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        검색결과 16

        1.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The emergence of micropollutants in natural water sources due to the overuse of anthropogenic chemicals in industry and households has threatened the production of clean and safe tap water in drinking water treatment plants. Conventional physicochemical processes such as coagulation/flocculation followed by sand filtration are not effective for the control of micropollutants, whereas chemical oxidation processes (applying chlorine, permanganate, ozone, etc.) are known to be promising alternatives. Determining the optimum oxidant dose is important issue related to the production of disinfection by-products as well as unnecessary operating cost, and is made possible by simulations of target-micropollutant abatement based on kinetic model equation consisting of second-order rate constant (between the oxidant and the target) and oxidant exposure. However, the difficulty in determining oxidant exposure as a function of complex water quality parameters limits the field application of kinetic model equation. With respect to representative oxidants used in drinking water treatment plants, this article reviews two main approaches for determining oxidant exposure: i) direct measurement in situ and ii) prediction by empirical models based on key water quality parameters. In addition, we discussed research requirements to improve the predictive accuracy of the empirical models for oxidant exposure and to develop a rational algorithm to determine optimal oxidant dose by considering the priority of the target pollutants to be treated.
        4,800원
        4.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Industrial wastewater often contains a number of recalcitrant organic contaminants. These contaminants are hardly degradable by biological wastewater treatment processes, which requires a more powerful treatment method based on chemical oxidation. Advanced oxidation technology (AOT) has been extensively studied for the treatment of nonbiodegradable organics in water and wastewater. Among different AOTs developed up to date, ozonation and the Fenton process are the representative technologies that widely used in the field. Based on the traditional ozonation and the Fenton process, several modified processes have been also developed to accelerate the production of reactive radicals. This article reviews the chemistry of ozonation and the Fenton process as well as the cases of application of these two AOTs to industrial wastewater treatment. In addition, research needs to improve the cost efficiency of ozonation and the Fenton process were discussed.
        5,200원
        6.
        2016.10 구독 인증기관·개인회원 무료
        This study evaluated the physicochemical quality characteristics of raw and roasted beans of fully washed specialty Bourbon cultivar ofCoffea Arabica“BM 139" from seven of the major coffee growing areas in Rwanda in comparison with a wet processed Typica cultivar from Yirgacheffe, Ethiopia and a dry processed red Bourbon cultivar from Cerrado, Brazil. Tested samples had moisture content between 7.7 and10.2%. Raw coffee from Brazil had the lowest density and darker than samples from other regions. Other samples showed no significant differences in true density. Raw coffee from Kayumbu coffee washing station (CWS), Kamonyi district showed the lowest total phenolic content of 38.4 mg/g solid whereas raw coffee from Nyamyumba CWS, Rubavu district had the highest content of 46.8 mg/g solid. DPPH radical scavenging activity (RSA) ranged from 89.9 to 91.8% and varied little between samples. Raw coffee from Yirgacheffe, Ethiopia showed the highest total titratable acidity of 1.48% as citric acid and totalcaffeoylquinic acidof 82.62 mg/g solid whereas that from Brazil had the highest caffeine content of 18.5 mg/g solid. Raw coffee from Karenge CWS, Rwamagana district was characterized by having the lowest caffeine and trigonelline content (13.4 and 10.3 mg/g solid, respectively). After roasting, there was a drop in most physicochemical characteristics. Raw and roasted coffee samples from Rulindo and Kirorero CWS indicated higher bulk densities which might be due to higher altitudes of these two areas. Caffeine and RSA were not affected by the roasting process. The Brazilian coffee was characterized by higher caffeine content in raw as well as roasted forms. After roasting, coffees from Rwanda were more acidic than Brazilian and Ethiopian coffees. This study revealed that the physicochemical characteristics of the Bourbon cultivar may vary depending on the geographical sub-regions which is due to environmental conditions, processing and agricultural practices.
        7.
        1997.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Arthrobacter sp. L-3로부터 glucose isomerase의 생산성을 검토하였다. 배지의 탄소원으로는 glucose와 xylose를 혼합해서 공급한 것이 효소 생산성이 가장 높았다. 질소원으로는 yeast extract가 가장 높은 효소 생산성을 나타내었다. Glucose isomerase의 생산성은 배양시간이 40시간일 때 가장 높게 나타났다.
        4,000원
        8.
        1996.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        칡(Peuraria thunbergiana Bentham) 의 뿌리에서 추출한 조효소액을 황산암모늄으로 분획하고 이온교환 크로마트그래픽 및 겔여과에 의해 부분 정제하고 얻은 β-amylase의 효소학적 특성을 검토한 결과는 다음과 같다. 칡뿌리 β-amylase는 황산암모늄 0.4포화 이하의 획분에서 85% 이상의 활성을 나타내었으며, 가용성 전분을 기질로하여 maltose 를 생성하여 전형적인 β-amylase의 특성을 나타내었다. 또한 최적 pH, 최적 온도는 pH 6.0 및 50℃ 이었으며 pH 6.5∼7.0, 50℃이하에서 안정하였다. 기질농도에 대한 Km은 66.7mg% 이었으며 금속이온은 카드뮴, 알루미늄, 철, 은, 수은, 구리 등의 이온에 의해 효소활성이 저해되었다.
        4,000원
        9.
        1995.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This survey of 180 6th-grade students was focused on the differences of nutritional and anthropometric status according to calorie intakes. The results were summarized as followed: 1) All nutrient intakes of boys were higher than those of girls, and both groups had lower calcium and iron intakes compared with RDA. But all the nutrient intakes were showed significantly different among three groups divided by percentile of calorie intake(lower 25%, 25-75% and upper 25%), therefore it suggested that subjects had a large individual variance. 2) Mean height, weight, TSK, and blood pressure of boys were 145.5㎝, 40.6kg, 19.3mm, and 114.5/68. 4㎜Hg respectively, and girls were 148.4cm, 38.9kg, 16.7mm, 112.3/67.0mmHg. The differences in anthropometric status according calorie and calcium intake were not found. This study showed protein intake had influence on height and weight of boys.
        4,000원
        10.
        1994.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        시판되는 조제분유를 제조회사별로 구입하여 guinea pig를 이용한 PCA inhibition test로 allergenicity를 측정한 결과 다음과 같은 결론을 얻었다. 저 allergy분유는 negative반응을 나타내었고 조제분유는 positive 반응을 나타냈으나 제조회사별로 차이가 있었다. 가장 allergenicity가 강한 것은 B회사제품으로 대조군과 비교하여 착색된 직경의 크기나 색에 있어 차이가 없었으며 A회사 제품은 B회사 제품보다 allergenicity가 적은 것으로 나타났다. C회사 제품은 미약한 반응을 나타내 제조과정중 allergenicity가 감소되었음을 알 수 있었다. 이들 회사간의 allergenicity의 차이는 사용한 재료의 종류 및 사용비율, 열처리의 정도, 기타 제조공정상의 차이점에 기인된다고 사료된다.
        4,000원
        11.
        1993.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        당화효소와 호정화효소의 생산능력이 높고 향도 좋은 Aspergillus oryzae L2와 밀가루로써 누룩을 제조할 때에 당화효소와 단백질분해효소의 생산을 위한 배양조건을 검토하였다. 밀가루를 가열처리 했을 때에는 날밀가루에 비하여 단백질분해효소의 생산은 증가되었으나 당화효소의 생산은 감소되었다. 밀가루에 0.5%의 염산을 함유하는 물을 급수했을 때에는 당화효소와 단백질분해호소의 생산이 현저하게 감소되었다. 급수비율은 밀가루에 대하여 28%일 때가 가장 좋았다. 국균을 접종한 후 즉시 성형을 하는 것보다 20시간 전 배양을 한 후에 성형을 하는 것이 당화효소의 생산에 좋았고 단백질분해효소의 생산은 성형을 하지 않은 것이 좋았다. 당화효소생산의 최적온도는 36℃이었고 단백질분해효소생산의 최적 온도는 28℃이었다.
        4,000원
        12.
        2019.09 KCI 등재 서비스 종료(열람 제한)
        단층 비지는 단층의 미끌림에 의해 입도와 결정도가 낮아지는 특성을 가지는 것으로 알려져 있다. 활석을 비롯한 층상규산염 광물은 단층 비지에 존재하며 단층 약화에서 중요한 역할을 할 수 있는데, 특히 광물 표면에 흡착된 물분자의 존재 여부에 따라 마찰계수가 달라진다. 본 연구에서는 고에너지 볼 밀을 이용해 입도와 결정도를 체계적으로 변화시킨, 분쇄 전후 활석의 함수율과 탈수반응 거동의 변화를 통해 활석이 단층 약화에 미치는 영향에 대해 알아보고자 하였다. 적외선 분광분석 및 열분석 결과, 분쇄 전 활석은 소수성을 띠며 물분자가 거의 존재하지 않는다. 이후 최대 720분까지 진행된 분쇄를 통해 입도가 약 100~300 nm 내외까지 감소하고 비정질화가 진행된 활석에서는 물분자에 의한 함수량이 분쇄 전에 비하여 약 8 wt.% 증가하였다. 또한 분쇄된 시료를 가열할 경우, 분쇄 전에 비하여 기화되는 수증기의 양이 증가한다. 입도 및 결정도 감소에 따라 탈수산기 반응 온도도 분쇄 전 약900 °C에서 720분 분쇄 후 약 800 °C로 감소하였다. 이와 같이 분쇄된 활석의 입도 및 결정도 감소에 의해 소수성이 친수성으로 바뀌며 층상 규산염 광물의 마찰계수를 낮출 것으로 생각된다. 지진 사이클을 통해 반복되는 단층의 미끌림은 지속적으로 단층 비지에 존재하는 활석의 마찰 계수를 낮출 것으로 생각되며, 오래된 단층이 점점 약화되는 원인에 대한 실마리를 제공할 수 있을 것으로 기대된다.
        13.
        2016.05 서비스 종료(열람 제한)
        Background : Curcuma longa L., in the family Zingiberaceae, is distributed in tropical and/or sub-tropical regions mainly in India and China. This species is commonly called turmeric, powder is used as medicinal herbs and/or flavor enhancer. It has been cultivated in southern region mainly Jindo. However, it might be possible to extend cultivation regions due to rise in average temperature. In order to select superior lines based on agronomic characteristics, we analyzed multivariate and estimated selection effects from C. longa germplasm. Methods and Results : The C. longa germplasm were cultivated in an experimental field located in Eumseong, NIHHS, RDA. The harvested roots were investigated in agronomic characteristics included in yield and then considered its relationship among the 9 germplasm by multivariate analysis method. Results from principal component analysis (PCoA) showed that it represented 70.00% and 80.44% accumulated explanation from four and five principal compounds (PC). PCoA was conducted from 9 agronomic characteristics and then correlation coefficient has been showed by analysis between each main component value and agronomic characteristics. Value of the first PC was 2.25, 24.96% explanation of total dispersion, plant height, number of rootlet and weight of rootlet were correlated with a somewhat higher level as 0.41, 0.43 and 0.52. Value of the fifth PC was 0.94, 10.43% explanation of total dispersion, the number of shoots was correlated with a higher level as 0.87. Selection effects with outstanding candidate lines including higher lines were estimated at 126.13% in yield. Conclusion : These data on multivariate based on agronomic characteristics will be give us invaluable breeding information by selection of superior lines.
        14.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        A new light green seed coat Azuki bean cultivar, "Yeonkeum" was developed at the National Institute of Crop Science(NICS) and the Yeongnam Agricultural Research Institute (YARI) in 2005. Yeonkeum was selected from the cross between Jaja-sodun and "IT12099
        16.
        1999.12 KCI 등재 서비스 종료(열람 제한)
        The Photodegradation efficient of total organic compounds in the drinking water has been studied using the methods of photocatalytic reaction and laser beam irradation. The results are summarized as follows; 1. The photodegradation efficiency of total organic compounds shows as 50% to 80% as within one hour and after this the efficiency is decreased slowly. 2. The photodegradation efficiency of total organic compounds shows as 65 to 90% within 3.3min. when Nd : YAG beam is irradiated to the water layer. 3. An excellent observation of the organic compound removal efficiency gives revealed in that case of the longest wavelength of 532nm is irradiated among the three kinds of laser beam sources of 532nm, 355nm and 266nm. 4. The organic compound removal efficiency shows high in the case of UV beam irradiation in the thin layer of water. However the efficiency is not depended on the thickness of water layer severely. 5. The removal efficiency of the organic compounds in the direct irradiation shows higher than the indirect irradiation in the case of UV beam, but the efficiency is not depended on the direction of irradiation in the case of Nd : YAG beam irradiation.