scholarly journals Determination of mechanical and thermal properties of electrical insulation material at 4.2 K

2012 ◽  
Author(s):  
K.-P. Weiss ◽  
S. Westenfelder ◽  
A. Jung ◽  
N. Bagrets ◽  
W. Fietz
Keyword(s):  
Thermal Properties ◽  
Electrical Insulation ◽  
Mechanical And Thermal Properties ◽  
Insulation Material

scholarly journals Measurement Method for the Simultaneous Determination of Thermal Resistance and Temperature Gradients in the DeterMination of Thermal Properties of Textile Material Layers

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6853
Author(s):  
Snježana Firšt Rogale ◽  
Dubravko Rogale ◽  
Željko Knezić ◽  
Nikolina Jukl
Keyword(s):  
Thermal Properties ◽  
Thermal Resistance ◽  
Temperature Gradients ◽  
Thermal Parameters ◽  
Textile Material ◽  
Insulation Material ◽  
Measuring Device ◽  
New Device ◽  
Air Layers

The thermal properties of most clothing products are still not designed according to engineering science due to the lack of simple and acceptable measuring equipment and methods; the type of thermal insulation material, the number of layers of clothing and their thickness are thus chosen empirically. The novelty of this study was the development of a new measuring device and method for simultaneous measurements in the determination of the thermal resistance in one or more textile material layers, such as in multilayer composite clothing. Temperature gradients of textile material layers are presented, as well as the theoretical principles of operation and practical results. Four materials for the production of protective jackets were selected, from which different combinations of composite clothing were constructed and the thermal parameters were measured with a new method and a new device, both individually for the built-in materials and for the composites. Subsequently, five test jackets with the same arrangement of textile material layers as the previously tested composites were produced, and measurements of important thermal parameters were recorded with a thermal mannequin. The determined temperature gradients and measurement results are presented, and based on these it was determined that the total thermal resistance was not equal to the algebraic sum of the resistances of the individual textile material layers in the horizontal position; it was, however, higher, increasing from 30% to 94% due to small air layers caused by crimping and protruding fibres of yarn in the textile fabrics. The same textile material layers built into clothing in the vertical position allowed the formation of significantly wider air layers that increased the thermal resistance by between 2.5 and 9 times.

scholarly journals Determination of the Mechanical and Thermal Properties, and Impact Sensitivity of Pressed HMX-based PBX

2019 ◽  
Vol 16 (2) ◽  
pp. 299-315
Author(s):  
Yuxiang Li ◽  
Peng Wu ◽  
Cheng Hua ◽  
Jun Wang ◽  
Bing Huang ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Impact Sensitivity ◽  
Mechanical And Thermal Properties

Tribiological behavior of modified phenolic resin composites for braking applications

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fikrat Yusubov
Keyword(s):  
Thermal Properties ◽  
Phenolic Resin ◽  
Degradation Mechanism ◽  
Mechanical And Thermal Properties ◽  
Content Type ◽  
Dry Conditions ◽  
Powder Metallurgy Methods ◽  
Thermal Stability Of

Purpose The purpose of this paper is to investigate the influence of binder effect on tribological behavior of brake friction composite materials: a case study of phenolic resin modified by N-Methylaniline. Design/methodology/approach Four different friction materials have been fabricated by varying modified phenolic resin content. The samples were prepared by the conventional powder metallurgy methods following ball milling, mixing, pre-forming, hot pressing and post-curing processes. Thermogravimetric analysis was used to determination of the degradation mechanism of organic components and study of thermal stability of the samples. A friction test was carried out in dry conditions using a vertical tribometer. Analysis of worn surfaces was performed using a scanning electron microscope. Findings The experimental results revealed that the sample containing 25 Wt.% phenolic resin has good mechanical and thermal properties with stable friction characteristics. Originality/value This paper presents the effect of N-methylaniline modified phenolic resin on friction composites to improve tribological performance by its thermal properties.

Effects of aramid fibers and colloidal particle fillers in composite ethylene propylene diene monomer rubber thermal insulators for rocket motor insulation

2017 ◽  
Vol 52 (15) ◽  
pp. 1989-1995 ◽  
Author(s):  
AM El-Dakhakhny ◽  
AF Ahmed ◽  
M Rutkevičius ◽  
S El-Marsafy ◽  
E Abadeer
Keyword(s):  
Thermal Properties ◽  
Rocket Motor ◽  
Mechanical And Thermal Properties ◽  
Insulation Material ◽  
Ethylene Propylene Diene Monomer ◽  
Rocket Motors ◽  
Ethylene Propylene ◽  
Ablation Resistance ◽  
Solid Rocket ◽  
Hybrid Reinforcement

In this study, we develop and characterize an asbestos-free rubber composite for potential use as a rocket motor insulator. The insulator is based on ethylene propylene diene monomer blended with aramid fiber (Kevlar) in the pulp form (KP), together with alumina and/or silica as reinforcement. Different formulations based on these fillers were prepared. The fillers were dispersed in the ethylene propylene diene monomer polymeric matrix to obtain a homogenous master batch for curing. We analyzed and compared physical, mechanical and thermal properties of different compositions (density, hardness, tensile strength, elongation, ablation resistance and mass loss on heating). Reinforcement of ethylene propylene diene monomer with Kevlar improves the performance of the material with respect to mechanical and thermal properties, while not improving well the performance with respect to ablation resistance. Using hybrid reinforcement (KP + alumina + silica) within ethylene propylene diene monomer improves the performance of ethylene propylene diene monomer with respect to mechanical properties, thermal properties, ablation resistance and thermal decomposition resistance. The optimum performance of the insulation material was achieved when the formulation consisted of 10 part per hundred ratio KP with even amounts of alumina and silica. A novel composite engineered for improved insulation of solid rocket motors using the hybrid reinforcements was developed for the first time, which can be applied in future space missions.

scholarly journals Determination of Some Mechanical and Thermal Properties of Cattle Manure Pellets

2017 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Javad Rezaeifar ◽  
Mansoureh Pourjafar
Keyword(s):  
Shear Stress ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Organic Materials ◽  
Cattle Manure ◽  
Natural State ◽  
Mechanical And Thermal Properties ◽  
Livestock Waste ◽  
Valuable Source

<p>One of the important subsidiary materials of livestock units is excreta. The livestock waste (including the combination of the Cattle Manure and products case in the bed) as a valuable source of the minerals (Nitrogen 1.78 % , phosphor us 0.5% and potassium 0.99%).For the transportation of the cattle manure in the natural state is difficult and costly due to being low the special mass and the nature of mass. It is produced around 6 million thons the cattle manure yearly in Iran which it is usually filled in the place according to the lack of organic materials of the soils country, the use of the cattle manure causes increasing the productivity of crops. We usually need to some of the mechanical and thermal properties of the cattle manure for producing the pellet by Extruder, so we Survey some of the mechanical and thermal properties of the cattle manure pellet in this research such as the shear stress and the coefficient of thermal diffusivity cattle manure. We obtain the coefficient of the thermal diffusivity manure (</p>

scholarly journals Electrical, mechanical and temperature characterization of commercialy available LTCC dielectric materials

2013 ◽  
Vol 67 (4) ◽  
pp. 621-628 ◽  
Author(s):  
Goran Radosavljevic ◽  
Andrea Maric ◽  
Michael Unger ◽  
Nelu Blaz ◽  
Walter Smetana ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Chemical Composition ◽  
Dielectric Materials ◽  
Accurate Information ◽  
Composition Analysis ◽  
Mechanical And Thermal Properties ◽  
Thermal Coefficient ◽  
Technical Documentation ◽  
Successful Design

Presented paper deals with mechanical, electrical and thermal properties of several commercially available materials that are widely used for fabrication of electronic components, sensor systems etc. In the LTCC (Low Temperature Co-fired Technology). Having complete and accurate information of material chemical composition, its electrical and mechanical properties are essential for successful design of various components and/or systems. In many cases, available technical documentation provided by the manufacturers contains less information than designers require for complete pre-design analysis of system behavior in real time environment. Three offently exploited commercialy available dielectric materials provided by Heraeus company (Heraeus CT700, Heraeus CT707 and Heraeus CT800) are investigated. Electrical, mechanical and thermal properties analyses have been conducted in order to determine some of the important material properties. A full chemical composition analysis was performed resulting in determination of materials' chemical composition, followed with determination of relative permittivity value, elasticity modulus and relative thermal coefficient value.

Preparative Techniques and its Performance of Chemically Foamed Cement Paste

2013 ◽  
Vol 690-693 ◽  
pp. 700-703
Author(s):  
Xin Wei Ma ◽  
Xue Ying Li
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Bulk Density ◽  
Cement Paste ◽  
Expanded Polystyrene ◽  
Mechanical And Thermal Properties ◽  
Insulation Material ◽  
Light Weight ◽  
Preparation Process ◽  
Composite Walls

The foamed cement paste (FCP) is a kind of inorganic insulation material. It is characterized by its light weight, heat-insulating and fire-proofing properties, and the thermal conductivity is close to that of expanded polystyrene (EPS). The foamed cement paste is achieved by means of chemical reaction. The mixture proportion, the preparation process, mechanical and thermal properties are investigated in this paper. The results show that properly mixed paste foams stably, and the bulk density could be controlled. The hardened FCP could be used as insulating filler material in composite walls, as well as blocks for Thermal insulation walls.

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