Using as sintering additives and Si as a raw powder, the continuously porous in-situ bodies were fabricated by multi-pass extrusion process and their microstructures were investigated depending on the addition of carbon (0-9wt%) in the mixture powder. The introduction of fibers observed in the unidirectional continuous pores as well as in the pore-frame regions of the nitrided bodies can be an effective method in increasing the filtration efficiency. In the case of no carbon addition, the network type fibers with high aspect ratio appeared in the continuous pores with diameters of 150-200 nm. However, in the case of 9wt% C addition, the fibers were found without any network type and had diameters of 200-250 nm.

Room temperature kinetics of degradation of nerve agent simulants and sarin, an actual nerve agent at the surface of different carbon based adsorbent materials such as active carbon grade 80 CTC, modified whetlerite containing 2.0 and 4.0 % NaOH, active carbon with 4.0 % NaOH, active carbon with 10.0 % Cu (II) ethylenediamine and active carbon with 10.0 % Cu (II) 1,1,1,5,5,5-hexafluoroacetylacetonate were studied. The used adsorbent materials were characterized for surface area and micropore volume by N2 BET. For degradation studies solution of simulants of nerve agent such as dimethyl methylphosphonate (DMMP), diethyl chlorophosphate (DEClP), diethyl cyanophosphate (DECnP) and nerve agent, i.e., sarin in chloroform were prepared and used for the uniform adsorption on the adsorbent systems using their incipient volume at room temperature. Degradation kinetics was monitored by GC/FID and was found to be following pseudo first order reaction. Kinetics parameters such as rate constant and half life were calculated. Half life of degradation with modified whetlerite (MWh/NaOH) system having 4.0 % NaOH was found to be 1.5, 7.9, 1206 and 20 minutes for DECnP, DEClP, DMMP and sarin respectively. MWh/NaOH system showed maximum degradation of simulants of nerve agents and sarin to their hydrolysis products. The reaction products were characterized using NMR technique. MWh/NaOH adsorbent was also found to be active against sulphur mustard.

전라남도 순천시 서 면 청소골 일대에 분포하는 히어 리개체군의 분포특성과 개체군 동태를 조사하였다. 히어리개체군은 계곡부와 인접한산림 가장자리를 따라 대상으로 분포하였으며,북사면,북서사면 및 북동사면에만 분포하는 특이성을 보였다. 교목층이 형성된 삼림내에서 아교목층이나 관목층을 이루고 있으며,종조성에 있어서는 히어리가 분포하지 않는 인접지 역 삼림식생과 별다른 차이는 없었다. 25 m2당 평균개체수와 개체당 평균 맹아지는 각각 6.25주 및 3개로서 다른 지 역 에 비해 낮은 밀도를 나타냈으며, 이 지 역의 히어 리개체군이 쇠퇴해가고 있음을 알 수 있었다.

우리나라 특산수종인 히어리 분포지 특성에 대해 현지 조사와 문헌조사를 실시하였다. 히 어리 분포는 전라남도 지역의 보성군, 광양시, 순천시 일대, 고흥군 점암면, 구례군 간전면, 장흥군 천관산, 지리산 노고단 전라북도 남원시 천황산, 지리산 뱀사골과 반야봉, 경상남도 산청군, 하동군, 남해군, 경기도 포천시 백운산에 출현하는 것으로 확인되었으며, 히어리 분포역에서 식물상은 70과 159속 216종 22변종 4품종 총 242종류가 확인되었다 분류군별로는 양치식 물이 5.8%, 나자식물이 3.7%, 단자엽식물이 18.6%, 쌍자엽식물이 71.9%로 분석되었으며, 생활형별 분류에서 1년생이 1.7%, 다년생이 98.3%로 분석 되었다. 생장형 별 비교에서는 초본성이 44.2%, 덩굴성이 12.4%, 관목성이 17.8%, 교목성이 25.6%로 나타났다. 히어리 군락 분포 유형은 전형적으로 북사면, 북동사면, 또는 북서사면이었으며, 전라남도 승주읍 신전리 자생지는 교목상 숲으로 인해 쇠퇴하는 경향을 보였다.

Sexing from bovine embryos which were fertilized in vitro implicate a possibility of the sex-controlled cattle production. This study was carried out to investigate the possibility of determining of embryo sex by fluorescence in situ hybridization (FISH) technique. FISH was achieved in in vitro fertilized bovine embryos using a bovine Y-specific DNA probe which constructed from the btDYZ-1 sequences. To evaluate Y-chromosome specificity of the FISH probe, metaphase spreads of whole embryos and lymphocytes were prepared and tested. A male-specific signal was detected on 100% of Y chromosome bearing metaphase specimens. Using the FISH technique with a bovine Y-specific probe, 232 whole embryos of 8 cell- to blastocyst-stage were analyzed. Observing the presence of the Y-probe signal on blastomeres, 102 embryos were predicted as male, and 130 embryos as female. The determining rate of embryo sex by FISH technique was about 93% regardless of embryonic stages. In conclusion, the FISH using a bovine Y-specific DNA probe is an accurate, reliable and quick method for determining the sex of bovine embryos.

Nano-sized was in situ synthesized in copper matrix through self-propagating high temperature synthesis (SHS) with high-energy ball milled Ti-B-Cu elemental mixtures as powder precursors. The size of particles in the product of SHS reaction decreases with time of preliminary mechanical treatment ranging from 1 in untreated mixture to 0.1 in mixtures milled for 3 min. Subsequent mechanical treatment of the product of SHS reaction allowed the particles to be reduced down to 30-50 nm. Microstructural change of -Cu nanocomposite during spark plasma sintering (SPS) was also investigated. Under simultaneous action of pressure, temperature and electric current, titanium diboride nanoparticles distributed in copper matrix move, agglomerate and form a interpenetrating phase composite with a fine-grained skeleton.

Synthesis and characteristics of Cu nanopowder were considered by in-situ characterization method using SMPS in pulsed wire evaporation process. With increasing pressure in chamber, particle size and degree of agglomeration increased by increase of collision frequency. Also, it was found from the XRD analyses and BET measurements that crystallite size and particle size decreased with elevating applied voltage. However, SMPS measurements and TEM observation revealed the increase of particle size and degree of agglomeration with increase of applied voltage. These results suggested that particle growth and agglomeration depend on overheating factor in chamber at the early stage and thermal coagulation in filtering system during powder formation until collection.