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.

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.

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.

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.

해상풍력 발전설비의 고능률 용접기술

김영식,길상철,Kim, Youngsik,Kil, Sangcheol 대한용접접합학회 2015 대한용접·접합학회지 Vol.33 No.3

The offshore wind power plants are watched as a new market to accomplish the needed energy, bringing technical and economical challenges. Advanced countries in the field of wind industry are now appling the 600 MPa, 150~200 mm thick high strength steel to offshore wind power plants. Moreover, the high efficient welding methods which is weldable ultra tick high strength steel with 1 pass welding are developed and applied in manufacturing the offshore wind tower. This article deals with the present world wide status of offshore power plants and the tendency of the development of high efficient welding technology for constructing the offshore wind tower. This article intends to offer the materials for development and raising of the domestic offshore wind power technology.

한국인의 평생건강관리 프로그램

김영식,Kim, Yeong-Sik 한국건강관리협회 2004 한국건강관리협회지 Vol.2 No.1

On the Rotational Barrier of Organic Molecules (I). Role of Axial Carbon in Ethane

김영식,김호징,Young Sik Kim,Hojing Kim Korean Chemical Society 1982 대한화학회지 Vol.26 No.3

에탄의 회전 장벽에 미치는 두개의 탄소 원자의 영향을 알아보기 위해 6개의 수소만으로 이루어진 탄소가 없는 에탄올 모델로 택하여 이 모델 분자의 Staggered 및 eclipsed꼴의 에너지를 McWeeny의 open-shell RHF-SCF방법으로 계산하고,staggred에서 eclipsed로 꼴이 변할때의 천이밀도를 조사 하였다. 예상대로 모델 분자에서는 ecliped꼴이 staggered꼴보다 안정하였다. 이 탄소없는 에탄의 천이 밀도와 실제 에탄의 천이 밀도를 비교 분석하여, 에탄의 회전 장벽은 중심축 위치에 있는 두개의 탄소 원자로 인해 staggered에서 eclipsed꼴로 변함에 따라 수소 원자 주위의 전자 밀도가 희석되고, 탄소 원자 주위와 탄소-탄소 결합 공간으로 끌리므로 해서, 전자 에너지 감소가 핵간 반발 에너지의 증가를 상쇄하지 못하는데 기인한다는 것을 알게 되었다. In order to analyze the role of axial carbon atoms in rotational barrier of ethane, we take the carbonless ethane, as a model, which is made of six hydrogens in coordinates of ethane. The energy of the system is calculated by McWeeny's open-shell restricted Hartree-Foch selfconsistent-field (RHF-SCF) method, and the transition density on the staggered-to-eclipsed rotation is examined. As being expected, the eclipsed form of the model is more stable than the staggered one. Through the transition density comparison of this model and real ethane, it is found that the existence of the axial carbon atoms induces the electronic density to be diluted in the vicinity of protonic sites and to be attracted to the region of carbon atoms or further to C-C bond region as the barrier is traversed. This migration of electronic charge tell us that the barrier to the internal rotation of ethane originates from the fact that the magnitude of electronic energy depression is not large enough to offset the increased nuclear-nuclear repulsion on the staggered-to-eclipsed rotation.

마찰교반 점용접(FSSW)을 이용한 비철금속 접합기술의 연구 동향과 전망

김영식,Kim, Young-Sik 대한용접접합학회 2012 대한용접·접합학회지 Vol.30 No.3

강과 함께 하는 지역축제 1 - 산천어축제가 이뤄낸 지역의 변화

김영식,Kim, Yeong-Sik 한국하천협회 2013 하천과 문화 Vol.9 No.1