• Journal of the Microelectronics and Packaging Society
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• v.13 no.1 s.38
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• pp.37-42
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• 2006

The preparation and processing of PVP-gate insulators on the device performance have been studied in the fabrication of organic thin film transistors (OTFTs). One of polyvinyl series, poly-4-vinyl phenol(PVP) was used as a solute and propyleneglycol monomethyl etheracetate(PGMEA) as a solvent in the formation of organic gate solutions. The cross-linking of organic insulators was also attempted by adding the thermosetting material, poly (melamine-co-formaldehyde) as a hardener in the compounds. From the measurements of electrical insulating characteristics of metal-insulator-metal (MIM) samples, PVP-based insulating layers showed lower leakage current according to the increase of concentration of PVP and poly (melamine-co-formaldehyde) to PGMEA in the formation of organic solutions. The PVP(20 wt%) copolymer with composition of 20 wt% PVP to PGMEA and cross-linked PVPs in which 5 wt% and 10 wt% poly (melamine-co-formaldehyde) hardeners had been additional]y mixed into PVP(20 wt%) copolymers were used as gate dielectrics in the fabrication of OTFTs, respectively. In our experiments, the maximum field effect mobility of $0.31cm^2/Vs$ could be obtained in the 5 wt% cross-linked PVP(20 wt%) device and the highest on/off current ratio of $1.92{\times}10^5$ in the 10 wt% cross-linked PVP(20 wt%) device.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.237-243
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• 2001

The experiment was conducted to investigate the effect of different mulching materials on the growth and quality of oriental melon in protected cultivation. Soil temperature, plant growth and fruit quality were affected by different mulching materials, clear polyethylene (P.E.) film (control), clear inset between black P.E. film, green P.E. film. and recycled ethylene vinyl acetate (E.V.A.) film. The highest night soil temperature was at 20 cm depth under green P.E. film, but was at 5 cm depth under other materials. Difference of soil temperature as affected by mulching materials decreased with increasing soil depth. Plant height, number of nodes, leaf area index (LAI), crop growth rate (CGR), and relative growth rate (RGR) at 30 days after transplanting were significantly greater in the recycled E.V.A. film treatment than in the other treatments. Fresh weight of weeds growth under the mulching materials was not affected by mulching material at 30 days after transplanting. However, it was the greatest under clear P.E. film mulching at 90 days after transplanting. Harvesting time of recycled E.V.A. film was 2 days earlier than that of clear P.E. film. Difference in fruit weight and length, and soluble solid content were not affected by the mulching materials. Marketable yield was 2,426 kg.10a$^{-1}$ in recycled E.V.A. film treatment, which was 6% greater than in clear P.E. film treatment.

• Journal of Adhesion and Interface
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• v.16 no.2
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• pp.69-75
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• 2015

Stone board for the rock bed was needed to reduce weight using thin thickness and reinforced materials. In this work, stone/wood board for rock bed was studied. Stone and wood were attached to reduce total weight of stone for rock bed. For reinforcing wood heat treatment method was used to change surface and mechanical properties. Mechanical strength of heat treated wood increased more than neat condition. The optimum heat treatment condition was set on $100^{\circ}C$ under tensile, flexural loads whereas surface energy was also obtained by contact angle measurement. Optimum adhesive condition was to get the maximum adhesion between stone and wood. Lap shear test was performed for stone/wood board with different adhesives such as amine type epoxy, polyurethane, chloro-rubber and vinyl chloride acetate type. Fracture surface of lap shear test was shown at wood fracture part on stone using amine type epoxy adhesive. It was found that for high adhesion between stone and wood the optimum adhesive was epoxy type for the rock bed.

• Polymer(Korea)
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• v.27 no.6
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• pp.562-568
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• 2003

Environmental problems due to waste tire and waste plastics let us develop practical and economically feasible products. For this purpose, the characteristics of waste tire/plastic composites including various additives were examined using internal mixer. Experimental results indicated that the tensile strength and the flexural strength of waste tire/plastic composites decreased with the waste tire content. When 20 wt% of PP was added to the waste tire (60 wt%)/HDPE composites, the tensile strength was 1.5 times higher than the composite without PP, It was also found that the strain at break of composites increased by 2.5 times with 10 wt% addition of ethylene vinyl acetate and styrene ethylene butylenes styrene respectively. When 10 wt% of glass fiber was added to waste tire (60 wt%)/ HDPE composites, the tensile strength was 63% higher than the composite without glass fiber.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.8-14
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• 2013

The newly developed fertilizer is the slow-releasing fertilizer which can be used as a basal fertilizer without no additional fertilization at tillering stage. It has 30-4-6% of $N-P_2O_5-K_2O$ and was coated with mixture of LDPE (Low density polyethylene), EVA (Ethylene vinyl acetate), BDP (Bio degraded polymer), TALC and nonionic surfactant for the controlled release up to 50 days after application. Coating materials were designed to be decomposed naturally. This fertilizer can be applied directly to the seedling tray mechanically just before transplanting, resulting in significant labor saving effect. The developed slow-release fertilizer, which can replace both basal fertilization and top dressing at tillering stage by single application directly to seedling tray, showed the highest release at 14~21 days after transplanting. Considering the plant growth at different growth stages and yield, the optimal application rate of developed slow-release fertilizer was 300 g per rice nursery tray and the yield of rice at this application rate was 5.25 MT/ha. Rice quality in terms of head rice grain ratio, amylose content, whiteness, and taste value decreased as fertilization rate increased from 200 g to 500 g per nursery tray. Fertilization rate based on quantity of fertilizer ingredients (N, P, K) was reduced by 49.3% compared to the standard application rate and there was 49.2% reduction in labor input for fertilization.

• Journal of Soil and Groundwater Environment
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• v.17 no.5
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• pp.49-55
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• 2012

A 1.28 L-batch reactor and continuous-flow stirred tank reactor (CFSTR) fed with formate and trichloroethene (TCE) were operated for 120 days and 56 days, respectively, to study the effect of formate as electron donor on anaerobic reductive dechlorination (ARD) of TCE to cis-1,2-dichloroethylene (c-DCE), vinyl chloride (VC), and ethylene (ETH). In batch reactor, injected 60 ${\mu}mol$ TCE was completely degraded in the presence of 20% hydrogen gas ($H_2$) in less than 8 days by anaerobic dechlorination mixed-culture (300 mg-soluble protein), Evanite Culture with ability to completely degrade tetrachloroethene (PCE) and -TCE to ETH under anaerobic conditions. Once the formate was used as electron donor instead of hydrogen gas in batch or chemostat system, the TCE-dechlorination rate decreased and acetate production rate increased. It indicates that the concentration of hydrogen produced in both systems is possibly more close to threshold for homoacetogenesis process. Soluble protein concentration of Evanite culture during the batch test increased from 300 mg to 688 mg for 120 days. Through the protein monitoring, we confirmed an increase of microbial population during the reactor operation. In CFSTR test, TCE was fed continuously at 9.9 ppm (75.38 ${\mu}mol/L$) and the influent formate feed concentration increased stepwise from 1.3 mmol/L to 14.3 mmol/L. Injected TCE was accumulated at 18 days of HRT, but TCE was completely degraded at 36 days of HRT without accumulation of the injected-TCE during the left of experiment period, getting $H_2$ from fermentative hydrogen production of injected formate. Although c-DCE was also accumulated for 23 days after beginning of CFSTR operation, it reached steady-state in the presence of excessive formate. We also evaluated microbial dynamic of the culture at different chemical state in the reactor by DGGE (denaturing gradient gel electrophoresis).

• Journal of the Korean Wood Science and Technology
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• v.32 no.4
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• pp.66-73
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• 2004

Three species of Italian poplar (Populus euramericana), red pine (Pinus densiflora) and oriental oak (Quercus variabilis) were selected for this study. They were cut so that the distances between each of tips and roots for a pair of fingers were 0, 0.15, 0.30 and 0.45 mm. Poly vinyl acetate (PVAc) and resorcinol-phenol resin (RPR) were used for finger-jointing. Compressive test parallel to the grain was conducted for the finger-jointed specimens. The results were as follows: The efficiency of compressive Young's modulus of finger-jointed timber to solid wood indicated low values, whereas the efficiency of compressive strength indicated high values of more than 90% in all species, especially, it was found that those of red pine indicated markedly high values of more than 97%. The efficiency of compressive displacement of Italian poplar finger-jointed timber was 2 times higher than solid wood, and it was 1.2 and 1.3 times higher than solid woods in red pine and oriental oak, respectively. Also, it was found that 0, the distance between each tip and root for the fingers, indicated the highest efficiency of compressive strength performance in Italian poplar finger-jointed timber, and for red pine and oriental oak finger-jointed timbers, the distances of 0.15 and 0.30 were found to indicate the highest efficiency.

• Journal of the Korean Vacuum Society
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• v.20 no.3
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• pp.233-241
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• 2011

Currently, solar module is using the two methods such as a glass-filled method or a super-straight method. The common point of these methods is to use glass structure on the front of solar module. However, the reflectance of the solar module is high depending on the height of the incident sunlight due to the flat surface of the module front glass. Purposed to solve these problems, AG (anti-glare) structures were formed on the glass surface. Next is fabrication methods of AG structure. First, uneven structure made by micro blaster equipment was dipped in Hydro-fluidic acid (HF) acid. HF acid process was carried out to remove particles and to make high transmittance. The reflectance and transmittance of the anti-glare glass was compared to those of the bare glass. The reflectance of anti-glare glass decreased approximately 1% compared with bare glass. The transmittance of anti-glare glass was similar to bare glass. According to the sample angle, the difference of the reflectance between bare glass and the anti-glare glass was about 19%. Isc and efficiency value of anti-glare glass on bare solar cell appeared about 3.01 mA and 0.228% difference compared with bare glass. Anti-glare glass on textured solar cell appeared about 9.46 mA and 0.741% difference compared with bare glass. As a result, the role of anti-glare in the substrate is to reduces the loss of sunlight reflected from the surface. In this study, therefore, AG structure on the solar cell was used to improve the efficiency of solar cell.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.907-914
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• 1996

To enhance the shelf-life and quality of baechu kimchi, the effects of CSP(crab shell powder) addition to kimchi was investigated. Overall qualities were deteriorated by fish odor, chewiness of particles, sharp pH increase at the early fermentation stage; therefore in order to solve these problems kimchi fermentation was carried out with kimchi containing 1, 3, 5% CSPB for salted baech weight at $10^{\circ}C$ for 300ays. Quality of kimchi was evalutated by the measurement of pH, acidity, colour L, a, and b value, the number of microbe and lactic acid bacteria, texture. Ten highly trained panelists were involved in the sensory evaluation. During the entire fermentation periods, pH, hardness, colour L, a and b value, the number of lactic acid bacteria of kimchi with CSPB were higher than those of control, but acidity was lower. Sensory quality showed that sour taste of control at 15-day fermentation was already strong. However, sour taste, crispness taste, and overall taste of kimchi with CSPB untill 20-day fermentation were good. Especially, overall taste of kimchi containing 3% CSPB at 30-day fermentation was good, but that of kimchi containing 5% showed fish odor from the early periods of fermentation.

• Biomedical Science Letters
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• v.2 no.2
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• pp.167-174
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• 1996

Alcoholics increased susceptibility to microbial infection that is associated with decreased immunity. but there has been little experimental evidence to support alcoholics-induced increase of microbial infection directly in non-specific immunity. Therefore, we were used the method of phagocytic-plaque including all the stimulating factors for the phagocytosis, subtypes of lymphocytes and T-lymphocyte proliferation. The experimental groups were divided into 3 groups: (1) alcoholics who were hospitalized less than 1 week (newly hospitalized alcoholics), (2) alcoholics who were hospitalized more than 2 weeks (old hospitalized alcoholics), (3) healthy blood donors. We have studied 98 alcoholics and 35 healthy blood donors and control groups. A physician has checked the biological markers and diagnosed the body-condition alcoholics. The immunity and non-specific immunity on the alcoholics were analyzed by using the simultest kit and flow cytometry. Proliferation of the lymphocytes was analyzed by the phytohemmagglutinine mitogen. Phagocytosis and migration properties of leukocytes were identified on the layer formed by Staphylococcus aureus Cowan I strain. Biological markers of alcoholics and control groups, by such as blood glucose, ${\gamma}$-glutamyl transpeptidase and mean corpuscular volumes of red blood cells, were determined by biochemical and hematological methods. Compared with control groups, cluster of differentiation (CD)3+, CD8+ and CD19+ in alcoholic were more decreased except CD4+/CD8+ ratio. Proliferation of the T-lymphocytes, phagocytosis and migration properties of the leukocytes in alcoholics were decreased compared with those of control groups. According to the results observed in our experiment, they can be summerized as follows: 1, Cellular, humoral and non-specific immunities, are markedly decreased in alcoholics than those in control groups. 2. It is inferred that Phagocytic plaque formation is a very useful method to evaluate phagocytosis and migration properties of the alcoholic leukocytes 3. It is thought that the subtypes of lymphocytes, especially CD4+/CD8+ ratio, are essential methods to analyzed the alcoholic immunity. 4. Specific and non-specific immunity on the old hospitalized alcoholics was slightly increased, which depends upon the alcoholic medication.