Effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding

2012 ◽  
Vol 28 (1) ◽  
pp. 167-170 ◽  
Author(s):  
Asli Secilmis ◽  
Mehmet Bulbul ◽  
Tugrul Sari ◽  
Aslihan Usumez
2010 ◽  
Vol 35 (2) ◽  
pp. 220-230 ◽  
Author(s):  
J. Leprince ◽  
J. Devaux ◽  
T. Mullier ◽  
J. Vreven ◽  
G. Leloup

Clinical Relevance This paper provides practitioners with useful information on the importance of aligning the spectra of the LCU and the material in terms of polymerization efficiency and temperature rise in the pulp chamber.


2021 ◽  
Vol 300 ◽  
pp. 01014
Author(s):  
Maode Li ◽  
Chuan He ◽  
Jinkui Zheng

Lithium-ion power battery has become an important part of power battery. According to the performance and characteristics of lithiumion power battery, the influence of current common charge and discharge and different cooling methods on battery performance was analysed in this paper. According to the software simulation, in the 5C charge-discharge cycle, the maximum temperature of the cells with regular arrangement is 57.97°C, the maximum temperature of the cells with staggered arrangement is 55.83°C, and the maximum temperature of phase change cooling is 47.42°C. The most important thing is that the temperature difference between the cells with phase change cooling is only 5.5°C. Some simulation results of air cooling and phase change show that phase change cooling can control the heat dissipation and temperature rise of power battery well. The research in this paper can provide better theoretical guidance for the temperature rise, heat transfer and thermal management of automotive power battery.


Author(s):  
M Ishizuka ◽  
G Peng ◽  
Y Kitamura

This paper is concerned with the natural cooling of electronic equipment casings. Effects of the size and the location of the outlet vent as well as the relative distance from the outlet vent location to the power heater position on the flow resistance have been investigated experimentally by using a simple model casing simulated for practical natural air cooled electronic equipment casings. The result shows that the mean temperature rise inside the casing increases with increase in the heater input power, but decreases linearly with increase in the vent porosity coefficient in logarithmic coordinates. As the heater approaches the outlet vent, the temperature rise increases linearly in the logarithmic scale. By defining a new dimensionless parameter called the equivalent Reynolds number, involving the Reynolds number and the porosity coefficient, the flow resistance coefficient is found to have a close logarithmic linear correlation, K = kxχ−1.5, with the equivalent Reynolds number. Its validation has been proved by the good agreement with experimental results. The result indicates that the relative distance from the outlet vent to the heat dissipation unit can be considered as a chimney height in the practical engineering design. Although further more detailed validations are needed, a useful correlation between the flow resistance coefficient, the Reynolds number and the porosity coefficient has been presented for the design application of natural cooling electronic casings.


1991 ◽  
Vol 113 (1) ◽  
pp. 56-62 ◽  
Author(s):  
A. M. Anderson ◽  
R. J. Moffat

This paper discusses forced convection heat transfer in a channel populated with discrete components similar to those found in electronics cooling situations. The temperature rise of each component is expressed as the sum of two parts; its adiabatic temperature rise, Tad–Tin, due to the thermal wakes of upstream components; and its self-heating temperature rise, Te–Tad due to its own power dissipation. A component’s temperature can be reduced either by reducing the adiabatic temperature rise or the self-heating temperature rise, or both. This investigation concentrates on the former: reducing the adiabatic temperature rise through increased thermal mixing in the coolant flow. The temperature of the air near the components exceeds the mean temperature of the cooling fluid, often by a large amount. In the present work, small scoops were installed in regions of high temperature but low velocity fluid (i.e., in between rows of components rather than in the free stream) to augment thermal mixing and reduce the nonuniformity. This approach does not induce as large a pressure drop as some conventional “turbulators” for a given decrease in operating temperature. In the present work, the scoops reduced the adiabatic temperature rises by 10 to 55 percent, resulting in up to 19 percent reduction in the overall temperature rise. The test section pressure drop increased 11 percent.


2014 ◽  
Vol 30 (11) ◽  
pp. 1280-1289 ◽  
Author(s):  
Luc D. Randolph ◽  
William M. Palin ◽  
David C. Watts ◽  
Mathieu Genet ◽  
Jacques Devaux ◽  
...  

2005 ◽  
Vol 72B (2) ◽  
pp. 254-259 ◽  
Author(s):  
Ay�e Unverdi Eldeniz ◽  
Aslihan Usumez ◽  
Serdar Usumez ◽  
Nilgun Ozturk

1992 ◽  
Vol 114 (4) ◽  
pp. 420-424 ◽  
Author(s):  
David Copeland

A series of experiments was performed to study forced convection from rectangular arrays of electronic components. Effects of channel height, planar spacing, component row number, and approach velocity are assessed. Correlations for the temperature rise of a component due to its own power and due to heating by upstream modules are presented. The components used were aluminum-capped ceramic pin grid array modules, of the same shape as “flatpacks”, measuring 37 mm square and 5.8 mm tall. The space between the rows and columns of modules was varied from near zero to about one module length. Channel height ranged from about two to five times module height. The air approach velocity ranged from 0.5 to 5.5 meters per second, corresponding to module length Reynolds numbers from 1000 to 11000. The heat transfer coefficient varied from 25 to 75 W/m2K. The temperature rise of a component due to its own power was found to be a strong function of velocity and less dependent on channel height and row number. The effect of velocity was weaker on the densest configuration than on the two sparser spacings. The two densest spacings had little dependence on channel height; the sparsest configuration had only a weak dependence on row number. The temperature rise of components downstream of a heated component exhibited similar but stronger dependence on velocity and channel height and the same dependence on row number.


2012 ◽  
Vol 608-609 ◽  
pp. 1571-1576 ◽  
Author(s):  
Zhi Jun Tang ◽  
Qun Zhi Zhu ◽  
Jia Wei Lu ◽  
Ming Yan Wu

Power battery thermal management system (BTMS) is very important for the safe operation of electric vehicles (EVs). The cooling effect of air cooling, phase change material(PCM)cooling and liquid cooling applyed to BTMS are compared. The experiment results show that, in comparison with air cooling, PCM cooling and liquid cooling methods can reduce the battery temperature rise effectively; in comparison with PCM cooling, liquid cooling has a better effect in the aspect of controlling the battery temperature rise.


2004 ◽  
Vol 1 (3) ◽  
pp. 136-144
Author(s):  
Nobuaki Sugiura

The cooling capability of a cabinet, which is affected by the air flow induced by the fan mounted on the subrack, is evaluated. The chimney effect has a relationship with the space, H0 to the 2nd power and this effect is in turn affected by the holed pattern of the front door. The concept of an effective coefficient for cooling capability affected by the exhausted air flow from the subrack is introduced, and a rough estimation of temperature rise is made possible by using this new coefficient and the physical parameters of a cabinet, subracks, and a fan.


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