Papers by Keyword: EP

Abstract: In this paper, the polyaniline (PANI) coated multi-walled carbon nanotubes (MWNTs) was prepared in situ polymerization. Adding PANI/MWNTs into epoxy resin（EP）, we got PANI / MWNTs / EP composite microwave absorbing materials. Through testing permittivity 、permeability and reflection loss of materials, the paper showed the effect of PANI/MWNTS to the dielectrical and microwave absorbing properties of materials.The results showed： PANI/MWNTs had great effect on dielectrical and microwave absorbing properties of materials. But the imaginary permeability was close to 0. That indicated that it mainly consumed electromagnetic wave by dielectric loss. In 200-1000MHZ, materials had better absorbing property and lower reflection loss (-13.6).

Abstract: Electronic Procurement (EP) is frequently defined as the sourcing of goods or services via. electronic means, usually through the internet. Use of IT into procurement can be termed as EP and involves electronic ordering, bidding and rendering via portals, extranets, private platforms, marketplaces, and/or EDI. It can also involve the use of purchasing cards, reverse auctions, and/or integrated automatic procurement systems to facilitate, the corporate buying process. EP offers number of advantages but its rate of adoption is very slow. This paper reports the findings of a survey carried out in 36 Indian organizations to ascertain the extent of adoption of EP and impact of IT on EP practices. Some of the important findings of the survey are; the main objective for adoption of EP are to enhance customer service and satisfaction, to produce highly reliable products, best product performance, to improve product quality, improve on time delivery, Government of India also promotes the adoption of EP for better transparency and to eliminate unethical practices, the extent of use of IT by organization’s key suppliers, competitors and customers is significant and security concerns through digital networks seem to be a greater threat. Paper concludes by discussing the major barriers in the adoption of EP along with the impact of EP on performance measures.

Abstract: In contemporary electronic technology era, the volume of electronic equipment and printed circuit board reduced so dramatically that the requirements of heat dissipation and insulation increase thereafter. In this research, γ-aminopropyltriethoxysilane (KH550)-treated boron nitride (BN) powder was used as a filler to modify epoxy composites. Effects of the BN particle size and concentration on the thermal conductivity of composites were investigated. SEM image showed the treated BN filler dispersed well in the composite matrix. Moreover, the thermal conductivity was enhanced as the BN concentration was increased. Similar phenomenon was also observed when the filler particle size was reduced. Results indicated that with increasing amount of BN addition, the composites’ thermal conductivity showed a nearly linear increase. When the mass fraction of BN was 30% and its particle size was 220 nm, the thermal conductivity reached 3.4 W/(m•k), which was 17 times as high as that of pure EP resin.

Abstract: Polyaniline(PANI) nanofibers were firstly prepared by rapid mixture method, EP/PANI nanocomposite was obtained by in-situ adding the PANI nanofibers to epoxy resin(EP). Thermal degradation behavior of PANI and kinetic analysis of thermal decomposition of EP/PANI nanocomposites were investigated in detail by using thermogravimetric analyser (TGA) in inert atmosphere. Typical three step decomposition profiles of PANI were obtained. On the basis of isoconversional analysis by the methods of Kissinger-Akahira-Sunose method(KAS method) and Flynn-Wall-Ozawa method(FWO method), it was found that the value of the activation energy of EP/PANI nanocomposites is higher than that of pure EP, which proves that PANI nanofibers obviously improve the thermal stability of pure EP.

Abstract: The medical stent is using widely for a surgical operation, because it can reduce the pain of cardiac. When it was developed initially, medical stent was made of stainless steel, however, the TiNi alloy is widely using presently instead of stainless steel. Because, TiNi alloy has not only super elasticity and Smart Material Effect (SME) but also excellent organism compatibility. For these reason, the TiNi alloy is currently highlighted for medical stent material better than other materials. Nevertheless, this TiNi alloy is not suitable to traditional machining process. When the traditional machining process is conducted to the TiNi alloy, it cannot be discharged the machining heat and inner stress. Also, traditional machining process makes a lot of microscopic burrs on the TiNi alloy surface. This microscopic burrs and the rough surface makes injury on vascular, so, it should be necessary non-traditional machining process without defect of traditional machining. In this paper, microscopic burrs on TiNi alloy for medical stent are removed, and surface roughness of the medical stent is evaluated by Electrochemical Polishing (EP) which is one of the non-traditional machining.

Abstract: In non-pulsed GMA welding, spatter can be reduced by controlling the short-circuit current to a low level just before the re-arcing. The reduction of spatter requires improving the accuracy of predicting the re-arcing by stabilizing the molten metal transfer, and improving the consistency of accuracy against disturbances. The Controlled Bridge Transfer (CBT) process, which optimizes the accuracy of predicting the re-arcing in real time in response to the molten metal transfer, realizes stable, low spatter level GMA welding.