• Mass Spectrometry Letters
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• 제2권1호
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• pp.24-27
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• 2011

Hyperthermal ion/surface collisions of bromotoluene radical cations were studied using perfluorinated (F-SAM) and hydroxyl-terminated (OH-SAM) self-assembled monolayer surfaces in a tandem mass spectrometer with BEEQ geometry. The isomers were differentiated by ion abundance ratios taken from surface-induced dissociation (SID). The dissociation rate followed the order of ortho > meta > para isomers. The peak abundance ratio of m/z 51 to m/z 65 showed the best result to discern the isomers. A dissociation channel leading to tolylium ion was suggested to be responsible for the pronounced isomeric differences. The capability of SID to provide high-energy activation with narrow internal energy distribution may have channeled the reaction into the specific dissociation pathway, also facilitating small differences in reaction rates to be effective in the spectral time window of this experiment. All of the molecular ions experiencing reactive collisions with the F-SAM surface undergo transhalogenation, in which a fluorine atom on the surface replaces the bromine in the incoming ions. This reactive collision was dependent on the laboratory collision energy occurring in ca. 40.75 eV range.

• 산경연구논집
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• 제10권11호
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• pp.35-47
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• 2019

Purpose: Current study focused on investigating the effects of the self-dissociation as a thought in which consumers dis-identify or dissociate with the threatened in-group and the escapism as a tendency of consumers' distracting themselves and avoiding their thoughts about the in-group under severe but adoptable criticism by turning their attention elsewhere on across-domain compensatory consumption intention. And It explored not only the positive roles of undesirability thought against the in-group in consumers' forming the self-dissociation and the escapism, but also the effects of negative emotion to the in-group felt at the place of being exposed to the criticism against the in-group on the escapism. Research design, data, and methodology: The experiment was performed with the in-group-threatening single factor within-subject design. Questionnaire data were collected from 196 undergraduate students, and the data were used to testing research hypotheses by structural equation model of Amos 21.0. Results: First, both the self-dissociation of consumers' dis-identifying with the in-group criticized severely by others and the escapism of their deliberately directing their thoughts and distracting their attention away from thinking the in-group positively influenced on the across-domain compensatory consumption intention. Second, the negative emotion positively influenced on the escapism. Third, the undesirability thought to the in-group under the severe criticism positively effected on the self-dissociation as well as the escapism. Putting in the nutshell, the findings of this study are consistent with the idea that consumers can overcome the negative self-discrepancy on one dimension of their social identity by distracting themselves and avoiding thinking about the threatened in-group to find meaning on another dimension which might lead them to the place of doing the across-domain compensatory consumption. Conclusions - Focusing on the results of this study, checking which aspects of consumers' social identity are linked to products or brands is at issue to marketers when the consumers are faced with the criticism against the in-group. The marketers should build the messages about their products or brand not related to the checked aspects, and communicate the messages, to lead the consumers to the place of doing the across-domain compensatory consumption by their products or brands.

• EDISON SW 활용 경진대회 논문집
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• 제3회(2014년)
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• pp.115-125
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• 2014

We investigate dissociation of diatomic molecules and anions using density functional theory (DFT) and density-corrected density functional theory (DC-DFT). We scan the potential energy curve of CH, NH and NO neutral molecule and its anion with both DFT and DC-DFT (in form of Hartree-Fock DFT, HF-DFT) using various functionals. Using CCSD(T) results as reference, we perform the error decomposition scheme recently proposed by Kim et al. The results show while most neutrals are $functio{\acute{n}}al$ error $domi{\bar{n}}ating$ normal calculations, $CH^-$ and $NO^-$ anions are density-driven error dominating abnormal calculations. In case of $NH^-$, traditional DFT goes to a wrong dissociation limit indicating abnormality, but both HF-DFT and CCSD(T) results need further investigation due to the kinks on the curve.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.123.2-123.2
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• 2011

Self-preservation effect was identified by means of macroscopic dissociation experiments after keeping natural gas hydrate samples at 258 K for 15 days. The hydrate samples were formed using synthetic natural gas hydrate whose compositions are 90% $CH_4$, 7% $C_2H_6$, and 3% $C_3H_8$. In addition, during the formation, heavy hydrocarbons of propane and ethane are found to occupy hydrate cages in a more favorable way than methane so as to change the gas composition after hydrate formation. Experimental results obtained in this study can provide useful information on applications of natural gas hydrate for storing or transporting natural gas in the form of solid hydrate.

• Ocean and Polar Research
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• 제26권3호
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• pp.515-521
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• 2004

The processes of formation and dissociation of gas hydrates were investigated by monitoring pressure and temperature variations in a pressure cell in order to understand the kinetic behavior of gas hydrate and the controlling factors fur the phase transition of gas hydrate below freezing. Gas hydrates were made kom guest gases ($CH_4,\;CO_2$, and their mixed-gas) and fine ice powder. We found that formation and dissociation speeds of gas hydrates were not controlled by temperature and pressure conditions alone. The results of this study suggested that pressure levels at the formation of mixed-gas hydrate determine the transient equilibrium pressure itself.

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.11-15
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• 2017

We present a study of transition metal compounds using density functional theory (DFT), and density-corrected density functional theory(DC-DFT). By replacing the self-consistent density with that obtained from Hartree-Fock calculation, i.e., HF-DFT, the abnormality driven by self-interaction error is removed in several important cases. We discuss when and how HF-DFT works by examining 3d orbital dimers using approximate functionals and by comparing the results from self-consistent-DFT and HF-DFT with experimental values.

• 대한화학회지
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• 제45권5호
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• pp.401-412
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• 2001

$H_{2n+1}^+$ (n=1~6) cluster들에 대하여 높은 수준의 순 이론적(ab initio) 양자역학적 방법을 사용하여 분자 구조, 진동 주파수(vibrational frequency), 그리고 해리 에너지 등을 계산하였다. 분자구조는 $H^+_g$까지는 TZ2P+ d CCSD(T) 수준에서 그리고 $H_{11}^+$과 $H_{13}^+$에 대해서는 TZ2P CCSD(T) 수준까지 최적화하였다. 진동 주파수는 여러 basis set에서 SCF 방법으로 계산하였으며, 본 연구에서 최적화된 모든 분자구조들이 local minimum 구조임을 확인하였다. $H_{2n+1}^+$로부터 $H_2$ 의 해리 에너지($D_e$)는 각각의 최적화된 분자구조에서의 에너지 차로부터 계산하였으며, 영점 진동에너지(ZPVE)를 고려하여, 지금까지의 이론 및 실험결과($D_0$)와 비교하였다.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1470-1474
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• 2009

Thermal and photochemistry of methyl iodide ($CH_3I)\;adsorbed\;on\;D_2O$ ice film on Cu(111) at 100 K were studied using temperature-programmed desorption (TPD) time-of-flight mass spectrometry (TOF-MS), X-ray and ultraviolet photoelectron spectroscopies. On the basis of TPD, multilayer and monolayer $CH_3I$ molecules desorb from $D_2O$ ice layer at 120 and 130 K, respectively. Photo-irradiation at 100 K exhibits dramatic changes in the TPD and I $3d_{5/2}\;XPS\;of\;CH_3I$ on ice film, due to a dramatic dissociation of $CH_3I$. The dissociation is likely activated by solvated electrons transferred from the metal substrate during photo-irradiation. No other photo-initiated reaction products were found within our instrumental detection limit. During photo-irradiation, the $CH_3I$, $CH_3$ and I could be trapped (or solvated) in ice film by rearrangement (and self-diffusion) of water molecules. A newly appeared parent molecular desorption peak at 145 K is attributed to trapped $CH_3I$. In addition, the $CH_3$ and I may diffuse through ice and chemisorb on Cu(111), indicated by TPD and I $d_{5/2}$ XPS taken with photo-irradiation time, respectively. No molecular ejection was found during photo-irradiation at 100 K. The work functions for $CH_3I/Cu(111),\;D_2O/Cu(111)\;and\;CH_3I/D_2$O/Cu(111) were all measured to be about 3.9 eV, 1.0 eV downward shift from that of clean Cu(111).

• Bulletin of the Korean Chemical Society
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• 제23권2호
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• pp.245-252
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• 2002

The computationally simple quantum mechanical method (VSCF-DWB-IOS) has been applied to studying the Ar-$CO_2$ vibrational predissociation phenomenon. The new methodology utilizes the vibrational self-consistent field method to determine the vibrational structure of the van der Waals complex, the distorted-wave Born approximation for dissociating process, and the infinite-order sudden approximation for the continuum dissociating product of $CO_2$. The dissociation due to the coupling of the symmetric stretching vibrational motion of $CO_2$ with the motion of the Ar van der Waals mode has been extensively investigated. The lifetimes of transient excited vibrational states, linewidths of absorption peak, and the rotational state distributions of the product, $CO_2$ have been computed. It has been found that the lifetime of the Ar-$CO_2$ in excited vibrational state is very long compared with that of triatomic van der Waals complexes and the product $CO_2$ carries a major portion of dissociation energy as a rotational energy.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제13권1호
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• pp.3-14
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• 2002

아동에 가해지는 정신적 외상의 충격은 아동의 심리발달에 지울 수 없는 상처를 남김으로써 향후 심각한 정신장애를 일으키는 결정적 원인이 된다. 아동기 외상의 현상학적 특징과 외상에 관여하는 신경생물학적 기전을 살펴보았고, 아동기에 경험하는 외상이 인격의 발달에 미치는 영향과 그와 관련한 정신병리를 알아보았다. 외상에 노출된 아동은 공통적으로 자신이 경험한 공포사건을 시각적으로 재경험하거나 그 기억을 반복하며, 놀이나 행동을 통해서도 외상사건을 반복하려는 경향을 보인다. 일회의 충격적 사건에 노출된 아동은 사건에 대한 지나친 기억과 집착을 보이고 지각왜곡이 심한 반면 장기간 반복되는 외상을 경험하는 아동은 정신적 무감각과 자기최면, 해리, 분노의 경향이 두드러진다. 소아·청소년에서는 외상 후 퇴행이 보다 현저하고 시간감각의 왜곡이 더 심하게 나타나며 아동의 연령이 어릴수록 자율신경계의 반응성이 증가하는 경향을 보인다. 외상적 충격에 노출되면 뇌내에서 즉각적이고 방대한 신경전달물질의 방출이 있게되는데, 자율신경계, 면역계, 시상하부-뇌하수체-부신피질 축(hypothalamic-pituitary-adrenal axis)이 활성화된다. 외상시 internal opiate가 활발한 작용을 하면서 아동으로 하여금 외상에 반응하지 않도록 하고 외상에 대한 감정반응 자체를 봉쇄할 수 있도록 해준다. 아동기 외상의 경우 central noradrenergic system에 변화가 초래되어 카테콜아민에 대해 과민감한 비정상적 소견을 보이게 된다. 체내 순환되는 cortisol 수치는 감소하고, glucocorticoid 수용체 농도와 반응성이 증가한다. 외상 후 발견되는 기억력 장애는 해마의 구조적 변화와 관련이 있는 것으로 보고되고 있다. 아동기 외상은 자기(self)와 대상(object)에 대한 내적 표상(internal representation)이 지속적으로 분화 발전하는 발달과정에서 일어난다는 점에서 인격의 발달에 심각한 영향을 미치게 된다. 해리, 신체화, 자학성, 자기애 장애의 정신병리로 발전하면서 경계성 인격장애, 자기애성 인격장애, 다중인격장애 등을 초래하게 된다.