• Proceedings of the Korean Fiber Society Conference
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• 1995.10a
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• pp.131-131
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• 1995

• Research in Plant Disease
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• v.10 no.4
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• pp.297-303
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• 2004

Bacterial blossom blight of kiwifruit (Actinidia deliciosa) has been mainly controlled by antibiotics. Among 15 candidate chemicals, streptomycin sulfate oxytetracycline WP, streptomycin copper hydroxide WP and oxolinic acid WP were selected as preventive bactericides against bacterial blossom blight of kiwfruit through in vitro and in vivo test. Spray of streptomycin sulfate oxytetracycline WP and streptomycin copper hydroxide WP at flowering period was most effective in controlling bacterial blossom blight of kiwifruit. Among the various combinations of spray times at different spray periods, optimum spray program of the preventive bactericides for the control of bacterial blossom blight of kiwifruit was turned out to be 3 times application with 10 day-interval from early May during the flowering season of kiwifruits.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.1
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• pp.58-63
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• 2005

PTFE (polytetrafluoroethylene) thin films were prepared from the pellets of the graphite doped PTFE via pulsed laser ablation with 1064 nm Nd:YAG laser. The graphite powder converts the absorbed photon energy into thermal energy which is transmitted to nearby PTFE. The PTFE is decomposed by thermal process. The deposited films were transparent and crystalline. SEM (scanning electron microscopy) and AFM (atomic force microscopy) analyses indicated that the film surface morphology changed to fibrous structure with increasing thickness. The fluorine to carbon ratios of the film were 1.7 and molecular axis was parallel with (100) Si-wafer substrate. These results obtained by XPS (X-ray photoelectron spectroscopy), FTIR (fourier transform infrared spectroscopy) and XRD (X-ray diffraction).

• Journal of Korea Game Society
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• v.12 no.4
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• pp.77-85
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• 2012

The purpose of this study was to investigate the effects of Tetris game on the cognitive abilities of students with mental retardation. Especially, this study focused on the arrangement of figures and the task attention. To do this, 33 students with mental retardation in a middle school participated and were assigned to the two treatment group. The experimental group did the Tetris game three times a week for 4 weeks, but the control group didn't the Tetris game. The experimental group revealed more higher improvement than the control group in the arrangement of figures and the task attention. The Tetris game can be used as an educational program to improve the cognitive abilities of students with mental retardation.

• Polymer(Korea)
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• v.28 no.6
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• pp.494-501
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• 2004

A new alkali developable photosensitive poly(amic acid) (PAA-0) with transmittance at 400 nm was synthesized from cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 2-(methacryloyloxy)ethyl-3,5-diamino-benzoate and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyl disiloxane in N-methyl-2-pyrrolidinone. Photosensitivity of the PAA-0 was investigated at 365-400 nm in the presence of a photoinitiator using a high pressure mercury lamp. The photo-cured poly(amic acid) was insoluble toward aqueous 2.38 wt% tetramethylammonium hydroxide solution. Negative pattern of the PAA-0 with 25 ${\mu}{\textrm}{m}$ resolution was obtained by developing with 2.38 wt% tetramethylammonium hydroxide solution after exposure of 600 mJ/$\textrm{cm}^2$ in the presence of 2,2-dimethoxy-2-phenyl-acetophenone as a photoinitiator. The patterned poly(amic acid) was converted to polyimide by thermal curing at 25$0^{\circ}C$ for 50 min, which showed chemical resistance against photoresist stripper as well as good transmittance at 400 nm.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.201-205
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• 2008

As an ongoing research program for the development of environmental friendly new soil-surface treatment herbicide, several tetrahydroindazole derivatives 6a - 6h possessing hydroxyalkyl subgroup were synthesized and shown to have interesting herbicidal activities exhibiting sumptoms as protoporphyrinogen IX oxidase inhibitor under pre-emergence upland greenhouse screening. Among derivatives tested, compound 6f showed superior herbicidal activity against problem weeds.

• Journal of the Korean Chemical Society
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• v.35 no.4
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• pp.335-342
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• 1991

The effect of pressure and temperature on the stabilities of the charge transfer complexes of 1,3,5-trinitrobenzene, tetrachloro-p-benzoquinone and tetracyanoethylene with hexamethylbenzene in carbon tetrachloride has been investigated by spectrophotometric measurements. The equilibrium constants for the formation of the complexes were obtained at various temperature and pressure, and thermodynamic parameters for the formation of the charge transfer complexes are calculated from these values. The relative stabilities of charge transfer complexes with hexamethylbenzene increase in the order; 1,3,5-trinitrobenzene < tetrachloro-p-benzoquinone < tetracyanoethylene. This may be regarded as an order of relative acidity of these compounds in complexation with hexamethylbenzene and is explained in terms of the negative inductive effect of the ${\pi}$ acceptors. The red-shift at higher pressure, the blue-shift at higher temperature and the relation between pressure and oscillator strength are discussed on the basis of thermodynamic functions.

• Journal of the Korean Chemical Society
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• v.18 no.1
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• pp.50-57
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• 1974

A practical method applicable to the synthesis of aromatic dihydrazines was proposed by reducing tetrazonium salt in strong mineral acid media. By diazotizing p-phenylenediamine with sodium nitrite in a medium of concentrated hydrochloric acid or 45 % perchloric acid at $-5 {\sim} -10{\circ}C$ and reducing the tetrazonium salt with stannous chloride, p-phenylenedihydrazine (PPDH) was separated in the form of hydrochloride as colorless fine needles. Since PPDH was subject to oxidation and unstable, the free base could not be isolated. PPDH${\cdot}$2HCl was decomposed at $^180{\circ}C$ without showing sharp melting point. It behaved largely as aromatic monohydrazines, and reacted immediately with aldehydes and ketones in acetate buffer, giving generally yellow to brownish condensation products, dihydrazones. This suggests that PPDH will react with dicarbonyl compounds producing high molecular polymers or cyclization products.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.461-477
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• 2017

Organosilicone-based surfactants, consisting of hydrophobic organosilicone groups coupled to hydrophilic polar groups, have been widely used in many industrial fields starting from polyurethane foam to construction materials, cosmetics, paints & inks, agrochemicals, etc., because of their low surface tension, lubricity, spreading, water repellency and thermal and chemical stability, resulted from the unique properties of organosilicone. Especially, organosiloxane surfactants, having low molecular weight siloxane as hydrophobe, exhibit low surface tension and excellent wettability and spreadability, leading to their applications as super wetter/super spreader, but have the disadvantage of vulnerability to hydrolysis. A variety of low molecular weight siloxane surfactant structures are required to provide the functional improvement and the defect resolution for reflecting the necessities in the various applications. This review includes the synthetic schemes of reactive tetrasiloxanes and disiloxanes as hydrophobic siloxane backbones, the main reaction schemes, such as hydrosilylation reaction, for coupling reactive tetrasiloxanes or disiloxanes to hydrophilic groups, and the main synthetic schemes of the tetra- and di-siloxane surfactants having polyether-, carbohydrate-, gemini-, bola-type surfactant structures.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.201-207
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• 1983

The rate constants for solvated electrons with benzene in the binary mixture (tetrahydrofuran-water) were measured at a various temperatures$(-18{\circ}C{\sim}+51{\circ}C)$ by photolysis. From Arrhenius plots of rate constants it was observed that the activation energies were decreased with increasing tetrahydrofuran(THF) content. Decreasing the viscosity of solvent mixtures by adding water, the rate constants were also decreased. It indicates that the reaction of solvated electrons are not controlled by diffusion. The change of activation enthalpy in kcal $M^{-1}$ and the rate constants in$ M^{-1}sec^{-1}$ were 4.90 and $8.80{\times}10^8$ for 30M% of THF, 2.80 and $5.14{\times}10^8$ for 49M% of THF, and -0.30 and %1.43{\times}10^8$ for 75M% of THF, respectively. The slope of the linear plot of activation enthalpies against activation entropies was $244{\circ}K$, which supports the reaction parameter is the change of activation entropy in the range of the experimental temperature. From the solvent effect on the activation energy, it was found that the step of the reaction, ${e_s}^-+B{\rightleftharpoons}B^-$ shifted to the exothermic reaction with increasing THF content.