• 한국재료학회지
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• 제31권11호
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• pp.626-634
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• 2021

Cu matrix composites reinforced with chopped carbon fiber (CF), which is cost effective and can be well dispersed, are fabricated using electroless plating and hot pressing, and the effects of content and alignment of CF on the thermal properties of CF/Cu composites are studied. Thermal conductivity of CF/Cu composite increases with CF content in the in-plane direction, but it decreases above 10% CF; this is due to reduction of thermal diffusivity related with phonon scattering by agglomeration of CF. The coefficient of thermal expansion decreases in the in-plane direction and increases in the through-plane direction as the CF content increases. This is because the coefficient of thermal expansion of the long axis of CF is smaller than that of the Cu matrix, and the coefficient of thermal expansion of its short axis is larger than that of the Cu matrix. The thermal conductivity is greatly influenced by the agglomeration of CF in the CF/Cu composite, whereas the coefficient of thermal expansion is more influenced by the alignment of CF than the aggregation of CF.

• BMB Reports
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• 제37권6호
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• pp.700-708
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• 2004

The genes located within the p74 gene region of the Choristoneura fumiferana granulovirus (ChfuGV) were identified by sequencing an 8.9 kb BamHI restriction fragment on the ChfuGV genome. The global guanine-cytosine (GC) content of this region of the genome was 33.02%. This paper presents the ORFs within the p74 gene region along with their transcriptional orientations. This region contains a total of 15 open reading frames (ORFs). Among those, 8 ORFs were found to be homologues to the baculoviral ORFs: Cf-i-p , Cf-vi, Cf-vii, Cf-viii (ubiquitin), Cf-xi (pp31), Cf-xii (lef-11), Cf-xiii (sod) and Cf-xv-p (p74). To date, no specific function has been assigned to the ORFs: Cf-i, Cf-ii, Cf-iii, Cf-iv, Cf-v, Cf-vi, Cf-vii, Cf-ix and Cf-x. The most noticeable ORFs located in this region of the ChfuGV genome were ubiquitin, lef-11, sod, fibrillin and p74. The phylogenetic trees (constructed using conceptual products of major conserved ORFs) and gene arrangement in this region were used to further examine the classification of the members of the granulovirus genus. Comparative studies demonstrated that ChfuGV along with the Cydia pomonella granulovirus (CpGV), Phthorimaea operculella granulovirus (PhopGV), Adoxophyes orana granulovirus (AoGV) and Cryptophlebia leucotreta granulovirus (ClGV) share a high degree of amino acids sequence and gene arrangement preservation within the studied region. These results support a previous report, which classified a granuloviruses into 2 distinct groups: Group I: ChfuGV, CpGV, PhopGV and AoGV and Group II: Xestia c-nigrum granulovirus (XcGV) and Plutella xylostella granulovirus (PxGV). The phylogenetic and gene arrangement studies also placed ClGV as a novel member of the Group I granuloviruses.

• 대한기계학회논문집A
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• 제38권1호
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• pp.11-16
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• 2014

CF8M (11% ferrite) 주조 스테인리스강의 $310^{\circ}C$ 순수환경에서의 저주기피로 수명에 미치는 수소 및 미세구조의 영향을 분석하였다. CF8M 의 경우, 공기환경 대비 $310^{\circ}C$ 순수환경에서의 피로수명의 감소는 단조재인 316LN 에 비해 다소 작았다. 미세구조 및 파면 분석을 통해, CF8M 의 저주기피로 수명의 감소는 316LN 의 경우와 마찬가지로 수소유기균열에 의한 것으로 판단되었다. 그러나, CF8M 의 경우, 페라이트상 경계에 수소유기균열에 의한 2 차 균열이 빈번히 발생함에 따라 균열 선단에서의 응력집중이 저하되는 효과가 있었다. 이러한 응력집중의 완화로 인해 수소유기균열에 의한 피로균열진전이 둔화되어 결과적으로 저주기피로 수명의 저하가 완화되는 것으로 판단되었다.

• The Plant Pathology Journal
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• 제25권3호
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• pp.291-293
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• 2009

The low virus titer in woody plant tissues and the presence of inhibitor compounds such as polyphenols, tannins and polysaccharides are common difficulties that compromise purification of plant viroids from their woody hosts. A simple, reliable method of RNA isolation using CF11 cellulose column on a microcentrifuge tube scale for detecting Apple scar skin viroid (ASSVd) in apple was developed. Total RNA extracted from leaf, woody bark and the fruit skin was used for reverse transcription. RT-PCR products could be detected from RNA prepared from dormant woody bark, fruit skin and fresh leaves with both the CF11 cellulose column method and NucliSens extractor in February, August and November. Meanwhile, with the RNeasy kit RT-PCR, products were detected only in leaves and not from bark or fruit skin. The PCR product, about 330 base pairs, was analyzed by agarose gel electrophoresis. The CF11 cellulose column method was effective for detecting ASSVd. The method enabled the processing of a large numbers of samples of dormant woody bark, leaf and fruit skin of apple.

• 한국식품과학회지
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• 제14권1호
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• pp.72-79
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• 1982

Aspergillus niger CF를 최초(最初)의 균주(菌株)로 하고 이것에 자외선조사처리(紫外線照射處理)를 하여 돌연변이균주(變異菌株) Asp. niger CF-11을 얻었으며 이어서 NTG 처리(處理)에 의(依)하여 Asp. neger CF-11 균주(菌株)에서 변이균주(變異菌株) Asp. niger CF-22 및 CF-21를 분리(分離)하였다. 변이균주(變異菌株)의 특징(特徵)을 조사(調査)하고 밀기울국(麴) 및 밀가루국(麴)에서의 효소생산(酵素生産) 및 산생성(酸生成)을 검토(檢討)한 결과(結果)는 아래와 같다. 1. Asp. niger CF-22 변이균주(變異菌株)는 포자두(胞子頭)의 색(色)이 변(變)한 tan type의 균주(菌株)였으며 CF-22는 최초(最初)의 친주(親株) CF에 비(比)하여 밀기울국배양(麴培養)의 최적조건(最適條件)에서 글루코아밀라아제활성(活性)이 약(約) 2배(倍), ${\alpha}-$아밀라아제활성(活性)은 약(約) 50% 증가(增加)되었다. 2. Asp. niger CF-21 변이균주(變異菌株)는 포자두(胞子頭)의 색(色)은 변(變)하지 않았으나 밀기울국(麴)에서 생육(生育)과 포자착성(胞子着性)이 최초(最初)의 친주(親株) CF보다 늦었다. 이 변이균주(變異菌株)의 산생성력(酸生成力)은 최초(最初)의 친주(親株)보다 약(約) 4배(倍) 많았다. 3. Asp. niger CF-22 변이균주(變異菌株) 및 CF-21 변이균주(變異菌株)는 최초(最初)의 친주(親株)보다 클루코아밀라아제 및 ${\alpha}-$아밀라아제활성(活性)은 증강(增强)되었으나 단백질 가수분해효소의 활성(活性)은 오히려 떨어졌다. 4. 밀기울국(麴)에서 Asp. niger CF-22 변이균주(變異菌株)의 글루코아밀아제 생성(生成)의 최적조건(最適條件)은 $30{\sim}35^{\circ}C$에서 $2{\sim}3$일간(日間)이었으며 ${\alpha}-$아밀라아제의 경우는 $30{\sim}35^{\circ}C$에서 2일간(日間)이었다. 5. Asp. neger CF-21 변이균주(變異菌株)의 산생성력(酸生成力)은 밀기울국(麴)에서 $30^{\circ}C$로 2일후(日後)에 최고(最高)에 달(達)하였으며 밀가루국(麴)에서는 $30^{\circ}C$로 3일후(日後)에 최고(最高)값을 나타내었다. 최적조건(最適條件)에서의 산생성력(酸生成力)은 밀기울국(麴)과 밀가루국(麴) 사이에 차(差)가 별(別)로 없었다.

• 한국전기전자재료학회논문지
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• 제17권11호
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• pp.1252-1257
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• 2004

This paper describes the information for quantitative simulation of weakly ionized plasma. In previous paper, we calculated the electron transport coefficients by using two-term approximation of Boltzmann equation. But there is difference between the result of the two-term approximation of the Boltzmann equation and experiments in pure CF$_4$ molecular gas and in CF$_4$+Ar gas mixture. Therefore, In this paper, we calculated the electron drift velocity (W) in pure CF$_4$ molecular gas and CF$_4$+Ar gas mixture (1 %, 5 %, 10 %) for range of E/N values from 0.17～300 Td at the temperature was 300 K and pressure was 1 Torr by multi-term approximation of the Boltzmann equation by Robson and Ness. The results of two-term and multi-term approximation of the Boltzmann equation have been compared with each other for a range of E/N.

• 한국초지조사료학회지
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• 제27권1호
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• pp.45-52
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• 2007

본 연구는 2003년 8월부터 2005년 12월까지 농촌진흥청 난지농업연구소의 기존 혼파 방목초지(해발 200m)에서 실시하였으며 방목 혼파초지에 우분퇴비 시용에 따른 사초생산성 및 토양 개선 효과를 구명하기 위하여 수행되었다. 화학비료 단용구, 우분퇴비 단용구, 화학 및 우분퇴비의 시용수준, 화학비료와 퇴비의 연차별 교호시용 등의 처리를 두어 우분퇴비 시용이 혼파초지의 사초생산성 및 토양성분에 미치는 영향을 조사하였다. 연간 총건물수량을 비교해보면 시험1년차에는 T1처리구가 11,342 kg/ha, 시험2년차에는 T5처리구가 13,468kg/ha, 3년차는 T6처리구가 10,724kg/ha로 가장 높은 수량을 보였으며 시험기간 동안 평균 건물수량은 화학비료구가 11,486kg/ha으로 가장 높은 건물생산성을 보였지만 처리 간 유의성은 없었다. 처리별 토양성분 변화는 퇴비구에서 화학비료구 보다 유효인산, 유기물 함량 등이 증가를 보임으로서 토양개선효과가 나타났으며 목초의 식생구성율은 처리구에 따라 큰 차이를 보이지 않았으며 봄철에는 화본과가 다소 높다가 여름철이 지나면서 두과와 잡초의 비율이 상승하는 경향을 보였다.

• 정보처리학회논문지C
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• 제12C권3호
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• pp.387-394
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• 2005

IEEE 802.11e를 포함한 IEEE 802.11x의 모든 매체접속제어 부계층은 형태는 다르지만 공통적으로 CP(Contention Period)와 CFP(Contention Free Period) 서비스 기능을 정의하고 있다. 본 논문에서는 현재 여러IEEE 802.11x PCF나 IEEE 802.11e HCCA 상에서 서비스되고 있는 기존 라운드로빈 방식의 폴링 기법을 수정하여 트래픽의 부하가 큰 채널을 선택하여 가중치를 주어 서비스할 수 있는 New-CF 방식을 제안하였다. NS-2로 기존 기법과의 비교를 수행한 시뮬레이션 결과 전체적인 통과율이 상승한 것을 검증하였다.

• 대한기계학회논문집A
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• 제23권11호
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• pp.2014-2021
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• 1999

The present investigation is concerned with the degradation characteristics of cast stainless steel(CF8M), exposed to the $\sigma$-phase degradation at $700^{\circ}C$. In the present paper, the degradation of CF8 M at $700^{\circ}C$ is evaluated by a non-destructive test, DL-EPR(double loop electrochemical potentiokinetic reactivation). The surface of specimens is observed by using scanning electron microscopy after DL-EPR test. Also. chromium contents of matrix, grain boundary and ferrite phase are analyzed by electron probe X-ray micro analyzer. Through the experiments, the following results are obtained 1) The degree of sensitization(DOS) of CF8M aged up to 15hr at $700^{\circ}C$ is increased with acing time while that is decreased with aging time from 15hr to 150hr. 2) The impact energy decreases with increase of $\sigma$-phase while DOS increases with $\sigma$-phase until aging time reaches to 15hr. After the aging time. 15hr, the $\sigma$-phase and the rate of impact energy with respect to aging time decreases. Therefore the degradation behavior of the CF8M can be evaluated by comparing SEM micrographs and the value of DOS.

• 한국염색가공학회지
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• 제11권1호
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• pp.25-33
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• 1999

PET fabric was grafted with $CF_4$ or $C_2F_6$ plasmas generated by glow discharge. The water repellency of plasma-treated fabrics were evaluated with contact angle meter. The change in surface morphologies was observed by SEM, and the change of surface chemical characteristics were analyzed by FT-IR, ESCA and microchemical analysis technique. The results obtained are as follows : 1) The contact angle of plasma-treated fabric was over $150^\circ{C}$. 2) It was observed by SEM that the surface of treated substrate was over coated with thin film formed by the fluorocarbon plasma treatment. 3) According to ESCA analysis, there were prevailing -CHF-, $-CF_2$- and a little $-CF_3$ components on fluorocarbon plasma treated substrate. -CHF- and $-CF_2$- components were reduced by washing, and $-CF_2$- component was recovered by heat treatment. 4) In consideration of quantitative analysis of fluorine and F/C ratio by ESCA, we found that fluorination reached to the inner of substrate.