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Appl. Sci., Volume 6, Issue 1 (January 2016) – 29 articles

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Open AccessEditorial
Acknowledgement to Reviewers of Applied Sciences in 2015
Appl. Sci. 2016, 6(1), 30; https://doi.org/10.3390/app6010030 - 21 Jan 2016
Viewed by 1563
Abstract
The editors of Applied Sciences would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2015. [...] Full article
Open AccessArticle
High Compact, High Quality Single Longitudinal Mode Hundred Picoseconds Laser Based on Stimulated Brillouin Scattering Pulse Compression
Appl. Sci. 2016, 6(1), 29; https://doi.org/10.3390/app6010029 - 20 Jan 2016
Cited by 20 | Viewed by 3649
Abstract
A high beam quality hundred picoseconds single-longitudinal-mode (SLM) laser is demonstrated based on stimulated Brillouin scattering (SBS) pulse compression and aberration compensation. Flash-lamp-pumped Q-switched Nd3+:Y3Al5O12 (Nd:YAG) SLM laser with Cr4+:Y3Al5O [...] Read more.
A high beam quality hundred picoseconds single-longitudinal-mode (SLM) laser is demonstrated based on stimulated Brillouin scattering (SBS) pulse compression and aberration compensation. Flash-lamp-pumped Q-switched Nd3+:Y3Al5O12 (Nd:YAG) SLM laser with Cr4+:Y3Al5O12 (Cr4+:YAG) as a saturable absorber is used as the seed source. By combining master-oscillator-power-amplifier (MOPA), a compact single-cell with FC-770 as working medium is generated as pulse compressor. The 7.8 ns SLM laser is temporally compressed to about 450 ps, and 200 mJ energy is obtained at 1064 nm without optical damage. The energy stability is better than 3% with beam quality factor M2 less than 1.8, which makes this laser system an attractive source for scientific and industrial applications. Full article
(This article belongs to the Section Optics and Lasers)
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Open AccessArticle
A Liquid-Solid Coupling Hemodynamic Model with Microcirculation Load
Appl. Sci. 2016, 6(1), 28; https://doi.org/10.3390/app6010028 - 20 Jan 2016
Cited by 2 | Viewed by 1707
Abstract
From the aspect of human circulation system structure, a complete hemodynamic model requires consideration of the influence of microcirculation load effect. This paper selected the seepage in porous media as the simulant of microcirculation load. On the basis of a bi-directional liquid-solid coupling [...] Read more.
From the aspect of human circulation system structure, a complete hemodynamic model requires consideration of the influence of microcirculation load effect. This paper selected the seepage in porous media as the simulant of microcirculation load. On the basis of a bi-directional liquid-solid coupling tube model, we built a liquid-solid-porous media seepage coupling model. The simulation parameters accorded with the physiological reality. Inlet condition was set as transient single-pulse velocity, and outlet as free outlet. The pressure in the tube was kept at the state of dynamic stability in the range of 80–120 mmHg. The model was able to simulate the entire propagating process of pulse wave. The pulse wave velocity simulated was 6.25 m/s, which accorded with the physiological reality. The complex pressure wave shape produced by reflections of pressure wave was also observed. After the model changed the cardiac cycle length, the pressure change according with actual human physiology was simulated successfully. The model in this paper is well-developed and reliable. It demonstrates the importance of microcirculation load in hemodynamic model. Moreover the properties of the model provide a possibility for the simulation of dynamic adjustment process of human circulation system, which indicates a promising prospect in clinical application. Full article
(This article belongs to the Special Issue Dynamical Models of Biology and Medicine) Printed Edition available
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Open AccessArticle
Sparse Representation-Based SAR Image Target Classification on the 10-Class MSTAR Data Set
Appl. Sci. 2016, 6(1), 26; https://doi.org/10.3390/app6010026 - 20 Jan 2016
Cited by 48 | Viewed by 2597
Abstract
Recent years have witnessed an ever-mounting interest in the research of sparse representation. The framework, Sparse Representation-based Classification (SRC), has been widely applied as a classifier in numerous domains, among which Synthetic Aperture Radar (SAR) target recognition is really challenging because it still [...] Read more.
Recent years have witnessed an ever-mounting interest in the research of sparse representation. The framework, Sparse Representation-based Classification (SRC), has been widely applied as a classifier in numerous domains, among which Synthetic Aperture Radar (SAR) target recognition is really challenging because it still is an open problem to interpreting the SAR image. In this paper, SRC is utilized to classify a 10-class moving and stationary target acquisition and recognition (MSTAR) target, which is a standard SAR data set. Before the classification, the sizes of the images need to be normalized to maintain the useful information, target and shadow, and to suppress the speckle noise. Specifically, a preprocessing method is recommended to extract the feature vectors of the image, and the feature vectors of the test samples can be represented by the sparse linear combination of basis vectors generated by the feature vectors of the training samples. Then the sparse representation is solved by l 1 -norm minimization. Finally, the identities of the test samples are inferred by the reconstructive errors calculated through the sparse coefficient. Experimental results demonstrate the good performance of SRC. Additionally, the average recognition rate under different feature spaces and the recognition rate of each target are discussed. Full article
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Open AccessReview
The Application of Cryogenic Laser Physics to the Development of High Average Power Ultra-Short Pulse Lasers
Appl. Sci. 2016, 6(1), 23; https://doi.org/10.3390/app6010023 - 20 Jan 2016
Cited by 9 | Viewed by 2687
Abstract
Ultrafast laser physics continues to advance at a rapid pace, driven primarily by the development of more powerful and sophisticated diode-pumping sources, the development of new laser materials, and new laser and amplification approaches such as optical parametric chirped-pulse amplification. The rapid development [...] Read more.
Ultrafast laser physics continues to advance at a rapid pace, driven primarily by the development of more powerful and sophisticated diode-pumping sources, the development of new laser materials, and new laser and amplification approaches such as optical parametric chirped-pulse amplification. The rapid development of high average power cryogenic laser sources seems likely to play a crucial role in realizing the long-sought goal of powerful ultrafast sources that offer concomitant high peak and average powers. In this paper, we review the optical, thermal, thermo-optic and laser parameters important to cryogenic laser technology, recently achieved laser and laser materials progress, the progression of cryogenic laser technology, discuss the importance of cryogenic laser technology in ultrafast laser science, and what advances are likely to be achieved in the near-future. Full article
(This article belongs to the Special Issue Diode-Pumped, Ultra-Short Pulse Lasers)
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Open AccessArticle
Alum as a Catalyst for the Synthesis of Bispyrazole Derivatives
Appl. Sci. 2016, 6(1), 27; https://doi.org/10.3390/app6010027 - 19 Jan 2016
Cited by 9 | Viewed by 1981
Abstract
Compounds with pyrazolemoieties as nitrogen-containing heterocyclic systems have received attention owing to their diverse biological activities. Alum (KAl(SO4)2∙12H2O) is an inexpensive, reusable and nontoxic catalyst used to synthesize 1H-pyrazole derivatives via the reaction of 3-methyl-1-phenyl-1 [...] Read more.
Compounds with pyrazolemoieties as nitrogen-containing heterocyclic systems have received attention owing to their diverse biological activities. Alum (KAl(SO4)2∙12H2O) is an inexpensive, reusable and nontoxic catalyst used to synthesize 1H-pyrazole derivatives via the reaction of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one and carbonyl compound under solvent-free conditions at 60 °C. The proposed method has been used for the preparation of 1H-pyrazole derivatives to yield green products for cleaning-in-place and to avoid toxic catalysts and hazardous solvents in accordance with the philosophy of sustainable chemistry. Full article
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Open AccessArticle
Comparative Study on Theoretical and Machine Learning Methods for Acquiring Compressed Liquid Densities of 1,1,1,2,3,3,3-Heptafluoropropane (R227ea) via Song and Mason Equation, Support Vector Machine, and Artificial Neural Networks
Appl. Sci. 2016, 6(1), 25; https://doi.org/10.3390/app6010025 - 19 Jan 2016
Cited by 19 | Viewed by 2380
Abstract
1,1,1,2,3,3,3-Heptafluoropropane (R227ea) is a good refrigerant that reduces greenhouse effects and ozone depletion. In practical applications, we usually have to know the compressed liquid densities at different temperatures and pressures. However, the measurement requires a series of complex apparatus and operations, wasting too [...] Read more.
1,1,1,2,3,3,3-Heptafluoropropane (R227ea) is a good refrigerant that reduces greenhouse effects and ozone depletion. In practical applications, we usually have to know the compressed liquid densities at different temperatures and pressures. However, the measurement requires a series of complex apparatus and operations, wasting too much manpower and resources. To solve these problems, here, Song and Mason equation, support vector machine (SVM), and artificial neural networks (ANNs) were used to develop theoretical and machine learning models, respectively, in order to predict the compressed liquid densities of R227ea with only the inputs of temperatures and pressures. Results show that compared with the Song and Mason equation, appropriate machine learning models trained with precise experimental samples have better predicted results, with lower root mean square errors (RMSEs) (e.g., the RMSE of the SVM trained with data provided by Fedele et al. [1] is 0.11, while the RMSE of the Song and Mason equation is 196.26). Compared to advanced conventional measurements, knowledge-based machine learning models are proved to be more time-saving and user-friendly. Full article
(This article belongs to the Special Issue Applied Artificial Neural Network) Printed Edition available
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Open AccessArticle
Evaluation of High-Speed Railway Bridges Based on a Nondestructive Monitoring System
Appl. Sci. 2016, 6(1), 24; https://doi.org/10.3390/app6010024 - 18 Jan 2016
Cited by 11 | Viewed by 3368
Abstract
Recently, trains’ velocities in Korea increased more than the speed used in the design of some bridges. Accordingly, this paper demonstrates the evaluation of a railway bridge due to high-speed trains’ movement. A nondestructive monitoring system is used to assess the bridge performance [...] Read more.
Recently, trains’ velocities in Korea increased more than the speed used in the design of some bridges. Accordingly, this paper demonstrates the evaluation of a railway bridge due to high-speed trains’ movement. A nondestructive monitoring system is used to assess the bridge performance under train speeds of 290, 360, 400 and 406 km/h. This system is comprised of a wireless short-term acceleration system and strain monitoring sensors attached to the bridge girder. The results of the analytical methods in time and frequency domains are presented. The following conclusions are obtained: the cross-correlation models for accelerations and strain measurements are effective to predict the performance of the bridge; the static behavior is increased with train speed developments; and the vibration, torsion, fatigue and frequency contents analyses of the bridge show that the bridge is safe under applied trains’ speeds. Full article
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Open AccessArticle
Effect of Different Heating Process on the Photoluminescence Properties of Perovskite Eu-Doped BaZrO3 Powder
Appl. Sci. 2016, 6(1), 22; https://doi.org/10.3390/app6010022 - 18 Jan 2016
Cited by 8 | Viewed by 2030
Abstract
In this study, BaZrO3:Eu0.025 powder was synthesized through the solid-state reaction method with two different heating processes. For the one-step process, the BaZrO3:Eu0.025 powder was heated to 1000 °C–1400 °C for 2 h. For the two-step heating [...] Read more.
In this study, BaZrO3:Eu0.025 powder was synthesized through the solid-state reaction method with two different heating processes. For the one-step process, the BaZrO3:Eu0.025 powder was heated to 1000 °C–1400 °C for 2 h. For the two-step heating process, the BaZrO3:Eu0.025 powder was pre-heated at 800 °C for 2 h, after being cooled to room temperature and ground, then the powder was heated to 1000 °C–1400 °C again for 2 h. The optimum excitation optical wavelength of BaZrO3:Eu0.025 powders were 271 nm and the maximum intensity of the emission spectrum of BaZrO3:Eu0.025 powders increased with increasing heating temperature. The all-heated BaZrO3:Eu0.025 powders showed two strong orange emission bands peaking at the wavelengths of 574 and 596 nm and two weak emission bands peaking at 620 and 650 nm. As the heating temperatures were 1300 °C and 1400 °C, the maximum intensity of one-step heating BaZrO3:Eu0.025 powders appeared at the 5D07F0 (574 nm) and the maximum intensity of one-step heating BaZrO3:Eu0.025 powders appeared at the 5D07F1 (596 nm) transitions of Eu3+ ions, respectively. Full article
(This article belongs to the Special Issue Ferroelectric Ceramics)
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Open AccessArticle
Analysis of the Stiffness Ratio at the Interim Layer of Frame-Supported Multi-Ribbed Lightweight Walls under Low-Reversed Cyclic Loading
Appl. Sci. 2016, 6(1), 21; https://doi.org/10.3390/app6010021 - 15 Jan 2016
Cited by 4 | Viewed by 2037
Abstract
By conducting low-reversed cyclic loading tests, this paper explores the load-bearing performance of frame-supported multi-ribbed lightweight wall structures. The finite-element software (OpenSees) is used to simulate the process with the shear wall width (at the frame-supported layer) and different hole opening approaches (for [...] Read more.
By conducting low-reversed cyclic loading tests, this paper explores the load-bearing performance of frame-supported multi-ribbed lightweight wall structures. The finite-element software (OpenSees) is used to simulate the process with the shear wall width (at the frame-supported layer) and different hole opening approaches (for multi-ribbed lightweight walls) as variables. The conclusions reflect the influence of the stiffness ratio at the interim layer on the load-bearing performance of the structure. On this basis, the paper identifies the preferable numerical range for engineering design, which provides a solid foundation for the theoretical advancement of the structures in this study. Full article
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Open AccessArticle
Using GM (1,1) Optimized by MFO with Rolling Mechanism to Forecast the Electricity Consumption of Inner Mongolia
Appl. Sci. 2016, 6(1), 20; https://doi.org/10.3390/app6010020 - 15 Jan 2016
Cited by 41 | Viewed by 2799
Abstract
Accurate and reliable forecasting on annual electricity consumption will be valuable for social projectors and power grid operators. With the acceleration of electricity market reformation and the development of smart grid and the energy Internet, the modern electric power system is becoming increasingly [...] Read more.
Accurate and reliable forecasting on annual electricity consumption will be valuable for social projectors and power grid operators. With the acceleration of electricity market reformation and the development of smart grid and the energy Internet, the modern electric power system is becoming increasingly complex in terms of structure and function. Therefore, electricity consumption forecasting has become a more difficult and challenging task. In this paper, a new hybrid electricity consumption forecasting method, namely grey model (1,1) (GM (1,1)), optimized by moth-flame optimization (MFO) algorithm with rolling mechanism (Rolling-MFO-GM (1,1)), was put forward. The parameters a and b of GM (1,1) were optimized by employing moth-flame optimization algorithm (MFO), which is the latest natured-inspired meta-heuristic algorithm proposed in 2015. Furthermore, the rolling mechanism was also introduced to improve the precision of prediction. The Inner Mongolia case discussion shows the superiority of proposed Rolling-MFO-GM (1,1) for annual electricity consumption prediction when compared with least square regression (LSR), GM (1,1), FOA (fruit fly optimization)-GM (1,1), MFO-GM (1,1), Rolling-LSR, Rolling-GM (1,1) and Rolling-FOA-GM (1,1). The grey forecasting model optimized by MFO with rolling mechanism can improve the forecasting performance of annual electricity consumption significantly. Full article
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Open AccessArticle
Fault-Tolerant Visual Secret Sharing Schemes without Pixel Expansion
Appl. Sci. 2016, 6(1), 18; https://doi.org/10.3390/app6010018 - 14 Jan 2016
Cited by 3 | Viewed by 2291
Abstract
Visual cryptography encrypts a secret image into two meaningless random images, called shares, such that it can be decrypted by human vision without any calculations. However, there would be problems in alignment when these two shares are staked by hand in practice. Therefore, [...] Read more.
Visual cryptography encrypts a secret image into two meaningless random images, called shares, such that it can be decrypted by human vision without any calculations. However, there would be problems in alignment when these two shares are staked by hand in practice. Therefore, this paper presents the fault-tolerant schemes of stacking two shares that are acquired from secret image encryption without pixel expansion. The main idea of these schemes is to combine several pixels as a unit and then to encrypt each unit into a specific combination of pixels. Both theoretical analysis and simulation results demonstrate the effectiveness and practicality of the proposed schemes. Full article
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Open AccessArticle
Nonlinear Adaptive Rotational Speed Control Design and Experiment of the Propeller of an Electric Micro Air Vehicle
Appl. Sci. 2016, 6(1), 17; https://doi.org/10.3390/app6010017 - 13 Jan 2016
Cited by 3 | Viewed by 2083
Abstract
Micro Air Vehicles (MAVs) driven by electric propellers are of interest for military and civilian applications. The rotational speed control of such electric propellers is an important factor for improving the flight performance of the vehicles, such as their positioning accuracy and stability. [...] Read more.
Micro Air Vehicles (MAVs) driven by electric propellers are of interest for military and civilian applications. The rotational speed control of such electric propellers is an important factor for improving the flight performance of the vehicles, such as their positioning accuracy and stability. Therefore, this paper presents a nonlinear adaptive control scheme for the electric propulsion system of a certain MAV, which can not only speed up the convergence rates of adjustable parameters, but can also ensure the overall stability of the adjustable parameters. The significant improvement of the dynamic tracking accuracy of the rotational speed can be easily achieved through the combination of the proposed control algorithm and linear control methods. The experimental test results have also demonstrated the positive effect of the nonlinear adaptive control scheme on the flight performance of the MAV. Full article
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Open AccessArticle
Residential Demand Response Scheduling with Consideration of Consumer Preferences
Appl. Sci. 2016, 6(1), 16; https://doi.org/10.3390/app6010016 - 12 Jan 2016
Cited by 30 | Viewed by 2875
Abstract
This paper proposes a new demand response scheduling framework for an array of households, which are grouped into different categories based on socio-economic factors, such as the number of occupants, family decomposition and employment status. Each of the households is equipped with a [...] Read more.
This paper proposes a new demand response scheduling framework for an array of households, which are grouped into different categories based on socio-economic factors, such as the number of occupants, family decomposition and employment status. Each of the households is equipped with a variety of appliances. The model takes the preferences of participating households into account and aims to minimize the overall production cost and, in parallel, to lower the individual electricity bills. In the existing literature, customers submit binary values for each time period to indicate their operational preferences. However, turning the appliances “on” or “off” does not capture the associated discomfort levels, as each appliance provides a different service and leads to a different level of satisfaction. The proposed model employs integer values to indicate household preferences and models the scheduling problem as a multi-objective mixed integer programming. The main thrust of the framework is that the multi-level preference modeling of appliances increases their “flexibility”; hence, the job scheduling can be done at a lower cost. The model is evaluated by using the real data provided by the Department of Energy & Climate Change, UK. In the computational experiments, we examine the relation between the satisfaction of consumers based on the appliance usage preferences and the electricity costs by exploring the Pareto front of the related objective functions. The results show that the proposed model leads to significant savings in electricity cost, while maintaining a good level of customer satisfaction. Full article
(This article belongs to the Special Issue Smart Grid: Convergence and Interoperability)
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Open AccessArticle
Numerical Study on Hydrodynamic Performance of Bionic Caudal Fin
Appl. Sci. 2016, 6(1), 15; https://doi.org/10.3390/app6010015 - 12 Jan 2016
Cited by 10 | Viewed by 1939
Abstract
In this work, numerical simulations are conducted to reveal the hydrodynamic mechanism of caudal fin propulsion. In the modeling of a bionic caudal fin, a universal kinematics model with three degrees of freedom is adopted and the flexible deformation in the spanwise direction [...] Read more.
In this work, numerical simulations are conducted to reveal the hydrodynamic mechanism of caudal fin propulsion. In the modeling of a bionic caudal fin, a universal kinematics model with three degrees of freedom is adopted and the flexible deformation in the spanwise direction is considered. Navier-Stokes equations are used to solve the unsteady fluid flow and dynamic mesh method is applied to track the locomotion. The force coefficients, torque coefficient, and flow field characteristics are extracted and analyzed. Then the thrust efficiency is calculated. In order to verify validity and feasibility of the algorithm, hydrodynamic performance of flapping foil is analyzed. The present results of flapping foil compare well with those in experimental researches. After that, the influences of amplitude of angle of attack, amplitude of heave motion, Strouhal number, and spanwise flexibility are analyzed. The results show that, the performance can be improved by adjusting the motion and flexibility parameters. The spanwise flexibility of caudal fin can increase thrust force with high propulsive efficiency. Full article
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Open AccessArticle
The Effects of Adhesive and Bonding Length on the Strain Transfer of Optical Fiber Sensors
Appl. Sci. 2016, 6(1), 13; https://doi.org/10.3390/app6010013 - 11 Jan 2016
Cited by 16 | Viewed by 1919
Abstract
Optical fiber sensors have been extensively adapted as structural health monitoring devices. Due to the existence of the adhesive layer, a portion of the strain is absorbed by the adhesive. As a result, the structural strain sensed by the optical fiber is underestimated [...] Read more.
Optical fiber sensors have been extensively adapted as structural health monitoring devices. Due to the existence of the adhesive layer, a portion of the strain is absorbed by the adhesive. As a result, the structural strain sensed by the optical fiber is underestimated and required to be corrected. An analytical solution is presented through which it is possible to establish the relationship between the strains in the host structure and the surface bonded optical fiber sensor. Experimental measurements based on the Mach–Zehnder interferometric technique were performed to validate the theoretical prediction and reveal the differential strains between the optical fiber strain sensor and test specimen. Parametric studies show that the percentage of the strain in the test specimen actually transferred to the optical fiber is dependent on the bonding length of the optical fiber and the adhesive. The strain transfer is increasing from 56% to 82% as the bonding length increases from 5 cm to 12 cm with the epoxy adhesive. The general trend of the strain transfer obtained from both experimental tests and theoretical predictions shows that the longer the bonding length and the stiffer the adhesive, the more strain is transferred to the optical fiber. Full article
(This article belongs to the Special Issue Selected Papers from the 2015 International Conference on Inventions)
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Open AccessArticle
A Synchrophasor Based Optimal Voltage Control Scheme with Successive Voltage Stability Margin Improvement
Appl. Sci. 2016, 6(1), 14; https://doi.org/10.3390/app6010014 - 07 Jan 2016
Cited by 3 | Viewed by 2463
Abstract
This paper proposes an optimal control scheme based on a synchronized phasor (synchrophasor) for power system secondary voltage control. The framework covers voltage stability monitoring and control. Specifically, a voltage stability margin estimation algorithm is developed and built in the newly designed adaptive [...] Read more.
This paper proposes an optimal control scheme based on a synchronized phasor (synchrophasor) for power system secondary voltage control. The framework covers voltage stability monitoring and control. Specifically, a voltage stability margin estimation algorithm is developed and built in the newly designed adaptive secondary voltage control (ASVC) method to achieve more reliable and efficient voltage regulation in power systems. This new approach is applied to improve voltage profile across the entire power grid by an optimized plan for VAR (reactive power) sources allocation; therefore, voltage stability margin of a power system can be increased to reduce the risk of voltage collapse. An extensive simulation study on the IEEE 30-bus test system is carried out to demonstrate the feasibility and effectiveness of the proposed scheme. Full article
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Open AccessArticle
Lamb Wave Interaction with Adhesively Bonded Stiffeners and Disbonds Using 3D Vibrometry
Appl. Sci. 2016, 6(1), 12; https://doi.org/10.3390/app6010012 - 07 Jan 2016
Cited by 13 | Viewed by 3468
Abstract
There are many advantages to adhesively bonding stiffeners onto aircraft structures rather than using traditional mechanical fastening methods. However there is a lack of confidence of the structural integrity of adhesively bonded joints over time. Acousto-ultrasonic Lamb waves have shown great potential in [...] Read more.
There are many advantages to adhesively bonding stiffeners onto aircraft structures rather than using traditional mechanical fastening methods. However there is a lack of confidence of the structural integrity of adhesively bonded joints over time. Acousto-ultrasonic Lamb waves have shown great potential in structural health monitoring applications in both metallic and composite structures. This paper presents an experimental investigation of the use of acousto-ultrasonic Lamb waves for the monitoring of adhesively bonded joints in metallic structures using 3D scanning laser vibrometry. Two stiffened panels were manufactured, one with an intentional disbonded region. Lamb wave interaction with the healthy and disbonded stiffeners was investigated at three excitation frequencies. A windowed root-mean-squared technique was applied to quantify where Lamb wave energy was reflected, attenuated and transmitted across the structure enabling the size and shape of the defect to be visualised which was verified by traditional ultrasonic inspection techniques. Full article
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Open AccessReview
Visualizing the Knowledge Domain of Nanoparticle Drug Delivery Technologies: A Scientometric Review
Appl. Sci. 2016, 6(1), 11; https://doi.org/10.3390/app6010011 - 07 Jan 2016
Cited by 28 | Viewed by 2986
Abstract
The scientific literature of nanoparticle drug delivery technologies (NDDT) between 2005 and 2014 was reviewed. The visualized co-citation network of its knowledge domain was characterized in terms of thematic concentrations of co-cited references and emerging trends of surging keywords and citations to references [...] Read more.
The scientific literature of nanoparticle drug delivery technologies (NDDT) between 2005 and 2014 was reviewed. The visualized co-citation network of its knowledge domain was characterized in terms of thematic concentrations of co-cited references and emerging trends of surging keywords and citations to references through a scientometric review. The combined dataset of 25,171 bibliographic records were constructed through topic search and citation expansion to ensure adequate coverage of the field. While research in gold nanoparticle and magnetic nanoparticle remains the two most prominent knowledge domains in the NDDT field, research related to clinical and therapeutic applications has experienced a considerable growth. In particular, clinical and therapeutic developments in NDDT have demonstrated profound connections with the mesoporous silica nanoparticle research and microcrystal research. A rapid adaptation of mesoporous silica-based nanomaterials and rare earth fluoride nano-/microcrystal in NDDT is evident. Innovative strategies have been employed to exploit the multicomponent, chemical synthesis, surface modification, and controlled release imparting functionalized targeting capabilities. This study not only facilitated the connection of authors and research themes in the NDDT community, but also demonstrated how research interests and trends evolve over time, which greatly contributes to our understanding of the NDDT knowledge domains. Full article
(This article belongs to the Section Nanotechnology and Applied Nanosciences)
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Open AccessArticle
A Novel Tunable Multi-Frequency Hybrid Vibration Energy Harvester Using Piezoelectric and Electromagnetic Conversion Mechanisms
Appl. Sci. 2016, 6(1), 10; https://doi.org/10.3390/app6010010 - 05 Jan 2016
Cited by 35 | Viewed by 3451
Abstract
This paper presents a novel tunable multi-frequency hybrid energy harvester (HEH). It consists of a piezoelectric energy harvester (PEH) and an electromagnetic energy harvester (EMEH), which are coupled with magnetic interaction. An electromechanical coupling model was developed and numerically simulated. The effects of [...] Read more.
This paper presents a novel tunable multi-frequency hybrid energy harvester (HEH). It consists of a piezoelectric energy harvester (PEH) and an electromagnetic energy harvester (EMEH), which are coupled with magnetic interaction. An electromechanical coupling model was developed and numerically simulated. The effects of magnetic force, mass ratio, stiffness ratio, and mechanical damping ratios on the output power were investigated. A prototype was fabricated and characterized by experiments. The measured first peak power increases by 16.7% and 833.3% compared with that of the multi-frequency EMEH and the multi-frequency PEH, respectively. It is 2.36 times more than the combined output power of the linear PEH and linear EMEH at 22.6 Hz. The half-power bandwidth for the first peak power is also broadened. Numerical results agree well with the experimental data. It is indicated that magnetic interaction can tune the resonant frequencies. Both magnetic coupling configuration and hybrid conversion mechanism contribute to enhancing the output power and widening the operation bandwidth. The magnitude and direction of magnetic force have significant effects on the performance of the HEH. This proposed HEH is an effective approach to improve the generating performance of the micro-scale energy harvesting devices in low-frequency range. Full article
(This article belongs to the Special Issue Ferroelectric Ceramics)
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Open AccessArticle
A Notched Long-Period Fiber Grating Magnetic Field Sensor Based on Nanoparticle Magnetic Fluid
Appl. Sci. 2016, 6(1), 9; https://doi.org/10.3390/app6010009 - 04 Jan 2016
Cited by 6 | Viewed by 2575
Abstract
In this paper, we propose using an inductively coupled plasma (ICP) etching technique to fabricate a notched long-period fiber grating (NLPFG) for magnetic sensing application. An optical fiber magnetic field sensor based on NLPFG filled with nanoparticle magnetic fluid is proposed and demonstrated. [...] Read more.
In this paper, we propose using an inductively coupled plasma (ICP) etching technique to fabricate a notched long-period fiber grating (NLPFG) for magnetic sensing application. An optical fiber magnetic field sensor based on NLPFG filled with nanoparticle magnetic fluid is proposed and demonstrated. The magnetic fluid nanoparticles were attached on the grating structure section and used as a magneto-optical sensing layer to measure magnetic flux density. The external applied magnetic flux density ranged from 0 to 27.74 mT. As the magnetic flux density was increased, the spectra of the NLPFG were changed. The resonant wavelength of the attenuation band did not shift obviously, but the transmission loss of the resonant dip was increased by 3.48 dB from −19.41 dB to −15.93 dB. The experimental results indicated that the sensitivity of the sensor is approximately 0.125 dB/mT. Full article
(This article belongs to the Special Issue Selected Papers from the 2015 International Conference on Inventions)
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Open AccessArticle
Synthesis and Anticancer Activity of Novel Thiazole-5-Carboxamide Derivatives
Appl. Sci. 2016, 6(1), 8; https://doi.org/10.3390/app6010008 - 04 Jan 2016
Cited by 13 | Viewed by 2355
Abstract
A series of novel 2-phenyl-4-trifluoromethyl thiazole-5-carboxamide derivatives have been synthesized and evaluated for their anticancer activity against A-549, Bel7402, and HCT-8 cell lines. Among the tested compounds, highest activity (48%) was achieved with the 4-chloro-2-methylphenyl amido substituted thiazole containing the 2-chlorophenyl group on [...] Read more.
A series of novel 2-phenyl-4-trifluoromethyl thiazole-5-carboxamide derivatives have been synthesized and evaluated for their anticancer activity against A-549, Bel7402, and HCT-8 cell lines. Among the tested compounds, highest activity (48%) was achieved with the 4-chloro-2-methylphenyl amido substituted thiazole containing the 2-chlorophenyl group on the two position of the heterocyclic ring. Other structurally similar compounds displayed moderate activity. The key intermediates have been fully characterized. Full article
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Open AccessArticle
Coordinated Volt/Var Control in Distribution Systems with Distributed Generations Based on Joint Active and Reactive Powers Dispatch
Appl. Sci. 2016, 6(1), 4; https://doi.org/10.3390/app6010004 - 04 Jan 2016
Cited by 5 | Viewed by 2802
Abstract
One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC). Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution [...] Read more.
One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC). Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution System Operator (DSO) procures its active and reactive power requirements from Distributed Generations (DGs) along with the wholesale electricity market. This paper proposes a new operational scheduling method based on a joint day-ahead active/reactive power market at the distribution level. To this end, based on the capability curve, a generic reactive power cost model for DGs is developed. The joint active/reactive power dispatch model presented in this paper motivates DGs to actively participate not only in the energy markets, but also in the VVC scheme through a competitive market. The proposed method which will be performed in an offline manner aims to optimally determine (i) the scheduled active and reactive power values of generation units; (ii) reactive power values of switched capacitor banks; and (iii) tap positions of transformers for the next day. The joint active/reactive power dispatch model for daily VVC is modeled in GAMS and solved with the DICOPT solver. Finally, the plausibility of the proposed scheduling framework is examined on a typical 22-bus distribution test network over a 24-h period. Full article
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Open AccessFeature PaperReview
Novel Molecular Non-Volatile Memory: Application of Redox-Active Molecules
Appl. Sci. 2016, 6(1), 7; https://doi.org/10.3390/app6010007 - 26 Dec 2015
Cited by 6 | Viewed by 2821
Abstract
This review briefly describes the development of molecular electronics in the application of non-volatile memory. Molecules, especially redox-active molecules, have become interesting due to their intrinsic redox behavior, which provides an excellent basis for low-power, high-density and high-reliability non-volatile memory applications. Recently, solid-state [...] Read more.
This review briefly describes the development of molecular electronics in the application of non-volatile memory. Molecules, especially redox-active molecules, have become interesting due to their intrinsic redox behavior, which provides an excellent basis for low-power, high-density and high-reliability non-volatile memory applications. Recently, solid-state non-volatile memory devices based on redox-active molecules have been reported, exhibiting fast speed, low operation voltage, excellent endurance and multi-bit storage, outperforming the conventional floating-gate flash memory. Such high performance molecular memory will lead to promising on-chip memory and future portable/wearable electronics applications. Full article
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Open AccessArticle
On the Use of the Humanoid Bioloid System for Robot-Assisted Transcription of Mexican Spanish Speech
Appl. Sci. 2016, 6(1), 1; https://doi.org/10.3390/app6010001 - 25 Dec 2015
Viewed by 2403
Abstract
Within the context of service robotics (SR), the development of assistive technologies has become an important research field. However, the accomplishment of assistive tasks requires precise and fine control of the mechanic systems that integrate the robotic entity. Among the most challenging tasks [...] Read more.
Within the context of service robotics (SR), the development of assistive technologies has become an important research field. However, the accomplishment of assistive tasks requires precise and fine control of the mechanic systems that integrate the robotic entity. Among the most challenging tasks in robot control, the handwriting task (transcription) is of particular interest due to the fine control required to draw single and multiple alphabet characters to express words and sentences. For language learning activities, robot-assisted speech transcription can motivate the student to practice pronunciation and writing tasks in a dynamic environment. Hence, this paper is aimed to provide the techniques and models to accomplish accurate robot-assisted transcription of Spanish speech. The transcriptor is integrated by a multi-user speech recognizer for continuous speech and the kinematic models for the Mexican Spanish alphabet characters. The Bioloid system with the standard humanoid configuration and no special modifications or tools was considered for implementation. Particularly, the proposed transcriptor could perform the handwriting task with the Bioloid’s two two DOF (degrees-of-freedom) arms. This enabled writing of one-line short and long sentences with small alphabet characters (width <1.0 cm). It is expected that the technique and models that integrate the transcriptor can provide support for the development of robot-assisted language learning activities for children and young adults. Full article
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Open AccessArticle
Acoustic Emission Activity for Characterizing Fracture of Marble under Bending
Appl. Sci. 2016, 6(1), 6; https://doi.org/10.3390/app6010006 - 24 Dec 2015
Cited by 7 | Viewed by 2179
Abstract
The present paper occupies with the acoustic emission (AE) monitoring of fracture of marble. The specimens belong to two different material types and were tested in three-point bending after being ultrasonically interrogated. Consequently, they were repaired by means of suitable epoxy agent and [...] Read more.
The present paper occupies with the acoustic emission (AE) monitoring of fracture of marble. The specimens belong to two different material types and were tested in three-point bending after being ultrasonically interrogated. Consequently, they were repaired by means of suitable epoxy agent and mechanically re-loaded. Apart from the well-known correlation of pulse velocity to strength, which holds for the materials of this study as well, AE provides some unique insight in the fracture of the media. Parameters like the frequency content of the waveforms, and their duration among others show a transition in relation to the load. According to their strength class, the specimens exhibit distinct AE characteristics even at low load, enabling to judge their final strength class after having sustained just a small percentage of their ultimate capacity. More importantly, the AE activity during reloading indicates the quality of repair; specimens with good restoration of strength, exhibited similar AE activity to the intact specimens, while specimens with lower repaired capacity exhibited random behavior. This work discusses the passive monitoring of marble fracture and shows that AE parameters that have been used to successfully characterize cementitious materials, provide good results in monolithic materials like marble as well. It is suggested that AE monitoring during a proof loading can provide good information on the potential strength class, which is especially useful for repaired specimens, where the pulse velocity cannot be easily used. Full article
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Open AccessArticle
Auralization of Accelerating Passenger Cars Using Spectral Modeling Synthesis
Appl. Sci. 2016, 6(1), 5; https://doi.org/10.3390/app6010005 - 24 Dec 2015
Cited by 17 | Viewed by 3055
Abstract
While the technique of auralization has been in use for quite some time in architectural acoustics, the application to environmental noise has been discovered only recently. With road traffic noise being the dominant noise source in most countries, particular interest lies in the [...] Read more.
While the technique of auralization has been in use for quite some time in architectural acoustics, the application to environmental noise has been discovered only recently. With road traffic noise being the dominant noise source in most countries, particular interest lies in the synthesis of realistic pass-by sounds. This article describes an auralizator for pass-bys of accelerating passenger cars. The key element is a synthesizer that simulates the acoustical emission of different vehicles, driving on different surfaces, under different operating conditions. Audio signals for the emitted tire noise, as well as the propulsion noise are generated using spectral modeling synthesis, which gives complete control of the signal characteristics. The sound of propulsion is synthesized as a function of instantaneous engine speed, engine load and emission angle, whereas the sound of tires is created in dependence of vehicle speed and emission angle. The sound propagation is simulated by applying a series of time-variant digital filters. To obtain the corresponding steering parameters of the synthesizer, controlled experiments were carried out. The tire noise parameters were determined from coast-by measurements of passenger cars with idling engines. To obtain the propulsion noise parameters, measurements at different engine speeds, engine loads and emission angles were performed using a chassis dynamometer. The article shows how, from the measured data, the synthesizer parameters are calculated using audio signal processing. Full article
(This article belongs to the Special Issue Audio Signal Processing) Printed Edition available
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Open AccessArticle
Flexible Transmission Network Expansion Planning Considering Uncertain Renewable Generation and Load Demand Based on Hybrid Clustering Analysis
Appl. Sci. 2016, 6(1), 3; https://doi.org/10.3390/app6010003 - 23 Dec 2015
Cited by 3 | Viewed by 2530
Abstract
This paper presents a flexible transmission network expansion planning (TNEP) approach considering uncertainty. A novel hybrid clustering technique, which integrates the graph partitioning method and rough fuzzy clustering, is proposed to cope with uncertain renewable generation and load demand. The proposed clustering method [...] Read more.
This paper presents a flexible transmission network expansion planning (TNEP) approach considering uncertainty. A novel hybrid clustering technique, which integrates the graph partitioning method and rough fuzzy clustering, is proposed to cope with uncertain renewable generation and load demand. The proposed clustering method is capable of recognizing the actual cluster distribution of complex datasets and providing high-quality clustering results. By clustering the hourly data for renewable generation and load demand, a multi-scenario model is proposed to consider the corresponding uncertainties in TNEP. Furthermore, due to the peak distribution characteristics of renewable generation and heavy investment in transmission, the traditional TNEP, which caters to rated renewable power output, is usually uneconomic. To improve the economic efficiency, the multi-objective optimization is incorporated into the multi-scenario TNEP model, while the curtailment of renewable generation is considered as one of the optimization objectives. The solution framework applies a modified NSGA-II algorithm to obtain a set of Pareto optimal planning schemes with different levels of investment costs and renewable generation curtailments. Numerical results on the IEEE RTS-24 system demonstrated the robustness and effectiveness of the proposed approach. Full article
(This article belongs to the Special Issue Smart Grid: Convergence and Interoperability)
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Open AccessArticle
Effect of Post-Annealing on the Microstructure and Microwave Dielectric Properties of Ba(Co0.7Zn0.3)1/3Nb2/3O3 Ceramics
Appl. Sci. 2016, 6(1), 2; https://doi.org/10.3390/app6010002 - 22 Dec 2015
Cited by 1 | Viewed by 2005
Abstract
The effects of post-annealing on the crystal structure, microstructure, and microwave dielectric properties for Ba(Co0.7Zn0.3)1/3Nb2/3O3 ceramics were investigated. The as-prepared materials were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The [...] Read more.
The effects of post-annealing on the crystal structure, microstructure, and microwave dielectric properties for Ba(Co0.7Zn0.3)1/3Nb2/3O3 ceramics were investigated. The as-prepared materials were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The microwave dielectric properties are measured at 6 GHz using a network analyzer. Ba5Nb4O15 and/or Ba8(Co,Zn)1Nb6O24 secondary phases were found on the surface according to sintering conditions due to volatilization of some Zn and Co elements. The experimental results show that the beneficial effect of the annealing steps to improved the microwave dielectric properties. Excellent microwave dielectric properties were achieved for the coarse-grained microstructures by a higher sintering temperature and with a shorter holding time followed by annealing steps at lower temperatures with a longer holding time. This improvement can be attributed to 1:2 cation ordering within the crystal, which is taking place during annealing process. The Ba(Co0.7Zn0.3)1/3Nb2/3O3 ceramic could be used successfully for realization of dielectric microwave resonators, since it has a high quality factor Qf value of 123,700 GHz, a high dielectric constant εr value of 34.5 and a temperature coefficient of the resonant frequency τf of 0 ppm/°C. Full article
(This article belongs to the Special Issue Ferroelectric Ceramics)
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