• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.269-276
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• 2001

Several experiments including persistence, distribution, leaching, and terminal residue trials were carried out to investigate the behavior of cyclosulfamuron in rice paddies. Cyclosulfamuron was gradually dissipated in two different soils showing the first-order kinetics. Half-lives of the herbicide were calculated to be $17{\sim}30$ and $14{\sim}16$ days under field and laboratory conditions, respectively. In the paddy soil/water system, the residue tended to reside more in the soil phase as time elapsed. Cyclosulfamuron was less persistent in paddy water than in soil with half-lives of 10 and 19 days, respectively. No cyclosulfamuron was leached below 20 cm-deep soil during water percolation with 50 cm hydraulic head, while some downward mobility was observed within the soil column. When EC and SC formulations of cyclosulfamuron were applied to the paddy field at 120 or 150-day pre-harvest intervals, its terminal residues in hulled rice were all less than 0.01 mg/kg, irrespective of formulation type and application timing. In rice straw, however, some residues were found at $<0.02{\sim}0.05$ mg/kg as SC formulation was applied. Rapid dissipation, restricted mobility, and low terminal residues of cyclosulfamuron in rice paddies suggest that no significant residues would be transported or carried over to the non-target environment.

• Economic and Environmental Geology
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• v.22 no.4
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• pp.381-393
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• 1989

Hydrogeological modelling was performed to evaluate groundwater flow system in Igsan Area. The study area extends over $790km^2$. The geology consists of Jurassic Daebo granite and gneissose granite and Precambrian metamorphic rocks. The capability of pumping yield is the highest in gneissose granite region among them due to comparatively thick weathered zone with thickness ranging from 10m to 25m. The Colorado State University Finite Difference Model was used for the model simulation. The model was divided into 28 rows and 31 columns with variable grid spacing. The model was calibrated under steady-state and unsteady-state conditions. In the steady-state simulation, the model results were compared with measured water table contours in September 1985 with determining hydraulic conductivities and net recharge rates during rainy season. Unsteady state simulation was done to know the aquifer response due to groundwater abstraction. The non- steady state calibration was conducted to determine the distribution and magnitudes of specific yields and discharge/recharge rates during dry season as matching water level altitudes in May 1986. The calibrated model was used to simulate water level vaiation caused by groundwater withdrawal and natural recharge from 1 October, 1985 until 30 September, 1995. The calibrated model can be used to groundwater development schemes on regional groundwater levels, but it cannot be used to simulate local groundwater level change at a specific site.

• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.6-12
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• 1992

To study the effects of irrigation on the mulberry, 3 experiments were conducted. In experiment 1, four treatments, conventional (no irregation), drip irrigation, fertigation and fertigation with 20% extra fertilizer were examined. Irrigation hose was hurried at 20cm depth under the surface (Experiment 1). Water potential was controled at 0.1, 0.2, 0.5 and 1.0 bar to understand the optimum irrigation potential under rain-block system with plastic film hose(experiment 2). Five leading mulberry varieties, Cheongilppong, Youngcheonppong, Suseongppong, Kaeryangppong and Shinilppong were examined for irrigation response(experiment 3). Fertigation and fertigation with extra fefilizer increased yield by 22%, repectively compared with conventional. Irrigation increased by 8%, but with no significance statistically compared with the conventional. Irrigation, especially fertigation increased water content, P$_2$O$_{5}$, $K_2$O and CaO in leaves, suggested improving leaf quality in fall. Fertigation increased available P$_2$O$_{5}$ content in the sub-soil. More root distribution showed at the sub-soil in fertigation. Weed did not occured in fertigation due to sub-soil fertilization, whereas the conventional received surface fertilization showed 931kg/10 a weed in fresh weight. No effect showed at the 20% extra fertilizer than the conventional amount Maximun yield showed at the 0.5 bar water potential. Irrigation increased yield by 22-25% with Cheongilppong and Yongcheonppong, and by 9-13% with Suseongppong, Shinilppong and Kaeryangppong.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.2
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• pp.133-139
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• 2014

Oil-in-water nanoemulsions were prepared in the system of water/Span 80-Tween 80/long-chain paraffin oil via the PIC (phase inversion composition) method. With the increase of preparation temperature from $30^{\circ}C$ to $80^{\circ}C$, the diameter of emulsion droplets decreased from 120 nm to 40 nm, proving the formation of nanoemulsions. By varying the HLB (hydrophilic lipophilic balance) of mixed surfactants, we found that there was an optimum HLB around 12.0 ~ 13.0 corresponding to the minimum droplet size. The viscosity of nanoemulsions clearly increased with droplet volume fraction, f, but the droplet size slightly increased. Significantly, at ${\phi}{\leq}0.3$, the size distribution of nanoemulsions kept constant more than 2 months. These results proved that the viscous paraffin oil can hardly be dispersed by the PIC method at $30^{\circ}C$, but the increase in preparation temperature makes it possible for producing monodisperse nanoemulsions. Once the nanoemulsion is produced, the stability against Ostwald ripening is outstanding due to the extremely low solubility of the liquid paraffin oil in the continuous phase. The highly stable nanoemulsions are of great importance in cosmetic applications.

• Journal of Korean Public Health Nursing
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• v.2 no.2
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• pp.45-61
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• 1988

Clonorchiasis should be realized as an important public health problems in Korea by their wide distribution, high prevalence rate and heavy infection intensity. This study was designed to obtain the infection rate, contributing factors as well as the behavior of infected persons among the factory workers in Pohang area where that parasite still remains as a problem. Study was undertaken from September '86 to October '87. Clonorchiasis skin test was performed for 3180 factory workers, and stools of skin test positive reactors were examined. Praziquantel was prescribed to stool examination positive persons for clonorchis sinensis ova. After one year. stool examination was repeated for them who received medicine. At the same time. a structured questionnaire was given and the results were analyzed and compared with control group. The results of this study are summarized as follows; 1. The infection rate of Clonorchis sinensis. 1) Clonorchiassis skin test positive rate was $26.2\%$ (834/3180). 2) Stool(Clonorchis sinensis ova) positive rate among skin test positive reactors was $21.6\%$ (129/598) All 129 infected persons were male. 2. Contributing factors of Clonorchis sinensis infection. 1) The chance of infection was higher in low-educated peple(p<0.01) 2) Stool(Clonorchis sinensis ova)positive rate was higher among the persons who reside near the riverside now(p<0.01), or among the persons who long history of riverside residence(p<0.01) 3) The infection rate was higher in thoes who like sliced raw fresh water fishes than in those who like cooked fishes(p<0.05). 4) Correct answering rate for questions about the cause and route of Clonorchis sinensis infection was low in infected persons. 5) The infection rate was lower among those who had experience of previous clonorchiasis test(p<0.01). 6) Family members of infected persons show higher rates of infection(p <0.01). 3. Treatment effect and compliance of infected person to treatment. 1) After one year, negative stool conversion rate was $85.4\%$. 2) $70.8\%$ of infected persons took the medicine; Only $3.1\%$ of them consulted to physician to know the medication effect; As many as $29.4\%$ of them continued to consume raw fresh water fishes. As a conclusion, City of Pohang area, Hyung San River in the center, is an endemic area of clonorchiasis. Current clonorchiasis control system seemed to be ineffective; many of the skin test positive group did not submitted their stool for examination; only $70.8\%$ of infected persons took the medicine even though the drugs were given free of charge; $29.4\%$ continued to consume raw fresh water fishes after taking medicine. Therefore. proper education program should be provided to improve the compliance to treatment. Follow-up for infected cases is mandatory to prevent waste of restricted budget.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.616-621
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• 2017

The objective of this study was to investigate the physicochemical properties of domestic strong wheat flour (DSWF). Three commercial DSWFs (D1, D2, and D3) were compared with imported strong wheat flour (ISWF). DSWFs had higher moisture content, crude protein content, lightness, and whiteness than ISWF. DSWFs showed lower solvent retention capacity and water absorption index than ISWF. DSWFs also showed significantly higher water solubility index than ISWF (P<0.05). Setback values by rapid visco analysis were significantly higher in D1 and D2 than in ISWF and D3, which means ISWF and D3 were better in retarding retrogradation. Differential scanning calorimetry results showed that ISWF required 6.2 J/g of energy for phase transition, whereas DSWFs needed 6.67~7.13 J/g. The farinograph results showed that ISWF had higher water absorption, longer dough stability time, and significantly higher softening of dough at 20 min than DSWF (P<0.05). Dough resistance and extensibility were higher in ISWF than in DSWFs.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.3
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• pp.23-35
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• 2012

The optimum location of the prehistoric sites of Ulsan Metropolitan City are investigated by both quantile and natural breaks methods through GIS, and the settlement pattern is studied based on the possibility of presence of the prehistoric sites which are also analyzed with these methods. Such factors including elevation, slope, distance from the nearest water, aspect, geological features, soil drainage classes, subsoil and land use recommended are employed in the analysis. The optimum geographical environment is the place where it includes the water-base in the area that is the southern aspect of the gentle slope land of lowland. The geology is the Quaternary alluvium. The drainage class is fine and the deep soil saturn is the fine loamy soil and the recommendation of land use is the area that is the field. As a result of the forecast of distribution, the prehistoric sites showed the higher possibility of presence in the downstream region where the Taehwa river and Dongcheon river join because the region come close to the watercourse and the drinking water use is easy. And the aspect and elevation is the low area. The alluvium accumulated from the upper stream of the Taehwa river and Dongheon river was made roomily, the area where is suitable for the farming life. Therefore, this region is judged that the possibility of presence of the prehistoric sites is high.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.195-209
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• 2003

Spatial-Stochastic Neural Networks Model(SSNNM) is used to estimate long-term streamflow in the parallel reservoir groups. SSNNM employs two kinds of backpropagation algorithms, based on LMBP and BFGS-QNBP separately. SSNNM has three layers, input, hidden, and output layer, in the structure and network configuration consists of 8-8-2 nodes one by one. Nodes in input layer are composed of streamflow, precipitation, pan evaporation, and temperature with the monthly average values collected from Andong and Imha reservoir. But some temporal differences apparently exist in their time series. For the SSNNM training procedure, the training sets in input layer are generated by the PARMA(1,1) stochastic model and they covers insufficient time series. Generated data series are used to train SSNNM and the model parameters, optimal connection weights and biases, are estimated during training procedure. They are applied to evaluate model validation using observed data sets. In this study, the new approaches give outstanding results by the comparison of statistical analysis and hydrographs in the model validation. SSNNM will help to manage and control water distribution and give basic data to develop long-term coupled operation system in parallel reservoir groups of the Upper Nakdong River.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.1
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• pp.45-50
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• 2009

By Laser Through-Silicon-Via process, debris and particles occur when you are forming. Therefore the research of TSV cleaning become important to remove those particles and debris. Both chemical cleaning method that uses a surfactant and physical cleaning method that uses a brush were studied with the via of $30{\mu}m$ diameter and $100{\mu}m$ depth on the 8 inch CMOS Image Sensor wafer. On the DI water and a surfactant in mixture ratio of 2:1, debris show $73{\mu}m^2$ per $0.054mm^2$. Cleaning is superior by lower mixture ratio of DI water and surfactant. In addition, It is less than 5% of debris distribution in the laser condition changed by Laser's frequency and its speed and cleaning had no effect. In the physical cleaning, there are no crack and damage when the system condition is set by $1000{\sim}3000rpm$ strip, $50{\sim}3000rpm$ rinsing, and $200{\sim}300rpm$ brushing Therefore, debris and particles can be removed by enforced chemical method and physical method.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.57-65
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• 2014

Spatial and temporal distributions of zooplankton were measured in an oligotrophic pumped storage-type hydroelectric reservoir which was composed of two reservoirs exchanging water daily, with water going up at night and going down during the day. Repetitive diel disturbance of the water column can be a unique feature of this reservoir system. Chl-${\alpha}$ concentration was highest in the early winter season. Phytoplankton density was lower in summer monsoon due to high flushing rate on rainy days. The zooplankton density was higher in the smaller upper reservoir possibly due to lower fish density in the upper reservoir. In the seasonal variation a time gap was observed between the phytoplankton bloom and the zooplankton bloom (particularly a rotifer, Keratella cochlearis). It is likely to that Keratella production is partially supported by heterotrophic food sources than phytoplankton. The dominance of a mixotrophic dinoflagellate (Peridinium bipes f. ocultatum) might have complicated the trophic relationship between phytoplankton and zooplankton. Our results provide some ecological information of zooplankton community in a highly disturbed alpine reservoir ecosystem relying on mostly allochthonous organic matter.