• Nuclear Engineering and Technology
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• v.51 no.8
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• pp.1991-1997
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• 2019

In this manuscript, we present a method for the direct calculation of an ambient dose equivalent (H^* (10)) for the external gamma-ray exposure with an energy range of 40 keV to 2 MeV in an electronic personal dosimeter (EPD). The designed EPD consists of a 3 × 3 ㎟ PIN diode coupled to a 3 × 3 × 3 ㎣ CsI (Tl) scintillator block. The spectrum-to-dose conversion function (G(E)) for estimating H^* (10) was calculated by applying the gradient-descent method based on the Monte-Carlo simulation. The optimal parameters for the G(E) were found and this conversion of the H^* (10) from the gamma spectra was verified by using ²⁴¹Am, ¹³⁷Cs, ²²Na, ⁵⁴Mn, and ⁶⁰Co radioisotopes. Furthermore, gamma spectra and H^* (10) were obtained for an arbitrarily mixed multiple isotope case through Monte-Carlo simulation in order to expand the verification to more general cases. The H^* (10) based on the G(E) function for the gamma spectra was then compared with H^* (10) calculated by simulation. The relative difference of H^* (10) from various single-source spectra was in the range of ±2.89%, and the relative difference of H^* (10) for a multiple isotope case was in the range of ±5.56%.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.80-85
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• 2004

The purpose of this experiment was to assess seasonal variation of feed utilization by feed sources and to obtain information on the use of feed resources by comparing seasonal changes of dry matter intake, digestibility, nitrogen balance and feeding behavior in spotted deer (Cervus nippon) fed forest by-product silage (FBS) and corn silage (CS). Dry matter intake (DMI) of FBS was higher than that of CS in both winter and summer. While DMI of both diets was higher in summer, this was not significant at the 5% level. In contrast to DMI, digestible dry matter intake (DDMI) was higher for CS than for FBS in both seasons, but the difference was not significant. Digestibility of dry matter and crude protein was significantly higher (p<0.01) for CS than for FBS, whereas digestibility of crude fiber was significantly higher (p<0.01) for FBS than for CS in both seasons. Seasonal digestibility of dry matter and crude fiber for FBS was significantly greater (p<0.01) in summer than in winter: In summer, seasonal digestibility was 57.2% for dry matter and 55.5% for crude fiber, and in winter, 50.8% for dry matter and 30.7% for crude fiber. On the other hand, seasonal digestibility of crude protein was higher (p<0.01) in winter (42.1%) than in summer (32.3%). No significant difference (p>0.05) was found between the two seasons and diets for nitrogen intake (NI), 18.7 g/d in summer and 19.4 g/d in winter for FBS, 17.7 g/d in summer and 17.7 g/d in winter for CS. Fecal nitrogen was higher (p<0.01) for FBS than for CS and varied little seasonally. There was significant difference (p<0.01) between two seasons in urinary nitrogen, which was little difference between two diets. Retained nitrogen (RN) was different significantly (p<0.01) between two diets in both seasons, but there was little difference between seasons. Deer usually spent longer time on eating FBS than eating CS. Eating FBS took 221 min in summer and 187 min in winter, whereas eating CS took 113 min in summer and 109 min in winter. Deer spent less time on eating food in winter than in summer. Time spent on rumination was longer for FBS than for CS: for FBS, 504 min in summer and 456 min in winter, for CS, 423 min in summer and 279 min in winter. Time varied seasonally with both diets.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.2
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• pp.117-124
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• 2023

X-ray diffraction analysis, X-ray fluorescence analysis, thermal differential and thermos gravimetric analysis, cation exchange capacity analysis, and Cesium (Cs), Strontium (Sr) adsorption experiments were performed to investigate the physical and chemical properties of natural zeolite from Guryongpo in Korea. As a result of X-ray diffraction analysis, minerals such as mordenite, heulandite, clinoptilolite, and illite are contained, and as a result of X-ray fluorescence analysis, elements such as SiO₂, Al₂O₃, CaO, K₂O, MgO, Fe₂O₃ and Na₂O are contained, and the cation exchange capacity was 148.6 meq/100 g. As a result of thermal differential and thermos gravimetric analysis, it was confirmed that the thermal stability was excellent up to 600 ℃. As a result of the adsorption equilibrium experiment over time, the equilibrium was reached within 30 min. for Cesium (Cs) and within 8 hr. for Strontium (Sr), and the adsorption rates of Cesium (Cs) and Strontium (Sr) were 80% and 18%, respectively. As a result of the single-component isothermal adsorption experiment, in conformed to the Langmuir model, and the maximum Cesium (Cs) adsorption amount was 131.5 mg/g, which was high, while the Strontium (Sr) maximum adsorption amount was 29.5 mg/g, which was low. In the case of the natural zeolite used in this study, the content of minerals including 8-rings such as clinoptilolite, heulandite, and mordenite is high, showing high selectivity for Cesium (Cs).

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.1-11
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• 2004

PAN-4A composite ion exchanger was more selective for Sr ion than other cations and PAN-KCoFC composite ion exchanger has much higher ion exchange capacity for Cs ion than other cations. The ion exchange capacities obtained from Dubinin-Polanyi equation were 3.93 meq/g for Sr ion and 1.50 meq/g for Cs ion using PAN-4A and PAN-KCoFC ion exchangers, respectively. The modified Dubinin-Polanyi model fit the experimental data accurately in multi-component system. The effective surface diffusivities $(D_{s, cff})$ for Sr and Cs ions of PAN-4A and PAN-KCoFC ion exchangers were slightly increased with the different particle sizes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1336-1342
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• 2006

This study was performed to investigate the effect of ethanol extract of Chaenomeles sinensis Koehne (CS) on alcohol-induced liver damage in rats. Male Sprague-Dawley rats weighing $135{\pm}10g$ were divided into 6 groups for 4 weeks; normal group (ND), alcohol (35%, 10 mL/kg/day) treated group (ET), CS ethanol extract 200 mg/kg/day treated group (ND-CSL), CS ethanol extract 400 mg/kg/day treated group (ND-CSH), CS ethanol extract 200 mg/kg/day and alcohol treated group (ET-CSL), and CS ethanol extract 400 mg/kg/day and alcohol treated group (ET-CSH). The body weight gain and food efficiency ratio were no differences between ND and ET. There were increases in the activities of serum alanine aminotransferase (ALT), asparate aminotransferase (AST), and alkaline phosphatase (ALP) in ET. On the other hand, the administration of CS decreased ALT, AST and ALP activities in serum. It was also observed that the hepatic activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and xanthine oxidase (XO) increased by alcohol treatment were also markedly decreased in the CS administered groups as compared with ET. The activities of hepatic SOD, catalase, GSH-Px and XO were riot significantly different among the normal diet groups. Contents of thiobarbituric acid reactive substances (TBARS) were increased by the administration of alcohol, on the other hand, the administration of CS reduced TBARS value in the liver. In addition, the content of glutathione (GSH) in the liver was decreased by alcohol administration, however, GSH increased after administering CS. In conclusion, the administration of alcohol develops the hyperoxidation of liver lipids through tile increase in enzymes activity related to the lipid peroxiation, however, it was decreased after administring CS. Thus, CS may have a possible protective effect on ethanol-induced hepatotoxicity in rat liver.

• Journal of the Mineralogical Society of Korea
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• v.26 no.3
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• pp.209-218
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• 2013

This study was to characterize the minerals in fractured and bedrock zone, and determine quantitatively sorption for radioactive cesium ($^{137}Cs$) at the Korean nuclear facility site. The rock samples were granite group that mainly consists of quartz and feldspar with 10~20% mica minerals. Chlorite was observed as secondary mineral for the rock samples collected from fractured zone, but not for bedrock samples. The $^{137}Cs$ sorption distribution coefficients increased to $K_d$ = 880~960 mL/g in the fractured zone because of the presence of secondary minerals formed by weathering processes, compared to the bedrock zone ($K_d$ = 820~840 mL/g). These results suggest that the released $^{137}Cs$ to groundwater environment could be significantly retarded in the fractured zone in the case of severe nuclear accident at the study site.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.309-314
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• 1985

Autoxotrophic mutants of a cellulolytic baterium Cellulomonas sp. CS 1-1 were grown at $30^{\circ}C$ for 6hr using a complete medium containing 0.5M sucrose and for another 90 min after addition of 0.3 U/ml penicillin G, and were protoplasted by 0.2mg/ml lysozyme for 2hr. Prototrophic recombinants were obtained at the rates of $10^{-3}$ to $10^{-5}$by fusing the protoplasts in the presence of 40% polyethyleneglycol3350. Nystatin could be used to eliminate fungal contamination during the regeneration of the plotaplasts.

• Journal of Soil and Groundwater Environment
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• v.26 no.5
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• pp.29-38
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• 2021

This study investigated the mineralogical properties of bentonite and illite and evaluated the Cs sorption at various concentrations (C_w≈1-10⁵ ㎍/L). Bentonite samples, collected from South Korea and USA, majorly consisted of Ca- and Na-montmorillonite, showed large cation exchange capacity (CEC, 91.4 and 47.3 meq/100 g) and specific surface area (SSA, 46.1 and 39.7 m²/g). In contrast, illite sample (USA) had relatively low values for 14.4 meq/100g of CEC and 29.3 m²/g of SSA, respectively. Bentonite and illite had different non-linear sorption for Cs along with C_w. At low C_w<10 ㎍/L, illite showed higher sorption capacity than bentonite despite low CEC because of the existence of specific sorption sites at the weathered mineral edge. However, as C_w increased, bentonite represented high sorption capacity because the cation exchange between Cs and interlayer cations was effective at high C_w conditions. These results implicated that the Cs concentration is important to evaluate the sorption performance of bentonite and illite. Finally, the Cuadros' kinetic model for illitization using various K concentrations (2×10^-5 and 1.7×10^-3 mol/L) and temperature (100-200℃) showed that up to 50% of the montmorillonite in bentonite could be converted to illite, suggesting that the illitization should be considered to evaluate the sorption performance of the bentonite in deep geological disposal repository.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1201-1207
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• 2020

This study explored whether MXene (Ti₃C₂T_x) could remove radioactive Cs⁺ from model nuclear wastewater. Various adsorption tests were performed and the physical aspects of the interaction were investigated. We varied the MXene dosage, Cs⁺ initial concentration, solution pH, solution temperature and exposure time. MXene adsorption exhibited very fast kinetics, based on the fact that equilibrium was achieved within 1 h. MXene exhibited an outstanding adsorption capacity (148 mg g^-1) at adsorbent and adsorbate concentrations of 5 and 2 mg L^-1, respectively, at neutral pH condition (i.e., pH 7). We explored Cs⁺ adsorption by MXene in the presence of four different ions (NaCl, KCl, CaCl₂ and MgCl₂) and three different organic acids (sodium oleate, oxalic acid, and citric acid). The Cs⁺ removal rate changed in the presence of these components; adsorption of Cs⁺ by MXene thus involved ion exchange, supported by both Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. We confirmed that MXene was re-usable for at least four cycles. MXene is cost-effective and practical when used to adsorb radionuclides (e.g., Cs⁺) in nuclear wastewater.

• Journal of Ginseng Research
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• v.27 no.3
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• pp.98-102
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• 2003

The aim of this study is to evaluate clinical usefulness of Korean red ginseng (RG) on various postmenopausal syndromes. Total plasminogen inhibitor-l (tPAI-l) in peripheral blood from 9 postmenopausal women with climacteric syndromes (CS) was measured before and 3 months after treatment with daily oral administration of 6 g RG and that from 8 postmenopausal women without any CS was also measured as healthy controls. Blood samples were collected in the early morning on the bed-rest. Psychological conditions of postmenopausal women with CS were measured before and 3 months after treatment with RG using simplified menopausal index (SMI). In addition, OKETSU (blood stagnation) syndrome scores and KI deficiency (generalized energy stagnation) scores proposed by Terasawa et al., were recorded before and 3 months after treatment with RG in postmenopausal women with CS and in healthy postmenopausal women. OKETSU syndrome scores and tPAI-l levels in postmenopausal patients with CS were significantly (P<0.001 and P<0.01) higher than those in healthy postmenopausal women without CS. Similarly, SMI scores and KI deficiency scores in postmenopausal patients with CS were about three-fold higher than those without any CS. When RG was administered for 3 months, KI deficiency scores and OKETSU scores as well as SMI scores declined around the levels of healthy postmenopausal women. Although tPAI-1 levels significantly (P<0.05) decreased after treatment with RG, those did not reach the levels of healthy postmenopausal women. Clinical usefulness of administration of RG to postmenopausal women with CS was confirmed from evaluation not only by modem medicine but also by traditional KAMPO medicine.