• 대한전기학회논문지
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• 제40권2호
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• pp.135-143
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• 1991

The setting problem of protective devices in power distribution systems is a combinatorial search problem involving a lot of trial & errors to search for a proper solution which has a great impact for the system reliability. This paper discusses the nature of the problem and proposes a scheme to prune the decision tree achieving the efficient search for a setting solution by applying heuristic rules which utilize pattern informations of backup and primary devices. Its effectiveness is demonstrated through many tests on real systems.

• 한국분말재료학회지
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• 제11권3호
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• pp.217-223
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• 2004

Submicron nickel powders were prepared from aqueous solution under hydrothermal condition. The experimental conditions including the types of protective agents, concentration of the solution and the pH were studied in detail. Starting concentration of nickel ion is a dominant factor affecting particle size. It was shown that the subsequent addition of Poly Vinyl Pyrrolidone(PVP) and Sodium Dodecyle Sulfate(SDS) can help to disperse the nickel powder. X-ray diffraction and SEM were employed to characterize the products.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.152-157
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• 2001

This paper was studied on the characteristics of crevice corrosion prevention of SS 400 in marine environment. In NaCl solution, polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 applied cathodic protection and non cathodic protection was measured according to the NaCl concentration. The main results obtained are as follows : The weight loss rate of Al-alloy galvanic anode was increased as the concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, that of Al-alloy galvanic anode become decreased. The protective potential of SS 400 used Al-alloy galvanic anode becomes more cathodic polarization with increasing concentration of NaCl solution. Effects of oxygen on the weight loss rate of Al-alloy sacrificial anode for cathodic protection as the concentration of 3.5% NaCl solution become sensitive than that of 0% NaCl solution.

• 한국해양공학회지
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• 제25권1호
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• pp.32-38
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• 2011

Galvanized steel has gone through a chemical process to keep it from corroding. The steel gets coated in layers of zinc because rust will not attack this protective metal. For countless outdoor, marine, or industrial applications, galvanized steel is an essential fabrication component. The reduction of the corrosion rate of zinc is an important topic. In the past, a very popular way to reduce the corrosion rate of zinc was to use chemical conversion layers based on $Cr^{+6}$. However, a significant problem that has arisen is that the use of chromium salts is now restricted because of environmental protection legislation. Therefore, it is very important to develop new zinc surface treatments that are environmentally friendly to improve the corrosion resistance of zinc and adhesion with a final organic protective layer. In this study, a Urethane solution (only Urethane 20 wt.%; S-700) and an organic/inorganic solution with Si (Si polysilicate 10 wt.% + Urethane 10 wt.%; LRO-317) are used. Based on the salt spray test of 72 h, S-700 and LRO-317 had a superior effect for the corrosion resistance on EGI and HDGI, respectively.

• Journal of Chest Surgery
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• 제22권4호
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• pp.580-588
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• 1989

The potential for enhancing myocardial protection by adding high-energy phosphate to cardioplegic solutions [St. Thomas Hospital solution] was investigated in a rat heart model of cardiopulmonary bypass and ischemic arrest. Creatine phosphate was evaluated as an additive to the St. Thomas Hospital cardioplegic solution. Creatine phosphate 10.0 mmol/L as the optimal concentration which improved recovery of aortic flow and cardiac output after a 30 minute period of normothermic [37oC] ischemic arrest. In comparing mechanical function in both groups the mean postischemic recoveries of aortic flow, cardiac output, stroke volume and stroke work [expressed as a percentage of its preischemic control] were significantly greater in STH-CP group than in CP- free control group. In addition to improving function and decreasing CK release, CP reduced reperfusion arrhythmias significantly decreasing the time between cross-clamp removal and return to regular rhythm from 81.8 * 13.9 [sec] in CP-free group to 35.9 * 6.8 [sec] in CP group [P< 0.05] so, exogenous CP exerts potent protective and antiarrhythmic effects when added to the St. Thomas Hospital cardioplegic solution. However, the mechanism of action remains to be elucidated.

• Corrosion Science and Technology
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• 제15권1호
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• pp.13-17
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• 2016

The aim of this study was to evaluate the use of iron-nickel oxide ($Fe_2O_3$.NiO) nanopowder (FeNi) as an anti-corrosion pigment for a different application. The corrosion protection ability and the mechanism involved was determined using aqueous solution of FeNi prepared in a corrosive solution containing 3.5 wt.% NaCl. Anti-corrosion abilities of aqueous solution were determined using electrochemical impedance spectroscopy (EIS) on line pipe steel (API 5L X-80). The protection mechanism involved the adsorption of metallic cations on the steel surface forming a protective film. Analysis of EIS spectra revealed that corrosion inhibition occurred at low concentration, whereas higher concentration of aqueous solution produced induction behavior.

• 통상정보연구
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• 제17권3호
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• pp.133-152
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• 2015

중소기업 기술유출의 원인은 중소기업의 법률적 대처능력 부족과 기술인력의 유출로 대변할 수 있다. 또한 기술유출피해 중소기업 중 절반 정도가 다시 동일한 피해를 경험하고 있고, 외부 유출시에도 해당 기술에 대한 개발사실과 시기를 입증하지 못하는 등 기술유출 후에도 특별한 조치를 취하지 못하고 있는 실정이며, 보안인프라 투자 곤란, 보안업무 관련 지식부족, 영업비밀 보호 전담직원의 미보유, 법적 제도적 장치 미흡 등이 현재까지의 애로사항으로 파악되고 있다. 또한, 하도급 거래 등에서 대 중견 중소기업간 기술유출 유용 등 불공정행위의 증가로 중소기업의 성장을 저해하고, 기업간 동반성장 기반이 약화되고 있다. 본 연구는 실증분석을 통해 핵심인력의 기술유출 원인을 살펴보았고, 처우 불만과 직업의 불안정성, 직무발명 보상의 열악함 등으로 나타났다. 본 연구의 결론 및 시사점으로 중소기업의 기술유출과 기술인력의 유출을 방지하기 위해서는 사전적 예방조치 강화와 기술보호 관련법의 적극적인 활용, 특허분쟁시 중소기업에게 소송지원, 핵심기술인력의 유출을 방지할 수 있는 정당한 보상 등이 개선되어야 할 것이다.

• 한국농촌생활과학회지
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• 제6권1호
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• pp.1-10
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• 1995

To lead rural clothing management in the rural household, we assessed in terms of the wearing of pesticide protective clothing and care methods of contaminated clothing, consumer consciousness, the discard method of clothing et al. in rural areas of Gyonggi-Do by sampling 122 households. The results are as following ; 1. The behavior for laundering management didn't appropriate in view of certification of label about laundry method, frequency of laundry and quantitative use of detergent. Also family's cooperative attitude wasn't insufficient. 2. Reasons of dissatisfaction about retained clothing were decreased in order of discoloration, shrink or breakage after laundry, breakage of seam or cloth, unlabel, allergy from cloth. The solution of trouble was acted passively. 3. Reasons of hoarding of clothing were high because of change on size, fashion, and low because of wornout. Still-wearable garments were discarded in proportion of one to one. 4. The ratio of putting on the fatigue cap which the Once of Rural Development has propagated was under 10 percent. 5. Protective clothes against agricultural chemicals had not been prepared and contaminated clothing was often washed with regular family wash.

• Journal of Chest Surgery
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• 제17권4호
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• pp.565-573
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• 1984

The increasing use of cardioplegic solution for the reduction of ischemic tissue injury requires that all cardioplegic solution be carefully assessed for any protective or damaging properties. This study describes functional assessment of the efficiency of steroid in cardioplegic solution by using a Langendorffs perfusion model. Isolated rat heart were subject to a 2 minute period of coronary infusion with the steroid mixed cold cardioplegic solution immediately before and also at the midpoint of a 60 minutes period of hypothermic [10\ulcorner\ulcorner] ischemic arrest. The result of this study were as follows: 1.Spontaneous heart beat after ischemic arrest occurred 14 second later Langendorffs reperfusion in the steroid mixed Young & GIK group and 16 second later in the control group. [Young & GIK without steroid] A good recovery state of spontaneous heart beat was shown in both groups. 2.The percentage of recoveries of heart rate during the 30 minute after postischemic Langendorffs reperfusion was; at first 5 minute 106.3\ulcorner.7% [P<0.05] in the steroid mixed Young & GIK group. This percentage of recovery of steroid mixed Young & GIK group was significantly greater than the control group during the first 5 minute course. 3.The percentage of recovery of coronary flow during the 30 minute after postischemic Langendorffs reperfusion was; at first 5 minute 101\ulcorner.2% in the steroid mixed Young & GI K group. This percentage of recovery of the steroid mixed Young & GIK group was not significantly than the control group during the first 5 minute.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.202-203
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• 2018

Chemistry and microstructure of steel reinforcement bars play an important role to control the corrosion in concrete environments. In present study, we have chosen two different microstructure of steel rebars produced from companies and assessed their corrosion characteristics in simulated concrete pore (SCP) solution with prolonged exposure periods. Hot rolled steel rebar showed more corrosion resistance compare to thermo-mechanically treated (TMT) one. The growth of passive is greater in hot rolled (A) than TMT (B) due to orientation of microstructure. TMT steel rebar exhibit distorted microstructure with many micro cells which enhances the galvanic coupling and induce the deterioration while on the other hand hot rolled rebars exhibit fine grain boundary which responsible in growth of uniform, adherent and protective passive film resultant improved impedance was observed.