• 환경위생공학
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• 제21권3호
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• pp.52-60
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• 2006

The ion exchange resins have been synthesized from chlormethyl styrene-1,4-divinylbenzene(DVB) with 1%, 2%, and 20%-crosslinking and macrocyclic ligand of cryptand 21 by copolymerization method and the adsorption characteristics of uranium(VI), copper(II) and dysprosium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, equilibrium time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium$(UO^{2+}_2)\;>\;copper(Cu^{2+})\;>\;dysprosium(Dy^{3+})$ ion. The adsorption was in order of 1%, 2%, and 20% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Journal of Advanced Marine Engineering and Technology
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• 제30권5호
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• pp.623-628
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• 2006

Laser material processing is a very fast advancing technology for various industrial applications. because of many advantages. Its major advantage of less and controlled heat input has been exploited successfully for the very critical application of aluminium alloy welding. This study suggested the occurrence source of weld-defects and its solution methods in a welding of lithium ion battery by pulsed Nd:YAG laser. In experiment. battery case has changed over joint geometry from welding of side position to flat one. In the case of a electrolyte injection hole in order to seal it. welding is carried out after pressing Al ball. At this time. an eccentric degree. contact length and gap are worked as a major parameters. As improving the method of Al ball pressing. it was able to reduce an eccentricity. increase the contact length and decrease gap. As a results of a experiment. a sound weld bead shape and crack-free weld bead can be obtained.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.339-343
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• 2005

Laser material processing is a very fast growing technology for various industrial applications, because of many advantages. Its major advantage of less and controlled heat input has been exploited successfully for the very critical application of aluminium alloy welding. This study suggested the occurrence source of weld-defects and its solution methods in a welding of lithium ion battery by pulsed Nd:YAG laser. In experiment, battery case has changed over joint geometry from welding of side position to flat one. In case of a electrolyte injection hole in order to seal it, welding is carried out after pressing Al ball. At this time, an eccentric degree, contact length and gap are worked as a major parameters. As improving the method of Al ball pressing, it was able to reduce an eccentricity, increase the contact length and decrease gap. As a results of a experiment, a sound weld bead shape and crack-free weld bead can be obtained.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.3088-3092
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• 2013

A novel PVC membrane sensor for perindopril based on perindopril-phosphotungstate ion pair complex was prepared. The influence of membrane composition (i.e. percent of PVC, plasticizer, ion-pair complex, and kind of plasticizer), inner solution, pH of test solution and foreign cations on the electrode performance was investigated. The optimized membrane demonstrates Nernstian response ($30.9{\pm}1.0$ mV per decade) for perindopril cations over a wide linear range from $9.0{\times}10^{-7}$ to $1{\times}10^{-2}$ M at $25^{\circ}C$. The potentiometric response is independent of the pH in the range of 4.0-9.5. The proposed sensor has the advantages of easy preparation, fast response time. The selectivity coefficients indicate excellent selectivity for perindopril over many common cations (e.g., $Na^+$, $K^+$, $Mg^{2+}$, $Cu^{2+}$, $Ni^{2+}$, rhamnose, maltose, glycine and benzamide. The practical applications of this electrode was demonstrated by measuring the concentrations of perindopril in pure solutions and pharmaceutical preparations with satisfactory results.

• KSBB Journal
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• 제25권5호
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• pp.459-465
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• 2010

A simple and efficient analytical method for the simultaneous determination of seven tar color additives was developed using ion pair high performance liquid chromatography. The conditions for HPLC analysis were as follows: column, ${\mu}$-Bondapak C18 (10 ${\mu}m$, 300 ${\times}$ 3.9 mm i.d.); gradient mobile phase, 0.025 mol/L ammonium acetate (containing 0.01 mol/L tetrabutylammonium bromide)-acetonitrile-methanol (65:25:10) as a mobile for fraction A and 0.025 mol/L ammonium acetate (containing 0.01 mol/L tetrabutylammonium bromide)-acetonitrilemethanol (40:50:10) as a mobile for fraction B; flow rate, 1.0 mL/ min; detection wavelength, 254/520/620 nm. We could attain to the detection limits as 0.01~0.05 ${\mu}$g/mL (254 nm) and 0.005~0.01 ${\mu}$g/mL (520 nm) for six red tar color additives, and 0.05 ${\mu}$g/mL (254 nm) and 0.002 ${\mu}$g/mL (620 nm) for Fast green FCF. This analytical method was applicable to determine the tar color additives contained in several commercial cold syrups.

• The Korean Journal of Physiology and Pharmacology
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• 제8권1호
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• pp.33-41
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• 2004

We developed a cardiac cell model to explain the phenomenon of mechano-electric feedback (MEF), based on the experimental data with rat atrial myocytes. It incorporated the activity of ion channels, pumps, exchangers, and changes of intracellular ion concentration. Changes in membrane excitability and $Ca^{2+}$ transients could then be calculated. In the model, the major ion channels responsible for the stretch-induced changes in electrical activity were the stretch-activated channels (SACs). The relationship between the extent of stretch and activation of SACs was formulated based on the experimental findings. Then, the effects of mechanical stretch on the electrical activity were reproduced. The shape of the action potential (AP) was significantly changed by stretch in the model simulation. The duration was decreased at initial fast phase of repolarization (AP duration at 20% repolarization level from 3.7 to 2.5 ms) and increased at late slow phase of repolarization (AP duration at 90% repolarization level from 62 to 178 ms). The resting potential was depolarized from -75 to -61 mV. This mathematical model of SACs may quantitatively predict changes in cardiomyocytes by mechanical stretch.

• Transactions on Electrical and Electronic Materials
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• 제9권5호
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• pp.198-201
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• 2008

The electro-optical (EO) characteristics of the one-side rubbing twisted nematic (TN) - liquid crystal display (LCD) on the polyimide (PI) surface with one-side ion beam (IB) irradiation were successfully studied. The good LC alignment for the one-side rubbing TN-LCD on the PI surface with one-side IB irradiation was observed. The suitable transmittance-voltage curves for the one-side rubbing TN-LCD on the PI surface with one-side IB irradiation were measured. Also, the good response time characteristics of the one-side rubbing TN-LCD on the PI surface with one-side IB irradiation were measured. The fast response time can be achieved for the one-side rubbing TN-LCD on the PI surface with one-side IB irradiation.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4209-4214
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• 2022

Precise modelling of the interaction of ions with materials is important for many applications including material characterization, ion implantation in devices, thermonuclear fusion, hadron therapy, secondary particle production (e.g. neutron), etc. In this study, a new approach using the Geant4 toolkit in combination with the Bayesian regularization (BR) learning algorithm of the feed-forward neural network (FFNN) is developed to estimate the range of ions in materials accurately and quickly. The different incident ions at different energies are interacted with the target materials. The Geant4 is utilized to model the interactions and to calculate the range of the ions. Afterward, the appropriate architecture of the FFNN-BR with the relevant input features is utilized to learn the modelled ranges and to estimate the new ranges for the new cases. The notable achievements of the proposed approach are: 1- The range of ions in different materials is given as quickly as possible and the time required for estimating the ranges can be neglected (i.e. less than 0.01 s by a typical personal computer). 2- The proposed approach can generalize its ability for estimating the new untrained cases. 3- There is no need for a pre-made lookup table for the estimation of the range values.

• 대한화학회지
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• 제42권3호
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• pp.297-301
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• 1998

올리고당의 구조중 연결위치(linkage position)는 충돌 탄뎀 질량분석법(FAB CAD MS/MS: Fast Atom Bombardment Collision Activated Dissociation Mass Spectrometry/Mass Spectrometry)을 이용하여 알 수 있다. 연결위치-이성질체 올리고당을 아세틸화시키면 자유올리고당보다 연결위치의 구별이 쉽고 독특한 분절이온 패턴을 얻을 수 있다. 그 이유는 연결위치에 따라 각 올리고당이 충돌에너지(collision energy)를 흡수하여 glycosidic 결합 주위를 회전하는 회전운동의 자유도가 달라지기 때문이다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 추계학술대회
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• pp.92-95
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• 1994

As computer systems to make medical practice easy are widely used, a special hardware system processing medical data fast becomes more important. To meet the urgent demand for high speed image processing, especially image compression and decompression, we designed and implemented the medical image CODEC (COder/BECoder) based on MISD(Multiple Instruction Single Data stream) architecture to adopt parallelism in it. Considering not being a standart scheme of medical mage compression/decompress ion, the CODEC is designed programable and general. In this paper, we use JPEG (Joint Photographic Experts Group) algorithm to process images fast and evalutate it.