In order to prevent the oxide formation on the surface of nano-size iron particles and thereby to improve the oxidation resistance, iron nanoparticles synthesized by a chemical vapor condensation method were directly soaked in hexadecanethiol solution to coat them with a polymer layer. Oxygen content in the polymer-coated iron nanoparticles was significantly lower than that in air-passivated particles possessing iron-core/oxide-shell structure. Accordingly, oxidation resistance of the polymer-coated particles at an elevated temperature below in air was times higher than that of the air- passivated particles.

The purpose of this study was to examined the relationship of juvenile delinquents' multifactorial self concept and probability of re-offense. The sample of research was consisted of juvenile offenders in juvenile protection facilities and juvenile prison which are located in Seoul, Busan, Gwangju, Cheon. The result from the regressions to the future probability of re-offense with multifactorial self concepts shows that moral-ethical self concept was negaively related with the probability of re-offense in the four type of delinquent behaviors except rape, personality-related self concept was negatively related with the robbery, violent behavior and rape, social self concept was negatively related with the theft but positively related with violent behavior, ability-related self concept was positively related with rape, and family self concept was negatively related with probability of all the type of delinquent behaviors. The result from the regressions with the interaction terms shows that the four interaction terms significantly were related with the probability of re-offense.

Ultrafine titanium carbide particles were synthesized by the reaction of liquid-magnesium and vaporized TiCl+CCl(x = 1 and 2) solution. Fine titanium carbide particles with about 50 nm were successfully produced by combining Ti and C atoms released by chloride reduction of magnesium, and vacuum was then used to remove the residual phases of MgCl and excess Mg. Small amounts of impurities such as O, Fe, Mg and Cl were detected in the product, but such problem can be solved by more precise process control. The lattice parameter of the product was 0.43267 nm, near the standard value. With respect to the reaction kinetics, the activation energy for the reactions of TiCl+CCland Mg was found to 69 kJ/mole, which was about half value against the use of TiCl+CCl, and such higher reactivity of the former contributed to increase the stoichiometry until the level of TiC and decrease the free carbon content below 0.3 wt.%.

Ultra fine titanium carbide particles were synthesized by novel metallic thermo-reduction process. The vaporized TiC1+ gases were reacted with liquid magnesium and the fine titanium carbide particles were then produced by combining the released titanium and carbon atoms. The vacuum treatment was followed to remove the residual phases of MgC1 and excess Mg. The stoichiometry, microstructure, fixed and carbon contents and lattice parameter were investigated in titanium carbide powders produced in various reaction parameters.

Nanostructured Cu-AlO composite powders were synthesized by thermochemical process. The synthesis procedures are 1) preparation of precursor powder by spray drying of solution made from water-soluble copper and aluminum nitrates, 2) air heat treatments to evaporate volatile components in the precursor powder and synthesis of nano-structured CuO + O, and 3) CuO reduction by hydrogen into pure Cu. The suggested procedures stimulated the formation of the gamma-AlO, and different alumina formation behaviors appeared with various heat treating temperatures. The mean particle size of the final Cu/AlO composite powders produced was 20 nm, and the electrical conductivity and hardness in the hot-extruded bulk were competitive with Cu/AlO composite by the conventional internal oxidation process

In this paper, the interactive effects of major factors on juvenile delinquency were examined using multiple regression analysis. Major factors on juvenile delinquency are attachment to the parents, supervision of the parents, school achievement, strain caused by school achievement(achievement strain), strain caused by college(or job) entrance (entrance strain), the degree of contact with delinquent peers(delinquent contact) and the degree of bond with delinquent peers(delinquent bond). Interaction terms were created by multiplying each of the major factors. Juvenile delinquency was measured by three methods; the times of minor delinquency, the times of serious delinquency, and the seriousness measure of the committed delinquent behavior by seriousness scale. Three sets of regressions were then performed. First, minor delinquency measure was regressed on the seven variables of major factors, with and without the twelve interaction terms. Second, serious delinquency measure was regressed on the seven variables of major factors, with and without the twelve interaction terms. Third, seriousness measure was regressed on the seven variables of major factors, with and without the twelve interaction terms. The result from the regressions with the interaction terms shows that the twelve interaction terms significantly increase the amount of explained variance in both serious delinquency and seriousness degree but not in minor delinquency. The amount of explained variance in the serious delinquency is increased from 26.8% to 31.5%, or 17.6%. Explained variance in seriousness of delinquency is increased from 31.2% to 34.0%, or 9.0%. But increasement in minor delinquency is not significant, from 43.9% to 44.3%, only 0.9%. The five terms of twelve interaction terms have a significant effect on the serious delinquency or the seriousness of delinquency; 'attachment × entrance strain', 'attachment × delinquent contact', 'supervision × delinquent contact', 'school achievement × delinquent contact', and 'school achievement × delinquent bond'. Overall, the paper indicates that the addition of the interaction terms substantially improves the prediction of serious delinquency.

유전적으로 우수한 능력을 보유하고 있으나 정상적으로 번식이 불가능한 젖소 16두를 간이 난자 체취기를 이용하거나 장기공태 젖소 5두를 초음파 난자체취기를 이용하여 미성숙난자를 채취하므로서 체외수정란을 안정적으로 생산하기 위해 채취기기의 효율성과 반복채란에 미치는 영향을 조사한 결과는 다음과 같다. 1 공란우당 채취회수는 간이 난자 체취기 8.8회였고, 초음파기기는 8.8회였으며, 공란우당 평균 회수된 난포란은 각각 4.39개와 4.14개로 채취기기간에