This study was carried out to produce monozygotic twin calves by transfer of bisected embryos. Four Korean native cattle donors were superovulated with FSH and flushed to collect embryos on day 6 or 7 of the estrus cycle. Morula and early blastocyst embryos showed 1 or 2 grade were bisected with microblade and each set of demi-embryos without zona pellucida were transferred nonsurgically to 10 recipients respectively. The results obtained were as follows; 1. Twenty four demi-embryos (92.3%) were separated from 13 original embryos and among them 20 demi-embryos (83.3%) had normal appearance without severe damage. 2. Four sets of fresh demi-embryos were transferred to 4 recipients and one recipient was twin pregnant 3. Six sets of frozen-thawed demi-embryos were transferred to 6 recipients. Two recipients were pregnant, one of them twin.

Chitin was isolated from crab shells by modified Hackman's method, which was treated again with aqueous sodium hydroxide solution to give alkali chitin(sodium alkoxide of chitin). And after, the alkali chitin is allowed to react with monochloroacetic acid to synthesize 6-O-(carboxymethyl) chitin [CM-Chitin] under diminished pressure. In order to synthesize high performance CM-Chitin as hygroscopic agent, it was measured that the yield and degree of subsititution of each CM-Chitin according to molar ratio(monochloroacetic acid equivalent mol/N-acetyl-D-glucosamine residue) and their moisture-absorption and moisture-release properties were measured and compared with those of hyaluronic acid. The moisture-absorption and moisture-release properties of CM-Chitin, especially 0.8 in degree of substitution, were found quite similar to those of hyaluronic acid. The preliminary results show that CM-Chitin might be used as hygroscopic agent instead of hyaluronic acid in field of cosmetics.

In order to obtain a good microorganism capable of degrading microcrystaline cellulose (avicel), the screening test was carried out from soil and brown-rot wood. 8 strains which had good avicel-hydrolyzing activity were isolated. Among them, HK 47 which exhibited the highest avicel hydrolyzing activity was identified as Trichoderma sp. HK 47. Maximum avicel-hydrolyzing enzyme production from Trichoderma sp. HK 47 was obtained with the optimum medium contained carboxymethylcellulose 1.5% as carbon source, NaNO_3 0.75% as nitrogen source, KH_2PO_4 0.5%, MgSO_4·7H_2O 0.1%, Tween 80 0.005% (V/V) during stationary cultivation at pH 6.0, 30℃. In this case, the production of avicel-hydrolyzing enzyme was 0.028U/㎖.

최근 유한요소해석에서 보다 정확한 해를 위한 적응해석법에 대해 많은 연구가 이루어지고 있다. 본 논문은 요소 면적당의 오차를 균일화하여 절점을 최적의 위치로 변화시키는 r법과 오차가 큰 요소를 같은 모양의 요소로 세분시키는 h법을 혼합한 rh형 적응해석법을 사용하였다. 그 결과 같은 자유도에서 h법과 rh법의 오차감소율과 수렴속도는 거의 같에 나타났지만, rh법은 h법만 사용했을 때보다 전체 자유도 증가를 최대한 억제한 상태에서 정확한 유한요소해를 얻을 수 있었다.

These studies were conducted to: a) investigate work patterns and productivity indices, b) rate performance levels of employees and c) determine the suggested levels of personnel and labor hours for the effective labor control in school foodservice. Eighteen elementary school foodservices in Seoul were selected in order to analyze work patterns by the work sampling methodology. Allowance time and performance rating by VTR observation was done to determine the standardized labor hours. The results were as follows. The average percentage of each work function of the total work functions such as direct work function, indirect work function and delay were 65.57%, 8.12%, 26.31% respectively. The productivity index is 0.92 min/meal. The average working and delay hours per week of the foodservice director, foodservice employees and supply person were 33.64 hours, 23.25 hours, 38.52 hours respectively. The percentage of delay hours of total labor hours for foodservice employees and supply person were 42.27% and 24.0%. The standardized work hours and the appropriate levels of foodservice employees of 17 elementary school foodservices were examined: The average rating of the foodservice employees work was 1.19 and British Insulated Calendarer Cables (BICC) allowance rate was 19.40% on the average. The total work hours of foodservice employees were 172.64 hours per week and levels of personnel were 4.53 persons. BICC allowance rate was applied: The standardized work hours per week was 180.95 hours and appropriate levels of personnel were 4.11 persons based on legal 44 working hours.