• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.179-184
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• 1982

To describe a mathematical heat transfer model in saturated paddy soils, an analytical solution of the heat flow equation incorporated with the heat transfer by mass flow of water was obtained under the assumptions: 1) the diurnal (or annual) changes in temperature at a depth follow harmonic curves, 2) the temperature at the infinite depth be constant and 3) the temperatures of soil and water at the one depth be identical. The calculation of thermal diffusivities of the soil is possible with the known values of the physical parameters of each component in the soil matrix (heat capacity, density and porosity), percolation rate and the minimum and maximum temperatures at two different depths. The calculated thermal diffusivities using the solution were $9.5cm^2/hr$ for the loam soil with the percolation rate of 0.88cm/day and $13.9cm^2/hr$ for the sandy loam soil with the percolation rate of 2.64 cm/day.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.293-298
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• 2017

BACKGROUND: Pyrethroids (PYRs) are a widely used insecticide in agriculture and household area. In mammals, PYRs such as deltamethrin is metabolized to 3-phenoxybenzoic acid (3-PBA) in liver that is mainly excreted in urine. This study is designed to single exposure of deltamethrin to rats in a dose-dependent manner and identify the correlation between deltamethrin exposure and its metabolite (3-PBA) in urine. METHODS AND RESULTS: Exposure levels of deltamethrin were control (0 mg/kg bw), low (0.0705 mg/kg bw), medium (0.705 mg/kg bw) and high (7.05 mg/kg bw) dose. Low concentration was derived by ussing Korea predictive operator exposure model (KoPOEM). Dermal exposure persisted for 6 h, and urine specimens were collected for 24 h. The urine matrix was removed after a series of procedures and 3-PBA was analyzed by gas chromatography/mass spectrometry. CONCLUSION: There was a strong correlation ($R^2=0.83$) between the amount of oral exposure to delta me thrin and urinary levelof3-PBAexcreted. In dermal exposure groups of deltamethrin except high-dose, also there was a good correlation between urinary 3-PBA and deltamethrin exposure, but not stronger than in oral deltamethrin exposure groups. Based on these results, therefore, the amount of 3-PBA in urine can be used as a good monitoring indicator that reflexing the exposure level of deltamethrin to human body.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.3
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• pp.238-246
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• 2012

Once oil is spilled into marine environment, it experiences various weathering processes among which evaporation is the most dominant process in the initial stage of weathering. This study aimed to elucidate the effects of evaporation on the physicochemical properties of spilled oil using standardized laboratory experiments. Laboratory evaporation process was successfully reproduced using controlled rotary evaporation method. In case of Iranian Heavy crude (IHC), evaporation rate after 48 hours was $29.3{\pm}0.4%$ (n=40, p<0.001). Evaporation was simulated using ADIOS2 weathering model and the result was in agreement with laboratory experiment. Chemical composition changes of petroleum hydrocarbons including alkanes, polycyclic aromatic hydrocarbons (PAHs) and biomarkers by evaporation rate were also analyzed. As oil evaporated, low molecular weight alkanes and PAHs decreased, while biomakers showed conservative characteristics. Among biomarkers, $17{\alpha}(H)$, $21{\beta}(H)$-hopane was used for calculation of weathering rates, which matched with evaporative mass losses. Weathering rate calculation using hopane showed that stranded oils of weathering stage I (28.9%) and mesocosm oil weathering experiment till 5 days (26.5%) were mainly affected by evaporation process.

• Journal of Life Science
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• v.20 no.11
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• pp.1738-1741
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• 2010

Caliper measurements of tumor volume have been widely used in the assessment of tumors in animal models. However, experiments based on caliper data have resulted in unreliable estimates of tumor growth, due to necrotic areas of tumor mass. To overcome this systematic bias, we engineered a new luciferase-expressing rat prostate cancer cell line (MLL-Luc) that produces bioluminescence from viable cancer cells. MLL-Luc cells showed a strong correlation between bioluminescence intensity and cell number ($R^2$=0.99) and also accurately quantified tumor growth, with reduced bioluminescence signals caused by necrotic cells in a subcutaneous MLL-Luc xenograft model. The accurate quantification of tumor growth with bioluminescence imaging (BLI) was confirmed by a better antitumor effect of combination chemotherapy, compared to that based on caliper measurements with a correlation between the bioluminescence signal and tumor volume ($R^2$=0.84). These data suggest that bioluminescent MLL xenografts are a powerful and quantitative tool for monitoring tumor growth and are useful in evaluating the efficacy of anticancer drugs, with less systematic bias.

• Journal of Life Science
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• v.24 no.7
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• pp.721-727
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• 2014

Mushroom-derived ${\beta}$-glucan, a polysaccharide (GLP) isolated from the mycelium of Ganoderma lucidum, was previously shown to have inhibitory effects against tumor-bearing mice in vivo. We investigated the apoptotic effect of mushroom-derived ${\beta}$-glucan in a sarcoma-180 tumor cell- bearing mice model using an ELISA to determine the levels of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in the mice. The morphology of the tumor cells was assessed with transmission electron microscopy (TEM). GLP was injected into the tumor-bearing mice at a dose (i.p.) of 20 mg/kg for 10 days. After 30 days, the tumor mass from the inguinal region was collected, weighed, and assayed using TEM and a TNF-${\alpha}$ ELISA kit. The tumors that developed in the mice treated with GLP were 71.4% smaller than those in the control group, showing the ability of GLP to inhibit tumor growth. The levels of TNF-${\alpha}$ in the serum of the sarcoma-180 bearing mice were 12 times greater than in the serum of the nonbearing tumor mice. An ultrastructural study demonstrated that the GLP-treated sarcoma-180 tumor cells were condensed, with rearranged chromatin. In addition, the marginated chromatin in nucleus induced the nuclear compartment, and there were many vacuolization in the cell. GLP could be an effective apoptosis-inducing compound in sarcoma-type cancers.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.89-96
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• 1982

The purpose of this study is to identify the phases of four different types, low-copper lathe cut (Type II, class 1) and spherical (Type II, class 2) amalgam alloys which are made by Caulk company and high copper Dispersalloy (Type II, class 3) made by Johnson & Johnson and Tytin (Type I, class 2) made by S.S. White and to determine the Vickers hardness number on the individual phase and four different types of dental amalgam. After each amalgam alloy and Hg measured exactly by the balance was triturated by the mechanical amalgamator (De Trey), the triturated mass was inserted into the cylindrical metal mold which was 4 mm in diameter and 12mm in height and was pressed by the Instron Universal Testing machine (Model 1125) at the speed of 1mm/minute with 143$kg/cm^2$ according to the A.D.A. Specification No. 1. The Specimen removed from the mold, mounted and stored in the room temperature for 7 days. The speciman was polished with the emery paper from #220 to #1200 and finally on the polishing cloth with 0.3 and 0.05 um $Al_2O_3$ powder suspended in water. And then each specimen was etched by Allan's method and washed with Sodium Bisulfinite for 30 seconds. Finally differentiation and metallography on each phase were obtained by using metallographical microscope (Versamet, Union) and microhardness was obtained by using microhardness tester (MVH-2, Torsee). The results were as follows: 1. In the low-copper amalgam, the ${\gamma}$, ${\gamma}_1$ and ${\gamma}_2$ phase were observed and in the high-copper amalgam, the ${\gamma}$, ${\gamma}_1$. ${\epsilon}$ and ${\eta}$ phases were observed but ${\gamma}_2$ phase was not observed. 2. Among the microhardness of each amalgam phase measured under pressing a vickers diamond indenter with 2.0gm load for 30 seconds, e phase has the highest V.H.N (314 ${\pm}$ 20), and in low-copper amalgam 12 phase has the lowest V.H.N. (29${\pm}$1) and ${\eta}$ phase which was observed in high-copper amalgam has 230${\pm}$13 V.H.N and this phase is considerd to contribute to strengthen the handness in amalgam. 3. The V.H.N. measured under pressing a Vickers diamond indenter with 300.0gm load for 30 seconds in low-copper amalgam was lower than that of high-copper amalgam.

• Culinary science and hospitality research
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• v.17 no.2
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• pp.51-73
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• 2011

Companies are required to invest in numerous intial marketing costs for establishing brand power, thus, many companies in the foodservice industry are increasing their budgets on communication to strengthen their own brand equity components such as brand recognition, brand royalty, perceived quality and associated image using mass media that has not been used before. For this study, 617 samples were analyzed by such analytic methods as a frequency analysis, cross-tabulation, a factor analysis and a reliability analysis for validity, and a confirmatory factory analysis, a model adequacy evaluation, and a path analysis using AMOS 17.0. The hypothesis verification by the AMOS analysis has revealed that all hypotheses positively influenced contract foodservice brands, and the brand recognition of a university contract foodservice company has an impact on sincerity and refinement. Therefore, positive brand image formation encourages strong brand establishment between a university contract foodservice business and customers, and this study strongly suggests continuous further studies about constructing a positive brand image.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1119-1126
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• 2018

Objective: Present investigation was aimed to study the Single Nucleotide Variants of the luteinizing hormone beta ($LH{\beta}$) gene and to analyze their association with the semen quality (fresh and post-thawed frozen semen) and luteinizing hormone (LH) concentrations in Murrah buffalo bulls. Methods: Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and Sanger sequencing method is used to study genetic variability in $LH{\beta}$ gene. LH assay was carried out using enzyme-linked immunosorbent assay method. A fixed general linear model was used to analyze association of single nucleotide polymorphism (SNP) of $LH{\beta}$ gene with semen quality in 109 and LH concentrations in 80 Murrah bulls. Results: $LH{\beta}$ gene was found to be polymorphic. Total six SNPs were identified in $LH{\beta}$ gene g C356090A, g C356113T, g A356701G, g G355869A, g G356330C, and g G356606T. Single Stranded Conformational Polymorphism variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on sperm concentration (million/mL), percent mass motility, acrosome integrity and membrane integrity in fresh and frozen semen whereas significant (p<0.05) effect was observed on percent live spermatozoa. SSCP variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on luteinizing hormone concentrations too. Conclusion: The observed association between SSCP variants of $LH{\beta}$ gene with semen quality parameters and LH concentrations indicated the possibilities of using $LH{\beta}$ as a candidate gene for identification of markers for semen quality traits and LH concentrations in Murrah buffaloes.

• Journal of the Korea Safety Management & Science
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• v.21 no.4
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• pp.75-80
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• 2019

Sales of the Korean clothing industry grew to 16.9 percent on-year in 2010, but the growth rate dropped to 3 percent from 2011 to 2016 and the overall market began to slump to 1.1.6 percent in 2017. The competitiveness of clothing companies is also a major sector in logistics capability, and the average logistics cost of domestic clothing companies is 8.3 percent of sales in 2011, higher than the average 8 percent of domestic industries, and 36.4 percent of the total storage cost in 2011, higher than the 28.8 percent share of the total storage cost of domestic companies. As domestic production conditions such as wage hikes and labor disputes worsened in the 1990s, production facilities were rapidly moved overseas, which led many clothing companies to have no production facilities or a minimal production base in Korea and focus on marketing and design capabilities. The total storage capacity and storage efficiency of the logistics center became very important as the products were changed to the form of mass warehousing and small-volume forwarding. Research shows that building column spacing, a model of this research, can affect the amount of hanger rack storage empirically, so for sustainable growth of clothing companies, it is necessary to improve competitiveness in the logistics market by reducing costs and improving efficiency to overcome difficulties in corporate management. Because logistics costs are 8.3 percent and operating profit to sales ratio is 2 percent, it is expected that operating profit will increase by 41.5 percent if logistics costs are reduced by 10 percent. If 10% of storage cost is saved based on storage cost, operating profit is expected to increase by 15% To strengthen the competitiveness of the clothing industry, a reduction in logistics costs is essential. Therefore, the purpose of this study is to provide hints that logistics experts can have empirically small amounts in reducing storage costs through column spacing adjustment of logistics centers that have not been dealt with statistically until now, and to contribute to the continued growth of clothing companies and the development of the domestic logistics industry.

• Journal of Life Science
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• v.19 no.8
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• pp.1067-1072
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• 2009

Stromal derived factor-1 (SDF-1 or CXCL12), one of the CXC chemokines, is widely expressed in many tissues, including the thymus. The thymus can regenerate to its normal mass within 14 days after acute involution induced by cyclophosphamide (CY) in adult rats. Despite the established role of SDF-1 signaling in the development of T and B lymphocytes in the thymus, it has not yet been associated with the regeneration of the adult thymus. The purpose of this study was to investigate whether SDF-1, which is expressed in thymic stromal cells, is modulated during thymic regeneration in adult rats. Here, we showed that SDF-1 mRNAs were expressed in high levels in the thymocyte and thymic stromal cells at day 7 of the CY model. SDF-1 protein was shown to be present at the cortex-medulla junction, paraseptum and within the thymic medulla. Double-immunofluorescence for SDF-1 and ED-1 showed that strong SDF-1 expression was detected in the macrophages of the medulla region displaying immunoreactivity for ED-1 during thymus regeneration. Taken together, our results demonstrated that SDF-1 expression increased in regenerating thymic macrophages, suggesting the roles of SDF-1 as a chemo-attractant for damaged cells produced in the process of thymic regeneration after acute involution induced by CY.