scholarly journals Multiparameter Analysis for Efficiency Improvement of Single-Phase Capacitor Motor

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Vasilija Sarac ◽  
Tatjana Atanasova-Pacemska
Keyword(s):  
Parametric Analysis ◽  
Single Phase ◽  
Electricity Consumption ◽  
Design Parameters ◽  
Magnetic Flux Density ◽  
Operating Characteristics ◽  
Widespread Application ◽  
Electrical Motors ◽  
Multiparameter Analysis ◽  
The Impact

Single-phase motors are known for their small power ratings and their usage in various household appliances. Although they are not large electricity consumers, their widespread application contributes to the overall electricity consumption. In addition, standard IEC 60034-30-1:214 defines the efficiency levels for single- and three-phase motors and stipulates the increased electrical efficiency for the electrical motors. Therefore, this paper sets the parametric analysis of permanently split capacitor motor with five different design parameters that have impact on the efficiency of the motor. As an output from the parametric analysis, two different optimized motor models are obtained with increased efficiency. The impact of each parameter on motor efficiency—as well as on the other operating characteristics, like starting torque, overloading capacity, rated current, starting current, total losses, and power factor—is analyzed and adequate conclusions are derived. The obtained motor models are verified with Finite Element Method (FEM) for magnetic flux density distribution.

scholarly journals A New Approach for Design Optimization and Parametric Analysis of Symmetric Compound Parabolic Concentrator for Photovoltaic Applications

2021 ◽  
Vol 13 (9) ◽  
pp. 4606
Author(s):  
Faisal Masood ◽  
Perumal Nallagownden ◽  
Irraivan Elamvazuthi ◽  
Javed Akhter ◽  
Mohammad Azad Alam
Keyword(s):  
Parametric Analysis ◽  
Concentration Ratio ◽  
Synergistic Effects ◽  
Geometric Optimization ◽  
Design Parameters ◽  
Imaging Device ◽  
Compound Parabolic Concentrator ◽  
Photovoltaic Applications ◽  
Half Angle ◽  
The Impact

A compound parabolic concentrator (CPC) is a non-imaging device generally used in PV, thermal, or PV/thermal hybrid systems for the concentration of solar radiation on the target surface. This paper presents the geometric design, statistical modeling, parametric analysis, and geometric optimization of a two-dimensional low concentration symmetric compound parabolic concentrator for potential use in building-integrated and rooftop photovoltaic applications. The CPC was initially designed for a concentration ratio of “2×” and an acceptance half-angle of 30°. A MATLAB code was developed in house to provoke the CPC reflector’s profile. The height, aperture width, and concentration ratios were computed for different acceptance half-angles and receiver widths. The interdependence of optical concentration ratio and acceptance half-angle was demonstrated for a wide span of acceptance half-angles. The impact of the truncation ratio on the geometric parameters was investigated to identify the optimum truncation position. The profile of truncated CPC for different truncation positions was compared with full CPC. A detailed statistical analysis was performed to analyze the synergistic effects of independent design parameters on the responses using the response surface modeling approach. A set of optimized design parameters was obtained by establishing specified optimization criteria. A 50% truncated CPC with an acceptance half-angle of 21.58° and receiver width of 193.98 mm resulted in optimum geometric dimensions.

scholarly journals Evaluation of Treatment Effect with Paired Failure Times in a Single-Arm Phase II Trial in Oncology

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Matthieu Texier ◽  
Federico Rotolo ◽  
Michel Ducreux ◽  
Olivier Bouché ◽  
Jean-Pierre Pignon ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Phase Ii ◽  
Treatment Effect ◽  
Parametric Method ◽  
Design Parameters ◽  
Nonparametric Method ◽  
Operating Characteristics ◽  
Phase Ii Trials ◽  
The Times ◽  
The Impact

In early phase clinical trials of cytotoxic drugs in oncology, the efficacy is typically evaluated based on the tumor shrinkage. However, this criterion is not always appropriate for more recent cytostatic agents, and alternative endpoints have been proposed. The growth modulation index (GMI), defined as the ratio between the times to progression in two successive treatment lines, has been proposed for a single-arm phase II trials. The treatment effect is evaluated by estimating the rate of patients having a GMI superior to a given threshold. To estimate this rate, we investigated a parametric method based on the distribution of the times to progression and a nonparametric one based on a midrank estimator. Through simulations, we studied their operating characteristics and the impact of different design parameters (censoring, dependence, and distribution) on them. In these simulations, the nonparametric estimator slightly underestimated the rate and had slightly overconservative confidence intervals in some cases. Conversely, the parametric estimator overestimated the rate and had anticonservative confidence intervals in some cases. The nonparametric method appeared to be more robust to censoring than the parametric one. In conclusion, we recommend the nonparametric method, but the parametric method can be used as a supplementary tool.

Operational Performance and Locally Resolved Outflow of Brush Seals

2019 ◽  
Author(s):  
Fabian Schur ◽  
Jens Friedrichs
Keyword(s):  
Operational Performance ◽  
Design Parameters ◽  
Steam Turbines ◽  
Test Rig ◽  
Rotating Shaft ◽  
Experimental Conditions ◽  
Widespread Application ◽  
Backing Plate ◽  
Brush Seals ◽  
The Impact

Abstract As a result of the superior leakage efficiency of brush seals compared to conventional labyrinth seals, compliant contacting filament seals are used to increase the efficiency of jet engines as well as stationary gas and steam turbines. The widespread application of brush seals at different and varying pressure differences combined with variable contacting velocities at the rotor surface requires a profound understanding of the influences of different design parameters on the operational leakage performance. In order to systematically investigate the impact of different design parameters on sealing performance, a new cold air test rig was developed. The new test rig with rotating shaft enables hot-wire anemometry measurements downstream of the seals. These measurements provide insight into the locally resolved flow structure in addition to the integral leakage measurements. For the investigations, one welded and five different clamped brush seals at rotational speeds up to 3000rpm and pressure differences across the seals up to 500kPa are considered. Therefore, the influence of two different designs on the flow through the bristles is presented. For the clamped brush seals, variations of the front and backing plate are investigated. Additionally, the effects of bristle diameter and three different axial inclinations of the bristle pack on the sealing efficiency are shown. Furthermore, initial wear development during the first 30 to 60 hours of brush seal operation at varying experimental conditions is presented and linked to the design parameters. Consequently, the effects of major design aspects on the operational performance of brush seals are examined and presented.

scholarly journals Impact of Number of Phases on Electromagnetic Torque Characteristics of Transverse Flux Permanent Magnet Machines

2019 ◽  
Vol 8 (4) ◽  
pp. 118-129
Author(s):  
A. Alaeddini ◽  
H. Tahanian ◽  
A. Darabi
Keyword(s):  
Permanent Magnet ◽  
Single Phase ◽  
Torque Ripple ◽  
Design Parameters ◽  
Permanent Magnet Machines ◽  
Electromagnetic Torque ◽  
Simulation Results ◽  
Transverse Flux ◽  
Multi Phase ◽  
The Impact

This paper presents an investigation on the influences of number of phases of Transverse Flux Permanent Magnet (TFPM) machines on the characteristics of developed electromagnetic torque. Electromagnetic torque is expressed in terms of the Fourier series of phase currents and internal voltages. After some algebraic and trigonometric calculations, a general equation is obtained that establishes a relationship between the electromagnetic torque ripples, number of phases and harmonic contents of both internal voltages and phase currents. This result is significant when it is required to design a few specific number of identical single-phase TFPM machines which finally they will be assembled such that to build a multi-phase machine with a minimum torque ripple. The design parameters of a case study Claw Pole TFPM machine are introduced with some details and a few FE based simulation results are given as the validations of the analytical approach of the present paper. The simulation results show clearly the impact of each harmonic of the internal voltages and phase currents on the torque ripple for various numbers of phases leading the designer to find out which number of single-phase machine combinations is the optimum one regarding the torque ripple.

Application of vacuum belt press filters for cane mud filtration and performance comparison with rotary filters

2014 ◽  
pp. 298-301 ◽  
Author(s):  
Arnaud Petit
Keyword(s):  
Electricity Consumption ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Vacuum Filter ◽  
Sugar Mill ◽  
Belt Press ◽  
Vacuum Belt ◽  
And Performance ◽  
Mud Filtration ◽  
The Impact

Bois-Rouge factory, an 8000 t/d cane Reunionese sugarcane mill, has fully equipped its filtration station with vacuum belt press filters since 2010, the first one being installed in 2009. The present study deals with this 3-year experience and discusses operating conditions, electricity consumption, performance and optimisation. The comparison with the more classical rotary drum vacuum filter station of Le Gol sugar mill highlights advantages of vacuum belt press filters: high filtration efficiency, low filter cake mass and sucrose content, low total solids content in filtrate and low power consumption. However, this technology needs a mud conditioning step and requires a large amount of water to improve mud quality, mixing of flocculant and washing of filter belts. The impact on the energy balance of the sugar mill is significant. At Bois-Rouge mill, studies are underway to reduce the water consumption by recycling low d.s. filtrate and by dry cleaning the filter belts.

scholarly journals Impact of Passive Energy Efficiency Measures on Cooling Energy Demand in an Architectural Campus Building in Karachi, Pakistan

2021 ◽  
Vol 13 (13) ◽  
pp. 7251
Author(s):  
Mushk Bughio ◽  
Muhammad Shoaib Khan ◽  
Waqas Ahmed Mahar ◽  
Thorsten Schuetze
Keyword(s):  
Energy Efficiency ◽  
Energy Demand ◽  
Electricity Consumption ◽  
Information Modeling ◽  
Base Case ◽  
Energy Efficiency Measures ◽  
Efficiency Measures ◽  
The Impact ◽  
Cooling Energy Demand ◽  
Campus Building

Electric appliances for cooling and lighting are responsible for most of the increase in electricity consumption in Karachi, Pakistan. This study aims to investigate the impact of passive energy efficiency measures (PEEMs) on the potential reduction of indoor temperature and cooling energy demand of an architectural campus building (ACB) in Karachi, Pakistan. PEEMs focus on the building envelope’s design and construction, which is a key factor of influence on a building’s cooling energy demand. The existing architectural campus building was modeled using the building information modeling (BIM) software Autodesk Revit. Data related to the electricity consumption for cooling, building masses, occupancy conditions, utility bills, energy use intensity, as well as space types, were collected and analyzed to develop a virtual ACB model. The utility bill data were used to calibrate the DesignBuilder and EnergyPlus base case models of the existing ACB. The cooling energy demand was compared with different alternative building envelope compositions applied as PEEMs in the renovation of the existing exemplary ACB. Finally, cooling energy demand reduction potentials and the related potential electricity demand savings were determined. The quantification of the cooling energy demand facilitates the definition of the building’s electricity consumption benchmarks for cooling with specific technologies.

Design of a Robust Memristive Spiking Neuromorphic System with Unsupervised Learning in Hardware

2021 ◽  
Vol 17 (4) ◽  
pp. 1-26
Author(s):  
Md Musabbir Adnan ◽  
Sagarvarma Sayyaparaju ◽  
Samuel D. Brown ◽  
Mst Shamim Ara Shawkat ◽  
Catherine D. Schuman ◽  
...  
Keyword(s):  
Unsupervised Learning ◽  
Recognition Task ◽  
Single Layer ◽  
Process Variations ◽  
Spike Timing ◽  
System Level ◽  
Design Parameters ◽  
Digital Pulse ◽  
Neuromorphic System ◽  
The Impact

Spiking neural networks (SNN) offer a power efficient, biologically plausible learning paradigm by encoding information into spikes. The discovery of the memristor has accelerated the progress of spiking neuromorphic systems, as the intrinsic plasticity of the device makes it an ideal candidate to mimic a biological synapse. Despite providing a nanoscale form factor, non-volatility, and low-power operation, memristors suffer from device-level non-idealities, which impact system-level performance. To address these issues, this article presents a memristive crossbar-based neuromorphic system using unsupervised learning with twin-memristor synapses, fully digital pulse width modulated spike-timing-dependent plasticity, and homeostasis neurons. The implemented single-layer SNN was applied to a pattern-recognition task of classifying handwritten-digits. The performance of the system was analyzed by varying design parameters such as number of training epochs, neurons, and capacitors. Furthermore, the impact of memristor device non-idealities, such as device-switching mismatch, aging, failure, and process variations, were investigated and the resilience of the proposed system was demonstrated.

Making Up 3D Bodies

2021 ◽  
Vol 4 (2) ◽  
pp. 1-9
Author(s):  
Kiona Hagen Niehaus ◽  
Rebecca Fiebrink
Keyword(s):  
Software Tool ◽  
The Body ◽  
Design Parameters ◽  
Artistic Practice ◽  
Human Form ◽  
Modeling Systems ◽  
Exploratory Approach ◽  
Disability Status ◽  
High Level ◽  
The Impact

This paper describes the process of developing a software tool for digital artistic exploration of 3D human figures. Previously available software for modeling mesh-based 3D human figures restricts user output based on normative assumptions about the form that a body might take, particularly in terms of gender, race, and disability status, which are reinforced by ubiquitous use of range-limited sliders mapped to singular high-level design parameters. CreatorCustom, the software prototype created during this research, is designed to foreground an exploratory approach to modeling 3D human bodies, treating the digital body as a sculptural landscape rather than a presupposed form for rote technical representation. Building on prior research into serendipity in Human-Computer Interaction and 3D modeling systems for users at various levels of proficiency, among other areas, this research comprises two qualitative studies and investigation of the impact on the first author's artistic practice. Study 1 uses interviews and practice sessions to explore the practices of six queer artists working with the body and the language, materials, and actions they use in their practice; these then informed the design of the software tool. Study 2 investigates the usability, creativity support, and bodily implications of the software when used by thirteen artists in a workshop. These studies reveal the importance of exploration and unexpectedness in artistic practice, and a desire for experimental digital approaches to the human form.

scholarly journals Simulation Tests of a Cow Milking Machine—Analysis of Design Parameters

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1358
Author(s):  
Ewa Golisz ◽  
Adam Kupczyk ◽  
Maria Majkowska ◽  
Jędrzej Trajer
Keyword(s):  
Mathematical Model ◽  
Simplified Model ◽  
Design Parameters ◽  
Degree Polynomial ◽  
Fourth Degree ◽  
Local Loss ◽  
Linear Drag ◽  
Milking Machine ◽  
Machine Analysis ◽  
The Impact

The objective of this paper was to create a mathematical model of vacuum drops in a form that enables the testing of the impact of design parameters of a milking cluster on the values of vacuum drops in the claw. Simulation tests of the milking cluster were conducted, with the use of a simplified model of vacuum drops in the form of a fourth-degree polynomial. Sensitivity analysis and a simulation of a model with a simplified structure of vacuum drops in the claw were carried out. As a result, the impact of the milking machine’s design parameters on the milking process could be analysed. The results showed that a change in the local loss and linear drag coefficient in the long milk duct will have a lower impact on vacuum drops if a smaller flux of inlet air, a higher head of the air/liquid mix, and a higher diameter of the long milk tube are used.

Sign in / Sign up

Export Citation Format

Share Document