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        검색결과 12

        2.
        2023.11 구독 인증기관·개인회원 무료
        High level radioactive waste (HLW) final disposal repository is faced thermos-hydro-mechanical - radioactive condition because it is placed over 500 m in depth and waste emits decay heats for decades. Repository will be operated around 100 years and will be closed after all the wastes are disposed. The integrity of engineered barriers including buffer, backfill, concrete plug and canister and natural barrier (natural rock mass) will be stood during operating periods. Monitoring sensors for concrete and rock mass is conducted using piezo based sensors such as accelerometer or acoustic emission (AE) sensors. Typical accelerometer for harsh conditions is commonly expensive and data/power cable can be a potential groundwater inflow and nuclide outflow path. The fiber optic accelerometer whose data and power cable are united and has limited volume. Therefore, it can be a potential alternative sensor of piezo based sensors. The temperature limits and accelerated tests for fiber optic sensors are conducted. Most of sensors gives a malfunction around 130°C. The results of these experimental tests give a possibility of communications in compacted bentonite buffer and will be utilized for the design of monitoring systems for the repository.
        3.
        2022.10 구독 인증기관·개인회원 무료
        The integrity of the disposal repository structure must be guaranteed for few hundreds to few hundred thousand years until toxicity of radioactive waste is surely degraded. Acoustic emission (AE) method is widely utilized to evaluate the integrity of the structure because it can detect crack wave signals of the structures. It is well known that the cracking AE energy is proportional to the volume of the structure (Fractal theory). However, it is hard to destroy whole structures for obtaining AE energy. Therefore, the scaled specimens are prepared to obtain the relationship between volume of the structure and AE energy. The specimens are prepared with same of Wolsong Low and Intermediate Level Radioactive Waste Disposal Center (WLDC) silo concrete recipe. Their diameters are from 50 mm to 150 mm in each 10 mm and their heights are twice of the diameter. One set of 50 mm to 150 mm specimens (11 specimens in one set) are made in single mixers to maintain uniformity. Surface of the specimens are flatten with cement milk to prevent from applying load with eccentricity. The uniaxial compression test is performed by controlling displacement as 0.1 mm/min. The fractal constant is obtained using least square function from volume-cumulative AE energy relationship.
        4.
        2022.05 구독 인증기관·개인회원 무료
        Low and intermediate radioactive wastes in South Korea have been disposed in Wolsong Low and Intermediate Level Radioactive Waste Disposal Center (WLDC), Gyeongju. This repository structure is planned to be operated few hundred years while toxicity of the waste is sufficiently decayed. The structural integrity of the repository is required to protect the waste in safe. The integrity of the structure is commonly estimated using acoustic emission (AE) method. The integrity of the structure using AE is obtained by following process: 1) Estimation of maximum acoustic crack energy of the structure, 2) Acoustic signal measurement and filtering, and 3) Measurement of simultaneous acoustic cracking energy. The damage of the structure can be obtained from cumulative cracking energy from the structure divided by the predicted maximum cracking energy of the structure. Estimation of maximum cracking energy is gained by the specimens whose components are identical to the repository structure. The cracking energy of the different specimens are obtained during uniaxial compressive test and volume of the specimen is calculated. Then, the fractal coefficient for the structure is obtained and the maximum crack energy of the target structure can be calculated. The specimens whose diameters vary from 50 mm to 150 mm and heights are twice of the diameter are made with same recipe of WLDC silo concrete. The uniaxial compression test is conducted with loading rate of 0.1 mm·min−1. The fractal coefficient is obtained by least square method from the volume-cumulative energy relationship.
        5.
        2022.05 구독 인증기관·개인회원 무료
        High level nuclear waste (HLW) is surely disposed in repository in safe by being separated from human life zone. Deep geological disposal method is one of the most potent disposal method. Deep geological repository is exposed to high pressure and groundwater saturation due to its depth over 500 m. And it is also exposed to high temperature and radiation by spent fuels. Thus, HLW repository suffers extremely complex thermo-hydro-mechanical-radioactive condition. Long-term integrity of repository should be verified because the expected lifetime of the repository is over 10,000 years. However, the integrity of monitoring sensors are not reach the endurance lifetime of the repository with present technology. And the disposal condition, thermo-hydro-mechanical-radioactive, should shorten the estimated lifetime of the monitoring sensors. Therefore, it is necessary to improve the long-term integrity of the monitoring sensors. Although long-term tests are required to identify the prolonged durability of monitoring sensors, accelerated tests can help curtail test period. Accelerated tests is classified into accelerated stress test and accelerated degradation test and their methodology and theories are investigated. Their tests are design and proceed by following process: 1) identify failure modes, 2) select accelerated stress parameter, 3) Determine stress level, 4) Determine testing time and number of specimens, 5) Define measurement paremeter and failure criteria, 6) Suggest measurement method and measurement duration. Literature reviews were conducted to identify the influence of the disposal conditions such as thermo-hydro-mechnical-radioactive on integrity of material and monitoring sensors. The investigated data reported in this paper will be utilized to verify the improvement of integrity of monitoring sensors.
        8.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Flexion-relaxation phenomenon (FRP) was a term which refers to a sudden onset of myoelectric silence in the erector spinae muscles of the back during standing full forward flexion. Hamstring muscle length may be related to specific pelvic and trunk movements. Many studies have been done on the FRP of the erector spinae muscles. However, no studies have yet investigated the influence of hamstring muscle flexibility on the FRP of the hamstring muscle and lumbopelvic kinematics during forward bending. Objects: The purpose of this study was to examine the flexion-relaxation ratio (FRR) of the hamstring muscles and lumbopelvic kinematics and compare them during forward bending in subjects with different hamstring muscle flexibility. Methods: The subjects of two different groups were recruited using the active knee extension test. Group 1-consisted of 13 subjects who had a popliteal angle under 30°; Group 2-consisted of 13 subjects who had a popliteal angel above 50°. The kinematic parameters during the trunk bending task were recorded using a motion analysis system and the FRRs of the hamstring muscles were calculated. Differences between the groups were identified with an independent t-test. Results: The subjects with greater hamstring length had significantly less lumbar spine flexion movement and more pelvic flexion movement. The subjects with greater pelvic flexion movement had a higher rate of flexion relaxation during full trunk bending (p<.05). Conclusion: The results of this study suggest that differences in hamstring muscle flexibility might cause changes in people’s hamstring muscle activity and lumbopelvic kinematics.
        4,000원
        9.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The active knee extension (AKE) test commonly used to assess the flexibility of the hamstring muscles. Many researchers have tested the reliability of the AKE test; however, no published studies have examined the intrarater and interrater reliability of the AKE test using a PBU. Objects: The purpose of this study was to determine the intrarater and interrater reliability of the AKE test performed with a pressure biofeedback unit (PBU) on healthy subjects. Methods: Sixteen healthy male participants volunteered and gave informed consent to participate in this study. Two raters conducted AKE tests independently with a PBU. Each knee was measured twice, and the AKE testing was repeated one week after the first round of testing. Results: The interrater reliability’s intraclass correlation coefficients (ICC2,1) were .887∼.986 for the right knees and .915∼.988 for the left knees. In addition, the intrarater (test-retest) reliability (ICC3,1) values ranged between .820∼.915 and .820∼.884 for Raters 1 and 2, respectively. The values for the standard error of mesurement were low for all tests (.81∼2.97˚); the calculated minimum detectable change was 2.24∼8.21˚. Conclusion: These findings suggest that the AKE test performed with a PBU had excellent interrater and intrarater reliability for assessing hamstring flexibility in healthy young males.
        4,000원
        10.
        2020.05 KCI 등재 서비스 종료(열람 제한)
        This study analyzed the quality characteristics of black garlic made from Seosan Yukjok Garlic and elephant garlic in Seosan, Chungnam province. Of the inorganic components, Mg content was the highest in all treatment groups, and the Ca content was high in each of the 15 day treatments. The content of K was high after 10 days aging in Yukjok garlic and after 15 days in the elephant garlic. The Fe, Na, K, and Mg content was high in Yukjok black garlic after 15 days, and Na, K, Ca, and Mg were high in the elephant black garlic aged for 15 days. The crude fat content was high in both Yukjok black garlic and elephant black garlic after 15 days. Vitamin C content was highest in both types of garlic after aging for 15 days. An analysis of four kinds of organic acids showed that citric acid was the only organic acid to appear in raw garlic of Yukjok garlic and elephant garlic. Black Yukjok garlic and elephant black garlic had a greater total amino acid content than the raw garlic of either type. However, among the tested amino acids, 13 kinds of amino acids were at their highest after five days of ripening in Yukjok black garlic, while 15 kinds of amino acids were abundant in elephant garlic after the same period. Eight kinds of amino acids were high after aging for 15 days. Through this study, it was confirmed that, in the process of making black garlic, changes in the main components of the garlic occur through different routes, and these changes vary depending on the garlic species. Therefore, this study provided basic data for the processing of Seosan's Yukjok black garlic and elephant black garlic.
        11.
        2015.07 서비스 종료(열람 제한)
        Carotenoid isomerase (CRTISO) catalyzes the isomerization of prolycopene to all-trans-lycopene in the carotenoid biosynthetic pathway. We isolated two full-length cDNA gene, CuCRTISO and CuCRTISO-like, from Citrus unshiu. To confirm whether these two genes have the function of the carotenoid isomerase, The full-length cDNA of CuCRTISO and CuCRTISO-like gene, respectively, were fused with 35S promoter and NOS terminal region and then transformed into tomato CRTISO mutant, Tangerine, which shows orange fruit due to lack of carotenoid isomerase activity. The mature fruit color of the transgenic line expressing CuCRTISO gene changed from orange to red, which was similar to the fruit color of the tomato “Money Maker”. We also carried out HPLC analysis to detect all-trans lycopene, which is produced from prolycopene by carotenoid isomerase. In the transgenic line expressing CuCRTISO the all trans lycopene was detected from mature fruit but in the tangerine mutant several prolycopenes were detected from it. On the other hand, the transgenic line expression of CuCRTISO gene retained the orange-color fruit at the mature stage as Tangerine mutant. These studies indicate that the CuCRTISO gene has a function of carotenoid isomerase and also plays a role of it in other plant species, and that the CuCRTISO-like gene might be not enough to produce the all trans lycopene or has a another unknown function(s).
        12.
        2014.07 서비스 종료(열람 제한)
        Carotenoid isomerase (CRTISO) catalyzes the isomerization of prolycopene to all-trans-lycopene in the carotenoid biosynthetic pathway. We isolated a full-length promoter region of CuCRTISO from Citrus unshiu. We determined if the promoter encoded organ-specific or developmental-specific expression, and identified possible cis-acting promoter elements. The full-length promoter and two truncated versions were fused to the β-glucuronidase (GUS) gene and transformed into Arabidopsis thaliana. Transgenic lines expressing the full-length promoter (pCiso-Prom1) and truncated promoters (pCiso-Prom2 and pCiso-Prom3) showed the same developmental and organ-specific activity. GUS expression was detected in the cotyledon and root at 5 and 10 days after germination, mature leaf, and anther. The CuCRTISO promoter contained several cis-acting elements involved in hormonal and environmental stress. Drought stress or abscisic acid treatment did not induce GUS expression in any transgenic lines. Heat stress induced GUS expression in the pCiso-Prom1 line; this promoter construct contains the heat-stress responsive element (HSE). Ethylene and cold-stress treatments induced GUS expression only in the pCiso-Prom3 line, although all transgenic lines contained the same cis-acting ethylene and low-temperature response elements. which could indicate the existence of unknown repressor element(s) in the CuCRTISO promoter. These studies indicate that CuCRTISO promoter activity is regulated in a developmental and organ-specific manner that responds to heat, cold, and ethylene. These results provide new insights into the role of cis-acting element(s) in CuCRTISO promoter activity. (This research was supported by the Basic Science Research Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2010-0007627 and 2009-0094059), and by Golden Seed Project, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Ministry of Oceans and Fisheries (MOF), Rural Development Administration (RDA) and Korea Forest Service (KFS), Republic of Korea)