Particulates
Mostrando 1-12 de 110 artigos, teses e dissertações.
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1. Comparative analysis of niobium and vanadium carbide efficiency in the high energy mechanical milling of aluminum bronze alloy
Abstract This study aims to analyze the efficiency of niobium and vanadium carbides in the high energy mechanical milling of aluminum bronze alloy. Two series of experiments were made following the same steps for both niobium carbide (NbC) and vanadium carbide (VC) additions: 30 g of chips were weighed and placed in a stainless steel jar with 3 % of carbide
REM, Int. Eng. J.. Publicado em: 2018-03
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2. Weldability Study of LM25/ZrO2 Composites by Using Friction Welding
ABSTRACT In this paper aluminum (LM25) alloy was chosen as a base matrix metal, and it was reinforced with 0, 3, 6, 9, 12% of Zirconium dioxide (ZrO2) particulates based on weight fraction method. Stir casting method was used to cast LM25/ZrO2 composite material. The cast samples were subjected to physical and mechanical test viz, density, hardness, tensile,
Matéria (Rio J.). Publicado em: 10/08/2017
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3. Effect of Cryogenic Chill on Mechanical Properties of ASTM A 494 M Grade Nickel Based Alloy Metal Matrix Composites
An investigation in the present research was made to fabricate and evaluate the microstructure and mechanical properties of metal matrix composites developed using cryogenically cooled copper chills, consisting of ASTM A 494 M grade nickel alloy matrix and garnet particles as the reinforcement. The particle's amount added ranges from 3 wt. % to 12 wt. % in s
Mat. Res.. Publicado em: 26/09/2016
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4. Desenvolvimento de um sistema para detecção de dispersóides no ar
The amount of dust suspended in air can be harmful to human health if not complied with the limits previously established by the WHO (World Health Organisation). The air is polluted when it contains elements foreign to its natural composition: oxygen, nitrogen, noble gases and water vapor and even carbon dioxide. The most common forms of air pollution are ca
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/04/2011
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5. Levantamento dos níveis de radioatividade natural em águas do alto Vale do Ribeira à planície costeira do litoral sul do Estado de São Paulo / Assessment of natural radioctivity levels in waters from Higher Ribeira Valley until the southern Sao Paulo State coastal plain
The complex exchange of fluvial, subsurface and seawater within a coastal area directly affects global biogeochemical cycles and the application of isotopic tracers, mainly natural radionuclides from U and Th series, is a powerful tool to track sources and sinks of trace elements and nutrients to this systems. The unique Ra signature applied to quantify the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/11/2010
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6. Efeitos antrópicos sobre concentrações de metais alcalinos na região da microbacia do Arroio Araçá, Canoas - Rio Grande do Sul
This work presents alterations in the concentrations of alkaline metals sodium, lithium and potassium, in abiotic compartments, at Araçá stream micro-basin, located in Canoas, RS. Its spring is located in a low populational density region and crosses an elevated environmental impacted urban area. Its final course crosses an agricultural area. Samples of at
Química Nova. Publicado em: 2009
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7. CONSTRUÇÃO DE UM MAGNETÔMETRO HALL PARA CARACTERIZAÇÃO DE PARTÍCULAS MAGNÉTICAS UTILIZADAS EM ENSAIOS IMUNOLÓGICOS / HALL MAGNETOMETER CONSTRUCTION FOR CHARACTERIZATION OF MAGNETIC PARTICULATES USED IN IMMUNOASSAYS
Ensaios imunológicos em amostras biológicas são baseados em métodos que quantificam a ligação antígeno-anticorpo através de um marcador ligado ao anticorpo. Recentemente, métodos magnéticos de detecção têm sido aplicados através da utilização de marcadores contendo nanopartículas magnéticas em seu interior. Isto pode levar a um diagnóstico
Publicado em: 2009
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8. Using energy dispersive X ray fluorescence (EDXRF) technique to evaluate the suspended particulate matter from Limeira city, State of São Paulo, Brazil / Utilização da técnica de fluorescência de raios X por dispersão em energia (EDXRF) na avaliação do material particulado em suspensão na cidade de Limeira - SP
The main objective of this work was to evaluate the chemical composition of the suspended particulate matter from the atmosphere of the city of Limeira, State of São Paulo, by energy dispersive X-ray fluorescence (EDXRF) technique. A stacker filter sampler was used to collect the fine (particles with aerodynamic diameter between 2.5 and 10 müm) and the gro
Publicado em: 2009
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9. Estudo do processo de dispersão de emissões veiculares em uma microrregião de Belo Horizonte utilizando simulação numérica / Study of the dispersion process of vehicular emissions at a specific site in Belo Horizonte using numerical simulation
A poluição urbana é um sério problema ambiental que vem se agravando nos países em desenvolvimento. No Brasil, as concentrações de poluentes atmosféricos têm crescido rapidamente nas principais regiões urbanas durante as últimas décadas. Esta expansão tem ocorrido principalmente devido ao crescente número de veículos automotivos em circulaçã
Publicado em: 2009
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10. Caracterização de Ametistas Naturais
This research intends to investigate the formation of color in samples of natural amethyst from different origins after submitting them to gamma irradiation, as well to develop an identification method of uncolored crystals with potential for development of color. The techniques of infrared spectroscopy, ultraviolet-visible spectroscopy and atomic emission s
Publicado em: 2008
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11. A influência das características da areia artificialmente britada nas propriedades do estado fresco do concreto
This work reports on the properties of the fresh state of concrete when different petrografic types of crushed sand are used. It focuses on the characteristics of these aggregates which exert a dominant influence on the concrete properties. To reach the main goal of this work, five different lithological types of crushed sand were used, which have been ident
Publicado em: 2008
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12. Hidrocarbonetos policíclicos aromáticos como traçadores da queima de cana-de-açúcar: uma abordagem estatística
In this study atmospheric particulates of PAHs were measured in Araraquara, Piracicaba and São Paulo in July 2003 (sugarcane harvest season in Araraquara and Piracicaba) and in Araraquara in March of 2003. The results were normalized to the total PAH concentrations. Comparison among the sites and principal component analysis (PCA) were used to investigate p
Química Nova. Publicado em: 2007-06