• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.79-84
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• 2017

The solar cells should be protected from the moisture and oxygen in order to sustain the properties and reliability of the devices. In this research, we prepared the protection films on the flexible plastic substrates by spray coating method using organic-inorganic hybrid solutions. The protection characteristics were studied depending on the various process conditions (nozzle distance, thicknesses of the coatings, film structures). The organic-inorganic solutions for the protection film layer were synthesized by addition of $Al_2O_3$ ($P.S+Al_2O_3$) and $SiO_2$ ($P.S+SiO_2$) nano-powders into PVA (polyvinyl alcohol) and SA (sodium alginate) (P.S) organic solution. The optical transmittances of the protection film with the thicknesses of $5{\mu}m$ showed 91%. The optical transmittance decreased from 81.6% to 73.6% with the film thickness increased from $78{\mu}m$ to $178{\mu}m$. In addition, the protective films were prepared on the PEN (polyethylene naphthalate), PC (polycarbonate) single plastic substrates as well as the Acrylate film coated on PC substrate (Acrylate film/PC double layer), and $Al_2O_3$ film coated on PEN substrate ($Al_2O_3$ film/PEN double layer) using the $P.S+Al_2O_3$ organic-inorganic hybrid solutions. The optimum protection film structure was studied by means of the measurements of water vapor transmittance rate (WVTR) and surface morphology. The protective film on PEN/$Al_2O_3$ double layer substrate showed the best water protective property, indicating the WVTR value of $0.004gm/m^2-day$.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.1-10
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• 2005

The purpose of this study was to evaluate the potential of a gamma irradiation to decompose 2,4,6-trinitrotoluene(TNT) in an aqueous solution. The decomposition reaction of TNT by gamma irradiation was a pseudo first-order kinetic over the applied initial concentrations($25{\sim}100mg/L$). The dose constant was strongly dependent on the initial TNT concentration. The removal of TNT was more efficient at pH below 3 and at pH above 11 than at neutral pH(pH 5-9). The required irradiation dose to remove over 99% of TNT was 40, 80 and 10 kGy, individually at pH 2, 7 and 13. The dose constant was increased by 1.6 fold and over 15.6 fold at pH 2 and 13, respectively, when compared with that at pH 7 When irradiation dose of 200 kGy was applied, the removal efficiencies of TOC were 91, 46 and 53% at pH 2, 7 and 13, respectively. Ammonia and nitrate were detected as the main nitrogen byproducts of TNT and glyoxalic acid and oxalic acid were detected as organic byproducts. The results showed that a gamma irradiation was an attractive method for the decomposition of TNT in an aqueous solution. However, regarding the application of high energy radiation for the TNT decomposition and mineralization, an application of an acidic pH below 3 to the solution before irradiation should be considered.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.51-58
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• 2009

The compost leachate was dark-colored solution that leaches out of the bottom of the compost pile. The compost leachate was rich in nutrients and can potentially used in plant culture. In the organic production, commercial liquid fertilizer was used to insure the availability of nutrients during the formation of the yield. The cost of supplemental liquid fertilizer could be reduced by developing a fertilizer based on animal fertilizer. This experiment was conducted to investigate the effect of different combination of compost leachate and conventional inorganic solution in hydroponic culture for lettuce growth. Six different treatments were applied. The compost leachate(CL) and nutrient solution(NS) were mixed by six different mixing ratios of 0:100, 20:80, 40:60, 60:40%, 80:20 and 100%:0% based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of leaf lettuce. The concentration of nutrient solution was adjusted 1.5 mS/cm in EC. The compost leachate was low in phosphorus(P), calcium(Ca), magnesium(Mg), but rich in potassium(K). The plant height of lettuce treated with CL 20+NS 80% was similar with 100% NS of control plot. Plant height was highest in the plot of CL 20+NS 80%. The treatment of 100% compost leachate was lowest in the growth characteristics of leaf lettuce. Number of leaf was very low in 100% compost leachate compared with plot of chemical nutrient solution. In the beginning of growth stage, SPAD value was reduced in plot treated with CL100%, but CL20+NS80% plot was higher compared to 100% compost leachate. SPAD value of leaf lettuce leaves was decreased as the amount of CL was increased. The dry weight of lettuce were 107.4, 104.2g in plot of NS 100% and CL 20%+NS80%, respectively. The leaf number and plant weight were decreased at high application plots of compost leachate. The leaf lettuce showed lowest in the plot treated with 100% compost leachate, and the growth of lettuce severely decreased after application of 100% CL treatment. The results showed that compost leachate can be use as liquid fertilizer for the organic hydroponic production. The mixture solution of 20% of compost leachate and 80% of nutrient solution could be used as a nutrition solution in hydroponic culture of leaf lettuce. Our studies have shown that is possible to produce using compost leachate, although growth is slower than when using a conventional inorganic hydroponic solution.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.30-36
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• 2022

A sensor is needed to continuously and automatically measure the change in HNS concentration in industrial facilities that directly discharge to the sea after water treatment. The basic function of the sensor is to be able to detect ppb levels even at room temperature. Therefore, a method for increasing the sensitivity of the existing sensor is proposed. First, a method for increasing the conductivity of a film using a conductive carbon-based additive in a nanoparticle thin film and a method for increasing ion adsorption on the surface using a catalyst metal were studied.. To improve conductivity, carbon black was selected as an additive in the film using ITO nanoparticles, and the performance change of the sensor according to the content of the additive was observed. As a result, the change in resistance and response time due to the increase in conductivity at a CB content of 5 wt% could be observed, and notably, the lower limit of detection was lowered to about 250 ppb in an experiment with organic solvents. In addition, to increase the degree of ion adsorption in the liquid, an experiment was conducted using a sample in which a surface catalyst layer was formed by sputtering Au. Notably, the response of the sensor increased by more than 20% and the average lower limit of detection was lowered to 61 ppm. This result confirmed that the chemical resistance sensor using metal oxide nanoparticles could detect HNS of several tens of ppb even at room temperature.