• Korean Journal of Agricultural Science
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• v.9 no.2
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• pp.576-583
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• 1982

The variation of free amino acids during the tomato producing was studied using a tomato variety, Kagome 77. The concentration of free amino acids in fresh and heated pulp, and in puree and paste was analyzed by using automatic amino acid analyzer, Hitachi model KLA-5. 1. A significant difference in decomposition rate of glutamine and asparagine among amide group was recognized. For instance, the glutamine decomposed fast and no glutamine was found in the paste, while 56% of asparagine was found in the paste. 2. The diminishing quantity of glutamic acid among acid group was highest among all free amino acids. The quantity of aspartic acid was next to the glutamine. The percents of glutamic acid and aspartic acid left over were 38% and 24%, respectively. 3. Glycine, alanine, valine, isoleucine and leucine of neutral amino acids tended to be reduced a little during the heating, concentrating process. 4. No apparent variation was found for the lysine and histidine belonging to basic amino acids. while arginine increased a little. 5. Tyrosine, phenylalanine and tryptophane of aromatic group seemed to increase a little during the heating process. But the variations of them during the concentrating process were not recognized. 6. The methionine content, sulfur containing amino acid decreased a little throughout the process. But the decrease of ${\gamma}-amino$ butyric acid of non-protein was not apparently recognized. 7. The amino acid contents of fresh pulp were found as following order: glutamic acid>${\gamma}$-amino butyric acid>glutamine>aspartic acid>asparagine. The amino acid contents of paste were as glutamic acid>${\gamma}$-amino butyric acid>aspartic acid and aspargine. The percent distribution of aromatic and basic amino acids increased, even it was not great. 8. When amino acids were analyzed by Hitachi KLA-5, unknown peak which was never app eared in the fresh pulp before tryptophane was appeared when processed. The peak became greater when heated and concentrated. Later it was known that the peak was not due to lysinoalanine or ornithine.

• Journal of the Korean Chemical Society
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• v.37 no.3
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• pp.351-354
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• 1993

Z-1-Ethyl-2-nitro-l-butenyl-(4'-methyl)-phenyl sulfone, C$_{13}$H$_{17}$NO$_4$S, Mr = 293.4, monoclinic space group P2$_1$/c, a = 12.194(7), b = 7.290(4), c = 16.532(14)${\AA}$, ${\beta}$ = 103.4(2)$^{\circ}$, V = 1429.5 ${\AA}^3$, Z = 4, D$_c$ = 1.32 gcm$^{-3}$, ${\lambda}$(Mo K${\alpha}$) = 0.71069 ${\AA}$, ${\mu}$ = 2.2 cm$^{-1}$, F(000) = 600, T = 298 K, R = 0.030 for 1762 unique observed reflections with I > 1.0${\sigma}$(I). A molecule has a cis-typed molecular structure having the form of "the substituted butene backbone, C-C(S)=C(NO$_2$)-C, connecting to a sulfur atom with the methylbenzene ring and to a nitro group. The methylbenzene ring and the substituted butene moiety are nearly planar with the maximum deviations from their own molecular planes, 0.018 ${\AA}$ for the C(1) atom of the benzene group and 0.045 ${\AA}$ for the N atom of the NO$_2$ group, respectively. The angles to the plane of the butene backbone are 88.5$^{\circ}$from the plane of the methyl-benzene and 78.6$^{\circ}$from the plane of the nitro group. Rotation of the nitro group from the butene plane seems to reduced contribution of resonance structure involving the nitro group, and resultant repulsion between the O(2) atom of SO$_2$ and the O(3) atom of NO$_2$ appears to be 2.894 ${\AA}$ longer than an expected van der Waals distance of 2.80 ${\AA}$.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.1
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• pp.47-53
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• 2011

$SF_6$ (Sulfur hexafluoride) possesses high GWP (Global Warming Potential) as sepcified by the IPCC (Intergonvernmental Panel of Climate Change). Recently, the recovery-separtion of $SF_6$ research area, including permeation properties studies using various membrane's materials and the practical operation of recovery-separtion using membrane of waste $SF_6$ gas is in the initial state. The separation efficiency of a single $SF_6$ and waste $SF_6$ mixture was evaluated using a PSF (polysulfone), PC (tetra-bromo polycarbonate) and PI (polyimide) hollow fiber membranes. According to the results of single gases permeation properties, PI membrane has the highest permselectivity of $N_2$ gas in $N_2/SF_6$ gas. Under the condition of P=0.5 MPa, the highest concentration of recovered $SF_6$ is 95.6 vol % in the separation experiment of $SF_6/N_2$ mixture gas by PC membrane. Under the operation pressure of P=0.3 MPa at a fixed retentate flow rate fixed of 150 cc/min, the maximum recovery efficiency of $SF_6$ is up to 97.8% by PSF membrane. From the results above, it is thought that the separation and recovery technique of $SF_6$ gas using membrane will be used as the representative eco-technology in the $SF_6$ gas treatment in the future.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.2
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• pp.152-156
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• 1987

A mixed population of marine bacteria was obtained to catalize the biodegradation of bunker-C fuel oil by means of the enrichment culture technique. Samples used for the enrichment culture were collected from sea water and sediments in the vicinity of Pusan, Chungmu, and Ulsan in Korea. As the biodegradation of bunker-C oil proceeded, the number of bacteria increased from $1.1\times10^6\;to\;8.7\times10^8$ cells per ml when pH was bufferized by 0.1 M Tris-HCl buffer to 7.6, then oil dispersion increased to $OD^{540}$ 2.2 and approximately $48\%$ of the oil was biodegradated in 10 days. Oil dispersion was absolutely dependent on the addition of nitrogen and phosphate sources in sea water. High and low sulfur-containing bunker-C and crude oil could be dispersed similarly. Bunker-C oil was dispersed rapidly at the pH ranging from 7.0 to 8.0 and dispersed to the amount of 7.5 g per liter of sea water medium.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.176-188
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• 2008

Anthropogenic emissions of nitrogen oxides and sulfur dioxide in Northeast Asia are of great concern because of their impact on air quality and atmospheric chemistry on regional and intercontinental scales. Satellite remote sensing based on DOAS (Differential Optical Absorption Spectroscopy) technique has been preferred to measure atmospheric trace species and to investigate their emission characteristics on regional and global scales. Absorption spectra obtained by the satellite-born instrument, SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) have been utilized to retrieve the information of $SO_2$ and $NO_2$ over Northeast Asia. $SO_2$ levels over Northeast Asia were in order of East China, Yellow Sea, South Sea and Korean Peninsula with mean vertical columns of $1.78({\pm}1.0){\times}10^{16}$, $1.11({\pm}0.67){\times}10^{16}$, $0.60({\pm}0.63){\times}10^{16}$, $0.71({\pm}0.65){\times}10^{16}\;molecules/cm^2$, respectively. $NO_2$ levels were in order of East China, Yellow Sea, Korean Peninsula, and South Sea with mean vertical columns of $1.2({\pm}0.56){\times}10^{16}$, $0.38({\pm}0.19){\times}10^{16}$, $0.48({\pm}0.28){\times}10^{16}$, $0.26({\pm}0.16){\times}10^{16}\;molecules/cm^2$, respectively. High levels of $SO_2$ and $NO_2$ were observed over East China, in particular in winter by the contribution of heating fuel combustion exhausts. The $SO_2$ and $NO_2$ levels over East China were the highest in January with 34% and 42% higher over the annual means. Low levels of $SO_2$ ranged over Korean peninsula, while $NO_2$ levels were relatively high, in particular in winter. The $SO_2$ and $NO_2$ levels over Yellow Sea were relatively higher compared to those over Korean peninsula and South Sea, which could be mainly attributed to their transport from East China.

• Molecules and Cells
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• v.39 no.8
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• pp.594-602
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• 2016

Alkyl hydroperoxide reductase subunit C from Pseudomonas aeruginosa PAO1 (PaAhpC) is a member of the 2-Cys peroxiredoxin family. Here, we examined the peroxidase and molecular chaperone functions of PaAhpC using a site-directed mutagenesis approach by substitution of Ser and Thr residues with Cys at positions 78 and 105 located between two catalytic cysteines. Substitution of Ser with Cys at position 78 enhanced the chaperone activity of the mutant (S78C-PaAhpC) by approximately 9-fold compared with that of the wild-type protein (WT-PaAhpC). This increased activity may have been associated with the proportionate increase in the high-molecular-weight (HMW) fraction and enhanced hydrophobicity of S78C-PaAhpC. Homology modeling revealed that mutation of $Ser^{78}$ to $Cys^{78}$ resulted in a more compact decameric structure than that observed in WT-PaAhpC and decreased the atomic distance between the two neighboring sulfur atoms of $Cys^{78}$ in the dimer-dimer interface of S78C-PaAhpC, which could be responsible for the enhanced hydrophobic interaction at the dimer-dimer interface. Furthermore, complementation assays showed that S78C-PaAhpC exhibited greatly improved the heat tolerance, resulting in enhanced1 survival under thermal stress. Thus, addition of Cys at position 78 in PaAhpC modulated the functional shifting of this protein from a peroxidase to a chaperone.

• The Journal of Engineering Geology
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• v.17 no.2 s.52
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• pp.187-196
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• 2007

The Dalseong acid mine drainage were studied focused on the characters of schwertmannite that controls geochemistry of the stream. Besides chemical analysis of stream water, particle size analysis, XRD SEM and TEM were performed on precipitates of streams and on wasted metalliferous ores. The AMD discharged from the abandoned mine reveals a decrease of pH and EC downward stream. Euhedral sulfur occurs as equigranular aggregates on the altered pyrite while fine acicula goethite coalesces to form cross, star, or starfish-like shapes. Water chemistry plotted on the Eh-pH diagram shows that schwertmannite and ferrihydrite are stable phases. Reddish brown precipitates consist of mostly schwertmannite with less goethite, whereas yellowish brown precipitates are composed of geothite with less schwertmannite. The particle size of precipitates ranges $d(0.1)\;0.861{\mu}m{\sim}3.769{\mu}m,\;d(0.5)\;3.984{\mu}m{\sim}15.255{\mu}m,\;and\;d(0.9)\;9.875{\mu}m{\sim}56.726{\mu}m$. Schwertmannite is characterized by equigranular spheric form. Pincushion or spicule with 100nm width and $200{\sim}300nm$length form on schwertmannite sphere with radial growth patterns. It is highly probable that reddish or yellowish brown precipitates formed in many AMDs may contain schwerhnannite. Because it can serve as sink for removing heavy elements by adsorption in AMD system, there is a need to correctly identify schwertmannite in precipitates and to characterize its phase stability.

• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.105-114
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• 1973

The crystal structure of morpholinothiosemicarbazide has been determined by single crystal X-ray analysis. The lattice constants are a = 4.19(2), b = 6.56(2) and c = 26.67(4)${\AA}$. The unit cell contains 4 molecules and the space group is$P2_12_12_1$. The atomic parameters have been refined by least-squares method to a final R value of 0.07, based on the 651 observed reflexions. The amino nitrogen atom forms hydrogen bonds to the sulfur atoms of the other molecules related by the two-fold screw axis parallel to the a-axis, the distances of the hydrogen bonds being 3.48 and 3.49${\AA}$. On the other hand, the imino nitrogen atom forms a hydrogen bond to the amino nitrogen atom of the other molecule related by the two-fold screw axis parallel to the a-axis, the distance of the hydrogen bond being 3.04${\AA}$. These three hydrogen bonds arrange the molecules around the two-fold screw axis. Apart from the hydrogen bonding system the structure is held together by van der Waals forces.

• Membrane Journal
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• v.22 no.3
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• pp.201-207
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• 2012

In this study, we investigated permeation of single gas ($N_2$, $O_2$, $CF_4$, and $SF_6$) through flat sheet membrane composed of PDMS (poly-dimethylsiloxane) and PEBAX (polyether block amides). Gas permeation experiment was performed with various feed pressure. Permeability was estimated using permeation flux measured by continuous-flow technique. The permeability of gases except $SF_6$ in PDMS were decreased with the upstream pressure increased. $SF_6$ is much more permeable than $CF_4$, which is due to higher critical temperature of $SF_6$. The permeability decreased in the following order: $O_2$ > $N_2$ > $SF_6$ > $CF_4$. On the other hand, the permeability of gases in PEBAX followed the order: $O_2$ > $N_2$ > $CF_4$ > $SF_6$ which are opposite of the order of kinematic diameter (${\AA}$)($SF_6$ > $CF_4$ > $N_2$ > $O_2$). The $SF_6/CF_4$ pure gas selectivity in PDMS was 2.1 at 0.7 MPa.

• Elastomers and Composites
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• v.21 no.1
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• pp.13-19
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• 1986

The effects of several vulcanizing accelerators on the determination of kinetic parameters of natural rubber vulcanizate was studied by DSC. Kinetic parameters were determined by means of the calculation procedures of Borchardt-Daniels and Oscillating Disk Rheometer (ODR) cure curve analysis, using both DSC exothermal thermogram and ODR cure curve. In order to examine the credibility in the DSC method the same compound which was und for DSC method was used for the comparison with the results of ODR data. Upon this method, kinetic rate constant (k), and Arrehenius parameter (Ea, ko, n) have been determined for rubber compounds via a new method using DSC thermogram and ODR cure curve. In the comparison of DSC and ODR results, kinetic parameters has shown good agreements between two results. Consequently, from the present studies, it is shown that the DSC thermoanalytical method can provide an alternate new method of kinetic study of rubber vulcanization.