Temperature Sensitivity Coefficients of Heat Transfer Processes in Myocardium, with Special Reference to the Determination of Tissue Perfusion

Author(s):  
Robert C. Eberhart ◽  
Avraham Shitza
2018 ◽  
Vol 194 ◽  
pp. 01013 ◽  
Author(s):  
Ilnur N. Madyshev ◽  
Oksana S. Dmitrieva ◽  
Andrey V. Dmitriev

One of the ways of intensifying the heat and mass transfer processes in gas-fluid systems is designing jet-film contact devices with a developed surface of phase contact at high flow velocities. A contact jet-film device has been developed. The results of numerical investigation of the operation of this device are presented. There were determined the coefficients of heat transfer to the air from the surface of liquid inside of the drain cup of contact device. The criterion equations of convective heat transfer for engineering calculations of jet-film contact devices is corrected.


2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Heinz Herwig

Entropy generation in a velocity and temperature field is shown to be very significant in momentum and heat transfer problems. After the determination of this postprocessing quantity, many details about the physics of a problem are available. This second law analysis (SLA) is a tool for conceptual considerations, for the determination of losses, both in the velocity and the temperature field, and it helps to assess complex convective heat transfer processes. These three aspects in conjunction with entropy generation are discussed in detail and illustrated by several examples.


Author(s):  
Heinz Herwig

Entropy generation in a velocity and temperature field is shown to be very significant in momentum and heat transfer problems. After the determination of this post-processing quantity many details about the physics of a problem are available. This second law analysis (SLA) is a tool for conceptual considerations, for the determination of losses, both in the velocity and the temperature field, and it helps to assess complex convective heat transfer processes. These three aspects in conjunction with entropy generation are discussed in detail and illustrated by several examples.


Author(s):  
A J Fletcher ◽  
A Fioravanti

The passage of an ultrasonic wave through a mixture of polyborosiloxane and silicon carbide abrasive, when used in a honing process, causes heating due to the attenuation of the said wave. This is critical to the honing process since the temperature in the components being treated must be limited to about 70° C. A numerical model of the heat generation and transfer processes in the polishing medium is being formulated, which requires knowledge of the thermophysical properties of the mixture. This investigation concentrates on the experimental determination of thermal conductivity, specific heat capacity and surface heat transfer coefficient for various mixtures of polyborosiloxane and silicon carbide abrasive. Theoretical, semi-empirical and empirical models are derived for the variation of these thermal properties as functions of both material composition and temperature.


Author(s):  
Yu. P. Morozov

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.


2001 ◽  
Vol 32 (7-8) ◽  
pp. 7
Author(s):  
M. I. Osipov ◽  
K. A. Gladoshchuk ◽  
A. N. Arbekov

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