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        검색결과 693

        65.
        2022.10 구독 인증기관·개인회원 무료
        During electrorefining, fission products, such as Sr and Cs, accumulate in a eutectic LiCl-KCl molten salt and degrade the efficiency of the separation process by generating high heat and decreasing uranium capture. Thus, the removal of the fission products from the molten salt bath is essential for reusing the bath, thereby reducing the additional nuclear waste. While many studies focus on techniques for selective separation of fission products, there are few studies on processing monitoring of those techniques. In-situ monitoring can be used to evaluate separation techniques and determine the integrity of the bath. In this study, laser-induced breakdown spectroscopy (LIBS) was selected as the monitoring technique to measure concentrations of Sr and Cs in 550°C LiCl-KCl molten salt. A laser spectroscopic setup for analyzing high-temperature molten salts in an inert atmosphere was established by coupling an optical path with a glove box. An air blower was installed between the sample and lenses to avoid liquid splashes on surrounding optical products caused by laser-liquid interaction. Before LIBS measurements, experimental parameters such as laser pulse energy, delay time, and gate width were optimized for each element to get the highest signal-to-noise ratio of characteristic elemental peaks. LIBS spectra were recorded with the optimized conditions from LiCl-KCl samples, including individual elements in a wide concentration range. Then, the limit of detections (LODs) for Sr and Cs were calculated using calibration curves, which have high linearity with low errors. In addition to the univariate analysis, partial least-squares regression (PLSR) was employed on the data plots to obtain calibration models for better quantitative analysis. The developed models show high performances with the regression coefficient R2 close to one and root-mean-square error close to zero. After the individual element analysis, the same process was performed on samples where Sr and Cs were dissolved in molten salt simultaneously. The results also show low-ppm LODs and an excellent fitted regression model. This study illustrates the feasibility of applying LIBS to process monitoring in pyroprocessing to minimize nuclear waste. Furthermore, this high-sensitive spectroscopic system is expected to be used for coolant monitoring in advanced reactors such as molten salt reactors.
        68.
        2022.10 구독 인증기관·개인회원 무료
        Material balance evaluation is an important measure to determine whether or not nuclear material is diverted. A prototype code to evaluate material balance has been developed for uranium fuel fabrication facility. However, it is difficult to analyze the code’s functionality and performance because the utilization of real facility data related to material balance evaluation is very limited. It is also restricted to deliberately implement various abnormal situations based on real facility data, such as nuclear diversion condition. In this study, process flow simulator of uranium fuel fabrication facility has been developed to produce various process data required for material balance evaluation. The process flow simulator was developed on the basis of the Simulink-SimEvents framework of the MathWorks. This framework is suitable for batch-based process modeling like uranium fuel fabrication facility. It dynamically simulates the movement of nuclear material according to the time function and provides process data such as nuclear material amount at inputs, outputs, and inventories required for Material Unaccounted For (MUF) and MUF uncertainty calculation. The process flow simulator code provides these data to the material balance evaluation code. And then the material balance evaluation code calculates MUF and MUF uncertainty to evaluate whether or not nuclear material is diverted. The process flow simulator code can simulate the movement of nuclear material for any abnormal situation which is difficult to implement with real process data. This code is expected to contribute to checking and improving the functionality and performance of the prototype code of material balance evaluation by simulating process data for various operation scenarios.
        74.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Alfalfa is one of the most useful forage crops worldwide, containing a high level of amino acids that are essential to both human and animal health. However, amino acids and their concentrations may differ between plant parts. Hence, detecting amino acids in different plant parts would be useful in the development of diet supplements. The purpose of this study was to determine the amino acid content in alfalfa leaves, stems, and inflorescences using an amino acid analyzer. Asparagine and glutamic acid were the most abundant amino acids found in stems, leaves, and inflorescences than other amino acids. All parts of alfalfa had low concentrations of cysteine and methionine. All amino acids except asparagine were present in the highest concentration in leaves followed by inflorescences. Leaf had a rich amino acid content, namely asparagine, glutamic acid, leucine, proline, and lysine. However, the stem had a lower amino acid composition than the leaf or inflorescence. Overall, the data showed determining the amino acid content of forages provides a good approach to making animal feed with essential and specific amino acids and preventing excessive inclusion of amino acids.
        4,000원
        75.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        African swine fever (ASF) is a hemorrhagic viral disease of pigs requiring laboratory diagnosis for confirmation. Though tissue and blood samples are considered optimal for ASF diagnosis, collection of these samples can be laborious, time-consuming, and pose a risk of contaminating the environment. Here, we suggest an alternative non-invasive sampling method, hair plucking, for ASF diagnosis. ASF virus was detected in plucked hair samples from experimentally infected pigs. Although the sensitivity was inferior to whole blood, the results suggest that hair plucking can be an alternative method that can also improve animal welfare.
        3,000원
        76.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        새롭게 육성된 낭충봉아부패병 저항성 신품종 토종벌(Apis cerana koreana) 과 기존 농가에서 관행적으로 사육되는 토종벌 사이의 형태학적 차 이를 육안으로 확연하게 구분하는 것은 어렵지만 본 연구에서는 신품종 토종벌(A. c. koreana) 을 기존 토종벌(A. c. koreana) 품종 및 계통 간 형태학적 비교를 통해 신품종 만의 특성을 결정할 수 있는 표현형 정보를 제공하였다. 신품종 토종벌(A. c. koreana)의 외부형질을 이용한 품종 특성은 22가지의 형태학적 특성을 기하학적, 형태학적 분석 방법을 적용하고 토종벌(A. c. koreana)의 로얄젤리 생산량, 일벌, 여왕벌, 수벌의 특성을 비교 분석하였다. 본 연구 결과, 신품종 토종벌(A. c. koreana)은 기존 토종벌과 앞날개의 길이에 차이를 보였으며, 중국의 동양종꿀벌(A. cerana)과 비교한 결과, 일벌은 몸무게, 혀의 길이, 앞날개의 길이 등의 값이 높았다. 또한, 신품종 토종벌(A. c. koreana)은 A. cerana indica 보다 두 가지 부위에서 형태학적인 차이를 보였다. 그리고 신품종 토종벌(A. c. koreana)은 로얄젤리를 다른 품종과 비교하여 많이 분비하여 봉군의 발육에 긍정적인 영향을 끼쳤다. 따라서 본 연구결과는 신규 육성 토종벌(A. cerana)에 대한 형태학적 분석 방법을 이용하여 품종을 분류하는데 도움이 될 것으로 기대한다.
        4,000원
        77.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Zanthoxylum schinifolium is an important short-term income species and a useful resource with various physiological activities. In this study, the distribution and characteristics of seed-rich individuals of Z. schinifolium trees were analyzed. Seed-rich individuals were selected from three regions in consideration of seed yield and growth factors. As a result of the leaf shape survey, the length and width of the leaves were shorter in Jeju and longer in Geochang and Hadong compared to the average. There were very large differences in seed production between individuals within the Z. schinifolium group. The amount of seeds was higher in Jeju and Hadong than in Geochang. As a result of analyzing the correlation between the seven morphological characteristics, the overall correlation coefficient was in the range of -0.910 ~ 0.933. Total seed mass (TS) and seed weight (SW) showed a strong positive (+) correlation. As a result of the principal component analysis, it was classified into two categories. The first principal component showed a high correlation in the order of total seed weight and total seed amount, and the second principal component showed a high correlation with seed length and tree height. As a result of comparing seed production for two years, it was found that there was no change in production. As a result of examining seed viability using the TTC method, all of Z. schinifolium seeds showed more than 90% vitality. It is judged that the above results will serve as basic data for the development of a new variety of seed-rich Z. schinifolium trees.
        4,000원
        78.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: There is a research report that lumbar mobilization for healthy people improves the knee extension angles and Q-angle related muscle activity (Q: quadriceps muscle). However, there is a lack of research on the effect of lumbar mobilization on gait variables such as cadence and gait speed, especially when mobilizing the central part of the lumbar spine from posterior to anterior. Objectives: To examine the effect of lumbar central PA mobilization in healthy people on cadence and gait speed. Design: Pilot study. Methods: There were 34 participants in this study. In the experimental group, lumbar posterior-anterior joint mobilization was performed once in Grade III-IV for 5 minutes, focusing on the segment with reduced movement. In the control group, lumbar posteroanterior mobilization was performed once in a total of Grade I-II for 5 minutes. To measure cadence and gait speed, STT-IWS and iSen System (San Sebastian, Spain) were used. Results: The comparison of cadence between groups, CG (Control group) increased cadence was about 6 more than EG (Experimental group) cadence, but it was not statistically significant. The gait speed of EG and CG was .30- .31, which was similar between the two groups, and the before and after values were also similar. There is no statistically significant difference Conclusion: The cadence and gait speed of the experimental group were not statistically significantly different than those of the placebo group.
        4,000원
        79.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Previous studies have reported that improving the spinal stability could be more effective in the prevention and treatment of recurrence. Lumbar stabilization exercise is known to strengthen the lumbar extension muscles and enhance physical, psychological and social functions. Objectives: To investigated the effect of lumbar spiral stenosis on the kinetic link training and lumbar stabilization exercise. Design: A randomized controlled trial. Methods: Study was preformed by randomly allocated 28 LSS participants into a kinetic link training group (KLT, n=14) and a lumbar stabilization exercise group (LSE, n=14). Kinetic link training and lumbar stabilization exercise were performed to subjects in both groups 5 times a week for 6 weeks. To verify the effect of LSS, changes in VAS, ODI, and proprioception before and after intervention were observed. Results: In KLT, statistically significant changes were found in VAS, ODI, and Proprioception before and after intervention. In LSE, there were significant changes in VAS and ODI before and after intervention. KLT and LSE before and after intervention indicated significant differences in proprioception. Conclusion: KLT and LSE are applied to LSS, there are effects of pain decrease, lumbar recovery and proprioception improvement.
        4,000원
        80.
        2022.05 구독 인증기관·개인회원 무료
        In a nuclear facility, the base metal can be radiologically contaminated during the operation. They must be decontaminated to reduce the radiation exposure to workers before decommissioning of the nuclear facility. In order to decontaminate the nuclear facility, it is possible to apply a perfluorocarbon (PFC) based emulsion consisted of surfactant and decontamination reagent. The PFC has high resistance for the radiation decomposition, and PFC based emulsion can be easily stabilized using the ultrasonication method. During decontamination process, a dispersion stability of the emulsion affects to the decontamination performance because the decontamination reagents dispersed in the emulsion contact contaminated surface. In this study, the dispersion stability the PFC based emulsion was evaluated following the composition of the emulsion and dispersion condition such as temperature, ultrasonication time. It was confirmed that the concentration of surfactant is highly related to the dispersion stability from the result of Turbiscan analysis using the multiple light scattering method. It was also verified that the droplet size of the decontamination reagent in the stable emulsion was smaller than that in the unstable emulsion. This phenomena can be explained by the relationship between the interfacial tension and droplet size. Finally, the recovering test of the PFC from the spent PFC-based decontamination emulsion was conducted using distillation method. The distillation test was performed using vacuum distillation unit, and the distillation temperature was 80°C. From the distillation test, about 95 % of PFC was recovered by distillation. From this result, it is considered that PFC-based decontamination emulsion reduces the volume of the secondary waste.
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