• Korean Journal of Materials Research
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• v.19 no.12
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• pp.644-648
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• 2009

Temperature dependency of resistivity of the carbon black-polyethylene composites below and above percolation threshold is studied based on the electrical conduction mechanism. Temperature coefficient of resistance of the composites below percolation threshold changed from minus to plus, increasing volume fraction of carbon black; this trend decreased with increasing volume fraction of carbon black. The temperature dependence of resistivity of the composites below percolation threshold can be explained with a tunneling conduction model by incorporating the effect of thermal expansion of the composites into a tunneling gap. Temperature coefficient of resistance of the composites above percolation threshold was positive and its absolute value increased with increasing volume fraction of carbon black. By assuming that the electrical conduction through percolating paths is a thermally activated process and by incorporating the effect of thermal expansion into the volume fraction of carbon black, the temperature dependency of the resistivity above percolation threshold has been well explained without violating the universal law of conductivity. The apparent activation energy is estimated to be 0.14 eV.

• Journal of Oriental Neuropsychiatry
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• v.19 no.1
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• pp.97-105
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• 2008

Objective : The objective of this study is to investigate the intellectual characteristics of the specific language impairment(SLI) and the borderline intelligence-language disorder (BI-LD). Method : 30 Children participated in this study, IS children with SLI(K-WISC-ill FIQ above 85, Test of Problem Solving score below -1.25SD, verbal comprehension factor index of K-WISC III below 80), 14 children with BI-LD(K-WISC-ill FIQ $70^{\sim}85$, Test of Problem Solving score below -1.25SD, verbal comprehension factor index of K-WISC III below 80). All students were evaluated with K-WISC III, Test of Problem Solving. full-scale IQ (FSIQ), \ verbal intelligence quotient (VIQ), Verbal Comprehension Index, and Test of Problem Solving score were compared between two groups. Result : All subtests scores of PIQ in the SLI were significantly higher than those in the BI-LD. there was no significant difference in the subtests scores of VIQ. In the VIQ subtests, Information, Arithmetic, Comprehension score were higher in the SLI compared to the BI-LD, but the score of Similarities and Vocabulary were similar between two groups. Conclusion: These results suggest that inspite of the difference of PIQ, SLI and BI-LD have similar language abilities, and there are some different intellectual characteristics between SLI and BI-LD

• Geomechanics and Engineering
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• v.21 no.3
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• pp.301-313
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• 2020

In the process of mining closely spaced coal seams, the problem of roadway arrangement in lower coal seams has long been a concern. By means of mechanical model calculation and numerical simulation postprocessing, the distribution of the stress deviator below the floor of a goaf and the evolution of the stress deviator in the vertical and horizontal directions are studied under the influence of horizontal stress. The results of this theoretical study and numerical simulation show that the stress deviator decreases exponentially with increasing depth from the floor below the coal side. With the increase in the horizontal stress coefficient λ, the stress deviator concentration area shifts. The stress deviator is concentrated within 10 m below the goaf and 15 m laterally from the coal side; thus, the magnitude of the surrounding rock stress deviator should be considered when planning the construction of a roadway in this area.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.326-331
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• 2015

High salinity and sodicity of soils play a negative role in producing crops in reclaimed tidal lands. To evaluate the effects of soil ameliorants on salt removal in a highly saline and sodic soil of reclaimed tidal land, we conducted a column experiment with treating gypsum, compost, and phosphate at 0-2 cm depth and measured the salt concentration of leachate and soil. Electrical conductivity of leachate was $45-48dSm^{-1}$ at 1 pore volume (PV) of water and decreased to less than $3dSm^{-1}$ at 3 PV of water. Gypsum significantly decreased SAR (sodium adsorption ratio) of leachate below 3 at 3 PV of water and soil ESP (exchangeable sodium percentage) below 3% for the whole profile of soil column. Compost significantly decreased ESP of soil at 0-5 cm depth to 5% compared with the control (20%). However, compost affected little the composition of cations below a depth of 5 cm and in leachate compared with control treatment. It was concluded that gypsum was effective in ameliorating reclaimed tidal lands at and below a soil layer receiving gypsum while compost worked only at a soil layer where compost was treated.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.873-882
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• 2021

In this study, a study was conducted to develop a system for predicting/responding to black ice occurring on roads in winter. Tests conditions were studied by making models of cement concrete pavement and asphalt concrete pavement. In order to freeze water on the manufactured model package, an tests was conducted at a temperature below zero using a freezer, and the freezing process was photographed using a thermal imaging camera. Black ice is generated when water is present on the road surface and the temperature is below freezing or the road surface temperature is below the dew point temperature. Under sub-zero conditions, the pavement, water, and ice were classified with a thermal imaging camera. As a result of the tests, it was possible to distinguish with a thermal imaging camera at a temperature below freezing in the same freezer due to the difference in the emissivity of the packaging, water, and ice. In the process of changing from water to ice during the tests, it was analyzed that ice and water were clearly distinguished by the thermal imaging camera due to the difference in emissivity and reflectance, so black ice could be predicted using the thermal imaging camera.

• Journal of Forest and Environmental Science
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• v.39 no.2
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• pp.96-104
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• 2023

The successful restoration program requires a comprehensive understanding of variables influencing seedling efficiency. Below-ground is hypothesized to have a major impact on seedling performance of species when planted in agriculture, and degraded areas with different types of mulching. This study investigated on Sg. Terla Forest Reserve in Cameron Highlands Pahang, Malaysia. In this study randomized complete block design (RCBD) was used. The excavation method was applied to study the root system development, above, and below ground biomass distributions under different types of mulching: coconut mulching (CM), oil palm mulching (OM), plastic mulching (PM) and control (CK). The root diameter, main root length, lateral root length, root coiling, and root direction toward to sun were recorded. The results in this study indicate that mulching had significant effect on root diameter, main root length, and root distributions among treatments while for lateral root length, root: shoot ratio, dry biomass distributions, and above and below ground biomass did not showed significant effect among treatments. The highest values for root diameter, lateral root length, main root length, root distributions, dry biomass distributions and above and below ground biomass were showed in CM treatments. However 75% of root coiling was observed in seedlings between treatments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.403-410
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• 2009

This study was conducted to investigate the hygienic quality of commercial Kwamegi, a Korean traditional food, made from semi-dried Pacific saury. The hygienic qualities of 10 Kwamegi samples were examined from the 15 commercially available types. Samples with code 3, 4, 6, 11 and 12 were acceptable based on criteria suggested by Ministry for Food, Agriculture, Forestry and Fisheries (i.e. moisture below 50%, total mercury below 0.5 ppm, lead below 2.0 ppm, viable cells below $1.0{\times}10^5$ CFU/g and coliform count below $1.0{\times}10^3$ MPN/100g. Peroxide value of commercial Kwamegi ranged from 15.3-104.1 meq/kg. Agmatine sulfate, cadaverine, histamine, tyramine, spermidine, dopamine and spermine were found in all of the 15 commercially available Kwamegi, while tryptamine and 2-phenylethylamine were not detected. Putrescine dihydrochloride was only detected in 7 samples. The histamine content of commercial Kwamegi ranged from 33-124mg/kg, which is believed to be an acceptable limit according to guidelines from other countries. Cadaverine can be used as a potential index for freshness of commercial Kwamegi as there is a good correlation between volatile basic nitrogen and biogenic amine contents.

• Korean journal of applied entomology
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• v.20 no.1 s.46
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• pp.37-41
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• 1981

Mycelial growth and production of macroconidia by Cylindrocladium crotalariae on either PDA or water agar containing soybean leaf pieces adjusted to different water potentials with KCI. were consistently maximal at -14bars. Mycelial growth by this fungus was nii at about -100 bars and below at 30C, -80 bars and below at 25C and -64 bars and below at 20C. Sporulation was prevented at -64 bars and below at $20^{\circ}C\;and\;25^{\circ}C$. Perithecial andmicrosclerotial formation was maximal at abot -1.4 to - 3.0 bars (the basal medium without sait). Percentage of spore germination for this fungus was uniformly maximal at all water potentials between -1.4 bars (the highest tested) and - 20 bars, was progressively less as the water potential lowered below -20 bars, and was prevented at - 60 bars.

• Archives of Reconstructive Microsurgery
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• v.20 no.1
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• pp.51-56
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• 2011

During below knee amputation, the amputation stump must be covered with well-vascularized and sensate soft tissue. Many flaps can be used for this purpose, but available reconstructive options are limited. We performed reverse flow ALT flap elevation on two patients with below knee amputations to reconstruct defects in the stumps. The sizes of the defects in the stumps were $4{\times}16$ cm and $5{\times}5$ cm, respectively. The most distal portion of the defects were located 20 cm and 16 cm lateral to the knee joint in a curve, respectively. The size of the elevated flap was $5{\times}18$ cm for case 1 and $18{\times}10$ cm for case 2. The respective pivot points of the pedicles were 7 cm and 6 cm above the patella and the respective lengths of the pedicles were 17 cm and 16 cm. In both cases, venous congestion occurred on the second postoperative day and the flap distal to 10 cm or more from below the knee joint was necrotized at the second postoperative week. Surgeons should be cautious when using a reverse ALT flap to reconstruct a soft tissue defect located 10 cm or more distal from below the knee joint. Since a pedicle longer than 15 cm may develop partial necrosis of the flap, simultaneous application of antegrade venous drainage is recommended.

• Journal of Environmental Science International
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• v.20 no.3
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• pp.291-299
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• 2011

The main objectives of this research are to investigate characteristics of ozone solubility due to low solubility of conventional bubbles-ozone generators, evaluate the treatment characteristics of reclaiming textile wastewater for industrial water by means of micro/nano bubbles-dissolved ozone flotation(MNB-DOF) process. The textile wastewater used in this research was obtained from final effluent of the textile wastewater in B city. There is a 400L reactor which consists of a micro-nano bubble system and a ozone generator for experiments. As a result of generating micro-nano bubbles (below $0.5{\mu}m$) by using of MNB-DOF process, it improved ozone solubility due to higher ozone transfer rates. Consequently, the shorter ozonation time clearly indicates the lower power costs. The reported results clearly indicated that MNB-DOF process can be effectively and inexpensively. Results of the experiments through MNB-DOF process in this study satisfy all reclaiming standards as industrial water: pH 6.5~8.5, SS 10 mg/L or below, $BOD_5$) 6 mg/L or below, turbidity 10 NTU or below, Coliforms 1,000/100 mL or below. Therefore there is a possibility of the reclaiming of the textile wastewater as industrial water.