• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.197.1-197
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• 2001

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.149-149
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• 2002

• Archives of Plastic Surgery
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• v.50 no.3
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• pp.248-253
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• 2023

Metal fixation systems for cranial bone flaps cut by a drill are convenient devices for cranioplasty, but cause several complications. We use modified craniotomy using a fine diamond-coated threadwire saw (diamond T-saw) to reduce the bone defect, and osteoplasty calcium phosphate cement without metal fixation. We report our outcomes and tips of this method. A total of 78 consecutive patients underwent elective frontotemporal craniotomy for clipping of unruptured intracranial aneurysms between 2015 and 2019. The follow-up periods ranged from 13 to 66 months. The bone fixation state was evaluated by bone computed tomography (CT) and three-dimensional CT (3D-CT). The diamond T-saw could minimize the bone defect. Only one wound infection occurred within 1 week postoperatively, and no late infection. No pain, palpable/cosmetically noticeable displacement of the bone flap, fluid accumulations, or other complications were observed. The condition of bone fixation and the cosmetic efficacy were thoroughly satisfactory for all patients, and bone CT and 3D-CT demonstrated that good bone fusion. No complication typical of metal fixation occurred. Our method is technically easy and safety, and achieved good mid-term bone flap fixation in the mid-term course, so has potential for bone fixation without the use of metal plates.

• Journal of Advanced Engineering and Technology
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• v.4 no.4
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• pp.431-436
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• 2011

This study was carried out to reduce the problem during distillation process, which separate U, TRU (TRans Uranium) metal electro deposit, Cd and LiCl-KCl eutectic salt generating from LCC (Liquid Cadmium Cathode) electro winning process. The cadmium recovering apparatus was manufactured to separate for each metal using solid-liquid separation method. The apparatus consists of the first sieve for the separation of U and TRU metal electrodeposit, the second sieve for the separation of LiCl-KCl eutectic salt, cadmium collection basket, and a heating furnace. In addition, the size of each sieve is 2 mm to 3 mm. In this experiment, a metal wire was employed to replace TRU metal electrodeposit and U, which exist actually in a LCC crucible. In the solid state, The LiCl-KCl is separated at 340℃ at which the solid and the liquid of the remaining cadmium and LiCl-KCl eutectic salt coexists in each, after the metal wire separated at 500℃. As a result, it seems that it would be beneficial to set the processing condition in the distillation process with the additional treatment process of cadmium and LiCl-KCl eutectic salt.

• Composites Research
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• v.13 no.6
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• pp.39-46
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• 2000

Electrical discharge machining (EDM) cuts metal by discharging electric current across a thin gap between tool and workpiece. Electrical discharge wire cutting, a special form of EDM, uses a continuously moving conductive wire as an electrode, and is widely used for the manufacture of punches, dies and stripper plates. In the wire cutting process, the moving wire is usually supported by cantilever arm and wire guides. As the wire traveling speed has been increased in recent years to improve productivity, the vibration of the cantilever arm occurs, which reduces the positional accuracy of the machine. Therefore, the design and manufacture of the cantilever arm with high dynamic characteristics have become important as the machining speed increases. In this paper, the cantilever arm for guiding the moving wire was designed and manufactured using carbon fiber epoxy composite in order to improve the static and dynamic characteristics. Specimens for the composite cantilever arm were manufactured and tested to investigate the effect of the number of reinforcing plies and length fitted to steel flange on the load capacity. Also, the finite element analysis using layer and contact elements was performed to compare the calculated results with the experimental ones. From the results, the prototype of the composite cantilever arm for the electrical discharge wire cutting machine was manufactured and the static and dynamic characteristics were compared with those of the conventional steel cantilever arm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.6
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• pp.543-550
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• 2002

In this paper, the $CF_4$ decomposition rate and by-product were investigated for two simulated plasma reactors which are metal particle reactor and spiral wire reactors as a function of mixed gases. The $CF_4$ decomposition rate by plasma reactor with metal particle electrode had a gain of 20~25% over that by plasma reactor with spiral wire electrode. The $CF_4$ decomposition efficiency increases with increasing applied voltage up to the critical voltage for spark formation. The $CF_4$ decomposition efficiency of metal particle reactor was about 80% at AC 24kV. The $CF_4$ decomposition rate used Ar-$N_2$ as base gas was the highest among three base gases of $N_2$, $Ar-N_2$, air. The by-products of the $N_2$, $N_2Ar$ base as were similar, but in case of air base they were different.

• Journal of Welding and Joining
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• v.14 no.1
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• pp.57-67
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• 1996

With an expansion in automation of welding processes, emphasis has been shifted from other welding processes to the GMA welding. However, there is a problem with this process that the spatter occurs very frequently. In GMA welding, there are several types in the way of metal transfer from the electrode wire to the weld pool, which have a close relatonship with the spatter genetration. This study was concerned with the spatter occurring in the short-circuiting transfer. In welding with short-circuiting, the electromagnetic force formed by the welding current facilitatics the rupture of the metal bridge between the wire and workpiece and ensures the normal process of the welding process. However, the spatter can be genetrated from the droplet because of the upward magnetic force, when the droplet contacts with the weld pool. The passage of current through the bridge results in the accumulation of the thermal energy, which causes the bridge to explode in the final stage of short-circuiting, thus forming the spatter. Based on the above phenomena in conjunction with other experimental results published, the physical phenomenon related with the occurrence of spatter was modeled and the current waveform was investigated to reduce the spatter. Finally, the fuzzy rule based method was proposed to predict the time of short-circuiting and arcing in the metal transfer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.912-916
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• 2002

In this paper, the $CF_4$ decomposition rate and by-product were investigated for a simulated two plasma reactors which are metal particle reactor and spiral wire reactor as function of mixed gases. The $CF_4$ decomposition rate by plasma reactor with metal particle electrode had a gain of 20~25[%] over that by plasma reactor with spiral wire electrode. The $CF_4$ decomposition efficiency increases with increasing applied voltage up to the critical voltage for spark formation. The $CF_4$ decomposition efficiency of metal particle reactor was about 80[%] at AC 24[kV]. The $CF_4$ decomposition rate used $Ar-N_2$ as base gas was the highest among three base gases of $N_2$, $Ar-N_2$, air. The by-products of the $N_2$, $Ar-N_2$ base as were similar, but in case of air base they were different.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.153-162
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• 2005

The structural specification of the rockfall prevention fence installed on the road section is computed according to the hypothetic rockfall energy, and the absorbable energy of the rockfall prevention fence is defined as the sum of the absorption energies of the wire rope, one of the components, the steel support and the wire netting. But the results of the field tests confirmed that the absorption energy of the rockfall prevention fence is not the sum of the energies sustainable by the components, but it is affected by the absorbable energy of part of the components. This shows there are problems with the method of computing the absorption energy of the rockfall prevention fence of the road. So in this paper, as a way of solving the problems, the effects of improving the performance through positional changes of the existing components and the effects of improving the performance through structural changes by expanded metal are checked through tests, and a plan was proposed to solve the problems with the standards of installing the conventional rockfall prevention fence.

• Journal of Welding and Joining
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• v.21 no.5
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• pp.568-574
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• 2003

In the welding for the steel structure of H-beam with mild steel and 490N/$\textrm{mm}^2$ high tensile steel, we applied the fillet weld mostly and 6-8mm weld length(AISC-spec.). And a new developed metal-cored-wire is used in automatic welding as well as semi-automatic welding. In this study we have attempted to raise the welding productivity and to stabilize the quality on horizontal positions of fillet welding with the following items: - We improved the weld productivity using metal based cored wire with a high deposition rate in the steel structure of H-beam. - We tested the weldability and evaluated the quality of the weldmetal by horizontal fillet $CO_2$ welding. The process is carried out in combination with a special purpose metal-based FCW with excellent resistance to porosity and high welding speed. - We studied the micro structure of the weldmetal by the various welding conditions. - We studied the effect of welding residual stress by the welding conditions in T-joint. Therefore, it can be assured that more productive and superior quality of the weldmetal can be taken from this study results.