Dissertations / Theses: 'Vibrational energy transfer rates'

1

Wilson, Graham John. "Energy transfer in gases and cryogenic liquids." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239254.

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Turnidge, Martin Laurence. "Vibrational energy transfer at low temperatures and the use of infrared laser excitation for trace detection." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337427.

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Ahn, Tai Sang. "Determination of Vibration-to-Vibration Energy Transfer Rates of Nitrogen, Oxygen, and Hydrogen Using Stimulated Raman Scattering." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1104163814.

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4

Wickham-Jones, C. T. "Studies of vibrational energy transfer of small molecules." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371569.

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Reid, Jonathan Philip. "Vibrational energy transfer in gases at low temperatures." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362081.

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Williams, H. T. "Energy transfer in gases and liquids at low temperatures." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233537.

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7

White, Allen Ray. "Experimental and computational study of vibrational energy transfer in nitric oxide." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1190120014.

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8

Bechara, J. N. "Stimulated and vibrational energy transfer processes in vibrationally excited nitric oxide." Thesis, Queen's University Belfast, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374205.

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White, Allen R. "Experimental and computational study of vibrational energy transfer in nitric oxide." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1190120014.

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10

Rock, Andrew Boyd, and n/a. "Low Energy Collision Induced Vibrational Relaxation in B3II+ou Iodine." Griffith University. School of Science, 1996. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050920.144408.

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Understanding energy transfer processes is an essential prerequisite for the deep understanding of all chemical processes. This thesis investigates the process of vibrational relaxation (or deexcitation) of highly vibrationally and electronically excited molecular iodine (I2) induced by very low energy collisions in a supersonic free jet with six foreign gases. In an investigation of the state-to-field relaxation of I2 (B 3II+ou, v = 16) induced by collisions with He at temperatures of 2 to 12 K we find that the absolute relaxation rates are an order of magnitude smaller than those at 300 K and that the explanation of the magnitudes of these rates does not require enhancement due to low energy orbiting resonances. We find that the rates scale well with estimated collision encounter rates that account for the attractive part of the intermolecular potential. A second investigation with a much wider scope explores vibrational relaxation from v = 21 to 24 with six foreign gases: He, Ne, Ar, H2, D2 and N2. For this investigation a new type of experimental procedure has been designed and implemented that records a detailed and complete map of the fluorescence from B3II+ouI2 that is resolved with respect to both fluorescence frequency and time. These not only yield state-to-field rates, but coupled with a novel deconvolution method for growth curve fitting, yield absolute state-to-state rates for vibrational relaxation processes with Av=-1, -2, -3 and -4. The dependence of the relaxation rates on the collision partner, temperature and Av are discussed. An exponential dependence on the vibrational energy gap may be adequate to characterise the Av dependence of vibrational relaxation. The frequency resolution of the experimental data also reveals that some of the energy released by vibrational de-excitation is transferred to the rotation of the I2 molecule. We find this process is best characterised by an exponential dependence on the change of I2 angular momentum and that its extent scales with the mass of the collision partner. Measurements of the low-energy collision-induced quenching of B 3II+ouI2 are also reported for all six foreign gases. The possibility arises from the rates that the mechanism for quenching by H2 and D2 at low temperatures is different to that of the other gases and to that for H2 and D2 at high temperatures.

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Essenhigh, Katherine Anne. "Energy transfer and chemistry of carbon monoxide in vibrational mode non-equilibrium." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124292824.

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Thesis (Ph. D.)--Ohio State University, 2005. Title from first page of PDF file. Document formatted into pages; contains xiv, 172 p.; also includes graphics (some col.). Includes bibliographical references (p. 167-172). Available online via OhioLINK's ETD Center

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12

Sahm, David Karl. "The classical mechanics of mode-mode energy transfer in polyatomic molecules." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/29997.

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Fujiwara, Hiroki. "Solvent-side observation on vibrational energy transfer by transient grating spectroscopy: Azulene derivatives." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/124369.

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Minehardt, Todd Jason. "Classical and quantum dynamics of vibrational energy flow in benzene : the CH(v=2) overtone /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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Thesis (Ph. D.)--University of Texas at Austin, 1999. In "CH(v=2)" in the title, v is the Greek letter upsilon. Vita. Includes bibliographical references (leaves 85-88). Available also in a digital version from Dissertation Abstracts.

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Vennekate, Hendrik. "S2 State Photodissociation of Diphenylcyclopropenone, Vibrational Energy Transfer along Aliphatic Chains, and Energy Calculations of Noble Gas-Halide Clusters." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2014. http://hdl.handle.net/11858/00-1735-0000-0022-5EDA-5.

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McQuilken, Andrew Lynn. "Some pulsed IR and UV studies of vibrational energy transfer processes in selected triatomic molecules." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336132.

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McNaghten, Edward Dennison. "Some studies of gas phase vibrational energy transfer processes using the IR-UV double resonance technique." Thesis, Queen's University Belfast, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329391.

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18

Winnard, Thomas Johan. "Theoretical Parametric Study of Through-Wall Acoustic Energy Transfer Systems." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103387.

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Technological advances require novel solutions for contactless energy transfer. Many engineering applications require unique approaches to power electrical components without using physical wires. In the past decade, awareness of the need to wirelessly power electrical components spawned many forays into the field of wireless power transfer (WPT). WPT techniques include capacitive energy transfer, electromagnetic inductive power transfer, electromagnetic radiative power transfer, electrostatic induction, and acoustic energy transfer. Acoustic energy transfer (AET) has many advantages over other methods. These advantages include lower operating frequency, shorter wavelengths enabling the use of smaller sized receiver and transmitter, extended transmitter-to-receiver distance therefore more manageable design constraints, achieving lower attenuation, higher penetration depth, and no electromagnetic losses. Most AET systems operate in the ultrasonic frequency range and are more commonly referred to as ultrasonic acoustic energy transfer (UAET) systems. Through-wall UAET systems are constructed of a transmitter bonded to a transmission elastic layer, which in turn is bonded to a receiver. The transmitter and receiver layers are constructed of a piezoelectric material. Piezoelectric materials behave according to the piezoelectric effect, which is when a material generates an electric charge in response to mechanical strain. The transmitter utilizes the reverse of the piezoelectric effect. A sinusoidal input voltage is applied to the transmitter, inducing vibrations in the transmitter. The vibration-induced acoustic waves emanating from the transmitter travel through the initial bonding layer, the transmission layer, and the final bonding layer to the receiver. In turn, the acoustic waves cause the receiver to deform and undergo strain. This induces a flow of charge in the receiver, which is an electric current. The receiver feeds current to a resistive load. In this manner, energy is acoustically transferred between two transducers without wires. The performance of UAET systems can be evaluated based on power transfer efficiency, voltage magnification, and input admittance. UAET systems require extensive modeling before experimental assembly can be attempted. The analytical models of UAET are either based on the mechanics of the constitutive relations of piezoelectricity and solid mechanics or using equivalent circuit methods. The equivalent circuit method approximates the physics of the UAET system with electrical assumptions. The mechanics-based method is the most comprehensive description of the physics of all the intermediate layers in a UAET system. The mechanics-based method has been based on the assumption that the UAET system is operated in the thickness mode of vibration, i.e., piston-like vibration mode where the transmitter and receiver disks vibrate only in the thickness direction. This poses an issue for disks with aspect ratios between 0.1 and 20 because the piezoelectric transducers vibrate in both the radial and thickness modes. In addition to this assumption, most of the works on UAET models only have accounted for the piezoelectric and transmission layers. The effects of the bonding layers were not considered. Bonding the piezoelectric layers to the transmission layer introduces epoxy material with mechanical properties that are not accounted for. The epoxy layers are extra barriers to the transmission that introduce attenuation and alter the vibrational and acoustical behaviors of the UAET system. Investigations into UAET commonly focus on metal through-wall applications. Alternate transmission layer materials are not investigated and the impact of varying mechanical properties on the performance of a through-wall UAET system has not been comprehensively studied. Even with the metal transmission layers, the impact of the metal thickness has not been extensively investigated thoroughly. This work addresses the issues of the thickness-mode assumption in UAET modeling, the effects of epoxy layers, the impacts of the metal layer geometry, and the performance of UAET systems with alternate transmission layer materials. Particularly, (1) we showed that the thickness-mode assumption, that has been used in the UAET modeling leads to inaccurate results. (2) We modified the available acoustic electro- elastic theoretical modeling to include the effects of radial modes as well as the epoxy bonding layers. (3) We showed that the geometry of the elastic/metal layer requires optimization for peak system efficiency. (4) The results show that using alternate transmission layer materials impacts the performance of UAET systems. The results of this work were investigated using an improved 5-layer analytical model and finite element modeling in COMSOL Multiphysics. Master of Science Wireless power transfer (WPT) is an innovative solution to the problem of powering sophisticated technological applications. Such instances include the powering of implanted medical devices, recharging inaccessible sensor networks, and wireless powering of components in sealed containers. Acoustic energy transfer (AET) is a feasible WPT method that addresses these needs. AET is based on the propagation of acoustic waves to a piezoelectric receiver which converts the vibrations caused by incident acoustic waves into electrical energy. Most AET systems operate in the ultrasonic frequency range, and so AET can also be referred to as ultrasonic acoustic energy transfer (UAET). Through-wall UAET systems are constructed from a transmitter that is bonded to a transmission elastic layer. The transmission layer is bonded to a receiver. The transmitter and receiver are made of a piezoelectric material. This thesis addresses the modeling process of through-wall UAET systems. In previous works, the fundamental assumption has been that such systems vibrate purely in the thickness mode. Additionally, other investigations did not comprehensively analyze the effects of the bonding layers, ascertain the performance of non-metal transmission layers, or provide practical insight on the effect of the resistive loading on such systems. This work addresses all these issues with a mathematical framework and finite element modeling results.

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Kaganas, Gary H. "Comparing Remote Data Transfer Rates of Compact Muon Solenoid Jobs with Xrootd and Lustre." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1534.

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To explore the feasibility of processing Compact Muon Solenoid (CMS) analysis jobs across the wide area network, the FIU CMS Tier-3 center and the Florida CMS Tier-2 center designed a remote data access strategy. A Kerberized Lustre test bed was installed at the Tier-2 with the design to provide storage resources to private-facing worker nodes at the Tier-3. However, the Kerberos security layer is not capable of authenticating resources behind a private network. As a remedy, an xrootd server on a public-facing node at the Tier-3 was installed to export the file system to the private-facing worker nodes. We report the performance of CMS analysis jobs processed by the Tier-3 worker nodes accessing data from a Kerberized Lustre file. The processing performance of this configuration is benchmarked against a direct connection to the Lustre file system, and separately, where the xrootd server is near the Lustre file system.

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Lau, Jascha Alexander [Verfasser]. "Vibrational Energy Transfer Between CO Molecules on a NaCl(100) Surface Studied by Infrared Fluorescence Spectroscopy / Jascha Alexander Lau." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2021. http://d-nb.info/1232492876/34.

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21

Hung, Yi-chen Hung. "CARS Measurements of Vibrational Energy Transfer in Nanosecond Pulse Electric Discharges in Nitrogen, Air, and Their Mixtures with Carbon Dioxide." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1468959981.

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Thorn, Penny Anne, and penny thorn@flinders edu au. "Electronic State Excitations in the Water Molecule by Collisions with Low Energy Electrons." Flinders University. Chemistry, Physics and Earth Sciences, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20080714.112505.

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The present study was largely concerned with measuring accurate absolute values for the electronic state excitation cross sections in H2O, in the incident electron energy range 15eV to 50eV. It is hoped that these data will eventually help to improve the current state of electron - molecule scattering theory, as well as being useful in various fields of modelling. As an illustration of this latter point, the cross sections determined here were used to calculate quantities of importance in atmospheric modelling, namely, electron energy transfer rates and rates for the excitation of water molecules by auroral secondary electrons.

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Lee, Wonchul. "Development of Raman and Thomson scattering diagnostics for study of energy transfer in nonequilibrium, molecular plasmas." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1054652829.

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Thesis (Ph. D.)--Ohio State University, 2003. Title from first page of PDF file. Document formatted into pages; contains xvi, 210 p.; also includes graphics (some col.) Includes bibliographical references (p. 178-184). Available online via OhioLINK's ETD Center

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24

Alexander, William Andrew. "Theoretical and experimental studies of energy transfer dynamics in collisions of atomic and molecular species with model organic surfaces." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/26857.

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A full understanding of chemical reaction dynamics at the gas/organic-surface interface requires knowledge of energy-transfer processes that happen during the initial gas/surface collision. We have examined the influence of mass and rovibrational motion on the energy-transfer dynamics of gas-phase species scattering from model organic surfaces using theory and experiment. Molecular-beam scattering techniques were used to investigate the rare gases, Ne, Ar, Kr, and Xe, and the diatomics, N2 and CO, in collisions with CH3- and CF3-terminated self-assembled monolayer (SAM) surfaces. Complementary molecular-dynamics simulations were employed to gain an atomistic view of the collisions and elucidate mechanistic details not observable with our current experimental apparatus. We developed a systematic approach for obtaining highly accurate analytic intermolecular potential-energy surfaces, derived from high-quality ab initio data, for use in our classical-trajectory simulations. Results of rare gas scattering experiments and simulations indicate mass to be the determining factor in the energy-transfer dynamics, while other aspects of the potential-energy surface play only a minor role. Additionally, electronic-structure calculations were used to correlate features of the potential-energy surface with the energy-transfer behavior of atoms and small molecules scattering from polar and non-polar SAM surfaces. Collisions of diatomic molecules with SAMs are seen to be vibrationally adiabatic, however translational energy transfer to and from rotational modes of the gas species, while relatively weak, is readily apparent. Examination of the alignment and orientation of the final rotational angular momentum of the gas species reveals that the collisions induce a stereodynamic preference for the expected "cartwheel" motion, as well as a surprising propensity for "corkscrew" or "propeller" motion. The calculated stereodynamic trends suggest that the CH3-SAM is effectively more corrugated than the CF3-SAM. Finally, the feasibility for collisional-energy promoted, direct gas/organic-surface reactions was interrogated using the 1,3-dipolar azide-alkyne cycloaddition reaction. We found that geometrical constraints prevented the reaction from proceeding at the probed conditions. Ph. D.

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25

Biggs, Jason Daniel 1978. "Theoretical studies of the external vibrational control of electronic excitation transfer and its observation using polarization- and optical phase-sensitive ultrafast spectroscopy." Thesis, University of Oregon, 2010. http://hdl.handle.net/1794/11074.

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xvi, 218 p. : ill. (some col.) Our theoretical studies involve the control of electronic energy transfer in molecular dimers through the preparation of specific vibrational coherences prior to electronic excitation. Our control strategy is based upon the fact that, following impulsive electronic excitation, nuclear motion acts to change the instantaneous energy difference between site-excited electronic states and thereby influences short-time electronic excitation transfer (EET). By inducing coherent intramolecular vibration in one of the chromophores prior to short-pulse electronic excitation, we exert external control over electronic dynamics. As a means to monitor this coherent control over EET, we propose using multidimensional wave-packet interferometry (md-WPI). Two pairs of polarized phase-related femtosecond pulses following the control pulse would generate superpositions of coherent nuclear wave packets in optically accessible electronic states. Interference contributions to the time- and frequency-integrated fluorescence signal due to overlaps among the superposed wave packets provide amplitude-level information on the nuclear and electronic dynamics. We test both the control strategy and its spectroscopic investigation by calculating pump-probe difference signals for various combinations of pulse polarizations. That signal is the limiting case of the control-influenced md-WPI signal in which the two pulses in the pump pulse-pair coincide, as do the two pulses in the probe pulse-pair. We present calculated pump-probe difference signals for a variety of systems including a simplified model of the covalent dimer dithia-anthracenophane (DTA) in which we treat only the weakly Franck-Condon active ν 12 anthracene vibration at 385 cm -1 . We further present calculated nl-WPI difference signals for an oriented DTA complex, which reveal amplitude-level dynamical information about the interaction of nuclear motion and electronic energy transfer. We also present pump-probe difference signals from a model system in which a CF 3 group, whose torsional angle is strongly Franck-Condon active, has been added to the anthracene monomers which make up DTA. We make use of electronic structure calculations to find the torsional potential of the monomer, from which we calculate the spectroscopic signals of the dimer. We show that a significant measure of control over short-time EET is achievable in this system. This dissertation includes previously published coauthored material. Commitee in charge: Dr. Michael E. Kellman, Chair; Dr. Jeffrey A. Cina, Advisor; Dr. David R. Herrick; Dr. Andrew H. Marcus; Dr. Daniel A. Steck

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Vennekate, Hendrik [Verfasser], Dirk [Akademischer Betreuer] Schwarzer, Jürgen [Akademischer Betreuer] Troe, and Peter [Akademischer Betreuer] Vöhringer. "S2 State Photodissociation of Diphenylcyclopropenone, Vibrational Energy Transfer along Aliphatic Chains, and Energy Calculations of Noble Gas-Halide Clusters / Hendrik Vennekate. Gutachter: Dirk Schwarzer ; Jürgen Troe ; Peter Vöhringer. Betreuer: Dirk Schwarzer." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2014. http://d-nb.info/1052136087/34.

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27

Brumfield, Brian. "Electronic to Vibrational Energy Transfer from Cl* (3 ²P_1/2) to N₂O(ν₁): Failure of a Simple Kinetic Mechanism". Wright State University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=wright1133802860.

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Munson, Brian R. "Electronic to Vibrational Energy Transfer from Cl^* (²P_1/2) to CH₄ and CD₄." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1239995101.

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Eberl, Katharina Barbara [Verfasser], Jens [Akademischer Betreuer] Bredenbeck, Jens [Gutachter] Bredenbeck, and Josef [Gutachter] Wachtveitl. "Applying non-canonical amino acids for investigation of vibrational energy transfer and dynamic allostery in a synaptic protein domain / Katharina Barbara Eberl ; Gutachter: Jens Bredenbeck, Josef Wachtveitl ; Betreuer: Jens Bredenbeck." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2020. http://d-nb.info/1222102676/34.

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30

Wagner, Roman Jonathan Viktor. "The Dynamics of Highly Vibrationally Excited CO Scattered from Metal Surfaces." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://hdl.handle.net/11858/00-1735-0000-002E-E619-C.

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Vadlamani, Agasteswar. "Enhanced Biomass and Lipid Productivities of Outdoor Alkaliphilic Microalgae Cultures through Increased Media Alkalinity." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1481307126330107.

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Guichard, Vincent. "Etude par spectrometrie raman de resonnance d'amines a l'etat de radical-cation et a l'etat triplet : contribution a l'etude des etats radicalaires et excites des derives benzeniques." Paris 6, 1988. http://www.theses.fr/1988PA066276.

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Etude structurale par spectrometrie raman de resonance des etats monocationique et triplet de quelques amines aromatiques, composes modeles de photochimie. Analyse des spectres de plusieurs especes structuralement proches. On montre que les etats ionises et triplet des benzenes substitues par des groupes mesomeres donneurs ont plusieurs points communs qui resultent d'interactions orbitalaires analogues entre le cycle benzenique et le substituant

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Robinson, Jeanne Marie. "Overtone vibration-laser double resonance measurements of vibrational energy transfer rates and mechanisms in HF and DF." 1985. http://catalog.hathitrust.org/api/volumes/oclc/13640676.html.

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McDowell, Derek Ray. "New views of collisional vibrational relaxation: Energy removal rates and energy distributions of triplet state pyrazine." Thesis, 1997. http://hdl.handle.net/1911/19184.

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Collisional energy removal rates from vibrationally excited T$\sb1$ pyrazine are measured using the refined and validated Competitive Radiationless Decay (CRD) method. Optical excitation followed by intersystem crossing prepares a vibrationally excited vapor sample of T$\sb1$ pyrazine. $\rm T\sb{n}\gets T\sb1$ transient absorption kinetics, measured with a S/N ratio of ca. 1000, provides the collisional dependence of the average triplet radiationless decay rate constant. Using a calibration between this decay constant and the triplet vibrational energy, the collisional history of the sample's vibrational energy content is deduced. This leads to the rate of collisional energy removal as a function of the triplet pyrazine's vibrational energy content. Results with a variety of small relaxers comprise the most useful database to date on collisional vibrational relaxation of a triplet state polyatomic. We find the following order of relaxer effectiveness per collision:$$\rm He{<}H\sb2{<}Ne{<}D\sb2{<}Ar{<}N\sb2{<}Kr{<}Xe{<}CO{<}CH\sb4{<}CO\sb2{<}H\sb2O$$These triplet state energy removal rates exceed those recently reported for vibrationally excited ground state pyrazine by a factor of ca. 7. In addition, a new method for determining the distribution of vibrational energy contents in an excited polyatomic sample is applied to vibrationally excited T$\sb1$ pyrazine. The T$\sb1$ population decays with a distribution of rate constants corresponding to the underlying distribution of vibrational energies. This rate constant distribution is extracted from decay kinetics through the use of a multi-Gaussian distribution model. The calibration between decay constant and triplet vibrational energy is used to deduce the molecular vibrational energy distribution, providing the first experimental view of an excited sample's vibrational energy distribution. Relatively narrow nascent vibrational energy distributions are progressively broadened during the early collisional encounters with a relaxer. These new vibrational energy distributions and the collisional energy removal results suggests a threshold for enhanced relaxation near 2000 cm$\sp{-1}$ of donor vibrational energy. These intriguing results should stimulate further theoretical and experimental research into the collisional relaxation of electronically excited molecules.

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Lee, Mi Kyung. "Computational models for coupled electronic-vibrational energy transfer in biological photosynthetic complexes." Thesis, 2018. https://hdl.handle.net/2144/31687.

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The specialized pigment-protein complexes involved in the first process of photosynthesis are light-harvesting structures that are composed of networks of chromophores in protein scaffolds. Though light-harvesting complexes vary in chromophore composition and protein structure, they are capable of transferring the absorbed energy as molecular excitation energy from chromophore to chromophore with maximal efficiency. Thus, numerous interdisciplinary studies focus on elucidating energy transfer mechanisms in these biological complexes and how the same principles can be applied to artificial photosynthetic and photovoltaic machines. From advanced spectroscopic measurements and theoretical models, the interaction between the excited electronic states and the nuclear vibrational degrees of freedom is now established to be crucial for efficient energy transfer. In light-harvesting complexes of plants and bacteria, it is now understood that the classical-like vibrational modes of the protein and solvent environment drive energy transfer between the energetically close electronic states of the chromophores. On the other hand, recent spectroscopic measurements on algae light-harvesting complexes discovered signatures of quantized, high frequency vibrational modes of the chromophore. Unfortunately, a deterministic interpretation of the data and the underlying Hamiltonian is hindered due to significant inhomogeneous spectral line-broadening. Though numerous model Hamiltonians have been proposed from theoretical work, various computational approximations employed in these studies necessitate empirical parameter tuning in order to obtain agreement with benchmark linear optical spectra. Thus in this work, we present a simple, but improved, computational prescription to compute the ensemble of Hamiltonians for four closely-related algae light-harvesting complexes. We verify the reliability of our proposed models by comparing simulated optical spectra with experimental measurements. We show that static disorder and inhomogeneous broadening are significant for phycobiliproteins due to large site energy fluctuations. We also show that the nuclear environment plays an important role in defining the trapping state, or the final energy acceptor. Finally, our work for the first time suggests that EET dynamics can be tuned by varying the titration states of the chromophores.

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Rensberger, Karen Jane. "Overtone vibration-laser double resonance measurements of vibrational energy transfer in HF and DF." 1987. http://catalog.hathitrust.org/api/volumes/oclc/16125013.html.

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Thesis (Ph. D.)--University of Wisconsin--Madison, 1987. Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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37

"Study Of Electron And Energy Transfer Modulation In Molecules Using Time-resolved Vibrational Spectroscopy." Tulane University, 2015.

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Electron transfer is one of the fundamental process occurring in many chemical reactions. Electron transfer process has been under intensive study for many applications, for example artificial photosynthesis, where electrons from photo-excited chromophore molecules are harnessed to produce solar fuels in various forms. Transition metal complexes, such as ruthenium and rhenium complexes, play an important role in the continuing development of artificial photosynthetic devices. The electron transfer process in chromophores involving transition metal complexes often occurs on an ultrafast time scale from sub-ps to ns. To resolve such dynamics, ultrafast spectroscopic techniques are required. A variety of ultrafast techniques, such as time-resolved infrared spectroscopy and multi-pulse transient absorption spectroscopy, were used in this study to unravel the excited state electron transfer dynamics in a series of Re(I) complexes. Transition metal complexes often feature excited states that involve only partial electron transfer between the electron donating and accepting ligands, even for ligands with strong electron donating and accepting properties. It is often difficult to design a compact complex feature a full electron transfer excited state. Therefore, part of the work presented in this thesis was dedicated to the study of the electron transfer extent in the excited states of a series of [Re(N,N)(CO)3L]+ compounds, where N,N stands for electron accepting and L stands for electron donating ligands. By carefully designing the structure and redox properties of both the electron donor and acceptor, we demonstrated that essentially a full-electron charge transfer excited state can be prepared, while the designed Re(I) complex is still compact. To further extend the understanding of the electron transfer in transition metal complexes, modulation of the electron transfer rate in a compact Re(I) complex was studied. By perturbing the electron transfer process with a femtosecond mid-IR pulse, we showed that a 28% increase of the electron transfer rate was achieved. This study demonstrated the possibility of using a small energy mid-IR quanta to change the energy conversion process in a chromophore. Vibrational energy transfer in molecules is another important process in nature. Detailed understanding of the vibrational energy transfer on a molecule level is fundamentally important and essential for the development of molecular optical devices. It was recently discovered that the transport of vibrational energy in molecules can be fast and efficient due to its ballistic character. To understand the mechanism of the ballistic energy transport, experiments with several series of oligomers were performed using a relaxation-assisted two-dimensional infrared method. The energy transport speed was found to be dependent on transport initiation method and the transport pathways for different cases of initiation were identified. Detailed analysis on the chain band structure, group velocity and vibrational relaxation dynamics is presented. acase@tulane.edu

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Xavier, Francis George Densingh. "NONADIABATIC COLLISIONS OF PROTON WITH CO AND O2 MOLECULES : A QUANTUM MECHANICAL STUDY." Doctoral thesis, 2010. http://hdl.handle.net/10316/95854.

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Documentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeiros Nonadiabatic phenomena are ubiquitous in nature. The dynamics of proton-molecule collisions often evolve on highly coupled electronic potential energy surfaces leading to inelastic and charge transfer processes. In this thesis, we have investigated the quantum dynamics of energy transfer processes involving the inelastic vibrational excitations and the vibrational charge transfer collisions in the H+ + CO and the H+ + O2 systems on our newly obtained quasi-diabatic ab initio potential energy surfaces for collision energies 0-30 eV and compared the collision attributes with the earlier theoretical results as well as the available stateto- state experimental data obtained from the molecular beam study and H+/H energy-loss spectra. We have described the computational details of the ab initio potential energy surfaces at the configuration interaction level of accuracy employing the correlation consistent polarized valence triple zeta basis sets. We report the details of time-independent quantum dynamics calculations for the inelastic vibrational excitations and vibrational charge transfer processes under the framwork of vibrational close-coupling rotational infinite order sudden approximation. To the best of our knowledge the present ab initio global adiabatic and quasi-diabatic potential energy surfaces for the ground and the first excited electronic states for the H+ + CO system are being presented perhaps for the first time in the literature. The present theoretical results are found to be in good agreement with those of experiments for the inelastic vibrational excitations and they are in overall qualitative agreement for charge transfer channel in the experimental trend. It is suggested that quantitative agreement between theory and experiment can be achieved by modelling the dynamics as a three- and four-state process. For the H+ + O2 system. quantum dynamics with the two-state (the ground and the first excited electronic states) coupling yields results in general agreement with the experiments. Significant improvement is achieved when the dynamics is carried out with four-state (the ground and the lowest three excited electronic states) coupling. However, some quantitative agreement between theory and experiment is still lacking, which can be settled through an elaborate and more refined (over a fine mesh of molecular orientation) computations within the VCC-RIOSA framework. A summary of the present study is given at the end with the concluding remarks and the future direction of research followed by bibliography.

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Huang, Hong-Yi. "Topic I:Rotational and vibrational energy transfer effect of CH B2Sigma-(v'=1) Topic II:Vibrational distribution of Br2 molecule following photo-dissociation of bromine containing molecules by using cavity ring down absorption spectroscopy." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1307200420511500.

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Huang, Hong-Yi, та 黃鴻一. "Topic I：Rotational and vibrational energy transfer effect of CH B2Σ-(v’=1)Topic II：Vibrational distribution of Br2 molecule following photo-dissociation of bromine containing molecules by using cavity ring down absorption spectroscopy". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/52174443145415196502.

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博士 國立臺灣大學 化學研究所 92 Part I In this thesis, it will be separated into two individual parts: part I and part II. Each part has two chapters. In the chapter 1 of part I, some basic background of spectroscopy and Fourier transform infrared method is illustrated. And in the chapter 2 of part I, the fine state-resolved rotational and vibrational energy transfer of CH B2Σ- (v’=1, N) by collisions with Ar, CO, and N2O is illustrated. It is the first time to observe the rotational energy transfer and vibrational energy transfer processes of a specific fine state for B 2Σ- (v’=1) of CH radical. We use pump-probe technique to determine RET and VET rate constants of CH B (v’ = 1, 0≦ N ≦ 6) with collisions of Ar, CO, and N2O. The RET is anticipated to be larger than VET for each collider. The determined RET rate constants range from 10-11 to 10-10 cm3 molecule-1 s-1, while the determined VET rate constants range from 10-12 to 10-11 cm3 molecule-1 s-1. The relative values of RET and VET rate constants are consistent with the results founded by Cooper and Whitehead. The findings of multi-quantum changing within single collision suggest that the collisions possibly dominated by the long-range attractive force. The k’VET shows no rotational quantum number dependence for these three quenching gases. This conclusion is the same as the results reported previously by Crosley et al. and Whitehead et al. The kVET of N2O is three times larger than that of CO and nine times larger than that of Ar, respectively. This result is related to polyatomic effect, permanent dipole moment, and inefficient vibration-translation transfer. The number of internal degrees of freedom of N2O is larger than that of CO and Ar, therefore N2O can remove more energy than CO and Ar within single collision. In other words, N2O is more efficient than CO and Ar. Polyatomic effect and permanent dipole moment play a role in vibration and rotational energy transfer process. Part II In the chapter 1 of part II, the basic working principle of cavity ring-down absorption spectroscopy (CRDAS) is introduced. In the first section in the chapter 2 of part II, the total continuous absorption which includes A – X, B – X, and C – X transition of pure diatomic bromine is obtained by using CRDAS. In the second section, the primary photodissociation channels of CHBr3 and CH2Br2 which is ignored in the past studies have been investigated. CHBr3 + hν -->�� CHBr + Br2 CH2Br2 + hν -->�� CH2 + Br2 The quantum yields of Br2 are found to be 0.23±0.05 and 0.26±0.07 following photodissociation of CHBr3 and CH2Br2 at 248nm, respectively. According to the absorption spectrum, the nascent vibrational distribution can be obtained. The bromine molecules resulted from photodissociation of CHBr3 or CH2Br2 at 248 nm are both lying at a vibrationally hot distribution. The excited parent molecules (CHBr3 and CH2Br2) may couple into highly vibrational levels of their electronic ground state via internal conversion, which could lead to vibrationally hot Br2 photofragment.

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Dostál, Jakub. "Studie fotosyntetického aparátu zelených sirných bakterií metodou koherentní dvourozměrné elektronové spektroskopie." Doctoral thesis, 2014. http://www.nusl.cz/ntk/nusl-342359.

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The process of photosynthesis begins with a capture of sunlight and its quick conversion into the chemical energy. Both these primary processes take place in a specially designed photosynthetic apparatus that is present in cells of all photosynthetic organisms. In green sulfur bacteria the apparatus consists of a massive light-harvesting antenna (chlorosome), intermediate antennas (baseplate complex and FMO proteins) and of the reaction center, where the conversion into the chemical energy occurs. The energy flow through the apparatus can be monitored by time-resolved spectroscopy techniques. Coherent two-dimensional electronic spectroscopy (2DES) in one of such techniques, which combines high temporal and spectral resolution, and therefore it is especially well suited for studying multichromophoric systems such as photosynthetic apparatus. This thesis describes the principles of the 2DES technique and outlines the basic facts about the photosynthetic apparatus of green sulfur bacterium Chlorobaculum tepidum. Finally, it summarizes the investigation of the photosynthetic machinery using 2DES. Results presented in this thesis provide new insights into the exciton diffusion and vibrational coherences within chlorosomes, excitonic structure of the baseplate and the overall energy flow through the entire...

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Winkler, Kathrin. "Ultraschnelle, lichtinduzierte Primärprozesse im elektronisch angeregten Zustand des Grün Fluoreszierenden Proteins (GFP)." Doctoral thesis, 2003. http://hdl.handle.net/11858/00-1735-0000-0006-B0C1-3.

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Wagener, Philipp. "Photodissoziation von Polyhalogenmethanen in Fluiden: Kurzzeitdynamik und Mechanismen." Doctoral thesis, 2008. http://hdl.handle.net/11858/00-1735-0000-0006-ACB1-4.

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Grimm, Christian. "Femtosekunden Photolyse von Diiodmethan in überkritischen Fluiden: Konkurrenz zwischen Photodissoziation und Photoisomerisierung." Doctoral thesis, 2003. http://hdl.handle.net/11858/00-1735-0000-0006-AD49-8.

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Dissertations / Theses on the topic 'Vibrational energy transfer rates'

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