• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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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.

• 한국분말재료학회지
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• 제11권3호
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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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• 제27권3_4호
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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 $C_p(3)$.

• 대한수학회논문집
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• 제18권4호
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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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• 제61권2호
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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.

• 한국자원식물학회지
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• 제31권6호
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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).

• 한국축산식품학회지
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• 제31권4호
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• pp.580-587
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• 2011

본 연구는 감마선 조사가 건조-발효햄의 조직감, 지방산, 유리아미노산 및 관능적 특성에 미치는 영향을 조사하기 위해 실시하였다. 경도(hardness) 및 부착성(adhesiveness) 의 경우 조사 처리구가 유의적으로 낮게 나타났다(p<0.01). 검성(gumminess)의 경우에는 2 및 4 kGy처리구가 대조구 및 1 kGy처리구보다 유의적으로 높은 값을 나타내었다(p<0.01). 지방산의 경우 처리구의 포화지방산(SFA)(C14:0, C16:0, C18:0)은 유의적으로 높았고(p<0.05), 불포화지방산 (UFA)(C16:1, C18:1 및 C18:3), trans 지방산, n-3 및 n-6 지방산 의 함량은 4 kGy처리에서 감소하였다(p<0.05). 감마선 조사처리는 phosposerine, aspartic acid, glutamic acid를 증가 시켰으나, lysine은 감소시켰다(p<0.05). 관능검사의 경우, 황취(sulfur odor) 및 지방산화 맛(fat pungent flavor)은 4 kGy에서 가장 높게 나타났으며(p<0.05), 곰팡이 냄새(moldy odor) 및 곰팡이 맛(moldy flavor)은 낮게 나타났다(p<0.05). 이상의 결과 감마선 조사가 조직감, 지방산조성 및 관능적 특성에 영향을 미쳤다.

• 대한지역사회작업치료학회지
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• 제7권2호
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• pp.1-8
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• 2017

목적 : 본 연구는 정상 성인을 대상으로 삼킴 시 물의 온도와 양에 따른 목뿔위근육과 목뿔아래근육의 활성도를 측정하여, 임상에서 삼킴장애를 평가하기 위한 기초자료로 활용하고자 하였다. 연구 방법 : 건강한 성인 27명을 대상으로 물의 양과 온도에 따른 목뿔위근육과 목뿔아래근육의 근활성도를 비교하기 위하여 양은 3 mL, 20 mL로, 온도는 $4^{\circ}C$, $22^{\circ}C$, $40^{\circ}C$로 각각 설정하였고, 대상자별로 기준값(reference voluntary contraction, %RVC)을 설정하기 위하여, 침을 삼키는 동안 오른쪽 및 왼쪽 목뿔위근육과 목뿔아래근육의 활성도를 3회 측정하여 평균값을 사용하였다. 연구 장비는 안드로이드 기반 근전도 측정 장비인 2EM(4D-MT, Relive, Gimhae, Korea)을 이용하여 자료를 수집, 처리하였다. 결과 : 양을 기준으로 비교했을 때 왼쪽 목뿔아래근육은 $4^{\circ}C$, $22^{\circ}C$, $40^{\circ}C$에서 (p=.00; p=.00; p=.00), 오른쪽 목뿔아래근육은 $22^{\circ}C$와 $40^{\circ}C$에서 (p=.01; p=.01), 왼쪽 목뿔위근육은 $4^{\circ}C$에서 (p=.03), 3 mL 물보다는 20 mL 물을 삼킬 때 근활성도가 증가하였다. 온도를 기준으로 분석한 결과 20 mL의 물을 삼킬 때 $4^{\circ}C$, $22^{\circ}C$ 보다는 $40^{\circ}C$ 조건에서 오른쪽 목뿔위근육의 근활성도가 유의하게 감소하였다 (p=.04). 결론 : 20 mL가 3 mL보다 오른쪽 및 왼쪽 목뿔아래근육, 왼쪽 목뿔위근육에서 근활성도가 유의하게 증가하였고, $40^{\circ}C$가 $4^{\circ}C$, $22^{\circ}C$보다 오른쪽 목뿔위근육에서 근활성도의 유의한 감소를 보였으나, 양과 온도를 모두 고려한 일부조건에서만 의미가 있었다. 추후에는 점도, 맛 등의 다른 변수를 고려하여 건강한 대상자 뿐 아니라 신경계 손상환자를 대상으로 한 임상연구가 더 필요할 것이다.

• 한국축산식품학회지
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• 제27권2호
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• pp.171-178
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• 2007

본 연구는 숙성온도와 숙성기간이 한우 거세우 배최장근의 육질 특성에 미치는 영향을 구명하고자 숙성온도를 0, $4^{\circ}C$로 하여 2, 7, 14, 21, 28, 49일 동안 숙성하면서 한우 거세우 배최장근의 pH, 전단력, MFI, 가열 및 육즙감량, 전자현미경 관찰, 관능검사 및 아미노산 조성을 분석하였다. pH는 숙성온도가 $0^{\circ}C$일 때 숙성 21일까지, 숙성온도가 $4^{\circ}C$일 때 숙성 14일까지 증가하다가 감소하였다(p<0.05). 전단력 값은 숙성 14일부터 28일까지 $4^{\circ}C$에서 숙성한 배최장근이 $4^{\circ}C$보다 유의적으로 낮았고, 숙성기간이 경과함에 따라 유의적으로 연도가 향상되었다(p<0.05). MFI의 경우 $4^{\circ}C$에서 숙성한 배최장근 보다 $0^{\circ}C$에서 높은 경향을 보였고, 숙성기간이 경과함에 따라 유의적으로 증가하였다(p<0.05). $0^{\circ}C$에서 숙성한 배최장근의 가열 및 육즙감량이 $4^{\circ}C$보다 적은 경향이었고, 숙성기간이 경과함에 따라 유의적으로 증가하였다(p<0.05). 관능검사에서 연도와 다즙성은 $0^{\circ}C$에서 숙성한 배최장근이 $4^{\circ}C$ 보다 좋은 평가를 보였고, 숙성기간이 경과하면서 유의적으로 높은 평가를 얻었다(p<0.05). 전자현미경에 의한 미세구조 변화는 $4^{\circ}C$에서 숙성한 배최장근이 $0^{\circ}C$보다 1주일 빠르게 Z-disk의 붕괴가 확실하게 관찰되었고, 숙성기간이 경과하면서 Z-disk의 붕괴정도가 많아졌다. 아미노산 함량 변화는 $4^{\circ}C$에서 숙성한 배최장근이 $0^{\circ}C$보다 높은 경향이었고, 숙성기간이 경과하면서 각 아미노산 조성의 함량이 유의적으로 증가하였다(p<0.05). 이상의 결과를 종합하면, 한우 거세우 등심의 최적 숙성 조건은 $0^{\circ}C$에서는 14일간, $4^{\circ}C$에서는 7일간 숙성하는 것이 바람직한 것으로 사료되며, 향후 숙성기술의 산업적 적용을 위하여 한우의 부위 및 근육별 적정 숙성기간 설정 연구가 필요할 것으로 생각된다.

• Applied Biological Chemistry
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• 제39권6호
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• pp.472-476
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• 1996

P.putida NCIMB 9869와 P. putida NCIMB 9866의 분해 plasmid pRA 4000과 pRA500으로부터 p-cresol mothylhydroxylase(PCMH)의 flavoprotein(pchF) 및 cytochrome(pCHC) subunit의 구조유전자를 sequencing하였다. 이 두개의 유전자의 DNA 및 아미노산의 염기 서열은 이미 발표를 하였다. 이 두 개의 유전자 이외에도 aldehyde dehydrogenase 유전자가 확인되었다. 이 aldehyde dehydrogenase는 p-hydroxybezaldehyde를 p-hydroxybenzonate로 전환시키는데 p-hydroxybezaldehyde는 P-cresol의 PCMH에 의한 분해 산물이다. 그 외에도 P. putida 9869의 protocatechuate 3,4-dioxigenase의 alpha(pcaG) 및 beta(pcaH) subunit 가 확인되었다. 반면에 P. putida 9866는 상응하는 영역에 이 유전자들을 가지고 있지 않았다(protocatechuate는 p-hydroxyben-zonate hydroxylase에 의해 p-hydroxybenzonate로부터 생성된다). pchC와 pchF사이에 open reading frame이 존재하며 9866로 부터는 추가로 다른 하나의 open reading frame (ORF')가 존재한다. 9869과 9866의 유전자 구조는 각각 dhal-pchC-ORF-pchF-pcaGH과 ORF'-dhal-pchC-ORF-pchF다.