• 한국해양공학회지
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• 제15권4호
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• pp.53-59
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• 2001

The Primary Production of phytoplanktons produces organic matter in high concentration in eutrophicated Hakata Bay, Japan, even during the winter season in spite of low water temperature. Phytoplanktons are considered to have any biological capabilities to keep activities of photosynthesis under the unfavorable conditions, and this affects water quality of the bay. In this study, seasonal variations in primary production efficiency were predicted by using a simple box-type ecosystem model, which introduced the concept of efficiency for absorption of solar radiation energy in relation to growth of phytoplanktons under the low solar radiation intensity. According to the simulation result of primary production, it was organic pollution comes from dissolved organic carbon (DOC) throughout the year, DOC of which is originated from the primary production of phytoplanktons on biological response of the seasonal variation of ambient conditions.

• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.747-751
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• 1999

The Hohenheim in vitro gas test was used to assess the nutritional value of some crop residues of known in vivo digestibility. The crop residues are groundnut shells (GNS) corn cobs (CC); cassava peels (CaP); unripe and ripe plantain peels (UPP, RPP) and citrus pulp/peels (CPP). Compared to other crop residues, crude protein (CP) content of CC was low. Except for CaP and CPP that had low neutral detergent fibre (NDF) and acid detergent fibre (ADF), other residues contained a high amount of cell wall constituents. Net gas production was significantly different among the crop residues (p<0.05). Gas production was highest in CPP followed by CaP. CC, UPP and RPP have the same volume of net gas production, while the least net gas production was in GNS. True dry matter (TDM) digestibility was significantly different (p<0.05) among the residues. GNS was the least in TDM digestibility. CaP, UPP and RPP had similar TDM digestibility values, while the highest TDM digestibility was obtained in CPP. OM digestibility was different among the residues (p<0.05). CaP and CPP had the same ME value while CC, UPP and RPP had close ME values and GNS the least in ME (p<0.05). The potential extent (b) and rate (c) of gas production were statistical different among the residues (p<0.05). The Hohenheim gas test gave high in vitro organic matter (OM) digestibility for CC, CaP, UPP and RPP and CPP. Fermentable carbohydrates and probably available nitrogen in the crop residues influenced net gas production. The results showed that crop residues besides, providing bulk are also a source of energy and fermentable products which could be used in ruminant livestock production in the tropics.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.226-235
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• 2000

A survey on feeding practices was conducted with thirty-one cattle farmers belonging to three categories: households without land and no income from agricultural labour (Class 100;10 farms), households without land but deriving considerable income from agricultural labour (Class 101;10 farms), and households with land and without income from agricultural labour (Class 110;11 farms). Information on the types of feeds given of one year. In addition, samples of the feeds offered and refused were collected every two weeks and analysed for dry matter, organic matter (OM), crude protein (CP) and in vitro organic matter digestibility (OMD). Grass was usually cut at an early stage of growth, as such the CP(11.8%) and OMD (62%) were relatively high. All types of rice straw (whole, lower and upper part) and sugarcane forage (tops and leaves) were low in CP (<6 and <8.9%, respectively) and OMD (<45 and <47%, respectively). Rice bran and tofu waste was of much better quality than any other feed. The average number of different feeds in the rations (mean of all farms) was 1.98, with a lower value for class 101 (1.80), than for classes 100 and 110 (2.11 and 2.02, respectively). Of the total amount of OM consumed, 42% was rice straw, 21% grass, 19% maize forage, 10% sugarcane forage, <4% other forages (soya and groundnut straw), 1.3% rice bran and 2.9% tofu waste. The total amount of OM offered varied from <80 $g/kg^{0.75}/d$ in August/September to 1.5 times as much in May (P<0.01). The intake of digestible organic matter (IDOM) for farm class 110 ($37.7g/kg^{0.75}/d$) was significantly (p<0.001) lower than that for classes 100 and 101 (44.1 and $41.3g/kg^{0.75}/d$, respectively). The highest CP/IDOM ratio was recorded for farm class 101 (0.201 as compared to 0.181-0.184).

• 한국축산시설환경학회지
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• 제18권2호
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• pp.63-74
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• 2012

사육밀도의 차이가 지렁이의 생육, 체조직으로의 유기물 전환효율 및 분립생산량에 미치는 영향을 조사한 결과를 요약하면 다음과 같다. 1. 공시 한우분의 탄질율은 25.1로, 지렁이 먹이로 적합한 탄질율로 추정되었다. 2. 지렁이 생체중과 먹이 량의 비율이 1:32였던 S-3에서 생체중 증가율과 체조직으로의 유기물 전환효율이 유의하게 높은 값을 나타내었는데, 이 비율을 사육공간으로 나타내면 $56.6cm^3$이었다. S-3에서 사육기간 평균 생체중 증가율과 체조직으로의 유기물 전환효율은 각각 10.63 mg/day와 6.65%를 나타내었다. 3. 지렁이 생체중과 먹이 량의 비율 1:8이었던 S-1에서 사육기간 중 분립비율이 가장 높았지만, 생체중 증가율과 체조직으로 유기물 전환효은 -값을 나타내었다. 이는 개체 간 먹이 경합이 심해진 결과로 추정된다. 4. 사육밀도가 높아짐에 따라 지렁이 분립의 pH, 전 질소함량, 유효인산함량, 양이온치환능력 (CEC) 및 양이온 함량이 유의하게 증가되었다. 특히 유효인산함량, 양이온치환능력 및 양이온함량은 사육기간이 길어짐에 따라 유의하게 증가되었다. 5. 지렁이 분립의 이화학적 특성으로 볼 때, 상토 재 또는 토양개량제로서 유용성이 높다고 판단되었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.1398-1402
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• 2005

Riverbank filtration is a natural process using alluvial aquifers to remove contaminants and pathogens in river water for the production of drinking water. In riverbank filtration, the understanding of contaminant transport is an important task for the production of high quality drinking water. This study investigates the transport behavior of hydrophobic organic contaminants when colloids (dissolved organic matter and bacteria) are present in the aquifer. A mathematical model for the transport of contaminants is developed and solved numerically for various situations. Results show that in the riverbank filtration the presence of DOM and bacteria enhances the mobility of contaminant significantly. Sensitivity analysis indicates that the distribution of the total aqueous Phase contaminant is significantly affected by distribution coefficients which account for affinity of solid or colloidal Phase to contaminant.

• 한국유기농업학회지
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• 제16권3호
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• pp.287-298
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• 2008

우분에 왕겨와 볏짚을 1:1, 1:2, 1:3의 부피비율로 혼합한 먹이조건이 지렁이의 생육, 분립생산량, 체조직으로의 유기물 전환율 및 전환효율을 조사하여, 적정 먹이조건을 추정하였다. 1. 우분+왕겨 혼합구가 우분+볏짚 혼합구보다 지렁이의 증체속도, 증식효율 및 분립생산량이 많았다. 특히 우분+왕겨 1:3 혼합비율이 지렁이 생육에 가장 알맞은 먹이조건이었다(Table 2). 2. 우분+왕겨 혼합 구에서 지렁이 체조직으로의 유기물 전환율과 전환효율이 높았던 것은 먹이 중의 휘발성 고형분과 전탄소함량이 높았기 때문이었다(Table 1, 4). 4. 지렁이 분변토는 약알칼리성이고, 전질소함량, 유효인산함량, CEC 및 치환 성 양이온 함량이 높아서 친환경 농자재로 유용하게 활용될 수 있다고 판단된다(Table 5).

• 한국초지학회:학술대회논문집
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• 한국초지조사료학회 2005년도 학술심포지엄, 제43회 학술발표회
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• pp.160-161
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• 2005

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.517-522
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• 2007

The aim of this study was to compare in vitro gas production kinetics, metabolizable energy (ME), organic matter digestibility (OMD) and microbial protein (MP) production of widely used legume hays in ruminant nutrition in Turkey. Gas production were determined at 0, 3, 6, 12, 24, 48, 72 and 96 h and their kinetics were described using the equation p = a+b ($1-e^{-ct}$). There were significant differences among legume hays in terms of chemical composition. The crude protein content of legume hays ranged from 11.7 to 18.6% of dry matter (DM); crude fat from 2.1 to 3.5% DM; neutral detergent fiber from 35.6 to 52.0% DM; acid detergent fiber from 32.0 to 35.5% DM and acid detergent lignin 1.7 to 11.0% DM. Total gas production after 96 h incubation ranged between 61.67 and 76.00 ml/0.200 g of substrate. At 24, 72 and 96 h incubation the total gas production for common vetch were significantly (p<0.01) higher than those of the other legume hays. The ME, OMD and MP of legume hays ranged from 9.09 to 11.12 MJ/kg DM, 61.30 to 75.54% and 90.35 to 138.05 g/kg DM, respectively. The ME, OMD and MP of common vetch was significantly (p<0.01) higher than those of the other hays due to low cell-wall contents and high crude protein. At the end of the experiment, differences in chemical composition of legume hays resulted in the differences in the in vitro gas production, gas production kinetics and the estimated parameters such as ME, OMD and MP. Common vetch can be recommended to hay producers and ruminant breeders, due to high ME, OMD and MP production.

• Asian-Australasian Journal of Animal Sciences
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• 제8권1호
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• pp.83-88
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• 1995

An experiment was conducted to study the comparative performance of cattle fed young or mature guinea grass (Panicum maximum Jacq. ecotype A) and urea supplemented rice straw. Evaluation was based on intake and digestibility parameters. Twelve crossbred bulls calves weighing $90{\pm}15$ kg were offered young (4 weeks regrowth) or mature (9 weeks regrowth) grass in the long or chopped (10-15 cm) form, and rice straw supplemented with urea. The diets were offered 30-60% in excess of voluntary intake, and the experiment consisted of two periods. The crude protein content of the young grass, mature grass and the straw offered were 12.2, 5.4 and 7.7%, respectively, and the refusal was 10.1, 3.9 and 7.0%, respectively. The organic matter digestibility of the young grass (69%) was significantly higher than the mature grass (62.5%) and straw (55.8%) diets. The organic matter intake (kg/100 kg LW/day) of the unchopped and chopped grass diets were 2.6 and 3.3 respectively, and these values were significantly higher (p < 0.01) than the young grass (2.3) and straw (2.1) diets. The digestible organic matter intake (DOMI) of the mature grass diet offered in the chopped form (2.1 kg/100 kg LW/day) was significantly higher (p < 0.01) than the other three diets. The DOMI of the young and mature grass offered in the long form was similar (1.6 kg/100 kg LW/day), but were significantly better (p < 0.01) than the urea supplemented straw diet.

• 한국초지조사료학회지
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• 제4권3호
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• pp.220-225
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• 1984

1. 낙동강(洛東江) 하류(下流) 갈대군락(群落)에서 유기탄소(有機炭素)의 생성(生成), 분해(分解) 및 축적(蓄積)을 이론적(理論的) 분석(分析)에 의(衣)해서 평가하였다. 2. $m^2$당(當) 낙엽(落葉)의 유기물(有機物), 유기탄소(有機炭素)의 함량(含量)은 각각(各各)이였으며 초지상(草地床)의 함량(含量)은 1154.96g과 669.93g 이었다. 3. 시별(尸別) 유기물(有機物), 유기탄소(有機炭素)의 함량(含量)은 광합성부(光合成部)에서는 120-140cm에 가장 많았으며, 비광합성부(非光合成部)에서는 0-20cm에 가장 많았다. 4. 안정(安定)된 상태(狀態)의 초지생태계(草地生態系)에서 년(年) 낙엽(落葉) 총생산량(總生産量)과 토양(土壤)의 윗부분(F, H 및 A층)의 비(比)로 결정(決定)된 분해상수(分解常數) k는 0.884이었다. 5. 낙동강(洛東江) 하류(下流) 갈대군락(群落)에서 유기탄소(有機炭素) 50%. 95%, 99%가 분해(分解)되는데 걸리는 시간(時間)은 각각(各各) 0.784, 3.394. 5.656년(年)이었다.