• International Journal of Naval Architecture and Ocean Engineering
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• 제10권6호
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• pp.794-802
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• 2018

The ice resistance series charts for icebreaking ships were developed through a series of systematic model tests in the ice tank of the Korean Research Institute of Ship and Ocean Engineering (KRISO). Spencer's (1992) component-based scaling system for ship-ice model tests was applied to extend the model ship correlations. Beam to draft ratio (B/T), length to beam ratio (L/B), block coefficient ($C_B$) and stem angle (${\alpha}$) were selected as geometric parameters for hull form development. The basic hull form (S1) of twin pod type with B/T of 3.0, L/B of 6.0, $C_B$ of 0.75 and stem angle of $25^{\circ}$ was generated with a modern hull design concept. A total of 13 hulls were designed varying the geometric parameters; B/T of 2.5 and 3.5, L/B of 5.0 and 7.0, $C_B$ from 0.65 to 0.85 in intervals of 0.05, and 5 stem angles from $15^{\circ}$ to $35^{\circ}$. Ice resistance tests were first carried out with the basic hull form in level ice with suitable speed. Four more tests for $C_B$ variations from 0.65 to 0.85 were conducted and two more for beam to draft and length to beam ratios were also performed to study the effect of the geometric parameters on ice resistance. Ice resistance tests were summarized using the volumetric coefficient, $C_V$ ($={\nabla}/L^3$), instead of L/B and $C_B$ variations. Additional model tests were also carried out to account for the effect of the stem angle, ice thickness and ice strength on ice resistance. In order to develop the ice resistance series charts with a minimum number of experiments, the trends of the ice resistance obtained from the experiments were assumed to be similar for other model ship with different geometric parameters. A total of 18 sheets composed of combinations of three different beam to draft ratios and six block coefficients were developed as a parameter of $C_V$ in the low speed regions. Three correction charts were also developed for stem angles, ice thickness and ice strength respectively. The charts were applied to estimate ice resistance for existing icebreaking ships including ARAON, and the results were satisfactory with reasonable accuracy.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.802-811
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• 2020

Objective: Two experiments were conducted to investigate the effects of dietary sucralose on diet preference and growth performance of weaned piglets, and a third experiment was a 28-d safety study to examine if high-dose sucralose could affect the health state of weaned piglets. Methods: In experiment one, 48 piglets had free access to a corn-soybean based diet and the same diet supplemented with 150 mg/kg sucralose for 15 d. In experiment two, 180 piglets were blocked into 5 treatments with 6 replications. They were fed basal diets supplemented with 0, 75, 150, 225, and 300 mg/kg sucralose for 28 days. In experiment three, 108 piglets were randomly assigned to 3 treatments and fed diets supplemented with 0, 150 (suitable level), and 1,500 (ten-fold suitable level) mg/kg sucralose for 28 d. Results: The experiment 1 showed that piglets preferred (p<0.05) diets containing sucralose during experimental period. In experiment 2, piglets fed a diet supplemented with 150 mg/kg sucralose had a higher average daily gain (ADG) and average daily feed intake (ADFI) than pigs in the control group and other treatment groups during the experiment period. The concentrations of sucralose over 150 mg/kg may decrease feed intake. However, no difference in feed conversion ratio was observed. In experiment 3, piglets fed diet supplemented with 150 mg/kg sucralose had a higher ADG and ADFI than that of pigs in the control group and 1,500 mg/kg treatment groups during the experiment period. Clinical blood metabolites, organ index and histological morphology were not significantly different between sucralose treatments. Conclusion: Sucralose can promote feed intake and thereby improve growth performance of weaned piglets. Moreover, inclusion of 1,500 mg/kg sucralose was demonstrated to have no observed adverse effects. Supplementing 150 mg/kg sucralose for weaned piglets is recommended in this study.

• 한국식품과학회지
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• 제42권5호
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• pp.578-585
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• 2010

초등학교 급식의 메뉴별 나트륨 함량이 중학교 급식의 나트륨 함량보다 높았으나 음식 섭취량이 중학생이 많아서 나트륨 섭취량은 중학생이 초등학생 보다 유의적으로 많이 섭취했다(p<0.05). 비빔밥, 덮밥 등 간장이나 고추장을 기본으로 한 소스류 첨가가 많은 일품식류는 급식 자체의 섭취량 또한 높아서 다른 음식군과 확연히 구분될 만큼 나트륨 섭취에 크게 기여하였다. 반면 나트륨 함량이 높은 구이류 메뉴는 김구이처럼 섭취중량이 매우 작은 경우가 있어서 나트륨섭취에 기여하는 수준은 크게 높지 않았으며 김치류와 무침나물류 또한 해당 음식의 섭취량이 낮아서 나트륨 섭취에 크게 기여하지는 않았다. 초등학생의 끼니당 나트륨 섭취량 평균은 802.2 mg/인으로 WHO 일일섭취권고량(2,000 mg)의 40.1%로 나타났다. 중학생의 경우 1회 점심식사 분량의 나트륨 섭취량 평균은 1,055.9 mg/인으로 WHO 일일섭취권고량(2,000 mg)의 52.8%를 섭취하고 있는 것으로 나타났다. 후식이 높은 칼륨/나트륨 비율을 나타냈는데 과일류가 112.0로 가장 높았으며 음료 및 차류 8.6, 유제품이 3.2로 높은 비율을 나타냈다. 주식류에서는 밥류가 칼륨/나트륨 비율이 22.3으로 칼륨/나트륨 비율이 1이상을 나타내고 그 외의 주식류 및 부식류 전항목은 1이하로 나트륨이 높음을 알 수 있었다. 초등학교 급식(0.66)이 중학교 급식(0.62) 보다 높은 칼륨/나트륨 비율을 보였는데, 이는 초등학교에서 후식으로 과일을 제공한 횟수가 많아 나트륨에 대한 칼륨의 비율을 더 높인 것으로 판단된다. 초등학생, 중학생 모두 한끼 나트륨섭취권장량인 1/3 RDI(WHO, 2000 mg)인 667 mg을 초과하는 비율이 높았다. 따라서 학교급식에서 나트륨 섭취량을 권장섭취량 수준으로 낮추기 위해서 레시피 개선, 학생영양(교)사 교육 및 올바른 식생활에 대한 교육 및 홍보가 병행되어야 할 것으로 생각된다.