체결압이 고분자연료전지 기체확산층의 표면성질에 미치는 영향

안은진,박구곤,윤영기,박진수,이원용,김창수,Ahn, Eun-Jin,Park, Gu-Gon,Yoon, Young-Gi,Park, Jin-Soo,Lee, Won-Yong,Kim, Chang-Soo 한국전기화학회 2007 한국전기화학회지 Vol.10 No.4

고분자연료전지에 사용되는 다공성 매체인 기체확산층은 그 특성에 따라 원활한 기체의 확산과 물 배출을 결정지으며 그 결과 연료전지 성능과 내구성에까지 영향을 미친다. 최적의 물관리와 기체확산층 내에서의 이상(two phase) 유동이해를 위해서는 실제 체결 조건에서의 기체확산층의 성질을 아는 것이 중요하다. 이에 대해 물리적, 전기화학적, 기계적 성질을 알기 위한 실험 등이 수행되어져 왔다. 하지만 실제 스택의 체결 조건에서 기체확산층의 표면 화학적 변화에 대한 실험은 그다지 알려져 있지 않다. 본 연구에서는 단순한 체결 과정만으로도 기체확산층에 대한 물리화학적인 변화를 야기할 수 있음을 확인하였으며, 기체확산층을 구성하는 탄소 섬유 및 PTFE의 손상과 변형을 전자주사현미경으로 직접 관찰할 수 있었다. 관찰된 물리적 손상이 표면의 소수성 변화에 미치는 영향을 알아보기 위해 표면 원소성분 분석과 농도가 다른 에탄올 수용액 흡수량 측정을 수행하였다. 그 결과 체결압에 의해서 분리판의 rib 전단 및 아래에서 심한 파손이 일어나며, 탄소 섬유의 끊어짐 및 섬유 사이에 존재하는 탄소 파우더 역시 심하게 눌린 현상을 관찰할 수 있었다. 체결과정을 경험한 기체확산층에 대한 liquid uptake양을 확인한 결과, 표면 PTFE 함량의 상대적 감소가 기체확산층의 표면을 소수성에서 친수성으로 변화시켰음을 직접적으로 확인하였다. Characteristics of GDL (Gas Diffusion Layer) mainly determine the gas diffusion and water removal in a cell, thereby changing the performance and affecting durability of PEFC. To optimize the water management and understand the two phase flow in a GDL, it is important to study the behaviors of GDL micro structure under the real operating condition. In the clamped condition of cell, the GDL beneath the rib is more compressed than beneath the channel. Many researches on physical, electrochemical, mechanical behaviors of gas diffusion layer has been conducted. However, changes in surface properties under clamped condition have rarely studied. In present study, the morphology of broken connections of carbon fibers and detachment of PTFE coatings on the fibers were shown from the microscopic observations. In addition, changes in wetting properties of GDL by compression were investigated by using XPS and liquid uptake methods. The hydrophobic characteristics of GDL surface beneath the rib of the flow field plate are changed due to the deformation of micro structure.

건설사업 참여주체(발주자, CMr, 설계자, 시공자) 관점에서 건설사업관리 성과측정에 관한 연구

안은진,유병기,이윤선,김재준,Ahn, Eun-Jin,Yoo, Byeong-Gi,Lee, Yoon-Sun,Kim, Jae-Jun 한국건설관리학회 2008 건설관리 : 한국건설관리학회 학회지 Vol.9 No.3

건설업은 일반 제조업의 생산과정과는 달리 다양한 참여주체들이 모여 프로젝트 성공이란 하나의 목표아래 정보를 공유하며 업무를 진행하므로 한 프로젝트마다 일시적인 팀워크가 형성된다. 다양한 참여주체들은 건설공사의 단계별 역할이 다르며, 업무 및 이에 따른 이해관계 역시 복잡하게 얽혀있다. 건설프로젝트의 효율적인 관리와 경영의 최적화를 위하여 CM제도가 도입이 되었다. 따라서 CM제도의 성공을 위해서는 주요 참여주체(발주자, CMr, 설계자, 시공자)의 협력관계가 요구된다. CM제도가 도입된 이래 성공적으로 사업을 수행하기 위한 일환으로 CM성과측정에 대한 많은 노력이 있었으나, 발주자의 입장에서만 바라본 항목으로 측정되고 있다. 이에 본 연구에서는 CM성과를 객관적으로 측정하기 위해서 건설프로젝트의 주요 참여주체인 발주자, CMr, 설계자, 시공자의 균형적인 시각을 바탕으로 한 성과측정 항목의 필요성을 제기 하고자 한다. 건설프로젝트의 주요 참여주체인 4자(발주자, CMr, 설계자, 시공자)의 협력관계를 살펴본 뒤 각 주체에 따라 성과항목에 대한 인식차이가 있다는 것을 검증하였다. The production process of construction industry is different from thing of the general manufacturing, likewise various participants make temporary teamwork for success of the project through sharing of information. But, the each role of participants is Individually changed to step in construction process stage and moreover it has complicated, entangled interests. The CM(so it called Construction Management as an abbreviation word) system was inducted for the effective management and operation of construction project. The key of the CM success depends on the cooperative relationship relation to major participants. There are lots of studies and efforts for the performance measures of the CM, however existing performance index is only measured as the viewpoint of project owner. Therefore it needs to make up for balanced view through combination of the four-way view of participants. In this study, we should search for cooperative relationship of project participants, and then we should suggest to define the difference of project in their viewpoints.

경도인지장애 노인 여성의 인지기능이 보행 능력 및 일상생활 체력에 미치는 영향

안은진(An, Eun-Jin) 한국체육과학회 2023 한국체육과학회지 Vol.32 No.1

성별과 세대에 따른 부모됨의 동기 및 저출산 현상에 대한 인식

안은진(Ahn Eun-Jin),최효진(Choi Hyo-Jin),유계숙(Yoo Gye-Sook) 가정과삶의질학회 2007 가정과삶의질연구 Vol.25 No.6

일반 근로자와 불규칙 근무 직종 근로자의 일-가족 갈등, 직무스트레스, 가족친화제도 이용에 대한 차이 연구

안은진 ( Eun Jin Ahn ),유계숙 ( Gye Sook Yoo ) 한국가족관계학회 2009 한국가족관계학회지 Vol.14 No.3

서울지역의 흡연자와 비흡연자의 식이 패턴 및 흡연 행동 특성에 관한 연구

신경옥,안은진,최경순,정근희,Shin Kyung-Ok,An Eun-Jin,Choi Kyung-Soon,Chung Keun-Hee 동아시아식생활학회 2006 동아시아식생활학회지 Vol.16 No.1

The traditional Korean diet, which is high in rice and vegetables, is fast being replaced by a Western style diet as the standard of living goes up. In addition to this, cigarette smoking has taken on serious proportions, especially amongst those of the younger generation. Because Seoul (and it's surrounding areas) is the hub of Education and Business, it is densely populated and heavily polluted Consequently health-related issues and diseases are starting to resemble those prevalent in Western communities. Historically, stomach cancer was the #1 killer-disease in Korea, but nowadays lung cancer ranks either 1st or 2nd on the list of killer-disease in Korea. This is presumably due to the lethal combination of heavy smoking and pervasive air pollution. Despite these disquieting facts, almost no study had been made of the nutritional patterns and dietary habits of smoking and non-smoking young adults in the Seoul area. Therefore the purpose of this study is to compare the dietary and nutritional patterns of young smokers with those of young non-smokers in and around Seoul. This is done with regards to their eating habits and lifestyles, as well as the dietary components that contribute towards maintaining good health. The results showed that compared to non-smokers, smokers manifested irregular eating patterns and also tended to overindulge on fast- or junk foods. In contrast to this, non-smokers enjoyed a healthier diet, which was high in brown rice, grains, legumes, fresh fruit and vegetables, and 'kimchi'. Amongst the male subjects of this study, it was found that smokers consumed significantly less vitamin $B_2$, calcium, and phosphorous than non-smokers. It was also established that in general, stress-generated smoking habits were formed during the high school years of the younger generation. In conclusion: Because smokers maintain a less healthy diet and life-style, it is to recommended that a 'Health Education Program' be developed which could guide young smokers into adopting better dietary habits and life styles.

아로마 마사지요법이 초산모의 정상분만에 미치는 영향

홍상진 ( Sang Jin Hong ),안은진 ( Eun Jin An ) 대한한방신경정신과학회 2006 동의신경정신과학회지 Vol.17 No.1

Objective: As this is a quasi-experimental study by the post-test design for a nonequivalent control group, it was attempted to verify the effect of massage using aroma oil on whether or not the normal vaginal delivery of primiparous mothers. Methods : As for the experimental treatment, it applied the aroma oil massage to the experiment group when the cervical dilatation was 4∼5cm, and as for the data analysis, it conducted the significance test using the program of SPSS 12K for Windows, with Chi-square test (x²) and t-test. Results : The experiment group that carried out the aroma massage therapy, was high in the cases of normal vaginal delivery(P<0.05), compared to the control group that did not carry out the aroma massage therapy. Conclusion : The experiment group, which received the aroma massage therapy, had significant difference in the cases of normal vaginal delivery, compared to the control group that did not receive the aroma therapy, thus the aroma massage therapy is thought to be a nursing-intervention plan, which can be usefully applied as to the primiparous mothers aiming at normal vaginal delivery.

가스확산층을 통과하는 반응가스 우회유동이 고분자 연로전지의 성능에 미치는 영향

조중원(Cho, Choong-Won),안은진(Ahn, Eun-Jin),이승보(Lee, Seung-Bo),이원용(Lee, Won-Yong) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.11

A serpentine channel geometry often used in a polymer electrolyte membrane fuel cell has a strong pressure gradient between adjacent channels in specific regions. The pressure gradient helps some amount of reactant gas penetrate through a gas diffusion layer(GDL). As a result, the overall serpentine flow structure is slightly different from intention of a designer. The purpose of this paper is to examine the effect of serpentine flow structure on current density distribution. By using a commercial code, STAR-CD, a numerical simulation is performed to analyze the fuel cell with relatively high aspect ratio active area. To increase the accuracy of the numerical simulation, GDL permeabilities are measured with various compression conditions. Three-dimensional flow field and current density distribution are calculated. For the verification of the numerical simulation results, water condensation process in the cathode channel is observed through a transparent bipolar plate. The result of this study shows that the region of relatively low current density corresponds to that of dropwise condensation in cathode channels.

사행유로를 갖는 고분자연료전지내부에서 가스확산층을 통과하는 반응가스 우회유동에 대한 연구

조중원(Choong-Won Cho),안은진(Eun-Jin Ahn),이승보(Seungbo Lee),윤영기(Young-Gi Yoon),이원용(Won-Yong Lee) 대한기계학회 2009 大韓機械學會論文集B Vol.33 No.4

A serpentine channel geometry often used in a fuel cell has a strong pressure gradient between adjacent channels in specific regions. The pressure gradient helps some amount of reactant gas penetrate through a gas diffusion layer(GDL). As a result, the overall serpentine flow structure is slightly different from the intention of a designer. The purpose of this paper is to examine the effect of serpentine flow structure on current density distribution. By using a commercial code, STAR-CD, a numerical simulation is performed to analyze the fuel cell with high aspect ratio of active area. To increase the accuracy of the numerical simulation, GDL permeabilities are measured with various compressive forces. Three-dimensional flow field and current density distribution are calculated. For the verification of the numerical simulation results, water condensation process in the cathode channel is observed through a transparent bipolar plate. The result of this study shows that the region of relatively low current density corresponds that of dropwise condensation in cathode channels.

거동장애노인을 위한 신체자극 복합 체조 프로그램 개발 및 효과

김설향(Kim, Seol-Hyang),안은진(An, Eun-Jin) 한국사회체육학회 2015 한국사회체육학회지 Vol.0 No.59

The purpose of this study is to provide a gymnastics program to seniors suffering from mild dementia and walking problems. For twenty four weeks, twenty eight seniors suffering from mild dementia and walking problems exercised with this new gymnastic program. The study subjects exercised, using this program three times per week. As a result, the movement index after the gymnastic program came out to be 46.78±17.86, higher than the score 38.35±21.7. The difference came out to be<SUP>*</SUP>p<.05, <SUP>**</SUP>p<.01. The left hand grasping power increased to 20.28 from 18.48; the average difference was <SUP>*</SUP>p<0.5. The right arms strength increased to 20.16 from 18.37, although this difference did not count statistically important. The cardiovascular endurance increased to 186.11 from 160.5. And, this difference was <SUP>*</SUP>p<.05, statistically meaningful.