Thermal Diffusivity
Mostrando 1-12 de 67 artigos, teses e dissertações.
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1. Determining the In Situ Apparent Thermal Diffusivity of a Sandy Soil
ABSTRACT: The thermal wave amplitude method is used to determine soil thermal diffusivity in situ for a sandy soil in Mexico (Coatzacoalcos, Veracruz). Soil diurnal temperature fluctuations were measured from depths of 0.05 to 0.65 m, in 0.01 m increments, during the months of April and August. Five mean diffusivity values were obtained experimentally, corre
Rev. Bras. Ciênc. Solo. Publicado em: 14/11/2018
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2. Microscopía fototérmica para el estudio de transformaciones de fase
ABSTRACT A novel system allowing a high spatial resolution mapping of the thermal diffusivity as a function of temperature up to 1800 K is presented. The system is based on a photothermal technique recently developed by the group, consisting in measuring, with a probe laser beam, the curvature induced by local heating with a modulated pump laser. A microscop
Matéria (Rio J.). Publicado em: 19/07/2018
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3. Propiedades físicas y cristalinas del Cd1-xZnxTe (0 ≤ x ≤ 1)
ABSTRACT Cd1-xZnxTe (0 ≤ x ≤ 1) and ZnTe are II-VI semiconductors, which are used in single crystalline structure to improve their crystalline and electrical properties. The CZT and ZnTe must possess high crystalline and electrical quality to be used, the first in x or γ-ray detectors, and as substrates for suitable epitaxial films for detecting IR radi
Matéria (Rio J.). Publicado em: 19/07/2018
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4. Structural, Thermal, Optical, and Photoacoustic Study of Mechanically Alloyed Nanocrystalline SnTe
A nanostructured SnTe phase was produced by mechanical alloying after 2 h of milling. Part of the as-milled powder was annealed and its X-ray diffraction (XRD) pattern was recorded. The XRD patterns of the as-milled and annealed samples were refined using the Rietveld method. After annealing, partial decomposition of the SnTe phase was observed and corrobora
Mat. Res.. Publicado em: 07/06/2018
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5. Modeling of the temperature field generated by the deposition of weld bead on a steel butt joint by FEM techniques and thermographic images.
The aim of this work is to predict the temperature field generated by welding a steel butt joint (API 5L X80). The prediction was modeled by finite element software Abaqus where the subroutine was developed in Fortran so that heat source motion may be included. The motion was based on the Goldak's double ellipsoid. In the model material nonlinearities were i
Mat. Res.. Publicado em: 23/02/2018
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6. Hourly, Daily, and Monthly Soil Temperature Fluctuations in a Drought Tolerant Crop
ABSTRACT Soil temperature is a physical property of great agricultural importance in the soil-plant relationship and in energy exchange with the atmosphere. This study was conducted in a degraded Cambissolo Háplico Ta Eutrófíco (Cambisol; Inceptisol) in the Irecê Identity Territory, Bahia, Brazil, aiming to evaluate the hourly, daily, and monthly fluctua
Rev. Bras. Ciênc. Solo. Publicado em: 22/01/2018
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7. Influence of Nanoxides on Diffusivity and Solubility of Hydrogen in Pd-based alloys
The hydrogen interaction in palladium alloys with addition of Ce, Zr and Y was studied. These alloys are produced by arc-melting and then cold rolled into thin foils. Heat treatment at 800ºC for 24h in air atmosphere is applied to induce internal oxidation. Hydrogen permeation tests and TDS (Thermal Desorption Spectroscopy) are carried out to evaluate hydro
Mat. Res.. Publicado em: 11/01/2018
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8. Energy efficiency and moisture diffusivity of apple slices during convective drying
Abstract The present study aimed at investigating the influences of drying air temperature and flow rate on energy parameters and dehydration behaviour of apple slices. For this purpose, apple slices were dried in a convective dryer at air temperatures of 50, 60 and 70 °C, and air velocities of 1, 1.5 and 2 m s–1. Dehydration rate increased as the air tem
Food Sci. Technol. Publicado em: 26/02/2016
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9. Photoacoustic Thermal Characterization of Banana Fibers
Natural fibers are attracting the interest of engineering sectors owing to specific advantages such as lightweight and lower cost as well as an inherent condition of being renewable, biodegradable, recyclable and environmentally correct with respect to CO2 emission. In addition, several natural fibers present mechanical and thermal properties appropriate for
Mat. Res.. Publicado em: 2015-12
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10. Simulation of the Microstructural Evolution of Pure Material and Alloys in an Undercooled Melts via Phase-field Method and Adaptive Computational Domain
The phase-field methods were developed mainly for studying solidification of pure materials, being then extended to the solidification of alloys. In spite of phase-field models being suitable for simulating solidification processes, they suffer from low computational efficiency. In this study, we present a numerical technique for the improvement of computati
Mat. Res.. Publicado em: 2015-06
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11. DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
AbstractEnhanced heat transfer in tubes under laminar flow conditions can be found in coils or corrugated tubes or in the presence of high wall relative roughness, curves, pipe fittings or mechanical vibration. Modeling these cases can be complex because of the induced secondary flow. A modification of the Graetz problem for non-Newtonian power-law flow is p
Braz. J. Chem. Eng.. Publicado em: 2015-06
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12. Análise teórico-experimental da difusividade térmica em material opaco utilizando o Método Flash / THEORETICAL-EXPERIMETAL AALYSIS FOR THERMAL DIFFUSIVITY MEASUREMETS O OPAQUE MATERIALS WITH LASER FLASH METHOD
Este trabalho propõe a caracterização térmica de um sólido opaco utilizando o Método Flash como técnica de estimação de propriedades termofísicas do mesmo. A caracterização térmica de materiais corresponde à identificação das propriedades de transporte de calor. As propriedades que despertam maior interesse entre os pesquisadores são: calor
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/07/2012