• Journal of Environmental Health Sciences
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• v.13 no.1
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• pp.7-16
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• 1987

A study was carried out to determine the adequacy of springs as drinking water in summer and in winter separately. In this study, environmental sanitation, physio-chemical examination, bacteriologic contamination and the content of heavy metal were included. For this study, samples were collected from 8 springs which were located in the suburbs of Chunchon city. The following results were obtained. 1. There was the covering system in 1 out of 8 springs. 6 out of 8 springs showed contaminating source within lorn. 2. In physio-chemical test, six out of 8 springs were found to be unsafe for the legitimate standard of safty water. 3. Bateriologic examination clone during summer showed the evidence of coilform group at 7 out of 8 springs and during winter showed positivity at 3 out of 8 springs. 4. In the study for heavy metal content, all places showed high iron level beyond the standard level of salty water, and 4 places showed high contents of fluorine, mangan and lead.

• Economic and Environmental Geology
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• v.29 no.5
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• pp.589-595
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• 1996

The concentration of radioactive elements was measured from the groundwater samples of Taejeon Area. U and Rn concentrations of very high level were detected from many places, especially around Yusung. These levels are much higher than the concentration standards for the drinking water proposed by the United States Environmental Protection Agency. However, in Korea, there are no standard levels for the radioactive elements in drinking water yet. We think that it is necessary to provide such standards as soon as possible, and that the determination of radioactive elements in groundwater should be included in the routine analysis items for the drinking water quality, because many people currently use such relatively high level radioactive groundwater as their drinking water, especially around Yusung area.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.268-273
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• 2013

This study aims to investigate contamination level and effective clinical disinfection methods of dental air/water syringes (AWS) by using microbial incubation. This study used AWS of ten dental unit chairs of Hospital. Total 180 samples were obtained. There are six groups of samples: non-sterilized (group 1), sanitized with wet-gauze (group 2), sanitized with 78% ethanol sponge for 10 seconds (group 3), sanitized with 78% ethanol sponge for 20 seconds (group 4), sanitized with 1 : 100 diluted High Level Disinfectant$^{(R)}$ (group 5), autoclaved (group 6). Group 1 and 2 showed statistically significant level of CFUs than Group 4, 5 and 6 (p < 0.05). Group 4, 5 and 6 did not show any noticeable CFU. Sanitizing AWS tips with ethanol and High level Disinfectant$^{(R)}$ proves to be a useful and practical method for preventing cross-infections.

• Geomechanics and Engineering
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• v.29 no.6
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• pp.683-696
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• 2022

Dams are inevitably planned to be built on thick overburden with high permeability and deformability. The connection part between concrete cut-off wall in overburden and earth core in dam body is not only a key part of the anti-seepage system, but also a weak position. Large uneven settlement will be aroused at the concoction part. However, the interaction behavior and the scope of the connection part cannot be determined effectively. In this paper, numerical analysis of a high earth core dam built on thick overburden was carried out with large deformation FE method. The mechanical behavior of the connection part was detail studied. It can be drawn that there is little differences in dam integral deformation for different analysis method, but big differences were found at the connection part. The large deformation analysis method can reasonably describe the process that concrete wall penetrates into soil. The high plasticity clay has stronger ability to adapt to large uneven deformation which can reduce stress level, and stress state of concrete wall is also improved. The scope of high plasticity clay zone in the connection part can be determined according to stress level of soils and penetration depth of concrete wall.

• Journal of the Korean Magnetics Society
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• v.21 no.1
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• pp.32-36
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• 2011

We fabricated a sensor for measuring the water level and water temperature using GMR-SV (giant magnetoresistance-spin valve) device, simultaneously. It could be applied to the medical cooling system of the potassium titanylphosphate KTP) laser system for the therapy of a benign prostatic hyperplasia. The middle point of GMR-SV device was set to the near position of a high magnetic sensitivity with 2.8%/Oe. The sensitivity for the water level and water temperature of the fabricated sensor were $400\;m{\Omega}/mm$ and $100\;m{\Omega}/^{\circ}C$, respectively.

• Journal of Environmental Science International
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• v.21 no.8
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• pp.965-975
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• 2012

Loading of NPS pollutant was valued through simulation by using BASINS/HSPF model which can simulate runoff volume in rainfall by time. For the verification of the model, it was analyzed the scatter diagram of the simulation value and measure value of water quality and runoff volume in Dongcheon estuary. Using the built model, a study on the time-variant characteristics of runoff and water quality was simulated by being classified into four cases. The result showed the simulation value was nearly same as that of the measured runoff. In the result of fit level test for measured value and simulated value, correlation of runoff volume was computed high by average 0.86 and in the water quality items, fit level of simulation and measurements was high by BOD 0.82, T-N 0.85 and T-P 0.79.

• Proceedings of the KSRS Conference
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• v.1
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• pp.25-28
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• 2006

We propose a new method of masking cloud-affected pixels in satellite ocean color imageries such as of GLI. Those pixels, mostly found around cloud pixels or in scattered cloud area, have anomalous features in either in chlorophyll-a estimate or in water reflectance. This artifact is most likely caused by residual error of inter-band registration correction. Our method is to check the pixel-wise 'soundness' of the spectral water reflectance Rw retrieved after the atmospheric correction. First, we define two spectral ratio between water reflectance, IRR1 and IRR2, each defined as RW(B1)/RW (B3) RW (B3) and as RW (B2)/RW(B4) respectively, where $B1{\sim}B4$ stand for 4 consecutive visible bands. We show that an almost linear relation holds over log-scaled IRR1 and IRR2 for shipmeasured RW data of SeaBAM in situ data set and for GLI cloud-free Level 2 sub-scenes. The method we propose is to utilize this nature, identifying those pixels that show significant discrepancy from that relationship. We apply this method to ADEOS-II/GLI ocean color data to evaluate the performance over Level-2 data, which includes different water types such as case 1, turbid case 2 and coccolithophore bloom waters.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.569-575
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• 2008

The principal objective of this study was to determine the appropriate water content for optimal texture in high omega-3 fatty acid saury nuggets. The approach adopted in this study essentially involved variations in water levels(0{\sim}25%$). The main ingredients of the nuggets included saury mince, mild pizza cheese and hydrated textured soy protein concentrate. The formulated products were molded(dia. 4.5, thickness 1.5 cm, 20 g), battered lightly, flash-fried far 4 min at $160^{\circ}C$ and frozen until they were tested. The frozen nuggets were cooked to $65^{\circ}C$, then subjected to sensory evaluation, texture analysis at 80% deformation, and expressible fluid tests. The moisture contents in the nugget batter and the cooked nuggets were determined. In our sensory evaluation, nugget texture was adjudged the best in the nuggets prepared with a 20% water level(S5). The hardness and chewiness in the nuggets were reduced with increases in the water level. However, when the nuggets contain more than 15% water(S4, S5, S6), we noted no significant differences in the hardness values. The difference in moisture content between the uncooked nugget bat or and the cooked nugget was most profound in the nugget prepared with a water level 25%(S6). The nugget prepared with a water level 25% was also the highest in expressible fluids, and was also highest in internal moisture content. The texture preference of nuggets was correlated positively with moistness(r=0.881) and moisture content(r=0.827), and correlated negatively with firmness(r=-0.870) and cohesiveness(r=-0.839), and these correlations were significant.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.479-484
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• 2006

Ecophysiological parameters of non-transgenic sweetpotato (NT) and transgenic sweetpotato (SSA) plants were compared to evaluate their resistance to multiple environmental stresses. Stomatal conductance and transpiration rate in NT plants decreased markedly from Day 6 after water was withheld, whereas those values in SSA plants showed relatively higher level during this period. Osmotic potential in SSA plants was reduced more negatively as leaf water potential decreased from Day 8 after dehydration treatment, while such reduction was not shown in NT plants under water stressed condition. SSA plants showed less membrane damage than in NT plants. As water stress and high light stress, were synchronously applied to NT and SSA plants maximal photochemical efficiency of PS II ($F_v/F_m$) in NT plants markedly decreased, while that in SSA plants was maintained relatively higher level. This trend of changes in $F_v/F_m$ between SSA plants and NT plants was more conspicuous as simultaneously treated with water stress, high light and high temperature stress. These results indicate that SSA plants are more resistive than NT plants to multiple environmental stresses and the enhanced resistive characteristics in SSA plants are based on osmotic adjustment under water stress condition and tolerance of membrane.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.14-30
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• 2000

Hierarchically controlled sequence stratigraphic analysis shows that the Lower Ordovician mixed carbonate-siliciclastic Mungok Formation, Korea consists of three depositional sequences: T1, T2, and T3. Sequence boundaries are generally marked by abrupt transition from coarse-grained shallow-water carbonates to fine-grained deeper-water carbonates mixed with fine-grained siliciclastics, and show indication of subaerial exposure such as karstification. Within this sequence stratigraphic framework, facies characteristics indicate that the Mungok sequences were mostly deposited in subtidal ramp environments. High-frequency cycles consist of upward-shallowing facies successions. Cycles of shallow-water and basinal deposits are not represented well, probably due to cycle amalgamation. Cycle stacking patterns do not show a consistent thickness change that reflects a large-scale sea-level change due to unfilled accommodation space. The Mungok sequences show that many factors including relative sea-level change and topography are involved in controlling sequence development on carbonate ramps. The depositional setting evolved from the high-energy ramps in the sequences T1 and T2 into the low-energy ramp in the sequence T3. Topography is interpreted to have been responsible for the different energy regimes of the carbonate ramps in the Mungok sequences. The high ramp gradient in the sequences T1 and T2 seems to be caused by space-time-dissociated differential sedimentation resulting in spatially narrow distribution of sediment filling, which in turn may be related to high rate of relative sea-level change. In contrast, low ramp gradient was maintained in the sequence T3 during slow changes of relative sea level resulting in broad distribution of sediment filling.