• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1119-1127
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• 2010

In this paper, the design and nonlinear simulation of a multistable electromagnetic microactuator, which provides four stable equilibrium positions within its operating range, have been discussed. Quadstable actuator motion has been made possible by using both X- and Y-directional bistable structures with snapping curved beams. Two pairs of the curved beams are attached to an inner frame in both X- and Y-directions to realize independent bistable behavior in each direction. For the actuation of the actuator at the micrometer scale, an electromagnetic actuation method in which Lorentz force is taken into consideration was used. By using this method, micrometer-stroke quadstability in a plane parallel to a substrate was possible. The feasibility of designing an actuator that can realize quadstable motion by using the electromagnetic actuation method has been thoroughly clarified by performing nonlinear static and dynamic analyses and electrothermal coupled-field analysis of the multistable microactuator.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.845-851
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• 2014

Dielectrophoresis (DEP) is defined as the motion of suspended particles in solvent resulting from polarization forces induced by an inhomogeneous electric field. DEP has been utilized for various biological applications such as trapping, sorting, separation of cells, viruses, nanoparticles. However, the analysis of DEP trapping has mostly employed the period-averaged ponderomotive forces while the dynamic features of DEP trapping have not been attracted because the target object is relatively large. Such approach is not appropriate for the nanoscale analysis in which the size of object is considerably small. In this study, we thoroughly investigate the dynamic response of trapping to various system parameters and its influence on the trapping stability. The effects of particle conductivity on its motion are also focused.

• Research in Plant Disease
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• v.26 no.3
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• pp.144-158
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• 2020

Quantitative reverse transcription PCR is used for gene expression analysis as the accurate and sensitive method. To analyze quantification of gene expression changes in apple plants, 10 housekeeping genes (ACT, CKL, EF-1α, GAPDH, MDH, PDI, THFs, UBC, UBC10, and WD40) were evaluated for their stability of expression during infection by Apple stem grooving virus (ASGV) or in cold-stress apple plant buds. Five reference-gene validation programs were used to establish the order of the most stable genes for ASGV as CKL>THFs>GAPDH>ACT, and the least stable genes WD40CKL>UBC10, and the least stable genes were ACT

• Journal of the Korean Chemical Society
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• v.59 no.1
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• pp.36-44
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• 2015

This article describes synthesis and electrochemical properties of layer-by-layer self-assembled multilayer film composed of polyaniline (PANi), graphene oxide (GO) and phytic acid (PA), whereby the GO was electrochemically reduced to ERGO, resulting in $(PANi/ERGO/PANi/PA)_{10}$ film electrode. Especially, we examined the possibility to improve the volumetric capacitive property of $(PANi/ERGO)_{20}$ film electrode via combining a spherical hexakisphosphate PA nanoparticle into the multilayer film that would dope PANi properly and also increase the porosity and surface area of the electrode. The electrochemical performances of the multilayer film electrodes were investigated using a three-electrode configuration in 1 M $H_2SO_4$ electrolyte. As a result, the $(PANi/ERGO)_{20}$ electrode showed the volumetric capacitance of $666F/cm^3$ at a current density of $1A/cm^3$, which was improved to the volumetric capacitance of $769F/cm^3$ for the $(PANi/ERGO/PANi/PA)_{10}$ electrode, in addition to the cycling stability maintained to 79.3% of initial capacitance after 1000 cycles. Thus, the electrochemical characteristics of the $(PANi/ERGO)_{20}$ electrode, which was densely packed by ${\pi}-{\pi}$ stacking between the electron-rich conjugate components, could have been improved through structural modification of the multilayer film via combining a spherical hexakisphosphate PA nanoparticle into the multilayer film.

• Proceedings of the KHEEA Conference
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• 2002.08a
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• pp.5-19
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• 2002

재한국, 1995년제일차출대국가제정적가정과교육과정. 지후, 한국적가정과교육과정경마료7차적수정여개혁과정. 재차과정중, 가정과정불단지추극출신, 기과목명칭재변화, 필수자선 등 선과성질야재변화, 과치함축, 여기술과정합. 이차, 가정과변위남녀생공수적과목, 저취순응료사회발전적수요. 종한국적교육과정래간, 1년급도10년급시국민공용기본교육계단, 11년급도12년급시자선교육계단. 거차, 가정과교육과정적접배위여하 : 소학(5~6학년)위실과, 중학화고중(7~10학년)위"기술.가정", 고중(11~12학년)위"가전과학". 장종2003년개시실시적가정과과시안배위여하 : 소학각2과시, 7~12학년시각2.3.3.3과시, 11~12학년위6개등차. 최근, 청소년문제, 교육환경, 상시인성, 가정파양, 소비과잉, 학대아동, 등사회문제도근가정생활유착밀절적연계, 인차, 재반지교육중, 가정교육응수중시. 단시, 실제상병불시여차. 작위교육주체적교사화부모도몰유인식도저개실정. 인차, 가정학자여교사유심요주근지거연구가정교육. 우기시, 유필요근중국, 일본, 등저사아주국가호상교류화합작적과정중거탐색가정교육적안정발전. 하면파미래가정학육발전적방향건의여하 : 1) "가정" 과시이가정과위연구대상적가정학적독립적연구요영역. 가정경적연구감상시 "가정", 타이가정생활질량적제고위기연구목적. 인차, 재가정교육중, 과목적명칭명명위 "기술. 가정", "가정일반". "가사" 시부합리적. 이응위 "가정" 2) 가정교육웅사중시성각색적변환, 직업적인직변고적각도출발, 사소학도고중분개위필수화선수과, 유남녀생공수. 3) 가정과과시재축점축단. 도시유우교육과정적축단이인기적피면불료적현상. 단시고 여가정과시실천, 실험성과목응보장기최저적과시, 최기마필수유지현재적과시. 4) 향래, 한국적가정교육과정기이가정과위기본철학배경화리념, 우급시파국가교육과정적배경화이념, 가정학적발전동태반영재교육과정중, 즉강조즘요교. 단시, 경력료반복적변혁지후, 최근, 각중시즘양거배양학생적십 요 양적능력여가치. 인차, 가정교육파교육목라방재즘루거제고가정생활적질량, 즘루거호조화가정생활화직업생활, 즘양거개발합리지해결화실천가정생활적가치관. 5) 최근, 가정교육파교육방향화목라방재거배양학생작위독립적개인, 작위가족적성원, 작위사회성원래주인생도로적능력. 인차, 가정교육이인적생활위중심. 우거섭급학생재성장과정중소우도적문제,재거포괄재가정화사회생활중소우도적문제. 즉거배양해결가정생활중소우도적소유적 문종적종합능력. 6) 가정과재교학방법화교학평개상, 응채용실험, 실습, 관찰 등방식, 응반체험성, 실천성경험. 위차, 응필편기험적실험, 실습설비. 7) 확정교육과정편제적치후, 응제고일반교육학자적참여율, 가정교육학자응적극참여 제정교청정책적유관교육적각종위원회. 재제정정책적과정중각진소능, 적극제출건고성적의황. 8) 한, 중, 일 삼국권원층립가정교육과정도작사, 위삼국교육과정적량호발전주공헌.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.522-534
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• 1995

Background: In the pathogenesis of acute lung injury induced by lipopolysaccharide(LPS), oxygen radiclls are known to be involved in one part. Superoxide dismutase(SOD) protects oxygen radical-induced tissue damage by dismutating superoxide to hydrogen peroxide. In eukaryotic cells, two forms of SOD exist intracellularly as a cytosolic, dimeric copper/zinc-containing SOD(CuZnSOD) and a mitochondrial, tetrameric manganese-containing SOD(MnSOD). But there has been little information about SOD gene expression and its regulation in pulmonary alveolar macrophages(PAMs). The objective of this study is to evaluate the SOD gene expression induced by LPS and its regulation in PAMs of rat. Method: In Sprague-Dawley rats, PAMs obtained by broncholaveolar lavage were purified by adherence to plastic plate. To study the effect of LPS on the SOD gene expression of PAMs, they were stimulated with different doses of LPS($0.01{\mu}g/ml{\sim}10{\mu}g/ml$) and for different intervals(0, 2, 4, 8, 24hrs). Also for evaluating the level of SOD gene regulation actinomycin D(AD) or cycloheximide(CHX) were added respectively. To assess whether LPS altered SOD mRNA stability, the rate of mRNA decay was determined in control group and LPS-treated group. Total cellular RNA extraction by guanidinium thiocyanate/phenolfchlorofonn method and Northern blot analysis by using a $^{32}P$-labelled rat MnSOD and CuZnSOD cDNAs were performed. Results: The expression of mRNA in MnSOD increased dose-dependently, but not in CuZnSOD. MnSOD mRNA expression peaked at 8 hours after LPS treatment. Upregulation of MnSOD mRNA expression induced by LPS was suppressed by adding AD or CHX respectively. MnSOD mRNA stability was not altered by LPS. Conclusion: These findings show that PAMs of rat could be an important source of SOD in response to LPS, and suggest that their MnSOD mRNA expression may be regulated transcriptionally and require de novo protein synthesis without affecting mRNA stability.

• Journal of the Korean Vacuum Society
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• v.18 no.3
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• pp.197-202
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• 2009

The long term stability of ion current of QMS has been one of key parameters for monitoring gas process in vacuum. The time dependence of ionic current was monitored while the pressure of nitrogen gas was kept at a fixed pressure by introducing the gas into vacuum chamber. The chamber was evacuated to ${\sim}3{\times}10^{-9}\;Torr$ to reduce background signals before the measurement. Two ion sources were tested; one had brownish or black color due to gas contamination and the other one was new, i.e. cleaner. At a nitrogen pressure of $1{\times}10^{-5}\;Torr$, the ionic currents measured by the contaminated ion source decreased faster with time. The decrease rate was respectively ${\sim}46%$ for cleaner one and ${\sim}84%$ for contaminated one after ${\sim}5.5%$ hours. In order to test the effect of filament material on the ion current decrease, we fabricated a tungsten(W) filament which consisted of two parts; one half was made of W and the other was coated with yttria. The similar decrease of ionic currents were shown for the two types of filaments, indicating that slight change of temperature of filament due to material difference i.e. baking effect could not improve the origin of ionic current decrease. Overall the decreasing rate of ionic current is more closely associated with contaminated ion source of QMS rather than its filament materials.