• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.2
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• pp.145-151
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• 1994

앞 턱 부위가 짧고 후방으로 위치해 있을 때 턱의 높이를 증가시키고 전방으로 돌출시키는 축조 이부성형술의 방법으로는, 매식체 삽입술, 골 절단술, 골 절제술 또는 이들을 동시에 시행하는 혼합술등이 행해져 왔다. 그러나 매식체 삽입술에서는 감염 또는 매식체의 유동성 등의 합병증의 발병이 빈발하고 매식체의 밑 부위에 골이 흡수된다든지 연조직의 변화를 예측하기 어렵다든지 하는 복잡한 문제점들이 종종 보고되고 있다. 따라서 매식체를 이용하지 않는 골 절단술이나 골 절제술만을 이용한 다양한 방법의 이부성형술이 많이 시행되고 있다. 하악골이 전후방 관계로 발육부전인 환자에게 양측 하악지 시상분할술을 시행하여 전방 이동시킨 후 앞 턱의 위치를 좀더 개선하기 위하여 $Michel{\'{e}}t$ 테크닉의 변형법을 이용한 이부성형술을 추가로 시행하였다. 이 방법의 이부성형술은 턱의 수직적, 수평적 길이를 증가시키기 위하여 하악결합면 부위에 장부와 장붓구멍 모양을 한 골 절단술을 시행하고 광범위한 연조직경을 보존하여 골편으로의 혈류 차단을 최소화하였으며 나사를 이용한 견고한 고정을 용이하게 하였다. 이 술식은 턱을 수직적으로 증가시킬 때 두 골편 사이의 공간에 골 이식을 시행할 필요가 없으며, 금속판을 이용하지 않아도 정확한 위치에 골편을 고정하기가 용이하고, 또한 고정용 나사가 향후 골형성 부위에 위치하게 된다는 장점을 경험하게 되어 이에 한 증례를 보고하는 바이다.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.05a
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• pp.98-102
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• 2004

반도체 산업용 실리콘 잉곳의 절단공정에서 발생하는 폐슬러지 중에는 고순도의 실리콘이 함유되어 있으며, 이 슬러지로부터 분리, 회수한 Si로부터 실리콘화합물 합성하였다. 고비점의 potasium alkoxide 촉매 존재하에서 금속 실리콘과 에탄을 혹은 메탄올과 같은 알코올과의 고액반응에 의해 알콕시 실란을 합성할 수가 있었다 알콕시 실란을 합성반응속도는 반응온도에 크게 의존하였고 최적반응 온도는 $180^{\circ}C{\sim}195^{\circ}C$ 정도이었다. 촉매 첨가량에 따라 알콕시 실란의 반응율이 달라졌으며, 알콕시 실란의 반응율은 최고 90%로 높은 값을 나타내었다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.2
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• pp.181-189
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• 2017

The purpose of this paper is to evaluate several leading options for the management of radioactive metallic waste against a set of general criteria including safety, cost effectiveness, radiological dose to workers and volume reduction. Several options for managing metallic waste generated from decommissioning are evaluated in this paper. These options include free release, controlled reuse, and direct disposal of radioactive metallic waste. Each of these options may involve treatment of the metal waste for volume reduction by physical cutting or melting. A multi-criteria decision analysis was performed using the Analytic Hierarchy Process (AHP) to rank the options. Melting radioactive metallic waste to produce metal ingots with controlled reuse or free release is found to be the most effective option.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.4
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• pp.223-231
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• 2022

Residual stress that can occur during the metal additive manufacturing process is an important factor that must be properly controlled for the precise production of metal parts through 3D printing. Therefore, in this study, the factors affecting these residual stresses were investigated using an experimental method. For the experiment, a specimen was manufactured through an additive manufacturing process, and the amount of deformation was measured by cutting it. By appropriately calibrating the measured data using methods such as curve fitting, it was possible to quantitatively analyze the effect of process parameters and metal powder reuse on deformation due to residual stress. From this result, it was confirmed that the factor that has the greatest influence on the magnitude of deformation due to residual stress in the metal additive manufacturing process is whether the metal powder is reused. In addition, it was confirmed that process parameters such as laser pattern and laser scan angle can also affect the deformation.

• Explosives and Blasting
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• v.36 no.3
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• pp.19-28
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• 2018

Locally damaged structures caused by earthquake or extraordinary external forces have been required to rapidly be dismantled because of its possibility of additional collapses. Particularly, steel frame structures were demolished by the shaped charge blasting method. Recently a research suggested a shape charge blasting technique which uses bent-shaped charge holder of copper plate and emulsion explosive charge to cut thick steel plates. This study simulated the cutting performance of the bent-shaped charge holder with considering types of explosives, thickness of copper liner and stand-off distances using LS-DYNA software. The shape charge blasting test of a 25mm thickness steel plate were used to calibrate the input parameters of the numerical models. The penetration depth and penetration width were analysed with different types of explosives, thickness of copper liner and stand-off distances.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.10
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• pp.1940-1954
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• 1992

Fine grid computations were attempted to analyze the turbulent flows in the near wall low Reynolds number region and the numerical analyses were incorporated by a finite-volume discretization with full find grid system and low Reynolds number k-.epsilon. model was employed in this region. For the improvement of low Reynolds number k-.epsilon. model, modification coefficient of eddy viscosity $f_{\mu}$ was derived as a function of turbulent Reynolds number $R_{+}$ and nondimensional length $y^{+}$ from the concept of two length scales of dissipation rate of turbulent kinetic energy. The modification coefficient $f_{\epsilon}$ in .epsilon. transport equation was also derived theoretically. In the turbulent kinetic energy equation, pressure diffusion term was added in order to consider low Reynolds number region effect. The main characteristics of this low Reynolds number k-.epsilon. model were founded as : (1) In high Reynolds number region, the present model has limiting behavior which approaches to the high Reynolds number model. (2) Present low Reynolds number k-.epsilon. model dose not need additional empirical constants for the transport equations of turbulent kinetic energy and dissipation of turbulent kinetic energy in order to consider wall effect. Present low Reynolds number turbulence model was tested in the pipe flow and obtained improved results in velocity profiles and Reynolds stress distributions compared with those from other k-.epsilon. models.s.s.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.659-663
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• 2016

The efficiency of a heterogeneous ruthenium zirconia catalyst ($Ru(OH)_x/ZrO_2$) was demonstrated to the selective oxidative transformation of alkenes or alkynes. The scissions of C-C double bonds to aldehydes and triple bonds to diketones or carboxylic acids were carried out with (diacetoxyiodo)benzene as an oxidant under dichloromethane (5 mL)/water (0.5 mL) solvent system at $30^{\circ}C$ for wide range of substrates. The $Ru(OH)_x/ZrO_2$composite showed higher catalytic activity and selectivity than other ruthenium-based homogeneous or heterogeneous catalysts for the scission reaction. The catalyst exhibited a high mechanical stability, and no leaching of the metal was observed during the reaction. These features ensured the reusability of the catalyst for several times for the oxidative cleavage of unsaturated hydrocarbons.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.305-309
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• 1983

The effect of the nucleic acid related compounds, amino acids and ureas on the breakage of calf thymus DNA were investigated with or without inorganic salts. PTU and Cys-SH possessed the ability of DNA strand breaks without metal ions. Tyr, Phe and Trp induced a weak DNA lesions in the presence of $CuSO_4$. Cys-SH with concentrations of 5mM in the presence of metal ion, $CuSO_4$, showed the strong ability to break the DNA. Various metal solutions($500{\mu}M$) except $Sn^{2+}$ did not show the DNA-breaking action. The DNA strands were damaged by some amino acids in the presence of $Cu^{2+}$, $Ni^{2+}$, $Mn^{2+}$, $Zn^{2+}$ and $Sn^{2+}$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.139-165
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• 2019

The current status and prospect of decommissioning technology development at KAERI are reviewed here. Specifically, this review focuses on four key technologies: decontamination, remote dismantling, decommissioning waste treatments, and site remediation. The decontamination technologies described are component decontamination and system decontamination. A cutting method and a remote handling method together with a decommissioning simulation are described as remote dismantling technologies. Although there are various types of radioactive waste generated by decommissioning activities, this review focuses on the major types of waste, such as metal waste, concrete waste, and soil waste together with certain special types, such as high-level and high-salt liquid waste, organic mixed waste, and uranium complex waste, which are known to be difficult to treat. Finally, in a site remediation technology review, a measurement and safety evaluation related to site reuse and a site remediation technique are described.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.99-104
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• 1998

산업현장에서 많이 쓰이는 절삭설비(Metal Working : MW)는 매우 다양하여 일일이 열거하기는 어렵고 주로 자동차생산업종, 농기구제조업종, 각종 기계기구 생산업종, 경금속가공업종 등에서 매우 광범위하게 사용되고 있다. 이들 업종에서 연마, 절단, 천공, 드릴링, 터닝(turning)등을 수행하는 많은 근로자들이 다량의 MWF(Metal Working Fluids) 뿐만 아니라 열악한 소음환경에 노출되고 있다. (중략)