• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1449-1450
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• 2011

The SiC-$ZrB_2$ composites were produced by subjecting a 40:60 (vol.%) mixture of zirconium diboride($ZrB_2$) powder and ${\beta}$-silicon carbide (SiC) matrix to spark plasma sintering(SPS) under argon atmosphere at 50MPa(P50) and 60MPa(P60) pressure. The relative density, 94.13% of P60 sample was lower than that, 94.75% of P50 sample. Reactions between ${\beta}$-SiC and $ZrB_2$ were not observed via x-ray diffraction (hereafter, XRD) analysis. The trend of flexural strength of SiC-$ZrB_2$ composites were in accordance with the relative density. The properties of a SiC-$ZrB_2$ composites through SPS under argon atmosphere were positive temperature coefficient resistance in the temperature range from $25^{\circ}C$ to $500^{\circ}C$, and electrical resistivity of P50 and P60 sample were $6.75{\times}10^{-4}$ and $7.22{\times}10^{-4}{\Omega}{\cdot}cm$ at room temperature, respectively.

• Journal of Powder Materials
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• v.11 no.3
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• pp.259-264
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• 2004

Aluminum based metal matrix composite reinforced with SiC particles was fabricated by the powder-in sheath rolling method. A stainless steel tube with outer diameter of 12 mm and wall thickness of 1mm was used as a sheath. Mixture of aluminum powder and SiC particles of which volume content was varied from 5 to 20vol.% was filled in the tube by tap filling and then rolled to 75% reduction at ambient temperature. The rolled specimen was sintered at 56$0^{\circ}C$ for 0.5hr. The tensile strength of the (SiC)$_{p}$/Al composite increased with the volume content of SiC particles, and at 20vol.% it reached a maximum of 100㎫ which is 1.6 times higher than unreinforced material. The elongation decreased with the volume content of $Al_{2}$O$_{3}$ particles. The mechanical properties of the (SiC)$_{p}$/Al composite fabricated by the powder-in sheath rolling is compared with that of (Al$_{2}$O$_{3}$)$_{p}$/Al composite by the same process.ess.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.653-659
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• 2009

It is proved that if $M\;=\;B_p(3)$ or $C_p(3)$, p is an odd prime, G is a finite group and has the same order components of M, then $G\;{\cong}\;Bp(3)$ or $C_p(3)$.

• Communications of the Korean Mathematical Society
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• v.18 no.4
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• pp.695-701
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• 2003

In this paper, we have characterizations of almost P-spaces which are analogous characterizations of P-spaces and we will show that if X is an almost P-space such that it is $C^{*}-embedded$ in every almost P-space in which X is embedded, then $$\mid${\upsilon}X-X$\mid${\leq}1$ and that if $$\mid${\upsilon}X-X$\mid${\leq}1$ and ${\upsilon}X$ is Lindelof, then for any almost P-space Y in which X is dense embedded, then X is $C^{*}-embeded$ in Y.

• Journal of Korean Neurosurgical Society
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• v.61 no.2
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• pp.186-193
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• 2018

Objective : The purpose of this study was to evaluate pain-related behaviors after bilateral C2 root resection and change in pain patterns in the suboccipital region in rats. Methods : Male Sprague-Dawley rats were randomly assigned to three groups (n=25/group); $n{\ddot{a}}ive$, sham, and C2 resection. Three, 7, 10, and 14 days after surgery, cold allodynia was assessed using $20{\mu}L$ of 99.7% acetone. c-Fos and c-Jun were immunohistochemically stained to evaluate activation of dorsal horn gray matter in C2 segments of the spinal cord 2 hours, 1 day, 7 days, and 14 days after surgery. Results : Three days after surgery, the response to acetone in the sham group was significantly greater than in the $n{\ddot{a}}ive$ group, and this significant difference between the $n{\ddot{a}}ive$ and sham groups was maintained throughout the experimental period (p<0.05 at 3, 7, 10, and 14 days). Seven, 10, and 14 days after surgery, the C2 root resection group exhibited a significantly greater response to acetone than the $n{\ddot{a}}ive$ group (p<0.05), and both the sham and C2 resection groups exhibited significantly greater responses to acetone compared with 3 days after surgery. No significant difference in cold allodynia was observed between the sham and C2 root resection groups throughout the experimental period. Two hours after surgery, both the sham and C2 root resection groups exhibited significant increases in c-Fos- and c-Jun-positive neurons compared with the naive group (p=0.0021 and p=0.0358 for the sham group, and p=0.0135 and p=0.014 for the C2 root resection group, respectively). One day after surgery, both the sham and C2 root resection groups exhibited significant decreases in c-Fos -positive neurons compared with two hours after surgery (p=0.0169 and p=0.0123, respectively), and these significant decreases in c-Fos immunoreactivity were maintained in both the sham and C2 root resection groups 7 and 14 days after surgery. The sham and C2 root resection groups presented a tendency toward a decrease in c-Jun-positive neurons 1, 7, and 14 days after surgery, but the decrease did not reach statistical significance. Conclusion : We found no significant difference in cold allodynia and the early expression of c-Fos and c-Jun between the sham and C2 resection groups. Our results may support the routine resection of the C2 nerve root for posterior C1-2 fusion, but, further studies are needed.

• Korean Journal of Plant Resources
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• v.31 no.6
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• pp.660-666
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• 2018

In order to understand the characteristics of soil according to the cultivation environment of Chinese bellflower (Platycodon grandiflorum A.), soil chemical properties of 12 collected soil samples from 6 cultivated fields in Okcheon, Chungbuk province in August. 2017 were analyzed. The soil pH was distributed within the range of 4.61 to 5.25 at all cultivation years and E.C (Electric Conductivity) and T-N (Total Nitrogen) of the cultivation year were not significant. Available $P_2O_5$ was higher than the average for medicinal crops and P. grandiflorum in Korea and C.E.C (Cation Exchange Capacity) was inconsistent for each cultivation year. In particularly, it was validated that the content of exchangeable cations K, Ca, Ma, and Na in this experiment was similar to that of C.E.C according to the cultivation years, because C.E.C had a high correlation with the exchangeable cations. For the available $P_2O_5$, as affected by trans-planting, 5Y-NT-H (cultivated 5 years and non-transplanted) had 58 mg/kg, while 5Y-T-H (cultivated 5 years and transplanted) had 246 mg/kg. The soil pH was found to be lower (acidic) in diseased soils than healthy soils. E.C was confirmed to be was higher in diseased soils than healthy soils except for the one cultivated for 2 years. The contents of T-N and available $P_2O_5$ were higher in diseased soil except for the one cultivated for 5 years and 11 years. The exchangeable cation K and Na tended to be higher in diseased soils rather than that in healthy soils, and the exchangeable cation Ca and Mg contents were higher in healthy soils than in diseased soils. The C.E.C of the soil was lower than that of healthy soils in all of the years except for the one which was cultivated for 5 years (transplanted).

• Food Science of Animal Resources
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• v.31 no.4
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• pp.580-587
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• 2011

In this study, the effects of gamma-irradiation (1, 2 and 4 kGy) on texture profiles, fatty acid composition, free amino acids and sensory evaluation of dry-fermented sausage were evaluated. The hardness and adhesiveness of irradiated samples were significantly lower (p<0.01) than that of the control, while the gumminess of samples irradiated with 2 and 4 kGy was higher than the other tested samples (p<0.01). The sample irradiated at 4 kGy had a higher saturated fatty acid (SFA) content (C14:0, C16:0, C18:0) and significantly lower (p<0.05) unsaturated fatty acid content (UFA) (C16:1, C18:1, C18:3), trans, n-3 and n-6 fatty acid than the non-irradiated sample. Gamma-irradiation resulted in an increase (p<0.05) in phosposerine, aspartic acid and glutamic acid and a decrease (p<0.05) in glutamic acid in free amino acids. For the samples irradiated at 4 kGy, the sulfur odor and fat pungent flavor were significantly higher (p<0.05) and the moldy odor and moldy flavor were significantly lower than the control sample. In conclusion, gamma-irradiation had a significant effect on the texture profiles, fatty acid composition and sensory evaluation of dry-fermented sausage.

• The Journal of Korean society of community based occupational therapy
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• v.7 no.2
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• pp.1-8
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• 2017

Objectives : This study was conducted to investigate the activity of the supra and infrahyoid muscles according to the temperature and the amount of water in healthy adults. Methods : The amount of water was set to 3 mL and 20 mL, and the temperature was subdivided into $4^{\circ}C$, $22^{\circ}C$, and $40^{\circ}C$ in order to compare the activity of the supra and infrahyoid muscles in twenty-seven healthy adults. We used the mean value of the activity of the supra and infrahyoid muscles while they were swallowing saliva in order to set the reference voluntary contraction (%RVC). Results : Muscle activity was significantly increased when they swallowed 20 mL of water rather than 3 mL in the left infrahyoid muscles at $4^{\circ}C$, $22^{\circ}C$ and $40^{\circ}C$ (p=.00; p=.00; p=.00), the right infrahyoid muscles at $22^{\circ}C$and $40^{\circ}C$ (p=.01; p=.01), the left suprahyoid muscles at $4^{\circ}C$ (p=.03). Muscle activity of the right suprahyoid muscles was significantly decreased at $40^{\circ}C$ compared to $4^{\circ}C$ and $22^{\circ}C$ when they swallowed 20 mL of water (p=.04). Conclusion : In the future, other variables such as viscosity and taste should be considered, and further studies on patients with impaired nervous system as well as healthy subjects will be needed.

• Food Science of Animal Resources
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• v.27 no.2
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• pp.171-178
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• 2007

This study was conducted to investigate the effect of ageing temperature(0 and $4^{\circ}C$) and time(2, 7, 14, 21, 28, and 49 days) on the meat quality of longissimus muscle from Hanwoo steer. The pH, Warner-Bratzler shear force(WBSF), myofibrillar fragmentation index(MFI), cooking and purge loss, sensory, morphological changes, and amino acid composition were assessed. The pH of longissimus muscle increased significantly(p<0.05) for 21 days at $0^{\circ}C$ and 14 days at $4^{\circ}C$, but decreased thereafter. Longissimus muscle aged from 14 days to 28 days at $4^{\circ}C$ had a lower WBSF than longissimus muscle aged at $0^{\circ}C$(p<0.05). The WBSF of longissimus muscle decreased significantly(p<0.05) with ageing time. The MFI, cooking and purge loss, tenderness, and juiciness scores were higher for longissimus muscle aged at $4^{\circ}C$ than at $0^{\circ}C$. As ageing time increased, the MFI, cooking and purge loss, tenderness, juiciness, and amino acid composition of longissimus muscle increased significantly(p<0.05) with ageing at 0 or $4^{\circ}C$. Transmission electron microscopy showed Z-disk degradation and morphological changes of the myofibrils correlating with increased tenderness during the ageing time. Based on these results, the proper ageing conditions of longissimus muscle of Hanwoo steer were 14 days of ageing at $0^{\circ}C$ or 7 days of ageing at $4^{\circ}C$. However, further study on the application of ageing technology to this industry is necessary for the optimization of ageing conditions for the sub-primals or muscles from Hanwoo beef.

• Applied Biological Chemistry
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• v.39 no.6
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• pp.472-476
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• 1996

The major portions of two DNA fragments, one from degradative plasmid, pRA4000 from Pseudomonas putida NCIMB 9866, and the other from degradative plasmid, pRA500 from P. putida NCIMB 9869, which harbor the structural genes for the flavoprotein (pchF) and cytochrome (pchC) subunits of p-cresol methylhydroxylase (PCMH), have been sequenced. The DNA and deduced amino acid sequences for pchC and pchF have been published. In these fragments, a coding region (dhal) for an aldehyde dehydrogenase has been identified. It is proposed that this gene encodes for the aldehyde dehydrogenase which converts p-hydroxybenzyaldehyde to p-hydroxybenzoate. p-Hydroxybezealdehyde is the product of oxidation of p-cresol by PCMH. The fragment from P. putida 9869 also harbors the genes for the ${\alpha}$ (pcaG) and ${\beta}$ (pcaH) subunits of protocatechuate 3,4-dioxigenase. The fragment from 9866 does not have any portion of these genes in the corresponding region A possible open reading frame (ORF) between pchC and pchF is seen for both clones, and a second putative open reading frame (ORF') also exists in the 9866 clone. The gene organizations are dhal-pchC-ORF-pchF-pcaGH for the DNA fragment from 9869, and ORF-dhal-pchC-ORF-pchF for the DNA fragment from 9866.