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        검색결과 10

        1.
        2023.11 구독 인증기관·개인회원 무료
        Radioactive contamination distribution in nuclear facilities is typically measured and analyzed using radiation sensors. Since generally used detection sensors have relatively high efficiency, it is difficult to apply them to a high radiation field. Therefore, shielding/collimators and small size detectors are typically used. Nevertheless, problems of pulse accumulation and dead time still remain. This can cause measurement errors and distort the energy spectrum. In this study, this problem was confirmed through experiments, and signal pile-up and dead time correction studies were performed. A detection system combining a GAGG sensor and SiPM with a size of 10 mm × 10 mm × 10 mm was used, and GAGG radiation characteristics were evaluated for each radiation dose (0.001~57 mSv/h). As a result, efficiency increased as the dose increased, but the energy spectrum tended to shift to the left. At a radiation dose intensity of 400 Ci (14.8 TBq), a collimator was additionally installed, but efficiency decreased and the spectrum was distorted. It was analyzed that signal loss occurred when more than 1 million particles were incident on the detector. In this high-radioactivity area, quantitative analysis is likely to be difficult due to spectral distortion, and this needs to be supplemented through a correction algorithm. In recent research cases, the development of correction algorithms using MCNP and AI is being actively carried out around the world, and more than 98% of the signals have been corrected and the spectrum has been restored. Nevertheless, the artificial intelligence (AI) results were based on only 2-3 overlapping pulse data and did not consider the effect of noise, so they did not solve realistic problems. Additional research is needed. In the future, we plan to conduct signal correction research using ≈10×10 mm small size detectors (GAGG, CZT etc.). Also, the performance evaluation of the measurement/analysis system is intended to be performed in an environment similar to the high radiation field of an actual nuclear facility.
        2.
        2023.05 구독 인증기관·개인회원 무료
        The Korea Laboratory Accreditation Scheme (KOLAS) is the national accreditation body responsible for providing accreditation services to testing and calibration laboratories. The primary objective of KOLAS is to promote the quality and reliability of laboratory testing by providing nationally and internationally recognized accreditation services. Laboratories accredited by KOLAS are required to meet rigorous international standards set by the International Organization for Standardization (ISO) and are subject to regular assessments to ensure ongoing compliance with the standards. KOLAS accreditation is highly regarded both domestically and internationally, and is recognized for providing high-quality and reliable testing services. The nuclear analysis laboratory at KINAC has been working to establish a quality management system to ensure the external reliability of analytical results and to secure its position as an authorized testing agency. To achieve this, a detailed manual and procedure for nuclear material analysis were developed to conform to the international standards of ISO/IEC 17025. This study presents the preparation process for establishing the management system, focusing on meeting technical and quality requirements for the implementation of the ISO/IEC 17025 standard in the KINAC nuclear analysis laboratory, specifically in the field of chemical testing (dosimetry, radioactive, and neutron measurement subcategories). The preparation process involved two tracks. The first track focused on satisfying technical requirements, with Thermal Ionization Mass Spectrometer (TIMS) and Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) selected as the major equipment for analysis. Analytical methods for determining isotope ratios and concentrations of nuclear materials were determined, and technical qualification was ensured through participation in proficiency test programs, inter-experimenter comparison tests, and uncertainty reports. The second track focused on developing the quality system, including quality manuals, procedures, and guidelines based on the requirements of the ISO/IEC 17025 standard. Various implementation documents were produced during the six-month pilot period, in accordance with the three levels of documents required by the standard. Implementation of ISO/IEC 17025 is expected to have a systematic quality management process for the analysis lab’s operations and to increase confidence in KINAC’s nuclear analysis.
        5.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2 week study was conducted to investigate the effects of Interferential Current(IC) and Kaltenborn-Evjenth Orthopedic Manual Therapy(KEOMT) on functional constipation. Interventions were applied to spinal segments between T9-L2 which provides innerva˗ tions to the gastrointestinal tract. Subjects(n=24) were randomly allo˗ cated to two treatment groups: the IC group or the KEOMT group. Results for the IC therapy demonstrated significant decrease with the colonic transit time(CTT) as well as scores on the constipation assessment scale(CAS). The frequency of defecations per week had increased significantly(p<0.05). The KEOMT displayed decreased CTT in the left colon region. The scores on the CAS were reduced and frequency of defecations per week had increased significantly (p<0.05). This study not only showed that both modes of therapy improved symptoms of constipation, but also optimized gastrointesti˗ nal content movement, eventuating in a more normalized CTT. In conclusion, both the IC therapy and the Kaltenborn-Evjenth Orthopedic Manual Therapy have shown to be effective interventions for improving functional constipation.
        4,000원
        6.
        2015.06 서비스 종료(열람 제한)
        Diffuse involvement of the right pulmonary artery (PA) associated with fistula between the PA and coronary artery is report-ed in a woman with Takayasu’s arteritis. Both the subclavian arteries were totally occluded and drained by the meanderinged artery arising from both common carotid arteries. Lung perfusion scan revealed perfusion defect of right lung. Two fistulas were identified. A large fistula was between the right PA and left circumflex artery. A small fistula was between the right PA and left anterior descending artery. This is a rare case of Takayasu’s arteritis presenting with a coronary – pulmonary artery fistula that is secondary to a diffuse unilateral involvement of PA.
        9.
        2001.06 KCI 등재 서비스 종료(열람 제한)
        One-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D SDS-PAGE) was used to determine whether it would provide improved resolving power of hordein proteins concomitant with improved identification of Korean barley cultivars and germplams. This system gave rapid and reproducible separations of hordein polypeptides. Total fourteen of clear and easily scorable subunits were identified in Korean barley cultivars and germplasms and their polymorphic constitutions could provide biochemical genetic information in progeny analysis and endosperm quality improvement in barley breeding programs. Each hordein polypeptides residing in B, C, and D hordein pattern designations were scored to prepare a cultivar catalogue of protein patterns. On the basis of this character, 7 hordein polypeptide patterns were constructed from 108 barley cultivars and experimental lines. The molecular weight of hordein subunits in Korean barley cultivars and experimental lines varied in the range of 98 to 48 kDa. In contrast, less polymorphic hordein polypeptides were found in the low protein barley lines including malting barleys than those found in Korean barley cultivars and experimental lines
        10.
        2000.03 KCI 등재 서비스 종료(열람 제한)
        The environment in which a given genotype is grown may influence its grain quality characteristics. When varieties are ~times evaluated over numerous environments, a variety environment interaction usually is observed, but the relative magnitude of environmental(E), genetic(G), and G ~times E effects on quality is unclear. In order to determine relative contribution of genotype, environment, and G ~times E interaction to the variations observed in grain quality characteristics, 18 Korean wheat cultivars and experimental lines were evaluated in two environments in 1998 and 1999. Correlation coefficients between grain quality and agronomic characteristics were also estimated. The analysis of variance for the optical density obtained by reaction bet- ween gliadin and anti-gliadin polyclonal antibody (AGPab) indicated that gliadin content measured by Enzyme-Linked Immunosorbent Assay(ELISA) was significantly in- fluenced by environment and cultivar differences. The significant differences of year and year ~times location were also found. The ratio of the variances associated with environmental effects to the variances associated with genetic effect gave relatively greater influence of environmental factor on gliadin content. The different protein content from same genotype grown in different environment might be associated with degree of storage protein accumulations. Significant relationships between ELISA and protein content, yield, ten spike weight, and ten spike number were detected. Polyphenol oxidase (PPO) activity was significantly influenced by year, location, cultivar and year ~times location. The variance in grain PPO activities among growing years appeared larger than the variation produced by the cultivar examined. This suggested that the growing environment contributed more to variability in grain PPO concentration.