Дисертації з теми "Powder wires"
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1
Latif, Sofia. "Microstructural Characterisation of Magnesium Diboride Powder-in-Tube Wires and Tapes." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504420.
Повний текст джерела
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Souza, Élton José de [UNESP]. "Fabricação e caracterização de fios supercondutores do sistema BSCCO pelo método Powder-In-Tube (PIT)." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/91976.
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Com o surgimento da supercondutividade as pesquisas envolvendo aplicações desta, em especial no transporte de energia, obtiveram um avanço promissor ao longo dos anos. Assim, este trabalho objetivou a fabricação de fios supercondutores utilizando o método Powder-In-Tube (PIT), no qual foi inserido dentro de um tubo de prata o pó da cerâmica supercondutora do sistema BSCCO. Estudos preliminares foram feitos em pastilhas feitas com o mesmo material supercondutor e após alguns resultados foram confeccionados os fios supercondutores. Medidas de caracterização foram feitas dentre elas a difratometria de raios-X, medidas elétricas pelo método de quatro pontas e microscopia do tipo (FEG-MEV) equipado com EDS para determinar a morfologia e composição química dos elementos na amostra. Os resultados de difratometria de raios-X apresentaram a formação das fases desejadas do sistema BSCCO de diferentes concentrações dentre elas as fases Bi-2212 Bi- 2223 e Bi-2234 contidas nas amostras sintetizadas. As medidas elétricas detectaram uma queda abrupta na resistência elétrica dos fios mostrando a faixa de transição supercondutora das amostras estudadas. As medidas de densidade de corrente com base no critério de corrente de 1μV/cm, utilizadas nos fios confeccionados, foram obtidos valores da ordem de 1,30 – 3,90 (KA/m2). Nas imagens de microscopia vale ressaltar uma melhora na interação entre os grãos supercondutores nas amostras submetidas a um maior tempo de sinterização e também foi possível verificar e analisar através da extrusão a compactação do pó cerâmico dentro do tubo de prata. O EDS detectou a composição química dos elementos nas amostras bem como a concentração das fases em determinadas regiões analisadas
With the emergence of superconductivity research involving applications of this, particularly in the transport of energy, had a promising advance over the years. This study aims to manufacture superconducting wires using the method Powder-In-Tube (PIT), which was inserted inside a tube of silver powder of superconducting ceramic BSCCO system. Preliminary studies were done on pellets made with the same superconducting material, and after some results were prepared the superconducting wires. Characterization measurements were made among them the X-ray diffraction, electrical measurements by the method of four points and type of microscopy (FEG-SEM) equipped with EDX to determine the morphology and chemical composition of the elements in the sample. The results of X-ray diffraction showed the formation of the desired phases for this type of superconductor, ie the BSCCO system between them was possible to determine the Bi-2212 phase, Bi-2223 and Bi-2234 contained in the synthesized samples. The electrical measurements have detected a sudden drop in electrical resistance of the wires showing the range of superconducting transition with good accuracy. It was possible to perform the calculation of current density in the wires made based on a criterion of 1 μV/cm were obtained and values of around 1,30– 3,90 (KA/m2). The values are consistent with the specifications of the samples and within the limits of our research. In microscopy images is noteworthy improvement in the interaction between the superconducting grains in samples submitted to a higher sintering time and it was possible to verify and analyze the compaction of ceramic powder into silver tube through the extrusion process. The EDX detected the chemical composition of the elements in the samples in a qualitative way
3
Souza, Élton José de. "Fabricação e caracterização de fios supercondutores do sistema BSCCO pelo método Powder-In-Tube (PIT) /." Ilha Solteira : [s.n.], 2011. http://hdl.handle.net/11449/91976.
Повний текст джерелаАнотація:
Orientador: Cláudio Luiz CarvalhoBanca: Haroldo Naoyuki Nagashima
Banca: Isaias Gonzaga de Oliveira
Resumo: Com o surgimento da supercondutividade as pesquisas envolvendo aplicações desta, em especial no transporte de energia, obtiveram um avanço promissor ao longo dos anos. Assim, este trabalho objetivou a fabricação de fios supercondutores utilizando o método Powder-In-Tube (PIT), no qual foi inserido dentro de um tubo de prata o pó da cerâmica supercondutora do sistema BSCCO. Estudos preliminares foram feitos em pastilhas feitas com o mesmo material supercondutor e após alguns resultados foram confeccionados os fios supercondutores. Medidas de caracterização foram feitas dentre elas a difratometria de raios-X, medidas elétricas pelo método de quatro pontas e microscopia do tipo (FEG-MEV) equipado com EDS para determinar a morfologia e composição química dos elementos na amostra. Os resultados de difratometria de raios-X apresentaram a formação das fases desejadas do sistema BSCCO de diferentes concentrações dentre elas as fases Bi-2212 Bi- 2223 e Bi-2234 contidas nas amostras sintetizadas. As medidas elétricas detectaram uma queda abrupta na resistência elétrica dos fios mostrando a faixa de transição supercondutora das amostras estudadas. As medidas de densidade de corrente com base no critério de corrente de 1μV/cm, utilizadas nos fios confeccionados, foram obtidos valores da ordem de 1,30 - 3,90 (KA/m2). Nas imagens de microscopia vale ressaltar uma melhora na interação entre os grãos supercondutores nas amostras submetidas a um maior tempo de sinterização e também foi possível verificar e analisar através da extrusão a compactação do pó cerâmico dentro do tubo de prata. O EDS detectou a composição química dos elementos nas amostras bem como a concentração das fases em determinadas regiões analisadas
Abstract: With the emergence of superconductivity research involving applications of this, particularly in the transport of energy, had a promising advance over the years. This study aims to manufacture superconducting wires using the method Powder-In-Tube (PIT), which was inserted inside a tube of silver powder of superconducting ceramic BSCCO system. Preliminary studies were done on pellets made with the same superconducting material, and after some results were prepared the superconducting wires. Characterization measurements were made among them the X-ray diffraction, electrical measurements by the method of four points and type of microscopy (FEG-SEM) equipped with EDX to determine the morphology and chemical composition of the elements in the sample. The results of X-ray diffraction showed the formation of the desired phases for this type of superconductor, ie the BSCCO system between them was possible to determine the Bi-2212 phase, Bi-2223 and Bi-2234 contained in the synthesized samples. The electrical measurements have detected a sudden drop in electrical resistance of the wires showing the range of superconducting transition with good accuracy. It was possible to perform the calculation of current density in the wires made based on a criterion of 1 μV/cm were obtained and values of around 1,30- 3,90 (KA/m2). The values are consistent with the specifications of the samples and within the limits of our research. In microscopy images is noteworthy improvement in the interaction between the superconducting grains in samples submitted to a higher sintering time and it was possible to verify and analyze the compaction of ceramic powder into silver tube through the extrusion process. The EDX detected the chemical composition of the elements in the samples in a qualitative way
Mestre
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FERNANDES, MARCOS G. "Obtanção de fios em ligas cobre-magnésio para utilização em linhas de transmissão de energia elétrica." reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10030.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Шкіндер, Олексій Миколайович. "Створення порошкових дротів з покращеними властивостями для дугового наплавлення". Master's thesis, КПІ ім. Ігоря Сікорського, 2019. https://ela.kpi.ua/handle/123456789/31447.
Повний текст джерелаАнотація:
В наш час швидко розвивається промисловість. Тож вироблення порошкових дротів що в свою чергу вимагає великої кількості обладнання різного типу. Використання системи в поточному виробництві дозволяє забезпечити виготовлення високоякісного порошкового дроту з гарантованими властивостями, що найбільш точно відповідають вимогам технічної документації.
Завдяки новому, більш ефективному технологічному процесу, теоретично можна збільшити продуктивність, швидкість та економічність виготовлення.Nowadays the industry is developing rapidly. Therefore, powder coils are manufactured, which use a wide variety of types of equipment in their work. The systems used in the current production make it possible to manufacture high quality powder wire with guaranteed power properties, which requires exacting of technical documentation. Thanks to a new, higher technological process, it is theoretically possible to increase the productivity, speed and economy of production.
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Menck, Peter-Johannes. "How wires shape volumes." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://dx.doi.org/10.18452/16930.
Повний текст джерелаАнотація:
Diese Arbeit ist der Frage gewidmet, wie die Stabilität eines Stromnetzes mit seiner Topologie zusammenhängt. Stabilität wird hier mit Hilfe von Bassin-Stabilität vermessen, einer nichtlokalen und nichtlinearen Methode, mit der sich quantifizieren lässt, wie stabil ein Stromnetz gegen große Störungen ist. Netzartige Systeme werden mit den Methoden der Theorie komplexer Netzwerke beschrieben. Bassin-Stabilität wird zunächst formal eingeführt. Dann wird die Methode angewendet, und zwar einmal auf abstrakte und einmal auf konkrete Weise. Der abstrakte Ansatz ist dadurch motiviert, dass die Funktion eines Stromnetzes auf dem synchronen Zusammenwirken seiner Komponenten beruht. Er betrifft die Frage, wie generelle dynamische Netzwerke strukturiert sein sollten, um stabile Synchronisation zu unterstützen. Es stellt sich heraus, dass Netzwerke mit maximaler Bassin-Stabilität am entgegengesetzten Ende eines gewissen netzwerktheoretischen Spektrums angesiedelt sind als Netzwerke, die optimal sind in Hinsicht auf lokale Stabilität. Dies deutet darauf hin, dass in der Entwicklung von synchron funktionierenden Systemen die Optimierung auf lokale Stabilität hin und die gleichzeitige Optimierung auf nichtlokale Stabilität hin als entgegengesetzte Kräfte gewirkt haben. Der konkrete Ansatz geht aus von einem Stromnetzmodell aus der Ingenieuersliteratur. Bassin-Stabilität wird komponentenweise eingesetzt, um zu untersuchen, wie der Grad der Stabilität eines Stromnetzes gegen große Einzelknoten-Störungen beeinflusst wird von gewissen Mustern in der Netztopologie. Simulationen in einem Ensemble von Stromnetzen bringen diverse Statistiken hervor, die alle eine wesentliche Beobachtung stützen: Ausgerechnet das kostengünstigste und weitverbreitetste Anschlussschema - bestehend aus Stichleitungen - vermindert die Netzstabilität beträchtlich. Es lässt sich ein fundamentales Designprinzip ableiten: Vermeide Stichleitungen.This thesis addresses the question how the stability of a power grid depends on the network topology. Stability is assessed here by means of basin stability, a nonlocal and nonlinear inspection scheme that allows to quantify how stable a power grid is against large perturbations. Networked systems are characterized using the instruments of complex network theory. A rigorous definition of basin stability is provided. Then, basin stability is applied once in an abstract and once in a more applied way. The abstract approach is motivated by the fact that power grids rely on the synchronous operation of their components, and focusses on the problem how general dynamical networks should be structured to support a stable synchronous state. It turns out that networks with maximum basin stability are located at the opposite end of a certain network-theoretical spectrum than networks optimal with respect to local stability. This suggests that, during the evolution of synchronizing networks, the optimization for local stability and the simultaneous optimization for nonlocal stability have acted as opposing forces. The more applied approach draws on a power grid model from the engineering literature. A component-wise version of basin stability is used to assess how a grid''s degree of stability against large single-node perturbations is influenced by certain patterns in the wiring topology. Simulations in an ensemble of power grids yield various statistics that all support one main finding: The widespread and cheapest of all connection schemes, so-called dead ends and dead trees, strongly diminish stability. The inverse is also true: `Healing'' dead ends by addition of transmission lines substantially enhances stability. This indicates a basic design principle for future power grids: avoid dead ends.
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Yavaş, Mert Okur Salih. "Fabrication and characterization of MgB2 powders and Cu-Clad MgB2 wires/." [s.l.]: [s.n.], 2005. http://library.iyte.edu.tr/tezler/master/fizik/T000373.pdf.
Повний текст джерела
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Najar, salwan. "Simulering av 1-Wire sensorer." Thesis, KTH, Skolan för teknik och hälsa (STH), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104086.
Повний текст джерелаАнотація:
The 1-wire bus is a communication bus system which is designed to provide data, signals and power over a single signal with low data rates, a high resolution and a long range. It is typically used to communicate with small inexpensive devices, as temperature sensors, which is worked as a slave with the master computer (PC). The 1-wire bus system provides the sufficient control and operation signal, a unique ID serial number of each sensor and it supports multiple temperature sensors by a driving power (Parasite Power) on single line. On the 1-Wire bus system, temperature sensors are supplied by two types of power supplies, external Power supply and Parasitic Power. The aim of this project is to program the microprocessor (Arduino) by using Arduino programming language to work as a temperature sensor type DS18B20 and also as a slave on the 1-Wire bus system. This report explains the 1-Wire bus system techniques and how the communication is achieved between the master and the slave (sensors) to measure the temperature values. The measured temperature values are collected from the output of each active sensor on the 1-Wire bus. These data are displayed by the personal computer (PC) which is worked as a master on the 1-Wire bus, and the data are represent the measured temperature values from twelve active sensors on the bus system. In this thesis, the temperature values from the 12 active sensors can be read and displayed on the master (PC) by using the following programs: Open Logger One Wire (OLOW) program, One Wire Viewer, DigiTemp and OWFS and I validated all the temperature values from these active sensors which are read and monitored by the drive bus programs. The comparison is done among the measured temperature values to see if the active sensors are given accurate temperature values with different drive bus programs. The project shows that the sensors can be connected in a network with the master, by using 1-Wire bus techniques. This thesis will be used by Karolinska University Hospital, and it can also be developed for different requirements in the future.
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Zuber, Paul. "Wire topology optimisation for low power CMOS." kostenfrei, 2007. http://mediatum2.ub.tum.de/doc/618152/document.pdf.
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Casique, Rodriguez Irene. "Power, autonomy and division of labor in Mexican dual-earner families /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Syed, Waheed Ul Haq. "Combined wire and powder deposition for laser direct metal additive manufacturing." Thesis, University of Manchester, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.556499.
Повний текст джерела
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Melangret, Michel. "Definition of Apparent Power in 3-Phase 4-Wire Non-Sinusoidal Power Systems." Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5163.
Повний текст джерелаАнотація:
Includes abstract.Includes bibliographical references (leaves 120-125).
The thesis starts by collating and comparing most power theories in the instantaneous and average power domain. The instantaneous theories are reformulated and classified into three groups, which can be linked with one equation. Introducing a new instantaneous theory based on vector space allows the fundamental properties of the groups to be examined and provides the means to extend instantaneous power into the rms domain and calculate the compensating currents required. The approach results in power components that can be attributed a real physical interpretation. The new approach to three phase power theory has significant potential for education, the practical design of active compensators, and the revision of international standard definitions of power.
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Malengret, Michel. "Definition of apparent power in 3-phase 4-wire non-sinusoidal power systems." Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5174.
Повний текст джерелаАнотація:
Includes abstract.Includes bibliographical references (leaves 120-125).
The thesis starts by collating and comparing most power theories in the instantaneous and average power domain. The instantaneous theories are reformulated and classified into three groups, which can be linked with one equation. Introducing a new instantaneous theory based on vector space allows the fundamental properties of the groups to be examined and provides the means to extend instantaneous power into the rms domain and calculate the compensating currents required. The approach results in power components that can be attributed a real physical interpretation. The new approach to three phase power theory has significant potential for education, the practical design of active compensators, and the revision of international standard definitions of power.
14
Bakkabulindi, Geofrey. "Planning Models for Single Wire Earth Return Power Distribution Networks." Licentiate thesis, KTH, Elektriska energisystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107160.
Повний текст джерелаАнотація:
The high cost of grid extension to rural areas, often characterized by scattered communities with low load densities, requires the use of low cost electrification technologies to ensure economic viability. In Single Wire Earth Return (SWER) power distribution networks, the earth itself forms the current return path of the single phase system leading to significant cost savings on conductors, poles and poletop hardware compared to conventional systems. However, challenges exist in SWER with regard to earthing and safety as well as the dependence on earth conductivity to supply consumer loads. This work presents models for the optimal planning of SWER distribution networks. The earth return path is modeled as a conductor based on the Carson line model taking into consideration specific ground properties of the considered location. A load flow algorithm for radial SWER networks is subsequently formulated whereby both overhead line and ground voltages and currents are determined. First, heuristic planning models are developed based on the SWER load flow model. The objective of the heuristic models is to determine the optimum feeder configuration and overhead conductor subject to SWER load flow constraints and load growth over several time periods. Whereas the resulting solutions are good, they may not necessarily be globally optimum. Optimization models are then developed using mixed integer non-linear programming (MINLP) with the aim of obtaining global solutions to the SWER network planning problem. Since the MINLP formulations are limited to the accurate analysis of limited size networks, considerations and approximations for the analysis of larger networks are presented. The developed models are applied to a case study in Uganda to test their practical application. In addition, comparative studies are done to determine how the proposed optimization models compare with previous distribution planning models. The numerical analysis includes the impact of deterministic distributed generation on the SWER planning problem. Results showed consistent performance of the proposed heuristic and optimization models, which also compared well with conventional models. The optimization models gave more cost-effective solutions to the SWER planning problem than the heuristic models. However, the former models had higher computational cost than the latter. The inclusion of distributed generation allowed for cheaper network solutions to be obtained. The models are applicable to the planning of Single Wire Earth Return networks for isolated mini-grids, grid-extension to previously un-electrified rural areas as well as the upgrade of SWER feeders in existing installations.QC 20121207
Sustainable Technological Development in the Lake Victoria Region
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Naylor, Matthew J. "Development of high temperature superconducting materials for power applications." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301420.
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Sun, Bo. "A FPGA-based power electronics controller for three-phase four-wire hybrid active power filters." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2547180.
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Abioye, Taiwo E. "Laser deposition of Inconel 625/tungsten carbide composite coatings by powder and wire feedstock." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14253/.
Повний текст джерелаАнотація:
There is an increasing global demand to extend the life span of down-hole drilling tools in order to improve operation effectiveness and efficiency of oil and gas production. Laser cladding of tungsten carbide/Ni-based alloy metal matrix composite (MMC) coatings is currently being utilised for this purpose. However, the effect of tungsten carbide dissolution on the corrosion performance of the MMC coatings has not been completely understood. In this work, a study was carried out in which laser cladding of a stainless steel substrate using (i) Inconel 625 wire and (ii) tungsten carbide powder (Spherotene)/Inconel 625 wire was undertaken. This work was performed using a fibre laser system and has examined the process characteristics, the microstructure and the corrosion performance of the clad layers. Process characteristics studies were carried out by visual observation of the cladding process within a process window (laser power: 1-1.8 kW, traverse speed: 100-300 mm min-1, wire feed rate: 400-1000 mm min-1, powder feed rate: 25 g min-1). The microstructures were investigated using a combination of optical microscopy, scanning electron microscopy (with energy dispersive X-ray analysis) and X-ray diffraction. The volume fraction of tungsten carbide retained in the composite coatings was determined using image processing software. Corrosion performance was assessed using electrochemical corrosion testing in de-aerated 3.5 wt.% NaCl solution. Well bonded, minimally diluted, pore- and crack-free Inconel 625 wire and Spherotene (WC/W2C) powder/Inconel 625 wire composite coatings were successfully deposited. Cladding process characteristics were categorised into wire dripping, smooth wire deposition and wire stubbing within the range of parameters used in this work. Process maps which predict the characteristic of Inconel 625 wire and Spherotene (WC/W2C)/Inconel 625 wire fibre laser cladding at varying cladding conditions within the process window were developed. The volume fraction of tungsten carbide (WC/W2C) retained in the composite coatings was found to decrease with increasing laser power, traverse speed and wire feed rate. Tungsten carbide dissolution was found to result in the precipitation of intermetallic compounds including M6C and M23C6 in the γ-Ni matrix, which is rich in W and C. The increase in tungsten carbide dissolution was also found to increase the propensity for corrosion in the MMC coatings compared to the Inconel 625 wire coatings. As a result, the corrosion performance of the tungsten carbide/Ni based alloy MMC coatings can be improved by reducing the level of tungsten carbide dissolution through process control.
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Zhang, Huibin. "Application of multilevel inverter as shunt active power filter in three-phase three-wire power system." Thesis, University of Strathclyde, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501797.
Повний текст джерелаАнотація:
This research investigates application issues of the active power filter to three-phase three-wire systems, with unbalanced, distorted loads where the line impedance gives rise to voltage distortion at the point of common coupling. Five shunt active power filters are investigated: two-level, wye connected cascaded three and five level, and diode-clamped three and five level. Capabilities of the different shunt active power filter topologies to mitigate voltage/current distortion, compensate reactive power, and balance real power from the source are investigated. Results indicate that neutral point clamped multilevel inverters have advantages over wye cascaded multilevel inverters when operating under asymmetrical load conditions.
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Mukherjee, Tonmoy Shankar. "High performance, low-power and robust multi-gigabit wire-line design." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/39515.
Повний текст джерелаАнотація:
The object of this research is to develop robust wire-line systems which demonstrate high performance while simultaneously consuming low power. The main focus of this work is the Clock and Data Recovery (CDR) system, which is the primary circuit of any modern wire-line transceiver. Different techniques starting from circuit-level to system-level have been investigated in this work to improve the performance of multi-gigabit CDRs. A 62 GHz bandwidth amplifier has been presented to address the need for a scalable amplifier for CDR needs. A new technique has been proposed to improve the radiation immunity of latches, to reduce the BER in CDRs occurring due to package radiations. An injection-lock based clock recovery method was investigated as an alternative to PLL based CDRs as they can be used for burst-mode wire-line communication. The investigation yielded the vulnerability of the method to jitter (false-locking and high jitter transfer), the attenuation of which is critical to commercial CDRs. A novel false-lock detector system has been proposed and demonstrated for the first time as a robust solution to the issue of false-locking of CDRs due to repetitive patterns. The implementation of the final CDR system required the use of an L-C tank VCO, the components of which are generic for all commercial CDRs. A new systematic layout technique for the VCO has been proposed and demonstrated in this work to substantially improve the layout area and the associated parasitics, approximately by 70 %. This new layout addresses a critical yet often neglected part of VCO design. Furthermore, a new concept has been proposed to optimize static dividers with respect to their power consumption and number of devices.
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Farayibi, Peter Kayode. "Laser cladding of Ti-6Al-4V with carbide and boride reinforcements using wire and powder feedstock." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14268/.
Повний текст джерелаАнотація:
The growth in the use and wear of Ti-based alloy components in mining and offshore explorations has led to a search for techniques to re-engineer such components for reuse. The most desirable method of restoring/protecting the component surfaces is by hard-facing to enhance longevity in service. Laser cladding is one of the viable techniques to achieve a thick coating on such components which involves the addition of reinforcing particulates to improve surface properties such as hardness, wear and erosion resistance amongst others. A fundamental study and understanding of the resultant microstructure-property of the laser clad, hard-facing composite becomes necessary. In this study, laser cladding of Ti-6Al-4V wire with Spherotene particulate reinforcement and laser cladding of modified pre-blend of Ti-6Al-4V and TiB_2 powder were undertaken. The resulting physical and microstructural characteristics, hardness, and performance characteristics of laser clad composites were investigated. Samples from the as-deposited laser clad composites were characterised using optical microscopy, scanning electron microscopy (with chemical microanalysis) and X-ray diffraction. Performance characteristics were examined via erosion testing of the laser clad Ti-6Al-4V/Spherotene using plain and abrasive water jetting, and tensile testing of the laser clad Ti-6Al-4V/TiB_2 composite. The results showed that a crack and pore free clad containing as high as 76 wt.% Spherotene in the Ti matrix was achieved at an energy density of 150 J.mm^-2, 275 mm/min traverse speed, 700 mm/min wire feed rate and 30 g/min powder feed rate. The microstructure of the laser clad Ti-6Al-4V/Spherotene is characterised by nano-sized precipitates of reaction products (W and TiC) uniformly distributed in a beta-Ti solid solution matrix. Matrix hardness is enhanced by the presence of the reaction products in the Ti ranging between 410-620 kgf.mm^-2. Moreover, the modication made to the 90 wt.% Ti-6Al-4V/10 wt.% TiB2 feedstock by attaching the TiB2 to Ti-6Al-4V allowed uniform distribution of reinforcing element in the deposited composite. The composite microstructure on solidication is characterised by TiB eutectic needle-like features uniformly distributed in a Ti-rich primary phase. The hardness of the composite ranged between 440-480 gf.mm^-2. Tensile tests showed that the mean elastic modulus of Ti-6Al-4V/TiB_2 composite is 145 GPa, which is a 27% improvement when compared to that of Ti-6Al-4V. Erosion test indicated that the Ti-6Al-4V/Spherotene composite offered as high as 13 and 8 times resistance of that of Ti-6Al-4V when subjected to PWJ and AWJ impacts respectively.
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Gross, David [Verfasser]. "Copper Metallization on Silicon Power Devices for Heavy Copper Wire-Bonding / David Gross." Aachen : Shaker, 2016. http://d-nb.info/1122546432/34.
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Mok, Sui Him. "Deposition of Ti-6Al-4V using a high power diode laser and wire." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442310.
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Le, Minh-Nhat Ba. "ADVANCED THERMOSONIC WIRE BONDING USING HIGH FREQUENCY ULTRASONIC POWER: OPTIMIZATION, BONDABILITY, AND RELIABILITY." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/177.
Повний текст джерелаАнотація:
Gold wire bonding typically uses 60 KHz ultrasonic frequency. Studies have been reported that increasing ultrasonic frequency from 60KHz to 120KHz can decrease bonding time, lower bonding temperature, and/or improve the bondability of Au metalized organic substrates. This thesis presents a systematic study of the effects of 120 KHz ultrasonic frequency on the reliability of fine pitch gold wire bonding. Two wire sizes, 25.4 and 17.8 μm in diameter (1.0 and 0.7 mil, respectively) were used. The gold wires were bonded to metalized pads over organic substrates with five different metallization. The studies were carried out using a thermosonic ball bonder that is able to easily switch from ultrasonic frequency from 60 KHz to 120 KHz by changing the ultrasonic transducer and the ultrasonic generator. Bonding parameters were optimized through design of experiment methodology for four different cases: 60 KHz with 25.4 μm wire, 60 KHz with 17.8 μm wire, 120 KHz with 25.4 μm wire, and 120 KHz with 17.8 μm wire. The integrity of wire bonds was evaluated by the wire pull and the ball bond shear tests. With the optimized bonding parameters, over 2,250 bonds were made for each frequency and wire size. The samples were then divided into three groups. The first group was subjected to temperature cycling from -55°C to +125°C with one hour per cycle for up to 1000 cycles. The second group was subject to thermal aging at 125°C for up to 1000 hours. The third group was subject to humidity at 85°C/85% relative humidity (RH) for up to 1000 hours. The bond integrity was evaluated through the wire pull and the ball shear tests immediately after bonding, and after each 150, 300, 500, and 1000 hours time interval in the reliability tests. The pull and shear data are then analyzed to compare the wire bond performance between different ultrasonic frequencies.
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Lam, Chi Seng. "An adaptive low dc-voltage controlled LC coupling hybrid active power filter in three-phase four-wire power systems." Thesis, University of Macau, 2012. http://umaclib3.umac.mo/record=b2580608.
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Odemark, Ylva. "Wakes behind wind turbines - Studies on tip vortex evolution and stability." Licentiate thesis, KTH, Mekanik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93806.
Повний текст джерелаАнотація:
The increased fatigue loads and decreased power output of a wind turbine placed in the wake of another turbine is a well-known problem when building new wind power farms. In order to better estimate the total power output of a wind power farm, knowledge about the development and stability of wind turbine wakes is crucial. In the present thesis, the wake behind a small-scale model turbine was investigated experimentally in a wind tunnel. The velocity in the wake was measured with hot-wire anemometry, for different free stream velocities and tip speed ratios. To characterize the behaviour of the model turbine, the power output, thrust force and rotational frequency of the model were also measured. These results were then compared to calculations using the Blade Element Momentum (BEM) method. New turbine blades for the model was constructed using the same method, in order to get an estimate of the distribution of the lift and drag forces along the blades. This information is needed for comparisons with certain numerical simulations, which however remains to be performed.By placing the turbine at different heights in a turbulent boundary layer, the effects of forest turbulence on wind turbine outputs (power and thrust) could also be investigated.The evolution of the tip vortices shed from the turbine blades was studied by performing velocity measurements around the location of the tip vortex breakdown. The vortices' receptivity to disturbances was then studied by introducing a disturbance in the form of two pulsed jets, located in the rear part of the nacelle. In order to introduce a well-defined disturbance and perform phase-locked measurements, a new experimental setup was constructed and successfully tested for two different disturbance frequencies. The mean streamwise velocity and the streamwise turbulence intensity was found to scale well with the free stream velocity and the spreading of the wake was found to be proportional to the square root of the downstream distance. The comparison for power and thrust between measurements and BEM calculations showed good agreement in some cases but worse agreement when the pitch angle of the blades was small.The velocity measurements showed that the tip vortices can be susceptible to disturbances and an earlier breakdown could be detected. However, more measurements need to be made to fully investigate the dependance on disturbance frequency and amplitude.QC 20120504
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SUGIURA, Yoshie, Takaya YAMAZATO, Masaaki KATAYAMA, and 正昭 片山. "Measurement of Narrowband Channel Characteristics in Single-Phase Three-Wire Indoor Power-Line Channels." IEEE, 2008. http://hdl.handle.net/2237/11152.
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Yuen, Albert Wai Ling Materials Science & Engineering Faculty of Science UNSW. "Collector current density and dust collection in wire-plate electrostatic precipitators." Awarded by:University of New South Wales. Materials Science and Engineering, 2006. http://handle.unsw.edu.au/1959.4/28274.
Повний текст джерелаАнотація:
Even minimal improvements in particle collection efficiency of electrostatic precipitators significantly reduce dust emission from fossil-fuelled power stations and reduce pollution. Yet current designs rely on the Deutsch collection theory, which was developed for tubular precipitators and has been applied to wire-plate precipitators on the assumption that the inter-electrode electric fields at the same discharge distance in both were similar. Differences in geometry and associated collector electric fields and current density non-uniformity have not been taken into account, although the collector electric field and current density of the wire-plate precipitator are not uniform. And observations show that precipitated dust patterns and the distribution of collector current density are interrelated. Investigations revealed a simple square law relationship between the collector electric field and the collector current density in the space charge dominated coronas. Applying this relationship to the Deutsch collection theory led to a current-density-based collection formula that takes into account the non-uniform collector current density distribution. The current-density-based collection formula is then used to assess the impact of collector current density on collection efficiency, the results closely following published measurements. Applying the current-density-based collection formula to estimate the dust accumulation shows that most of the dust accumulates at collector locations facing the corona wires. The effect of the non-uniform precipitated dust layer on collection performance is assessed using the distributed corona impedance - the ratio of the inter-electrode voltage and the non-uniform collector current. Re-distribution of the collector current profile as dust builds up is also compatible with published measurements. Finally this is applied to optimize the wire-plate precipitator collection performance. This shows that optimal collection performance is obtained with the wire-wire spacing less than the wire-plate distance, once again confirming published experimental results. This is the first analytical approach to show better collection performance can be achieved at the ratio of wire-wire spacing/wire-plate distance not equal to unity, which has been the standard industry practice since 1960.
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Chen, Zheng. "Electrical Integration of SiC Power Devices for High-Power-Density Applications." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23923.
Повний текст джерелаАнотація:
The trend of electrification in transportation applications has led to the fast development of high-power-density power electronics converters. High-switching-frequency and high-temperature operations are the two key factors towards this target. Both requirements, however, are challenging the fundamental limit of silicon (Si) based devices. The emerging wide-bandgap, silicon carbide (SiC) power devices have become the promising solution to meet these requirements. With these advanced devices, the technology barrier has now moved to the compatible integration technology that can make the best of device capabilities in high-power-density converters. Many challenges are present, and some of the most important issues are explored in this dissertation.
First of all, the high-temperature performances of the commercial SiC MOSFET are evaluated extensively up to 200 degree C. The static and switching characterizations show that the device has superior electrical performances under elevated temperatures. Meanwhile, the gate oxide stability of the device - a known issue to SiC MOSFETs in general - is also evaluated through both high-temperature gate biasing and gate switching tests. Device degradations are observed from these tests, and a design trade-off between the performance and reliability of the SiC MOSFET is concluded.
To understand the interactions between devices and circuit parasitics, an experimental parametric study is performed to investigate the influences of stray inductances on the MOSFETs switching waveforms. A small-signal model is then developed to explain the parasitic ringing in the frequency domain. From this angle, the ringing mechanism can be understood more easily and deeply. With the use of this model, the effects of DC decoupling capacitors in suppressing the ringing can be further explained in a more straightforward way than the traditional time-domain analysis. A rule of thumb regarding the capacitance selection is also derived.
A Power Electronics Building Block (PEBB) module is then developed with discrete SiC MOSFETs. Integrating the power stage together with the peripheral functions such as gate drive and protection, the PEBB concept allows the converter to be built quickly and reliably by simply connecting several PEBB modules. The high-speed gate drive and power stage layout designs are presented to enable fast and safe switching of the SiC MOSFET. Based on the PEBB platform, the state-of-the-art Si and SiC power MOSFETs are also compared in the device characteristics, temperature influences, and loss distributions in a high-frequency converter, so that special design considerations can be concluded for the SiC MOSFET.
Towards high-temperature, high-frequency and high-power operations, integrated wire-bond phase-leg modules are also developed with SiC MOSFET bare dice. High-temperature packaging materials are carefully selected based on an extensive literature survey. The design considerations of improved substrate layout, laminated bus bars, and embedded decoupling capacitors are all discussed in detail, and are verified through a modeling and simulation approach in the design stage. The 200 degree C, 100 kHz continuous operation is demonstrated on the fabricated module. Through the comparison with a commercial SiC phase-leg module designed in the traditional way, it is also shown that the design considerations proposed in this work allow the SiC devices in the wire-bond structure to be switched twice as fast with only one-third of the parasitic ringing.
To further push the performance of SiC power modules, a novel hybrid packaging technology is developed which combines the small parasitics and footprint of a planar module with the easy fabrication of a wire-bond module. The original concept is demonstrated on a high-temperature rectifier module with SiC JFET. A modified structure is then proposed to further improve design flexibility and simplify module fabrication. The SiC MOSFET phase-leg module built in this structure successfully reaches the switching speed limit of the device almost without any parasitic ringing.
Finally, a new switching loop snubber circuit is proposed to damp the parasitic ringing through magnetic coupling without affecting either conduction or switching losses of the device. The concept is analyzed theoretically and verified experimentally. The initial integration of such a circuit into the power module is presented, and possible improvements are proposed.Ph. D.
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Ng, Fan. "Operation and DC-link voltage control of three-phase four-wire unified power quality conditioners." Thesis, University of Macau, 2007. http://umaclib3.umac.mo/record=b1677859.
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Lok, Io Keong. "Study of soft-switching techniques on three-level three-phase four-wire active power filters." Thesis, University of Macau, 2010. http://umaclib3.umac.mo/record=b2493512.
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Wen, Sihua. "Thermal and Thermo-Mechanical Analyses of Wire Bond vs. Three-dimensionally Packaged Power Electronics Modules." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/30823.
Повний текст джерелаАнотація:
The goal of more efficiently and more reliably realizing energy conversion in the power electronics industry is pushing the limits of current wire bonding packaging technology. Emerging three-dimensional power packaging techniques have shown their potential to replace wire bonding technology down the road. However, these innovative technologies have not yet been fully understood in terms of thermal and thermo-mechanical performance. Therefore, a comparative evaluation between the thermally induced response in conventional wire bonding (a 2-Dimensional technology) and 3-Dimensional packaging technologies is essential.
Thermal and thermo-mechanical analysis using the Finite Element Method (FEM) has been performed to evaluate a three-dimensional power module packaged in a Metal Post Interconnected-Parallel Plate Structure (the MPIPPS), and the result is compared with that of a wire bond module.
Under the same single-sided cooling conditions, thermal modeling results show a significantly lower junction temperature of 17oC in the MPIPPS module than that in the wire bond module, due to the more uniform heat flow distribution in the MPIPPS module. The top DBC (direct bonded copper) substrate in the MPIPPS module helps direct the excessive heat generated from IGBT (Insulated Gate Bipolar Transistor) chips to diode chips (which dissipates less heat). The maximum junction temperature is reduced to 108 oC in the MPIPPS module by the implementation of double-sided cooling, which the wire bonding technique can not achieve. Subsequent thermo-mechanical analysis reveals the weak points in both modules during temperature cycling and power cycling. In the wire bond module, temperature cycle results have shown more severe stress and strain than that those of the power cycling conditions in the regions where the wires attach the device emitter pads. In the MPIPPS module, the solder joints exhibit high plastic and creep deformation. Power cycling produces more inelastic deformation at the solder joints between the posts and device, due to local over-heating, which causes more severe high-temperature creep deformation. Using a deformation-based thermal fatigue theory, the solder joint fatigue lives are predicted. Compared with the commercial wire bond module temperature cycle test, the fatigue life of MPIPPS is limited.
We conclude that the MPIPPS module is better in thermal management but is thermo-mechanically less reliable than the wire bond module.Master of Science
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Rachmildha, Tri Desmana. "La commande hybride prédictive d’un convertisseur quatre bras." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT044H/document.
Повний текст джерелаАнотація:
Dans une large variété d'applications industrielles, il existe une demande croissante pour améliorer la qualité de l'énergie fournie par les systèmes électriques. En plus de la fiabilité et de la disponibilité d'énergie électrique, la qualité de la puissance fournie devient maintenant une question importante. Parmi les causes de la pauvre qualité de puissance, les harmoniques sont considérés comme la raison qui contribue à la majorité de pannes de courant. Beaucoup d'efforts ont été développés pour résoudre le problème des perturbations harmoniques comme, par exemple, installer des dispositifs spéciaux tels que les filtres actifs. Ce travail de thèse traite le développement d’une commande directe de puissance utilisant l'approche prédictive hybride. La commande hybride considère chaque vecteur de tension du convertisseur comme une entité discrète qui sera appliquée pour commander un système linéaire continu. Un critère pour calculer le vecteur optimal de tension à appliquer sera établi à partir d’un modèle prédictif. Le vecteur optimal de tension à appliquer pour chaque période de commutation, et le correspondant temps d'application seront utilisés pour approcher la valeur réelle des variables d'état du système au point de référence désiré. Deux théories de puissance instantanées seront employées, p-q et p-q-r, pour une application de filtre active parallèle de puissance dans un système triphasé de 4 fils. Ces théories instantanées de puissance ont été développées pour être appliquées aux systèmes non équilibrés utilisant les variables de puissance pour obtenir les courants qui devraient être injectés par le filtre actif. Le filtre actif produira la puissance réactive demandée par la charge et compensera la composante d'ondulation de la puissance active de sorte que la source livre seulement la puissance active constanteIn a wide variety of industrial applications, an increasing demand exists to improve the quality of the energy provided by electrical systems. Besides the reliability and availability of electric power, the power quality is now becoming an important issue. Among the causes of the poor power quality, the harmonics are included as the reason which contributes the majority of power failures. Many efforts have been developed to solve the harmonics problem as, for instance, to install special devices such as active filters. This research work deals with the development of direct power control using the hybrid predictive control approach. The hybrid control considers each voltage vector of the converter as a discrete entity which will be applied to control a continuous linear system. One criterion to calculate the optimal voltage vector to apply will be established for the predictive control model. The optimal voltage vector to apply for each switching period, and the corresponding application time will be used to approach the actual value of the state variables of the system to the desired reference point. Two instantaneous power theories will be used, i.e. pq0 and pqr instantaneous power theory for a shunt active power filter application implemented in 3-phase 4-wire system. These instantaneous power theories have been developed to be applied to unbalanced systems using the power variables to obtain the currents that should be injected from active filters. The active filter will produce the required reactive power for the load and compensate the ripple component of active power so that the source only delivers constant active power
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Yarber, Robert K. "Development and calibration of two and four wire water surface wave height measurement systems." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23863.
Повний текст джерелаАнотація:
Approved for public release; distribution is unlimitedCapacitance and conductance measurements using two and four wire techniques were developed and statically and dynamically calibrated in this thesis. The voltage sensitivities range from 7.3 to 8.1 ± 0.1 mV/cm for the two wire capacitance system static calibrations. This is ± 5.2% of the limiting theoretical value. The voltage sensitivities range from 0.3 to 0.4 ± 0.1 V/cm for the four wire conductance system static calibrations. Dynamic calibrations were only completed for the conductance system. The dynamic calibration results were weakly frequency dependent with a qj-0.15 decay in a limited, 2-4 Hz range. Wind power spectrum measurements were taken in the existing Upper Ocean Simulations Facility at the Naval Postgraduate School. There was excellent agreement in the spectra with both techniques. Driven gravity wave frequency downshifting and wind energy dumping was observed in the combined gravity wave and wind-wave measurements. The power spectra peaked near two Hertz and decayed at 50 to 70 dB per decade, or as CO -5 to G)" 7 for both systems. Gravity wave phase speed and wavelength measurements were performed with the capacitance system. The results were approximately 40% higher than theory.
http://archive.org/details/developmentcalib00yarb
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Sandvik, Christian Mclisky. "Wave-to-Wire Model of the Wave Energy Converter Bolt2 : Control and Power Extraction with an All-Electric Power Take-Off System." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18393.
Повний текст джерелаАнотація:
Fred Olsen is currently testing their latest wave energy converter outside of Falmouth Bay in England, preparing it for commercial exploitation at the Wavehub-project. Previous studies have shown that this device has potential for increased power extraction using reactive control, but so far these investigations have focused on the hydrodynamics of the device and on reducing the peak-to-average power ratio while omitting the effect of the electric power take off system. This thesis shows the development of the hydrodynamic model of the device as well as a detailed model of the all-electric power take-off system consisting of a permanent magnet synchronous generator, inverter and DC-link. Vector Control is used to control the Permanent Magnet Synchronous Generator, and field weakening control of the generator is applied in order allow over-speed operation. Time domain wave-to-wire simulations are performed to evaluate the power take off capabilities of the modelled wave energy converter with different control parameters. When tuned according to approximate complex conjugate control the accumulated average generator losses become large, giving a very low overall system efficiency. Optimal control with respect to electrical output power is found to be with low added mass, and when compared to pure passive loading a 1% increase in annual energy production is achieved. The main factor that reduces the effect of reactive control is found to be the minimum load-force constraint of the device, which cannot be lower than 1 ton. Example simulations on a device with different force constraint are performed which verifies this characteristic.These results suggests that the Bolt2 has limited potential for increase in power extraction by implementing reactive control. The analysis in this thesis is nevertheless valuable, as it demonstrates how a wave-to-wire model can be used for power take-off investigations, annual energy production estimations and evaluations of different control techniques.
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Joseph, Andrew Paul. "Assessing the effects of GMAW-Pulse parameters on arc power and weld heat input /." Connect to resource, 2001. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1130521651.
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Zhan, Ming Hui. "Analysis and evaluation of soft-switching techniques for 3-phase 4-wire shunt power quality compensators." Thesis, University of Macau, 2006. http://umaclib3.umac.mo/record=b1678022.
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Yang, Li. "A damage-based time-domain wear-out model for wire bond interconnects in power electronic modules." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13646/.
Повний текст джерелаАнотація:
In the Physics-of-Failure based approach to reliability design and assessment, which aims to relate lifetime to the identified root-cause of the potential failures, the development of effective failure mechanism models is a crucial task. The extent and rate of wire bond degradation depends on both the magnitude and duration of exposure to the loads. In the existing physics-of-failure models for wire bond interconnects, lifetime is accounted for by loading amplitude alone and is usually derived based on a regular thermal cycle of a known duration. They are not ready to predict life of arbitrary mission profiles and the effects of time at temperature on the wear-out behaviour are not addressed, leading to substantial errors for thermal cycling regimes with high peak temperatures. In this thesis, a new lifetime prediction model for wire bonds is proposed based on some phenomenological considerations, which accounts not only for the damage accumulation processes but also the damage removal phenomena during thermal exposure. The methodology discards the usual cycle-dependent modelling methodology and is instead based on a time domain representation so that it can more accurately reflect the observed temperature-time effects and related phenomena. This new time-based presentation allows estimation on the bonding interface damage condition at regular time intervals through a damage based crack propagation model which includes the effect of temperature and time dependent material properties. Meanwhile, bond degradation state is indicated in the form of crack growth and shear force reduction that are predicted by the total interface damage as a function of time. The model is calibrated and validated by the experimental results from wire material characterization tests and accelerated thermal cycling which demonstrates the advantages over the cycle-based methodologies.
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Andersson, Tobias, and Jonathan Toft. "Data communication and power supply on a two conductor system." Thesis, Uppsala universitet, Elektricitetslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-359781.
Повний текст джерелаАнотація:
This master thesis aimed to develop a prototype of a hardware platform which allowed digital communication as well as DC power to be transmitted over one pair of wires. The prototype was used as a pre-study for Axis Communications AB that wanted a bit rate high enough to transmit digital audio, as well as enough power to supply a set of speakers. The prototype included one circuit to send power and data (master), as well as two receivers (slaves). With this configuration data rates of up to 17 Mbps were achieved as well as an output power of 90 W from master. The data was transmitted on a RS-485 bus type, which was AC coupled to a 48 V DC bias. Because of the AC coupling, the bit stream needed to alternate, therefore Manchester encoded data, or similar, was recommended. The receiver cards included a buck converter to supply the circuits with a stable 5 V DC. The converters needed at least 10 V supply voltage to function, which gave a theoretical max range in cabling when accounting for voltage drop in the cables. For a 0.75 mm² power cord at max allowed current, this range was 500 metres per wire.
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Anosike, Nnamdi Benedict. "Technoeconomic evaluation of flared natural gas reduction and energy recovery using gas-to-wire scheme." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8625.
Повний текст джерелаАнотація:
Most mature oil reservoirs or fields tend to perform below expectations, owing to
high level of associated gas production. This creates a sub-optimal performance
of the oil production surface facilities; increasing oil production specific
operating cost. In many scenarios oil companies flare/vent this gas. In addition
to oil production constraints, associated gas flaring and venting consists an
environmental disasters and economic waste. Significant steps are now being
devised to utilise associated gas using different exploitation techniques. Most of
the technologies requires large associated gas throughput.
However, small-scale associated gas resources and non-associated natural gas
reserves (commonly referred to as stranded gas or marginal field) remains
largely unexploited. Thus, the objective of this thesis is to evaluate techno-
economic of gas turbine engines for onsite electric power generation called gas-
to-wire (GTW) using the small-scaled associated gas resources. The range of
stranded flared associated gas and non-associated gas reserves considered is
around 10 billion to 1 trillion standard cubic feet undergoing production decline.
The gas turbine engines considered for power plant in this study are based on
simple cycle or combustion turbines. Simple cycle choice of power-plant is
conceived to meet certain flexibility in power plant capacity factor and
availability during production decline. In addition, it represents the basic power
plant module cable of being developed into other power plant types in future to
meet different local energy requirements.
This study developed a novel gas-to-wire techno-economic and risk analysis
framework, with capability for probabilistic uncertainty analysis using Monte
Carlo simulation (MCS) method. It comprises an iterative calculation of the
probabilistic recoverable reserves with decline module and power plant
thermodynamic performance module enabled by Turbomatch (an in-house
code) and Gas Turb® software coupled with economic risk modules with
@Risk® commercial software. This algorithm is a useful tool for simulating the
interaction between disrupted gas production profiles induced by production
decline and its effect on power plant techno-economic performance over
associated gas utilization economic life. Furthermore, a divestment and make-
up fuel protocol is proposed for management of gas turbine engine units to
mitigate economical underperformance of power plant regime experienced due
to production decline.
The results show that utilization of associated gas for onsite power generation is
a promising technology for converting waste to energy. Though, associated gas
composition can be significant to gas turbine performance but a typical Nigerian
associated gas considered is as good as a regular natural gas. The majority of
capital investment risk is associated with production decline both natural and
manmade. Finally, the rate of capital investment returns decreases with smaller
reserves.
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Mulpuri, Vamsi. "Failure Analysis and High Temperature Characterization of Silicon Carbide Power MOSFETs." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron151076214366849.
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Knott, Ryan Christopher. "High temperature durability of metals for use in a particle heating receiver for concentrated solar power." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53117.
Повний текст джерелаАнотація:
An experimental investigation is presented on a novel High Temperature Falling Particle Receiver for Concentrated Solar Power (CSP) to quantify the extent of erosion of the receiver structural materials by the flowing particulate matter. The current receiver design uses a series of metal wire mesh screens to slow down the particulate flow through the receiver in order to increase their residence time thereby achieving the desired temperature rise within the receiver without the need for particulate recirculation. The solid particulates are gravity fed through the receiver where they absorb the incident thermal energy before flowing to a high temperature storage bin upstream of a heat exchanger where the heat stored in the particulate material is transferred to the working fluid for the power cycle. To assess the effective life of the receiver, this experimental investigation is undertaken. This thesis includes the development of an apparatus to test wire meshes under high temperature and particle abrasion conditions, and the presentation and analysis of these results.
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Joshi, Ajay Jayant. "Wave-Pipelined Multiplexed (WPM) Routing for Gigascale Integration (GSI)." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10549.
Повний текст джерелаАнотація:
The main objective of this research is to develop a pervasive wire sharing technique that can be easily applied across the entire range of on-chip interconnects in a very large scale integration (VLSI) system. A wave-pipelined multiplexed (WPM) routing technique that can be applied both intra-macrocell and inter-macrocell interconnects is proposed in this thesis. It is shown that an extensive application of the WPM routing technique can provide significant advantages in terms of area, power and performance. In order to study the WPM routing technique, a hierarchical approach is adopted. A circuit-level, system-level and physical-level analysis is completed to explore the limits and opportunities to apply WPM routing to current VLSI and future gigascale integration (GSI) systems. Design, verification and optimization of the WPM circuit and measurement of its tolerance to external noise constitute the circuit-level analysis. The physical-level study involves designing wire sharing-aware placement algorithms to maximize the advantages of WPM routing. A system-level simulator that designs the entire multilevel interconnect network is developed to perform the system-level analysis. The effect of WPM routing on a full-custom interconnect network and a semi-custom interconnect network is studied.
43
Ersoy, Mehmet Okan. "Application Of A Natural-resonance Based Feature Extraction Technique To Small-scale Aircraft Modeled By Conducting Wires For Electromagnetic Target Classification." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/12605522/index.pdf.
Повний текст джерелаАнотація:
The problem studied in this thesis, is the classification of the small-scale
aircraft targets by using a natural resonance based electromagnetic feature extraction
technique. The aircraft targets are modeled by perfectly conducting, thin wire
structures. The electromagnetic back-scattered data used in the classification process,
are numerically generated for five aircraft models.
A contemporary signal processing tool, the Wigner-Ville distribution is
employed in this study in addition to using the principal components analysis
technique to extract target features mainly from late-time target responses. The
Wigner-Ville distribution (WD) is applied to the electromagnetic back-scattered
responses from different aspects. Then, feature vectors are extracted from suitably
chosen late-time portions of the WD outputs, which include natural resonance related
v
information, for every target and aspect to decrease aspect dependency. The database
of the classifier is constructed by the feature vectors extracted at only a few reference
aspects. Principal components analysis is also used to fuse the feature vectors and/or
late-time aircraft responses extracted from reference aspects of a given target into a
single characteristic feature vector of that target to further reduce aspect dependency.
Consequently, an almost aspect independent classifier is designed for small-scale
aircraft targets reaching high correct classification rate.
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Menck, Peter Johannes [Verfasser], Jürgen [Akademischer Betreuer] Kurths, Marc [Akademischer Betreuer] Timme, and Michael [Akademischer Betreuer] Zaks. "How wires shape volumes : on the relation between network topology and nonlocal power grid stability / Peter-Johannes Menck. Gutachter: Jürgen Kurths ; Marc Timme ; Michael Zaks." Berlin : Humboldt Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://d-nb.info/1049519663/34.
Повний текст джерела
45
XU, PENG. "HYBRID X-BAND POWER AMPLIFIER DEVELOPMENT FOR 3D-IC PHASED ARRAY MODULE." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1049977754.
Повний текст джерела
46
Möllerström, Erik. "Vertical Axis Wind Turbines : Tower Dynamics and Noise." Licentiate thesis, Högskolan i Halmstad, Energiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-242267.
Повний текст джерелаАнотація:
Vertical axis wind turbines (VAWTs) have with time been outrivaled by the today common and economically feasible horizontal axis wind turbines (HAWTs). However, VAWTs have several advantages such as the possibility to put the drive train at ground level, lower noise emissions and better scaling behavior which still make them interesting for research. The work within this thesis is made in collaboration between the Department of Construction and Energy Engineering at Halmstad University and the Division for Electricity at Uppsala University. A 200 kW VAWT owned by the latter and situated close to Falkenberg in the southwest of Sweden has been the main subject of the research even if most learnings has been generalized to fit a typical vertical turbine. This particular turbine has a wooden tower which is semi-guy-wired, i.e. the tower is both firmly attached to the ground and supported by guy-wires. This thesis has two main topics both regarding VAWTs: eigenfrequency of the tower and the noise generated from the turbine. The eigenfrequency of a semi-guy-wired tower is studied and an analytical expression describing this is produced and verified by experiments and simulations. The eigenfrequency of the wire itself and how it is affected by wind load are also studied. The noise characteristics of VAWTs have been investigated, both theoretically and by noise measurement campaigns. Both noise emission and frequency distribution of VAWTs has been studied. The work has resulted in analytical expressions for tower and wire eigenfrequency of a semi-guy-wired tower as well as recommendations for designing future towers for VAWTs. The noise emission of VAWTs has been studied and proven low compared to HAWTs. The noise frequency distribution of the 200 kW VAWT differs significantly from that of a similar size HAWTs with for example lower levels for frequencies below 3000 Hz.
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Brown, Monique. "Benevolent Sexism, Perceived Fairness, Decision-Making, and Marital Satisfaction: Covert Power Influences." Antioch University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1387296162.
Повний текст джерела
48
Tu, Sheng-Hung, and 涂昇宏. "Wire Length and Domino Power Minimization Based on Multiple Wire Replacement Techniques." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/44616357882225893383.
Повний текст джерелаАнотація:
碩士國立中正大學
資訊工程研究所
88
Dynamic logics such as domino logic can be a substitute on higher performance circuit design for static CMOS logic. Usually, such substitution can lead to delay and area reduction. Our objective in this thesis attempts to reduce the power consumption of domino circuits. In order to achieve this goal, we introduced a logic synthesis tool, called the alternative node technique, which can perform multiple wire replacement at the same time. By observing the monotone property of domino logic, we can achieve the goal of power reduction by extending the alternative node technique to reduce the total switching probability in a domino circuit. In addition, we also have proposed an effective framework which combines the logic and layout synthesis algorithms to further improve the wire (interconnection) length. The results show that the flexibility of the Alnode technique can be successfully extended to power reduction and wire length minimization with little run time.
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Chen, Ben-Sheng, and 陳本盛. "Three-Phase Four-Wire Active Power Filters." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/41253884785347453692.
Повний текст джерелаАнотація:
碩士國立臺灣大學
電機工程學研究所
88
In a distribution system, switching power electronic devices, especially all kinds of AC to DC converters, have been widely used in recently years. This causes very serious harmonic pollution problems. In order to reduce the harmonic, passive L-C filters have been widely employed in practice. Since many drawbacks have been observed in passive compensation methods, active filters will be examined in this work. A survey of the literatures on active filters indicate that, while analog circuits are used as the control kernels of the filters in some products and laboratory prototypes, digital control methods are most widely used. On this thesis digital system architecture is used to set up the control kernel. This three-phase four-wire active power filter is PC-based with an Adventec PCL-1800 data acquisition board. In this thesis, the principles of the three-phase four-wire active power filter are described first. Then from results of matlab simulations and experiments, it is found that the harmonic currents can be compensated and the power factor can be improved by the proposed active power filter.
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Chen, Jen-Yuan, and 陳人源. "The study of wire parameters of power specification in wire bend process because." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/17450869661548755495.
Повний текст джерелаАнотація:
碩士國立高雄大學
電機工程學系碩士班
102
Wire bonding is a key process in most IC packaging except for flip chip package. There are variety of wire materials such as alumina wire, gold wire, silver wire, and recently developed copper wire to meet with the requirements for mechanical adhesion, electrical characteristics and cost. As known that IC packages are more versatile and high power specification. Since, most studies were focused on the mechanical adhesion issues in wire bonding. This thesis is focused on the study of the optimization of the electrical properties of wire bonding based on fundamental electro-magnetic principle. The experiments results of I-V testing show that by shortening the wire length or by parallel wires bonding can effectively increase the current loading of wire bonding. These results of wire bonding optimization approach can be helpful to promote the efficiency of wire bonding for high power electronics packages.