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Appl. Sci., Volume 8, Issue 6 (June 2018)

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Cover Story (view full-size image) Auxetics expand laterally when stretched, contract when compressed and dome when curved – which [...] Read more.
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Open AccessFeature PaperArticle The Effects of Camelina “Soheil” as a Novel Biodiesel Fuel on the Performance and Emission Characteristics of Diesel Engine
Appl. Sci. 2018, 8(6), 1010; https://doi.org/10.3390/app8061010
Received: 24 May 2018 / Revised: 7 June 2018 / Accepted: 16 June 2018 / Published: 20 June 2018
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Abstract
In this research, a new cultivar of Camelina “Soheil” seed oil (CSO) was investigated as a novel feedstock for biodiesel production. Maximum oil content of CSO seed was about 29%. Physical and chemical characteristics of CSO were investigated. The biodiesel production process was
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In this research, a new cultivar of Camelina “Soheil” seed oil (CSO) was investigated as a novel feedstock for biodiesel production. Maximum oil content of CSO seed was about 29%. Physical and chemical characteristics of CSO were investigated. The biodiesel production process was optimized by using the response surface methodology (RSM) reaction parameters, including molar ratio (methanol to oil), reaction time, and concentration of catalyst are studied. The result showed that the conversion of biodiesel was 98.91% under the optimized conditions of 10.18:1 molar ratio and 1.15 wt % concentration of catalyst for a reaction time of 7.33 min. By investigating the properties of the fuel, it turned out that biodiesel from new cultivar of CSO oil complied with the limits prescribed in the ASTM D6751 standards, and that this seed oil could be introduced as a new feedstock for biodiesel production. Also, the performance and emission of a diesel engine were investigated with CSO biodiesel. All of the engine experiments were performed under the constant speed of 2100 rpm at loads of 0%, 25%, 50%, 75%, and 100%. Results indicated that by using the biodiesel-diesel blends, the brake power, and the CO2 and NOx emissions increased, while the SFC and CO and UHC emissions decreased. Full article
(This article belongs to the Special Issue Renewable Fuels)
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Open AccessArticle Laboratory Evaluation on Performance of Compound-Modified Asphalt for Rock Asphalt/Styrene–Butadiene Rubber (SBR) and Rock Asphalt/Nano-CaCO3
Appl. Sci. 2018, 8(6), 1009; https://doi.org/10.3390/app8061009
Received: 11 May 2018 / Revised: 11 June 2018 / Accepted: 18 June 2018 / Published: 20 June 2018
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Abstract
As a natural modifier of asphalt, rock asphalt has been widely used to improve its thermal stability and aging resistance. However, the thermal cracking resistance of asphalt modified by rock asphalt is unsatisfactory. In order to improve the thermal cracking resistance in low
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As a natural modifier of asphalt, rock asphalt has been widely used to improve its thermal stability and aging resistance. However, the thermal cracking resistance of asphalt modified by rock asphalt is unsatisfactory. In order to improve the thermal cracking resistance in low temperature, two kinds of modifiers—styrene–butadiene rubber (SBR) and nano-CaCO3—were selected as the compound modifiers, and then implemented to improve the low-temperature performance of the binder. Then, compound asphalt modified by Buton rock asphalt (BRA) was chosen as the study subject. The thermal stability and aging resistance of asphalt modified by BRA, compound-modified asphalt by BRA/SBR, and compound-modified asphalt by BRA and nano-CaCO3 were determined to identify whether the compound modifiers in the asphalt would have a negative effect on the thermal stability and aging resistance of the asphalt. The dynamic shear rheometer (DSR) test was employed to evaluate the thermal stability. The thin film oven test (TFOT) and pressure aging vessel (PAV) were adopted to determine the aging resistance. The viscoelastic characteristics of asphalt with and without modifiers were revealed to evaluate the low-temperature crack resistance of asphalt modified by compound modifiers. The bending beam rheometer (BBR) creep test was conducted in three test temperatures in order to determine the creep stiffness modulus of the BRA compound-modified asphalt. The viscoelastic model considering the damage caused by loading was established; then, the creep compliance and parameters of the viscoelastic damage model were implemented to evaluate the low-temperature performance of the compound-modified asphalt. The results show that the compound modifiers have little negative effects on the thermal stability and aging resistance of asphalt. The thermal crack resistance of the compound-modified asphalt by BRA/SBR was the best, followed by the compound-modified asphalt by BRA and nano-CaCO3 within the three materials. The accuracy of forecasting the characteristics of compound-modified asphalt was improved by using the viscoelastic model and considering the damage effect. Full article
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Open AccessArticle Modelling Shear Induced Diffusion Based Particle Segregation: A Basis for Novel Separation Technology
Appl. Sci. 2018, 8(6), 1008; https://doi.org/10.3390/app8061008
Received: 28 May 2018 / Revised: 13 June 2018 / Accepted: 19 June 2018 / Published: 20 June 2018
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Abstract
Shear induced diffusion (SID) based flow segregation is a technique that can be used for concentration and fractionation purposes, and it has the potential to become an economical and sustainable alternative for e.g., membrane separation. When compared to conventional microfiltration, problems related to
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Shear induced diffusion (SID) based flow segregation is a technique that can be used for concentration and fractionation purposes, and it has the potential to become an economical and sustainable alternative for e.g., membrane separation. When compared to conventional microfiltration, problems related to fouling and cleaning are expected to be minimal. To make the best use of the opportunities that this technique holds, detailed insights in flow and particle behavior are needed. Modelling this process allows for us to chart particle segregation in flow, as well as the effect of suspension removal through a pore and the restoration of the flow profile after the pore. As a starting point, we take the computation fluid dynamics (CFD) model that is presented in a previous study. A difference in channel height to particle diameter ratio influences the entrance length of the SID profile as well as its fully developed profile. When extracting liquid through one pore, particles are systematically transmitted at a lower concentration (59–78%) than is present in the bulk. The recovery lengths of the SID profile after the pore were short, and thus pores can be placed at realistic distances, which forms a good foundation for further design of this novel separation technology that will ultimately be applied for fractionation of particles taking relatively small differences in diffusive behavior as a starting point. Full article
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Open AccessArticle Modified LMS Strategies Using Internal Model Control for Active Noise and Vibration Control Systems
Appl. Sci. 2018, 8(6), 1007; https://doi.org/10.3390/app8061007
Received: 26 April 2018 / Revised: 14 June 2018 / Accepted: 19 June 2018 / Published: 20 June 2018
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Abstract
Traditional adaptive filtering algorithms are non-recursive systems that cannot use a time-variant reference input in real time and are not appropriate for control signals with uncertainties and unanticipated conditions. The main purpose of this research is to design novel adaptive digital filtering algorithms
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Traditional adaptive filtering algorithms are non-recursive systems that cannot use a time-variant reference input in real time and are not appropriate for control signals with uncertainties and unanticipated conditions. The main purpose of this research is to design novel adaptive digital filtering algorithms based on internal model control (IMC). The new methods consist of a process model for the target plant so as to estimate its dynamic behavior for active vibration and noise attenuation schemes in order to improve the stability, robustness, and tracking performance. On the basis of on the existing least mean squares, the methods are combined with an internal model controller, or the whole adaptive filtering system could become a feedback control system structure based on IMC. The performances were validated in numerical simulations with various conditions that could have happened in realistic applications, and the results were compared with the original algorithms. This study shows that the active noise and vibration systems that are applied to vehicles, mechanical systems, and other targets are enhanced through improving the performance of conventional adaptive filtering algorithms and by using internal model control effectively. Full article
(This article belongs to the Special Issue Active and Passive Noise Control)
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Open AccessArticle Programmable Zoom Lens System with Two Spatial Light Modulators: Limits Imposed by the Spatial Resolution
Appl. Sci. 2018, 8(6), 1006; https://doi.org/10.3390/app8061006
Received: 10 May 2018 / Revised: 1 June 2018 / Accepted: 14 June 2018 / Published: 20 June 2018
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Abstract
In this work we present an experimental proof of concept of a programmable optical zoom lens system with no moving parts that can form images with both positive and negative magnifications. Our system uses two programmable liquid crystal spatial light modulators to form
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In this work we present an experimental proof of concept of a programmable optical zoom lens system with no moving parts that can form images with both positive and negative magnifications. Our system uses two programmable liquid crystal spatial light modulators to form the lenses composing the zoom system. The results included show that images can be formed with both positive and negative magnifications. Experimental results match the theory. We discuss the size limitations of this system caused by the limited spatial resolution and discuss how newer devices would shrink the size of the system. Full article
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Open AccessArticle The Use of Co-Precipitation to Produce Nano-Mn–Zn Ferrite ([MnxZn1−x]Fe2O4) from Waste Batteries
Appl. Sci. 2018, 8(6), 1005; https://doi.org/10.3390/app8061005
Received: 25 April 2018 / Revised: 1 June 2018 / Accepted: 16 June 2018 / Published: 20 June 2018
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Abstract
This study uses pure materials or waste batteries to produce a nanoscale Mn–Zn ferrite. Acid is used to dissolve the battery into solution and then co-precipitation is used to produce nanoscale ferrite. When the calcination temperature in an air atmosphere exceeds 600 °C,
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This study uses pure materials or waste batteries to produce a nanoscale Mn–Zn ferrite. Acid is used to dissolve the battery into solution and then co-precipitation is used to produce nanoscale ferrite. When the calcination temperature in an air atmosphere exceeds 600 °C, α-Fe2O3 is generated and there is a decrease in the saturated magnetization. Using waste batteries to produce [Mn0.54Zn0.46]Fe2O4 at a pH of 10, the saturated magnetization is 62.85 M (emu/g), which is optimal. At a pH of 10, the particulate diameter is largest, at about 40 nm. The stronger the crystal phase of Mn–Zn ferrite, the greater is the saturated magnetization. The ferrite crystal phase is analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and a vibrating sample magnetometer (VSM). The stronger the crystal phase, the larger is the average particulate diameter. The magnetic properties, the particulate diameter and the magnetic flux density of ferrite powders that are prepared under different conditions are studied. [MnxZn1−x]Fe2O4 ferrite powders can be used as an iron core and as resonance imaging materials. Full article
(This article belongs to the Section Materials)
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Open AccessArticle Evaluation of the Implicit Gradient-Enhanced Regularization of a Damage-Plasticity Rock Model
Appl. Sci. 2018, 8(6), 1004; https://doi.org/10.3390/app8061004
Received: 11 May 2018 / Revised: 28 May 2018 / Accepted: 29 May 2018 / Published: 20 June 2018
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Abstract
In the present publication, the performance of an implicit gradient-enhanced damage-plasticity model is evaluated with special focus on the prediction of complex failure modes such as shear failure. Hence, it complements studies on predominant mode I failure frequently found in the literature. To
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In the present publication, the performance of an implicit gradient-enhanced damage-plasticity model is evaluated with special focus on the prediction of complex failure modes such as shear failure. Hence, it complements studies on predominant mode I failure frequently found in the literature. To this end, an implicit gradient-enhanced damage-plasticity rock model is presented and validated by means of 2D and 3D finite element simulations of both laboratory tests on intact rock specimens as well as a large-scale structural benchmark related to failure of rock mass. Thereby, a wide range of loading conditions comprising unconfined and/or confined, tensile and/or compressive stress states is considered. The capability of the gradient-enhanced rock model for representing the mechanical response objectively with respect to the finite element discretization and realistically compared to measurement data is assessed. It is shown that complex failure modes and the respective load–displacement curves are predicted in a mesh-insensitive manner. Full article
(This article belongs to the Special Issue Computational Methods for Fracture)
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Open AccessArticle Stability of Cu-Precipitates in Al-Cu Alloys
Appl. Sci. 2018, 8(6), 1003; https://doi.org/10.3390/app8061003
Received: 30 May 2018 / Revised: 9 June 2018 / Accepted: 9 June 2018 / Published: 20 June 2018
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Abstract
We present first principle calculations on formation and binding energies for Cu and Zn as solute atoms forming small clusters up to nine atoms in Al-Cu and Al-Zn alloys. We employ a density-functional approach implemented using projector-augmented waves and plane wave expansions. We
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We present first principle calculations on formation and binding energies for Cu and Zn as solute atoms forming small clusters up to nine atoms in Al-Cu and Al-Zn alloys. We employ a density-functional approach implemented using projector-augmented waves and plane wave expansions. We find that some structures, in which Cu atoms are closely packed on {100}-planes, turn out to be extraordinary stable. We compare the results with existing numerical or experimental data when possible. We find that Cu atoms precipitating in the form of two-dimensional platelets on {100}-planes in the fcc aluminum are more stable than three-dimensional structures consisting of the same number of Cu-atoms. The preference turns out to be opposite for Zn in Al. Both observations are in agreement with experimental observations. Full article
(This article belongs to the Special Issue Mechanical Behaviour of Aluminium Alloys)
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Open AccessArticle Manufacturing of Non-Stick Molds from Pre-Painted Aluminum Sheets via Single Point Incremental Forming
Appl. Sci. 2018, 8(6), 1002; https://doi.org/10.3390/app8061002
Received: 29 May 2018 / Revised: 17 June 2018 / Accepted: 18 June 2018 / Published: 20 June 2018
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Abstract
The process of single point incremental formation (SPIF) awakens interest in the industry of mold manufacturing for the food industry. By means of SPIF, it is possible to generate short series of molds or mold prototypes at low cost. However, these industries require
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The process of single point incremental formation (SPIF) awakens interest in the industry of mold manufacturing for the food industry. By means of SPIF, it is possible to generate short series of molds or mold prototypes at low cost. However, these industries require such molds to be functional (non-sticky) and to have an adequate geometry accuracy. This study presents a technique that enables direct manufacturing of molds from pre-coated sheets with non-stick resins. It has also studied the influence of two technological variables in the process (feed-rate and pitch) for different geometrical parameters of the mold. Low values of these variables result in a lower overall error in the profile obtained. However, in order to obtain greater detail in particular parameters (angles, depth), it is necessary to use higher values of feed-rate and pitch. Full article
(This article belongs to the Special Issue Mechanical Behaviour of Aluminium Alloys)
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Open AccessArticle Automatic Bowel Motility Evaluation Technique for Noncontact Sound Recordings
Appl. Sci. 2018, 8(6), 999; https://doi.org/10.3390/app8060999
Received: 9 May 2018 / Revised: 8 June 2018 / Accepted: 13 June 2018 / Published: 19 June 2018
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Abstract
Information on bowel motility can be obtained via magnetic resonance imaging (MRI)s and X-ray imaging. However, these approaches require expensive medical instruments and are unsuitable for frequent monitoring. Bowel sounds (BS) can be conveniently obtained using electronic stethoscopes and have recently been employed
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Information on bowel motility can be obtained via magnetic resonance imaging (MRI)s and X-ray imaging. However, these approaches require expensive medical instruments and are unsuitable for frequent monitoring. Bowel sounds (BS) can be conveniently obtained using electronic stethoscopes and have recently been employed for the evaluation of bowel motility. More recently, our group proposed a novel method to evaluate bowel motility on the basis of BS acquired using a noncontact microphone. However, the method required manually detecting BS in the sound recordings, and manual segmentation is inconvenient and time consuming. To address this issue, herein, we propose a new method to automatically evaluate bowel motility for noncontact sound recordings. Using simulations for the sound recordings obtained from 20 human participants, we showed that the proposed method achieves an accuracy of approximately 90% in automatic bowel sound detection when acoustic feature power-normalized cepstral coefficients are used as inputs to artificial neural networks. Furthermore, we showed that bowel motility can be evaluated based on the three acoustic features in the time domain extracted by our method: BS per minute, signal-to-noise ratio, and sound-to-sound interval. The proposed method has the potential to contribute towards the development of noncontact evaluation methods for bowel motility. Full article
(This article belongs to the Special Issue Modelling, Simulation and Data Analysis in Acoustical Problems)
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Open AccessArticle A Versatile Velocity Map Ion-Electron Covariance Imaging Spectrometer for High-Intensity XUV Experiments
Appl. Sci. 2018, 8(6), 998; https://doi.org/10.3390/app8060998
Received: 22 April 2018 / Revised: 14 June 2018 / Accepted: 15 June 2018 / Published: 19 June 2018
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Abstract
We report on the design and performance of a velocity map imaging (VMI) spectrometer optimized for experiments using high-intensity extreme ultraviolet (XUV) sources such as laser-driven high-order harmonic generation (HHG) sources and free-electron lasers (FELs). Typically exhibiting low repetition rates and high single-shot
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We report on the design and performance of a velocity map imaging (VMI) spectrometer optimized for experiments using high-intensity extreme ultraviolet (XUV) sources such as laser-driven high-order harmonic generation (HHG) sources and free-electron lasers (FELs). Typically exhibiting low repetition rates and high single-shot count rates, such experiments do not easily lend themselves to coincident detection of photo-electrons and -ions. In order to obtain molecular frame or reaction channel-specific information, one has to rely on other correlation techniques, such as covariant detection schemes. Our device allows for combining different photo-electron and -ion detection modes for covariance analysis. We present the expected performance in the different detection modes and present the first results using an intense high-order harmonic generation (HHG) source. Full article
(This article belongs to the Special Issue Extreme Time Scale Photonics)
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Open AccessArticle Spatial Magnetic-Field Description Method Aimed at 2 × 25 kV Auto-Transformer Power Supply System in High-Speed Railway
Appl. Sci. 2018, 8(6), 997; https://doi.org/10.3390/app8060997
Received: 14 May 2018 / Revised: 8 June 2018 / Accepted: 8 June 2018 / Published: 19 June 2018
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Abstract
Complete and accurate spatial magnetic field description is the premise of effectively assessing the power supply capability of a high-speed railway (HSR). Its evaluation indicators are the current distributions and the integrated impedance of traction network. This paper proposes a spatial magnetic-field description
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Complete and accurate spatial magnetic field description is the premise of effectively assessing the power supply capability of a high-speed railway (HSR). Its evaluation indicators are the current distributions and the integrated impedance of traction network. This paper proposes a spatial magnetic-field description method for the auto-transformer (AT) power supply system. Due to the limitations of previous approaches, all the real loop circuits of the AT system are considered for structuring a loop circuit matrix. At first, different description processes are divided, respectively, into those for the right side and the left side of the load. Then, considering that two types of return conductors exist in an AT system, a certain current ratio deduced in existing studies is introduced. As the introduced current ratio of the left side of the load is approximate, an iterative scheme is adopted. By constantly adjusting current ratio to satisfy a constraint condition of circuit voltages, accurate traction network impedance is obtained. Last, in order to verify the effectiveness of the proposed description method, two real-life experiments in a Chinese HSR line are performed, which indicate that the proposed method can not only directly reflect complete and accurate current distribution, but also deduce the exact traction network integrated impedance. Full article
(This article belongs to the Section Energy)
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Open AccessArticle CO2 Capture by Alkaline Solution for Carbonate Production: A Comparison between a Packed Column and a Membrane Contactor
Appl. Sci. 2018, 8(6), 996; https://doi.org/10.3390/app8060996
Received: 25 May 2018 / Revised: 12 June 2018 / Accepted: 15 June 2018 / Published: 19 June 2018
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Abstract
A comparison between a traditional packed column and a novel membrane contactor used for CO2 absorption with carbonate production is addressed in this paper. Membrane technology is generally characterized by a lower energy consumption, it offers an independent control of gas and
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A comparison between a traditional packed column and a novel membrane contactor used for CO2 absorption with carbonate production is addressed in this paper. Membrane technology is generally characterized by a lower energy consumption, it offers an independent control of gas and liquid streams, a known interfacial area and avoids solvent dragging. Those advantages make it a potential substitute of conventional absorption towers. The effect of the concentration and the flow rates of both the flue gas (10–15% of CO2) and the alkaline sorbent (NaOH, NaOH/Na2CO3) on the variation of the species present in the system, the mass transfer coefficient, and the CO2 removal efficiency was evaluated. Under the studied operation conditions, the membrane contactor showed very competitive results with the conventional absorption column, even though the highest mass transfer coefficient was found in the latter technology. In addition, the membrane contactor offers an intensification factor higher than five due to its compactness and modular character. Full article
(This article belongs to the Special Issue Carbon Capture Utilization and Sequestration (CCUS))
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Open AccessArticle Economic Evaluation of Smart PV Inverters with a Three-Operation-Phase Watt-Var Control Scheme for Enhancing PV Penetration in Distribution Systems in Taiwan
Appl. Sci. 2018, 8(6), 995; https://doi.org/10.3390/app8060995
Received: 20 May 2018 / Revised: 7 June 2018 / Accepted: 7 June 2018 / Published: 19 June 2018
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Abstract
The paper presents an economic evaluation, including a cost-benefit analysis and a sensitivity analysis, of smart photovoltaic (PV) inverters with a novel Watt-Var control scheme for enhancing PV penetration in distribution systems in Taiwan. The novel Watt-Var control scheme with three operation phases
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The paper presents an economic evaluation, including a cost-benefit analysis and a sensitivity analysis, of smart photovoltaic (PV) inverters with a novel Watt-Var control scheme for enhancing PV penetration in distribution systems in Taiwan. The novel Watt-Var control scheme with three operation phases is utilized to avoid the voltage violation problem during peak solar irradiation period and increase the PV real power injection, and thus can get higher PV penetration in distribution systems. To evaluate the benefit and cost of the PV investment project, the annual revenue of PV power sales, the initial capital investment cost for a PV project with or without a smart inverter, and the operating and maintenance (O&M) cost are taken into account. The paper demonstrates the analyses of net present value (NPV) and benefit-cost ratio (BCR) for the PV project. In addition, the paper also presents a sensitivity analysis to deal with the project uncertainty with respect to some affecting parameters. The analyzing results show that, under the feed-in tariffs (FITs) policy, with proper selection of PV and smart inverter capacities, the investment can be profitable, and the smart PV inverter can greatly enhance the PV penetration in distribution systems in Taiwan. These results can provide some useful information for making policy to encourage investment in solar PV industry. Full article
(This article belongs to the Special Issue Selected Papers from the 2017 International Conference on Inventions)
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Open AccessArticle Acoustic Improvement of Stator–Rotor Interaction with Nonuniform Trailing Edge Blowing
Appl. Sci. 2018, 8(6), 994; https://doi.org/10.3390/app8060994
Received: 16 May 2018 / Revised: 4 June 2018 / Accepted: 16 June 2018 / Published: 19 June 2018
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Abstract
The results of unsteady-flow simulations and experiments are discussed to investigate active noise-reduction effects on the stator–rotor interaction in a single-stage low-speed compressor with nonuniform trailing edge blowing. It is found that for the investigated type of stator–rotor interaction noise, nonuniform trailing edge
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The results of unsteady-flow simulations and experiments are discussed to investigate active noise-reduction effects on the stator–rotor interaction in a single-stage low-speed compressor with nonuniform trailing edge blowing. It is found that for the investigated type of stator–rotor interaction noise, nonuniform trailing edge blowing has beneficial noise-reducing effects. The overall aim is to demonstrate that nonuniform trailing edge blowing can compensate momentum loss and reduce the axial thrust on rotor blades. The results illustrate how nonuniform trailing edge blowing influences the sound pressure level of the blade-passing frequencies and results in active noise reduction effects. The study was conducted using a trailing edge blowing system, a four-hole dynamic flow-field measurement system, and phase lock technology. The results obtained show that nonuniform trailing edge blowing leads to substantial noise-reduction effects, lowering sound levels by more than 10 dB with about 5‰ of inlet mass flow. Full article
(This article belongs to the Special Issue Active and Passive Noise Control)
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