Novel Nanostructure Composite Dielectric with High Insulation Performance: Silica-Based Nanometer-Sized Porous Composite Insulating Paper Reinforced by Ceramic Fibers

2019 ◽  
Author(s):  
Wenxia Sima ◽  
Jiahui He ◽  
Potao Sun ◽  
Ming Yang ◽  
Ze Yin ◽  
...  
Keyword(s):  
Ceramic Fibers ◽  
Porous Composite ◽  
Insulating Paper ◽  
High Insulation ◽  
Insulation Performance

Indoor Thermal Environments Investigation in Winter of Rural Houses in Yinchuan

2012 ◽  
Vol 209-211 ◽  
pp. 289-293 ◽  
Author(s):  
Quan He ◽  
Da Long Liu ◽  
Qun Zhang
Keyword(s):  
Energy Consumption ◽  
Thermal Environment ◽  
Thermal Environments ◽  
New Type ◽  
High Insulation ◽  
Heating Energy Consumption ◽  
Heating Mode ◽  
Straw Bale ◽  
Insulation Performance ◽  
Partial Interval

The main considerations of building some new-type rural houses in Yinchuan are to improve indoor thermal environment and to reduce heating energy consumption by passive solar use and high-insulation envelope. Two houses were measured, a traditional one with adobe walls and a wooden roof, and a newly-built one with straw-bale insulation. Results show: (1) the linear layout of the traditional house leads to a higher heating energy consumption than the new one with climatic buffers; (2) the new house with straw-bale bricks have better thermal insulation performance than the traditional one with adobe wall; (3) lacking thermal storage is one of the main causes of larger indoor temperature fluctuation in the new house; (4) as a traditional partial interval heating mode, the “Kang”(a bed-stove made of bricks or fired clay) in the bedroom uses energy efficiently and improves the indoor thermal comfort.

Prediction on Coupling Loss Factors of Building Members

2015 ◽  
Vol 744-746 ◽  
pp. 1589-1592
Author(s):  
Jun Xin Lan ◽  
Xian Feng Huang ◽  
Shang You Wei ◽  
Zhi Xiang Zhuang
Keyword(s):  
Energy Loss ◽  
Building Material ◽  
Loss Factor ◽  
Building Materials ◽  
Sound Insulation ◽  
Coupling Loss ◽  
High Insulation ◽  
The Relationship ◽  
Insulation Performance ◽  
Coupling Loss Factor

Coupling Loss Factor (CLF) is a parameter describing building sound loss, which can be stand for energy loss in the process of crossing the structure. A low value of CLF refers to the high insulation performance of building member. Therefore, reducing the coupling loss is a favorable way to improve the sound insulation. For the purpose of exploring the relationship between the properties of building materials and CLF, the commonly used building materials are selected to analyze. It is indicated that the properties of building material have obvious effects on the CLF. As the consequence, some predictions and analysis are carried out in this paper.

Development of High Insulation Frame to Improve the Insulation Performance of Windows

2021 ◽  
Vol 28 (4) ◽  
pp. 362-368
Author(s):  
Han Sol Lee ◽  
Gyeong-Seok Choi ◽  
Hosang Ahn ◽  
Jae Sik Kang
Keyword(s):  
High Insulation ◽  
Insulation Performance

scholarly journals Multichannel and Super-flexible SiZrOC Ultrafine Fibers for High Temperature Thermal Insulation

2021 ◽  
Author(s):  
Xiaoshan Zhang ◽  
Qiong Tian ◽  
Bing Wang ◽  
Nan Wu ◽  
Cheng Han ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Insulation ◽  
Porous Ceramic ◽  
Temperature Stability ◽  
Ceramic Fibers ◽  
High Temperature Stability ◽  
Electrospinning Technique ◽  
Excellent Thermal Stability ◽  
Ultrafine Fibers ◽  
Insulation Performance

Abstract Light but robust porous ceramic fibers with combined properties of super flexibility, excellent thermal stability and thermal insulation performance are attractive for use in extreme conditions, especially in the field of aerospace. However, the practical application of traditional porous ceramic fibers are usually limited by their brittle nature and poor mechanical properties. Herein, we designed a multichannel SiZrOC ultrafine fiber (MSUF) composed of ZrO2, SiOxCy and free carbon phases by electrospinning technique. The resulting fibers exhibited integrated properties of excellent fire resistance, high temperature stability, thermal shock resistance and temperature-invariant flexibility. More importantly, the fancy multichannel structure and components of the fiber provides it with outstanding thermal insulation performance with low thermal conductivity (0.041 W m-1·K-1 at 25 ºC and 0.141 W m-1·K-1 at 1000 ºC). The successful fabrication of such flexible porous MSUFs may provide a new approach to design high performance thermal insulators for high temperature thermal insulation.

scholarly journals Fabrication of ZnO-Al2O3-PTFE Multilayer Nano-Structured Functional Film on Cellulose Insulation Polymer Surface and Its Effect on Moisture Inhibition and Dielectric Properties

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1367 ◽  
Author(s):  
Cong Liu ◽  
Jian Hao ◽  
Yanqing Li ◽  
Ruijin Liao
Keyword(s):  
Contact Angle ◽  
Power Transformer ◽  
Polymer Surface ◽  
Rf Magnetron Sputtering ◽  
Hydroxyl Group ◽  
Breakdown Field ◽  
Water Contact ◽  
Insulating Paper ◽  
Cellulose Insulation ◽  
Insulation Performance

After a century of practice, cellulose insulating polymer (insulating paper/pressboard) has been shown to be one of the best and most widely used insulating materials in power transformers. However, with the increased voltage level of the transformer, research has focused on improving the insulation performance of the transformer’s cellulose insulation polymer. Considering the complex environment of the transformer, it is not enough to improve the single performance of the insulating polymer. In this study, a nano-structured ZnO-Al2O3-PTFE (polytetrafluoroethylene) multifunctional film was deposited on the surface of insulating pressboard by radio frequency (RF) magnetron sputtering. The effect of the multilayered ZnO-Al2O3-PTFE functional film on the dielectric and water contact angle of the cellulose insulating polymer was investigated. The scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) showed that the nano-structured ZnO-Al2O3-PTFE functional film was successfully deposited on the cellulose insulation pressboard surface. The functional film presented an obvious stratification phenomenon. By analyzing the result of the contact angle, it was found that the functional film shields the hydroxyl group of the inner cellulose and improves hydrophobicity. The AC breakdown field strength of the treated samples was obviously increased (by 12 to ~17%), which means that the modified samples had a better dielectric insulation performance. This study provides a surface modification method to comprehensively improve electrical properties and the ability to inhibit the moisture of the cellulose insulating polymer, used in a power transformer.

scholarly journals Main routes of the porous composite materials creation

2020 ◽  
Vol 12 (5) ◽  
pp. 256-269
Author(s):  
P.G. Kudryavtsev
Keyword(s):  
Thermal Decomposition ◽  
Composite Materials ◽  
Porous Materials ◽  
Microphase Separation ◽  
High Surface ◽  
High Surface Area ◽  
Selective Dissolution ◽  
High Porosity ◽  
Ceramic Fibers ◽  
Porous Composite

This paper is devoted to an overview of the main ways of creating porous composite materials. Porous materials are solids containing free space in the form of cavities, channels, or pores, which determine the presence of an internal interfacial surface. The analysis of the general methods of obtaining porous materials. A deposition is one of the most common methods for producing porous materials. Thermal decomposition, as a method used to obtain porous oxide materials by thermal decomposition of various compounds. Hydrothermal synthesis is widely used to produce zeolites. Selective dissolution of individual components of a substance using chemical reactions is also one of the effective methods for creating or increasing porosity. The paper discusses the methods of forming highly porous refractory materials. There are two main ways of forming refractory ceramic products. The first way is the direct sintering of dispersions of ceramic fibers. The second method is the use of a binder, which can significantly reduce the temperature of obtaining a porous product. The possibilities of obtaining porous nanocomposites based on aerogels are shown. Composite materials are usually obtained by combining two different materials. In general, the creation of composites is used to take advantage of each type of material and to minimize their disadvantages. Aerogels are fragile substances. But with the introduction of another component into their structure, it is possible to increase the strength of the material. Such materials have the desired optical properties, high surface area, and low density like silica aerogel. A review of methods for obtaining porous materials using the phenomenon of spinodal decomposition has been carried out. Materials whose structure is formed in microphase separation during polymerization or polycondensation have high permeability and a sufficiently large specific surface. A significant advantage of such materials is high porosity, which can reach 80% or more

Use of EDS mapping to characterize thermochemical stability of fibers in intermetallic matrix composites

1992 ◽  
Vol 50 (1) ◽  
pp. 160-161
Author(s):  
John R. Porter
Keyword(s):  
Spatial Information ◽  
Beam Current ◽  
Fiber Types ◽  
Ceramic Fibers ◽  
Dye Transfer ◽  
Science Center ◽  
Commercial Development ◽  
Nih Image ◽  
Intermetallic Matrix Composites ◽  
Thermochemical Stability

New ceramic fibers, currently in various stages of commercial development, have been consolidated in intermetallic matrices such as γ-TiAl and FeAl. Fiber types include SiC, TiB2 and polycrystalline and single crystal Al2O3. This work required the development of techniques to characterize the thermochemical stability of these fibers in different matrices.SEM/EDS elemental mapping was used for this work. To obtain qualitative compositional/spatial information, the best realistically achievable counting statistics were required. We established that 128 × 128 maps, acquired with a 20 KeV accelerating voltage, 3 sec. live time per pixel (total mapping time, 18 h) and with beam current adjusted to give 30% dead time, provided adequate image quality at a magnification of 800X. The maps were acquired, with backgrounds subtracted, using a Noran TN 5500 EDS system. The images and maps were transferred to a Macintosh and converted into TIFF files using either TIFF Maker, or TNtolMAGE, a Microsoft QuickBASIC program developed at the Science Center. From TIFF files, images and maps were opened in either NIH Image or Adobe Photoshop for processing and analysis and printed from Microsoft Powerpoint on a Kodak XL7700 dye transfer image printer.

A TEM investigation of silicon nitride whiskers

1987 ◽  
Vol 45 ◽  
pp. 160-161
Author(s):  
Tapan Roy
Keyword(s):  
Silicon Nitride ◽  
High Resolution ◽  
Ceramic Matrix Composites ◽  
High Resolution Electron Microscopy ◽  
Molten Silicon ◽  
Matrix Composites ◽  
Ceramic Fibers ◽  
Resolution Electron ◽  
Point To Point ◽  
Technological University

Ceramic fibers are being used to improve the mechanical properties of metal matrix and ceramic matrix composites. This paper reports a study of the structural and other microstructural characteristics of silicon nitride whiskers using both conventional TEM and high resolution electron microscopy.The whiskers were grown by T. E. Scott of Michigan Technological University, by passing nitrogen over molten silicon in the presence of a catalyst. The whiskers were ultrasonically dispersed in chloroform and picked up on holey carbon grids. The diameter of some whiskers (<70nm) was small enough to allow direct observation without thinning. Conventional TEM was performed on a Philips EM400T while high resolution imaging was done on a JEOL 200CX microscope with a point to point resolution of 0.23nm.

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