• The Korean Journal of Pesticide Science
• /
• v.8 no.3
• /
• pp.151-161
• /
• 2004

Three dimensional quantitative structure-activity relationships (3D-QSAR) studies for the protox inhibition activities against root and shoot of rice plant (Orysa sativa L.) and barnyardgrass (Echinochloa crus-galli) by a series of new A=3,4,5,6-tetrahydrophthalimino, B=3-chloro-4,5,6,7-tetrahydro-2H-indazolyl and C=3,4-dimethylmaleimino group, and R-group substituted on the phenyl ring in 1-(5-methyl-3-phenylisoxazolin-5-yl)methoxy-2chloro-4-fluorobenzene derivatives were performed using comparative molecular field analyses (CoMFA) methodology with Gasteiger-Huckel charge. Four CoMFA models for the protox inhibition activities against root and shoot of the two plants were generated using 46 molecules as training set and the predictive ability of the each models was evaluated against a test set of 8 molecules. And the statistical results of these models with combination (SIH) of standard field, indicator field and H-bond field showed the best predictability of the protox inhibition activities based on the cross-validated value $r^2_{cv.}$ $(q^2=0.635\sim0.924)$, conventional coefficient $(r^2_{ncv.}=0.928\sim0.977)$ and PRESS value $(0.091\sim0.156)$, respectively. The activities exhibited a strong correlation with steric $(74.3\sim87.4%)$, electrostatic $(10.10\sim18.5%)$ and hydrophobic $(1.10\sim8.30%)$ factors of the molecules. The steric feature of molecule may be an important factor for the activities. We founded that an novel selective and higher protox inhibitors between the two plants may be designed by modification of X-subsitutents for barnyardgrass based upon the results obtained from CoMFA analyses.

• Journal of Soil and Groundwater Environment
• /
• v.17 no.3
• /
• pp.21-31
• /
• 2012

This paper presents the short-term and long-term measures to determine the fugitive dust concentration in a contaminated site, which is a crucial step for the determination of particulate emission factor (PEF) for risk assessment. As a long-term measure, USEPA method employing Q/C value (inverse of the ratio of the geometric mean air concentration to the emission flux at center of a 0.5-acre square source) seems to be suitable as it reflects regional-specific meteorological conditions. However, it requires nation-wide database collection and interpretation. Use of ASTM method is an alternative as a short-term measure. The method is readily field-applicable as PEF calculation equation is simple and input parameters can be easily derived at the site of interest as well without the nation-wide efforts. Using ASTM method, PEF at the Former Janghang Smelter Site was determined. According to various mode of aggregate size distribution and fractions of vegetative cover, which are the most important factors in PEF calculation, PEF values at the Former Janghang Smelter Site varied greatly. When the mode of aggregate size distribution was set at 0.25 mm, PEF values at the Former Janghang Smelter Site was 5~20 times higher than the default PEF value (i.e., 35 ${\mu}g/m^3$) shown in the current Korean Soil Contamination Risk Assessment Guidance. On contrast, when the mode was set at 2 mm, PEF values at the Former Janghang Smelter Site was 160~640 times lower than the default PEF value in the Korean Guidance.

• Journal of Korea Soil Environment Society
• /
• v.3 no.2
• /
• pp.13-29
• /
• 1998

Recently, It is increasing popularity to research on the soil remediation in aspect of management by reason of the hazardous impact on the contaminated soil in Korea. It was investigated high levels of arsenic salts in soil near abandoned five mines(Darak, Daduk, Jingok, Dalsung, Ilkwang) located in Youngnam area. Arsenic, classified as group A(Human Carcinogens) from IRIS, have shown statistically significant increment in skin cancer with oral exposure. This paper was conducted to predict excess cancer risk value (to the skin cancer) based on multiple pathway such as soil ingestion, dermal uptake and food(plant) ingestion contaminated by arsenic, and also, to identify the remedial goal regarded in future land use. The mine having the highest arsenic level was Daduk(mean : 1950mg/kg) and the next rank was Jingok(1690mg/kg), Ilkwang(352.37mg/kg), Dalsung(86.08mg/kg), Darak(0.83mg/kg). The chronic daily intake to the multiple exposure were calculated using Monte-Carlo simulation regarded in future land use and used q: value was $1.5(mg/kg/day)^{-1}$ to the oral proposed by IRIS(1997). The computated excess cancer risk 95th value to all the mine regarding future land use as residential and rural area were more than $10^{-4}$. If the level of acceptable risk is aimed for 1$\times$$10^{-6}$, it could be used Darak as commercial and industrial area without soil remediation due to the lowest risk value(6$\times$$10^{-8}$ and 3$\times$$10^{-8}$). Computated remedial goal based on 1$\times$$10^{-6}$ of acceptable risk to the future land use as the residential, rural, commercial and industrial area were 0.02mg/kg, 0.003mg/kg, 97.31mg/kg and 194.62mg/kg, respectively.

• Journal of the Korean Magnetics Society
• /
• v.12 no.6
• /
• pp.218-223
• /
• 2002

We investigated the magnetic properties of High Flux-type $Ni_{x}Fe_{100-x}$(x=40∼50, wt.％) permalloy powders and dust cores. The powder was prepared by conventional gas atomization in mass production scale. At the composition of $Ni_{x}Fe_{55}$, saturation magnetization was maximum. In case of lower Ni content than X=45, the $M_{s}$, decreased largely with the decrease in Ni content, which is due to the invar effect. The permeability of compressed powder cores increased with the decrease in Ni content, which was considered to be due to the decrease in the magnetostriction. In addition, the dust core with Ni=45％ showed the lowest core loss because of the increase in electrical resistivity leading to the low eddy current loss. From the better frequency dependence of permeability, larger Q value and superior DC bias characteristics of Ni=45％ than those of Ni=50％ core, it was confirmed that the 45％Ni-55％Fe powder alloy was better material for the dust core than commercial High Flux core materials.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.6B
• /
• pp.399-406
• /
• 2012

The objective of this research is to develop greenhouse gas generation models and estimation method of their parameters for solid waste landfills. Two models obtained by differentiating the Modified Gompertz and Logistic models were employed to evaluate two parameters of a first-order decay model, methane generation potential ($L_0$) and methane generation rate constant (k). The parameters were determined by the statistical comparison of predicted gas generation rate data using the two models and actual landfill gas collection data. The values of r-square obtained from regression analysis between two data showed that one model by differentiating the Modified Gompetz was 0.92 and the other model by differentiating the Logistic was 0.94. From this result, the estimation methods showed that $L_0$ and k values can be determined by regression analysis if landfill gas collection data are available. Also, new models based on two models obtained by differentiating the Modified Gompertz and Logistic models were developed to predict greenhouse gas generation from solid waste landfills that actual landfill generation data could not be available. They showed better prediction than LandGEM model. Frequency distribution of the ratio of Qcs (LFG collection system) to Q (prediction value) was used to evaluate the accuracy of the models. The new models showed higher accuracy than LandGEM model. Thus, it is concluded that the models developed in this research are suitable for the prediction of greenhouse gas generation from solid waste landfills.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.212-217
• /
• 2020

The purpose of this study was to analyze the volatility and properties of a time series for tangerine prices in Jeju using the GARCH model of Bollerslev(1986). First, it was found that the time series for the rate of change in tangerine prices had a thicker tail rather than a normal distribution. At a significance level of 1%, the Jarque-Bera statistic led to a rejection of the null hypothesis that the distribution of the time series for the rate of change in tangerine prices is normally distributed. Second, the correlation between the time series was high based on the Ljung-Box Q statistic, which was statistically verified through the ARCH-LM test. Third, the results of the GARCH(1,1) model estimation showed statistically significant results at a significance level of 1%, except for the constant of the mean equation. The persistence parameter value of the variance equation was estimated to be close to 1, which means that there is a high possibility that a similar level of volatility will be present in the future. Finally, it is expected that the results of this study can be used as basic data to optimize the government's tangerine supply and demand control policy.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.6
• /
• pp.3729-3734
• /
• 2013

The aim of this study was to evaluate expression of COX-1 in renal cell carcinoma (RCC) and its prognostic value. mRNA of COX-1 was detected in 42 paired RCC and adjacent normal tissues with quantitative realtime polymerase chain reaction (qRT-PCR). Expression of COX-1 was also evaluated in 196 RCC sections and 91 adjacent normal tissues with immunohistochemistry. Statistical analysis was performed to assess COX-1 expression in RCC and its prognostic significance. The results of qRT-PCR showed mRNA levels of COX-1 in RCC tissues to be significantly higher than that in adjacent normal tissues (p < 0.001). Immunohistochemical assays also revealed COX-1 to be overexpressed in RCC tissues (p < 0.001). Statistical analysis demonstrated high expression of COX-1 was correlated with tumour size (p = 0.002), pathological stage (p = 0.003), TNM stage (p = 0.003, 0.007, 0.027, respectively), and tumour recurrence (p < 0.001). Survival analysis indicated patients with high expression of COX-1 had shorter survival time (p < 0.001), and COX-1 was an independent predictor. This is the first study to reveal overexpression of COX-1 in RRC and point to use as a prognostic marker in affected patients.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.3
• /
• pp.112-117
• /
• 2017

Ion exchange fiber, PADD was synthesized by the reaction between PAN based acrylic fiber and DETA with $AlCl_3{\cdot}6H_2O$, and was analyzed by FT-IR and SEM to investigate its characteristics. The experimental results of Cr(VI) removal by PADD were better fitted with Langmuir adsorption isotherm, and the maximum uptake value ($Q_{max}$) was calculated to be 6.93 mmol/g. The kinetic data can be well described by Lagergen pseudo-second order rate model. The Cr(VI) adsorption capacity of PADD was 4.11 mmol/g at pH 2, which shows the effect of pH changes on the removal of Cr(VI). The adsorption selectivity of Cr(VI) was higher than phosphate and As(V). Total ion exchange capacity of PADD was 4.70 mmol/g, which was measured by acid-base back titration.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.26 no.2
• /
• pp.33-41
• /
• 2018

Large amounts of leaves from street trees fall onto the streets annually and need to be cleaned and treated. Cherry trees are common street trees in Korea. The adsorption characteristics of Pb(II) by cherry leaf (CL) and cherry leaf-derived biochar (CB) were studied through a series of batch experiments. CB was produced through the carbonization of CL at $800^{\circ}C$ for 90 min. Carbonization increased the C content and pH value, while decreased H and O contents. Well developed pore structure was observed at the surface of CB. The pseudo-second order model better described the kinetics of Pb(II) adsorption onto CL and CB, indicating that the rate-limiting step of the heavy metal sorption is chemical sorption. Fast adsorption rates and high adsorption capacities were obtained by the carbonization from CL to CB. Langmuir models better adequately described the Pb(II) adsorption onto CL and CB. Maximum adsorption capacities of Pb(II) expressed by Langmuir constant, $Q^0$ were 37.31 mg/g and 94.34 mg/g, when CL and CB were used as adsorbents, respectively.

• Journal of Korean Society of Forest Science
• /
• v.105 no.3
• /
• pp.284-293
• /
• 2016

In order to assess th changes in vegetation characteristics over time in the forest-lands which is isolated by urbanization, vegetation surveys based on the Braun-Blanquet phytosociological method was carried out in 1996 and 2015 on Mt. Hwangyeong located in the center of Busan metropolitan city, South Korea. The number of vegetation types based on floristic composition showed no significant changes, the vegetation units under the community levels was more or less represents the difference. the average total vegetation cover and average number of species per unit area ($100m^2$) was increased 16% and 2 species, respectively. The relative importance value (RIV) for each tree species, Quercus spp. like as Q. mongolica and Q. serrata was decreased, while the warmth-tolerant trees, evergreen broad-leaved trees, and mesophyte like Lindera erythrocarpa, Styrax japonica, Osmanthus heterophyllus, and Stephanandra incisa was increased significantly. Changes of the life form spectrums of vascular plants did not substantially, hemicryptophyte(H) and therophyte (Th) was decreased, while nanophanerophyte(N) was increased significantly. Also through the creating of large-scale vegetation map (based on physiognomic vegetation types) was compared the spatial distribution characteristics of each vegetation types.