• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.859-867
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• 2011

The cold start problem is one of major obstacles to overcome for the commercialization of fuel cell vehicles. However, the cold start characteristics of fuel cell systems are very complicated since various phenomena, i.e. ice-blocking, electro-chemical reactions, heat transfer, and defrosting of BOP components, are involved in them. This paper presents a framework to approach the problem at a full stack scale using Axiomatic Design (AD). It was characterized in terms of Functional Requirements (FRs) and Design Parameters (DPs) while their relations were established in a design matrix. Considering the design matrix, the endplates should have low thermal conductivity and capacity without increase in weight or decrease in structural stiffness. Consequently, composite sandwich endplates were proposed and examined both through finite element analyses and experiments simulating cold start conditions. From the examinations, it was found that the composite sandwich endplates significantly contributed to improving the cold start characteristics of PEMFC.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.241-243
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• 2005

This paper describes development of intelligent solid insulated switchgear for next generation distribution line. Nowadays, for switchgear, increased to substitute eco-friendly environment and smart ability. In relation to a project to development of intelligent solid insulated switchgear, a comparison of insulation for substitution insulation medium, to show a composition of intelligent solid Insulated switchgear and valuation on characteristics for each of module.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.245-250
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• 1986

Antibiotic resistant bacteria isolated from the river water in Cheongju City were studied on the transfer of their R-plasmids in water environment. The R-plasmids were transferred by conjugation between the isolates ai the frequencies of 1.1$\times$10$^{-6}$ to 1.2$\times$10$^{-7}$ under laboratory condition and 1.2$\times$10$^{-7}$ to 1.0$\times$10$^{-9}$ in natural environment. The R-plasmids isolated from those bacteria were also transferred into the recipient cells of E. coli HB101 at the frequencies of 1.7-6.7$\times$10$^{-6}$. The AP$^{r}$Cm$^{r}$Tc$^{r}$-plasmid of isolate T-44 which were transformation by conjugation and transformation was determined to be 9.01 kilobses in molecular size. When the AP$^{r}$Cm$^{r}$Tc$^{r}$-plasmid DNA was treated with restriction endonuclease, the plasmid appeared to have one restriction site for EroRI and BamHI, respectively, and three sites for Pst I endonuclease.

• Research in Plant Disease
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• v.7 no.1
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• pp.1-7
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• 2001

An isolate of Cucumber mosaic cucumovirus(CMV) was isolated from Hydrangea macrophylla for. otaksa(Sieb. et Zucc. ) Wils. showing mosaic symptoms, and designated as Hm-CMV. Hm-CMV was characterized by the tests of host range, physical properties, serological properties, RNA and coat protein compositions, and reverse transcription and polymerase chain reaction (RT-PCR) analysis. Twelve species in 4 families were used in the host range test of Hm-CMV and could be differentiated from Y-CMV used as a control CMV by the ringspot and line pattern on inoculated leaves of several tobacco plants. Thevirus produced local lesions on inoculated leaves of Chenopodium amarticolor, C. quinoa and Vigna unguiculata. The physical properties of the virus were as follows; thermal inactivation point(TIP) was 60$\^{C}$, dilution end point (DEP) was 10$\^$-3/, and longevity in vitro (LIP) was 3∼4 days. Hm-CMV was serologically identical to Y-CMV. SDS-polyaciylamide gel electrophoresis(SDS-PAGE) showed one major protein band of about 28 kDa. In RNA or dsRNA analysis, Hm-CMV consisted of four RNA or dsRNA species, but satellite RNA was not detected. In RT-PCR using CMV-common primer and CMV subgroup I-specific primer, bothe amplified expected size of about 490 bp and 200 bp DNA fragments from Hm-CMV, respectively. Restriction enzyme analysis of the 490 bp RT-PCR products using EcoR I and Msp I showed that Hm-CMV belonged to CMV subgroup I. However, Hm-CMV could be differentiated from other CMV subgroup I isolates by RNA fingerprinting by arbitrarily primed polymerase chain reaction (RAP-PCR).

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.389-398
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• 1992

Molecular cloning was carried out on the Danish strain of bovine viral diarrhea virus(BVDV) to construct strategy for the diagnostic tools and effective vaccine of BVD afterwards. A recombinant DNA clone(No. 29) was established successfully from cDNA for viral RNA tailed with adenine homopolymer at 3'-end. $^{32}P$-labeled DNA probes of 300~1,800bp fragments, originating from the clone 29, directed specific DNA-RNA hybridization results with BVDV RNA. Recombinant DNA of the clone 29 was about 5,200bp representing 41.6% of the full length of Danish strain's RNA, and restriction sites were recognized for EcoR I, Sst I, Hin d III and Pst I restriction enzymes in the DNA fragment.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.536-543
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• 1995

Multicopy integration vector is a very useful vector system in that they can be integrated into chromosomal DNA in several copies and stably maintained under non-selective conditions. To develop a multicopy integration vector system in the yeast Yarrowia lipolytica, P-type ribosomal DNA was cloned from Y lipolytica. A HindIII-BglII fragment of the cloned rDNA and a promoterless URA3 gene were inserted into pGEM1, generating multicopy integration vectors, pMIYL-1 and pMIYL-2. The rDNA fragment is for targeted homologous recombination between the vector and the chromosomal DNA of Y. lipolytica, and the promoterless URA3 gene is a defective selection marker for inducing multicopy integration. pMIYL-1 and pMIYL-2 have an unique restriction enzyme site, KpnI, and two unique restriction enzyme sites, KpnI and EcoRI, repectively, which can be used for targeting of the vectors into the rDNA of Y. lipolytica chromosomal DNA. After transformation of the vectors into Y. lipolytica, copy number and stability were analyzed by Southern hybridization. The vectors were found to be present in less than 5 copies per cell and were stably maintained during growth in non-selective media.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.30-38
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• 2010

The contribution of a type II restriction-modification system (R-M system) to genome integrity and cell viability was investigated. We established experimental conditions that enabled the achievement of hemimethylated and unmethylated states for the specific bases of the recognition sequences of the host's DNA. To achieve this, we constructed the MboII R-M system containing only one (i.e., M2.MboII) out of two functional MboII methyltransferases found in Moraxella bovis. Using the incomplete R-M system, we were able to perturb the balance between methylation and restriction in an inducible manner. We demonstrate that upon the SOS-induced DNA repair in mitomycin C treated cells, restriction significantly reduces cell viability. Similar results for the well-studied wild-type EcoRI R-M system, expressed constitutively in Escherichia coli, were obtained. Our data provide further insights into the benefits and disadvantages of maintaining of a type II R-M system, highlighting its impact on host cell fitness.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1368-1374
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• 2005

To investigate the genetic relationships among various cattle breeds, bovine mtDNA D-loop region was used in 411 animals of 18 cattle breeds, including 8 Asian Bos taurus, 7 European Bos taurus, 1 Asian Bos indicus, and 2 African Bos indicus. The size of amplified PCR products from mtDNA D-loop region was 964 bp and the products were digested by 15 different restriction enzymes. Two different band patterns were identified in eight restriction enzymes (BstXI, Hae III, Msp I, Apa I, Taq I, Alu I, BamH I, EcoN I) and the rest of restriction enzymes showed more than 3 different band patterns among which Apo I and MspR9 resulted in 7 different restriction patterns. The genotypes, number of haplotype, effective number of haplotype, and degree of heterozygosity were analyzed. Based on all the PCR-RFLP data, different haplotypes were constructed and analyzed for calculating genetic distances between these breeds using Nei's unbiased method and constructing a phylogenetic tree.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.34-41
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• 1991

To explore the possibility of introducing Zea mays transposable element Ac(activator) which can be used as a mutagen and gene tag in tobacco plants other than maitre, we tried to introduce a cloned Ac element into tobacco cells by an Agrobacterium tumefaciens binary vector system. Transformation of N. babacum cv. Burley 21 tissues and regeneration to whole plant were carried out. The frequency of the transformed callus induced in shoot induction media was higher than that of transformed callus induced in callus induction media. However, the calli were not grown in the second selection media, and became yellow senescent calli. Regenerated tobacco plantlets with foreign gene were also obtained in shoot induction media containing 100 $\mu\textrm{g}$/ml kanamycin and 100$\mu\textrm{g}$/ml carbenicillin. The leaf tissues of transformant was also resistant to 1000 $\mu\textrm{g}$/ml kanamycin. The chromosomal DNAs of transformant and normal plant of N. tabacum were digested by EcoR I and Hind III but not by Pst I.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.394-399
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• 1986

From the lysates of the 7 selected strains of Pseulomonas utilizing 2-methyl-4-chlorophenoxyactate as a sole source of carbon and energy, several MCPA plasmids, which encodes genes for the degradation of 2-methyl-4-chlorophenoxyacetate, were isolated, and measured their molecular weight as well as genetic characters such as resistance to antibiotics and degradative ability of other chlorinated herbicides. Transmissibility of the MCPA plasmids, pKU1, pKU15, and pKU17 was tested by conjugation or transformation and the restriction pattern of pKU15 for Pvu II, Hind III, EcoR I, Xho I, Bgl II, and Ava II was analyzed.