Silver-palladium alloy deposited by DC magnetron sputtering method as lubricant for high temperature application

The silver-palladium(Ag-Pd) alloy coating as a solid lubricant was investigated for its application to the high temperature stud bolts used in nuclear power plants. A hex bolt sample was prepared in the following steps: 1) bolt surface treatment using alumina grit blasting for cleaning and increasing the surface area; 2) nickel(Ni) film coating as a glue layer on the surface of the bolt; and 3) Ag-Pd alloy coating on the Ni film. The films were deposited by using a direct current(DC) magnetron sputtering system. The thickness and composition of the Ag-Pd alloy film have effect on the friction coefficient, which was determined using axial force measurement. A 500 nm-thick Ag-Pd (80:20, molar ratio) alloy film has the lowest friction coefficient of 0.109. A cyclic test was conducted to evaluate the durability of bolts coated with either the Ag-Pd (80:20) alloy film or N-5000 oil. In a cycle, the bolts were inserted into a block using a torque wrench, which was followed by heating and disassembling. After only one cycle, it was not possible to remove the bolts coated with the N-5000 oil from the block. However, the bolts coated with the Ag-Pd (80:20) alloy could be easily removed up until 15 cycles.     

Application of artificial neural network for predicting plain strain fracture toughness using tensile test results

A back‐propagation neural network was applied to predicting the K_IC values using tensile material data and investigating the effects of crack plane orientation and temperature. The 595 K_IC data of structural steels were used for training and testing the neural network model. In the trained neural network model, yield stress has relatively the most effect on K_IC value among tensile material properties and K_IC value was more sensitive to K_IC test temperature than to crack plane orientation valid in the range of material data covered in this study. The performance of the trained artificial neural network (ANN) was evaluated by comparing output of the ANN with results of a conventional least squares fit to an assumed shape. The conventional linear or nonlinear least squares fitting methods gave very poor fitting results but the results predicted by the trained neural network were considerably satisfactory. This study shows that the neural network can be a good tool to predict K_IC values according to the variation of the temperature and the crack plane orientation using tensile test results.     

A Fuzzy Shape Control Method for Stainless Steel Strip on Sendzimir Rolling Mill

 The strip shape in the stainless steel process has made an issue of the strip quality. The objective of the shape control is to minimize the shape deviation and to maintain symmetrical shape patterns in the lateral direction. The method of the shape recognition employs the least square method. The shape deviation is controlled by the fuzzy shape controller (FSC). The experiments have been performed online for various stainless materials, thicknesses, and strip widths. The test results show very efficient performances in respect of stable target tracking and symmetrical and minimal fluctuation of the strip shape.     

Forecasting promising technology using analysis of patent information:Focused on next generation mobile communications

In order to forecast promising technologies in the field of next generation mobile communication, various patent indicators were analyzed such as citation per patent, patent family information, patent share, increase rate, and patent activity. These indicators were quantified into several indexes and then integrated into an evaluation score to provide promising technologies. As a result of the suggested patent analysis, four technologies out of twenty two in details classification were selected, which showed outstanding technology competitiveness, high patent share and increasing rates as well as high recent-patent-ratios and triad-patent-family-ratios. Each of the selected technologies scored more than 10 points in total, and the following four technologies were suggested as promising ones in the field of next generation mobile communication： 1） 3GPP based mobile communication, 2） beyond 4G mobile communication, 3） IEEE 802.16 based mobile communication, which are in medium classification of broadband mobile communication system, and 4） testing/certification system of mobile communication, which is in medium classification of mobile communication testing/certification system.     

Lubrication Property of Magnetorheological Fluid With Nano-Silica Additives Under Magnetic Field

Magnetorheological(MR)fluid is colloidal suspension and stiffens into semi-solid when subjected to a magnetic field.In order to investigate the effect of magnetic field on lubrication property of MR fluid with nano-silica additives,a pin-on-disc tribometer is used to carry out friction and wear experiment of steel under the magnetic field.The MR fluids with different additive concentrations are prepared and their theological properties are examined via a rotational rheometer.Different lubrication performance of the MR fluid with nano-silica additives with and without magnetic field is presented.In addition,through observing the morphology and analyzing the elemental composition of the worn surfaces,the effects of additives on the lubrication property are investigated.     

Design of IEEE1451.5 WTIM for Industrial Network Based on Ubiquitous Sensor Network

Recently,the use of ubiquitous sensor network technology has spread vastly.The ubiquitous sensor networks are widely deployed in factory automation as they provide effective measuring solution for instruments.The wired/wireless network module,which provides the interface to connect to the u-sensor network,is needed but there is no perfect standardization about the interface.In this situation,the interface compatibility between measuring instrument can be maintained using the IEEE1451 international standard.In this paper,the Wireless Transducer Interface Module(WTIM)based on IEEE1451.5 was designed.It connects to the measuring instrument,like the multi-meter,power meter,and etc.,to support the RS232 interface.As these devices cannot connect to network without a module,we use the WTIM to help these devices connect to network system.Its function was verified through the ubiquitous network connection and data transfer between monitoring PC and measuring instrument.This technology is expected to reduce cost in order to construct the wireless industry automation system using existing devices.     

Limonoid Debittering of Citrus Juice Sera By Immobilized Cells of Corynebacterium fascians

Corynebacterium fascians cells capable of metabolizing limonoids were prepared conveniently with inexpensive carbon sources such as fructose, galactose and citric acid. Cells thus obtained were immo-bilized in acrylamide gel and used in a biological debittering process previously developed. The process significantly reduced limonin and nomilin contents of citrus juice sera. It was particularly effective toward the reduction of nomilin. The debittering treatment did not have adverse effects on the composition of other citrus constituents such as citric, malic, ascorbic acids, fructose, glucose and sucrose.