• Science of Emotion and Sensibility
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• v.18 no.1
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• pp.49-58
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• 2015

This paper investigated far-infrared emission characteristics of ZrC imbedded heat storage knitted fabrics for emotional garment. For this purpose, ZrC imbedded heat storage PET was spun with high viscosity PET imbedded ZrC powder on the core part and low viscosity PET on the sheath part by conjugated spinning method. Ingredient analysis and far-infrared emission characteristics assessment of spun filament were carried out by EDS and FT-IR spectrometer. Two kinds of knitted fabrics were made using texturized ZrC imbedded PET for measuring thermal characteristics of ZrC imbedded heat storage PET. Zr peak was certified by EDS measurement and it was confirmed that content of Zr was 19.29%. Far-infrared analysis revealed that emission power at the range of wavelength, $5{\sim}20{\mu}m$ was $3.65{\times}10^2W/m^2$, and emissivity was 0.906. Heat storage analysis by KES-F7 system revealed that $Q_{max}$ of ZrC imbedded PET knitted fabric was lower than that of regular PET one and warmth keepability rate was higher than that of regular one, which means that ZrC imbedded PET knitted fabric has heat storage property. Thermal conductivity of ZrC imbedded PET knitted fabric was higher than that of regular PET one which was caused by high thermal conductivity of Zr itself. Hand property of ZrC imbedded knitted fabric was not inferior compared to regular PET knitted fabric, which preferably was found to be dependent on knit structure and surface property.

• Journal of Plant Biology
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• v.36 no.4
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• pp.383-389
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• 1993

The effects of light and $CO_2$ on the electrophysiological characteristics of guard cells in the intact leaf and in the detached epidermis have been investigated. Guard cells in intact leaves showed the membrane hyperpolarization in response to light. The biggest induced change of the membrane potential difference (PD) in the guard cells of the intact leaf was 13 m V by light and 42 mV by $CO_2$ in Commelina communis. Similar results were obtained with Tradescantia virginiana. However, there were no changes of membrane PD in detached epidermis. In order to determine the influence of the mesophyll on the changes of membrane PD, infiltration of the mesophyll cells with photosynthetic inhibitors was performed. In CCCP infiltrated leaf discs the guard cell membrane was depolarized slightly by red-light and hyperpolarized by $CO_2$, but in leaf discs infiltrated with DCCD and DCMU the guard cell membrane was hyperpolrized by both red-light and $CO_2$ as the control leaf discs. In azide infiltrated leaf discs the guard cell membrane showed no response to light and there was a much reduced membrane hyperpolarization by $CO_2$ compared to other responses. It was likely that azide caused leaf damage and the activity of cell metabolism was decreased greatly, resulting in small membrane PD changes by $CO_2$ and no changes by redlight. Therefore, it can be suggested that red light was sensed by the mesophyll and the light induced guard cell membrane hyperpolarization was related to energy produced by cyclic-photophosphorylation, but ${CO_2}-induced$ guard cell membrane hyperpolarization was not related to photosynthesis. Alkalisation of the vacuole was observed when the intact leaf was exposed to $CO_2$, indicating that membrane hyperpolarization was mainly the result of proton efflux.efflux.

• Economic and Environmental Geology
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• v.35 no.6
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• pp.545-552
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• 2002

In order to investigate the influence of nuclear power plant operation on its nearby environment, soil, stream and marine sediment samples were collected in the vicinity of the Youngkwang Nuclear Power Plant in Korea, and analyzed for artificial and natural radionuclide radioactivity. From the analytical result, Cs-137 was detected in most soil samples. but it may have been derived fiom past nuclear weapon tests because Cs-134 having short half-live was not detected. The radioactivities of Cs-137 in the sediment samples were also detected which are within the normal range in the sediments based upon the published literature between 1997 and 1999. For the quality control of radioactivity analysis of environmental samples, sets of marine sediments in the Gamami area were analyzed using two HPGe Gamma-ray Spectroscopes (30% and 45%) according to the geostatistical sampling strategy, and Cs-137 and K-40 results were interpreted by analysis of variance (ANOVA). In the two-way ANOVA, variances derived from the geochemical variation were significant, but errors from sampling and analytical procedures are negligible. In conclusion. all the radioanalytical procedures of this study including sampling are validated to be acceptable.

• Analytical Science and Technology
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• v.9 no.3
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• pp.262-269
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• 1996

The muiltiwire proportional counter for the measurement of low-level and environmental $\alpha$ particles emitting nuclides was developed. External dimension of the devloped multiwire proportional counter is $350{\times}290{\times}30mm$ and the sensitivity area is $250{\times}200mm$. The wall material of the detector was selected the stainless steel to prevent the deformation by external impact and to obtain minimum background. The anode and cathode wires were used the stainless steel material of diameter $50{\mu}m$. The spacing of each wires are 10.0mm, 5.0mm and the numbers of total wire are 21, 42 lines, respectively. The multiwire proportional counter was designed that the measurement source is placed within the detector to prevent the wall absorption effect and the efficiency variation by various source heights. The characteristics of the developed detector have been investigated to obtain the plateau, operating voltage, background, counting efficiency, position sensitivity and energy resolution etc. For the $^{241}Am$ nuclide, the calculated LLD(Lower Limit of Detection) is 5.0mBq/L which is lower than 40mBq/L of recommended LLD value by ISO(International Organization for Standardization).

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.557-563
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• 2018

Coincidence summing correction effects are known to be greater as the efficiency of the detector increases and as the distance between the source and the detector increases. A point source($^{60}Co$) was used to vary the distance in the direction of the detector's center axis and in the radial direction to obtain the P/T ratio for Coincidence summing correction calibration. In this study, values for coincidence summing corrected calibration of the values in the central and radial directions were applied to the mixed volume source(450 ml CRM source) to compare the overall peak efficiency change according to P/T with Geant4. In addition, the efficiency obtained from the mapping method is applied to the seaweed, a marine sample, and the compatibility of the P/T ratio with the detector and sample very dose together. The efficiency corrected to 1,836 keV was applied to the energy zone affected by the efficiency of 500 keV and the relative error of the measured and corrected values was well matcched by the 3.2 % peak efficiency correction. As with 450 mL CRM source, the larger the volume, the lower the P/T ratio was by ${\pm}5%$. This is due to the increased scattering of gamma-rays emitted as the source becomes farther away from the detector, and this change in P/T has been confirmed to affect the Coincidence summing corrected peak efficiency.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.379-386
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• 2008

Calcined clay granules (pellet) have been used as a soil conditioner. The space among the pellets can secure drainage of water in soil and, simultaneously, can keep water for plants in the inner pore of that. However, the usage of the pellet has been restrained because fabrication of that requires a high energy and cost for heating over the temperate of $1000^{\circ}C$. Recently, SCS(Self-propagating Combustion and Sintering) method was developed and this method use the combustion energy of the preliminary mixed combustible. The SCS method is suitable to fabrication of small porous aggregate and requires a very low cost. This research applied the SCS method to coal refuses for fabrication of soil conditioner pellets. The coal refuses were pulverized under the size of $100{\mu}m$ and the pulverized powders were pelletized to the size of 4~6mm. The pellets were heated at the temperature of $1200^{\circ}C$ in the SCS furnace that was specially prepared for this research. Characteristics of the pellets were investigated and were compared with that of ordinary calcined clay pellet of kaolin; porosity, pore size distribution, bulk density, pH and etc.. Characteristics of the moisture retention in the pellets were measured by the centrifugal method: ASTM D425-88. The pellets of the coal refuses showed the higher values of the field capacity and the plant-available water than that of kaolin pellet. These results suggest the very low cost process that can utilize the coal refuses and can fabricate the lightweight porous soil conditioner of the very high plant-available water.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.492-506
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• 2013

The historical accounts and materials about the eruption of Mt. Baekdusan as observed by the geological survey is now showing some signs of waking from a long slumber. As a response of the volcanic eruption of Mt. Baekdusan, water release may occur from the stored water in Lake Cheonjii caldera. The volcanic flood is crucial in that it has huge potential energy that can destruct all kinds of man-made structures and that its velocity can reach up to 100 km $hr^{-1}$ to cover hundreds of kilometers of downstream of Lake Cheonji. The ultimate goal of the study is to estimate the level of damage caused by the volcanic flood of Lake Cheon-Ji caldera. As a preliminary study a scenario-based numerical analysis is performed to build hydrographs as a function of time. The analysis is performed for each scenario (breach, magma uplift, combination of uplift and breach, formation of precipitation etc.) and the parameters to require a model structure is chosen on the basis of the historic records of other volcanos. This study only considers the amount of water at the rim site as a function of time for the estimation whereas the downstream routing process is not considered in this study.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.8
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• pp.492-497
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• 2015

VOCs (Volatile Organic Compounds) are generally generated in the painting process, or at the company and laundry where use organic solvents. The VOCs consist of various hydrocarbons and has low calorific value due to its dilution with atmospheric air. Therefore, the VOCs are difficult to burn by a conventional fuel combustor. In this study, a novel plasma dump combustor was proposed for the treatment of low calorific VOC gases. This combustor was designed a combination of the characteristics in a plasma burner, a dump combustor and a 3D matrix burner. The combustor has good structure for maintaining enough residence time and reaction temperature for stable flame formation and VOC destruction. For investigating the performance characteristics of the plasma dump combustor, an experiment was achieved for VOC feed rate, VOC injector position, etc. Toluene was used as a surrogate of VOC. The novel combustor gave better performance than a conventional combustor, showing that VOC destruction rate and energy efficiency were 89.64% and 12.27 kg/kWh respectively, at feeding rate of 450 L/min of VOC of 3,000 ppm of toluene concentration.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.534-543
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• 2008

The experimental study with the prototype provides more acceptable data than the others. But there are so many limited conditions to perform the experimental study with the prototype. So the theoretical similitude with the scaled model and the numerical study with the CFD method have been chosen alternatively to analysis the fume movement. In this study, the ventilation was estimated from the results of the numerical study based on the experimental results as the boundary conditions. The grid A and B were same size and shape with the models which was used in the experimental study and consisted with 163,839, 122,965 cells respectively. The height of the fume layer was estimated form the mole fraction of fume components and the ventilation was determined by the velocity and temperature of the fume. The results of this study showed that the fume movements estimated from the numerical study are enough to apply to the prototype if there are proper heat loss correction factors. The numerical study is easier to change study conditions and faster to get results from the study than the experimental study. So if we find some proper heat loss correction factors, it's possible to execute the various and advanced study with the numerical study.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.59-64
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• 2010

Building a firebreak against surface forest fire is a typical indirect suppression method that stops spread of flame by removing surface fuel, such as fallen leaves and bushes. In the sense of fire dynamic, building a firebreak is to set a section which will block thermal energy from igniting on virgin fuel. This study suggests and evaluates a calculation method for width of firebreak against surface fire for variant wind and slope conditions by applying the Point Source Model (PSM) to fallen leaves of Pinus densiflora. Width of firebreak was measured based on the distance the threshold radiant heat igniting Pinus densiflora fallen leaves at the heat flux of $4.9\;kW/m^2$ reaches. As a result, at the wind velocity of 0~5 m/s and on the slope of $0{\sim}50^{\circ}$, the appropriate width of a firebreak was 0.35~0.65 m for the mean flame height and 0.75~1.05 m for the maximum flame height. Accordingly, considering the factor of safety, the most appropriate width of a firebreak is 1.05 m based on the maximum flame height. Additional comparative analyses through experiments and field surveys are deemed necessary to determine appropriate widths of firebreak for different types of surface fuel.