• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.1
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• pp.33-40
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• 2006

The characteristics of the aluminum waste melting and the distribution of the radioactive nuclides have been investigated for the estimation on the volume reduction and the decontamination of the aluminum wastes from the decommissioning of the TRIGA MARK it and III research reactors at the Korea Atomic Energy Research Institute(KAERI). The aluminum wastes were melted with the use of the fluxes such as flux $A:NaCl-KCl-Na_3AlF_6$, flux B:NaCl-NaF-KF, flux $C:CaF_2$, and flux $D:LiF-KCl-BaCl_2$ in the DC graphite arc furnace. For the assessment of the distribution of the radioactive nuclides during the melting of the aluminum, the aluminum materials were contaminated by the surrogate nuclides such as cobalt(Co), cesium(Cs) and strontium(Sr). The fluidity of aluminum melt was increased with the addition of the fluxes, which has slight difference according to the type of fluxes. The formation of the slag during the aluminum melting added the flux type C and D was larger than that with the flux A and B. The rate of the slag formation linearly increased with increasing the flux concentration. The results of the XRD analysis showed that the surrogate nuclide was transferred to the slag, which can be easily separated from the melt and then they combined with aluminum oxide to form a more stable compound. The distribution ratio of cobalt in ingot to that in slag was more than 40% at all types of fluxes. Since vapor pressures of cesium and strontium were higher than those that of the host metals at the melting temperature, their removal efficiency from the ingot phase to the slag and the dust phase was by up to 98%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.305-312
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• 1997

Juveniles of black seabream, Acanthopagrus schlegeli were fed with the diets containing 0, 10, 20, 50 and 100 ppm of 3,5,3'-triiodo-1-thyronine $(T_3)$ respectively to assess the effect of this hormone on skeletal development and the change of physiological conditions for 50 days. $(T_3)$ treatment lasted for initial 40 days. Fish were fed the prescribed diet by hand to satiation in $2\~4$ times per day. After an initial 40 days period, skeletal development and abnormality were examined, and after a 50 days period, food intake, hepatosomatic index (HSI), thyroid cell height (TCH) and body proximate composition were also examined. Although toed intake was not different among 0, 10 and 20 ppm, the food intake of black seabream fed with the diets containing 50 and 100 ppm of $T_3$was significantly lower than those of 10 ppm. After the initial 40 days of $T_3$ administration, $T_3$ increased the relative growth of operculum, head, caudal fin and pectoral fin to body length, resulting in severe morphological abnormalities at the highest dose. Black seabream treated with 50 and 100 ppm of $T_3$ had abnormal shapes such as lordosis and opercular curl. The HSI parameters were reversely correlation with the dietary concentration of $T_3$. After the initial 40 days of this experiment, atrophy of thyroid gland was observed in fish administered with 50 and 100 ppm of $T_3$. On the 50th day of this experiment, atrophy of thyroid gland was observed only in the group administered with 100 ppm of $T_3$, and no difference was observed on TCH among the rest fours of experimental groups. At the end of the experiment the whore body proximate analyses indicated that there were significant effects of $T_3$ level on moisture, protein, lipid and ash contents.

• Journal of Korea Water Resources Association
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• v.53 no.6
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• pp.427-436
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• 2020

It is uncertain how global climate change will influence future drought characteristics over the Korean peninsula. This study aims to project the future droughts using climate change and land use change scenarios over the Korean peninsula with the land surface modeling system, i.e., Weather Research and Forecasting Model Hydrological modeling system (WRF-Hydro). The Representative Concentration Pathways (RCPs) 2.6 and 8.5 are used as future climate scenarios and the Shared Socio-economic Pathways (SSPs), specifically SSP2, is adopted for the land use scenario. The using Threshold Level Method (TLM), we identify future hydrological and ecological drought events with runoff and Net Primary Productivity (NPP), respectively, and assess drought characteristics of durations and intensities in different scenarios. Results show that the duration of drought is longer over RCP2.6-SSP2 for near future (2031-2050) and RCP8.5-SSP2 (2080-2099) for the far future for hydrological drought. On the other hand, RCP2.6-SSP2 for the far future and RCP8.5-SSP2 for the near future show longer duration for ecological drought. In addition, the drought intensities in both hydrological and ecological drought show different characteristics with the drought duration. The intensity of the hydrological droughts was greatly affected by threshold level methods and RCP2.6-SSP2 for far future shows the severest intensity. However, for ecological drought, the difference of the intensity among the threshold level is not significant and RCP2.6-SSP2 for near future and RCP2.6-SSP2 for near future show the severest intensity. This study suggests a possible future drought characteristics is in the Korea peninsula using combined climate and land use changes, which will help the community to understand and manage the future drought risks.

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.73-81
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• 2014

The in vitro production of porcine embryos was essential to increase of blastocyst development rate and select of high quality blastocyst in early stage. There were a lot of reports about in vitro porcine embryo development, but there was no report about the selection of high quality embryos. Therefore, in this study, we investigated the effect of vitamin $K_1$ (vit $K_1$) on the development and survival rate of porcine in vitro fertilized embryos. When vit $K_1$ was treated for 24 hr at day 1 in vitro culture, blastocyst development rate in the control group ($35.5{\pm}3.2%$) was significantly lower compared to $1.0{\mu}M$, $3.0{\mu}M$, or $6.0{\mu}M$ groups ($14.5{\pm}4.3$, 0.0, or 0.0%; p<0.05). The survival rates of blastocysts at day 8 in $1.0{\mu}M$, $3.0{\mu}M$ or $6.0{\mu}M$ of vit $K_1$ treated groups ($22.2{\pm}2.9$, 0.0 or 0.0%) were significantly lower than that of the control group ($31.8{\pm}2.6%$; p<0.05). We were added at $1.0{\mu}M$, $3.0{\mu}M$ or $6.0{\mu}M$ vit $K_1$ for different durations of time at day 1 in vitro culture. The development rate and survival rate in the group of $1.0{\mu}M$ vit $K_1$ for 6 hr was $26.5{\pm}2.9%$ and $47.2{\pm}2.8%$, respectively, which were differed significantly in the group of 12 hr (p<0.05). In the group of $3.0{\mu}M$ vit $K_1$, the blastocyst development in control group was $36.4{\pm}3.1%$ but, the survival rate $41.7{\pm}3.2%$ in the group of 3.0 hr was significantly higher than that of the control group (p<0.05). In the group of $6.0{\mu}M$ vit $K_1$, the control group's the blastocyst development was $32.0{\pm}2.8%$ and the 0.5 hr supplement group's survival rates was $42.9{\pm}1.8%$ higher than other groups. We added vit $K_1$ at day 1, day 2, day 4 and day 6 of in vitro culture, on the based the results of supplemented concentration and duration. In the group of $1.0{\mu}M$ 6.0 hr addition, the blastocyst development rate of day 4 and the survival rate of day 2 were the highest in each group. In the groups of $3.0{\mu}M$ 3.0 hr addition or $6.0{\mu}M$ 0.5 hr addition, the blastocyst development ($59.5{\pm}4.1%$ and $50.0{\pm}3.6%$) and survival rates ($72.7{\pm}5.4%$ and $79.2{\pm}4.0%$) on day 4 were significantly higher than that of control and other experiment groups (p<0.05). Meanwhile, the number of cells in blastocysts that produced by vit $K_1$ supplementation was $53.4{\pm}5.8$, $49.4{\pm}3.8$ and $51.5{\pm}4.5$ respectively, which were significantly higher than that of $40.2{\pm}2.3$ in the control group (p<0.05). There was no difference of the number of apoptotic cells between control and experiment groups. In addition, gene expression of survival blastocyst, the Bax mRNA expression was similar between the control and the experiment groups. However, Bcl-xL mRNA expression's in the group of $6.0{\mu}M$ 0.5 hr on day 4 was highest among control and experiment groups (p<0.05). In this study suggested that the control of concentration, duration and time was effective on the survival and cell number of porcine blastocyst derived from in vitro. We are not know what the exact reasons of the effect of vit $K_1$ on embryo development and need to fur ther study. However, vit $K_1$ might be using the selection of high quality porcine blastocyst.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.735-741
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• 2004

Blood cardioplegia is known as an established cardioplegic solution during open heart surgery. Recently, the Histidine-Tryptophan-Ketoglutarate (HTK) solution has been introduced as a cardioplegia in Korea. This study was designed to compare the myocardial protective effect between the cold blood cardioplegia (CBC) and HTK solution. Material and Method: Forty patients who underwent valve surgery or coronary artery bypass surgery were randomly divided into CBC group (n=20) and HTK group (n=20). The perioperative hemodynamic and clinical data were analyzed. The concentration of CK-MB, Troponin 1 and Lactate from coronary sinus and radial arterial blood were compared for the evaluation of the myocardial damage. The postoperative serial CK-MB levels were measured. Result: The characteristics of preoperative patients were similar in two groups. The hemodynamic parameters and postoperative clinical data were also similar between the two groups. There were no statistical significances between the CBC and HTK group in the difference of biochemical markers: Δ CK-MB (15.3$\pm$26.0 vs 19.3$\pm$14.3), ΔTro-1 (2.4$\pm$4.9 vs 2.0$\pm$2.20), ΔLac (1.6$\pm$1.0 vs 1.9$\pm$2.5). The serial CK-MB levels were not significantly different between the two groups. Conclusion: These results suggested that the myocardial protective effect of HTK solution was similar to cold blood cardioplegia during open heart surgery.

• Food Science and Preservation
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• v.23 no.4
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• pp.591-598
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• 2016

The purpose of this study was to screen desirable yeast strains for alcoholic fermentation of tomato paste without sugar addition. The moisture, crude protein, crude fat, ash, and soluble nitrogen contents of the tomato paste ($25^{\circ}Brix$) were found to be 67.33%, 1.90%, 0.03%, 0.02%, and 30.72%, respectively. Free sugars found in the paste were fructose and glucose. Most abundant free amino acids of the paste were glutamic, aspartic, and ${\gamma}$-aminobutyric acids. Total seven yeast strains (Saccharomyces cerevisiae KDH (TWA), S. cerevisiae Lalvin ICVD-47 (TWB), S. cerevisiae Lalvin RC-212 (TWC), S. cerevisiae Lalvin K1-V1116 (TWD), S. bayanus Lalvin EC-1118 (TWE), S. cerevisiae Enoferm (TWF), and S. cerevisiae DJ97(KCTC8842P) (TWG)) were tasted for alcohol fermentation of the tomato paste. The highest alcohol content (8.2%) and the lowest residual sugar content ($13.25^{\circ}Brix$) were observed in the tomato paste fermented using the S. cerevisiae Lalvin ICVD-47 strain (TWB) after 3 day and 4 day of fermentation, respectively. Sugar and reducing sugar contents, and pH of the tomato paste were not remarkably affected by the difference in yeast strains used, showing $13.25{\sim}13.45^{\circ}Brix$, 28.37~28.48 mg/mL, and 4.43~4.54, respectively, after 4 day of fermentation. Color and total acid content were significantly affected by the types of yeast strains and fermentation time, but the numerical changes were negligible. These results indicate that TWB would be the suitable strain for alcoholic fermentatiom of tomato paste based on its highest alcohol production and the lowest residual sugar content produced during fermentation.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.108-113
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• 1997

A field experiment was conducted to evaluate effect of phosphate coated slow release fertilizer on the directly seeded rice. Odae byeo was seeded by drill under dry condition. The soil was a sandy clay loam soil located in the Experimental Farm of the Kangweon National University, Chuncheon, Kangweon-Do. The yield of rice from the urea applicated directly seeded field was 84.9% of the yield from the transplanted field, and showed no difference between split application treatments. The yield from the phosphate coated slow release fertilizer was the highest showing 110.7% of the yield from the urea application. The yield from the polymer coated slow release fertilizer was 90.4%. The yield from the organic fertilizer 400kg/10a treatment was 81.8% and was 94.8% from the organic fertilizer 600kg/10a treatment. In 1996 experiment, the yield from the phosphate coated slow release fertilizer was higher than the yield from the transplanted field. The $NO_3-N$ and $NH_4-N$ concentrations in soil solution at the depth of 15cm revealed that nitrogen leaching was the highest from the urea N40-0-30-30 treatment, and the lowest from the phosphate coated slow release fertilizer. The phosphorus concentration showed similar pattern. Therefore, use of phosphate coated slow release fertilizer increased rice yield and decreased loss of nitrogen and phosphorus loss.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.139-143
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• 2007

This study was performed to investigate the reproductive characteristics of the cloned Hanwoo bulls produced by SCNT. The semen ejaculated from the cloned bulls (C-38 and C-39) and normal Hanwoo bull was properly measured the volume, the number of sperm, and the viability of frozen-thawed sperm. The sperm activity was analyzed using computer assisted sperm analysis (CASA). To analyze fertilizing ability of the cloned bulls, in vitro fertilization and artificial insemination were performed using the frozen-thawed semen. There were no differences in semen volume, sperm concentration, and the viability of frozen-thawed sperm between cloned bulls and normal bull. The difference was statistically significant in total motility, curvilinear velocity (VCL), straight-line velocity (VSL), and average-path velocity (VAP) of both cloned bulls compared to those of normal Hanwoo bull, respectively (p<0.05). The cleavage and blastocyst development rate were not different between the groups. five cloned cows were artificially inseminated using the frozen-thawed semen of C-38, two of them became pregnant. Two second generation calves (one male and one female) were produced. Based on these results, the cloned Hanwoo bulls showed normal reproductive abilities of semen parameters and sperm activity to their comparators and produced cloned calves, although there are some individual differences on the parameters.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.1
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• pp.73-82
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• 2009

Injectable calcium phosphate cement (CPC) has been used as bone substitute successfully due to good biocompatibility and osteoconductivity. One of the important mechanical characteristics of CPC is flowablility, which can be evaluated by measuring rheological parameters. However, there have been few studies that measured rheological properties of CPC. The purpose of this study was to evaluate the effects of temperature and concentrations of 2 kinds of setting solutions, hydroxyprophyl methylcellulose (HPMC) and polyacrylic acid (PAA), on rheological properties of CPC. The CPC used was dicalcium phosphate dihydrate (DCPD). Rheological properties of CPC paste were measured using rheometer. The effect of concentrations of each solution (2% and 1% HPMC and 35% and 17.5% PAA) was evaluated. The effect of temperature ($25^{\circ}C$ and $37^{\circ}C$) on the rheological properties of CPC was also investigated. The statistical analysis was carried out with Mann-whitney test with Bonferronis collection. CPC with both setting solutions showed shear thinning behavior. Higher concentrations of setting solution (2% HPMC and 35% PAA) produced significantly higher viscosity than lower concentrations of setting solution (1% HPMC and 17.5% PAA). CPC with HPMC showed significantly higher viscosity at $37^{\circ}C$ that at $25^{\circ}C$. CPC with PAA showed lower viscosity at $37^{\circ}C$ than at $25^{\circ}C$, although the difference was not statistically significant. The results showed that CPC with HPMC or PAA solutions are pseudoplastic and the concentrations of setting solutions and temperature may have an effect on the rheological properties of CPC paste. These results showed that the flowability of injectable CPC could be improved by use of increasing frequency of oscillation. In clinical practice, the use of ultrasonic vibration would be helpful in application of injectable CPC. CPC with HPMC could be more easily applicated at $25^{\circ}C$ than $37^{\circ}C$. The use of lower concentrations of HPMC and PAA solution would be beneficial in terms of flowability.

• Journal of Korea Water Resources Association
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• v.41 no.12
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• pp.1219-1230
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• 2008

Stream inflows induced by flood runoffs have a higher density than the ambient reservoir water because of a lower water temperature and elevated suspended sediment(SS) concentration. As the propagation of density currents that formed by density difference between inflow and ambient water affects reservoir water quality and ecosystem, an understanding of reservoir density current is essential for an optimization of filed monitoring, analysis and forecast of SS and nutrient transport, and their proper management and control. This study was aimed to quantify the characteristics of inflow density current including plunge depth($d_p$) and distance($X_p$), separation depth($d_s$), interflow thickness($h_i$), arrival time to dam($t_a$), reduction ratio(${\beta}$) of SS contained stream inflow for different flood magnitude in Daecheong Reservoir with a validated two-dimensional(2D) numerical model. 10 different flood scenarios corresponding to inflow densimetric Froude number($Fr_i$) range from 0.920 to 9.205 were set up based on the hydrograph obtained from June 13 to July 3, 2004. A fully developed stratification condition was assumed as an initial water temperature profile. Higher $Fr_i$(inertia-to-buoyancy ratio) resulted in a greater $d_p,\;X_p,\;d_s,\;h_i$, and faster propagation of interflow, while the effect of reservoir geometry on these characteristics was significant. The Hebbert equation that estimates $d_p$ assuming steady-state flow condition with triangular cross section substantially over-estimated the $d_p$ because it does not consider the spatial variation of reservoir geometry and water surface changes during flood events. The ${\beta}$ values between inflow and dam sites were decreased as $Fr_i$ increased, but reversed after $Fr_i$>9.0 because of turbulent mixing effect. The results provides a practical and effective prediction measures for reservoir operators to first capture the behavior of turbidity inflow.