Biocomposites reinforced with natural fibers: 2000–2010

In this review, the technologies and working principles of different materials used in supercapacitors are explained. The most important supercapacitor active materials are discussed from both research and application perspectives, together with brief explanations of their properties, such as specific surface area and capacitance values. A review of different supercapacitor electrolytes is given and their positive and negative features are discussed. Finally, cell configurations are considered, pointing out the advantages and drawbacks of each configuration.

Review on supercapacitors: Technologies and materials

Low cost adsorbents for the removal of organic pollutants from wastewater.

https://dr.ntu.edu.sg/bitstream/10356/146755/2/Published_Spintronics%20based%20random%20access_a%20review.pdf

Spintronics based random access memory: a review

Perspectives on oblique angle deposition of thin films: From fundamentals to devices

This is a laboratory study on the aging of SIR and hydrophobicity recovery. UV radiation, corona discharges, acid rain, dry-band arcing are employed as sources of the aging. Chemical and morphological analysis is used to detect the surface chemical and structural changes derived from these stresses. The nature of highly mobile low molecular weight (LMW) chains achieving a quick recovery of the hydrophobicity is carefully examined. Their generation and extinction caused by these stresses are investigated. From this study, it is shown that oxidation that induces crosslinking, branching, interchanging and a formation of silanol groups are the most dominant chemical reactions during the aging of SIR. Furthermore, silanol groups that are byprodncts of oxidation restrict the diffusion of mobile LMw chains, which decreases the recovery speed of hydrophobicity and accelerates the aging. A typical aging scenario of SIR from the installation to the end of their life is drawn.

Electrical and environmental aging of silicone rubber used in outdoor insulation

Tracking and erosion of high temperature vulcanizing (HTV)-silicone rubber (SIR) and the suppression mechanism of alumina trihydrate (ATH) filler were investigated in the present study. The tracking and erosion resistance of HTV-SIR filled with 0 to 60%wt ATH was evaluated by employing an IEC 587 inclined plane (IP) tracking and erosion test, during which leakage current pulses on HTV-SIR were counted. Surface temperature distributions and the occurrences of thermal spots >400/spl deg/C also were observed by means of an infrared thermovision study. We employed thermogravimetry (TG)-differential thermal analysis (DTA)-mass spectrometer (MS) to observe the thermal degradation of unfilled and filled HTV-SIR in both air and argon. The test results indicate that 40%wt is a critical ATH level and whether tracking and erosion is allowed in the IP tracking and erosion test. Highly filling ATH (>40%wt) reduces the number of low unit silicone oligomer precursors which promote dry-band arcing as well as the presence of residual carbon which leads to carbonization. Chemical modifications of water vapor liberated from heated ATH to methyl groups, which occurs at the thermal decomposition temperature of silicone rubber, were found to result in the above process. The protection mechanisms of ATH for the tracking and erosion of HTV-SIR are formulated herein.

Tracking and erosion of HTV silicone rubber and suppression mechanism of ATH

Electrical double-layer capacitance of micro- and mesoporous activated carbon prepared from rice husk and beet sugar

Leakage current produced on contaminated ceramic and polymeric insulating surfaces was analyzed using a wavelet transform technique providing time-frequency domain information. Salt-fog tests with and without the deposition of non-soluble contamination were conducted in a laboratory, during which the leakage current was separated into sinusoidal, local arc, or their transition components per halfwave of power frequency. The wavelet transform allowed the detection of the zero-cross point of the base current at 50 Hz without the need for voltage information. The source information regarding the distortion level (I/sub 150 Hz//I/sub 50 Hz/) of the current half-wave separated by the zero-cross point and a time lag to onset in current attributable to arcs are used in order to obtain the above three components. The time-integrated values (cumulative charges) of these components were found to correlate with hydrophobicity and contamination level. It was shown that time variations of the cumulative charges and of their component ratios were useful for estimating the conditions of ceramic and polymeric insulating surfaces.

Seiji Kumagai

Papers

Electrical and environmental aging of silicone rubber used in outdoor insulation

Tracking and erosion of HTV silicone rubber and suppression mechanism of ATH

Electrical double-layer capacitance of micro- and mesoporous activated carbon prepared from rice husk and beet sugar

Leakage current characterization for estimating the conditions of ceramic and polymeric insulating surfaces

Oil adsorbent produced by the carbonization of rice husks.