Silicon quantum dots (Si QDs) in a superlattice for high efficiency tandem solar cells were fabricated by magnetron rf sputtering and their characteristics were investigated. SiC/Si1-xCx superlattices were deposited by co-sputtering of Si and C targets and annealed at 1000˚C for 20 minutes in a nitrogen atmosphere. The Si QDs in Si-rich layers were verified by transmission electron microscopy (TEM) and X-ray diffraction. The size of the QDs was observed to be 3-6 nm through high resolution TEM. Some crystal Si and -SiC peaks were clearly observed in the grazing incident X-ray diffractogram. Raman spectroscopy in the annealed sample showed a sharp peak at 516 cm-1 which is an indication of Si QDs. Based on the Raman shift the size of the QD was estimated to be 4-6 nm. The volume fraction of Si crystals was calculated to be about 33%. The change of the FT-IR absorption spectrum from a Gaussian shape to a Lorentzian shape also confirmed the phase transition from an amorphous phase before annealing to a crystalline phase after annealing. The optical absorption coefficient also decreased, but the optical band gap increased from 1.5 eV to 2.1 eV after annealing. Therefore, it is expected that the optical energy gap of the QDs can be controlled with growth and annealing conditions.

The purpose of this study was to determine the effect of different feeding ratios of whole crop barley silage on the embryo production in Hanwoo donors. All donors were basically fed 2.5 kg concentrate daily. Donors were divided into three groups according to the different feeding of forage; hay 70% and rice straw 30% (control, n = 21), whole crop barley silage 80% and rice straw 20% (T1, n = 25), and whole crop barley silage 60% and rice straw 40% (T2, n = 23) fed based on TDN 6.70/ BW 500 kg. All Hanwoo donors received a CIDR together with injections of 1 mg estradiol benzoate and 50 mg progesterone (, Day 0). Four days later, they were superovulated with 28 mg FSH twice daily IM in decreasing doses over 4 days. Then donors received 2 doses of (25 and 15 mg) with the 5th and 6th injections of FSH on Day 6. CIDR were withdrawn at the 6th FSH injection and the donors received GnRH 36 h after the second injection. The donors were artificially inseminated twice, at 8 and 24 h after GnRH, and embryos were recovered 7 or 8 days after the 1st insemination. The flush rate of the donors following positive superovulation responses did not differ among groups (76.2~96.0%, p>0.05). The number of corpus luteum (CL) at embryo recovery also did not differ among groups (10.6~14.0, p>0.05). Furthermore, the mean numbers of total ova (9.4, 10.5 and 12.0) and transferable embryos (5.3, 12.0 and 6.5) did not significantly differ among the control, T1 and T2 groups, respectively (p>0.05). However, mean concentrations of serum of the T1 (64.2 ng/ml) and T2 groups (55.7 ng/ml) were higher than that of control group (43.3 ng/ml, p<0.01), while serum cholesterol concentrations in the control (105.8 mg/dl) and T2 groups () were significantly lower than in the T1 group (121.1 mg/dl, p<0.05). Conclusively, whole crop barley silage can be fed a good substitute for hay forage for Hanwoo donors. Furthermore the ratios of whole crop barley silage 60% and rice straw 40% might be more worthful for embryo production.

To enhance the embryo preservation technology and better application of embryo transfer technique to the field (dairy science or animal reproduction. etc.), we examined the viabilities of bovine embryos produced in vitro and in vivo after cryopreservation according to their developmental stage and thawing temperature. Bovine embryos from in vivo/vitro fertilization (Hanwoo) were examined at day 7, 8, and 9. Survival rates and total cell numbers of in vivo fertilized embryos were as follows: morulae 68.8% and ; blastocysts 80.5% and ; expanded blastocysts 77.4% and , respectively. Rates of embryo development for blastocysts and expanded blastocysts after thawing were significantly higher than that of morula stage embryos (p<0.05). While survival rates of in vitro fertilized embryos according to developmental stage showed no significant difference among groups (morula 67.9%; blastocyst 74.3%; and expanded blastocyst 79.4%), total cell numbers were significantly lower than those of other groups (morula ; blastocyst ; and expanded blastocyst ) For the viability according to thawing temperature, survival rate was higher in .

This study compared the pregnancy rates of Korean native donor cattle after either a timed artificial insemination (TAI) or embryo transfer (TET) following the synchronization of ovulation using a controlled internal drug release (CIDR) device together with estradiol benzoate (EB) and prostaglandin (). Fifty five cows and 8 heifers which had been previously used for embryo production were assigned to two treatments: (1) Thirty-two cattle received a CIDR device and 2 mg EB (Day 0), 25 mg injection at the time of CIDR removal on Day 7, and 1 mg EB injection on Day 8. All of the cattle received a TAI 30 h (Day 9) after the second EB injection (TAI group). (2) Thirty-one cattle received the same hormonal treatments as in the TAI group. The cattle with corpus luteum (CL) received a TET on Day 16 using frozen-thawed embryos (TET group). Ultrasonographic observations demonstrated that the proportion of cattle with synchronized ovulation on Day 10 and the concomitant formation of new CL on Day 13 did not differ between groups (p>0.05); the overall mean rates were 65.1 and 73.0%, respectively. The conception and pregnancy rates did not differ (p>0.05) between the TAI (12.5% and 12.5%) and TET groups (13.0% and 9.7%), respectively. We conclude that the pregnancy rate following TAI or TET in Korean native donor cattle was poor, which might be due in part to a poor synchrony of ovulation and concomitant CL formation.

The aim of present experiment was to examine hatching rate as in vitro indicator of viability of porcine embryos before early stage embryo transfer such as zygotes or 2-cell stage embryos. Cumulus-oocyte complexes (COCs) collected from ovaries were matured in North Carolina State University 23 (NCSU-23) containing 10% porcine follicular fluid (pFF), 10 ng/ml epidermal growth factor (EGF), follicle stimulating hormone (FSH), luteinizing hormone (LH), and 1mg/ml cysteine. After 24 hours, the COCs were transferred to the same medium without hormones. After 65h of maturation, oocytes were exposed to phosphate buffered saline (PBS) with 7% ethanol (v/v) for 7 minutes, and then the oocytes were washed and cultured in tissue culture medium (TCM) 199 containing 5 ug/ml cytochalasin B for 5h at in an atmosphere of 5% and 95% air with high humidity. After cytochalasin B treatment, the presumptive parthenotes were cultured in porcine zygote medium (PZM)-5 and cleavage of the parthenotes was assessed at 72h of activation, Normally cleaved parthenotes were cultured for an additional 8 days to evaluate their ability to develop to blastocyst and hatching stages. The fetal bovine serum (FBS) were added at Day 4 or 5 with concentrations of 2.5, 5 or 10%. The blastocyst rates were ranged within in each treatment. However hatching rate was dramatically decreased in non-addition group. In this experiment, embryo viability in female reproductive tract may be estimated before embryo transfer with in vitro culture adding FBS by hatching ability.

해월송전선의 해상고에 의하며 선박의 항로가 제한되는 해역에 있어서, 해월송전선에 관하여 현재 알 수 있는 정보는 아주 제한적인데, 주어진 정보를 토대로 송전선철탑들 사이의 임의의 위치에서도 해월송전선의 해상고를 알아낼 수 있는 방법을 제시하였다. 그리고 해월송전선의 하부를 선박이 항해할 경우의 안전성을 평가할 수 있는 방법론적 모델을 제시하였다. 실제 표본선박이 항해한 궤적을 조사하여 통계처리를 한 결과, 선박이 안전통항구간을 벗어날 확률은 약 0.00001 정도로 밝혀졌다. 따라서 네델란드 응용과학연구소의 보고서에 의한 안전기준(항만 내, 방파제 입구 부근에서는 0.0001 이하이면 안전하다고 판단.)보다 10배 정도 더 안전하다고 판단된다.

강원도 서남부에 위치하고 있는 원주시와 횡성군에 소재하고 있는 치악산(1,288 m), 태기산(1,261.4 m), 오봉산(1,126.2 m), 응봉산(1,094.9 m), 어답산(789.4 m), 덕고산(521.2 m), 덕가산(700.5 m), 성지봉(791 m)의 관속식물상을 2008년 4월부터 2009년 5월까지 총 23회에 걸쳐 조사하였고, 이전 조사에서 증거표본이 제시되어 있는 발교산(998.4 m), 오음산(930.4 m), 백운산(1,037.1 m), 치악산(1,288 m)의 자료를 전체 소산식물목록에 포함시켰다. 본 조사에서 생육이 확인된 관속식물의 총 분류군 수는 97과 383속 680종 1아종 111변종 12품종으로 총 804분류군이었으며, 문헌상 증거표본이 있는 경우의 자료를 추가하면 총 105과 418속 818종 1아종 138변종 16품종으로 총 973분류군으로 한반도 전체관속식물종의 21.14%에 해당된다. 조사지 전반의 식생은 소나무와 낙엽활엽수의 혼효림이며, 식생이 비교적 우수한 지역은 치악산의 구룡사로 부터 세렴폭포를 거쳐 비로봉에 이르는 계곡, 및 태기산의 큰성골계곡과 태기분교터에서 낙수대에 이르는 능선의 동사면 지역이다. 비교적 많은 분류군이 채집된 10개 과는 국화과, 벼과, 장미과, 미나리아재비과, 콩과, 사초과, 백합과, 범의귀과, 산형과, 꿀풀과의 순이며 전체 생육분류군의 49.12%이다. 조사지에서 생육이 확인된 특산식물은 금강초롱꽃, 모데미풀, Pyrus ussuriensis var. diamanti-ca Uyeki(금강산돌배)를 포함하는 38분류군이고, 산림청지정 희귀 및 멸종위기식물은 금강초롱꽃, 왕제비꽃, Viola diamantica Nakai(금강제비꽃), 금마타리를 포함하는 24분류군이며, 환경부지정 식물구계학적특정식물종은 총 88분류군으로서 Ⅴ등급에 속하는 식물은 좀가물고사리, 금강초롱꽃, 물쇠뜨기, 노랑붓꽃, 솔나리, 큰연영초, 목련(식재), 천마, 좀미역고사리, 승마, 모데미풀, 왕제비꽃의 12분류군이다. 또한 귀화식물은 47분류군으로서 전체식물의 4.83%, 유용식물은 총 609분류군으로서 식용식물 334분류군, 약용식물 269분류군, 관상용식물 127분류군, 사료식물 332분류군, 산업용식물 3분류군, 목재용식물 31분류군, 섬유용식물 13분류군으로 각각 구분되고, 이는 전체식물의 13.23%에 해당한다.

본 연구는 찔레 에탄올 추출물의 세포 활성 및 티로시나아제활성 저해를 분석하였다. 찔레 추출물의 세포활성을 분석한 결과 찔레 잎과 뿌리 추출물의 경우에는 추출물을 처리하지 않은 대조군과 유사한 결과를 관찰하였다. 모든 농도에서 세포 활성이 나타나지 않아 티로시나아제 활성 저해 효과를 분석한 결과 찔레 잎과 뿌리추출물은 상대적으로 고농도(200 μg/ml)에서 약 30~32% 정도를 저해하는 효과를 나타냈다. 또한 B16 세포에서 티로시나아제활성 저해 효과를 분석한 결과 상대적으로 고농도(200 μg/ml)에서 양성대조군인 알부틴보다 20~25% 정도 낮은 저해 효과를 나타냈다. 멜라닌 함량 저해 효과를 분석한 결과 찔레 잎과 뿌리 추출물의 경우 티로시나아제의 저해 효과와 유사하게 농도 의존적인 저해효과를 나타내는 것을 관찰하였다. RT-PCR 방법으로 분석한 결과, 추출물 처리군들은 정상대조군과 비교하여 티로시나아제 mRNA 수준이 유의적으로 차이가 나지 않았으며, 또한 농도 의존적인 변화도 없었다.

외국인선원 고용 확대의 주된 요인으로 주장되고 있는 선원의 부족문제, 그 중에서도 국적외항상선의 해기사의 수급현황을 객관적인 자료에 기초하여 분석함으로써 외국인 해기사의 고용범위 조정에 대한 합리적인 근거를 제시하였다. 우리나라 해기사의 수급현황을 분석하기 위하여, 3 4급 해기사의 신규양성 공급 상황을 조사하였고, 해기사의 취업 및 이직현황을 조사하였다. 또한 국적외항상선 척수의 증감상황을 조사하여 선복량의 증가에 따른 해기사의 신규수요 현황도 조사하는 등 여러 요인을 고려한 해기사의 수급현황을 분석하였다. 그 결과 국적외항상선에 공급되는 해기사는 매년 64명 정도가 남아도는 것으로 파악되었다.