Boron Nitride
Mostrando 13-24 de 29 artigos, teses e dissertações.
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13. Taguchi's technique in machining of metal matrix composites
This paper presents the study on Taguchi's optimization methodology, which is applied to optimize cutting parameters in turning of age hardened Al6061-15% vol. SiC 25 µm particle size metal matrix composites with Cubic boron nitride inserts (CBN) KB-90 grade using steam as cutting fluid. Analysis of variance (ANOVA) is used to study the effect of process pa
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2009-03
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14. Synthesis of nanostructured boron nitride and its potentially for application in cosmetology / Sínteses e caracterização de nitreto de boro nanoestrutrado com potencialidade de aplicação em cosmetologia
Regular use of appropriate cosmetics is an important resource for the maintenance of the skin health and, consequently, its beauty. The effect of ultraviolet rays is harmful to the health of the skin and can result in increase of the cancer incidence, aging and other undesirable cutaneous changes. The effects of the infra-red rays are less described in the s
Publicado em: 2009
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15. Study of Electronic Structure of nanobelts Boron Nitride using calculations First Principles / Estudo de Estrutura Eletrônica de Nanofitas de Nitreto de Boro utilizando Cálculos de Primeiros Princípios
Recentemente, foi descoberto experimentalmente a existência de Nanofitas de Nitreto de Boro (BN) de tamanho finito, em nanoesferas porosas de BN (100-400 nm de diâmetro), sintetizada pela reação de B2O3 com esferas de carbono contendo nanoporos preenchidos por Nitrogênio a uma temperatura de 17500C. No entanto não existia uma investigação teórica da
Publicado em: 2009
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16. Estudo do mecanismo de deposição de filmes finos de nitreto de boro assistida por feixe de íons / Study of the deposition mechanism of boron nitride thin films by ion seam assisted deposition
Filmes finos de BN foram depositados em uma ou duas camadas, em temperaturas entre a temperatura ambiente e 400oC, por deposição a vapor de átomos de boro sobre substratos de Si (111) ou Si (100), com irradiação simultânea de íons de argônio e/ou nitrogênio. A energia de íons variou de 400 a 1000 eV, e a razão de chegada ARR(N/A), definida pela ra
Publicado em: 2009
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17. Estudo de Impurezas de Carbono em Nanoestruturas de BN
In this work, we performed an analysis of the structural and electronic stability of nanostructures of Boron Nitride (BN), such as layers, tubes and cones, when doped with Carbon, through first-principles calculations as implemented in code SIESTA. We found that substitutional doping of Carbon for either a single Boron or a single Nitrogen atom produces sign
Publicado em: 2008
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18. Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA
In this work, we sought to modify PHB, processing it in the melted state, and to evaluate the effect of the modifications on its mechanical properties and biodegradation characteristics. The following systems were therefore studied: a PHB/EVA blend, in a 90/10 ratio, with an ethylene-co-vinyl acetate copolymer containing 28% of VA; a PHB and PHB/EVA blend wi
Publicado em: 2008
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19. Nanoosciladores atomísticos de nanotubos de Carbono e de Nitreto de Boro / Atomistic nanooscillators of Carbon nanotubes and Boron Nitride
The Nanotechnology quickly advances to the development of new nanodevices. One of most important in the electronics is clocks that they synchronize the functioning of diverse devices in a determined circuit. In this work we study the development of nanooscillators based upon Carbon nanotubes and Boron-Nitride nanotubes. The atom that oscillates in the interi
Publicado em: 2007
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20. Study of First Principles of Bundles of Nanotubes of Boron Nitride, under Pressure Hydrostatic / Estudo de Primeiros Princípios de Bundles de Nanotubos de Nitreto de Boro sob Pressão Hidrostática
In this work were studied the electronic, vibrations and structural properties of boron nitride nanotube bundles (16,0), (12,0) and (8,0), when submitted to the hydrostatic pressure changes. To study such properties, we used the ab initio method employing density functional theory in the approach of the generalized gradient approximation. All the simulations
Publicado em: 2007
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21. Study on the behavior of the minimum quantity lubricant - MQL technique under different lubricating and cooling conditions when grinding ABNT 4340 steel
Energy consumption, air pollution and industrial waste have received special attention from public authorities in recent years. The environment has become one of the most important subjects in the context of modern life, for its deterioration impacts the quality of life populations. Driven by pressure from environmental agencies, politicians have drawn up ev
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2005-06
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22. High speed machining of aero-engine alloys
Materials used in the manufacture of aero-engine components generally comprise of nickel and titanium base alloys. Advanced materials such as aero-engine alloys, structural ceramic and hardened steels provide serious challenges for cutting tool materials during machining due to their unique combinations of properties such as high temperature strength, hardne
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2004-03
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23. Influence of boron compounds addition in the silicon carbide - nitride bonded refractoryes oxidation resistence / Estudo da influência da adição de compostos de boro na resistência à oxidação de refratários a base de carbeto de silício-liga de nitreto.
Neste trabalho foi avaliada a influência da adição de boro em um refratário comercial a base de carbeto de silício liga de nitreto, sendo que este tipo de material é comumente utilizado como cerâmica estrutural a altas temperaturas em função de sua combinação de propriedades, tais como manutenção da resistência mecânica a altas temperaturas, r
Publicado em: 2004
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24. Analysis of the performance of superabrasive and alumina grinding wheels with different bonds and machining conditions
This paper presents a review of researches on CBN (cubic boron nitride) grinding wheels with the purpose of identifying the state of art in abrasive machining and serving as the basis for future researches and laboratory tests. The scientific studies investigated here report on interesting results involving grinding, published by Brazilian and foreign author
Materials Research. Publicado em: 2003-06