Diamonds
Mostrando 1-12 de 31 artigos, teses e dissertações.
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1. Diamonds from the Santo Antônio River (Delfinópolis, Minas Gerais): probable relationship with the Canastra-3 Kimberlite
Abstract The study identifies the Canastra-3 Kimberlite magnetic anomaly as the likely primary source of the alluvial diamonds recovered by "garimpeiros" in the Santo Antônio River basin (Delfinópolis, southwestern Minas Gerais). This conclusion is based on cumulative geophysical, hydrographic, metallogenical and mineral geochemistry evidences. The study a
REM, Int. Eng. J.. Publicado em: 2020-03
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2. A BUSCA POR CHUMBO E PRATA EM MINAS GERAIS COMO ALTERNATIVA ÀS ESGOTADAS MINAS DE OURO E DIAMANTES NO SÉCULO XIX
At the turn of the nineteenth century, a frantic search took place in Minas Gerais for minerals that could prove to be of economic value and thus compensate for the decline in the production of gold and diamonds, the mainstay of the economy in the preceding century. This article addresses the search for new mineral wealth, involving the work of many differen
Quím. Nova. Publicado em: 2019-01
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3. Mineral inclusions in diamonds from Chapada Diamantina, Bahia, Brazil: a Raman spectroscopic characterization
Abstract The Chapada Diamantina, located in the central region of the State of Bahia, is of important historical significance due to its diamond occurrences. Discovered in the nineteenth century, comprehensive research about the regional diamonds and their origins are still limited, demanding more investigation in the matter. Looking for insights about their
REM, Int. Eng. J.. Publicado em: 2018-03
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4. Anatase crystals of unusual habit in quartz veins from the Diamantina region (Espinhaço Range, Minas Gerais)
Abstract The Espinhaço Range, in the Diamantina region (central part of the State of Minas Gerais), is known worldwide as a famous source of associated occurrence of quartz, rutile and/or anatase crystals. The latter is also a classic accompanying mineral of diamonds in the alluvial placers. Primary anatase is related to hydrothermal quartz veins cutting ge
REM, Int. Eng. J.. Publicado em: 2018-03
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5. A Novel Porous Diamond - Titanium Biomaterial: Structure, Microstructure, Physico-Mechanical Properties and Biocompatibility
ABSTRACT With the aim of introducing permanent prostheses with main properties equivalent to cortical human bone, Ti-diamond composites were processed through powder metallurgy. Grade 1 titanium and mixtures of Ti powder with 2%, 5% and 10 wt% diamond were compacted at 100MPa, and then sintered at 1250°C/2hr/10-6mbar. Sintered samples were studied in the po
An. Acad. Bras. Ciênc.. Publicado em: 11/12/2017
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6. The kimberley process certification system - KPCS and diamond production changes in selected African countries and Brazil
After more than a decade since its creation, the KPCS is undergoing questioning as to efficiency in combating the irregular trade of diamonds, among the countries with significant production for the global market, mainly Angola, the Democratic Republic of the Congo and Zimbabwe. Governments and institutions are considering it to be conducive to serious viola
Rem: Rev. Esc. Minas. Publicado em: 2015-09
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7. Thermal Damage in Diamonds: the Protective Effect of Titanium Coating
Many of the applications of diamonds expose them to high temperatures and atmospheres containing oxygen. Under these circumstances two important phenomena responsible for the thermal damage of diamonds are: oxidation and graphitization. It is well known that coatings on diamonds provide a better performance, but the amount of information in literature about
Mat. Res.. Publicado em: 2015-08
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8. Study of the TiC Coating on Powder Metallurgy Diamonds Tool's Performance
Some diamond tools use iron in their composition, and it is known that iron is a strong catalyst for the graphitization of diamonds. This graphitization occurs mainly during the processing of composite materials - conventional sintering or hot pressing, and during cutting operations. This work studies the effect of TiC coating on diamond, on structure, micro
Mat. Res.. Publicado em: 2015-06
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9. Preliminary viability studies of fibroblastic cells cultured on microcrystalline and nanocrystalline diamonds produced by chemical vapour deposition method
Implant materials used in orthopedics surgery have demonstrated some disadvantages, such as metallic corrosion processes, generation of wear particles, inflammation reactions and bone reabsorption in the implant region. The diamond produced through hot-filament chemical vapour deposition method is a new potential biomedical material due to its chemical inert
Mat. Res.. Publicado em: 13/11/2012
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10. GEODIVERSIDADE E LÓGICAS TERRITORIAIS NA CHAPADA DIAMANTINA - BAHIA. / GEODIVERSITY AND LOGIC IN TERRITORIAL CHAPADA DIAMANTINA - BAHIA.
The Chapada Diamantina, located in the central part of Bahia state, has a rich geodiversity which happens to be the set of a variety of earth materials, forms and processes that constitute and shape the Earth, with scientific, cultural, educational and/or recreational value. This set consists of geologic formations and structures, morphology, mineral deposit
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/10/2011
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11. Espectroscopia Raman em Cristais de L-Valina Deuterada e L-Isoleucina sob Altas PressÃes / Raman Spectroscopy in Crystals Deuterated L-valine and L-isoleucine in High Pressures
In this thesis, are studied by Raman spectroscopy of two amino acid crystals subjected to conditions of high pressures. The first is a sample of deuterated L-Valine. Initially, an attempt was made to identify all the bands that appear in the Raman spectrum of deuterated L-Valine, comparing with the results of L-Valine hydrogenated in the litera- ture. The fo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 24/09/2010
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12. RESISTÊNCIA À FRATURA DE DENTES COM DIFERENTES GRAUS DE FRAGILIZAÇÃO RADICULAR RECONSTRUÍDOS COM OU SEM PINOS ACESSÓRIOS / FRACTURE STRENGTH OF WEAKENED TEETH RESTORED WITH OR WITHOUT ACCESSORY POSTS.
At this work, fracture strength of bovine teeth with different weakened root levels and rebuilded with glass fiber posts used in a unique way or associated with accessory glass fiber posts was evaluated. Fifty bovine mandibular incisors with similar mesio-distal and bucco-lingual dimensions were used at the study. They were sectioned at 14 mm from the apex a
Publicado em: 2010