• Conservation Science in Museum
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• v.20
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• pp.13-30
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• 2018

Ancient metal objects with inlaid designs were mainly decorated using the wire inlay technique in which "V"- or "U"-shaped grooves were cut in a metal object and then filled with gold or silver. Previous studies on ancient metal objects featuring wire inlay generally attempted to ascertain the inlay techniques applied by examining photomicroscopes acquired during conservation treatment. However, they had limitations when examining wire inlay technique to the minute details. Wire inlay technique can be better investigated by enlarging X-ray films of relics using stereoscopic microscopy under transmitted light. The core processes of the wire inlay technique involve cutting grooves using a chisel and creating the inlay wires, but researchers hold varying opinions about the two processes. This study analyzed the entirety of the materials able to shed light on the main processes applied in Baekje wire inlay by examining X-ray films of relics through stereoscopic microscopy. This exhaustive research revealed that two types of techniques were used for wire inlay during the Baekje period. One is a plastic process of engraving dotted lines using a chisel and is found mostly in objects from the Cheonan and Gongju areas. The other is a cutting process that incises fine lines and was used mostly in relics from the Osan, Seosan, and Wanju areas. It is likely that the Baekje wire inlay techniques feature regional differences because the respective techniques were used or introduced by different groups of people.

• Advances in materials Research
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• v.4 no.3
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• pp.165-178
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• 2015

Friction coefficient of epoxy metal matrix composites were investigated. The main objective was to increase the friction coefficient through rubber sole sliding against the epoxy floor coating providing appropriate level of resistance. This was to avoid the excessive movement and slip accidents. Epoxy metal matrix composites were reinforced by different copper wire diameters. The epoxy metal matrix composites were experimentally conducted at different conditions namely dry, water and detergent wetted sliding, were the friction coefficient increased as the number of wires increased. When the wires were closer to the sliding surface, the friction coefficient was found to increase. The friction coefficient was found to increase with the increase of the copper wire diameter in epoxy metal matrix composites. This behavior was attributed to the fact that as the diameter and the number of wires increased, the intensity of the electric field, generated from electric static charge increased causing an adhesion increase between the two sliding surfaces. At water wetted sliding conditions, the effect of changing number of wires on friction coefficient was less than the effect of wire diameter. The presence of water and detergent on the sliding surfaces decreased friction coefficient compared to the dry sliding. When the surfaces were detergent wetted, the friction coefficient values were found to be lower than that observed when sliding in water or dry condition.

• Journal of Welding and Joining
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• v.7 no.1
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• pp.42-50
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• 1989

The application of fracture mechanics is being increased gradually to assess the safety of welded structures containing crack. Fatigue crack propagation behavior and elastic-plastic fracture toughness J$_{IC}$ of home made flux cored wire(1.22mm) CO$_{2}$ weldments was discussed. Especially fatigue crack propagation test was carried out by .DELTA.K control instead of load control and elastic-plastic fracture toughness J$_{IC}$ was obtained by ASTM-R curve method on C.T.specimen in transverse direction of weldments. The results obtained are as follows; (1) Weld metal presented an almost complete similarity to base metal on fatigue crack propagation rate in transverse direction. (2) Weld metal was more than base metal on J$_{IC}$ value in transverse direction. (3) F.C.W. CO$_{2}$ weldments had an excellent characteristic of fatigue crack propagation rate and J$_{IC}$ in less than 50kg/mm$^{2}$ steel grade, this would result from that weld metal had good static strength.trength.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.240-243
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• 2005

This study deals with the shape optimization of a wire spacer fuel assembly of Liquid Metal Reactors (LMRs). The Response Surface based optimization Method is used as an optimization technique with the Reynolds-averaged Navier-Stokes analysis of fluid flow and heat transfer using Shear Stress Transport (SST) turbulence model as a turbulence closure. Two design variables namely, pitch to fuel rod diameter ratio and lead length to fuel rod diameter ratio are selected. The objective function is defined as a combination of the heat transfer rate and the inverse of friction loss with a weighting factor. Three level full-factorial method is used to determine the training points. In total, nine experiments have been performed numerically and the resulting datas have been analysed for optimization study. Also, a comparison has been made between the optimized surface and the reference one in this study.

• Transactions of Materials Processing
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• v.17 no.8
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• pp.649-656
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• 2008

Springback is one of factors affecting precision in metal forming. Its effect is particularly prominent in bending process. In this study, bending and forging process are used in order to manufacture a micro spring with two bending region from $60{\mu}m$ diameter wire. Springback in the process lowers the precision of the micro spring. Overbending for springback compensation has wide usage in a general way. However, this method requires repeated modifications of press dies until the tolerance is allowable, which causes that production cost and time increase. In this paper, we analyzed the mechanism of springback in the forming process of the micro spring using finite element method. In addition, a simple method to control springback without modifying dies was proposed by performing numerical analysis with various parameters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1659-1666
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• 2010

In this study, a new type of wire-woven cellular metal named WBD(wire-woven bulk diamond) was developed. Like WBK(wire-woven bulk Kagome), WBD is composed of helically formed wires; WBK was introduced a few years ago, and its mechanical, thermal properties, and engineering applications have been extensively investigated. The number of wires that pass by one another at each cross point in WBD is four, whereas that in WBK is three. The mechanical behavior of WBD subjected to compression was investigated and the results were compared to those for WBK. For a given slenderness ratio the density and yield strength of WBD were about twice as high as those for WBK, but elastic stiffness of WBD was not that higher than that for WBK.

• Journal of Powder Materials
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• v.9 no.6
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• pp.433-440
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• 2002

Synthesis and compaction of Al-base nano powders by pulsed discharge method were investigated. The aluminum based powders with 50 to 200 nm of diameter were produced by pulsed wire evaporation method. The powders were covered with very thin oxide layer. The perspective process for the compaction and sintering of nanostructured metal-based materials stable in a wide temperature range can be seen in the densification of nano-sized metal powders with uniformly distributed hard ceramic particles. The promising approach lies in utilization of natural uniform mixtures of metal and ceramic phases, e.g. partially oxidized metal powders as fabricated in our synthesis method. Their particles consist of metal grains coated with oxide films. To construct a metal-matrix material from such powder, it is necessary to destroy the hard oxide coatings of particles during the compaction process. This goal was realized in our experiments with intensive magnetic pulsed compaction of aluminum nanopowders passivated in air.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1171-1173
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• 1993

Dielectric breakdown strength of LDPE films was investigated using metal electrodes and semiconductive electrodes respectively. In both of two cases, the results show that there are characteristics of dependence on thickness and dependence on temperature. However, there are some differences in both cases.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.521-522
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• 2008

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.619-626
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• 2020

This study aimed to identify the error rates in Catheter Calibration Mode, Auto Calibration Mode, and Segment Calibration Mode among many calibration modes as a quantitative evaluation tool used for predicting the diameter and length of balloon or stent in percutaneous intravascular balloon dilatation or stent insertion. Our experiment was conducted with Copper Wire of 2 mm × 80 mm (diameter × length) manufactured elaborately for quantitative evaluation in calibration and Metal Ball of 5, 10, 15, 30, and 40 mm and Acryl Phantom of 25 mm, 50 mm, 75mm, 100 mm, 125 mm, 150mm, 175 mm, and 200 mm. At each height, subtraction images were acquired with a cineangiograph and Stenosis Analysis Tool as a software provided by the equipment company was used for measurement. To evaluate the error rates in Catheter Calibration Mode, Copper Wire was put on each acryl phantom before shooting. Copper Wire of 2 mm in diameter was set as a diameter for catheter, and Copper Wire of 8 mm in length was measured with Multi-segments. As a result, the error rates appeared at 1.13 ~ 5.63%. To evaluate the error rates in Auto Calibration Mode, the height of acryl was entered at each height of acryl phantom and the length of 8 mm Copper Wire was measured with Multi-segments and as a result, the error rates appeared at 0 ~ 0.26%. To evaluate the error rates in Segment Calibration Mode, each metal ball on the floor of table was calibrated and the length of 8 mm Copper Wire on each acryl phantom was measured and the length of 8 mm Copper Wire depending on the changes of acryl phantom height was measured with Mutli-segments and as a result, the error rates appeared at 1.05 ~ 19.04%. And in the experiment on OID changes in Auto Calibration Mode, the height of acryl phantom was fixed at 100mm and OID only changed within the range of 450 mm ~ 600 mm and as a result, the error rates appeared at 0.13 ~ 0.38%. In conclusion, it was found that entering the height values in Auto Calibration Mode, among these Calibration Modes for evaluating quantitative vascular dimensions provided by the software was the calibration method with the least error rates and it is thus considered that for calibration using a metal ball or other objects, putting them in the same height as that of treatment sites before calibrating is the method that can reduce the error rates the most.