Corundum
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Recovery of α-Al2O3 from Ionizing Radiation Dosimetric Sensors
Corundum, sapphire or α-Al2O3 is an important technological material in many optical and electronic applications such as solid-state lasers, optical windows and, more recently, as a radiation detector. Landauer (Glenwood, IL, USA) accumulated large number of archived and stored Luxel™ dosemeters composed of Al2O3:C, which were subjected to a recovery proc
Mat. Res.. Publicado em: 2015-02
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2. Augmentation of wear-protective coatings for non-ferrous alloys by the addition of Cr and Ni elements
A number of Al-, Mg- and Ti-base alloys were preconditioned by oxidation via Plasma-electrolytic oxidation (PEO) followed by the addition of Cr and Ni elements in the coating pores by chemical precipitation and a final stage of mechanical treatment. The overall effect was a combination of hardness and resistance to wear. PEO voltage level was found to be a f
Mat. Res.. Publicado em: 2014-12
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3. Synthesis of indium tin oxide nanoparticles by a nonhydrolytic sol-gel method
Indium tin oxide nanoparticles were synthesized in two different sizes by a nonhydrolytic sol-gel method. These powders were then transformed into ITO via an intermediate metastable state at between 300 and 600 ºC. The presence of characteristic O-In-O and O-Sn-O bands at 480 and 670 cm-1 confirmed the formation of ITO. The X-ray diffraction patterns indica
Química Nova. Publicado em: 2012
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4. Aplicações de microcospia eletrônica de varredura (MEV) e sistema de energia dispersiva (EDS) no estudo de gemas exemplos brasileiros
This paper presents results of SEM and EDS study in some Brazilian gemstones. Emerald from Campos Verdes (GO) contains several mineral inclusions as talc, dolomite, chromite, pyrite, magnetite, etc. Sylvite crystals was firstly identified by SEM/EDS. These salt inclusions suggest percolation of K-bearing fluids during emerald crystallization. Emerald from Ca
Publicado em: 2010
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5. Crescimento de cristais de rubi e safira pelo método do fluxo
This work reports the growth of corundum crystals by the flux method. The main objective was the evaluation of versatility, effectiveness and real possibilities of the flux method to the synthesis and doping of monocrystals with impurities of particular interest. In this work the chosen impurities were i) Cr and ii) Fe and Ti, aiming the synthesis of rubies
Química Nova. Publicado em: 2010
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6. Investigação da adsorção de arsênio e ácidos organofosfônicos em minerais de alumínio através de uma nova abordagem baseada na teoria do funcional de densidade
O arsênio é um elemento ubíquo, encontrado na atmosfera, em águas superficiais e subterrâneas, solos e rochas, e também nos seres vivos. Sua mobilização no meio ambiente depende de vários fatores como clima, intemperismo e atividade biológica, por exemplo. Entretanto, fatores antropogênicos como a mineração e queima de combustíveis fósseis tam
Publicado em: 2008
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7. Effect of silica on phospholipids in the rat lung
Grünspan, M., Antweiler, H., and Dehnen, W. (1973).British Journal of Industrial Medicine,30, 74-77. Effect of silica on phospholipids in the rat lung. The total amount of phospholipids and the contents of sphingomyelin, phosphatidylcholine, phosphatidylserine, and phosphatidylethanolamine have been estimated in the lungs of rats from 2 to 90 days after int
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8. Pneumoconiosis in Makers of Artificial Grinding Wheels, Including a Case of Caplan's Syndrome*
Mass miniature radiography surveys in a factory producing artificial grinding wheels detected cases of pneumoconiosis, mostly of the silicotic type. All cases were traced to the department where the so-called “bond” is prepared and mixed with the abrasive grains of carborundum and artificial corundum. This ceramic-vitrified bond, similar in composition t
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9. Pulmonary response to agate dust in vivo and cytotoxic and haemolytic effects in vitro.
The pulmonary response to agate dust in vivo was investigated and also its cytotoxic action on peritoneal macrophages and sheep erythrocytes in vitro. The results were compared with quartz dust as the known fibrogenic dust and emery dust (Corundum) was used as a control dust. Agate increased the wet and dry weight of lungs and induced increased collagen form
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10. Inorganic particulates in pneumoconiotic lungs of hard metal grinders.
Data from the analysis of lung dust in 16 metal grinders who had been exposed to hard metals between five and 44 years is reported. The mean latent time between the first exposure and analysis in biopsy or necropsy specimens was 33.6 years. Mineralogical and elementary analysis by a variety of techniques showed small or trace amounts of hard metal in all lun
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11. Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos
Beck, E. G., Holt, P. F., and Manojlović, N. (1972).Brit. J. industr. Med.,29, 280-286. Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos. The effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos are compared. Glass fibre behaves like chrysotile in producing an increase in cell
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12. Pb(II) distributions at biofilm–metal oxide interfaces
The distribution of aqueous Pb(II) sorbed at the interface between Burkholderia cepacia biofilms and hematite (α-Fe2O3) or corundum (α-Al2O3) surfaces has been probed by using an application of the long-period x-ray standing wave technique. Attached bacteria and adsorbed organic matter may interfere with sorption processes on metal oxide surfaces by changi
The National Academy of Sciences.