• The Journal of the Acoustical Society of Korea
• /
• v.20 no.4
• /
• pp.62-70
• /
• 2001

Based on the recently developed resonance scattering theory for elastic waves, a relationship between the stress components, which may be measured using ultrasonic transducers, of partial waves scattered from cylindrical fluid scatterer, cavity, and resonance scatterer has been derived. The computed resonance scattered stresses exhibit frequency behaviors similar to the corresponding scattering coefficients: particularly, abrupt changes in phase by 180°near the resonant frequencies. By studying the behavior of pressure in the fluid scatterer, the physics of the theory has been further understood. Using the method studied and developed in this paper, nondestructive characterization of fluid inclusions in elastic media is expected to become more reliable.

• Korean Journal of Poultry Science
• /
• v.29 no.3
• /
• pp.171-176
• /
• 2002

Two experiments were conducted to investigate the effects of taurine supplementation on the egg production and egg quality in laying hen. In experiment 1, 19-wk-old laying hens were allowed one of four taurine supplemented diets (0 (control), 0.4, 0.8, and 1.2% taurine) for 10 weeks. The mean egg weight was lower about 1.2g in the 0.8% diet compared to the control. Egg production rate, egg mass, and feed intake in layers fed with 0.4, 0.8, and 1.2% taurine supplemented diets decreased by 8%∼24%, 3%∼l4% and 11%∼l5%, respectively, relative to the control. However, the feed conversion, parameters of egg quality, and the concentration of triacylglycerol and the level of cholesterol in yolk were not different among the treatments. In experiment 2, 81-wk-old laying hens were allocated one of three taurine supplemented diets(0 (control), 1 and 2% taurine) for 6 weeks. The egg weight, egg production rate, egg mass, feed intake, feed conversion, parameters of egg quality, and level of yolk cholesterol were not different among the treatments, but the concentration of triacylglycerol in yolk was higher by 14%∼19% compared to the control. In conclusion, these results indicated that taurine supplementation in early laying stage of layers decreased hen performance.

• Korean Journal of Poultry Science
• /
• v.50 no.1
• /
• pp.15-22
• /
• 2023

This study was to investigate the relationship between chick weight in the growing period and the laying performance of Korean native chicken (KNC) breeders. We measured the body weights of 1,384 KNC breeders at 1-140 days of age at two-week intervals. The age at first egg laying, hen-day and hen-housed egg production, and the egg weights were investigated. Correlation coefficients between the body weight and egg production traits were analyzed. The results showed that the correlation coefficients between body weight and age at first egg laying were significantly positive before 4 weeks, but negative after 8 weeks of age. The correlation coefficients between body weight and egg production rate were estimated to be negative before 8 weeks and positive after 12 weeks of age. Coefficients of hen-day and hen-housed egg production were similar. There was little correlation between body weight and egg weight at 32 weeks of age, whereas a low positive correlation was with egg weight at 50 weeks. In conclusion, there was little correlation between body weight and laying performance before 8 weeks of age, whereas a significant positive correlation was with body weight after 12 weeks. The results suggest that as the chick's weight increases in the late growing stage, sexual maturity is faster, the egg production rate is higher, and the egg weight increases. Therefore, the weight management of KNC female breeders is very important in the late growing stage, and the body weight of chicks must be maintained above the standard weight.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.371-371
• /
• 2012

단일 Si 나노와이어 전체에 대한 편광 및 공간 분해된 라만 산란 실험을 보고한다. 투과전자현미경 실험을 통해 나노와이어가 길이 방향으로 성장함에 따라서 두께가 점차 증가할 뿐만 아니라 결정 방향이 비균질적으로 형성됨을 알 수 있었다. 비균질적인 결정성은 아래 부분에서 두드러지게 나타났다. Si 나노와이어의 길이 방향으로 공간 분해된 마이크로-라만 산란 실험을 수행한 결과 에너지 및 선폭에 변화가 있음을 알았다. 이러한 변화와 결정 방향의 비균질성을 이해하기 위하여 나노와이어의 위 부분과 아래 부분으로부터 각각 편광 라만 산란 실험을 하였다. 라만 편광 선택 규칙을 이용하여 입사 편광 각도의 변화에 따른 광학 포논의 세기 변화를 분석한 결과 결정 방향이 부분적으로 어긋나 있는 나노와이어의 아래 부분에서의 편광 비율의 수치가 위 부분에서의 수치보다 작게 나타남을 알 수 있었으며 이는 결정성의 변화와 일치한다.

• KOREAN POULTRY JOURNAL
• /
• v.53 no.10
• /
• pp.124-127
• /
• 2021

고병원성 AI 발생, 계란 살충제 파동, 저난가 시대 등 지난 3년간 산란계 산업에 많은 어려움들이 있었다. 이러한 어려움 속에서도 30년 넘게 양계업을 해오며 높은 산란 성적률을 보여주며 2대를 이은 농장 운영으로 탄탄한 사육 현장을 보여주고 있는 충남 아산시 소재의 신창농장의 김병규 대표를 찾았다.

• Journal of radiological science and technology
• /
• v.32 no.4
• /
• pp.393-399
• /
• 2009

In this study, we measured the dose distribution of scattered ray in X-ray radiography room using an ion chamber and examined the dependency of scattered ray content on the scattered ray source and exposure condition. To study the factors of scattered ray occurrence in the acryl phantom, we measured the change in the scatted ray content according to the X-ray tube voltage (40~140 kV) and the field size ($10{\times}10\;cm^2$, $20{\times}20\;cm^2$, $35{\times}35\;cm^2$). For the $35{\times}35\;cm^2$ field size, the side-scattering rate ranged from 3.1% to 14.5%. The scattered ray contributions of the phantom, collimator, X-ray tube and wall were also measured. The scattered ray contribution of the phantom was higher than 95.4% for the entire tube voltage, and those of the collimator, X-ray tube and wall were 2.6%, 1.3% and 0.7%, respectively.

• Korean Journal of Poultry Science
• /
• v.14 no.2
• /
• pp.125-135
• /
• 1987

Total 720 brown layers were fed 9 rations differing in metabolizable energy (2500, 2700 and 2900 kcal/kg) and crude protein (13, 15 and 17%) levels for a period of 12 weeks in order to study the effects of dietary energy and protein levels on the performance of brwon layer in summer. As metabolizable energy level increased from 2500 to 2900Kcal/kg of feed egg production, daily feed and protein intake were decreased, but daily energy intake, energy requirement and feed cost per kilogram of egg mass were increased. There were no significant difference in egg weight, feed conversion and motality among dietary energy levels. On the other hand, as dietary Protein level increased from 13 to 17% egg Production, egg weight, daily protein intake and protein requirement per kilogram of egg mass were increased, but feed and energy requirement and feed cost per kilogram or egg mass were decreased. However daily feed intake and mortality were not affected by dietary protein level.

• KOREAN POULTRY JOURNAL
• /
• v.4 no.3 s.29
• /
• pp.92-97
• /
• 1972

B.S.Pomeroy 박사의 산란계 질병에 대한 예방과 치료약품을 소개함과 아울러 현재 국내에서 발생되는 질병명 및 시판되는 약약품등을 필자의 편의대로 설명하였다. 국내에서 발병되는 질병명은 한국가금협회 산란계 능력검정시(1971.8.1$\~$1972.1.31)안양 가축위생연구소에 의뢰한 가검물의 진단을 참고로 한 것인데 요약하면 CRD, 마렉병, 곰팡이성폐렴, 살모넬라 균증, 류코싸이토준증, 임파구성백혈병, 지방과자등, 대장균증, 뇨산침착증, 간파열증, 장염, 비특이성장염, 혈종, 탈홍등이다.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2003.05a
• /
• pp.61-72
• /
• 2003

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 1998.04a
• /
• pp.87-102
• /
• 1998