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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.
371

Application of ab-initio calculations to modeling of nanoscale diffusion and activation in silicon /

Diebel, Milan. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 121-127).
372

Influence of gamma irradiation on chemical vapor deposited boron-doped diamond films

Mulakaluri, Murali Kiran Gupta, Sanju. January 2009 (has links)
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 23, 2010). Thesis advisor: Dr. Sanju Gupta. Includes bibliographical references.
373

Ex situ variable angle spectroscopic ellipsometry studies on chemical vapor deposited boron-doped diamond films layered structure and modeling aspects /

Dudipala, Ajay Prasad Reddy Gupta, Sanju. January 2008 (has links)
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 7, 2009) Thesis advisor: Dr. Sanju Gupta. Includes bibliographical references.
374

Cubic boron nitride/nanodiamond composite films for the application in SAW devices

Lung, Kai Chun. January 2005 (has links) (PDF)
Thesis (M.Sc.)--City University of Hong Kong, 2005. / At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.
375

Relocation of a neutron capture prompt gamma-ray analysis facility at the University of Missouri Research Reactor and measurement of boron in various materials /

Lai, Chao-Jen, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 112-118). Also available on the Internet.
376

Efeito de boro e zinco na cultura do milho

Jamami, Nestor [UNESP] 07 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-07Bitstream added on 2014-06-13T18:40:32Z : No. of bitstreams: 1 jamami_n_dr_botfca.pdf: 208227 bytes, checksum: 4ba2dd57ca0e59b17f7210bbcd16076b (MD5) / O presente trabalho foi conduzido em condições de campo com o objetivo de estudar os efeitos de boro e zinco sobre o crescimento e produção da cultura do milho. O experimento foi realizado em um Latossolo Vermelho-Amarelo no município de São Carlos - SP, utilizando-se delineamento experimental em blocos casualizados, com quatro repetições, em esquema fatorial 3 x 3, sendo os tratamentos constituídos de três doses de boro (0, 1 e 2 kg/ha) e três doses de zinco (0, 2 e 4 kg/ha). Foi utilizado o híbrido comercial de milho AG-1043. As fontes de boro e zinco foram, respectivamente, o ácido bórico e o sulfato de zinco, aplicados ao solo juntamente com a adubação com N, P e K por ocasião do plantio. A semeadura foi realizada em 07 de dezembro de 1999, com densidade populacional de 55.000 plantas por hectare. Aos trinta dias após a emergência foram realizadas medidas para a comprimento de planta, diâmetro de colmo, área foliar, matéria seca das folhas e de toda a planta e a partir destes foram calculadas a área foliar específica, razão de peso foliar e razão de área foliar. Também foram feitas análises químicas para os teores foliares dos nutrientes. Aos sessenta e aos noventa dias após a emergência foram realizadas as mesmas análises, determinando-se os resultados para os respectivos períodos. A aplicação de boro e de zinco não resultou em elevação dos teores foliares destes nutrientes nas épocas analisadas e também não resultou em ganhos no rendimento de grãos, verificando-se a interação entre boro e zinco quando da análise para a matéria seca de folhas e peso total das plantas aos noventa dias. Concluiu-se que as aplicações de boro e zinco ao solo não resultaram ganhos de produtividade, sendo que os teores encontrados inicialmente no solo foram considerados suficientes para a produtividade atingida. / The objective of this research was to study the effects of boron and zinc on growth and yield corn. The experiment was carried out in São Carlos, São Paulo State, Brazil. The experimental design was randomized block with 3 x 3 factorial distribution of the treatments and four replications . The treatments were three doses of boron (0, 1 and 2 kg/ha) and three doses of zinc (0, 2 and 4 kg/ha). It was utilized a commercial hybrid corn “AG 1043”. The source for boron was boric acid and the source for zinc was sulfate of zinc applied together N, P and K in the sowing. The sowing occurred in December 07 of 1999, with density of 55000 plants by hectare. In the thirty, sixty and ninety days of emergency were measured the plant height, culm, diameter, leaf area, dry matter weight and calculated other factors and they were realized chemical analyses to verify the content of nutrients in the leaves. At the harvest was determined the yield and data of the ear. The application of boron and zinc didn’t increase the content of both nutrients in the leaves and neither resulted in increase of yield of kernel. It was concluded that it didn’t interaction between boron and zinc to corn productivity. The appliance of boron and zinc don’t result in increase of productivity because the content in the soil before of the experiment installation were enough to yield reached.
377

Caracterização de um aço microligado ao boro e tratado termicamente utilizado na fabricação de tubos

Silva, Ronaldo Cristiano [UNESP] 14 August 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-14Bitstream added on 2014-06-13T20:16:11Z : No. of bitstreams: 1 silva_rc_me_guara.pdf: 9001097 bytes, checksum: 6f1a3bc8edbfd3fd88699167a64182bc (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Na exploração e produção de petróleo e gás existe uma demanda crescente por aços especiais e de alta resistência. Com os campos mais fáceis e de melhor relação custo benefício já em produção, as empresas estão se movendo para exploração e produção de áreas não convencionais. O aumento da perfuração nessas áreas críticas traz um impacto direto no consumo de produtos de alta tecnologia, como tubulações fabricadas com aços de alta resistência. Para obtenção de aços de alta resistência, o mercado tem investido no desenvolvimento de aços, com progresso considerável nos processamentos térmicos e termomecânicos. Neste contexto, a martensita revenida, obtida através de têmpera e revenimento, representa uma alternativa importante, tendo em vista que esta estrutura pode aumentar a resistência, mantendo um bom nível de tenacidade. Os aços ligados ao boro são de baixo custo, boa temperabilidade e baixa dureza do material na condição após laminado, o que facilita sua conformação, e o torna um boa opção para fabricação de tubos. Com o tratamento térmico de têmpera e revenimento, há a possibilidade de obtenção de distintas propriedades mecânicas em função da variação das temperaturas de revenimento. Neste projeto, objetivou-se otimizar os parâmetros de tratamento térmico (têmpera e revenimento), para obtenção de uma microestrutura martensítica revenida, a partir de um aço de baixo carbono ligado ao boro utilizado na fabricação de tubos. Foram realizadas caracterizações mecânicas e microestruturais do material tratado termicamente em distintas faixas de temperatura. O material apresentou alta temperabilidade após têmpera, e foi possível verificar a mudança das propriedades em função das distintas temperaturas de revenimento. As características microestruturais e mecânicas (resistência à tração, limite de escoamento e ductilidade) são apresentadas neste trabalho. / The exploration and production of oil and gas has increased its demand for special steels and high resistance steels. With the easiest, most cost-effective fields already in production, oil companies are now moving to non-traditional areas and fields that are more difficult to develop. Increased drilling in those critical environments will have a direct impact in the consumption of high-steel grade tubulars. In oder to attend this demand, the market has invested in R&D of high resistance steels, focusing on heat treatment and thermomechanical processes. In this sense, tempered martensite microstructure represents a good steel design alternative, since that microstructure can increase steel resistance maintaining its toughness properties. Boron bearing steels are low cost, have excellent hardenability and low hardness on the as-rolled condition, which makes it a good alternative for pipe manufacturing. This characteristic has put the tempered martensite as one of the microstructures with high potential in terms of utilization for pipe manufacturing. The quench and tempering heat treatments gives the possibility of obtaining different mechanical properties as a result of changes in the tempering temperatures. This project aimed to optimize quench and tempering heat treatment processes in order to obtain tempered martensite microstructures utilizing a boron microalloyed steel. The material presented high hardenability after quenching and it was verified mechanical properties changes after tempering at different temperatures. The microstructural characteristics and mechanical properties (tensile strength, yield strength and ductility) are presented in this work.
378

Boron in Disguise: Towards BN Biomimics / Towards BN Biomimics

Abbey, Eric Ryan, 1980- 09 1900 (has links)
xv, 219 p. : ill. (some col.) / Chemists have long recognized the potential of the BN bond to mimic CC double bonds in aromatic systems. Phenyl and indole are two of the most important arenes in natural systems, as well as medicine, applied chemistry, and materials science. Despite the potential of BN arenes as phenyl and indole mimics in biomolecules, few isoelectronic and isostructural BN biomolecules have been synthesized. Substitution of BN for C=C imparts tunability to aromatic systems, giving new and potentially valuable properties to the resulting molecules. Our group has sought to expand the utility of BN arenes by developing the synthetic arsenal available to chemists seeking to incorporate the BN bond into biological and other organic molecules of importance. The scope of this dissertation is twofold: (1) development of the first "fused" BN indole, including a survey of its reactivity towards electrophiles, synthesis of the parent N -H compound with complete characterization, and a comparison to natural indole and (2) expansion of the synthetic methodologies for constructing 1,2-dihydro-1,2-azaborine derivatives, including complete structural characterization of a family of "pre-aromatic" and aromatic compounds and a protection-free synthesis of azaborines. The contributions outlined in this dissertation expand both the fundamental understanding of BN isosterism in aromatic molecules and the synthetic toolbox for chemists seeking to incorporate BN arenes into biological and other organic motifs. This dissertation includes previously published and unpublished coauthored material. / Committee in charge: Professor Kenneth M. Doxsee, Chair; Professor Shih-Yuan Liu, Advisor; Professor Victoria J. DeRose, Member; Professor Michael M. Haley, Member; Professor Janis Weeks, Outside Member
379

Efeitos de auxinas e boro no enraizamento de estacas caulinares de louro (Laurus nobilis L.)

Herrera, Tatiana Isabel Reategui [UNESP] 12 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-12Bitstream added on 2014-06-13T18:55:01Z : No. of bitstreams: 1 herrera_tir_me_botfca.pdf: 147969 bytes, checksum: c8e7a80ad8aa3713918b778bac59b151 (MD5) / O presente trabalho teve como objetivo estudar o efeito de ácido indolbutírico (IBA) no enraizamento de estacas apicais de louro (Laurus nobilis L.) aplicado sozinho ou em conjunto com ácido bórico, em câmara de nebulização com temperatura e umidade controladas. As estacas foram coletadas de ramos jovens (mais externos) de louro, no dia 14 de fevereiro de 2001 entre 7:00 e 9:00 horas da manhã e transportadas ao Laboratório de Fisiologia Vegetal do Departamento de Botânica, do Instituto de Biociências – UNESP, onde procedeu-se ao preparo das mesmas. Dos ramos foram retiradas estacas apicais mantendo-se apenas duas folhas na parte superior, sendo o comprimento de 15cm. Após o preparo das estacas, estas receberam diferentes concentrações de ácido indol-butírico (IBA) a 0, 50, 150 e 300mg.L-1, misturado ou não com boro 150mg.mL-1, onde as suas bases permaneceram imersas por 24 horas. Logo após os tratamentos, as estacas foram colocadas em bandejas de isopor contendo como substrato, casca de arroz carbonizada e mantidas sob nebulização. A coleta das estacas foi realizada 70 dias após a instalação, onde foram avaliadas a porcentagem de estacas enraizadas, porcentagem de estacas com calo, porcentagem de estacas vivas, porcentagem de estacas mortas, número de raízes formadas e comprimento das raízes. Os resultados obtidos mostraram que, o IBA 50mg.L-1 proporcionou a maior porcentagem de estacas enraizadas (54,17%). A adição de boro aos tratamentos auxínicos levou a maior porcentagem de estacas com calos e menor porcentagem de estacas mortas. O tratamento com IBA 50mg.L-1 + boro proporcionou o maior número de raízes nas estacas (10,12) e maior comprimento dessas raízes (46,57mm). / The purpose of this study was to evaluate the effect of the indolebutyric acid (IBA) on laurel (Laurus nobilis L.) stem cuttings rooting applied with or without boric acid, carried within greenhouse with mist, on controlled temperature and humidity. The cuttings was obtained as harvest of laurel plants, in February, 14, in the between at 7:00 and 9:00 hours, and transported for the Plant Physiology Laboratory from Department of Botany of Institute of Bioscience - UNESP where was preceded the preparation of cuttings. The cuttings was taked of apical portion and leaving two leaves by the up-side. The cuttings’ lenght was 15cm. The cuttings were treated with indole-butyric acid (IBA) at 0, 50, 150 and 300mg.L-1 with or without 150mg.mL-1 of boron, where 1cm of the cutting base was immersed for 24 hours. After the treatments, the cuttings were put in styrofoam trays with carbonized rice hull and maintained on intermittent mist during 70 days when was evaluated the rooting percentage, stem cuttings with callus percentage, live cuttings percentage, dead cuttings percentage, roots number and roots length. The results showed that IBA 50mg.L-1 enhanced the rooting percentage (54,17%). Auxins treatments with boron enhanced the stem cuttings with callus percentage and lower dead cuttings percentage. The treatments with IBA 50mg.L-1 + boron showed the higher root number in stem cuttings (10,12) and higher length of this roots (46,57mm).
380

Fontes e modos de aplicação de boro na cultura do eucalipto (clone I144)

Celestrino, Thiago de Souza [UNESP] 25 February 2014 (has links) (PDF)
Made available in DSpace on 2014-12-02T11:16:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-25Bitstream added on 2014-12-02T11:20:55Z : No. of bitstreams: 1 000798550.pdf: 1149304 bytes, checksum: c3d6fc76a077bdaec50d2eb2d909483b (MD5) / Os solos de Cerrado apresentam baixo teor de boro no solo, sendo comum a suplementação deste elemento através da adubação via solo e foliar. Portanto, é importante definir qual o melhor modo de aplicação e fonte de B para o bom desenvolvimento e produtividade do eucalipto, com menor custo possível. Assim, objetivou-se, com este trabalho, comparar o efeito de fontes de B com alta e baixa solubilidade na cultura do eucalipto, bem como a aplicação foliar do micronutriente. O experimento foi conduzido na Fazenda Renascença, localizada no município de Três Lagoas/MS, com latitude 20o 34’ S e longitude 51o 50’ O e altitude de aproximadamente 305 m, no período de 02/2012 a 02/2014. O delineamento experimental foi o de blocos casualizados com seis tratamentos e cinco repetições, dispostos em um esquema fatorial de 3 x 2, sendo: 0 kg ha-1 de B, 1 kg ha-1 de B utilizando como fonte o ácido bórico (alta solubilidade, 17% B) ou 1 kg ha-1 de B utilizando como fonte o borogran (baixa solubilidade, 10% B), aplicados no sulco de plantio, com ou sem aplicações de ácido bórico via foliar na dose de 0,5% de ácido bórico na calda com volume de 250 L ha-1. Com a omissão de B via foliar houve incremento em altura de plantas nos tratamentos que receberam a aplicação do micronutriente no plantio, diferindo significativamente da testemunha. Porém, ambas as fontes, independente da solubilidade, apresentaram resultados semelhantes. As duas aplicações de B via foliar foram suficientes para que houvesse incremento em altura de plantas, quando comparadas aos tratamentos que não receberam aplicação de B no plantio. Aos 18 e 24 meses após o plantio foi constatado aumento no teor foliar de B nos tratamentos que receberam aplicação foliar. A aplicação de B no plantio, independente da fonte utilizada, assim como aplicação foliar do elemento, foram suficientes para reduzir os sintomas de deficiência de B. Com relação às fontes ... / Cerrado soils present low levels of boron being common supplementation of this element through soil and foliar fertilization. Therefore, it is important to define how better mode of application and source for the successful development and productivity of eucalyptus, with possible cost savings. Thus, this study aimed to compare the effect of B sources with high and low solubility applied in soil and high solubility applied on leaf of Eucalyptus spp. The experiment was conducted at farm Renascença, located in Três Lagoas/MS with latitude 20 34 'S and longitude 51 50' W and altitude of approximately 305 m, in 02/2012 to 02/2014. It was used a randomized block design with six treatments and five replications arranged in a factorial scheme 2 x 3, being: 0 kg ha- 1 B, 1 kg ha- 1 B, using boric acid as source (high solubility, 17 % B) or 1 kg ha-1 B, using as source borogran (low solubility, 10 % B), applied at planting, with or without application of boric acid foliar at 0.5% in a volume of 250 Lha-1. With the omission of B foliar there was an increase in plant height in treatments with the application of boron at planting, differing from the control. However, both of these sources, regardless of the solubility, showed similar results. The two foliar applications of B were sufficient for getting an increase in plant height when compared to treatments without B application at planting. At 18 and 24 months after planting there was increased on B foliar content in treatments with foliar application. Applying B at planting, regardless of source, as well as foliar application, were sufficient to reduce the symptoms of B deficiency. Regarding the sources used at planting, dose of 1kg ha-1 B, showed similar results on plant height, DBH and volume of wood. However, borogran increased the conten of B in the soil after 24 months of planting, from 20 to 40 cm layer, which can be beneficial for crop over time

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