• Nuclear Engineering and Technology
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• 제20권2호
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• pp.88-104
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• 1988

이차원의 유한요소법을 이용하여 axisymmetric R-$\theta$system으로 나누어서 정상과 부하추종 운전시에 핵연료 페렛트와 피복관의 열역학적 거동을 분석하기 위해서 FURA전산코드를 개발하였다. 온도분포와 내부압력을 정확히 계산하기 위해서 페렛트와 피복관의 변형과 핵분열의 기체방출을 전체 핵연료봉 길이로 고려하였다. 열역학적 평 형방정식을 얻기 위해서 Galerkin's Technique과 가상일의 원리를 사용하였고 역학적 해석을 위해서 탄성-소성, 크리프뿐만아니라 스엘링, 재배열, 고밀화 현상등을 고려하였다. 기하학적 모델에서는 4-결점 요소라 페레트 길이의 1/2만을 택하였다. 비선형식을 안정하게 해석하기 위해서 음해법을 도입하여 뉴튼-랩손 반복법을 적용하였다 이 코드의 검증은 해석해와 실험데이타로 비교하였다. 핵연료봉의 일반적인 거동은 axisymmetry system으로 계산하였고 균열된 페레트에 접촉하는 피복관의 거동은 R-$\theta$system을 사용하였다. 부하추종에 의한 피복관의 변형시효의 민감도는 출력율, 진동수, 진폭등으로 비교하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1725-1733
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• 2019

Objective: Evaluate the partial replacement of soybean meal with different protein sources in piglet feed during the nursery phase in terms of digestibility of feed, nitrogen balance, growth performance and blood parameters. Methods: Experiment I involved 24 crossbred entire male pigs with an initial body weight (BW) of $18.28{\pm}0.7kg$ and used a randomized complete block design consisting of 3 treatments (fish meal, FM; soybean protein concentrate, SPC; and soybean meal, SBM) and 8 replicates, with 1 pig per experimental unit. Experiment II involved 1,843 crossbred male and female pigs with an initial BW of $6.79{\pm}0.90kg$ and was based on a completely randomized design with a $2{\times}3$ factorial arrangement (2 sexes and 3 protein sources) and 13 replicates. Results: The results of Exp. I indicate effects (p<0.05) of dietary protein sources on digestible protein (FM, 17.84%; SPC, 16.72%, and SBM, 18.13%) and on total nitrogen excretion (TNE, $g/kg\;BW^{0.75}/d$) in which pigs fed with SBM-based feed had TNE values that were 5.36% and 3.72% greater than SPC and FM, respectively. In the Exp. II, there was difference (p<0.01) between sexes in the pre-starter I and starter phases, and total period in average daily feed intake (ADFI), which were greater in females, and between the protein sources, ADFI, final weight and daily weight gain. For urea in the pre-starter II and starter phases and glucose in the pre-starter II phase, there was a difference (p<0.05) between protein sources and between sexes, in starter phase in urea concentrations (females: 57.11 mg/dL and males: 50.60 mg/dL). Conclusion: The use of SBM as only protein source influences larger TNE ($g/kg\;BW^{0.75}/d$), reduces the growth performance of piglets and increases plasma urea concentrations in prestarter II phase.