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1,7,13-Triaza-4,10,16-Trioxacyclooctadecane 화합물과 중금속이온의 착화반응에 관한 연구
오제직,홍춘표,최석남,엄준식 공주대학교 사범대학 과학교육연구소 1996 과학교육연구 Vol.27 No.1
1,7,13-Triaza-4,10,16-trioxacyclooctadecane을 Matell등이 제안한 방법을 수정하여 합성하였다. 수용액에서 합성한 이 화합물의 환원파의 가역성을 조사하고, 수용액에서 ??및 ??이온과 1,7,13-Triaza-4,10,16-trioxacyclooctadecane 화합물의 착물 형성에 대하여 폴라로그래피로 환원파의 유형, 가역성 및 안정도상수 등을 측정하였다. 1,7,13-Triaza-4,10,16-trioxacyclooctadecane 화합물은 준가역 반응임을 알 수 있고, 환원파의 유형은 약간의 반응전류가 포함된 것을 알 수 있다. Cu(Ⅱ)-1,7,13-Triaza-4,10,16-trioxacyclooctadecane 착물의 환원전류의 유형은 확산지배적이었으며 착물의 산화, 환원 반응은 비가역반응이었다. Co(Ⅱ)- 1,7,13-Triaza-4,10,16-trioxacyclooctadecane 착물의 반파전위는 리간드의 농도가 증가할수록 음전위 쪽으로 이동하였으며, 그 결과 Co(Ⅱ)이온 및 Cu(Ⅱ)이온과 1,7,13-Triaza-4,10,16-trioxacyclooctadecane 의 반응에서는 1:2 착물이 형성되는 것을 알 수 있다. Co(Ⅱ) 및 Cu(Ⅱ)의 금속이온과 1,7,13-Triaza-4,10,16-trioxacyclo octadecane 리간드의 안정도상수를 구하였다. Co-리간드 착물의 안정도 상수는 ??, ??이고, Cu-리간드 착물의 안정도 상수는 ??, ?? 이다. Cu(Ⅱ)-1,7,13-Triaza-4,10,16-trioxacyclo octadecane 의 안정도 상수가 큰 이유는 금속 이온의 크기와 금속의 산도 영향으로 추측된다. Marcrocyclic compound 1,7,13-Triaza-4,10,16-trioxacyclooctadecane compound was prepared by modified method of Martell and co-workers. Marcrocyclic compound was investigated by polarograph on the reversibility of its reduction wave in aqueous solution. We investigated also to polarograph complexation of Co(Ⅱ) and Cu(Ⅱ) metal ions with 1,7,13-Triaza-4,10,16-trioxacyclooctadecane in aqueous solution. 1,7,13-Triaza-4,10,16-trioxacyclooctadecane compound obserbed the oxidation peak, and the value of current function get out of a few at 1. Therefore, the reducton reaction of its compound was pseudo-reversibility. The type of reduction current on the Cu(Ⅱ)-1,7,13-Triaza-4,10,16-trioxacyclooc-tadecane complex was diffusion controled, and reduction reaction was irreversible. The half wave potential of metal-ligand complexes shifted towards to more negative potentials with increasing the concentration of 1,7,13-Triaza-4,10,16-trioxacyclooctadecane. It indicates the formation of complexes both Cu(Ⅱ)-N₃O₃and Co(Ⅱ)-N₃O₃compound. The overall formation constant for the two possible Cu(Ⅱ)-N₃O₃complexes were determined: ??, ?? and Co(Ⅱ)-N₃O₃complexes were determined: ??, ??. The order of complex stability was Cu(Ⅱ)>Co(Ⅱ), therefore Cu(Ⅱ) were complexed more better than Co(Ⅱ) with 1,7,13-Triaza-4,10,16-trioxacyclooctadecane.
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열풍 건조 국내산 알팔파 이용 TMR의 혼합 급여가 홀스타인 착유우의 반추 활동량, 우유 생산 및 성분에 미치는 영향
엄준식,임동현 한국초지조사료학회 2024 한국초지조사료학회지 Vol.44 No.2
The objective of this study was to investigate the comparison of feeding a total mixed ration (TMR) containing imported alfalfa hay and TMR containing hot-air dried domestic alfalfa on rumination activity, milk production, and composition in lactating dairy cows. Ten Holstein dairy cows were divided into two groups: control (imported alfalfa hay + TMR) and treatment (hot-air dried domestic alfalfa + TMR) groups. The study was conducted over a total period of 18 days, including a 13-days adaptation period and a 5-days main experimental period. The results indicated no differences in total digestible nutrient and net energy intake between the imported and hot-air dried alfalfa. Body weight was not significantly different between the two groups (p>0.05), however, total feed intake and rumination time were significantly and tendentially higher in the treatment group compared with control group, respectively (p<0.001; p=0.075). Milk yield was not significantly different between the two groups (p>0.05), however, milk fat (kg) and lactose (%) concentration were significantly higher in the treatment group compared with control group (p=0.016; p=0.02). This study confirms that feeding TMR with hot-air dried domestic alfalfa results in no differences of feed intake, rumination activity, and milk productivity. Therefore, it is considered that hot-air dried domestic alfalfa can be used as a substitute for imported alfalfa on lactating dairy cows.
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엄준식,김언태,김현상,최유영,이신자,Lee Sang Suk,김선호,Lee Sung Sill 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.12
Objective: The aim of the study was to conduct metabolic profiling of dairy cattle serum and urine using proton nuclear magnetic resonance (1H-NMR) spectroscopy and to compare the results obtained with those of other dairy cattle herds worldwide so as to provide a basic dataset to facilitate research on metabolites in serum and urine. Methods: Six dairy cattle were used in this study; all animals were fed the same diet, which was composed of total mixed ration; the fed amounts were based on voluntary intake. Blood from the jugular neck vein of each steer was collected at the same time using a separate serum tube. Urine samples were collected by hand sweeping the perineum. The metabolites were determined by 1H-NMR spectroscopy, and the obtained data were statistically analyzed by performing principal component analysis, partial least squares-discriminant analysis, variable importance in projection scores, and metabolic pathway data using Metaboanalyst 4.0. Results: The total number of metabolites in the serum and urine was measured to be 115 and 193, respectively, of which 47 and 81, respectively were quantified. Lactate (classified as an organic acid) and urea (classified as an aliphatic acylic compound) exhibited the highest concentrations in serum and urine, respectively. Some metabolites that have been associated with diseases such as ketosis, bovine respiratory disease, and metritis, and metabolites associated with heat stress were also found in the serum and urine samples. Conclusion: The metabolites measured in the serum and urine could potentially be used to detect diseases and heat stress in dairy cattle. The results could also be useful for metabolomic research on the serum and urine of ruminants in Korea. Objective: The aim of the study was to conduct metabolic profiling of dairy cattle serum and urine using proton nuclear magnetic resonance (<sup>1</sup>H-NMR) spectroscopy and to compare the results obtained with those of other dairy cattle herds worldwide so as to provide a basic dataset to facilitate research on metabolites in serum and urine.Methods: Six dairy cattle were used in this study; all animals were fed the same diet, which was composed of total mixed ration; the fed amounts were based on voluntary intake. Blood from the jugular neck vein of each steer was collected at the same time using a separate serum tube. Urine samples were collected by hand sweeping the perineum. The metabolites were determined by <sup>1</sup>H-NMR spectroscopy, and the obtained data were statistically analyzed by performing principal component analysis, partial least squares-discriminant analysis, variable importance in projection scores, and metabolic pathway data using Metaboanalyst 4.0.Results: The total number of metabolites in the serum and urine was measured to be 115 and 193, respectively, of which 47 and 81, respectively were quantified. Lactate (classified as an organic acid) and urea (classified as an aliphatic acylic compound) exhibited the highest concentrations in serum and urine, respectively. Some metabolites that have been associated with diseases such as ketosis, bovine respiratory disease, and metritis, and metabolites associated with heat stress were also found in the serum and urine samples.Conclusion: The metabolites measured in the serum and urine could potentially be used to detect diseases and heat stress in dairy cattle. The results could also be useful for metabolomic research on the serum and urine of ruminants in Korea.
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엄준식,최종대 한국구조물진단유지관리공학회 2013 한국구조물진단유지관리공학회 논문집 Vol.17 No.6
본 연구에서는 강거더 연속교에 대해 국내외 설계기준에 규정되어 있는 활하중으로 인한 충격계수를 실험을 통해 검증하였다. 대부분의 도로교의 설계기준에서는 도로교의 경우 충격계수를 약 0.3 정도의 값으로 규정하고 있으나, 연속교의 경우에는 명확한 규정 및 명시가 없는 상황이다. 그러므로 단순교에 적용되는 충격계수를 연속교에 동일하게 적용하는 것이 일반적이다. 이 연구에서는 현장실험을 통해 연속교의 충격계수가 단순교에 적용되는 경우와 같이 사용될 수 있는지를 검증하였다. 현장실험 결과 얻어진 충격계수는 2차선 교량에서 1대의 만재트럭이 통과했을 경우 가장 하중이 많이 작용한 거더에서 0.2 이내의 충격계수가 계측되었으며, 2개의 차선을 통시에 만재트럭이 통과한 경우 그 충격계수는 0.05 이내의 값을 얻었다. The objective of the paper is to present the results of analytical and experimental studies dealing with dynamic load for continuous steel girder bridges due to normal truck traffic. Various bridge design codes specify dynamic load factor (defined as a fraction of static portion of live load) for short span structures at the level of about 0.3. However, there are not definite values specified for continuous brigdes. Therefore, it is an usual practice to use the code specified dynamic load factors for simple span bridges to continuous bridges without clear background. The field measurement results indicate that the actual dynamic load factors are less than 0.2 for a single truck, and less than 0.05 for two trucks side-by-side, regardless of positive and negative moment region.
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Reliability Analysis Modeling for LRFD Design of Bridge Abutments
엄준식 한국지반공학회 2014 한국지반공학회논문집 Vol.30 No.8
The objective of this paper is to develop a rational reliability analysis procedure for the LRFD design provisions of bridge substructures. A bridge abutments is considered in this study. The reliability analysis is applied to determine the relationship between the major design parameters for bridge abutment and reliability index. The considered load components include dead load, vertical and horizontal earth pressure, earth surcharge, and vehicle live load. Several limit states are considered: foundation bearing capacity, sliding, and overturning. The analysis results show that the most important parameter in the reliability analysis is the effective stress friction angle of the soil. The reliability indices are calculated using Monte Carlo simulations for a selected bridge abutment. The results of the sensitivity analysis indicate that reliability index is most sensitive with regard to resistance factor and horizontal earth pressure factor.
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