• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 613
  • 177
  • 155
  • 146
  • 82
  • 39
  • 38
  • 28
  • 24
  • 20
  • 15
  • 13
  • 10
  • 7
  • 4
  • Tagged with
  • 1706
  • 492
  • 475
  • 301
  • 269
  • 249
  • 238
  • 204
  • 183
  • 176
  • 170
  • 166
  • 166
  • 164
  • 134
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

マイクロ波無線送電に適用した超広負荷範囲に対応できるレクテナの開発 / Development of a Rectenna Adapted to Ultra-wide Load Range for Microwave Power Transmission

黄, 勇 23 March 2015 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第18992号 / 工博第4034号 / 新制||工||1621 / 31943 / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 篠原 真毅, 教授 和田 修己, 教授 山川 宏 / 学位規則第4条第1項該当
172

Low Voltage Multi-level Converters using Split-wound Coupled Inductors

Ewanchuk, Jeffrey Unknown Date
No description available.
173

DC to AC inverter card with IGBTs : Construction and performance

Eriksson, Johannes January 2012 (has links)
This paper presents the construction and evaluation of a DC to AC inverter with IGBT:s and the basic PCD-layout for the single IGBT drivers. The main work consisted of constructing a PCB-card for controlling a number of IGBT:s, simulate its properties and test driving it. The schematic of the card is an extension of the recommended use of the optocoupler HCPL316J with a few modulations made for the special demands on the Division of Electricity at Uppsala University. Even though, some basic changes were made in the schematic in this work, the main changes concerned choice of components due to economy and space and did not change the electrical properties of the card notably. Except several electrical properties that will be the main focus in this paper, size and price are two things that also have been taken under consideration during the work. In the paper, many parts and components will be described to fully explain the function of the cards properties. This is for future reference and documentation and was one of the goals of the project.
174

'Vivre et mourir en la religion ancienne romaine et Catholique' : Catholic activism in South-west France, 1560-1570

Gould, Kevin January 2003 (has links)
This thesis determines the impact of Catholic activism in south-west France during the 1560s. Using manuscript and archival material, it examines the nascence, infrastructure and aims of the various ligues and associations of the period, and assesses their ability to secure hegemony by usurping local administrative and military apparatus. The thesis is divided into four parts: Part I studies Catholic activism at Bordeaux and the Bordelais. Chapters 1 and 2 establish the demography and structure of government there and evaluate antecedents to the ligues of the 1560s: namely the activities of the confraternity of Saint- Yves, the basoche and the syndicat of 1561. Chapter 3 examines the role of the Catholic nobility in the internecine struggles of the period, and Chapter 4 explores the post-1568 domination of military and bureaucratic offices at Bordeaux by a coalition of leading Catholic activists. Part II focuses on events at Agen and the Agenais. Chapter 5 details the establishment of an executive council of Catholic notables within the town, while Chapter 6 assesses the role of the local nobility in supporting this coalition government after 1563. Part III concentrates on affairs at Toulouse. Chapter 7 examines the birth of formal Catholic activism within the town, focussing on the enterprises of the confraternity, basochiens and militant court officials. Chapter 8 analyses the reinvigoration of Catholic endeavours at Toulouse after 1567, gauging the success of a policy to finance the Catholic war effort by sequestering Protestant goods, and appraising the somewhat anachronistic phenomenon of the croisade of 1568. Part IV considers the extent to which national and European dimensions influenced the form and nature of Catholic activism during the 1560s. Chapter 9 examines the impact of Catholic grandee patronage on the ligues of the south-west, and assesses the resurgence in confraternal activism after 1567. Chapter 10 examines the influence of Spain and the papacy on the evolution of the associations, and explores the level of reciprocity between ligueurs and European potentates. Chapter 11 details the ambitions of Catholic powers to remove the Calvinist queen of Navarre, Jeanne d' Albret, from power in Béarn and Navarre, and assesses the role played by the ligueurs in this enterprise.
175

French colonial discourses : the case of French Indochina 1900-1939

Cooper, Nicola J. January 1997 (has links)
This thesis focuses upon French colonial discourses at the height of the French imperial encounter with Indochina: 1900-1939. It examines the way in which imperial France viewed her role in Indochina, and the representations and perceptions of Indochina which were produced and disseminated in a variety of cultural media emanating from the metropole. Framed by political, ideological and historical developments and debates, each chapter develops a socio-cultural account of France's own understanding of her role in Indochina, and her relationship with the colony during this crucial period. The thesis asserts that although consistent, French discourses of Empire do not present a coherent view of the nation's imperial identity or role, and that this lack of coherence is epitomised by the Franco-indochinese relationship. The thesis seeks to demonstrate that French perceptions of Indochina were marked above all by a striking ambivalence, and that the metropole's view of the status of Indochina within the Empire was often contradictory, and at times paradoxical. Indeed, the thesis argues that Indochina was imagined through a series of antitheses which reflect the incoherent nature of French colonial discourse during this period. This thesis uses as its primary material a variety of key cultural media which informed the popular perception of Indochina during this period: metropolitan and Franco-indochinese school manuals; the writings and designs of French colonial urbanists; the works of influential colonial apologists; 'official' texts relating to the organisation and impact of the Exposition coloniale of 1931; travel journalism; and metropolitan fiction relating to Indochina. The discursive approach that this thesis takes, focusing clearly upon the socio-cultural dimension, should provide an important re-evaluation of French Indochina and its legacy, and should make a contribution to the understanding of France's relations with her colonial territories during the first half of the twentieth century.
176

A Transformerless High Step-up DC-DC Converter For DC Interconnects

Soong, Theodore 16 August 2012 (has links)
The proliferation of distributed energy resources (DER)s has prompted interest in the expansion of DC power systems. The technological limitations that hinder the expansion of DC power systems are the absence of DC circuit breakers and high step-up/high step-down DC converters for interconnecting DC systems. This thesis presents a transformerless high step-up DC-DC converter intended for use as an interconnect between DC systems. The converter is required to operate at medium to high voltage (>1kV) and provide high voltage gain (>5). This work details the steady state operation and dynamic model of the proposed converter. The component ratings are identified and converter design limitations are investigated. A 100V:1kV/4kW prototype is produced to verify the analytic steady state model and measure efficiency. An experimental efficiency of 90% was achieved at a step-up ratio of 1:10, however efficiency at low power is limited due to the need to circulate power.
177

A Transformerless High Step-up DC-DC Converter For DC Interconnects

Soong, Theodore 16 August 2012 (has links)
The proliferation of distributed energy resources (DER)s has prompted interest in the expansion of DC power systems. The technological limitations that hinder the expansion of DC power systems are the absence of DC circuit breakers and high step-up/high step-down DC converters for interconnecting DC systems. This thesis presents a transformerless high step-up DC-DC converter intended for use as an interconnect between DC systems. The converter is required to operate at medium to high voltage (>1kV) and provide high voltage gain (>5). This work details the steady state operation and dynamic model of the proposed converter. The component ratings are identified and converter design limitations are investigated. A 100V:1kV/4kW prototype is produced to verify the analytic steady state model and measure efficiency. An experimental efficiency of 90% was achieved at a step-up ratio of 1:10, however efficiency at low power is limited due to the need to circulate power.
178

Gut situiert: Bankwatch-NGOs in Washington, DC

Bläser, Ralf January 2005 (has links)
Zugl.: Köln, Univ., Diss., 2005. - Zsfassung in engl. Sprache
179

Estudos sobre a eficiência da polinização por Apis mellifera L. e insetos nativos na produção de sementes de Adesmia latifolia (Spreng.) Vog.

Camacho, Júlio César Brião January 2003 (has links)
Com o objetivo de determinar a eficiência da ação polinizadora de Apis mellifera L. no rendimento de sementes de Adesmia latifolia, estabeleceu-se três tratamentos na Estação Experimental Agronômica da UFRGS, em Eldorado do Sul (300 S, 510 W) nos anos de 2000, 2001 e 2002. A partir da floração, analisou-se a freqüência de visitas por A. mellifera e outros insetos nas flores de A. latifolia pelo teste de Qui-quadrado, já o número de inflorescências por área, número de flores, flores abortadas e lomentos por inflorescência foi através da análise de regressão. Os resultados indicaram que A. mellifera não é eficiente na polinização de A. latifolia, sendo esta cultura dependente de insetos nativos como Megachile sp. e Centris sp para produção de sementes. A média de produção de sementes na área controlada e livre foi 5,4 e 83,5 kg/ha, respectivamente, enquanto na área isolada não houve produção de sementes. A baixa freqüência (10%) de visitas de A. mellifera na área livre em comparação com os insetos nativos (90%) indica que o néctar não é atrativo para as abelhas A. mellifera pois tem uma baixa concentração de açúcares totais (5,7%).
180

Estudos sobre a eficiência da polinização por Apis mellifera L. e insetos nativos na produção de sementes de Adesmia latifolia (Spreng.) Vog.

Camacho, Júlio César Brião January 2003 (has links)
Com o objetivo de determinar a eficiência da ação polinizadora de Apis mellifera L. no rendimento de sementes de Adesmia latifolia, estabeleceu-se três tratamentos na Estação Experimental Agronômica da UFRGS, em Eldorado do Sul (300 S, 510 W) nos anos de 2000, 2001 e 2002. A partir da floração, analisou-se a freqüência de visitas por A. mellifera e outros insetos nas flores de A. latifolia pelo teste de Qui-quadrado, já o número de inflorescências por área, número de flores, flores abortadas e lomentos por inflorescência foi através da análise de regressão. Os resultados indicaram que A. mellifera não é eficiente na polinização de A. latifolia, sendo esta cultura dependente de insetos nativos como Megachile sp. e Centris sp para produção de sementes. A média de produção de sementes na área controlada e livre foi 5,4 e 83,5 kg/ha, respectivamente, enquanto na área isolada não houve produção de sementes. A baixa freqüência (10%) de visitas de A. mellifera na área livre em comparação com os insetos nativos (90%) indica que o néctar não é atrativo para as abelhas A. mellifera pois tem uma baixa concentração de açúcares totais (5,7%).

Page generated in 0.0325 seconds