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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.
41

Efeitos da dinâmica da nanopartícula catalisadora e controle da direção de crescimento de nanofios semicondutores / Effects of the catalyst nanoparticle dynamics and control of the growth direction of semiconductor nanowires

Zavarize, Mariana, 1990- 28 July 2017 (has links)
Orientador: Mônica Alonso Cotta / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-09-02T10:59:50Z (GMT). No. of bitstreams: 1 Nica_MarianaZavarize_M.pdf: 75724631 bytes, checksum: 1480ea9eb35b1740d4b908e32d13c9c4 (MD5) Previous issue date: 2017 / Resumo: Neste trabalho, estudamos o crescimento de nanofios planares de InP pelo mecanismo Vapor-Líquido-Sólido (VLS), com o objetivo de entender a dinâmica da nanopartícula metálica catalisadora durante o processo. Para isso utilizamos substratos de GaAs (111)A e o sistema de Epitaxia de Feixe Químico (CBE). O óxido nativo não foi totalmente removido termicamente antes do crescimento, com o objetivo de manter o nanofio isolado eletricamente do substrato. Como um dos objetivos do trabalho, estudamos a possibilidade de controle da direção de crescimento do nanofio planar através de diferentes tratamentos de superfície, e de modo independente da cristalografia do substrato utilizado. As amostras processadas e/ou crescidas foram caracterizadas por técnicas de microscopia eletrônica (varredura e transmissão) e microscopia de força atômica. Investigamos inicialmente como a camada de óxido influencia as direções de crescimento dos nanofios planares no substrato não tratado. Posteriormente, processamos padrões de linhas com rugosidade ligeiramente diferente da mostrada pelo substrato, utilizando técnicas como Litografia por Feixe de Elétrons (EBL), Corrosão por Feixe de Íons Focalizados (FIB) e Ataque por Íons Reativos (RIE). Os padrões gravados eram compostos por linhas perpendiculares com várias micra de comprimento e larguras de dezenas de nm. Observamos que existe uma relação direta do diâmetro do nanofio com a orientação que este assume ao chegar à região onde se encontra a linha (se segue alinhado à linha ou se a ignora; ou se muda sua orientação). Nossos resultados podem ser explicados pelas diferentes energias de superfície presentes no problema, que afetam a dinâmica da nanopartícula catalisadora. Nosso trabalho também mostra que é possível obter maior controle da orientação espacial do nanofio planar crescido, controlando o processamento da superfície e o diâmetro da nanopartícula / Abstract: In this work, we studied the growth of InP planar nanowires by the vapor-liquid-solid (VLS) mechanism, in order to understand the metallic catalyst nanoparticle dynamics during this process. In our studies, we used GaAs (111)A substrates and the Chemical Beam Epitaxy (CBE) system. The native oxide layer was not completely thermally desorbed, in order to keep the nanowire electrically isolated from the substrate. As one of the goals of this work, we study the possibility to control nanowire growth direction via different surface treatments, independently of the substrate crystallography. Our processed and/or grown samples were characterized by electron (scanning and transmission) and atomic force microscopy. We first investigated how the oxide layer influences the growth directions of planar nanowires on unprocessed substrates. Subsequently, patterns of lines with roughness slightly different from those shown by the substrate were patterned using techniques such as Electron-beam Lithography (EBL), Focused Ion-beam Corrosion (FIB) and Reactive Ion Etching (RIE). These patterns were composed of perpendicular lines with several micra in length and tens of nanometers wide. We observed that there is a direct relation between the nanowire diameter and the orientation that the nanowire assumes when it reaches the region where the line is located (if the nanowire aligns with the line or ignores it, or if its orientation changes). Our results can be explained by the different surface energies present in the problem, which affect the dynamics of the catalytic nanoparticle. Our work also shows that it is possible to obtain better control of the spatial orientation of the grown planar nanowire, by controlling the surface processing and the nanoparticle diameter / Mestrado / Física / Mestra em Física / 132655/2015-2 / CNPQ
42

Postavení zemědělské výroby ve členských zemích EU / Agricultural production in the member countries of EU

Šrámek, Přemysl January 2007 (has links)
Zemědělství představovalo v minulosti jednu z nejdůležitějších sfér lidské činnosti a i dnes uspokojuje jako producent potravin nejdůležitější základní lidskou potřebu. Zemědělský patří k často kritizovaným oblastem v EU. V práci jsem porovnával vývoj, kterým prošlo zemědělství za posledních 45 let a zhodnotit jeho význam na celkovou hospodářskou činnost a konkurenceschopnost vůči okolnímu světu.
43

A Studey of Silicon Dioxide Deposited by Liquid Phase Deposition Method on CuInSe2 and CuGaSe2

Chen, Chien-An 01 August 2000 (has links)
In this paper, we use a room temperature processing system, Liquid Phase Deposition(LPD) method, to grow silicon dioxide. The advantages are cheap equipment, low temperature growth, and no thermal stress. The quality is good enough to be used in IC devices. To inverstigate the properties of silicon Dioxide, we have done different physical and chemical test, including AES,TEM,FTIR,P-etch rate. We used the high frequency C-V curve to study the interface properties. The leakage current help to clarify the film quality. Moreover, we also discuss the growth mechanism in order to more understanding of LPD method.
44

Representations of the prostitute in contemporary Russian literature and film /

Schuckman, Emily E. January 2008 (has links)
Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 310-341).
45

Beiträge zur Kenntnis des Gewerbes im hellenistischen Ägypten.

Reil, Theodor. January 1913 (has links)
Leipzig, Phil. Diss. v. 9. Dez. 1913, Ref. Wilcken, Lipsius. / Soll erweit. ersch. in : Studien z. Geschichte d. Hellenismus u. d. röm. Kaiserzeit. [Geb. 19. Nov. 89 Dresden ; Wohnort : Leipzig ; Staatsangeh. : Sachsen ; Vorbildung : Wettiner-G. Dresden Reife 08 ; Studium : Freiburg 1, Leipzig 7 S. ; Rig. 28. Febr. 13. 14. Mai 12.].
46

Vladimir Nabokov et son ombre russe /

Guy, Laurence. January 2007 (has links)
Rev. Diss. Univ. Paris IV, 1994.
47

Vliv větrné eroze na vybrané půdní vlastnosti

Hejlová, Ivana January 2007 (has links)
No description available.
48

Produkce bílkovin v mléce krav v populaci černostrakatého skotu v České republice

Jahodová, Jarmila January 1997 (has links)
No description available.
49

Desempenho vitivinícola da Cabernet Sauvignon em dois sistemas de condução e três porta-enxertos em região de altitude / Viticultural performance of Cabernet sauvignon in two training systems and three rootstocks in high altitudes region

Brighenti, Alberto Fontanella 25 February 2010 (has links)
Made available in DSpace on 2016-12-08T16:44:35Z (GMT). No. of bitstreams: 1 PGPV10MA050.pdf: 404855 bytes, checksum: 36e6d7d5b5fb8a59d940f37f3e2de324 (MD5) Previous issue date: 2010-02-25 / Rootstocks are used primarily for pest resistance, they are a link between the soil and the scion, play an important role in vine adaption to environmental factors. Rootstocks and training systems can influence the productivity, fruit and wine composition. The objective of this study was evaluate the influence of three rootstocks and two training systems on vineyard productivity, scion growth, physical-chemical quality of fruits and wine chemical composition of Cabernet Sauvignon grapevine produced in high altitude regions of Santa Catarina State. The study was conducted in a experimental vineyard located at the city of Painel (28°01‟02 S and 50°08‟57 W, altitude 1200 m). The cultivar evaluated was Cabernet Sauvingon grafted on Paulsen 1103 (V. berlandieri x V. rupestris), Couderc 3309 and 101-14 Mgt (V. riparia x V. rupestris), the training systems evaluated were vertical shoot positioning trellis and Y trellis. The plants were five years old and the spacing was 3,0 x 1,5 m. The experiment was evaluated at the seasons 2007/08 and 2008/09. According to the results, plants grafted on 1103P and trained in vertical shoot positioning trellis have lowest yields, 3309C is the rootstock less vigorous and and acts positively on fruit set. The high productivity of Y trellis reflect negatively increasing grape acidity. The rootstocks 1103 P and 101-14 Mgt, presents the best results for grape anthocyanins contents. The wine color is not affected by the rootstocks and the training systems. Wine made with grapes from plants grafted on 1103P and trained in Y trellis have higher rates of total polyphenols index and tannins than wines made from grapes of plants trained in vertical shoot positioning trellis and grafted on 1103P. / Os porta-enxertos são usados primariamente como uma forma de resistência a pragas e doenças, eles são uma ligação entre o solo e a copa e desempenham um papel importante na adaptação da videira a fatores ambientais. Os porta-enxertos e os sistemas de condução podem influenciar na produtividade, na composição da fruta e do vinho. O objetivo deste trabalho foi avaliar a influência de três porta-enxertos e dois sistemas de condução na produtividade do vinhedo, no crescimento da copa, na qualidade físico-química dos frutos e na composição química do vinho elaborado com a uva Cabernet Sauvignon, produzida nas regiões de altitude, do estado de Santa Catarina. O experimento foi conduzido em um vinhedo experimental da Epagri - Estação Experimental de São Joaquim, localizada no município de Painel (28°01‟02 S e 50°08‟57 O, altitude 1.200m). O trabalho foi executado com a variedade Cabernet Sauvignon, enxertado sobre Paulsen 1103 (Vitis berlandieri x Vitis rupestris), Couderc 3309 (Vitis riparia x Vitis rupestris) e 101-14 Mgt (Vitis riparia x Vitis rupestris), em dois sistemas de condução, espaldeira e manjedoura, com cinco anos de plantio, no espaçamento de 3,0 x 1,5 m. O experimento foi avaliado nas safras 2007/08 e 2008/09. De acordo com os resultados obtidos conclui-se que plantas enxertadas em 1103P e conduzidas em espaldeira apresentam as menores produtividades, 3309C é o porta-enxerto menos vigoroso e atua de forma positiva na frutificação efetiva. A produtividade elevada do sistema manjedoura reflete de forma negativa no aumento da acidez da uva. Os porta-enxertos 1103 P e 101-14 Mgt, apresentam os melhores resultados para antocianinas das uvas. A cor dos vinhos não é afetada pelos porta-enxertos e pelos sistemas de condução. Vinhos elaborados com frutos de plantas enxertadas em 1103P e conduzidas em manjedoura apresentaram maiores índices de polifenóis totais e taninos do que os vinhos originados de uvas de plantas conduzidas em espaldeira e enxertadas em 1103P
50

Filosofický a teologický pojem hodnoty se zřetelem na etiku v sociální práci / Philosophical and Theological Concept of Value with Respect to Ethics in Social Work

MACHULOVÁ, Helena January 2008 (has links)
This diploma work is focused on the concept of value in social work. First I analyzed both Czech and foreign literature dealing with ethics of social work. Having found no satisfactory definition of value in that actual literature, I tried to clarify it. In the 3rd chapter the theories of value of main proponents of axiology and their predecessors are discussed. The concept of value of Dietrich von Hildebrand is discussed in detail, because it is the best theory for the purpose of the ethics of social work according to my opinion that is explained in the chapter 4.1. From this point of view I commented values that can be found in the Code of the social workers. In the last chapter I try to suggest the theological approach in the value discussion on several biblical texts and their interpretations that can be used in practical Bible work with people in social or pastoral work.

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