• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.99-100
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• 2009

SGOI 1T-DRAM cells with various Ge mole fractions were fabricated and compared to the SOI 1T-DRAM cell. SGOI 1T-DRAM cells have a higher leakage current than SOI 1T-DRAM cell at subthreshold region. The leakage current due to crystalline defects and interface states at Si/SiGe increased with Ge mole. This phenomenon causes sensing margin and the retention time of SGOI 1T-DRAMs decreased with increase of Ge mole fraction.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.23-26
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• 2012

Experimental study was conducted to elucidate flame extinction phenomena in counterflow flame. Using a curtain helium flow significantly reduced buoyancy such that the flame can be positioned at the center between the upper and lower nozzles even at the velocity ratio of 1.0. The curves of critical diluent mole fraction versus global strain rate have C-shapes. The flame oscillation was observed prior to low strain rate flame extinction at both flame conditions with and without minimizing buoyancy force. The results show that, at low strain rate flame, the self-excitation frequency with the order of 1.0 Hz in the case of utilizing pure helium gradually decreases in increase of $N_2$ mole fraction in the curtain flow, meaning that buoyancy suppresses the self-excitation of the outer edge flame.

• Elastomers and Composites
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• v.51 no.3
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• pp.181-187
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• 2016

Transparent acrylic pressure sensitive adhesives (PSAs) were successfully prepared by photopolymerization with 2-ethylhexyl acrylate (2-EHA) and 2-hydroxyethyl acrylate (2-HEA) as a default constituent and with isobornyl acrylate (IBOA) and N-(isobutoxymethyl)acrylamide (IBMA) as a variable constituent. The IBMA mole fraction effect in the acrylic PSAs was investigated on adhesion performances and the optical properties including 85/85 test as well as the characteristics (solid content, and molecular weight) of the PSA syrups were also investigated. Regardless increasing the IBMA mole fraction in the acrylic PSAs, the acrylic PSAs exhibited almost the same adhesion performance such as $180^{\circ}$ peel strength (~4.0 kg/25 mm) and probe tack (~0.27 kg). All the acrylic PSA samples also showed high transmittance (more than 91%), low haze (less than 1.0%) and low color-difference (less than 1.0) before and after 85/85 test.

• Korean Membrane Journal
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• v.7 no.1
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• pp.51-57
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• 2005

Pervaporation with a membrane is one of the economic technologies for separation of liquid mixtures including organic/water mixtures. The ZSM-5 membrane was used fur pervaporation of dichloromethane, 1,2-dichloroethane and trans-1,2-dichloroethylene from their aqueous solutions since its physical property shows very hydrophobic. ZSM-5 crystals were hydrothermally grown and deposited on the inside of a porous sintered stainless steel tube by the secondary growth method. Fluxes of dichlorinated organic compounds were observed to be $50{\~}429\;g/m^2/h$ while separation factors were $15{\~}320$ depending on a mole fraction of a dichlorinated organic compound in a feed solution ranged from 0.0001 to 0.001 mole fraction and the operation temperature between $25^{\circ}C\;and\;35^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.15 no.2
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• pp.95-105
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• 1971

The apparent molal volumes ${\phi}_v$ of a series of homologous tetraalkylammonium chlorides, $Me_4NCl, Et_4NCl, Pr_4NCl,\;and\;Bu_4NCl$, in a series of isopropanol-water mixtures have been determined at $30^{\circ}C$ from precision density measurements using pycnometers. The values of ${\phi}_v$ extrapolated to infinite dilution give partial molal volumes $\={V}^{\circ}$s which are almost additive for successive homologues and enable one to determine the absolute individual ionic partial molal volumes. The experimental results are discussed in terrns of the varying size and surface charge of the ions and the structure of the binary solvent mixtures. The results indicate that at 0.1 mole fraction isopropanol the maximum structuredness of water causes a minimum in the tetraalkylammonium-cation partial molal volumes, while at 0.2 mole fraction the solvent structure is such that the free volumes is a minimum and the electrostrictive effect of chloride ion is a maximum.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.4
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• pp.527-535
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• 1997

Vapor-liquid equilibrium apparatus is designed and set up. The vapor-liquid equilibrium data of the binary system HFC32/134a are measured in the range between 258.15 and 283.15K at compositions of 0.2, 0.4, 0.6 and 0.8 mole fraction of HFC32. Twenty-two equilibrium data are obtained. Based upon the present data, the binary interaction parameter for Carnahan-Starling-De Santis equation of state is calculated. Temperature range of data is extended to 313.04K using the data in the open literatures. Interaction parameters are determined at nine isotherms.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.485-490
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• 2004

Sawtooth mixing device used in a non-premixed burner is evaluated for flame stabilization and NO$_{x}$ reduction. Three mixers with different blade angles are tested. Methane is delivered through the fuel jet and air passes through the co-flow annulus. The flame mode changes (attached flame, lifted flame and extinction) against the fuel flow speed are measured, and the stability diagram is drawn. Moreover, by traversing thermocouple and sampling probe in the flame, the distribution of temperature and NO$_{x}$ mole fraction are measured. With the change in blade angle, flame shape, flame stabilization, the distribution of temperature and NO$_{x}$ mole fraction are changed considerably.rably.

• Journal of the Korean Society of Combustion
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• v.17 no.4
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• pp.38-43
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• 2012

Experimental study was conducted to elucidate flame extinction phenomena in counterflow flame. Using a curtain helium flow significantly reduced buoyancy such that the flame can be positioned at the center between the upper and lower nozzles even at the velocity ratio of 1.0. The curves of critical diluent mole fraction versus global strain rate have C-shapes. The flame oscillation was observed prior to low strain rate flame extinction at both flame conditions with and without minimizing buoyancy force. The results show that, at low strain rate flame, the self-excitation frequency with the order of 1.0 Hz in the case of utilizing pure helium gradually decreases in increase of $N_2$ mole fraction in the curtain flow, meaning that buoyancy suppresses the self-excitation of the outer edge flame.

• Bulletin of the Korean Chemical Society
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• v.6 no.5
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• pp.259-263
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• 1985

Rate Constants for the solvolysis of p-methylbenzyl chloride in various ethanol-water mixtures were studied at 30 and $40^{\circ}C$ under various pressures up to 1600 bar. The rates of reaction were increased with increasing temperature and pressure, and decreased with increasing solvent composition of ethanol mole fraction. From the rate constants, the values of the activation parameters (${\Delta}V^{\neq},{\Delta}{\beta}^{\neq},{\Delta}H^{\neq}\;and\;{\Delta}S^{\neq}$) were evaluated. The values of ${\Delta}V^{\neq}\;and\;{\Delta}{\beta}^{\neq}$ exhibit the extremum behavior at about 0.30 mole fraction of ethanol. This behavior is discussed in terms of solvent structure variation (electrostriction). From the relation between the reaction rate and the dielectric constant of solvent or the number of water molecule participated in the transition state, it could be postulated that the reaction proceeds through $S_N1$ mechanism.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.57-61
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• 2002

Ternary $SrO-B_2O_3-SiO_2$ glasses were fabricated as a function of R(${\equiv}SrO\;mole%/B_2O_3\;mole%$) and K(${\equiv}SiO_2\;mole%/B_2O_3\;mole%$). The structures of these glasses were investigated through Infrared transmittance, vicker's hardness, and refractive index. The results indicated : First, in the infrared transmittance spectra, when R increased, the intensities of the absorption bands around $1200{\sim}1600cm^{-1}$ resulting from the B-O stretching vibration bond in the symmetrical trigonal $BO_3$ units decreased, and these of the absorption bands around $800{\sim}1200cm^{-1}$ caused by the B-O stretching vibration bond of the tetrahedral $BO_4$ units varied. Also, the intensities of the absorption bands for the B-O stretching vibration bond in trigonal $BO_3$ units increased and these of the bands for B-O stretching vibration bond in tetrahedral $BO_4$ units decreased as K increased. Second, the increase and the decrease of vicker's hardness values for these glasses depended on the fraction of $BO_4$ units and it of $BO_3$ units, respectively. The refractive index of these glasses mostly depended on the SrO contents and only slightly depended on the fraction of $BO_4$ and $BO_3{^-}$ units.