Internal Energy Distributions of OH Products in the Reaction of O(³P_J) with HSiCl₃

Kwak, Hyon-Tae,Ha, Seung-Chul,Jang, Sung-Woo,Kim, Hong-Lae,Park, Chan-Ryang Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.2

The OH($X^2{\Pi},\;{\nu}$"=0, 1) internal state distributions from the reaction of electronically ground state oxygen atoms with HSi$Cl_3$ were measured using laser-induced fluorescence. The ground-state O$(^3P_J)$ atoms with kinetic energies above the reaction barrier were produced by photolysis of N$O_2$ at 355 nm. The OH product revealed strong vibrational population inversion, P(${\nu}$"=1)/P(${\nu}$"=0) = 4.0 ${\pm}$ 0.6, and rotational distributions in both vibrational states exhibit substantial rotational excitations to the limit of total available energy. However, no preferential populations in either of the two $\Lambda$ doublet states were observed from the micropopulations, which supports a mechanism involving a direct abstraction of hydrogen by the atomic oxygen. It was also found that the collision energy between O and HSi$Cl_3$ is effectively coupled into the excitation of the internal degrees of freedom of the OH product ($<f_{vib}>$ = 0.62, and $<\;f_{rot}>$ = 0.20). The dynamics appear consistent with expectations for the kinematically constrained reaction which supports the reaction type, heavy + light-heavy $\rightarrow$ heavy-light + heavy (H + LH′ $\rightarrow$ HL + H′). The dynamics of oxygen atom collision with HSi$Cl_3$ are discussed in comparison to those with Si$H_4$.

Determination of electron energy probability function in low-temperature plasmas from current - Voltage characteristics of two Langmuir probes filtered by Savitzky-Golay and Blackman window methods

Roh, H.J.,Kim, N.K.,Ryu, S.,Park, S.,Lee, S.H.,Huh, S.R.,Kim, G.H. Elsevier 2015 Current Applied Physics Vol.15 No.10

Acceptable data for electron energy probability function (EEPF) measurement in low-pressure plasmas require a small depletion in near-zero electron energy and a large dynamic range in the high-energy regime. The voltage drop across internal resistance and noise from the data acquisition system cause a rounding of the EEPF near the zero electron energy and a reduction in the dynamic range due to a low signal-to-noise ratio of the high-energy regime, respectively, leading to erroneous interpretation in the EEPF measurement. A digital smoothing filter can be employed to reduce the noise signal, but it can also cause additional depletion near the zero energy. In order to obtain reliable EEPF data, a novel technique is proposed using two Langmuir probes with differing collecting areas and the Savitzky-Golay and Blackman window methods. The technique enables the internal resistance effect to be removed using a slope of the current - voltage characteristic taken from the probes. In addition, the Savitzky-Golay and Blackman window methods in the technique apply separately to two regimes of the EEPF, i.e., the near-zero energy regime and the inelastic energy regime, because appropriate smoothing methods that minimize loss and distortion of information differ for the two regimes. This allows one to decrease the noise signal, minimizing the additional depletion near the zero energy. This technique improves the dynamic range of the EEPF from 30 to 55 dB to 65-105 dB and provides more accurate electron density and effective electron temperature from the EEPF, compared to those of the conventional technique.

Determination of electron energy probability function in lowtemperature plasmas from current e Voltage characteristics of two Langmuir probes filtered by SavitzkyeGolay and Blackman window methods

노현준,김남균,유상원,박설혜,이석환,허성렬,김곤호 한국물리학회 2015 Current Applied Physics Vol.15 No.10

Acceptable data for electron energy probability function (EEPF) measurement in low-pressure plasmas require a small depletion in near-zero electron energy and a large dynamic range in the high-energy regime. The voltage drop across internal resistance and noise from the data acquisition system cause a rounding of the EEPF near the zero electron energy and a reduction in the dynamic range due to a low signal-to-noise ratio of the high-energy regime, respectively, leading to erroneous interpretation in the EEPF measurement. A digital smoothing filter can be employed to reduce the noise signal, but it can also cause additional depletion near the zero energy. In order to obtain reliable EEPF data, a novel technique is proposed using two Langmuir probes with differing collecting areas and the SavitzkyeGolay and Blackman window methods. The technique enables the internal resistance effect to be removed using a slope of the current e voltage characteristic taken from the probes. In addition, the SavitzkyeGolay and Blackman window methods in the technique apply separately to two regimes of the EEPF, i.e., the nearzero energy regime and the inelastic energy regime, because appropriate smoothing methods that minimize loss and distortion of information differ for the two regimes. This allows one to decrease the noise signal, minimizing the additional depletion near the zero energy. This technique improves the dynamic range of the EEPF from 30 to 55 dB to 65e105 dB and provides more accurate electron density and effective electron temperature from the EEPF, compared to those of the conventional technique.

Internal Energy Distributions of OH Products in the Reaction of O(3PJ) with HSiCl3

Hyon Tae Kwak,Seung Chul Ha,Sungwoo Jang,Hong Lae Kim,Chan Ryang Park 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.2

The OH(X2Π, υ"=0, 1) internal state distributions from the reaction of electronically ground state oxygen atoms with HSiCl3 were measured using laser-induced fluorescence. The ground-state O(3PJ) atoms with kinetic energies above the reaction barrier were produced by photolysis of NO2 at 355 nm. The OH product revealed strong vibrational population inversion, P(υ"=1)/P(υ"=0) = 4.0 ± 0.6, and rotational distributions in both vibrational states exhibit substantial rotational excitations to the limit of total available energy. However, no preferential populations in either of the two Λ doublet states were observed from the micropopulations, which supports a mechanism involving a direct abstraction of hydrogen by the atomic oxygen. It was also found that the collision energy between O and HSiCl3 is effectively coupled into the excitation of the internal degrees of freedom of the OH product (<fvib> = 0.62, and < frot> = 0.20). The dynamics appear consistent with expectations for the kinematically constrained reaction which supports the reaction type, heavy + light-heavy → heavy-light + heavy (H + LH′ → HL + H′). The dynamics of oxygen atom collision with HSiCl3 are discussed in comparison to those with SiH4.

UNDERSTANDING OF THE SPARK EFFECT OF ELECTRON COLLISION BY A CAPACITIVE DISCHARGE IGNITION IN A CONSTANT VOLUME COMBUSTION CHAMBER

Kwonse Kim,Kyung Tae Lee,최문석,Dooseuk Choi 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.1

This work is to investigate the physical effect of plasma discharge in atmospheric air using a capacitive discharge ignition (CDI) system. Also, to specifically investigate the kernel effects of CDI system, this work represents the different characteristics including the spark ignition, electric current, integral energy, spark propagation, flame growth, and kernel distribution comparing with the conventional spark ignition. In the experimental setup, the system is composed of a constant volume combustion chamber (CVCC), spark plug, transformer, capacitor device, mass flow controllers, regulators, high-speed camera, and LabVIEW software and cDAQ. The experiment carried out a wide range as the following conditions: J type spark plug, central type electrode, 1.0 mm plug gap, atmospheric air of initial pressure, 292 K of room temperature, 0.75 ms of spark duration, 420 V of CDI voltage, and 12.5 V of initial transformer voltage. As a result, the spark flame kernel of 400V CDI is increased by MEHV comparing with the conventional spark and the improved effect can be seen in 50 μs. Consequently, the plasma effect of MEHV based on CDI system has a linear characteristic regarding spark kernel growth by capacitance energy comparing with the conventional spark.

한국의 신재생에너지 발전량, 이산화탄소 배출량, 국제무역, 실질GDP, 비신재생에너지 발전량 간의 장·단기 영향

김창범 한국무역보험학회 2023 무역금융보험연구 Vol.24 No.1

Purpose : This paper empirically investigates the relationships among new renewable energy generation (NRE), carbon dioxide emissions (CDE), real GDP (RGDP), International Trade (INTRAD), nuclear power generation (NUC) and thermal power generation (HEAT) in Korea. Research design, data, methodology : This study estimated the short-run and long-run effects among PNRE, PCDE, PRGDP, INTRAD, PNUC and PHEAT converted to per capita variables annual data from 1981 to 2020 using the ARDL model and a variety cointegration equation. Results : The PNRE, PNUC and PHEAT have a two-way and positive effect on INTRAD and PRGDP while changes in PNRE and PNUC have a bidirectional relationship with change in PRGDP and change in INTRAD has a unidirectional relationship with change in PNRE. Conclusions : The linkage strategy between the NRE and nuclear power generation should be established along with energy efficiency policies to expand the RGDP and INTRAD.

Efficient and reliable calculation of rice-ramsperger-kassel-marcus unimolecular reaction rate constants for biopolymers: Modification of beyer-swinehart algorithm for degenerate vibrations

Moon, Jeong Hee,Sun, Meiling,Kim, Myung Soo Springer New York LLC 2007 Journal of the American Society for Mass Spectrome Vol.18 No.6

<P>The Beyer-Swinehart (BS) algorithm, which calculates vibrational state density and sum, was modified for simultaneous treatment of degenerate vibrations. The modified algorithm was used in the grouped-frequency mode of the Rice-Ramsperger-Kassel-Marcus (RRKM) unimolecular reaction rate constant calculation for proteins with relative molecular mass as large as 100,000. Compared to the original BS method, reduction in computation time by a factor of around 3000 was achieved. Even though large systematic errors arising from frequency grouping were observed for state densities and sums, they more or less canceled each other, thus enabling reliable rate constant calculation. The present method is thought to be adequate for efficient and reliable RRKM calculations for any macromolecule in the gas phase such as the molecular ions of proteins, nucleic acids, and carbohydrates generated inside a mass spectrometer. The algorithm can also be used to calculate the internal energy distribution of a macromolecule at thermal equilibrium.</P>

Dynamics of OH Production in the Reaction of O(1D2) with Cyclopropane

장성우,Sung Il Jin,HongLaeKim,Hyung Min Kim,Chan Ryang Park 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.6

The OH(X2Π, υ" = 0,1) internal state distribution following the reaction of electronically excited oxygen atom (O(1D2)) with cyclo-C3H6 has been measured using laser-induced fluorescence, and compared with that following the reaction of O(1D2) with C3H8. The overall characteristics of the OH internal energy distributions for both reactions were qualitatively similar. The population propensity of the П(A′) Λ-doublet sub-level suggested that both reactions proceeded via an insertion/elimination mechanism. Bimodal rotational population distributions supported the existence of two parallel mechanisms for OH production, i.e., statistical insertion and nonstatistical insertion. However, detailed analysis revealed that, despite the higher exoergicity of the reaction, the rotational distribution of the OH following the reaction of O(1D2) with C3H8 was significantly cooler than that with cyclo-C3H6, especially in the vibrational ground state. This observation was interpreted as the effect of the flexibility of the insertion complex and faster intramolecular vibrational relaxation (IVR).

압력변화와 소리특성 변화에 대한 상관관계 연구

김봉영(Bong-Young Kim),배명진(Myung-Jin Bae) 인문사회과학기술융합학회 2018 예술인문사회융합멀티미디어논문지 Vol.8 No.7

수박과 통조림은 내부용량과 내부압력의 상태에 따라 미세하게 다른 소리가 난다. 숙달된 검사원은 제품의 미세한 소리차이를 인지하여 제품의 상태를 파악한다. 제품의 내부 압력이 변하게 되면 제품표면을 기준으로 음향임피던스의 불균형이 발생한다. 또한, 음향임피던스의 불균형은 밀폐용기의 진동을 방해하게 된다. 본 논문에서는 밀폐된 용기의 진공실험을 통해 변화된 압력에 따라 나타나는 소리특성 변화를 확인코자 한다. 실험결과 외부와 내부의 압력차가 없는 경우에 용기가 250, 563, 906, 1219Hz에서 공명하는 반면 내부 압력을 낮춘 0.8bar의 진공도에서는 188, 281, 563, 1250Hz로 공명하여, 공명주파수 Shift 현상을 확인하였다. 또한, 각 압력상태에 따라 공명주파수의 에너지 분포도 및 분산을 확인한 결과 진공도가 높을수록 공명주파수별 에너지 크기가 균일해지는 것을 확인할 수 있었다. 이러한 실험결과로 압력의 변화에 따라 소리가 다르게 나타나는 정도의 상관관계를 확인하였다. The watermelon and the canned goods sound differently depending on the internal capacity and the internal pressure. The skilled inspectors recognize the fine sound difference of the product and understand the state of the product. If the internal pressure of the product changes, an unbalance of the acoustic impedance occurs on the product surface. In addition, the unbalance of the acoustic impedance suppresses the vibration of the closed container. In this paper, we investigate the change of the sound characteristics according to the changed pressure through the vacuum experiment of the closed container. The experimental results show that the vessel resonates at 250, 563, 906, and 1219 Hz when there is no external and internal pressure difference, while it resonates at 188, 281, 563, and 1250 Hz at the vacuum of 0.8 bar, As a result, resonance frequency shift phenomenon was confirmed. Also, the energy distribution and variance of the resonance frequency were checked according to each pressure condition, and it was confirmed that the energy level per resonance frequency was much more similar to the degree of vacuum. As a result of these experiments, we confirmed the correlation between the change of pressure and the sound appearing differently.

Dissociation kinetics of singly protonated leucine enkephalin investigated by time-resolved photodissociation tandem mass spectrometry

Moon, Jeong Hee,Yoon, So Hee,Bae, Yong Jin,Kim, Myung Soo Springer-Verlag 2010 Journal of the American Society for Mass Spectrome Vol.21 No.7

<P>The yields of post-source decay (PSD) and time-resolved photodissociation (PD) at 193 and 266 nm were measured for singly protonated leucine enkephalin ([YGGFL + H]<SUP>+</SUP>), a benchmark in the study of peptide ion dissociation, by using tandem time-of-flight mass spectrometry. The peptide ion was generated by matrix-assisted laser desorption ionization (MALDI) using 2,5-dihydroxybenzoic acid as the matrix. The critical energy (E<SUB>0</SUB>) and entropy (ΔS‡ at 1000 K) for the dissociation were determined by Rice-Ramsperger-Kassel-Marcus fit of the experimental data. MALDI was done for a mixture of YGGFL and Y<SUB>6</SUB> and the plume temperature determined by the kinetic analysis of [Y<SUB>6</SUB> + H]<SUP>+</SUP> data were used to improve the precision of E<SUB>0</SUB> and ΔS‡ for [YGGFL + H]<SUP>+</SUP>. E<SUB>0</SUB> and ΔS‡ thus determined (E<SUB>0</SUB> = 0.67 ± 0.08 eV, ΔS‡=−24.4 ± 3.2 eu with 1 eu = 4.184 J K<SUP>−1</SUP>mol<SUP>−1</SUP>) were significantly different from those determined by blackbody infrared radiative dissociation (BIRD) (E<SUB>0</SUB> = 1.10 eV, ΔS‡ = −14.9 eu), and by surface-induced dissociation (SID) (E<SUB>0</SUB> = 1.13 eV, ΔS‡ = −10.3 eu). Analysis of the present experimental data with the SID kinetics (and BIRD kinetics also) led to an unrealistic situation where not only PSD and PD but also MALDI-TOF signals could not be detected. As an explanation for the discrepancy, it was suggested that transition-state switching occurs from an energy bottleneck (SID/BIRD) to an entropy bottleneck (PSD/PD) as the internal energy increases.</P>