Processing and thermal characteristics of human hair fiber-reinforced polymer composites

2019 ◽  
Vol 28 (4) ◽  
pp. 252-264
Author(s):  
Bishnu Prasad Nanda ◽  
Alok Satapathy
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Human Hair ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Fiber Reinforced Polymer Composites ◽  
Mathematical Correlation ◽  
Low Thermal Expansion ◽  
Hair Fiber

Human hair is a biofiber having an exceptional chemical composition, higher strength in tension, and slow decomposition rate. In the present work, composites are fabricated by simple hand layup technique with epoxy matrix and different proportions of hair fiber (0, 5, 10, 15, and 20 wt%). Physical, mechanical, microstructural, and thermal characterization of the composite samples has been done by following the proper ASTM standards. A theoretical model has been developed to predict the effective thermal conductivity of the composite. Based on this model, a mathematical correlation between the effective thermal conductivity of the composite and the fiber content is developed. The results obtained from this correlation are in good agreement with the experimental data. This study explores the possibility of fabricating a class of epoxy composites with higher mechanical strength, superior insulation capability, improved glass transition temperature, and a low thermal expansion coefficient.

scholarly journals Impact of spineless cactus cultivation (O. Ficus-indica) on the thermal characteristics of soil

2018 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Willames De Albuquerque Soares
Keyword(s):  
Heat Capacity ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Biological Processes ◽  
Volumetric Heat Capacity ◽  
Average Value ◽  
Brazilian Semiarid ◽  
Cultivation Techniques ◽  
Soil Changes

Temperature is a fundamentally important factor for understanding the physical, chemical, and biological processes that occur in soil. However, there are few studies in the Brazilian semiarid zone that seek to understand how soil degradation affects its thermal characteristics. The objective of this study was to evaluate the influence of cultivation techniques on the thermal characterization of soil, using the model proposed by Johansen. The study was conducted in the Agreste region of the state of Pernambuco, Brazil on two plots of land, one with native vegetation (Caatinga) and the other with spineless cactus (O. ficus - indica). It was observed that the procedures used to prepare the soil for cultivation of spineless cactus caused a reduction in the capacity to transmit the surface temperature to the interior of the soil. Changes in the physical properties of the soil required for cultivation resulted in a reduction in the average value of the volumetric heat capacity of about 22%; an increase of approximately 5% in the average volumetric heat capacity and a 26% increase in the thermal diffusivity of the soil, as well as a reduction of approximately 50% in the heat flux from the surface of the soil.

Evaluation of Thermal Characterization Techniques and Tools for Thermal Conductivity Measurement of Sub 100 Angstrom Thick Silicon Layers

2007 ◽  
Author(s):  
Keivan Etessam-Yazdani ◽  
Mehdi Asheghi
Keyword(s):  
Thermal Conductivity ◽  
Conductivity Measurement ◽  
Thermal Characterization ◽  
Phonon Transport ◽  
Thermal Conductivity Measurement ◽  
Great Success ◽  
Silicon Structures ◽  
Thin Silicon ◽  
20 Nm

Experimental measurement of thermal conductivity is considered the most reliable tool for the study of phonon transport in ultra-thin silicon structures. While there has been a great success in thermal conductivity measurement of ultra-thin silicon layers down to 20 nm over the past decade, it is not clear if the existing techniques and tools can be extended to the measurements of sun 100 Angstrom layers. In this paper, an analytical study of the feasibility of electrical Joule heating and thermometry in patterned metal bridges is presented. It is concluded that thermal conductivity of silicon layers as thin as 5 nm can be obtained (uncertainty 20%) by performing steady-state measurements using an on-substrate nanoheater structure. The thermal characterization of silicon layers as thin as 1 nm may be possible using frequency domain measurements.

Thermal Characterization of Non-Isolated DC to DC Convertor

2011 ◽  
Author(s):  
Shiladitya Chakravorty ◽  
Bahgat Sammakia ◽  
Varaprasad Calmidi
Keyword(s):  
Power Dissipation ◽  
High Performance ◽  
Field Effect Transistors ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Input Voltage ◽  
Thermal Design ◽  
Power Module ◽  
Improved Performance

Improved performance of semiconductor devices in recent years has resulted in consequent increase in power dissipation. Hence thermal characterization of components becomes important from an overall thermal design perspective of the system. This study looks at a high performance non-isolated point of load power module (a DC to DC converter) meant for advanced computing and server applications. Thermal characteristics of the module were experimentally analyzed by placing the power module on a bare test board (with no insulation) inside a wind tunnel with thermocouples attached to it. There were three devices on this module that dissipate power. There were two FETs (Field Effect Transistors) and an inductor which can be considered as sources. The consolidated power dissipation from the module was calculated by measuring the input voltage and input current while keeping the output voltage and current constant. Temperatures at various points on the module and the test card were recorded for different air flow velocities and overall power dissipation. Subsequently this set up was numerically analyzed using a commercially available computational fluid dynamics (CFD) code with the objective of comparing the results with experimental data previously obtained.

scholarly journals Thermal characterization of different graphite polystyrene

2018 ◽  
Vol 9 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Á. Lakatos ◽  
I. Deák ◽  
U. Berardi
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Thermal Characterization ◽  
Expanded Polystyrene ◽  
High Moisture ◽  
Insulating Materials ◽  
Insulation Materials ◽  
Vacuum Insulation ◽  
Study Laboratory

The development of high performance insulating materials incorporating nanotechnologies has enabled considerable decrease in the effective thermal conductivity. Besides the use of conventional insulating materials, such as mineral fibers, the adoption of new nano-technological materials such as aerogel, vacuum insulation panels, graphite expanded polystyrene, is growing. In order to reduce the thermal conductivity of polystyrene insulation materials, during the manufacturing, nano/micro-sized graphite particles are added to the melt of the polystyrene grains. The mixing of graphite flakes into the polystyrene mould further reduces the lambda value, since graphite parts significantly reflect the radiant part of the thermal energy. In this study, laboratory tests carried out on graphite insulation materials are presented. Firstly, thermal conductivity results are described, and then sorption kinetic curves at high moisture content levels are shown. The moisture up-taking behaviour of the materials was investigated with a climatic chamber where the relative humidity was 90% at 293 K temperature. Finally, calorific values of the samples are presented after combusting in a bomb calorimeter.

Effective Thermal Conductivity of Six Sigma’s Copper Reinforced Column Grid Array Interconnect for Ceramic Microelectronic Packages

2010 ◽  
Author(s):  
Mark Eblen
Keyword(s):  
Thermal Conductivity ◽  
Integrated Circuits ◽  
Effective Thermal Conductivity ◽  
Flip Chip ◽  
Heat Removal ◽  
Thermal Design ◽  
Printed Wiring Board ◽  
Wiring Board ◽  
High Lead

Thermal management of flip chip style integrated circuits often relies on thermal conduction through the ceramic package and high lead solder grid array leads into the printed wiring board as the primary path for heat removal. Thermal analysis of this package configuration requires accurate characterization of the sometimes geometrically complex package-to-board interface. Given the unique structure of the Six Sigma column grid array (CGA) interconnect, a detailed finite element submodel was used to numerically derive the effective thermal conductivity with comparisons to a conventional CGA interconnect. Once an effective thermal conductivity value is obtained, the entire interconnect layer can be represented as a fictitious cuboid layer for inclusion in a more traditional “closed-form” thermal resistance calculation. This method allows the package designer a quick and robust method to evaluate initial thermal design study tradeoffs.

scholarly journals Review on Techniques for Thermal Characterization of Graphene and Related 2D Materials

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2787
Author(s):  
Jing Liu ◽  
Pei Li ◽  
Hongsheng Zheng
Keyword(s):  
Thermal Conductivity ◽  
Energy Transport ◽  
Large Deviation ◽  
2D Materials ◽  
Single Layer ◽  
Thermal Characterization ◽  
Great Depth ◽  
Characterization Methods ◽  
Critical Issues

The discovery of graphene and its analog, such as MoS2, has boosted research. The thermal transport in 2D materials gains much of the interest, especially when graphene has high thermal conductivity. However, the thermal properties of 2D materials obtained from experiments have large discrepancies. For example, the thermal conductivity of single layer suspended graphene obtained by experiments spans over a large range: 1100–5000 W/m·K. Apart from the different graphene quality in experiments, the thermal characterization methods play an important role in the observed large deviation of experimental data. Here we provide a critical review of the widely used thermal characterization techniques: the optothermal Raman technique and the micro-bridge method. The critical issues in the two methods are carefully revised and discussed in great depth. Furthermore, improvements in Raman-based techniques to investigate the energy transport in 2D materials are discussed.

scholarly journals Thermal Characterization of a New Bio-Based Insulation Material Containing Puffed Rice

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5700
Author(s):  
Maatouk Khoukhi ◽  
Abeer Dar Saleh ◽  
Ahmed Hassan ◽  
Shaimaa Abdelbaqi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Characterization ◽  
Insulation Material ◽  
Optimal Range ◽  
Insulation Materials ◽  
Material Optimization ◽  
Sample Amount ◽  
Puffed Rice ◽  
Influential Parameters

Although many advanced insulation materials have been recently developed, very few are eco-friendly and their production requires a substantial amount of energy and complex manufacturing processes. To address this issue, a bio-based thermal insulation material was developed using short- and long-grained puffed rice. A set of experiments was subsequently carried out to identify the best rice type and the optimal range for the most influential parameters (sample amount, temperature, and moisture level). Our findings revealed that short-grained rice exhibited greater puffing ability and was thus adopted in further material optimization experiments. These assessments indicated that the most optimal thermal conductivity of the insulation material and the highest puffing ratio was attained at 12–15% moisture, 260–270 °C temperature, and 15–18 g sample weight. The thermal properties, including thermal conductivity and fire reaction, and thermal performance of samples obtained using these parameters were similar to those of common insulation materials.

Thermal Characterization of Aluminum and Steel Foams

2012 ◽  
Author(s):  
James D. Playford ◽  
S. Midturi ◽  
S. B. Pidugu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Accurate Determination ◽  
Thermal Characterization ◽  
Metal Foams ◽  
Published Data ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Energy Absorbers

Metallic foams are a new class of ultra-lightweight materials with potential applications in such industries as automobile, aerospace, and energy industries. These materials when realized in product form can serve as efficient heat exchanges, energy absorbers, and thermal protective and hydrogen storage devices. Accurate determination of thermal conductivity and understanding of heat transfer characteristics is important in designing such products incorporating metal foams. The present research characterizes the effective thermal conductivity and heat transfer characteristics of DUOCEL AL 6106-T6 and Stainless Steel 314 open cell foams by experiments at near room temperature conditions. The effective thermal conductivity of these materials has been determined experimentally. Thermal conductivity of metal foams increased with increasing mechanical stress. The effect of porosity on the thermal conductivity of ERG supplied aluminum and NASA-GRC supplied SS 314 are also studied and compared with the published data in literature, however, in our studies systematic dependency of porosity is not observed. Experiments also conducted to quantify forced convective heat transfer characteristics under laminar flow conditions. Heat transfer coefficient increases with increased Reynolds number but results are not conclusive in case of natural convection.

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