• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.9
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• pp.895-903
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• 2001

Evaporation cooling phenomena of droplets containing fire suppression agents on a hot metal surface were experimentally investigated. Solution of water containing potassium acetate (30-50% by weight) and sodium bromide (10-30% by weight) were used in the experiments, and surface temperatures were ranged from 70-116$^{\circ}C$. The evaporation time of the droplet on the heated surface was determined by using frame-by-frame analysis of the video records. It is found that the apparent evaporation time is shorter in turns of pure water, sodium bromide solution and potassium acetate solution. However, the time averaged heat flux is higher in turns of pure water, sodium bromide solution and potassium acetate solution. In-depth temperature variation of the hot metal does not occur significantly by the kinds of additive.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.300-302
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• 2001

폴리카본산계 기능성 고분자를 합성해서 고성능 감수제 원료로 활용하여 고유동화 혼화제를 개발하고자 한다. 폴리카본산계 기능성 고분자를 합성한 후, 이를 고유동, 고강도 혼화제 원료로의 제반 물성을 확인하고, 이를 현장에 적용하여 현재의 제품을 획기적으로 개선하고, 혼화제 품질의 우위성을 확보하기 위해 1) 시멘트 및 골재 표면에서의 적절한 계면활성을 갖는 분자설계를 하였으며, 2)분자량의 조절 기술의 개발을 개발하였다. 합성에 있어서 첫째, 시멘트 및 골재 표면에서의 적절한 계면활성을 갖는 분자설계와 둘째, Mw 5,000정도의 분자량을 갖는 감수제의 합성기술을 개발하였다. 이렇게 제조된 고성능 유동화제의 화학구조 해석을 해석하고 분자량 및 분자량 분포를 측정한 다음, 시멘트 페이스트의 유동성, 점도, 슬럼프로스 등을 측정하여 고성능 유동화제의 성능인 시멘트 페이스트의 유동성을 시험하였다. 그 결과 고유동성을 갖는 것과 장시간 안정한 유동성을 나타내었으며, 경과 시간에 따른 겉보기 점도변화를 측정한 결과 점도의 상승이 초기에 일어나다가 시간의 경과에 따라 점도가 감소하는 경향을 나타내었다. 따라서 경과시간에 따른 유동성 손실을 억제할 것으로 기대한다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.322-327
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• 2002

산화성고체는 우리 생활에 아주 유용한 화학물질로서, 표백제, 화약류, 산소발생제, 화공품, 합성 원료, 농약등의 여러 방면에 사용되고 있다. 한편, 반응성이 큰 것이 많고, 단독으로 또는 가연물과의 혼합에 의해서 폭발성 또는 폭발적 연소성을 가지는 경우가 있다. 이러한 위험성을 바르게 인식하고 안전한 취급을 하는 것 이산화제로 인한 사고를 예방하는데 중요한 요인이 된다.(중략)

• Horticultural Science & Technology
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• v.18 no.6
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• pp.827-833
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• 2000

This study was carried out to investigate the effect of plant growth retardants (daminozide, chlormequat, uniconazole, paclobutrazole) and fungicides of triazole chemical (hexaconazole, microbutanil, difenoconazole, terbuconazole, bitertanol) on the growh of 'New Guinea' impatiens. Plant height and canopy were decreased by all kinds of plant growth retardants tested in both 'Anguilla' and 'Papete'. Especially, uniconazole and paclobutrazole were most effective in inhibition of top growth. However, the content of chlorophyll increased at all treatments of plant growth retardants and stem diameter tended to be increased at the highest concentration of all kinds of plant growth retardants tested. The results in all cultivars tested, with the experiment of triazole fungicides, were similar to the results of experiment with plant growth retardants. These results suggest that fungicides of triazole chemical such as hexaconazole, microbutanil, difenoconazole, terbuconazole and bitertanol can be used for the promotion of quality in potted 'New Guinea' impatiens.

• Journal of Food Hygiene and Safety
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• v.3 no.2
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• pp.83-88
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• 1988

Propyl gallate used as an antioxidant was examined for its effects on murine Immune system and metbemoglobin content treated with anillne. As immunotoxicology assay parameters, we adopted circulating leukocytes and immunoorgan weights for pathtoxicology, IgM plaque forming cells and Artbus reaction for humoral immunity. Propyl gallate's effects were observed as follows; 1. Propyl gallate decreased circulating leukocyte counts, dose dependently. 2. Relative immunoorgan weigbts were not affected. 3. Propyl gallate diminisbed IgM PFCs/spleen cell and IgM PFCs/spleen. 4. Propyl gallate decreased Arthus reaction. 5. Propyl gallate did not affect metbemogiobin content treated wltb aniIIne.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.595-600
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• 1997

To extend the shelf-life of Kochujang, the effects of anti-browning agents and their optimum concentrations were evaluated using organic acids as synergists. Among the physicochemical analyses, amino nitrogen content exhibited the highest correlation with sensory score. Ascorbic acid and citric acid were selected among the anti-browning agents(ascorbic acid, potassium sorbate, calcium chloride) and organic acids(citric acid, lactic acid, oxalic acid) tested on the basis of the highest amino nitrogen content during storage at 55$^{\circ}C$. The appropriate concentration of ascorbic acid was 0.03% based on amino nitrogen content during storage at 55$^{\circ}C$. Combination of 0.06% citric acid with 0.03% ascorbic acid showed the highest amino nitrogen content during storage at 55$^{\circ}C$. From the results, the 0.03% ascorbic acid and 0.06% citric acid were selected as additives for extending the shelf-life. Control(no additive) and additives(0.03% ascorbic acid and 0.06% citric acid) were tested for physicochemical and sensory analyses during storage at 45$^{\circ}C$ and 55$^{\circ}C$. Amino nitrogen content was also highly correlated with sensory score, The marginal amounts of amino nitrogen for control and additives were 174.9mg% and 173.2mg%, respectively. Degradation rate of amino nitrogen was a first order reaction. Compared to control, the predicted shelf-life for adding additives increased 69% and 56% at 45$^{\circ}C$ and 55$^{\circ}C$, respectively.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.405-410
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• 2004

This study was performed to investigate the antioxidative activity of soybean products extracts using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and thiobarbituric acid (TBA) method for application of animal products. All three extracts (natto, soybean paste, soybean milk extract) were found to have an ability to donate hydrogen to DPPH. Especially, natto and soybean paste extract were more effective than that of soybean milk on the antioxidative activities. Natto and soybean paste extract were stronger than butylhydroxy toluene (BHT), butyl hydroxyl anisole (BHA) (5${\times}$10$^{-4}$ M) and ascorbic acid (5.7${\times}$10$^{-3}$ M) previously well known as antioxidants. These extracts also showed a synergistic effect. TBA values of natto (45.8％) and soybean paste extract (45.2％) were stronger than that of soybean milk extract (33.6％). These results suggest that soybean product extracts have antioxidative activities and synergistic effects.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.409-411
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• 2017

미사일 추력기 체계에 적용되는 하이드라진[$N_2H_4$]추진제는 MSDS-OHS 유해성 분류상 급성독성 물질로서 사용이 제한되고 있는 바, 다양한 대체물질이 개발 중이다. 최근 해외에서 안전성과 취급이 우수한 질산 히드록실암모늄[$NH_3OHNO_3$]과 암모늄 디나이트라마이드[$NH_4N(NO_2)_2$] 기반 단일계 액상추진제가 개발중이며, 이 물질들을 이용한 추력기 시스템 적용 시험이 진행되고 있다. 그러나 저온에서의 연로물질 산성화 반응으로 인한 디나이트라마이드[$N(NO_2)_2{^-}$] 물질의 분해는 나이트레이트[$NO_3{^-}$] 이온 생성을 촉진시키며, 부수적으로 발생하는 침전물은 촉매 및 노즐의 막힘 현상을 유발하므로 추력기 성능의 저해요인으로 작용한다. 그러므로 저온분해 방지를 위한 첨가제 조성 개발 및 열분해 특성 연구가 최근의 관심사이다. 본 연구는 합성/정제/추출한 암모늄 디나이트라마이드 산화제를 주요 조성물로 적용하였으며, 염기성 안정화제를 질량비율 4~5% 첨가하여 산성화 반응을 억제시킨 단일계 액상추진제(KMP) 형태로 제조하였다. 합성한 추진제는 시차주사열량계(DSC)를 이용하여 분해온도를 측정하여 열안정성을 평가해보았다.

• Journal of the Korean Applied Science and Technology
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• v.9 no.2
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• pp.175-179
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• 1992

In order to investigate the effect of tannic acid and ${\alpha}$-tocopherol on methyl linoleate autoxidation and on inhibition activity of lipoxygenase in phospholipid, the rate of formation of methyl linoleate hydroperoxide was measured by HPLC. The reaction mixture contained methyl linoleate 70mM, radical initiator AMVN 0.7mM, tannic acid and ${\alpha}$-tocopherol 0.7mM, each, in a mixture of hexane/isopropanol(1 : 1, v/v). Under this reaction condition, tannic acid was good enough antioxidant. The tannic acid and ${\alpha}$-tocopherol for the inhibition activivity of lipoxygenase were measured at the reaction conditions: phospholipid $1{\mu}M$. tannic acid and ${\alpha}$-tocopherol were reacted as an inhibitor of lipoxygenase in phospholipid, especialy in phosphatidy lcholine.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.6
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• pp.353-355
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• 2000

The seasonal occurrence of aphids was investigated in the soybean Held to increase the control efficiency of aphid vectors of Soybean Mosaic Virus. The patterns of aphids occurrence were different according to planting time. There were two peaks in late June and mid-August in aphid population in optimum seeding (May 20), whereas the peak was around mid-June in early seeding(Apr, 20). Acyrthosiphon solani was dominant Species in early seeding, while Aphis glycines was dominant in optimum seeding. In early seeding, SMV incidence increased rapidly between 20 June and 30 June, suggesting that virus spread was strongly correlated with increased colonization of aphids. Imidacloprid WP, benfuracarb EC and acephate WP showed a good effect for the control of aphids without phytotoxicity. In the plot with infurrow treatment of imidachloprid G until 52 days after shooting, aphids were controled effectively. Acephate WP was applied as a foliar spray at V4, V6, or V4/V6 stage and all the treatments were effective on reducing: SMV incidence.