Zero Temperature Coefficient
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. Experimental and numerical investigation of the microwave dielectric properties of the MgTiO3 ceramic matrix added with CaCu3Ti4O12
Abstract This paper describes an experimental and numerical investigation of the dielectric resonators based on the MgTiO3 ceramic matrix, which relates to their dielectric properties in microwave. The resonators are compounds of the MgTiO3 added with 4, 6, 8, 10 and 12 wt% of the CaCu3Ti4O12. The manufacturing process of the resonators is based on the solid
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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2. Estudo do ponto invariante com a temperatura ("Zero Temperature Coefficient") em transistores SOI Mosfet fabricados com tecnologia ultra-submicrométrica. / Zero temperature coefficient study in SOI mosfets with submicrometer technology.
Neste trabalho é apresentado um estudo do ponto ZTC (Zero Temperature Coefficient) em dispositivos SOI MOSFETs, funcionando em modo parcialmente (PD-SOI) e totalmente (FD-SOI) depletados. O estudo é realizado a partir de um modelo analítico simples, proposto para determinação da tensão de polarização da porta do transistor no ponto ZTC (VZTC), atrav�
Publicado em: 2011
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3. Atomistic simulations of supercooled gallium / Simulações atomisticas do galio super-resfriado
Recently, the existence of a liquid-liquid transition in pure substances has been proposed as an explanation of anomalous behaviors such as the increase of response functions (isothermal compressibility, coefficient of thermal expansion, specific heat) with decreasing temperature displayed by some liquids. The existence of this type of transition has been de
Publicado em: 2009
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4. The double gaussian distribution of inhomogeneous barrier heights in Al/GaN/p-GaAs (MIS) schottky diodes in wide temperature range
The current-voltage (I-V) characteristics of metal-insulator-semiconductor (Al/GaN/p-GaAs) Schottky barrier diodes (SBDs) were investigated over a wide temperature range of 80-380 K. By using the thermionic emission (TE) theory, the zero bias barrier height ΦB0 calculated from I-V characteristics was found to increase with increasing temperature as the idea
Brazilian Journal of Physics. Publicado em: 2008-12
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5. AdsorÃÃo dos corantes reativos azul 5G e azul turquesa QG em carvÃo ativado comercial / Adsorption of reactive dyes 5G and turquoise QG onto commercial activated coal
The textile industries understand one of the largest of the world now in production terms and number of generated jobs. They are characterized by requesting great amounts of water, coloring and chemical products used along a complex productive chain. Besides the enormous consumption of water, those industries generate effluent composed by organic and complex
Publicado em: 2008
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6. Temperature dependent molecular dynamic simulation of friction
In this work we present a molecular dynamics simulation of a FFM experiment. The tip-sample interaction is studied by varying the normal force in the tip and the temperature of the surface. The friction force, cA, at zero load and the friction coefficient, m, were obtained. Our results strongly support the idea that the effective contact area, A, decreases w
Brazilian Journal of Physics. Publicado em: 2006-09
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7. Numerical prediction of nonequilibrium hypersonic flow around Brazilian satellite SARA
Hypersonic flows past Brazilian satellite SARA at zero angle of attack in chemical and thermal nonequilibrium are investigated using an axisymmetric Navier-Stokes solver. The numerical solutions were carried out for freestream conditions equivalent to a typically re-entry trajectory with a range of Mach numbers from 10 to 25. The gas was chemically composed
Brazilian Journal of Physics. Publicado em: 2005-03
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8. Balanço de energia e evapotranspiração de cafezal adensado em crescimento sob irrigação localizada. / Energy balance and evapotranspiration in a high density young coffee under located irrigation.
The objectives of this study were to evaluate the magnitude of global evapotranspiration (ETc) in a high density young coffee crop (3.5mx0.9m) under drip irrigation, the ETc partition considering hedgerows and interrows, and the partition of the available radiant energy between sensible and latent heat fluxes. The experiments were conducted from September 20
Publicado em: 2005
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9. Temperature coefficient of piezoelectric constants in Pb(Mg1/3 Nb2/3)O3 - PbTiO3 ceramics
In this work, the thermal stability of piezoelectric constants of PMN-PT ceramics in the tetragonal and rhombohedral phases were investigated in a wide range of temperatures. The results showed that the tetragonal PMN-PT presented higher thermal stability and, consequently, the temperature coefficients for the piezoelectric constants were approximately zero.
Materials Research. Publicado em: 2004-06
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10. Cálculo, via grupo de renormalização, da relaxação nuclear de uma impureza em meio metálico. / Renormalization group calculation of nuclear spin-lattice relaxation for one impurity in a metal.
The nuclear magnetic relaxation rate for an impurity in a metallic environment has been calculated as a function of temperature. Our calculations are based on the spin-degenerate Anderson model originally developed to describe dilute magnetic alloys. The relevance to heavy férmions, Valence fluctuation, and chemisorption on metallic surfaces is discussed. T
Publicado em: 1989
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11. Particle-hole symmetry in the antiferromagnetic state of the cuprates
In the layered cuprate perovskites, the occurrence of high-temperature superconductivity seems deeply related to the unusual nature of the hole excitations. The limiting case of a very small number of holes diffusing in the antiferromagnetic (AF) background may provide important insights into this problem. We have investigated the transport properties i
The National Academy of Sciences.
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12. Thermodynamic studies of polymerization of deoxygenated sickle cell hemoglobin.
Solubilities of deoxygenated sickle cell hemoglobin (deoxy-Hb S), at varying pH and temperature over a range of concentrations encompassing those found in erythrocytes, were measured. The technique involved ultracentrifugation, which gave values of the supernatant concentration and the mass of the sedimented material. The data establish that the solubility o