High Pressures And High Temperatures
Mostrando 1-12 de 83 artigos, teses e dissertações.
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1. Simple Niobium Catalysts Applied in Reflux and Ultrasound-Assisted Systems for Biofuel Synthesis
Using niobium compounds as heterogeneous catalysts in biodiesel production is a promising methodology from economic and environmental viewpoints. However, the application of niobium catalysts still is a challenge due to the high temperatures and pressures for moderate biofuel yields. Therefore, easily handled and applied materials have been developed to opti
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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2. Calibration of high-temperature furnace assemblies for experiments between 200 and 600 MPa with end-loaded piston-cylinder apparatuses
Abstract We present pressure calibration results for piston-cylinder –” and 1” high temperature furnace assemblies in the 200-600 MPa range aiming to expand its applicability to simulate upper crustal conditions. The furnace assemblies were made up by crushable MgO, graphite heater, pyrex glass spacer, and NaCl sleeve. Twenty-one experiments were carri
Braz. J. Geol.. Publicado em: 15/04/2019
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3. Storage of purified biogas (biomethane) at low pressure
ABSTRACT The global use of fossil energy sources has led to the need to develop technologies capable of mitigating its consequences. One such option is anaerobic biodigestion, which is already scientifically well-established, although the use of its main products (biogas and biomethane) still requires further development before they can be employed in automo
Braz. arch. biol. technol.. Publicado em: 22/10/2018
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4. Influence of water in the MQL technique in the grinding of steel AISI 4340 using CBN wheels
Abstract Usually, machining employs cooling methods to avoid high temperatures. In most cases, the cutting fluid is applied with high flow and low pressures. This technique consumes a large amount of cutting fluid that causes serious problems in the environment and in the health of the worker. An alternative to the conventional cooling method is the Minimum
REM, Int. Eng. J.. Publicado em: 2018-07
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5. SORÇÃO DE CO2 UTILIZANDO LÍQUIDO IÔNICO ADITIVADO COM EXTENSORES DE ÁREA SUPERFICIAL
The study of environmentally friendly CO2 sorption agents are growing due to the need of mitigate this gas from atmosphere. Ionic Liquids (ILs) present the advantage of having low vapor pressures and being chemically and thermally stable. Besides, their properties can be designed by varying the groups of the cation or anion. Yet, these compounds present a lo
Quím. Nova. Publicado em: 2018-06
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6. A Dual-mode model interpretation of CO2/CH4 permeability in polysulfone membranes at low pressures
ABSTRACT An asymmetric membrane of polysulfone (PSf) was synthesized by phase inversion method. Permeation experiments were carried out between 2 to 5 bar pressure, and at temperatures 20 to 45°C. The dense-selective layer of PSf membrane presents regular thickness (about 5 µm), and was not possible to observe the formation of macrovoids in porous layer. T
An. Acad. Bras. Ciênc.. Publicado em: 2018-04
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7. Electron microprobe Th-U-Pb monazite dating and metamorphic evolution of the Acaiaca Granulite Complex, Minas Gerais, Brazil
Abstract The Acaiaca Complex (AC) is located in southeastern Minas Gerais state, and comprises felsic, mafic, ultramafic, and aluminous granulites as well as lower grade gneisses and mylonites. The complex is distributed over an area of ca. 36 km by 6 km, surrounded by amphibolite facies gneisses of the Mantiqueira Complex (MC). The discrepancy in the metamo
Rem: Rev. Esc. Minas. Publicado em: 2016-03
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8. Syntesis of Carbon Nanostructures Near Room Temperature Using Microwave PECVD
Carbon nanostructures (nanotubes, nanofibers and nanosponges) were synthesized onto Si (001) substrates using a microwave assisted plasma enhanced chemical vapor deposition (PECVD) from C2H2-Ar mixtures at low substrate temperatures (120 °C). Catalytic films (Ni and Cu) 3 nm thick were used. Different structures were formed, depending on the C2H2 partial pr
Mat. Res.. Publicado em: 2015-08
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9. Thin Tin and Tio2 Film Deposition in Glass Samples by Cathodic Cage
Thin nitride and titanium dioxide films were produced using an innovative technique called cathodic cage depositon. Uniformity, three-dimensionality and high rate deposition are some of the advantages of this technique. In this study we discuss the influences of temperature, treatment time and gaseous atmosphere on the characteristics of the deposited films.
Mat. Res.. Publicado em: 2015-04
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10. THERMOPHYSICAL PROPERTIES OF 1-BUTYL-3-METHYLIMIDAZOLIUM BIS(TRIFLUOROMETHYLSULFONYL)IMIDE AT HIGH TEMPERATURES AND PRESSURES
Abstract Pressure-density-temperature (p, ρ ,T) data of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][NTF2] at T = (273.15 to 413.15) K and pressures up to p =140 MPa are reported with an estimated experimental relative combined standard uncertainty of Δ ρ / ρ = ±(0.01 to 0.08)% in density. The measurements were c
Braz. J. Chem. Eng.. Publicado em: 2015-03
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11. Modelagem dos fenômenos de transporte termo-hídricos em meios porosos submetidos a temperaturas elevadas : aplicação a uma bicamada rocha-concreto
Concrete is an extremely complex material, whose properties are not yet fully understood. The diculties in describing and predicting the behavior of concrete structures are due to aspects related to the heterogeneity of medium - which is porous and multiphase - presenting uids in liquid and gas forms. When exposed to high temperature conditions, such diculti
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/08/2011
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12. Construção de uma célula-autoclave para medidas eletroquímicas a altas temperaturas
Measurements at high temperature using liquid solutions require special cells and materials which are able to support the temperature and pressure developed inside. The constructed cell was designed to support pressures up to 20 bar, temperatures relatively high up to around 200 ºC, depending on the pressure developed inside the system. It also supports agg
Química Nova. Publicado em: 2011-09