanning Angle, Flying Altitude, and Pulse Density for
           Forest Foliage Profile Retrieval

    • Authors: Haiming Qin, Cheng Wang, Xiaohuan Xi, Jianlin Tian, Guoqing Zhou
      First page: 712
      Abstract: Foliage profile is a key biophysical parameter for forests. Airborne Light Detection and Ranging is an effective tool for vegetation parameter retrieval. Data acquisition conditions influence the estimation of biophysical parameters. To acquire accurate foliage profiles at the lowest cost, we used simulations to explore the effects of data acquisition conditions on forest foliage profile retrieval. First, a 3-D forest scene and the airborne small-footprint full-waveform LiDAR data were simulated by the DART model. Second, the foliage profile was estimated from LiDAR data based on a Geometric Optical and Radiative Transfer model. Lastly, the effects of the airborne LiDAR scanning angle, flying altitude, and pulse density on foliage profile retrieval were explored. The results indicated that the scanning angle was an important factor in the foliage profile retrieval, and the optimal scanning angle was 20°. The optimal scanning angle was independent of flying altitude and pulse density, and combinations of multiple scanning angles could improve the accuracy of the foliage profile estimation. The flying altitude and pulse density had little influence on foliage profile retrieval at plot level and could be ignored. In general, our study provides reliable information for selecting the optimal instrument operational parameters to acquire more accurate foliage profiles and minimize data acquisition costs.
      PubDate: 2017-07-10
      DOI: 10.3390/app7070712
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 713: On the Delayed Scaled Consensus
           Problems

    • Authors: Yilun Shang
      First page: 713
      Abstract: In this note, we study the scaled consensus (tracking) problems, wherein all agents reach agreement, but with different assigned ratios in the asymptote. Based on the nearest neighbor-interaction rules, the scaled consensus processes are characterized with and without time delay. We consider both the signal transmission and signal processing delays and calculate the final scaled consensus values. When the underlying communication network contains a spanning tree, it is found that the scaled consensus can be achieved independent of the transmission delays while the specified consensus values in the asymptote depend on the initial history of the agents over a period of time. This phenomenon is in sharp contrast to the case of processing delays, where large delays are likely to jeopardize the consensus behavior, but the scaled consensus values once achieved are the same as the undelayed case.
      PubDate: 2017-07-11
      DOI: 10.3390/app7070713
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 714: Member Discrete Element Method for
           Static and Dynamic Responses Analysis of Steel Frames with Semi-Rigid
           Joints

    • Authors: Jihong Ye, Lingling Xu
      First page: 714
      Abstract: In this paper, a simple and effective numerical approach is presented on the basis of the Member Discrete Element Method (MDEM) to investigate static and dynamic responses of steel frames with semi-rigid joints. In the MDEM, structures are discretized into a set of finite rigid particles. The motion equation of each particle is solved by the central difference method and two adjacent arbitrarily particles are connected by the contact constitutive model. The above characteristics means that the MDEM is able to naturally handle structural geometric nonlinearity and fracture. Meanwhile, the computational framework of static analysis is consistent with that of dynamic analysis, except the determination of damping. A virtual spring element with two particles but without actual mass and length is used to simulate the mechanical behaviors of semi-rigid joints. The spring element is not directly involved in the calculation, but is employed only to modify the stiffness coefficients of contact elements at the semi-rigid connections. Based on the above-mentioned concept, the modified formula of the contact element stiffness with consideration of semi-rigid connections is deduced. The Richard-Abbort four-parameter model and independent hardening model are further introduced accordingly to accurately capture the nonlinearity and hysteresis performance of semi-rigid connections. Finally, the numerical approach proposed is verified by complex behaviors of steel frames with semi-rigid connections such as geometric nonlinearity, snap-through buckling, dynamic responses and fracture. The comparison of static and dynamic responses obtained using the modified MDEM and those of the published studies illustrates that the modified MDEM can simulate the mechanical behaviors of semi-rigid connections simply and directly, and can accurately effectively capture the linear and nonlinear behaviors of semi-rigid connections under static and dynamic loading. Some conclusions, as expected, are drawn that structural bearing capacity under static loading will be overestimated if semi-rigid connections are ignored; when the frequency of dynamic load applied is close to structural fundamental frequency, hysteresis damping of nonlinear semi-rigid connections can cause energy dissipation compared to rigid and linear semi-rigid connections, thus avoiding the occurrence of resonance. Additionally, fracture analysis also indicates that semi-rigid steel frames possess more anti-collapse capacity than that with rigid steel frames.
      PubDate: 2017-07-11
      DOI: 10.3390/app7070714
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 715: Reduction of Hexavalent Chromium
           Using Sorbaria sorbifolia Aqueous Leaf Extract

    • Authors: Shashi Dubey, Mika Sillanpaa, Rajender Varma
      First page: 715
      Abstract: Aqueous plant leaves extract (PLE) of an abundant shrub, Sorbaria sorbifolia, was explored for the reduction of hexavalent chromium, Cr(VI), to trivalent chromium, Cr(III). The effect of contact time, pH, PLE quantity, ionic strength, hardness, temperature and effective initial Cr(VI) ion concentration were tested; Cr(VI) reduction followed the pseudo-first order rate kinetics and maximum reduction was observed at pH 2. Significantly, Cr(VI) reduction efficacies varied from 97 to 66% over the pH range of 2 to 10, which bodes well for PLE to be used for the reduction of Cr(VI) also at a higher pH. PLE-mediated Cr(VI) reduction displays considerable efficiency at various ionic strengths; however, hardness strongly affects the reduction ability. Higher temperature significantly enhances the Cr(VI) reduction. This study reveals the potential use of PLE as a green reducing agent in aqueous extract for the efficient reduction of Cr(VI) to Cr(III).
      PubDate: 2017-07-11
      DOI: 10.3390/app7070715
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 716: Numerical Study on Dynamic Response
           of a Horizontal Layered-Structure Rock Slope under a Normally Incident Sv
           Wave

    • Authors: Zhifa Zhan, Shengwen Qi
      First page: 716
      Abstract: Several post-earthquake investigations have indicated that the slope structure plays a leading role in the stability of rock slopes under dynamic loads. In this paper, the dynamic response of a horizontal layered-structure rock slope under harmonic Sv wave is studied by making use of the Fast Lagrangian Analysis of Continua method (FLAC). The suitability of FLAC for studying wave transmission across rock joints is validated through comparison with analytical solutions. After parametric studies on Sv wave transmission across the horizontal layered-structure rock slope, it is found that the acceleration amplification coefficient η, which is defined as the ratio of the acceleration at the monitoring point to the value at the toe, wavily increases with an increase of the height along the slope surface. Meanwhile, the fluctuation weakens with normalized joint stiffness K increasing and enhances with normalized joint spacing ξ increasing. The acceleration amplification coefficient of the slope crest ηcrest does not monotonously increase with the increase of ξ, but decreases with the increase of K. Additionally, ηcrest is more sensitive to ξ compared to K. From the contour figures, it can also be found that the contour figures of η take on rhythm, and the effects of ξ on the acceleration amplification coefficient are more obvious compared to the effects on K.
      PubDate: 2017-07-11
      DOI: 10.3390/app7070716
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 717: Investigation into the Vibrational
           Responses of Cylinder Liners in an IC Engine Fueled with Biodiesel

    • Authors: Guoxing Li, Fengshou Gu, Tie Wang, Jianjun You, Andrew Ball
      First page: 717
      Abstract: The paper presents a study of the relationship between the combustion behavior and vibration response of internal combustion (IC) engines fueled with biodiesel based on finite element modelling along with experimental evaluation. An improved finite element (FE) model is established and validated to predict the dynamic responses of cylinder liners with respect to two main sources: combustion shock and piston side thrust. Based on the validated FE model, the response characteristics of the cylinder liner in an IC engine fueled with biodiesel and its causal relationship with excitation sources have been predicted. Due to the lower calorific value of biodiesel, a greater amount of fuel is injected into the combustion chamber to maintain power outputs, which results in a prolonged combustion duration and subsequent higher overall vibration levels, compared with that of diesel. The advanced ignition of biodiesel is the main cause to the compound effect on the coupling of piston side-thrust force, thereby resulting in a nonlinear increase in the root mean square (RMS) of local vibration response close to the combustion top dead center (TDC). These key findings provides insight understandings for not only biodiesel combustion diagnostics but also more accurate diagnostics of fossil diesel based on nonintrusive vibrations.
      PubDate: 2017-07-13
      DOI: 10.3390/app7070717
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 718: Permeability and Stiffness Assessment
           of Paved and Unpaved Roads with Geocomposite Drainage Layers

    • Authors: Cheng Li, Jeramy Ashlock, David White, Pavana Vennapusa
      First page: 718
      Abstract: Poor subsurface drainage is frequently identified as a factor leading to the accelerated damage of roadway systems. Geocomposite drainage layers offer an alternative to traditional methods but have not been widely evaluated, especially in terms of the impact of changes on both drainage capacity and stiffness. In this study, both paved and unpaved test sections with and without an embedded geocomposite drainage layer were constructed and tested. The geocomposite layers were installed directly beneath the roadway surface layers to help the rapid drainage of any infiltrated water and thus prevent water entering the underlying foundation materials. The laboratory, field, and numerical analysis results showed that the geocomposite layers increased the permeability of roadway systems by two to three orders of magnitude and that it can effectively prevent the surface and foundation materials from becoming saturated during heavy rainfall events. For the stiffness of the sections, the paved sections with and without a geocomposite layer showed that the composite modulus values measured at the surface were more reflective of the foundation layer support conditions beneath the geocomposite layer than the geocomposite layer itself. The unpaved road section with the geocomposite layer yielded lower composite modulus values than the control section but showed overall better road surface conditions after a rain event due to the improved subsurface drainage condition.
      PubDate: 2017-07-13
      DOI: 10.3390/app7070718
      Issue No: Vol. 7, No. 7 (2017)
       
  • Applied Sciences, Vol. 7, Pages 719: Analysis on the Accuracy of Intraoral
           Scanners: The Effects of Mandibular Anterior Interdental Space

    • Authors: Ji-hye Chun, Ji Tahk, Youn-Sic Chun, Ji-Man Park, Minji Kim
      First page: 719
      Abstract: In this study, we evaluated the effects of mandibular anterior interdental space on the accuracy of intraoral scanners. Four models of mandibular arch with varying distances of anterior interdental space were analyzed; incisors were evenly spaced out between the two canines by 0 mm, 1 mm, 3 mm, and 5 mm. The full arch of each model was scanned 10 times with iTero® and Trios®. The images were superimposed with those from the reference scanner (Sensable S3) and compared using Geomagic Verify. Statistical analysis was conducted using a t-test, paired t-test, and one-way analysis of variance (ANOVA). Differences in the accuracy of images were statistically significant according to both iTero® and Trios®; a greater deviation was noted with increasing anterior interdental space (p < 0.05). Upon dividing the lower arch into five sections, larger deviation was observed with iTero® in the molar area, except in the model with 1 mm space. With Trios®, the largest deviation was observed in the right molar area in all models. The maximum deviations of intermolar width were 0.66 mm and 0.76 mm in iTero® and Trios®, respectively. This comparison suggests that Trios® demonstrates a higher accuracy than iTero® in all models and in all sections of the arch. However, the mean deviations indicate that both iTero® and Trios® are clinically acceptable.
      PubDate: 2017-07-13
      DOI: 10.3390/app7070719
      Issue No: Vol. 7, No. 7 (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 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)
       
  • Applied Sciences, Vol. 7, Pages 636: Random Forest Prediction of IPO
           Underpricing

    • Authors: David Quintana, Yago Sáez, Pedro Isasi
      First page: 636
      Abstract: The prediction of initial returns on initial public offerings (IPOs) is a complex matter. The independent variables identified in the literature mix strong and weak predictors, their explanatory power is limited, and samples include a sizable number of outliers. In this context, we suggest that random forests are a potentially powerful tool. In this paper, we benchmark this algorithm against a set of eight classic machine learning algorithms. The results of this comparison show that random forests outperform the alternatives in terms of mean and median predictive accuracy. The technique also provided the second smallest error variance among the stochastic algorithms. The experimental work also supports the potential of random forests for two practical applications: IPO pricing and IPO trading.
      PubDate: 2017-06-20
      DOI: 10.3390/app7060636
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 637: Functionalization of a Hydrophilic
           Commercial Membrane Using Inorganic-Organic Polymers Coatings for Membrane
           Distillation

    • Authors: Lies Eykens, Klaus Rose, Marjorie Dubreuil, Kristien De Sitter, Chris Dotremont, Luc Pinoy, Bart Van der Bruggen
      First page: 637
      Abstract: Membrane distillation is a thermal separation technique using a microporous hydrophobic membrane. One of the concerns with respect to the industrialization of the technique is the development of novel membranes. In this paper, a commercially available hydrophilic polyethersulfone membrane with a suitable structure for membrane distillation was modified using available hydrophobic coatings using ORMOCER® technology to obtain a hydrophobic membrane that can be applied in membrane distillation. The surface modification was performed using a selection of different components, concentrations, and application methods. The resulting membranes can have two hydrophobic surfaces or a hydrophobic and hydrophilic surface depending on the application method. An extensive characterization procedure confirmed the suitability of the coating technique and the obtained membranes for membrane distillation. The surface contact angle of water could be increased from 27° up to 110°, and fluxes comparable to membranes commonly used for membrane distillation were achieved under similar process conditions. A 100 h test demonstrated the stability of the coating and the importance of using sufficiently stable base membranes.
      PubDate: 2017-06-20
      DOI: 10.3390/app7060637
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 638: Levels of Organic Pollution
           Indicators in Groundwater at the Old Landfill and Waste Management Site

    • Authors: Eugeniusz Koda, Anna Miszkowska, Anna Sieczka
      First page: 638
      Abstract: The aim of this paper was to assess groundwater quality in a landfill and waste management site, with special regard to levels of organic pollution indicators: chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total organic carbon (TOC). Analysis of specific indicators was conducted for piezometers located in the area of the Radiowo landfill, the composting plant and the facilities adjacent to the landfill. The article discusses the temporal and spatial changes of selected organic pollution indicators. Based on the results of groundwater monitoring, several maps of COD, BOD and TOC areal distribution were provided. Statistical distribution of monitoring data was presented using box-and-whisker plots. Pearson’s correlation coefficients between selected pollution indicators were measured with a significance level set at p < 0.01 and p < 0.05. The strongest correlation was observed between BOD and COD. The maximum BOD/COD ratio was observed at the level of 1.561 before the closure of the vertical barrier, whereas, at present, average values of this ratio are below 0.18. The results indicate significant improvement of groundwater quality in the landfill site after the closure of the vertical barrier. In particular, this refers to BOD values, which decreased even 160 times in the 1998–2016 monitoring period.
      PubDate: 2017-06-20
      DOI: 10.3390/app7060638
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 639: Multidisciplinary Aerodynamic Design
           of a Rotor Blade for an Optimum Rotor Speed Helicopter

    • Authors: Jiayi Xie, Zhifeng Xie, Ming Zhou, Jun Qiu
      First page: 639
      Abstract: The aerodynamic design of rotor blades is challenging, and is crucial for the development of helicopter technology. Previous aerodynamic optimizations that focused only on limited design points find it difficult to balance flight performance across the entire flight envelope. This study develops a global optimum envelope (GOE) method for determining blade parameters—blade twist, taper ratio, tip sweep—for optimum rotor speed helicopters (ORS-helicopters), balancing performance improvements in hover and various freestream velocities. The GOE method implements aerodynamic blade design by a bi-level optimization, composed of a global optimization step and a secondary optimization step. Power loss as a measure of rotor performance is chosen as the objective function, referred to as direct power loss (DPL) in this study. A rotorcraft comprehensive code for trim simulation with a prescribed wake method is developed. With the application of the GOE method, a DPL reduction of as high as 16.7% can be achieved in hover, and 24% at high freestream velocity.
      PubDate: 2017-06-20
      DOI: 10.3390/app7060639
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 640: FERMI: Present and Future Challenges

    • Authors: Luca Giannessi, Claudio Masciovecchio
      First page: 640
      Abstract: We present an overview of the FERMI (acronym of Free Electron laser Radiation for Multidisciplinary Investigations) seeded free electron laser (FEL) facility located at the Elettra laboratory in Trieste. FERMI is now in user operation with both the FEL lines FEL-1 and FEL-2, covering the wavelength range between 100 nm and 4 nm. The seeding scheme adopted for photon pulse production makes FERMI unique worldwide and allows the extension of table top laser experiments in the extreme ultraviolet/soft X-ray region. In this paper, we discuss how advances in the performance of the FELs, with respect to coherent control and multi-colour pulse production, may push the development of original experimental strategies to study non-equilibrium behaviour of matter at the attosecond-nanometer time-length scales. This will have a tremendous impact as an experimental tool to investigate a large array of phenomena ranging from nano-dynamics in complex materials to phenomena that are at the heart of the conversion of light into other forms of energy.
      PubDate: 2017-06-21
      DOI: 10.3390/app7060640
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 641: Design and Implementation of an
           Interactive Interface for Demand Response and Home Energy Management
           Applications

    • Authors: Barış Yener, Akın Taşcıkaraoğlu, Ozan Erdinç, Mustafa Baysal, João Catalão
      First page: 641
      Abstract: Demand response (DR) implementations have recently found wide application areas in the context of smart grids. The effectiveness of these implementations is primarily based on the willingness of end-users to be involved in such programs. In this paper, an interactive and user-friendly interface is presented in order to facilitate and accordingly to increase the participation of end-users in DR programs. The proposed interface has the capability of providing the targeted information about the DR events to end-users and system operators, as well as allowing end-users to interactively monitor and control the progress of their appliances. In addition to its benefits to system operators and thus to the improved operation of power systems, the proposed interface particularly aims to exploit the potential energy-related cost savings by providing the required information and resources to end-users via mobile phone. A separate interface apart from the mentioned end-user oriented interface has also been developed for the system operator to more effectively check the status of DR applications in detail. The capabilities of the proposed concept are evaluated in a real smart home in terms of various aspects.
      PubDate: 2017-06-21
      DOI: 10.3390/app7060641
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 642: Computational Analysis and Artificial
           Neural Network Optimization of Dry Turning Parameters—AA2024-T351

    • Authors: Waqas Saleem, Muhammad Zain-ul-abdein, Hassan Ijaz, Abdullah Salmeen Bin Mahfouz, Anas Ahmed, Muhammad Asad, Tarek Mabrouki
      First page: 642
      Abstract: In dry turning operation, various parameters influence the cutting force and contribute in machining precision. Generally, the numerical cutting models are adopted to establish the optimum cutting parameters and results are substantiated with the experimental findings. In this paper, the optimal turning parameters of AA2024-T351 alloy are determined through Abaqus/Explicit numerical cutting simulations by employing the Johnson-Cook thermo-viscoplastic-damage material model. Turning simulations were verified with published experimental data. Considering the constrained and nonlinear optimization problem, the artificial neural networks (ANN) were executed for training, testing, and performance evaluation of the numerical simulations data. Two feedforward backpropagation neural networks were developed with ten hidden neutrons in each hidden layer. The Log-Sigmoid transfer function and the Levenberg-Marquardt algorithm were applied in the model. The ANN models were studied with four input parameters: the cutting speed (200, 400, and 800 m/min), tool rake angle (5°, 10°, 14.8°, and 17.5°), cutting feed (0.3 and 0.4 mm), and the contact friction coefficients (0.1 and 0.15).The two target parameters include the tool-chip interface temperature and the cutting reaction force. The performance of the trained data was evaluated using root-mean-square error and correlation coefficients. The ANN predicted values were compared both with the Abaqus simulations and the published experimental findings. All of the results are found in good approximation to each other. The performance of the ANN models demonstrated the fidelity of solving and predicting the optimum process parameters.
      PubDate: 2017-06-21
      DOI: 10.3390/app7060642
      Issue No: Vol. 7, No. 6 (2017)
       
  • Applied Sciences, Vol. 7, Pages 643: Arginine-Mediated Self-Assembly of
           Porphyrin on Graphene: A Photocatalyst for Degradation of Dyes

    • Authors: Duong La, Rahul Hangarge, Sidhanath V. Bhosale, Ha Ninh, Lathe Jones, Sheshanath Bhosale
      First page: 643
      Abstract: Porphyrin nanostructures with well-controlled size, shape and functionality can be used for visible-light photocatalysis. In this work, a graphene@porphyrin nanofibre composite was successfully fabricated via arginine-mediated self-assembly of tetrakis (4-carboxyphenyl) porphyrin (TCPP) on graphene nanoplates (GNPs). The formation and crystallisation of the graphene@porphyrin nanofibre composite was fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), fourier transform infrared (FTIR), ultraviolet-visible (UV-vis) and fluorescence spectroscopy. The assembled TCPP nanofibers were 50–200 nm in diameter with length in micrometers long, which were densely and uniformly distributed on the surface of graphene. The GNPs@TCPP nanofibers showed enhanced visible-light photocatalytic activity in comparison with free-standing TCPP nanorods for the degradation of Rhodamine B (RhB) and methyl orange (MO). The possible photodegradation mechanism of these dyes by the GNPs@TCPP nanofiber photocatalyst was proposed.
      PubDate: 2017-06-21
      DOI: 10.3390/app7060643
      Issue No: Vol. 7, No. 6 (2017)
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.145.101.33
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016