• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2725-2732
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• 2020

This paper presents the neutronics benchmark analysis of the first core of the Indonesian multipurpose research reactor RSG-GAS (Reaktor Serba Guna G.A. Siwabessy) calculated by the Serpent Monte Carlo code and the newly released ENDF/B-VIII.0 nuclear data library. RSG-GAS is a 30 MWth pool-type material testing research reactor loaded with plate-type low-enriched uranium fuel using light water as a coolant and moderator and beryllium as a reflector. Two groups of critical benchmark problems are derived on the basis of the criticality and control rod calibration experiments of the first core of RSG-GAS. The calculated results, such as the neutron effective multiplication factor (k) value and the control rod worth are compared with the experimental data. Moreover, additional calculated results, including the neutron spectra in the core, fission rate distribution, burnup calculation, sensitivity coefficients, and kinetics parameters of the first core will be compared with the previous nuclear data libraries (interlibrary comparison) such as ENDF/B-VII.1 and JENDL-4.0. The C/E values of ENDF/B-VIII.0 tend to be slightly higher compared with other nuclear data libraries. Furthermore, the neutron reaction cross-sections of ¹⁶O, ⁹Be, ²³⁵U, ²³⁸U, and S(𝛼,𝛽) of ¹H in H₂O from ENDF/B-VIII.0 have substantial updates; hence, the k sensitivities against these cross-section changes are relatively higher than other isotopes in RSG-GAS. Other important neutronics parameters such as kinetics parameters, control rod worth, and fission rate distribution are similar and consistent among the nuclear data libraries.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4253-4264
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• 2022

Since the implementation of the phosphate project in Bled El-Hadba (BEH) deposit, western region of Tébessa, no detailed study has been conducted to assess the natural radioactivity distribution and the associated radiological risk parameter for this open-pit mine. For the sake of determining a credible premining reference database for the region of interest, 21 samples were collected from different geological layers of the above-mentioned deposit. Gamma Spectrometry was applied for measuring radioactivity using a high resolution HPGe semiconductor detector. The obtained activity results have shown a significant broad variation in the radioactive contents for the different phosphate samples. The total average concentrations (in Bq·kg^-1) for ²²⁶Ra, ²³⁸U, ²³⁵U, ²³²Th and ⁴⁰K computed for the different type of phosphate layers were found to be 570 ± 169, 788 ± 280, 52 ± 18, 66 ± 6 and 81 ± 18 respectively. The mean activity concentrations of the measured radionuclides were compared to other regional and worldwide deposits. The ratios between the detected radioisotopes have been calculated for spatial distribution of natural radionuclides in the study area. Based on the aforementioned activity concentrations, the corresponding radiation hazard parameters were assessed. Correlations between the obtained parameters were drawn and a multivariate statistical analysis (Pearson Correlation, Cluster and Factor analysis) was carried out in order to identify the existing relationships.

• Journal of Radiation Protection and Research
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• v.39 no.1
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• pp.54-60
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• 2014

IAEA has employed various types of radiation detectors - HPGe, NaI, CZT - for accountancy of nuclear material. Among them, HPGe has been mainly used in verification activities required for high accuracy. Due to its essential cooling component(a liquid-nitrogen cooling or a mechanical cooling system), it is large and heavy and needs long cooling time before use. New hand-held portable HPGe has been developed to address such problems. This paper deals with results of performance evaluation test of the new hand-held portable HPGe prototype which was used during IAEA's inspection activities. Radioactive spectra obtained with the new portable HPGe showed different characteristics depending on types and enrichments of nuclear materials inspected. Also, Gamma-rays from daughter radioisotopes in the decay series of $^{235}U$ and $^{238}U$ and characteristic x-rays from uranium were able to be remarkably separated from other peaks in the spectra. A relative error of enrichment measured by the new portable HPGe was in the range of 9 to 27%. The enrichment measurement results didn't meet partially requirement of IAEA because of a small size of a radiation sensing material. This problem might be solved through a further study. This paper discusses how to determine enrichment of nuclear material as well as how to apply the new hand-held portable HPGe to safeguard inspection. There have been few papers to deal with IAEA inspection activity in Korea to verify accountancy of nuclear material in national nuclear facilities. This paper would contribute to analyzing results of safeguards inspection. Also, it is expected that things discussed about further improvement of a radiation detector would make contribution to development of a radiation detector in the related field.

• Journal of the Korean Home Economics Association
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• v.42 no.11
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• pp.223-235
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• 2004

This study investigated the integrated effects of family and school factors on the cyber behavior of adolescents. Specifically, the purposes of this study were to categorize adolescents into groups by family and school factors and to find investigate differences among the groups regarding cyber behavior (internet use, internet purpose, and internet experience). no study distributed the questionnaires to middle and high school adolescent students of five representative cities in South Korea. The total respondents were 2240 (960 from Seoul/kyongki, and 320 each from Taegu, Pusan, Kwangiu, and Taejon). The response rate w3s 98.7%. no data were analyzed by factor analysis, cluster analysis, ANOVA, and Duncan test. The results showed that Korean adolescents were segmented into four groups (family preference/school preference group, family dissatisfaction/teacher dissatisfaction group, family average/school average group, family average/peer dissatisfaction group). The four groups were significantly different in regard to cyber behavior. For example, the family dissatisfaction/teacher dissatisfaction group u%d internet to relieve stress and used communication more than the other groups. Also, the group had more diverse cyber behavior including internet addiction. The implications of the study were further discussed.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.05a
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• pp.235-242
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• 1998

Aiming at one of decisive alternatives for long term aspect of nuclear power concerns, an integral and closed nuclear system, AMBIDEXTER (Advanced Molten-salt Break-even Inherently-safe Dual-mission Experimental and TEst Reactor) concept is under development. The AMBIDEXTER complex essentially comprises two mutually independent loops of the radiation/material transport and the heat/energy conversion, centered at the integrated reactor assembly, which enables one to utilize maximum benefits of nuclear energy under minimum risks of nuclear radiation. And it provides precious radioisotopes and radiation sources from its waste stream. Also the reactor operates at very low level of fission products inventory throughout its lifetime. The nuclear and thermalhydraulic characteristics of the molten TH/$^{233}$ U fuel salt extend the capability of the self-sustaining AMBIDEXTER fuel cycle to enhance resource security and safeguard transparency. The reactor system is consisted of a single component module of the core, heat exchangers and recirculation pumps with neither pipe connections nor active valves in between, which will significantly improve inherent features of nuclear safety. States of the core technologies associated with designing and developing the AMBIDEXTER concept are mostly available in commercialized form and thus demonstration of integral aspects of the concept should be the prime area in future R＆D programs.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1832-1836
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• 2006

Mesorhizobium sp. LUK, which utilizes 3-amino-3-phenylpropionic acid as the sole source of nitrogen with high enantioselectivity (E(S)>100), was isolated using enrichment culture. The enzyme involved in the utilization of (S)-3-amino-3-phenylpropionic acid was confirmed to be a transaminase and was purified by 235-folds with a specific activity of 0.72 U/mg. The molecular weight of the purified protein was ca. 47 kDa and the active enzyme was determined as a dimer on gel filtration chromatography. The N-terminal sequence was obtained from the purified protein. Spontaneous decarboxylation of produced ${\beta}-keto$ acids was observed during the chiral resolution of 3-amino-3-phenylpropionic acid.

• The Journal of the Korean dental association
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• v.9 no.5
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• pp.235-239
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• 1971

The effects of folic acid on the oral mucosa of albino rats were histochemically studied in the twenty four male rats, weighing abut 100gm. Seven groups of 3 each were injected with 0.2ml folic acid (folic acid 0.5mg. was dissolved in physiological saline 0.2ml) subcutaneously, during 1,2,3,5,7,10 and 14 days respectively. Oral mucosa of rats sere removed from upper molar region and fixed in 10% formalin, cold absolute alcohol, Carnoy's solution and acetone. The serial sections were histochemically stained by McManu's PAS reaction, Mowry's metachromasia, alloxan-Schiff reaction, and azo dye method for alkaline phosphatase. The comparative staining method was hematoxylin-eosin stain. The results were as follows: 1) Alkaline phosphatase reaction of stratum spinosum and stratum granulosum tended to increase after 7 and 10 days of folic acid administration. 2) PAS reactions of basement membrane and lamina propria increased after folic acid administration. 3) Metachromasia of stratum spinosum and stratum granulosum were slightly increased after 3,5 and 7days of folic acid administration and returned to the level of Control after 10 days. 4) In the oral mucosa, alloxan-Schiff reaction increased after 7 days of folic acid administration.

• Journal of Radiation Protection and Research
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• v.26 no.3
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• pp.275-279
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• 2001

In uranium enrichment plants and nuclear fuel fabrication facilities, exact measurement of fissile isotope enrichment of uranium is required for material accounting in international safeguards inspection as well as process quality control. The purpose of this study was to develop a simple measurement system which can portably be used at nuclear fuel fabrication plants especially dealing with low enriched uranium. For this purpose, a small size CZT (CdZnTe) detector was used, and the detector performance in low uranium gamma/X -rays energy range was investigated by use of various enriched uranium oxide samples. New enrichment measurement technique and analysis method for low enriched uranium oxide, so-called, 'semi-peak ratio technique' was developed. The newly developed method was considered as an alternative technique for the low enrichment and would be useful to account nuclear material in safeguarding activity at nuclear fuel fabrication facility.

• Journal of Korean Public Health Nursing
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• v.31 no.3
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• pp.554-566
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• 2017

Purpose: The study was conducted to investigate the effects of knowledge and attitude towards dementia on social distance from senile dementia among university students. Methods: The study was a descriptive study based on 235 university students. Data were collected from September 1 to 15, 2017 using a structured self-report questionnaire. Dementia knowledge, dementia attitude, and social distance from senile dementia were measured. Data were analyzed using descriptive statistics, t-test, one-way ANOVA, Mann-Whitney U-test, Kruskal-Wallis test, Pearson's correlation coefficients and hierarchical multiple regression. Results: After adjusting for the general and dementia-related characteristics of the participants, the significant predictors of social distance from senile dementia among university students were dementia attitude. Moreover, knowledge and attitude towards dementia explained 27.8% of the variance in social distance from senile dementia among university students. Conclusion: The results indicate that educators need to make efforts to improve dementia attitude and to develop plans to increase dementia knowledge in order to reduce university students' prejudice against senile dementia.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.235-241
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• 2008

Please Interests in the medical service are increasing in internet environment as life quality of the people improves because of development in information and medical technology. The medical information in today's modern internet environment can violate privacy of the patients. Many medical institutions in Korea are very passive in the privacy protection of patients in the internet environment. The law, standard scheme and systematic guidance to prevent drain of medical information are not developed. This study examines cases of infringement pattern on information of each patient in the internet environment. This study will also try to find a solution to protect the personal information of patients in the internet environment in the measures of law system, technique and management.