• Journal of Korean Vacuum Science & Technology
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• 제6권2호
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• pp.84-87
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• 2002

The Si$_{1-x}$ Gex/Si surface alloy (x = 0.3, 0.4 and 0.5), which are prepared by solid source MBE and have the SiGe epilayer thickness of 50$\AA$, are annealed with different parameters. The surface structure analyses of the heterostructure samples are made on a triple-axis X-ray diffractometer in grazing incidence X-ray diffraction (GIXRD) geometry. It has been found that with different annealing time (1.5h, 18h, 64h) and annealing temperature (550 $^{\circ}C$, 750 $^{\circ}C$), the SiGe epilayer experienced different strain relaxation process, which was deduced from the GIXRD measurements of the in-plane (220) diffraction peak of Si(001) substrate and the relevant (220) surface diffraction of SiGe epilayer. The results show that the stress relieving and the lateral strain relaxation in the SiGe/Si heterostructure can be promoted by correct annealing, which is very helpful for the preparation of SiGe/Si strained superlattice with fine strain crystallization..

• Asian-Australasian Journal of Animal Sciences
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• 제20권5호
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• pp.789-794
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• 2007

A PCR-aided monitoring of verotoxin-producing Escherichia coli (VTEC) was performed over the period of 12 months by using fresh feces collected monthly from 5 dairy cows that had been identified as VTEC carriers. The PCR products were confirmed to be verotoxin genes by Southern hybridization using a gene fragment of verotoxin 2 as a probe. Although seasonal variation of VTEC shedding seemed to depend on each cow, several factors may have influenced the frequency of detection. Shedding of VTEC tended to be reduced during grazing from the middle of May up to the beginning of October. Only one cow was positive for VTEC in August. Dry-off was also suggested to have a depressive effect on VTEC shedding, i.e. 3 of 4 dry cows showed no shedding of VTEC. Contrary to these factors, winter or indoor rearing tended to increase VTEC with only 5/24 samples being negative during the period from November to April. Total VFA concentration was higher (p<0.05) in VTEC-positive feces than in VTEC-negative feces, while fecal pH and VFA proportions were not different. Partial sequences of verotoxin genes from feces of 4 VTEC-positive cows were nearly identical (99-100%), suggesting that gut bacteria sharing the same gene were distributed among the cows. The present results indicate that grazing and dry-off could be factors which reduce VTEC shedding, while winter/indoor rearing may be a factor which increases the shedding, possibly through on-farm interactions.

• Asian-Australasian Journal of Animal Sciences
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• 제15권2호
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• pp.209-212
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• 2002

The understanding of seasonal forage intake of grazing deer is essential for the development of supplementary feeding strategies in southern Australia. The alkane technique is used in other animal species for estimating feed intake of individual animals and their diet composition. To assess the potential of using alkanes as a marker for predicting feed intake of fallow deer, the daily faecal recovery of alkanes and excretion rate of dosed artificial alkanes (C32 and C36) were measured with 6 deer fed three forage based diets. The artificial alkane capsule designed for use in sheep is suitable for fallow deer. Faecal samples need to be collected over days 7-19 after dosing. The daily excretion rate was 40 mg for C32 and 37 mg for C36. The faecal recovery of natural alkanes is incomplete and the faecal concentrations of alkanes need to be adjusted for an accurate estimation of intake. The actual feed intake of 6 experimental deer over a 5 day period was accurately estimated ($R^2$=0.52) using alkanes.

• 한국수산과학회지
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• 제36권5호
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• pp.469-473
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• 2003

Transplantation of Sargassum horneri to natural substrate using the rope seeding method was undertaken. Seeding of S. horneri was grown on net in an indoor tank up to 0.2-0.3 cm in frond length for 2 months, and then transplanted to an architecture tile $(10\times10\;cm)$ with underwater glue and an iron pipe. After two months, number of S. horneri on the tile decreased because of grazing by herbivores. However, S. horneri on the iron pipe grew up to 0.5-2.0 cm in frond length. After 7 months, they rapidly grew up to a frond length of 11.0-203.0 cm with a mean frond length of 122.6 cm. S. horneri grew up to a maximum frond length of 313.0 cm, and mean frond length of 228.0 cm, after 10 months. The artificial S. hornevi beds can be used to clean the seawater and also be utilized as a source of marine biomass as well as for supplying habitat, shelter and spawning beds for fish and invertebrates.

• 한국초지조사료학회지
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• 제24권2호
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• pp.171-176
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• 2004

유기조사료 생산을 위한 방목초지의 역할을 구명하기 위해 2000년부터 2002년까지 경기도 수원시 소재 축산기술연구소에서 수행되었다. 유기재배에 따른 목초의 생산성을 구명하기 위해 대조구(표준관리), 친환경구, 유기구를 처리구로 하여 수행되었다. 그 결과는 다음과 같다. 1. 건물수량은 대조구, 친환경구, 유기구의 순으로 많았으나, 유기구와 대조구의 수량차이가 14% 정도로 작았다. 2. 사료가치와 식생에서는 큰 차이가 없었다. 위 시험의 결과 방목초지는 유기적 재배에서도 양호한 상태로 유지되어 초지는 유기조사료 생산에 적합한 작목으로 판명되었다.

• The Korean Journal of Ecology
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• 제8권3호
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• pp.153-161
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• 1985

Energy flow through the trophic levels was studied at a salt marsh ecosystem distinguished into low and high marsh. Gross primary productions of Suaedeto-Salicornietum and Artemisieto-Limonietum at low marsh were 8, 299 and 13, 154kca/$m^2$/yr, and those of Calama-grostetum and Sonchuso-Setaetum at high marsh were 17, 899 and 15, 177kca/$m^2$/yr, respectively. Efficiencies of solar energy utilization of plants were 1.7 and 2.6% at the former, and were 3.6 and 3.2% at the latter. Of gross productions, net primary productions were 3, 977 and 5, 280kca/m2/yr at low marsh and were 6, 354 and 5, 329kca/$m^2$/yr at high marsh, and the remainder, 52~67%, was consumed by respiration of plants. A small amount (0.03~0.04%) of the net primary production was flowed through grazing food chain and most amout was transferred into dead parts. Of dead parts, 40% was accuulated as litter and the rest was decomposed into detritus. In the detritus food chain, a little energy was utilized by detritus feeder, and a major by microorganism. The amounts of energy flowed through grazing and detritus feeders at high marsh were much more than those at low marsh, but tertary production as spider was Vice versa.

• Asian-Australasian Journal of Animal Sciences
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• 제26권3호
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• pp.349-357
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• 2013

The aim of this study was to evaluate the efficiency of supplements containing different energy sources in relation to mineral supplementation of steers grazing guineagrass (Panicum maximum cv Tanz$\hat{a}$nia) pasture, during the dry season. The experimental design was a randomized block with three treatments and four replications. The treatments consisted of a mineral supplementation and two other supplements, one based on corn seed and the other based on soybean hulls, and provided at 0.8% of body weight. Forty-eight, 12 month-old crossbred steers with an average initial body weight of 267 kg, were assigned to twelve paddocks (1,125 ha) of guineagrass. The animals that were fed with soybean hulls and corn seed presented a greater average daily gain (0.982 and 0.937) when compared with the mineral supplementation. Soybean hulls can be used as a satisfactory food source, replacing corn as an energy source in the supplementation of beef cattle without compromising animal performance.

• 한국음향학회지
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• 제21권4호
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• pp.421-429
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• 2002

해수면에서의 음파산란 특성을 파악하기 위한 해수면 후방산란실험을 2000년 11월 동해시 연안에서 수행하였다. 평면입사각의 범위는 20°∼40°였고 주파수는 60 kHz였다. 실험해역의 풍속은 3 m/s, 해수면 거칠기는 1 m이하로 관측되었다. 분석된 해수면 후방산란강도는 경계면 산란강도 예측 모델에 비해서 높게 나타났으며 이러한 차이는 작은 평면입사각에서 더욱 크게 나타났다. 이러한 차이를 설명하기 위하여 해수면 부근의 공기방울층에 의한 산란 효과를 고려한 결과 실측치와 모델이 잘 일치하였다.

• 한국초지조사료학회지
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• 제13권4호
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• pp.286-293
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• 1993

본 시험은 톨 페스큐가 우점된 방목초지에서 소비구(T$_1$; 120-100-100 kg/ha), 보비구(T$_2$: 280-200-240kg) 및 보비+보파구(T$_3$)등 3개 처리에 3원 교잡종 육성우를 이용하여 1991년 4월 16일부터 11월 1일까지 199일 동안 계절별 목초 생산량에 따라 방목두수를 증.감 조절하여 보충사료 급여없이 계속방목 방법으로 수행되었던 바 얻어진 결과는 다음과 같다. 1. 처리별 식생은 소비구(T$_1$)에서 tall fescue가 60~70% 크게 우점된데 비해 보비구(T$_2$)에서 tall fescue는 40~50% 다소 낮았고 보비+보파구(T$_3$)에서는 tall fescue, orchardgrass, perennial ryegrass등이 각각 30.5%. 23.8%, 21.4%를 나타냈다. 2. ha당 목초 건물수량은 소비구(T$_1$)가 11.952kg인데 비해 보비구(T$_2$) 13,277kg, 보비+보파구(T$_3$) 14,431kg으로 각각 11%. 21% 증수되었다. 3. 처리별 ha당 일평균 방목두수(AU)는 T$_1$이 2.4 AU인데 비해 T$_2$가 3.0 AU, T$_3$가 3.3 AU로 높았으며 어느 처리에서나 봄철에 높은 방목두수를 보였다. 4. 년간 ha당 총 방목일수(animal unit day; AUD) 는 T$_1$이 481 AUD인데 비해 T$_2$가 559 AUD, T$_3$가664 AUD로 각각 24%, 38%의 높은 방목일수를 나타냈다. 5. 년 평균 두당 일당 증체량은 T$_1$이 0.64kg, T$_2$ 0.64kg, T$_3$ 0.68kg으로 처리간 큰 차이는 없었으나 어느 처리에서나 봄철에 높은 증체량을 나타냈다. ha당 1일 평균 증체량은 T$_1$이 3.0kg, T$_2$ 3.8kg, T$_3$4.4kg로 T$_3$가 높은 증체량을 보였다. 6. 연간 총 ha당 증체량은 T$_1$가 601kg인데 비해 T$_2$ 762kg. T$_3$ 877kg으로 각각 27%, 46%의 높은 증체량을 보였다. 7. 방목축 100kg당 1일 목초 채식량은 처리간 큰 차이 없이 4.0~4.5kg 이었으나 어느 처리에서나 여름철에 가장 낮은 채식량을 나타냈다. 8. 처리별 목초내 조성분 함량에서 조단백질은 T$_1$이 다른 처리에 비해 낮은 반면 조섬유 함량은 다소 높게 나타냈다. P, K, Ca 함량 등도 T$_1$에서 다소 낮은 함량을 보였다.

• 한국초지조사료학회지
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• 제38권4호
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• pp.331-336
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• 2018

본 연구는 한우 번식우에 있어서 영양대사물질 분석을 통하여 영양수준을 구명하여 번식우의 수태율 개선을 위한 기초 자료로 활용하기 위해서 실시하였다. 번식우의 정확한 영양수준 분석을 위해서 사료급여량을 80%, 100%, 120%로 구분하여 사양관리를 실시한 결과 Cholesterol과 BUN 농도가 120% 급여구에서 유의적으로 높은 결과를 나타내었다(p<0.05). 방목우 중에서 임신우와 비임신우의 영양대사물질 수준 분석 결과, Cholesterol, AST, NEFA 농도가 임신우에 비해 비임신우에서 유의적으로 높은 결과를 보였다(p<0.05). 이와 같이 임신과 관련한 영양수준 분석에 Cholesterol, AST, NEFA 의 3가지 항목을 설정하는 것이 필요할 것으로 사료된다. 방목과 사사 사육에 대한 결과 분석에서 Glucose 농도는 방목우 84.8, 비방 목우 56.0 mg/dl 으로서 방목우에서 유의적으로 높은 결과를 보였고(p<0.05), Cholesterol 수준은 방목우에서 142.5 mg/dl로서 사사 사육 128.9 mg/dl 보다 유의적으로 높았으며(p<0.05), ALT(34.4 vs 27.1 IU/l)와 NEFA 농도(317.8 vs 160.2 ЧEq/l) 역시 방목우에서 유의적으로 높은 결과를 보였다(p<0.05). 결론적으로, 암소에 사료 급여시 Cholesterol, ALT, NEFA 수준을 낮출 수 있도록 하는 것이 한우 암소의 수태율을 높일 수 있을 것으로 사료된다.