• Journal of the Korean institute of surface engineering
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• v.18 no.3
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• pp.116-124
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• 1985

Chemical vapor deposition of $SnO_2$ on Pyrex glass substrate has been investigated using $SnCl_4$ and Oxygen at relatively low temperatures(300-500$^{\circ}C$). The critical flow rate, which delineated the surface reaction controlled region from the mass transfer controlled region, was increased with deposition temperature. The apparent activation energy obtained in surface reaction controlled region was about 6Kcal/mole. The results show that deposition rate, electrical conductivity and transmittance were affected mainly by partial pressure of $SnCl_4$, but little by partial pressure f oxygen. The % transmission of 5000A-thick $SnO_2$ film was about 90% in visible spectrum region and sheet resistance was varied in 0.1-10${\Omega}$ per square shaped portion of the outer surface of the oxide.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.241-252
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• 2000

Twenty-two water samples(fifteen groundwater and seven geothermal water samples) were collected to elucidate chemical characteristics of the ground and geothermal waters in the Haeundae hot spring area and its vicinity. Major and honor elements were analyzed for ground and geothermal water samples. The concentrations of $K^+$, Na+$, $Ca^{2+}$, $SO_4^{2-}$, $Cl^-$, ^F^-$ and $SiO_2$ were higher in the geothermal water samples than the groundwater samples except $HCO_3^- and Mg^{2+}$ ions. Based on the contents of Fe, Zn, Cu, Al, Mn and Pb, some of the ground and geothermal water samples are contaminated by anthropogenic sources. The ground waters shown on the Piper diagram belong to $Ca-HCO_3$ type, while the geothermal waters Na-Cl type. The graphs of $Cl^-$ versus $Na^+$, $Ca^{2+}, Mg^{2+}, K^+, SO_4^{2-} and HCO_3^-$ indicate that the groundwater is related partly with mineral-water reaction and partly with anthropogenic contamination, while the geothermal water is related with saline water. On the phase stability diagram, groundwater and thermal water mostly fall in the field of stability of kaolinite. This indicates that the ground and geothermal waters proceed with forming kaolinite. Factor and correlation analyses were carried out to simplify the physicochemical data into grouping some factors and to find interaction between them. Based on the Na-K, Na-K-Ca and Na-K-Ca-Mg geothermometers and silica geothermometers, the geothermal reservoir is estimated to have equilibrium temperature between 125${$\mid$circ}C$ and 160${$\mid$circ}C$.

• Applied Biological Chemistry
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• v.25 no.2
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• pp.67-74
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• 1982

Morphology, physicochemical properties, pasting properties in the presence of various anionic ions and aging of gels of Akibare (Japoica type) and Milyang 23 (Indica type) rice starch were studied, Both starches. were polygonal with length in the range of $3{\sim}6{\mu}m$. Starch granules of Akibare were somewhat smaller than those of Milyang 23. X-ray diffraction study demonstrated that peak shape and intensity were significantly different between the two starches. Akibare and Milyang 23 rice starch had amylose content of 18.5 and 19.5% and water binding capacity of 106 and 100%, respectively. Milyang 23 rice starch had a higher swelling power than Akibare starch. A relationship between percent solubility and swelling power implied that bonding forces within the granules of the both starches were different. The optical transmittance of 0.1% suspension of the two starches increased rapidly from $60^{\circ}C$. In the range of $60{\sim}90^{\circ}C$, the two starches showed a single gelatinization pattern. Amylograms of the two starches in the presence of various anionic ions showed that pasting temperature and peak temperature were progressively increased in the order of SCN-${SO_4}^=$. SCN- and I- ions increased the peak height of Akibare rice starch while only SCN- ion was effective for Milyang 23 rice starch. There were no differences in the rates of retrogradation of 45% gels of the two starches stored at $21^{\circ}C$.

• Carbon letters
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• v.12 no.4
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• pp.236-242
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• 2011

The oxyfluorination effects of activated carbon nanofibers (OFACFs) were investigated for $CO_2$ storage. Electrospun CFs were prepared from a polyacrylonitrile/N,N-dimethylformamide solution via electrospinning and heat treatment. The electrospun CFs were chemically activated in order to generate the pore structure, and then oxyfluorination was used to modify the surface. The samples were labeled CF (electrospun CF), ACF (activated CF), OFACF-1 ($O_2:F_2$ = 7:3), OFACF-2 ($O_2:F_2$ = 5:5) and OFACF-3 ($O_2:F_2$ = 3:7). The functional group of OFACFs was investigated using X-ray photoelectron spectroscopy analysis. The C-F bonds formed on surface of ACFs. The intensities of the C-O peaks increased after oxyfluorination and increased the oxygen content in the reaction gas. The specific surface area, pore volume and pore size of OFACFs were calculated by the Brunauer-Emmett-Teller and density functional theory equation. Through the $N_2$ adsorption isotherm, the specific surface area and pore volume slightly decreased as a result of oxyfluorination treatment. Nevertheless, the $CO_2$ adsorption efficiency of oxyfluorinated ACF improved around 16 wt% due to the semi-ionic interaction effect of surface modificated oxygen functional groups and $CO_2$ molecules.

• Journal of Sericultural and Entomological Science
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• v.38 no.1
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• pp.7-12
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• 1996

Reproducible the random amplified polymorphic DNAs(RAPDs) patterns were obtained in the two silkworm strains(J111, Galwon) by adjusting concentration optimized of Taq DNA polymerase(one unit), dNTP(200$\mu$M), MgCl2(1.5mM) and template DNA(30ng). In addition, anealing temperature ranging 35$^{\circ}C$ to 42$^{\circ}C$ by the adjusted condition was investigated and fixed at 35$^{\circ}C$ in this study. Variation among individuals and between male and female of Jam 113 strain was not authorized. DNA polymorhpisms among silkworms were authorized by five RAPD markers using OPM04 random primer. Using the primer showing polymorhpims between parents(J111, Galwon) in thirty three individuals, RAPD-PCR for F2 analysis was performed and segregated 3 : 1 in the F2 population. Consequently, RAPDs detected in the parents were obtained as genetic markers, which can be used for construction of genetic map for this industrially particular insect, silkworm Bombyx mori

• Korean Journal of Agricultural Science
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• v.35 no.1
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• pp.1-9
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• 2008

There were four types of Doenjang fermentation as following conditions for investigation ; 1) low temperature fermentation at $13^{\circ}C$ for 180 days, 2) low temperature at $13^{\circ}C$ for 7 days to room temperature at $30^{\circ}C$ for 10 days, to low temperature at $13^{\circ}C$ for 163 days, and for 173 days, 3) low temperature at $13^{\circ}C$ 7 days to room temperature at $30^{\circ}C$, 4) room temperature at $30^{\circ}C$ for 180 days. There were no changes of moisture, NaCl and total nitrogen content during fermentation period of four types conditions, but pH and amino type nitrogen decreased in room temperature at $30^{\circ}C$ for 180 days. It required 3 times more fermentation period until same quantity of the amino type nitrogen. The low temperature fermentation sample was lower than room temperature fermentation sample in pH and amino type nitrogen. The yeast decreased in low temperature fermentation sample taken 15 to 30 days longer than room temperature sample. The yeast is increased up to 30 days, and decreased little by little. After 60 days, it remained a few without effectiveness on the Doenjang quality. The low temperature fermentation sample showed brighter than room temperature fermentation sample. Different fermentation condition affected Doenjnag quality, especially, low temperature fermentation sample showed bright color in Doenjnag. So low temperature fermentation must be expected as good method for getting high quality Doenjnag.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.323-332
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• 1996

Precipitation samples were collected by the wet-only sampling method at Seoul from September 1993 to June 1995. Sample were analysed for the anions $(NO_3^-, NO_2^-, SO_4^{2-}, Cl^-, and F^-)$ and cations $(Na^+, K^+, Ca^{2+}, Mg^{2+}, and NH_4^+)$ in addition to pH and electric conductivity. In order to establish the chemical analysis data of high quality, the assurance checks for analytical data of precipitation were performed by considering the ion balance and by comparing the measured conductivity with the calculated conductivity. As we applied the various assurance checking methods by the ion balance used until recently to a data set measured in this study, the f value expressed as $\Sigma C/\Sigma A$ was found to be not appropriate for the data screening. Also, the scattering plot between cations and anions in each sample was found to show the general tendency of ion balance but was proved to not quantitate the standard of data screening at a data set of samples of various concentration levels. The h value defined as (A-C)/C for C $\geq$ A and (A-C)/A for C < A was used to check the ion balance. However, the standard of data screening by h value must very in response to total ion concentration of samples. In this study, the quality assurance of chemical analysis data was checked by considering both the ion balance of evaluating by h value and the conductivity balance. Further the quality control was achieved by these quality assurance methods. As the result, 67 samples among total 77 were obtained as valid. As the central tendency value for a statistical summary in the analytical parametr of samples, the volume-weighted mean value was found to represent more the general chemistry of precipitation rather than the arithmetic mean. The volume-weighted mean pH was 5.0 and 25% of samples was less than this mean. The concentrations of sufate and nitrate in precipitation were 90.4 ueq/L and 32.4 ueq/L which made up 59% and 21% of all anions. The raion of $SO_4^{2-}/(NO_3^- + NO_2^-)$ in precipitation was 2.7, which indicates that the contributions of $H_2SO_4$ and $HNO_3$ to the acidity of precipitation are 70% and 30%, respectively.

• Bulletin of the Korean Chemical Society
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• v.16 no.10
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• pp.912-915
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• 1995

Ornidazole, C7H10ClN3O3, crystallizes in the triclinic, space group P1^, with a=13.605(2), b=14.054(1), c=8.913(5) Å, α=71.59(2), β=78.73(2), γ=64.86(1)°, μ=3.26 cm-1, Dc=1.499 g/cm3, Dm=1.497g/cm3, F(000)=684, and z=6. Intensities for 2693 unique reflections were measured on a CAD4 diffractometer with graphite-monochromated Mo-Kα radiation. The structure was solved by direct method and refined by block-diagonal least squares to a final R of 0.081 (Rw=0.047) for 1952 reflections with Fo>3σ (Fo). The asymmetric unit contains three independent molecules of the title compound. The bond lengths and bond angles are comparable with the values found in the other nitro-substituted compounds. The nitro groups are rotated (6.9°, 6.6°, 2.6° for the three independent molecule, respectively) about the C-N axes from the imidazole planes. The crystal structures are linked by two intermolecular hydrogen bonds of O-H---N type and one intermolecular hydrogen bond of O-H---O type.

• Mycobiology
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• v.37 no.3
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• pp.211-214
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• 2009

An actinomycete strain was isolated from northern part of Bangladesh and identified as a new Streptomyces species on the basis of its morphological, biochemical, cultural characteristics and 16S rRNA data. Attempts were made to optimize the culture conditions for the production of antimicrobial metabolites by this strain. Antimicrobial metabolites production was started after 7 days of incubation of culture broth and reached its maximum levels after 10 days and thereafter gradually decreased. The maximum production of antimicrobial metabolites was obtained when the culture medium pH was adjusted to 8. The optimum temperature for antimicrobial metabolites production was $39^{\circ}C$, indicated the new strain as mesophilic organism. Basel medium supplemented with glucose and yeast extract as carbon and nitrogen sources, respectively, was proved to be the best for the production of bioactive metabolites. Maximum production of bioactive metabolites was when NaCl concentration was 1% and among different minerals tested, $K_2HPO_4$ and NaCl showed positive influence on antibiotic production by the strain.

• Journal of the Korean Chemical Society
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• v.41 no.12
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• pp.645-652
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• 1997

Hydride complexes Cp*Ru(CO)(PR3)H (Cp*=η5-C5Me5, PR3=PMe3, PEt3, PMePh2, PPh3, PCy3)(4a-4f) were synthesized by the reaction of the corresponding chloro complex Cp*Ru(CO)(PR3)Cl (3a-3f) with various hydridic reagent (NaBH4, LiAlH4, LiBEt3H) or NaOMe. Irradiation of Cp*Ru(CO)(PCy3)H (5e) in C6D6 solution with UV light caused H/D exchange reaction between coordinated Cp*, PCy3 and/or Ru-H ligand proton and a deuterium of the deuterated aromatic solvent through a series of inter- and intramolecular C-H activation. The proposed mechanism was described.