하나로 조사시험용 다공 원통헝 구조물의 온도해석

최영진,강영환,이영신,Choi Young-Jin,Kang Young-Hwan,Lee Young-Shin 한국전산구조공학회 2004 한국전산구조공학회논문집 Vol.17 No.4

재료나 핵연료조사시험에서 다공원통형구조물의 모든 구성품에서 감마열 및 fission과 같은 열원이 발생한다. 본 연구는 조사시험중 다공원통형구조물의 열적건전성을 평가하기 위해 온도분포에 대한 일반해를 구하는데 그 목적이 있다. 다공원통형 구조물의 온도해석을 위해 2차원 열전토 방정식을 이용하였다. 유한요소해석은 ANSYS 6.1을 이용하여 수행하였다. 다공원통형 구조물의 온도해석에서 이론해석결과와 유한요소해석결과는 홀의 개수가 3개 이하에서는 온도가 서로 잘 일치하는 것으로 나타났다. 구조물의 홀 개수가 4개일때, 온도분포해석에 대한 두 결과의 차이가 증가하였다. During the irradiation tests of material and fuel rod, all components of the cylindrical structure with multiple holes act like heat sources due to high gamma heat and fission heat. The objective of this study is to formulate the general solution for the temperature distribution to estimate the thermal integrity of structure during irradiation tests. For the temperature distribution analysis, the two-dimensional heat conduction theory is used. The unmerical analysis is performed by the commercial finite element analysis code, ANSYS 6.1. If the cylindrical structure with hole number would not exceed three holes, the analysis results and finite element results are good agreement together. For the structure with four holes, the discrepancy between FE results and analysis results of the structural temperature distribution is increased.

충주(忠州)댐 우안(右岸) 산사태(山沙汰)에 관한 연구(硏究)

최영진,송무영,Choi, Young Jin,Song, Moo Young 대한자원환경지질학회 1991 자원환경지질 Vol.24 No.3

Analysis for landslides was studied in framework of Chungju dam right abutment, 6.5km northeast of Chungju city. $5.5{\times}10^6m^3$ landslide materials were excavated during dam construction for safety of the Chungju dam. Geology of study area is composed mainly of meta sediments such as dolomitic limestone, quartzite and schist which are dipping toward the Nam Han river. Scanline survey of discontinuities was performed for slope stability, resistivity exploration was performed for the evaluation of potential failure plane, and direct shear strength test of rocks and soils was performed for the effect on landslide. Monitoring systems of tiltmeter, tensiometer, ground water observation hole and level monument were installed during dam construction and interpreted for the evaluation of slope instability. Kinematic solution of the geological structure and evaluation using safety factor for slope may prove the failure of the slope.

가상 생리적압력하에서 Porcelain Laminate Veneer 접착시 상아질 접착제의 변연 누출에 관한 연구

최영진,이호용,Choi, Young-Jin,Lee, Ho-Young 대한치과보철학회 1993 대한치과보철학회지 Vol.31 No.1

The purpose of this study was to evlauate the microleakage of 3 dentin bonding agents using different dentin pretreatment method under simulated physilogic pressure in cementing the porcelain laminate veneer. Noncarious 60 human maxillary molars were selected and randomly assigned to 4 groups of 15 each. The group with the margin placed on the enamel was classified as the control and the groups with the margin placed on root surface were subdivided into 3 groups according to the dentin bonding agents used. The group using All Bond 2 was classified as experimental group 1, the group using Scotchbond MP was classified as experimental group 2, and the group using Gluma was classified as experimental group 3. Roots were removed at 3mm below the cementoenamel junction, and reductions of the teeth for the porcelain laminate veneer were done on the mesial 1/2 of the buccal surface of each teeth. The pulp was extirpated and the pulp chamber was cleaned with 37% phosphoric acid for the patency of dentinal tubule. Under simulated physiologic pressure, porcelain laminate veneers were cemented to the teeth using each dentin bonding agent and luting cement. After cementation, all samples were stored at 36t in water for 24 hours and thermocycled for 1500 cycles, then immersed in 0.5% basic fuchsin solution and the teeth were sectioned longitudinally by using diamond saw and the extent of microleakage was measured. The following results were obtained, 1. Microleakage was observed in a few samples of control group but all the samples of experimental groups. 2. The control group showed the less extent of microleakage than the experimental groups. In experimental groups the experimental group 1 & the experimental group 2 showed similiar extent of microleakage and the experimental group 3 showed the greater extent of microleakage than other groups. Conclusively, practicing the porcelain laminate veneers in the clinic, although the margin of the porcelain laminate veneer should be placed on enamel, in the case that it is inevitable to place the margin of the porcelain laminate veneer on the root surface, it is recommened to use dentin bonding agents which use no dentin pretreatment or a dentin pretreatment which can leave the smear plugs.

LS-DYNA3D 및 ABAQUS/Explicit Code를 이용한 사용후 핵연료 운반용기의 자유낙하 충격특성연구

최영진,김승중,김용재,이재형,이영신,Choi, Young-Jin,Kim, Seung-Joong,Kim, Yong-Jae,Lee, Jae-Hyung,Lee, Young-Shin 한국전산구조공학회 2005 한국전산구조공학회논문집 Vol.18 No.1

방사선물질을 수송하기 위한 용기는 가상 사고조건에서도 안전해야만 한다. 운반용기 설계요구조건은 실험 및 유한요소 해석을 통해 구조적 건전성을 확보하여야 한다. 최근에는 실험보다 유한요소해석을 이용한 방법이 상대적으로 비용이 적기 때문에 주로 사용된다. 그러나 기계적인 반응이 복잡하기 때문에 프로그램을 적용하는 사용자의 방법에 의해 결과가 결정되고 해석하는 동안 여러가지 문제를 발생시킬 수 있다. 본 논문에서, 유한요소해석은 LS-DYNA3D와 ABAQUS/Explicit을 이용하여 운반용기의 9m 자유낙하충격실험에 대한 해석기술과 여러가지 손상을 갖는 경우를 발견하기 위해 연구하였다. 운반용기의 각각의 경우를 비교하고 사용후 핵연료 운반용기의 낙하 실험에 대해서 신뢰할 수 있는 비교적 간단한 해석 기술을 제안하였다. The package used to transport radioactive materials, which is called by the shipping cask, must be safe under normal and hypothetical accident conditions. These requirements for the cask design must be verified through test or finite element analysis. Since the cost for FE analysis is less than the one for test, the verification by FE analysis is mainly used. But due to the complexity of mechanical behaviors, the results depend on how users apply the codes and can cause severe errors during analysis. In this paper, finite element analysis is carried out for the 9 meters free drop condition of the hypothetical accident conditions using LS-DYNA3D and ABAQUS/Explicit. We have investigated the analyzing technique lot the free drop impact test of the cask and investigated several vulnerable cases. The analyzed results were compared with each other. We have suggested a reliable and relatively simple analysis technique for the drop test of spent nuclear fuel casks.

국립중앙도서관 소장의 「Jusikbangmun (주식방문)」을 통해 본 조선 후기 음식에 대한 고찰

최영진,Choi, Young-Jin 한국식생활문화학회 2016 韓國食生活文化學會誌 Vol.31 No.6

This study is a comparative study on a cookbook published in 1900s titled "Jusikbangmun", one of collections of the National Central Library, along with other cookery books in Joseon Dynasty in the late 1800s to early 1900s. "Jusikbangmun" consists of 51 recipes, including 45 kinds of staple foods and six kinds of brews. More than 60% of the recipes deal with staple dishes and side-dishes, whereas the rest deal with ceremonial dishes and drinking. The "Jusikbangmun" applies a composite method of cooking from boiling and steaming to seasoning with oil spices. The ingredients are largely meats rather than vegetables, which is distinguished other cookery books in the Joseon Dynasty. Only "Jusikbangmun" deals with such peculiar recipes as 'Kanmagitang', 'Bookyengsumyentang', 'Jeryukpyen', 'Yangsopyen', and 'Dalgihye'. It is estimated that "Jusikbangmun" was published around the 1900s based on findings that "Jusikbangmun" is more similar with "Buinpilgi" and "Joseonyorijebeop" in the early 1900s than with "Kyuhapchongseo", "Siyijenseo" and "Jusiksieui" in 1800s. Therefore, "Jusikbangmun" is a valuable resource, we can use understand the food culture of the late Joseon period.

의료기관 홍보에 대한 의료기관 종사자의 태도 및 인식

최영진,임복희,황병덕,Choi, Young-Jin,Im, Bock-Hee,Hwang, Byung-Deog 보건의료산업학회 2009 보건의료산업학회지 Vol.3 No.2

The aim of this study is to provide basic data in establishing marketing strategies for hospital by analyzing effective public relations of hospital through attitude and awareness on medical public relations by employee of hospital. The awareness on medical public relations by employee of hospitals were highest among aged 50s or above and above university graduates from the level of education, and from hospital management from types of duties and from those who have worked for more than 10 years. The methods medical public relations positively regarded by employee of hospitals were 'Appearing at health programs' followed by 'Periodicals like magazines and books', 'Issuing of hospital bulletins to homes of patients visiting hospitals'.

구강점막 상피세포에 대한 치과 주조용 비귀금속 합금의 세포독성

최영진,육종인,정문규,Choi, Young-Jin,Yook, Jong-In,Chung, Moon-Kyu 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.6

Although many studies on the cytotoxicity of the dental cast base metal alloys and their components have been carried out, the results are rather conflicting because of the different type of cells used and the various experimental procedures taken. Recently a number of scientists have claimed that it would be preferable to focus on the use of cells from relevant specific location of the human bodies. Consequently, the primary cultured oral keratinocyte derived from oral mucous along with nickel chloride and several of widely used dental cast base metal alloys(two Ni-Cr alloys and one Co-Cr alloy)in domestic were selected for this study, from which 1) The amounts of released metal ions were determined using atomic absorption spectrometry, 2) The cytotoxicity of nickel chloride and dental cast base metal alloys was evaluated via MTT assay, and finally, 3) The amounts of released metal ions and the cytotoxicity of nickel chloride were correlated with the cytotoxicity of dental cast base metal alloys And, the results were summarized as follows; 1. Nickel ion from Ni-Cr alloys and Cobalt ion from Co-Cr alloys resulted in maximum releasing rate during first 2h hours, followed by a decrease in releasing rate with time. Chromium ion were found to be minimal in all alloys. 2. In cytotoxic test. with $40{\mu}M,\;80{\mu}M$ of nickel chloride, there were observed an increase in the relative cell number compared to control samples after 24 hours. With $160{\mu}M$, there was found to be no difference in the relative cell number with control, except that 48 hour showed a increase in relative cell number. With $320{\mu}M$, the relative cell number remained constant and decreased after 48 hours, and with $640{\mu}M$, a continuing decrease in relative cell number was observed throughout test period. 3 The sensitivity of primary cultured oral epithelium to nickel was lower compared to the cells used in other studies. 4. CB-80 Soft and Regalloy showed no cytotoxicity to primary cultured oral epithelium and New crown resulted in a slight cytotoxicity. In conclusion, it was shown that the primary cultured oral keratinocytes could be applied successfully as testing cells in cytotoxicity test. Futhermore, the dental cast base metal alloys used in this study were found to be biocompatible.

대체 감미료를 사용한 Sponge Cake의 특성

최영진,김광옥,Choi, Young-Jin,Kim, Kwang-Ok 한국식품조리과학회 1990 한국식품조리과학회지 Vol.6 No.2

The characteristics of sponge cakes containing sucrose or other sweeteners for diabetes mellitus patients were investigated through physical measurement and sensory evaluation. The results are as follows: The physical properties of cake batters and cakes with sweeteners were different from each other in viscosity, specific gravity, standing height, firmness, and springiness. from the result of sensory evaluation, it was shown that cakes containing sorbitol and fructose had high quality even though they were not as good as cake with sucrose. However, cakes with saccarine and stevioside showed much difference compared with cake with sucrose. The characteristics of sponge cake with combined sweeteners (sorbitol plus stevioside) were compairable to those of sucrose cake. There was little difference in specific gravity. The result of sensory evaluation indicated the combined use of both sweetenes could produce bette cakes than either stevioside or sorbitol. Practical utilization of this cake would be provided under the sensory evaluation on these cakes by diabetes mellitus patients.

금속 Ca증기에 의한 고체 Nd 금속의 탈산

최영진,김상욱,전병서,송창빈,오윤석,이영주,Choi, Yonug-Jin,Kim, Sang-Wuk,Jeon, Byung-Seo,Song, Chang-Bin,Oho, Yoon-Seok,Lee, Young-Joo 한국재료학회 2017 한국재료학회지 Vol.27 No.5

As a basic study for the removal of oxygen in solid Nd metal by metal Ca vapour, by using the thermodynamic data such as ${\Delta}G-T$ diagrams and Nd-O and Nd-Ca equilibrium diagrams, the amount of residual oxygen in solid Nd metal formed based on deoxidation reaction by Ca vapour, instead of by direct contact of solid Nd metal and Ca solution, was determined. Deoxidation experiments were carried out for solid Nd metal in a temperature range of $890{\sim}970^{\circ}C$ for 1h to 4h and content of addition Ca of 0.6~1.8 g (5~15 wt% of solid Nd metal). As a result, it was found that as deoxidation temperature increased, dissolved oxygen decreased. Especially, it was observed that a small amount of Nd-Ca alloy liquid was formed on the surface of the solid Nd metal sample deoxidized at $970^{\circ}C$ for approximately 1 hour. Also, it was found that if the content of addition Ca was 1.8 g (15 wt% of solid Nd metal) the amount of produced Nd-Ca alloy increased slightly. However, for the Nd sample with which the deoxidation reaction was performed at $930^{\circ}C$ for 4h with content of addition of Ca of 1.5 g (13 wt% of Nd metal), the residual oxygen was found to decreased to 12.00 ppm.

리튬이온전지용 산화갈륨 (β-Ga₂O₃) 나노로드 (Nanorods) 음극 활물질의 물리적.전기화학적 특성

최영진,류호석,조규봉,조권구,류광선,김기원,Choi, Young-Jin,Ryu, Ho-Suk,Cho, Gyu-Bon,Cho, Kwon-Koo,Ryu, Kwang-Sun,Kim, Ki-Won 한국전기화학회 2009 한국전기화학회지 Vol.12 No.2

고순도의 $\beta-Ga_{2}O_{3}$ 나노로드(nanorods)가 니켈산화물 나노입자를 촉매로 사용하고 갈륨금속분말을 원료물질로 이용하여 화학기상증착법으로 합성되었다. 전계방출형 주사전자현미경을 이용하여 $\beta-Ga_{2}O_{3}$ 나노로드를 관찰한 결과, 평균직경은 약 160 nm 그리고 평균길이는 $4{\mu}m$였으며 vaporsolid(VS) 성장기구를 통하여 성장되었음을 알 수 있었다. X-선 회절시험과 고분해능 투과전자 현미경을 이용한 결정구조 분석 결과, 합성된 나노로드의 내부는 단사정계 결정구조를 가지는 단결정의 $\beta-Ga_{2}O_{3}$로 이루어져 있고 외벽은 비정질 갈륨옥사이드로 이루어진 코어-셀 구조로 구성되어 있는 것을 확인하였다. 합성된 $\beta-Ga_{2}O_{3}$ 나노로드를 음극 활물질로 사용하여 전극을 제조하고 전기화학적 특성을 분석한 결과, 리튬/$\beta-Ga_{2}O_{3}$ 나노로드 전지는 첫 방전 시 867 mAh/g-$\beta-Ga_{2}O_{3}$의 높은 용량을 나타내었으나 초기 비가역 용량으로 인해 62%의 낮은 충 방전 효율을 나타내었다. 그러나 5 사이클 이후 높은 충 방전 효율을 보이며 30 사이클까지 안정된 사이클 특성을 나타내었다. $\beta-Ga_{2}O_{3}$ nanorods were synthesized by chemical vapor deposition method using nickel-oxide nanoparticle as a catalyst and gallium metal powder as a source material. The average diameter of nanorods was around 160 nm and the average length was $4{\mu}m$. Also, we confirmed that the synthesis of nanorods follows the vapor-solid growth mechanism. From the results of X-ray diffraction and HR-TEM observation, it can be found that the synthesized nanorods consisted of a typical core-shell structure with single-crystalline $\beta-Ga_{2}O_{3}$ core with a monoclinic crystal structure and an outer amorphous gallium oxide layer. Li/$\beta-Ga_{2}O_{3}$ nanorods cell delivered capacity of 867 mAh/g-$\beta-Ga_{2}O_{3}$ at first discharge. Although the Li/$\beta-Ga_{2}O_{3}$ nanorods cell showed low coulombic efficiency at first cycle, the cell exhibited stable cycle life property after fifth cycle.