Showing papers by "Yonsei University published in 1975"

Mössbauer study of antiferromagnetic CuFeS2

Abstract: Mossbauer spectra of a synthesized CuFeS2 sample were taken at various temperatures ranging from liquid-nitrogen temperature to 820°K. Clear six-line magnetic hyperfine patterns were observed even above 700°K, which was the reported upper limit for the existence of six-line pattern for natural chalcopyrites. No appreciable central peak was observed above 600°K. Isomer shift indicates the ferric character of the Fe ion. No appreciable quadrupole splittings were observed. This is consistent with the almost perfect tetrahedral co-ordination of Fe ions. The Neel temperature was determined to be (815±3)°K.

Behaviour Of Mast Cells In Mice In The Course Of Entamoeba Histolytica Infection By Strains

Abstract: The present report deals with the behaviour of mast cells in mice in the course of Entamoeba histolytica infection by the strains. Mice weighing about l6 gm were used for three experimental groups; control, sham infection and experimental. The experimental group was infected with Entamoeba histolytica trophozoites directly into cecum by laparotomy. Strains isolated from three hepatic amoebic abscess cases were used. Mesenteric samples from the region of terminal ileum were fixed in methyl alcohol and stained with Pugh's solution. The ulcers in cecum were examined. Changes in number and structure of mesenteric mast cells and blood eosinophils were as follows. 1. The number of mast cell in mesenteric tissues of the infected group increased from first day of the infection and persisted up to 34th day of the observation period. 2. Degranulation and disruption of mast cells increased in the infected group compared with groups of the sham operation and the contro1, but showed no difference by the strains of Entamoeba histolytica. 3. The blood eosinophilia was observed in the infected group and persisted until the observation period. 4. Ulcers in cecum were found in all the infected groups. The results above indicate that mast cells are keenly related with the course of Entamoeba histolytica infection.

N-Ion Implantation into ZnSe

Abstract: Low resistivity n-type ZnSe single crystals implanted with 60 keV or 60 and 25 keV N-ions were converted to p-type conductivity after proper annealing. The type conversion was confirmed by a thermal probe method, I–V characteristics and a photovoltaic effect. Photo luminescent and electroluminescent measurements showed the edge emission (2.68 eV), intense green (2.38 eV) and faint red (1.99 eV) bands at 77°K. The green emission quenched out completely at room temperature and only weak red band (l.97 eV) remained. The radiative recombination of the anomalous emission intensity at 77°K can be attributed to the coorperation of the radiative recombination of the implanted nitrogen center (0.09 eV) and the intrinsic edge emission.

Perceived Trustworthiness of Occupations Personality Effects and Cross-Cultural Generalizability

Abstract: The present study examines the perceived trustworthiness of nineteen selected occupations based on U.S. and Korean student samples. Specifically, it compares the rating and ranking methods of assessing trustworthiness, examines the possibility of sex and culture differences, and evaluates the effects of subjects' levels of trustfulness. The relative trustworthiness of the nineteen occupations was highly similar across rating and ranking methods, sex, culture, and level of trustfulness. However, there was a significant relationship between level of trustfulness and level of perceived trustworthiness. Implications of these findings for future work on trustworthiness, and for survey research in general, are discussed.