• Environmental Engineering Research
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• 제25권2호
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• pp.135-146
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• 2020

This study was aimed to investigate the possibility of using raw and anaerobically-digested piggery wastewater as culture media for a green microalga Chlorella vulgaris (C. vulgaris). Due to high concentration of ammonia and dark color, the microalga did not grow well in this wastewater. In order to solve this problem, air stripping and NaOCl-treatment were applied to reduce the concentration of NH₃-N and the color intensity from the wastewater. Algal growth was monitored in terms of specific growth rate, biomass productivity, and nutrient removal efficiency. As a result, C. vulgaris grew without any sign of inhibition in air-stripped and 10-folds diluted anaerobically-digested piggery wastewater with enhanced biomass productivity of 0.57 g/L·d and nutrient removal of 98.7-99.8% for NH₃-N and 41.0-62.5% for total phosphorus. However, NaOCl-treatment showed no significant effect on growth of C. vulgaris, although dark color was removed greatly. Interestingly, despite that the soluble organic concentration after air stripping was still high, the biomass productivity was 4.4 times higher than BG-11. Moreover, air stripping was identically effective for raw piggery wastewater as for anaerobic digestate. Therefore, it was concluded that air stripping was a very effective method for culturing microalgae and removing nutrients from raw and anaerobically-digested piggery wastewaters.

• 대한영양사협회학술지
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• 제4권2호
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• pp.245-253
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• 1998

In this study, the food cost for the urban worker's living expenses was estimated for the Korea Labor Union. The urban workers living expenses are minimum of healthy and decency level expenses with allowances for minimum quality of life. Thus, the food cost should be enough for purchasing proper kinds and amount of foods which can supply sufficient nutrient to maintain health and which should reflect current food consumption patterns. To estimate the food cost, the Korean Recommended Dietary Allowances was used to calculate the amount of nutrients which should be supplied. The National nutrition survey and the Food balance sheet, were used to estimate the current consumption patterns for the kind and amount of food. To estimate price for each food item, the market survey was executed in six large cities. Also, to verify the estimated food cost, actual food costs were surveyed. For 5 kinds of model household, dietary allowances were calculated for the each nutrient. Using the Korean food guides, the number of serving for each food group were decided for the model households. In each food group, the amount and kind of foods were decided by the current food consumption pattern. The kind and amount of food were adjusted by the amount of calculated nutrient. When the amount of nutrient was between 90% and 110% of the recommended dietary intake, it was accepted. With these amount and kinds of foods, the food cost were calculated using the market survey. Considering extra expenses for the eating-out and processed foods, extra expenses are added. As a results, for single person family, the estimated food cost was 149,210won per month. For two, three, four and five person family, the estimated food costs were 245,179won, 381,182won, 501,669won and 687,980won per month, respectively. The estimated food cost were lower in the single and two person family than the actual food cost by the survey. The cost for eating-out gave major differences. In the future, to estimate food cost, the food consumption patterns for the different kind of household, sex and age should be studied carefully. Also, the pattern of eating-out should by analyzed.

• 한국식품조리과학회지
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• 제31권2호
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• pp.214-224
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• 2015

This study was conducted to identify the combination of foods and foodservice menu patterns, food supply rankings and dietary quality through the a collection of school menus from the fifth week of October 2009, up to the fourth week of November 2009, in three American international schools in Korea. The results of analysis were as follows. For the basic pattern of American international school foodservice menu, dietary patterns comprised of rice, soup, five side dishes, Kimchi and snacks were 23.19%, while menu pattern comprised of rice, soup, four side dishes, Kimchi and snacks were 18.84%. The two dietary patterns accounted for 42.03%. For the foodservice frequency and food rankings from No. 1 to No. 5, vegetables and seasoned vegetables were the highest, followed by cooked rice, Kimchi, soup, and stir-fried foods. For nutrients, the intake ratio of carbohydrates, protein and fat for the calories provided at the three schools was 57:18:24, 53:18:29, and 55:18:27. Compared with 55~70:7~20:15~25 according to by Korean nutrition standards, carbohydrates and protein were adequate, but fat was high. For the recommended nutrient intake (RNI), the provided nutrient ratio was higher than the RI of nutrition standards in schools. For the average nutrient adequacy ratio (NAR), all three schools were above 1. School C had an above-average ratio for vitamin B-complex and vitamin A. Phosphorus showed a significant difference in the nutrient density. For DDS, school C provided all five main food groups every day.

• 한국환경농학회지
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• 제33권1호
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• pp.24-29
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• 2014

생 대추 재배에 적합한 양분관리를 위한 기초 자료를 얻고자 2011년과 2012년에 보은군 일원 서로 다른 30개 지점에서 토양 화학성을 조사하였다. 조사 토양에 대한 pH 적정범위 분포율은 2011년도 및 2012년도에 각각 27% 및 33%였고, 유기물의 분포율은 두해 모두 30%였다. 유효인산의 적정범위 분포율은 각각 7% 및 13%였고, 적정범위 이상이 각각 73% 및 57%였다. 치환성 K의 적정범위 분포율은 각각 37% 및 30%였고, 적정범위 이상이 63% 및 67%였다. 조사지점에 대한 토성 분포비율은 양질사토, 사양토, 미사질양토 및 양토가 각각 10%, 43%, 37% 및 10%이었다.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.92-98
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• 2013

Microalgal cultivation using wastewater is now regarded as essential for biodiesel production, as two goals can be achieved simultaneously; that is, nutrient removal efficiency and biomass production. Therefore, this study examined the effects of carbon sources, the N:P ratio, and the hydraulic retention time (HRT) to identify the optimal conditions for nutrient removal efficiency and biomass production. The effluent from a 2nd lagoon was used to cultivate microalgae. Whereas the algal species diversity and lipid content increased with a longer HRT, the algal biomass productivity decreased. Different carbon sources also affected the algal species composition. Diatoms were dominant with an increased pH when bicarbonate was supplied. However, 2% $CO_2$ gas led to a lower pH and the dominance of filamentous green algae with a much lower biomass productivity. Among the experiments, the highest chlorophyll-a concentration and lipid productivity were obtained with the addition of phosphate up to 0.5 mg/l P, since phosphorus was in short supply compared with nitrogen. The N and P removal efficiencies were also higher with a balanced N:P ratio, based on the addition of phosphate. Thus, optimizing the N:P ratio for the dominant algae could be critical in attaining higher algal growth, lipid productivity, and nutrient removal efficiency.

• 농업과학연구
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• 제49권4호
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• pp.871-879
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• 2022

An increasing global population requires a greater food supply, and accordingly there is demand for enhanced production of rice, as a major crop plant that covers half of the world's population. Rice production in arid area is extremely difficult due to poor soil fertility, salinity, deficit of irrigation water, and weather conditions. The aim of the present study was to determine whether various fertilization recipes could provide a countermeasure to allow rice production while also providing soil amendment such as soil pH adjustment. The study was conducted at an experimental field of the United Arab-Emirates (UAE) from January to April, 2022. Rice seedlings (cv. Asemi, alkaline-resistant) were transplanted in plastic containers, and different types of water and nutrient managements were employed as follows: water management (flooding and aerobic for NPKs treatment group) and nutrient management (NPKs, slow release fertilizers [SRFs] and SRFs + NPK-1 treatment groups with flooding). Water and nutrient management did not show any effect on soil pH adjustment. Rice growth was significantly enhanced in the flooding compared to the aerobic condition, whereas the effect of nutrient management clearly differed among the treatment groups, with SRFs + NPK-1 showing the best results followed by SRFs and NPKs. Most of the fertilization groups markedly accumulated soluble sugars in the shoots and grains of rice plants, but concomitantly a decrease in the roots. Overall, the level of starch showed a tendency of relatively slight perturbation by fertilization. Taken together, the results indicate that soil physical structure should be preferentially amended to find the key for suitable rice production.

• 한국물환경학회지
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• 제16권4호
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• pp.513-521
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• 2000

Intermittently aerated activated sludge process was applied as a water reuse process of $70m^3/day$ for the upgrade of organic, nitrogen and phosphorus removal efficiency and clarifier performance. After application of the intermittently aeration, removal efficiency of BOD, SS, T-N and T-P were achieved 95%, 90%, 80% and 60%, respectively. Removal efficiencies in intermittently aerated process were considerably increased. comparing to those of continuously aerated activated sludge process. Also sludge rising problem in clarifier was improved. Average concentration of supplied reusing water were BOD 5 mg/L, turbidity 4 NTU and after chlorination, residual chlorine 0.4 mg/L, coliform 0 MPN/100mL. Intermittently aerated activated sludge process could be one of the best alternative process for the retrofit of conventional activated sludge process for the removal of nutrient in water reuse system.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1674-1680
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• 2004

The objective of this study was to compare the Dutch DVE/OEB system and the NRC-2001 model in the prediction of supply of protein to dairy cows from processed field tick beans. Comparisons were made in terms of 1) ruminally synthesized microbial CP, 2) truly absorbed protein in the small intestine, and 3) degraded protein balance. The results showed that the predicted values from the DVE/OEB system and the NRC-2001 model had significant correlations with high R (>0.90) values. However, using the DVE/OEB system, the overall average microbial protein supply based on available energy was 16% higher and the truly absorbed protein in the small intestine was 9% higher than that predicted by the NRC-2001 model. The difference was also found in the prediction of the degraded protein balances (DPB), which was 5% lower than that predicted based on data from the NRC-2001 model. These differences are due to considerably different factors used in calculations in the two models, although both are based on similar principles. It need to mention that this comparison was based on the limited data, the full comparison involving various types of concentrate feeds will be investigated in the future.

• 생물환경조절학회지
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• 제18권4호
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• pp.348-353
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• 2009

절화 장미 'Vital'을 코코피트와 펄라이트(3 : 1, v/v) 혼합배지에서 2006년 4월 20일부터 이듬 해 10월 15일까지 용기재배를 하였다. 사용한 양액은 애지현(愛知懸) 장미 표준액으로 고온기와 저온기에 양액의 조성을 달리하였으며, 계절별로 양액농도를 표준액의 0.7배, 1.0배, 그리고 1.3배액으로 처리하였는데 표준액의 계절별 급액농도는 4~6월은 $1.4dS{\cdot}m^{-1}$, 7~8월은 $1.0dS{\cdot}m^{-1}$, 9~10월은 $1.4dS{\cdot}m^{-1}$, 11~3월은 $1.6dS{\cdot}m^{-1}$였다. 급액량은 FDR 수분센서를 이용하여 -5kPa에서 급액하여 주당 120mL씩 공급하였다. 수확은 7회 하였는데 수량은 3차까지는 처리간에 차이가 없었지만, 4차 수확부터는 1.3배구의 수량이 다른 처리구에 비하여 적었다. 절화장미의 가장 중요한 상품요소인 절화장을 재배시기별로 조사하였을 때 0.7배구는 표준액구와 비교 하여 총수량은 적은 경향이었으나 70cm 이하의 하품 생산량이 적고, 91cm 이상 상품성이 우수한 절화의 생산량이 많았다. 그 외에도 0.7배 처리구는 절화중, 화경경, 화중 등 상품성이 우수하였다. 이상의 결과를 종합하면, 유기물인 코코피트를 주재료로 하여 펄라이트와 혼합한 배지를 이용하여 절화장미 수경재배 시에는 재배기간이 길어질수록 배지내에 무기성분이 집적되기 때문에 기존의 무기물 배지를 이용할 때 보다 표준액의 0.7배액 정도로 낮은 농도로 급액하면 상품성이 우수한 절화를 생산할 수 있을 것으로 사료된다.

• 한국해양학회지:바다
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• 제3권1호
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• pp.25-33
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• 1998

황해 중동부 해역에서 영양염 원소들의 시, 공간적 변화를 살펴보기 위해 1995년 5월과 1995년 11월, 1996년 6월의 세 차례에 걸쳐 현장조사를 실시하고, 표층수에 대해 염분, 온도, 부유물질 및 입자태 유기탄소와 암모니아, 질산염, 아질산염, 인산염, 규산염 등의 영양염 원소를 분석하였다. 세차례의 현장 조사에서 표층수의 영양염 농도 분포는 암모니아를 제외하면 일반적으로 6월이 가장 낮고 11월이 가장 높은 값을 보이는 한편, 암모니아는 5월에 가장 낮은 농도 분포를 보이고 11월에 가장 높은 값을 보였다. 봄에는 5월에 식물 플랑크톤의 1차 생산 활동으로 영양염이 고갈된 외해역의 표층수는 6월로 되면서 수온약층과 조석전선의 발달로 저층과 강으로부터의 영양염 공급이 더욱 제한되고, 봄철 식물 플랑크톤 대번식기에 증식된 동물 플랑크톤 또는 그 배설물 등이 박테리아에 의해 분해되는 과정에서 암모니아가 수층으로 공급되는 것으로 보인다. 한편, 11월에는 늦가을로 접어들면서 봄-여름철에 형성된 성층이 깨지고 수층의 수직 혼합이 활발해지면서 성층기간 동안 저층수에 축적되었던 영양염 원소들이 표층으로 공급되는 것으로 보인다.