열분해와 Hot Injection법을 이용한 CoSb₃ 나노분말합성

김민숙,안종필,김경자,박주석,김경훈,김형순,Kim, Min-Suk,Ahn, Jong-Pil,Kim, Kyung-Ja,Park, Joo-Seok,Kim, Kyoung-Hun,Kim, Hyung-Sun 한국세라믹학회 2013 한국세라믹학회지 Vol.50 No.6

$CoSb_3$ with its high electrical conductivity, Seebeck coefficient and rather low thermal conductivity is quite a promising material for thermoelectric conversion applications. A potentially high figure of merit (ZT) can be achieved by a nanostructure evolution of thermoelectric materials. In this work, $CoSb_3$ nanoparticles were synthesized through a thermal decomposition method in cooperation with a hot injection technique. Nano-sized $CoSb_3$ particles were obtained through the thermal decomposition reaction between the pre-heated cobalt-oleate at $320^{\circ}C$ and the injected antimony oleate with room temperature. The results showed that the particle size was increased with increasing synthesis temperature and the crystallinity of particles was improved with temperature but the decomposition of $CoSb_3$ was observed at $320^{\circ}C$. The $CoSb_3$ particles synthesized at $300^{\circ}C$ showed a high purity and an homogeneous shape with average particle size of 26 nm.

서스펜션 플라즈마 스프레이 코팅법을 이용한 이트리아 코팅막 제조와 특성

김민숙,소성민,김형순,박성환,함영재,전민석,김경훈,Kim, Min Suk,So, Sung Min,Kim, Hyung Soon,Park, Seong Hwan,Ham, Young Jae,Jeon, Min Seok,Kim, Kyoung Hun 한국결정성장학회 2019 한국결정성장학회지 Vol.29 No.6

The suspension plasma spraying is a modification of conventional plasma spray techniques that has been developed to overcome the challenge of using fine particles in plasma spray processes. In this study, microstructure developments and mechanical property of yttrium oxide (Y₂O₃) coatings prepared by the suspension plasma spray coating technique have been investigated to determine the effect of processing parameters including plasma gun current and total gas flow. The results showed that a highly dense Y₂O₃ coating having low porosity of 0.2 vol% without any lamellar structures can be achieved at the optimum condition of gun current 200 A and total gas flow 220 L/min. 서스펜션 플라즈마 스프레이 법은 미세한 분말을 용사 공정에 적용함으로써 전통적인 플라즈마 스프레이 법의 단점을 극복하고자 개발된 코팅법이다. 본 연구에서는 고밀도의 Y₂O₃ 코팅막을 제조하기 위해 서스펜션 플라즈마 스프레이법을 이용하여 플라즈마 건의 전류량과 총 가스 유량을 공정변수로 하여 코팅막을 제조하였으며, 그에 따른 코팅막 특성에 대한 연구를 하였다. 코팅막의 미세구조 및 물리적 특성 평가 결과 플라즈마 건 전류량 200 A, 총 가스 유량 220 L/min의 조건에서 층상 결함 없이 0.2 vol%의 매우 낮은 기공률을 갖는 고밀도의 Y₂O₃ 코팅막을 제조할 수 있었다.

방전플라즈마 소결 공정을 이용한 CoSb₃/Al/Ti/CuMo 접합 특성

김민숙,안종필,김경훈,김경자,박주석,서원선,김형순,Kim, Min Suk,Ahn, Jong Pil,Kim, Kyoung Hun,Kim, Kyung Ja,Park, Joo Seok,Seo, Won Seon,Kim, Hyung Sun 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.6

$CoSb_3$-based skutterudite compounds are candidate materials for thermoelectric power generation in the mid-temperature range (600 - 900 K) because their thermoelectric properties can be enhanced by doping and filling. The joining property of thermoelectric module electrodes containing thermoelectric materials is of great importance because it can dominate the efficiency of the thermoelectric module. This study examined the properties of $CoSb_3$/Al/Ti/CuMo joined by the spark plasma sintering technique. Titanium thin foil was used to prevent the diffusion of copper into $CoSb_3$ and Aluminum thin foil was used to improve the adhesion between $CoSb_3$ and Ti. The insertion of an Aluminum interlayer between the Ti and $CoSb_3$ was effective for joining $CoSb_3$ to Ti by forming an intermediate layer at the Al-$CoSb_3$ boundary without any micro cracks. Specifically, the adhesion strength of the Ti/Al/$CoSb_3$ joining interface showed a remarkable improvement compared with our previous results, without deterioration of electrical property in the interface.

Oral Administration of Loquat Suppresses DMBA-induced Breast Cancer in Rats

김민숙,Mi Kyoung You,김현아,류동영,정규식,Yong Jae Kim,Hum Young Baek 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.2

This study was to demonstrate whether loquat leaves protect against 7,12-dimethylbenz[α]anthracene (DMBA)-induced breast cancer in female rats. Rats were fed control diet (NC, DC), ethanol (DE), or water extract of loquat leaves (DW) until sacrifice. At 50 days of age,animals in the DC, DE, and DW groups were given a single intra-gastric dose of DMBA (50 mg/kg) dissolved in corn oil. Both the water and ethanol extracts of loquat leaves decreased the incidence of tumors, with water extract having the higher inhibitory effect. Ethanol extract significantly decreased the multiplicity of tumors. Loquat extracts significantly decreased tumor cell proliferation and the tumor grade based on the degree of tubule formation. These results suggest that both water and ethanol extracts of loquat leaves inhibit the development of breast cancer. Such inhibition may be based on the suppression of initiation and tumor cell proliferation.

철근 콘크리트 플랫 플레이트 처짐의 변동성 평가

김민숙,조은선,이영학,Kim, Min Sook,Jo, Eunsun,Lee, Young Hak 한국전산구조공학회 2014 한국전산구조공학회논문집 Vol.27 No.6

불확실성을 가지는 콘크리트의 특성으로 인해 철근 콘크리트 부재의 처짐에는 높은 변동성이 발생할 수 있다. 그러나 현행 설계규준은 이를 고려하지 않고 경험적인 데이터에 바탕을 두고 있으며, 부재의 최소 두께 또는 최대 허용 처짐만을 제시하고 있다. 본 논문에서는 철근 콘크리트 플랫 플레이트의 처짐 예측이 가능한 유한요소해석 모델에 확률해석 모델을 적용하여 철근 콘크리트 플랫 플레이트 처짐의 변동성을 평가하고자 하였다. 이를 위해 콘크리트, 철근, 부재치수, 인장강성에 관련된 8개 요소를 변수로 한 몬테카를로 시뮬레이션을 수행하였다. 해석결과, 스팬의 크기가 증가할수록 하중으로 인한 처짐에 더 민감하게 반응하는 것으로 나타났으며, 재하되는 활하중의 크기가 클수록, 슬래브의 두께가 작을수록 처짐의 변동성이 큰 것으로 나타났다. The deflection of reinforced concrete members can be highly variable, due to uncertainties in the characteristics of the concrete. However, current standards do not take this problem into account, instead recommending only the minimum thickness and maximum allowable deflections based on empirical data. This paper is aimed at evaluation deflection variabilities by applying a probabilistic analysis model to a finite element analysis model. To evaluate the variabilities of deflections, a Monte Carlo simulation, which incorporated the eight parameters related to concrete, reinforcement, member size, and tension stiffening. The results showed that lager spans were more sensitive to the deflection due to loads and that as the applied live loads were increases and the slab thickness were decreased, the deflection variability increased.

『청교(淸交)』로 보는 한국 건축문화재 조사 및 보존에 관한 연구

김민숙,Kim, Min-Suk 한국건축역사학회 2014 건축역사연구 Vol.23 No.4

The magazine (Bulletin) of "Seikou" was made by conservation engineers to exchange information about the survey and repair work of historic buildings in Japan before World War II. This magazine has 26 volumes in total, and was published periodically four times a year from April 1937 to December 1943. Publisher is Nindokai that is supposed to the forerunner of Bunkenkyo (the Japanese Association for Conservation of Architectural Monuments). Only 3 or 4 organizations except personal possession have it now. And it has a limit to use the contents of the article as a general historical material. So, it was rare that experts and researcher used to the "Seikou". However, this study focuses on the articles of the Korean historic building, which is sometimes appeared in it, although there are few. The purpose of this paper is to clarify the fact-finding of the conservation for the Korean historic building in Japanese colonial period by analyzing the articles in historical records of "Seikou".

횡방향 전단 보강 간격에 따른 넓은 보의 전단성능

김민숙,Kim, Min Sook 한국공간구조학회 2016 한국공간구조학회지 Vol.16 No.1

갈고리 발가락에 대한 근위지절관절 굴곡 방지 테이프가 뇌졸중 환자의 보행에 미치는 효과

김민숙,구봉오,Kim, Min-Suk,Goo, Bong-Oh 대한고유수용성신경근촉진법학회 2011 PNF and Movement Vol.9 No.3

Purpose : We investigated the effect of anti-flexion taping at the proximal interphalangeal joints on the gait in stroke patients with clawing toe. Methods : Nineteen patients (mean age $63.26{\pm}9.16$ years) with clawing toe were studied. Gait performance was measured under two different conditions : (1) non-tape (2) application of tape. Gait velocity, step time and stride length were examined with the GAITRite system Results : Compared to the non-tape control condition, step time of the hemiparetic side increased significantly after the application of tape(p=0.03). There was no significant mean differences between the taped and control conditions for stride length of the hemiparetic side and velocity. Conclusion : Whilst the anti-flexion tape at the proximal interphalangeal joints changed the walking by providing significant step time effect, positive changes were noted in stride length of the hemiparetic side after tape application. These findings indicate that anti-flexion tape procedures do not significantly alter stride length of the hemiparetic side and velocity.

GFRP 판으로 보강된 플랫 플레이트의 전단강도식에 관한 규준의 비교 분석

김민숙,황승연,김희철,이영학,Kim, Min Sook,Hwang, Seung Yeon,Kim, Heecheul,Lee, Young Hak 한국전산구조공학회 2014 한국전산구조공학회논문집 Vol.27 No.4

본 논문에서는 유공형 형상의 GFRP 판으로 전단 보강된 플랫 플레이트의 전단거동을 실험을 통해 평가하였다. GFRP 판은 개구부가 있는 판의 형태로서 콘크리트와의 일체화 거동을 위하여 콘크리트에 매립하여 시공하였다. 실험 변수로는 기둥면과 첫 번째 GFRP 판의 세로 스트립 사이의 간격, GFRP 판의 세로 스트립의 개수를 선정하였다. GFRP 판의 세로 스트립의 개수가 증가할수록 전단강도도 증가하는 결과를 보여주었다. 실험결과를 바탕으로 GFRP 판으로 보강된 플랫 플레이트의 전단강도가 ACI 318, BS 8110, EUROCODE 2, KCI에서 제시하고 있는 전단강도와 비교하여 가장 합리적인 규준을 평가하였다. In this study, shear test performed to investigate the shear behavior of flat plate that reinforced by embedded GFRP(glass fiber reinforced polymer) plate with openings. Shape of the GFRP shear reinforcement is a plate with several openings to ensure perfect integration with concrete. The test parameters include the distance between the column face and the first line of GFRP plate and number of GFRP plate vertical strip. The result of test showed that when number of GFRP plate vertical strip was increased, shear strength improved. The shear strength for flat plate reinforced GFRP plate in various codes including ACI 318, BS 8110, EUROCODE 2, and KCI were compared to provide more rational approach for reinforced concrete flat plates with GFRP plate.

철근콘크리트 플랫 플레이트의 뚫림전단 거동에 관한 해석적 연구

김민숙,이영학,김희철,Kim, Min-Sook,Lee, Young-Hak,Kim, Hee-Cheul 한국전산구조공학회 2010 전산구조공학 Vol.23 No.4

본 논문에서는 플랫 플레이트 구조의 뚫림전단 거동을 평가할 수 있는 유한요소해석 모델을 제시하고 변수 해석을 통해 플랫 플레이트 구조의 뚫림전단 거동에 영향을 미치는 인자들을 파악함으로써 향후 현행 설계식 보정에 있어 기초자료를 제공함에 그 목적을 두었다. 전단변형을 고려하기 위해 Reissner-Mindlin 가정이 도입된 퇴화 쉘 요소를 선택하였으며, 철근콘크리트의 재료적 비선형 거동을 고려하기 위해 적층쉘 개념을 적용한 유한요소해석 모델을 제시하였다. 유한요소해석 모델의 신뢰성을 검증하기 위해 기존 실험결과와 비교하였으며, 그 결과 유한요소해석 모델이 실험결과를 비교적 잘 예측하는 것으로 나타났다. 제시한 유한요소해석 모델을 사용한 변수해석을 통해 휨 철근비와 슬래브의 두께가 증가할수록 플랫 플레이트의 전단강도 또한 증가하는 것을 알 수 있었다. A finite element model for punching shear of flat plate structures is presented. A parametric study also has been conducted to verification of influence of several parameters in terms of the flexural reinforcement ratio, slab thickness. Reisnner-Mindlin assumptions are adopted to consider of shear deformation. Layered shell element is considered for the material non-linearities. The finite element model of this study was verified comparing with existing experimental results. The model is able to predict the capacity of the flat plate structures. The punching shear of flat plate structures varied depending on the flexural reinforcement ratio, slab thickness.