• Hip & pelvis
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• v.34 no.2
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• pp.106-114
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• 2022

Purpose: While initial fixation using a press-fit of the acetabular cup is critical for the durability of the component, restoration of the hip center is regarded as an attributable factor for implant survival and successful outcome. In protrusio acetabuli (PA), obtaining both restoration of the hip center and the press-fit of the acetabular cup simultaneously might be difficult during total hip arthroplasty (THA). We tested the hypothesis that use of a medialized cup, if press-fitted, will not result in compromise of the implant stability and outcome after cementless THA of PA. Materials and Methods: A total of 26 cementless THAs of 22 patients with PA were reviewed. During THA, press-fit of the cup was prioritized rather than hip center restoration. A press-fit was obtained in 24 hips. A pressfit could not be obtained in the two remaining hips; therefore, reinforcement acetabular components were used. Restoration of the hip center was achieved in 17 cups; 15 primary cups and two reinforcement components; it was medialized in nine cups. Implant stability and modified Harris hip score (mHHS) between the two groups were compared at a mean follow-up of 5.1 years (range, 2-16 years). Results: Twenty-six cups; 17 restored cups and nine medialized press-fitted cups, remained stable at the latest follow-up. A similar final mHHS was observed between the restored group and the medialized group (83.6±12.1 vs 83.8±10.4, P=0.786). Conclusion: Implant stability and favorable results were obtained by press-fitted cups, irrespective of hip center restoration. THA in PA patients showed promising clinical and radiological results.

• Microbiology and Biotechnology Letters
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• v.42 no.1
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• pp.51-57
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• 2014

In this study, the antioxidative effects and component analysis of Polygonum aviculare (P. aviculare) extracts were investigated. The ethyl acetate and the aglycone fraction from P. aviculare extracts were more active than (+)-${\alpha}$-tocopherol and $\small{L}$-ascorbic acid, which are known as strong antioxidants for their antioxidative activity by the DPPH method and chemiluminescence assay. The cellular protective effects of fractions of P. aviculare on the rose-bengal sensitized photohemolysis of human erythrocytes, increased in a concentration dependent manner ($1-10{\mu}l$). In particular, the ethyl acetate fraction at a concentration of $10{\mu}l$ showed the most prominent protective effect among all the extracts (${\tau}_{50}$, 314.70 min). TLC and HPLC chromatogram of the ethyl acetate fraction of P. aviculare extracts revealed 3 main bands (PA8, PA5, PA6) and peaks (peak 1, peak 2, peak 3), which were identified as myricetin-3-O-rhamnoside (myricitrin, PA8, peak 1), quercetin-3-${\alpha}$-rhamnoside (quercitrin, PA6, peak 3) by LC/ESI-MS/MS and $^1H$-NMR respectively. These results indicate that fractions from P. aviculare could be applicable to new functional cosmetics as antioxidants.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.96-96
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• 2012

복합분자펌프는 기존의 터보분자펌프 turbine blade에 spiral grooved를 추가하여 초고진공(10-8Pa)에서 저진공(330Pa)까지 넓은 압력범위에서 사용할 수 있고 이 펌프를 사용함으로서 완전 oil free한 진공시스템을 만들 수 있는 특징을 가지고 있다. 특히, 회전체를 비접촉으로 지지하는 자기베어링 방식을 적용함으로써, 진동은 극히 작고 베어링수명은 길면서 중저진공에 대한 배기속도가 크고 임의의 방향으로 접속이 가능하여 반도체 및 디스플레이 제조 공정과 같은 첨단산업의 다양한 분야에 쉽게 적용되고 있으며, 그 적용 분야와 시장은 계속 성장하고 있다. 고 진공과 배기 속도의 달성을 위해서, 고속으로 이동하는 격면과 기체분자를 충돌시켜, 기체 분자를 원하는 방향으로 유도하는 작동원리를 가지고 있다. 특히 공기분자의 밀도가 매우 낮은 희박가스 상태에서 고속 회전하는 blade로 공기분자를 쳐내면서 작동됨으로써 날개의 상하 압력차에 의한 공기력보다도 날개의 고속회전이 매우 중요시되고 압력으로는 10-1 Pa 이하의 분자영역에서 그 성능을 최고로 발휘할 수 있다. 이러한 복합 펌프의 주요 장점은 다음과 같다. 1. 10-8 Pa (10-10 torr) ~ 10 Pa (1 torr) 까지 넓은 영역에서 배기가 가능하다. 2. 탄화수계의 대하여 높은 압축특성을 가지고 있고, 윤활유를 사용하지 않으므로 얻을 수 있는 진공상태가 고청정하다(oil free). 3. 정밀 5축제어 자기베어링으로 완전히 부상하여 회전함으로서 마모가 없고 진동이 최소화하였을 뿐 만 아니라, 또한 운전음도 거의 없다. 4. 설치조건에 제한이 없고 고장이 거의 없다. 특히 복합분자펌프는 탄화수소화합물이 없는 진공을 생성시키면서 구성요소가 간단한 반면 폭넓은 진공대역을 충족하기 때문에 산업계와 연구계의 주요 첨단 분야에서 광범위하게 사용되고 있으며, 최근 반도체 및 디스플레이, 바이오엔지니어링 등의 발전으로 적용분야가 넓어지고 있다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.88-88
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• 2011

복합분자펌프는 기존의 터보분자펌프 turbine blade에 spiral grooved를 추가하여 초고진공(10-8 Pa)에서 저진공(330Pa)까지 넓은 압력범위에서 사용할 수 있고 이 펌프를 사용함으로서 완전 oil free한 진공시스템을 만들 수 있는 특징을 가지고 있다. 특히, 회전체를 비접촉으로 지지하는 자기베어링 방식을 적용함으로써, 진동은 극히 작고 베어링수명은 길면서 중저진공에 대한 배기속도가 크고 임의의 방향으로 접속이 가능하여 반도체 및 디스플레이 제조 공정과 같은 첨단산업의 다양한 분야에 쉽게 적용되고 있으며, 그 적용 분야와 시장은 계속 성장하고 있다. 고 진공과 배기 속도의 달성을 위해서, 고속으로 이동하는 격면과 기체분자를 충돌시켜, 기체 분자를 원하는 방향으로 유도하는 작동원리를 가지고 있다. 특히 공기분자의 밀도가 매우 낮은 희박가스 상태에서 고속 회전하는 blade로 공기분자를 쳐 내면서 작동됨으로써 날개의 상하 압력차에 의한 공기력보다도 날개의 고속회전이 매우 중요시 되고 압력으로는 10-1 Pa 이하의 분자영역에서 그 성능을 최고로 발휘 할 수 있다. 이러한 복합 펌프의 주요 장점은 다음과 같다. 1. 10-8 Pa (10-10torr)~10 Pa (1 torr) 까지 넓은 영역에서 배기가 가능하다. 2. 탄화수계의 대하여 높은 압축특성을 가지고 있고, 윤활유를 사용하지 않으므로 얻을 수 있는 진공상태가 고청정하다(oil free). 3. 정밀 5축제어 자기베어링으로 완전히 부상하여 회전함으로서 마모가 없고 진동이 최소화하였을 뿐만 아니라, 또한 운전음도 거의 없다. 4. 설치조건에 제한이 없고 고장이 거의 없다. 본 논문에서는 이러한 복합분자펌프의 개발을 위하여, 상기 연구기관에서 수행된 내용을 소개하고 있으며, 펌프 시스템의 기본 설계 및 자기베어링 시스템의 설계 결과 및 수치해석 결과를 나타내었다.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.2
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• pp.51-59
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• 1986

Hydrodesulfurization of dibenzothiophene (DBT) dissolved in n-heptane was studied over sulfided $Ni - W/\gamma - Al_2O_3$ catalyst at temperature ranges from 513 to 573 K and at pressure ranges from 20 to 60 x $10^5$ Pa. Hydrogenation of biphenyl (BP) and cyclohexylbenzene (CHB) observed in products were also run. The products were almost biphenyl and cyclohyxylbenzene, and the conversion of DBT was very sensitive to temperature. Concerning the products distribution while the formation of biphenyl decreased, the formation of cyclohexylbenzene increased in the range of high pressure. The reaction network was found to be sequential reaction which formed cyclohexybenzent through the intermediate of biphenyl. The disappearances of DBT and biphenyl were the first order with respect to DBT and biphenyl and their activation energys were 24.3 and 13.6 Kcal/mol, respectively.

• Membrane Journal
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• v.23 no.5
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• pp.352-359
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• 2013

In the present study, $CO_2$ permeation through a hydrophilic NaY zeolite membrane was studied under permeate evacuation mode for $CO_2$ single gas, $CO_2-N_2$ and $CO_2-O_2$ binary mixtures, and $CO_2-N_2-O_2$ ternary mixture. It was reconfirmed that the $CO_2$ permeation was governed by surface diffusion and the $CO_2$ selectivity was induced from blocking effect of adsorbed $CO_2$ molecules. The $CO_2$ permeance measured in permeate evacuation mode was much lower than that done in He sweeping mode, but was comparable to that obtained under feed pressurization mode. The NaY zeolite membrane showed a considerable $CO_2$ separation for $14%CO_2-80%N_2-6%O_2$ mixture : $CO_2$ permeance was about $1{\times}10^{-7}mol/m^2secPa$ and $CO_2$ selectivity was more than 10. Therefore, it was concluded that NaY zeolite membrane was one of promising membranes for post-combustion CCS process.

• Food Science and Preservation
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• v.5 no.2
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• pp.123-126
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• 1998

This study was carried out investigate to optimum levels of nitrogen and phosphate fertilizer to get a higher yield and a quality of an onion(Allium Cepa L.) from 1993 to 1994. Three fertilizer levels were applied with 120, 240 and 360kg/ha of nitrogen and 100, 200 and 300kg/ha of P2O5 during the onion growing season. After harvesting the onion, it was storaged at given deposit. The growth and yield of the onion were better at the fertilizer levels of both 240 and 360kg/ha of nitrogen and of both 200 and 300kg/ha of P2O5 than at the level of 120kg/ha in nitrogen and 100kg/ha of P2O5. The content of total nitrogen and P2O5 in plant was decreased with reduced application levels of nitrogen and phosphate fertilizer. The rotting rate was higher at the levels of both 360kg/ha in nitrogen and 300kg/ha in P2O5 than the other treatment during the storage period. The sprouting rate tended to be high at 240kg/ha of nitrogen and 100kg/ha of P2O5.

• Journal of Chest Surgery
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• v.21 no.6
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• pp.957-969
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• 1988

There is tendency of increasing number and decreasing age of patients who are indicated for Rastelli operation for their cyanotic congenita heart disease. So there is the need to find the creiterion which saves the patients from early postoperative hemodynamic disturbances. We reviewed the 26 patients who had been performed Rastelli operation at Seoul national University hOipital from January 1981 to June 1988. mean age of the patients was 7.8 $\pm$ 3.4 years (range 2.5-1.5 years), mean body surface area(BSA) 0.79 $\pm$ 0.25 $m^{2}$(range 0.49-1.51 $m^{2}$) and mean hematocrit 57.95 $\pm$ 12%(range 48-80%). We diveded these patients into survived group and died group before postoperative 72 hours, and analysed preoperative arterial oxygen saturation($SaO_{2}$), the ratio of diameter of fight pulmonary artery to ascending aorta(RA:/AA), the ratio of both right and left pulmonary artery diameter to descending thoracic aorta(RPA+LPA/DTA), pulmonary artery index(PA index), cardiopulmonary bypass time, aorta cross-clamping time, postoperative perfusion state and total amount of dopamine infused postoperatively. The results showed that RPA+LPA/DTA and PA index were statistically significatn factors to influence early postoperative cardiac death rate (P<0.05). Especially there were good linear correlations between PA index(X) and perpheral perfusion index(Y)(Y = -1.15 + 0.02 X, r = 0.86, P<0.01) and between PA index(X) and total amount of dopamine infused before postoperative 72 hours(mg/kg, Y)(Y = 61.94 - 0.15 X, r = - 0.80, P<0.01). Also there were tendencies that the higher RPA + LPA/DTA(Y), the betterperipheral perfusion (X) and the lower need of dopamine(X), but no statistical significance. (Y = 0.78 + 1.60 X, r = 0.49, P>0.05) And the discrimant analysis showed that patients with PA index over 221 $mm^{2}$/BSA could undergo correction with 25 per cent of error rate. In conclusion, early postoperative hemodynamic states could be predicted by preoperatively measured PA index, and which can be used as a criterion for Rastelli operation performed on cyanotic congenital heart disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.497-502
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• 2019

Metal oxide nanostructures are promising materials for advanced applications, such as high sensitive gas sensors, and high capacitance lithium-ion batteries. In this study, tin oxide (SnO) nanostructures were grown on a Si wafer substrate using a two-zone horizontal furnace system for a various substrate temperatures. The raw material of tin dioxide ($SnO_2$) powder was vaporized at $1070^{\circ}C$ in an alumina crucible. High purity Ar gas, as a carrier gas, was flown with a flow rate of 1000 standard cubic centimeters per minute. The SnO nanostructures were grown on a Si substrate at $350{\sim}450^{\circ}C$ under 545 Pa for 30 minutes. The surface morphology of the as-grown SnO nanostructures on Si substrate was characterized by field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). Raman spectroscopy was used to confirm the phase of the as-grown SnO nanostructures. As the results, the as-grown tin oxide nanostructures exhibited a pure tin monoxide phase. As the substrate temperature was increased from $350^{\circ}C$ to $424^{\circ}C$, the thickness and grain size of the SnO nanostructures were increased. The SnO nanostructures grown at $450^{\circ}C$ exhibited complex polycrystalline structures, whereas the SnO nanostructures grown at $350^{\circ}C$ to $424^{\circ}C$ exhibited simple grain structures parallel to the substrate.

• Korean Journal of Materials Research
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• v.11 no.12
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• pp.1014-1019
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• 2001

The diamond thin film was deposited on Si(100) substrate from$CH_3OH/H_2O$mixtured gas using a hot filament chemical vapor deposition(HFCVD) method. The deposition condition for samples has been varried with the$CH_3OH/H_2O$composition. Scanning electron microscopy(SEM) and Raman spectroscopy has been employed for the sample analysis. The diamond sample has been obtained below 20Pa with$CH_3OH/H_2O$mixtured gas. The crystallinity of diamond film improved as the composition $CH_3OH$decreases from 60Vol% to 52Vol%, and the sample structure changed from the cauliflower to the diamond structure. But the sample structure was becomes cauliflower at 50Vol% of in$CH_3OH$ in the $CH_3OH/H_2O$. It was shown that the$CH_3OH$ has threshold composition.