• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.213-223
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• 2002

This study was conducted to investigate the influence of feeding various Lactobacillus on production performance, nutrients digestibility, intestinal microflora, and fecal $NH_{3}$ gas emission in laying hens. Three hundred and sixty ISA Brown layers, 21 weeks of age, were randomly allotted to nine treatments, with low replicates per treatment. Nine treatments consisted of Control(no Lactobacillus), Lactobacillus crispatus avibrol(LCB: KFCC-11195), Lactobaciilus reuteri avibro2(LRB: KFCC-11196), Lactobacillus crispatus avihenl(LCH: KFCC-11197), Lactobacillus vaginalis avihen2(LVH: KFCC-11198). Each Lactobacillus was added at two levels ($10^{4}$and $10^{7}$ cfu/g diets). Egg production, and egg weight were measured daily. A metabolism trial was conducted following the 12-week feeding trial, during which egg qualities, intestinal microflora and fecal $NH_{3}$ gas emission were examined. Egg production and daily egg mass improved significantly by the addition of various Lactobacillus(P<0.05), of which effect was more notable during the latter part of the feeding trial. But, no significant differences were found among Lactobacillus strains and between two levels of supplementation. Egg weight and feed intake showed no difference among all treatments. Feed conversion ratio of birds fed lactobacillus was significantly improved compared to that of the Control(P<0.05), but not different among lactobacillus treatments. Digestibility of crude protein, ether extract and crude ash improved significantly in lactobacillus treatments(P<0.05). However, there were not statistically different by adding levels and strains. Total counts of Lactobacillus spp. in ileum of layers fed Lactobacillus were significantly higher than that of the control, but no consistent trend was found in cecum. There were no significant differences in intestinal yeast and anaerobes counts among all treatments. The Lactobaciilus supplementation did not exert my effect on the eggshell quality and Haugh unit. Fecal $NH_{3}$ gas emission decreased significantly in Lactobacillus treatments, and showed no difference between the two supplementation levels. From the result of this study, it could be concluded that dietary supplementation of Lactobacillus, regardless of their species, Improves the laying performance and decreases the fecal ammonia gas emission. The proper level of supplementation appears to be $10^{4}$ cfu/g of diet.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.667-676
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• 2008

This experiment was conducted to investigate the effects of dietary supplementation of various Lactobacilli strains on growth performance, intestinal microflora, ileal villi development and ileal mucosal surface of broiler chickens. Six hundred 1-d-old male chicks(Avian) were randomly divided into five groups of four replicates, each replicates containing 30 birds and fed corn-soybean meal diets containing Latobaillus were isolated from cecum of chichens at 107cfu/g diet for five weeks. The treatments were control(antibiotics-free diet), Lactobacillus crispatus avibro1(LCB), Lactobacillus reuteri avibro2(LRB), Lactobacillus crispatus avihen1(LCH) or Lactobacillus vaginalis avihen2(LVH). The body weight gain in groups fed Lactobacillus significantly improved as compared to those of control(P<0.05). Feed intake was not statistically different among the groups. The number of Lactobacillus in ileum and cecum of chicks fed various Lactobacillus tended to be increased or significantly increased as compared to those of the control(P<0.05), but there was difference by age of chicks and species of Lactobacillus. The number of yeast was significantly increased in cecum and ileum at three weeks old chicks fed Lactobacilli compared with the control(P<0.05). The anaerobes’ number of ileum and cecum tended to increase or significantly increased in Lactobacillus treatments compared with the control(P<0.05). The ileal villi length extended greatly at three weeks of age in groups fed Lactobacillus compared with the control(P<0.05). The length of ileal villi in chicks fed Lactobacillus was continuously increased up to five weeks of age, but did not increased in the control(P<0.05). Lactobacillus was found on ileal mucosal surface. And ileal mucosal surface was maintained better with Latobacillus feeding. These results suggest the possibility that cecal Lactobacillus of chickens could be used as probiotics by improving the growth performance and promoting development of ileal villi in broiler chicks.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.6
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• pp.533-540
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• 2012

Rubber laminated bearings with lead core are highly affected by changes in temperature because key materials which are rubber and lead have temperature dependencies. In this study, two full scale LRB(D800, S=5) are manufactured and temperature dependency tests on shear properties are accomplished. The shear properties at the 3rd cycle are used at $-10^{\circ}C$, $0^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$, $40^{\circ}C$ respectively. The double shear configuration, simultaneously testing two pieces, is applied for compression shear test in order to minimize the friction effects due to the test machine, described in ISO 22762-1:2010. Characteristic strength, post-yield stiffness, effective stiffness, equivalent damping ratio are estimated and presented coefficient due to the temperature changes.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.305-311
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• 1998

최근들어 고려된 LBB(Leak Before Break) 적용요건중 동적파괴시힘 절차에는 울진 3&4호기 이후 파단전누설개념이 적용되는 배관이 탄소강으로 제작될 경우. 이 배관이 Dynamic Strain Aging (DSA)에 의해 파괴저항치가 감소되지 않는다는 것이 정량적으로 입증되지 않는 한, 동 배관의 파괴 물성치 결정시 DSA의 영향이 고려되어야 하며, DSA 영향을 평가하기 위해서는 동적과괴시험이 수행되어야 함을 요건화 하고 있다. 본 연구에서는 DSA 효과에 의한 파괴저항(J-R) 특성의 저하가차세대원전 원자로냉각재배관 파단전누설개넘(LBB) 적용시 설계 안전여유도에 영향을 미치지 않는 정도임을 평가하는데 있다. 따라서 ASME Section III에서 탄소강으로 분류하고 있는 강종별 파괴인성 변화를 고찰하고, 차세대원전 주냉각재배관 재료인 SA508 Class la의 최대 파괴인성 감소치를 예측하여, 울진 3&4호기에서 측정된 엘보우용 SA516-Gr.70 강의 DSA 영향 평가 결과와 비교 분석하여 차세대원전 주냉각재배관의 DSA영향을 평가하였다. 도출된 결론으로는 DSA 영향을 고려한 SA508 Class la의 J 및 dJ/dA 값은 극히 보수적으로 추정할 때 50% 이상 감소하는 것으로 예측된다. 이러한 DSA 영향을 고려하였을 경우 배관재 모재의 파괴인성치는 Weld-SAW의 J/T 값 수준으로 감소하였다. 그러나 현 LRB 해석이 가장 낮은 J/T값을 갖는 Weld-SAW Auto의 균열길이 2a인 J/T선도에 의거하여 수행되고 있다는 점을 고려한다면 비록 DSA가 배관재에 영향을 주는 가장 보수적인 값(J 및 dJ/dA값을 50% 이상)을 사용한다고 하더라도 차세대원전 LBB 적용에 문제가 되지 않음을 알 수 있다. 즉 차세대원자로 주냉각재배관에 LBB를 적용하는데는 DSA 영향은 상대적으로 중요하지 않다는 결론을 얻었다. 표면에 수소화물이 농축되어 있는 hydride layer가 형성됨을 관찰하였으며 ～5,000ppm 이상의 경우에는 수소화물의 방향성이 random하였으며 특히, ZIRLO$^{TM}$ 시편의 경우에서는 원주방향으로 길게 이어진 수소화물과 기계적 성질에 치명적인 반경방향의 수소화물이 평행하게 배열된 것을 관찰하였다.하였을 때는 Li$_2$O의 첨가에 의해 치밀화가 주로 일어났고, 반면에 $N_2$-7vol.%H$_2$ 분위기에서 소결하면 Li$_2$O의 첨가에 의해 작은 기공은 소멸되고 큰 기공이 생성되었다.지나치게 모국어의 영향만 강조하고 다른 요인들에 대해서는 다분히 추상적인 언급으로 끝났지만 이 분석을 통 해서 배경어, 목표어, 특히 중간규칙의 역할이 괄목할 만한 것임을 가시적으로 관찰할 수 있 다. 이와 같은 오류분석 방법은 학습자의 모국어 및 관련 외국어의 음운규칙만 알면 어느 학습대상 외국어에라도 적용할 수 있는 보편성을 지니는 것으로 사료된다.없다. 그렇다면 겹의문사를 [-wh]의리를 지 닌 의문사의 병렬로 분석할 수 없다. 예를 들어 누구누구를 [주구-이-ν가] [누구누구-이- ν가]로부터 생성되었다고 볼 수 없다. 그러므로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어([$[W1]_{XO-}$ $[W1]_{XO}$ ]$_{XO}$)로

• Korean Journal of Poultry Science
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• v.28 no.1
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• pp.27-40
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• 2001

This study was conducted to investigate the effects of feeding various Lactobacillus on performance, nutrients digestibility, intestinal microflora, and fecal noxious gas of broiler chicks. One thousand eighty one dat old male broiler chicks were fed into Lactobacillus crispatus avibrd 1(LCB), Lactobacillus reuteri avibro 2(LRB), Lactobacillus crispatus avihen 1(LCH), and Lactobacillus vaginalis avehen 2(LVH) at the level of $10^{4}$ and 10(sup)7cfu/g diet. There were four replicates with thirty chicks per pen. Diets contained ME 3,100, 3,100kcal/kg, and CP 22.0, 20.0% for starting and finishing period, respectively. Weight gain of checks fed Lactobacillus spp. tended to increase from the first week and was higher from 50 to 100g in Lactobacillus treatments than control. Feed intake and feed conversion were not statistically different of all treatments. Dry Matter(DM) digestibility of Lactobacillus treatments was tended to improve compared to that of control, but was not significantly different. Protein and Ca digestibility were also tended to improve in Lactobacillus treatments relative that of control. Lactobacillus treatments showed improved tendency in crude ash and fat compared to those of control, whereas phosphorus digestibility was not consistency. Nutrients digestibilities of bird fed LCH were superior to those of other treatments. It showed significantly higher in Ca and P digestibility than control(P〈0.05). Total Lactobacillus spp. of birds fed various lactobacillus was significantly higher in ileum for five weeks(P〈0.05), but was not different at cecum. Yeast was thought to be not completely attached to intestinal lumen for one week. However, total number of yeast was significantly increased in cecum and ileum from three weeks old chicks(P〈0.05). The number of anaerobes exhibited to tendency the increase in Lantobacillus treatments from one week old of age at both ileum and cecum. Moisture contents of birds fed Lactobacillus spp. was shown from 27 to 30% at five weeks old, whereas it was 38.2% in control. It decreased approximately 25% in Lactobacillus treatments relative to that of control and showed significance between them(P〈0.05). Fecal $NH_{3}$ gas emission was significantly decreased in Lactobacillus treatments and maintained $\frac{1}{3}$to $\frac{1}{2}$ of control(P〈0.05). LCH and LVH treatments were most effective to decrease fecal $NH_{3}$ gas and especiallt impreved ti significantly at the level of the level of 10(sup)7cfu/g diets covpared to that of $10^{4}$ cfu/g diets and control(P〈0.05). In conclusion, feeding Lactobacillus spp. increase performance and nutrients digestibilities of broiler chicks and improve environments of house. Proper supplemental level of Lactobacillus spp. is considered more than $10^{4}$ cfu/g diet.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.124-125
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• 2002

Two experiments were conducted to investigate the response of chitosan supplementation in diet on the major economic traits of broiler in two different breeds. In the both experiments, the Arbor Acres and Ross breeds were used as experimental stocks and two groups were assigned in each breed. The control group birds(CON) were fed with basal diet only and the experimental group birds(EXP) were fed with basal diet added with 10.5mg chitosan/bird/day. The chitosan was supplied to birds from day-old in experiment 1 and from 15-day-old in experiment 2. In experiment 1, the mean body weight at 35-day-old were significantly(P〈0.05) heavier by 121.2 g and 243.7 g in the EXP groups than in the CON groups of Arbor Acres and Ross, respectively. Whereas, the mean body weights at 35-day-old in experiment 2 were lighter by 91.7 g and 70.2 g in the EXP groups than in the CON groups of Arbor Acres and Ross, respectively : however, the comparisons between breeds in the mean body weight at 35-day-old did not show significant difference in each other in both breeds. In the mean feed conversion ratio of Arbor Acres from 14 to 35-day old in experiment 1, it did not show significant difference between EXP and CON groups although the feed conversion ratio of the EXP group of Ross was significantly higher(P〈0.05) than the CON group. In experiment 2, the feed conversion ratios from 14 to 35-day-old did not show significant differences between the two breeds. The percentage of mean abdominal fat depositions of EXP groups in both breeds In experiment 1 were significantly(P〈0.05) higher than those of CON groups. And the percentage of mean abdominal fat deposition of Ross was significantly(P〈0.05) lower than that of Arbor Acres. In experiment 2, the percentage of mean abdominal fat depositions did not show significant difference between EXP and CON groups in both breeds. Whereas, the interaction effects between breed and experimental groups on the above economic traits did not show significant in both experiments.