Papers by Keyword: Conductivity

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Authors: Takeshi Mitani, Naoyoshi Komatsu, Tetsuo Takahashi, Tomohisa Kato, Toru Ujihara, Yuji Matsumoto, Kazuhisa Kurashige, Hajime Okumura
Abstract: We have investigated the solution growth under various Al-N co-doping conditions. Both p-type and n-type 4H-SiC were successfully grown under Al-N co-doping conditions, while using the effect of Al-addition to stabilize both growth surface and polytype. The doping and electrical properties were investigated systematically. Interaction between Al and N in the incorporation process and electrical property under heavily co-doped conditions were discussed.
Authors: Sarojini Swain, Subhendu Bhattacharya, Ram Avatar Sharma, Lokesh Chaudhari
Abstract: Hydroxyl modified multi-walled carbon nanotubes (OH-MWCNT)/ polyurethane (PU) and graphene nanosheets (GNS)/PU composites were prepared by dispersing the OH-MWCNT and GNS at different wt % in to the PU matrix. It was found that the electrical percolation threshold of the GNS/PU composite is much higher compared to that of OH-MWCNT/PU and also the electrical conductivity of the OH-MWCNT/PU composite is higher than the GNS/PU composite in the same level of filler content. This may be due to the two composites having different electrical conduction mechanisms: The OH-MWCNT/PU composite represents a three dimensional conduction system while, the GNS/PU composite represents a two dimensional conduction system. The improvement in the electrical conductivity with the incorporation of GNS as a filler in the composite is far lower than what theoretically expected. It is also observed that the tensile strength of the OH-MWCNT/PU composite is higher compared to the GNS/PU in the same level filler content.
Authors: Li Guo, Yuan Bao Sun, Jian Qiang Hu, Zhi Jie Huang
Abstract: We described a facile approach to carrying out secondary doping of polyaniline nanofibers. SEM, UV-VIS-NIR and XRD techniques were used to characterize the secondary doping and de-doping of polyaniline nanofibers. The conductivity of secondary doping and de-doping of polyaniline nanostructure with m-cresol is higher than before secondary doping of it accompany with keeping nanostructure. A new approach to improving electric performance of polyaniline nanostructure was provided.
Authors: Sang An Ha, Dong Kyun Kim, Dong Won Lee, Byong Ho Jung, Jong Moon Lee, Jei Pil Wang
Abstract: The present study is aimed at deriving study factors appropriate for removal of heavy metals in a region with combined contamination of non-biodegradable organics or heavy metal ions in soil or underground water contamination or a region with underground water contamination using a composite alternating current electromagnetic field with combined modulation of an electric and a magnetic field. In addition, it is directed at deriving fundamental experiment, design factors that can be utilized in removing organic contaminants or metal-organic complexes having polarity of an electric charge. The continuous-type apparatus for fusion process in a composite alternating current electric field employed in the present study was designed to process a maximum of 260 L. Each configuration is provided with electrolytic decomposition apparatus, Magnetic Equipment, Power supply and Electrode plates with an adjustable distance between electrodes. By measuring oxidation and reduction processes of ions appearing in chemical reaction processes, electric potentials produced by injection of a negative reactivity electrode into an aqueous solution in a reversible redox equilibrium condition were measured.
Authors: Tian Guo Zhou, Peng Li, Xue Fei Zhang
Abstract: ɸ9mm aluminum alloy rods were prepared by Castex process with on-line solution. The rods were subsequently cold-drawn to ɸ 4 mm wires followed final artificial aging treatment. The microstructures and properties of ɸ 4 mm finish wires were investigated. The results show the tensile strength and equivalent conductivity of the T6-treated wires are 340MPa and 54.21%IACS respectively, it is good competent in the requirement for aluminum alloy-reinforced.
Authors: Ding Wei Weng, Qun Lei, Zi Yi Guo, Yong Luo
Abstract: This paper firstly analyze the relationship between the fracture net pressure and the sand to fluid ratio (SOR), and the conclusion is that the high SOR could accumulate high net pressure to make the natural fractures open in natural fractured sandstone reservoir. Then relationship between the cumulative oil production and opening the natural fractures is analyzed by means of reservoir numerical simulation, and the conclusion is that the cumulative oil production increased apparently as the area of opening natural fractures increasing. Based on the analyses, a new method of optimizing fracture conductivity to elevate the stimulating reservoir volume (SRV) was formed: firstly, evaluate the stress field and calculate the critical net pressure of the natural fractures opening; secondly, determine the average proppant concentration according the relationship between the net pressure and proppant concentration; thirdly, calculate the fracture conductivity according to the proppant concentration; at last, optimize the fracture length. There are two key works: one is acquiring the accurate principal stress combining the indoor experiment and field test; the other one is acquiring accurate conductivity of proppant, and long term conductivity experiments are recommended.
Authors: Guo Xuan Xiong, Hai Qing Huang, Chuo Yang
Abstract: A ferrocenyl Schiff base monomer was synthesized through the condensation of ferrocenecarboxaldehyde and phenylenediamine under neutral conditions, and then been used to produce copolymer materials with terephthaloyl chloride monomer by the Friedel-Crafts method. The model compound and copolymer of a novel poly(ferrocene-Schiff base) and their charge transfer complex with iodine was successful obtained, their structures been characterized by 1H-NMR spectra, infrared spectra, and ultraviolet spectra. In addition, the effects of iodine doping degree on its structure was studied, the electrical measurement results showed its conductivity can be increased several orders of magnitude after doping with iodine, the maximum conductivity at room temperature is 3.17×10-4 S•cm-1.
Authors: Wen Liang Chen, Chun Ping Huang, Li Ming Ke
Abstract: Carbon nanotubes(CNTs) reinforced copper matrix composites were successfully produced by Friction Stir Processing (FSP). The effect of applying multiple FSP passes on the forming of composites was studied, the microstructure, microhardness and conductivity of the good forming composite were analyzed. The experimental results showed that CNTs uniformly distributed and good forming composite can be obtained by three FSP passes. Compared to the parent material, the grain size of the composite has significantly refined, and the microhardness of the composite has also greatly improved, but the conductivity of the composite has a small decrease.
Authors: Ming Kuen Chang, Hsin Hong Hsieh, Siou Jyuan Li
Abstract: Intrinsically conductive polymer-Polyaniline had high conductivity and many other properties, such as environmental stability and rather simple synthesis. In addition, doping with organic acids could enhance its processing, so it had wide range of applications, such as solar cells, antistatic and electromagnetic interference shielding. In this study, the organic amine 1-Dodecylamine (DOA) modification of sodium montmorillonite (NA+-MMT), and conducting polymer / layered silicate salt nanocomposites (PANI-PTSA/DOA-MMT) had been prepared by doping aniline with organic acid (PTSA), then added organic clay. The thermal, electrical properties and EMI effects of nanocomposites had discussed by XRD, TEM, EMI, TGA analysis, conduction measure and EMI tested. The results indicated the organo-clay interlayer distance expanded from 1.29 to 1.8 nm, and DOA-MMT dispersed in the material, that formed an exfoliated nanocomposite. The thermal stability of nanocomposites depended on content of DOA-MMT, material had the better thermal stability when DOA-MMT load was 5 wt. %. The nanocomposites had the best conductivity when DOA-MMT load was 1 wt. % as well as the electromagnetic shielding effectiveness was increase with increase in conductivity. In addition, the electromagnetic shielding of nanocomposites also depended on thickness and frequency of electromagnetic wave, the electromagnetic shielding was increased with increase in thickness and frequency.
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