• 한국태양에너지학회 논문집
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• 제34권1호
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• pp.98-104
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• 2014

Photovoltaic (PV) cell is considered as one of the finest ways to utilize the solar power. A study of improving solar cell's efficiency is important because the lifetime of solar cell is determined by photovoltaic module technology. Therefore, oxidation (and/or corrosion) of solder materials will be one of the primary yield and long-term reliability risk factor. Recently, the development of lead-free solder alloy has been done actively about lead-free solder alloys of the thermodynamic and mechanical properties. However, the oxidation behavior have rarely been investigated In this study, the oxidations of 60 wt% Sn-40 wt% Pb, 62 wt% Sn-36 wt% Pb -2 wt% Ag, 50wt% Sn-48 wt% Bi-2 wt% Ag alloys for the interconnect ribbon after exposure in atmosphere at $100^{\circ}C$ for several times were investigated. The wettability of 62 wt% Sn-36 wt% Pb-2 wt% Ag and 50 wt% Sn-48 wt% Bi-2 wt% Ag solders was also studied to compare with that of 60 wt% Sn-40 wt% Pb alloy. The results howed that the zero cross time and the wetting time of 50 wt% Sn-48 wt% Bi-2 wt% Ag solder were better than other two samples. The surface of tested samples was analyzed by XPS. The XPS result showed that in all samples, SnO grew first and then the mixture of SnO and $SnO_2$ was detected. $SnO_2$ grew predominantly for the long time aging. Moreover XPS depth profile analysis has found surface enrichment of tin oxide.

• 대한화장품학회지
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• 제42권2호
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• pp.145-152
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• 2016

피부의 가장자리에 위치한 표피는 개체의 생존에 절대적으로 중요하며, 기저막에 위치한 표피줄기세포에 의해 평생 끊임없이 재생되고 있다. 표피줄기세포는 한정된 세포분열을 진행하고 각질세포로 분화하는 transit amplifying (TA)세포를 만들어 냄으로써 오랜 기간 재생에 필요한 많은 각질세포를 만들어 낼 수 있다. 본 연구에서는 표피줄기세포 세포분열 활성화 화합물로 목단으로부터 추출한 페오놀(paeonol)을 350여 개의 화합물들로부터 검색해 냈다. 이러한 세포분열 활성화 효능은 표피줄기세포 특이적으로 나타나며, 표피줄기세포의 지표로 알려진 p63 단백질의 발현 경향은 페오놀을 처리한 표피줄기세포에서 변화하지 않음을 유세포분석법으로 확인하였다. 콜로니형성 분석에서는 페오놀을 처리한 표피줄기세포가 1.3배 이상 더 나은 콜로니 형성능을 보여 주었다. 그리고 PCR array 분석을 통해서 페오놀의 효능은 여러 신호전달에 의해 나타남을 알 수 있었다. 이러한 결과들로부터 페오놀이 줄기세포성에 영향을 주지 않고 표피줄기세포의 재생능력을 향상시키므로 표피줄기세포 활성화 물질로서 화장품 소재로 적용될 수 있을 것으로 판단된다.

• 한국보건간호학회지
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• 제16권2호
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• pp.354-377
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• 2002

Aging population is a global trend and Korea is no exception. Due to the progress of the medical and scientific sectors, increase in the average lifetime incurred increase in the number of elderly people. Meanwhile, the family function of supporting the elderly has become a major issue in a society due to the changes in the society's structure and increased entry of the women into the workforce. As a means to substitute the protection of the elderly who are not protected at their respective homes and to replace the tending needs, weekly protection centers and short-stay centers for the elderly were established and operated in Seoul since 1992. However, structured and satisfactory services are not yet to be provided, thus this research intends to understand the current situation at the short-stay centers for the elderly, to identify users' characteristics and to conduct study on nursing need for the health reasons so that the results of the research can be utilized as basic data for the development of nursing care program. Towards this end, this research targeted 142 elderly people who were undergoing treatment at the 11 short-stay centers for the elderly out of total of 13 located in Seoul that were willing to cooperate. The research was conducted from April to May 2002, with the measurement tool developed by Rhee, Seon-ja (2001) to measure the level of nursing need. Then data was collected and analyzed using SPSS program. The results are as follows. The general characteristics of users of the short-stay centers for the elderly were: 123 females $(86.6\%)$, 19 males $(13.4\%)$ and 72 elderly were over the age of 80 $(50.7\%)$. Among these, 24$(16.9\%)$ were living by themselves. Among the illnesses that the subjects were inflicted with were: dementia $(54.2\%)$, stroke $(54.1\%)$ and high blood pressure $(50.7\%)$, in the respective order. Despite the fact that they were diagnosed with illnesses, $47.2\%$ responded that they do not undergo special treatment due to financial reasons. When the level of needs for nursing care among the elderly who use the short-stay centers is divided into informational. physical. and emotional need levels and scored between zero to two, the level of emotional need is the highest with 1.80, followed by physical (1.45) and informational (1.44) need levels. As for the realities of services at the centers and improvement areas, restriction on term was cited as the greatest inconvenience with $38.7\%$, followed by lack of budget (24 respondents, $16.9\%$). Wishful services were financial assistance $(46.5\%)$, medical and nursing services $(40.1\%)$, meal provision service $(8.5\%)$ and counseling service $(4.9\%)$, in the respective order. Based on the above mentioned results, the research identified the need to develop nursing program for the patients of dementia that can be applied onto the short-stay centers and the need to develop volunteer service, backed by societal support. Also, placement of specialized cadre of professionals is needed so that medical and nursing service functions can be provided in a complementary manner.