암, 수 분리사육시 사료 내 단백질 함량이 육성 - 비육돈에 성장성적, 혈액성상, 돈육 품질 그리고 경제성분석에 미치는 영향

학위논문 (석사)-- 서울대학교 대학원 : 농업생명과학대학 농생명공학부, 2018. 2. 김유용.Split-sex feeding system has been broadly utilized in foreign countries however, it has not worked well for animal industry in Korea. The split-sex feeding means that gilts and barrows are separated and fed their diet with different feeding program. This is based on the finding that gilts and barrows have different growth rates, feed efficiencies and nutrient requirements. So far, the most of feeding study for pigs has designed in the absence of separation of barrows and gilts. Thus, the role of sex in experimental diet impacts on efficiency of feed utilization has not been assessed. A study was conducted to evaluate the effects of split-sex feeding with different protein contents in diet on growth performance, blood profiles, pork quality and economic analysis in pigs from growing to finishing. A total of 160 growing pigs ([Yorkshire × Landrace] × Duroc), averaging 30.55 ± 5.925 kg body weight, were assigned into one of five treatments. Each treatment diet is provided as followed by treatment 1) control (CON): barrows and gilts were penned together with protein requirement of NRC (2012), 2) Gilt: gilts were separately penned with protein requirement of NRC (2012) 3) Barrow : barrows separately penned with protein requirement of NRC (2012) 4) Gilt –1% : gilts were separately penned with 1 % lower protein requirement of NRC (2012) 5) Barrow – 1% : barrows were separately penned with 1 % lower protein requirement of NRC (2012). In feeding trials, the split-sex feeding by NRC requirement had no significant differences on BW, ADG and G:F ratio compared with those of CON treatment (mixed treatment). However, split-sex feeding fed low protein diet had detrimental effects on growth performance. The blood creatinine in gilts was higher than that of barrows at 6 week. The BUN (blood urea nitrogen) concentration was decreased as dietary protein level decreased at 3 and 6 weeks and gilts showed lower BUN concentration than barrows at 9 week. The backfat thickness of barrows showed significantly higher than that of gilts regardless of dietary treatments. Pork color, cooking loss, shear force and proximate analysis of longissimus muscle were not affected by dietary protein, however, barrows showed higher WHC (water holding capacity) than that of gilts. The greatest economical profit was obtained in condition of sex split feeding without lowering CP in the diet. In conclusion, split-sex feeding had no detrimental effects on growth performance and pork quality but economical profit was decreased when pigs were fed low protein diet.Ⅰ. Introduction 1 Ⅱ. Literature Review 3 1. Introduction 3 1.1 Non-systematic swine management in domestic swine farms 5 2 split-sex feeding 7 2.1 Growth pattern by sex 7 2.2 Protein deposition by sex 9 2.3 Lipid deposition by sex 10 2.4 Nutrient requirements by sex 12 3. Dietary protein level in growing-finishing pig 15 3.1 Dietary protein level and protein deposition 15 3.2 Effect of dietary protein level on growth performance 16 3.3. Effect of dietary protein level on carcass characteristics 17 3.4. split-sex feeding by dietary protein levels 18 Ⅲ. Effect of split-sex feeding with Different Protein Diet on Growth Performance, Blood Profile, Pork quality and Economic Analysis in Pigs from Growing to Finishing 20 Abstract 20 Introduction 22 Materials and Methods 23 Results and Discussion 28 Implication 36 Ⅳ. Literature Cited 50 Ⅴ. Summary in Korean 73 Ⅵ. Acknowledgement 75Maste

축 압축력을 받는 유연식 라이저의 극한 강도의 간략화 모델을 이용한 유한 요소 해석

학위논문 (석사)-- 서울대학교 대학원 공과대학 조선해양공학과, 2017. 8. 장범선.Flexible risers are pipes connecting the offshore platform to the subsea flow line and transporting gas and oil. Flexible risers can encounter many uncertain factors during their installation and operation process. Especially, during installation process, due to the pressure unbalance, flexible risers can be subject to axial compression, which is an undesirable force. Axial compression can result in failure modes such as radial buckling. Therefore, it is very necessary to analysis failure modes and to evaluate the ultimate strength of flexible risers. Ultimate strength assessment of flexible risers is very complicated and time-consuming. This is because it includes many difficult points such as material nonlinearity, large deformation, and nonlinear contact mechanism. Also, it is difficult to understand structural behaviors under various loads. This paper introduces practical and stable methods for ultimate strength assessment using simplified FE models. In particular, numerical methods are provided to increase convergence of nonlinear analysis. In addition, the effects of ovalizations and external pressure are examined.1. Introduction 1 1.1. Introduction to Flexible Riser 1 1.2. Research Background 3 1.3. Previous Studies 8 1.4. Research Objective 11 2. Analytical Method 15 2.1. Elastic stiffness of flexible riser 15 2.1.1. Behavior about axisymmetric loads 15 2.1.2. Behavior about bending moment 27 2.2. Analytical Explanation of Radial Buckling 29 3. Research Model 29 3.1. Properties of 2.5-inch Flexible Riser 29 3.2. Simplification of Geometry of Layers 32 4. Numerical Method 35 4.1. Process of Numerical Method 35 4.1.1. Mesh Generation 35 4.1.2. Contact Setting 37 4.1.3. Analysis Setting 41 4.2. Simplification of Composition of Model 43 4.2.1. Determination of EQP 46 4.2.2. Verification of EQP 49 4.2.3. 3D 5-layered Model 50 5. Verification of Model 52 5.1. Axial tension test 52 5.1.1. Solid Model vs Shell Model 53 5.1.2. Isotropic Assumption 57 5.1.3. 8-lyaered Model vs 5-layered Model 59 5.2. Bending Test 61 6. Application to Ultimate Strength Analysis 61 6.1. Radial Buckling 61 7. Conclusion 74 Reference 76Maste

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