Effects of temperature dependence in the attenuation coefficient on the error in certifying a waveguide noise generator

1982 ◽  
Vol 25 (11) ◽  
pp. 954-956
Author(s):  
O. G. Petrosyan
Keyword(s):  
Temperature Dependence ◽  
Attenuation Coefficient ◽  
Noise Generator ◽  
Effects Of Temperature

Temperature Dependence of Ultrasonic Propagation Speed and Attenuation in Canine Tissue

2002 ◽  
Vol 24 (4) ◽  
pp. 246-260 ◽  
Author(s):  
U. Techavipoo ◽  
T. Varghese ◽  
J.A. Zagzebski ◽  
T. Stiles ◽  
G. Frank
Keyword(s):  
Temperature Dependence ◽  
Attenuation Coefficient ◽  
Propagation Speed ◽  
Ablative Therapies ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Ultrasonic Propagation ◽  
Reported Data ◽  
Increasing Temperature

Previously reported data on the temperature dependence of propagation speed in tissues generally span only temperature ranges up to 60°C. However, with the emerging use of thermal ablative therapies, information on variation in this parameter over higher temperature ranges is needed. Measurements of the ultrasonic propagation speed and attenuation in tissue in vitro at discrete temperatures ranging from 25 to 95°C was performed for canine liver, muscle, kidney and prostate using 3 and 5 MHz center frequencies. The objective was to produce information for calibrating temperature-monitoring algorithms during ablative therapy. Resulting curves of the propagation speed vs. temperature for these tissues can be divided into three regions. In the 25–40°C range, the speed of sound increases rapidly with temperature. It increases moderately with temperature in the 40–70°C range, and it then decreases with increasing temperature from 70–95°C. Attenuation coefficient behavior with temperature is different for the various tissues. For liver, the attenuation coefficient is nearly constant with temperature. For kidney, attenuation increases approximately linearly with temperature, while for muscle and prostate tissue, curves of attenuation vs. temperature are flat in the 25–50°C range, slowly rise at medium temperatures (50–70°C), and level off at higher temperatures (70–90°C). Measurements were also conducted on a distilled degassed water sample and the results closely follow values from the literature.

scholarly journals A general model for effects of temperature on ectotherm ontogenetic growth and development

2011 ◽  
Vol 279 (1734) ◽  
pp. 1840-1846 ◽  
Author(s):  
Wenyun Zuo ◽  
Melanie E. Moses ◽  
Geoffrey B. West ◽  
Chen Hou ◽  
James H. Brown
Keyword(s):  
Climate Change ◽  
Simple Model ◽  
Total Energy ◽  
Temperature Dependence ◽  
General Model ◽  
Growth And Development ◽  
Biomass Accumulation ◽  
Rate Of Development ◽  
Body Sizes ◽  
Effects Of Temperature

The temperature size rule (TSR) is the tendency for ectotherms to develop faster but mature at smaller body sizes at higher temperatures. It can be explained by a simple model in which the rate of growth or biomass accumulation and the rate of development have different temperature dependence. The model accounts for both TSR and the less frequently observed reverse-TSR, predicts the fraction of energy allocated to maintenance and synthesis over the course of development, and also predicts that less total energy is expended when developing at warmer temperatures for TSR and vice versa for reverse-TSR. It has important implications for effects of climate change on ectothermic animals.

scholarly journals Brain size varies with temperature in vertebrates

2014 ◽  
Author(s):  
James F Gillooly
Keyword(s):  
Body Size ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Temperature Dependence ◽  
Aerobic Capacity ◽  
Brain Size ◽  
Metabolic Rates ◽  
Temperature Dependent ◽  
Spatial And Temporal Scales ◽  
Effects Of Temperature

The tremendous variation in brain size among vertebrates has long been thought to be related to differences in species’ metabolic rates. Species with higher metabolic rates can supply more energy to support the relatively high cost of brain tissue. And yet, while body temperature is known to be a major determinant of metabolic rate, the possible effects of temperature on brain size have scarcely been explored. Thus, here I explore the effects of temperature on brain size among diverse vertebrates (fishes,amphibians, reptiles, birds and mammals). I find that, after controlling for body size,brain size increases exponentially with temperature in much the same way asmetabolic rate. These results suggest that temperature-dependent changes in aerobic capacity, which have long been known to affect physical performance, similarly affect brain size. The observed temperature-dependence of brain size may explain observed gradients in brain size among both ectotherms and endotherms across broad spatial and temporal scales.

Rheology of Liquid Al, Zn and Zn-7wt%Al Systems

2011 ◽  
Vol 690 ◽  
pp. 226-229 ◽  
Author(s):  
Manickaraj Jeyakumar ◽  
Sumanth Shankar
Keyword(s):  
Shear Rate ◽  
Liquid Metal ◽  
Temperature Dependence ◽  
Arrhenius Equation ◽  
Flow Behavior ◽  
Pure Aluminum ◽  
High Shear Rate ◽  
High Shear ◽  
Shear Rates ◽  
Effects Of Temperature

The flow behavior and viscosity of pure aluminum, zinc and Zn-7wt%Al liquids were quantified with the effects of temperature and shear rate by rotational rheometry experiments. These systems exhibited a non-Newtonian, shear thinning and non-thixotropic flow behavior where in the liquid metal viscosity decreases with increasing shear rates. The temperature dependence of viscosity followed the Arrhenius equation. Moreover, at high shear rate regimes the flow resembles a nearly Newtonian behaviour.

Temperature dependence of the ultrasonic attenuation coefficient for ErRh4B4 between 1.5 K and 20 K

1980 ◽  
Vol 80 (1) ◽  
pp. 72-74 ◽  
Author(s):  
Susan C. Schneider ◽  
Moises Levy ◽  
David C. Johnston ◽  
Bernd T. Matthias
Keyword(s):  
Temperature Dependence ◽  
Attenuation Coefficient ◽  
Ultrasonic Attenuation

Effects of temperature on the photovoltage of Au–InSb Schottky barriers

1977 ◽  
Vol 55 (13) ◽  
pp. 1145-1149 ◽  
Author(s):  
P. Rochon ◽  
E. Fortin ◽  
J. C. Woolley
Keyword(s):  
Temperature Dependence ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Photovoltaic Cell ◽  
Interface States ◽  
Schottky Barriers ◽  
Experimental Results ◽  
Effect Of Temperature ◽  
Effects Of Temperature

The effect of temperature on the magnitude of the photovoltage ofa Au–InSb Schottky barrier is investigated in the range 60–250 K. Analysis of the variation of photo voltage with temperature shows that the barrier height [Formula: see text], which for Au–InSb is mostly determined by interface states, varies slowly with temperature. A model, taking into account the temperature dependence of the different components of the photovoltaic cell, is developed to explain the rapid increase in photovoltage with decreasing temperature, and its predictions are tested against experimental results.

scholarly journals Combined natural convection and radiation with temperature-dependent properties

2018 ◽  
Vol 22 (2) ◽  
pp. 921-930
Author(s):  
Tien-Chun Cheng ◽  
Chung-Jen Tseng ◽  
Ling-Chia Weng ◽  
Shih-Kuo Wu
Keyword(s):  
Natural Convection ◽  
Rayleigh Number ◽  
Temperature Dependence ◽  
Energy Transport ◽  
Radiation Condition ◽  
Radiative Properties ◽  
Discrete Ordinates ◽  
Radiation Parameter ◽  
Effects Of Temperature ◽  
Energy Equations

This paper investigates the effects of temperature dependence of radiative properties of a medium on radiation and natural convection interaction in a rectangular enclosure. The radiative transfer equation is solved using the discrete ordinates method, and the momentum, continuity, and energy equations are solved by the finite volume method. Effects of the conduction-to-radiation parameter, Rayleigh number, and optical thickness are discussed. Results show that temperature dependence of radiative properties affects the temperature gradient, and hence the energy transport even in relatively weak radiation condition. On the other hand, temperature dependence of radiative properties has relatively insignificant effects on convection characteristics, even though it does affect the way that energy transfers into the system. As conduction-to-radiation parameter is decreased or Rayleigh number is increased, the effects of temperature dependence of radiative properties become more significant.

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