• 한국자원식물학회지
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• 제20권2호
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• pp.145-149
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• 2007

콩나물의 형태는 상품성에 커다란 영향을 미친다. 본 연구는 상면살수 방식과 하면담수 방식에서 압착이 콩나물의 생장과 형태에 미치는 영향을 조사하고자 상면살수 방식에서는 상하로 재배통을 포개어 이를 매일 교환하거나, 계속 압착하는 방법과 하면담수 방식에서는 4일부터 압착을 가하거나 계속 압착하는 방법으로 처리를 가하여 시험을 수행하였던 바 그 결과를 요약하면 다음과 같다. 1. 개체당 형성된 세근수는 상면살수 및 하면담수 방식 모두 압착 강도가 강할수록 적었다. 2. 상면살수 방식에서 하배축은 계속 압착시 가장 짧았던 반면, 뿌리는 압착하지 않거나 계속 압착시 가장 길었다. 하면담수 방식에서는 하배축 길이에서만 무압착에서 가장 길고 계속 압착시 가장 짧았다. 3. 관수방식에 관계없이 자엽 바로 아래의 hook 직경은 압착 처리간 차이가 없었던 반면, 하배축 중간부분의 직경은 압착강도가 강할수록 굵어지는 경향을 보였다. 4. 생산수율과 관련된 개체당 전체생체중은 상면살수 방식에서는 무압착시 가장 적었으며, 압착 강도가 강할수록 증가하여 계속 압착시 가장 많았다. 그러나 하면담수 방식에서 전체생체 중은 압착처리간 차이가 없었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2248-2250
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• 2000

We investigated properties of PZT composite for medical ultrasonic transducer array (briefly UTA) for medicine applications fabricated by micro pressing and dicing method. Dicing method was the fabrication process of conventional ultrasonic transducer array by dicing sintered PZT sheet. Micro pressing method was the proposed process using pressing PZT green sheet by PMMA micro mold from LIGA process. Microstructures, electrical and electro -mechanical properties of fabricated UTAs of two cases were analyzed. Thickness mode electro-mechanical coupling coefficient of two cases have same values of 51%. Sintered PZT Microstructures of them showed dense and uniform. Micro pressing method was very mass productive process because of using batch type LIGA process. From results, we found micro pressing method was more competitive than dicing method for UTA fabrication. For further study, uniformity of microstructures and electro-mechanical properties of large scale, and fabrication processes of Ni plating and PMMA molding should be improved and investigated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.291-295
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• 2005

The PEMFC behavior is quite complex and is influenced by several factors, including composition and structure of electrodes and membrane type. Fabrication of MFA is important factor for proton exchange membrane fuel cell. MFA of PEMFC with hot pressing and direct coating method were prepared, and performances were evaluated and compared each other. The effect of MEA preparation methods, hot pressing methods and direct coating methods, on the cell performance was analyzed by impedance spectroscopy and SEM. The performance of PEMFC wi th direct coat ing method was better than wi th hot pressing method because membrane internal resistance and membrane-:-interfacial resistance were reduced by elimination of hot pressing process in MEA fabrication. In addition the micro structure of MEA with direct coating method reveals uniform interface between membrane and catalyst layer.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.230-234
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• 2005

Fabrication of MEA is important factor for proton exchange membrane fuel cell (PEMFC). MEA of PEMFC with hot pressing and direct coating method were prepared, and performances were evaluated and compared each other. The effect of MEA preparation methods, hot pressing methods and direct coating methods, on the cell performance was analyzed by impedance spectroscopy and SEM. The performance of PEMFC with direct coating method was better than with hot pressing method because membrane internal resistance and membrane-interfacial resistance were reduced by elimination of hot pressing process in MEA fabrication. In addition the micro structure of MEA with direct coating method reveals uniform interface between membrane and catalyst layer.

• 화훼연구
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• 제16권1호
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• pp.49-56
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• 2008

장미의 대표적인 화색인 적색 'Red Corvette', 분홍색 'Nobless'b, 황색 'Golden Metal' 및 백색 'Rose Yumi' 꽃을 재료로 건조방법에 따른 화색의 변화를 조사하고, 4주 및 8주간의 광처리(2,000lux, 16시간, 형광조명) 뒤의 화색 변화를 조사하였다. 모든 종류에서 실리카겔 매트로 압화 하는 처리구가 압화 당시와 광처리 후 화색변화가 가장 적었고, 전기압화기의 사용으로 꽃잎은 갈변화가 촉진되었다. 장미 적색은 한국산 시트지, 분홍색과 황색은 한국산 전기압화기, 장미 백색은 일본산 전기압화기 처리구가 화색의 변화가 가장 심하였다. 압화 당시 화색의 변화가 가장 컸던 것은 적색 장미였고, 그 다음이 분홍색, 황색, 백색 순이었다. 광처리에 의한 화색 변화정도가 가장 심했던 것은 황색 품종이었고, 다른 3종류는 다소 안정적이었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.119-122
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• 2006

In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve full density of 1 vol.% carbon nanotube (CNT)-metal matrix composites with superior mechanical properties by improved particle bonding and least grain growth, which were considered as a bottle neck of the bottom-up method using the conventional powder metallurgy of compaction and sintering. ECAP (equal channel angular pressing), the most promising method in SPD, was used for the CNT-Cu powder consolidation. The powder ECAP processing with 1, 2, 4 and 8 route C passes was conducted at room temperature. It was found by mechanical testing of the consolidated 1 vol.% CNT-Cu that high mechanical strength could be achieved effectively as a result of the Cu matrix strengthening and improved particle bonding during ECAP. The ECAP processing of powders is a viable method to achieve fully density CNT-Cu nanocomposites.

• 대한기계학회논문집A
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• 제24권9호
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• pp.2211-2219
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• 2000

Near net shape forming of 316L stainless steel powder was investigated under hot isostatic pressing. To simulate densification and deformation of a powder compact in a container during hot isostatic pressing, the constitutive model of Abouaf and co-workers was implemented into a finite element analysis. An optimal design technique based on the design sensitivity was applied to the container design during hot isostatic pressing. The optimal shape of the container was predicted from the desired final shape of a powder compact by iterative calculations. Experimental data of 316L stainless steel powder showed that the optimally designed container allowed precise forming of the desired powder compact during hot isostatic pressing.

• 한국정밀공학회지
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• 제22권5호
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• pp.205-213
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• 2005

This paper addresses a method for numerical simulation in the pressing process of hot glass. Updated Lagrangian finite element formulations are employed for the flow and energy equations to accommodate moving meshes. The model is assumed axi-symmetric and creep flow is assumed due to the high viscosity. Commercial software ANSYS is used to solve the coupled flow and energy equations. Moving contact points as well as free surface during the pressing are effectively calculated and updated by utilizing API functions of CAD software Unigraphics. The mesh distortion problem near the wall is overcome by automatic remeshing, and the temperatures of the new mesh are conveniently interpolated by using a unique function of ANSYS. The developed model is applied to the pressing process of TV glasses. In conclusion, the presented method shows that the pressing process accompanying moving boundary can be simulated by effectively combining general purpose software without resorting to special dedicated codes.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.425-426
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• 2008

Elasto-plastic finite element analysis was carried out for analyzing the severe plastic deformation behavior of copper specimens during groove pressing. Deformation localization was studied in terms of strain variations along the longitudinal direction. Plastic strain is lower at the local interface between the shear and the flat regions, which receive very little shear during the pressing cycle. Strain localization is more intensified with the number of rove pressing cycles, although the average strain level increases.

• 에너지공학
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• 제1권1호
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• pp.58-65
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• 1992

인산형 연료전지의 전극성능의 향상을 위해 Hot Pressing공정을 사용하여 Pt이 담지된 다공성 탄소전극(Pt/C)을 제조하였다. Hot pressing의 조건, 촉매층에서의 PTEE 함량을 변화시켜 제조한 Pt/C 전극의 전기화학적 산소환원특성 및 인산형 단위전지 성능특성을 비교하였다. 실험결과 Hot Pressing의 최적조건은 36$0^{\circ}C$, 10kg/$\textrm{cm}^2$이었다. 최대성능은 촉매층에 30wt%의 PTFE 함량을 가진 전극에서 얻어졌으며, 이때 백금의 이용율은 80%이었다. 단위전지의 성능측정 결과, hot pressing한 전극의 성능은 700㎷에서 200mA/$\textrm{cm}^2$이었으며 200시간동안 안정적인 성능이 유지되었다.