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  • 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.
31

琵琶記傳奇之硏究. / Pi pa ji chuan qi zhi yan jiu.

January 1972 (has links)
手稿本 / 論文(碩士)--香港中文大學,1972. / 參考文獻: p. 234 - 242 / 馬珍波. / Chapter 第一章 --- 琵琶記作者高明 / Chapter 第一節 --- 生平 / Chapter 第二節 --- 著述 / Chapter 第三節 --- 琵琶記作者與高明 / Chapter 第二章 --- 琵琶記劇本背景 / Chapter 第一節 --- 題材背景 / Chapter 第二節 --- 編劇手法 / Chapter 第三章 --- 琵琶記特色 / Chapter 第一節 --- 結構 / Chapter 第二節 --- 文辭 / Chapter 第四章 --- 結論
32

Determination of Optimal True Digestible Calcium to True Digestible Phosphorus Ratio in Growing Pigs

Johnson, Ntinya 15 March 2013 (has links)
Three studies were conducted. In the first study, 12 Yorkshire barrows (initial BW of 23.2 ± 2.0 kg) were allotted to 2 dietary treatments with 6 replications per treatment using a completely randomized design to determine apparent Ca and P digestibility (AD), true digestibility (TD) and endogenous output (EO) in a corn/SBM-based diet. All pigs were placed in individual feeder pens that allowed for easy collection of individual feces. The AD of Ca and P were 28.4% and 23.9%, respectively. Their TD of 42% and 40% for Ca and P respectively were significantly (P < 0.05) higher than the corresponding AD. EO was 0.8g for Ca and 1.3g for P per kg of dry matter intake (DMI). In the second study, the optimal dietary ratio of true digestible Ca and P was determined in terms of its effect on growing pig performance, excretion of Ca and P in feces and urine in a corn/SBM-based diet using a randomized complete block design. Thirty six growing barrows (initial BW: 24.2 ± 1.9 kg) were allotted to 6 dietary treatments with 6 replications per block. Six corn/SBM-based diets with very similar nutrient contents were formulated but differed in their dietary ratio of Ca to P. The balances of Ca and P and their true digestibility/retention were calculated for each diet. Animal performance and true retention of both Ca and P was optimal (P < 0.05) with diet 2 with a true digestible Ca to P ratio of 0.82: 1 compared to other experimental diets. The third study was conducted with a similar protocol to that used in experiment 1 involving 12 barrows (initial BW: 23.9 ± 1.1 kg) to determine Mg, Cu, Fe, Mn, Se and Zn TD values for the growing pig. Se and Zn AD of 73.9% and 9.5% significantly (P < 0.05) underestimated their TD of 82.1% and 15%, respectively. Se and Zn EO were 0.00004mg and 0.01 mg/kg of DMI, respectively. The TD and EO for Mg, Cu, Fe and Mn could not be estimated because of their negative AD.
33

Origin and Geochemistry of Modern Bahamian Ooids

Duguid, SARAH 27 January 2009 (has links)
The Bahamian Archipelago is one of the few locations in the world where ooid formation is actively occurring. Ooid cortices from six locations in the region were incrementally dissolved and analyzed for 14C, δ18O, δ13C, Mg/Ca and Sr/Ca ratios. Ooids were examined under SEM after each step in the incremental analyses to characterize the nature of dissolution. Radiocarbon dating indicates that surface ooids began forming across the Archipelago between 1000 and 2800 yr BP and continue to form today. The ooids have the same pattern of microboring alteration across the region. The surface and outer cortex of the ooids are punctuated with unfilled microborings, whereas the inner cortex contains two morphologies of aragonite cement filling the microborings. The two morphologies of cement form in association with two different species of cyanobacteria, one is Solentia sp. the other is interpreted to be Hyella sp.. The chemistry of ooids from across the region is remarkably similar. δ18O and δ13C values for all samples vary directly, having a slope of approximately 1. The outer cortex has low δ18O and δ13C values of -3.4‰ and 0.2‰ respectively, whereas the δ18O and δ13C values of the inner cortex are high with values of 1.9‰ and 6.8‰ respectively. The presence of aragonite cement in microborings in the inner cortex increases the overall isotopic composition of both oxygen and carbon in the ooid, causing it to appear close to equilibrium with seawater. The isotopic variation in δ18O and δ13C within the cortex can be characterized as a mixing line between the low values in the unaltered ooid laminae and the aragonite cement in the microborings. The most exterior portion of the ooid has very high Mg/Ca values and is interpreted as an amorphous calcium carbonate (ACC) coating. There are two other phases in the cortex, both being aragonite. The outer cortex has a higher Mg/Ca ratio and lower Sr/Ca ratio than the inner cortex. This difference in chemistry is a result of the presence of aragonite cement in the inner cortex. Stable isotopic and trace element results coupled with SEM investigations indicate that microbes do not play a role in ooid formation, but instead alter the texture and chemistry of ooids after they have formed. This alteration occurs throughout the entire shoal region. A new model of ooid formation is proposed whereby a veneer of ACC precipitates on an ooid while it is at the sediment-water interface (the active phase). This veneer of ACC later recrystallizes to aragonite needles, possibly nucleating on organic material and a new cortex layer is formed. Observations from this study lead to a deeper understanding of the chemical processes involved in ooid genesis, which allows for a better understanding of paleoenvironments hosting ooid formation. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2009-01-27 13:29:42.765
34

Writing from the inside : domesticity and transcendence in the works of Bahiņā Bāī (c. 1628-1700)

Parasharami, Preeti Ashok. January 2006 (has links)
Bahiṇa Bai was a female poet-Saint whose participation in the Maharashtrian devotional movement known as the Varkari Panth transformed the image of female devotionalism in the region. A collection of her poetic writings, the Samta Bahiṇabaica Gatha, demonstrates her struggle to reconcile the demands of domesticity with those of devotionalism. Bahiṇa Bai simultaneously extols the roles of the pativrata, devoted wife, and the bhakta, the devotee, in her lyrical compositions, and resolves the tensions between domesticity and devotion by merging her husband's identity with that of Viṭhoba, a localized force of Viṣṇu. This thesis argues that Bahiṇa Bai's rebellion against a parochial vision of female spirituality integrates elements of Brahmanic orthodoxy, non-dual philosophy and bhakti practice.
35

Architecture and the bee : virtue and memory in Filarete's Trattato di architettura

Yocum, Carole. January 1998 (has links)
Antonio Averlino, known as Filarete (1400--1469), wrote that architecture is a gestational process, likening the architect to the mother and the father as the client. The process requires the architect-mother to " fantasticare e pensare e rivoltarselo per la memoria," fermenting ideas and incubating them in conjunction with one's memory. The intent is to understand mnemonics as a creative operation in Filarete's Trattato di Architettura. A key to this lies with Filarete's personal symbol, the bee. The bee's process of mellification acts as a metaphor of the architect's gestational design. The bee, long utilized as a memorative trope, points towards other memory models created throughout the treatise, culminating with the design for the House of Vice and Virtue. Directing the reader and inhabitants of the city in a social narrative, Filarete's architecture reveals the dependence upon remembrance and virtue for the city's creation and public rituals to sustain its life.
36

Conversor CA-CA para eletrodomésticos alimentados por tensão bi-volt

Friedemann, Romeu Antunes January 2007 (has links)
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia Elétrica / Made available in DSpace on 2012-10-23T03:44:36Z (GMT). No. of bitstreams: 1 244797.pdf: 4988368 bytes, checksum: 153329d7a575fc508d0192b04854f007 (MD5) / Este trabalho apresenta o estudo de um conversor CA-CA com tensão eficaz de saída controlada e freqüência constante, destinado à aplicação em eletrodomésticos alimentados em tensões "bi-volt", e que utilizam acionamentos com motor de indução monofásico. Na escolha da topologia, foram levados em conta fatores como a faixa de operação do conversor (tensões de entrada e saída), potência do equipamento, o rendimento, o atendimento às normas de segurança, compatibilidade eletromagnética, qualidade de energia e, principalmente, o custo. Duas topologias de conversores CA-CA indiretos com capacitor de barramento da ordem dos F são escolhidas para um estudo das características peculiares e suas implicações. São analisadas formas adequadas de controlar as estruturas e uma delas é escolhida para implementação de um protótipo a fim de se comprovar os resultados teóricos. Um protótipo com potência de 500W e tensão de saída de 110V para uma carga R-L com fator de deslocamento superior a 0,6 é implementado, sendo alimentado em 110V e 220V. Toda a metodologia para o projeto é apresentada sequencialmente, desde o estágio de potência até os estágios de comando e controle, sendo os resultados experimentais comparados com os resultados teóricos, validando o estudo.
37

Estudo de um condicionador de tensão alternada com compensação série, utilizando um conversor indireto CA-CA com alimentação a jusante

Soeiro, Thiago Batista January 2007 (has links)
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica / Made available in DSpace on 2012-10-23T14:08:28Z (GMT). No. of bitstreams: 1 241121.pdf: 4062469 bytes, checksum: 22a6ee51e80b5a46aef72aef1d4cbb36 (MD5) / Este trabalho apresenta o estudo de um condicionador de tensão ca operando em malha fechada. A topologia proposta possui compensação série de tensão alternada, cuja configuração lhe permite operar com apenas parte da potência de carga. O princípio de funcionamento é basicamente o de uma fonte de tensão controlada, que objetiva o condicionamento da tensão de saída, frente às perturbações do sistema. Para a análise da operação em malha fechada utiliza-se uma técnica de controle linear. São apresentados a metodologia de projeto, os resultados por simulação e os ensaios de um protótipo de 10 kVA, validando a teoria e comprovando as características da topologia proposta. This work presents the study of an ac line conditioner with closed loop operation. The proposed topology has serial ac voltage compensation, which configuration allows operate with only a part of the load power. The principle of operation is basically that of a controlled voltage source, which provides the conditioning of output voltage face of system´s perturbation. For analysis of closed loop operation, a technique of linear control is used. Design methodology, simulation and experimental results of a 10 kVA prototype are presented, to validate the theoretical analysis and to prove the expected characteristics of the proposed topology.
38

Modelagem de equipamentos FACTS de segunda geração no problema de fluxo de potência ótimo

Silva, Danilo Dupin da January 2008 (has links)
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica. / Made available in DSpace on 2012-10-24T00:50:14Z (GMT). No. of bitstreams: 1 261777.pdf: 2905263 bytes, checksum: f8caea9698147b232df8e98453b61597 (MD5) / Esta dissertação apresenta uma modelagem detalhada dos Equipamentos FACTS (Flexible AC Transmission Systems) baseados em conversores CC-CA no problema de Fluxo de Potência Ótimo (FPO). O objetivo da modelagem é analisar o impacto desses equipamentos na operação em regime permanente de sistemas elétricos de potência. Três equipamentos são considerados: o STATCOM (Compensador Estático Síncrono), SSSC (Compensador Série Síncrono Estático) e o UPFC (Controlador Unificado de Fluxo de Potência). Feita a modelagem, os estudos têm início com uma busca do melhor ponto de inserção do equipamento no sistema. Esse ponto é obtido através de indicadores de sensibilidade fornecidos pelo programa de FPO implementado. Posteriormente, é feita uma comparação das Regiões de Segurança do sistema definidas com e sem o equipamento FACTS em operação. O aumento da Região de Segurança indica a melhoria geral das condições operativas, obtida pela inserção do equipamento. O algoritmo primal-dual de Pontos Interiores é usado na resolução do problema FPO. O desempenho do algoritmo é analisado com os equipamentos FACTS operando livremente e em suas capacidades máximas. São analisados resultados de simulações com diferentes sistemas teste.
39

Sistemas de conversão estatística aplicados em equipamentos com terminais a enrolamentos abertos ou em estrela.

CARLOS, Gregory Arthur de Almeida. 02 May 2018 (has links)
Submitted by Jesiel Ferreira Gomes (jesielgomes@ufcg.edu.br) on 2018-05-02T23:31:51Z No. of bitstreams: 1 GREGORY ARTHUR DE ALMEIDA CARLOS – TESE (PPGEE) 2016.pdf: 26196429 bytes, checksum: b0f539b04f91868561f613e31cebcc23 (MD5) / Made available in DSpace on 2018-05-02T23:31:51Z (GMT). No. of bitstreams: 1 GREGORY ARTHUR DE ALMEIDA CARLOS – TESE (PPGEE) 2016.pdf: 26196429 bytes, checksum: b0f539b04f91868561f613e31cebcc23 (MD5) Previous issue date: 2016-05-25 / Capes / Neste documento, s~ao propostas topologias de conversores que utilizam estruturas trifásicas, a três ou quatro fi os, alimentando equipamentos (motores ou transformadores) com terminais dispostos a enrolamentos abertos ou com conexão em estrela (Y ). Dentre os equipamentos mencionados tem-se: i) restaurador dinâmico de tensão (DVR), ii) ltro ativo de potência (APF) paralelo, iii) fi ltro ativo de potência (APF) série, iv) sistema de acionamento CA-CC-CA série/paralelo e v) sistema baseados em conversores com braços de dois e três-níveis. Para cada topologia estudada, são abordados os seguintes pontos: modelagem da con figuração, estratégias PWM, estratégia de controle. Também é realizado um estudo comparativo entre as topologias propostas e algumas convencionais, avaliando seus desempenhos atrav es de algumas guras de m erito as quais englobam distorções harmônicas das tensões e correntes, estimativa de perdas nos conversores e níveis de tensão no barramento CC. Resultados de simulação e experimentais são apresentados para fins de validação. / This document reports studies on converter topologies applied in three-phase, four-wire or three-wire, systems feeding open-end winding (OEW) equipment or Wye-connected equipment. Such equipment are considered in this work as induction motors or transformers. The devices associated with these equipment are: i) dynamic voltage restorer (DVR), ii) Shunt Active Power Filter (Shunt-APF), iii) Series Active Power Filter (Series-FAP), iv) AC-DCAC series/parallel motor drive, v) Systems with converters based on two- and three-level leg connections. Each studied topology presents its con guration model, PWM strategy, control strategy. Comparative studies considering proposed and some conventional topologies are presented highlighting the harmonic distortion for the voltages and currents, semiconductor losses estimation, dc-link voltage ratings, etc. Simulation and Experimental results are presented for validation purposes. Keywords: Dynamic voltage restorer, shunt active power lter, series active power lter, ac-dc-ac motor drive system, series-connected conveters, parallel-connected converters, converters based on two- and three-level leg connections.
40

A razão Sr/Ca em hidroxiapatita produzida a partir de células ósseas humanas em ambientes com diferentes concentrações de estrôncio / Sr/Ca ratio in hydroxyapatite produced by osteoblastic human cells with variation of strontium concentration in cells environment

Priscila Ribeiro dos Santos 05 December 2008 (has links)
Esta dissertação de mestrado descreve o estudo realizado sobre como a oferta de estrôncio afeta a razão Sr/Ca em hidroxiapatita formada in vitro. Este trabalho pretende dar subsídios para que posteriormente seja possível fazer um estudo da razão Sr/Ca em função da temperatura também em hidroxiapatita formada in vitro. Foram utilizadas células osteoblásticas da linhagem MG-63 com concentrações de estrôncio no meio de cultura que variaram de 0,0 até 33,0 microgramas por mL de meio. Os nódulos ósseos formados pelas células foram caracterizados pelas técnicas Absorção de Infravermelho por Transformada de Fourier (FT-IR), que foi utilizada com o objetivo de identificar ligações de fosfato nas amostras, e Difração de Raios-X (XRD), que teve como objetivo confirmar a presença de hidroxiapatita nos minerais formados e comparar a cristalinidade do material com e sem estrôncio. A quantificação da razão Sr/Ca foi feita utilizando as técnicas Retro-espalhamento Rutherford (RBS) e Emissão de Raios-X por Indução de Partículas (PIXE), que são capazes de fazer a identificação e quantificação elementar. Os resultados obtidos mostram que os nódulos formados são compostos por hidroxiapatita. Com relação à quantificação, mostrou-se que não foi possível substituir mais de 10% do íons de cálcio por íons de estrôncio, o que está de acordo com previsões teóricas. Além disso, para altas concentrações de estrôncio no meio a mineralização do cálcio diminuiu duas ordens de grandeza e as medidas da razão Sr/Ca obtiveram resultados bastante dispersos, indicando uma possível mudança metabólica das células que parece inviabilizar o bom funcionamento fisiológico das mesmas. / This Masters dissertation describes the study of how the availability of strontium affects Sr/Ca ratio of in vitro hydroxyapatite. This work intends to provide the basic understanding needed to a future study of how temperature changes Sr/Ca ratio in this material. MG-63 cells were grown in the culture medium doped with 0.0, 1.0, 2.0, 4.1, 8.2, 16.4, 22.9 and 33.0 micrograms of Sr/mL. The nodules formed by osteoblastic cells were characterized by Fourier Transform Infrared Spectroscopy (FT-IR) technique, used to identify phosphate domain, and X-Ray Diffraction (XRD) technique, which was used to verify the presence of crystallized hydroxyapatite in the mineral composition with and without strontium. Quantification of Sr/Ca ratio was made using the Rutherford Backscattering (RBS) and Particle Induced X-Ray Emission (PIXE) techniques, which are used to do elementary identification and quantification. The results of characterization confirmed the presence of hydroxyapatite in the cultivated MG-63 cells. The experiments have shown that it was not possible to replace more than 10% of the calcium ions by strontium, which is consistent with theoretical predictions. In addition, high concentrations of strontium in the growing solution, reduced the mineralization yield and also the Sr/Ca ratio, indicating a possible change in the metabolism of the cells.

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