• Korean Journal of Materials Research
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• v.31 no.11
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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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• v.37 no.6
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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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.11-16
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• 2014

The effects of environment and microstructure on low cycle fatigue (LCF) behaviors of CF8M stainless steels containing 11% of ferrites were investigated in a $310^{\circ}C$ deoxygenated water environment. The reduction of LCF life of CF8M in a $310^{\circ}C$ deoxygenated water was smaller than 316LN stainless steels. Based on the microstructure and fatigue surface analyses, it was confirmed that the hydrogen induced cracking contributed to the reduction in LCF life for CF8M as well as for 316LN. However, many secondary cracks were found on the boundaries of ferrite phases in CF8M, which effectively reduced the stress concentration at the crack tip. Because of the reduced stress concentration, the accelerated fatigue crack growth by hydrogen induced cracking was less significant, which resulted in the smaller environmental effects for CF8M than 316LN in a $310^{\circ}C$ deoxygenated water.

• The Plant Pathology Journal
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• v.25 no.3
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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.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.72-79
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• 1982

Several mutants were isolated from the parent strain of Aspergillus niger CF: the first mutant strain CF-11 was obtained by UV irradiation, and the second mutant strain CF-21 and CF-22 were from NTG (N-methyl-N'-nitroso-N-nitroso-guanidine) treatment on the CF-11. These mutants were characterized, and their enzyme and acid production on wheat bran Koji and wheat flour Koji were studied. Asp. niger CF-22 mutant appeared to be tan type which conidial heads were discolored. It's glucoamylase activity was inreased approximately two times and its ${\alpha}-amylase$ about 50 percent as compared with that of the parent strain of Asp. niger CF, when grown on wheat bran Koji under the optimal conditions. Asp. niger CF-21 mutant showed slower growth rate and poor sporulation than the wild type, although its conidial heads were not discolored. Approximately 4-fold increment in its acid production was observed as compared with the weld type. The activities of glucoamylase and ${\alpha}-amylase$ of the Asp. niger CF-22 and CF-21 mutants were higher than those of the wild type, but their protease activity was rather lower. The maximum production of glucoamylase by the Asp. niger CF-22 mutant was obtained after 2 to 3 days incubation on wheat bran at 30 to $35^{\circ}C;$ ${\alpha}-amylase$2 days incubation at 30 to $35^{\circ}C$. The maximal levels of acid production by the mutant CF-21 was appeared after 2 days incubation on wheat bran Koji, and after 3 days on wheat flour Koji at $30^{\circ}C$. Little differences in the levels of acid production were observed between on wheat bran and flour Koji.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.11
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.1
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• pp.45-52
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• 2007

This study was conducted from 2003 to 2005 at crop field of National Institute of Subtropical Agriculture, RDA, in Jeju. The treatment consisted of chemical fertilizer 100%(CF 100%, T1), cattle manure 100%(CM 100%, T2), CF 50%+CM 50%(T3), CF 25%+CM 75%(T4), CM 100%(1st yr.)+CF 100%(2nd yr,)+CM(3rd yr)(T5), CM 100%(1st yr.)+CF 100%(2nd yr.)+CF(3rd yr.)(T6). The highest substitution effect of chemical fertilizer for cattle manure indicated that the highest yield(Avg. 11,169 kg/ha) obtained from CM 100%(1 yr.)+CF 100%(2 yr.) treatment. The forage yield of CM 100%(1 yr.)+CF 100%(2 yr.) was 4% more than CM 100% application whereas was 3% less than CF 100% application. Changes of physical and chemical properties of soils for applications of CF 100% and CM 100% was clearly in cattle manure application. Especially, cattle manure application in pasture were superior to chemical fertilizer application with respect to organic matter(OM, %), total nitrogen(T-N, %), and avaliable phosphorous($P_2O_5$, %) contents of soils. In this present study, cattle manure application recorded slightly lower forage yields than CF 100% application but the combined use of cattle manure and chemical fertilizer was attribute to reduction of chemical fertilizer application rate as well as maintaining soil health on long-term basis.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.387-394
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• 2005

Every MAC (Medium Access Control) sub-layers of IEEE 802.11x, including IEEE 802.11e, defines Connection-based and CF (Contention Free)-based service functions in common. In this paper, a New-CF method is proposed. In the proposed method, conventional Round Robin method, which is used as a polling method by IEEE 802.11x PCF (Point Coordination Function) or IEE 802.11e HCCA, is modified to give weights to channels with heavier traffic load and to provide those weighted channels with more services. Based on NS-2 simulations, it is verified the proposed method shows better throughput in general, particularly under unbalanced traffic load conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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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.

• Textile Coloration and Finishing
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• v.11 no.1
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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.