• Journal of Plant Biotechnology
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• v.40 no.3
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• pp.135-140
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• 2013

A less simple approach developed for generation of marker-free transgenic plants is to select transformants without the use of selective marker genes. Some results about development of marker-free transgenic plants were obtained using a non-selective approach in several crops such as rice, potato and tobacco. However, the study did not provide evidence on detailed characterization of introduced gene on genome, a critical step for confirming the stable integration and transmission of a foreign gene. In this study, we evaluated structure and integration sites of transgene (mCry1Ac) in the transgenic Bt rice plants which were made via conventional Agrobacterium-mediated transformation by non-selective method. Structure and integration sites of transgene in these transgenic plants had similar fashion as those recovered under selection.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.525-536
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• 2004

The objective of this study was to identify the quantitative traits loci(QTL) for meat quality traits in pigs. Three-generation resource population was constructed from a cross between Korean native boars and Landrace sows. The resource population including founders, $F_1$ and $F_2$ was genotyped for 23 microsatellite markers on chromosome 7. The sex average total length of linkage map on chromosome 7 was estimated 154.6 cM. Meat quality traits including meat pH, meat color, drip loss, shear force, heating loss, crude fat, crude protein, crude ash and water content in muscle were collected from $F_2$ animals. For the QTL mapping, we used $F_2$ QTL Analysis Servlet of QTL express for web-based QTL mapping tools(http://qtl.cap.ed.ac.uk/). The QTLs for CIE-a and CIE-b on SSC7 were significantly detected at 1% and 5% chromosome-wide level, respectively.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.716-722
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• 2014

Aminopeptidase-active fractions from crude extract of the hepatopancreas of a common squid (Todarodes pacificus) were obtained using acetone (AC; 30-40%) and ammonium sulfate precipitation (AS; 60-70% saturation), anion exchange (AE-II; 0.2 M NaCl) and gel filtration chromatography (GF-I; 30-50 kDa), respectively. The debittering capacity of GF-I fraction based on the aminopeptidase activity (89.2 U/mg), recovery (56.6%) and sensory evaluation (1.0) was better than that of other fractions. Release of amino acids increased as incubation time was increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides, as revealed by reverse-phase HPLC profiles. Peaks 3, 5 and 6 showed the decreased area (%), whereas peaks 1, 2 and 4 showed the increased area. The GF-I fractions were found to be suitable for reducing bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.6-13
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• 2006

Tin doped indium oxide(ITO) and Al doped zinc oxide(ZnO:Al) films, which are widely used as a transparent conductor in optoelectronic devices, were prepared by using the capacitively coupled DC magnetron sputtering method. ITO and ZnO:Al films with the optimum growth conditions showed each resistivity of $1.67{\times}10^{-3}[{\Omega}-cm],\;2.2{\times}10^{-3}[{\Omega}-cm]$ and transmittance of 89.61[%], 90.88[%] in the wavelength range of the visible spectrum. The two types of 5 inch-PDP cells with ZnO:Al and ITO transparent electrodes were made under the same manufacturing conditions. The PDP cell with ZnO:Al film was optimally operated in the mixing gas rate of Ne(base)-Xe(8[%]), and at gas pressure of 400[Torr]. It also shows the average measured brightness of $836[cd/m^2]$ at voltage range of $200{\sim}300$[V]. Luminous efficiency, one of the key parameter for high brightness and low power consumption, ranges from 1.2 to 1.6[lm/W] with increasing frequency of ac power supplier from 10 to 50[Khz]. The brightness and luminous efficiency are lower than those with ITO electrode by about 10[%]. However, these values are considered to be enough for the normal operation of PDP TV.

• Journal of Internet Computing and Services
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• v.19 no.3
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• pp.57-66
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• 2018

EDISON ( EDucation-research Integration through Simulation On the Net) is a web simulation service based on cloud compu-ting. EDISON provides that web service and provide analysis result to users through pre-built infrastructure and various calcu-lation nodes computational science engineering problems that are difficult or impossible to analysis as user's personal resources to users. As a result, a simulation execution environment is provided in a web portal environment so that EDISON can be ac-cessed regardless of a user's device or operating system to perform computational science engineering analysis simulation. The purpose of this research is to design and construct a workbench based real - time dynamic service to provide an integrat-ed user interface to the EDSION system, which is a computational science engineering simulation and analysis platform, which is currently provided to users. We also devised a workbench-based user simulation service environment configuration. That has a user interface that is similar to the computational science engineering simulation software environment used locally. It can configure a dynamic web environment such as various analyzers, preprocessors, and simulation software. In order to provide these web services, the service required by the user is configured in portlet units, and as a result, the simulation service using the workbench is constructed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.32-32
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• 2012

화석연료의 남용으로 지구 온난화가 심화되어 환경과 생태계변화가 가속화되고 있고, 급속한 산업의 발달과 인류 삶의 질 향상에 따른 에너지 수요가 급증하고 있는 실정에 있으며, 일본 후쿠시마 원전사태로 원자력 에너지의 위험성으로 지구 인류환경은 심각한 국면을 맞이 하고 있어 대체 에너지의 하나로 핵융합 에너지 필요성이 증대되고 있다. 핵융합 에너지 연구 개발은 우리나라에서 KSTAR가 1997년부터 건설하기 시작하여 지난 2007년에 완공되어 지금 운용 중에 있고, 국제적으로 미국, EU, 러시아, 중국, 한국, 일본 인도가 참여하는 ITER 국제 공동프로젝트가 2004년에 건설을 시작하여 프랑스 카다라쉬에 실증 플란트를 건설 중에 있다. 이러한 핵융합 반응을 위해서는 10e-7이상의 높은 진공과 1억$^{\circ}C$ 이상에서 중수소와 삼중수소가 반응하여 발생하는 플라즈마를 제어 할 필요가 있으며, 초고온의 핵융합 플라즈마를 가두고 가동시키기 위해서는 약 12Tesla이상의 고자장 마그넷이 필요하다. 현재 ITER 실증 플란트에 사용되는 고자장 마그넷은 TF (Toroidal Field)코일과 CS (Central Field)코일에 Nb3Sn 초전도선재가 핵심부품으로 사용되고 있으며 ITER프로젝트에서는 약 850톤의 Nb3Sn 초전도선재가 사용될 전망이다. 그 중에서 일본 25%, EU, 러시아와 한국이 각각 20%, 중국7%, 미국8% 할당되어 참여국 대부분은 초전도선재를 전략적으로 공급하고 있다. 초전도 선재의 크롬도금은 1~2 마이크로미터 이하의 균일하고 얇은 도금 두께와 밀착성이 우수한 품질이 요구된다. 일반적으로 크롬도금은 산업현장에서 컨베이어 벨트 방식으로 장식이나, 내식성 및 내마모성의 특성을 필요로 할 때 사용되고 있으나, 선재에 크롬도금을 릴투릴(Reel to Reel) 방식으로 적용되는 경우는 세계적으로 아주 드물다. 핵융합 마그넷의 CICC(Conduct In Cable Conduit)도체를 만들기 위해서는 초전도선재를 이용, 3(Sc 2+OFC 1)$^*3^*5^*5^*6$형태로 연선과 케이블링을 하게 되며, 초전도 선재를 연선하고 케이블링을 할 때 크롬 도금층이 박리될 가능성이 있어 크롬도금 방법과 프로세스를 특별히 고안할 필요가 있다. ITER핵융합로 마그넷의 TF코일은 높이 14m, 폭 9m 최대자장 12Tesla, 최대전류 68kA, CICC도체 직경이 40mm로서 그 초전도 조관/도체 내부에 0.82mm 직경의 Nb3Sn 초전도 선재가 약 1350가닥으로 연선과 케이블링으로 구성되어 있다. ITER 핵융합 마그넷용 초전도 선재의 크롬도금은 마그넷 권선 후 Nb3Sn 초전도물질을 형성하기 위해서 $650^{\circ}C$에서 500시간 열처리를 실시하며 열처리 시 초전도 선재의 소선들 사이에 발생할 수 있는 소착을 방지하고, 초전도 선재에서 발생하는 AC loss를 감소시키며, Quench시 발생되는 열을 쉽게 확산시킴으로써, 초전도 마그넷의 열적 안정성(Thermal Stability) 향상과 필요에 따라서 소선간 통전울 가능하게 한다. 고려제강의 자회사인 케이에이티는 크롬도금 밀착성이 우수하고 도금두께 0.1마이크로 미터 이내 제어가 가능한 얇고 균일한 도금품질을 개발하여 한국형 핵융합 실험로인 KSTAR에 65톤 전량 공급하였고, 크롬 도금된 무산소동 선재 32톤과 초전도 선재 93톤을 전량 ITER 프로젝트에 공급하고 있으며, 2013년도 상반기에는 공급을 마무리할 예정이다.

• Journal of Surface Science and Engineering
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• v.53 no.2
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• pp.59-66
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• 2020

Effects of Na₂SiO₃ concentration added into 0.1 M NaOH + 0.05 M NaF solution on the formation behavior and properties of PEO films on AZ91 Mg alloy were investigated under 1200 Hz of alternating current (AC) by voltage-time curves, in-situ observation of arc generation behavior and measurements of film thickness, surface roughness and micro vickers hardness. In the absence of Na₂SiO₃ in the 0.1 M NaOH + 0.05 M NaF solution, about 4 ㎛ thick PEO film was formed within 1 min and then PEO film did not grow but white spots were formed by local burning. Addition of Na₂SiO₃ up to 0.2 M caused more increased formation voltage and growth of PEO film with uniform generation of arcs. Addition of Na₂SiO₃ from 0.2 M to 0.4 M showed nearly the same voltage-time behavior and uniform arc generation. Addition of Na₂SiO₃ more than 0.5 M resulted in a decrease of formation voltage and non-uniform arc generation due to local burning. PEO film growth rate increased with increasing added Na₂SiO₃ concentration but maximum PEO film thickness was limited by local burning if added Na₂SiO₃ concentration is higher than 0.5 M. Surface roughness of PEO film increased with increasing added Na₂SiO₃ concentration and appeared to be proportional to the PEO film thickness. PEO film hardness increased with increasing added Na₂SiO₃ concentration and reached a steady-state value of about 930 H_V at more than 0.5 M of added Na₂SiO₃ concentration.

• Journal of Korea Foundry Society
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• v.22 no.1
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• pp.42-48
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• 2002

Effects of coating treatment of metallic Cu, Ni-P film on $SiC_p$, for $SiC_p$/iron aluminide composites were studied. Porous hybrid preforms were fabricated by reactive sintering after mixing the coated $SiC_p$, Fe and Al powders. Then the final composites were manufactured by squeeze casting after pouring AC4C Al alloy melts in preforms. The change of reactive temperature, density, microstructure of the preforms and microstructure of the composites were investigated. The exprimental results were summarized as follows. The thickness of Cu and Ni-P metallic layer formed on $SiC_p$ by electroless plating method were about $0.5{\mu}m$ and coated uniformly. There was no remakable change in the ignition temperature with variation of the mixing ratio of Fe and Al powder while in the case of coated $SiC_p$ it was lower about $20^{\circ}C$ than in the non-coated $SiC_p$. The maximum reaction temperature increased with increasing Al contents, but decreased with increasing $SiC_p$ contents. Expansion ratio of preform after reactive sintering increased with amount of Cu coated $SiC_p$. In the case of Fe-70at.%Al, the expansion ratio was about 7% up to 8wt.% of $SiC_p$, addition but further addition of $SiC_p$, increased the ratio significantly. And in the case of Fe-50 and 60at.%Al, it was about 20% up to 16wt.% of $SiC_p$ addition and about 28% in 24wt.% of $SiC_p$, addition. The microstructures of compounds showed that the grains became finer as amount of $SiC_p$, and mixing ratio of iron powder increased and the shape of compounds was changed gradually from irregular to spheroidal.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.729-734
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• 2002

In this study, the polyaniline films of emeraldine base(EB) and lucoemeraldine base(LEB) form chemically doping with poly(sodium-4 styrenesulfonate, PSS) were prepared by casting the mixed solution of chloroform and m-cresol on ITO(indium tin oxide) electrode. By analyzing UV-vis spectra of the mixed solutions, the effects of the secondary doping by m-cresol were obtained. And the conductivity of polyaniline film was increased with increasing m-cresol content. The results suggest that the improvement of conductivity obtained by secondary doping results primarily from interaction of polyaniline and m-cresol. As the results of analyzing cyclic voltammograms, it was known that the redox peak currents of polyaniline electrode prepared from LEB were larger and more reversible than those of polyaniline electrodes prepared from EB. The charge transfer resistances($R_{ct}$) of polyaniline electrodes were reduced with increasing m-cresol content, and LEB/PSS electrodes were smaller than EB/PSS electrodes. This result agrees to the analysis of the redox peak current of cyclic voltammograms. The solution resistance and the capacity of electrical double layer almost unchanged in all prepared polyaniline electrodes. It was confirmed that solution resistance was independent of frequency factor in AC impedance spectra. Also the polyaniline film doping with PSS was revealed pseudo n-type characteristics of conducting polymer.

• Carbon letters
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• v.11 no.4
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• pp.279-284
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• 2010

Graphene is one of the most promising materials for many applications. It can be used in a variety of applications not only as a reinforcement material for polymer to obtain a combination of desirable mechanical, electrical, thermal, and barrier properties in the resulting nanocomposite but also as a component in energy storage, fuel cells, solar cells, sensors, and batteries. Recent research at Michigan State University has shown that it is possible to exfoliate natural graphite into graphite nanoplatelets composed entirely of stacks of graphene. The size of the platelets can be controlled from less than 10 nm in thickness and diameters of any size from sub-micron to 15 microns or greater. In this study we have investigated the influence of melt compounding processing on the physical properties of a polyamide 6 (PA6) nanocomposite reinforced with exfoliated graphite nanoplatelets (xGnP). The morphology, electrical conductivity, and mechanical properties of xGnP-PA6 nanocomposite were characterized with electrical microscopy, X-ray diffraction, AC impedance, and mechanical properties. It was found that counter rotation (CNR) twins crew processed xGnP/PA6 nanocomposite had similar mechanical properties with co-rotation (CoR) twin screw processed or with CoR conducted with a screw design modified for nanoparticles (MCoR). Microscopy showed that the CNR processed nanocomposite had better xGnP dispersion than the (CoR) twin screw processed and modified screw (MCoR) processed ones. It was also found that the CNR processed nanocomposite at a given xGnP content showed the lowest graphite X-ray diffraction peak at $26.5^{\circ}$ indicating better xGnP dispersion in the nanocomposite. In addition, it was also found that the electrical conductivity of the CNR processed 12 wt.% xGnP-PA6 nanocomposite is more than ten times higher than the CoR and MCoR processed ones. These results indicate that better dispersion of an xGnP-PA6 nanocomposite is attainable in CNR twins crew processing than conventional CoR processing.