티타니아 세라믹 熔射皮膜의 機械的 特性에 미치는 熔射條件의 影響에 관한 硏究

김영식,김영식,Kim, Yeong-Sik,Kim, Yeong-Sik 한국마린엔지니어링학회 1991 한국마린엔지니어링학회지 Vol.15 No.3

The purpose of this investigation is to examine the effects of spraying conditions on the mechanical properties of flame-sprayed titania ceramic coating layer. Titania ceramic was sprayed onto the mild steel substrate under the various spraying conditions. Spraying distances were 100, 150, 200, 250mm respectively and pinch air pressures were 0.2 0.3, 0.4 MPa at each spraying distance. The mechanical properties such as microhardness, adhesive strength and erosion wear resistance were tested for the specimens sprayed under the various spraying conditions above mentioned. The optimum operational conditions obtained through the experimental results were 150mm of spraying distance and 0.3 MPa of pinch air pressure.

레토르트 및 감마선 조사에 의한 화닭 덮밥 소스의 미생물 제어 효과 비교

김영식,김현주,윤요한,신명곤,김천제,신미혜,이주운,Kim, Young-Sik,Kim, Hyun-Joo,Yoon, Yo-Han,Shin, Myung-Gon,Kim, Cheon-Jei,Shin, Mee-Hye,Lee, Ju-Woon 한국축산식품학회 2010 한국축산식품학회지 Vol.30 No.1

This study evaluated the antimicrobial effects of retort process and gamma irradiation on reduction of total bacterial populations in spicy chicken sauce, which is served on top of the steamed rice. Commercial spicy chicken sauce was treated with retort and gamma ray at 0, 1, 3, 5, and 10 kGy. Total aerobic bacterial populations were then enumerated on plate count agar and isolated bacteria from the test samples were identified using PCR analysis. Moreover, gamma ray sensitivity of identified bacteria was evaluated by $D_{10}$ values, and genotoxicity of gamma-irradiated samples was examined. Gamma irradiation at 3 kGy reduced total aerobic bacterial cell counts in spicy chicken sauce below detection limit, but total aerobic bacterial cell counts in test samples treated with retort were 2.1 log CFU/g. Identified bacteria from the samples were Bacillus subtilis, B. amyloiquefaciense, and B. pumils, and the $D_{10}$ values for B. subtilis and B. cereus were 0.39 ($R^2\;=\;0.921$) and 0.28 log CFU/g ($R^2\;=\;0.904$), respectively. The SOS chromotest showed that the gamma-irradiated spicy chicken sauce did not cause mutagenicity. These results indicate that gamma irradiation of spicy chicken sauce could be useful in ensuring microbial safety.

가정의학과 외래 우울증환자에서 moclobemide의 안전성 및 유효성 평가를 위한 시판후조사

김영식,이근미,김병성,신호철,성은주,이상엽,문유선,송상욱,김철환,선우성,Kim, Young-Sik,Lee, Keun-Mi,Kim, Byung-Sung,Shin, Ho-Cheol,Sung, Eun-Ju,Lee, Sang-Yeoup,Moon, Yoo-Sun,Song, Sang-Wook,Kim, Cheol-Hwan,Sunwoo, Sung 대한임상약리학회 2002 臨床藥理學會誌 Vol.10 No.1

Background : Depression is quite a common disease in primary care however, studies for the safety and effectiveness of antidepressants in primary care setting are rare in Korea. Objectives : This multi-centered post-marketing study was performed to evaluate the safety and effectiveness of Moclobemide and to find out the factors related to the adherence among patients with depression in family practice. Methods : A total of 386 patients were enrolled from July 1999 to January 2000 by twenty family doctors from fifteen family practice centers. They were prescribed Moclobemide and were reevaluated at the 4th, 8th, and l2th week. Evaluation of compliance, safety and effectiveness were performed with pre-made, structured self-reported questionnaires. Evaluation of effectiveness was also performed utilizing self-rating depression scale (SDS). Results : Among 386 patients, safety was evaluated in 310 patients and effectiveness was evaluated in 239 patients. During the first 12 weeks, the number of subjects continuing with Mocclobemide was 136(37.1%). 141 subjects (38.4%) discontinued taking the drug and 90 subjects (24.5%) dropped out at the 12th week. Considering drop-out patients as ineffective cases, overall effectiveness was estimated to be 84.5%. Symptoms improved with time in patients whose follow-up were completed (P<0.01). The SDS score decreased by an average of ${6.8{\pm}9.1(12.2{\pm}19.1%)}$ after 12 weeks(p<0.01). During the study, 33(10.6%) subjects reported adverse events. The most commonly reported adverse events, in descending order, were dizziness(2.3%), headache(1.6%), insomnia(1.3%), facial edema(1.3%), constipation(1.0%), nausea(1.0%) and tremor(1.0%). The main reasons for discontinuing antidepressants were attributed to improvement of symptoms and manifestation of adverse events. Conclusion : The percentage of adherence at 12th week of Moclobemire among patients suffering from depression in the family practice outpatient clinic was shown to be 49%. The antidepressant effect and safety of Moclobemide was relatively superior.

고탄소강의 연속 건식 신선 공정에서 선재의 온도 예측 기법 개발

김영식,김동환,김병민,김민안,박용민,Kim, Yeong-Sik,Kim, Dong-Hwan,Kim, Byeong-Min,Kim, Min-An,Park, Yong-Min 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.2

Wire drawing process of the high carbon steel with a high speed is usually conducted at room temperature using a number of passes or reductions through consequently located dies. In multi-stage drawing process, temperature rise in each pass affects the mechanical properties of final product such as bend, twist and tensile strength. Also, this temperature rise during the deformation is the reason that the wire in drawing process is broken by the embrittlement due to rapid strain aging effect. This paper presents the estimation of the wire temperature for the multi-stage wire drawing process. Using the proposed calculation method of wire temperature, temperature rise at deformation zone as well as temperature drop in block considering the heat transfer between the block and wire were calculated. As these calculated wire temperatures were applied to the real industrial fields, it was known that the calculated results were in a good agreement with the measured wire temperature.

철근콘크리트 원형기둥의 나선철근 최소철근비에 대한 평가

김영식,김형국,박천범,김상우,김길희,Kim, Young-Seek,Kim, Hyeong-Gook,Park, Cheon-Beom,Kim, Sang-Woo,Kim, Kil-Hee 한국구조물진단유지관리공학회 2017 한국구조물진단유지관리공학회 논문집 Vol.21 No.6

원형 기둥의 나선철근은 축방향 철근의 위치 고정 및 좌굴방지와 코어콘크리트의 충분한 횡구속으로 기둥의 연성거동에 효과적인 역할을 한다. 각국은 기둥에 요구되는 연성을 확보하기 위하여 나선철근의 최소철근비를 제시하고 있다. ACI 318-14와 국내 콘크리트 구조설계 기준에서 제시하는 나선철근 최소철근비는 Richart et al.(1928)의 이론에 기초하여 개발되었으며 현재까지 사용되고 있다. 그러나 Richart et al.(1928)의 이론은 현대의 고강도 콘크리트, 고강도철근 그리고 나선철근의 배근조건 등의 영향을 고려하지 못한다. 이 연구에서는 나선철근으로 구속된 철근콘크리트 원형 기둥의 내력회복 및 연성증진에 요구되는 나선철근에 대한 수정 최소철근비 산정식을 제시한다. 수정 최소철근비 산정식은 콘크리트 압축강도, 나선철근 항복강도, 기둥의 단면적, 나선철근 배근간격, 나선철근 직경의 영향을 고려하고 있다. 이 논문에서는 재료강도 및 나선철근 최적비를 변수로 한 실험체의 일축 압축실험을 통하여 ACI 318-14에 제시하는 나선철근 최소철근비 산정식의 타당성을 검토하고, 그 결과를 토대로 나선철근 최소철근비 산정식의 수정방안을 고찰하였다. Spiral reinforcement in a circular column plays an effective role in the ductile behavior of a column through position fixing and buckling restraining of the longitudinal reinforcement, and confining core-concrete. Each country has suggested the minimum volumetric ratio of spiral reinforcement in order to secure the ductility of concrete columns. The minimum volumetric ratio of spiral reinforcement suggested by ACI 318-14 and the national concrete structure design standard was developed based on the theory of Richard et al. (1928); furthermore it has been used until now. However, their theory cannot consider the effects of high strength concrete and high strength reinforcement, and arrangement condition of the spiral reinforcement. In this study, a modified minimum volumetric ratio equation is suggested, which is required to improve the ductility of reinforced concrete circular columns and to recover their stress. The modified minimum volumetric ratio equation suggested here considers the effect of the compressive strength of concrete, the yield strength of spiral reinforcement, the cross sectional area of columns, the pitch of spiral reinforcements and the diameter of spiral reinforcement. In this paper, the validity of the minimum volumetric ratios from ACI 318-14 and this study was investigated and compared based on the results of uniaxial compression experiment for specimens in which the material strength and the spiral reinforcements ratio were used as variables. In the end of the study, the modification method for the suggested equation was examined.

Indium Tin Oxide (ITO) 투광성 박막의 제조 및 전자파 차폐특성

김영식,전용수,김성수,Kim, Yeong-Sik,Jeon, Yong-Su,Kim, Seong-Su 한국재료학회 1999 한국재료학회지 Vol.9 No.11

투명차폐재를 목적으로 Indium Tin Oxide (ITO) 투광성 박막을 제조하고 전자파 차폐특성에 대해 조사하였다. 박막은 RF magnetron co-sputtering 증착장비를 사용하여 제작하였다. RF 인가전력, Ar 및 $O_2$분압, 기판온도를 변화시키며 전기전도도와 투광성을 겸비한 박막의 조성과 구조에 관한 실험을 진행하였다. 최적의 증착조건은 $300^{\circ}C$의 기판온도, 20sccm의 아르곤 유량, 10sccm의 산소유량, 그리고 In과 Sn의 인가전력이 각각 50W와 30W일 경우였으며, 이때 얻어진 박막은 육안으로 분명할 정도의 투광성을 보였고 5.6$\times10^4$mho/m의 높은 전기전도도를 나타내었다. 이렇게 제조된 ITO 박막의 전자파 차폐효과를 차폐이론에 의해 분석하였다. 박막의 전기전도도, 두께, skin depth로부터 차폐기구(흡수손실, 반사손실, 다중반사 보정항)에 대해 고찰하였다. 계산된 차폐효과는 26dB의 값을 보여 투광성 차폐재로 ITO 박막의 사용 가능성을 제시할 수 있었다. Indium Tin Oxide (ITO) films were fabricated by vacuum deposition technique and their microwave shielding properties were investigated for the application to the transparent shield material. The vacuum coating was conducted in a RF co-sputtering machine. The film composition and structure associated with the sputtering conditions (argon and oxygen pressure. substrate temperature. RF input power) were investigated for the attainment of high electrical conductivity and good transparency. The electrical conductivity of IT0 films fabricated under the optimum deposition conditions (substrate temperature : $300^{\circ}C$. Ar flow rate : 20 sccm, Oxygen flow rate : 10 sccm, In/Sn input power : 50/30 W) showed 5.6$\times10^4$mho/m. The optical transparency is also considerably good. The microwave shielding properties including the dominant shielding mechanism are investigated from the electrical conductivity, thickness and skin depth of the ITO films. The total shielding effectiveness is then estimated to be 26 dB, which provides a suggestion that the IT0 films can be effectively used as the transparent shield material.

한국인의 평생건강관리 프로그램

김영식,Kim, Yeong-Sik 한국건강관리협회 2004 한국건강관리협회지 Vol.2 No.3

Lifetime Health Maintenance Program(LHMP) for Koreans is the Korean guide to clinical preventive services which include screening for chronic diseases, counseling and immunization. The Korean Task Force on the LHMP vigorously reviews evidence for interventions to prevent over 50 different illnesses and conditions which are important in Korea. The problems addressed in this program are common ones seen every day by primary care physicians in Korea: cardiovascular, infectious diseases, gastrointestinal and endocrine diseases, cancers, alcohol and smoking, and many others. Primary care clinicians have a key role in screening for many of these problems and immunizing against others. Of equal importance, however, is the clinician's role in counseling patients to change unhealthful behaviors related to diet, smoking, exercise, injuries, and sexually transmitted diseases. The recommendations are grouped by age, sex, and other risk factors.

전단보강근이 없는 철근콘크리트보의 매립형 CFRP 전단보강효과에 대한 연구

김영식,박성무,Kim, Young-Sik,Park, Sung-Moo 한국공간구조학회 2005 한국공간구조학회지 Vol.5 No.2

철근콘크리트구조물은 시간이 경과함에 따라 노후화현상이 일어난다. 이에 갱생수단으로 보수 보강이 이루어지고 있다. 현재 보강재료로써 FRP가 높은 관심과 더불어 많은 활용을 하고 이에 대한 연구가 이루어지고 있다. 본 연구에서는 전단보강근이 없는 철근콘크리트보에 매립형 탄소섬유막대(CFRP)를 전단보강하여 그에 따른 효과를 파악하기 위해 시험체를 제작하여 실험을 수행하였다. 전단보강근이 없는 철근콘크리트보에 매립형 탄소섬유막대(CFRP)를 전단보강하여 탄소섬유막대(CFRP)의 순수전단내력을 파악하고, 전단보강에 따른 시험체의 전단파괴거동을 파악하고자 한다. 또한 실험변수를 탄소섬유막대(CFRP)의 보강량과 보강간격으로 두어, 이에 따른 전단보강효과를 파악하고자 한다. The reinforced concrete becomes deteriorated. In strengthening of reinforced concrete structure, it is recently useing FRP. The purpose of this study is to investigate the shear resisting effort of filling-up CFRP in reinforced concrete beams without web reinforced. Six specimens were manufactured and tested. In the test result, it was analysis. The main variables in the test were a space and volume of CFRP.

Ni 계 초내열합금의 PTA 오버레이 층 특성에 관한 연구

김영식,최영국,이광렬,Kim Young-Sik,Choi Young-Goog,Lee Kwang-Ryeol 대한용접접합학회 2006 대한용접·접합학회지 Vol.24 No.3

The Plasma Transferred Arc (PTA) overlaying method is lately introduced as one of the most useful surface modification method of the engine component. In this paper, the characteristics of the Co-base and Ni-base super alloy overlay layers by PTA method were investigated through the metallurgical, abrasive and cavitation erosion test. Experimental results showed that the abrasive wear resistance of the Co-base Stellite 6 overlayer was the most superior and followed in order of Nimonic 80A, Inconel 625 and Inconel 718. However, the cavitation erosion characteristic of the Stellite 6 overlayer was the most inferior and it was better in order of Inconel 625, Inconel 718 and Nimonic 80A.

플라즈마 표면 처리가 $BaTa_2O_6$박막의 전기적 특성에 미치는 효과에 관한 연구

김영식,이윤희,주병권,성만영,오명환,Kim, Young-Sik,Lee, Yun-Hi,Ju, Byeong-Kwon,Sung, Mang-Young,Oh, Myung-Hwan 대한전기학회 1999 전기학회논문지C Vol.48 No.5

Direct current(d.c.)leakage current voltage characteristics of radio-frequencymagnetron sputtered BaTa\sub 2\O\sub 6\ film capacitors with aluminum(A1) top and indium tin oxide (ITO) bottom electrodes have been investigatedas a function of applied field and temperature. In order to study surfacetreatment effect on the electrical characteristics of as-deposited film weperformed exposure of oxygen plasma on $BaTa_2O_6$ surface. d. c.current-voltage (I-V), bipolar pulse charge-voltage (Q-V), d. c. current-time (I-t) andcapacitance-frequency (C-f) analysis were performed on films. All ofthe films exhibita low leakage current, a high breakdown field strength (3MV/cm-4.5MV/cm), and high dielectric constant (20-30). From the temperature dependence of leakage current,we can conclude that the dominant conduction mechanism is ascribed toSchottky emission at high electric field (>1MV/cm) and hopping conduction at lowelectric field (<1MV/cm). According to our results, the oxide plasma surfacetreatmenton as-deposited $BaTa_2O_6$ resulted in lowering interfacebarrier height and thus, leakage current when a negative voltage applied to the A1 electrode. This can be explained by reduction of surface contamination via etching surface and filling defects such as oxygen vacancies.