• Title/Summary/Keyword: Ionization rate

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A Study on Fuel Transport Characteristics in a Port Fuel Injected Sl Engine during Transient Condition (흡기포트 분사방식의 가솔린 엔진에서 급가속시 연료 거동에 관한 연구)

  • 황승환;조용석;이종화
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.3
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    • pp.20-27
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    • 2003
  • In this paper, the fuel transport characteristics during transient condition was studied by using a Fast Response Flame Ionization Detector(FRFID). The quantitative measurement method for the inducted fuel mass into cylinder is studied. The inducted fuel mass into the cylinder was estimated by using calculated air-fuel ratio by hydrocarbon concentration of cylinder and air flow model. In order to estimate the transportation of injected fuel from the intake port into cylinder, the wall wetting fuel model was used. The two coefficient $\alpha$,$\beta$) of the wall-wetting fuel model was determined from the measured fuel mass that was inducted into the cylinder at the first cycle after injection cut-off To reduce an air/fuel ratio fluctuation during rapid throttle opening, the appropriate fuel injection rate was obtain from the wall wetting model with empirical coefficients. Result of air/fuel ratio control, air/fuel excursion was reduced.

A New Technology for Strengthening Surface of Forging Die

  • Xin Lu;Zhongde Liu
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10b
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    • pp.189-192
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    • 2003
  • The Electro-thermal Explosion Coating (EEC) technique is a new surface treatment technology emerged in recent years. It uses an electrical discharge (with very high voltage from 5 to 30 kV or more) to produce a pulse current with large density inside the material to be deposited, the metal wire undergo the heating, melting, vaporization, ionization and explosion processes in a very short time (from tens ns to several hundreds ${\mu}s$), and the melted droplets shoot at the substrate with a very high velocity (3000 - 4500 m/s), so that the coating materials can be deposited on the surface of the substrate. Coatings with nano-size grains or ultra- fine grains can be formed because of rapid solidification (cooling rate up to $10^6-10^9\;k/s$). Surface of the substrate (about $1-5{\mu}m$ in depth) can be melted rapidly and coatings with very high bonding strength can be obtained.

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Remediation effect of indoor airborne fungi by operating the ionizing air cleaner in the university office.

  • Heo, S.M.;Song, J.H.;Paik, N.W.
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2003.06a
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    • pp.181-182
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    • 2003
  • Our study from Feburary to March, 2003, were done in university office A and B, located in Seoul. This study was carried out to investigate the reduction of the airborne fungi before and after we activate the air cleaner which using ionization. And the method of assessment was done by the CAMNEA method. The result was as follows. 1. In the research office A, the concentration of the airborne fungi was 18(${\pm}$11.3) CFU/㎥ before the ionizing air cleaner system was turned on: whereas three days after this result the concentration decreased to less than 1 CFU/㎥. 2. In the laboratory office B, the concentration was 210.6(${\pm}$5.3) CFU/㎥ before using the air cleaner and was decreased to 32.2(t 10.3) CFU/㎥ after using the air cleaner. The remediation rate in the experiment was 85 percentile,

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A model for neural trigger circuit using AlGaAs/GaAs MQW-IMD (AlGaAs/GaAs MQW-IMD를 사용하는 신경구동회로의 모델)

  • Song, Chung-Kun
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.4
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    • pp.47-56
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    • 1995
  • In this paper the model of the MQE-IMD-based neural trigger circuit is improved, where MQW-IMD is a new semiconductor device proposed and experimentally demonstrated by the author for the hardware implementation of the neural networks. The electron energy of AlXGa1-XAsbarrier is calculated by Ensemble Monte Carlo simulation according to the variation of Al mole fraction x and the applied electric field, whtich had been roughly estimated in the previous paper because of the difficulty to get the data. And in the consideration of the tunneling of the confined electrons within the quantum well the accuracy of the impact ionization rate is enhaned. Finally, the dependance of the frequency of pulse-train on the number of quantum wells can be calculated by modelling the effect of the distance of the induced positive charge from the cathode on the electric field at the cathode.

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Laccase of Lentinus edodes Catalyzed Oxidation of Amines and Phenolic Compounds: A Semiempirical Quantum Chemical Consideration

  • Pankratov, Alexei N.;Tsivileva, Olga M.;Nikitina, Valentina E.
    • BMB Reports
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    • v.33 no.1
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    • pp.37-42
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    • 2000
  • Based on the study by Leatham and Stabmann concerned with the rates (v) of amines and phenolic compounds oxidation catalyzed by laccase of basidiomycete Lentinus edodes (Berk.) Sing., as well as on the results of semiempirical quantum chemical computations using the PM3 method, the linear correlations of v and lnv values with first vertical ionization potentials of the substrates molecules and radicals derived from them, spin densities on N and O atoms of the above radicals, and with the radicals reorganization energies have been found.

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H/D substitution makes difference in photochemical studies: the case of dimethylamine

  • Kim, So-Yeon;Lee, Jeongmook;Kim, Sang Kyu
    • Rapid Communication in Photoscience
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    • v.4 no.3
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    • pp.63-66
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    • 2015
  • When the molecule in the excited state is subject to prompt predissociation, it is quite nontrivial to obtain vibrational structure of the excited state in general. This applies to the case of photochemistry of dimethylamine (DMA:$(CH_3)_2NH$). When DMA is excited to its first electronically excited state ($S_1$), the N-H bond dissociation occurs promptly. Therefore, $S_1$ vibronic bands are homogeneously broadened to give extremely small ionization cross sections and heavily-congested spectral features, making infeasible any reasonable spectral assignment. Here, we demonstrate that the predissociation rate of the excited state could be significantly reduced by the NH/ND substitution to give the much better-resolved $S_1$ spectral feature, revealing the vibrational structure of the excited state of $DMA-d_1$ ($(CH_3)_2ND$) for the first time.

Measurement of Optogalvanic Signal in Hollow Cathode Discharge Tube (Hollow cathode discharge tube에서의 광검류 신호 측정)

  • 이준회;정기주
    • Journal of the Korean Vacuum Society
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    • v.11 no.2
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    • pp.119-126
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    • 2002
  • The optogalvanic signals were measured using hollow cathode discharge tube with argon as buffer gas at change of discharge currents. A change of ionization rate due to electron collision causes an increase or decrease of the electric conductivity, This change in electric conductivity generates the optogalvanic signal. We conclude that optogalvanic signal has close relation with change of the lowest metastable atoms density at low current.

UV-LASER INDUCED SURFACE REACTION - DESORppTION AND ETCHING

  • Murata, Yoshitada
    • Proceedings of the Korean Vacuum Society Conference
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    • 1992.02a
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    • pp.3-10
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    • 1992
  • pphotostimulated desorpption of NO chemisorbed on ppt(001) at 80K has been studied by the (1+1)-resonance-enhanced multipphoton ionization((1+1)-REMppI) technique. A linearly ppolarized ArF excimer laser ( =193 nm, 6.41eV) is used as the ppumpp laser. A high adsorpption rate selectivity was found in the expposure deppendence of the NO desorpption yield. The NO desorpption yield increases drastically when the amount of NO expposure exceeds ~1.8 L. This result shows that the amount of NO sppecies with a large cross section for pphotostimulated desorpption increases drastically at higher NO coverages. Using scanning tunneling microscoppy, we have observed structural modifications of the chlorinated Si(111)-7$\times$7 surface induced by 266nm laser irradiation. At very low laser fluence of 0.7mJ/$\textrm{cm}^2$, at which thermal desorpption can be ignored, a pperiodic stripped ppattern of a single domain is imaged. This ppattern consists of flat terraces and narrow grooves of ~60 and ~10A in width, resppectively.

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Study on Characteristics of Plasma in Hollow Cathode Discharge (Hollow Cathode Discharge에서 플라즈마 특성에 관한 연구)

  • Yoon, Man-Young;Shin, Jong-Soon
    • Journal of the Korean Graphic Arts Communication Society
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    • v.23 no.2
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    • pp.93-101
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    • 2005
  • The measured plasma temperature of Ar hollow cathode discharge for several metal cathodes are about $620\;{\sim}\;780K$ at discharge current of $7\;{\sim}\;10mA$. The optogalvanic signals were measured using hollow cathode discharge tube with argon as buffer gas at change of discharge currents. A change of ionization rate due to electron collision causes an increase or decrease of the electric conductivity. This change in electric conductivity generates the optogalvanic signal. We conclude that optogalvanic signal has close relation with the lowest metastable atoms density at low current.

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