• Nuclear Engineering and Technology
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• v.5 no.3
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• pp.202-213
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• 1973

In a continuation of the 1st series of these studies, a separation of the components in organic phases obtained from Szilard Chalmer reactions of aromatic chloro derivatives was attempted to clarify the conditions of isolating the main component. Though it was unable to isolate all constituents of organic phases, the main component was well isolated by means of a simple distillation or a thin layer chromatography. It was identified that the main component was a recombined product of the recoiled $^{38}$ Cl atom with the original sample. In cases of solid samples the main component amounted about 80-60% of the radio activity of the organic phase, whereas the main component from liquid samples gave less than 70% of the radio activity of the organic phase. A prolonged irradiation could increase the yield of a main component, but it was, in case of a radiation senintive compound, decreased as the irradiation is extended. The number of aide produets separated from an organic phase of a liquid sample was greater than that of a solid sample, and hence the main component of a solid sample was isolated easier. The overall fields of the labelled main products of 22 kinds of compounds were listed and a procedure of the separation of the main component by a thin layer chromatograply was proposed and evaluated. The feasibility of the present procedure for labelling purpose was also reviewed with respects to the chemical structure of a compound.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.112-117
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• 2011

A series of experiments was conducted to investigate the herbicidal activity of natural compound chrysophanic acid under the greenhouse condition in 16 weed species. Chrysophanic acid showed non-selective herbicidal activity. While chrysophanic acid exhibited severe injury by foliar treatment, little or no injury was found by the soil treatment. Among the tested weeds, the most effective activity was found in grass and broad leaf weeds, a lower significant difference in herbicidal activity was found in sedge. At early post-emergence, weeds appeared to be very susceptible to chrysophanic acid with $2,000{\mu}g\;mL^{-1}$. The higher the natural compound concentrations, the lower weed growth. At middle post-emergence, weeds appeared to be very effective to chrysophanic acid with $30,000{\mu}g\;mL^{-1}$.

• Journal of Powder Materials
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• v.10 no.2
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• pp.123-128
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• 2003

$TiO_2$ nanopowder was synthesized by chemical vapor condensation (CVC) process and its photocatalytic property depending on microstructure was considered in terns of decomposition rate of organic compound. In order to control microstructure of $TiO_2$ nanopowder such as particle size and degree of agglomeration, precursor flow rate representing number concentration was changed as a process variable. In TEM observation, spherical $TiO_2$ nanoparticles with average size of 20 nm showed gradual increases in particle size and degree of agglomeration with increase of precursor flow rate. Also decomposition rate of organic compound increased with decreasing precursor flow rate. Thus, it was concluded that photocatalytic property was enhanced by targe surface area of disperse $TiO_2$ nanoparticles synthesized at lower precursor flow rate condition in CVC process.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.7
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• pp.627-636
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• 2001

This paper presents a numerical analysis of the emission process of volatile organic compound(VOC) from building material and its diffusion in a room. A polypropylene styrene-butadiene rubber(SBR) floor plate is chosen as the emission source of VOC. This study investigates spatial concentration distributions and time history of room-averaged VOC concentration for both with and without flushing. The results of this study show that for calculation based on ten-days period the room averaged VOC concentrations with and without flushing are quite different. the results thus suggest the need of flushing for new buildings.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.4
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• pp.285-290
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• 2007

This study has been numerically conducted to investigate the removal efficiency of Volatile Organic Compound (VOC) in photocatalytic micro-reactor. This study has placed emphasis on the improvements of the working condition of photocatalytic micro-reactor. The micro-reactor consists of 19 microchannels with a rectangular cross-section. For the validation of the current numerical study, a computation has been carried out to simulate an existing experimental study on the cylindrical reactor, which has shown a good agreement. The degradation characteristics with different inlet concentrations and velocities have been obtained. The current results can be used for the design of advanced photocatalytic micro-reactor.

• Journal of Information Display
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• v.10 no.3
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• pp.121-124
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• 2009

In this study, 6,13-Bis(4-propylphenyl)pentacene was synthesized and characterized. The structures of the products that were obtained during the reaction steps were identified via FT-IR and NMR spectroscopy and elemental analysis. The compound was found to be soluble in organic solvents like chloroform, dichloromethane, THF, and toluene. The charge transport mobility was $10^{-4}cm^2V^{-1}s^{-1}$, and the on/off current ratio was $10^2$, while the compound was 2.5 times more stable under oxidation in a solution compared with pentacene.

• Textile Coloration and Finishing
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• v.26 no.2
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• pp.143-149
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• 2014

The designed dye material, namely 2-(4-(9H-carbazol-9-yl)benzylidene) compound, was synthesized. After the reaction, the solid was filtered and purified by recrystalization with acetone/water. To confirm and analyze its synthesis and structural formation, the single crystal was prepared and its measurement was carried out. A yellow needle crystal of $C_{22}H_{13}N_3$ were made on a Rigaku R-AXIS RAPID diffractometer using graphite monochromated CuK${\alpha}$ radiation. All details were suggested and introduced to support and communicate this study.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.6
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• pp.743-757
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• 2006

Volatile organic compound (VOC) has been well-known to Korea since the end of 1990's however, it has not been well documented until now. In this study, present ambient VOC levels, VOC emission sources, and VOC control technologies were reviewed and discussed. In addition, VOC management strategies to cut down ozone concentrations were suggested based on the present VOC database. For anthropogenic VOC reduction, VOC emitted from painting processes and automobiles should be controlled in the first place in large cities such as Seoul, Daegu, and Incheon. For natural VOC management, low emission trees need to be planted in those cities. It is also very significant to keep updating present and future VOC emission inventories for efficient VOC control strategies. As a conclusion, more systematic VOC control road-map based on BACT (best available control technology) needs to be made up. and more economical and efficient VOC control techniques have to be developed under strong national support in order to lower toxic VOC and photochemical oxidant levels.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1194-1201
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• 2004

Michael addition of certain nucleophiles on ${\alpha}$ , ${\beta}$-unsaturated ketones 1 led to the formation of adducts 2-7 as well as the reaction of arylidene derivatives with secondary amines afforded the amino compounds 9 and 11. Also, dialkylmalonates were treated with ${\alpha}$-cyano cinnamide to afford 13. On the other hand, double Michael cycloaddition of ethylcyanoacetate or tetrachlorophthalic anhydride to the suitable divinylketone were synthesized to produce 15-17. Selected compounds (13 and 6) were screened for muscle relaxant, anticonvulsant, and sedative activities using established pharmacological models. Their activities were compared with that of phenobarbital sodium taken as standard. Compound 6 was the most potent muscle relaxant while compounds 13a and 13c offered the highest anticonvulsant activity. Meanwhile compound 13c showed the highest potentiation of phenobarbital induced sleep in mice.

• Journal of Environmental Health Sciences
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• v.35 no.1
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• pp.53-57
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• 2009

In order to treat the complex wastewater containing organic compound and solids, pre-treatment system associated with molecular separation process were investigated. The reductions of COD and turbidity were obtained after coagulation processes using Alum (Aluminium sulfate, $Al_2(SO_4)_2{\cdot}18H_{2}O$) and PACl (poly aluminium chloride as 17% $Al_{2}O_{3}$). The results of study were as follows: using variable dosage of Alum, COD removal was highest at 4,000 mg/l, and the reduction of COD and turbidity was 42% and 92%, respectively. The optimum coagulation would be effective at pH 7.3 than pH 9.0 by the addition of alum at a concentration of 6,000 mg/l and PACl was add at 4.25% in raw complex wastewater with 2,000 mg/l alum at pH 7.3, the reduction of COD was reduced by 32%. But coagulation aid experiments indicated that PACl would be more effective in sludge separation ability than COD removal efficiency.