The effect of thermal resistance value to the external deterioration due to climate impact

2005 ◽  
pp. 591-598
Keyword(s):  
Thermal Resistance ◽  
Climate Impact ◽  
Resistance Value

Photothermoelectric resistance effect observed in Ti/SiO2/Si structure induced by 10.6 μm CO2 laser

2020 ◽  
Vol 34 (34) ◽  
pp. 2050391
Author(s):  
Xu Sun ◽  
Pengfei Zhu ◽  
Kun Zhu ◽  
Yunxia Ping ◽  
Chaomin Zhang ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Motion Direction ◽  
Change Rate ◽  
Continuous Irradiation ◽  
Drift Motion ◽  
Diffusion Motion ◽  
Si Films ◽  
Value Changes ◽  
And Diffusion ◽  
Resistance Value

A novel photothermoelectric resistance effect of the Ti/SiO2/Si films induced by 10.6 [Formula: see text]m CO2 laser is discovered and investigated. The transient response of the resistance is observed and analyzed in this work. Under the continuous irradiation of the laser, the thermal resistance value changes with the irradiating time and gradually reaches a stable saturation. The results indicate that the rise time of thermal resistance is shortened and its change rate increased as laser power gets higher. The inner battery of the ohmmeter exerts the positive or negative bias voltage, causing the diffusion motion direction of the hot electrons to be opposite or the same direction with the drift motion, which can increase or decrease the thermal resistance value. Those experimental phenomena are explained by the drift and diffusion motion of the electrons. Based on the results, the Ti/SiO2/Si structure is an attractive candidate for thermal effect devices.

Thermal Characterization of Two Opposing Carbon Nanotube Arrays Using Diffraction-Limited Infrared Microscopy

2005 ◽  
Author(s):  
Xuejiao Hu ◽  
Matt Panzer ◽  
Kenneth E. Goodson
Keyword(s):  
Thermal Resistance ◽  
Contact Region ◽  
Thermal Characterization ◽  
Interface Structure ◽  
Infrared Microscopy ◽  
Carbon Nanotube Arrays ◽  
Cnt Arrays ◽  
Significant Temperature ◽  
Resistance Value

Due to their extremely high thermal conductivity, carbon nanotubes (CNTs) have received many research interests for thermal management applications. An advanced thermal interface structure made by two opposing, partially over-lapped CNT arrays is designed for thermally connecting two contact surfaces. The performance of this interface structure is thermally characterized using diffraction-limited infrared microscopy. Significant temperature discontinuities are found at the end of the CNT-CNT contact region, which indicates a large thermal resistance between CNTs. Due to this inter-tube resistance, the thermal performance of the CNT-based interface structure is far below expectation, with a thermal resistance value of about 3.8 × 10−4 K·m2/W. Possible mechanisms of heat transfer between CNTs, which result in the large inter-tube resistance, are discussed.

The Durability of Flame Retardant and Thermal Protective Cotton Fabrics during Domestic Laundering

2012 ◽  
Vol 441 ◽  
pp. 255-260 ◽  
Author(s):  
Wei Bang Chen ◽  
Ying Ying Wan ◽  
Fei Que ◽  
Xue Mei Ding
Keyword(s):  
Thermal Resistance ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Protective Clothing ◽  
Flame Retardants ◽  
Thermal Protection ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Before And After ◽  
Resistance Value

Flame retardant fabrics have been broadly used for protective clothing, which have strictly requirements on both flame retardancy and thermal protection. Usually, domestic laundering will be carried out frequently to clean these protective garments. However, little research on the performance durability of this type of fabrics after domestic laundering has been reported. This paper selected fabrics of 8 types of cotton and its blend fibers, which were treated with flame retardants Pyrovatex CP, Proban, CFR-201, SCJ-968 respectively. The damaged length, after flame time, after glow time, TPP value, thermal resistance value, weight, thickness, air permeability and water vapor permeability (WVP) of the samples were measured before and after 15 cycles domestic laundering cycles. Results show that the flame retardancy of the 8 fabrics reduce with launderings as measured by the increase in damaged length and after glow time. The TPP increase probably resulted from the increase in the thickness and thermal resistance of the finished fabrics. Domestic laundering resulted in only a slight change in the comfort properties of the fabrics.

scholarly journals Measuring the Rate of Heat Loss Across Selected Building Materials

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Genesis Zambrano ◽  
Keyword(s):  
Thermal Resistance ◽  
Heat Loss ◽  
Thermal Performance ◽  
Building Materials ◽  
Thermal Conductance ◽  
High Thermal Resistance ◽  
Resistance Value

The rate of heat loss is analyzed for three materials: glass, brick and wood. To do this, the initial and final temperatures are set to 75℉ and 100℉, respectively, and the dimensions of each material are chosen to be 5ft by 5ft with a thickness of 2 inches. The objective of this paper is to see which material is best for insulating heat, thus enhancing the thermal performance of a building. Results from this study suggest that glass and brick have a higher rate of heat loss (high thermal conductance values and low thermal resistance values) compared to wood and are therefore poor insulators whereas wood, with a lower rate of heat loss (low thermal conductance value and a high thermal resistance value) serves as a better insulator.

scholarly journals Method for Determining the Optimum Insulation Thickness of the Plaster Tow Material: Influence of the Heat Exchange Coefficient in Transient Regime

2021 ◽  
Vol 16 (3) ◽  
pp. 53
Author(s):  
Papa Touty TRAORE ◽  
Fatimata BA ◽  
Babou DIONE ◽  
Moussa DIENG
Keyword(s):  
Heat Exchange ◽  
Thermal Resistance ◽  
Numerical Method ◽  
Transient Regime ◽  
Exchange Coefficient ◽  
Heat Exchange Coefficient ◽  
Insulation Thickness ◽  
Resistance Value ◽  
Optimum Insulation Thickness

In this paper, we have applied a numerical method to determine the optimum insulation thickness of the tow plaster plane material. The influence of the exchange coefficients at the level of the two faces of the material has been highlighted. The optimum insulation thickness of the material is at the area where the thermal resistance value of the material is the maximum. We added the relative thermal resistance to show how the optimum insulation thickness changes when the exchange coefficients change values.

Effect of Melt Temperature on the Interfacial Thermal Resistance and Solidification Behaviour of Al/SiCp Composites

2014 ◽  
Vol 606 ◽  
pp. 35-40
Author(s):  
P. Gurusamy ◽  
S. Balasivanandha Prabu ◽  
R. Paskaramoorthy
Keyword(s):  
Thermal Resistance ◽  
Squeeze Casting ◽  
Solidification Time ◽  
Interfacial Thermal Resistance ◽  
Theoretical Expression ◽  
Melt Temperature ◽  
Squeeze Pressure ◽  
Solidification Behaviour ◽  
Resistance Value ◽  
Good Agreement

The effect of melt temperature on the interfacial thermal resistance and solidification behaviour of A356/10% SiCp during squeeze casting is studied. The melt pouring temperatures are considered in the investigation within the range of 750 - 900°C respectively. The squeeze pressure is kept constant at 100 MPa. It was observed that the solidification time increased with the melt temperature from 40 seconds at 750°C to 51 seconds at 900°C. The results also showed that the cooling rate decreased with melt temperatures. The solidification time calculated from the theoretical expression was found to be in good agreement with that obtained from the experimental cooling curves. The interfacial thermal resistance value increases from 0.000043 to 0.000203 m2 K/W when the melt temperature is increased from 750 to 900°C.

Energy absorption and thermal comfort of segmented pad for hip protective garment

2019 ◽  
Vol 31 (4) ◽  
pp. 564-577 ◽  
Author(s):  
Wiah Wardiningsih ◽  
Olga Troynikov
Keyword(s):  
Thermal Resistance ◽  
Energy Absorption ◽  
Evaporative Resistance ◽  
Content Type ◽  
Wear Comfort ◽  
And Performance ◽  
Index Value ◽  
Dry Thermal Resistance ◽  
Relationship Of ◽  
Resistance Value

Purpose The purpose of this paper is to investigate the influence and relationship of segment area and opening area in segmented protective pad in comparison to non-segmented pad to the energy absorption and performance attributes relevant to thermophysiological wear comfort. Design/methodology/approach The compressive stress-strain curves were obtained using Instron Tester and were used to analyse the energy absorption of the pads and the segmented pad assemblies. The dry thermal resistance and evaporative resistance of the non-segmented and segmented protective pads were obtained using MTNW Sweating Guarded Hot Plate. Findings The compression test results and performance attributes relevant to thermophysiological wear comfort test result demonstrated that the area segment and opening area of segmented pad influenced their energy absorption value, dry thermal resistance value and evaporative resistance value (permeability index value). Originality/value The results are expected to be useful for design and engineering of hip impact protective garments. Hip impact protective pads are used to prevent hip fractures in elderly people as a result of fall.

Experimental and Simulation Study of the Effect of Power Package Configuration on its Thermal Performance

2011 ◽  
Author(s):  
Cong Yue ◽  
Jun Lu ◽  
Xiaotian Zhang ◽  
Yueh-Se Ho
Keyword(s):  
Thermal Resistance ◽  
Power Supply ◽  
Size Variation ◽  
Element Model ◽  
Power Device ◽  
Simulation Approach ◽  
Power Semiconductor ◽  
Die Attach ◽  
Semiconductor Packages ◽  
Resistance Value

RthJA (Junction-to-Ambient Thermal Resistance) for power device packages was measured and modeled in order to correlate the results from our experiments and simulations. The packages studied, including TO (Transistor Outline), DFN (Dual Flat Non-Leaded), SOP (Small Outline Package) and DPAK with sizes from 3×3mm to 15×10mm, were tested under natural convection environment. An important observation from our testing is the significant influence of the external wires connecting the test coupon to the power supply on the thermal resistance value derived from the test data. The increase in the RthJA based on the test is more than 50% for TO packages and 19% for smaller packages once the external wires changed from gauge 18 to 30. A simple yet effective simulation approach was then introduced to predict RthJA incorporating the critical influence from the external wire size variation. With the validated finite element model, the effects of package factors such as package outline, die size, die attach, encapsulation and interconnection on the thermal resistances of the power semiconductor packages were studied by simulation to provide further insights and guides for new package developments.

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