• 한국미생물·생명공학회지
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• 제24권4호
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• pp.500-506
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• 1996

Bacillus subtilis SH-1 screened from coastal sea water of South Korea was used to produce bacteriolytic enzyme. The production of bacteriolytic enzyme by immobilized cells was investigated. The optimum conditions for the continuous production of the bacteriolytic enzyme using immobilized cells were 2.4 mm diameter of 0.3% alginate beads, 20 ml/h of substrate feeding rate and 20 l/min of aeration rate. A productivity of 76.5 to 88.0 units/ml could be obtained for 25 days by continuous column reactor under the optimum conditions.

• 한국물환경학회지
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• 제23권3호
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• pp.367-370
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• 2007

Numerous sets of simulation were conducted in order to find out the optimum operational conditions of the existing BNR process using GPS-X program. The model of ASM3 and modified Bio-P module were applied for simulations. From the result of this study, effluent quality was closely related with the step feeding rate and influent C/N ratio. The effluent TN concentration seemed to be significantly affected by step feeding rate at the low C/N condition. But at the high C/N condition, the effluent concentration of TP rather than that of TN was affected by the control of step feeding rate.

• Journal of Welding and Joining
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• 제11권2호
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• pp.74-85
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• 1993

Effect of Si metal powders addition with the plasma transferred arc(PTA) overlaying process on characteristics of the alloyed layer in aluminum alloy(A5083) has been investigated. The overlaying conditions were 175-250A in plasma arc current, 500mm/min in travel speed, the 5-20g/min in powder feeding rate. Main results obtained are summarized as follows. 1)Sufficient size of molten pool on surface of base metal was required for forming an alloyed layer; in a fixed travel, the formation of alloyed layer with clear and beautiful surface depend upon the plasma arc current and powder feeding rate; the greater plasma arc current and the smaller powder feeding rate were, the better bead was formed. Optimum alloyed conditions by which an excellent alloyed bead obtained was 225A in plasma arc current. PTA process made it possible to form an alloyed layer with up to 67wt% Si. 2)Microstructure in the alloyed layer was in accord with prediction from the Al-Si phase diagram 3)The hardness of the alloyed layer increased in proportion to Si content. 4)As volume fraction of primary Si increased, the specific wearness of the alloyed layer was significantly improved. However, no further improvement was found when the volume fraction was greater than about 30%. 5)Utilizing the PTA process, a crack free alloyed layer with maximum hardness of about Hv 310 could be obtained.

• 한국양식학회지
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• 제18권2호
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• pp.98-106
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• 2005

본 연구는 지질과 단백질 함량이 다른 두 종류 부상사료의 적정 공급횟수와 공급율을 조사하기 위해 평균 체중 55.1 g의 넙치를 각 수조마다 20마리씩 3반복으로 수용하여 58일 동안 사육하였다. 사료공급휫수는 1일 3회, 1일 2회 및 1일 1회로 설정하였으며 사료 공급량은 만복 및 만복의 80%로 각각 설정하였다. 생존율은 모든 실험 구에서 82% 이상이였으며, 평균 증중량은 EP1의 1일 2회 만복 공급구가 가장 높은 증중량을 보였으며, EP1의 1일 2회 및 3회 제한 공급구와 EP2의 1일 2회 제한 공급구가 가장 낮았다. 일일사료섭취율은 EP1의 1일 2회와 1일 3회 만복 공급구가 가장 높았고, EP2의 1일 3회 만복 공급구와 유의한 차이가 없었다(P>0.05). 사료효율과 단백질효율은 사료 조성, 공급횟수 및 공급을 모두 영향을 받지 않았다(P>0.05). 사육실험 종료시, 근육의 수분 함량은 동일한 사료와 공급휫수에서 제한 공급구가 만복 공급구에 비해 높았다. 이상의 결과들로 보아 평균체중 $55{\sim}90g$인 넙치의 성장을 위해 EP1과 EP2를 1일 2회 만복으로 공급하는 것이 적합할 것으로 판단된다.

• 한국축산시설환경학회지
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• 제16권1호
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• pp.61-80
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• 2010

Poultry welfare has recently appeared as worldwide concern as well as Korea. The recent action plan for farm animal welfare introduced by the European Commission intends to expand the body of regulatory standards. In this context, many countries and/or organization are on the verge of establishing the most optimum poultry welfare standards. To establish the most optimum standards, comparative analysis of feeding regimen before and after welfare-bestowed environment need to be preceded. Most guidelines or standards for poultry welfare do not suggest the nutritional requirements and feeding system in detail, although it is deterimental especially for the farmer. This review intends to find scientific base to establish detailed welfare feeding guidelines. However, only limited research has been conducted in the view of actual poultry welfare. The results indicated the incidence of SDS, ascites, skeletal dysfunctions caused by fast growth rate in broiler, feather pecking and cannibalism in laying hen, and feed restriction in broiler breeder could be reduced by changing nutritional regimen and feeding strategies or both. The regimen and feeding strategies are certainly near to the direction that the poultry welfare ought to be in the right track. In this article, feeding and drinking guidelines in many standards as well as welfare feeding experiments have been reviewed and compared In the view of chicken productivity, welfare physiology and poultry health.

• 한국양식학회지
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• 제21권4호
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• pp.299-303
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• 2008

외해가두리 시험양식 대상종으로 선정된 돌돔에 대하여 저수온기($15^{\circ}C$)에 1년어(62.7 g)와 2년어(344.7 g)에 대한 적정 배합사료 공급량을 조사한 결과, 돌돔 1년어(62.7g)의 적정배합사료 공급율은 어체중의 1.61% (만복의 90%)일 때 증체율 및 사료효율에서 높은 값을 나타내었다. $15^{\circ}C$에서 돌돔 2년어(344.7 g)에 대하여 적정 공급율을 조사한 결과는 어제중의 0.28% (만복의 80%)일 때 가장 높은 성장을 하였으나 시험구간에 오차가 컸고, 전반적으로 낮은 값을 나타내었다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.171-172
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• 2006

The effect of the preparation factors, such as the feeding mode and rate of raw materials, the reaction temperature and the surfactant on the size distribution of molybdenum trioxide particle were investigated by orthogonal test. The optimum conditions for the preparation of $MoO_3$ precursors are as following; opposite feeding fast, reaction temperature of $60^{\circ}C$ and adding dispersant.

• 한국양식학회지
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• 제10권3호
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• pp.311-320
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• 1997

조피볼락 사육시 수온과 먹이공급량이 성장과 사료효율에 미치는 영향을 알기위하여 사육수온과 먹이공급량을 달리하여 사육실험을 한 결과는 다음과 같다. 사육수온 12, 15 및 $18^{\circ}C$에서 사육한 결과 $15^{\circ}C$ 실험구에서 일간사료섭취율 및 일간성장률은 3.64 및 1.66%로 다른 실험구에 비하여 높게나타났으나, 사료효율은 40.7-45.7%로 실험구간에 차이가 없었다. 먹이공급량을 어체중의 0.0-3.0% 범위로 하여 사육실험한 결과 사료효율은 절식구를 제외한 나머지 실험구에서는 41.1-57.2%의 범위로 유의차가 없었고, 일간성장률은 1.5-3.0%공급구에서는 0.79-0.86%의 범위로 차이가 없었다. 어체분석결과 육질부비율은 전실험구에서, 간중량지수, 장중량지수 및 비만도는 1.0-3.0% 공급구에서 차이가 없었다. 혈액성상 분석결과 TP 및 TG는 전실험구에서, GOT, GPT, TG, GL 및 Ht는 1.0-3.0% 공급구에서 차이가 없었다. 이상의 결과로부터 조피볼락 1년생은 육상수조양식시 사육수온은 15-18$^{\circ}C$에서, 먹이공급량은 포식량의 약 70-80%가 적당한 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1319-1327
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• 2014

Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish, (Sebastes schlegeli) reared at the temperatures of $15^{\circ}C$ and $19^{\circ}C$. Fish averaging $92.2{\pm}0.7$ g (mean${\pm}$standard deviation [SD]) at $15.0{\pm}0.5^{\circ}C$ and $100.2{\pm}0.4g$ ($mean{\pm}SD$) at $19.0{\pm}0.5^{\circ}C$ water temperature were randomly distributed into each of 15 indoor tanks containing 250-L sea water from a semi-recirculation system. A total of five feeding frequency groups were set up in three replicates as follows: one meal in a day at 08:00 hour, two meals a day at 08:00 and 17:00 hours, three meals a day at 08:00, 14:00, and 20:00 hours, four meals a day at 08:00, 12:00, 16:00, and 20:00 hours, and one meal every 2 days at 08:00 hour. Fish were fed at the rate of 1.2% body weight (BW)/d at $15^{\circ}C$ and 1.5% BW/d at $19^{\circ}C$. At the end of 8 wks of feeding trial weight gain and specific growth rate were significantly higher at the fish fed groups of one meal a day and two meals a day at $15^{\circ}C$ and fish fed groups of 1 meal every 2 days at $19^{\circ}C$ were significantly lower than those of all other fish fed groups. Glutamic oxaloacetic transaminase and glutamic pyruvic transaminase of fish fed group at 1 meal every 2 days was significantly higher than those of all other fish fed groups in both experiments. Weight gain, specific growth rate and condition factor were gradually decreased as the feeding frequency increased. The results indicate that growing Korean rockfish 92 and 100 g perform better at $15^{\circ}C$ than $19^{\circ}C$ water temperature. As we expected, current results have indicated that a feeding frequency of 1 meal a day is optimal for the improvement of weight gain in growing Korean rockfish grown from 92 g to 133 g at $15^{\circ}C$ and 100 g to 132 g at $19^{\circ}C$ water temperature.

• Fisheries and Aquatic Sciences
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• 제8권4호
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• pp.228-234
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• 2005

Despite the relatively high production of fingerlings of the olive flounder Paralichthys olivaceus, its larval rearing in terms of first feeding has not been fully analyzed. We evaluated the variations of amino acids and fatty acids of starved larvae over 96 hr after hatching. We also investigated depletion of the yolk and oil globule of starved larvae and those fed the rotifer Brachionus plicatilis. In addition, the optimum size of the rotifers according to the mouth size of the larvae, and the point of no return with delay of the first feeding, were also examined. The amino acids in the egg decreased abruptly during embryo development. At 48 to 72 hr after hatching, the amino acids of starved larvae decreased by $30-40\%$ from the level in newly hatched larvae. The concentrations of fatty acids in newly hatched larvae were lower than those of floating eggs and dropped sharply at 48 hr after hatching, when the yolk disappeared. The starved larvae depleted their yolksacs and oil globules earlier than the fed larvae did. At 84 hr after hatching, rotifers were detected for the first time in the guts of the larvae, which were about 3 mm in total length. The point of no return appeared to be close to the fourth day from the first feeding. For a high survival rate of P. olivaceus larvae, the first feeding should occur before the third day after hatching.