• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.211-220
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• 2016

This study was to develop the analytical reference material of green-pepper for multi-residue analysis of pesticides. According to the ISO Guide 35, ISO Guide 13528 and EURL-PT protocol, the homogeneity, stability, assigned value and uncertainty were calculated to assess if it was suitable to be used as the proficiency test or quality control. The values of the within-bottle standard variation ($s_{wb}$) and the between-bottle standard variation ($s_{bb}$) were 1.7~3.7% of assigned value according to the requirement of the ISO guide 35. And, the uncertainty ($u^*{_{bb}}$) due to inhomogeneity was 0.8~1.1% for all pesticides. The storage stabilities of ten-pesticides at various conditions were assessed. For all target pesticides, the slop ($b_1$) values were smaller than the corresponding values of $[t_{0.95,n-2}{\times}s(b_1)]$ specified by the ISO guide 35, indicating that there were no statistically significant decreases in the concentration of the target pesticides when the analytical reference material was stored at room temperature ($20{\sim}30^{\circ}C$) for 7 days, freezing ($-20^{\circ}C$) for 30 days and deep freezer ($-80^{\circ}C$. except for bifenthrin, fenpropathrin) for 245 days. For proficiency test by using it developed by Korea Institute of Toxicology, inter-lab test was performed with eight organization performing the residual pesticide analysis. We found that there were some different results among them. Some were assessed as questionable or unacceptable for two pesticides and one organization didn't analyze the six pesticides. From these results, this green-pepper analytical reference material containing ten-pesticides could be used as a tool for the proficiency test to improve the reliability or consistency for pesticide residue's results.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.248-254
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• 2012

BACKGROUND: In order to elucidate residual characteristics of difenoconazole and thiamethoxam by treatment to sweet persimmons for one year and to generate the data for the maximum residue limit (MRL) establishment for those pesticides in or on sweet persimmon. METHODS AND RESULTS: Systemic fungicide difenoconazole WP (10% a.i.) and systemic insecticide thiamethoxam WG (10% a.i.) were sprayed onto 12~25-years-old sweet persimmons according to its preharvest interval (PHI), respectively, and then fresh sweet persimmons were harvested at 0, 1, 3, 7, 14, 21 days after treatment from pesticide-sprayed plots at each 3 sites. The analytical methods were evaluated to limit of quantification, linearity, specificity, reproducibility and recoveries. The crop samples were extracted with acetone and performed dichloromethane partition process. The extracted samples of difenoconazole were analyzed by GC-ECD and the thiamethoxam extracted samples were analyzed by HPLC with good sensitivity and selectivity of the method. The average recoveries of difenoconazole ranged from 87.5 to 99.5% with the percentage of coefficient variation in the range 4.1~7.6% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg). And the average recoveries of thiamethoxam and clothianidin ranged from 88.8 to 98.9% and 83.2 to 96.6% with the percentage of coefficient variation in the range 3.6~5.0% and 3.8~9.4% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg), respectively. The residue amounts ranges of difenoconazole were 0.2~0.56 mg/kg and the residue amount was decreased below the MRL level, 1.0 mg/kg, after 1 day harvest. The residue amounts ranges of thiamethoxam were 0.08~0.28 mg/kg and the residue amount was decreased below the MRL level, 0.5 mg/kg, after 1 day harvest. And the residue amount of clothianidin was below then 0.03 mg/kg for only one test site of 14 and 28 day samples. CONCLUSION: As a result, the residual amounts of difenoconazole and thiamethoxam were not exceeded the MRL of established criteria for sweet persimmon. The biological half-lives of difenoconazole and thiamethoxam were 13.6, 19.4, 16.3 and 10.0, 15.3, 14.0 days at each three test sites, respectively.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.1-12
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• 2004

The summer distribution of $Cha-{alpha}$ and physical processes for simulating outbreak region of red tide were estimated by the Eco-Hydrodynamic model in Chinhae Bay. As a result of simulation of surface residual currents, the southward flow come in contact with the northward flow at the inlet and western part of bay in case of windlessness and below wind velocity 2 m/sec. As wind velocity increases, the velocity and direction of currents were fairly shifted. The predicted concentration of $Cha-{alpha}$ exceeded 20 mg/㎥ in Masan and Haengam Bays, and most regions were over 10 mg/㎥, which meant the possibility of red tide outbreak. From the results of the contributed physical processes to $Cha-{alpha}$, accumulation sites were distributed at the northern part of Kadok channel, around the Chilcheon island, the western part of Kajo island and some area of Chindong Bay. On the other hand, inner parts of the study area such as Masan Bay were estimated as the sites of strong algal activities. Masan and Haengam Bay are considered as the initial outbreak region of red tide by the modeling and observed data, and then red tide expanded to other areas such as physical accumulation region and western inner bay, as depending on environmental variation. The increase of wind velocity led to decrease of $Cha-{alpha}$ and enlargement of accumulation region. The variation of intensity of radiation and sunshine duration caused to rapidly fluctuation of $Cha-{alpha}$: however, it was not largely affected by the variation of pollutant loads from the land only.

• Korean Journal of Remote Sensing
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• v.32 no.3
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• pp.307-321
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• 2016

Planetary Boundary Layer Height (PBLH) is a major input parameter for weather forecasting and atmosphere diffusion models. In order to estimate the sub-grid scale variability of PBLH, we need to monitor PBLH data with high spatio-temporal resolution. Accordingly, we introduce a LIdar observation VEhicle (LIVE), and analyze PBLH derived from the lidar loaded in LIVE. PBLH estimated from LIVE shows high correlations with those estimated from both WRF model ($R^2=0.68$) and radiosonde ($R^2=0.72$). However, PBLH from lidar tend to be overestimated in comparison with those from both WRF and radiosonde because lidar appears to detect height of Residual Layer (RL) as PBLH which is overall below near the overlap height (< 300 m). PBLH from lidar with 10 min time resolution shows typical diurnal variation since it grows up after sunrise and reaches the maximum after 2 hours of sun culmination. The average growth rate of PBLH during the analysis period (2014/06/26 ~ 30) is 1.79 (-2.9 ~ 5.7) m $min^{-1}$. In addition, the lidar signal measured from moving LIVE shows that there is very low noise in comparison with that from the stationary observation. The PBLH from LIVE is 1065 m, similar to the value (1150 m) derived from the radiosonde launched at Sokcho. This study suggests that LIVE can observe continuous and reliable PBLH with high resolution in both stationary and mobile systems.

• Progress in Medical Physics
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• v.20 no.2
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• pp.80-87
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• 2009

Phase transformation, superelastic characteristics and variation of surface residual stress were studied for Nitinol shape memory alloy through application of UNSM technology, and life extension methods of stent were also studied by using elastic resilience and corrosion resistance. Nitinol wire of ${\phi}1.778$ mm showed similar surface roughness before and after UNSM treatment, but drawing traces and micro defects were all removed by UNSM treatment. It also changed the surface residual stress from tensile to compressive values, and XRD result showed less intensive austenite peak and clear martensite and additional R-phase peaks after UNSM treatment. Fatigue resistance could be greatly improved through removal of surface defects and rearrangement of surface residual stress from tensile to compressive state, and development of surface modification system to improve not only bio-compatability but also resistance to corrosion and wear will make it possible to develop vascular stent which can be used for circulating system diseases which run first cause of death of recent Koreans.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.81-87
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• 2015

The present study was aimed to predict the pre-harvest residue limits (PHRLs) of pyrimethanil (fungicide) and methoxyfenozide (insecticide) in grape, and to estimate their biological half-lives and residual characteristics. The pesticides were sprayed once on grape in two different fields 10 days before harvest. At the end of 0, 1, 2, 3, 5, 7 and 10 days after application, samples were harvested for further analysis. The residual pesticides were extracted with acetonitrile and partitioned with dichloromethane, and the high-performance liquid chromatography with diode array detector (HPLC/DAD) was employed for the residue analysis. The results obtained in the present study show that the limit of detection of both pesticides were found to be $0.01mg\;kg^{-1}$. The recoveries of these pesticides were ranged between 80.6% and 102.5% with coefficient of variation lower than 10%. The biological half-lives of both pesticides were observed in field 1 and field 2 which shows 7.7 and 7.4 days for pyrimethanil and 5.1 and 6.1 days for methoxyfenozide, respectively. Further, the PHRL of pyrimethanil and methoxyfenozide was found to be $8.90mg\;kg^{-1}$ and $5.51mg\;kg^{-1}$, respectively at 10 days before harvest. Consequently, the present study suggests that the residual amounts of both pesticides will be lower than the maximum residue limits (MRLs) when grape is harvested.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.57-62
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• 2017

BACKGROUND: Pesticide residue analysis is essentially required for safety evaluation of agricultural products. Bistrifluron and chlorantraniliprole have been currently considered as potentials to deeply evaluate their residues in agricultural products because they are frequently found in strawberry. This work was performed to investigate the residual patterns of bistrifluron and chlorantraniliprole in strawberry after harvest. METHODS AND RESULTS: Strawberry was treated with bistrifluron and chlorantraniliprole 0, 1, 2, 3, 5, 7 and 10 days before harvest under greenhouse conditions. The strawberry samples were subjected to solvent and solid phase extractions followed by LC-MS/MS analysis. There covery percentages of bistrifluron and chlorantraniliprole for tified in the control samples ranged from approximately 82 to 103% with the method limit of 0.005 mg/kg. The concentrations of bistrifluron and chlorantraniliprole in strawberry samples decreased significantly in 10 days after treatment, giving the safety levels of 0.04 to 0.06 mg/kg at 10 days after application, as considered maximum residue limit. The half-lives of bistrifluron and chlorantraniliprole based on first order kinetics were determined to 6.3 days and 6.4 days, respectively. CONCLUSION: Bistrifluron and chlorantraniliprole are suggested to use in strawberry 10 days before harvest to reach residual safety levels.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.205-211
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• 2000

This study was conducted to evaluate the residual effects of basic oxygen furnace (BOF) slag applied in rice paddy fields as soil conditioner one year before. The experimental fields of Lim et al. (2000) located in Youjung and Nampyung were used for this purpose. Both variety (Oryza sativa L. cv. Dongjinbyeo) and cultural practices were the same as those in Lim et al. (2000). Soil chemical properties, plant height, number of tillers per plant, yield and yield components were observed. The temporal variation of treatment mean value in soil chemical properties appeared to be similar trends in both Youjung and Nampyung experimental fields. Soil pH and Ca content were still significantly higher than those in control treatment up to July of the second season, but decreased progressively as time passed. However, the effects lasted longer as slag rate became higher. BOF slag seems to have residual effects as a soil conditioner or Ca fertilizer in soil for two years. BOF slag rate of $4Mg\;ha^{-1}$ raised soil pH almost the same as lime rate of $2Mg\;ha^{-1}$. Content of $SiO_2$ in soil applied slag appeared to be higher compared with control. Fe and Mg content in soil with slag treatment was significantly higher than that of control in 1997, but it was almost the same level as that of control in 1998. In YouJung experimental field, rough rice yield of slag teatment became higher as slage rate incresed. Slag rate of $12Mg\;ha^{-1}$ showed the highest rough rice yield of $5,400kg\;ha^{-1}$ among treatment, which was 14% higher than that of control with $4,720kg\;ha^{-1}$. Slag rate of $12Mg\;ha^{-1}$ showed relatively higher plant height and higher number of tillers at the early growth stage compared with other treatments. In NamPyung experimental field, rough rice yield was the highest at the plot of lime rate $2Mg\;ha^{-1}$ and became higher as slag rate increased. There were no significant differences in rough rice yield between lime treatment and slag treatments. Slag rate of $12Mg\;ha^{-1}$ showed the highest rough rice yield of $7,170kg\;ha^{-1}$ among slag treatment, which was 8% significantly higher than that of control with $6,670kg\;ha^{-1}$. Slag rate of $12Mg\;ha^{-1}$ showed relatively slower growth in plant height at the early growth stage, but superior growth at the later growth stage, and significantly higher number of spiklets per panicle and 1000-grain weight than that of control.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.194-200
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• 2009

Purpose: This aim of this study was to evaluate changes in gastric volume and organ position as a result of delayed gastric emptying after a subtotal gastrectomy performed as part of the treatment of stomach cancer. Materials and Methods: The medical records of 32 patients who underwent concurrent chemoradiotherapy after a subtotal gastrectomy from March 2005 to December 2008 were reviewed. Of these, 5 patients that had more than 50 cc of residual gastric food detected at computed tomography (CT) simulation, were retrospectively enrolled in this study. Gastric volume and organ location was measured from CT images obtained before radiotherapy, twice weekly. In addition, authors evaluated the change of radiation dose distribution to planning the target volume and normal organ in a constant radiation therapy plan regardless of gastric volume variation. Results: A variation in the gastric volume was observed during the radiotherapy period (64.2~340.8 cc; mean, 188.2 cc). According to the change in gastric volume, the location of the left kidney was shifted up to 0.7 - 2.2 cm (mean, 1.2 cm) in the z-axis. Under-dose to planning target volume (V43, 79.5${\pm}$10.4%) and over-dose to left kidney (V20, 34.1${\pm}$12.1%; Mean dose, 23.5${\pm}$8.3 Gy) was expected, given that gastric volume change due to delayed gastric emptying wasn't taken into account. Conclusion: This study has shown that a great change in gastric volume and left kidney location may occur during the radiation therapy period following a subtotal gastrectomy, as a result of delayed gastric emptying. Detection of patients who experienced delayed gastric emptying and the application of gastric volume variation to radiation therapy planning will be very important.

• Korean Journal of Environmental Agriculture
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• v.15 no.1
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• pp.1-10
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• 1996

The contents of heavy metals in soil near the Janghang smelter area were observed to understand present status and relationship between their fraction and the absorption by rice. The soil samples were taken from the eight sites of the paddy fields in 1982 and 1990, and analysis on heavy metals including Cd, Zn, Cu and Pb was performed. The results were as follows: Total contents of heavy metals in the samples of 1990 were higher than those of 1982. The order of increasing ratio was Cu > Zn > Pb > Cd and the variation of Cd content by sequential differente extracting was residual > exchangeable > dilute acid-extractable fractions and its increasing range was from 38 to 71% during nine years. The ratio of immobile heavy metals bound within an oxide or silicate matrix of Fe-Mn oxide bound and residual in surface soil was that Cd, Pb, Cu and Zn were 31.65, 42.22, 76.57 and 79.49%, respectively, and their mobile ratios of exchangeable, dilute acid-extractable and organically bound were more than 20.28%. Those of mobile Cd, Pb, Cu and Zn were 68.35, 55.78, 23.43 and 20.28%, respectively. Correlation between the heavy metal contents in surface soil and those in tissue of rice plant, such as leaf blade, leaf sheath, stem and panicle axis, were significant, but were not significant in subsurface soil. The dilute acid-extractable and organically bound fractions of Cd, Cu, Pb and Zn in surface soil were more significantly correlated with those in tissues of paddy rice.