Achieving higher power transfer efficiency with permissible output load power is a formidable challenge in designing a magnetically coupled resonant wireless power transfer system. Consequently, to instigate the power...
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Achieving higher power transfer efficiency with permissible output load power is a formidable challenge in designing a magnetically coupled resonant wireless power transfer system. Consequently, to instigate the power transfer characteristics, the theoretical models based on reflected load theory as well as lumped circuit models have been employed, which have been substantiated with the experimental measurements. It has been apprehended that maximum efficiency as well as the power delivered to the load can be enriched from the depreciated value through appropriate deliberation of coil's quality factor (coil design dependent) and coupling coefficient with acceptable operating frequency under different electric load conditions. The obtained results illuminate the correlation between the maximum power transfer ability and the quality factor of the coils, as well as the coupling coefficient, under different electric load conditions.
A general algorithm for the kinematic synthesis of Geneva mechanisms with curved slots is introduced here, when a suitable displacement program is given with the aim of avoiding the typical shock-loading problems of c...
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A general algorithm for the kinematic synthesis of Geneva mechanisms with curved slots is introduced here, when a suitable displacement program is given with the aim of avoiding the typical shock-loading problems of conventional Geneva mechanisms. Moreover, the effects of the design parameters are analyzed through significant numerical examples. These parameters are: number of driving cranks;number of slots;imposed displacement program;and pin radius of the driving crank for the Geneva mechanism.
Organic Rankine Cycle (ORC) is a suitable way to recover the waste heat of internal combustion engines. Since the engine usually operates under different working conditions, the waste heat recovery system is also unde...
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Organic Rankine Cycle (ORC) is a suitable way to recover the waste heat of internal combustion engines. Since the engine usually operates under different working conditions, the waste heat recovery system is also under unstable state. Consequently, it is quite meaningful to research the dynamic behavior of the ORC. The dynamic math model of the ORC for waste heat recovery of a natural gas engine is established by Simulink in this paper. Based on these, the effects of design parameters of evaporating pressure, condensing pressure, exhaust outlet temperature and working fluids on the ORC dynamic behavior are researched. The results indicate that the dynamic response speed of the ORC just varies a little with the design evaporating pressure, condensing pressure and exhaust outlet temperature. By contrast, different working fluids lead to quite different dynamic response speed. As a result, when designing the ORC, the working fluid should be considered much more to match the dynamic characters of the engine working condition. Furthermore, it is found that ORCs designed under different evaporating pressure, condensing pressure, exhaust outlet temperature can apply the same PID controller, while it is not suitable for ORCs with different working fluids which have quite distinctive critical temperature. (C) 2018 Elsevier Ltd. All rights reserved.
The operating characteristics of thirteen municipal wastewater treatment plants (WWTPs) with design capacities between 50,000 and 300,000 m(3)/d (mean 75,000 m(3)/d) were studied. The treatment processes used by these...
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The operating characteristics of thirteen municipal wastewater treatment plants (WWTPs) with design capacities between 50,000 and 300,000 m(3)/d (mean 75,000 m(3)/d) were studied. The treatment processes used by these plants included one biofilter (BIO);two A/O (activated sludge anaerobic and aerobic processes in sequence);four A2/O (modified A/O with anaerobic, annoxic (denitrification) and aerobic cells in sequence);three oxidation ditches (OXD);two A/B (absorption-bio-oxidation two-stage [anaerobic cell followed by aerobic cell]);and one sequencing batch reactor (SBR). The study objective was to determine whether the WWTPs were operating at design conditions, and if not, to try to identify the causes of under-performance. All the WWTPs produced a treated effluent quality which was in compliance with a few exceptions. Nine WWTPs were operating with a mean of 62% of the design hydraulic flows. Thirteen WWTPs were operating at a mean of 56% of the design five-day biochemical oxygen demand (BOD) and at 84% of the design total suspended solids (TSS) loadings. Three WWTPs received high-strength wastewater (WW) (BOD >400 mg/L), four normal-strength WW (BOD = 150 to 260 mg/L) and five received weak-strength WW (BOD <150 mg/L). WW strength appeared to be a local characteristic. The mean capital treatment plant costs for one cubic metre of WW per day was 232 USD (104 to 444 USD);consequently, between 80 and 100 MUSD capital investment in WWTPs is unused.
One of the main difficulties in the use of an economic design of reliable optimum values for the design parameters compared with a control chart is the computation of the design parameters n ( sample size), h ( sampli...
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One of the main difficulties in the use of an economic design of reliable optimum values for the design parameters compared with a control chart is the computation of the design parameters n ( sample size), h ( sampling interval) and k ( control limit factor). A very simple procedure is described in this research to determine the design parameters of an x control chart in Duncan's economic model, such that they minimise the expected total costs per time unit. Numerical examples give more accurate and more published results.
Two conditions for minimal wear of the front wheel tyres are defined. Methods to comply with these conditions through the design parameters of the steering axle are stated. An optimization of the steering axle paramet...
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Two conditions for minimal wear of the front wheel tyres are defined. Methods to comply with these conditions through the design parameters of the steering axle are stated. An optimization of the steering axle parameters of a concrete agricultural tractor was performed using the formulated conditions. An experimental corroboration was finally carried out.
Utilization of relay stations (RSs) in massive multiple input multiple output (MIMO) systems is a challenging task. This paper proposes a relay-aided massive MIMO system under realistic circuit power consumption. The ...
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Utilization of relay stations (RSs) in massive multiple input multiple output (MIMO) systems is a challenging task. This paper proposes a relay-aided massive MIMO system under realistic circuit power consumption. The main focus is to search the optimal design parameters (i.e., number of RSs N, the number of RS antennas R, the number of BS antennas M, the number of user equipments K, the transmit power at base station (BS) p(BS), and the transmit power at RS p(RS) for maximum energy efficiency (EE). The channel estimation and an arbitrary path loss with perfect and imperfect channel state information are considered. EE optimization problem is formulated with the objective of finding optimal design parameters. This paper also solves an optimization problem using three optimization algorithms, which are standard alternating algorithm, the Charnes-Cooper transform method-based scheme and the Dinkelbach's method-based scheme. Results are used to demonstrate the impacts of various system parameters on the EE performance.
In spite of all innovations in stent design, commonly used metallic stents present several problems such as corrosion, infection and restenosis, leading to health complications or even death of patients. In this conte...
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In spite of all innovations in stent design, commonly used metallic stents present several problems such as corrosion, infection and restenosis, leading to health complications or even death of patients. In this context, the present paper reports a systematic investigation on designing and development of 100% fiber based stents, which can eliminate or minimize the problems with existing metallic stents. For this purpose, braided stents were produced by varying different materials, structural and process parameters such as mono-filament type and diameter, braiding angle and mandrel diameter. The influence of these design parameters on mechanical behavior as well as stent's porosity was thoroughly investigated, and suitable parameters were selected for developing a stent with mechanical characteristics and porosity matching with the commercial stents. According to the experimental results, the best performance was achieved with a polyester stent designed with 0.27 mm monofilament diameter, braiding angle of 35 degrees and mandrel diameter of 6 mm, providing similar properties to commercial Nitinol stents. (C) 2015 Elsevier Ltd. All rights reserved.
In high-speed serializer/deserializer (SerDes) channels, reducing impedance mismatches at the differential via is crucial to minimize signal reflection. However, due to the complex 3-D structure of the differential vi...
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In high-speed serializer/deserializer (SerDes) channels, reducing impedance mismatches at the differential via is crucial to minimize signal reflection. However, due to the complex 3-D structure of the differential via, obtaining optimal design parameters for impedance matching can be a time-consuming process. This article introduces an equation-based time-domain reflectometry (TDR) estimation model for the differential via, which is validated by comparing it with a commercial model of the coupled transmission line. In addition, this article proposes a method to optimize the design parameters of the differential via using a figure of merit (FOM) based on TDR impedance in a particle swarm optimization (PSO) algorithm. The optimization procedure is applied to an actual printed circuit board (PCB) design, and the simulation results, including TDR, ${S}$ -parameters, and bit error rate (BER) at 1E -12 contours, validate the optimization performance. To further verify the optimization performance in a realistic scenario, test coupons are fabricated, and the TDR impedance is measured, demonstrating excellent performance in real-world conditions.
This study aims to provide basic data for green building projects with respect to the thermal environment of the architecture-urban level scale in combination with outdoor thermal environment problems and the heat isl...
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This study aims to provide basic data for green building projects with respect to the thermal environment of the architecture-urban level scale in combination with outdoor thermal environment problems and the heat island phenomenon using numerical simulation. The study models were selected typical flat and tower apartment residential housing in Korea: 54 cases were defined using an orthogonal array table based on experimental design. These cases are analyzed to quantify the outdoor thermal comfort (mean radiation temperature distribution) and heat island potential (HIP) change throughout a day according to several design variables (building type, site planning type, facade direction, and landscape ratio). A three-dimensional numerical simulation of all surface temperatures is performed. The results are analyzed statistically using multivariate analysis of variance. It was quantitatively characterize the effects of the design parameters on the outdoor thermal environment of the apartment housing. An evaluation index of the design parameters is proposed. A designer can apply the proposed index in the design process and in feedback for green apartment housing projects. (C) 2012 Elsevier Ltd. All rights reserved.
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