Investigation on Delamination Characteristics of 2-Ply Clad Metals and Adhesive Joints for Aluminum/Stainless Steel via the Peel Test

Jun‑Hyung Sim,Yungeun Ha,Min‑Kyun Kim,Min‑Joong Kim,Young‑Rae Cho 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

Bonding properties are important for metallic multilayer composites (MMCs) comprising different materials or materialswith different mechanical properties. In this study, we fabricated 2-ply Al/stainless steel (STS) clad metals and Al/adhesive(adh)/STS joints. To manufacture samples with various mechanical properties, T6 heat treatment was performed on cladmetals, and adhesive joints of several thicknesses were prepared. For each sample, the bonding strength was characterizedvia a T-peel test and the results were analyzed using the peeling angle. For 2-ply Al/STS clad metals, the T6 heat treatmentresulted in opposite trends in the mechanical properties. The bonding strength of 2-ply Al/STS clad metals was affectedby the peeling angle, i.e., a small peeling angle provided a small bonding strength at the interface. However, for the 2-plyAl/adh/STS joints, the bonding strength of adhesives on metals depended on each adherend of the stress state. As the differencein mechanical properties between the two adherends increased, the difference in each peeling angle of Al and STSalso increased. The peeling angle of adherends reached a limiting value when the sample contacted the clamping jig head;therefore, a new term, apparent bonding strength (ABS), is necessary to differentiate this new strength from the bondingstrength obtained under non-contact conditions. We believe that the concept of peeling angle and ABS proposed herein willplay a crucial role in describing the delamination behavior and bonding strength of MMCs via the peel test.

농촌관광에 대한 도시민 선호분석

조재환,김태균,박시현,박준형 한국농업정책학회, 한국축산경영학회 2003 농업경영정책연구 Vol.30 No.3

This paper analyzes urban residents' preference on rural tourism using a survey data. The results show that even though urban residents are unaware of rural tourism, people who have experienced rural tourism set a high value on it. Urban residents are willing to pay about 93,600Won for rural tourism. These results indicate that there is a lot of potential demand for rural tourism. The results of this paper could be an important information to develop the rural tourism.

KS-62 균주에 의한 펄프 표백 폐액처리에 관한 연구

조준형,은주영 江原大學校 附設 環境硏究所 2000 環境硏究 Vol.17 No.-

High colored Kraft bleaching effluent is one of the main constrains in pulp and paper indus-try due to its dissloved lignin derivatives. The degradation of lignin in pulp and paper mill effluent is mainly caused by white-rot fungi. This paper showed that the treatment with KS-62 fungus significantly reduced the color and chemical oxygen demand in the effluent. The amounts of Mn ions in the wastewater would play roles in the induction and activity of MnP (managanese peroxidase). Extracellular MnP was isolated from the fungus KS-62. The treat-ment with the MnP had the most effective decolorization in the wastewater treatment using nutrients medium.

인도네시아 지진해일에 대한 의료지원보고

조수형,김선표,최웅지,김성중,조남수,이준영,문성표 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.2

An unprecedented magnitude of disaster, Tsunami, washed away Southeast Asia, on December 26, 2004. and more than 200,000 peoples were killed by the disaster. Staffs of our hospital visited Indonesia for voluntary medical supports from January 12, to January 21, 2005. We summarize here our 10 days' experiences in Indonesia.

콘크리트 포장의 하부 지지력계수 산정식 개발

조윤호,한상기,김준형 중앙대학교 기술과학연구소 1999 기술과학연구소 논문집 Vol.29 No.-

외국의 설계 지침을 근간으로 콘크리트 포장을 설계하고 있는 국내 포장 기술자들은 흙의 지지력 계수 추정에 어려움을 겪고 있다. 길바탕흙(Roadbed Soil)의 평판재하실험 결과(??)를 선택층 및 하나 혹은 여러 층위의 지지력계수(??)로 변환하는 것은 현 설계 지침에 상세한 과정이 없으므로 혼란이 가중되고 있다. 이에 대하여 본 논문은 흙의 지지력계수 산정과정 전반에 걸쳐 국내의 문제점을 살펴보고, 바람직한 설계 방향을 제시하였다. 국내에 존재하는 포장의 형식을 조사하여 대표적인 보조기층재료와 두께 따라 ??값에서 ??값을 추정하는 설계 입력변수 변환 모형을 제시하였는데, 포장 거동 해석 모형은 AASHTO 추정식에 사용했던 다탄성 해석이론인 ELSYM5가 사용되었다. 역학적 모형 해석에 어려움을 겪는 기술자들이 간편하게 사용할 모형을 개발였는데 기층 및 보조 기층의 두께 및 재료 물성에 따라 총 990회의 거동 해석이 진행되었고, 회귀 분석을 이용하여 추정모형을 선정하였다. 또한 제시된 회귀식은 기존의 개발 모형과 비교를 통해 실무 적용이 타당하다고 판단하였다. Design of concrete pavement in Korea is mainly based on the guide developed from the AASHTO. However, many input parameters were not calibrated for the materials used in the highway. Subgrade modulus for the rigid pavement could not be correctly estimated due to lack of procedure to transfer modulus of subgrade reaction(??) to composite modulus of subgrade reaction(??), for example. This paper describes the way how to develop transforming equation and the model for estimating ??. Typical concrete sections were selected from the survey of pavement constructed in airport and highway. A layered elastic model, ELSYM5, that shows the behavior of concrete pavement under traffic loading was adapted for calculation of theoretical subgrade modules. Total 990 of calculation were performed. Regression model was suggested for the design based purely on analytical work so that further research work to verify the model from the field should be carried out.

정압여과에 따른 비뉴우튼 유체의 여과 특성치의결정법

趙駿衡 江原大學校 附設 環境硏究所 1991 環境硏究 Vol.8 No.-

A Filtration theory for the power-law non-Newtonian fluids has become increasingly important in broad area of industry. Filtration characteristics of non-Newtonian fluids-solids mixture are investigated by use of a specially designed filter having a hole at the top of the filter chamber. On the basis of the principle of sudden reduction in filtration area of the cake surface, a method is developed for determining such overall filtration characteristics as the ratio of wet to dry cake mass and the average specific filtration resistance _(av) for power-law fluids. It is shown that the results obtained from the newly developed non-Newtonian filtration technique can be used to approximate the local porosity ε and the local specific filtration resistance α.

Information Technology의 기존 관광산업에 대한 영향 및 향후 Trend에 대한 전망 : 사이버여행사 수익모델을 중심으로 Profit Model of Cyber Travel Agency

조현준,나윤중,임형순,엄서호 한국문화관광학회 2001 문화관광연구 Vol.3 No.1

IT has an influence on the travel agency as chance and threat. The purpose of this study is to find what profit model of cyber travel agency. Ernst&Young's five business profit models that are based on target audience and transaction focus is selected to evaluated existing model of cyber travel agency. Those are off-line facilitator, gateway, context provider, commerce destination, online exchange. The result of this study show that there is no specific profit model in domestic cyber and on-offline travel agencies. Just Portal cyber travel agencies abroad have a few profit model. They have online exchange model, which are various target audience and abound provide contents.

반복 용체화처리에 의해 조직제어된 Ti-6Al-4V 합금의 인장성질

조형준,임영호,이준희 동아대학교 공과대학 부설 한국자원개발연구소 1994 硏究報告 Vol.18 No.2

The purpose of the present study is to improve the tensile properties of the beta-quenched with little strain due to processing, only by heat treatment. Control of volume fraction, morphology and distribution of alpha is of great importance in achieving desired mechanical properties with a good combination of strength and elongation. Accordingly, a cyclic solution treatment has been proposed to obtain bimodal structures of equiaxed and acicular alphas. The microstructures of the specimens subjected to the Cyclic Ⅲ solution treatment consisted of nearly equiaxed and acicular alphas with the matrix of the tempered martensite. As a result, the tensile properties became almost equivalent to the specimens of the double solution treatment in the α+β region.

초고속 전송에 대한 Ultrashort Laser Pulse의 새로운 스펙트럼 분석

전진성,조형래,오용선 韓國海洋大學校電波通信硏究所 1999 電波通信硏究所論文集 Vol.1 No.-

본 논문에서는, Class-2 PRS 모델의 전달함수인 Raised-Cosine 펄스를 이용하여 극초단 레이저펄스의 전송특성을 분석하였다. 이는 Class-1 PRS 모델에서와 같이 부분응답시스템의 수정된 모델로부터 얻어지는 고차원펄스를 이용하여 그 차수의 증가에 따라 FWHM폭이 현저히 감소하여 분석하고자 하는 극초단펄스의 형태에 근접하는 펄스를 제시하였으며, 그 스펙트럼과 전송대역폭도 차수에 따라 일률적으로 유도되므로 Gaussian, Sech형태의 펄스 같은 고전적인 방법과는 달리 광범위하고 정확한 전송특성을 분석하는데 매우 유용함을 밝혔다. 먼저, 부분응답시스템의 일반적인 모델을 수정하여 어떤 형태의 고차원펄스도 적용할 수 있는 새로운 방법을 제안하였다. 그리고 제안된 모델을 이용하여 어떠한 형태의 FWHM을 가지는 극초단펄스의 전송에 대한 새로운 분석 방법을 제안하였다 제안된 방법을 사용하여, 설정 펄스 폭을 τ=1(㎰)으로 설정, 고차원펄스의 차수 n=1~100에서 얻어지는 FWHM 1(㎰)~100(fs)의 극초단펄스의 스펙트럼을 제시하였고, Class-2 PRS 모델의 FWHM 폭이 Class-1 PRS 모델보다는 차수 n에 따라서 약 50~100(fs)정도 좁은 FWHM 폭을 가짐을 밝혔다. 이에 대한 전송특성은 레이저펄스의 보편적인 신호방식인 Unipolar 체계로 설정하여, 가능한 펄스간격에 따른 PSD를 유도하여 제시하였다. 이러한 결과들은 고전적인 실험 방법과는 일치함을 물론 미래 극초단펄스 연구에 대한 혁신적인 방법으로 사용될 수 있을 것이다. In this paper, we analyze transmission characteristics of ultrashort laser pulses using the property of Raised-cosine pulse which are systematically obtained following Class-2 PRS model. The high-order pulses are easily derived from a modified PRS system model as Class-1 PRS model. This may be based on the fact that the spectra and bandwidths of the high-order pulses are beautifully related to their orders. And we make clear they are very useful to cover wider area and more accurate transmission characteristics of ultrashort pulses than Gaussian or Sech pulse approximations used conventionally. First modifying the generalized PRS system model, we propose a new model for deriving any type of high-order pulse. And we offer a novel analysis method of ultrashort pulse transmission which has any shape and FWHM, using the proposed model. In addition, by fixing the pulse range τ=1(㎰) and varying the order of the pulse from n=1 to n=100, we obtain spectra of ultrashort pulses with 1(㎰)~100(fs) FWHM's, and width of FWHM in the Class-2 PRS model 50~100(fs) smaller than Class-1 PRS model. As a one-step further, we derive PSD's of their pulse trains when they are applied to Unipolar signaling scheme. These PSD's are decided in the range of possible pulse intervals. All of these results are not only coincided with some conventional experimental works but also will be applied to any pioneering ultrashort pulse in the future.

전통 곶감의 수출시장 소비자선호 분석

조재환,김태균,박준형 한국농업정책학회, 한국축산경영학회 2001 농업경영정책연구 Vol.28 No.3

This study analyzes the foreign consumers' preferences and the willingness to pay for the Korean traditional dried persimmons by conducting surveys to Japanese, Americans, Canadians, Europeans, Australians, and New Zealanders. The results show that the potential export demand is largest to Japanese and those to U.S. and Europe are sufficient. The results also indicate that the price has to be reduced and the quality has to be improved in order to extend the export demand for the Korean traditional dried persimmons.