• Composites Research
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• 제34권1호
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• pp.35-46
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• 2021

본 논문은 차량에 사용되는 B필러의 강화재를 기존의 스틸 소재에서 CFRP(Carbon Fiber Reinforced Plastics)와 GFRP(Glass Fiber Reinforced Plastics)로 대체하여 경량화하는 것이 목표다. 이를 위해서는 무게는 감소시키면서 기존 B필러를 대체할 수 있는 구조안정성을 확보해야 한다. 기존 B필러는 스틸 아우터(outer)를 포함하여 다양한 형상의 스틸 강화재로 구성되며, 이와 같은 스틸 강화재 중 2가지의 스틸 강화재를 복합재로 대체하고자 한다. 이와 같은 스틸 강화재는 강화재 각각을 따로 제작하여 용접을 통해 결합되지만, 복합재 강화재는 패치(patch) 형태의 CFRP와 리브(rib) 구조의 GFRP를 활용하여 압축과 사출 공정을 통해 한번에 제작된다. CFRP는 B필러의 고강도부에 부착되어 측면 하중에 저항하도록 하였으며, GFRP 리브는 위상 최적화(Topology optimization) 기법을 통해 비틀림과 측면 하중을 저항하도록 설계하였다. 구조해석을 통해 기존 스틸 강화재와 비교 분석을 수행하였고, 경량화율을 산출하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1424-1431
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• 2016

The objective of this study was to evaluate the effect of diets containing different amounts of wheat, as a partial or whole substitute for corn, on digestibility, digestive enzyme activities, serum metabolite contents and ruminal fermentation in beef cattle. Four Limousin${\times}$LuXi crossbred cattle with a body weight ($400{\pm}10kg$), fitted with permanent ruminal, proximal duodenal and terminal ileal cannulas, were used in a $4{\times}4$ Latin square design with four treatments: Control (100% corn), 33% wheat (33% substitution for corn), 67% wheat (67% substitution for corn), and 100% wheat (100% substitution for corn) on a dry matter basis. The results showed that replacing corn with increasing amounts of wheat increased the apparent digestibility values of dry matter, organic matter, and crude protein (p<0.05). While the apparent digestibility of acid detergent fiber and neutral detergent fiber were lower with increasing amounts of wheat. Digestive enzyme activities of lipase, protease and amylase in the duodenum were higher with increasing wheat amounts (p<0.05), and showed similar results to those for the enzymes in the ileum except for amylase. Increased substitution of wheat for corn increased the serum alanine aminotransferase concentration (p<0.05). Ruminal pH was not different between those given only corn and those given 33% wheat. Increasing the substitution of wheat for corn increased the molar proportion of acetate and tended to increase the acetate-to-propionate ratio. Cattle fed 100% wheat tended to have the lowest ruminal $NH_3-N$ concentration compared with control (p<0.05), whereas no differences were observed among the cattle fed 33% and 67% wheat. These findings indicate that wheat can be effectively used to replace corn in moderate amounts to meet the energy and fiber requirements of beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.861-867
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• 2005

Feeding values of soybean hulls (SH) were compared to those of wheat bran (WB) for swine diets by chemical compositions, a digestion trial, a preference test by self-selection, and two feeding trials. The SH and the WB appeared to have, on airdry basis, 11.1 vs. 15.4% CP, 32.5 vs. 8.7% crude fiber (CF), 36.8 vs. 10.7% ADF, 0.6 vs. 0.1% Ca, and 492 vs. 92 ppm Fe, respectively. Lysine and total sulfur-containing amino acids in the SH were 0.66 vs. 0.37%, respectively. Apparent digestibility values of the SH were 71% for dry matter, 50% for CP, and 74% for CF. Apparent digestible energy and MEn values of the SH were 2,420 and 2,370 kcal kg$^-1$, respectively, which were comparable to those of the WB, 2,420 and 2,275 kcal kg$^-1$ (NRC, 1998), respectively. The first feeding trial was conducted with 72 crossbred growing pigs with an average weight of 29.6 kg. The pigs when fed the diets containing 0, 6 and 10% SH by replacing the WB on a weight basis for 42 days did not show significant differences in body weight gain and feed/gain ratio among the treatments. The same trends were observed in the second trial with 60 crossbred finishing pigs with an average weight of 64.5 kg when fed the diets containing 12% SH or WB for 41 days. Back-fat thickness and adjusted loin eye muscle area of the finisher pigs were also not significantly different between the two groups. When allowed to self-select from two different feed troughs containing 10% SH or WB for two weeks, two groups of 80 pigs with 10 pigs per pen consumed the two diets exactly in equal proportion. In conclusion, the soybean hulls can be included up to 10 and 12% for growing or finishing pig diets, respectively, replacing the wheat bran on a weight basis without any adverse effects on palatability of diets and animal performances.

• 원예과학기술지
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• 제35권3호
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• pp.289-299
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• 2017

The objective of this study was to determine the effect of replacing perlite (PL) with pellets processed with poultry feather fiber as an inert material to prepare growing medium. The growth and flowering of Salvia splendens 'Vista Red' grown in individual growing medium $Biosangto^{(R)}$, peat moss (PM), PL, and two pellets (P45-1 and P45-2) were evaluated. Peat moss was mixed with PL, P45-1, or P45-2 at various ratios (1:0 to 1:3 or 3:1 by volume) to investigate the feasibility of replacing PL with pellets. Nutrient composition of the growing medium and leaf tissues was analyzed. The number of florets, inflorescence length, plant height, and fresh weight of plants grown in media containing P45-1 or P45-2 were reduced compared to those grown in individual growing medium PM or PL. As the mixing ratio of P45-1 or P45-2 to PM was higher, the growth of salvia, such as inflorescence length, plant height, number of leaves, and fresh weight was inhibited. Our results indicate that mixing three parts PM with one part of P45-1 (PM/P45-1/3:1) or P45-2 (PM/P45-2/3:1) accelerated flowering and increased the number of florets and leaves compared to other mixing ratios of PM and pellets media. The concentrations of phosphorus (P), calcium (Ca), boron (B), iron (Fe), and copper (Cu) in individual growing medium PL, P45-1, and P45-2 were significantly lower than those in PM. The concentration of N was the highest in leaves of plants grown in P45-1 or P45-2 amended media, and the concentrations of P, Ca, and zinc (Zn) in leaves were lower in individual growing medium P45-1 or P45-2 than in PM and PL. The pH of PM/P45-1/3:1 or PM/P45-2/3:1 media was maintained at optimal level (5.8-5.9) and the concentrations of macro- and micro-elements in the media and leaves were considered to be optimal levels. Therefore, mixing three parts PM with one part P45-1(PM:P45-1/3:1) or P45-2 (PM:P45-2/3:1) is recommended for improved growth and flowering in salvia. This suggests that P45-1 or P45-2 can replace PL as an inert material to prepare growing medium.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.825-834
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• 2005

Two experiments were conducted with growing crossbred Super-Meat ducks at the experimental duck farm of Cantho University to evaluate the effects of reducing the proportion of soybean meal (SBM) in a broken rice (BR)-SBM mixture and providing soya waste (SW) ad libitum (Expt. 1), and reducing the proportion of fish meal (FM) in a BR-FM mixture and supplying ensiled shrimp waste (ESW) ad libitum (Expt.2). Both experiments included five treatments, with three replicates and ten growing ducks per replicate. In Expt.1, the five diets were based on BR and five levels of SBM, with SW offered ad libitum. The control diet (SBM25) consisted of 75% BR and 25% SBM, and the other four treatments included SBM levels of 20% (SBM20), 14% (SBM14), 8% (SBM8) and 0% (SBM0) mixed with BR to 100%, and with SW ad libitum. In Expt. 2, the control diet consisted of 86% BR and 14% FM, and the other dietary treatments had FM levels of 11% (FM11), 8% (FM8), 4% (FM4) and 0% (FM0) mixed with BR, and with ESW ad libitum. In Expt. 1, total intakes of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF) and metabolizable energy (ME) were higher for birds given SW (p<0.001). Total CP intake was highest on the SBM20 diet, and lowest on the SBM0 diet (p<0.001). Lower daily gain (DG) was found for the SBM0 diet (p<0.01). Carcass weights were higher on the control treatment, with the lowest values on the SBM0 diet (p<0.001). Gizzard weights were higher on diets with high intakes of SW (p<0.05). In Expt. 2, birds with high intakes of ESW (FM4 and FM0) had lower (p<0.01) daily intakes of DM. The total CP intakes declined (p<0.001) with higher intakes of ESW. The highest DG were for the control and FM11 diets, while the lowest value was for diet FM0 (p<0.001). The poorest feed conversion ratio (FCR) was for the FM0 treatment (p<0.01). Lower weights of carcass and breast muscle were found on the FM0 diet (p<0.001). Feed costs per kg gain were only slightly different between diets. However, the lowest feed cost was for ducks on the SBM0 and FM11 diets in Expt.1 and Expt. 2, respectively.

• Journal of Animal Science and Technology
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• 제51권3호
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• pp.241-248
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• 2009

본 연구는 팽이버섯 재배 후 폐기물로 방치되어온 팽이 버섯 폐 배지를 거세한우 사육용 조사료로의 사료적 가치를 규명하기 위해 반추위 누관이 장착된 면양 3두를 이용한 대사시험과 12개월령의 거세한우 24두를 이용하여 20개월령까지 8개월간 사양 실험을 실시하였다. 대사시험의 경우 시판 한우 비육 전기용 배합사료(70%)와 볏짚(30%, 건물 기준)을 급여하였으며(대조구, CON) 시험구의 경우 발효 팽이버섯 폐 배지(fermented spent mushroom compost, FSMC)를 대조구 볏짚 급여량의 30% (FSMC-30) 또는 60% (FSMC-60, 건물 기준) 수준으로 대치하여 급여하였다. 거세한우를 대상으로 한 사양시험 사료 역시 대사시험과 동일한 방법으로 제조된 발효 팽이버섯 폐 배지를 동일한 비율로 볏짚을 대치하여 급여하였다. 면양 반추위액의 pH는 발효팽이버섯 폐 배지가 포함된 시험사료(FSMC-30 및 FSMC-60)에 의한 영향을 받지 않았다. 반추위액의 암모니아의 농도는 사료 급여 후 3시간에서 볏짚의 60%를 FSMC로 대치하여 급여한 처리구(FSMC-60)에서 암모니아 농도가 가장 높았다(P<0.045). Acetate 조성비율은 사료 급여 후 1시간 및 3시간에서 볏짚대신 발효팽이버섯 폐 배지를 60% 대치 급여한 처리구(FSMC-60)에 비하여 볏짚을 급여한 대조구에서 더 높았다(P<0.001). 이와는 반대로 propionate 조성 비율은 모든 반추위액 채취 시간에 걸쳐 FSMC-60 처리구에서 가장 높은 것으로 나타났다(P<0.027~P<0.002). Butyrate의 경우 타 처리구에 비하여 볏짚대신 발효팽이버섯 폐 배지를 30% 대치 급여한 처리구(FSMC-30)에서 사료 급여 30분 전(P<0.031)과 급여 후 1시간(P<0.011) 및 6시간(P<0.039)에 높은 조성 비율을 보였다. Propionate에 대한 acetate의 비율($C_2/C_3$)은 FSMC-60 처리구에서 가장 낮은 것으로 나타났다. 시험사료의 건물(EDDM), 조단백질(EDCP), 조지방(EDEE) 및 NDF(EDNDF) 유효 분해율은 볏짚에 대한 발효팽이버섯 폐 배지 대치에 의한 영향을 받지 않은 것으로 조사되었다. 조단백질(P<0.031)과 NDF (P<0.006)의 전장 소화율은 조사료로서 볏짚만을 급여한 처리구에서 높았지만 발효팽이버섯 폐 배지를 볏짚의 60% 수준으로 대치 급여한 처리구(FSMC-60)에서 가장 낮은 것으로 나타났다. 거세한우의 총 증체량 및 평균 일당증체량은 시험사료에 의한 영향을 받지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.502-511
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• 2005

The effects of different levels of crude protein (CP) and cottonseed meal replacing for soybean meal in cassava chips and rice straw-based diets for mid-lactating cows (100-150 day in milk [DIM]), were studied using 32 multiparous Holstein Fresian crossbred dairy cows. Diets containing 10.5, 12.5, 13.7, 14.4% CP of the rations and 0, 12.1, 14.9, 17.8% cottonseed meal were fed to cows for 60 days. Thirty two cows were randomly divided into four dietary treatments using a Randomized complete block design. Four dietary treatments were offered in the form of total mixed ration (TMR) with concentrate to roughage (chopped rice straw) at 60:40 and offered ad libitum. Dry matter (DM) and neutral detergent fiber (NDF) intakes tended to linearly increase with increasing dietary CP levels. Intakes and digestibility of crude protein increased linearly with increasing dietary CP level (p<0.01). Crude protein digestibility of the 10.5% CP diet was lower (p<0.05) than that in diets with higher levels of CP, while there were no significant differences among the other three levels of CP (12.5, 13.7 and 14.4%). Daily milk yield tended to increase with increased CP from 10.5 to 14.4%. Income over feed in terms of US$/kg of milk increased with increased CP from 10.5 to 13.7% and decreased when the CP level was higher than 13.7% (quadratic effect p<0.09). Milk composition was not significantly affected by increasing level of CP, however there were relatively high contents of protein and fat among treatments. The proportion of milk-urea N (MUN), ammonia-N ($NH_3$-N) and bloodurea N (BUN) were closely correlated and increased linearly with increasing CP levels (p<0.01). Balanced diet was found in diet containing 12.5 and 13.7% CP of the rations when BUN and MUN were used as indicators of the protein to energy ratio in the diet. Conclusions can be made that increasing dietary CP levels from 10.5 to 13.7% using cottonseed meal as the main source to completely replace soybean meal was beneficial to cows consuming rice straw and cassava chips based-diets. Increasing the CP level above 13.7% of total ration did not additionally improve milk yield and composition or net income.

• 한국강구조학회 논문집
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• 제16권5호통권72호
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• pp.609-619
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• 2004

유럽을 중심으로 스틸스터드의 약점으로 지목 받고 있는 열교현상을 억제하기 위한 스터드 개선 연구가 활발히 진행되고 있다. 이 연구는 크게 마감재와 접촉 면적을 줄이는 방법, 웨브면에서 열전달 경로를 늘이는 방법, 열전도성이 낮은 소재를 사용하는 방법, 그리고 스터드를 피복하는 방법으로 구분할 수 있다. 비교적 저층의 주거용 건축물을 대상으로 하는 국외의 경우 에너지 소비에 초점이 맞춰져 있지만, 본 연구의 경우 중층화를 대비하여 구조적 성능도 고려하여 아연도금강판(SGC58)과 FRP를 에폭시로 부착하여 150SL 형태의 복합스터드를 개발하였다. 복합스터드의 소재로는 두께 1.0mm과 1.2mm 강판과 두께 4mm(4ply), 6mm(6ply)의 FRP를 적용하였고, 4가지의 접합 상세에 대한 제작 및 실험을 통해 최종적으로 우수한 결과를 보인 2가지를 선택하였다. 이와 같은 과정을 거쳐 개발된 복합스터드의 압축 성능을 확인하기 위해 2가지 접합 상세에 대해 단면 높이인 150mm에 대해 3, 6, 9, 12배 길이에 대해 압축 실험을 계획하였고, 기존 스틸 스터드와 비교하기 위하여 동일 형태의 비교 실험체도 제작하였다. 실험결과, 복합스터드의 최대하중은 강판 두께 1.0mm인 경우 동일 두께의 스틸 스터드보다 평균 1.62배, 1.2mm인 경우 평균 1.46배 증가하였으며, 가력 종료 시점에 이르기까지 일체 거동을 보여 구조적으로 우수함이 입증되었다.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.801-811
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• 2020

The main objective of this in vitro study was to evaluate red ginseng byproduct (RGP) as a protein resource and its effects on rumen fermentation characteristics, microflora, CO2, and CH4 production in ruminants. Four treatments for in vitro fermentation using buffered rumen fluid over a 48 h incubation period were used: 1, RGP; 2, corn gluten feed (CGF); 3, wheat gluten (WG); and 4, corn germ meal. In vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), in vitro crude protein digestibility (IVCPD), volatile fatty acids, pH, and ammonia nitrogen (NH3-N) were estimated after 48 h incubation. Gas production was investigated after 3, 6, 12, 24, 36 and 48 h. The CO2 and CH4 were evaluated after 12, 24, 36, and 48 h. A significant difference in total gas production and CO2 emissions was observed (p < 0.01) at all incubation times. CH4 production in RGP were higher (p < 0.05) than that in other treatments but a higher CH4 portion in the total gas production was observed in WG (p < 0.05) at 48 h incubation. The IVDMD, IVNDFD, and IVCPD of RGP was lower than those of other conventional ingredients (p < 0.01). The RGP had the lowest NH3-N value among the treatments (p < 0.01). The RGP also had the lowest total VFA concentration (p < 0.01), but presented the highest acetate proportion and acetate to propionate ratio among the treatments (both, p < 0.01). The abundance of Prevotella ruminicola was higher in RGP than in WG (p < 0.01), whereas RGP has lower methanogenic archaea (p < 0.01). In conclusion, based on the nutritive value, IVDMD, low NH3-N, and decreased methanogenic archaea, RGP inclusion as a protein source in ruminant diets can be an option in replacing conventional feed sources.

• Animal Bioscience
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• 제35권1호
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• pp.29-38
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• 2022

Objective: The objective of this study was to compare the feeding value, meat nutrients and associative effects of a diet comprised of various corn silages inclusion with peanut vine or wheat straw in finishing beef cattle. Methods: One hundred and eighty Simmental crossbred beef steers were blocked and assigned to the follow treatments: i) whole plant corn silage-based diet (control, WPCS), ii) mixed forages-based diet (replacing a portion of corn silage with wheat straw, WPCSW), iii) corn stalklage-based diet (CS), and iv) sweet corn stalklage-based diet (SCS). Each group consisted of 5 repeated pens with 9 steers/pen. The diets were formulated to be isonitrogenous and isoenergetic with same forage to concentrate ratio. Experimental diets were fed for 90 d. Results: The effective ruminal degradability of dry matter and crude protein were highest for WPCS diet (p<0.05), for neutral detergent fiber was highest in SCS diet (p<0.05). The average daily gain was greater for cattle offered the WPCS diet, intermediate with WPCSW and SCS and lowest with CS (p<0.001). The concentration of non-esterified fatty acid in serum was higher for steers fed with CS and SCS diets than those offered WPCS and WPCSW steers (p<0.001). The treatments did not affect the general nutritional contents and amino acids composition of Longissimus dorsi of steers (p>0.05). Conclusion: The corn silage-based diet exhibited the highest feeding value. The sweet corn stalklage and wheat straw as an alternative to corn silage offered to beef cattle had limited influence on feeding value and meat nutrients. However, the value of a corn stalklage-based diet was relatively poor. To sum up, when the high quality forage resources, such as corn silage, are in short supply, or the growth rate of beef cattle decreases in the later finishing period, the sweet stalklage and wheat straw could be used as a cheaper alternative in feedlot cattle diet without sharp reducing economic benefits.