• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.276-283
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• 2018

For the first time, polyvinyl chloride (PVC) was used as an easily-handled chlorine source for preparation of isotropic pitch-based carbon fiber (IPCF) incorporating ethylene bottom oil (EO) as a raw material. Pitch precursors were prepared by the chlorination-dehydrochlorination triggered by chlorine radicals originated from PVC; aromatization and poly-condensation reactions occurred by polyene-type radicals from PVC. Radical production and co-carbonization were facilitated by pretreatments of EO through vacuum distillation, bromination, and additional heat treatment. Pitches were prepared by the co-carbonization of pretreated EO and EO containing 20 wt% PVC, and had higher yields and better spinnability than those by simple distillation.

• Journal of Microbiology
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• v.44 no.3
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• pp.276-283
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• 2006

The thermophilic fungus Thermoascus aurantiacus 179-5 produced large quantities of a glucosidase which preferentially hydrolyzed maltose over starch. Enzyme production was high in submerged fermentation, with a maximal activity of 30 U/ml after 336 h of fermentation. In solid-state fermentation, the activity of the enzyme was 22 U/ml at 144 h in medium containing wheat bran and 5.8 U/ml at 48 h when cassava pulp was used as the culture medium. The enzyme was specific for maltose, very slowly hydrolyzed starch, dextrins (2-7G) and the synthetic substrate (${\alpha}$-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II ${\alpha}$-glucosidase. The optimum temperature of the enzyme was $70^{\circ}C$. In addition, the enzyme was highly thermostable (100% stability for 10 h at $60^{\circ}C$ and a half-life of 15 min at $80^{\circ}C$), and stable within a wide pH range.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.6
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• pp.283-288
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• 2010

Nanosized NiO powder was prepared by mixing an acid nickel salt and a base nickel salt and their reduction behavior was studied. Ni formate was employed as an acid salt and nickel hydroxide and basic nickel carbonate as base salts. One equivalent acid salt was mixed with 9 equivalent base salt. The mixture of the formate and the carbonate produced ~100 run spherical NiO powder by heat treatment at $750^{\circ}C$/2 h, but the mixture of the formate and the hydroxide gave rise to ~100 nm pseudo spherical NiO powder by heat treatment at $600^{\circ}C$/2 h and grew fast to give pseudo cubic crystals of 100~600 run by heat treatment at $750^{\circ}C$/2 h. Reduction by hydrogen gas proceeded much faster for the one with the hydroxide than that with the carbonate to give porous body with well grown necks. Their behavior was studied by analysis of TG/DSC, XRD, and SEM.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.283-286
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• 1999

Transparent conductive aluminum-doped ZnO(AZO) films Were prepared by a ultrasonic spray pyrolysis method at the substrate temperature below 23$0^{\circ}C$. A vertical type hot wall furnace was used as a reactor in the deposition system. Zinc acetate dissolved in methanol was selected as a precursor. The substrate temperature was varied from 18$0^{\circ}C$to 24$0^{\circ}C$. Aluminum (Al) was doped into ZnO films by incorporating anhydrous aluminum chloride (AlCl$_3$) in the zinc acetate solution. The proportion of the Al in the starting solution was varied from 0 wt % to 3.0 wt %. The crystallographic properties and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The resistivity of the films was measured by the Van der Pauw method, and the mobility and carrier concentration were obtained through the Hall effect measurements Transmittance was measured in the visible region. The effects of substrate temperature and aluminum content in the starling solution on the structural and electrical properties of the AZO films are discussed

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.465-474
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• 2014

To validate the accuracy of the boiling heat flux partitioning model, an experiment was performed to investigate how the wall heat flux is divided into the three heat transfer modes of evaporation, quenching, and single-phase convection during subcooled nucleate boiling on a vertical wall. For the experimental partitioning of the wall heat flux, the wall heat flux and liquid-vapor distributions were simultaneously obtained using synchronized infrared thermometry and the total reflection technique. Boiling experiments of water with subcooling of $10^{\circ}C$ were conducted under atmospheric pressure, and the results obtained at the wall superheat of $12^{\circ}C$ and average heat flux of $283kW/m^2$were analyzed. There was a large difference in the heat flux partitioning results between the experiment and correlation, and the bubble departure diameter and bubble influence factor, which account for a portion of the surrounding superheated liquid layer detached by the departure of a bubble, were found to be important fundamental boiling parameters.

• Journal of Life Science
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• v.19 no.1
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• pp.34-39
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• 2009

Alginate with a MW of 1,283 kDa was hydrolyzed with 0.4 M organic acids at $100^{\circ}C$ for 3 hr. Molecular weights of alginates hydrolyzed with organic acids ranged from 7.5 to 53.2 kDa. There was no significant difference in the molar ratio of mannuronate to guluronate in alginates hydrolyzed with organic acids. Acetic add was found to be the most effective organic acid for hydrolysis of alginate. The MW of alginate decreased with increasing concentration and reaction time with acetic acid as a hydrolyzing agent. The correlations between the MW of hydrolyzed alginate and concentration of acetic acid as well as reaction time with 0.4 M acetic acid were plotted and the relevant equations obtained in this study. Polymannuronate and polyguluronate were isolated by pH adjustment of alginate hydrolyzed with 0.4 M acetic add. The molar percentages of mannuronate in polymannuronates isolated from alginate hydrolyzed with 0.4 M acetic acid at $100^{\circ}C$ were increasing in proportional to the reaction time such as 75% for 1 hr, 90% for 3 hr, and 98% for 5 hr of reaction time.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1373-1380
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• 2014

The thyroid hormone responsive protein (THRSP) gene is a functional gene that can be used to indicate the fatty acid compositions. This study investigates the relationships of exonic single nucleotide polymorphisms (SNPs) in the THRSP gene and fatty acid composition of muscle fat and marbling score in the 612 Korean cattle. The relationships between fatty acid composition and eight SNPs in the THRSP gene (g.78 G>A, g.173 C>T, g.184 C>T, g.190 C>A, g.194 C>T, g.277 C>G, g.283 T>G and g.290 T>G) were investigated, and according to the results, two SNPs (g.78 G>A and g.184 C>T) in exon 1 were associated with fatty acid composition. The GG and CC genotypes of g.78 G>A and g.184 C>T had higher unsaturated fatty acid (UFA) and monounsaturated fatty acid (MUFA) content (p<0.05). In addition, the $ht1^*ht1$ group (Val/Ala haplotype) in a linkage disequilibrium increased MUFAs and marbling scores for carcass traits (p<0.05). As a result, g.78 G>A and g.184 C>T had significantly relationships with UFAs and MUFAs. Two SNPs in the THRSP gene affected fatty acid composition, suggesting that GG and CC genotypes and the $ht1^*ht1$ group (Val/Ala haplotype) can be markers to genetically improve the quality and flavor of beef.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2903-2908
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• 2013

Background: Various oncogenes related to cancer have been extensively studied and several polymorphisms have been found to be associated with breast cancer. The current report outlines analysis of germ-line polymorphisms for C677T, A1298C (MTHFR), Leiden, R2 (FV) and 5G/4G (PAI-1) in Turkish breast cancer patients. We studied 51 cases diagnosed with invasive ductal and operable with lymph node-positive breast cancer and 106 women as a control group. Materials and Methods: Peripheric blood-DNA samples were used for genotyping by StripAssay technique which is based on the reverse-hybridization principle and real-time PCR methods and results were compared statistically. Results: The frequency of the MTHFR gene 677T and 1298A alleles were significantly higher in cancer patients than in the healthy subjects. The T allele frequency in codon 677 was 2.3-fold and C allele frequency was 3.1-fold increased in BC when compared to the control group for the MTHFR gene. Both differences were statistically significant (OR: 2.295, CI: 1.283-4.106), p<0.006 and (OR: 3.131, CI:1.826-5.369), p<0.0001 respectively. The R2 allele frequency of FV gene was 5.1-fold increased in the current BC when compared to the control group and that difference was also statistically significant (OR: 5.133, CI: 1.299-20.28), p<0.02. Conclusions: The present data suggest that germ-line polymorphisms of C677T, C1298A for MTHFR and R2 for FV are associated in breast cancer and may be additional prognostic markers related to breast cancer survival. The results now need to be confirmed in a larger group of patients.

• Economic and Environmental Geology
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• v.10 no.1
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• pp.1-18
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• 1977

Chongyang tungsten ore deposits, one of the most important tungsten mines in South Korea, me open space filling hydrothermal vein deposits embedded in Precambrian biotite gneiss and, Cretaceous (?) granite porphyry. Some wolframite-bearing quartz veins are closely associated with -quartz porphyries which strike about $N15^{\circ}-25^{\circ}W$ and dip $800^{\circ}SE$ to vertical. Mineralization took place in near vertical vein systems of 5 to 2000 meter long in the biotite gneiss and granite porphyry stock during early Cretaceous and Tertiary (?) period. The hydrothermal mineral paragensis has indicated that there were two major stages: vein and vug stages. The principal vein mineral is wolframite in a gangue of quartz with small amount of fluorite, pyrite, beryl and carbonate minerals. Present in minor amounts are molybdenite, bithmuthinite, native bismuth, arsenopyrite, galena, chalcopyrite, pyrrhotite, sphalerite and scheelite. Fluid inclusion study from the minerls at Chongyang mine reveals that vein stage fluids attained a temperature range of $200^{\circ}C-355^{\circ}C$ and vug stage $160^{\circ}C-350^{\circ}C$. The filling temperatures show the higher range of $200^{\circ}-355^{\circ}C$ in quartz and $280^{\circ}C-348^{\circ}C$ in beryls, whereas the lower emperature range of $283^{\circ}C-295^{\circ}C$ in rhodochrosite and $160^{\circ}-253^{\circ}C$ in fluorites. These temperatures are in reasonably good agreement with mineral paragnesis in this ore deposits. Volfamite minerals were analysed for major components. $WO_3$, MnO and FeO by wet chemical method. Chemical analysis indicates that they contain 70.56-71.54% $WO_3$, 8.52-10.01% MnO and 10.00-11.58% FeO. MnO/FeO ratios of wolframites shows the range of 0.78-0.94 which maybe indicates a comparatively high temperature type of hydrothermal deposits.

• The Korean Journal of Pain
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• v.33 no.3
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• pp.275-283
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• 2020

Background: Previous studies showed neurography and tractography of the greater occipital nerve (GON). The purpose of this study was determining diffusion tensor imaging (DTI) parameters of bilateral GONs and dorsal root ganglia (DRG) in unilateral cervicogenic headache as well as the grading value of DTI for severe headache. The correlation between DTI parameters and clinical characteristics was evaluated. Methods: The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in bilateral GONs and cervical DRG (C2 and C3) were measured. Grading values for headache severity was calculated using a receiver operating characteristics curve. The correlation was analyzed with Pearson's coefficient. Results: The FA values of the symptomatic side of GON and cervical DRG (C2 and C3) were significantly lower than that of the asymptomatic side (all the P < 0.001), while the ADC values were significantly higher (P = 0.003, P < 0.001, and P = 0.003, respectively). The FA value of 0.205 in C2 DRG was considered the grading parameter for headache severity with sensitivity of 0.743 and specificity of 0.999 (P < 0.001). A negative correlation and a positive correlation between the FA and ADC value of the GON and headache index (HI; r = -0.420, P = 0.037 and r = 0.531, P = 0.006, respectively) was found. Conclusions: DTI parameters in the symptomatic side of the C2 and C3 DRG and GON were significantly changed. The FA value of the C2 DRG can grade headache severity. DTI parameters of the GON significantly correlated with HI.