• Research in Plant Disease
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• v.11 no.2
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• pp.208-212
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• 2005

At the survey of June, 2002, total 294 dead frees were found in 20 ha of Black pine (Pinus thunbergii) forest located in the western coastal region of Korean peninsula. The dead trees were scattered over the 27 place as groups of about ten trees each. As a result of the field survey on the relationship between the conditions of dead trees and the occurrence of fruiting bodies of Rhizina undulata around the dead and/or dying trees, from June 2002 to August 2004 in the four plots, the occurrence of infected trees was observed as a shape of an irregular concentric circle from the first infected tree and R. undulata was found mainly around the dead tree. Because there was no observation of any other insects and pathogens which would kill trees, the cause of tree death in groups was considered owing to R. undulata. From the analysis of the physical and chemical proper ties of the soil collected from the damaged areas, the pH of soil was between 4.6 and 5.8 and the contents of soil nutrients were very low. Any "fire" trace was not found at all the 27 damaged places in the area, Taean, Chungcheongnam-Do, which are generally known as an important factor to initiate development of the disease. Therefore, further examination is needed to verify precisely about other environmental factors related with the group dying of the Black pines in this area beside 'fire'.

• Tunnel and Underground Space
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• v.11 no.1
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• pp.42-58
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• 2001

In order to protect the environment from waste disposal activities, the prediction of the flux and flow paths of the contaminants from underground facilities should be assessed as accurately as possible. Especially, the prediction of the pathways and travel times of the nuclides from high level radioactive wastes in a deep repository to biosphere is one of the primary tasks for assessing the ultimate safety and performance of the repository. Since the contaminants are mainly transported with groundwater along the discontinuities developed within rock mass, the characteristics of groundwater flow through discontinuities is important for the prediction of contaminant fates as well as safety assessment of a repository. In this study, the actual fracture network could be effectively generated based on in situ data by separating geometric parameter and hydraulic parameter. The calculated anisotropic hydraulic conductivity was applied to a 3D porous medium model to calculate the path flow and travel time of the large studied area with the consideration of the complex topology in the area. Using the model, the pathways and travel times for groundwater were analyzed. From this study, it was concluded that the suggested techniques and procedures for predicting the pathways and travel times of groundwater from underground facilities to biosphere is acceptable and those can be applied to the safety assessment of a repository for radioactive wastes.

• Journal of Korea Water Resources Association
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• v.38 no.5 s.154
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• pp.379-390
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• 2005

This study is to trace the change of stream shape using the past series of aortal photographs and topographic maps, and to compare the land use changes of inland along the stream. For the Gyeongan first & second class of local stream, aerial photographs of 1966, 1981 and 2000 were selected and ortho photographs were made with interior orientation and exterior orientation, respectively. In addition, topographic maps of 1914 - 1915 were used to compare with stream of 1966, 1981 and 2000. As apparent changes of the stream, the consolidated reaches of stream with levee construction were straightened and their stream width widened. Especially the stream width of inlet part of Paldang lake was widened almost twice because of the rise of water level by dam construction in 1974. The land use maps (1966, 1981, 2000) of riparian areas were also made, respectively and classified into 6 categories (water, forest, agricultural land, urban area, road, sandbar) by digitizing, The main changes of land use were agricultural land, urban area, road and sandbar.

• Analytical Science and Technology
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• v.12 no.4
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• pp.318-325
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• 1999

Sludges from the wastewater of hanji production were analysed to see that sludges from the bleaching process, the bleach washing process, and the paper preparation process were fibrous, while sludges from the process cooking with NaOH and the process of final chemical and microbiological treatment were non-fibrous. Sludge solution from the bleaching process had the most amount of solid matters. Sludges from the bleaching process, the bleach washing process, and the final chemical and microbiological treatment process contained about 80-90 %(w/w) moisture. Owing to hypochlorite ion, pH of sludge from the bleaching process was higher than any other sludge samples. The inorganic components of sludges were determined by ICP-AES. The major inorganic component of sludge from the process cooking with NaOH was Na, while the sludge from the bleaching process had Na and Ca, major components in the final chemical and microbiological treatment process were Ca and Al. Trace amount of Mg, Fe, K, P, Mn and Ti were observed in sludges. Sludge from the bleaching process had ashes more than any other sludges. Shape of sludges observed by SEM was appeared to fibrous or crystalline, and the breadth of fibrous sludge was $5{\sim}50{\mu}m$. The sludge from the bleaching process had the most amount of matters soluble by cold and hot water and by alcohol-benzene.

• Journal of Pharmaceutical Investigation
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• v.28 no.4
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• pp.283-288
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• 1998

Lovastatin, one of the potent cholesterol-lowering agents, is an inactive lactone prodrug which is metabolized to its active open acid, lovastatin acid (LVA). Bioequivalence study of two lovastatin preparations, the test drug ($Mevacor^{\circledR}$: Chungwae Pharmaceutical Co., Ltd.) and the reference drug ($Lovaload^{\circledR}$: Chong Kun Dang Pharmaceutical Co., Ltd.), was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Fourteen healthy male volunteers, $23.9{\pm}3.9$ years old and $67.6{\pm}8.0$ kg of body weight in average, were divided randomly into two groups and administered the drug orally at the dose of 160 mg as lovastatin in a $2{\times}2$ crossover study. Plasma concentrations of lovastatin acid were analysed by HPLC method for 12 hr after administration. The extent of bioavailability was obtained from the plasma concentration-time profiles of total lovastatin acid after alkaline hydrolysis of the plasma samples. By alkaline hydrolysis, trace amounts of unmetabolized lovastatin were converted to lovastatin acid. The $AUC_{0-12hr}$ was calculated by the linear trapezoidal rule method. The $C_{max}$ and $T_{max}$ were compiled directly from the plasma drug concentration-time data. Student's t-test indicated no significant differences between the formulations in these parameters. Analysis of variance (ANOVA) revealed that there were no differences in AUC, $C_{max}$, and $T_{max}$ between the formulations. The apparent differences between the formulations were far less than 20% (e.g., 7.07, 5.77 and 1.18% for AUC, $C_{max}$, and $T_{max}$, respectively). Minimum detectable differences(%) between the formulations at ${\alpha}=0.05$ and $1-{\beta}=0.8$ were less than 20% (e.g., 17.2, 15.1, and 15.9% for AUC, Cmax, and Tmax, respectively). The 90% confidence intervals for these parameters were also within ${\pm}20%$ (e.g.. $-5.20{\sim}19.3$, $-5.00{\sim}16.5$, and $-10.2{\sim}12.5%$ for AUC, $C_{max}$, and $T_{max}$, respectively). These results satisfied the bioequivalence criteria of KFDA guidelines, indicating that the two formulations of lovastatin were bioequivalent.

• Journal of Conservation Science
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• v.29 no.4
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• pp.355-366
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• 2013

Diverse scientific analyses, including microstructure, ICP-AES, SEM-EDS, and P-XRF(Bench Top type and Gun type), were carried out on 6 bronze artefacts which handed from generation to generation. Also, we attempted to study applicability for authenticity of the bronze artefacts using scientific analyses based on the specific element. The results of ICP-AES analysis showed that the bronze were formed from an alloy of Cu, Sn, Pb with trace elements such as Ag, As, Co, Fe, but there were not Zn found. The result of P-XRF are 10~25% lower in Cu and 10~20% higher in Sn than that of ICP-AES. This is because of destannification that the compound of $SnO_2$ are present on the surface. The results of SEM-EDS represented that there is lead segregation. It was difficult to study applicability for authenticity of bronze artefact according to the microstructures and chemical components of the bronze artefacts. Therefore, as bronze artefacts have shown different corrosion materials depending on the buried environment and conserving environment, identifying the authenticity would be possible on the basis of the additional researches on the corrosion and comparative research of ancient art.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.171-187
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• 1998

Garlic occupies a special position among the many foods of vegetable origin because it is the sole food for Koreans during the their lives. And vitamin A has been ingested by forms of food or additives. Cadmium has been described as one of the most dangerous trace elements in the food and environment of man and livestocks. Since the de novo synthesis of stress proteins can be detected early after exposure to some agents, analysis of cadmium-induced changes in gene expression , ie. alterations in patterns of protein synthesis, may be useful to develop as biomarkers of exposure and damage for food hygiene. He acute and chronic combine effects of cadmium (Cd, CdCl2 20mg/kg), garlic oil(Dds: diallyl disulfide 50mg/kg, 3 times a week) and vitamin A(Ra: retinol acetate 50,000 IU/kg, 3 times a week) on Wistar male rats were evaluated concerning cadmium contents, tissues enzyme activity, HSP expression histopathological and electron microscopical examinations. The results of the study are as follows ; 1. Less cadmium was absorbed through the digestive tracts, but the ratio of contents in tissue were not changed by the simultaneous adminstration of diallyl disufide or retinol acetate. 2. ALT(alanine aminotransferase) , AST(aspartate aminotransferase), glucose, BUN (blood urea nitrogen), creatinine, the key indices of the clinical changes in hepatic and renal function were significantly hanged by the cadmium treatment after 1 week in liver, after 4 weeks in kidney. 3. Histopathological changes in cadmium treated rats were appeared at 8 weeks age treatment in kidneys. Homogenous eosinophilic material was accumulated in cortical and collecting tubular lumens at 16 weeks. Degenerated or necrotized tubular cells were observed in cortex and medulla. Degenerated seminiferous tubules and homogeneous eosinophilic material was seen in interstitial tissue of rat treated with cadmium for 16 weeks. Calcium deposits were seen in degenerated seminiferous tubules and the tubules showed severe calcification of rat treated with cadmium for 16 weeks. Electron microscope changes in kidney were observed in rats treated with CdCl2 20 mg/kg. Proximal convoluted tubule cells showed selling of cytoplasm and narrow lumen. Capillary endothelial cells showed cytoplasmic vacuoles and swelling. Degenerated epithelial cells were accumulated in tubular lumen of kidney. 4. Enhanced synthesis of 70 KDa relateve molecular mass proteins were detected in 2 hours after cadmium, exposure, with maximum activity occurring at 8~48 hours. Induction of HSP 70 was evident at proximal tubules and glomeruli in kidney. Testicular cells produced enough HSP to be detected normally. From the above results, it could be concluded that HSP70 induction by the cadmium treatment was a rapid reaction to indicated the exposure of xenobiotics, and retinol acetate reduced the cadmium induced nephrotoxicity.

• The Korean Journal of Food And Nutrition
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• v.19 no.3
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• pp.318-326
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• 2006

Soy sauce was prepared with the addition of Gorosoe and Kojesu saps instead of tap water to make ordinary soy sauce, respectively. The changes of free sugar, organic acid, mineral, amino acid and nucleotides and other compounds during the fermentation of soy sauce were assessed. The free sugar were found to be fructose, glucose, galactose and sucrose in soy sauce of saps but sucrose was not detected in ordinary soy sauce. Galactose contents were dominant free sugar in all samples. The contents of butyric acid were dominant among 7 kinds of organic acid while fumaric acid was trace amount during the fermentation of soy sauce. The contents of potassium and phosphorus among 13 kinds of minerals were dominant during the fermentation of soy sauce. In the amino acid composition of soy sauce, dominant amino acid was glutamic acid(185.6${\pm}$1.0 mg/100 ml above), but proline and arginine were not detected. AMP detected above 7.5${\pm}$O.2 ${\mu}$mol/100 ml was dominant while inosine was not detected during the fermentation of soy sauce. The results of sensory evaluation in the fermented soy sauce of Gorosoe was 'liked more' than that of soy sauce of Kojesu and control.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.590-603
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• 2006

Size-and time-resolved aerosol samples were collected using an eight-stage Davis rotating unit for monitoring (DRUM) sampler from 23 March to 29 April 2001 at Gosan, Jeju Island, Korea, which is one of the super sites of Asia-Pacific Regional Aerosol Characterization Experiment(ACE-Asia). These samples were analyzed using synchrotron X-ray fluorescence for 3-hr average concentrations of 19 elements including Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, and Pb. The size-resolved data sets were then analyzed using the positive matrix factorization(PMF) technique to identify possible sources and estimate their contributions to particulate matter mass. PMF analysis uses the uncertainty of the measured data to provide an optimal weighting. Twelve sources were resolved in eight size ranges($0.09{\sim}12{\mu}m$) and included continental soil, local soil, sea salt, biomass/biofuel burning, coal combustion, oil combustion, municipal incineration, nonferrous metal source, ferrous metal source, gasoline vehicle, diesel vehicle, and volcanic emission. The PMF result of size-resolved source contributions showed that natural sources represented by local soil, sea salt, continental soil, and volcanic emission contributed about 79% to the predicted primary particulate matter(PM) mass in the coarse size range ($1.15{\sim}12{\mu}m$) while anthropogenic sources such as coal combustion and biomass/biofuel burning contributed about 58% in the fine size range($0.56{\sim}2.5{\mu}m$). The diesel vehicle source contributed mostly in ultra-fine size range($0.09{\sim}0.56{\mu}m$) and was responsible for about 56% of the primary PM mass.

• Analytical Science and Technology
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• v.6 no.1
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• pp.107-119
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• 1993

The purpose of this study is to investigated the elution behavior of platinoid metal acetylacetonates, which is the key to elucidate their retention mechanism and optimize their RPLC separation conditions. The retention data of four platinoid metal acetylacetonates have been measured on four different columns in methanol-water and acetonitrile-water systems. The retention of uncharged platinoid metal acetylacetonates is interpreted by solvophobic effect. The retention of platinoid metal acetylacetonates is also greatly influenced by the geometric structure of the complexes. The square planar chelates, $Pd(acac)_2$, $Pt(acac)_2$, are retained longer than the octahedral chelates, $Rh(acac)_3$, $Ir(acac)_3$. It is likely due to that square planar chelates show greater interaction with nonpolar stationary phase than octahedral chelates. The results of van't Hoff plots have shown that platinoid metal acetylacetonates is operated on the same retention mechanism in the temperature range of $25{\sim}45^{\circ}C$. The study of the retention mechanism by the enthalpy-entropy compensation phenomenon has indicated that the retention mechanism of octahedral chelates and square planar chelates do not vary with the composition change of methanol-water mobile phase, respectively. In acetonitrile-water mobile phase, however, the retention mechanism is observed to be more complicated. Optimum condition for the separation of four platinoid metal acetylacetonates is found to be 40% methanol, polymeric C18 column, and $45^{\circ}C$.