• 항공우주시스템공학회지
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• 제17권1호
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• pp.51-58
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• 2023

별도의 점화원 없이 스스로 점화가 가능한 접촉점화 추진제는 부식성과 독성으로 인하여 취급의 어려움이 있다. 따라서 독성이 적거나 없는 친환경 접촉점화 추진제의 개발이 필요하며, 본 연구에는 친환경 접촉점화 추진제의 기초 연구를 수행하였다. 산화제로 95%의 과산화수소, 연료로 CNU_HGFv1를 사용하였으며 액적 낙하 시험, 점화 시험 및 연소 시험을 통하여 추진제의 점화 및 연소 특성을 확인하였다. 액적 낙하 시험 결과 점화지연 시간은 9.7ms 이며, 점화시험에서는 약 27ms로 추진제로 사용하기에 충분히 빠른 것을 확인하였다. 연소시험 결과 약 11.7bar에서 연소 효율 95.4~98.1%를 달성하였으며, 하드스타트 및 연소 불안정 없이 빠르고 안정적인 연소가 가능함을 확인하였다.

• 한국환경농학회지
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• 제33권3호
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• pp.155-163
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• 2014

BACKGROUND: Recent studies for heavy metal stabilization in soil were mainly focused on finding out new materials and its efficiency. But, such a stabilization method can cause disturbance to soil, leading improper environment for agriculture. The object of this study was to demonstrate the effect of the incorporation of green manure crops on heavy metal-contaminated soil. METHODS AND RESULTS: Soil contaminated with heavy metals was collected from the agricultural soils affected by the abandoned mine. Lime stone was selected and treated to contaminated soil. Three kinds of legume green manure crops; Alfalfa (Medicago sativa), Hairy vetch (Vicia villosa), Red clover (Trifolium pratense) were subsequently cultivated in greenhouse condition. It was found that lime stone increased soil pH and decreased the amount of heavy metal absorption by green manure. The application of green manure residues on soil increased soil pH and inorganic nitrogen. CONCLUSION: The C/N ratio of three green manures was low, indicating fast decomposition rate, resulting in nitrogen supplement, consequently. Considering the point that the soil was used for agricultural purpose, it was recommended that hairy vetch and red clover were preferred. Nevertheless, the heavy metal availability was also increased. Thus, it seemed that further study was needed to confirm that how long maintain a phenomenon.

• 대한지역사회영양학회지
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• 제13권6호
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• pp.829-839
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• 2008

The purpose of this study was to investigate the relation of the fast food and beverage intake on sociality and anger expression of adolescents. Questionnaires were distributed to the adolescents of 599 middle and high school students in Busan. According to the results, the preference-intake frequency analysis (PEA) on fast food grid, high preference and high intake frequency were 'dukbokki', 'chicken' and 'mandu' and low preference and high intake frequency were 'ramyon', 'gimbab. PEA on beverage grid, high preference and high intake frequency were 'milk-dairy product', 'fruit juice', 'isotonic beverage' and low preference and high intake frequency were 'carbonate drink'. The intake frequency of 'pizza', 'sandwich', 'udong', and 'dukbokki' had a positive relationship with sociality. 'Hamburger', 'chicken', 'french fry', 'gimbab', 'mandu', and 'ramyon' showed a positive relationship with anger-out. The intake frequency of 'carbonated drink' had a negative relationship with anger-control, but 'green tea' showed a positive relation with it. 'Carbonate drink', 'isotonic beverage', 'coffee', and 'milkshake' had a negative relationship with anger-out. The explanation power ($R^2$) of intake of fast food and beverage on sociality was $0.019{\sim}0.038$, and 'carbonated drink' and 'coffee' had a negative influence on sociality. The explanation power ($R^2$) of intake of fast food and beverage on anger expression was $0.011{\sim}0.041$, and 'carbonated drink' had a negative influence on angercontrol. 'Hamburger', 'carbonated drink', and 'coffee' showed a positive influence on anger-out. From these results, it was necessary to develop the practical eating-out habits program on proper fast food and beverage choice for adolescents.

• 한국전기전자재료학회논문지
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• 제27권3호
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• pp.178-183
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• 2014

Recently, various type of nanomaterials such as nanorod, nanowire, nanotube and their core/shell nanostructures have attracted much attention in photocatalyst due to their unique properties. Among them, Type-II core/shell heterostructures have extensively studied because it has exhibited improved electrical and optical properties against their single-component nanostructure. Such structures are expected to offer high absorption efficiency and fast charge transport due to their stepwised energetic combination and large internal surface area. Thus, it has been considered as potential candidates for high efficient photocatalytic activity. In this work, we introduce a novel chemical conversion process to synthesize Type-II ZnO/ZnSe core/shell heterostructures. A plausible conversion mechanism to ZnO/ZnSe core/shell heterostructres was proposed based on SEM, XRD, TEM and XPS analysis. The ZnO/ZnSe heterostructures exhibited excellent photocatalytic activity toward the decomposition of RhB dye compared to the ZnO nanorod arrays due to enhanced light absorption and the type-II cascade band structure.

• International Journal of Costume and Fashion
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• 제10권2호
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• pp.61-71
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• 2010

The purpose of this study was first, to examine the causes for the recent acceleration in the increase of textile/apparel waste and the current practices for reducing waste in the global textile and apparel industry; and second, to explore the influence of sustainability and social responsibility on fashion trends. Extensive literature on sustainable apparel and sustainable and socially responsible practices by global textile and apparel firms was reviewed in conducting this research. First, an accelerated fashion diffosion speed due to fast fashion was focused on as a cause for the increase in textile/apparel waste whereas mass customization was focused on as a potential solution for reducing waste. Then, the influence of the social trend toward sustainability and social responsibility on fashion trends was discussed, particularly the trends toward green products and recycled fashion, the trend against using real for or leather, and minimum-fabric-waste fashion in design and product development. This study furthers consumers' understanding of sustainability and social responsibility related to fashion trends and hopefully increases their consciousness in becoming socially responsible consumers. This study will also contribute to better decision-making in apparel and textile firms to produce sustainable fashion products.

• Carbon letters
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• 제10권2호
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• pp.123-130
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• 2009

Multi-elements doped $TiO_2$ was prepared as a new photocatalyst in order to decrease the band gap of $TiO_2$ by sol-gel process which can provide the large active sites of $TiO_2$. Multi-elements were doped by using a single precursor, tetraethylammonium tetrafluoroborate (TEATFB). By the benefit of large specific surface area of $TiO_2$ prepared by sol-gel process, catalysts showed initial fast removal of dye. The photoactivity showed that the doped catalysts significantly promote the light reactivity than undoped $TiO_2$. The commendable photoactivity of prepared catalysts is predominantly attributable to the doping of anions which may reduce the band gap.

• 한국전기전자재료학회논문지
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• 제31권7호
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• pp.486-489
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• 2018

Solution-processed organic light-emitting diodes (OLEDs) have the advantages of low cost, fast fabrication, and large-area devices. However, most studies on solution-processed OLEDs have mainly focused on solution-processable hole transporting materials or emissive materials. Here, we report fully solution-processed green OLEDs including hole/electron transport layers and emissive layers. The electrical and optical properties of OLEDs based on solution-processed TPBi (2,2',2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)) as the electron transport layer were investigated with respect to the spin speed and the number of layers. The performance of OLEDs with solution-processed TPBi exhibits a power efficiency of 9.4 lm/W. We believe that the solution-processed electron transport layers can contribute to the development of efficient fully solution-processed multilayered OLEDs.

• 한국광학회지
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• 제8권3호
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• pp.199-203
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• 1997

안구표면과 같은 미세구면의 변위를 알아내기 위하여 Twyman-Green 간섭계를 이용하였으며 반송무늬(carrier fringe)를 형성시켜 푸리에 변환법으로 미세구면의 변위분포를 측정하였다. 기준위치에서 일정한 반송무늬가 형성되도록 한 후 구면이 변화할 때 반송무늬의 변화방향을 관측하였으며, 반송무늬의 변화방향에 의해 구면의 변화방향을 알아내었다. 푸리에 변환법(Fourier transform method)을 이용하여 CCD카메라에서 받아들여진 한 장의 간섭무늬로부터 위상분포를 얻어내고 구면의 변위 분포를 계산하였다. 공간주파수 영역에서 변위에 대한 정보를 분리함으로써 간섭무늬의 배경분포 및 잡음을 제거하였으며, 구면의 변위에 대한 3차원 분포를 이론적인 계산값의 측정오차가 .lambda./10 이내에서 얻어내었다.

• 한국버섯학회지
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• 제12권2호
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• pp.132-137
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• 2014

균상느타리버섯에서 발생하는 곰팡이 병해 중에서 가장 많은 문제를 발생하는 것은 Trichoderma disease 또는 green mould 등으로 불리우는 푸른곰팡이병이다. 이 병은 Trichoderma, Penicillium, Aspergillus 등의 속(genus)에 포함되는 종들에 의해 발병되는 병을 총칭하는 것으로 발생빈도와 피해가 가장 큰 것은 Trichoderma 속의 병원균에 의해 발생하였다. 느타리버섯 균상에 분리된 병원균은 T. longibrachiatum, T. koningii, Trichoderma virens, T atroviride, T. hazianum, T. pseudokoningii 6종이었으며, 발생빈도가 높은 것은 T. virens, T. hazianum, T. longibrachiatum 3종이었고, 각각의 균은 배양적 특성 및 병원성도 각기 다른 특성을 보이고 있었다. T. longibrachiatum 균사생장이 매우 빠르고, 포자형성이 빠르며, 특히 후막포자형성이 잘되는 특성을 있으며, 후기에는 진한 녹색으로 변색된다. Trichoderma koningii는 균사생장은 빠르고, 공중균사가 많은 편이며, 포자는 공중균사에 밀집되어 형성된다. 특히 Trichoderma virens 같은 경우에는 포자형성에 의한 색깔변화가 느리며, 감염후기에 발견되어 그 피해가 심한 편이었다. Trichoderma atroviride. 균사생장은 보통이며, 포자형성은 공중균사에 드물게 형성되며, 후기에는 진녹색을 띤다. 이균의 특징은 coconut 냄새와 유사한 향기가 나는 것이다. T. hazianum은 초기에는 균사가 백색으로 매우 빠르고, 공중균사에 포자가 형성하며, 후기에는 진한 녹색으로 변색된다. 공중 균사에 형성된 포자는 육안적으로 pustules or tufts의 형태를 나타내었다. Trichoderma pseudokoningii 균사생장은 빠르며, 포자형성은 접종부위를 중심으로 형성되며, 후기에는 환무니를 형성하며, 특히 배지 색이 변색되고 후막포자 잘 형성되는 특징이 있었다.

• 동의생리병리학회지
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• 제21권2호
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• pp.425-431
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• 2007

The purpose of this study was to observe the effects of Achyranthes Radix(AR) and electroacupuncture(EA) in rats with rheumatoid arthritis induced by type II collagen for 28 days. Control group was daily administered 0.9% NaCl 0.5 $m{\ell}$, Group I was daily administered 0.9% NaCl 0.5 $m{\ell}$ to arthritic rats, Group II was orally administered with Achyranthes Radix 500 mg/kg 0.5 $m{\ell}$ to arthritic rats. Group III was given 2 Hz EA of chok samni acupoint(ST36) in the test group for 30 min/days to arthritic rats. Group IV was daily orally administered with Achyranthes Radix 500 mg/kg 0.5 $m{\ell}$ and 2 Hz EA of chok samni acupoint(ST36) in the test group for 30 min/days to arthritic rats. This studies have been designed to evaluate the hind paw edema, assessment of arthritis indices, analgetic effects by analysis of blood chemistry(WBC, CRP, ALP, AST). In each group, histologic observations, Safranin O-fast green stain were observed and analyzed. The following results were obtained. Group II, III, IV were significantly decreased arthritis indices and the rate of paw edema compared with Group I . Especially group IV was the most significantly decreased. The WBC, CRP, AST, ALT was that Group II, III, IV were significantly decreased compared with Group I . In conclusion, Achyranthes Radix and Ea contribute to the improvement of blood chemistry and change in safranin O-fast green by knee joint of arthritic rats.