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        검색결과 31

        1.
        2023.11 구독 인증기관·개인회원 무료
        When occurring at a nuclear power plant (NPP) by accidents, accurate prediction and identification of the process of radioactive material dispersing into atmosphere is important to protect public and environment. Atmosphere dispersion of radioactive materials is significantly influenced by wind direction and wind speed. The government and nuclear operator continuously monitor wind data at nuclear sites through meteorological tower to prepare for such accidents involving the release of radioactive materials. The purpose of this study is to construct wind rose diagrams at 5 NPP sites (Kori, Saewool, Wolsong, Hanbit, Hanul). Wind roses serve as invaluable tool for identifying wind patterns in each region and visualizing wind directions. This can be utilized to predict the dispersion pathway and extent range of radioactive materials carried by the wind. This program will take on the role of establishing appropriate evacuation routes or shelter locations for residents when reliable wind data is not immediately available during an NPP accident. The wind data used in the study was collected from a meteorological tower located at the NPP site, and measurements were taken at 1-hour intervals for each operation over a period of ten years. The collected data underwent preprocessing, followed by the development of Python code to render the wind rose diagrams in an interpretable format. The future direction of this study will be focused on enhancing this program by integrating geographical mapping capabilities. With these advancements, it will become feasible to superimpose shelter positions on a map in accordance with prevailing wind directions. These improvements will contribute to the development of additional protective measures for residents and the proposal of alternative shelter options in response to potential radioactive material releases.
        2.
        2022.10 구독 인증기관·개인회원 무료
        When decommissioning a nuclear power plant, the structure must be made to a disposable size. In general, the cutting process is essential when dismantling a nuclear power plant. Mainly, thermal cutting method is used to cutting metal structures. The aerosols generated during thermal cutting have a size distribution of less than 1 μm. The contaminated structures are able to generate radioactive aerosols in the decommissioning. Radioactive aerosols of 1 μm or less are deposited in the respiratory tract by workers’ breathing, causing the possibility of internal exposure. Therefore, workers must be protected from the risk of exposure to radioactive aerosols. Prior knowledge of aerosols generated during metal cutting is important to ensure worker safety. In this study, the physical and chemical properties of the aerosol were evaluated by measuring the number and mass concentrations of aerosols generated when cutting SUS304 and SA508 using the laser cutting method. High-resolution aerosol measuring equipment (HR-ELPI+, DEKATI) was used to measure the concentration of aerosols. The HR-ELPI+ is an impactor-type aerosol measuring equipment that measures the aerosol number concentration distribution in the aerodynamic diameter range of 6 nm to 10 um in real-time. And analyze the mass concentration of the aerosol according to the diameter range through the impactor. ICP-MS was used for elemental mass concentration analysis in the aerosol. Analytical elements were Fe, Cr, Ni and Mn. For the evaluation of physical and chemical properties, the MMAD of each element and CMAD were calculated in the aerosol distribution. Under the same cutting conditions, it was confirmed that the number concentration of aerosols generated from both materials had a uni-modal distribution with a peak around 0.1 um. CMAD was calculated to be 0.072 um for both SUS304 and SA508. The trend of the CMAD calculation results is the same even when the cutting conditions are changed. In the case of MMAD, it was confirmed that SUS304 had an MMAD of around 0.1 μm in size for only Fe, Cr and Mn. And SA508, Fe, Cr, Ni and Mn were all confirmed to have MMAD around 0.1 μm in size. The results of this study show that a lot of aerosols in the range of less than 1 μm, especially around 0.1 μm in size, are generated when metal is cut using laser cutting. Therefore, in order to protect the internal exposure of workers to laser metal cutting when decommissioning NPPs, it is necessary to protect from nano-sized aerosols beyond micron size.
        4.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The oxygen uptake efficiency slope (OUES) is the most important index for accurately measuring cardiopulmonary function in patients with acute ischemic heart disease. However, the relationship between the OUES variables and important cardiopulmonary function parameters remain unelucidated for patients with acute ischemic heart disease, which accounts for the largest proportion of heart disease. Objects: The present cross sectional clinical study aimed to determine the multiple relationships among the cardiopulmonary function variables mentioned above in adults with acute ischemic heart disease. Methods: A convenience sample of 110 adult inpatients with ischemic heart disease (age: 57.4 ± 11.3 y; 95 males, 15 females) was enrolled at the hospital cardiac rehabilitation center. The correlation between the important cardiopulmonary function indicators including peak oxygen uptake (VO2 peak), minute ventilation (VE)/carbon dioxide production (VCO2) slope, heart rate recovery (HRR), and ejection fraction (EF) and OUES was confirmed. Results: This study showed that OUES was highly correlated with VO2 peak, VE/VCO2 slope, and HRR parameters. Conclusion: The OUES can be used as an accurate indicator for cardiopulmonary function. There are other factors that influence aerobic capacity besides EF, so there is no correlation with EF. Effective cardiopulmonary rehabilitation programs can be designed based on OUES during submaximal exercise in patients with acute ischemic heart disease.
        4,000원
        5.
        2022.05 구독 인증기관·개인회원 무료
        At high temperatures, molten salt has heat transfer properties like water. Molten salt has the characteristics of a strong natural circulation tendency, large heat capacity, and low thermal conductivity. Unlike sodium, molten salt does not react explosively exothermically with air. However, molten salt has a strong tendency to corrode materials, and its properties are easily changed by a sensitive reaction to oxygen and moisture. Therefore, it is necessary to study material corrosion properties and chemical control methods for nuclear fuel salts, which are eutectic mixtures. In this study, the optimal operation method of the thermal convection loop is established to perform the experiments on the molten salt. The process describes briefly as follows. The operation step consists of preparation, purification, transportation, and operation. In the preparation, the step checks the entire structure and equipment (TC, blower, vacuum pump, etc.). And melt the salt mixture at a high temperature (670°C) slowly in the purification step. Before injecting the molten salt, the surface temperature of the entire loop must retain temperature (about 500°C) constantly. Completely melted molten salt in the melting pot is flow along the pipe of the thermal convection loop in the transportation step. Lastly, the convection of molten salt goes to keep by the temperature difference. The thermal convection loop can be utilized for various experiments such as corrosion tests, component analyses, chemistry control, etc.
        6.
        2022.05 구독 인증기관·개인회원 무료
        Molten salt used in the multipurpose molten salt experiment must be of high purity. Depending on the purpose of the experiment, only the base component of the molten salt be used, or a component simulating a nuclear fission product be added to the base component and used. In all cases, an increase in the concentration of impurities such as oxygen and moisture may lead to an erroneous interpretation when analyzing the experimental results. Therefore, molten salt should be purified before use. In this study, the purification of molten salt is described for multi-purpose molten salt experiments. The salt mixture is selected as MgCl2-NaCl and is quantified at a mixing ratio of 43mol%:57mol%. The salt mixture is treated in a glove box environment because of must minimize the reaction of adsorbing oxygen and moisture when the salt mixture is exposed to the atmosphere. MgCl2 is more likely to contain water than NaCl, the purification of the NaCl-MgCl2 mixture is established according to the purification process for removing water from MgCl2. A process for purifying the salt mixture briefly consists as follows: drying moisture, melting salts, purification, removing HCl, and stabilization. Through the process be able to obtain high-purity molten salt and more accurate experiment results.
        7.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Non-destructive estimation of leaf area is a more efficient and convenient method than leaf excision. Thus, several models predicting leaf area have been developed for various horticultural crops. However, there are limited studies on estimating the leaf area of strawberry plants. In this study, we predicted the leaf areas via nonlinear regression analysis using the leaf lengths and widths of three-compound leaves in five domestic strawberry cultivars (‘Arihyang’, ‘Jukhyang’, ‘Keumsil’, ‘Maehyang’, and ‘Seollhyang’). The coefficient of determination (R2) between the actual and estimated leaf areas varied from 0.923 to 0.973. The R2 value varied for each cultivar; thus, leaf area estimation models must be developed for each cultivar. The leaf areas of the three cultivars ‘Jukhyang’, ‘Seolhyang’, and ‘Maehyang’ could be non-destructively predicted using the model developed in this study, as they had R2 values over 0.96. The cultivars ‘Arihyang’ and ‘Geumsil’ had slightly low R2 values, 0.938 and 0.923, respectively. The leaf area estimation model for each cultivar was coded in Python and is provided in this manuscript. The estimation models developed in this study could be used extensively in other strawberry-related studies.
        4,000원
        9.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The kidney is a highly complex organ, and acute or chronic renal diseases can occur with various complications such as diabetes and hypertension. So far, no target specific treatment is available in acute or chronic renal failure, necessitating the development of alternative therapeutic strategy. Recent experimental findings suggest that the renal function and structure can be restored after being treated with various sources of stem/progenitor cells. In this review, we discuss up-to-date findings of the potential of renal progenitor/stem cells in alleviating renal injuries with a focus on preclinical studies. We also review cellular mechanisms underlying the therapeutic function of these cells.
        4,000원
        12.
        2018.11 구독 인증기관·개인회원 무료
        Acute kidney injury (AKI) is a disorder that is manifested by a sudden decrease of renal function within several hours, and AKI remains a significant cause that can lead to increasing morbidity and mortality. Although AKI has been extensively studies in animal models, translating the results from animal studies into clinical use has not been successful due to various factors including basal etiology of kidney deficiency and comorbidities and the complexity of this pathology. As a golden parameter, measuring serum creatinine (SCr) and blood urea nitrogen (BUN) has been conventionally used for determining the renal function, however, these biomarkers has been regarded suboptimal to identify renal injuries in early stages. In this study, we attempted to screen other serum biomarkers in early AKI event using cynomolgus monkeys. Two male monkeys, aged 60 months, were subjected to ischemic injury by unilateral clamping of renal pedicles for forty five minutes and then subsequently reperfused; the unclamped kidney was regarded as non-injured controls. Compared with control kidneys, we have found that the concentration of several inflammatory proteins including MCP1, TGFα, GSTα, were higher in the renal vein of injured kidney compared with control side after 24 and 48 hours of AKI. However, changes of serum level of KIM-1, which is one of the most-widely studied marker in rodent studies, were not different after AKI. Our results provide an useful information while developing a novel marker in AKI.
        13.
        2017.10 구독 인증기관·개인회원 무료
        Morphology of antennal sensilla and their distribution were investigated in male and female adults of Plautia stali,a major pest of tree fruits, using scanning electron microscopy. Antennae of P. stali was composed of a scape, a pediceland three flagella in both sexes. Four types of sensilla (s. trichodea, s. basiconica, s. chaetica, s. coeloconica) were identifiedfrom both sexes. Among them, s. trichodea and s. basiconica were multiporous, others are not. They distributed in varyingnumbers. Sexual dimorphism was not shown in the distribution of the four sensilla types. But their distribution was characterizedalong antennal segments in both sexes. This study will be useful in electrophysiological and behavioral studies on theolfactory sensory function of each morphological type of sensilla.
        14.
        2017.04 구독 인증기관·개인회원 무료
        Morphology of antennal sensilla and their distribution were investigated in male and female adults of Ooencyrtus nezarae, an egg parasitoid of Riptortus pedestris, using scanning electron microscopy. Antennae of O. nezarae was composed of scape, pedicel and seven flagella in both sexes. Six types of sensilla (s. trichodea, s. basiconica, s. chaetica, s. campaniformia, s. sickle-shaped and unknown s.) were identified from both sexes. Among them, s. trichodea and s. sickle-shaped were multiporous, others are not. They distributed in varying numbers. Sexual dimorphism was clearly observed in the distribution of s. trichodea (only on male antennae) and unknown sensilla (only on female antennae). These findings would be helpful for further studies on detailed sex specific-receptive functions of each antennal sensilla.
        15.
        2016.10 구독 인증기관·개인회원 무료
        Euzophera batangensis (Lepidotera: Pyralidae) is seriously damaging trunks or branches of persimmon tree (Diospyros sp.). We tested the attractiveness of (Z)-9-tetradecen-1-ol (Z9-14OH) and (Z9,E12)-tetradeca- 9,12-dien-1-ol (Z9,E12-14OH) with single or blended baits at southern parts of Korea in 2014 and 2015. The monoene was not attractive at all at three places during the two years. In 2014, diene was equally or more attractive than the mixture in Jinju and Suncheon, respectively. In 2015 too, the attractiveness of diene and mixture was not different in Jinju and Munsan. Monitoring of the seasonal occurrence of E. batangesis with the sex pheromone components revealed that it occurred three times a year; the first occurrence from early April to mid May, the second from early Jun to mid July, and the third from late August to late September.
        16.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effects of vibration on Golgi tendon organ(GTO) and Hold-Relax of PNF in muscular activity and gait factors on Delayed Onset Muscle Soreness(DOMS). This study was conducted on 20 subjects. they were divided into two groups; Hold-Relax of PNF(n=10), Vibration on GTO(n=10). Both of the group was performed interventions 1 times a day for 3 days. The data was analyzed by the repeated-ANOVA for comparing before, after 24h and after 48h changes of factors in each group and the Independent t-test for comparing the between groups. The results are as follows. There was statistically significant difference of before, after 24h and after 48h vibration on GTO group and Hold-Relax of PNF group in muscular activity and gait factors on DOMS.(p<0.05). There was no statistically significant difference of between vibration on GTO group, but there was statistically significant difference Hold-Relax of PNF group in EMG, step width, step length, stride length(p>0.05). As a results of this study, Hold-Relax of PNF group are effective in improving muscular activity and gait factors
        4,000원
        18.
        2012.11 구독 인증기관·개인회원 무료
        The mushrooms have been used as traditional medicines and food resources in many countries. The objective of this study was to determine antioxidant compounds and to evoluate tyrosinase inhibitory activity of extracts from Hypsizigus marmoreus. The pileus and stipe of Hypsizigus marmoreus were extracted with methanol and water, separately. The methanol extract of Hypsizigus marmoreus were fractioned by hexane, chloroform, ethylacetate and buthanol. The concentrations of total polyphenolics and flavonoids in methanol extracts were investigated by colorimetric methods. The concentrations of total polyphenolics and flavonoids in methanol extract of the pileus was higher than methanol extract of the stipe. The DPPH redical scavenging activity of the pileus extract was also higher than stipe extract in methanol extract. The IC50 of DPPH redical scavenging activity of the pileus and stipe in methanol extract were 18 mg/ml and 1 10 mg/ml, respectively. The IC50 of tyrosinase inhibitory activity of the pileus and stipe in methanol extract were 500 mg/ml and 1,000 mg/ml in methanol extract. These results suggest that Hypsizigus marmoreus can be potentially used as a source of natural antioxidant agent in the cosmetic industry as well as the food, pharmaceutical and medicinal industry.
        19.
        2008.02 구독 인증기관 무료, 개인회원 유료
        This paper describes the traditional Ondol medical care, the specific combination of ancient and contemporary examples to be articulated. As a traditional Korean culture, to be extracted from the historical perspective, it described the relationship and origins between them, From a health perspective, in accordance with the logic and pharmacologyit introduced Ondol as the important principle of health care equipment. The modern architecture of some common harmful to the body, from the perspective of Ondol, it should be improved and based on scientific proof to the theory.
        4,000원
        20.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        Interlellkin • 8(IL-8) is an important cytokine involved in tllmor growth and angiogenesis in a variety of malig nancies. bllt the regll lation of IL-8 in 01 외 cancer cells are llnderstood . We invesLigated whether mi togen-activated protein kinases pathway is involved in iron chelator-mediated lL-8 produdion in inunortalized and malignant oral keratinocytes. In this study we examined the role of p38 and extracellular signal- reglllated kinase• 1/2 in the expression of [L-8 by DFO. Incllbation of IHOK and HN12 cel ls with DF'O increased the expression of 11-8 mRNA. as well as the release of IL-8 protein. The signal transdllction study revealed that both p38 and ERK1/2 were significantly activated in response to DFO. Accord ingly. the selective inhibitors for both kinases‘ eit her a lone or combination. abolished DFO- induced lL-8 secretion. indicating an importance of MAP kinase pathway. Interestingly. however‘ inhibition of the p38 and ERK pathway more attenuated IL-8 secretion in IHOK than in HN12 cells. DFO induced NF-kB activation , suggesting a NF-kB- dependent mechanism in DFO- induced IL-8 production. In addition, p38 and ERK inhi bition resulted in the accelerated degradation of lL-8 mRNA, suggesting that in IHOK and HN12 cells, p38 and ERK cunLr iullLe Lo DFO imluced IL-8 secretion by IHOK and HN12 cells via a posttranscriptional mechanism that involves stabilization 01' the IL-8 transcript. Finally. we investigatecl llsing specific inhibitors : 8NP and G8NO for NO c1onor. PDTC for potent inhibitor of NF-kB. Cycloheximide for inhibition of de novo protein synthesis. We observecl 8NP ancl PD1'C clepenclent IL-8 gene incluction in IHOK cell s. but not in HN12 cells used specific inhibitors‘ Collectively. these results demonstrate that‘ targeting MAP kinase ancl NF-kB pathway may be a potentiaI approacb to controlling the angiogenes is ancl growth 이 human oral cancers
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