scholarly journals Breakdown of quantum-to-classical correspondence for diffusion in a high-temperature thermal environment

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Dekel Shapira ◽  
Doron Cohen
Keyword(s):  
High Temperature ◽  
Thermal Environment ◽  
Classical Correspondence

EFFECTS OF THERMAL ENVIRONMENTS ON THE THERMAL SHOCK RESISTANCE OF ULTRA-HIGH TEMPERATURE CERAMICS

2008 ◽  
Vol 22 (14) ◽  
pp. 1375-1380 ◽  
Author(s):  
WEIGUO LI ◽  
DAINING FANG
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Thermal Environment ◽  
Transfer Condition ◽  
Ultra High Temperature Ceramics ◽  
Thermal Environments ◽  
Shock Resistance ◽  
Ultra High Temperature

In the present study, the temperature-dependent thermal shock resistance parameter of Ultra-High Temperature Ceramics (UHTCs) was measured based on the current evaluation theories of thermal shock resistance parameters, since the material parameters of UHTCs are very sensitive to the changes of temperature. The influence of some important thermal environment parameters on the thermal shock resistance and critical temperature difference of rupture of UHTCs were studied. By establishing the relation between the temperature and the thermal or mechanical properties of the UHTCs, we found that thermal shock behavior of UHTCs is strongly affected by the surface heat transfer coefficient, heat transfer condition and initial temperature of the thermal shock.

scholarly journals Response of Functionally Graded Material Plate under Thermomechanical Load Subjected to Various Boundary Conditions

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Manish Bhandari ◽  
Kamlesh Purohit
Keyword(s):  
High Temperature ◽  
Boundary Conditions ◽  
Thermal Loading ◽  
Thermal Environment ◽  
Shear Deformation Theory ◽  
Light Metal ◽  
Functionally Graded ◽  
Numerical Results ◽  
Element Formulation ◽  
Power Law Distribution

Functionally graded materials (FGMs) are one of the advanced materials capable of withstanding the high temperature environments. The FGMs consist of the continuously varying composition of two different materials. One is an engineering ceramic to resist the thermal loading from the high-temperature environment, and the other is a light metal to maintain the structural rigidity. In the present study, the properties of the FGM plate are assumed to vary along the thickness direction according to the power law distribution, sigmoid distribution, and exponential distribution. The fundamental equations are obtained using the first order shear deformation theory and the finite element formulation is done using minimum potential energy approach. The numerical results are obtained for different distributions of FGM, volume fractions, and boundary conditions. The FGM plate is subjected to thermal environment and transverse UDL under thermal environment and the response is analysed. Numerical results are provided in nondimensional form.

scholarly journals Composite design and thermal comfort evaluation of safety helmet with PCM cooling

2020 ◽  
pp. 250-250
Author(s):  
Wentao Hu ◽  
Zu`an Liu ◽  
Meng Yuan ◽  
Ying Peng ◽  
Xi Meng ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Comfort ◽  
Thermal Environment ◽  
Cooling Effect ◽  
Absorption Cooling ◽  
Temperature Environment ◽  
Cooling Technology ◽  
Fan Cooling ◽  
Change Material ◽  
High Temperature Environment

Higher temperature and humidity will adversely affect the thermal comfort of helmet users. In order to improve the comfort level of the helmet and obtain an optimal cooling helmet model, four kinds of helmet models were established by using phase-change material (PCM) heat-absorbing cooling technology and fan cooling technology. Through the air conditioning system, the working states of four kinds of helmet models in the thermal environment of 30? were simulated, and the thermal comfort of four kinds of helmet models was evaluated. The results show that: high temperature environment is an important factor affecting the cooling effect of fan helmet (b) fan, Under high temperature environment, the helmet with fan cooling technology has a certain cooling effect in the early stage, but after 30 minutes, the cooling effect becomes worse and worse. Under high temperature environment, PCM safety helmet (c) has a good cooling effect, but poor ventilation results in the excreted sweat clinging to the scalp and hair, resulting in a poor user experience. There are defects in using phase-change material (PCM) heat absorption cooling technology or fan cooling technology alone. The helmet (d) combines PCM heat absorption cooling technology with fan cooling technology, so that the cooling effect and internal thermal environment stability of the helmet are the best, and the thermal sensation of human body is the best. Therefore, the helmet (d) is an optimal design model.

scholarly journals The thermal environment of sperm affects offspring success: a test of the anticipatory paternal effects hypothesis in the blue mussel

2021 ◽  
Vol 17 (7) ◽  
pp. 20210213
Author(s):  
Rowan A. Lymbery ◽  
W. J. Kennington ◽  
Jonathan P. Evans
Keyword(s):  
High Temperature ◽  
Blue Mussel ◽  
Thermal Environment ◽  
Paternal Effects ◽  
Second Stage ◽  
Mediated Effects ◽  
The Many ◽  
Normal Offspring ◽  
By Products ◽  
Better Than

There has been an explosion of recent evidence that environments experienced by fathers or their ejaculates can influence offspring phenotypes (paternal effects). However, little is known about whether such effects are adaptive, which would have far-reaching implications for the many species facing rapidly changing environments. For example, some arguments suggest paternal effects might be a source of cross-generational plasticity, preparing offspring to face similar conditions to their father (anticipatory hypothesis). Alternatively, ejaculate-mediated effects on offspring may be non-adaptive by-products of stress. Here, we conduct an experiment to distinguish between these predictions, exposing ejaculates of the externally fertilizing mussel Mytilus galloprovincialis to ambient (19°C) and high (24°C) temperatures, then rearing offspring groups in temperatures that match and mismatch those of sperm. We find that, overall, high temperature-treated sperm induced higher rates of normal offspring development and higher success in transitioning to second-stage larvae, which may represent adaptive epigenetic changes or selection on sperm haplotypes. However, the progeny of high temperature-treated sperm did not perform better than those of ambient temperature-treated sperm when rearing temperatures were high. Overall, these findings offer little support for the anticipatory hypothesis and suggest instead that beneficial paternal effects may be eroded when offspring develop under stressful conditions.

scholarly journals Thermal Environment Map in Street Canyon for Implementing Extreme High Temperature Measures

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 550
Author(s):  
Hideki Takebayashi ◽  
Mai Okubo ◽  
Hiroki Danno
Keyword(s):  
High Temperature ◽  
Street Canyon ◽  
Thermal Environment ◽  
Detailed Calculation ◽  
Mean Radiant Temperature ◽  
The North ◽  
Environment Map ◽  
Extreme High Temperature ◽  
Typical Summer ◽  
Radiant Temperature

The thermal environment map in street canyon is derived by using GIS building data and more detailed calculation, and its effectiveness is considered for implementing extreme high temperature measures. The influence of mean radiant temperature (MRT) is more dominant than the wind velocity on the distribution of standard new effective temperature (SET*) on the typical summer day in street canyon in the urban area of Kobe city, and the solar radiation shading is more effective in suppressing the rise of SET* in the daytime than improving the land coverage. The following strategy of extreme high temperature measures is derived by considering the thermal environment map in street canyon. Pedestrians may find the shaded places on the north-south road until 10:00 a.m. and after 3:00 p.m., due to the eastern building’s shade in the morning and the western building’s shade in the afternoon.

scholarly journals Some Effects on the Temperature of the Mine Air at the Heading Face

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Van Quang NGUYEN ◽  
Van Thinh NGUYEN ◽  
Cao Khai NGUYEN ◽  
Van Chung PHAM
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Temperature Distribution ◽  
Air Temperature ◽  
Significant Influence ◽  
Thermal Environment ◽  
Simulation Method ◽  
Forced Ventilation ◽  
Ansys Cfx ◽  
Ventilation Method

Currently, with the increase in mining output leading to deeper mining levels, the volume ofheading face serving production has also increased. The thermal environment tends to worsen whendigging deep due to the geothermal's effect, which increases the air temperature at the heading face.According to QCVN01/2011-BCT, the temperature at the heading face is not allowed to exceed 300C. Toensure this, in Vietnam today, mainly forced ventilation method uses local fans to provide a clean amountof air to ensure a favorable environment for workers. With the forced ventilation method, the duct positionis usually arranged on the side, and the distance from the duct mouth to the heading face is determined toensure that l < 6√s. In this study, a numerical simulation method by Ansys CFX software is applied tostudy the influence of several factors such as duct position, air temperature of duct, and roughnesscharacteristics of roadway on the temperature of the mine air at the heading face. The models are set upwith six duct positions and four air temperature of duct parameters. Model 1 (y =1.1 m) is better thanmodels 2 to 6 in terms of temperature distribution and the lowest temperature values. Four models havedifferent wind temperatures, and we can see the significant influence of the inlet air temperature of theduct on the thermal environment of the heading face. The results show that with the model T = 297.15K,the temperature value on the roadway length is guaranteed as specified < 303K. The result is a referencefor determining the duct position and cool for the high-temperature heading face.

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