• Title/Summary/Keyword: material well-being

검색결과 487건 처리시간 0.023초

갓 형상에 따른 폴리머 현수애자의 열화특성 (Performance of Polymer Suspension Insulator with Shed Profile)

  • 조한구;이운용;강성화;임기조;여학규;지원영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.539-542
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    • 2003
  • Recently, the polymer insulators which are being used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination which lead to the well known phenomenon of dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. The shape design of porcelain insulator is formalized but design standard for polymer insulator is no standardized up to now, much research is necessary in real condition. In this paper, the aging property of polymer insulator with shed shape(regular, alternative type) is analyzed through numerical analysis, CEA(canadian electricity association) tracking wheel test and IEC 61109 Annex C.

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유한요소법을 이용한 분말야금 공정 해석 및 설계 (Analysis and Design of Powder Metallurgy Process using Finite Element Method)

  • 권영삼;이민철;정성택;정석환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 춘계학술대회 논문집
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    • pp.241-244
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    • 2005
  • Though the history of finite element analysis in field of powder metallurgy is not short, industrial engineer is still being dependent on the trial and error approach based on engineer's experience in selecting process conditions. This problem is mainly due to the difficulty in establishing models for the behavior of a powder compact during compaction and sintering as well as finding material parameters for the models and the absence of CAE software with which industrial engineer can easily investigate the effect of process conditions on the quality of product. Therefore, we established very simple and cheap procedure to find material parameters for powder compaction behavior and implemented it in self-developed commercial CAE software for powder metallurgy, PMsolver. Basically, the development strategy of PMsolver lies on simplification and convenience so as for industrial engineers to use it with least training. Using PMsolver, optimal process conditions were found for some geometry and powders. Prior to process condition design, the accuracy of finite element analysis was verified.

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화학물질 유해성에 대한 작업자와 관리자들의 인식 (Perception of Workers and Managers for the Chemical Hazard)

  • 조용민;김희정;최재욱
    • 한국산업보건학회지
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    • 제22권4호
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    • pp.293-300
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    • 2012
  • Objectives: In chemical hazard communication, information receiver's perception is a important factor, but the study on the perception was few. Therefore, this study evaluated the perception of managers and workers group about chemical hazard communication by chemical hazard communication tools that were being used in fields. Methods: 91 managers and 238 workers were surveyed in two companies where use chemicals. All subjects were asked about the comprehensibility and perception for MSDS and GHS Pictograms being used in their workplaces through face-to-face interviews. Results: Most of the respondents knew MSDS, and more than half of the respondents had used MSDS once or more per year. The level of use to find the information on chemicals with MSDS was higher in the managers in comparison with workers. Also, the managers could understand and find the information on MSDS easier(p < 0.05). In the question asking the meaning of GHS Pictograms, the managers responded more correctly, as well(p < 0.05). 86.8% of the managers and 62.6% of the workers were conscious of the possible health hazards of chemicals that they could be exposed at work. However, among the respondents conscious of the health hazards, only less than 70% were well aware of the contents of the health hazards correctly. Conclusions: In chemical hazard communication, it is very important to evaluate whether information receiver have proper and correct knowledge and perception or not and actions based on the evaluations as well as provide correct information.

영유아 행복을 위한 부모역량 실태 (The Current Status of Parental Capacity for Children's Happiness)

  • 장혜진;윤은주
    • 한국보육지원학회지
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    • 제10권2호
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    • pp.295-317
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    • 2014
  • 본 연구는 영유아 부모역량 제고를 위하여 영유아의 행복이라는 관점에서 부모역량 Self-checklist 를 개발하여 영유아 행복을 위한 부모역량 현황을 조사하였다. 연구방법으로 관련 선행연구 고찰을 바탕으로 학계 전문가, 유치원 어린이집 교사, 영유아 부모, 유아를 대상으로 면담을 실시하였으며 Self-checklist 최종 문항 선정을 위해 48인의 델파이 조사를 실시하였다. 부모역량 현황 조사를 위해 전국단위 지역별로 할당하여 영유아 부모 1,000명을 대상으로 조사를 실시하였으며 모 580명, 부 420명이 참여하였다. 부모역량 현황을 살펴보면 유형면에서는 인식, 실행, 성장역량 순으로 높게 나타났으며 내용면에서는 영유아 발달과 건강과 안전 영역 점수가 높았고 생활지도나 지역사회 연계가 가장 낮게 나타났다. 부모 관련 변인별로는 모든 측면에서 모에 비해 부의 역량이 낮았으며 전반적으로 부모 연령이 낮을수록, 부모 학력이 높을수록, 소득수준이 높을수록 부모역량이 높은 것으로 나타났다.

고도불포화지방산 생합성: 식물에서의 대사공학적 응용 (Biosynthesis of Polyunsaturated Fatty Acids: Metabolic Engineering in Plants)

  • 김순희;김소연;김종범;노경희;김영미;박종석
    • Journal of Applied Biological Chemistry
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    • 제52권3호
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    • pp.93-102
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    • 2009
  • Polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have significantly beneficial effects on health in relation to cardiovascular, immune, and inflammatory conditions and they are involved in determining the biophysical properties of membranes as well as being precursors for signaling molecules. PUFA biosynthesis is catalyzed by sequential desaturation and fatty acyl elongation reactions. This aerobic biosynthetic pathway was thought to be taxonomically conserved, but an alternative anaerobic pathway for the biosynthesis of PUFA is now known to contain analogous polyketide synthases (PKS). Certain fish oil can be a rich source of PUFA although processed marine oil is generally undesirable as food ingredients because of the associated objectionable flavors that are difficult and cost-prohibitive to remove. Oil-seed plants contain only the 18-carbon polyunsaturated fatty acid alpha-linolenic acid, which is not converted in the human body to EPA and DHA. It is now possible to engineer common oilseeds which can produce EPA and DHA and this has been the focus of a number of academic and industrial research groups. Recent advances and future prospects in the production of EPA and DHA in oilseed crops are discussed here.

폐석분 함유율에 따른 최적의 콘크리트 탄성계수 추정 (Presumption of Optimum Concrete Elastic Modulus according to Content of Crushed Stone Powder)

  • 박도경;양극영
    • 한국건축시공학회지
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    • 제6권1호
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    • pp.101-107
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    • 2006
  • While a Study with regard to the measurement on Concrete Strength and the Change of Drying Shrinkage in accordace with Content Ratio of Crushed Stone Powder, it is being analyzed as the result that the strength according to Content Ratio of crushed Stone Powder is somewhat lowering. Accordingly, it is the real situation that the Concrete mixed with Crushed Stone Powder is utilized for non-structural material, not for the structural material. Therefore, this Research willing to furnish the suitable utilizing scheme for construction site as well as practical life by means of conduct the experiment on both Concrete Pressure Strength according to mixture with Crushed Stone Powder and Elastic Modulus, it also presumes the optimum Elastic Modulus Equation after analysis of comparison with common concrete strength. As the result of the experiment, in case of the Content Ratio of Crushed Stone Powder is less than 5%, it did not display a big difference in its both strength and matter-property compare with common concrete. In case of Elastic Modulus, when the Pressure Strength is 50% and 40% respectively, the Elastic Modulus Equation accords very well with the provided condition of Quadratic function, and as the result of the Presumption on Elastic Modulus according to Content of Crushed Stone Powder, in case the Pressure Strength is 50%, Elastic Modulus Equation showed that Error Ratio of Cubic function is at degree of 0.0005%, in case the Pressure Strength is 40%, Elastic Modulus Equation was accorded well with the value of the experimental data likely as the Error Ratio of Cubic function is at the degree around 0.0034%, respectively.

옥상조경용 경량 토양의 혼합비와 토심이 3가지 자생초화류의 생육에 미치는 영향 (Effects of Light-Weight Soil Mixture and Depth on the Three Native Plants in Extensive Roof Garden)

  • 김명회;방광자;주진희;한승원
    • 한국조경학회지
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    • 제31권1호
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    • pp.101-107
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    • 2003
  • Focusing on native plants that have a high possibility of being introduced as extensive rooftop material, this study was conducted to realize extensive and easy-to-manage rooftop gardens and to raise the utilization of native plants by verifying their growing response to soil media and depth. Its result is as follows: 1) In the case of Chrysanthemum zawadskii, the top growth was better in sandy loam than in P$_1$V$_1$P$_2$, and P$_1$V$_1$P$_3$, but the mortality rate was high, making it unsuitable soil. Regarding soil depth the mortality rate was lower in 10cm than in 5cm, and it grew well in 10cm. When using it for rooftop gardens, it would be desirable to keep the minimum viable soil depth over loom. 2) In the case of Sedium middendorffianum the mortality rate was 0% regardless of soil media and depth making it very suitable material for rooftop garden. Although the flowering rate was somewhat lower in P$_1$V$_1$P$_2$, and P$_1$V$_1$P$_3$ than in sandy loam, the mortality rate was low and the root growth was good. Therefore, provided that fertilizing is managed well, it is a plant that can be highly utilized. 3) In the case of Allium senescens, the mortality rate was 0% regardless of soil or soil depth, making it a very suitable plant for extensive rooftop gardens. Although top growth was poorer in P$_1$V$_1$P$_2$, and P$_1$V$_1$P$_3$than in sandy loam the root growth was good. Therefore, provided that fertilizing is managed well, it is a plant that can be highly utilized. In conclusion the study revealed that suitable species for extensive rooftop gardens are Sedium middendorffianum and Allium senescens. However, Chrysanthemum zawadskii can be utilized greatly when fertilizing is managed regularly in artificial mixed soil over l0cm.

농산 부산물인 밤껍질을 이용한 버섯균의 배양 (Cultivation of Several Mushrooms Using Chestnut Peels as an Agricultural By-product)

  • 이상선;이정우;홍성운;조남석
    • Journal of the Korean Wood Science and Technology
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    • 제27권2호
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    • pp.78-86
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    • 1999
  • 농산 부산물인 밤껍질을 이용하여 버섯균의 배양 및 재배실험을 통하여 버섯재배에 관련된 기초자료를 얻고자 실시하였으며, 특히 밤껍질을 이용한 느타리 및 표고버섯 재배를 중심으로 재배특성을 고찰하였다. 밤껍질의 내피는 외피 비하여 영양이 많은 관계로 곰팡이에 의하여 많이 오염되었으나, 균사의 생장은 좋았다. 밤껍질외피는 내피에 비하여 리그닌 함량이 높았으며, 균사의 성장은 불량하였는데, 이는 버섯생장에 필요한 영양성분이 부족하기 때문인 것으로 판단된다. 느타리와 노루궁뎅이 버섯은 밤껍질의 내피에서 잘 성장하였고, 자실체도 잘 형성되었다. 표고의 경우는 균사의 성장은 잘 되었으나, 자실체 형성은 좋지 않았다. 밤껍질외피에서 균사성장이 불량한것은 mineral 성분의 부족이 원인인 것으로 생각되며, 톱밥, 미강 및 mineral 등 다른 기질 첨가로 버섯재배가 가능하였다. 기질에서 버섯균의 성장을 $CO_2$ 생산량으로 조사하였는바 표고와 느타리의 성장은 기질에 따라 다소 다른 면을 보였다. 본 연구의 결과로부터 밤껍질내피는 그대로 버섯재배에 사용할 수 있었으며, 밤껍질외피에도 적절한 영양원을 첨가한다면 버섯균사 배양 및 재배에 사용 가능한 것으로 판단된다.

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무대 의상에 나타난 블랙의 미적 특성 - 뮤지컬 '시카고'를 중심으로 - (The Study on the Aesthetic Characteristics in Black Shown in Stage Costume - Focused on Musical 'Chicago' -)

  • 한나라;김영삼
    • 복식문화연구
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    • 제18권6호
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    • pp.1291-1304
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    • 2010
  • This study examined that the black dress is the one of having aesthetic value as well as symbolism while delivering specific image, from the perspective of color, which is essential element in forming design of the Stage Costume. This study carried out the theoretical research of centering on the literature consideration and the empirical research of centering on a case side by side. It analyzed the works and design based on the clothing, which had been performed in Korea with a revival version of Musical 'Chicago'. Aesthetic characteristics in more than two are being shown in one dress. If so, the following are the results that considered on aesthetics characteristics in black, which were shown in Stage Costume of Musical 'Chicago', which is increasing the theme consciousness through Stage Costume, which is simple and sexy black. First, as emotion of coming to stay in agony and sadness on the basic fact called death, the Stage Costume in black led to being shown sorrow of implying death, fear and murder. Second, the dignity, which corresponds to noble beauty in the aesthetic category, expresses dignity and elegance with flat material in black, and is revealed the aspect of expressing fashion, which emphasized spirit rather than body. Third, as the aesthetic characteristic of causing sexual desire, the sensuality was shown, which has the aspect of being expressed through exposure, concealment and emphasis. Fourth, it was expressed with androgyny, which evokes androgynous image. Fifth, black in Musical 'Chicago' formed the whole mood with a sense of weight by arranging the whole feeling with color in similar tone, thereby having been indicated the harmony of being formed with theme, which is aimed to be indicated in drama.

잣기름 성분분석 및 비만 예방효과 연구 (Analysis of Pine Nut Oil Composition and Its Effects on Obesity)

  • 김경곤;강윤환;김대중;김태우;최면
    • 한국식품과학회지
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    • 제46권5호
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    • pp.630-635
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    • 2014
  • 본 연구에서는 성분분석을 통해 품질이 확인된 PNO의 항비만효과를 세포수준에서 확인하고 기능성소재로서의 연구 가능성을 제시하고자 수행하였다. 그 결과 PNO는 기존에 알려진 바와 같이 linoleic acid, oleic acid, pinolenic acid, 및 palmitic acid가 분석되었으며 정량을 위한 표준물질인 undecanoic acid의 함량을 기준으로 확인한 결과 linoleic acid 43.4%, oleic acid 25.7%, pinolenic acid로 예측되는 11번 unknown peak 12.8%, palmitic acid 5.2% 및 다수의 미량 성분을 함유하고 있었다. 세포독성 실험을 통해 0.2 mg/mL 농도 까지 독성이 관찰되지 않음을 확인하였으며 그 이상의 농도에서도 PNO보다는 용매 DMSO에 의한 독성이 관찰되었다. PNO를 이용하여 항비만 효과에 대한 잠재적 기능 및 기전을 연구하기 위해 Oil Red O staining, $PPAR{\gamma}$ 및 aP2 mRNA 발현 확인 그리고 leptin의 분비량 측정을 진행하였다. 그 결과 PNO는 MDI solution 처리를 통해 분화가 유도된 mature adipocyte에서 지방적(lipid droplet) 형성을 유의하게 억제하는 것을 확인할 수 있었으며 이는 PNO가 항비만 활성에 잠재적으로 기능을 할 수 있음을 의미한다. 또한 $PPAR{\gamma}$와 aP2 mRNA 발현을 확인한 결과, 두 유전자가 유의한 수준으로 MDI control 대비 감소하는 반면 SREBP-1c, $C/EBP{\alpha}$, glucokinase, phosphoenolpyruvate carboxykinase 및 perilipin에는 영향이 없는 것을 확인할 수 있었다(data not shown). RT-PCR 결과는 PNO의 처리가 지방대사 및 축적을 단백질 및 유전자 발현조절 기전에 의해 억제할 수 있음을 제시하여 주며, 추가적인 연구가 필요함을 시사한다. 마지막으로 확인한 PNO의 leptin 방출유도 실험을 통해 leptin이 PNO의 처리에 의해 농도 의존적으로 방출량이 증가됨을 확인할 수 있었다. Leptin은 식욕억제 효과가 있는 호르몬으로 잘 알려져 있다. 이는 PNO가 기존에 알려진 cholecystokinin과 glucagon like peptide-1 (GLP-1)의 분비증가를 통해 식욕을 억제할 뿐만 아니라 leptin의 방출을 유도하여 추가적인 식욕억제작용을 유도할 수 있음을 의미한다. 위의 연구결과를 종합하면 PNO는 불포화지방산이 다량 함유된 우수한 식물성유지이며 기능적으로 항비만 효능을 잠재적으로 가지는 우수한 소재임을 확인할 수 있었다. 따라서 본 연구결과를 기초자료로 하여 효과적인 기능성 식품 및 소재의 개발을 위해 체계적이고 과학적인 연구가 필요할 것으로 판단된다.