Investigation of the Thermal Transfer Behavior of Single Layer Woven Fabrics at Different Temperatures

2016 ◽  
Vol 11 (2) ◽  
pp. 155892501601100 ◽  
Author(s):  
Xiaoxia Liu ◽  
Tingting Wang ◽  
Mingyu Zhuang ◽  
Binjie Xin ◽  
Wei Liu
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Fiber Type ◽  
Single Layer ◽  
Woven Fabrics ◽  
Thermal Transfer ◽  
Data Regression ◽  
Different Temperatures ◽  
Wire Method ◽  
Transfer Behavior

The thermal conductivity of several high performance woven fabrics at temperatures ranging from −50? to 200? was measured using the hot wire method to explore the relationship between the thermal conductivity and temperature. Data regression of the least squares was used to obtain curves of the thermal conductivity of various fabrics vs. temperature. Results show that the thermal transfer process in woven fabrics is mainly thermal conduction consisting of phonon and molecular conduction. Thermal conductivity as a function of temperature varies as temperature range changes, and is significantly affected by fiber type.

scholarly journals Moisture Vapor Permeability and Thermal Wear Comfort of Ecofriendly Fiber-Embedded Woven Fabrics for High-Performance Clothing

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6205
Author(s):  
Hyun-Ah Kim
Keyword(s):  
Thermal Conductivity ◽  
Pore Size ◽  
High Performance ◽  
Woven Fabrics ◽  
Vapor Permeability ◽  
Measuring Methods ◽  
Wear Comfort ◽  
Thermal Wear ◽  
Moisture Vapor ◽  
Yarn Structure

This study examined the moisture vapor permeability and thermal wear comfort of ecofriendly fiber-embedded woven fabrics in terms of the yarn structure and the constituent fiber characteristics according to two measuring methods. The moisture vapor permeability measured using the upright cup (CaCl2) method (JIS L 1099A-1) was primarily dependent on the hygroscopicity of the ecofriendly constituent fibers in the yarns and partly influenced by the pore size in the fabric because of the yarn structure. On the other hand, the moisture vapor resistance measured using the sweating guarded hot plate method (ISO 11092) was governed mainly by the fabric pore size and partly by the hygroscopicity of the constituent ecofriendly fibers. The difference between the two measuring methods was attributed to the different mechanisms in the measuring method. The thermal conductivity as a measure of the thermal wear comfort of the composite yarn fabrics was governed primarily by the pore size in the fabric and partly by the thermal characteristics of the constituent fibers in the yarns. Lastly, considering market applications, the Coolmax®/Tencel sheath/core fabric appears useful for winter warm feeling clothing because of its the good breathability with low thermal conductivity. The bamboo and Coolmax®/bamboo fabrics are suitable for summer clothing with a cool feel because of their high thermal conductivity with good breathability. Overall, ecofriendly fibers (bamboo and Tencel) are of practical use for marketing environmentallyfriendly high-performance clothing.

Microstructure of sputter deposited Ni-Sb ohmic contacts on GaAs

1989 ◽  
Vol 47 ◽  
pp. 450-451
Author(s):  
S. Yegnasubramanian ◽  
V.C. Kannan ◽  
R. Dutto ◽  
P.J. Sakach
Keyword(s):  
High Performance ◽  
Ohmic Contacts ◽  
Surface Defects ◽  
Pure Metal ◽  
Device Fabrication ◽  
Native Oxide ◽  
Metal Thin Films ◽  
Recent Developments ◽  
Different Temperatures ◽  
Sputter Deposited

Recent developments in the fabrication of high performance GaAs devices impose crucial requirements of low resistance ohmic contacts with excellent contact properties such as, thermal stability, contact resistivity, contact depth, Schottky barrier height etc. The nature of the interface plays an important role in the stability of the contacts due to problems associated with interdiffusion and compound formation at the interface during device fabrication. Contacts of pure metal thin films on GaAs are not desirable due to the presence of the native oxide and surface defects at the interface. Nickel has been used as a contact metal on GaAs and has been found to be reactive at low temperatures. Formation Of Ni2 GaAs at 200 - 350C is reported and is found to grow epitaxially on (001) and on (111) GaAs, but is shown to be unstable at 450C. This paper reports the investigations carried out to understand the microstructure, nature of the interface and composition of sputter deposited and annealed (at different temperatures) Ni-Sb ohmic contacts on GaAs by TEM. Attempts were made to correlate the electrical properties of the films such as the sheet resistance and contact resistance, with the microstructure. The observations are corroborated by Scanning Auger Microprobe (SAM) investigations.

HOT WIRE METHOD FOR DETERMINATION OF THE THERMAL CONDUCTIVITY OF SUGAR CANE FIBERS

2020 ◽  
Author(s):  
Marcelo Borges dos Santos ◽  
CLAUDIA BITTENCOURT ◽  
Ana Carolina Mendonça Mansur ◽  
Luís Mauro Moura ◽  
Carlos Augusto Castro Ferreira
Keyword(s):  
Thermal Conductivity ◽  
Sugar Cane ◽  
Hot Wire ◽  
Wire Method

OLIN C197

Alloy Digest ◽  
1999 ◽  
Vol 48 (1) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Wear Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Performance ◽  
Corrosion And Wear ◽  
Contact Forces ◽  
High Current ◽  
Lower Strength ◽  
Current Carrying Capability

Abstract Olin C197 is a second-generation high performance alloy developed by Olin Brass. It has a strength and bend formability similar to C194 (see Alloy Digest Cu-360, September 1978), but with 25% higher electrical and thermal conductivity. High conductivity allows C197 to replace brasses and bronzes in applications where high current-carrying capability is required. Also, the strength of C197 provides higher contact forces when substituted for many lower strength coppers. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion and wear resistance as well as forming and joining. Filing Code: CU-627. Producer or source: Olin Brass.

Study of Transcrystallization in Polymer Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
Benjamin S. Hsiao ◽  
J. H. Eric
Keyword(s):  
Thermal Conductivity ◽  
Free Energy ◽  
Carbon Fiber ◽  
Plasma Treatment ◽  
Polymer Composites ◽  
High Performance ◽  
Interfacial Strength ◽  
Fiber Surface ◽  
Semicrystalline Polymers ◽  
First Case

AbstractTranscrystallization of semicrystalline polymers, such as PEEK, PEKK and PPS, in high performance composites has been investigated. It is found that PPDT aramid fiber and pitch-based carbon fiber induce a transcrystalline interphase in all three polymers, whereas in PAN-based carbon fiber and glass fiber systems, transcrystallization occurs only under specific circumstances. Epitaxy is used to explain the surface-induced transcrystalline interphase in the first case. In the latter case, transcrystallization is probably not due to epitaxy, but may be attributed to the thermal conductivity mismatch. Plasma treatment on the fiber surface showed a negligible effect on inducing transcrystallization, implying that surface-free energy was not important. A microdebonding test was adopted to evaluate the interfacial strength between the fiber and matrix. Our preliminary results did not reveal any effect on the fiber/matrix interfacial strength of transcrystallinity.

scholarly journals Apparatus for routine measurements of the thermal conductivity of ice cores

1999 ◽  
Vol 29 ◽  
pp. 151-154 ◽  
Author(s):  
Crescenzo Festa ◽  
Aristide Rossi
Keyword(s):  
Thermal Conductivity ◽  
Ice Cores ◽  
Maximum Temperature ◽  
Transient Hot Wire ◽  
Hot Wire ◽  
Standard Samples ◽  
Experimental Conditions ◽  
Heating Source ◽  
Central Segment ◽  
Wire Method

AbstractAn apparatus is described for measuring the thermal conductivity of ice by the transient hot-wire method. Thermal conductivity A, is determined by tracking the thermal pulse induced in the sample by a heating source consisting of a platinum resistor. A central segment of the same platinum heating resistor acts also as a thermal sensor. A heat pulse transferred to the ice for a period of 40s gives a maximum temperature increment of about 7-14°C. In good experimental conditions, the expected reproducibility of the measurements is within ±3%. The accuracy of the method depends on whether the instrument has been calibrated by reliable standard samples, certified by absolute methods.

scholarly journals Improved Copper–Epoxy Adhesion by Laser Micro- and Nano-Structuring of Copper Surface for Thermal Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1721
Author(s):  
Mario Mora ◽  
Hippolyte Amaveda ◽  
Luis Porta-Velilla ◽  
Germán F. de la Fuente ◽  
Elena Martínez ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bonding Strength ◽  
Copper Surface ◽  
Heat Sinks ◽  
Electrical Insulation ◽  
Cryogenic Temperatures ◽  
Shear Tests ◽  
Patterned Structures ◽  
Different Temperatures ◽  
Mechanical Tensile

The objective of this work is the enhancement of metal-to-metal bonding to provide high thermal conductivity together with electrical insulation, to be used as heat sinks at room and cryogenic temperatures. High thermal conductive metal (copper) and epoxy resin (Stycast 2850FT) were used in this study, with the latter also providing the required electrical insulation. The copper surface was irradiated with laser to induce micro- and nano-patterned structures that result in an improvement of the adhesion between the epoxy and the copper. Thus, copper-to-copper bonding strength was characterized by means of mechanical tensile shear tests. The effect of the laser processing on the thermal conductivity properties of the Cu/epoxy/Cu joint at different temperatures, from 10 to 300 K, is also reported. Using adequate laser parameters, it is possible to obtain high bonding strength values limited by cohesive epoxy fracture, together with good thermal conductivity at ambient and cryogenic temperatures.

scholarly journals Decoupling electron and phonon transport in single-nanowire hybrid materials for high-performance thermoelectrics

2021 ◽  
Vol 7 (20) ◽  
pp. eabe6000
Author(s):  
Lin Yang ◽  
Madeleine P. Gordon ◽  
Akanksha K. Menon ◽  
Alexandra Bruefach ◽  
Kyle Haas ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Transport ◽  
Electrical Transport ◽  
High Performance ◽  
Figure Of Merit ◽  
Phonon Transport ◽  
Core Shell ◽  
Nanowire Diameter ◽  
High Performing ◽  
Polycrystalline Thin Films

Organic-inorganic hybrids have recently emerged as a class of high-performing thermoelectric materials that are lightweight and mechanically flexible. However, the fundamental electrical and thermal transport in these materials has remained elusive due to the heterogeneity of bulk, polycrystalline, thin films reported thus far. Here, we systematically investigate a model hybrid comprising a single core/shell nanowire of Te-PEDOT:PSS. We show that as the nanowire diameter is reduced, the electrical conductivity increases and the thermal conductivity decreases, while the Seebeck coefficient remains nearly constant—this collectively results in a figure of merit, ZT, of 0.54 at 400 K. The origin of the decoupling of charge and heat transport lies in the fact that electrical transport occurs through the organic shell, while thermal transport is driven by the inorganic core. This study establishes design principles for high-performing thermoelectrics that leverage the unique interactions occurring at the interfaces of hybrid nanowires.

scholarly journals 2D MoS2 Encapsulated Silicon Nanopillar Array with High-Performance Light Trapping Obtained by Direct CVD Process

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 267
Author(s):  
Minyu Bai ◽  
Zhuoman Wang ◽  
Jijie Zhao ◽  
Shuai Wen ◽  
Peiru Zhang ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
High Performance ◽  
Low Cost ◽  
Light Trapping ◽  
Incident Light ◽  
Single Layer ◽  
Chemical Vapor ◽  
Optoelectronic Device ◽  
Planar Silicon ◽  
Shortwave Infrared

Weak absorption remains a vital factor that limits the application of two-dimensional (2D) materials due to the atomic thickness of those materials. In this work, a direct chemical vapor deposition (CVD) process was applied to achieve 2D MoS2 encapsulation onto the silicon nanopillar array substrate (NPAS). Single-layer 2D MoS2 monocrystal sheets were obtained, and the percentage of the encapsulated surface of NPAS was up to 80%. The reflection and transmittance of incident light of our 2D MoS2-encapsulated silicon substrate within visible to shortwave infrared were significantly reduced compared with the counterpart planar silicon substrate, leading to effective light trapping in NPAS. The proposed method provides a method of conformal deposition upon NPAS that combines the advantages of both 2D MoS2 and its substrate. Furthermore, the method is feasible and low-cost, providing a promising process for high-performance optoelectronic device development.

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