In KAERI, the nuclide management technology is currently being developed for the reduction of disposal area required for spent fuel management. Among the all fission products of interest, Cs, I, Kr, Tc are considered to be significantly removed by following mid-temperature and high-temperature treatment, however, a difficulty of spent-fuel thermal treatment experiment limits the development of such thermal treatment. In this study, we applied our previously developed two-stage diffusion release model coupled to UO2 oxidation model to the development of optima thermal treatment scenario. Since the formation of cesium pertechnetate should be avoided and the fission release behavior is considerably affected by the extent of oxygen, we obtained oxygen-content dependent model parameters for two-stage fission release model and applied the model to the evaluation of fission release behavior to different oxygen content and thermal treatment procedure. It was found that the developed fission release model closely describes the experimental behavior of fission product of interest, implying a validity of model prediction and the thermal treatment condition reducing the chemical reaction between cesium and technetium could be developed.

Effect of oxygen content in the ultrafine tungsten powder fabricated by electrical explosion of wire method on the behvior of spark plasma sintering was investigated. The initial oxygen content of 6.5 wt% of as-fabricated tungsten powder was reduced to 2.3 and 0.7 wt% for the powders which were reduction-treated at 400˚C for 2 hour and at 500˚C for 1h in hydrogen atmosphere, respectively. The reduction-treated tungsten powders were spark-plasma sintered at 1200-1600˚C for 100-3600 sec. with applied pressure of 50 MPa under vacuum of 0.133 Pa. Maximun sindered density of 97% relative density was obtained under the condition of 1600˚C for 1h from the tungsten powder with 0.7 wt% oxygen. Sintering activation energy of 95.85kJ/mol-1 was obtained, which is remarkably smaller than the reported ones of 380~460kJ/mol-1 for pressureless sintering of micron-scale tungsten powders.

This research was planned and executed to evaluate how the composition of Yack-sun (oriental diet therapy) tea can effect the health conditions of people who are suffering from diet-related diseases such as being overweight, obese and hyperlipidemic, by taking Yack-sun tea in a form of nutritional supplement with daily meals. We produced Kangjieum with Lycense Mill., Polygonum multflorum Thunb, Cassia tora L., Crataegus pinnatifida Bge and Salvia miltiorrhiza Bge. We evaluated the effects of this tea on serum lipids, on homocysteine concentration, and on active oxygen contents, oxidative stress by clinical practices. We have determined that this tea has a significant effect on decreasing body fat content, decreasing total cholesterol, decreasing LDL-cholesterol, and decreses triglyceride and homocysteine concentrations. In addition, blood active oxygen content and oxidative stress were significantly decreased. We think that scientific and objective evaluation was performed on the components of Kangjieum prescription. We concluded that we could apply the components, not only in a form of tea, but also in other forms of various foods. The information we received from this conclusion will be basic information on how we can apply oriental medicinal resources into other food and will be a steppingstone for medicinal herbs to place a foot in the field of functional food research, which already draws sizable attention world-wide.

The effect of oxygen on the shape memory characteristics in Ti-18Nb-6Zr-XO (X = 0-1.5 at%) biomedical alloys was investigated by tensile tests. The alloys were fabricated by an arc melting method at Ar atmosphere. The ingots were cold-rolled to 0.45 mm with a reduction up to 95% in thickness. After severe cold-rolling, the plate was solution-treated at 1173 K for 1.8 ks. The fracture stress of the solution-treated specimens increased from 450 Mpa to 880 MPa with an increasing oxygen content up to 1.5%. The fracture stress increased by 287MPa with 1 at% increase of oxygen content. The critical stress for slip increased from 430 MPa to 695 MPa with an increasing oxygen content up to 1.5 at%. The maximum recovery strain of 4.1% was obtained in the Ti-18Nb-6Zr-0.5O (at%) alloy. The martensitic transformation temperature decreased by 140 K with a 1.0 at% increase in O content, which is lower than that of Ti-22Nb-(0-2.0)O (at%) by 20 K. This may have been caused by the effect of the addition of Zr. This study confirmed that addition of oxygen to the Ti-Nb-Zr alloy increases the critical stress for slip due to solid solution hardening without being detrimental to the maximum recovery strain.

목 적: 단백질 침전물이 콘택트렌즈의 함수율, 산소투과성 및 접촉각에 미치는 영향을 조사하였다. 방 법: Polymacon과 etafilcon A 재질의 소프트콘택트렌즈를 착용기간에 따라 수집하여 단백질 침전물을 추출하고 fluorometer를 이용하여 단백질 침전물을 정량하였다. 사용하지 않은 polymacon과 etafilcon A 콘택트렌즈를 lysozyme과 albumin 단백질이 포함된 인공눈물에 넣어 일정하게 단백질을 부착시키고 부착된 단백질 침전물을 정량한후 중량측정법, 전기분해 자동분석법 및 sessile drop 방법을 사용하여 함수율, 산소투과성 및 접촉각을 측정하여 대조군과 비교하였다. 결 과: Polymacon 재질의 콘택트렌즈에 부착된 단백질 침전물 양은 착용기간에 따라 차이가 없었으나, etafilcon A 재질의 콘택트렌즈는 착용기간에 따라 빠르게 증가하였다. 일정하게 단백질을 부착시킨 소프트 렌즈의 경우 함수율은 polymacon 렌즈와 etafilcon A 렌즈에서 모두 감소하였고, 산소투과성도 polymacon 렌즈와 etafilcon A 렌즈에서 모두 감소하였으며 접촉각은 polymacon 렌즈와 etafilcon A 렌즈에서 모두 증가하였다. 결 론: 소프트콘택트렌즈에 부착된 단백질 침전물은 렌즈의 함수율과 산소투과성을 저하시키고 접촉각을 증가시켜 콘택트렌즈 착용 시 불편감을 유발하는 원인이 될 수 있으며 특히 고함수 이온성 재질인 etafilcon A의 경우 더욱 문제가 될 것으로 사료된다.

In this study, dietary Rhus verniciflua Stockes were feeded on the porks and Hanwoo beef to determinate sanitation effects. this experiment was performed to measure oxygen contents and total flavor compounds of pork and beef inoculated Pseudomonas aeruginosa in headspace with SPME-GC. The headspace oxygen contents in Hanwoo beef were no difference on the diet supplementation ratio of Rhus verniciflua Stokes during storage at 5℃. Headspace oxygen contents of teratment dieted for 5 and 6months were higher than that of treatment dieted for 3 and 4months. No remarkable difference was observed in headspace oxygen contents in pork between control and treatment during storage at 0℃. Oxygen contents in pork of treatment diet containing 4% Rhus verniciflua Stokes was higher than that of treatment were lower than that of control on Hanwoo beef. Flavor compounds were the lowest in diet supplemented 6% of Rhus verniciflua Stokes during 4 months. Flavor compounds of pork is no change at 0℃. The longer storage periods It had the more increasing total flavor compounds and Rhus verniciflua Stokes supplement ratio had no effects on change of total flavor compounds. Such as this experiment, Flavor compounds and oxygen contents in headspace could be analyzed by SPME-GC method promptly and easily in accordance with, it is expected to apply SPME-GC method to evaluation of food quality.

Many researchers have defined critical chloride content as a specific value. The studies reporting critical threshold chloride content have involved the experimental measurement of the average amount of the total chloride content. The studies have tried to define the critical chloride content within the scope of their experimental concrete mix proportion at arbitrary time. However, there is no agreement on its value. The purpose of this study is to explore the combined effect of oxygen and chloride on reinforcement corrosion. In the experimental recipe, water soluble oxygen is taken into account to define the critical chloride content. Corrosion current density of reinforcement was measured by linear polarization resistance method.

방사선후처리로서 산소가 수분함량이 다른 수도종자에 미치는 영향을 조사코저 수분함량 5.6∼14.7%까지의 종자에 3∼25kR의 방사선량을 조사한 후 산소 및 질소로 bubbling한 상태에서 hydration처리하였다. 효과가 현저하여 5.6∼12.9%까지는 산소처리에 의한 묘장 및 생존율의 감소가 나타났지만 13.9%부터 그 이상에서는 차이가 없었다. 엽록소돌연변이율 및 불임율은 6.5%의 저수분에서 13.0%의 고수분함량에 이르기까지 공히 산소처리에 의한 영향이 있었고 특히 저수분함량일수록 또는 방사선량이 높을수록 그차이는 현저하였다.