• Economic and Environmental Geology
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• v.43 no.6
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• pp.589-601
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• 2010

Recently it has been frequently reported arsenic contamination of geologic origin in groundwater. The iron-impregnated ranular activated carbon (Fe-GAC) was developed for effective removal of arsenic from groundwater n the study. Fe-GACs were prepared by impregnating iron compounds into a supporting medium (GAC) with 0.05 M iron nitrate solution. The materials were used in arsenic adsorption isotherm tests to know the effect of iron impregnation time, batch kinetic tests to understand the influence of pH, and column tests to evaluate for the preliminary operation of water treatment system. The results showed that the minimum twelve hours of impregnation time were required for making the Fe-GAC with sufficient iron content for arsenic removal, confirmed by a high arsenic adsorption capacity evaluated in the isotherm tests. Most of the impregnated iron compounds were iron hydroxynitrate $Fe_4(OH)_{11}NO_3{\cdot}2H_2O$ but a mall quantity of hematite was also identified in X-ray diffraction(XRD) analysis. The batch isotherms of Fe-GAC for arsenic adsorption were well explained by Langmuir than Freundlich model and the iron contents of Fe-GAC have positive linear correlations on logarithmic plots with Freundlich distribution coefficients ($K_F$ and Langmuir maximum adsorption capacities ($Q_m$. The results of kinetic experiments suggested hat Fe-GAC had he excellent arsenic adsorption capacities regardless of all pH conditions except for pH 11 and could be used a promising adsorbents for groundwater arsenic removal considering the general groundwater pH range of 6-8. The pseudo-second order model, based on the assumption that the ate-limiting step might be chemisorption, provided the best correlation of the kinetic experimental data and explained the arsenic adsorption system f Fe-GAC. The column test was conducted to valuate the feasibility of Fe-GAC use and the operation parameters in arsenic groundwater treatment system. The parameters obtained from the column test were the retardation actor of 482.4 and the distribution coefficient of 581.1 L/mg which were similar values of 511.5-592.5 L/mg acquired from Freundlich batch isotherm model. The results of this study suggested that Fe-GAC could be used as promising adsorbent of arsenic removal in a small groundwater supply system with water treatment facility.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.429-439
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• 2013

This study was conducted to identify the relationship between environmental factors and algal bloom, and provide information for efficient management based on the results of monitoring the environmental parameters and algal diversity in the Jundai reservoir from March 2011 to October 2013. Little change in the weather conditions was observed during the study period except for a slight decrease in rainfall. Concentration of TN and TP in the reservoir exceeded water quality standards for agriculture and significant correlation between algal growth and environmental factors was observed. Phytoplankton in Jundai reservoir included 6 classes, 40 genus, 62 species, and the phytoplankton abundance was in the range of $1.3{\times}10^4{\sim}2.8{\times}10^6$ cells $mL^{-1}$. The annual average of phytoplankton abundance and Chl-a gradually decreased as TN and TP concentrations decreased. Overall Anabaena sp., Oscillatoria sp., and Microcystis sp. were the dominant species in Jundai reservoir. As the water temperature increased, the dominant species were Anabaena sp., Microcystis sp. and Oscillatoria sp., in that order. Anabaena sp. was dominant from spring to early summer with increase in water temperature and pollutant concentrations, and high correlation with environmental factors was observed. Microcystis sp. was dominant depending on changes in the nutrient levels. In the case of Oscillatoria sp., there was no significant correlation between phytoplankton biomess and Chl-a. However, efficient management of water environment and practical control of algal bloom in small scale reservoir polluted by livestock and farm irrigation should be achieved by identification of the relationship between algal growth and environmental factors.

• Analytical Science and Technology
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• v.25 no.2
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• pp.121-126
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• 2012

It is essential to evaluate the quality of Hanji record paper without damaging the record paper by previous destructive methods. The samples were Hanji record paper produced in the 1900s. Near-infrared (NIR) spectrometer was used as a non destructive method for evaluating the quality of record papers. Fourier transform (FT) spectrometer was used with 12,500 to 4,000 $cm^{-1}$ wavenumber range for quantitative analysis and it has high accuracy and good signal-to-noise ratio. The acidity and moisture content of Hanji record paper were measured by integrating sphere as diffuse reflectance type. The acidity (pH) of chemical factors as a quality evaluated factor of Hanji was correlated to NIR spectrum. The NIR spectrum was pretreated to obtain the coefficients of optimum correlation. Multiplicative scatter correction (MSC) and First derivative of Savitzky-Golay were used as pretreated methods. The coefficients of optimum correlation were calculated by PLSR (partial least square regression). The correlation coefficients ($R^2$) of acidity had 0.92 on NIR spectra without pretreatment. Also the standard error of prediction (SEP) of pH was 0.24. And then the NIR spectra with pretreatment would have better correlation coefficient ($R^2$ = 0.98) and 0.19 as SEP on pH. For moisture contents, the linearity correlation without pretreatment was higher than the case with pretreatment (MSC, $1^{st}$ derivative). As the best result, the $R^2$ was 0.99 and SEP was 0.45. This indicates that it is highly proper to evaluate the quality of Hanji record papers speedily with integrated sphere and FT NIR analyzer as a non-destructive method.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.32-40
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• 2015

This study was implemented to evaluate food safety on residual pesticides in agricultural products of Korea and to use as a data base for the establishment of food policy. A total of 196 pesticide upon these products were analyzed using multi class pesticide multiresidue methods of Korean Food Code, and 232 samples of 15 agricultural products collected from 9 regions were supplied for this study. In the results, 64 kinds of pesticides were detected in 53 samples, chlorpyrifos and procymidone of them were shown a high frequency of detection in the analyzed pesticides. Among them, two samples (chlorpyrifos in perilla leaves and picoxystrobin in peach) were detected over Maximum Residue Limits (MRLs). The levels of the detected pesticide residues were within safe levels. Also, the intake assessment for pesticide residues including chlorpyrifos at multi pesticide residue monitoring were carried out. The result showed that the ratio of EDI (estimated daily intake) to ADI (acceptable daily intake) was 0.001~0.902% which means that the detected pesticide residues were in a safe range so that residual pesticides in the agricultural products in Korea are properly controlled.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.5-13
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• 2015

A chromatographic method for the determination of imazapyr, a non-selective herbicide, in agricultural commodities was developed to use safety control of pesticide residue on crops, and was fully validated as an official method for residue analysis. Agricultural commodities, mandarin (fruit), hulled rice (cereal grains), pepper (vegetables), potato (potatoes) and soybean (beans) were extracted with methanol and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2.5 by 4N hydrochloric acid. Finally, they were analyzed by high performance liquid chromatography coupled to UV detector (HPLC-UVD). The developed method had the linearity in the range of test concentrations with coefficients of determination ($r^2$) more than 0.99. Recovery studies were carried out at three concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. Recoveries were ranged between 72.1 to 108.0%, with relative standard deviations less than 10%. A consistent recovery was determined according to the CODEX guidelines (CAC/GL40, 2003). Finally, LC/MS with selected ion monitoring was also applied to confirm the suspected residues of imazapyr in agricultural samples. This developed method for determination of imazapyr residues in agricultural commodities. can be used as an official method.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.69-76
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• 2017

Purpose: The purpose of this study was to verify dosimetric results and reproducibility of position during craniospinal irradiation (CSI) using tomotherapy (Accuray Incorporated, USA). Also, by comparing with conventional CSI Technique, we confirmed the efficiency of using a Tomotherapy. Materials and Methods: 10 CSI patients who get tomotherapy participate. Patient-specific quality assurances (QA) for each patient are conducted before treatment. When treating, we took Megavoltage Computed Tomography (MVCT) that range of head and neck before treatment, L spine area after treatment. Also we conducted in-vivo dosimetry to check a scalp dose. Finally, we made a 3D conventional radiation therapy(3D-CRT) of those patients to compare dosimetric differences with tomotherapy treatment planning. Results: V107, V95 of brain is 0 %, 97.2 % in tomotherapy, and 0.3 %, 95.1 % in 3D-CRT. In spine, value of V107, V95 is 0.2 %, 18.6 % in tomotherapy and 89.6 %, 69.9 % in 3D-CRT. Except kidney and lung, tomotherapy reduced normal organ doses than 3D-CRT. The maximum positioning error value of X, Y, Z was 10.2 mm, -8.9 mm, -11.9 mm. Through in-vivo dosimetry, the average of scalp dose was 67.8 % of prescription dose. All patient-specific QA were passed by tolerance value. Conclusion: CSI using tomotherapy had a risk of parallel organ such as lung and kidney because of integral dose in low dose area. However, it demonstrated dosimetric superiority at a target and saved normal organ to reduce high dose. Also results of reproducibility were not exceeded margins that estimated treatment planning and invivo dosimetry showed to reduce scalp dose. Therefore, CSI using tomotherapy is considered to efficient method to make up for 3D-CRT.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.146-158
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• 2012

This study aims to discussion the characteristics of location and spatial organization of the Seoul Sajikdan that has significance as one of national ceremonial place in Joseon Dynasty to understand its landscape architectural characteristics. To do this, we studied in two ways; review of historical documents and analysis of the present conditions and photographing, research materials about the form of physical structure. Through these ways, the results are as follows. First, in case of construction, Sajikdan took fundamental shape in Tae-jong 16 year(1416), since then it had been changed during Imjin War, reign of Suk-jong, and Japanese Colonial Era. It took present shape through restoration of Seoul Sajikdan in 1998. Second, in case of location, Sajikdan abuts onto southeastern range of Mt. Inwang that is Wubaekho(右白虎) of inner four mountain(內四山) of Hanyang, and it has a topography of west-high-east-low type. Also its territory is up to Maedong elementary school, the office of Sajik-dong, and a Dangun shrine. Third, in case of spatial organization, Sadan and Jikdan are in harmony of Yin-Yang(陰陽) and arranged in the center. As making Yumun and Sinmun(神門) at the center of four side of Yuwon and Juwon(周垣), they show organization of the Five Elements. And subsidiary buildings are thought that its arrangement was considered functional similarity and use convenience. Finally, in case of spatial component, Danyu structures are Sadan and Jikdan that hold a Sajikdaeje(社稷大祭), Yuwon that surround two altars, and Juwon that is outer fence of Yuwon. Architectures are Sajikdan Jeongmun, Sinsil, and Anhyangcheong. Also Prunus yedoensis, Zelkova serrata, Acer palmatum, are planted, but Pinus densiflora was main species and there needs to be replanted suitably to the site.

• Journal of Soil and Groundwater Environment
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• v.6 no.3
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• pp.53-59
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• 2001

There is a lot of method to manage the insanitary landfill but vertical cutoff walls have been widespreadly used and were installed into the subsurface to act as a barrier to horizontal groundwater flow, The stabilized material such as specialized cement or mixed soil with additives has been generally applied for the materials of the deep soil mixing barrier in korea. The amount of the stabilized material is dependent on the field conditions, because the mixing ratio of the material and the field soil should achieve a requirement in the coefficient of permeability, lower than 1.0$\times$$10^{7}$cm/sec. This study determined the quantity and optimized function ratio of the stabilized material in the formation process of the mixed barrier that was added with stabilized material on the field soil classified into SW-SC under USCS (Unified Soil Classification System). After that the fly ash and lime were selected as an additives an that could improve the function of the stabilized material and then the method to improve the functional progress in the usage of putting into the stabilized material as an appropriate ratio was studied and reviewed. The author used the flexible-wall permeameter for measuring the permeability and unconfined compressive strength tester for compressive strength, and in the view of environmental engineering the absorption test of heavy metals and leaching test regulated by Korean Waste Management Act were performed. As the results, the suitable mixing ratio of the stabilized material in the deep soil mixing barrier was determined as 13 percent. To make workability easy, the ratio of stabilized material and water was proven to be 1 : 1.5. With the results, the range of the portion of the additives(fly ash : lime= 70 : 30) was proven to be 20-40% for improving the function of the stabilized material, lowering of permeability. In heavy metal absorption assessment of the mixing barrier system with the additives, the result of heavy metal absorption was proved to be almost same with the case of the original stabilized material; high removal efficiency of heavy metals. In addition, the leaching concentration of heavy metals from the leaching test for the environmental hazard assessment showed lower than the regulated criteria.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.105-111
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• 2010

Lentinus lepideus, known as train wrecker fungus, has been used for nutritional and medicinal purposes. Recently, commercial cultivation technique and a new cultivar of the mushroom were developed. To investigate the genetic diversity and phylogenetic relationship for identifying the mushroom strains and cultivar, one commercial and 13 strains of Lentinus lepideus from different geographical regions of Korea were analyzed by ITS regions of rDNA and RAPD of genomic DNA. Three strains of Lentinus edodes were also used for the analysis. The size of the ITS1 and ITS2 regions of rDNA from the different strains varied from 173 to 179 bp and 203 to 205 bp, respectively. The sequence of ITS1 was more variable than that of ITS2, while the 5.8S sequences were identical with 156 base pairs. A phylogenetic tree based on the ITS region sequences indicated that selected strains could be classified into four clusters, while 3 strains of L. edodes was divided into a new cluster. Ten primers out of 20 arbitrary primers used in the RAPD-PCR efficiently amplified the genomic DNA. The numbers of amplified DNA bands varied with the primers and strains, with polymorphic DNA fragments in the range from 0.2 to 2.6 kb. The results showed that phylogenetic relationship among Korean strains of Lentnus lepideus is high, but genetic diversity is low.

• Journal of Chest Surgery
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• v.32 no.9
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• pp.781-789
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• 1999

Background: Pulmonary artery banding(PAB) accompanies some risks in the aspect of band complications and mortality in the second-stage operation. To assess these risks of the second-stage operation after PAB, we reviewed the surgical results of the second-stage operation in the pediatric patients who had undergone PAB in infancy. Material and Method: From May 1988 to June 1997, a total of 29 patients with preliminary PAB underwent open heart surgery. Ages ranged from 2 to 45 months(mean 20.6$\pm$9.0 months). Preoperative congestive heart failure conditions were improved after PAB(elective operation group) in 27 patients, but early second-stage procedures were required in the remaining 2 patients due to sustaining congestive heart failure(early operation group). Preoperative surgical indications included 2 double outlet right ventricles(DORV group) and 27 ventricular septal defects as the main cardiac anomaly(VSD group). Result: The mean time interval from PAB to the second-stage operation was 15.5$\pm$8.7 months(range 5 days to 45 months). One patient in the DORV group underwent intraventricular tunnel repair and modified Glenn procedure in the other. In the VSD group, the VSD was closed with a Dacron patch in all patients. Concomitant procedures included a right ventricular infundibulectomy in 4 patients and a valvectomy of the dysplastic pulmonary valve in 1 patient. At the second-stage operations, pulmonary angioplasty was required due to the stenotic banding sites in 18 patients. One patient underwent complete ligation of the main pulmonary artery with the modified Glenn procedure. The mortality at the second-stage operation was 17.2%(5 patients). Causes of death were 4 low cardiac output, and 1 autoimmune hemolytic anemia. Diagnosis with DORV and the early operative group were the risk factors for operative death in this series. There was 1 late death. Conclusion: This study revealed the second-stage operation for pulmonary artery debanding and closure of VSD in children was complicated by the correction of the acquired lesions with a significantly high incidence of morbidity and early postoperative deaths. Primary repair is recommended for isolated VSD, if possible.