• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1040-1043
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• 2008

Klebsiella oxytoca CCUG 15788 is resistant to $Ni^{2+}$ at a concentration of 10 mM and grows in an inducible manner when exposed to lower concentrations of $Ni^{2+}$. The complete genomic sequence of a 4.2-kb HindIII-digested fragment of this strain was determined from genomic DNA. It was shown to contain four nickel resistance genes (nirA, nirB, nirC, and nirD) encoding transporter and transmembrane proteins for nickel resistance. When the plasmid pKOHI4, encoding nirABCD, was transformed into Escherichia coli JM109, the cells were able to grow in Tris-buffered mineral medium containing 3 mM nickel. TnphoA'-1 insertion mutants in the four nickel genes nirA, nirB, nirC, and nirD showed nickel sensitivity. The nir genes were heterogeneously expressed in E. coli, suggesting functional roles of these genes in nickel resistance.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.583-588
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• 2008

The planing craft is designed specifically to achieve comparatively high speed on the surface of the water. In general, the stepped hull craft has effect improvement in speed and fuel-efficiency because of the reduction of total resistance by a small wetted surface area without corresponding stepped hull craft. In this paper, the high speed stepped hull crafts with respect to the number of bottom steps were performed to compare the effect of resistance performance using at-sea model-test method. In conclusion, the stepped hull craft with twin-step was proved to be effective to reduce the total resistance.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.1
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• pp.7-12
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• 2000

This study was conducted to identify useful germ plasm sources of resistance to black shank, Phytophthora. parasitica, in Nicotiana tabacum and to characterize the interaction between host plant resistance to black shank and pathogen variability. The six internationally represen-tative set of black shank resistant and susceptible tobacco genotypes and four Korean lines were tested for black shank on the field infested with P. parasitica at Chonju Experiment Station, Korea Ginseng & Tobacco Research Institute during the 1992～1997 growing season. Almost 100% of the plants of the most susceptible genotype, Ky 14, did not survive. Complete survival of (MS Ky 14 x L8)F$_1$, which is resistant to reee 0 and ausceptible to reace 1, suggests that Race 0 is the only race of the P. parasitica in this bield. Coker 371 Gold and Beinhart 1000-1 having excellent resistance to black shank could be recommended as the parental cultivars for improving black shank resistance in Korea. Data of the diseased plants showed that KB 101 and KB 110 were medium high resistant and KB 103 and KB 108 being low resistant to black shank.

• Microbiology and Biotechnology Letters
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• v.5 no.1
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• pp.5-12
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• 1977

As a basic study for the application of the spore-tearing lactic acid bacteria to foods, the effects of the sporulating conditions on the growth and sporogenesis were studied were observed. The results obtained are as follow. 1. All carbohydrates added to sporulation media except dextrin decreased the sporulation rate and the thermal resistance of spores. Dextrin stimulated the growth, however, there in no effect on the thermal resistance. 2. As nitrogen source, the protein hydrolysates such as peptone, casamino acid were effective to obtain were spores of the increased thermal resistance. 3. Ca$\^$＋＋/, Mn$\^$＋＋/ of the metal ions added to casamino acid containing medium validly increased the total growth, sporulation rate and thermal resistance. Its optimum concentration was 40 ppm each. 4. Biotin of vitamines had an effect on the total growth, sporulation and thermal resistance of spores. Its optimum concentration was 30${\gamma}$/ml. 5. The resistant spores required the adequate maturation period, more than 36 hours, sufficient aeration. and optimum temperature, 37∼45$^{\circ}C$.

• Journal of Navigation and Port Research
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• v.36 no.3
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• pp.157-162
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• 2012

A planing craft is designed specifically to achieve comparatively high speed on the surface of the water. The frictional resistance of planing craft can be reduced further by injecting air to the craft's bottom. In this paper, the resistance characteristics of high speed planing crafts with & without air injection at the bottom were compared by sea model-test method. As a result, we conformed that planing craft with air injection has much greater the effect of resistance reduction.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.105-113
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• 2004

MRAM uses magneto-resistance material as a storage element, which stores cell data as a polarization of spin in a free magnetic layer. This magneto-resistance material has hysteresis, asteroid curve at the thermal variation, and R-V characteristics for switching the data. Therefore, a macro-model which can reproduce these characteristics is required for MRAM simulation. We propose a macro-model of TMR (Tunneling Magneto Resistance) that can reproduce all of these characteristics on HSPICE. Also we propose a novel sensing scheme, which generates reference resistance having the medium value, ( $R_{H}$+ $R_{L}$)/2, for a wide range of applied voltage and present simulation results based on the HSPICE macro-model of MTJ that we have developed.d.d.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.759-764
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• 2008

The planing craft is designed specifically to achieve comparatively high speed on the surface of the water. Most of planing crafts have installed the spray strip in decreasing of wave impaction and improving motion performance of rolling and pitching et al. It is known to reduce the spray and frictional resistance by the effect of lift and improvement of wave profile in high speed. In this paper, the high speed planing crafts with & without spray strip in bottom were performed to compare the resistance performance by model-test. In conclusion, the high speed planing crafts with spray strip in bottom was proved to effect of the resistance decrement of $3.0{\sim}5.0%$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.689-696
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• 2018

System grounding is applied to the neutral point of a power source to secure the from any abnormal voltage and/or grounding fault. System grounding, which is applied mainly in ships is an ungrounded and resistance grounded system. Vessels using the MV power system with 3.3kV, 6.6kV, and 11kV mainly adopt a high resistance grounding system among the resistance grounding systems. The ground fault accounts for 95% of all faults occurring in the electrical system and when a fault occurs, the line-to-ground voltage of the power system is increased excessively, which adversely affects the onboard insulation system. This study analyzed the variation characteristics of the line-to-ground voltage neutral point according to the degree of ground fault in a resistance ground system applied in vessels. For this purpose, the characteristics of the grounding system were first explained, and the modeling of the neutral point potential of the line-to-ground voltage of the resistance grounding system in the vessels was derived. Finally, this study examined how the line-to-ground voltage, line voltage, and neutral point change according to various variable environments through MATLAB simulations.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.620-624
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• 2011

'Hwaweon 4' was developed from a cross between the African upland cultivar, 'Moroberekan' and 'Ilpumbyeo' based on marker-aided backcross selection. The recurrent parent 'Ilpumbyeo' is a high grain quality cultivar with medium to late maturity. 'Hwaweon 4' is nearly isogenic to 'Ilpumbyeo' except a small Moroberekan introgressed segment on chromosome 4 harboring the resistance gene for blast. The preliminary and replicated yield trial was conducted at Chungnam National University in 2006 and 2007. The local adaptability test was carried out by the National Seed Management Office (NSMO) from 2008 to 2009. This cultivar was registered to NSMO with a cultivar designated as 'Hwaweon 4'. This cultivar averaged 76 cm in culm length and has medium growth duration. Milled rice of 'Hwaweon 4' is translucent and the grain quality traits are comparable to those of the recurrent parent. It has low protein content. The yield potential of 'Hwaweon 4' in grain was about 6.31 MT/ha at the ordinary fertilizer level for two years. This variety showed highly resistance reaction at the blast nursery test at four locations and also at the sequential planting method. This resistance is due to the resistance gene designated as Pi45(t) on chromosome 4 introgressed from the donor parent, 'Moroberekan'. The Pi45(t) gene would be useful inenhancing resistance to blast in rice breeding program.

• Progress in Superconductivity and Cryogenics
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• v.15 no.2
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• pp.48-51
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• 2013

The thermal contact resistance (TCR) is one of the important components in the cryogenic systems. Especially, cryogenic measurement devices using a cryocooler can be affected by TCR because the systems have to consist of several metal components in contact with each other for heat transferring to the specimen without cryogen. Therefore, accurate measurement and understanding of TCR is necessary for the design of cryogenic measurement device using a cryocooler. The TCR occurs at the interface between metals and it can be affected by variable factors, such as roughness of metal surface, contact area and contact pressure. In this study, we designed TCR measurement system at various temperatures using a cryocooler as a heat sink and used steady state method to measure the TCR between metals. The copper is selected as a specimen in the experiment because it is widely used as a heat transfer medium in the cryogenic measurement devices. The TCR between Cu and Cu is measured for various temperatures and contact pressures. The effect of the interfacial materials on the TCR is also investigated.