• The Korean Journal of Pesticide Science
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• v.13 no.2
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• pp.98-104
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• 2009

This study was carried out to investigate the residue patterns of two neonicotinoid insecticides, dinotefuran and thiacloprid, commonly used for cucumber, were subjected to indicate a residual characteristic under greenhouse conditions. The pesticides were sprayed onto the crop at recommended and double doses 7 days before harvest and then sampling was done 0, 2, 3, 5, and 7 days after spraying. The amounts of their residues in the crop were analyzed with an HPLC. Their detection limits were 0.01 mg/kg for dinotefuran and 0.005 mg/kg for thiacloprid. Mean recoveries of dinotefuran and thiacloprid were from 85.78 to 89.52 and from 85.71 to 95.31%, respectively. Half-lives of dinotefuran and thiacloprid were 2.8 and 1.8 days at the recommended dose and 2.8 and 1.5 days at the doubled dose, respectively. The ratios of the EDI to ADI by intake the crop harvested 7 days after spraying were less than 0.1% of their ADIs.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.3
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• pp.201-209
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• 2004

Important operation parameters and performance of a high temperature ceramic candle filter system were evaluated through a series of demonstration tests at a pilot-scale vitrification plant. At the initial period of each test, due to the growth of dust cake on the surface of ceramic candles, the pressure drop across the filter media increased sharply. After that it became stable to a certain range and varied continuously proportion to the face velocity of off-gas. On the contrary, at the initial period of each test, the permeability of filter element decreased rapidly and then it became stable. Back flushing of the filter system was effective under the back flushing air pressure range of 3∼5 bar. Based on the dust concentrations measured by iso-kinetic dust sampling at the inlet and outlet point of HTF, the dust collection efficiency of HTF evaluated. The result met the designed performance value of 99.9%. During the demonstration tests including a hundred hour long test, no specific failure or problem affecting the performance of HTF system were observed.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.232-237
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• 1997

Soybean plants inoculated Bradrhizobium japonicum MN 110 were grown in outdoor perlite pots with nitrogen free nutrient solution containing 1.0 mM-P(control) and 0.05 mM-P(stress) and harvested at 28, 35, 42 and 49 days after transplanting (DAT) to examine the effect of phosphorus deficiency on ureide concentration of and distribution to diffrent plant organ in nitrogen fixing soybean plant during the vegetative growth. Total dry mass of control plants increased 8.9 fold and that of phosphorus deficient plant increased 2.7 fold during the experimental period. Phosphorus deficiency reduced total phosphorus and nitrogen accumulation by 80%,40% respectively, at 28 DAT and 93%, 84%, respectively, at 49 DAT. Nitrogen concentration was reduced by phosphorus deficiency in all tissues with leaf and stem tissues affected to a greater degree than nodule and root tissues at every sampling date. Phosphorus deficiency significantly reduced soluble reduced-N and ureide-N concentration in leaf and stem but did not affect those in root. The proportion of soluble reduced-N in leaf was reduced from 60% to 50% but increased from 10% to 20% in the roots. The proportion of ureide-N in leaf of control plants was higher than that in phosphorus deficient plants, whereas, roots of phosphorus deficient plants contained a higher propotion of ureide-N than those of control plants. These indicated that phosphorus deficiency not only inhibit nitrogen fixation of nodules but also restrict the translocation of fixed nitrogen out of the root system into the xylem.(Received April 4, 1997; accepted May 2, 1997)

• The Journal of Engineering Geology
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• v.15 no.1
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• pp.29-39
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• 2005

For detecting a ground contamination survey, soil sampling method have been used a drilling or coring technique in general. However these methods are very difficult to systematically real-time monitoring of variation of contamination degree in field. ]'n this research frequency Domain Reflectometry (FDR) system was suggested and carried out to experimental approaches for determination of oil contamination on surface and underground. Experimental method using FDR method was discussed with feasibility of measurement in the laboratory column test. It is determined to degree of oil contamination due to response of dielectric constant re-lated with volumetric water content(θ/sub w/) and volumetric oil content( θ/sub al/ ) of saturated and unsaturated soil media. And physical properties such as effective porosity and oil residual ratio of saturated soil media were also measured through real-time monitoring works using installed FDR measurement sensors, which are defected characteristics of oil movement in the saturated soil media under the soil column tests. In the results of these experiments, a range of effective porosity was estimated to about 0.35 compared with initial porosity 0.40 of manufactured saturated soil media, which is also calculated to about 87.5% to the ratio of initial porosity to effective porosity. Finally oil residual ratio which is compared with volumetric water content and volumetric oil content was calculated about 62.5%.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.86-93
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• 2013

We monitored 32 wetlands in order to investigate the influence of aquatic plants on zooplankton density and diversity in the littoral zone in Gyeongsangnam-do from May to June in 2011. A total of 65 zooplankton species were identified in the study sites. Among them, the diversity of epiphytic zooplankton were higher (40 species) than planktonic zooplankton. Littoral zones of all wetlands were covered by various aquatic plants, and influenced the epiphytic zooplankton assemblages. Based on the data from $1{\times}1$ (m) quadrat sampling, epiphytic and planktonic rotifer density showed no significant relationships with macrophyte cover. However, the epiphytic cladocerans density significantly increased under high aquatic plant cover ($r^2=0.39$, p<0.05, n=32). Types of aquatic plants strongly influenced epiphytic zooplankton density. Upo and Jangcheok are locations which have well developed Phragmites communis and Ceratophyllum demersum communities in the littoral zone, and a higher density of epiphytic zooplankton was recorded on the surface of C. demersum. Especially, rotifers such as Lepadella, Monostyla and Testudinella showed obvious differences (One-way ANOVA, p<0.05 for all three species). This result suggests that epiphytic zooplankton have a substrate preference for larger surface areas, likely for adherence, on C. dimersum. In conclusion, the complex structure of the littoral plant community is expected to provide diverse refuge and microhabitats to epiphytic zooplankton.

• Health Policy and Management
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• v.22 no.1
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• pp.29-48
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• 2012

The purpose of this study is to analyze medical expenses by decedents in their last year of life and compare them with those by survivors during the year 2008. This study is conducted firstly in Korea, except some studies focusing on medical cost of decedents from specific diseases. To study this, national health insurance(NHI) claims data was used with medicaid claims data. The study group(decedents) was selected from the insurance entitlement file who were dropped out from January to December of 2008. The control group(survivors) was selected from the entitlement file by stratified sampling with keeping age-sex composition of the study group. The medical expenses of decedents during one year before death were measured and compared with those of survivors by sex and age. And the medical expenses were analyzed by causes of death, and also the expenses were examined by each item of medical services. On average, the medical expense amounted to 11 million Korean Won per decedent during their last year of life in 2008. The medical expense per decedent was 9.3 higher than that of survivor. The death-related expense of under the age 35 was about 16 million Won, compared with 4 million Won in the case of over the age 95, in average. The death-related expense is higher in younger ages. This means that more medical resources are put in to save life in younger ages. Total death-related expenditure took 8.3 percent in total NHI expenditures. Of the death-related medical expenses, the largest one was injection-related cost which shares twenty five percent, and the second largest one was hospitalization charges, and then the third one was surgery cost. The results of this study suggested that we should pay attention to the medical expenses in the last of year of life when we study health care expenditure in Korea. In addition, we have to deliberate health care policy to cope with medical expenditures before death in more efficient way.

• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.271-284
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• 2014

The objectives of this research were to analyse the microhabitat of Cobitis choii which is designated as an endangered fish species (I) and national monument species in Korea (No. 454), and provide valuable information of suitable replacement habitat in the future for a conservation of the population with rapid decreases by environmental pollution. Sampling and microhabitat analysis in three streams such as Baekgok, Yugu and Gap Stream, known as one of the least habitats in Korea showed that the mean number of Cobitis choii observed was 2.6. This result indicated that the richness was too low, so the species conservation was very urgent. Optimal physical microhabitat of the population was determined as environmental conditions with > 60% sand with 1 mm particle size, optimal water depth of 20 - 60 cm in the habitats, and the optimal current velocity of < 0.4 m/s. Under the circumstances of the microhabitat, optimal water volume (discharge) was 0 - 2 m3/s in the each sectional analysis and this reach was mainly composed of the stream section with intermittant slow runs and pools. These microhabitats were largely disturbed by physical modifications of habitat and chemical pollutions due to direct influences of nutrient-rich water inputs from the urban area and intensive agricultural pollutants. For these reasons, optimal habitat replacement are required in the future for the conservation of the species.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.149-154
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• 2012

The adsorption and desorption behavior of biofilter-medium was investigated on the performance of an adsorption column. Continuous flow-isothermal adsorption experiments were performed to treat waste air containing such a VOC as ethanol under the same condition of > 90% relative humidity as the condition of the feed to a biofilter process. In case of feeding waste air containing ethanol of 1,000 ppmv (or 2,050 mg ethanol/$m^3$) to the adsorption system at the rate of 2 L/min, the onsets of its breakthrough and reaching the state of dynamic equilibrium at the exit had been delayed 10 and 3 times, respectively, later than those at the 1st stage sampling port. Moreover, in case of 2,000 ppmv (or 4,100 mg ethanol/$m^3$), they had been delayed 9 and 3 times, respectively. Thus, regardless of feeding concentration, the ratios of delaying period were observed to be quite consistent each other at the exit of the adsorption column. With regard to the period of desorption, the ratios of delaying period were consistent each other to be 1.5 for both cases. In addition, the effect of microbial activity and sterilization-process was studied on adsorption equilibrium. The ethanol concentration in the vapor phase of vials packed with sterilized granular activated carbon (GAC) was quite consistent to that with unsterilized GAC. However, the ethanol concentrations in the vapor phase of vials packed with unsterilized compost and the unsterilized mixture of GAC and compost were higher than those with sterilized compost and the sterilized mixture of GAC and compost, respectively.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.238-245
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• 2013

The purpose of this study was to examine the influence of the self-control of dental hygiene students on their stress and stress-coping style. The subjects in this study were dental hygiene students who were selected by convenience sampling from three different colleges. After data were gathered, the answer sheets from 561 respondents were analyzed. The findings of the study were as follows: 1. Concerning the level of self-control, the dental hygiene students got a mean of 3.22. As to self-control by grade, the juniors got the highest scores of 3.27 (p<0.05), and those who were under heavier stress were poorer at self-control (p<0.05). 2. In regard to stress-coping style, they got a mean of 3.28 and 3.34 in active coping and passive coping respectively. Passive coping was more prevailing, and the students whose economic status was higher made more use of active coping styles (p<0.001). There were statistically significant differences in active coping styles according to stress level (p<0.01) and the effect of stress on health (p<0.05). 3. Better self-control led to more frequent use of active coping styles. The above-mentioned findings imply that self-control is one of factors to affect stress coping. Therefore the development of counseling programs is required to step up the improvement of self-control.

• Journal of the Korean Dietetic Association
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• v.10 no.2
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• pp.235-245
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• 2004

The Korea School Lunch Program mandates that school meals should safeguard the health and well-being of our children. School meals provide a nutritious diet that contains at least ⅓ of the daily Recommended Dietary Allowances of necessary nutrients at reasonable prices. This study was performed to assess the nutritional management of primary school meals, and to provide basic data for improvement of school meal nutritional guidelines. Three hundred and thirty six dietitians who worked at primary schools were recruited using a stratified sampling method. A survey was done by e-mail with a set of questionnaires about nutritional meal management. During school lunch planning, dietitians referred nutrition standards with priority, followed by students' food preferences and food hygiene. They considered energy as a most important nutrient during primary school lunch planning, followed by protein and calcium. Protein is usually over-served, whereas iron, vitamin A and calcium are usually under-served during primary school meal planning. For first and second grade primary students, grains, meat and vegetable side dishes seemed to be large compared to their eating capacity. Over 92% of school dietitians agreed the needs of food group standards for primary school lunch program. For making a checklist of the school lunch program, energy, protein and calcium were highly recommended, and meat.fish.egg group, vegetable.fruit group and dairy group were also highly recommended by school dietitians. Cooking method was also highly recommended. School dietitians proposed that remodeling of school kitchens and new cooking machine were the most important factors for improving school lunch system. These results suggest that food standards should be established for health-oriented nutritional management of primary school lunch programs. Nutritional checklists could include nutrient-rich foods and food groups, and items about cooking methods.