• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.84.2-84.2
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• 2015

Growing market of electric vehicles such as hybrid, plug-in hybrid, and bare electric vehicles in the world is accelerating the significance of Li-ion batteries as a renewable green energy. According to such market flow, the developing components such as cathode, anode, electrolyte, and separator, composing the Li-ion batteries, is significantly important tasks for the commercialization. In particular, development of the cathode material having high capacity and stable thermal stability is essential for long-distance electric vehicle in the near future. Herein we introduce various applications of Li-ion batteries such as portable electronics, electric vehicles, and energy storage system, and also its research trend, in particular on the cathode materials.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1531-1534
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• 2005

Nano pattern is being utilized to produce micro optical components, sensors, and information storage devices. In this study, a study on nano pattern fabrication using raster-scan type Focused Ion Beam (FIB) milling is introduced. Because the intensity of ion beam has Gaussian distribution, the overlapping of the Gaussian beam results in a 3D pattern, and the shape of the pattern can be adjusted by variation of FIB milling parameters, such as overlap, ion dose, and dwell time. The Gaussian shape of single beam intensity has been investigated by experiment, and 3D nano patterns with pitch of 200nm generated by FIB is demonstrated.

• Tribology and Lubricants
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• 제12권4호
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• pp.60-70
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• 1996

Scuffing and severe wear of the highly stressed sliding components have been very critical problems in the development of a rotary compressor. In order to improve durability and reliability of the compressor, plasma ion-nitriding was applied on the shaft and the vane surface. The effects of different treatment conditions on the mechanical and tribological properties of the ion-nitrided surfaces were investigated. Ion-nitrided surfaces showed better tribological performances than untreated surfaces. The best wear performance was observed when the shaft was nitrided in the condition of 450$\circ$C, 7 hours, $N_2:H_2=1:4$ gas mixture by forming a ductile nitrided layer which has $\gamma'$ phase microstructure. As nitrogen gas pressure increased, $\varepsilon$ phase layer was formed. This hard phase layer was observed to be more beneficial for the vane in reducing friction and wear.

• Journal of Korean Vacuum Science & Technology
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• 제7권1호
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• pp.1-7
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• 2003

The pressure distributions in the test stand built for developing KSTAR NBI ion sources were obtained using a network system composed of conductance elements modeling the ion source, the neutralizer, and other beam line components. The allowable regime was defined on the coordinates of the gas supply rate to the ion source and the neutralizer, considering the proper conditions of the three critical parameters, the ion source pressure for good arc discharge, the pressure integral in the neutralizer for sufficient neutralization, and the chamber pressure for minimum neutral beam loss. The neutral beam evolution along the path from the ion source extraction grid to the calorimeter through the neutralizer, the bending magnet and the vacuum chamber was estimated for typical pressure distributions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.130-132
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• 1994

We fabricated Ag ion exchange glass waveguide. Generally, ion-exchange glass waveguide. are suitable for passive integrated optical components such as directional and star couplers. Its advantages include low loss, ease of fabrication, and low material cost. So, we faricated Ag ion-exchange glass waveguides in AgNO$_3$ melt solution from 2 mole %. And we used Sodalime glass as a substrate in the fabrication process. As the results, we observed multivalent ion-exchange in a typical sodalime glass. Diffusion coefficient and depth are predicted by actual experimental data of Stewart. The exchange rate in silver-ion-exchanged waveguides are compared to the exchange time of waveguide fabrication.

• BMB Reports
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• 제56권3호
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• pp.145-152
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• 2023

Mechanosensitive ion channels sense mechanical stimuli applied directly to the cellular membranes or indirectly through their tethered components, provoking cellular mechanoresponses. Among others, Piezo1 mechanosensitive ion channel is a relatively novel Ca²⁺-permeable channel that is primarily present in non-sensory tissues. Recent studies have demonstrated that Piezo1 plays an important role in Ca²⁺-dependent cell death, including apoptosis and ferroptosis, in the presence of mechanical stimuli. It has also been proven that cancer cells are sensitive to mechanical stresses due to higher expression levels of Piezo1 compared to normal cells. In this review, we discuss Piezo1-mediated cell death mechanisms and therapeutic strategies to inhibit or induce cell death by modulating the activity of Piezo1 with pharmacological drugs or mechanical perturbations induced by stretch and ultrasound.

• 분석과학
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• 제20권3호
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• pp.255-260
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• 2007

A new method for the simultaneous determination of low molecular weight amines and quaternary ammonium ions based on the separation by IC with a suppressor and the detection by MS with ESI has been developed. The method has been applied to the analysis of a mixture containing tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, triethanolamine, trimethylamine and triethylamine. The constituents were separated by isocratic elution using an IonPac CS17 column, a cation-exchange column, and detected by conductivity and mass spectrometry. The newly developed method for the six components demonstrated that the repeatability in terms of relative standard deviation for three measurements was in the range of 0.1-0.5 %. The detection limits were between 0.2 and $0.9{\mu}g/mL$ by the IC/ESI-MS.

• 전자공학회논문지
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• 제50권10호
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• pp.124-131
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• 2013

플라즈마(Plasma) 공정 시뮬레이션에서 가장 중요한 요소는 식각(Etching) 과정으로 특성 정보 프로파일(Feature Profile)에 의존하는 식각 비율(Etch Rate)을 계산하는 것이다. 식각 비율을 결정 요소는 이온 플럭스(Ion Flux), 뉴트럴 플럭스(Neutral Flux), 가스 종 온도 등 다양하지만 본 논문에서는 이온 플럭스(Ion Flux)에 한정하여 고속으로 이온 플럭스를 계산하기 위한 스캔 방법을 제안했다. 그리고 일반적으로 많이 사용되어지는 몬테카를로(Monte Carlo) 방법과 제안 방법을 가우시안 분포 및 코사인 분포를 이용하여 실험하고 서로 비교 분석하였다. 본 논문에서 제안한 방법이 몬테카를로 방법과 비교 했을 때 보다 효율적으로 정확한 이온 플럭스를 계산 할 수 있음을 검증하였다.

• 한국재료학회지
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• 제15권1호
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• pp.54-60
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• 2005

Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. ion migration phenomena has been observed in the field of exposing the specific environment and using for a long tin e. This study was evaluated the generation time of ion migration and was investigated properly test method through water drop test and high temperature high humidity test. Also we observed direct causes and confirmed generation mechanism of dendritic growth as we reproduced the ion migration phenomena. We utilized PCB(printed circuit board) having a comb pattern as follows 0.5, 1.0, 2.0 mm pattern distance. Cu, SnPb and Au were electroplated on the comb pattern. 6.5 V and 15 V were applied in the comb pattern and then we measured the electrical short time causing by ion migration. In these results, we examined a difference of ion migration time depending on pattern materials, applied voltage and pattern spacing of PCB conductor.

• 환경위생공학
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• 제9권2호
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• pp.8-23
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• 1994

During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .