• Title/Summary/Keyword: Triple-Density

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Studies on the Adsorption Modeling of Cationic Heavy Metals(Pb, Cd) by the Surface Complexation Model (Surface Complexation Model을 이용한 양이온 중금속(Pb, Cd) 흡착반응의 모델화 연구)

  • 신용일;박상원
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.211-219
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    • 1999
  • Surface complexation models(SCMs) have been performed to predict metal ion adsorption behavior onto the mineral surface. Application of SCMs, however, requires a self-consistent approach to determine model parameter values. In this paper, in order to determine the metal ion adsorption parameters for the triple layer model(TLM) version of the SCM, we used the zeta potential data for Zeolite and Kaolinite, and the metal ion adsorption data for Pb(II) and Cd(II). Fitting parameters determined for the modeling were as follows ; total site concentration, site density, specific surface area, surface acidity constants, etc. Zeta potential as a new approach other than the acidic-alkalimetric titration method was adopted for simulation of adsorption phenomena. Some fitting parameters were determined by the trial and error method. Modeling approach was successful in quantitatively simulating adsorption behavior under various geochemical conditions.

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The Effect of Xylene and Formaldehyde Inhalation on Testicular Tissue in Rats

  • Gules, O.;Eren, U.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.11
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    • pp.1412-1420
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    • 2010
  • In this study, changes in testicular tissues of rats subjected to xylene and formaldehyde inhalation were evaluated. Three experimental groups were included in the study. Each group of rats was exposed to formaldehyde (6 ppm), technical xylene (300 ppm) or a combination of these two agents (150 ppm+3 ppm) for 8 weeks (8 h/d). Control groups were maintained for a period of eight weeks under the same conditions. Staining methods (triple staining, strep ABC method) were applied to examine histometric changes and relaxin like factor (RLF) expression in the testicular tissue. Immunostaining for RLF showed that density of staining for RLF decreased in rats exposed to formaldehyde. Formaldehyde or a combination of formaldehyde and xylene led to a decrease in seminiferous epithelial height. In conclusion, exposure of rats to formaldehyde and xylene-formaldehyde combinations adversely affects Leydig cells (RLF) and seminiferous epithelium of testicular tissue.

The Compressive Deformation Behavior of Nanocrystalline Al-5at.%Ti Alloy Prepared by Mechanical Alloying at Low Temperature (저온 기계적 합금화한 nanocrystalline Al-5at.%Ti 합금의 압축변형거동)

  • 정경화;오영민;김선진
    • Journal of Powder Materials
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    • v.6 no.4
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    • pp.277-285
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    • 1999
  • Mechanical properties of nanocrystalline Al-5at.%Ti alloy were investigated through high temperature compression test. Al-5at.%Ti nanocrystalline metal powders, which had finer and more equiaxed shape than those produced at room temperature, were produced by mechanical alloying at low temperature. The powders were successfully consolidated to 99fo of theoretical density by vacuum hot pressing. XRD and TEM analysis revealed that $Al_3Ti$ intermetallic compounds formed inside powders and pure Al region with coarse grains formed between powders, especially at triple junction. Mechanical properties in terms of hardness and strength were improved by grain size refinement, but ductility decreased presumably due to the formation of the weak interfaces between Al pool and powders.

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A study on the SONOS EEPROM devices (SONOS EEPROM소자에 관한 연구)

  • 서광열
    • Electrical & Electronic Materials
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    • v.7 no.2
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    • pp.123-129
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    • 1994
  • SONOS EEPROM chips, containing several SONOSFET nonvolatile memories of various channel size, have been fabricated on the basis of the existing n-well CMOS processing technology for 1 Mbit DRAM ($1.2\mu\textrm{m}$.m design rule). All the SONOSFET memories have the triple insulated-gate consisting of 30.angs. tunneling oxide, 205.angs. nitride and 65.angs. blocking oxide. The miniaturization of the devices for the higher density EEPROM and their characteristics alterations accompanied with the scaling-down have been investigated. The stabler operating characteristics were attained by increasing the ratio of the channel width to length. Also, the transfer, switching, retention and degradation characteristics of the most favorable performance devices were presented and discussed.

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Characteristics of Laminar Lifted Flame in High Temperature Coflow (고온 동축류에서 층류 화염의 부상특성)

  • Kim, Kil-Nam;Won, Sang-Hee;Cha, Min-Suk;Chung, Suk-Ho
    • Journal of the Korean Society of Combustion
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    • v.7 no.2
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    • pp.1-6
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    • 2002
  • Characteristics of laminar lifted flames of propane highly-diluted with nitrogen have been investigated at various temperatures of coflow air. At various fuel mole fractions, the base of laminar lifted flames has the structure of tribrachial (or triple) flame. The liftoff heights are correlated well with the stoichiometric laminar burning velocity considering initial temperature at a given coflow velocity. It shows that lifted flames are stabilized on the basis of the balance mechanism between local flow velocity and the propagation speed of tribrachial flame, regardless of the temperature of coflow and fuel mole fraction. Lifted flames exist for a jet velocity even smaller than the stoichiometric laminar burning velocity, and liftoff velocity increases more rapidly than stoichiometric laminar burning velocity as coflow temperature increases. These can be attributed to the buoyancy effect due to the density difference.

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SRAM소자의 SER 및 Latchup 신뢰성 연구

  • Lee Jun-Ha;Lee Heung-Ju;Jo Hyeon-Chan;Lee Gang-Hwan;Gwon O-Geun
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2005.05a
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    • pp.63-66
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    • 2005
  • A soft error rate neutrons is a growing problem for integrated circuits with technology scaling. In the acceleration test with high-density neutron beam, a latch-up prohibits accurate estimations of the soft error rate (SER). This paper presents results of analysis for the latch-up characteristics in the circumstance corresponding to the acceleration SER test for SRAM. Simulation results, using a two-dimensional device simulator, show that the deep p-well structure has better latch-up Immunity compared to normal twin and triple well structures. In addition, it is more effective to minimize the distance to ground power compared with controlling a path to the $V_{DD}$ power.

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Computational Study of the Molecular Structure, Vibrational Spectra and Energetics of the OIO Cation

  • Lee, Sang-Yeon
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1855-1858
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    • 2004
  • Molecular geometries for the cationic and neutral species of OXO (X=Cl, Br, and I) are optimized using the Hartree-Fock (HF) theory, the second order Moller-Plesset perturbation theory (MP2), the density functional theory with the B3LYP hybrid functional (B3LYP), and the coupled cluster theory using single and double excitation with a perturbational treatment of triplet excitation (CCSD[T]) methods, with two basis sets of triple zeta plus polarization quality. The single point calculations for these species are performed at the CCSD(T,Full) level. The harmonic vibrational frequencies for these species are calculated at the HF, MP2, B3LYP and CCSD(T) levels. The adiabatic ionization potential for OIO is calculated to be 936.7 kJ/mol at the CCSD(T,Full) level and the correct value is estimated to be around 945.4 kJ/mol.

Passivation Layer Structures with a Silicon Nitride film (질화실리콘막을 사용한 표면보호층 구조에 관한 연구)

  • 이종무
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.22 no.6
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    • pp.53-57
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    • 1985
  • Comparisons and analyses were made of the properties of double or triple passivation layer structures composed of APCVD SiOt or PSG and PECVD SiN films with various layer combinations and layer thicknesses. As a result of the analyses of the pro.peHics such as threshold-voltage shift, crack resistance, pinhole density, and moisture reslstancei a con-clusion was reached that the proper passivation layer structure is the double layer consisting of a 4,00$\AA$ or thicker PSG film and a 6,000$\AA$ SiN film.

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Analysis of Cell Latch-up Effect in SRAM Device (SRAM 소자의 Cell Latch-up 현상 분석)

  • Lee Jun-Ha;Lee Hoong-Joo
    • Proceedings of the KAIS Fall Conference
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    • 2004.11a
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    • pp.203-205
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    • 2004
  • A soft error rate neutrons is a growing problem for terrestrial integrated circuits with technology scaling. In the acceleration test with high-density neutron beam, a latch-up prohibits accurate estimations of the soft error rate (SER). This paper presents results of analysis for the latch-up characteristics in the circumstance corresponding to the acceleration SER test for SRAM. Simulation results, using a two-dimensional device simulator, show that the deep p-well structure has better latch-up immunity compared to normal twin and triple well structures. In addition, it is more effective to minimize the distance to ground power compared with controlling a path to the $V_{DD}$ power.

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Error correction codes to manage multiple bit upset in on-chip memories (온칩 메모리 내 다중 비트 이상에 대처하기 위한 오류 정정 부호)

  • Jun, Hoyoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.11
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    • pp.1747-1750
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    • 2022
  • As shrinking the semiconductor process into the deep sub-micron to achieve high-density, low power and high performance integrated circuits, MBU (multiple bit upset) by soft errors is one of the major challenge of on-chip memory systems. To address the MBU, single error correction, double error detection and double adjacent error correction (SEC-DED-DAEC) codes have been recently proposed. But these codes do not resolve mis-correction. We propose the SEC-DED-DAEC-TAED(triple adjacent error detection) code without mis-corrections. The generated H-matrix by the proposed heuristic algorithm to accomplish the proposed code is implemented as hardware and verified. The results show that there is no mis-correction in the proposed codes and the 2-stage pipelined decoder can be employed on-chip memory system.