We report the effect of Standard Clean-1 (SC-1) cleaning to remove residual Ti layers after silicidation to prevent Al diffusion into Si wafer for Ti Schottky barrier diodes (Ti-SBD). Regardless of SC-1 cleaning, the presence of oxygen atoms is confirmed by Auger electron spectroscopy (AES) depth profile analysis between Al and Ti-silicide layers. Al atoms at the interface of Ti-silicide and Si wafer are detected, when the SC-1 cleaning is not conducted after rapid thermal annealing. On the other hand, Al atoms are not found at the interface of Ti-SBD after executing SC-1 cleaning. Al diffusion into the interface between Ti-silicide and Si wafer may be caused by thermal stress at the Ti-silicide layer. The difference of the thermal expansion coefficients of Ti and Ti-silicide gives rise to thermal stress at the interface during the Al layer deposition and sintering processes. Although a longer sintering time is conducted for Ti-SBD, the Al atoms do not diffuse into the surface of the Si wafer. Therefore, the removal of the Ti layer by the SC-1 cleaning can prevent Al diffusion for Ti-SBD.

Graphene is an interesting material because it has remarkable properties, such as high intrinsic carrier mobility, good thermal conductivity, large specific surface area, high transparency, and high Young’s modulus values. It is produced by mechanical and chemical exfoliation, chemical vapor deposition (CVD), and epitaxial growth. In particular, large-area and uniform single- and few-layer growth of graphene is possible using transition metals via a thermal CVD process. In this study, we utilize polystyrene and boron oxide, which are a carbon precursor and a doping source, respectively, for synthesis of pristine graphene and boron doped graphene. We confirm the graphene grown by the polystyrene and the boron oxide by the optical microscope and the Raman spectra. Raman spectra of boron doped graphene is shifted to the right compared with pristine graphene and the crystal quality of boron doped graphene is recovered when the synthesis time is 15 min. Sheet resistance decreases from approximately 2000 Ω/sq to 300Ω/sq with an increasing synthesis time for the boron doped graphene.

There are various manufacturing processes for pure SiO2 that is used as abrasives, chemicals, filters, and glasses, and in metallurgy and optical industries. In the optical fiber industry, to produce SiO2 preform, SiCl4 is utilized as a raw material. However, the combustion reaction of SiCl4 has caused critical environmental issues, such as ozone deficiency by chlorine compounds, the greenhouse effect by carbon dioxide and corrosive gas such as hydrochloric acid. Thus, finding an alternative source that does not have those environmental issues is important for the future. Octamethylcyclotetrasiloxane (OMCTS or D4) as a chlorine free source is recently promising candidate for the SiO2 preform formation. In this study, we first conducted a vaporizer design to vaporize the OMCTS. The vaporizer for the OMCTS vaporization was produced on the basis of the results of the vaporizer design. The size of the primary particle of the SiO2 formed by OMCTS was less than 100 nm. X-ray diffraction patterns of the SiO2 indicated an amorphous phase. Fourier-transform infrared spectroscopy analysis revealed the Si-O-Si bond without the -OH group.

소나무재선충병의 나무주사는 살선충제를 중심으로 실시되어 왔으며, 매개충인 솔수염하늘소와 북방수염하늘소의 방제는 주로 항공방제나 지상방제를 통하여 이루어졌다. 본 연구에서는 나무주사를 통하여 매개충(솔수염하늘소)을 방제하기 위한 연구로 Abamectin+Acetamiprid ME, Thiamethoxam DC약제의 나무주사시 솔수염하늘소의 약효발현농도, 수목내 약제의 이동특성 및 치사율 등에 대해서 조사하였다. 실내 약효발현농도 시험에서는 Abamectin+Acetamiprid ME, Thiamethoxam DC 모두 0.1ppm 이상의 농도에서 평균 6일 경과 후 100.0% 치사하는 특성을 나타내었다. 또한 야산에서 나무주사를 통하여 솔수염하늘소에 대한 효과검토 결과, Abamectin+Acetamiprid ME, ThiamethoxamDC 모두 처리 60일 후 90.9%의 치사율(가지섭식 14일 후 기준)을 나타내었으며, 죽지 않는 개체는 가지의 약제침투특성차이에 의한 것으로 판단된다.

ZnO with wurtzite structure has a wide band gap of 3.37 eV. Because ZnO has a direct band gap and a large exciton binding energy, it has higher optical efficiency and thermal stability than the GaN material of blue light emitting devices. To fabricate ZnO devices with optical and thermal advantages, n-type and p-type doping are needed. Many research groups have devoted themselves to fabricating stable p-type ZnO. In this study, As+ ion was implanted using an ion implanter to fabricate p-type ZnO. After the ion implant, rapid thermal annealing (RTA) was conducted to activate the arsenic dopants. First, the structural and optical properties of the ZnO thin films were investigated for as-grown, as-implanted, and annealed ZnO using FE-SEM, XRD, and PL, respectively. Then, the structural, optical, and electrical properties of the ZnO thin films, depending on the As ion dose variation and the RTA temperatures, were analyzed using the same methods. In our experiment, p-type ZnO thin films with a hole concentration of 1.263 × 1018 cm−3 were obtained when the dose of 5 × 1014 As ions/cm2 was implanted and the RTA was conducted at 850 oC for 1 min.

Synthesis of nano-silica using water glass in a Sol-Gel process is one of several methods to manufacture nano-silica. In nano-silica synthesized from water glass, there are various metal impurities. However, synthesis of nano-silica using water glass in a Sol-Gel process is an interesting method because it is relatively simple and cheap. In this study, nano-silica was synthesized from water glass; we investigated the effect of pH on the synthesis of nano-silica. The morphology of the nanosilica with pH 2 was flat, but the surface of the nano-silica with pH 10 had holes similar to small craters. As a result of ICPOES analysis, the amount of Na in the nano-silica with pH 2 was found to be 170 mg/kg. On the other hand, the amount of Na in the nano-silica with pH 10 was found to be 56,930 mg/kg. After calcination, the crystal structure of the nano-silica with pH 2 was amorphous. The crystal structure of the nano-silica with pH 10 transformed from amorphous to tridymite. This is because elemental Na in the nano-silica had the effect of decreasing the phase transformation temperature

The purpose of this study is to produce wanted sex progeny of genetically confined White Hanwoo (albinism) with preselected sex sperm. One bull of White Hanwoo was chosen for semen donor and X sperm was sorted by MoFlo XDP cell sorter. To compare the pregnancy and birth rates, KPN straw was used as control, total number of unsorted sperm was 20×106/straw. Sexed X frozen semen with 2×106 cells or 4×106 cells per straw were in seminated twice on Hanwoo heifers. The abnormality of the sexed X semen was 24.9 ± 7.31% and distal reflex abnormality of mid piece was significantly (p<0.05) higher (11.7%) compared with that of KPN 768 (5.6%). There were no differences on the pregnancy and birth rates between 2×106 cells or 4×106 cells of X-sperm but KPN semen showed significant differences (p<0.05). The pregnancy rates of KPN 768, 2×106 cells and 4×106 cells X-sperm of White Hanwoo cattle were 85.0%, 26.3% and 50%. The birth rates were 80.0%, 15.8% and 21.4%, respectively. The female offspring rates of KPN 768, 2×106 cells and 4×106 cells X-sperm of White Hanwoo cattle were 43.8%, 100% and 100% (p<0.05). These results indicated that sex sorted White Hanwoo could be used for the production of wanted progeny with 2×106 cells/straw for AI. To increase the efficiency of calf production, the sperm number of sex sorted semen will be optimized for sex selection of White Hanwoo progeny.

Silica nano-powder (SNP) is an inorganic material able to provide high-performance in various fields because of its multiple functions. Methods used to synthesize high purity SNP, include crushing silica minerals, vapor reaction of silica chloride, and a sol-gel process using TEOS and sodium silicate solution. The sol-gel process is the cheapest method for synthesis of SNP, and was used in this study. First, we investigated the shape and the size of the silica-powder particles in relation to the variation of HCl and sodium silicate concentrations. After drying, the shape of nano-silica powder differed in relation to variations in the HCl concentration. As the pH of the solution increased, so did the density of crosslinking. Initially, there was NaCl in the SNP. To increase its purity, we adopted a washing process that included centrifugation and filtration. After washing, the last of the NaCl was removed using DI water, leaving only amorphous silica powder. The purity of nano-silica powder synthesized using sodium silicate was over 99.6%.

닭 정액의 주요성분인 glutamine은 정장의 주요 성분으로 정자의 생리 활성에 매우 중요 한 것으로 알려져 있으며 조류 정액 희석액의 주요성분으로 이용되어져 왔다. 그러나 glutamine은 액상의 배양액에서 변성이 일어날 수 있어 세포배양에는 alanyl glutamine을 이용하 여 장기 세포배양에 이용되고 있다. 본 연구에서는, alanyl glutamine을 이용하여 개발된 희 석제를 이용하고 닭 정액의 냉장보존에 이용하였으며, 닭 정자의 장기 생존성에 미치는 영 향을 조사하였다. 국립축산과학원 가축유전자원시험장에서 사양관리중인 오골계 수탉 또 는 레그혼에서 복부 마사지법으로 채취된 정액을 이용하였다. 채취한 정액은 96 mM L- Glutamine 또는 Alanyl Glutamine을 함유하는 희석액에 각각 1:8의 부피비율로 상온에서 희석하 여 상업용 냉장고와 4℃로 조절된 BOD 배양기에 보존을 실시하였다. 냉장되는 온도의 저 하 속도를 낮추기 위하여 상온에서 희석하는 온도와 동일한 온도의 증류수 300 ml을 비이 커에 담고 물위에 1.5 ml E-tube에 담아서 파리필름으로 밀봉하였다. 희석된 정자의 활력은 상업용 냉장고에 보존할 경우, 4일차까지 75.6%의 활력정자가 유지 되었으나 5일 이후에는 급격히 생존성이 저하되었으며 6일째에는 활력 정자의 수가 18%로 낮게 나타났다. 한편, BOD 배양기에서 보존된 동일한 정자는 9일까지 약 73%의 활력정자가 유지되었으며, 10일 이후에는 활력 정자의 수가 급격히 감소되는 현상을 관찰하였으며, 15일째에는 약 20%의 정자 활력이 유지되는 현상을 관찰하였다. 이러한 정자의 활성 유지는 정자의 미토콘드리 아 에 필요한 글루타민 에너지 공급원을 안정적으로 공급하는 기능에 의하여 유지 되는것으로 추정되며 특히 hyper activated sperm의 비율을 줄여주어 정자군의 노화를 방지할 수 있는 효과가 있는 것으로 추정되었다. 그러므로 조류 정액을 냉장 보존할 때, 알라닐글루타민을 희석액의 주요 성분으로 이용될 수 있음을 보여주고 있다.

닭 정액의 동결보존기술은 유전자원 보존의 수단으로 이용될 수 있는 기술로서 고병원성 조류인플루엔자 같은 악성질병에 의한 멸실을 방지하는 매우 중요한 기술이다. 닭의 정자 는 동결보호제와 동결에 이용되는 희석액에 따른 융해 후 정자의 활성도, 수정율 및 부화율의 변이가 매우 큰 것으로 알려져 있다. 가장 널리 사용되는 동결보호제인 Glycerol은 동결 정 액 제조에 가장 많이 이용되며 융해 후 닭 정자의 생존성이 비교적 우수한 것으로 알려져 있으나, 인공수정에 직접 이용할 경우에 수정율의 저하현상이 나타난다. 본 연구에서는 동 결보호제중 하나인 N-Methylacetamide(MA)를 이용하여 한국 재래계인 오계 수탉의 정자 를 동결보존, 융해 및 인공수정을 실시하여 수정율과 부화율을 조사하였다. 복부 마사지법으 로 채취한 정액을 5℃ 저온수조에 담아 실험실로 이송하였으며 MA을 함유하지 않은 희석액 (HS-1)에 1:1의 비율로 희석하여 30분간 5℃ 온도로 유지시켰다. 2차 희석액은 14, 18 그 리고 22%의 MA가 함유된 희석제를 이용하였으며 1차 희석된 정액과 1:1 비율로 희석하여 0.5ml 스트로에 충진 하였다. 액체질소 표면 위 4 cm에 설치된 간이 지지대에 밀봉된 스트 로를 30분간 정치하여 동결하는 간이동결법을 이용하였다. 동결된 정액을 1～2주간 보관한 후, 5℃로 조절된 저온수조에서 융해하고 운동성 있는 정자와 활력이 우수한 정자의 비율 을 비교 분석하였다. 동일한 방법으로 융해한 정액으로 인공수정을 실시하고 7일 간 수정 란을 수집하여 부화기에 배양하여 7일차에 발생란을 검란하였다. 대조군에서 희석된 정액 의 경우 98.4% 수정율이 관찰되었으며 실험군에서는 7, 9 및 11% MA의 경우 각각 21.5 %, 34.7% 및 25% 수정율이 관찰되었다. 수정율에 대한 부화율은 대조군에서 88.9%를 관 찰하였고 실험군은 100%, 89.5% 및 87.5%로 관찰되었다. 이러한 결과로 유추해 볼 때, 오 계 정자의 동결보존에 유용할 수 있는 MA의 농도의 범위는 약 9% 내외로 판단되며 특히 MA는 오계 수정란의 수정율과 부화율에 미치는 영향이 낮은 것으로 사료되었다.

This study was carried out to investigate the effects of semen on reproductive ability in crossbred Korean native chicken (KNC, 58-wk old). The body weight, volume of semen and concentration of spermatozoa, were 2.96 g, 0.40 ml, 36.58×108/ml, respectively, in KNC. The fertility and hatchability were 94.8% and 78.8% respectively in crossbred KNC. KNC(Y) was high compared to other strains in fertility. The other strains were not significantly different among 6 strains. The results of this experiment indicated that hatchability of (G) was high compared to other strains. The result of this study could be available to genetic improvement of reproductive traits as a basic reference in KNC strains. To achieve the more effective improvement of reproductive traits, addition research such as genetic parameter evaluation should be performed.

The aim of this study was to evaluate the effect of α-tocopherol on blastocysts development and subsequent cryosurvival of the vitrification. The α-tocopherol(0, 100, 200, 400 μM) was added in to culture medium for the bovine embryos. The blasocysts from the α-tocopherol and untreated control groups were then frozen-thawed, and their cryosurvival was assessed by in vitro culture for 48 h. There were no differences in the overall cleavage rate(56.14±4.66, 58.18±4.70, 62.97±6.86 and 51.17±7.28) among four treatment groups. However, in blastocyst development and total cell number were significantly higher in α-tocopherol 200 μM(38.60±7.12; 106.33±3.50) to culture medium than other treatment groups(29.30±5.24, 31.60±7.12 and 26.37±4.18; 101.36±5.12, 97.27±2.87, and 91.23±7.52 respectively). Before and after vitrification, the total cell number and blastocyst development of embryo were significantly higher in July to August than September to October. In conclusion, addition of α-tocopherol 200 μM to in vitro bovine embryo culture medium was beneficial for improving embryo quality by decreasing the embryo damage blsstocysts cell number and improving the tolerance of the embryos to cryopreservation.

The objective of this work was to determine the effect of corpus luteum (CL) grade on pregnancy rate after embryo transfer in Korean cattle and we found that CL development was linked to pregnancy rate. The in vivo derived blastocyst-stage embryos were transferred to 15 recipients synchronized in the estrus cycles. Based on size and palpable characteristics, CLs were categorized into three grade. The grade three CL is not to be identified by rectal palpation. The pregnancy rates tended to increase with the increase in CL size of recipients. In grade one, two, and three, the pregnancy rates were 62.5%, 50.0%, and 0%, respectively. This result suggests that pregnancy rates after embryo transfer might be affected by the CL status of recipients.

The changes of feeding pattern and the amount of insecticide penetrated into the leaf were monitored for 420 min after treatment of three concentrations of dinotefuran. At about 30 min after treatment of insecticide, the overall feeding pattern in EPG (Electrical Penetration Graph) monitoring was started to change, and there was significant difference in proportions of NP (non-penetration), PA (pathway activity), and phloem-feeding patterns among the different concentrations of dinotefuran treatment. Especially, as the amount of insecticide penetrated into a leaf increased, the reactive behaviors against this insecticide such as withdrawal of proboscis and movements of stylet of aphid were more quickly exhibited. And also, total time at which the proboscis of the aphids did not penetrate the plant was getting longer. The amount of dinotefuran penetrated into a leaf was monitored with HPLC. When the recommended concentration (100 ㎎/L) of the insecticide was treated, 5.24~7.24 ㎎/L of the insecticide was detected from the leaf, and the proboscis of the aphids was apparently withdrawn from the leaf at approximately 60 minutes after treatment of this insecticide.