• 제목/요약/키워드: Vibrational Mode

검색결과 213건 처리시간 0.028초

Assignment of Vibronic Emission Spectra of Jet-Cooled m-Tolunitrile

  • Park, Chan Ho;Lee, Sang-Kuk
    • Bulletin of the Korean Chemical Society
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    • 제27권9호
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    • pp.1377-1380
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    • 2006
  • The technique of corona-excited supersonic expansion was applied to produce electronically excited but rovibrationally cooled m-tolunitrile. The well-resolved vibronic emission spectrum of the jet-cooled m-tolunitrile in the $S_1\;\rightarrow \;S_0$ transition was recorded in the uv region using a Fourier transform spectrometer equipped with a Quartz-uv beam splitter. From an analysis of the spectrum observed, it was confirmed that the electronic transition and vibrational mode frequencies in the ground electronic state were accurately determined.

Finite element modeling of the vibrational behavior of multi-walled nested silicon-carbide and carbon nanotubes

  • Nikkar, Abed;Rouhi, Saeed;Ansari, Reza
    • Structural Engineering and Mechanics
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    • 제64권3호
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    • pp.329-337
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    • 2017
  • This study concerns the vibrational behavior of multi-walled nested silicon-carbide and carbon nanotubes using the finite element method. The beam elements are used to model the carbon-carbon and silicon-carbon bonds. Besides, spring elements are employed to simulate the van der Waals interactions between walls. The effects of nanotube arrangement, number of walls, geometrical parameters and boundary conditions on the frequencies of nested silicon-carbide and carbon nanotubes are investigated. It is shown that the double-walled nanotubes have larger frequencies than triple-walled nanotubes. Besides, replacing silicon carbide layers with carbon layers leads to increasing the frequencies of nested silicon-carbide and carbon nanotubes. Comparing the first ten mode shapes of nested nanotubes, it is observed that the mode shapes of armchair and zigzag nanotubes are almost the same.

에너지 트래핑 효과를 이용한 세라믹 필터의 공진주파수에 관한 연구 (A study on the resonant frequency of ceramic fitter using energy trapping effect)

  • 박기엽;김원석;송준태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1994년도 추계학술대회 논문집
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    • pp.139-142
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    • 1994
  • Ceramic filter using energy trapping pheonomenon is used bandpass filter at high frequency. In this paper, we analyzed theoretically ceramic filter characteristics of TS vibrational mode and also investigated experimentally it. The ceramic plate is PZT-4 poled in the thickness direction of Valpey Fisher Co. and electroded with two pairs. We analyzed the characteristics in appling to the all constant of ceramic and electrode material each other and vibrational mode. We also measured resonant frequency and bandpass width of the ceramic filter changing the thickness of ceramic plate and electrode spacing. Comparing of falter characteristics, theoretical value nearly corresponded with experimental value. So we saw that we can expect filter characteristics changing the thickness of ceramic plate and electrode spacing.

멜라토닌의 특성에 대한 이론적 연구 (Theoretical Study for the Characteristics of Melatonin)

  • 김동엽;정맹준;이철재
    • 한국산업융합학회 논문집
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    • 제15권2호
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    • pp.59-63
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    • 2012
  • Melatonin has been studied as a potential treatment of cancer, immune disorders, cardiovascular diseases, depression, seasonal affective disorder (SAD), circadian rhythm sleep disorders, sexual dysfunction and some forms of insomnia. Prolonged release melatonin has shown good results in treating insomnia in older adults. It may ameliorate circadian misalignment and SAD. Basic research indicates that melatonin may play a significant role in modulating the effects of drugs of abuse such as cocaine. A 2004 review found that melatonin significantly increased total sleep time in people suffering from sleep restriction. Therefore, in this study, in order to explain characteristics of melatonin, total energy, net charge, vibrational mode of melatonin are calculated by PM3 methods of HyperCam 6.0.

피나스테라이드의 특성에 대한 이론적 연구 (Theoretical Study for the Characteristics of Finasteride)

  • 이철재;정맹준;김동엽
    • 한국산업융합학회 논문집
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    • 제16권3호
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    • pp.69-74
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    • 2013
  • Finasteride, ($5{\alpha}$, $17{\beta}$)-N-(1,1-dimethylethyl)-3-oxo-4-azaandrost-1-ene-17-carboxamide), is a 5a-reductase enzyme inhibitor. This enzyme converts testosterone to the more potent androgen, a-dihydrotestosterone. This molecules a logical medical treatment for benign prostatic hyperplasia (BPH), as it induced a reduction in serum dihydrotestosterone and prostatic specific antigen levels with a concomittant increase in blood testosterone concentration . Despite its widespread use, little has been published concerning its molecular properties. Therefore, in this study, in order to explain characteristics of finasteride, total energy, net charge, vibrational mode of melatonin are calculated by PM3 methods of HyperCam 8.0.

설치면 강성에 따른 드럼세탁기의 동특성 및 설계대책 (The Influence of the floor rigidity on front-loading washer installation and its vibrational behavior)

  • 위훈;정지덕
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.248-251
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    • 2004
  • The vibrational behavior of a front load washing machine is heavily influenced by the floor stiffness on which the washing machine is installed. In case the floor stiffness is extremely low like a wooden floor (we call it a 'soft floor, S/F'), it is quite probable that a washer's rigid body mode exists in the operating frequency range. In this case, the outer frame vibration level would be very high, but the mitigation scheme is quite limited except the excitation force abatement by acquisition of the optimal inertia in the internal vibratory system and the diaphragm's stiffness with the minimum force transfer.

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Conformational Study of Benzene-Fused Ring Compound 1,2,3,4-Tetrahydronaphthalene Using Vibrational

  • 추재범;한성준;최영식
    • Bulletin of the Korean Chemical Society
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    • 제18권10호
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    • pp.1076-1082
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    • 1997
  • The infrared, Raman, and jet-cooled laser-induced fluorescence excitation spectra of 1,2,3,4-tetrahydronaphthalene have been recorded and analyzed. The observed vibrations have been assigned to understand the conformational behaviors in its electronic ground (S0) and excited (S1) states. Ab initio at the HF/6-31G** level and molecular mechanics (MM3) force field calculations have been carried out to generate the complete normal mode frequencies of the molecule in its S0 state. The vibrational frequencies calculated from the ab initio method show a better agreement with the observed infrared and Raman frequencies than those calculated from the MM3 method. In several cases, the normal mode calculations were very helpful to clarify some ambiguities of previous assignments. In addition, the ring inversion process between two twisted conformers of 1,2,3,4-tetrahydronaphthalene has been reexamined utilizing ab initio calculation. The results show that the ring inversion energy is in the range of 3.7-4.3 kcal/mol which is higher than the previously reported AM1 value of 2.1 kcal/mol.

LNG 화물창 비계 시스템의 구조해석 및 진동 특성 (Structural and Vibrational Characteristics for the Scaffolding System of LNG Cargo Containment)

  • 류봉조;신광복;남윤의;오부진;백수곤;김후식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.1197-1202
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    • 2007
  • The paper deals with the structural analysis and vibration test for the scaffolding system of LNG cargo containment. The eight-stories scaffolding system has telescopic area, working area, coner area and storage area in real system. In the structural analysis, the maximum displacement and stress of the each floor for the scaffolding system are investigated by finite element method. In the vibrational analysis, the natural frequencies and mode shapes for 8-stories scaffolding system of the LNG cargo containment are investigated. In order to compare theoretical natural frequencies with experimental ones, small size of 2-step scaffolding structure is used, and the theoretical results for natural frequency have a good agreement with experimental ones.

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한국형 틸팅열차 한빛200의 진동 특성에 관한 연구 (The Study on the Vibrational Characteristics of Korean Tilting Train Hanvit200)

  • 김남포;김정석;박태원
    • 한국소음진동공학회논문집
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    • 제18권8호
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    • pp.864-871
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    • 2008
  • The tilting trains can run on curve track about 30% faster than conventional train without affecting passenger comfort. As the tilting trains offer the optimum means of providing faster and more comfortable rail service with minimum of environmental disturbance and capital investment, it is widely adopted for commercial operation all over the world. Over several years, the Korea Railroad Research Institute(KRRI) and Ministry of Construction and Transportation(MOCT) have been developing 200 km/h Korean tilting train, Hanvit200. Hanvit200 adopts the pendulum type tilting mechanism and hybrid car body structure, mainly CFRP combined with steel. In this paper the vibrational characteristics of Hanvit200 was investigated through Eigen vector analysis, modal test and main line running test.

한국형 틸팅열차 한빛200의 진동 특성에 관한 연구 (The study on the vibrational characteristics of Korean Tilting Train, Hanvit200)

  • 김남포;한성호;최강윤;박태원
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 춘계학술대회논문집
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    • pp.519-524
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    • 2008
  • The tilting trains can run curve track about 30% faster than conventional train without affecting passenger comfort. As the tilting trains offer the optimum means of providing faster and more comfortable rail service with minimum of environmental disturbance and capital investment, it is widely adopted for commercial operation all over the world. Over several years, the Korea Railroad Research Institute(KRRI) and Ministry of Construction and Transportation(MOCT) have been developing 200 km/h Korean tilting train, Hanvit200. Hanvit200 adopt the pendulum type tilting mechanism and hybrid car body structure, mainly CFRP combined with steel. In this paper the vibrational characteristics of Hanvit200 was investigated through Eigen vector analysis, Modal Test and main line running test.

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