• 한국양식학회지
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• 제9권2호
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• pp.169-178
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• 1996

본 실험은 조피볼락의 비타민 C 요구량 설정을 위한 실험모델과 실험사료를 개발하고 각 조직 내의 비타민 C 축적량에 따른 영양특성 그리고 그에 따른 요구량을 제시하고자 실시되었다. 실험어는 실험시작 평균체중이 12.6 g인 조피볼락 치어를 사용하였으며, 6개 실험구로 나누어 3반복으로 비타민 C 첨가 농도를 달리한 6개의 반정제 실험사료를 공급하였다. 4주간의 예비사육 (대조구사료 공급)후 8주간의 사육 실험을 실시하였으며, 6가지 실험사료의 비타민 C 농도는 다음과 같다 ; 0 (대조구), 25, 50, 75, 150 and 1500 mg L-ascorbic acid/kg diet ($C_0,\;C_{25},\;C_{50},\;C_{75},\;C_{150},\;and\;C_{1500}$). 증중율과 사료전환효율은 대조구사료를 공급한 실험구가 $C_{150}$과 $C_{1500}$ 사료를 공급한 실험구보다 유의적으로 낮게 나타났다(P<0.05). Hematocrit은 대조구사료를 공급한 실험구가 다른 실험구들에 비해 유의적으로 낮게 나타났다(P<0.05). 근육 조직내의 비타민 C 농도는 대조구가 가장 낮아서 $C_{150}$과 $C_{1500}$ 실험구와 유의차를 보였고, 고농도 첨가구인 $C_{1500}$ 실험구가 다른 모든 실험구들에 비해서 유의적으로 높게 나타났다(P<0.05). 그러나 간, 아가미, 뇌조직의 비타민 C 농도는 $C_{1500}$ 실험구만 다른 실험구에 비해 유의적으로 높을뿐(P<0.05), 다른 실험구들간에는 유의적인 차이를 보이지 않았다(P>0.05), 따라서 조직내의 농도로는 근육에서 4.8 mg AA/kg 이하이면 성장, 사료효율, hematocrit에서의 결핍증상을 발견할 수 있을 것으로 판단되며, 사료내 비타민 C 요구량은 40 mg AA/kg diet 이상이고, 150 mg AA/kg diet이면 충분할 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권4호
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• pp.508-514
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• 2010

This study was conducted to evaluate the effects of dietary arachidonic acid (AA, 20:4n-6) levels on growth performance and body composition in juvenile eel, Anguilla japonica. Six semi-purified experimental diets were formulated to be isonitrogenous and iso-caloric containing 55.0% crude protein and 15% crude lipid (18.3 kJ of available energy $g^{-1}$). Six different levels of AA were added to the basal diet, with 0, 0.2, 0.4, 0.6, 0.8 or 1.2% on a dry matter (DM) basis, respectively ($AA_{0.07},\;AA_{0.22},\;AA_{0.43},\;AA_{0.57},\;AA_{0.78}\;or\;AA_{1.23}$). After a conditioning period, fish initially averaging 27${\pm}$0.5 g (mean${\pm}$SD) were randomly distributed into each aquarium as triplicate groups of 20 fish each. One of six experimental diets was fed on a DM basis to fish in three randomly selected aquaria at a rate of 2-3% of total body weight twice a day. At the end of the 12-week feeding trial, weight gain (WG) and feed efficiency (FE) of fish fed $AA_{0.78}$ and $AA_{1.23}$ diets were significantly higher than of fish fed $AA_{0.07},\;AA_{0.22},\;AA_{0.43}$ diets (p<0.05). Specific growth rate (SGR) of fish fed the $AA_{0.78}$ diet was significantly higher than of fish fed $AA_{0.07},\;AA_{0.22},\;AA_{0.43}$ diets (p<0.05). However, there were no significant differences in WG, SGR and FE among fish fed $AA_{0.57},\;AA_{0.78}\;or\;AA_{1.23}$ diets (p>0.05). Whole body AA deposition of fish fed the $AA_{1.23}$ diet was significantly higher than for the other diets (p<0.05). Broken-line model analysis on the basis of WG and SGR indicated that the dietary AA requirement could be greater than 0.69% but less than 0.71% of the diet in juvenile eel. The growth-promoting activity of AA observed in the present study provides strong support for the contention that dietary AA is essential for juvenile eel.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.19-19
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• 2003

This presentation reviewed the dietary vitamin C requirements in main marine finfish culture in Korea. In experiment I, an II-week feeding trial was conducted to study the effects of the different levels of dietary vitamin C on growth, tissue ascorbic acid concentrations and histopathological changes in parrot fish. Casein and gelatin based diets were formulated to contain 0, 60, 120, 240, 480 and 2000mg L-ascorbic acid (AA)kg diets on Ah equivalent basis in the form of L-ascorbyl-2-monophosphate (AMP), 60 and 240 mg AA/kg diet as L-ascorbic acid. Broken line analysis of weight gain indicated that the dietary vitamin C requirement of parrot fish is l18$\pm$12 mg AA/kg diet in the form of L-ascorbyl-2-monophosphate for maximum growth. In experiment II, a 12-week experiment was conducted to compare L-ascorbyl-2-monophosphate-Ca (AMP-Ca) with L-ascorbyl-2-monophosphate-Na/Ca (AMP-Na/Ca) for supplying the dietary vitamin C for juvenile Korean rockfish Sebastes schlegeli. Fish were fed one of 11 semi-purified diets containing equivalent of 0, 50, 100, 200, 400, and 800 mg ascorbic acid (AA)kg diet in the form of AMP-Ca or AMP-Na/Ca for 12 weeks. Broken line analysis of weight gain indicated that the dietary vitamin C requirement of Korean rockfish is 100 mg AA/kg diet in the form of AMP-Na/Ca, and 117 nag AA/kg diet in the form of AMP-Ca. In experiment III, a 12-week experiment was conducted to study the effects of different dietary levels of vitamin C, L-ascorbyl-2-polyphosphate (ASPP), on growth and tissue vitamin C concentrations in juvenile olive flounder. Fish were fed one of six semi-purified diets containing an equivalent of 0, 25, 50, 75, 150, or 1500 mg ascorbic acid (AA) kg 1 diet in the form of ASPP for 12 weeks. Based on broken line analyses for WG and PER, the optimum dietary levels of vitamin C were 91 and 93 mg AA/kg diet, respectively.

• 한국수산과학회지
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• 제29권5호
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• pp.643-650
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• 1996

본 실험은 조피볼락에서의 비타민 C 함량을 달리한 6가지 반정제사료를 28주간 공급했을때의 성장 효과와 그에 따른 네가지 조직에서의 비타민 C 축적량 및 비타민 C 요구량을 조사하기 위해 실시되었다. 4주간의 예비 사육 기간에는 어체내에 축적되어 있을 비타민 C 함량을 최소화하기 위해 비타민 C를 첨가하지 않은 $C_0$ 사료를 공급하였다. 실험어는 실험 시작 평균 체중이 12.6g인 조피볼락 치어를 사용하였으며, 6개 실험구로 나누어 3반복으로 하였으며, 6가지 실험 사료의 비타민 C 첨가 농도는 다음과 같다: 0, 25, 50, 75, 150 and 1500 mg L-ascorbic acid (AA)/kg diet $(C_0,\;C_{25},\;C_{50},\;C_{75},\;C_{150},\;&\;C_{1500})$. 총 28주간의 사육 실험 결과, 증체율, 사료전환효율, 일일성장율, 단백질전환효율은 $C_0$ 실험 구가 다른 모든 실험구들에 비해 유의적으로 낮게 나타났으며 다른 실험구들 간에는 유의적인 차이가 없었다 (P<0.05). 28주간 사육 실험 후의 조직내 비타민 C 분석결과, 네가지 조직 중 총 비타민 C 함량이 가장 높은 조직은 근육이며, 단위 무게당 비타민 C 함량이 가장 높은 조직은 뇌임을 알 수 있었다. 사료내 비타민 C 분석 결과, $C_25$ 사료구의 비타민 C 농도는 64.5mg AA/kg diet로 나타났다. 따라서 성장기 조피볼락에 있어서 사료내 비타민 C 요구량은 약 65mg AA/kg diet 정도일 것으로 추정된다.

• 한국가금학회지
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• 제49권1호
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• pp.33-43
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• 2022

The present study was conducted to determine the effect of reduced dietary crude protein (CP) with a synthetic indispensable amino acids (AA) supplement on the growth performance, economics, and breast meat quality. A total of 450 male broilers (Ross 308) were used from the age of 7 to 28 days. On d 7, the birds were individually weighed and randomly assigned to three treatment diets with six replicate pens for each treatment in a randomized complete block design. The experimental diets were: (1) a control diet, (2) a diet with a reduction of 1% of the dietary CP with synthetic AA supplements to meet the indispensable AA requirement (OAA) of broiler chickens, and (3) a diet with a reduction of 1% of the dietary CP with synthetic Lys, Met, and Thr supplementation to exceed 5% of the indispensable AA requirement (HAA). There were no differences among the treatments on the final body weight, weight gain, and feed intake. However, the HAA diet impaired the feed conversion ratio at d 21 and during the overall feeding periods (P<0.05). The predicted total feed intake and feed price required to reached 1.5 kg BW was higher than for the birds fed the HAA diet (P<0.05). The breast meat muscle fiber cross sectional area and fiber density varied between the treatments (P<0.05). However, there were no differences in breast meat weight. In conclusion, reducing 1% of dietary CP had no adverse effects on the growth performance or breast meat yields.

• 한국진공학회지
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• 제10권3호
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• pp.361-367
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• 2001

CMP(Chemical Mechanical Polishing)는 반도체 소자 제조공정 중 다층 배선구조의 평탄 경면화에 널리 이용되고 있다. 차세대 웨이퍼로 각광받는 SOI(Silicon On Insulator) 웨이퍼 제조공정 중 웨이퍼 표면 미소 거칠기를 개선하기 위해서 본 논문에서는 여러 가지 가공변수(슬러리와 연마패드)에 따른 CMP 연마능률과 표면 미소 거칠기 변화에 대해 연구하였다. 결과적으로 연마능률은 슬러리의 입자 크기가 증가할수록 이에 따라 증가하였으며, 미소 거칠기는 슬러리의 연마입자보다는 연마패드에 영향이 더욱 지배적이다. AFM(Atomic Force Microscope)에 의한 평가에서 표면 미소 거칠기가 27 $\AA$ Rms에서 0.64 $\AA$ Rms로 개선됨을 확인할 수 있었다.

• 한국산학기술학회논문지
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• 제5권4호
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• pp.367-370
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• 2004

초고속 RF IC의 핵심소자인 SiGe 에피텍시층을 가진 이종양극트란지스터(hetero junction bipolar transistor: HBT)를 0.35㎛급 Si-Ge BiCMOS공정으로 제작하였다. 낮은 VBE영역에서의 current gain의 선형성을 향상시키기 위하여 SiGe에피텍시층의 결함밀도를 감소시킬 수 있는 캐핑실리콘의 두께와 EDR온도의 최적화 공정조건을 알아보았다. 캐핑 실리콘의 두께를 200Å과 300Å으로 나누고 초고속 무선통신에서 요구되는 낮은 노이즈를 위한 EDR(Emitter Drive-in RTA)의 온도와 시간을 900-1000℃, 0-30 sec로 각각 변화시키면서 최적조건을 확인하였다. 실험범위 내에서의 최적공정조건은 300Å의 capping 실리콘과 975℃-30sec의 EDR 조건을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.849-856
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• 2017

Objective: The net energy requirement for the maintenance ($NE_m$) of broilers was determined using regression models by the indirect calorimetry method (ICM) or the comparative slaughter method (CSM). Methods: A $2{\times}4$ factorial arrangement of treatments including the evaluation method (ICM or CSM) and feed intake (25%, 50%, 75%, or 100% of ad libitum recommended) was employed in this experiment. In the ICM, 96 male Arbor Acres (AA) birds aged d 15 were used with 4 birds per replicate and 6 replicates in each treatment. In the CSM, 116 male AA birds aged d 15 were used. Among these 116 birds, 20 were selected as for initial data and 96 were assigned to 4 treatments with 6 replicate cages and 4 birds each. The linear regression between retained energy (RE) and metabolizable energy intake (MEI) or the logarithmic regression between heat production (HP) and MEI were used to calculate the metabolizable or net energy requirement for maintenance ($ME_m$) or $NE_m$, respectively. Results: The evaluation method did not detect any differences in the metabolizable energy (ME), net energy (NE), and NE:ME of diet, and in the MEI, HP, and RE of broilers. The MEI, HP, and RE of broilers decreased (p<0.01) as the feed intake decreased. No evaluation method${\times}$feed intake interaction was observed on these parameters. The $ME_m$ and $NE_m$ estimated from the linear relationship were 594 and 386 kJ/kg of body weight $(BW)^{0.75}/d$ in the ICM, and 618 and 404 kJ/kg of $BW^{0.75}/d$ in the CSM, respectively. The $ME_m$ and $NE_m$ estimated by logarithmic regression were 607 and 448 kJ/kg of $BW^{0.75}/d$ in the ICM, and were 619 and 462 kJ/kg of $BW^{0.75}/d$ in the CSM, respectively. Conclusion: The NEm values obtained in this study provide references for estimating the NE values of broiler diets.

• Structural Monitoring and Maintenance
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• 제9권1호
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• pp.43-57
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• 2022

One of the instances which demand structural engineer's greatest attention and upgradation is the changing live load requirement in bridge design code. The challenge increases in developing countries as the pace of infrastructural growth is being catered by the respective country codes with bigger and heavier vehicles to be considered in the design. This paper presents the case study of India where Indian Roads Congress (IRC) codes in its revised version from 2014 to 2017 introduced massive Special vehicle (SV) around 40 m long and weighing 3850 kN to be considered in the design of road bridges. The code does not specify the minimum distance between successive special vehicles unlike other loading classes and hence the consequences of it form the motivation for this study. The effect of SV in comparison with Class 70R, Class AA, Class A, and Class B loading is studied based on the maximum bending moment with moving load applied in Autodesk Robot Structural Analysis. The spans considered in the analysis varied from 10 m to 1991 m corresponding to the span of Akashi Kaikyo Bridge (longest bridge span in the world). A total of 182 analyses for 7 types of vehicles (class B, class A, class 70R tracked, class 70R wheeled, class AA tracked, AA wheeled, and Special vehicle) on 26 different span lengths is carried out. The span corresponding to other vehicles which would equal the bending moment of a single SV is presented along with a comparison relative to Standard Uniformly Distributed Load. Further, the results are presented by introducing a new parameter named Intensity Factor which is proven to relate the effect of axle spacing of vehicle on the normalized bending moment developed.

• Asian-Australasian Journal of Animal Sciences
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• 제15권2호
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• pp.247-253
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• 2002

Two experiments were conducted to investigate the impact of high temperature and dietary tryptophan (Trp) on performance, selected organ weights and plasma free amino acid (AA) concentrations in broiler chickens. In Experiment 1, exposure to $27-33^{\circ}C$ of chickens for 2 weeks from 2 weeks of age did not affect growth and plasma free AA concentration except for a decrease in the concentration of plasma tyrosine (Tyr). In Experiment 2, 2-week-old birds were allocated to one of three temperature treatments; $24^{\circ}C$ (control), $36^{\circ}C$ (heat stress, HS) and $24^{\circ}C$ pair-fed (24PF) for 2 weeks and fed on diets containing 50, 100 and 300% of NRC requirement for Trp. Heat stress caused a reduction of weight gain and feed intake irrespective of dietary Trp levels compared with control counterparts, while feeding of 300% Trp diet did not attenuate the reduced performance by HS exposure. In groups fed the 100% Trp diets, plasma aromatic AA (AAA) and Tyr concentrations were decreased in the HS birds compared with the 24PF group. Plasma concentrations in most of AA groups were increased by HS in chickens fed the 50% Trp diet, while those were not changed by HS in chickens fed the 300% Trp diet, compared with 24PF counterparts. The plasma Trp/LNAA (LNAA=large neutral AAs, which are comprised of BCAA, AAA and Trp) ratio was increased by HS in chickens fed the 100% Trp diet, while it was decreased in chickens fed on 50% Trp diet as compared with 24PF group. From these results, it is suggested that performance and plasma amino acid profile deranged by heat stress are modulated, at least, to be relieved from the heat stress by feeding 50% Trp diet but not at all by feeding 300% Trp diet. The involvement of altered plasma AA profiles, in particular plasma Tyr concentrations and Trp/LNAA ratio, is discussed in association with the performance characteristics of HS chickens.