WorldWideScience

Sample records for vibrationally energized molecules

  1. Spectroscopy and reactions of vibrationally excited transient molecules

    Energy Technology Data Exchange (ETDEWEB)

    Dai, H.L. [Univ. of Pennsylvania, Philadelphia (United States)

    1993-12-01

    Spectroscopy, energy transfer and reactions of vibrationally excited transient molecules are studied through a combination of laser-based excitation techniques and efficient detection of emission from the energized molecules with frequency and time resolution. Specifically, a Time-resolved Fourier Transform Emission Spectroscopy technique has been developed for detecting dispersed laser-induced fluorescence in the IR, visible and UV regions. The structure and spectroscopy of the excited vibrational levels in the electronic ground state, as well as energy relaxation and reactions induced by specific vibronic excitations of a transient molecule can be characterized from time-resolved dispersed fluorescence in the visible and UV region. IR emissions from highly vibrational excited levels, on the other hand, reveal the pathways and rates of collision induced vibrational energy transfer.

  2. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Keck, J.C.

    1979-01-01

    Vibrational excitation of molecules having components of a selected isotope type is used to produce a conversion from vibrational to translational excitation of the molecules by collision with the molecules of a heavy carrier gas. The resulting difference in translaton between the molecules of the selected isotope type and all other molecules of the same compound permits their separate collection. When applied to uranium enrichment, a subsonic cryogenic flow of molecules of uranium hexafluoride in combination with an argon carrier gas is directed through a cooled chamber that is illuminated by laser radiaton tuned to vibrationally excite the uranium hexafluoride molecules of a specific uranium isotope. The excited molecules collide with carrier gas molecules, causing a conversion of the excitation energy into a translation of the excited molecule, which results in a higher thermal energy or diffusivity than that of the other uranium hexafluoride molecules. The flowing molecules including the excited molecules directly enter a set of cryogenically cooled channels. The higher thermal velocity of the excited molecules increases the probability of their striking a collector surface. The molecules which strike this surface immediately condense. After a predetermined thickness of molecules is collected on the surface, the flow of uranium hexafluoride is interrupted and the chamber heated to the point of vaporization of the collected hexafluoride, permitting its removal. (LL)

  3. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Keck, J.C.

    1977-01-01

    A system for isotope separation or enrichment wherein molecules of a selected isotope type in a flow of molecules of plural isotope types are vibrationally excited and collided with a background gas to provide enhanced diffusivity for the molecules of the selected isotope type permitting their separate collection. The system typically is for the enrichment of uranium using a uranium hexafluoride gas in combination with a noble gas such as argon. The uranium hexafluoride molecules having a specific isotope of uranium are vibrationally excited by laser radiation. The vibrational energy is converted to a translation energy upon collision with a particle of the background gas and the added translation energy enhances the diffusivity of the selected hexafluoride molecules facilitating its condensation on collection surfaces provided for that purpose. This process is periodically interrupted and the cryogenic flow halted to permit evaporation of the collected molecules to provide a distinct, enriched flow

  4. Studies of interstellar vibrationally-excited molecules

    International Nuclear Information System (INIS)

    Ziurys, L.M.; Snell, R.L.; Erickson, N.R.

    1986-01-01

    Several molecules thus far have been detected in the ISM in vibrationally-excited states, including H 2 , SiO, HC 3 N, and CH 3 CN. In order for vibrational-excitation to occur, these species must be present in unusually hot and dense gas and/or where strong infrared radiation is present. In order to do a more thorough investigation of vibrational excitation in the interstellar medium (ISM), studies were done of several mm-wave transitions originating in excited vibrational modes of HCN, an abundant interstellar molecule. Vibrationally-excited HCN was recently detected toward Orion-KL and IRC+10216, using a 12 meter antenna. The J=3-2 rotational transitions were detected in the molecule's lowest vibrational state, the bending mode, which is split into two separate levels, due to l-type doubling. This bending mode lies 1025K above ground state, with an Einstein A coefficient of 3.6/s. The J=3-2 line mode of HCN, which lies 2050K above ground state, was also observed toward IRC+10216, and subsequently in Orion-KL. Further measurements of vibrationally-excited HCN were done using a 14 meter telescope, which include the observations of the (0,1,0) and (0,2,0) modes towards Orion-KL, via their J=3-2 transitions at 265-267 GHz. The spectrum of the J=3-2 line in Orion taken with the 14 meter telescope, is shown, along with a map, which indicates that emission from vibrationally-excited HCN arises from a region probably smaller than the 14 meter telescope's 20 arcsec beam

  5. Classical dynamics of triatomic system: energized harmonic molecules

    International Nuclear Information System (INIS)

    Parr, C.A.; Kuppermann, A.; Porter, R.N.

    1976-01-01

    The dynamical assumptions underlying the Slater and RRK classical-mechanical theories of unimolecular reaction rates are investigated. The predictions of these theories for several nonlinear, triatomic, harmonically-bonded molecular models are compared with the results obtained from the integration of the classical equations of motion. The accuracy of the small-vibration and weak-coupling assumptions are found to break down at energies above about one quarter of a bond dissociation energy. Nonetheless, the small-vibration approximation predicts reaction frequencies in good agreement with the exact results for the models. The effects of rotation on intramolecular energy exchange are examined and found to be significant

  6. Classical dynamics of triatomic system: energized harmonic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Parr, C A; Kuppermann, A; Porter, R N

    1976-01-01

    The dynamical assumptions underlying the Slater and RRK classical-mechanical theories of unimolecular reaction rates are investigated. The predictions of these theories for several nonlinear, triatomic, harmonically-bonded molecular models are compared with the results obtained from the integration of the classical equations of motion. The accuracy of the small-vibration and weak-coupling assumptions are found to break down at energies above about one quarter of a bond dissociation energy. Nonetheless, the small-vibration approximation predicts reaction frequencies in good agreement with the exact results for the models. The effects of rotation on intramolecular energy exchange are examined and found to be significant.

  7. The photodissociation and reaction dynamics of vibrationally excited molecules

    Energy Technology Data Exchange (ETDEWEB)

    Crim, F.F. [Univ. of Wisconsin, Madison (United States)

    1993-12-01

    This research determines the nature of highly vibrationally excited molecules, their unimolecular reactions, and their photodissociation dynamics. The goal is to characterize vibrationally excited molecules and to exploit that understanding to discover and control their chemical pathways. Most recently the author has used a combination of vibrational overtone excitation and laser induced fluorescence both to characterize vibrationally excited molecules and to study their photodissociation dynamics. The author has also begun laser induced grating spectroscopy experiments designed to obtain the electronic absorption spectra of highly vibrationally excited molecules.

  8. Spectroscopic and dynamical studies of highly energized small polyatomic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Field, R.W.; Silbey, R.J. [Massachusetts Institute of Technology, Cambridge (United States)

    1993-12-01

    The authors have initiated a program to perform spectroscopic and dynamic studies of small molecules. Large amplitude motions in excited acetylene were discussed along with plans to record the dispersed fluorescence (DF) and the stimulated emission pumping (SEP) spectra. SEP spectra were reported for the formyl radical. A Fourier transform spectrometer was discussed with respect to its ability to probe the structure of radicals. This instrument is capable of performing studies using various techniques such as magnetic rotation spectroscopy and sub-Doppler sideband-OODR Zeman (SOODRZ) spectroscopy.

  9. selective excitation of vibrational modes of polyatomic molecule

    Indian Academy of Sciences (India)

    Abstract. Mode-selective dynamics of triatomic molecule in the electronic ground state under continuous wave laser pulse is investigated for the discrete vibrational bound states. A non-perturbative approach has been used to analyse the vibrational couplings and dynamics of the molecule. Keywords. Polyatomic molecule ...

  10. Time Resolved Energy Transfer and Photodissociation of Vibrationally Excited Molecules

    National Research Council Canada - National Science Library

    Crim, F. F

    2007-01-01

    ...) in solution and in the gas phase. This second experiment is one of the few direct comparisons of intramolecular vibrational energy flow in a solvated molecule with that in the same molecule isolated in a gas...

  11. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    1979-01-01

    This invention relates to isotope separation employing isotopically selective vibrational excitation and vibration-translation reactions of the excited particles. Uranium enrichment, using uranium hexafluoride, is a particular embodiment. (U.K.)

  12. Test-Anchored Vibration Response Predictions for an Acoustically Energized Curved Orthogrid Panel with Mounted Components

    Science.gov (United States)

    Frady, Gregory P.; Duvall, Lowery D.; Fulcher, Clay W. G.; Laverde, Bruce T.; Hunt, Ronald A.

    2011-01-01

    rich body of vibroacoustic test data was recently generated at Marshall Space Flight Center for component-loaded curved orthogrid panels typical of launch vehicle skin structures. The test data were used to anchor computational predictions of a variety of spatially distributed responses including acceleration, strain and component interface force. Transfer functions relating the responses to the input pressure field were generated from finite element based modal solutions and test-derived damping estimates. A diffuse acoustic field model was applied to correlate the measured input sound pressures across the energized panel. This application quantifies the ability to quickly and accurately predict a variety of responses to acoustically energized skin panels with mounted components. Favorable comparisons between the measured and predicted responses were established. The validated models were used to examine vibration response sensitivities to relevant modeling parameters such as pressure patch density, mesh density, weight of the mounted component and model form. Convergence metrics include spectral densities and cumulative root-mean squared (RMS) functions for acceleration, velocity, displacement, strain and interface force. Minimum frequencies for response convergence were established as well as recommendations for modeling techniques, particularly in the early stages of a component design when accurate structural vibration requirements are needed relatively quickly. The results were compared with long-established guidelines for modeling accuracy of component-loaded panels. A theoretical basis for the Response/Pressure Transfer Function (RPTF) approach provides insight into trends observed in the response predictions and confirmed in the test data. The software developed for the RPTF method allows easy replacement of the diffuse acoustic field with other pressure fields such as a turbulent boundary layer (TBL) model suitable for vehicle ascent. Structural responses

  13. Role of vibrational dynamics in resonant positron annihilation on molecules.

    Science.gov (United States)

    Jones, A C L; Danielson, J R; Natisin, M R; Surko, C M

    2013-05-31

    Vibrational Feshbach resonances are dominant features of positron annihilation for incident positron energies in the range of the molecular vibrations. Studies in relatively small molecules are described that elucidate the role of intramolecular vibrational energy redistribution into near-resonant multimode states, and the subsequent coupling of these modes to the positron continuum, in suppressing or enhancing these resonances. The implications for annihilation in other molecular species, and the necessary ingredients of a more complete theory of resonant positron annihilation, are discussed.

  14. Vibrations of a molecule in an external force field.

    Science.gov (United States)

    Okabayashi, Norio; Peronio, Angelo; Paulsson, Magnus; Arai, Toyoko; Giessibl, Franz J

    2018-05-01

    The oscillation frequencies of a molecule on a surface are determined by the mass distribution in the molecule and the restoring forces that occur when the molecule bends. The restoring force originates from the atomic-scale interaction within the molecule and with the surface, which plays an essential role in the dynamics and reactivity of the molecule. In 1998, a combination of scanning tunneling microscopy with inelastic tunneling spectroscopy revealed the vibrational frequencies of single molecules adsorbed on a surface. However, the probe tip itself exerts forces on the molecule, changing its oscillation frequencies. Here, we combine atomic force microscopy with inelastic tunneling spectroscopy and measure the influence of the forces exerted by the tip on the lateral vibrational modes of a carbon monoxide molecule on a copper surface. Comparing the experimental data to a mechanical model of the vibrating molecule shows that the bonds within the molecule and with the surface are weakened by the proximity of the tip. This combination of techniques can be applied to analyze complex molecular vibrations and the mechanics of forming and loosening chemical bonds, as well as to study the mechanics of bond breaking in chemical reactions and atomic manipulation.

  15. Spectroscopic probes of vibrationally excited molecules at chemically significant energies

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, T.R. [Univ. of Rochester, NY (United States)

    1993-12-01

    This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

  16. Vibrationally coupled electron transport through single-molecule junctions

    Energy Technology Data Exchange (ETDEWEB)

    Haertle, Rainer

    2012-04-26

    Single-molecule junctions are among the smallest electric circuits. They consist of a molecule that is bound to a left and a right electrode. With such a molecular nanocontact, the flow of electrical currents through a single molecule can be studied and controlled. Experiments on single-molecule junctions show that a single molecule carries electrical currents that can even be in the microampere regime. Thereby, a number of transport phenomena have been observed, such as, for example, diode- or transistor-like behavior, negative differential resistance and conductance switching. An objective of this field, which is commonly referred to as molecular electronics, is to relate these transport phenomena to the properties of the molecule in the contact. To this end, theoretical model calculations are employed, which facilitate an understanding of the underlying transport processes and mechanisms. Thereby, one has to take into account that molecules are flexible structures, which respond to a change of their charge state by a profound reorganization of their geometrical structure or may even dissociate. It is thus important to understand the interrelation between the vibrational degrees of freedom of a singlemolecule junction and the electrical current flowing through the contact. In this thesis, we investigate vibrational effects in electron transport through singlemolecule junctions. For these studies, we calculate and analyze transport characteristics of both generic and first-principles based model systems of a molecular contact. To this end, we employ a master equation and a nonequilibrium Green's function approach. Both methods are suitable to describe this nonequilibrium transport problem and treat the interactions of the tunneling electrons on the molecular bridge non-perturbatively. This is particularly important with respect to the vibrational degrees of freedom, which may strongly interact with the tunneling electrons. We show in detail that the resulting

  17. The origin of small and large molecule behavior in the vibrational relaxation of highly excited molecules

    International Nuclear Information System (INIS)

    Gordon, R.J.

    1990-01-01

    An explanation is proposed for the qualitatively different types of behavior that have been reported for the vibrational relaxation of highly excited diatomic and polyatomic molecules. It is argued that all of the diatomic molecules that have been studied in bulk relax adiabatically at room temperature. In contrast, large polyatomic molecules have low frequency modes which act at ''doorway'' modes for the rest of the molecules, producing an impulsive relaxation mechanism. The theoretical work of Nesbitt and Hynes showed that impulsive collisions result in an exponential decay of the average vibrational energy of a Morse oscillator, whereas adiabatic collisions produce nonexponential power law behavior. We propose that this result explains a large body of data for the vibrational relaxation of small and large molecules

  18. selective excitation of vibrational modes of polyatomic molecule

    Indian Academy of Sciences (India)

    vnautiyal@himalaya.du.ac.in; sneh@del2.vsnl.net.in. MS received 3 September 2003; accepted 12 December 2003. Abstract. Mode-selective dynamics of triatomic molecule in the electronic ground state under continuous wave laser pulse is investigated for the discrete vibrational bound states. A non-perturbative approach ...

  19. Experimental determination of vibrational cross sections for diatomic molecules

    International Nuclear Information System (INIS)

    Noqueira, J.C.; Iga, I.; Lee Mu Tao; Lopes, M.C.A.; Almeida, D.P. de

    1988-01-01

    To obtain inelastic differential cross sections from electronic and vibrational molecular excitations by electron impact, it was constructed a new spectrometer to operate in the energy range from 100 to 500 eV. The deceleration lenses as well as the analyser were tested for nitrogen molecule and 350 eV electrons. (A.C.A.S.) [pt

  20. Theoretical methods for small-molecule ro-vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lodi, Lorenzo; Tennyson, Jonathan, E-mail: j.tennyson@ucl.ac.u [University College London, Department of Physics and Astronomy, Gower Street, London WC1E 6BT (United Kingdom)

    2010-07-14

    The solution of the first principle equations of quantum mechanics provides an increasingly accurate and predictive approach for solving problems involving atoms and small molecules. A general introduction to the methods used for the ab initio calculation of rotational-vibrational spectra of small molecules is presented, with a strong focus on triatomic systems. The use of multi-reference electronic structure methods to compute molecular potential-energy and dipole-moment surfaces is discussed. Issues related to the construction of such surfaces and the inclusion of corrections due to relativistic and non-Born-Oppenheimer effects are reviewed. The derivation of exact, internal-coordinate nuclear-motion-effective Hamiltonians and their solution using a discrete-variable representation are discussed. Sample results for the water molecules are used throughout the tutorial to illustrate the theoretical and numerical issues in such calculations. (phd tutorial)

  1. Hydroxyl molecule vibrational state deactivation with atomic and molecular oxygen in meso-pause region

    International Nuclear Information System (INIS)

    Perminov, V.I.; Semenov, A.I.; Shefov, N.N.

    1998-01-01

    Velocities of multi-quanta vibrational relaxation of hydroxyl excited molecules by collisions with oxygen atoms and molecules are determined. High-altitude distributions of concentrations of atomic oxygen and OH excited molecules, as well as photochemical processes of the OH molecule excitation in the meso-pause area were used for this purpose. Dependences of deactivation velocities for various vibrational levels are presented

  2. Structural characterization of chiral molecules using vibrational circular dichroism spectroscopy

    DEFF Research Database (Denmark)

    Lassen, Peter Rygaard

    2006-01-01

    chiral molecules. This project is about application of one such technique, circular dichroism (CD) spectroscopy, which measures the difference in absorption of left- and right circularly polarized light - hence the name circular dichroism. This study has focused on the infrared (IR) range because...... compounds of pharmaceutical interest. Others are transition metal complexes relevant for the search for parity-violation effects in vibrational spectroscopy (rhenium complexes), for asymmetric catalysis (Schiff-base complexes), or as model systems for metal centres in biology (Schiff-bases and heme....... Currently, only part of the enhancement can be reproduced theoretically, as demonstrated for the Schiff-bases. Their conformers and absolute configurations were also identified. As for proteins, the interpretation of their spectra is different, because the immense number of overlapping vibrational modes...

  3. Vibrational many-body methods for molecules and extended systems

    Science.gov (United States)

    Keceli, Murat

    Vibrational many-body methods for molecules and extended systems have been developed that can account for the effects of anharmonicity in the potential energy surfaces (PESs) on energies and other observable properties. For molecules, we present a general scheme to calculate anharmonic vibrational frequencies and vibrationally-averaged structures along with applications to some key species in hydrocarbon combustion chemistry: HCO+, HCO, HNO, HOO, HOO--, CH3+, and CH3. We propose a hybrid, compact representation of PESs that combines the merits of two existing representations, which are a quartic force field (QFF) and numerical values on a rectilinear grid. We employed a combination of coupled-cluster singles and doubles (CCSD), CCSD with a second-order perturbation correction in the space of triples [CCSD(2)T] and in the space of triples and quadruples [CCSD(2)TQ], and a correlation-consistent basis set series to achieve the complete-correlation, complete-basis-set limits of the potential energy surfaces. The mean absolute deviation between the predicted and the observed frequencies is 11 cm --1. For extended systems, we generalized the formulations of the vibrational self-consistent field (VSCF), vibrational Moller--Plesset perturbation (VMP), and vibrational coupled-cluster (VCC) methods on the basis of a QFF in normal coordinates. We have identified algebraically and eliminated several terms in the formalisms of VSCF that have nonphysical size dependence, leading to compact and strictly size-extensive equations. This size-extensive VSCF method (XVSCF) thus defined has no contributions from cubic force constants and alters only the transition energies of the underlying harmonic-oscillator reference from a subset of quartic force constants. The mean-field potential of XVSCF felt by each mode is shown to be effectively harmonic, making the XVSCF equations subject to a self-consistent analytical solution without a basis-set expansion and matrix diagonalization

  4. Vibrational properties of water molecules adsorbed in different zeolitic frameworks

    International Nuclear Information System (INIS)

    Crupi, V; Longo, F; Majolino, D; Venuti, V

    2006-01-01

    The perturbation of water 'sorbed' in samples of zeolites of different structural type, genesis, and cation composition (K-, Na-, Mg- and Ca-rich zeolites), namely the CHA framework of a synthetic K-chabazite, the LTA framework of synthetic Na-A and Mg50-A zeolites, and the NAT framework of a natural scolecite, has been studied by FTIR-ATR spectroscopy, in the -10 to +80 o C temperature range. The aim was to show how differences in the chemical composition and/or in the topology of the zeolite framework and, in particular, the possibility for the guest water molecules to develop guest-guest and/or host-guest interactions, lead to substantial differences in their vibrational dynamical properties. The spectra, collected in the O-H stretching and H 2 O bending mode regions, are complex, with multiple bands being observed. As far as water in the CHA and LTA frameworks is concerned, whose behaviour is governed by the balance of water-water, water-framework and water-extra-framework cations interactions, the assignment of the resolved components of the O-H stretching band has been discussed by fitting the band shapes into individual components attributed to H 2 O molecules engaged in different degrees of hydrogen bonding. A detailed quantitative picture of the connectivity pattern of water, as a function of temperature and according to the chemical and topological properties of the environment, is furnished. The H 2 O bending vibrational bands give additional information that perfectly agrees with the results obtained from the analysis of the O-H stretching spectral region. In the case of scolecite, a small-pored zeolite where water-water interactions are eliminated, the increased complexity observed in the infrared spectra in the O-H stretching and H 2 O bending regions was explained as due to the hydrogen bonding between the water molecules and the network, and also with the extra-framework cation. Furthermore, these observations have been correlated with the different

  5. Multiphoton excitations in vibrational rotational states of diatomic molecules in intense electromagnetic field

    Science.gov (United States)

    Faisal, F. H. M.; Rahman, N. K.

    1972-01-01

    A theory is presented and a calculational procedure is outlined for evaluating transition amplitudes of multiphoton excitations of vibrational-rotational levels in diatomic molecules. This theory can be utilized in studying behavior of molecules in intense electromagnetic fields.

  6. Process and system for isotope separation using the selective vibrational excitation of molecules

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Keck, J.C.

    1976-01-01

    This invention concerns the separation of isotopes by using the isotopically selective vibrational excitation and the vibration-translation reactions of the excited particles. UF 6 molecular mixed with a carrier gas, such as argon, are directed through a refrigerated chamber lighted by a laser radiation tuned to excite vibrationally the uranium hexafluoride molecules of a particular uranium isotope. The density of the carrier gas is preferably maintained above the density of the uranium hexafluoride to allow a greater collision probability of the vibrationally excited molecules with a carried molecule. In such a case, the vibrationally excited uranium hexafluoride will collide with a carrier gas molecule provoking the conversion of the excitation energy into a translation of the excited molecule, resulting in thermal energy or greater diffusibility than that of the other uranium hexafluoride molecules [fr

  7. Interaction of spin and vibrations in transport through single-molecule magnets.

    Science.gov (United States)

    May, Falk; Wegewijs, Maarten R; Hofstetter, Walter

    2011-01-01

    We study electron transport through a single-molecule magnet (SMM) and the interplay of its anisotropic spin with quantized vibrational distortions of the molecule. Based on numerical renormalization group calculations we show that, despite the longitudinal anisotropy barrier and small transverse anisotropy, vibrational fluctuations can induce quantum spin-tunneling (QST) and a QST-Kondo effect. The interplay of spin scattering, QST and molecular vibrations can strongly enhance the Kondo effect and induce an anomalous magnetic field dependence of vibrational Kondo side-bands.

  8. Interaction of spin and vibrations in transport through single-molecule magnets

    Directory of Open Access Journals (Sweden)

    Falk May

    2011-10-01

    Full Text Available We study electron transport through a single-molecule magnet (SMM and the interplay of its anisotropic spin with quantized vibrational distortions of the molecule. Based on numerical renormalization group calculations we show that, despite the longitudinal anisotropy barrier and small transverse anisotropy, vibrational fluctuations can induce quantum spin-tunneling (QST and a QST-Kondo effect. The interplay of spin scattering, QST and molecular vibrations can strongly enhance the Kondo effect and induce an anomalous magnetic field dependence of vibrational Kondo side-bands.

  9. Approximative Krieger-Nelkin orientation averaging and anisotropy of water molecules vibrations

    International Nuclear Information System (INIS)

    Markovic, M.I.

    1974-01-01

    Quantum-mechanics approach of water molecules dynamics should be taken into account for precise theoretical calculation of differential scattering cross sections of neutrons. Krieger and Nelkin have proposed an approximate method for averaging orientation of molecules regarding directions of incoming and scattered neutron. This paper shows that this approach can be successfully applied for general shape of water molecule vibration anisotropy

  10. Single-molecule electronics: Cooling individual vibrational modes by the tunneling current.

    Science.gov (United States)

    Lykkebo, Jacob; Romano, Giuseppe; Gagliardi, Alessio; Pecchia, Alessandro; Solomon, Gemma C

    2016-03-21

    Electronic devices composed of single molecules constitute the ultimate limit in the continued downscaling of electronic components. A key challenge for single-molecule electronics is to control the temperature of these junctions. Controlling heating and cooling effects in individual vibrational modes can, in principle, be utilized to increase stability of single-molecule junctions under bias, to pump energy into particular vibrational modes to perform current-induced reactions, or to increase the resolution in inelastic electron tunneling spectroscopy by controlling the life-times of phonons in a molecule by suppressing absorption and external dissipation processes. Under bias the current and the molecule exchange energy, which typically results in heating of the molecule. However, the opposite process is also possible, where energy is extracted from the molecule by the tunneling current. Designing a molecular "heat sink" where a particular vibrational mode funnels heat out of the molecule and into the leads would be very desirable. It is even possible to imagine how the vibrational energy of the other vibrational modes could be funneled into the "cooling mode," given the right molecular design. Previous efforts to understand heating and cooling mechanisms in single molecule junctions have primarily been concerned with small models, where it is unclear which molecular systems they correspond to. In this paper, our focus is on suppressing heating and obtaining current-induced cooling in certain vibrational modes. Strategies for cooling vibrational modes in single-molecule junctions are presented, together with atomistic calculations based on those strategies. Cooling and reduced heating are observed for two different cooling schemes in calculations of atomistic single-molecule junctions.

  11. Analysis of rotation-vibration relative equilibria on the example of a tetrahedral four atom molecule

    NARCIS (Netherlands)

    Efstathiou, K; Sadovskii, DA; Zhilinskii, BI

    2004-01-01

    We study relative equilibria ( RE) of a nonrigid molecule, which vibrates about a well-defined equilibrium configuration and rotates as a whole. Our analysis unifies the theory of rotational and vibrational RE. We rely on the detailed study of the symmetry group action on the initial and reduced

  12. Red-light initiated atmospheric reactions of vibrationally excited molecules.

    Science.gov (United States)

    Vaida, V; Donaldson, D J

    2014-01-21

    We present a brief review of long wavelength, red-light initiated chemistry from excited vibrational levels of the ground electronic state of atmospheric trace species. When sunlight driven electronic state reactions are not effective, photochemical processes occurring by vibrational overtone excitation have been found to be important in reactions of oxidized atmospheric compounds (acids, alcohols and peroxides) prevalent in the Earth's atmosphere. This review focuses on the fundamental energetic, mechanistic and dynamical aspects of unimolecular reactions of vibrationally excited atmospheric species. We will discuss the relevance of these red light initiated reactions to address the discrepancies between atmospheric measurements and results of standard atmospheric models.

  13. A Pictorial Visualization of Normal Mode Vibrations of the Fullerene (C[subscript 60]) Molecule in Terms of Vibrations of a Hollow Sphere

    Science.gov (United States)

    Dunn, Janette L.

    2010-01-01

    Understanding the normal mode vibrations of a molecule is important in the analysis of vibrational spectra. However, the complicated 3D motion of large molecules can be difficult to interpret. We show how images of normal modes of the fullerene molecule C[subscript 60] can be made easier to understand by superimposing them on images of the normal…

  14. Theoretical study of molecular vibration and Application to linear triatomic molecules: case of OCS

    International Nuclear Information System (INIS)

    Andrianavalomahefa, A.

    2014-01-01

    Our aim is to give a theoretical approach to the calculation of vibrational energy levels of polyatomic molecules. By using matrix calculation, we have to solve an eigenvalue equation that gives normal vibration frequencies of the system. A basis change introduces normal coordinates of vibration, which diagonalize the Hamiltonian. The harmonic approximation gives a rough evaluation of parameters which describe the system. Then, we introduce nonlinear terms to take into account the anharmonicity of interatomic bounds. Morse oscillator gives good approximation for diatomic molecules. We consider cubic and quartic potential terms for polyatomic molecules. We treat the problem both in classical and quantum approach. The results thus obtained are applied to study longitudinal vibration of carbonyl sulfide. [fr

  15. Vibrational-rotational relaxation of the simplest hydrogen-containing molecules (review)

    International Nuclear Information System (INIS)

    Molevich, N.E.; Oraevskii, A.N.

    1987-01-01

    In connection with the development of chemical lasers much attention is now devoted to the study of kinetic processes is gaseous mixtures containing the hydrogen halides. Vibrational relaxation of molecules if primarily studied without specifying its relation to the rational levels. Rotational relaxation is regarded a priori as faster than vibrational relaxation, so that the population of the rotational levels is assumed to be in equilibrium. This approach to the relaxation of hydrogen halide molecules (and other diatomic hydrogen-containing molecules), however, is unable to explain satisfactorily the results of the papers discussed below. An analysis of the data obtained in these papers leads to the conclusion that the general picture of relaxation in diatomic hydrogen-containing molecules must be viewed as a unified process of vibrational and rotational relaxation. It is shown that those effects observed during vibrational relaxation of such molecules which are unusual from the standpoint of the theory of vibrational-translational relaxation are well explained in terms of intermolecular vibrational-rotational relaxation together with pure rotational relaxation

  16. Rotation-vibrational spectra of diatomic molecules and nuclei with Davidson interactions

    CERN Document Server

    Rowe, D J

    1998-01-01

    Complete rotation-vibrational spectra and electromagnetic transition rates are obtained for Hamiltonians of diatomic molecules and nuclei with Davidson interactions. Analytical results are derived by dynamical symmetry methods for diatomic molecules and a liquid-drop model of the nucleus. Numerical solutions are obtained for a many-particle nucleus with quadrupole Davidson interactions within the framework of the microscopic symplectic model. (author)

  17. Analysis of micro vibration in gas film of aerostatic guide way based on molecule collision theory

    Directory of Open Access Journals (Sweden)

    Yang Shao Hua

    2016-01-01

    Full Text Available Micro vibration of the aerostatic guide way has a significant impact on its dynamic characteristics and stability, which limits the development of pneumatic component. High pressure gas molecules have been collided with the supporting surface and the internal surface of the throttle during the flow process. Variable impulse of the surfaces aside for the gas film are affected by the changes of impulse which formed irregular impact force in horizontal and vertical direction. Micro-vibration takes place based on the natural frequency of the system and its frequency doubling. In this paper, the vibration model was established to describe the dynamic characteristics of the gas film, and the formation mechanism of micro vibration in the film is defined. Through the simulation analysis and experimental comparison, formation mechanism of the micro vibration in the gas film is confirmed. It was proposed that the micro vibration of gas film can be produced no matter whether there is a gas chamber or not in the throttle. Under the same conditions, the micro vibration of the guide way with air chamber is greater than that without any chamber. The frequency points of the vibration peaks are almost the same, as well as the vibration pattern in the frequency domain.

  18. Femtosecond time-resolved studies of coherent vibrational Raman scattering in large gas-phase molecules

    International Nuclear Information System (INIS)

    Hayden, C.C.; Chandler, D.W.

    1995-01-01

    Results are presented from femtosecond time-resolved coherent Raman experiments in which we excite and monitor vibrational coherence in gas-phase samples of benzene and 1,3,5-hexatriene. Different physical mechanisms for coherence decay are seen in these two molecules. In benzene, where the Raman polarizability is largely isotropic, the Q branch of the vibrational Raman spectrum is the primary feature excited. Molecules in different rotational states have different Q-branch transition frequencies due to vibration--rotation interaction. Thus, the macroscopic polarization that is observed in these experiments decays because it has many frequency components from molecules in different rotational states, and these frequency components go out of phase with each other. In 1,3,5-hexatriene, the Raman excitation produces molecules in a coherent superposition of rotational states, through (O, P, R, and S branch) transitions that are strong due to the large anisotropy of the Raman polarizability. The coherent superposition of rotational states corresponds to initially spatially oriented, vibrationally excited, molecules that are freely rotating. The rotation of molecules away from the initial orientation is primarily responsible for the coherence decay in this case. These experiments produce large (∼10% efficiency) Raman shifted signals with modest excitation pulse energies (10 μJ) demonstrating the feasibility of this approach for a variety of gas phase studies. copyright 1995 American Institute of Physics

  19. Quasi continuum vibrational of molecules and isotopic selectivity properties induced by collisions

    International Nuclear Information System (INIS)

    Angelie, Christian

    1990-01-01

    This research thesis proposes an overview of knowledge on vibrationally highly excited states of molecules. The author shows that the statistic quasi-continuum formed by these states is preceded by a quasi continuum of weak transitions with a lower energy, and that these transitions remain structured and very narrow up to the dissociation energy and beyond. Collisions between molecules excited in their quasi continuum are then studied. The author particularly analyses a new phenomenon of isotopic selectivity which is important for the dissociation of a molecule colliding another molecule. It appears that this selectivity regarding selectivity is due to a selectivity of transferred energy which paradoxically increases with the molecule vibrational content because of a resonance phenomenon of energies transferred by dipole-dipole interaction [fr

  20. Vibrational energy transfer in selectively excited diatomic molecules

    International Nuclear Information System (INIS)

    Dasch, C.J.

    1978-09-01

    Single rovibrational states of HCl(v=2), HBr(v=2), DCl(v=2), and CO(v=2) were excited with a pulsed optical parametric oscillator (OPO). Total vibrational relaxation rates near - resonance quenchers were measured at 295 0 K using time resolved infrared fluorescence. These rates are attributed primarily to V - V energy transfer, and they generally conform to a simple energy gap law. A small deviation was found for the CO(v) + DCl(v') relaxation rates. Upper limits for the self relaxation by V - R,T of HCl(v=2) and HBr(v=2) and for the two quantum exchange between HCl and HBr were determined. The HF dimer was detected at 295 0 K and 30 torr HF pressure with an optoacoustic spectrometer using the OPO. Pulsed and chopped, resonant and non-resonant spectrophones are analyzed in detail. From experiments and first order perturbation theory, these V - V exchange rates appear to behave as a first order perturbation in the vibrational coordinates. The rotational dynamics are known to be complicated however, and the coupled rotational - vibrational dynamics were investigated theoreticaly in infinite order by the Dillon and Stephenson and the first Magnus approximations. Large ΔJ transitions appear to be important, but these calculations differ by orders of magnitude on specific rovibrational transition rates. Integration of the time dependent semiclassical equations by a modified Gordon method and a rotationally distorted wave approximation are discussed as methods which would treat the rotational motion more accurately. 225 references

  1. Numerical solutions of anharmonic vibration of BaO and SrO molecules

    Science.gov (United States)

    Pramudito, Sidikrubadi; Sanjaya, Nugraha Wanda; Sumaryada, Tony

    2016-03-01

    The Morse potential is a potential model that is used to describe the anharmonic behavior of molecular vibration between atoms. The BaO and SrO molecules, which are two almost similar diatomic molecules, were investigated in this research. Some of their properties like the value of the dissociation energy, the energy eigenvalues of each energy level, and the profile of the wavefunctions in their correspondence vibrational states were presented in this paper. Calculation of the energy eigenvalues and plotting the wave function's profiles were performed using Numerov method combined with the shooting method. In general we concluded that the Morse potential solved with numerical methods could accurately produce the vibrational properties and the wavefunction behavior of BaO and SrO molecules from the ground state to the higher states close to the dissociation level.

  2. Translational vibrations between chains of hydrogen-bonded molecules in solid-state aspirin form I

    Science.gov (United States)

    Takahashi, Masae; Ishikawa, Yoichi

    2013-06-01

    We perform dispersion-corrected first-principles calculations, and far-infrared (terahertz) spectroscopic experiments at 4 K, to examine translational vibrations between chains of hydrogen-bonded molecules in solid-state aspirin form I. The calculated frequencies and relative intensities reproduce the observed spectrum to accuracy of 11 cm-1 or less. The stronger one of the two peaks assigned to the translational mode includes the stretching vibration of the weak hydrogen bond between the acetyl groups of a neighboring one-dimensional chain. The calculation of aspirin form II performed for comparison gives the stretching vibration of the weak hydrogen bond in one-dimensional chain.

  3. Infrared-pump-x-ray-probe spectroscopy of vibrationally excited molecules

    Science.gov (United States)

    Ignatova, Nina; da Cruz, Vinícius V.; Couto, Rafael C.; Ertan, Emilie; Odelius, Michael; Ågren, Hans; Guimarães, Freddy F.; Zimin, Andrei; Polyutov, Sergey P.; Gel'mukhanov, Faris; Kimberg, Victor

    2017-04-01

    We develop a theory of infrared (IR)-pump-x-ray-probe spectroscopy for molecular studies. We illustrate advantages of the proposed scheme by means of numerical simulations employing a vibrational wave packet technique applied to x-ray absorption and resonant inelastic x-ray scattering (RIXS) spectra of the water molecule vibrationally excited by a preceding IR field. The promotion of the vibrationally excited molecule to the dissociative 1 a1-14 a1 and bound 1 a1-12 b2 core-excited states with qualitatively different shapes of the potential energy surfaces creates nuclear wave packets localized along and between the OH bonds, respectively. The projection of these wave packets on the final vibrational states, governed by selection and propensity rules, results in spatial selectivity of RIXS sensitive to the initial vibrationally excited state, which makes it possible to probe selectively the ground state properties along different modes. In addition, we propose to use RIXS as a tool to study x-ray absorption from a selected vibrational level of the ground state when the spectral resolution is sufficiently high to resolve vibrational overtones. The proposed technique has potential applications for advanced mapping of multidimensional potential energy surfaces of ground and core-excited molecular states, for symmetry-resolved spectroscopy, and for steering chemical reactions.

  4. Vibrational Probes: From Small Molecule Solvatochromism Theory and Experiments to Applications in Complex Systems.

    Science.gov (United States)

    Błasiak, Bartosz; Londergan, Casey H; Webb, Lauren J; Cho, Minhaeng

    2017-04-18

    The vibrational frequency of a chosen normal mode is one of the most accurately measurable spectroscopic properties of molecules in condensed phases. Accordingly, infrared absorption and Raman scattering spectroscopy have provided valuable information on both distributions and ensemble-average values of molecular vibrational frequencies, and these frequencies are now routinely used to investigate structure, conformation, and even absolute configuration of chemical and biological molecules of interest. Recent advancements in coherent time-domain nonlinear vibrational spectroscopy have allowed the study of heterogeneous distributions of local structures and thermally driven ultrafast fluctuations of vibrational frequencies. To fully utilize IR probe functional groups for quantitative bioassays, a variety of biological and chemical techniques have been developed to site-specifically introduce vibrational probe groups into proteins and nucleic acids. These IR-probe-labeled biomolecules and chemically reactive systems are subject to linear and nonlinear vibrational spectroscopic investigations and provide information on the local electric field, conformational changes, site-site protein contacts, and/or function-defining features of biomolecules. A rapidly expanding library of data from such experiments requires an interpretive method with atom-level chemical accuracy. However, despite prolonged efforts to develop an all-encompassing theory for describing vibrational solvatochromism and electrochromism as well as dynamic fluctuations of instantaneous vibrational frequencies, purely empirical and highly approximate theoretical models have often been used to interpret experimental results. They are, in many cases, based on the simple assumption that the vibrational frequency of an IR reporter is solely dictated by electric potential or field distribution around the vibrational chromophore. Such simplified description of vibrational solvatochromism generally referred to as

  5. Antibonding intermediate state in the theory of vibrational excitation of diatomic molecules by slow electrons

    International Nuclear Information System (INIS)

    Kazanskii, A.K.

    1982-01-01

    An exactly solvable model is constructed for the description of the processes that take place when a slow electron collides with a diatomic molecule (vibrational excitation, associative detachment, and dissociative attachment). As a particular model of the variant, the case of an antibonding (virtual) state of an intermediate state is considered, and a term of this state is parametrized in a very simple manner. The vibrational excitation and dissociative attachment are calculated for a system corresponding to the HCl molecule. The results are in good qualitative agreement with experiment

  6. Multiple scattering approach to the vibrational excitation of molecules by slow electrons

    International Nuclear Information System (INIS)

    Drukarev, G.

    1976-01-01

    Another approach to the problem of vibrational excitation of homonuclear two-atomic molecules by slow electrons possibly accompanied by rotational transitions is presented based on the picture of multiple scattering of an electron inside the molecule. The scattering of two fixed centers in the zero range potential model is considered. The results indicate that the multiple scattering determines the order of magnitude of the vibrational excitation cross sections in the energy region under consideration even if the zero range potential model is used. Also the connection between the multiple scattering approach and quasi-stationary molecular ion picture is established. 9 refs

  7. Catalytic synthesis of ammonia using vibrationally excited nitrogen molecules

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Henriksen, Niels Engholm; Billing, Gert D.

    1992-01-01

    The dissociation of nitrogen is the rate-limiting step in the catalytic synthesis of ammonia. Theoretical calculations have shown that the dissociative sticking probability of molecular nitrogen on catalytic active metal surfaces is enhanced by orders of magnitude when the molecules...

  8. Vibrational excitation in molecule--surface collisions due to temporary negative molecular ion formation

    International Nuclear Information System (INIS)

    Gadzuk, J.W.

    1983-01-01

    Inelastic electron scattering from gaseous and physisorbed diatomic molecules results in greatly enhanced vibrational overtone excitation if the incident electron has the appropriate energy to form a shape-resonance-induced temporary negative molecular ion. It is proposed here that due to the image potential lowering of the electron affinity level of a diatomic molecule in interaction with a metal surface, somewhere outside the surface an incident molecule would find its affinity level degenerate with or lower than the substrate Fermi level at which point a substrate electron could hop onto the molecule, in analogy with gas phase harpooning processes. A negative molecular ion is thus formed which remains until the molecular ion reflects from the surface and the affinity level rises above the Fermi level, thus permitting reverse electron hopping back into the metal. The lifetime of the molecular ion can be controlled by varying both the kinetic energy of the incident molecule and also the substrate work function. In analogy with the electron scattering events, greatly enhanced vibrational excitation of overtones is expected in the molecules of the scattered beam. Induced fluorescence probing of the vibrational state distribution should then yield fundamental information pertaining to the dynamics of charge transfer reactions and nonadiabatic effects in molecule--surface interactions. A theory of this phenomenon is here presented together with the numerical consequences for a model system designed to simulate N 2 or NO scattering from standard surface science metal surfaces

  9. Symmetry Beyond Perturbation Theory: Floppy Molecules and Rotation-Vibration States

    Science.gov (United States)

    Schmiedt, Hanno; Schlemmer, Stephan; Jensen, Per

    2015-06-01

    In the customary approach to the theoretical description of the nuclear motion in molecules, the molecule is seen as a near-static structure rotating in space. Vibrational motion causing small structural deformations induces a perturbative treatment of the rotation-vibration interaction, which fails in fluxional molecules, where all vibrational motions are large compared to the linear extension of the molecule. An example is protonated methane (CH_5^+). For this molecule, customary theory fails to simulate reliably even the low-energy spectrum. Within the traditional view of rotation and vibration being near-separable, rotational and vibrational wavefunctions can be symmetry classified separately in the molecular symmetry (MS) group. In the present contribution we discuss a fundamental group theoretical approach to the problem of determining the symmetries of molecular rotation-vibration states. We will show that all MS groups discussed so far are subgroups of the special orthogonal group in three dimensions SO(3) This leads to a group theoretical foundation of the technique of equivalent rotations. The MS group of protonated methane (G240) represents, to the best of our knowledge, the first example of an MS group which is not a subgroup of SO(3) (nor of O(3) nor of SU(2)). Because of this, a separate symmetry classification of vibrational and rotational wavefunctions becomes impossible in this MS group, consistent with the fact that a decoupling of vibrational and rotational motion is impossible. We want to discuss the consequences of this. In conclusion, we show that the prototypical floppy molecule CH_5^+ represents a new class of molecules, where usual group theoretical methods for determining selection rules and spectral assignments fail so that new methods have to be developed. P. Kumar and D. Marx, Physical Chemistry Chemical Physics 8, 573 (2006) Z. Jin, B. J. Braams, and J. M. Bowman, The Journal of Physical Chemistry A 110, 1569 (2006) A. S. Petit, J. E

  10. Symmetry of extremely floppy molecules: Molecular states beyond rotation-vibration separation

    Science.gov (United States)

    Schmiedt, Hanno; Schlemmer, Stephan; Jensen, Per

    2015-10-01

    Traditionally, molecules are theoretically described as near-static structures rotating in space. Vibrational motion causing small structural deformations induces a perturbative treatment of the rotation-vibration interaction, which fails in highly fluxional molecules, where all vibrational motions have amplitudes comparable in size to the linear dimensions of the molecule. An example is protonated methane (CH 5+ ) [P. Kumar and D. Marx, Phys. Chem. Chem. Phys. 8, 573 (2006); Z. Jin et al., J. Phys. Chem. A 110, 1569 (2006); and A. S. Petit et al., J. Phys. Chem. A 118, 7206 (2014)]. For these molecules, customary theory fails to simulate reliably even the low-energy spectrum [T. Oka, Science 347, 1313-1314 (2015) and O. Asvany et al., Science 347, 1346-1349 (2015)]. Within the traditional view of rotation and vibration being near-separable, rotational and vibrational wavefunctions can be symmetry classified separately in the molecular symmetry (MS) group [P. Bunker and P. Jensen, Molecular Symmetry and Spectroscopy, NRC Monograph Publishing Program (NRC Research Press, 2006)]. In this article, we discuss a fundamental group theoretical approach to the problem of determining the symmetries of molecular rotation-vibration states. We will show that all MS groups discussed so far are isomorphic to subgroups of the special orthogonal group in three dimensions SO(3). This leads to a group theoretical foundation of the technique of equivalent rotations [H. Longuet-Higgins, Mol. Phys. 6, 445 (1963)]. The group G240 (the MS group of protonated methane) represents, to the best of our knowledge, the first example of a MS group which is not isomorphic to a subgroup of SO(3) (nor of O(3) or of SU(2)). Because of this, a separate symmetry classification of vibrational and rotational wavefunctions becomes impossible in this MS group, consistent with the fact that a decoupling of vibrational and rotational motion is impossible. We discuss here the consequences of this. In

  11. Influence of vibrations of gas molecules on neutron reaction cross sections

    Science.gov (United States)

    Bowman, C. D.; Schrack, R. A.

    1980-01-01

    The change in molecular vibrational energy upon absorption of a neutron by a nucleus bound in a free molecule can influence resonance shape and other aspects of neutron reaction cross sections. A formalism is developed for centrosymmetric molecules such as UF6 and applied to the shape of the 6.67 eV resonance in 238U. The ratio of the resonance shape for 238UF6 gas and for solid 238U3O8 has been measured and compared with the calculation. Reasonable agreement is obtained indicating the validity of the calculation and the necessity to include vibration effects to avoid large errors in measurements and calculations on gascontaining systems. NUCLEAR REACTIONS 238U(n,γ) measured at 6.67 eV resonance; Effect of molecular vibrations studied experimentally and theoretically.

  12. Bibliography on electron collisions with molecules: rotational and vibrational excitations, 1980-2000

    Energy Technology Data Exchange (ETDEWEB)

    Itikawa, Yukikazu [Institute of Space and Astronautical Science, Sagamihara, Kanagawa (Japan)

    2001-04-01

    A list of papers reporting cross sections for electron-impact excitations of rotational and vibrational states of molecules is presented. The list includes both the theoretical and the experimental papers published in 1980-2000. An index by molecular species is provided at the end of the bibliography. (author)

  13. Vibration-translation energy transfer in anharmonic diatomic molecules. 2: The vibrational quantum number dependence

    Science.gov (United States)

    Mckenzie, R. L.

    1975-01-01

    A semiclassical model of the inelastic collision between a vibrationally excited anharmonic oscillator and a structureless atom was used to predict the variation of thermally averaged vibration-translation rate coefficients with temperature and initial-state quantum number. Multiple oscillator states were included in a numerical solution for collinear encounters. The results are compared with CO-He experimental values for both ground and excited initial states using several simplified forms of the interaction potential. The numerical model was also used as a basis for evaluating several less complete but analytic models. Two computationally simple analytic approximations were found that successfully reproduced the numerical rate coefficients for a wide range of molecular properties and collision partners. Their limitations were also identified. The relative rates of multiple-quantum transitions from excited states were evaluated for several molecular types.

  14. Vibrational Excitation of Diatomic Molecular Ions in Strong Field Ionization of Diatomic Molecules

    International Nuclear Information System (INIS)

    Kjeldsen, Thomas K.; Madsen, Lars Bojer

    2005-01-01

    A model based on the strong-field and Born-Oppenheimer approximations qualitatively describes the distribution over vibrational states formed in a diatomic molecular ion following ionization of the neutral molecule by intense laser pulses. Good agreement is found with a recent experiment [X. Urbain et al., Phys. Rev. Lett. 92, 163004 (2004)]. In particular, the observed deviation from a Franck-Condon-like distribution is reproduced. Additionally, we demonstrate control of the vibrational distribution by a variation of the peak intensity or a change of frequency of the laser pulse

  15. Mode coupling and multiquantum vibrational excitations in Feshbach-resonant positron annihilation in molecules

    Science.gov (United States)

    Gribakin, G. F.; Stanton, J. F.; Danielson, J. R.; Natisin, M. R.; Surko, C. M.

    2017-12-01

    The dominant mechanism of low-energy positron annihilation in polyatomic molecules is through positron capture in vibrational Feshbach resonances (VFR). In this paper, we investigate theoretically the effect of anharmonic terms in the vibrational Hamiltonian on positron annihilation rates. Such interactions enable positron capture in VFRs associated with multiquantum vibrational excitations, leading to enhanced annihilation. Mode coupling can also lead to faster depopulation of VFRs, thereby reducing their contribution to the annihilation rates. To analyze this complex picture, we use coupled-cluster methods to calculate the anharmonic vibrational spectra and dipole transition amplitudes for chloroform, chloroform-d1, 1,1-dichloroethylene, and methanol, and use these data to compute positron resonant annihilation rates for these molecules. Theoretical predictions are compared with the annihilation rates measured as a function of incident positron energy. The results demonstrate the importance of mode coupling in both enhancement and suppression of the VFR. There is also experimental evidence for the direct excitation of multimode VFR. Their contribution is analyzed using a statistical approach, with an outlook towards more accurate treatment of this phenomenon.

  16. Polyad quantum numbers and multiple resonances in anharmonic vibrational studies of polyatomic molecules.

    Science.gov (United States)

    Krasnoshchekov, Sergey V; Stepanov, Nikolay F

    2013-11-14

    In the theory of anharmonic vibrations of a polyatomic molecule, mixing the zero-order vibrational states due to cubic, quartic and higher-order terms in the potential energy expansion leads to the appearance of more-or-less isolated blocks of states (also called polyads), connected through multiple resonances. Such polyads of states can be characterized by a common secondary integer quantum number. This polyad quantum number is defined as a linear combination of the zero-order vibrational quantum numbers, attributed to normal modes, multiplied by non-negative integer polyad coefficients, which are subject to definition for any particular molecule. According to Kellman's method [J. Chem. Phys. 93, 6630 (1990)], the corresponding formalism can be conveniently described using vector algebra. In the present work, a systematic consideration of polyad quantum numbers is given in the framework of the canonical Van Vleck perturbation theory (CVPT) and its numerical-analytic operator implementation for reducing the Hamiltonian to the quasi-diagonal form, earlier developed by the authors. It is shown that CVPT provides a convenient method for the systematic identification of essential resonances and the definition of a polyad quantum number. The method presented is generally suitable for molecules of significant size and complexity, as illustrated by several examples of molecules up to six atoms. The polyad quantum number technique is very useful for assembling comprehensive basis sets for the matrix representation of the Hamiltonian after removal of all non-resonance terms by CVPT. In addition, the classification of anharmonic energy levels according to their polyad quantum numbers provides an additional means for the interpretation of observed vibrational spectra.

  17. Incorporating nuclear vibrational energies into the "atom in molecules" analysis: An analytical study.

    Science.gov (United States)

    Gharabaghi, Masumeh; Shahbazian, Shant

    2017-04-21

    The quantum theory of atoms in molecules (QTAIM) is based on the clamped nucleus paradigm and solely working with the electronic wavefunctions, so does not include nuclear vibrations in the AIM analysis. On the other hand, the recently extended version of the QTAIM, called the multi-component QTAIM (MC-QTAIM), incorporates both electrons and quantum nuclei, i.e., those nuclei treated as quantum waves instead of clamped point charges, into the AIM analysis using non-adiabatic wavefunctions. Thus, the MC-QTAIM is the natural framework to incorporate the role of nuclear vibrations into the AIM analysis. In this study, within the context of the MC-QTAIM, the formalism of including nuclear vibrational energy in the atomic basin energy is developed in detail and its contribution is derived analytically using the recently proposed non-adiabatic Hartree product nuclear wavefunction. It is demonstrated that within the context of this wavefunction, the quantum nuclei may be conceived pseudo-adiabatically as quantum oscillators and both isotropic harmonic and anisotropic anharmonic oscillator models are used to compute the zero-point nuclear vibrational energy contribution to the basin energies explicitly. Inspired by the results gained within the context of the MC-QTAIM analysis, a heuristic approach is proposed within the context of the QTAIM to include nuclear vibrational energy in the basin energy from the vibrational wavefunction derived adiabatically. The explicit calculation of the basin contribution of the zero-point vibrational energy using the uncoupled harmonic oscillator model leads to results consistent with those derived from the MC-QTAIM.

  18. Behavior of ro-vibrationally excited H2 molecules and H atoms in a plasma expansion

    International Nuclear Information System (INIS)

    Vankan, P.; Schram, D.C.; Engeln, R.

    2005-01-01

    The behavior in a supersonic plasma expansion of H atom and H2 molecules, both ground-state and ro-vibrationally excited, is studied using various laser spectroscopic techniques. The ground-state H2 molecules expand like a normal gas. The behavior of H atoms and H 2 rv molecules, on the other hand, is considerably influenced, and to some extend even determined, by their reactivity. The H atoms diffuse out of the expansion due to surface association at the walls of the vacuum vessel. Moreover, by reducing the surface area of the nozzle by a factor of two, the amount of H atoms leaving the source is increased by one order of magnitude, due to a decreased surface association of H atoms in the nozzle. The evolution of the ro-vibrational distributions along the expansion axis shows the relaxation of the molecular hydrogen from the high temperature in the up-stream region to the low ambient temperature in the down-stream region. Whereas the vibrational distribution resembles a Boltzmann distribution, the rotational distribution is a non-equilibrium one, in which the high rotational levels (J > 7) are much more populated than what is expected from the low rotational levels (J <5). We observed overpopulations of up to seven orders of magnitude. The production of the high rotational levels is very probably connected to the surface association in the nozzle

  19. Symmetry Adaptation of the Rotation-Vibration Theory for Linear Molecules

    Directory of Open Access Journals (Sweden)

    Katy L. Chubb

    2018-04-01

    Full Text Available A numerical application of linear-molecule symmetry properties, described by the D ∞ h point group, is formulated in terms of lower-order symmetry groups D n h with finite n. Character tables and irreducible representation transformation matrices are presented for D n h groups with arbitrary n-values. These groups can subsequently be used in the construction of symmetry-adapted ro-vibrational basis functions for solving the Schrödinger equations of linear molecules. Their implementation into the symmetrisation procedure based on a set of “reduced” vibrational eigenvalue problems with simplified Hamiltonians is used as a practical example. It is shown how the solutions of these eigenvalue problems can also be extended to include the classification of basis-set functions using ℓ, the eigenvalue (in units of ℏ of the vibrational angular momentum operator L ^ z . This facilitates the symmetry adaptation of the basis set functions in terms of the irreducible representations of D n h . 12 C 2 H 2 is used as an example of a linear molecule of D ∞ h point group symmetry to illustrate the symmetrisation procedure of the variational nuclear motion program Theoretical ROVibrational Energies (TROVE.

  20. Selective excitation of a vibrational level within the electronic ground state of a polyatomic molecule with ultra pulses

    CSIR Research Space (South Africa)

    de Clercq, L

    2010-09-01

    Full Text Available Coherent control of the upper vibrational level populations in the electronic ground state of a polyatomic molecule was simulated. Results indicate that selective excitation of a specific upper state level is possible...

  1. Selective excitation of a vibrational level within the electronic ground state of a polyatomic molecule with ultra short pulses

    CSIR Research Space (South Africa)

    De Clercq, L

    2010-09-01

    Full Text Available Coherent control of the upper vibrational level populations in the electronic ground state of a polyatomic molecule was simulated. Results indicate that selective excitation of a specific upper state level is possible....

  2. Molecules-in-molecules fragment-based method for the calculation of chiroptical spectra of large molecules: Vibrational circular dichroism and Raman optical activity spectra of alanine polypeptides.

    Science.gov (United States)

    Jose, K V Jovan; Raghavachari, Krishnan

    2016-12-01

    The molecules-in-molecules (MIM) fragment-based method has recently been adapted to evaluate the chiroptical (vibrational circular dichroism [VCD] and Raman optical activity [ROA]) spectra of large molecules such as peptides. In the MIM-VCD and MIM-ROA methods, the relevant higher energy derivatives of the parent molecule are assembled from the corresponding derivatives of smaller fragment subsystems. In addition, the missing long-range interfragment interactions are accounted at a computationally less expensive level of theory (MIM2). In this work we employed the MIM-VCD and MIM-ROA fragment-based methods to explore the evolution of the chiroptical spectroscopic characteristics of 3 10 -helix, α-helix, β-hairpin, γ-turn, and β-extended conformers of gas phase polyalanine (chain length n = 6-14). The different conformers of polyalanine show distinctive features in the MIM chiroptical spectra and the associated spectral intensities increase with evolution of system size. For a better understanding the site-specific effects on the vibrational spectra, isotopic substitutions were also performed employing the MIM method. An increasing redshift with the number of isotopically labeled 13 C=O functional groups in the peptide molecule was seen. For larger polypeptides, we implemented the two-step-MIM model to circumvent the high computational expense associated with the evaluation of chiroptical spectra at a high level of theory using large basis sets. The chiroptical spectra of α-(alanine) 20 polypeptide obtained using the two-step-MIM model, including continuum solvation effects, show good agreement with the full calculations and experiment. This benchmark study suggests that the MIM-fragment approach can assist in predicting and interpreting chiroptical spectra of large polypeptides. © 2016 Wiley Periodicals, Inc.

  3. Comparison of force fields and calculation methods for vibration intervals of isotopic H+3 molecules

    International Nuclear Information System (INIS)

    Carney, G.D.; Adler-Golden, S.M.; Lesseski, D.C.

    1986-01-01

    This paper reports (a) improved values for low-lying vibration intervals of H + 3 , H 2 D + , D 2 H + , and D + 3 calculated using the variational method and Simons--Parr--Finlan representations of the Carney--Porter and Dykstra--Swope ab initio H + 3 potential energy surfaces, (b) quartic normal coordinate force fields for isotopic H + 3 molecules, (c) comparisons of variational and second-order perturbation theory, and (d) convergence properties of the Lai--Hagstrom internal coordinate vibrational Hamiltonian. Standard deviations between experimental and ab initio fundamental vibration intervals of H + 3 , H 2 D + , D 2 H + , and D + 3 for these potential surfaces are 6.9 (Carney--Porter) and 1.2 cm -1 (Dykstra--Swope). The standard deviations between perturbation theory and exact variational fundamentals are 5 and 10 cm -1 for the respective surfaces. The internal coordinate Hamiltonian is found to be less efficient than the previously employed ''t'' coordinate Hamiltonian for these molecules, except in the case of H 2 D +

  4. Collision dynamics of methyl radicals and highly vibrationally excited molecules using crossed molecular beams

    International Nuclear Information System (INIS)

    Chu, P.M.Y.

    1991-10-01

    The vibrational to translational (V→T) energy transfer in collisions between large highly vibrationally excited polyatomics and rare gases was investigated by time-of-flight techniques. Two different methods, UV excitation followed by intemal conversion and infrared multiphoton excitation (IRMPE), were used to form vibrationally excited molecular beams of hexafluorobenzene and sulfur hexafluoride, respectively. The product translational energy was found to be independent of the vibrational excitation. These results indicate that the probability distribution function for V→T energy transfer is peaked at zero. The collisional relaxation of large polyatomic molecules with rare gases most likely occurs through a rotationally mediated process. Photodissociation of nitrobenzene in a molecular beam was studied at 266 nm. Two primary dissociation channels were identified including simple bond rupture to produce nitrogen dioxide and phenyl radical and isomerization to form nitric oxide and phenoxy radical. The time-of-flight spectra indicate that simple bond rupture and isomerization occurs via two different mechanisms. Secondary dissociation of the phenoxy radicals to carbon monoxide and cyclopentadienyl radicals was observed as well as secondary photodissociation of phenyl radical to give H atom and benzyne. A supersonic methyl radical beam source is developed. The beam source configuration and conditions were optimized for CH 3 production from the thermal decomposition of azomethane. Elastic scattering of methyl radical and neon was used to differentiate between the methyl radicals and the residual azomethane in the molecular beam

  5. Collision dynamics of methyl radicals and highly vibrationally excited molecules using crossed molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Chu, P.M.Y.

    1991-10-01

    The vibrational to translational (V{yields}T) energy transfer in collisions between large highly vibrationally excited polyatomics and rare gases was investigated by time-of-flight techniques. Two different methods, UV excitation followed by intemal conversion and infrared multiphoton excitation (IRMPE), were used to form vibrationally excited molecular beams of hexafluorobenzene and sulfur hexafluoride, respectively. The product translational energy was found to be independent of the vibrational excitation. These results indicate that the probability distribution function for V{yields}T energy transfer is peaked at zero. The collisional relaxation of large polyatomic molecules with rare gases most likely occurs through a rotationally mediated process. Photodissociation of nitrobenzene in a molecular beam was studied at 266 nm. Two primary dissociation channels were identified including simple bond rupture to produce nitrogen dioxide and phenyl radical and isomerization to form nitric oxide and phenoxy radical. The time-of-flight spectra indicate that simple bond rupture and isomerization occurs via two different mechanisms. Secondary dissociation of the phenoxy radicals to carbon monoxide and cyclopentadienyl radicals was observed as well as secondary photodissociation of phenyl radical to give H atom and benzyne. A supersonic methyl radical beam source is developed. The beam source configuration and conditions were optimized for CH{sub 3} production from the thermal decomposition of azomethane. Elastic scattering of methyl radical and neon was used to differentiate between the methyl radicals and the residual azomethane in the molecular beam.

  6. Collision dynamics of methyl radicals and highly vibrationally excited molecules using crossed molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Pamela Mei-Ying [Univ. of California, Berkeley, CA (United States)

    1991-10-01

    The vibrational to translational (V→T) energy transfer in collisions between large highly vibrationally excited polyatomics and rare gases was investigated by time-of-flight techniques. Two different methods, UV excitation followed by intemal conversion and infrared multiphoton excitation (IRMPE), were used to form vibrationally excited molecular beams of hexafluorobenzene and sulfur hexafluoride, respectively. The product translational energy was found to be independent of the vibrational excitation. These results indicate that the probability distribution function for V→T energy transfer is peaked at zero. The collisional relaxation of large polyatomic molecules with rare gases most likely occurs through a rotationally mediated process. Photodissociation of nitrobenzene in a molecular beam was studied at 266 nm. Two primary dissociation channels were identified including simple bond rupture to produce nitrogen dioxide and phenyl radical and isomerization to form nitric oxide and phenoxy radical. The time-of-flight spectra indicate that simple bond rupture and isomerization occurs via two different mechanisms. Secondary dissociation of the phenoxy radicals to carbon monoxide and cyclopentadienyl radicals was observed as well as secondary photodissociation of phenyl radical to give H atom and benzyne. A supersonic methyl radical beam source is developed. The beam source configuration and conditions were optimized for CH3 production from the thermal decomposition of azomethane. Elastic scattering of methyl radical and neon was used to differentiate between the methyl radicals and the residual azomethane in the molecular beam.

  7. Ro-vibrational coupling in high temperature thermochemistry of the BBr molecule

    Science.gov (United States)

    Buchowiecki, Marcin

    2018-01-01

    High temperature thermochemistry of the BBr molecule is investigated with the classical approach in the temperature range of 300-20,000 K. The role of ro-vibrational coupling is elucidated. The internal partition function, thermal energy, heat capacity, and entropy are calculated at three levels of approximation, i.e. taking into account bound states on the ground state (1 Σ), including also two excited states (3 Π and 1 Π), and finally adding the resonance and scattering states. The influence of these approximations on studied quantities is investigated. The entropy is found to be the least sensitive to approximations in the ro-vibrational coupling and the heat capacity the most sensitive.

  8. Rovibrational interaction and vibrational constants of the symmetric top molecule 14NF3.

    Science.gov (United States)

    Najib, Hamid

    2013-01-01

    Several accurate experimental values of the α(C) and α(B) rotation-vibration interaction parameters and ω(i), x(ij), and g(ij) vibrational constants have been extracted from the most recent high-resolution Fourier transform infrared, millimeter wave, and centimeter wave investigations in the spectra of the oblate symmetric top molecule (14)NF3. The band-centres used are those of the four fundamental, the overtones, the combination, and hot bands identified in the region between 400 cm(-1) and 2000 cm(-1). Comparison of our constants with the ones measured previously, by infrared spectroscopy at low resolution, reveals orders of magnitude higher accuracy of the new values. The agreement between our values and those determined by ab initio calculations employing the TZ2Pf basis is excellent.

  9. Rovibrational Interaction and Vibrational Constants of the Symmetric Top Molecule 14NF3

    Directory of Open Access Journals (Sweden)

    Hamid Najib

    2013-01-01

    Full Text Available Several accurate experimental values of the and rotation-vibration interaction parameters and , , and vibrational constants have been extracted from the most recent high-resolution Fourier transform infrared, millimeter wave, and centimeter wave investigations in the spectra of the oblate symmetric top molecule 14NF3. The band-centres used are those of the four fundamental, the overtones, the combination, and hot bands identified in the region between 400 cm−1 and 2000 cm−1. Comparison of our constants with the ones measured previously, by infrared spectroscopy at low resolution, reveals orders of magnitude higher accuracy of the new values. The agreement between our values and those determined by ab initio calculations employing the TZ2Pf basis is excellent.

  10. Time delay for resonant vibrational excitation in electron--molecule collisions

    International Nuclear Information System (INIS)

    Gauyacq, J.P.

    1990-01-01

    An analysis of the time delay associated with vibrational excitation in electron--molecule collision is presented. It consists of a direct study of the time dependence of the process for three model systems. An electron wave packet, that is narrow in time, is sent on the target and the amplitudes in the different inelastic channels are studied as functions of time. The time delay is found to correspond to very different time effects: broadenings, shifts in time of the wave packet, but also complex distortions that cannot be represented by a time delay. The direct analysis of the scattered wave also provides new insights into the vibrational excitation process. It should be a useful tool to analyze complex collision processes

  11. A study on the reduction of nitric oxide molecule (NO) to nitroxyl anion (NO{sup -}) by vibrational energy

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seon Woog [Silla Univ., Pusan (Korea, Republic of)

    2002-02-01

    It is shown that one-electron reduction of nitric oxide (NO) to nitroxyl anion (NO{sup -}) can be accelerated by vibrational energy. Potential energy surfaces of NO and NO{sup -} reveal that the vertical transition between them has favorable energetics for vibrationally excited molecule. Also, Franck-Condon factors between NO and NO{sup -} vibrational wave functions are calculated. It shows that the number of open channels increases with increased vibrational energy. These results mean that we can control the rate of reduction of NO to NO{sup -} by radiating an appropriate light.

  12. Communication: atomic force detection of single-molecule nonlinear optical vibrational spectroscopy.

    Science.gov (United States)

    Saurabh, Prasoon; Mukamel, Shaul

    2014-04-28

    Atomic Force Microscopy (AFM) allows for a highly sensitive detection of spectroscopic signals. This has been first demonstrated for NMR of a single molecule and recently extended to stimulated Raman in the optical regime. We theoretically investigate the use of optical forces to detect time and frequency domain nonlinear optical signals. We show that, with proper phase matching, the AFM-detected signals closely resemble coherent heterodyne-detected signals. Applications are made to AFM-detected and heterodyne-detected vibrational resonances in Coherent Anti-Stokes Raman Spectroscopy (χ((3))) and sum or difference frequency generation (χ((2))).

  13. ESR measurement of the concentration of vibrationally excited hydrogen and deuterium molecules

    International Nuclear Information System (INIS)

    Gershenzon, Yu.M.; Ivanov, A.V.; Il'in, S.D.; Kucheryavyi, S.I.; Rozenshtein, V.B.

    1988-01-01

    A method is described for measuring the concentration of vibrationally excited H 2 and D 2 molecules using an ESR microwave spectrometer. The essence of the method is the titration of H 2 (v = 1) and D 2 (v = 1) with D and H atoms and measurement of the concentrations of the titration products H and D, respectively. Stoichiometric titration coefficients were determined in the form of proportionality coefficients between the titration signals Δ[H], Δ[D] and the concentrations of H 2 (v = 1), D 2 (v = 1)

  14. Semiclassical S-matrix theory of vibrationally inelastic collisions between two diatomic molecules

    Science.gov (United States)

    Cohen, S. C.; Alexander, M. H.

    1974-01-01

    We derive a semiclassical S matrix for vibrationally inelastic collisions between two diatomic molecules, assuming a collinear geometry. Our theory incorporates a quantum mechanical superposition principle with classical dynamics and, as such, is an extension of the atom-diatomic molecule theory of Miller. The several approximations to the S matrix differ in the complexity with which the interference between various classical trajectories is treated. We report numerical calculations for H2-D2 and D2-D2 collisions based on two different interaction potentials. The cruder approximations yield transition probabilities which agree with exact quantum mechanical results to within a factor of 2. More sophisticated approximations to the S matrix yield excellent quantitative agreement with the quantum calculations.

  15. INTERACTION OF LASER RADIATION WITH MATTER: Effect of stimulated emission on the distribution of CO molecules over vibrational levels

    Science.gov (United States)

    Grigorian, G. M.; Kochetov, I. V.

    2008-10-01

    The vibrational distribution function (VDF) of CO molecules is measured in the presence and absence of generation in a CO laser pumped by a longitudinal dc discharge. Kinetic equations for the VDF and the Boltzmann equation for the energy distribution function of electrons are solved simultaneously in a theoretical model. A comparison of the experimental and calculated lasing spectra and VDF demonstrates their good agreement. By introducing an absorbing cell with different gases (NO, C2H4, CO2, C6H6) into a resonator, the influence of selection of laser lines on the lasing spectrum and the VDF of CO molecules is studied. It is shown experimentally that the population of CO molecules at vibrational levels involved in lasing and at higher levels strongly decreases and the VDF at lower levels changes insignificantly. It is demonstrated that the VDF shape of CO molecules at high vibrational levels can be changed by introducing intracavity absorption.

  16. FEMVib, an ab initio multi-dimensional solver for probing vibrational dynamics in polyatomic molecules and free radicals

    Science.gov (United States)

    Xu, Dong

    Accurate prediction of the vibrational spectra in polyatomic molecules and free radicals depends on obtaining high quality solutions to the vibrational Schrodinger equation. The quantum simple harmonic oscillator provides the traditional first approximation for modeling molecular vibrational states. Rarely does a vibrational analysis extend beyond this first approximation, and harmonic energy levels are routinely used to predict the infrared spectra and other dynamical properties of molecules. However, there are many large-amplitude molecular motions that are extremely anharmonic, including internal torsions about atom-atom single bonds, bending and stretching of weak bonds in van der Waals complexes, and isomerization along relocalization coordinates in free radicals. In these cases, the harmonic treatment provided by electronic structure quantum chemistry packages is completely inadequate. Furthermore, the anharmonicity often includes strong coupling among two or more distinct vibrational coordinates, necessitating a multi-dimensional analysis of the vibrational Schrodinger equation along the coupled coordinates. A novel ab initio solver package, FEMVib, is developed within the finite element method (FEM) framework. A mixed programming paradigm that combines C++, Fortran and Python is employed to take advantage of existing numerical libraries. FEMVib has been rigorously tested to resolve the eigenvalues and wavefunctions of hundreds of vibrational energy states to high accuracy and precision. It may be used to calculate the complete vibrational spectra of triatomic molecules or to approximate larger systems through a "relaxed" model that allows complete coupling of up to three selected vibrational coordinates. FEMVib provides physical chemists with a general, robust and accurate computational tool for molecular vibrational analysis.

  17. Effect of vibrational excitation on the dynamics of ion-molecule reactions

    International Nuclear Information System (INIS)

    Anderson, S.L.

    1981-11-01

    A new experimental technique for the study of vibrational effects on ion-molecule reaction cross sections is described. Vibrational and collision energy dependent cross sections are presented for proton and H atom transfer, charge transfer and collision induced dissociation reactions in various isotopic H 2 + + H 2 systems. Charge and proton transfer cross sections are presented for the reactions of H 2 + and D 2 + with Ar, N 2 , CO, and O 2 . All the reactions are shown to be highly influenced by avoided crossings between the ground and first excited potential energy surfaces. Because of the nature of the crossings, vibrational motion of the systems can cause both adiabatic and non-adiabatic behavior of the system. This makes the vibrational dependences of the various cross sections a very sensitive probe of the dynamics of the collisions particularly, their behavior in the region of the crossings. Evidence is seen for charge transfer between reagents as they approach each other, transition to and in some cases reactions on excited potential energy surfaces, competition between different channels, and strong coupling of proton and charge transfer channels which occurs only for two of the systems studied (H 2 + + Ar, N 2 ). Oscillatory structure is observed in the collision energy dependence of the endoergic H 2 + (v = 0) + Ar charge transfer reaction for the first time, and a simple model which is commonly used for atom-atom charge transfer is used to fit the peaks. Finally a simple model is used to assess the importance of energy resonance and Franck-Condon effects on molecular charge transfer

  18. Influence of vibrations and rotations of diatomic molecules on their physical properties: II. Refractive index, reactivity and diffusion coefficients

    International Nuclear Information System (INIS)

    Sharipov, Alexander S; Loukhovitski, Boris I; Starik, Alexander M

    2016-01-01

    The influence of the excitation of vibrational and rotational states of diatomic molecules (H 2 , N 2 , O 2 , NO, OH, CO, CH, HF and HCl) on refractive index, reactivity and transport coefficients was analyzed by using ab initio calculated data on the effective state-specific dipole moment and static polarizability obtained in the preceding paper of the present series. It has been revealed that, for non-polar molecules, the excitation both of vibrational and rotational degrees of freedom increases the averaged polarizability and, as a consequence, the refractive index. Meanwhile, for polar molecules, the effect of molecule excitation is more complex: it can either increase or decrease the refractive index. It was also shown that the excitation of molecules slightly influences the rate constants of barrierless chemical reactions between neutral particles; whereas, for ion–molecule reactions, this effect can be more pronounced. Analysis of the variation of diffusion coefficients, taking into account the effect of molecule excitation both on the collision diameter and on the well depth of intermolecular potential, exhibited that, for non-polar molecules, the effect associated with the change of collision diameter prevails. However, for polar molecules, the effect of the excitation of vibrational states on the well depth of intermolecular potential can compensate or even exceed the decrease of diffusion coefficient due to the averaged collision diameter rise. (paper)

  19. New theory for vibrational and rotational energy transfer in the collisions of atoms with symmetric top molecules

    Energy Technology Data Exchange (ETDEWEB)

    Clary, D.C.

    1984-11-15

    A new three-dimensional quantum-mechanical theory is described for calculating vibrational and rotational relaxation cross sections and rate constants for the collisions of atoms with prolate symmetric top or near-symmetric top molecules. The technique uses a wave function expansion in vibrational states coupled with azimuthal basis functions which describe the spinning of the top about its symmetry axis. The infinite-order-sudden method is used for the total rotational angular momentum of the molecule. The technique is applied to the computation of vibrational relaxation rate constants for the collisions of C/sub 2/H/sub 4/ with He atoms. Comparison is made with results calculated previously by using the sudden approximation for both the total and azimuthal rotational motion. Good agreement is obtained with vibrational relaxation rate constants measured in an infrared double resonance experiment.

  20. Influence of temperature on the selectivity of dissociation of CF3I molecules by multiphoton vibrational and subsequent electronic excitation

    International Nuclear Information System (INIS)

    Kudryavtsev, Y.A.

    1980-01-01

    A report is given of theoretical and experimental studies of the influence of temperature on the selectivity of separating carbon isotopes by multiphoton vibrational and subsequent electronic excitation of CF 3 I molecules. Carbon dioxide laser radiation was used for vibrational excitation and XeC1 and XeF excimer lasers were used for dissociation. A selectivity of 108 was achieved at 223 0 K

  1. Explicit Consideration of Water Molecules to Study Vibrational Circular DICHROÎSM of Monosaccharide's

    Science.gov (United States)

    Moussi, Sofiane; Ouamerali, Ourida

    2014-06-01

    Carbohydrates have multiples roles in biological systems. It has been found that the glycoside bond is fundamentally important in many aspects of chemistry and biology and forms the basis of carbohydrate chemistry. That means the stereochemical information, namely, glycosidic linkages α or β, gives an significant features of the carbohydrate glycosidation position of the glycosylic acceptor. For these reasons, much effort was made for the synthesis and analysis of the glycoside bond. Vibrational circular dichroism VCD has some advantages over conventional electronic circular dichroism (ECD) due to the applicability to all organic molecules and the reliability of ab initio quantum calculation. However, for a molecule with many chiral centers such as carbohydrates, determination of the absolute configuration tends to be difficult because the information from each stereochemical center is mixed and averaged over the spectrum. In the CH stretching region, only two VCD studies on carbohydrates have been reported and spectra--structure correlation, as determined for the glycoside band, remains to be investigated. T. Taniguchi and collaborators report that methyl glycosides exhibit a characteristic VCD peak, the sign of which solely reflects the C-1 absolute configuration. This work is a theoretical contribution to study the behaviour of VCD spectrum's of the monosaccharides when the water molecules are taken explicitly. This study is focused on six different monosaccharides in theirs absolute configuration R and S. We used the method of density functional theory DFT by means of the B3LYP hybrid functional and 6-31G * basis set.

  2. Advanced Applications of Vibrational Circular Dichroism: from Small Chiral Molecules to Fibrils

    Science.gov (United States)

    Dukor, Rina K.

    2017-06-01

    Vibrational Circular Dichroism (VCD), first discovered in the early 1970s, and commercialized in the late 1990's, is finally coming of age! No longer a curiosity of the few selected academic groups, it is now used by all major pharmaceutical companies, regulatory agencies, government labs and academic institutions. The main application for the technology has been determination of absolute configuration of small pharmaceutical molecules. In more recent years, this has extended to more complicated molecules such as natural products with many chiral centers and conformational flexibility. Other applications include determination of enantiomeric purity, chiral polymers, and characterization of other biological molecules such as proteins, carohydrates and nucleic acids. One of the most fascinating discoveries in the VCD field has been been unusual enhancement in intensity for proteins that form fibrils. We have demonstrated sensitivity of VCD to in situ solution-phase probe of the process of fibrillogenesis and subsequent development that currently can only be studied in detail with dried samples by such techniques as scanning electron microscopy or atomic force microscopy. We have further shown that several different proteins, that in their native state have different secondary structures, have a very similar unique signature of mature fibrils. In this presentation, we will discuss fundamentals of VCD, demonstrate a few examples of different applications and showcase the sensitivity to structure of fibrils, including new results on micro-sampling.

  3. Cross section data for electron-impact inelastic processes of vibrationally excited molecules of hydrogen and its isotopes

    CERN Document Server

    Celiberto, R; Laricchiuta, A; Capitelli, M; Wadehra, J M; Atems, D E

    2001-01-01

    An extensive cross section database for the electron-impact inelastic processes of vibrationally excited molecules of hydrogen and its isotopes is presented. The following inelastic processes are covered: electronic excitation (dissociative and nondissociative), direct ionization (dissociative and nondissociative), excitation-radiative decay vibrational excitation and dissociation, and dissociative electron attachment. The data have been compiled partly from the literature and partly generated theoretically for the present report. The data are presented in graphical form. The data are also presented by sufficiently accurate analytic fit functions. Mass-scaling relations are provided for cross section evaluation of those isotope molecules for which calculated data are not available.

  4. Microencapsulation of a hydrophilic model molecule through vibration nozzle and emulsion phase inversion technologies.

    Science.gov (United States)

    Dorati, Rossella; Genta, Ida; Modena, Tiziana; Conti, Bice

    2013-01-01

    The goal of the present work was to evaluate and discuss vibration nozzle microencapsulation (VNM) technology combined to lyophilization, for the microencapsulation of a hydrophilic model molecule into a hydrophilic polymer. Fluorescein-loaded alginate microparticles prepared by VNM and emulsion phase inversion microencapsulation (EPIM) were lyophilized. Morphology, particle size distribution, lyophilized microspheres stability upon rehydration, drug loading and in vitro release were evaluated. Well-formed microspheres were obtained by the VNM technique, with higher yields of production (93.3-100%) and smaller particle size (d50138.10-158.00) than the EPIM microspheres. Rehydration upon lyophilization occurred in 30 min maintaining microsphere physical integrity. Fluorescein release was always faster from the microspheres obtained by VNM (364 h) than from those obtained by EPIM (504 h). The results suggest that VNM is a simple, easy to be scaled-up process suitable for the microencapsulation hydrophilic drugs.

  5. Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

    International Nuclear Information System (INIS)

    Marinov, Daniil; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine; Guerra, Vasco

    2013-01-01

    A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1–5 Torr and discharge currents ∼40–120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O 3 * , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O 3 * is strongly coupled with those of atomic oxygen and O 2 (a 1 Δ g ) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established. (paper)

  6. Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

    Science.gov (United States)

    Marinov, Daniil; Guerra, Vasco; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine

    2013-10-01

    A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1-5 Torr and discharge currents ˜40-120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O_3^{*} , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O_3^{*} is strongly coupled with those of atomic oxygen and O2(a 1Δg) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established.

  7. S-matrix analysis of vibrational and alignment effects in intense-field multiphoton ionization of molecules

    Energy Technology Data Exchange (ETDEWEB)

    Requate, A.

    2007-03-15

    Theoretical analysis of the vibrational excitation of small molecules during multiphoton ionization in intense laser fields of optical and infrared frequencies. Analysis of the alignment dependence of the electron impact ionization of diatomic molecules in the presence of an intense laser field as the final step in the process of Nonsequential Double Ionization. Quantum mechanical description using S-matrix theory in Strong Field Approximation (SFA), i.e. beyond perturbation theory. (orig.)

  8. Modeling Stretching Modes of Common Organic Molecules with the Quantum Mechanical Harmonic Oscillator: An Undergraduate Vibrational Spectroscopy Laboratory Exercise

    Science.gov (United States)

    Parnis, J. Mark; Thompson, Matthew G. K.

    2004-01-01

    An introductory undergraduate physical organic chemistry exercise that introduces the harmonic oscillator's use in vibrational spectroscopy is developed. The analysis and modeling exercise begins with the students calculating the stretching modes of common organic molecules with the help of the quantum mechanical harmonic oscillator (QMHO) model.

  9. Study by photoelectron spectroscopy of isotopic effects in various polyatomic molecules. Comparison between experimental and calculated vibrational transitions probabilities

    International Nuclear Information System (INIS)

    Carlier, J.; Botter, R.

    1978-01-01

    Isotopic substitution of polyatomic molecules shift the spectrum in photoelectron spectroscopy. This effect is easier to detect with substitution of hydrogen by deuterium than with heavier elements. Hydrogen partially or totally substituted in ethylene by deuterium is studied by photoelectron spectroscopy for frequency attribution and experimental results are compared with frequency ratio calculated by the Teller-Redlich rule. Vibrational transition probabilities are also determined with a good precision. Ionization potentials are higher for molecules with heavy isotopes but for partially substituted molecules a variation of symetry could shift slightly potential curves [fr

  10. When polarons meet polaritons: Exciton-vibration interactions in organic molecules strongly coupled to confined light fields

    Science.gov (United States)

    Wu, Ning; Feist, Johannes; Garcia-Vidal, Francisco J.

    2016-11-01

    We present a microscopic semianalytical theory for the description of organic molecules interacting strongly with a cavity mode. Exciton-vibration coupling within the molecule and exciton-cavity interaction are treated on an equal footing by employing a temperature-dependent variational approach. The interplay between strong exciton-vibration coupling and strong exciton-cavity coupling gives rise to a hybrid ground state, which we refer to as the lower polaron polariton. Explicit expressions for the ground-state wave function, the zero-temperature quasiparticle weight of the lower polaron polariton, the photoluminescence line strength, and the mean number of vibrational quanta are obtained in terms of the optimal variational parameters. The dependence of these quantities upon the exciton-cavity coupling strength reveals that strong cavity coupling leads to an enhanced vibrational dressing of the cavity mode, and at the same time a vibrational decoupling of the dark excitons, which in turn results in a lower polaron polariton resembling a single-mode dressed bare lower polariton in the strong-coupling regime. Thermal effects on several observables are briefly discussed.

  11. Deactivation of vibrationally excited nitrogen molecules by collision with nitrogen atoms

    Energy Technology Data Exchange (ETDEWEB)

    Lagana, A.; Garcia, E.; Ciccarelli, L.

    1987-01-15

    A classical trajector study of the title reaction has been carried out at T = 1000 K on a tentative LEPS surface. Reactivity was found to be small at low vibrational states and to increase exponentially at higher vibrational energies. Nonreactive collisions were found to strongly adiabatic, while no bias toward a given final vibrational state was shown by reactive processes.

  12. The effect of the condensed-phase environment on the vibrational frequency shift of a hydrogen molecule inside clathrate hydrates.

    Science.gov (United States)

    Powers, Anna; Scribano, Yohann; Lauvergnat, David; Mebe, Elsy; Benoit, David M; Bačić, Zlatko

    2018-04-14

    We report a theoretical study of the frequency shift (redshift) of the stretching fundamental transition of an H 2 molecule confined inside the small dodecahedral cage of the structure II clathrate hydrate and its dependence on the condensed-phase environment. In order to determine how much the hydrate water molecules beyond the confining small cage contribute to the vibrational frequency shift, quantum five-dimensional (5D) calculations of the coupled translation-rotation eigenstates are performed for H 2 in the v=0 and v=1 vibrational states inside spherical clathrate hydrate domains of increasing radius and a growing number of water molecules, ranging from 20 for the isolated small cage to over 1900. In these calculations, both H 2 and the water domains are treated as rigid. The 5D intermolecular potential energy surface (PES) of H 2 inside a hydrate domain is assumed to be pairwise additive. The H 2 -H 2 O pair interaction, represented by the 5D (rigid monomer) PES that depends on the vibrational state of H 2 , v=0 or v=1, is derived from the high-quality ab initio full-dimensional (9D) PES of the H 2 -H 2 O complex [P. Valiron et al., J. Chem. Phys. 129, 134306 (2008)]. The H 2 vibrational frequency shift calculated for the largest clathrate domain considered, which mimics the condensed-phase environment, is about 10% larger in magnitude than that obtained by taking into account only the small cage. The calculated splittings of the translational fundamental of H 2 change very little with the domain size, unlike the H 2 j = 1 rotational splittings that decrease significantly as the domain size increases. The changes in both the vibrational frequency shift and the j = 1 rotational splitting due to the condensed-phase effects arise predominantly from the H 2 O molecules in the first three complete hydration shells around H 2 .

  13. Theoretical investigation of force field and vibrational spectrum of BF3 molecule by MO LCAO SCF method

    International Nuclear Information System (INIS)

    Ozerova, V.M.; Solomonik, V.G.; Krasnov, K.S.

    1982-01-01

    Non-empirical calculations of equilibrium internuclear distances, force constants, frequencies of normal vibrations, isotope shifts and vibration intensities in IR spectrum of BF 3 molecule have been made by MO LCAO SCF method using three bases of grouped gauss functions: DZ (9s5p/4s2p), TZ(10s6p/5s3p) and TZ+P (10s6p1d/5s3p1d). All the three bases lead to the results which are in good agreement with the experimental data. For instance, theoretical values of vibration frequencies differ from the experimental ones by average 3.2; 2.4 and 7.0% in the bases DZ, TZ and TZ+P respectively

  14. Dissociative electron attachment to vibrationally excited H2 molecules involving the 2Σg+ resonant Rydberg electronic state

    International Nuclear Information System (INIS)

    Celiberto, R.; Janev, R.K.; Wadehra, J.M.; Tennyson, J.

    2012-01-01

    Graphical abstract: Dissociative electron attachment cross sections as a function of the incident electron energy and for the initial vibration levels v i = 0–5, 10 of the H 2 molecule. Highlights: ► We calculated electron–hydrogen dissociative attachment cross sections and rates coefficients. ► Collision processes occurring through a resonant Rydberg state are considered. ► Cross sections and rates were obtained for vibrationally excited hydrogen molecules. ► The cross sections exhibit pronounced oscillatory structures. ► A comparison with the process involving the electron–hydrogen resonant ground state is discussed. - Abstract: Dissociative electron attachment cross sections (DEA) on vibrationally excited H 2 molecule taking place via the 2 Σ g + Rydberg-excited resonant state are studied using the local complex potential (LCP) model for resonant collisions. The cross sections are calculated for all initial vibrational levels (v i = 0–14) of the neutral molecule. In contrast to the previously noted dramatic increase in the DEA cross sections with increasing v i , when the process proceeds via the X 2 Σ u + shape resonance of H 2 , for the 2 Σ g + Rydberg resonance the cross sections increase only gradually up to v i = 3 and then decrease. Moreover, the cross sections for v i ⩾ 6 exhibit pronounced oscillatory structures. A discussion of the origin of the observed behavior of calculated cross sections is given. The DEA rate coefficients for all v i levels are also calculated in the 0.5–1000 eV temperature range.

  15. Systematic studies of molecular vibrational anharmonicity and vibration-rotation interaction by self-consistent-field higher derivative methods: Applications to asymmetric and symmetric top and linear polyatomic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Clabo, D.A. Jr.

    1987-04-01

    Inclusion of the anharmonicity normal mode vibrations (i.e., the third and fourth (and higher) derivatives of a molecular Born-Oppenheimer potential energy surface) is necessary in order to theoretically reproduce experimental fundamental vibrational frequencies of a molecule. Although ab initio determinations of harmonic vibrational frequencies may give errors of only a few percent by the inclusion of electron correlation within a large basis set for small molecules, in general, molecular fundamental vibrational frequencies are more often available from high resolution vibration-rotation spectra. Recently developed analytic third derivatives methods for self-consistent-field (SCF) wavefunctions have made it possible to examine with previously unavailable accuracy and computational efficiency the anharmonic force fields of small molecules.

  16. Systematic studies of molecular vibrational anharmonicity and vibration-rotation interaction by self-consistent-field higher derivative methods: Applications to asymmetric and symmetric top and linear polyatomic molecules

    International Nuclear Information System (INIS)

    Clabo, D.A. Jr.

    1987-04-01

    Inclusion of the anharmonicity normal mode vibrations [i.e., the third and fourth (and higher) derivatives of a molecular Born-Oppenheimer potential energy surface] is necessary in order to theoretically reproduce experimental fundamental vibrational frequencies of a molecule. Although ab initio determinations of harmonic vibrational frequencies may give errors of only a few percent by the inclusion of electron correlation within a large basis set for small molecules, in general, molecular fundamental vibrational frequencies are more often available from high resolution vibration-rotation spectra. Recently developed analytic third derivatives methods for self-consistent-field (SCF) wavefunctions have made it possible to examine with previously unavailable accuracy and computational efficiency the anharmonic force fields of small molecules

  17. Vibrationally quantum-state-specific dynamics of the reactions of CN radicals with organic molecules in solution

    Science.gov (United States)

    Rose, Rebecca A.; Greaves, Stuart J.; Oliver, Thomas A. A.; Clark, Ian P.; Greetham, Gregory M.; Parker, Anthony W.; Towrie, Michael; Orr-Ewing, Andrew J.

    2011-06-01

    The dynamics of reactions of CN radicals with cyclohexane, d12-cyclohexane, and tetramethylsilane have been studied in solutions of chloroform, dichloromethane, and the deuterated variants of these solvents using ultraviolet photolysis of ICN to initiate a reaction. The H(D)-atom abstraction reactions produce HCN (DCN) that is probed in absorption with sub-picosecond time resolution using ˜500 cm-1 bandwidth infrared (IR) pulses in the spectral regions corresponding to C-H (or C-D) and C≡N stretching mode fundamental and hot bands. Equivalent IR spectra were obtained for the reactions of CN radicals with the pure solvents. In all cases, the reaction products are formed at early times with a strong propensity for vibrational excitation of the C-H (or C-D) stretching (v3) and H-C-N (D-C-N) bending (v2) modes, and for DCN products there is also evidence of vibrational excitation of the v1 mode, which involves stretching of the C≡N bond. The vibrationally excited products relax to the ground vibrational level of HCN (DCN) with time constants of ˜130-270 ps (depending on molecule and solvent), and the majority of the HCN (DCN) in this ground level is formed by vibrational relaxation, instead of directly from the chemical reaction. The time-dependence of reactive production of HCN (DCN) and vibrational relaxation is analysed using a vibrationally quantum-state specific kinetic model. The experimental outcomes are indicative of dynamics of exothermic reactions over an energy surface with an early transition state. Although the presence of the chlorinated solvent may reduce the extent of vibrational excitation of the nascent products, the early-time chemical reaction dynamics in these liquid solvents are deduced to be very similar to those for isolated collisions in the gas phase. The transient IR spectra show additional spectroscopic absorption features centered at 2037 cm-1 and 2065 cm-1 (in CHCl3) that are assigned, respectively, to CN-solvent complexes and

  18. Expansion Hamiltonian model for a diatomic molecule adsorbed on a surface: Vibrational states of the CO/Cu(100) system including surface vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Qingyong, E-mail: mengqingyong@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian (China); Meyer, Hans-Dieter, E-mail: hans-dieter.meyer@pci.uni-heidelberg.de [Theoretische Chemie, Physikalisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)

    2015-10-28

    Molecular-surface studies are often done by assuming a corrugated, static (i.e., rigid) surface. To be able to investigate the effects that vibrations of surface atoms may have on spectra and cross sections, an expansion Hamiltonian model is proposed on the basis of the recently reported [R. Marquardt et al., J. Chem. Phys. 132, 074108 (2010)] SAP potential energy surface (PES), which was built for the CO/Cu(100) system with a rigid surface. In contrast to other molecule-surface coupling models, such as the modified surface oscillator model, the coupling between the adsorbed molecule and the surface atoms is already included in the present expansion SAP-PES model, in which a Taylor expansion around the equilibrium positions of the surface atoms is performed. To test the quality of the Taylor expansion, a direct model, that is avoiding the expansion, is also studied. The latter, however, requests that there is only one movable surface atom included. On the basis of the present expansion and direct models, the effects of a moving top copper atom (the one to which CO is bound) on the energy levels of a bound CO/Cu(100) system are studied. For this purpose, the multiconfiguration time-dependent Hartree calculations are carried out to obtain the vibrational fundamentals and overtones of the CO/Cu(100) system including a movable top copper atom. In order to interpret the results, a simple model consisting of two coupled harmonic oscillators is introduced. From these calculations, the vibrational levels of the CO/Cu(100) system as function of the frequency of the top copper atom are discussed.

  19. Vibrational Relaxation of Ground-State Oxygen Molecules With Atomic Oxygen and Carbon Dioxide

    Science.gov (United States)

    Saran, D. V.; Pejakovic, D. A.; Copeland, R. A.

    2008-12-01

    Vertical water vapor profiles are key to understanding the composition and energy budget in the mesosphere and lower thermosphere (MLT). The SABER instrument onboard NASA's TIMED satellite measures such profiles by detecting H2O(ν2) emission in the 6.8 μm region. Collisional deactivation of vibrationally excited O2, O2(X3Σ-g, υ = 1) + H2O ↔ O2(X3Σ-g, υ = 0) + H2O(ν2), is an important source of H2O(ν2). A recent study has identified two other processes involving excited O2 that control H2O(ν2) population in the MLT: (1) the vibrational-translational (V-T) relaxation of O2(X3Σ-g, υ = 1) level by atomic oxygen and (2) the V-V exchange between CO2 and excited O2 molecules [1]. Over the past few years SRI researchers have measured the atomic oxygen removal process mentioned above at room temperature [2] and 240 K [3]. These measurements have been incorporated into the models for H2O(ν2) emission [1]. Here we report laboratory studies of the collisional removal of O2(X3Σ-g, υ = 1) by O(3P) at room temperature and below, reaching temperatures relevant to mesopause and polar summer MLT (~150 K). Instead of directly detecting the O2(X3Σ-g, υ = 1) population, a technically simpler approach is used in which the υ = 1 level of the O2(a1Δg) state is monitored. A two-laser method is employed, in which the pulsed output of the first laser near 285 nm photodissociates ozone to produce atomic oxygen and O2(a1Δg, υ = 1), and the pulsed output of the second laser detects O2(a1Δg, υ = 1) via resonance-enhanced multiphoton ionization. With ground-state O2 present, owing to the rapid equilibration of the O2(X3Σ-g, υ = 1) and O2(a1Δg, υ = 1) populations via the processes O2(a1Δg, υ = 1) + O2(X3Σ-g, υ = 0) ↔ O2(a1Δg, υ = 0) + O2(X3Σ-g, υ = 1), the information on the O2(X3Σ-g, υ = 1) kinetics is extracted from the O2(a1Δg, υ = 1) temporal evolution. In addition, measurements of the removal of O2(X3Σ-g, υ = 1) by CO2 at room temperature will also

  20. Large Amplitude Motions in Polyatomic Molecule Spectra: Intramolecular Vibrational Redistribution and Isomerization

    National Research Council Canada - National Science Library

    Field, Robert

    1997-01-01

    Through Stimulated Emission Pumping (SEP) studies of highly excited vibrational levels of the electronic ground state of HCP, the spectroscopic signatures of bond breaking isomer/atom (HCP right arrow HPC...

  1. Structural and vibrational study of a neurotransmitter molecule: Dopamine [4-(2-aminoethyl) benzene-1,2-diol

    Science.gov (United States)

    Jha, Omkant; Yadav, T. K.; Yadav, R. A.

    2018-01-01

    Structural and vibrational studies for the most stable conformer of dopamine {4-(2-Aminoethyl) benzene-1, 2-diol} have been carried out at the DFT/B3LYP/6-311 ++G** level using the Gaussian 09 software. The IR and Raman spectra have been recorded and analyzed in light of the computed vibrational parameters using the DFT and the PEDs computed with the help of the GAR2PED software. Some of the fundamentals have considerably changed frequencies in going from benzene to dopamine. Except the rocking and wagging modes of the NH2 group the other four modes are pure group modes. The rocking and wagging modes of the NH2 group show mixing with the other modes. The two Osbnd H stretching vibrations are highly localized modes. The Kekule phenyl ring stretching mode is found to remain almost unchanged. The HOMO-LUMO study suggests the existence of charge transfer within the molecule and the energy gap supports the pharmacological active property of the dopamine molecule. The NBO analysis has been carried out to understand the proper and improper hydrogen bonding.

  2. Vibrational states of nano-confined water molecules in beryl investigated by first-principles calculations and optical experiments.

    Science.gov (United States)

    Belyanchikov, M A; Zhukova, E S; Tretiak, S; Zhugayevych, A; Dressel, M; Uhlig, F; Smiatek, J; Fyta, M; Thomas, V G; Gorshunov, B P

    2017-11-22

    Using quantum mechanical calculations within density functional theory, we provide a comprehensive analysis of infrared-active excitation of water molecules confined in nanocages of a beryl crystal lattice. We calculate infrared-active modes including the translational, librational, and mixed-type resonances of regular and heavy water molecules. The results are compared to the experimental spectra measured for the two principal polarizations of the electric field: parallel and perpendicular to the crystallographic c-axis. Good agreement is achieved between calculated and measured isotopic shifts of the normal modes. We analyze the vibrational modes in connection with the structural characteristics and arrangements of water molecules within the beryl crystal. Specific atomic displacements are assigned to each experimentally detected vibrational mode resolving the properties of nano-confined water on scales not accessible by experiments. Our results elucidate the applicability and efficiency of a combined experimental and computational approach for describing and an in-depth understanding of nano-confined water, and pave the way for future studies of more complex systems.

  3. Do vibrationally excited OH molecules affect middle and upper atmospheric chemistry?

    Directory of Open Access Journals (Sweden)

    T. von Clarmann

    2010-10-01

    Full Text Available Except for a few reactions involving electronically excited molecular or atomic oxygen or nitrogen, atmospheric chemistry modelling usually assumes that the temperature dependence of reaction rates is characterized by Arrhenius' law involving kinetic temperatures. It is known, however, that in the upper atmosphere the vibrational temperatures may exceed the kinetic temperatures by several hundreds of Kelvins. This excess energy has an impact on the reaction rates. We have used upper atmospheric OH populations and reaction rate coefficients for OH(v=0...9+O3 and OH(v=0...9+O to estimate the effective (i.e. population weighted reaction rates for various atmospheric conditions. We have found that the effective rate coefficient for OH(v=0...9+O3 can be larger by a factor of up to 1470 than that involving OH in its vibrational ground state only. At altitudes where vibrationally excited states of OH are highly populated, the OH reaction is a minor sink of Ox and O3 compared to other reactions involving, e.g., atomic oxygen. Thus the impact of vibrationally excited OH on the ozone or Ox sink remains small. Among quiescent atmospheres under investigation, the largest while still small (less than 0.1% effect was found for the polar winter upper stratosphere and mesosphere. The contribution of the reaction of vibrationally excited OH with ozone to the OH sink is largest in the upper polar winter stratosphere (up to 4%, while its effect on the HO2 source is larger in the lower thermosphere (up to 1.5% for polar winter and 2.5% for midlatitude night conditions. For OH(v=0...9+O the effective rate coefficients are lower by up to 11% than those involving OH in its vibrational ground state. The effects on the odd oxygen sink are negative and can reach −3% (midlatitudinal nighttime lowermost thermosphere, i.e. neglecting vibrational excitation overestimates the odd

  4. Zero-point vibrational corrections to isotropic hyperfine coupling constants in polyatomic molecules.

    Science.gov (United States)

    Chen, Xing; Rinkevicius, Zilvinas; Cao, Zexing; Ruud, Kenneth; Agren, Hans

    2011-01-14

    The present work addresses isotropic hyperfine coupling constants in polyatomic systems with a particular emphasis on a largely neglected, but a posteriori significant, effect, namely zero-point vibrational corrections. Using the density functional restricted-unrestricted approach, the zero-point vibrational corrections are evaluated for the allyl radical and four of its derivatives. In addition for establishing the numerical size of the zero-point vibrational corrections to the isotropic hyperfine coupling constants, we present simple guidelines useful for identifying hydrogens for which such corrections are significant. Based on our findings, we critically re-examine the computational procedures used for the determination of hyperfine coupling constants in general as well as the practice of using experimental hyperfine coupling constants as reference data when benchmarking and optimizing exchange-correlation functionals and basis sets for such calculations.

  5. Enhanced vibrational solvatochromism and spectral diffusion by electron rich substituents on small molecule silanes

    Science.gov (United States)

    Olson, Courtney M.; Grofe, Adam; Huber, Christopher J.; Spector, Ivan C.; Gao, Jiali; Massari, Aaron M.

    2017-09-01

    Fourier transform infrared and two-dimensional IR (2D-IR) spectroscopies were applied to two different silanes in three different solvents. The selected solutes exhibit different degrees of vibrational solvatochromism for the Si-H vibration. Density functional theory calculations confirm that this difference in sensitivity is the result of higher mode polarization with more electron withdrawing ligands. This mode sensitivity also affects the extent of spectral diffusion experienced by the silane vibration, offering a potential route to simultaneously optimize the sensitivity of vibrational probes in both steady-state and time-resolved measurements. Frequency-frequency correlation functions obtained by 2D-IR show that both solutes experience dynamics on similar time scales and are consistent with a picture in which weakly interacting solvents produce faster, more homogeneous fluctuations. Molecular dynamics simulations confirm that the frequency-frequency correlation function obtained by 2D-IR is sensitive to the presence of hydrogen bonding dynamics in the surrounding solvation shell.

  6. Vibrational relaxation of trapped molecules in solid matrices: OH(A 2Sigma+; v = 1)/Ar.

    Science.gov (United States)

    Ree, J; Kim, Y H; Shin, H K

    2009-01-07

    The vibrational relaxation of OH(A (2)Sigma(+);v=1) embedded in solid Ar has been studied over 4-80 K. The interaction model is based on OH undergoing local motions in a cage formed by a face-centered cubic stacking where the first shell atoms surround the guest and connect it to the heat bath through 12 ten-atom chains. The motions confined to the cage are the local translation and libration-rotation of OH and internal vibrations in OH...Ar, their energies being close to or a few times the energies of nearby first shell and chain atoms. The cage dynamics are studied by solving the equations of motion for the interaction between OH and first shell atoms, while energy propagation to the bulk phase through lattice chains is treated in the Langevin dynamics. Calculated energy transfer data are used in semiclassical procedure to obtain rate constants. In the early stage of interaction, OH transfers its energy to libration-rotation intramolecularily and then to the vibrations of the first shell and chain atoms on the time scale of several picoseconds. Libration-to-rotational transitions dispense the vibrational energy in small packages comparable to the lattice frequencies for ready flow. Energy propagation from the chains to the heat bath takes place on a long time scale of 10 ns or longer. Over the solid argon temperature range, the rate constant is on the order of 10(6) s(-1) and varies weakly with temperature.

  7. Rate coefficients for reactive elementary processes involving atoms and vibrationally excited molecules

    International Nuclear Information System (INIS)

    Lagana, A.; Ochoa de Aspuru, G.; Riganelli, A.; Garcia, E.

    1996-01-01

    To investigate reactions of atoms with simple molecules with new computation approaches and applying consolidated efficient numerical procedures to the calculation of experimental observables under a wide range of operating conditions were developed. A first family of reactions investigated using the described techniques and computational procedures are those of the nitrogen atom with some diatomic molecules (N 2 and O 2 ) as well as oxygen atom reactions with O 2 and HCl molecules

  8. Vibrational energy transfer in selectively excited diatomic molecules. [Relaxation rates, self-relaxation, upper limits

    Energy Technology Data Exchange (ETDEWEB)

    Dasch, C.J.

    1978-09-01

    Single rovibrational states of HCl(v=2), HBr(v=2), DCl(v=2), and CO(v=2) were excited with a pulsed optical parametric oscillator (OPO). Total vibrational relaxation rates near - resonance quenchers were measured at 295/sup 0/K using time resolved infrared fluorescence. These rates are attributed primarily to V - V energy transfer, and they generally conform to a simple energy gap law. A small deviation was found for the CO(v) + DCl(v') relaxation rates. Upper limits for the self relaxation by V - R,T of HCl(v=2) and HBr(v=2) and for the two quantum exchange between HCl and HBr were determined. The HF dimer was detected at 295/sup 0/K and 30 torr HF pressure with an optoacoustic spectrometer using the OPO. Pulsed and chopped, resonant and non-resonant spectrophones are analyzed in detail. From experiments and first order perturbation theory, these V - V exchange rates appear to behave as a first order perturbation in the vibrational coordinates. The rotational dynamics are known to be complicated however, and the coupled rotational - vibrational dynamics were investigated theoreticaly in infinite order by the Dillon and Stephenson and the first Magnus approximations. Large ..delta..J transitions appear to be important, but these calculations differ by orders of magnitude on specific rovibrational transition rates. Integration of the time dependent semiclassical equations by a modified Gordon method and a rotationally distorted wave approximation are discussed as methods which would treat the rotational motion more accurately. 225 references.

  9. Quantum control of molecular vibrational and rotational excitations in a homonuclear diatomic molecule: A full three-dimensional treatment with polarization forces

    Science.gov (United States)

    Ren, Qinghua; Balint-Kurti, Gabriel G.; Manby, Frederick R.; Artamonov, Maxim; Ho, Tak-San; Rabitz, Herschel

    2006-01-01

    The optimal control of the vibrational excitation of the hydrogen molecule [Balint-Kurti et al., J. Chem. Phys. 122, 084110 (2005)] utilizing polarization forces is extended to three dimensions. The polarizability of the molecule, to first and higher orders, is accounted for using explicit ab initio calculations of the molecular electronic energy in the presence of an electric field. Optimal control theory is then used to design infrared laser pulses that selectively excite the molecule to preselected vibrational-rotational states. The amplitude of the electric field of the optimized pulses is restricted so that there is no significant ionization during the process, and a new frequency sifting method is used to simplify the frequency spectrum of the pulse. The frequency spectra of the optimized laser pulses for processes involving rotational excitation are more complex than those relating to processes involving only vibrational excitation.

  10. Ab Initio Model for Vibrational Excitation of Polar Molecules by Low-Energy Electrons

    Science.gov (United States)

    Vanroose, W. I.; Rescigno, T. N.; McCurdy, C. W.

    2003-05-01

    Vibrational excitation of the hydrogen halides by electron impact has been a subject of continued interest ever since the first observations of pronounced threshold peaks in the cross sections by Rohr and Linder twenty five years ago. Two semi-empirical models have been developed to explain these features, one a virtual state model by Gauyacq and Herzenberg based on effective-range theory, the other by Domcke and co-workers based on a non-local Feshbach resonance model. We will show that a non-empirical model can be formulated which captures the essential features of the observed cross sections. The only parameters needed to implement the calculations are the potential energy curve of the negative ion in the region where it is bound, the potential curve of the neutral target and its R-dependent dipole moment. We use an effective range theory for the nuclear dynamics, which can be implemented without an expansion in target vibrational states, instead of non-local equations derived from Feshbach partitioning. Another new element is the use of a dipole coupled partial-wave model to predict the analytic continuation of the negative ion potential curve into the continuum. We will illustrate the new model with results for electron-HCl scattering.

  11. Rate coefficients for reactive elementary processes involving atoms and vibrationally excited molecules

    International Nuclear Information System (INIS)

    Lagana, A.

    1996-01-01

    To investigate reactions of atoms with simple molecules wa are both developing new computational approaches and applying consolidated efficient numerical procedures to the calculation of experimental observables under a wide range of operating conditions. Our work on the design of new theoretical and computational approaches to the accurate three dimensional calculation of reactive properties from first principles is based upon the use of the hyperspherical formalism. On the contrary, our work on the design of efficient parallel codes dealing with quantum reduced dimensionality techniques is based upon the use of Jacobi coordinates. The trajectory code makes use of position vectors with respect to the center of mass of the system. (author)

  12. A variable-temperature scanning tunneling microscope capable of single-molecule vibrational spectroscopy

    International Nuclear Information System (INIS)

    Stipe, B.C.; Rezaei, M.A.; Ho, W.

    1999-01-01

    The design and performance of a variable-temperature scanning tunneling microscope (STM) is presented. The microscope operates from 8 to 350 K in ultrahigh vacuum. The thermally compensated STM is suspended by springs from the cold tip of a continuous flow cryostat and is completely surrounded by two radiation shields. The design allows for in situ dosing and irradiation of the sample as well as for the exchange of samples and STM tips. With the STM feedback loop off, the drift of the tip-sample spacing is approximately 0.001 Angstrom/min at 8 K. It is demonstrated that the STM is well-suited for the study of atomic-scale chemistry over a wide temperature range, for atomic-scale manipulation, and for single-molecule inelastic electron tunneling spectroscopy (IETS). copyright 1999 American Institute of Physics

  13. Electronic structure of the BaO molecule with dipole moments and ro-vibrational calculations

    Science.gov (United States)

    Khatib, Mohamed; Korek, Mahmoud

    2018-03-01

    The twenty-three low-lying electronic states (singlet and triplet) of the BaO molecule have been studied by using an ab initio method. These electronic states have been investigated by using the Complete Active Apace Self-Consistent Field (CASSCF) followed by multi-reference configuration interaction (MRCI + Q) with Davidson correction. The potential energy curves, the internuclear distance Re, the harmonic frequency ωe, the rotational constant Be, the electronic energy with respect to the ground state Te and the static and transition dipole moment have been investigated. The Einstein spontaneous and induced emission coefficients A21 and B21ω as well as the spontaneous radiative lifetime τspon, emission wavelength λ21 and oscillator strength f21 have been calculated by using the transition dipole moment between some doublet electronic states. The calculation of the eigenvalues Ev, the rotational constant Bv, the centrifugal distortion constant Dv, and the abscissas of the turning points Rmin and Rmax have been done by using the canonical functions approach. A very good agreement is shown by comparing the values of our work to those found in the literature for many electronic states. Eighteen new electronic states have been studied here for the first time.

  14. Vibrational relaxation dynamics of SD molecules in As{sub 2}S{sub 3}: Observation of an anomalous isotope effect

    Energy Technology Data Exchange (ETDEWEB)

    Engholm, J.R.; Happek, U. [Univ. of Georgia, Athens, GA (United States); Rella, C.W. [Stanford Univ., CA (United States)] [and others

    1995-12-31

    It is generally assumed that the vibrational relaxation of molecular impurities in crystals and glasses mainly depends on the order of the decay process, with lower order processes leading to more rapid relaxation (a behavior that is known under the term {open_quotes}gap-law{close_quotes}). Here we present measurements that contradict this assumption. Using high intensity psec pulses of the Stanford FEL we measured the relaxation rate of the SD vibrational stretch mode (at a frequency of 1800 cm) by applying a pump-probe technique. We find relaxation rates on the order of 2x10{sup 9} sec{sup -1}, which are a factor of 2 lower than those found for the isotope molecule SH (at a frequency of about 2500 cm{sup - 1}) in the same host{sup 1}. We recall that the relaxation of the SD vibrational stretch mode is controlled by a lower order process as compared to the SH molecule, which is due to the smaller number of host vibrational quanta to match the energy of the stretch mode; a fact we have confirmed experimentally by temperature dependent relaxation measurements. Thus our remits are in marked contrast to the so-called {open_quotes}Gap-Law{close_quotes} and emphasize the importance of the molecule - host coupling in the relaxation dynamics.

  15. Numerical tests of a fixed vibrational basis/gaussian bath theory for small molecule dynamics in low-temperature media.

    Science.gov (United States)

    Chapman, Craig T; Cheng, Xiaolu; Cina, Jeffrey A

    2011-04-28

    A recently framed quantum/semiclassical treatment for the internal nuclear dynamics of a small molecule and the induced small-amplitude coherent motion of a low-temperature host medium (Chapman, C. T.; Cina, J. A. J. Chem. Phys.2007,127, 114502) is further analyzed and subjected to initial tests of its numerical implementation. In the illustrative context of a 1D system interacting with a 1D medium, we rederive the fixed vibrational basis/gaussian bath (FVB/GB) equations of motion for the parameters defining the gaussian bath wave packet accompanying each of the energy eigenkets of the quantum mechanical system. The conditions of validity for the gaussian-bath approximation are shown to coincide with those supporting approximate population conservation. We perform initial numerical tests of the FVB/GB scheme and illustrate the semiclassical description it provides of coherent motion in the medium by comparing its predictions with the exact results for a high-frequency system harmonic oscillator bilinearly coupled to a lower-frequency bath oscillator. Linear vibronic absorption spectra or, equivalently, ultrafast wave packet interferometry signals are shown to be readily and accurately calculable within the FVB/GB framework.

  16. Nodeless vibrational amplitudes and quantum nonadiabatic dynamics in the nested funnel for a pseudo Jahn-Teller molecule or homodimer

    Science.gov (United States)

    Peters, William K.; Tiwari, Vivek; Jonas, David M.

    2017-11-01

    The nonadiabatic states and dynamics are investigated for a linear vibronic coupling Hamiltonian with a static electronic splitting and weak off-diagonal Jahn-Teller coupling through a single vibration with a vibrational-electronic resonance. With a transformation of the electronic basis, this Hamiltonian is also applicable to the anti-correlated vibration in a symmetric homodimer with marginally strong constant off-diagonal coupling, where the non-adiabatic states and dynamics model electronic excitation energy transfer or self-exchange electron transfer. For parameters modeling a free-base naphthalocyanine, the nonadiabatic couplings are deeply quantum mechanical and depend on wavepacket width; scalar couplings are as important as the derivative couplings that are usually interpreted to depend on vibrational velocity in semiclassical curve crossing or surface hopping theories. A colored visualization scheme that fully characterizes the non-adiabatic states using the exact factorization is developed. The nonadiabatic states in this nested funnel have nodeless vibrational factors with strongly avoided zeroes in their vibrational probability densities. Vibronic dynamics are visualized through the vibrational coordinate dependent density of the time-dependent dipole moment in free induction decay. Vibrational motion is amplified by the nonadiabatic couplings, with asymmetric and anisotropic motions that depend upon the excitation polarization in the molecular frame and can be reversed by a change in polarization. This generates a vibrational quantum beat anisotropy in excess of 2/5. The amplitude of vibrational motion can be larger than that on the uncoupled potentials, and the electronic population transfer is maximized within one vibrational period. Most of these dynamics are missed by the adiabatic approximation, and some electronic and vibrational motions are completely suppressed by the Condon approximation of a coordinate-independent transition dipole between

  17. Full-dimensional vibrational calculations of five-atom molecules using a combination of Radau and Jacobi coordinates: Applications to methane and fluoromethane

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhiqiang; Chen, Jun [State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Zhaojun, E-mail: zhangzhj@dicp.ac.cn; Zhang, Dong H., E-mail: zhangdh@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Lauvergnat, David, E-mail: David.Lauvergnat@u-psud.fr [CNRS, Laboratoire de Chimie Physique (UMR 8000), Université Paris-Sud, F-91405 Orsay (France); Gatti, Fabien, E-mail: gatti@univ-montp2.fr [CTMM, Institut Charles Gerhardt (UMR 5253), CC 1501, Université Montpellier, F-34095 Montpellier, Cedex 05 (France)

    2016-05-28

    Full quantum mechanical calculations of vibrational energies of methane and fluoromethane are carried out using a polyspherical description combining Radau and Jacobi coordinates. The Hamiltonian is built in a potential-optimized discrete variable representation, and vibrational energies are solved using an iterative eigensolver. This new approach can be applied to a large variety of molecules. In particular, we show that it is able to accurately and efficiently compute eigenstates for four different molecules : CH{sub 4}, CHD{sub 3}, CH{sub 2}D{sub 2}, and CH{sub 3}F. Very good agreement is obtained with the results reported previously in the literature with different approaches and with experimental data.

  18. DCMB that combines divide-and-conquer and mixed-basis set methods for accurate geometry optimizations, total energies, and vibrational frequencies of large molecules.

    Science.gov (United States)

    Wu, Anan; Xu, Xin

    2012-06-15

    We present a method, named DCMB, for the calculations of large molecules. It is a combination of a parallel divide-and-conquer (DC) method and a mixed-basis (MB) set scheme. In this approach, atomic forces, total energy and vibrational frequencies are obtained from a series of MB calculations, which are derived from the target system utilizing the DC concept. Unlike the fragmentation based methods, all DCMB calculations are performed over the whole target system and no artificial caps are introduced so that it is particularly useful for charged and/or delocalized systems. By comparing the DCMB results with those from the conventional method, we demonstrate that DCMB is capable of providing accurate prediction of molecular geometries, total energies, and vibrational frequencies of molecules of general interest. We also demonstrate that the high efficiency of the parallel DCMB code holds the promise for a routine geometry optimization of large complex systems. Copyright © 2012 Wiley Periodicals, Inc.

  19. Dissociative electron attachment to vibrationally excited H{sub 2} molecules involving the {sup 2}{Sigma}{sub g}{sup +} resonant Rydberg electronic state

    Energy Technology Data Exchange (ETDEWEB)

    Celiberto, R., E-mail: r.celiberto@poliba.it [Department of Water Engineering and Chemistry, Polytechnic of Bari, 70125 Bari (Italy); Institute of Inorganic Methodologies and Plasmas, CNR, 70125 Bari (Italy); Janev, R.K., E-mail: r.janev@fz-juelich.de [Macedonian Academy of Sciences and Arts, P.O.B 428, 1000 Skopje (Macedonia, The Former Yugoslav Republic of); Institute of Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH Association EURATOM-FZJ, Partner in Trilateral Euregio Cluster, 52425 Juelich (Germany); Wadehra, J.M., E-mail: wadehra@wayne.edu [Physics Department, Wayne State University, Detroit, MI 48202 (United States); Tennyson, J., E-mail: j.tennyson@ucl.ac.uk [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2012-04-04

    Graphical abstract: Dissociative electron attachment cross sections as a function of the incident electron energy and for the initial vibration levels v{sub i} = 0-5, 10 of the H{sub 2} molecule. Highlights: Black-Right-Pointing-Pointer We calculated electron-hydrogen dissociative attachment cross sections and rates coefficients. Black-Right-Pointing-Pointer Collision processes occurring through a resonant Rydberg state are considered. Black-Right-Pointing-Pointer Cross sections and rates were obtained for vibrationally excited hydrogen molecules. Black-Right-Pointing-Pointer The cross sections exhibit pronounced oscillatory structures. Black-Right-Pointing-Pointer A comparison with the process involving the electron-hydrogen resonant ground state is discussed. - Abstract: Dissociative electron attachment cross sections (DEA) on vibrationally excited H{sub 2} molecule taking place via the {sup 2}{Sigma}{sub g}{sup +} Rydberg-excited resonant state are studied using the local complex potential (LCP) model for resonant collisions. The cross sections are calculated for all initial vibrational levels (v{sub i} = 0-14) of the neutral molecule. In contrast to the previously noted dramatic increase in the DEA cross sections with increasing v{sub i}, when the process proceeds via the X {sup 2}{Sigma}{sub u}{sup +} shape resonance of H{sub 2}, for the {sup 2}{Sigma}{sub g}{sup +} Rydberg resonance the cross sections increase only gradually up to v{sub i} = 3 and then decrease. Moreover, the cross sections for v{sub i} Greater-Than-Or-Slanted-Equal-To 6 exhibit pronounced oscillatory structures. A discussion of the origin of the observed behavior of calculated cross sections is given. The DEA rate coefficients for all v{sub i} levels are also calculated in the 0.5-1000 eV temperature range.

  20. Symbolic derivation of high-order Rayleigh-Schroedinger perturbation energies using computer algebra: Application to vibrational-rotational analysis of diatomic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, John M. [Kansas State Univ., Manhattan, KS (United States). Dept. of Chemistry

    1997-01-01

    Rayleigh-Schroedinger perturbation theory is an effective and popular tool for describing low-lying vibrational and rotational states of molecules. This method, in conjunction with ab initio techniques for computation of electronic potential energy surfaces, can be used to calculate first-principles molecular vibrational-rotational energies to successive orders of approximation. Because of mathematical complexities, however, such perturbation calculations are rarely extended beyond the second order of approximation, although recent work by Herbert has provided a formula for the nth-order energy correction. This report extends that work and furnishes the remaining theoretical details (including a general formula for the Rayleigh-Schroedinger expansion coefficients) necessary for calculation of energy corrections to arbitrary order. The commercial computer algebra software Mathematica is employed to perform the prohibitively tedious symbolic manipulations necessary for derivation of generalized energy formulae in terms of universal constants, molecular constants, and quantum numbers. As a pedagogical example, a Hamiltonian operator tailored specifically to diatomic molecules is derived, and the perturbation formulae obtained from this Hamiltonian are evaluated for a number of such molecules. This work provides a foundation for future analyses of polyatomic molecules, since it demonstrates that arbitrary-order perturbation theory can successfully be applied with the aid of commercially available computer algebra software.

  1. Rate coefficients for dissociative attachment and resonant electron-impact dissociation involving vibrationally excited O{sub 2} molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laporta, V. [Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari, Italy and Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Celiberto, R. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica, Politecnico di Bari, Italy and Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari (Italy); Tennyson, J. [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2014-12-09

    Rate coefficients for dissociative electron attachment and electron-impact dissociation processes, involving vibrationally excited molecular oxygen, are presented. Analytical fits of the calculated numerical data, useful in the applications, are also provided.

  2. Vibrational analysis of pyramidal XY3-type molecules based on high-level ab initio potential energy surfaces: application to NH3

    Science.gov (United States)

    Lin, H.; Thiel, W.; Yurchenko, S. N.; Carvajal, M.; Jensen, P.

    Variational calculations of the vibrational energies of the non-rigid and semirigid XY3 molecules, as ammonia and phosphine respectively, have been carried out [1,2]. In the procedure used is emphasized the umbrella motion due to the corresponding coordinate, for pyramidal non-rigid XY3 molecules, is the responsible of the torsional tunneling between different minima of the Potential Energy Surfaces. For the NH3 analytical potential energy surfaces were constructed from CCSD(T)/aug-cc-pVTZ ab initio data augmented by the results obtained by extrapolating CCSD(T)/aug-cc-pVXZ (X=T,Q,5) results to the complete basis set limit and adding corrections for core-valence correlation and relativistic effects. The vibrational energies were calculated by employing a kinetic energy operator expressed in terms of linearized internal coordinates. The exact internal coordinates were expressed as sixth-order Taylor expansions in the linearized coordinates. In the present work we show the latter improvement in the calculated vibrational energies with respect to the latter report [1]. This work is supported by the European Commission through contract no. HPRN-CT-2000-00022 ``Spectroscopy of Highly Excited Rovibrational States''.

  3. Calculation and fitting of potential energy and dipole moment surfaces for the water molecule: Fully ab initio determination of vibrational transition energies and band intensities

    International Nuclear Information System (INIS)

    Kedziora, G.S.; Shavitt, I.

    1997-01-01

    Potential energy and dipole moment surfaces for the water molecule have been generated by multireference singles-and-doubles configuration interaction calculations using a large basis set of the averaged-atomic-natural-orbital type and a six-orbital-six-electron complete-active-space reference space. The surfaces are suitable for modeling vibrational transitions up to about 11000cm -1 above the ground state. A truncated singular-value decomposition method has been used to fit the surfaces. This fitting method is numerically stable and is a useful tool for examining the effectiveness of various fitting function forms in reproducing the calculated surface points and in extrapolating beyond these points. The fitted surfaces have been used for variational calculations of the 30 lowest band origins and the corresponding band intensities for transitions from the ground vibrational state. With a few exceptions, the results compare well with other calculations and with experimental data. copyright 1997 American Institute of Physics

  4. Gyroscopic destabilisation in polyatomic molecules: rotational structure of the low-frequency bending vibrational states ν(23) and ν(11) of dimethylsulfoxide.

    Science.gov (United States)

    Cuisset, Arnaud; Sadovskií, Dmitrií A

    2013-06-21

    We give details of the spectroscopic observation of the gyroscopic destabilisation in the ν23 vibrational state of dimethylsulfoxide (DMSO) announced by Cuisset, Pirali, and Sadovskií [Phys. Rev. Lett. 109, 094101 (2012)]. Following the first successful high-resolution spectroscopic study of the rotational structure of the "perpendicular" band of DMSO at 324 cm(-1) associated with the ν23 bending vibrational mode, the rare subsystem of ν23 rotational levels consisting of a series of fourfold quasidegenerate levels (4-clusters) was identified. Our complete analysis of the underlying rotational dynamics uncovered a bifurcation leading to the gyroscopic destabilisation of one of the two stable principal axes of inertia, a phenomenon known previously only in a few triatomic molecules.

  5. Collisional energy transfer in polyatomic molecules at high temperatures: Master equation analysis of vibrational relaxation of shock-heated alkanes

    Science.gov (United States)

    Matsugi, Akira

    2015-08-01

    Collisional energy transfer plays an important role in unimolecular reaction kinetics. This Letter presents classical trajectory calculations of the energy transfer processes in collisions between selected alkanes (ethane, propane, isobutane, and neopentane) and krypton at high temperature. The primary aim of this study was to elucidate the validity of the predicted energy transfer parameters by performing master equation analyses of their vibrational relaxation times and comparing the predicted values with the available experimental data. The results demonstrate the ability of classical trajectory calculations to accurately predict the parameters for vibrational energy transfer.

  6. Stretching dependence of the vibration modes of a single-molecule Pt-H-2-Pt bridge

    DEFF Research Database (Denmark)

    Djukic, D.; Thygesen, Kristian Sommer; Untiedt, C.

    2005-01-01

    isotope substitution is obtained. The stretching dependence for each of the modes allows uniquely classifying them as longitudinal or transversal modes. The interpretation of the experiment in terms of a Pt-H-2-Pt bridge is verified by density-functional theory calculations for the stability, vibrational...

  7. Nanomechanical microcantilever operated in vibration modes with use of RNA aptamer as receptor molecules for label-free detection of HCV helicase.

    Science.gov (United States)

    Hwang, Kyo Seon; Lee, Sang-Myung; Eom, Kilho; Lee, Jeong Hoon; Lee, Yoon-Sik; Park, Jung Ho; Yoon, Dae Sung; Kim, Tae Song

    2007-11-30

    We report the nanomechanical microcantilevers operated in vibration modes (oscillation) with use of RNA aptamers as receptor molecules for label-free detection of hepatitis C virus (HCV) helicase. The nanomechanical detection principle is that the ligand-receptor binding on the microcantilever surface induces the dynamic response change of microcantilevers. We implemented the label-free detection of HCV helicase in the low concentration as much as 100 pg/ml from measuring the dynamic response change of microcantilevers. Moreover, from the recent studies showing that the ligand-receptor binding generates the surface stress on the microcantilever, we estimate the surface stress, on the oscillating microcantilevers, induced by ligand-receptor binding, i.e. binding between HCV helicase and RNA aptamer. In this article, it is suggested that the oscillating microcantilevers with use of RNA aptamers as receptor molecules may enable one to implement the sensitive label-free detection of very small amount of small-scale proteins.

  8. A Computer Assisted Procedure of Assignments of Vibration-Rotation Bands of Asymmetric and Symmetric Top Molecules

    Czech Academy of Sciences Publication Activity Database

    Urban, Štěpán; Behrend, J.; Pracna, Petr

    2004-01-01

    Roč. 690, - (2004), s. 105-114 ISSN 0022-2860 R&D Projects: GA MŠk ME 445; GA ČR GA203/01/1274 Institutional research plan: CEZ:AV0Z4040901 Keywords : assigments of vibration-rotation spectra * combination differences * Loomis-Wood algorithm Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.200, year: 2004

  9. Ab initio design of picosecond infrared laser pulses for controlling vibrational-rotational excitation of CO molecules

    Science.gov (United States)

    Herrmann, Thomas; Ren, Qinghua; Balint-Kurti, Gabriel G.; Manby, Frederick R.

    2007-06-01

    Optimal control of rovibrational excitations of the CO molecule using picosecond infrared laser pulses is described in the framework of the electric-nuclear Born-Oppenheimer approximation [G. G. Balint-Kurti et al., J. Chem. Phys. 122, 084110 (2005)]. The potential energy surface of the CO molecule in the presence of an electric field is calculated using coupled cluster theory with a large orbital basis set. The quantum dynamics of the process is treated using a full three dimensional treatment of the molecule in the laser field. The detailed mechanisms leading to efficient control of the selected excitation processes are discussed.

  10. Addition energies and vibrational fine structure measured in electromigrated single-molecule junctions based on an oligophenylenevinylene derivative

    DEFF Research Database (Denmark)

    Osorio, Edgar A.; O'Neill, Kevin; Stuhr-Hansen, Nicolai

    2007-01-01

    Transport trough electromigrated molecular junctions that contain an individual thiol end-capped oligophenylenevinylene molecule has been studied. At low temperatures more than fifteen excitations appear in the differential conductance map (see figure). Their energies agree with energies obtained...

  11. Satellites of Xe transitions induced by infrared active vibrational modes of CF4 and C2F6 molecules.

    Science.gov (United States)

    Alekseev, Vadim A; Schwentner, Nikolaus

    2011-07-28

    Absorption and luminescence excitation spectra of Xe/CF(4) mixtures were studied in the vacuum UV region at high resolution using tunable synchrotron radiation. Pressure-broadened resonance bands and bands associated with dipole-forbidden states of the Xe atom due to collision-induced breakdown of the optical selection rules are reported. The spectra display in addition numerous satellite bands corresponding to transitions to vibrationally excited states of a Xe-CF(4) collisional complex. These satellites are located at energies of Xe atom transition increased by one quantum energy in the IR active v(3) vibrational mode of CF(4) (v(3) = 1281 cm(-1)). Satellites of both resonance and dipole-forbidden transitions were observed. Satellites of low lying resonance states are spectrally broad bands closely resembling in shape their parent pressure-broadened resonance bands. In contrast, satellites of dipole-forbidden states and of high lying resonance states are spectrally narrow bands (FWHM ∼10 cm(-1)). The satellites of dipole-forbidden states are orders of magnitude stronger than transitions to their parent states due to collision-induced breakdown of the optical selection rules. These satellites are attributed to a coupling of dipole-forbidden and resonance states induced by the electric field of the transient CF(4) (v(3) = 0 ↔ v(3) = 1) dipole. Similar satellites are present in spectra of Xe/C(2)F(6) mixtures where these bands are induced by the IR active v(10) mode of C(2)F(6). Transitions to vibrationally excited states of Xe-CF(4)(C(2)F(6)) collision pairs were also observed in two-photon LIF spectra. © 2011 American Institute of Physics

  12. Application of R-matrix theory to resonant reactive electron-molecule scattering: Vibrational excitation and dissociative attachment of N2 and F2

    International Nuclear Information System (INIS)

    Wong, C.F.; Light, J.C.

    1984-01-01

    Based on the R-matrix approach of Schneider et al. [J. Phys. B 12, L 365 (1979)] to reactive electron-molecule scattering, a new propagative R-matrix method (PRMM) is presented which is more appropriate for polyatomic systems. The new method should be useful in other calculations where complicated integrals need to be propagated. We also introduce an effective R-matrix model (ERMM) in which the usual resonance parameters (potential and width) can be used as input in model R-matrix calculations. The PRMM and ERMM have been applied to the electron-N 2 system and the electron-F 2 system. The results agree very well with previous calculations for both vibrationally inelastic scattering and dissociative attachment when identical potentials and parameters are used

  13. Heterogeneous Dynamics of Coupled Vibrations

    NARCIS (Netherlands)

    Cringus, Dan; Jansen, Thomas I. C.; Pshenichnikov, Maxim S.; Schoenlein, RW; Corkum, P; DeSilvestri, S; Nelson, KA; Riedle, E

    2009-01-01

    Frequency-dependent dynamics of coupled stretch vibrations of a water molecule are revealed by 2D IR correlation spectroscopy. These are caused by non-Gaussian fluctuations of the environment around the individual OH stretch vibrations.

  14. Energías vs medio ambiente

    OpenAIRE

    Isabel Victoria Landa Fitzgerald; Juana María Robles Caycho

    2010-01-01

    Se presenta una actividad ABP de química en la que los alumnos investigan sobre diferentes tipos de energía: combustibles fósiles, energías alternativas y energía nuclear, y la influencia de ellas en el medio ambiente: efecto invernadero, smog fotoquímico, capa de ozono, lluvia ácida.

  15. Vibrational spectroscopy

    International Nuclear Information System (INIS)

    Fadini, A.

    1980-01-01

    We present 13 programs for the calculation of vibrational spectroscopic problems applied to small molecules with high symmetry. The programs are compiled for the well known programmable pocket calculator Texas Instruments SR-52. To the special problems, the mathematical formulas, input and output instructions, several numerical examples, literature and the programs with comments are given. Order n = 1: The force constants, isotopic vibrational frequencies and the vibrational amplitudes are calculated for the two mass system XY(Csub(infinitely v)). For the three mass system XY 2 (Dsub(infinitely h)) only the force constants and isotopic frequencies are calculated. Order n = 2: For the three mass systems XYZ(Csub(infinitely v)) and XY 2 (Csub(infinitely 2v)) the inverse matrices G of the kinetic energy are presented. For complete sets of data (with isotopic frequencies, Coriolis coupling constants etc.) the complete force constant matrices are calculated. For non complete sets of data one starts in most cases with diagonal force constant matrices. The complete force constant matrix F is calculated with a minimalisation approximation. The eigenvector matrices L result from the G - F - and N-matrices. The N-matrices are calculated from the G- and F-matrices or from the F- and L-matrices respectively. Order n = 3: The matrix G of the system XYZ(Csub(S)) is calculated. For higher orders n, the 'isotopic reduction method' for the calculation of single force constants of proper systems is described. (orig.) [de

  16. Energizing porters by proton-motive force.

    Science.gov (United States)

    Nelson, N

    1994-11-01

    It is generally accepted that the chemistry of water was the most crucial determinant in shaping life on earth. Among the more important chemical features of water is its dissociation into protons and hydroxyl ions. The presence of relatively high proton concentrations in the ambient solution resulted in the evolution of proton pumps during the dawn of life on earth. These proton pumps maintained neutral pH inside the cells and generated electrochemical gradients of protons (proton-motive force) across their membranes. The existence of proton-motive force enabled the evolution of porters driven by it that are most probably among the more primitive porters in the world. The directionality of the substrate transport by the porters could be to both sides of the membranes because they can serve as proton symporters or antiporters. One of the most important subjects of this meeting is the mechanism by which proton-motive and other ion-motive forces drive the transport processes through porters. Is there a common mechanism of action for all proton-driven porters? Is there some common partial reaction by which we can identify the way that porters are energized by proton-motive force? Is there a common coupling between proton movement and uptake or secretion of certain molecules? Even a partial answer to one of these questions would advance our knowledge... or confusion. As my mentor Efraim Racker used to say: 'If you are not totally confused you do not understand the issue'.

  17. Assessing energy efficiency of electric car bottom furnaces intended for thermal energization of minerals

    Science.gov (United States)

    Nizhegorodov, A. I.

    2017-01-01

    The paper deals with a new concept of electric furnaces for roasting and thermal energization of vermiculite and other minerals with vibrational transportation of a single-layer mass under constant thermal field. The paper presents performance calculation and comparative assessment of energy data for furnaces of different modifications: flame and electric furnaces with three units, furnaces with six units and ones with series-parallel connection of units, and furnaces of new concept.

  18. The Dynamics of Large-Amplitude Motion in Energized Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Perry, David S. [Univ. of Akron, OH (United States). Dept. of Chemistry

    2016-05-27

    Chemical reactions involve large-amplitude nuclear motion along the reaction coordinate that serves to distinguish reactants from products. Some reactions, such as roaming reactions and reactions proceeding through a loose transition state, involve more than one large-amplitude degree of freedom. Because of the limitation of exact quantum nuclear dynamics to small systems, one must, in general, define the active degrees of freedom and separate them in some way from the other degrees of freedom. In this project, we use large-amplitude motion in bound model systems to investigate the coupling of large-amplitude degrees of freedom to other nuclear degrees of freedom. This approach allows us to use the precision and power of high-resolution molecular spectroscopy to probe the specific coupling mechanisms involved, and to apply the associated theoretical tools. In addition to slit-jet spectra at the University of Akron, the current project period has involved collaboration with Michel Herman and Nathalie Vaeck of the Université Libre de Bruxelles, and with Brant Billinghurst at the Canadian Light Source (CLS).

  19. 2008 Vibrational Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Philip J. Reid

    2009-09-21

    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  20. Coherent vibrational dynamics

    CERN Document Server

    Lanzani, Guglielmo; De Silvestri, Sandro

    2007-01-01

    Vibrational spectroscopy is a powerful investigation tool for a wide class of materials covering diverse areas in physics, chemistry and biology. The continuous development in the laser field regarding ultrashort pulse generation has led to the possibility of producing light pulses that can follow vibrational motion coupled to the electronic transitions in molecules and solids in real time. Aimed at researchers and graduate students using vibrational spectroscopy, this book provides both introductory chapters as well as more advanced contents reporting on recent progress. It also provides a good starting point for scientists seeking a sound introduction to ultrafast optics and spectroscopic techniques.

  1. Energía de las olas

    Directory of Open Access Journals (Sweden)

    Luis Javier Chamorro Rendón

    1982-09-01

    Full Text Available La energía del oleaje del mar es enorme y muchas veces se manifiesta por los grandes destrozos que puede producir o por la facilidad de agitar cualquier cuerpo flotante. Esta gran cantidad de energía se ha tratado de aprovechar desde hace siglos Por ejemplo, en el siglo XIII los chinos trituraban minerales con molinos accionados por las olas. Leonardo Da Vinci dejo algunos diseños de mecanismos accionados por el oleaje Actualmente se han incrementado las investigaciones e inversiones para desarrollar generadores de energía. Mediciones de corta duración pueden situar con alguna precisión la energía de las olas de los 2.500 km de las costas del país entre 12.500 MW y 90000 MW.

  2. Molecular vibrations the theory of infrared and Raman vibrational spectra

    CERN Document Server

    Wilson, E Bright; Cross, Paul C

    1980-01-01

    Pedagogical classic and essential reference focuses on mathematics of detailed vibrational analyses of polyatomic molecules, advancing from application of wave mechanics to potential functions and methods of solving secular determinant.

  3. Investigation of energy stability, geometric structure, force fields, and vibrational spectra of LiNaF2, LiMgF3, and LiAlF4 molecules by means of MO LCAO SCF method

    International Nuclear Information System (INIS)

    Sliznev, V.V.; Solomonik, V.G.

    1986-01-01

    By the MO LCAO SCF method with Huzinaga-Dumming and McLean-Chandler two-exponent basis sets, supplemented by d-functions on the Period III atoms, ab initio calculations have been performed for the equilibrium geometric parameters, coefficients of the quadratic force field, vibrational frequencies and intensities in the IR spectra, dipole moments, ionization potentials (according to the Koopmans theorem), Mulliken populations, and enthalpy and entropy of complexation of the molecules LiNaF 2 , LiMgF 3 , and LiAlF 4 . A study has been made of the effects on the calculated results when the basis is extended by inclusion of polarization and diffuse functions on the fluorine atoms. The calculated characteristics are compared with the available experimental data. A reassignment has been performed for certain frequencies in the IR spectrum of LiNaF 2 , as assigned previously by S.J. Syvin, B.N. Syvin, and A Snelson, J. Phys. Chem., 74, No. 25, 4338 (1970). Certain frequencies of low-intensity vibrations have been predicted in the IR spectra, frequencies not yet found experimentally

  4. Pathways for Energization of Ca in Mercury's Exosphere

    Science.gov (United States)

    Killen, Rosemary M.

    2015-01-01

    We investigate the possible pathways to produce the extreme energy observed in the calcium exosphere of Mercury. Any mechanism must explain the facts that Ca in Mercury's exosphere is extremely hot, that it is seen almost exclusively on the dawnside of the planet, and that its content varies seasonally, not sporadically. Simple diatomic molecules or their clusters are considered, focusing on calcium oxides while acknowledging that Ca sulfides may also be the precursor molecules. We first discuss impact vaporization to justify the assumption that CaO and Ca-oxide clusters are expected from impacts on Mercury. Then we discuss processes by which the atomic Ca is energized to a 70,000 K gas. The processes considered are (1) electron-impact dissociation of CaO molecules, (2) spontaneous dissociation of Ca-bearing molecules following impact vaporization, (3) shock-induced dissociative ionization, (4) photodissociation and (5) sputtering. We conclude that electron-impact dissociation cannot produce the required abundance of Ca, and sputtering cannot reproduce the observed spatial and temporal variation that is measured. Spontaneous dissociation is unlikely to result in the high energy that is seen. Of the two remaining processes, shock induced dissociative ionization produces the required energy and comes close to producing the required abundance, but rates are highly dependent on the incoming velocity distribution of the impactors. Photodissociation probably can produce the required abundance of Ca, but simulations show that photodissociation cannot reproduce the observed spatial distribution.

  5. Transició Energètica

    OpenAIRE

    Farran, Assumpta

    2017-01-01

    La transició energètica ha de ser una política d’Estat, amb un pacte de país que defineixi i dissenyi el model energètic sobre el que volem edificar Catalunya. Estem davant d’un canvi de paradigma on un model centralitzat, fòssil,  nuclear i contaminant  pot donar pas a un nou model distribuït, democràtic i 100% renovable. Al llarg de 100 anys hem edificat un model legal, fiscal, financer, cultural i territorial que h...

  6. Arquitectura y energía natural

    OpenAIRE

    Serra Florensa, Rafael; Coch Roura, Helena

    2001-01-01

    Bibliografia La arquitectura se ha entendido normalmente como geometría y materia, abstracción dibujada y realidad tangible, pero raramente se ha valorado el papel de la energía: luz, sonido, calor, etc. en su definición. Desde la percepción ambiental y el confort hasta la constatación del valor espacial de la energía, se intentan facilitar al arquitecto los conceptos para encontrar la solución óptima de unas necesidades a menudo imprecisas. El conocimiento de los conceptos, sistemas y com...

  7. Final Technical Report, reEnergize Program

    Energy Technology Data Exchange (ETDEWEB)

    Wamstad-Evans, Kristi [City of Omaha; Williams, Eric [City of Omaha; Kubicek, Jason [City of Omaha

    2013-12-27

    The reEnergize Program helped to build a market for residential and commercial energy evaluations and upgrades. The program provided incentives to encourage participants to save energy, save money, and make their homes and businesses more safe, healthy, and comfortable. As part of the Better Buildings Neighborhood Program (BBNP), the successful investment of this $10 million grant toward market development was the first grant funding collaboration between the cities of Omaha and Lincoln. Through more than three years of work, thousands of participants, contractors, and community members worked together to make the reEnergize Program a demonstration of how to “Build Energy Smart Communities.”

  8. Energía de las olas

    OpenAIRE

    Chamorro Rendón, Luis Javier

    2011-01-01

    La energía del oleaje del mar es enorme y muchas veces se manifiesta por los grandes destrozos que puede producir o por la facilidad de agitar cualquier cuerpo flotante. Esta gran cantidad de energía se ha tratado de aprovechar desde hace siglos Por ejemplo, en el siglo XIII los chinos trituraban minerales con molinos accionados por las olas. Leonardo Da Vinci dejo algunos diseños de mecanismos accionados por el oleaje Actualmente se han incrementado las investigaciones e inversiones para des...

  9. Vibrational Spectroscopy and Astrobiology

    Science.gov (United States)

    Chaban, Galina M.; Kwak, D. (Technical Monitor)

    2001-01-01

    Role of vibrational spectroscopy in solving problems related to astrobiology will be discussed. Vibrational (infrared) spectroscopy is a very sensitive tool for identifying molecules. Theoretical approach used in this work is based on direct computation of anharmonic vibrational frequencies and intensities from electronic structure codes. One of the applications of this computational technique is possible identification of biological building blocks (amino acids, small peptides, DNA bases) in the interstellar medium (ISM). Identifying small biological molecules in the ISM is very important from the point of view of origin of life. Hybrid (quantum mechanics/molecular mechanics) theoretical techniques will be discussed that may allow to obtain accurate vibrational spectra of biomolecular building blocks and to create a database of spectroscopic signatures that can assist observations of these molecules in space. Another application of the direct computational spectroscopy technique is to help to design and analyze experimental observations of ice surfaces of one of the Jupiter's moons, Europa, that possibly contains hydrated salts. The presence of hydrated salts on the surface can be an indication of a subsurface ocean and the possible existence of life forms inhabiting such an ocean.

  10. Vibration mixer

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S.A.; Chernov, V.S.; Denisenko, V.V.; Gorodnyanskiy, I.F.; Prokopov, L.I.; Tikhonov, Yu.P.

    1983-01-01

    The vibration mixer is proposed which contains a housing, vibration drive with rod installed in the upper part of the mixing mechanism made in the form of a hollow shaft with blades. In order to improve intensity of mixing and dispersion of the mud, the shaft with the blades is arranged on the rod of the vibrator and is equipped with a cam coupling whose drive disc is attached to the vibration rod. The rod is made helical, while the drive disc of the cam coupling is attached to the helical surface of the rod. In addition, the vibration mixer is equipped with perforated discs installed on the ends of the rods.

  11. Temas de Física para Ingeniería: Trabajo y energía

    OpenAIRE

    Beléndez, Augusto; Pastor Antón, Carlos; Bernabeu, Guillermo

    1988-01-01

    Apuntes de Mecánica: "Trabajo y energía". Trabajo y potencia. Energía cinética, teorema de la energía cinética. Fuerzas conservativas, energía potencial. Energía potencial gravitatoria. Principio de conservación de la energía mecánica. Choques.

  12. Herbal Energizers: Speed By Any Other Name.

    Science.gov (United States)

    Jenkins, Andrew P.

    This guide focuses on over-the-counter (OTC) stimulants sold to high school aged athletes and dieters as "herbal energizers," food supplements, and fatigue reducers. While advertising often makes them appear healthful and harmless, all of these stimulants belong in the class "sympathomimetic amines," so called because they…

  13. Vibrational spectroscopy of Cm–C/Cb–Cb stretching vibrations of ...

    Indian Academy of Sciences (India)

    operator which conveniently describes stretching vibrations of biomolecules. For a copper tetramesityl porphyrin molecule, the higher excited vibrational levels are calculated by applying the U(2) algebraic approach. Keywords. Lie algebraic techniques; vibrational spectra; copper tetramesityl porphyrin. PACS Nos 31.65.

  14. Self-energizing electro-hydraulic brake

    OpenAIRE

    Liermann, Matthias

    2008-01-01

    This thesis presents research results on a new fluid-mechatronic brake principle. The Self-energizing Electro-Hydraulic Brake (SEHB) utilizes the effect of instable self-reinforcement in combination with a closed loop control. Background for the development of the brake concept is a train application. However, SEHB is not limited to any specific application. Main advantages of the concept are its minimal energy consumption, the closed loop control of the true brake torque and its feedback abi...

  15. PREFACE: Vibrations at surfaces Vibrations at surfaces

    Science.gov (United States)

    Rahman, Talat S.

    2011-12-01

    This special issue is dedicated to the phenomenon of vibrations at surfaces—a topic that was indispensible a couple of decades ago, since it was one of the few phenomena capable of revealing the nature of binding at solid surfaces. For clean surfaces, the frequencies of modes with characteristic displacement patterns revealed how surface geometry, as well as the nature of binding between atoms in the surface layers, could be different from that in the bulk solid. Dispersion of the surface phonons provided further measures of interatomic interactions. For chemisorbed molecules on surfaces, frequencies and dispersion of the vibrational modes were also critical for determining adsorption sites. In other words, vibrations at surfaces served as a reliable means of extracting information about surface structure, chemisorption and overlayer formation. Experimental techniques, such as electron energy loss spectroscopy and helium-atom-surface scattering, coupled with infra-red spectroscopy, were continually refined and their resolutions enhanced to capture subtleties in the dynamics of atoms and molecules at surfaces. Theoretical methods, whether based on empirical and semi-empirical interatomic potential or on ab initio electronic structure calculations, helped decipher experimental observations and provide deeper insights into the nature of the bond between atoms and molecules in regions of reduced symmetry, as encountered on solid surfaces. Vibrations at surfaces were thus an integral part of the set of phenomena that characterized surface science. Dedicated workshops and conferences were held to explore the variety of interesting and puzzling features revealed in experimental and theoretical investigations of surface vibrational modes and their dispersion. One such conference, Vibrations at Surfaces, first organized by Harald Ibach in Juelich in 1980, continues to this day. The 13th International Conference on Vibrations at Surfaces was held at the University of

  16. Dynamics of Activated Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, Amy S. [Univ. of Maryland, College Park, MD (United States)

    2016-11-16

    Experimental studies have been performed to investigate the collisional energy transfer processes of gas-phase molecules that contain large amounts of internal energy. Such molecules are prototypes for molecules under high temperature conditions relevant in combustion and information about their energy transfer mechanisms is needed for a detailed understanding and modeling of the chemistry. We use high resolution transient IR absorption spectroscopy to measure the full, nascent product distributions for collisions of small bath molecules that relax highly vibrationally excited pyrazine molecules with E=38000 cm-1 of vibrational energy. To perform these studies, we developed new instrumentation based on modern IR light sources to expand our experimental capabilities to investigate new molecules as collision partners. This final report describes our research in four areas: the characterization of a new transient absorption spectrometer and the results of state-resolved collision studies of pyrazine(E) with HCl, methane and ammonia. Through this research we have gained fundamental new insights into the microscopic details of relatively large complex molecules at high energy as they undergo quenching collisions and redistribute their energy.

  17. Isotope separation process by transfer of vibrational energy

    International Nuclear Information System (INIS)

    Angelie, C.; Cauchetier, M.; Paris, J.

    1983-01-01

    This process consists in exciting A molecules by absorption of a pulsed light beam, then in exciting until their dissociation X molecules, present in several isotopic forms, by a vibrational transfer between the A molecules and the X molecules, the A molecules having a dissociation energy greater than that of the X molecules, the duration and energy of the light pulses being such that the absorption time by the A molecules is less than the excitation time of the X molecules and the temperature conditions such that the thermal width of the vibration rays is at the most near the isotopic difference between the resonance rays of the two isotopic varieties [fr

  18. Optimal control of vibrational transitions of HCl

    Indian Academy of Sciences (India)

    2016-09-07

    Sep 7, 2016 ... Many H-abstraction reactions in chemistry involve halides like HCl, HBr and HI. And they often need to undergo coherent vibrational excitation to promote the reaction (for instance, the late-barrier reactions in chemistry require vibrationally hot reactant molecules to have the reaction promoted) efficiently.

  19. Dissimilar Dynamics of Coupled Water Vibrations

    NARCIS (Netherlands)

    Jansen, Thomas L. C.; Cringus, Dan; Pshenichnikov, Maxim S.

    2009-01-01

    Dissimilar dynamics of coupled stretch vibrations of a water molecule are revealed by two-dimensional, IR correlation spectroscopy. These are caused by essentially non-Gaussian fluctuations of the electric field exerted by the environment on the individual OH stretch vibrations. Non-Gaussian

  20. Dipole Correlation of the Electronic Structures of theConformations of Water Molecule Evolving Through theNormal Modes of Vibrations Between Angular (C2v to Linear(D∝h Shapes

    Directory of Open Access Journals (Sweden)

    Arindam Chakraborty

    2006-03-01

    Full Text Available In order to settle the issue of equivalence or non-equivalence of the two lone pairsof electrons on oxygen atom in water molecule, a quantum chemical study of the dipolecorrelation of the electronic structure of the molecule as a function of conformationsgenerated following the normal modes of vibrations between the two extremeconformations, C2v (∠HOH at 90o and D∝h (∠HOH at 180o, including the equilibrium one,has been performed. The study invokes quantum mechanical partitioning of moleculardipoles into bond moment and lone pair moment and localization of delocalized canonicalmolecular orbitals, CMO’s into localized molecular orbitals, LMO’s. An earlier suggestion,on the basis of photoelectron spectroscopy, that one lone pair is in p-type and the other is ins-type orbital of O atom of water molecule at its equilibrium shape, and also the qualitative“Squirrel Ears” structure are brought under serious scrutiny. A large number ofconformations are generated and the charge density matrix, dipole moment of eachconformation is computed in terms of the generated canonical molecular orbitals, CMO’sand then Sinanoğlu’s localization method is invoked to localize the CMO’s of eachconformation and the quantum mechanical hybridizations of all the bonds and lone pairs onO center are evaluated in terms of the localized molecular orbitals. Computed datademonstrate that the electronic structures i.e. two bond pairs and two lone pairs and itshybridization status of all conformations of water molecule are straightforward in terms ofthe LMO’s. It is further revealed that the pattern of orbital hybridization changescontinuously as a function of evolution of molecular shape. The close analysis of thegenerated LMO’s reveals that one lone pair is accommodated in a pure p orbital and anotherlone pair is in a hybrid

  1. Catalytic synthesis of ammonia using vibrationally excited nitrogen

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Billing, Gert D.; Hansen, Flemming Yssing

    1992-01-01

    to that from conventional synthesis. In the present study the nitrogen molecules are only excited at the inlet of a plug flow reactor, and the importance of vibrational relaxation is investigated. We show that vibrational excitation can give an enhanced yield of ammonia also in the situation where vibrational...

  2. Vibrational dynamics of crystalline L-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Bordallo, H.N.; Eckert, J. [Los Alamos National Lab., NM (United States); Barthes, M. [Univ. Montpellier II (France)

    1997-11-01

    The authors report a new, complete vibrational analysis of L-alanine and L-alanine-d{sub 4} which utilizes IINS intensities in addition to frequency information. The use of both isotopomers resulted in a self-consistent force field for and assignment of the molecular vibrations in L-alanine. Some details of the calculation as well as a comparison of calculated and observed IINS spectra are presented. The study clarifies a number of important issues on the vibrational dynamics of this molecule and presents a self-consistent force field for the molecular vibrations in crystalline L-alanine.

  3. Lattice Vibrations in Chlorobenzenes:

    DEFF Research Database (Denmark)

    Reynolds, P. A.; Kjems, Jørgen; White, J. W.

    1974-01-01

    Lattice vibrational dispersion curves for the ``intermolecular'' modes in the triclinic, one molecule per unit cell β phase of p‐C6D4Cl2 and p‐C6H4Cl2 have been obtained by inelastic neutron scattering. The deuterated sample was investigated at 295 and at 90°K and a linear extrapolation to 0°K...... was applied in order to correct for anharmonic effects. Calculations based on the atom‐atom model for van der Waals' interaction and on general potential parameters for the aromatic compounds agree reasonably well with the experimental observations. There is no substantial improvement in fit obtained either...

  4. Auditoria Energética Numa Escola

    OpenAIRE

    Lopes, Miguel Nuno da Silva Costa

    2015-01-01

    Devido ao crescente problema das alterações climáticas a União Europeia tem vindo a estabelecer um conjunto de metas ambiciosas para os países da sua comunidade com vista a melhorar a eficiência energética, para cumprir essas exigências Portugal tem vindo a implementar medidas para incentivar o uso de energias renováveis, mas não só, pois não é possível atingir as metas definidas sem o uso eficiente da energia, o que também tem sido promovido através de medidas definidas para os vários sector...

  5. Vibrations and reorientations of H2O molecules in [Sr(H2O)6]Cl2 studied by Raman light scattering, incoherent inelastic neutron scattering and proton magnetic resonance.

    Science.gov (United States)

    Hetmańczyk, Joanna; Hetmańczyk, Lukasz; Migdał-Mikuli, Anna; Mikuli, Edward; Florek-Wojciechowska, Małgorzata; Harańczyk, Hubert

    2014-04-24

    Vibrational-reorientational dynamics of H2O ligands in the high- and low-temperature phases of [Sr(H2O)6]Cl2 was investigated by Raman Spectroscopy (RS), proton magnetic resonance ((1)H NMR), quasielastic and inelastic incoherent Neutron Scattering (QENS and IINS) methods. Neutron powder diffraction (NPD) measurements, performed simultaneously with QENS, did not indicated a change of the crystal structure at the phase transition (detected earlier by differential scanning calorimetry (DSC) at TC(h)=252.9 K (on heating) and at TC(c)=226.5K (on cooling)). Temperature dependence of the full-width at half-maximum (FWHM) of νs(OH) band at ca. 3248 cm(-1) in the RS spectra indicated small discontinuity in the vicinity of phase transition temperature, what suggests that the observed phase transition may be associated with a change of the H2O reorientational dynamics. However, an activation energy value (Ea) for the reorientational motions of H2O ligands in both phases is nearly the same and equals to ca. 8 kJ mol(-1). The QENS peaks, registered for low temperature phase do not show any broadening. However, in the high temperature phase a small QENS broadening is clearly visible, what implies that the reorientational dynamics of H2O ligands undergoes a change at the phase transition. (1)H NMR line is a superposition of two powder Pake doublets, differentiated by a dipolar broadening, suggesting that there are two types of the water molecules in the crystal lattice of [Sr(H2O)6]Cl2 which are structurally not equivalent average distances between the interacting protons are: 1.39 and 1.18 Å. However, their reorientational dynamics is very similar (τc=3.3⋅10(-10) s). Activation energies for the reorientational motion of these both kinds of H2O ligands have nearly the same values in an experimental error limit: and equal to ca. 40 kJ mole(-1). The phase transition is not seen in the (1)H NMR spectra temperature dependencies. Infrared (IR), Raman (RS) and inelastic

  6. Vibrating minds

    CERN Multimedia

    2009-01-01

    Ed Witten is one of the leading scientists in the field of string theory, the theory that describes elementary particles as vibrating strings. This week he leaves CERN after having spent a few months here on sabbatical. His wish is that the LHC will unveil supersymmetry.

  7. Vibrational spectroscopy

    Science.gov (United States)

    Umesh P. Agarwal; Rajai Atalla

    2010-01-01

    Vibrational spectroscopy is an important tool in modern chemistry. In the past two decades, thanks to significant improvements in instrumentation and the development of new interpretive tools, it has become increasingly important for studies of lignin. This chapter presents the three important instrumental methods-Raman spectroscopy, infrared (IR) spectroscopy, and...

  8. Electron-excited molecule interactions

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Tennessee Univ., Knoxville, TN

    1991-01-01

    In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10 6 to 10 7 times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs

  9. Kinematic anharmonicity of internal rotation of molecules

    International Nuclear Information System (INIS)

    Bataev, V.A.; Pupyshev, V.I.; Godunov, I.A.

    2017-01-01

    The methods of analysis the strongly coupled vibrations are proposed for a number of molecules of aromatic and heterocyclic carbonyl (and some others) compounds. The qualitative principles are formulated for molecular systems with a significant kinematic anharmonicity.

  10. Vivienda unifamiliar de bajo consumo energético

    OpenAIRE

    Domínguez Alonso, Manuel; Cubillos Arias, Fernando

    2012-01-01

    Se describe y analiza una vivienda unifamiliar recientemente construida en Madrid, en donde se ha tenido presente la reducción del consumo energético, introduciendo junto a la energía solar, la bomba de calor, suelo radiante, recuperadores de calor, sistemas de refrigeración por agua, la inercia térmica, tanto en la construcción como en un acumulador de calor con materiales de cambio de fase (PCM). Se considera que puede reducirse grandemente las necesidades energéticas sin pérdida de grad...

  11. Experimental decoherence in molecule interferometry

    International Nuclear Information System (INIS)

    Hackermueller, L.; Hornberger, K.; Stibor, A.; Zeilinger, A.; Arndt, M.; Kiesewetter, G.

    2005-01-01

    Full text: We present three mechanisms of decoherence that occur quite naturally in matter wave interferometer with large molecules. One way molecules can lose coherence is through collision with background gas particles. We observe a loss of contrast with increasing background pressure for various types of gases. We can understand this phenomenon quantitatively with a new model for collisional decoherence which corrects older models by a factor of 2 π;. The second experiment studies the thermal emission of photons related to the high internal energy of the interfering molecules. When sufficiently many or sufficiently short photons are emitted inside the interferometer, the fringe contrast is lost. We can continuously vary the temperature of the molecules and compare the loss of contrast with a model based on decoherence theory. Again we find good quantitative agreement. A third mechanism that influences our interference pattern is dephasing due to vibrations of the interference gratings. By adding additional vibrations we study this effect in more detail. (author)

  12. Energía minihidráulica : una alternativa energética para electrificación rural

    OpenAIRE

    Agudelo Flórez, Sergio Cipriano; Chamorro Rendón, Luis Javier

    2002-01-01

    Entre las actividades del Grupo de Energía Alternativa (GEA) de la Facultad de Ingeniería de la Universidad de Antioquia, se pretende el desarrollo de prototipos que aprovechen las fuentes no convencionales para la producción de energía eléctrica y así satisfacer las necesidades insatisfechas de las viviendas rurales aisladas de la red energética nacional. En la región del Oriente antioqueño, se encontró un formidable recurso hidráulico de grandes ríos, quebradas y fuentes de agua cercanas a ...

  13. Low pressure tritiation of molecules

    International Nuclear Information System (INIS)

    Moran, T.F.; Powers, J.C.; Lively, M.O.

    1980-01-01

    A method is described of tritiating sensitive biological molecules by depositing molecules of the substance to be tritiated on a supporting substrate in an evacuated vacuum chamber near, but not in the path of, an electron beam which traverses the chamber, admitting tritium gas into the chamber, and subjecting the tritium to the electron beam. Vibrationally excited tritium gas species are generated which collide and react with the substance thus incorporating tritium atoms into the substance. (U.K.)

  14. Molecule Matters

    Indian Academy of Sciences (India)

    is a very stable and inert molecule due to the formation of a triple bond between the two atoms. Surpris- ingly isoelectronic molecules are quite reactive making dinitrogen very useful and unique. Dinitrogen (N. 2. ) is such an innocuous molecule that you might not think it worthy of special attention. We take this molecule for.

  15. Energizing Local Values For Tourism Services Improvement

    Directory of Open Access Journals (Sweden)

    Budi Purnomo

    2012-06-01

    Full Text Available People in most cultures would probably agree that politeness is needed during their interaction. However there may be differing opinions as to when they should be polite. In tourism industry, tourism service providers’ act as hosts and tourists act as guests. Typically hosts will try to act politely and use appropriate politeness norms when serving guests to ensure their satisfaction. The research findings show that the tourism service providers in Central Java use various unggah-ungguh ‘politeness norms’ when serving English speaking tourists and Indonesian speaking tourists. Besides that, there are some violations made by the tourism service providers in using unggah-ungguh ‘politeness norms’. The research findings also show that there are similar and different perspectives on unggah-ungguh ‘politeness norms’ between English speaking tourists with Western culture backgrounds and Indonesian speaking tourists with Indonesian culture backgrounds towards the politeness norms used by the tourism service providers in Central Java. The findings imply the needs of energizing unggah-ungguh ‘politeness norms’ which is discovered from well known noble Javanese values used by the tourism service providers for tourism service improvement.

  16. Combined optimization model for sustainable energization strategy

    Science.gov (United States)

    Abtew, Mohammed Seid

    Access to energy is a foundation to establish a positive impact on multiple aspects of human development. Both developed and developing countries have a common concern of achieving a sustainable energy supply to fuel economic growth and improve the quality of life with minimal environmental impacts. The Least Developing Countries (LDCs), however, have different economic, social, and energy systems. Prevalence of power outage, lack of access to electricity, structural dissimilarity between rural and urban regions, and traditional fuel dominance for cooking and the resultant health and environmental hazards are some of the distinguishing characteristics of these nations. Most energy planning models have been designed for developed countries' socio-economic demographics and have missed the opportunity to address special features of the poor countries. An improved mixed-integer programming energy-source optimization model is developed to address limitations associated with using current energy optimization models for LDCs, tackle development of the sustainable energization strategies, and ensure diversification and risk management provisions in the selected energy mix. The Model predicted a shift from traditional fuels reliant and weather vulnerable energy source mix to a least cost and reliable modern clean energy sources portfolio, a climb on the energy ladder, and scored multifaceted economic, social, and environmental benefits. At the same time, it represented a transition strategy that evolves to increasingly cleaner energy technologies with growth as opposed to an expensive solution that leapfrogs immediately to the cleanest possible, overreaching technologies.

  17. Chemical sputtering by impact of excited molecules

    International Nuclear Information System (INIS)

    Krstic, P.S.; Reinhold, C.O.; Stuart, S.J.

    2007-01-01

    We study chemical sputtering of deuterated amorphous carbon surfaces by D atoms, vibrationally excited D 2 , and dissociating D 3 molecules, in a range of impact energies, 7.5 - 30 eV/D. We analyze the role of the internal state, i.e. the vibrationally excited and dissociating states of the neutral molecules resulting from above-surface neutralization of impacting molecular ions in typical sputtering experiments. The sputtering yields are shown to considerably increase with the internal vibrational energy at the lowest impact energies. By comparison of calculated and measured yields we draw conclusions regarding the possible mechanisms for neutralization. (authors)

  18. Urban vibrations

    DEFF Research Database (Denmark)

    Morrison, Ann; Knudsen, L.; Andersen, Hans Jørgen

    2012-01-01

      lab   studies   in   that   we   found   a   decreased   detection   rate   in   busy   environments.   Here   we   test   with   a   much   larger   sample   and   age   range,   and   contribute   with   the   first   vibration  sensitivity  testing  outside  the  lab  in  an  urban   public...

  19. Vibrational and electronic spectroscopic studies of melatonin

    Science.gov (United States)

    Singh, Gurpreet; Abbas, J. M.; Dogra, Sukh Dev; Sachdeva, Ritika; Rai, Bimal; Tripathi, S. K.; Prakash, Satya; Sathe, Vasant; Saini, G. S. S.

    2014-01-01

    We report the infrared absorption and Raman spectra of melatonin recorded with 488 and 632.8 nm excitations in 3600-2700 and 1700-70 cm-1 regions. Further, we optimized molecular structure of the three conformers of melatonin within density functional theory calculations. Vibrational frequencies of all three conformers have also been calculated. Observed vibrational bands have been assigned to different vibrational motions of the molecules on the basis of potential energy distribution calculations and calculated vibrational frequencies. Observed band positions match well with the calculated values after scaling except Nsbnd H stretching mode frequencies. It is found that the observed and calculated frequencies mismatch of Nsbnd H stretching is due to intermolecular interactions between melatonin molecules.

  20. City of Phoenix - Energize Phoenix Program

    Energy Technology Data Exchange (ETDEWEB)

    Laloudakis, Dimitrios J.

    2014-09-29

    Energize Phoenix (EPHX) was designed as an ambitious, large-scale, three-year pilot program to provide energy efficiency upgrades in buildings, along Phoenix’s new Light Rail Corridor – part of a federal effort to reduce energy consumption and stimulate job growth, while simultaneously reducing the country’s carbon footprint and promoting a shift towards a green economy. The program was created through a 2010 competitive grant awarded to the City of Phoenix who managed the program in partnership with Arizona State University (ASU), the state’s largest university, and Arizona Public Service (APS), the state’s largest electricity provider. The U.S. Department of Energy (DOE) Better Buildings Neighborhood Program (BBNP) and the American Recovery and Reinvestment Act (ARRA) of 2009 provided $25M in funding for the EPHX program. The Light Rail Corridor runs through the heart of downtown Phoenix, making most high-rise and smaller commercial buildings eligible to participate in the EPHX program, along with a diverse mix of single and multi-family residential buildings. To ensure maximum impact and deeper market penetration, Energize Phoenix was subdivided into three unique parts: i. commercial rebate program, ii. commercial financing program, and iii. residential program Each component was managed by the City of Phoenix in partnership with APS. Phoenix was fortunate to partner with APS, which already operated robust commercial and residential rebate programs within its service territory. Phoenix tapped into the existing utility contractor network, provided specific training to over 100 contracting firms, and leveraged the APS rebate program structure (energy efficiency funding) to launch the EPHX commercial and residential rebate programs. The commercial finance program was coordinated and managed through a contract with National Bank of Arizona, NBAZ, which also provided project capital leveraging EPHX finance funds. Working in unison, approved contractors

  1. Molecule nanoweaver

    Science.gov (United States)

    Gerald, II; Rex, E [Brookfield, IL; Klingler, Robert J [Glenview, IL; Rathke, Jerome W [Homer Glen, IL; Diaz, Rocio [Chicago, IL; Vukovic, Lela [Westchester, IL

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  2. Systematic vibration thermodynamic properties of bromine

    Science.gov (United States)

    Liu, G. Y.; Sun, W. G.; Liao, B. T.

    2015-11-01

    Based on the analysis of the maturity and finiteness of vibrational levels of bromine molecule in ground state and evaluating the effect on statistical computation, according to the elementary principles of quantum statistical theorem, using the full set of bromine molecular vibrational levels determined with algebra method, the statistical contribution for bromine systematical macroscopic thermodynamic properties is discussed. Thermodynamic state functions Helmholtz free energy, entropy and observable vibration heat capacity are calculated. The results show that the determination of full set of vibrational levels and maximum vibrational quantum number is the key in the correct statistical analysis of bromine systematical thermodynamic property. Algebra method results are clearly different from data of simple harmonic oscillator and the related algebra method results are no longer analytical but numerical and are superior to simple harmonic oscillator results. Compared with simple harmonic oscillator's heat capacities, the algebra method's heat capacities are more consistent with the experimental data in the given temperature range of 600-2100 K.

  3. Phosphate vibrations as reporters of DNA hydration

    Science.gov (United States)

    Corcelli, Steven

    The asymmetric phosphate stretch vibrational frequency is extraordinarily sensitive to its local solvent environment. Using density functional theory calculations on the model compound dimethyl phosphate, the asymmetric phosphate stretch vibrational frequency was found to shift linearly with the magnitude of an electric field along the symmetry axis of the PO2 moiety (i.e. the asymmetric phosphate stretch is an excellent linear vibrational Stark effect probe). With this linear relationship established, asymmetric phosphate stretch vibrational frequencies were computed during the course of a molecular dynamics simulation of fully hydrated DNA. Moreover, contributions to shifts in the frequencies from subpopulations of water molecules (e.g. backbone, minor groove, major groove, etc.) were calculated to reveal how phosphate vibrations report the onset of DNA hydration in experiments that vary the relative humidity of non-condensing (dry) DNA samples.

  4. Catalytic synthesis of ammonia using vibrationally excited nitrogen

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Billing, Gert D.; Hansen, Flemming Yssing

    1992-01-01

    In a previous study we have considered the catalytic synthesis of ammonia in the presence of vibrationally excited nitrogen. The distribution over vibrational states was assumed to be maintained during the reaction, and it was shown that the yield of ammonia increased considerably compared...... to that from conventional synthesis. In the present study the nitrogen molecules are only excited at the inlet of a plug flow reactor, and the importance of vibrational relaxation is investigated. We show that vibrational excitation can give an enhanced yield of ammonia also in the situation where vibrational...

  5. The First Quantum Theory of Molecules

    Indian Academy of Sciences (India)

    IAS Admin

    with a kinetic energy proportional to the excess energy of that particle, subsequently called a photon. After one has recognized the quantum laws of nature, or the ... think of molecules as static entities, but Clausius had proposed a dynamic model in which molecules vibrated and rotated, in accordance with the recognition by ...

  6. The First Quantum Theory of Molecules

    Indian Academy of Sciences (India)

    IAS Admin

    In 1912, Bjerrum published the first quantum theory of molecules, to treat the vibrational and rotational energies of diatomic molecules. That theory was incorrect but prepared the next stages of development of quantum mechanics. The first quantum theory, which appeared in 1900, is considered to involve the derivation of a ...

  7. Hot Ground Vibration Tests

    Data.gov (United States)

    National Aeronautics and Space Administration — Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing...

  8. Electron attachment to excited molecules

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Pinnaduwage, L.A.; Datskos, P.G.

    1993-01-01

    Studies on electron attachment to molecules rotationally/vibrationally excited thermally or via infrared-laser excitation showed that the effect of internal energy of a molecule on its electron attachment properties depends on the mode--dissociative or nondissociative--of electron attachment. They quantified the effect of the internal energy of the molecule on the rate of destruction (by autodissociation or by autodetachment) of its parent transient anion. Generally, increases in ro-vibrational molecular energy increase the cross section for dissociative electron attachment and decrease the effective cross section for parent anion formation due mainly to increased autodetachment. These findings and their understanding are discussed. A discussion is given, also, of recent investigations of electron attachment to electronically excited molecules, especially photoenhanced dissociative electron attachment to long- and short-lived excited electronic states of molecules produced directly or indirectly by laser irradiation. These studies showed that the cross sections for dissociative electron attachment to electronically excited molecules usually are many orders of magnitude larger than those for the ground-state molecules. The new techniques that have been developed for such studies are briefly described also

  9. Theory of vibration protection

    CERN Document Server

    Karnovsky, Igor A

    2016-01-01

    This text is an advancement of the theory of vibration protection of mechanical systems with lumped and distributed parameters. The book offers various concepts and methods of solving vibration protection problems, discusses the advantages and disadvantages of different methods, and the fields of their effective applications. Fundamental approaches of vibration protection, which are considered in this book, are the passive, parametric and optimal active vibration protection. The passive vibration protection is based on vibration isolation, vibration damping and dynamic absorbers. Parametric vibration protection theory is based on the Shchipanov-Luzin invariance principle. Optimal active vibration protection theory is based on the Pontryagin principle and the Krein moment method. The book also contains special topics such as suppression of vibrations at the source of their occurrence and the harmful influence of vibrations on humans. Numerous examples, which illustrate the theoretical ideas of each chapter, ar...

  10. Control Operator for the Two-Dimensional Energized Wave Equation

    Directory of Open Access Journals (Sweden)

    Sunday Augustus REJU

    2006-07-01

    Full Text Available This paper studies the analytical model for the construction of the two-dimensional Energized wave equation. The control operator is given in term of space and time t independent variables. The integral quadratic objective cost functional is subject to the constraint of two-dimensional Energized diffusion, Heat and a source. The operator that shall be obtained extends the Conjugate Gradient method (ECGM as developed by Hestenes et al (1952, [1]. The new operator enables the computation of the penalty cost, optimal controls and state trajectories of the two-dimensional energized wave equation when apply to the Conjugate Gradient methods in (Waziri & Reju, LEJPT & LJS, Issues 9, 2006, [2-4] to appear in this series.

  11. Desarrollo de la Energía Mareomotriz en Chile.

    Directory of Open Access Journals (Sweden)

    Daniel Vega Salinas

    2014-10-01

    Full Text Available El presente artículo trata una revisión del estado del arte de la energía marina, que puede ser generada por las mareas o el oleaje, se analizaron las experiencias a nivel mundial, así como se estudió la factibilidad técnica y económica de la instalación de esta fuente de energía en Chile, específicamente para la industria del cultivo de salmón.

  12. Energía y cambio climático

    OpenAIRE

    Wilfredo Bulege Gutiérrez

    2014-01-01

    Es claro que el crecimiento de la población, la extracción de materiales, la producción alimentaria y el incremento de energía para todas las actividades humanas nos conducen a un estado de colisión con las capacidades de la biosfera y los ecosistemas en el proceso de asegurar la provisión de bienes y servicios indispensables para la vida (1). La producción de energía convencional y contaminante es hoy una de las más graves en este escenario, tanto que la comunidad internacional y las potenci...

  13. Panorama energético mundial y argentino

    OpenAIRE

    Guadagni, Alieto

    2007-01-01

    Estamos transitando aceleradamente de una etapa caracterizada por energía abundante, barata y exportada a otra etapa signada por la escasez, el alto costo y las importaciones. Esta es la triple tenaza energética que enfrenta la Argentina. Los actuales precios del petróleo están impulsando la producción de biocombustibles (biodiesel y etanol) en Brasil, la Unión Europea y los Estados Unidos, pero también muchos otros países como el nuestro. Se estima que su participación en el consumo mundi...

  14. Zero-point vibrational effects on optical rotation

    DEFF Research Database (Denmark)

    Ruud, K.; Taylor, P.R.; Åstrand, P.-O.

    2001-01-01

    We investigate the effects of molecular vibrations on the optical rotation in two chiral molecules, methyloxirane and trans-2,3-dimethylthiirane. It is shown that the magnitude of zero-point vibrational corrections increases as the electronic contribution to the optical rotation increases. Vibrat...... effects are the only source of optical activity, and we investigate the magnitude of these effects through calculations on mono-deuterated oxirane. (C) 2001 Elsevier Science B.V. All rights reserved....

  15. En cumplimiento con la orden ejecutiva del presidente Trump sobre la Independencia Energética

    Science.gov (United States)

    Acciones reglamentarias tomadas por la EPA, incluyendo audiencias públicas, para implementar la Orden Ejecutiva sobre la Independencia Energética y la propuesta derogación del Plan de Energía Limpia.

  16. Energía y cambio climático

    Directory of Open Access Journals (Sweden)

    Wilfredo Bulege Gutiérrez

    2014-06-01

    Full Text Available Es claro que el crecimiento de la población, la extracción de materiales, la producción alimentaria y el incremento de energía para todas las actividades humanas nos conducen a un estado de colisión con las capacidades de la biosfera y los ecosistemas en el proceso de asegurar la provisión de bienes y servicios indispensables para la vida (1. La producción de energía convencional y contaminante es hoy una de las más graves en este escenario, tanto que la comunidad internacional y las potencias ya han empezado a dar muestras de preocupación por la seguridad energética y, con ello por la amenaza del cambio climático. En el actual cambio climático por primera vez se viene demostrando que la humanidad ha cambiado decisivamente un ciclo liberando CO2 a la atmósfera a través de la quema de combustibles fósiles y cambios en el uso del suelo por más de 500 000 años. El origen del cambio climático se remonta a dos grandes transformaciones en el uso de la energía. En primer lugar, la energía hidráulica fue reemplazada por el carbón, una fuente de energía condensada por la naturaleza a lo largo de millones de años. Fue el aprovechamiento del carbón para nuevas tecnologías lo que propulsó la revolución industrial y desató aumentos sin precedentes en la productividad. La segunda gran transformación ocurrió 150 años más tarde. El petróleo había sido una fuente de energía humana durante milenios. En China, por ejemplo, se registran pozos petroleros ya en el siglo IV. No obstante, la utilización del petróleo para los motores de combustión interna a comienzos del siglo XX marcó el inicio de una revolución en el transporte. La quema de carbón y petróleo, junto con el gas natural, ha transformado a las sociedades humanas al proveerle la energía impulsora de grandes aumentos en la riqueza y la productividad, pero también ha impulsado el cambio climático (2. La economía humana ha crecido vertiginosamente, se multiplic

  17. Calculation of Vibrational Spectra of p-Ethylbenzenesulfonic Acid Hydrates

    Science.gov (United States)

    Zelenkovskii, V. M.; Bezyazychnaya, T. V.; Soldatov, V. S.

    2013-09-01

    Quantum-chemical calculations of vibrational spectra of the sulfonated ion-exchanger model p-ethylbenzenesulfonic acid hydrated by 1-10 water molecules and its dimer were calculated by the non-empirical SCF MO LCAO method with the 6-31G(d) basis set. The calculated results were compared with experimental IR and Raman spectra of sulfonated ion exchangers. The infl uence of hydration on the vibrational frequencies of functional groups in the ion exchangers was analyzed. It was shown that the sulfonic acid was completely dissociated if three and more water molecules per functional group were present. Bands near 1130 cm-1 were due to S-O-H bending vibrations in the absence of water molecules and C-S-O-H3O combination vibrations with 3-6 water molecules per sulfonic acid.

  18. Vibrational spectra of nickel metalloporphyrins: An algebraic approach

    Indian Academy of Sciences (India)

    ... molecules. In view of the considerable amount of experimental activity in this area, one needs theoretical models within which to interpret experimental data. Using Lie algebraic method, the vibrational energy levels of nickel metalloporphyrins like Ni(OEP), Ni porphyrin and Ni(TPP) are calculated for 16 vibrational modes.

  19. Ponte en onda: prende la energía limpia, (Spanish) Get Current

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-05-01

    Cambiar a tecnologías de energía limpia significa que fortalecemos la economía y protegemos al medio ambiente. Este libreto de actividades educativas para todas las edades promueve el uso consciente de la energía, con datos de distintas formas de energía aplicables y una variedad de rompecabezas y crucigramas en temas energéticos.

  20. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Molecule Matters – van der Waals Molecules - History and Some Perspectives on Intermolecular Forces ... Author Affiliations. E Arunan1. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  1. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Molecule Matters – van der Waals Molecules - History and Some Perspectives on Intermolecular Forces. E Arunan. Feature Article Volume 14 Issue 4 April 2009 pp 346-356 ...

  2. Dissociation Energies of Diatomic Molecules

    International Nuclear Information System (INIS)

    Qun-Chao, Fan; Wei-Guo, Sun

    2008-01-01

    Molecular dissociation energies of 10 electronic states of alkali molecules of KH, 7 LiD, 7 LiH, 6 LiH, NaK, NaLi and NaRb are studied using the highest three accurate vibrational energies of each electronic state, and an improved parameter-free analytical formula which is obtained starting from the LeRoy–Bernstein vibrational energy expression near the dissociation limit. The results show that as long as the highest three vibrational energies are accurate, the current analytical formula will give accurate theoretical dissociation energies D e theory , which are in excellent agreement with the experimental dissociation energies D e expt . (atomic and molecular physics)

  3. Vibrational population distributions in nonequilibrium nozzle expansion flows

    Science.gov (United States)

    Watt, W. S.; Rich, J. W.

    1971-01-01

    Experimental measurements and theoretical calculations of the vibrational population distribution in nonequilibrium nozzle expansion flows of gas mixtures are reported. These studies were directed toward determining whether vibrational energy exchange pumping could lead to laser action on the vibrational bands of a diatomic molecule. Three different types of experiments were conducted. These showed (1) that vibrational energy was preferentially transferred from N2 to CO in supersonic nozzle flows containing these gases; (2) that under some conditions this vibrational energy exchange pumping mechanism created population inversions in the vibrational levels of CO; and (3) that at large expansion ratios the magnitude of these population inversions was sufficient to sustain lasing in the nozzle. A theoretical model was developed to calculate vibrational state population distributions in gas dynamic expansions of a mixture of diatomic gases. Although only isothermal calculations have been completed, these data indicate that population inversions are predicted for conditions similar to those obtained in the nozzle expansion flows.

  4. Energy redistribution in diatomic molecules on surfaces

    International Nuclear Information System (INIS)

    Asscher, M.; Somorjai, G.A.

    1984-04-01

    Translational and internal degrees of freedom of a scattered beam of NO molecules from a Pt(111) single crystal surface were measured as a function of scattering angle and crystal temperature in the range 450 to 1250K. None of the three degrees of freedom were found to fully accommodate to the crystal temperature, the translational degree being the most accommodated and the rotational degree of freedom the least. A precursor state model is suggested to account for the incomplete accommodation of translational and vibrational degrees of freedom as a function of crystal temperature and incident beam energy. The vibrational accommodation is further discussed in terms of a competition between desorption and vibrational excitation processes, thus providing valuable information on the interaction between vibrationally excited molecules and surfaces. Energy transfer into rotational degrees of freedom is qualitatively discussed

  5. Thermodynamics properties of diatomic molecules with general molecular potential

    Science.gov (United States)

    Ikot, Akpan N.; Chukwuocha, E. O.; Onyeaju, M. C.; Onate, C. A.; Ita, B. I.; Udoh, M. E.

    2018-02-01

    In this paper, the energy spectra of the general molecular potential are obtained using the asymptotic iteration method within the framework of non-relativistic quantum mechanics.With the energy spectrum obtained, the vibrational partition function is calculated in a closed form and is used to obtain an expression for other thermodynamic functions such as vibrational mean energy U, vibrational mean free energy F, vibrational entropy S and vibrational specific heat capacity C. These thermodynamic functions are studied for the electronic state X1Σ _g^+ of K_2 diatomic molecules.

  6. Analysis of experimental positron-molecule binding energies

    International Nuclear Information System (INIS)

    Danielson, J R; Surko, C M; Young, J A

    2010-01-01

    Experiments show that positron annihilation on molecules frequently occurs via capture into vibrational Feshbach resonances. In these cases, the downshifts in the annihilation spectra from the vibrational mode spectra provide measures of the positron-molecule binding energies. An analysis of these binding energy data is presented in terms of the molecular dipole polarizability, the permanent dipole moment, and the number of π bonds in aromatic molecules. The results of this analysis are in reasonably good agreement with other information about positron-molecule bound states. Predictions for other targets and promising candidate molecules for further investigation are discussed.

  7. Planta de Energía Undimotriz en Dique Portuario

    OpenAIRE

    Carrillo, María

    2016-01-01

    Proyecto fin de carrera: Planta de oleaje, de energía undimotriz en dique de la propuesta de ampliación del Puerto de Tarifa, España. Documento 0: Viabilidad Pueden añadirse otros documentos del proyecto, en caso de interés.

  8. 29 CFR 1926.957 - Construction in energized substations.

    Science.gov (United States)

    2010-07-01

    ... exercised in the handling of busbars, tower steel, materials, and equipment in the vicinity of energized.... (1) Use of vehicles, gin poles, cranes, and other equipment in restricted or hazardous areas shall at all times be controlled by designated employees. (2) All mobile cranes and derricks shall be...

  9. Tunnel magnetoresistance of magnetic molecules with spin-vibron coupling

    Directory of Open Access Journals (Sweden)

    Ahmed Kenawy

    2017-05-01

    Full Text Available The effect of molecular vibrations on the tunnel magnetoresistance (TMR of a magnetic tunnel junction with a single spin-anisotropic molecule interconnecting its electrodes is investigated theoretically. We demonstrate that if these vibrations couple at the same time to the charge of tunneling electrons and to the spin of the molecule, the spin anisotropy of such a molecule becomes enhanced. This has, in turn, a profound impact on the TMR of such a device showing that molecular vibrations lead to a significant change of spin-polarized transport, differing for the parallel and antiparallel magnetic configuration of the junction.

  10. Optimal control of vibrational transitions of HCl

    Indian Academy of Sciences (India)

    Control of fundamental and overtone transitions of a vibration are studied for the diatomic molecule, HCl. Specifically, the results of the effect of variation of the penalty factor on the physical attributes of the system (i.e., probabilities) and pulse (i.e., amplitudes) considering three different pulse durations for each value of the ...

  11. Atkins' molecules

    CERN Document Server

    Atkins, Peters

    2003-01-01

    Originally published in 2003, this is the second edition of a title that was called 'the most beautiful chemistry book ever written'. In it, we see the molecules responsible for the experiences of our everyday life - including fabrics, drugs, plastics, explosives, detergents, fragrances, tastes, and sex. With engaging prose Peter Atkins gives a non-technical account of an incredible range of aspects of the world around us, showing unexpected connections, and giving an insight into how this amazing world can be understood in terms of the atoms and molecules from which it is built. The second edition includes dozens of extra molecules, graphical presentation, and an even more accessible and enthralling account of the molecules themselves.

  12. Interstellar Molecules

    Science.gov (United States)

    Solomon, Philip M.

    1973-01-01

    Radioastronomy reveals that clouds between the stars, once believed to consist of simple atoms, contain molecules as complex as seven atoms and may be the most massive objects in our Galaxy. (Author/DF)

  13. Elastic and inelastic vibrational cross sections for positron scattering by carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Tenfen, W. [Departamento de Física, Universidade Federal da Fronteira Sul, 85770-000, Realeza, Paraná (Brazil); Arretche, F., E-mail: fartch@gmail.com [Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina (Brazil); Michelin, S.E.; Mazon, K.T. [Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, Santa Catarina (Brazil)

    2015-11-01

    The vibrational cross sections of the CO molecule induced by positron impact is the focus of this work. The positron–molecule interaction is represented by the static potential plus a model potential designed to take into account the positron–target correlations. To calculate the vibrational cross sections, we applied the multichannel version of the continued fractions method in the close-coupling scheme. We present vibrational excitation cross sections and elastic ones, for the ground and excited vibrational states. The results are interpreted in terms of the vibrational coupling-scheme used in the scattering model.

  14. Proyecto de instalaciones energéticas renovables para edificio destinado a biblioteca

    OpenAIRE

    Manzanares Riguero, Verónica

    2013-01-01

    Este proyecto tiene como objetivo documentar el diseño de la integración de instalaciones energéticas renovables para un edificio destinado a biblioteca. Para ello se utilizarán sistemas energéticos renovables como paneles fotovoltaicos, paneles termodinámicos y microcogeneración. Se deberá saber la energía necesaria para mantener dicho edificio bajo las condiciones climáticas que imponga la normativa. Dicha energía será la que deberán aportar los sistemas energéticos renovables. Por lo...

  15. Sistema de Aprovechamiento de la Energía de las Olas del Mar

    OpenAIRE

    Pi Amorós, Gabriel

    2010-01-01

    Este documento describe un sistema de aprovechamiento de la energía transportada por el oleaje o energía undimotriz. El sistema no transformará la energía únicamente en electricidad si no que aprovecha dicha electricidad para producir hidrógeno mediante el proceso de la electrólisis del agua de mar. Es decir, el sistema propuesto es un sistema de generación de hidrógeno de origen renovable a partir de una fuente de energía renovable, la energía undimotriz. Las característica...

  16. Estudio del potencial de ahorro energético en edificación

    OpenAIRE

    Cifuentes García, Miguel Ángel

    2015-01-01

    Las conclusiones de este TFM son: -La Unión Europea tiene en la actualidad uno de los marcos normativos regulatorios más avanzados que le hace líder a nivel mundial en materia del uso eficiente de la energía.  -Es necesario romper la asociación entre el crecimiento energético y el consumo de energía, concienciando a la sociedad sobre los desafíos ambientales y el cambio climático, las ventajas de la eficiencia energética y la dependencia exterior.  -La eficiencia energétic...

  17. Estudio energético del sistema eléctrico en Ecuador. Impulso a la Energía Solar Fotovoltaica

    OpenAIRE

    Eras Almeida, Andrea Alejandra

    2012-01-01

    La realización de este proyecto en base a la legislación que promueve el desarrollo de la energía limpia, pretende mostrar los cambios que tendrá la matriz energética del Ecuador si se impone un aporte renovable a la producción de energía y sus beneficios con sus futuros proyectos emblemáticos. Así también, pretende el impulso a la energía solar fotovolataica a nivel de construcciones fijas, con inversión privada y para beneficio de la sociedad misma.

  18. Vibrations and Stability

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    About this textbook An ideal text for students that ties together classical and modern topics of advanced vibration analysis in an interesting and lucid manner. It provides students with a background in elementary vibrations with the tools necessary for understanding and analyzing more complex...... dynamical phenomena that can be encountered in engineering and scientific practice. It progresses steadily from linear vibration theory over various levels of nonlinearity to bifurcation analysis, global dynamics and chaotic vibrations. It trains the student to analyze simple models, recognize nonlinear...... and physics. This edition includes a new chapter on the useful effects of fast vibrations and many new exercise problems. Written for: Students in mechanical or structural engineering. Keywords: Nonlinear Vibrations, Bifurcations, Chaotic Vibrations, Vibrations and Stability....

  19. Human response to vibration

    National Research Council Canada - National Science Library

    Mansfield, Neil J

    2005-01-01

    .... Vibration measurements and standards are also addressed. This book meets the needs of those requiring knowledge of human response to vibration in order to make practical improvements to physical working environments...

  20. Vibrations and Stability

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    dynamical phenomena that can be encountered in engineering and scientific practice. It progresses steadily from linear vibration theory over various levels of nonlinearity to bifurcation analysis, global dynamics and chaotic vibrations. It trains the student to analyze simple models, recognize nonlinear...... and physics. This edition includes a new chapter on the useful effects of fast vibrations and many new exercise problems. Written for: Students in mechanical or structural engineering. Keywords: Nonlinear Vibrations, Bifurcations, Chaotic Vibrations, Vibrations and Stability.......About this textbook An ideal text for students that ties together classical and modern topics of advanced vibration analysis in an interesting and lucid manner. It provides students with a background in elementary vibrations with the tools necessary for understanding and analyzing more complex...

  1. Tunable Passive Vibration Suppressor

    Science.gov (United States)

    Boechler, Nicholas (Inventor); Dillon, Robert Peter (Inventor); Daraio, Chiara (Inventor); Davis, Gregory L. (Inventor); Shapiro, Andrew A. (Inventor); Borgonia, John Paul C. (Inventor); Kahn, Daniel Louis (Inventor)

    2016-01-01

    An apparatus and method for vibration suppression using a granular particle chain. The granular particle chain is statically compressed and the end particles of the chain are attached to a payload and vibration source. The properties of the granular particles along with the amount of static compression are chosen to provide desired filtering of vibrations.

  2. Vibration of plates

    CERN Document Server

    Chakraverty, Snehashish

    2008-01-01

    Plates are integral parts of most engineering structures and their vibration analysis is required for safe design. This work provides a comprehensive introduction to vibration theory and analysis of two-dimensional plates. It offers information on vibration problems along with a discussion of various plate geometries and boundary conditions.

  3. Vibrations and Eigenvalues

    Indian Academy of Sciences (India)

    We make music by causing strings, membranes, or air columns to vibrate. Engineers design safe structures by control- ling vibrations. I will describe to you a very simple vibrating system and the mathematics needed to analyse it. The ideas were born in the work of Joseph-Louis Lagrange (1736–1813), and I begin by quot-.

  4. Adhesion molecules

    CERN Document Server

    Preedy, Victor R

    2016-01-01

    This book covers the structure and classification of adhesion molecules in relation to signaling pathways and gene expression. It discusses immunohistochemical localization, neutrophil migration, and junctional, functional, and inflammatory adhesion molecules in pathologies such as leukocyte decompression sickness and ischemia reperfusion injury. Highlighting the medical applications of current research, chapters cover diabetes, obesity, and metabolic syndrome; hypoxia; kidney disease; smoking, atrial fibrillation, and heart disease, the brain and dementia; and tumor proliferation. Finally, it looks at molecular imaging and bioinformatics, high-throughput technologies, and chemotherapy.

  5. Matriz energética brasileira: uma prospectiva

    Directory of Open Access Journals (Sweden)

    Mauricio T. Tolmasquim

    2007-11-01

    Full Text Available O artigo apresenta uma prospectiva do setor energético brasileiro para o período 2005-30. As projeções apontam que o consumo de energia crescerá a taxas superiores às das últimas décadas e que a expansão da oferta energética poderá superar o dobro da atual capacidade instalada em todos os segmentos, especialmente os de petróleo, gás natural, etanol e eletricidade.The article presents a prospective for Brazilian energetic sector from 2005 to 2030. Projections state that consumption of energy will increase faster than in previous decades and that the supply of energetic power might be twice as big as today's capacity in all segments, specially oil, natural gas, ethanol and electricity.

  6. Statistical Distribution of Energization Overvoltages of EHV Cables

    DEFF Research Database (Denmark)

    Ohno, Teruo; Bak, Claus Leth; Ametani, Akihiro

    2013-01-01

    those on the overhead lines with respect to maximum, 2%, and mean values. As the minimum value is almost at the same level, standard deviations are smaller for the cables. The obtained statistical distributions in this paper are of a great importance in considering insulation levels of cable systems.......Statistical distributions of switching overvoltages have been used for decades for the determination of insulation levels of extremely high voltage (EHV) systems. Existing statistical distributions obtained in the 1970s are for overhead lines, and statistical distributions of switching overvoltages...... of EHV cables are not available to date. This paper derives the statistical distribution of energization overvoltages of EHV cables. Through the comparison of the statistical distributions of EHV cables and overhead lines, it has been found that line energization overvoltages on the cables are lower than...

  7. Studies on vibrational structure of diatomic molecular states

    International Nuclear Information System (INIS)

    Sun Weiguo; Hou Shilin; Ren Weiyi; Feng Hao

    2002-01-01

    Alternative expressions for vibrational and rotational spectrum constants and energies of diatomic molecular electronic states are suggested based on the perturbation theory. An algebraic method (AM) is proposed to generate converged full vibrational spectrum from limited energy data, and a potential variational method (PVM) is suggested to produce the vibrational force constants f n 's and rotational spectrum constants using the perturbation formulae and the AM vibrational constants. Applying this method to several diatomic electronic states, the calculation results show that: 1) the AM E υ max converges to correct molecular dissociation energy; 2) the AM not only reproduce the input energies, but also generate the E υ 's of high vibrational excited states which may be difficult to be obtained experimentally or theoretically; 3) the PVM vibrational force constants f n 's may be used to measure the relative chemical bond strength of different diatomic electronic states for a molecule quantitatively

  8. Spin-lattice relaxation in phosphorescent triplet state molecules

    International Nuclear Information System (INIS)

    Verbeek, P.J.F.

    1979-01-01

    The present thesis contains the results of a study of spin-lattice relaxation (SLR) in the photo-excited triplet state of aromatic molecules, dissolved in a molecular host crystal. It appears that SLR in phosphorescent triplet state molecules often is related to the presence of so-called (pseudo) localized phonons in the molecular mixed crystals. These local phonons can be thought to correspond with vibrations (librations) of the guest molecule in the force field of the surrounding host molecules. Since the intermolecular forces are relatively weak, the frequencies corresponding with these vibrations are relatively low and usually are of the order of 10-30 cm -1 . (Auth.)

  9. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Molecule Matters - Dinitrogen. A G Samuelson J Jabadurai. Volume 16 Issue 12 ... Author Affiliations. A G Samuelson1 J Jabadurai1. Department of Inroganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  10. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 5. Molecule Matters - N-Heterocyclic Carbenes - The Stable Form of R2 C: Anil J Elias. Feature Article Volume 13 Issue 5 May 2008 pp 456-467. Fulltext. Click here to view fulltext PDF. Permanent link:

  11. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Molecule Matters - A Chromium Compound with a Quintuple Bond. K C Kumara Swamy. Feature Article Volume 11 Issue 9 September 2006 pp 72-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  12. A new scaling algorithm for predicting vibrational spectra of ...

    Indian Academy of Sciences (India)

    Administrator

    RMS error 5 cm. –1. 4. Glycine molecule. Glycine exists as a neutral molecule in the gas phase. The vibrational spectrum of glycine in the gas phase has been studied recently by theory and experiment. 12. To check the methodology we tried. MP2/6-311++G** calculations on the most stable conformation of glycine. All the ...

  13. Anti-vibration gloves?

    Science.gov (United States)

    Hewitt, Sue; Dong, Ren G; Welcome, Daniel E; McDowell, Thomas W

    2015-03-01

    For exposure to hand-transmitted vibration (HTV), personal protective equipment is sold in the form of anti-vibration (AV) gloves, but it remains unclear how much these gloves actually reduce vibration exposure or prevent the development of hand-arm vibration syndrome in the workplace. This commentary describes some of the issues that surround the classification of AV gloves, the assessment of their effectiveness and their applicability in the workplace. The available information shows that AV gloves are unreliable as devices for controlling HTV exposures. Other means of vibration control, such as using alternative production techniques, low-vibration machinery, routine preventative maintenance regimes, and controlling exposure durations are far more likely to deliver effective vibration reductions and should be implemented. Furthermore, AV gloves may introduce some adverse effects such as increasing grip force and reducing manual dexterity. Therefore, one should balance the benefits of AV gloves and their potential adverse effects if their use is considered. © Crown copyright 2014.

  14. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  15. In-situ Studies of the Reactions of Bifunctional and Heterocyclic Molecules over Noble Metal Single Crystal and Nanoparticle Catalysts Studied with Kinetics and Sum-Frequency Generation Vibrational Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kliewer, Christopher J. [Univ. of California, Berkeley, CA (United States)

    2009-06-30

    Sum frequency generation surface vibrational spectroscopy (SFG-VS) in combination with gas chromatography (GC) was used in-situ to monitor surface bound reaction intermediates and reaction selectivities for the hydrogenation reactions of pyrrole, furan, pyridine, acrolein, crotonaldehyde, and prenal over Pt(111), Pt(100), Rh(111), and platinum nanoparticles under Torr reactant pressures and temperatures of 300K to 450K. The focus of this work is the correlation between the SFG-VS observed surface bound reaction intermediates and adsorption modes with the reaction selectivity, and how this is affected by catalyst structure and temperature. Pyrrole hydrogenation was investigated over Pt(111) and Rh(111) single crystals at Torr pressures. It was found that pyrrole adsorbs to Pt(111) perpendicularly by cleaving the N-H bond and binding through the nitrogen. However, over Rh(111) pyrrole adsorbs in a tilted geometry binding through the {pi}-aromatic orbitals. A surface-bound pyrroline reaction intermediate was detected over both surfaces with SFG-VS. It was found that the ring-cracking product butylamine is a reaction poison over both surfaces studied. Furan hydrogenation was studied over Pt(111), Pt(100), 10 nm cubic platinum nanoparticles and 1 nm platinum nanoparticles. The product distribution was observed to be highly structure sensitive and the acquired SFG-VS spectra reflected this sensitivity. Pt(100) exhibited more ring-cracking to form butanol than Pt(111), while the nanoparticles yielded higher selectivities for the partially saturated ring dihydrofuran. Pyridine hydrogenation was investigated over Pt(111) and Pt(100). The α-pyridyl surface adsorption mode was observed with SFG-VS over both surfaces. 1,4-dihydropyridine was seen as a surface intermediate over Pt(100) but not Pt(111). Upon heating the surfaces to 350K, the adsorbed pyridine changes to a flat-lying adsorption mode. No evidence was found for the pyridinium cation. The hydrogenation of the

  16. Dual traveling wave rotary ultrasonic motor with single active vibrator

    Science.gov (United States)

    An, Dawei; Yang, Ming; Zhuang, Xiaoqi; Yang, Tianyue; Meng, Fan; Dong, Zhaopeng

    2017-04-01

    Traveling wave rotary ultrasonic motor with double vibrators can improve the output performance effectively. However, the rotor has to be energized through a slip ring, which increases the complexity and reduces the reliability. Inheriting the concept of two traveling waves propagating in the stator and rotor, a dual traveling wave rotary ultrasonic motor energized only in the stator is proposed. By analyzing the oscillatory differential equation and the contact particles motion, a traveling wave is found in the rotor and the drive mechanism of dual traveling wave is studied. With the resonant rotor adopted, the consistent eigenfrequencies are calculated by finite element method and verified by an impedance analyzer. The performance experiment presents that the dual traveling wave rotary ultrasonic motor is superior to the motor with single traveling wave. The no-load speed is 60 rpm and the stalling torque is 0.85 Nm. Additionally, compared with a reported motor with double vibrators, the proposed motor presents the better output performance and the simpler design.

  17. Relationship between infrared and Raman intensities in molecules with polarized π electrons

    Science.gov (United States)

    Tommasini, M.; Castiglioni, C.; Del Zoppo, M.; Zerbi, G.

    1999-05-01

    A model is presented which allows to obtain a linear relationship between infrared and Raman intensity parameters of the strongest vibrational bands of push-pull conjugated molecules. The results obtained clarify the origin of the exceptionally large values of the vibrational first hyperpolarizability shown by these molecules.

  18. La energía humana el esfuerzo físico

    OpenAIRE

    Suárez Flórez, Luis

    2011-01-01

    Se llama la atención sobre la energía humana, su importancia como elemento de productividad y como principio ó quizás como fin de la actividad deportiva. Se estudia el máximo esfuerzo físico, así como también algunos conceptos acerca de la energía aeróbica y la energía anaeróbica.

  19. La energía humana el esfuerzo físico

    Directory of Open Access Journals (Sweden)

    Luis Suárez Flórez

    1991-01-01

    Full Text Available Se llama la atención sobre la energía humana, su importancia como elemento de productividad y como principio ó quizás como fin de la actividad deportiva. Se estudia el máximo esfuerzo físico, así como también algunos conceptos acerca de la energía aeróbica y la energía anaeróbica.

  20. Obtención de energía a partir de las corrientes marinas

    OpenAIRE

    Echeverría Cabodevilla, Álvaro

    2017-01-01

    El objetivo del proyecto es evaluar la viabilidad de una granja de energía hidrocinética en los territorios marinos españoles. Como se puede observar en el desarrollo del estudio, el resultado es negativo. En España no existe una gran zona que pueda ser utilizada para crear una granja de energía hidrocinética. La energía hidrocinética es aquella que utiliza la energía cinética del agua marina para obtener electricidad, principalmente los movimientos de agua de las corrientes ma...

  1. Energization of Long HVAC Cables in Parallel - Analysis and Estimation Formulas

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth

    2012-01-01

    The installation of long HVAC cables has recently become more common and it tends to increase during the next years. Consequently, the energization of long HVAC cables in parallel is also a more common condition. The energization of HVAC cables in parallel resembles the en-ergization of capacitor...... banks in parallel and high inrush currents are associated to both energization phenomena. The existing IEEE standard C37.012-2005 for capacitive switching proposes a formula that can be used to estimate the peak magnitude and frequency of the inrush current. However, for sake of simplicity, the formula...

  2. Energía Undimotriz, alternativa para la producción de Energía Eléctrica en la Provincia de Santa Elena

    Directory of Open Access Journals (Sweden)

    Rolando Calero

    2015-10-01

    Full Text Available La energía undimotriz, es la energía que permite obtener electricidad a partir de energía mecánica generada por el movimiento de las olas. Es uno de los tipos de energías renovables con más recientes estudios, y presenta enormes ventajas frente a otras energías renovables debido a que se tendría mayor facilidad para predecir condiciones geológicas óptimas que permitan la mayor eficiencia en sus procesos. Debido a que es más fácil llegar a predecir condiciones óptimas de oleaje, en comparación con la obtenida con  los vientos para obtener energía eólica, donde su variabilidad es menor.En este trabajo se espera aportar y dilucidar con datosespecíficos sobre la morfología de la zonamarítima en la provincia de Santa Elena, tratando depredecir si las características propias del lugar son idóneas  para producir electricidad en base a la implementación de energíaundimotriz, como fuente renovable no convencional utilizando las tecnologías actuales para este propósito.

  3. Vibrating fuel grapple. [LMFBR

    Science.gov (United States)

    Chertock, A.J.; Fox, J.N.; Weissinger, R.B.

    A reactor refueling method is described which utilizes a vibrating fuel grapple for removing spent fuel assemblies from a reactor core. It incorporates a pneumatic vibrator in the grapple head which allows additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  4. Importancia de las energías renovables en la seguridad energética y su relación con el crecimiento económico.

    Directory of Open Access Journals (Sweden)

    Lilian Paola Umbarila Valencia

    2015-12-01

    Full Text Available La creciente demanda de las necesidades sociales a nivel global, impulsada por los hábitos de vida y la forma en la que se organizan las regiones ha llevado al crecimiento paralelo de la industria y con ello al creciente aumento del consumo de energía. Este artículo de investigación reflexiona acerca de la relevancia que tienen las energías renovables para la seguridad energética, teniendo en cuenta la inestabilidad de los precios del petróleo y su influencia en el mercado de los hidrocarburos como fuente primaria de energía. Se evidencian los avances que han tenido las tecnologías de energías renovables a nivel global, regional y local y el rol que juegan en la independencia energética y en la mitigación del impacto ambiental. Se concluye que las naciones deben buscar la optimización de las energías renovables desde los ámbitos: local, regional y global propendiendo por su uso adecuado desde la legislación. El futuro de las energías renovables está dado por la rentabilidad, ya que para que el uso de éstas siga creciendo, deben seguir atrayendo capital lo cual significa que los inversores deben ver una rentabilidad competitiva. Otra recomendación importante es la integración de la energía renovable en la red, incluyendo fuentes de generación intermitentes e incluso imprevisibles. 

  5. Conocimiento de Energía: Principios Esenciales y Conceptos Fundamentales para la Educación de Energía

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-06-01

    This is the Spanish version of our Energy Literacy guidebook. Esta guía presenta conceptos de energía que, cuando se entienden y se aplican, ayudan a individuos y a comunidades a tomar decisiones sobre la energía con conocimiento de causa. No es un currículo sino que ofrece un marco sobre el cual puede basarse un plan de estudios. La guía se dirige a cualquier persona que participe en la educación de energía.

  6. Ciencia con Euclid: Materia y Energía Oscura

    OpenAIRE

    Pérez Garrido, Antonio; Díaz Sánchez, Anastasio; Jódar Ferrández, Ester; Toledo Moreo, Rafael; Villo Pérez, Isidro; Garrigós Guerrero, Francisco Javier; Martínez Álvarez, José Javier; Toledo Moreo, Francisco Javier; Ferrández Vicente, José Manuel

    2012-01-01

    Recientemente se aprobó la construcción del satélite espacial Euclid, que se encargará de indagar en dos de los grandes misterios actuales de la Ciencia: la materia oscura y la energía oscura. La UPCT participa tanto a nivel tecnológico como científico en esta misión espacial cuyo lanzamiento está previsto para el año 2019. Las primeras evidencias de la existencia de la materia oscura datan de 1932. Se presupone su existencia ya que, entre otras cosas, la distribución de velocidades de las es...

  7. La dependencia energética europea de Rusia

    OpenAIRE

    Sánchez Andrés, Antonio

    2008-01-01

    Con frecuencia se apunta que existe una dependencia energética de la UE que la hace muy vulnerable respecto a Rusia. En este trabajo se analizarán diversos contenidos de esa dependencia. En primer lugar, se estudiaran las ventas de gas y petróleo de Rusia a la UE. En segundo lugar, se abordan los problemas ligados a terceros países por donde transitan los hidrocarburos, que abren una dimensión nueva a la dependencia europea. En tercer lugar, se apuntan los proyectos de transporte que unen a R...

  8. Thermal ion-molecule reactions in oxygen-containing molecules

    International Nuclear Information System (INIS)

    Kumakura, Minoru

    1981-02-01

    The energetics of ions and the thermal ion-molecule reactions in oxygen-containing molecules have been studied with a modified time-of-flight mass spectrometer. It was found that the translational energy of ion can be easily obtained from analysis of the decay curve using the time-of-flight mass spectrometer. The condensation-elimination reactions proceeded via cross- and homo-elimination mechanism in which the nature of intermediate-complex could be correlated with the nature of reactant ion. It was elucidated that behavior of poly-atomic oxygen-containing ions on the condensation-elimination reactions is considerably influenced by their oxonium ion structures having functional groups. In addition, the rate constants of the condensation-elimination reactions have affected with the energy state of reactant ion and the dipole moment and/or the polarizability of neutral molecule. It was clarified that the rate constants of the ion-molecule clustering reactions in poly-atomic oxygen-containing molecules such as cyclic ether of six member rings are very large and the cluster ions are stable owing to the large number of vibrational degree of freedom in the cluster ions. (author)

  9. Modelling of energetic molecule-surface interactions

    International Nuclear Information System (INIS)

    Kerford, M.

    2000-09-01

    This thesis contains the results of molecular dynamics simulations of molecule-surface interactions, looking particularly at fullerene molecules and carbon surfaces. Energetic impacts of fullerene molecules on graphite create defect craters. The relationship between the parameters of the impacting molecule and the parameters of the crater axe examined and found to be a function of the energy and velocity of the impacting molecule. Less energetic fullerene molecules can be scattered from a graphite surface and the partitioning of energy after a scattering event is investigated. It is found that a large fraction of the kinetic energy retained after impact is translational energy, with a small fraction of rotational energy and a number of vibrational modes. At impact energies where the surface is not broken and at normal incidence, surface waves axe seen to occur. These waves axe used to develop a method of desorbing molecules from a graphite surface without damage to either the surface or the molecules being desorbed. A number of fullerene molecules are investigated and ways to increase the desorption yield are examined. It is found that this is a successful technique for desorbing large numbers of intact molecules from graphite. This technique could be used for desorbing intact molecules into a gas phase for mass spectrometric analysis. (author)

  10. Vibrational spectroscopy of proteins

    International Nuclear Information System (INIS)

    Schwaighofer, A.

    2013-01-01

    Two important steps for the development of a biosensor are the immobilization of the biological component (e.g. protein) on a surface and the enhancement of the signal to improve the sensitivity of detection. To address these subjects, the present work describes Fourier transform infrared (FTIR) investigations of several proteins bound to the surface of an attenuated total reflection (ATR) crystal. Furthermore, new nanostructured surfaces for signal enhancement were developed for use in FTIR microscopy. The mitochondrial redox-protein cytochrome c oxidase (CcO) was incorporated into a protein-tethered bilayer lipid membrane (ptBLM) on an ATR crystal featuring a roughened two-layer gold surface for signal enhancement. Electrochemical excitation by periodic potential pulses at different modulation frequencies was followed by time-resolved FTIR spectroscopy. Phase sensitive detection was used for deconvolution of the IR spectra into vibrational components. A model based on protonation-dependent chemical reaction kinetics could be fitted to the time evolution of IR bands attributed to several different redox centers of the CcO. Further investigations involved the odorant binding protein 14 (OBP14) of the honey bee (Apis mellifera), which was studied using ATR-FTIR spectroscopy and circular dichroism. OBP14 was found to be thermally stable up to 45 °C, thus permitting the potential application of this protein for the fabrication of biosensors. Thermal denaturation measurements showed that odorant binding increases the thermal stability of the OBP-odorant complex. In another project, plasmonic nanostructures were fabricated that enhance the absorbance in FTIR microscopy measurements. The nanostructures are composed of an array of round-shaped insulator and gold discs on top of a continuous gold layer. Enhancement factors of up to ⁓125 could be observed with self-assembled monolayers of dodecanethiol molecules immobilized on the gold surface (author) [de

  11. Theory of coherent molecule to surface electron injection: An ...

    Indian Academy of Sciences (India)

    Administrator

    erogeneous electron transfer from a molecule to a semiconductor occurs before full vibrational relaxa- tion of the excited molecule is achieved. 5,6. Accor- dingly, theoretical description of the decay of the initial state has been formulated to include vibra- tional coherence in the transfer process. 4. 2. Analytical model.

  12. SPECTRUM-GENERATING ALGEBRA FOR X(3) MOLECULES

    NARCIS (Netherlands)

    DIEPERINK, AEL; LEVIATAN, A

    1995-01-01

    A spectrum-generating algebra for a unified description of rotations and vibrations in polyatomic molecules is introduced. An application to nonlinear X(3) molecules shows that this model (i) incorporates exactly the relevant point group, (ii) provides a complete classification of oblate top states,

  13. Vibrational interference of Raman and high harmonic generation pathways

    International Nuclear Information System (INIS)

    Walters, Zachary B.; Tonzani, Stefano; Greene, Chris H.

    2009-01-01

    This paper presents a model of high harmonic generation which incorporates the internal vibrational degrees of freedom present in molecules. It is shown that vibrational dynamics during the HHG process cause the molecular wavefunction to interfere with itself, in a manner analogous to an optical beamsplitter. In addition, a semiclassical model of the continuum electron is developed which connects with rigorous treatments of electron-ion scattering.

  14. Molecular vibrational trapping revisited: a case study with D2+

    Science.gov (United States)

    Badankó, Péter; Halász, Gábor J.; Vibók, Ágnes

    2016-08-01

    The present theoretical study is concerned with the vibrational trapping or bond hardening, which is a well-known phenomenon predicted by a dressed state representation of small molecules like and in an intense laser field. This phenomenon is associated with a condition where the energy of the light induced, vibrational level coincides with one of the vibrational levels on the field-free potential curve, which at the same time maximizes the wave function overlap between these two levels. One-dimensional numerical simulations were performed to investigate this phenomenon in a more quantitative way than has been done previously by calculating the photodissociation probability of for a wide range of photon energy. The obtained results undoubtedly show that the nodal structure of the field-free vibrational wave functions plays a decisive role in the vibrational trapping, in addition to the current understanding of this phenomenon.

  15. Mechanical vibration and shock analysis, sinusoidal vibration

    CERN Document Server

    Lalanne, Christian

    2014-01-01

    Everything engineers need to know about mechanical vibration and shock...in one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to m

  16. Electron affinities of atoms, molecules, and radicals

    International Nuclear Information System (INIS)

    Christodoulides, A.A.; McCorkle, D.L.; Christophorou, L.G.

    1982-01-01

    We review briefly but comprehensively the theoretical, semiempirical and experimental methods employed to determine electron affinities (EAs) of atoms, molecules and radicals, and summarize the EA data obtained by these methods. The detailed processes underlying the principles of the experimental methods are discussed very briefly. It is, nonetheless, instructive to recapitulate the definition of EA and those of the related quantities, namely, the vertical detachment energy, VDE, and the vertical attachment energy, VAE. The EA of an atom is defined as the difference in total energy between the ground state of the neutral atom (plus the electron at rest at infinity) and its negative ion. The EA of a molecule is defined as the difference in energy between the neutral molecule plus an electron at rest at infinity and the molecular negative ion when both, the neutral molecules and the negative ion, are in their ground electronic, vibrational and rotational states. The VDE is defined as the minimum energy required to eject the electron from the negative ion (in its ground electronic and nuclear state) without changing the internuclear separation; since the vertical transition may leave the neutral molecule in an excited vibrational/rotational state, the VDE, although the same as the EA for atoms is, in general, different (larger than), from the EA for molecules. Similarly, the VAE is defined as the difference in energy between the neutral molecule in its ground electronic, vibrational and rotational states plus an electron at rest at infinity and the molecular negative ion formed by addition of an electron to the neutral molecule without allowing a change in the intermolecular separation of the constituent nuclei; it is a quantity appropriate to those cases where the lowest negative ion state lies above the ground states of the neutral species and is less or equal to EA

  17. Model Indepedent Vibration Control

    OpenAIRE

    Yuan, Jing

    2010-01-01

    A NMIFC system is proposed for broadband vibration control. It has two important features. Feature F1 is that the NMIFC is stable without introducing any invasive effects, such as probing signals or controller perturbations, into the vibration system; feature F2 is

  18. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 4th edition of this textbook on linear stochastic vibration...

  19. Handbook Of Noise And Vibration

    International Nuclear Information System (INIS)

    1995-12-01

    This book is about noise and vibration. The first chapter has explanations of noise such as basic of sound, influence of noise, assessment of noise, measurement of prevention of noise and technology, case of noise measurement and soundproof. The second chapter describes vibration with outline, theory of vibration, interpretation of vibration, measurement for reduction of vibration, case of design of protection against vibration. It deals with related regulation and method of measurement.

  20. Seguridad energética rusa: entre Europa y China

    Directory of Open Access Journals (Sweden)

    Antonio Sánchez

    2008-05-01

    Full Text Available Dentro de la seguridad energética rusa aparece como una debilidad importante la concentración de recursos en unos pocos clientes, en concreto en la UE. Por este motivo, las autoridades rusas están tratando de diversificar destinos de venta, tratando de abrir otros mercados, en especial en extremo oriente y, en particular en China. Esto acrecienta su seguridad energética, pero debilita la europea en caso de que la UE no adopte medidas activas. El abastecimiento a Europa desde Rusia, especialmente de gas, depende también de tres grandes limitaciones. En primer lugar, que existan nuevos yacimientos y su posibilidad de movilizarlos conforme aumenten las necesidades europeas. En segundo lugar, aparece el problema del surgimiento de competidores por el gas ruso y, en particular, recientemente se ha subrayado el papel de China como futuro cliente de gas ruso. En tercer lugar, se encuentra la posibilidad de que Rusia pueda ejercer un control especial sobre la oferta de gas mundial, que condicione en cantidad o/y precio el abastecimiento a Europa.

  1. Stimulus Novelty Energizes Actions in the Absence of Explicit Reward.

    Directory of Open Access Journals (Sweden)

    Raphael Koster

    Full Text Available Novelty seeking has been tied to impulsive choice and biased value based choice. It has been postulated that novel stimuli should trigger more vigorous approach and exploration. However, it is unclear whether stimulus novelty can enhance simple motor actions in the absence of explicit reward, a necessary condition for energizing approach and exploration in an entirely unfamiliar situation. In this study human subjects were cued to omit or perform actions in form of button presses by novel or familiar images. We found that subjects' motor actions were faster when cued by a novel compared to a familiar image. This facilitation by novelty was strongest when the delay between cue and action was short, consistent with a link between novelty and impulsive choices. The facilitation of reaction times by novelty was correlated across subjects with trait novelty seeking as measured in the Tridimensional Personality Questionnaire. However, this li between high novelty-seeking and action facilitation was driven by trials with a long delay between cue and action. This prolonged time window of energization following novelty could hint at a mechanistic underpinning of enhanced vigour for approach and exploration frequently postulated for novelty seeking humans. In conclusion, we show that stimulus novelty enhances the speed of a cued motor action. We suggest this is likely to reflect an adaptation to changing environments but may also provide a source of maladaptive choice and impulsive behaviour.

  2. Particle energization by inertial Alfven wave in auroral ionosphere

    Science.gov (United States)

    Kumar, S.

    2017-12-01

    The role of inertial Alfven wave in auroral acceleration region and in the inertial regime to energize the plasma particles is an interesting field and widely discussed observationally as well as theoretically in recent years. In this work, we present the density perturbations by inertial Alfvén wave (AW) in the auroral ionosphere. We obtain dynamical equations for inertial AW and fast mode of AW using two-fluid model and then solve them numerically in order to analyze the localized structures and cavity formation. The ponderomotive force due to the high frequency inertial AW changes the background density and is believed to be responsible for the wave localization or for the formation of density cavities in auroral ionosphere. These density cavities are believed to be the sites for particle energization. This perturbed density channel grow with time until the modulation instability acquires steady state. We find that the density cavities are accompanied by the high amplitude magnetic fields. The amplitude of the strongest density cavity is estimated as ˜ 0.26n0 (n0 is unperturbed plasma number density). The results presented here are found consistent with the observational studies using FAST spacecraft.

  3. Two-dimensional vibrational-electronic spectroscopy

    Science.gov (United States)

    Courtney, Trevor L.; Fox, Zachary W.; Slenkamp, Karla M.; Khalil, Munira

    2015-10-01

    Two-dimensional vibrational-electronic (2D VE) spectroscopy is a femtosecond Fourier transform (FT) third-order nonlinear technique that creates a link between existing 2D FT spectroscopies in the vibrational and electronic regions of the spectrum. 2D VE spectroscopy enables a direct measurement of infrared (IR) and electronic dipole moment cross terms by utilizing mid-IR pump and optical probe fields that are resonant with vibrational and electronic transitions, respectively, in a sample of interest. We detail this newly developed 2D VE spectroscopy experiment and outline the information contained in a 2D VE spectrum. We then use this technique and its single-pump counterpart (1D VE) to probe the vibrational-electronic couplings between high frequency cyanide stretching vibrations (νCN) and either a ligand-to-metal charge transfer transition ([FeIII(CN)6]3- dissolved in formamide) or a metal-to-metal charge transfer (MMCT) transition ([(CN)5FeIICNRuIII(NH3)5]- dissolved in formamide). The 2D VE spectra of both molecules reveal peaks resulting from coupled high- and low-frequency vibrational modes to the charge transfer transition. The time-evolving amplitudes and positions of the peaks in the 2D VE spectra report on coherent and incoherent vibrational energy transfer dynamics among the coupled vibrational modes and the charge transfer transition. The selectivity of 2D VE spectroscopy to vibronic processes is evidenced from the selective coupling of specific νCN modes to the MMCT transition in the mixed valence complex. The lineshapes in 2D VE spectra report on the correlation of the frequency fluctuations between the coupled vibrational and electronic frequencies in the mixed valence complex which has a time scale of 1 ps. The details and results of this study confirm the versatility of 2D VE spectroscopy and its applicability to probe how vibrations modulate charge and energy transfer in a wide range of complex molecular, material, and biological systems.

  4. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 12. Molecule Matters van der Waals Molecules - Noble Gas Clusters are London Molecules! E Arunan. Feature Article Volume 14 Issue 12 December 2009 pp 1210-1222 ...

  5. Structure, vibrations, and hydrogen bond parameters of dibenzotetraaza[14]annulene

    Science.gov (United States)

    Gawinkowski, S.; Eilmes, J.; Waluk, J.

    2010-07-01

    Geometry and vibrational structure of dibenzo[ b, i][1,4,8,11]tetraaza[14]annulene (TAA) have been studied using infrared and Raman spectroscopy combined with quantum-chemical calculations. The assignments were proposed for 106 out of the total of 108 TAA vibrations, based on comparison of the theoretical predictions with the experimental data obtained for the parent molecule and its isotopomer in which the NH protons were replaced by deuterons. Reassignments were suggesteded for the NH stretching and out-of-plane vibrations. The values of the parameters of the intramolecular NH⋯N hydrogen bonds were analysed in comparison with the corresponding data for porphyrin and porphycene, molecules with the same structural motif, a cavity composed of four nitrogen atoms and two inner protons. Both experiment and calculations suggest that the molecule of TAA is not planar and is present in a trans tautomeric form, with the protons located on the opposite nitrogen atoms.

  6. Vibrations of rotating machinery

    CERN Document Server

    Matsushita, Osami; Kanki, Hiroshi; Kobayashi, Masao; Keogh, Patrick

    2017-01-01

    This book opens with an explanation of the vibrations of a single degree-of-freedom (dof) system for all beginners. Subsequently, vibration analysis of multi-dof systems is explained by modal analysis. Mode synthesis modeling is then introduced for system reduction, which aids understanding in a simplified manner of how complicated rotors behave. Rotor balancing techniques are offered for rigid and flexible rotors through several examples. Consideration of gyroscopic influences on the rotordynamics is then provided and vibration evaluation of a rotor-bearing system is emphasized in terms of forward and backward whirl rotor motions through eigenvalue (natural frequency and damping ratio) analysis. In addition to these rotordynamics concerning rotating shaft vibration measured in a stationary reference frame, blade vibrations are analyzed with Coriolis forces expressed in a rotating reference frame. Other phenomena that may be assessed in stationary and rotating reference frames include stability characteristic...

  7. Vibrations in deformed nuclei

    International Nuclear Information System (INIS)

    Aprahamian, A.

    1992-01-01

    Quadrupole oscillations around a deformed shape give rise to vibrations in deformed nuclei. Single phonon vibrations of K = 0 (β) and K = 2 (γ) are a systematic feature in deformed nuclei, but the existence of multi-phonon vibrations had remained an open question until the recently reported results in 168 Er. In this nucleus, a two-phonon K = 4(γγ) band was observed at approximately 2.5 times the energy of the single γ vibration. The authors have studied several deformed rare-earth nuclei using the ( 4 He,2n) reaction in order to map out the systematic behavior of these multi-phonon vibrations. Recently, they have identified a similar K = 4 band in 154 Gd

  8. Simulating electric field interactions with polar molecules using spectroscopic databases.

    Science.gov (United States)

    Owens, Alec; Zak, Emil J; Chubb, Katy L; Yurchenko, Sergei N; Tennyson, Jonathan; Yachmenev, Andrey

    2017-03-24

    Ro-vibrational Stark-associated phenomena of small polyatomic molecules are modelled using extensive spectroscopic data generated as part of the ExoMol project. The external field Hamiltonian is built from the computed ro-vibrational line list of the molecule in question. The Hamiltonian we propose is general and suitable for any polar molecule in the presence of an electric field. By exploiting precomputed data, the often prohibitively expensive computations associated with high accuracy simulations of molecule-field interactions are avoided. Applications to strong terahertz field-induced ro-vibrational dynamics of PH 3 and NH 3 , and spontaneous emission data for optoelectrical Sisyphus cooling of H 2 CO and CH 3 Cl are discussed.

  9. Tensor-decomposed vibrational coupled-cluster theory

    DEFF Research Database (Denmark)

    Madsen, Niels Kristian; Godtliebsen, Ian Heide; Christiansen, Ove

    Vibrational coupled-cluster (VCC) theory is a highly accurate method for obtaining vibrational spectra and properties of small to medium-sized molecules. Calculating the vibrational energy and wave function requires the solution of a set of non-linear equations. We have implemented an array...... of any VCC calculation is the calculation of the error vector from a set of trial amplitudes. For high-order VCC methods this shows steep polynomial scaling w.r.t. the size of the moleule and the number of one-mode basis functions. Both the computational cost and the memory requirements of the VCC solver...

  10. Situación actual del sector energético en España

    Directory of Open Access Journals (Sweden)

    Carlos J. Pardo Abad

    2001-01-01

    Full Text Available La energía es un sector clave de la economía española y está presente en todos los procesos productivos. El artículo analiza al sector en los últimos años con datos procedentes de varios organismos públicos, referidos tanto al balance energético general como a los sectores energéticos, las energías renovables, la política energética y las relaciones entre energía y medio ambiente. Características básicas del sector en nuestro país son el incremento del consumo de energía, la progresiva liberalización y las grandes inversiones en energías renovables, sobre todo la eólica. Energy is a key sector of the Spanish economy and it is in all productivo processes.This article analyses the sector in the last fewyears with data from some public agencies, referred to the power balance as well as to nuclear power, coal, oil, natural gas, renewable energies, power policy and the relationship between energy and environment. The main eatures of energy in Spain are the increase of consumption, the growing liberation and the big investments in renewable energies, above all the eolic one.

  11. Voltage dip caused by the sequential energization of wind turbine transformers

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holbøll, Joachim; Sørensen, T.

    2009-01-01

    THIS paper presents the results from electromagnetic transient (emt) simulations using PSCAD, where the model of Nysted Offshore Wind Farm (NOWF) was created to simulate the voltage dips due to wind turbine transformer energization. Four different sequences energizing different numbers of wind tu...

  12. El futuro energético de Japón

    Directory of Open Access Journals (Sweden)

    María Francisca Casado

    2016-05-01

    Full Text Available Tras el triple desastre del 11 de marzo de 2011, Japón se encuentra en una encrucijada energética. A corto y medio plazo depende de las importaciones de combustibles fósiles para garantizar su seguridad energética, pero el largo plazo está por decidir y lo determinarán las decisiones que tome en estos años. Como consta en su Estrategia de Seguridad Nacional, para Japón la seguridad energética es una cuestión de seguridad nacional. El artículo revisa la trayectoria nuclear nipona, estudia cuáles son los factores que configuran el mercado eléctrico japonés y analiza su actual situación energética. Por otra parte, también repasa los principios que han marcado su política energética, deteniéndose a evaluar los dos últimos Planes Estratégicos de Energía –uno anterior y otro posterior a Fukushima- antes de adentrarse en el debate sobre la composición óptima del futuro mix energético para cumplir con su trilema de la seguridad energética, marcado por su compromiso con el medio ambiente.

  13. Ahorre Energía: Consejos para ahorro dinero y energía en su hogar (Spanish Brochure), Energy Saver Guide

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-11-01

    La versión en castellano de la guía del Departamento de Energía de los Estados Unidos que ayuda a consumidores a ahorrar energía y dinero en su hogar y en las carreteras. The Spanish-language version of U.S. Department of Energy's Energy Saver consumer guide to saving energy and money at home and on the road.

  14. Ahorre Energía: Consejos sobre el ahorro de dinero y energía en el hogar (Spanish Brochure), Energy Savers Guide

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-09-01

    La versión en castellano de la guía del Departamento de Energía de los Estados Unidos que ayuda a consumidores a ahorrar energía y dinero en el hogar y en las carreteras. The Spanish-language version of U.S. Department of Energy's consumer guide to saving energy and money at home and on the road.

  15. Testable, fault-tolerant power interface circuit for normally de-energized loads

    International Nuclear Information System (INIS)

    Hager, R.E.

    1987-01-01

    A power interface circuit is described for supplying power from a power line to a normally de-energized process control apparatus in a pressurized light water nuclear power system in dependence upon three input signals, comprising: voter means for supplying power to the normally de-energized load when at least two of the three input signals indicate that the normally de-energized load should be activated; a normally closed switch, operatively connected to the power line and the voter means, for supplying power to the voter means during ordinary operation; a first resistor operatively connected to the power line; a current detector operatively connected to the first resistor and the voter means; a second resistor operatively connected to the current detector and ground; and current sensor means, operatively connected between the voter means and the normally de-energized load, for detecting the power supplied to the normally de-energized load by the voter means

  16. Gasto energético en reposo y composición corporal en adultos

    OpenAIRE

    Vargas Z, Melier; Lancheros P., Lilia; Barrera P., María Del Pilar

    2011-01-01

    El requerimiento de energía  de una persona está relacionado con su gasto energético (GE) y se define como la energía que consume un organismo, está representado por la tasa metabólica basal (TMB), la actividad física (AF) y la termogénesis inducida por la dieta (TID). La TMB es la mínima cantidad de energía que un organismo requiere para estar vivo y representa del 60-70% del total del gasto energético (TGE), en la mayoría de los adultos sedentarios. La AF representa entre el 25-75% del TGE ...

  17. Fuentes convencionales y no convencionales de energía: estado actual y perspectivas

    Directory of Open Access Journals (Sweden)

    Paulo César Narváez Rincón

    2010-09-01

    Full Text Available Este artículo presenta un panorama mundial y nacional de las fuentes de energía y la distribución de su uso por tipo de combustible y los sectores a los que se destina. Describe algunas fuentes no convencionales de energía, haciendo énfasis en algunas cifras de aquellas que se clasifican como bioenergía y que se utilizan en mayor porcentaje en el transporte y en la generación de energía eléctrica. Introduce las políticas colombianas para el fomento del uso racional de la energía (URE y las fuentes de energía no convencionales (FENC y compara las metas colombianas con las que plantean la Comunidad Económica Europea y Estados Unidos.

  18. Modelado Energético de Convertidores Primarios para el Aprovechamiento de las Energías Renovables Marinas

    Directory of Open Access Journals (Sweden)

    Amable López

    2014-04-01

    Full Text Available Resumen: El objetivo principal de este artículo es presentar los métodos más habituales de aprovechamiento de distintos tipos de energías renovables procedentes del mar y analizar los modelos energéticos de los dispositivos utilizados para su explotación. Estos modelos son necesarios para el diseño del dispositivo así como para el estudio de su comportamiento dinámico. Su conocimiento resulta imprescindible también para su simulación dinámica y para el diseño de los algoritmos de control necesarios para conseguir una optimización energética y económica. En este trabajo se presentan algunos de los diferentes tipos de energías del mar, y se j ustifica el interés en el desarrollo de dispositivos específicos para el aprovechamiento de las corrientes marinas y de las olas, junto con una pequeña clasificación en función de la profundidad del agua en la zona de instalación de estos dispositivos. Para los convertidores de energía de las olas, generalmente, de tipo resonante, se presenta una metodología de tipo general, analizando los distintos campos de fuerzas actuantes y los métodos de obtención de las respuestas temporal y frecuencial. Para los dispositivos de aprovechamiento de las corrientes, se propone una metodología simplificada de modelado dinámico que puede ser utilizada en análisis del dispositivo concreto. Para ello se tiene en cuenta los perfiles hidrodinámicos que utilizan estos dispositivos, los datos del perfil de la corriente con la profundidad y del modelo de oleaje, y la dinámica propia del conjunto multiplicadora y generador eléctrico. La metodología propuesta se aplica al estudio de un caso concreto, correspondiente a un rotor de eje horizontal de un convertidor de energía de las corrientes. Los resultados obtenidos permiten analizar los efectos del oleaje y de las condiciones de flujo de la corriente no uniforme sobre las magnitudes energéticas más importantes. Abstract: The main objective of

  19. Nanostructure sensor of presence and concentration of a target molecule

    Science.gov (United States)

    Schipper, John F. (Inventor)

    2009-01-01

    Method and system (i) to determine when a selected target molecule is present or absent in a fluid, (2) to estimate concentration of the target molecule in the fluid and (3) estimate possible presence of a second (different) target molecule in the fluid, by analyzing differences in resonant frequencies of vibration of a thin beam suspended in the fluid, after the fluid has moved across the beam.

  20. Single Molecule Raman Detection of Enkephalin on Silver Colloidal Particles

    DEFF Research Database (Denmark)

    Kneipp, Katrin; Kneipp, Holger; Abdali, Salim

    2004-01-01

    the Raman signal the enkephalin molecules have been attached to silver colloidal cluster structures. The experiments demonstrate that the SERS signal of the strongly enhanced ring breathing vibration of phenylalanine at 1000 cm-1 can be used as “intrinsic marker” for detecting a single enkephalin molecule...... and for monitoring its diffusion on the surface of the silver colloidal cluster without using a specific label molecule....

  1. Single-Molecule Electronics with Cross- Conjugated Molecules: Quantum Interference, IETS and Non-Equilibrium "Temperatures"

    DEFF Research Database (Denmark)

    Jørgensen, Jacob Lykkebo

    Abstract The idea of using single-molecules as components in electronic devices is fas- cinating. For this idea to come into fruition, a number of technical and theo- retical challenges must be overcome. In this PhD thesis, the electron-phonon interaction is studied for a special class of molecules......, which is characterised by destructive quantum interference. The molecules are cross-conjugated, which means that the two parts of the molecules are conjugated to a third part, but not to each other. This gives rise to an anti-resonance in the trans- mission. In the low bias and low temperature regime......-conjugated molecules. We nd that the vibrational modes that would be expected to dominate, following the propensity, rules are very weak. Instead, other modes are found to be the dominant ones. We study this phenomenon for a number of cross-conjugated molecules, and link these ndings to the anti...

  2. Structural Stability and Vibration

    DEFF Research Database (Denmark)

    Wiggers, Sine Leergaard; Pedersen, Pauli

    This book offers an integrated introduction to the topic of stability and vibration. Strikingly, it describes stability as a function of boundary conditions and eigenfrequency as a function of both boundary conditions and column force. Based on a post graduate course held by the author at the Uni......This book offers an integrated introduction to the topic of stability and vibration. Strikingly, it describes stability as a function of boundary conditions and eigenfrequency as a function of both boundary conditions and column force. Based on a post graduate course held by the author...... and their derivation, thus stimulating them to write interactive and dynamic programs to analyze instability and vibrational modes....

  3. Study on infrared multiphoton excitation of the linear triatomic molecule by the Lie-algebra approach

    International Nuclear Information System (INIS)

    Feng, H.; Zheng, Y.; Ding, S.

    2007-01-01

    Infrared multiphoton vibrational excitation of the linear triatomic molecule has been studied using the quadratic anharmonic Lie-algebra model, unitary transformations, and Magnus approximation. An explicit Lie-algebra expression for the vibrational transition probability is obtained by using a Lie-algebra approach. This explicit Lie-algebra expressions for time-evolution operator and vibrational transition probabilities make the computation clearer and easier. The infrared multiphoton vibrational excitation of the DCN linear tri-atomic molecule is discussed as an example

  4. Vibration Analysis and the Accelerometer

    Science.gov (United States)

    Hammer, Paul

    2011-01-01

    Have you ever put your hand on an electric motor or motor-driven electric appliance and felt it vibrate? Ever wonder why it vibrates? What is there about the operation of the motor, or the object to which it is attached, that causes the vibrations? Is there anything "regular" about the vibrations, or are they the result of random causes? In this…

  5. Vibrational spectra and normal co-ordinate analysis of 2-aminopyridine and 2-amino picoline.

    Science.gov (United States)

    Jose, Sujin P; Mohan, S

    2006-05-01

    The Fourier transform infrared (FT-IR) and Raman (FT-R) spectra of 2-aminopyridine and 2-amino picoline were recorded and the observed frequencies were assigned to various modes of vibration in terms of fundamentals by assuming Cs point group symmetry. A normal co-ordinate analysis was also carried out for the proper assignment of the vibrational frequencies using simple valence force field. A complete vibrational analysis is presented here for the molecules and the results are briefly discussed.

  6. Smart Grid y la energía solar fotovoltaica para la generación distribuida: unarevisión en el contexto energético mundial

    OpenAIRE

    Luis Humberto Berrío; Carlos Zuluaga

    2014-01-01

    La Red Inteligente, considerada la siguiente generación de la red eléctrica tradicional, tiene entre sus objetivos la integración de fuentes de energía renovables. Por su parte, la demanda energética actual obliga a buscar nuevas formas de generación de energía, entre las cuales las fuentes de energía renovable están teniendo gran acogida, ya que son formas alter - nativas de generación de energía diferentes a las fuentes convencionales y no contaminan el medio ambiente. De hecho, este estudi...

  7. A vibration sieve

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S.A.; Denisenko, V.V.; Dzhalalov, M.G.; Kirichek, F.P.; Pitatel, Yu.A.; Prokopov, L.I.; Tikhonov, Yu.P.

    1982-01-01

    A vibration sieve is proposed which includes a vibration drive, a body and a screen installed on shock absorbers, a device for washing out the screen, and a subassembly for loading the material. To increase the operational reliability and effectiveness of the vibration sieve by improving the cleaning of the screen, the loading subassembly is equipped with a baffle with a lever which is hinged to it. The device for washing out the screen is made in the form of an electromagnet with a connecting rod, a switch and an eccentric, a friction ratchet mechanism and sprinkling systems. Here, the latter are interconnected, using a connecting rod, while the sprinkling system is installed on rollers under the screen. The electromagnetic switch is installed under the lever. The body is made with grooves for installing the sprinkling system. The vibration sieve is equipped with a switch which interacts with the connecting rod. The friction ratchet mechanism is equipped with a lug.

  8. Por uma nova ordem energética global? potencialidades e perspectivas da questão energética entre os países BRICS

    Directory of Open Access Journals (Sweden)

    José María Gómez

    2012-12-01

    Full Text Available O presente artigo propõe analisar a questão energética entre os BRICS e o potencial de rearticulação da ordem energética global que dela emerge. Para tal, realiza três movimentos. Em primeiro lugar, investiga o crescente impacto agregado dos países BRICS no cenário energético global, com vistas a analisar seu avanço em uma temática até então reduto dos países desenvolvidos. Em segundo lugar, aborda a matriz energética de cada um dos cinco países do ponto de vista de suas economias políticas e da questão da sustentabilidade. Em terceiro lugar, e com base na seção anterior, propõe mapear as áreas de conflito e de possível aproximação entre os BRICS, na tentativa de localizar as possibilidades e limites da sua cooperação energética. Com base nessa investigação, conclui que, diante das potencialidades para a cooperação entre os países, a organização de suas ofertas e demandas energéticas nacionais pode permitir ao agrupamento articular-se como um novo polo no cenário energético global.

  9. Aplicación electrónica para el ahorro de energía eléctrica utilizando una energía alternativa

    Directory of Open Access Journals (Sweden)

    Juan Carlos Cruz-Ardila

    2013-01-01

    Full Text Available El artículo presenta un trabajo orientado a disminuir el consumo de energía eléctrica entregada por la red eléctrica convencional, a través del aprovechamiento de la energía solar fotovoltaica. Se propone el diseño de un sistema de transferencia electrónica que facilita el uso de la energía eléctrica DC proveniente del panel solar, suprimiendo de esta manera, la utilización del inversor de voltaje, comúnmente usado en este tipo de aplicaciones y que eleva el costo de utilización de la energía solar. Se da a conocer inicialmente una revisión del estado del arte, que permite contextualizar el problema resuelto a partir de una energía renovable como la fotovoltaica, destacándose que actualmente España es el país con mayor desarrollo en este tema. Luego, se muestra el desarrollo secuencial del sistema de alimentación y la transferencia electrónica, haciendo una descripción de las variables identificadas y explicación, con el uso de diagramas de flujo, del sistema embebido implementado. También se da una descripción de los dispositivos usados tal como el sensor de corriente, la regulación y la rectificación. Se muestra el esquemático de la transferencia implementada. Finalmente, se revelan los resultados y las pruebas operacionales realizadas al sistema para demostrar la funcionalidad de la aplicación electrónica en el ahorro de la energía eléctrica utilizando una energía alternativa.

  10. Producción, Reservas y Sostenibilidad de la Energía en Venezuela

    Directory of Open Access Journals (Sweden)

    Juan Carlos Rojas-Zerpa

    2015-06-01

    Full Text Available El propósito del presente trabajo está relacionado con la evaluación de los recursos energéticos de Venezuela y su posicionamiento estratégico mundial, referido principalmente a la producción y consumo de energía primaria y reservas. Así mismo se han evaluado los recursos energéticos renovables con la finalidad de identificar oportunidades para el desarrollo de la energía sostenible. Los resultados indican que Venezuela posee recursos fósiles para más de 130 años de explotación, lo cual lo convierte en una potencia energética relevante en el contexto mundial. La potencialidad aprovechable de las energías renovables duplicó la producción de recursos fósiles en 2011. En la actualidad, el aprovechamiento de estas fuentes es inferior al 2 % del total disponible, lo que deja abierto un amplio rango de posibilidades para la diversificación de la matriz energética nacional mediante tecnologías limpias o sostenibles

  11. Intramolecular Vibrational Energy Transfer and Bond-Selected Photochemistry in Liquids

    National Research Council Canada - National Science Library

    Crim, F

    2001-01-01

    .... In the gas phase experiments, one pulse excited the first overtone of the O-H stretching vibration in nitric acid and the second pulse probed the excited molecule by excitation to a dissociative...

  12. Precise Ab-initio prediction of terahertz vibrational modes in crystalline systems

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd; Clark, Stewart J.

    2007-01-01

    We use a combination of experimental THz time-domain spectroscopy and ab-initio density functional perturbative theory to accurately predict the terahertz vibrational spectrum of molecules in the crystalline phase. Our calculations show that distinct vibrational modes found in solid-state materials...

  13. La inversión en energías renovables en Argentina

    OpenAIRE

    Recalde, Marina

    2017-01-01

    En este artículo se analiza en qué medida los factores del entorno de la política energética de un país en desarrollo, tal como Argentina, determinan la evolución de la inversión en energías renovables. La baja calidad institucional del país ayuda a crear condiciones no propicias que contrarrestan el efecto de la política energética, reduciendo los incentivos para invertir en tecnologías renovables. Es necesario entonces mejorar las condiciones institucionales de los países en desarrollo para...

  14. Asturias en el sistema energético: del nacionalismo a la globalización

    OpenAIRE

    Maurín Álvarez, Manuel

    2011-01-01

    Con una demanda energética regional estancada y al mismo tiempo en que se clausuran las últimas explotaciones mineras, principales proveedoras de materias primas energéticas autóctonas, Asturias se aventura a la construcción de infraestructuras de generación y transporte que permitirían duplicar en los próximos años una producción eléctrica que ya es excedentaria. La región se convierte así en una especie de «vientre de alquiler» energético, especializada en generar, con materias primas impor...

  15. Perspectivas de la situación energética mundial. Las oportunidades para Colombia

    OpenAIRE

    Arturo Infante Villarreal

    2007-01-01

    Casi la cuarta parte de la energía que consume Estados Unidos proviene de petróleo importado y sólo el 6% se origina en fuentes renovables, aunque el país produce 20% de la polución ambiental mundial y tiene sólo 4% de la población total. Los biocombustibles son una fuente potencial de energía renovable para Estados Unidos, y el resto del mundo, porque tienen un balance energético y ambiental bastante favorable. Si las condiciones de precios son adecuadas para los productores de las materias ...

  16. Eficiencia energética en el sector residencial de la ciudad de Cuenca, Ecuador

    OpenAIRE

    Baquero Larriva, María Teresa; Quesada Molina, Juan Felipe

    2016-01-01

    El objetivo de la presente investigación fue determinar en qué medida se puede reducir el consumo de energía en el sector residencial de la ciudad de Cuenca, manteniendo óptimas condiciones de confort. El estudio se centra en la definición de indicadores de eficiencia energética para la vivienda, mediante la determinación de la demanda de energía y la definición de los factores de mayor consumo, usando un enfoque cualitativo y cuantitativo. Se realizaron encuestas en 280 viviendas del sector ...

  17. Auditoria e optimização energética de uma unidade fabril

    OpenAIRE

    Vieira, Miguel Sérgio Martins

    2009-01-01

    A crise do petróleo em 1973 preocupou a população mundial e, desde então, os temas relacionados com a energia têm sido debatidos, sendo um dos mais importantes, a Melhoria da Eficiência Energética. O objectivo de corresponder às necessidades energéticas com a melhoria da eficiência em vez de aumentar a produção de energia tem sido, fortemente, ambicionado nos últimos anos. Esta Tese de Mestrado surge através da necessidade de uma unidade fabril reduzir a sua factura energética, que t...

  18. Balance de energía en cultivos hortícolas a campo en Rosario (Santa Fe, Argentina

    Directory of Open Access Journals (Sweden)

    J. Denoia

    2010-01-01

    Full Text Available Se analizó la gestión de la energía en cultivos de papa, tomate y lechuga en un área próxima a la ciudad de Rosario (Argentina. Se consideraron todos los ingresos de materia al sistema y su producción transformándolos en energía al multiplicar las cantidades de insumos por sus contenidos energéticos. Se analizó tanto la energía directa como la indirecta. Se estudió la gestión energética dentro de los límites físicos del sistema. Los indicadores empleados fueron: eficiencia energética (EfE y productividad energética (PE. Los balances energéticos de papa y tomate fueron negativos, mientras que en lechuga, la energía producida fue menor que la ingresada. La mayor eficiencia energética se registró en tomate (3,54, seguida por papa (2,69; la menor fue en lechuga (0,25. La energía ingresada en tomate resultó la más eficiente (88,6 kgMS/100 Mj, seguida por la de papa (16 kgMS/100 Mj y la de lechuga (10,8 kgMS/100 Mj.

  19. Vibrational and orientational dynamics of water in aqueous hydroxide solutions.

    Science.gov (United States)

    Hunger, Johannes; Liu, Liyuan; Tielrooij, Klaas-Jan; Bonn, Mischa; Bakker, Huib

    2011-09-28

    We report the vibrational and orientational dynamics of water molecules in isotopically diluted NaOH and NaOD solutions using polarization-resolved femtosecond vibrational spectroscopy and terahertz time-domain dielectric relaxation measurements. We observe a speed-up of the vibrational relaxation of the O-D stretching vibration of HDO molecules outside the first hydration shell of OH(-) from 1.7 ± 0.2 ps for neat water to 1.0 ± 0.2 ps for a solution of 5 M NaOH in HDO:H(2)O. For the O-H vibration of HDO molecules outside the first hydration shell of OD(-), we observe a similar speed-up from 750 ± 50 fs to 600 ± 50 fs for a solution of 6 M NaOD in HDO:D(2)O. The acceleration of the decay is assigned to fluctuations in the energy levels of the HDO molecules due to charge transfer events and charge fluctuations. The reorientation dynamics of water molecules outside the first hydration shell are observed to show the same time constant of 2.5 ± 0.2 ps as in bulk liquid water, indicating that there is no long range effect of the hydroxide ion on the hydrogen-bond structure of liquid water. The terahertz dielectric relaxation experiments show that the transfer of the hydroxide ion through liquid water involves the simultaneous motion of ~7 surrounding water molecules, considerably less than previously reported for the proton. © 2011 American Institute of Physics

  20. Exotic helium molecules; Molecules exotiques d'helium

    Energy Technology Data Exchange (ETDEWEB)

    Portier, M

    2007-12-15

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}P{sub 0}) molecule, or a {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 {+-} 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime {tau} = (1.4 {+-} 0.3) {mu}s is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  1. Raman Optical Activity of Biological Molecules

    Science.gov (United States)

    Blanch, Ewan W.; Barron, Laurence D.

    Now an incisive probe of biomolecular structure, Raman optical activity (ROA) measures a small difference in Raman scattering from chiral molecules in right- and left-circularly polarized light. As ROA spectra measure vibrational optical activity, they contain highly informative band structures sensitive to the secondary and tertiary structures of proteins, nucleic acids, viruses and carbohydrates as well as the absolute configurations of small molecules. In this review we present a survey of recent studies on biomolecular structure and dynamics using ROA and also a discussion of future applications of this powerful new technique in biomedical research.

  2. laser photoacoustic spectra and vibrational modes of heroin ...

    Indian Academy of Sciences (India)

    Heroin, morphine and narcotine are very large molecules having 50, 40 and 53 atoms respectively. Moderately high resolution photoacoustic (PA) spectra have been recorded in 9.6 m and 10.6 m regions of CO2 laser. It is very difficult to assign the modes of vibrations for PA bands by comparison with conventional low ...

  3. Vibrational spectra and normal coordinate analysis on structure of ...

    Indian Academy of Sciences (India)

    A normal coordinate analysis on chlorambucil and thioguanine has been carried out with a set of symmetry coordinates following Wilson's – matrix method. The potential constants evaluated for these molecules are found to be in good agreement with literature values thereby confirming the vibrational assignments.

  4. Vibrational echo spectral observables and frequency fluctuations of ...

    Indian Academy of Sciences (India)

    Deepak Ojha

    107 D2O molecules in a cubic box of edge length. 15.0 Å. The edge length was determined from the known experimental density of the solution at 300 K.51 ..... a theoretical study J. Phys. Chem. A 108 1275. 10. Bakker H J and Skinner J L 2009 Vibrational Spec- troscopy as a Probe of Structure and Dynamics in Liquid.

  5. CO 2 laser photoacoustic spectra and vibrational modes of heroin ...

    Indian Academy of Sciences (India)

    Heroin, morphine and narcotine are very large molecules having 50, 40 and 53 atoms respectively. Moderately high resolution photoacoustic (PA) spectra have been recorded in 9.6 m and 10.6 m regions of CO2 laser. It is very difficult to assign the modes of vibrations for PA bands by comparison with conventional low ...

  6. CO laser photoacoustic spectra and vibrational modes of heroin ...

    Indian Academy of Sciences (India)

    vibrations of these molecules for assignments of PA spectra. Keywords. Laser photoacoustic ... The assignment of these bands have been done in the light ofab initio calculations of normal mode frequencies. ..... a family of iteration methods called quasi-Newton methods which lead to very efficient geometry optimization.

  7. On the nature of highly vibrationally excited states of thiophosgene

    Indian Academy of Sciences (India)

    Understanding the nature of the highly excited molecu- lar eigenstates is equivalent to deciphering the mecha- nism of intramolecular vibrational energy redistribution. (IVR) occurring in the molecule.1 However, the assign- ment of eigenstates is far from simple. The existence of and interplay of several strong anharmonic ...

  8. Laser-induced vibrational dynamics of ozone in solid argon

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Amstrup, B.; Henriksen, Niels Engholm

    1997-01-01

    We consider the vibrational dynamics, induced by an intense infrared laser pulse, in an ozone molecule with isotopic substitution, that is, (OOO)-O-16-O-16-O-18 and compare the dynamics in the gas phase and in solid ar on. not perturbed by argon on a time-scale of a few picoseconds and selective...

  9. CO laser photoacoustic spectra and vibrational modes of heroin ...

    Indian Academy of Sciences (India)

    Abstract. Heroin, morphine and narcotine are very large molecules having 50, 40 and 53 atoms respectively. Moderately high resolution photoacoustic (PA) spectra have been recorded in 9.6 µm and 10.6 µm regions of CO2 laser. It is very difficult to assign the modes of vibrations for PA bands by comparison with ...

  10. Quantum control of vibrational excitations in a heteronuclear ...

    Indian Academy of Sciences (India)

    Optimal control theory is applied to obtain infrared laser pulses for selective vibrational excitation in a heteronuclear diatomic molecule. The problem of finding the optimized field is phrased as a maximization of a cost functional which depends on the laser field. A time dependent Gaussian factor is introduced in the field ...

  11. Quantum control of vibrational excitations in a heteronuclear ...

    Indian Academy of Sciences (India)

    WINTEC

    Abstract. Optimal control theory is applied to obtain infrared laser pulses for selective vibrational exci- tation in a heteronuclear diatomic molecule. The problem of finding the optimized field is phrased as a maximization of a cost functional which depends on the laser field. A time dependent Gaussian factor is introduced in ...

  12. Manipulation of molecular vibrational motions via pure rotational excitations

    DEFF Research Database (Denmark)

    Shu, Chuan-Cun; Henriksen, Niels Engholm

    2015-01-01

    The coupling between different molecular degrees of freedom plays a decisive role in many quantum phenomena, including electron transfer and energy redistribution. Here, we demonstrate a quantum-mechanical time-dependent simulation to explore how a vibrational motion in a molecule can be affected...

  13. Perspectivas de desarrollo de proyectos de energías alternativas ante la nueva regulación energética

    OpenAIRE

    Valencia Velásquez, Jaime Alejandro; Pérez O., Jaime A.; Moreno Ospina, Germán

    2000-01-01

    Los sistemas de generación de energía eléctrica a gran escala dominan los mercados energéticos, pensando en la palabra mercado desde una definición general y no sólo en la connotación actual que da la nueva regulación gubernamental en el campo energético. Este dominio de los mercados se ha dado porque en los balances económicos no se han incluido variables, y específicamente el medio ambiente, que ya empiezan a tener peso en el ámbito internacional. Se comentarán los planes de expansión de ge...

  14. Estudio del modelo energético de autoconsumo con balance neto para el riego agrícola mediante energía fotovoltaica

    OpenAIRE

    Hernández Calzada, José Ignacio

    2012-01-01

    El presente estudio examina la viabilidad económica de implantación de sistemas de energía fotovoltaica para suplir la energía eléctrica necesaria en los sistemas de riego agrario mediante un modelo de autoconsumo con balance neto con la red eléctrica. Para ello, se evalúan las necesidades hídricas de una rotación de cultivos específica en 4 zonas de Castilla y León, estableciendo los costes de la energía eléctrica para el suministro de riego. Únicamente en los casos de sistemas de riego con ...

  15. Vibration transducer calibration techniques

    Science.gov (United States)

    Brinkley, D. J.

    1980-09-01

    Techniques for the calibration of vibration transducers used in the Aeronautical Quality Assurance Directorate of the British Ministry of Defence are presented. Following a review of the types of measurements necessary in the calibration of vibration transducers, the performance requirements of vibration transducers, which can be used to measure acceleration, velocity or vibration amplitude, are discussed, with particular attention given to the piezoelectric accelerometer. Techniques for the accurate measurement of sinusoidal vibration amplitude in reference-grade transducers are then considered, including the use of a position sensitive photocell and the use of a Michelson laser interferometer. Means of comparing the output of working-grade accelerometers with that of previously calibrated reference-grade devices are then outlined, with attention given to a method employing a capacitance bridge technique and a method to be used at temperatures between -50 and 200 C. Automatic calibration procedures developed to speed up the calibration process are outlined, and future possible extensions of system software are indicated.

  16. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Molecule Matters van der Waals Molecules - Rg•••HF Complexes are Debye Molecules! E Arunan. Feature Article Volume 15 Issue 7 July 2010 pp 667-674. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 12. Molecule Matters van der Waals Molecules - Noble Gas Clusters are London Molecules! E Arunan ... Author Affiliations. E Arunan1. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  18. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Molecule Matters van der Waals Molecules - Rg•••HF Complexes are Debye Molecules! E Arunan ... Author Affiliations. E Arunan1. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  19. America Saves! Energizing Main Street's Small Businesses

    Energy Technology Data Exchange (ETDEWEB)

    Lindberg, James [National Trust for Historic Preservation, Washington, DC (United States)

    2016-09-30

    The America Saves! Energizing Main Street Small Businesses project engaged the 1,200-member National Main Street Center (NMSC) network of downtown organizations and other local, regional, and national partners to test a methodology for sharing customized energy efficiency information with owners of commercial buildings smaller than 50,000 square feet. Led by the National Trust for Historic Preservation’s Preservation Green Lab, the project marshalled local staff and volunteers to gather voluntarily-disclosed energy use information from participating businesses. This information was analyzed using a remote auditing tool (validated by the National Renewable Energy Lab) to assess energy savings opportunities and design retrofit strategies targeting seven building types (food service and sales, attached mixed-use, strip mall, retail, office, lodging, and schools). The original project design contemplated extensive leveraging of the Green Button protocol for sharing annualized utility data at a district scale. Due the lack of adoption of Green Button, the project partners developed customized approaches to data collection in each of twelve pilot communities. The project team encountered considerable challenges in gathering standardized annual utility data from local partners. After overcoming these issues, the data was uploaded to a data storehouse. Over 450 properties were benchmarked and the remote auditing tool was tested using full building profiles and utility records for more than 100 commercial properties in three of the pilot communities. The audit tool demonstrated potential for quickly capturing, analyzing, and communicating energy efficiency opportunities in small commercial buildings. However, the project team found that the unique physical characteristics and use patterns (partial vacancy, periodic intensive uses) of small commercial buildings required more trouble-shooting and data correction than was anticipated. In addition, the project revealed that

  20. Los tres principios de la economía de la energía

    OpenAIRE

    Carlos Giesecke

    1985-01-01

    El objetivo central de este artículo es presentar y explicar los tres prin- cipios básicos de la economía de la energía. El primer principio nos dice que los costos marginales de todas las fuentes de energía primaria y secundaria tie- nen una relación única. Esta relación depende de las posibilidades técnicas tanto del proceso de transformación productiva como de las alternativas de Sustitución en el consumo de energía del consumidor; según el nivel de com- petencia en el mercado de energía s...

  1. Situación energética de los hidrocarburos en el Perú

    OpenAIRE

    Rojas Lazo, Oswaldo; Rojas Rojas, Jorge; Salas Bacalla, Julio

    2014-01-01

    La tasa de crecimiento anual del consumo de energía en el mundo se incrementa a razón de 2 a 3%, teniendo a los hidrocarburos y el carbón como sus principales componentes. En el Perú las reservas probadas de energía son: gas (Camisea) con el 43% de la energía comercial, la hidroenergía 23,1%, los líquidos de gas natural con el 14,7% y otros con el 19.2%. La balanza comercial energética en el Perú es negativa, la producción de petróleo en los últimos años está descendiendo mientras que la prod...

  2. Costes de capacidad en un mercado eléctrico con energías intermitentes

    OpenAIRE

    Sánchez Mateos, Juan Pablo

    2011-01-01

    Se han publicado numerosos estudios en los que se indica que los costes de un sistema con energía eólica son superiores a los de otro sin energía eólica, así como que los precios de la energía son inferiores en el primero. Estas afirmaciones, sin embargo, no suelen tener en cuenta el parque de generación óptimo, y se trata de determinar, en un sistema tipo, estos costes adicionales. En el proyecto se determinará cuál es la diferencia entre los costes globales de un sistema con energía eólica ...

  3. Design of a hybrid power system based on solar cell and vibration energy harvester

    Science.gov (United States)

    Zhang, Bin; Li, Mingxue; Zhong, Shaoxuan; He, Zhichao; Zhang, Yufeng

    2018-03-01

    Power source has become a serious restriction of wireless sensor network. High efficiency, self-energized and long-life renewable source is the optimum solution for unmanned sensor network applications. However, single renewable power source can be easily affected by ambient environment, which influences stability of the system. In this work, a hybrid power system consists of a solar panel, a vibration energy harvester and a lithium battery is demonstrated. The system is able to harvest multiple types of ambient energy, which extends its applicability and feasibility. Experiments have been conducted to verify performance of the system.

  4. Cálculo del balance de energía para higuerilla (Ricinus communis L. desde las etapas de producción en campo hasta el valor energético de cada componente de la planta

    Directory of Open Access Journals (Sweden)

    Hipólito Ortíz-Laurel

    2017-01-01

    Full Text Available Introducción : Pruebas de balance de energía permiten redirigir los insumos desde las etapas de producción de un cultivo, e igualmente, precesar la cantidad de energía utilizada para cada proceso y así, verificar la eficiencia al transformar la energía contenida en el cultivo cuando debe cumplir con una función deseada. Método : la planta de higuerilla (Ricinus communis L. con propósitos de cultivo energético fue sembrada en campo y sometida a procesos de mantenimiento de l cultivo y en la cosecha, la planta completa fue colectada para análisis energético, donde cada una de sus partes inclu i das las semillas fueron evaluadas en función de su contenido de energía. Así, para determinar el balance de energía; los valores de la energía biológica de la planta fueron comparados con la energía aplicada en cada uno de los procesos técnicos y físicos para la producción del cult i vo y en su procesamiento . Resultados : La energía aplicada para producir el cultivo r esulta un 28% superior a la energía a obtener de la planta. Asimismo, la biomasa de la planta completa de higuerilla, sin contar las semillas genera el doble de energía comparado con el aceite de las semillas, por lo que, conviene utilizar toda la planta e n términos de energía . Conclusión : Es recomendable utilizar el aceite de las seillas como biomaterial, ya que el b a lance es positivo en un 15%.

  5. Ultrafast vibrational energy transfer at the water/air interface revealed by two-dimensional surface vibrational spectroscopy

    NARCIS (Netherlands)

    Zhang, Z.; Piatkowski, L.; Bakker, H.J.; Bonn, M.

    2011-01-01

    Water is very different from liquids of similar molecular weight, and one of its unique properties is the very efficient transfer of vibrational energy between molecules, which arises as a result of strong dipole-dipole interactions between the O-H oscillators. Although we have a sound understanding

  6. Implementación de energía solar y estudio de la energía eólica en Puerto Roma

    OpenAIRE

    Galarza Valarezo, Giovanny; Gordillo Vera, Carlos; Rivera Cáceres, Carlos

    2012-01-01

    Este proyecto de Tesis se basa en el estudio, diseño e implementación de un sistema para el aprovechamiento de la energía solar en la localidad de Puerto Roma, recinto ubicado en el Golfo de Guayaquil, Provincia del Guayas, debido al insuficiente suministró convencional eléctrico se implementó un sistema de iluminación mediante energía solar o fotovoltaico, beneficiando a seis familias, previo a una evaluación socio económica donde se planteó la solución integral solar. Además este proyec...

  7. Super-multiplex vibrational imaging

    Science.gov (United States)

    Wei, Lu; Chen, Zhixing; Shi, Lixue; Long, Rong; Anzalone, Andrew V.; Zhang, Luyuan; Hu, Fanghao; Yuste, Rafael; Cornish, Virginia W.; Min, Wei

    2017-04-01

    The ability to visualize directly a large number of distinct molecular species inside cells is increasingly essential for understanding complex systems and processes. Even though existing methods have successfully been used to explore structure-function relationships in nervous systems, to profile RNA in situ, to reveal the heterogeneity of tumour microenvironments and to study dynamic macromolecular assembly, it remains challenging to image many species with high selectivity and sensitivity under biological conditions. For instance, fluorescence microscopy faces a ‘colour barrier’, owing to the intrinsically broad (about 1,500 inverse centimetres) and featureless nature of fluorescence spectra that limits the number of resolvable colours to two to five (or seven to nine if using complicated instrumentation and analysis). Spontaneous Raman microscopy probes vibrational transitions with much narrower resonances (peak width of about 10 inverse centimetres) and so does not suffer from this problem, but weak signals make many bio-imaging applications impossible. Although surface-enhanced Raman scattering offers high sensitivity and multiplicity, it cannot be readily used to image specific molecular targets quantitatively inside live cells. Here we use stimulated Raman scattering under electronic pre-resonance conditions to image target molecules inside living cells with very high vibrational selectivity and sensitivity (down to 250 nanomolar with a time constant of 1 millisecond). We create a palette of triple-bond-conjugated near-infrared dyes that each displays a single peak in the cell-silent Raman spectral window; when combined with available fluorescent probes, this palette provides 24 resolvable colours, with the potential for further expansion. Proof-of-principle experiments on neuronal co-cultures and brain tissues reveal cell-type-dependent heterogeneities in DNA and protein metabolism under physiological and pathological conditions, underscoring the

  8. Far-infrared vibrational modes of DNA components studied by terahertz time-domain spectroscopy

    International Nuclear Information System (INIS)

    Fischer, B M; Walther, M; Jepsen, P Uhd

    2002-01-01

    The far-infrared dielectric function of a wide range of organic molecules is dominated by vibrations involving a substantial fraction of the atoms forming the molecule and motion associated with intermolecular hydrogen bond vibrations. Due to their collective nature such modes are highly sensitive to the intra- and intermolecular structure and thus provide a unique fingerprint of the conformational state of the molecule and effects of its environment. We demonstrate the use of terahertz time-domain spectroscopy (THz-TDS) for recording the far-infrared (0.5-4.0 THz) dielectric function of the four nucleobases and corresponding nucleosides forming the building blocks of deoxyribose nucleic acid (DNA). We observe numerous distinct spectral features with large differences between the molecules in both frequency-dependent absorption coefficient and index of refraction. Assisted by results from density-functional calculations we interpret the origin of the observed resonances as vibrations of hydrogen bonds between the molecules

  9. Vibrations in orthopedics.

    Science.gov (United States)

    Nokes, L D; Thorne, G C

    1988-01-01

    Measurements of various mechanical properties of skeletal material using vibration techniques have been reported. The purposes of such investigations include the monitoring of pathogenic disorders such as osteoporosis, the rate and extent of fracture healing, and the status of internal fixations. Early investigations pioneered the application of conventional vibration measurement equipment to biological systems. The more recent advent of the microcomputer has made available to research groups more sophisticated techniques for data acquisition and analysis. The economical advantages of such equipment has led to the development of portable research instrumentation which lends itself to use in a clinical environment. This review article reports on the developments and progression of the various vibrational techniques and theories as applied to musculoskeletal systems.

  10. Off-resonant vibrational excitation: Orientational dependence and spatial control of photofragments

    DEFF Research Database (Denmark)

    Machholm, Mette; Henriksen, Niels Engholm

    2000-01-01

    Off-resonant and resonant vibrational excitation with short intense infrared (IR) laser pulses creates localized oscillating wave packets, but differs by the efficiency of the excitation and surprisingly by the orientational dependence. Orientational selectivity of the vibrational excitation...... of randomly oriented heteronuclear diatomic molecules can be obtained under simultaneous irradiation by a resonant and an off-resonant intense IR laser pulse: Molecules with one initial orientation will be vibrationally excited, while those with the opposite orientation will be at rest. The orientation...

  11. Destructive de-energizing relationships: How thriving buffers their effect on performance.

    Science.gov (United States)

    Gerbasi, Alexandra; Porath, Christine L; Parker, Andrew; Spreitzer, Gretchen; Cross, Rob

    2015-09-01

    In this paper, we establish the relationship between de-energizing relationships and individual performance in organizations. To date, the emphasis in social network research has largely been on positive dimensions of relationships despite literature from social psychology revealing the prevalence and detrimental impact of de-energizing relationships. In 2 field studies, we show that de-energizing relationships in organizations are associated with decreased performance. In Study 1, we investigate how de-energizing relationships are related to lower performance using data from 161 people in the information technology (IT) department of an engineering firm. In Study 2, in a sample of 439 management consultants, we consider whether the effects of de-energizing relationships on performance may be moderated by the extent to which an individual has the psychological resource of thriving at work. We find that individuals who are thriving at work are less susceptible to the effects of de-energizing relationships on job performance. We close by discussing implications of this research. (c) 2015 APA, all rights reserved).

  12. Dissinfection of municipal sludge and wastewater by energized electrons

    International Nuclear Information System (INIS)

    Trump, J.G.; Wright, K.A.; Sinskey, A.J.; Shah, D.N.; Fernald, R.

    1979-01-01

    Laboratory studies at M.I.T. and high flow rate studies at the M.D.C. Deer Island Wastewater Treatment Plant in Boston have shown the practicality and cost effectiveness of disinfecting liquid municipal sludges by injecting energized electrons. A dosage of 400 Kilorads (4 Kilograys) reduces gram-negative bacteria, including coliforms, fecal coliforms, salmonellae and shigellae, in primary raw or anaerobically digested sludges to undetectable levels. Enteric viruses are reduced by one to two orders of magnitude. This treatment also destroys parasite eggs or renders them non-infectious. Model system studies indicate that trace toxic compounds such as PCBs in water are degraded. The estimated cost of sludge disinfection by electron treatment is about $0.80 per liquid tonne for modular systems of 650 liquid tonnes per day capacity. About 6 Kilowatt-hours of input electric power per tonne is required. The temperature rise of the disinfected watery sludge is about 2 0 C. Electron disinfection combined with subsurface soil injection offers an environmentally attractive, energy-efficient, and economic two -step process for land disposal of municipal sludges with water conservation and soil improvement benefits. Combined with widely-distributed ocean feeding, electron disinfection of the municipal sludge of coastal communities offers a safe marine nutrient for increasing fish population in treated ocean areas. The electron disinfection of effluent wastewater, in lieu of chlorination, is a future application which avoids the production of potentially toxic chlorinated hydrocarbons. (Author) [pt

  13. Calcium transport in vesicles energized by cytochrome oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Rosier, Randy N. [Univ. of Rochester, NY (United States)

    1979-01-01

    Experiments on the reconstitution of cytochrome oxidase into phospholipid vesicles were carried out using techniques of selectivity energizing the suspensions with ascorbate and cytochrome c or ascorbate, PMS, and internally trapped cytochrome c. It was found that the K+ selective ionophore valinomycin stimulated the rate of respiration of cytochrome oxidase vesicles regardless of the direction of the K+ flux across the vesicle membranes. The stimulation occurred in the presence of protonophoric uncouplers and in the complete absence of potassium or in detergent-lysed suspensions. Gramicidin had similar effects and it was determined that the ionophores acted by specific interaction with cytochrome oxidase rather than by the previously assumed collapse of membrane potentials. When hydrophobic proteins and appropriate coupling factors were incorporated into the cytochrome oxidase, vesicles phosphorylation of ADP could be coupled to the oxidation reaction of cytochrome oxidase. Relatively low P:O, representing poor coupling of the system, were problematical and precluded measurements of protonmotive force. However the system was used to study ion translocation.

  14. Energization of helium ions by proton-induced hydromagnetic waves

    International Nuclear Information System (INIS)

    Gendrin, R.; Roux, A.

    1980-01-01

    We consider the diffusion of He + ions under the influence of ion cyclotron waves generated in a plasma consisting of three different ion populations: a thermal isotropic population containing both H + and He + ions and an energetic H + population, with a positive anisotropy A=T/sub perpendicular//T/sub parallel/-1. We compute, in the velocity space upsilon/sub parallel/, upsilon/sub perpendicular/, the diffusion curves that He + ions will follow in the presence of ion cyclotron waves propagating in such a medium. We show that for small concentrations of the He + ions, of the order of 1 to approx.10%, these ions can be energized by such a process up to and above suprathermal energies (E> or approx. =20 eV). On some occasions the He + ions may even reach energies of the order of the Alfven energy of the cold plasma population: E/sub a/approx. =m/sub p/V/sub a/ 2 approx. =5 keV. Characteristic diffusion times, in pitch angle and energy, for both ion species, are evaluated. They are of the order of 2 to 20 min. These theoretical results are discussed in the frame of recent observations by Geos experimenters showing the close association that exists between the occurrence of ion cyclotron ULF waves and the presence of thermal or supra-thermal He + ions in the equatorial region of the magnetosphere

  15. Development and energization of IOT based RF amplifier

    International Nuclear Information System (INIS)

    Mandal, A.; Som, S.; Raj, P.R.; Manna, S.K.; Ghosh, S.; Seth, S.; Thakurta, S.; Thakur, S.K.; Saha, S.; Panda, U.S.

    2013-01-01

    A 704 MHz IOT based CW RF amplifier has been developed in VECC. It can also be used with proper tuning to power cavity modules operating at 650 MHz in high energy high intensity proton linear accelerator proposed to be built for ADSS/SNS programme in India and Project-X at Fermilab, USA. This IOT based amplifier provides up to 60 kW continuous wave RF power at 700 MHz. It required various power supplies, LCW cooling and forced air cooling for its operation. The auxiliary power supplies like Grid, Filament and Ion-pump, are floated and mounted on an isolated frame, i.e., HV deck. The mains inputs are electrically isolated by means of isolation transformer. Also, a Programmable Logic Controller (PLC) based interlocks along with high voltage collector power supply has been designed and developed for the safe operation of the RF amplifier. This paper discusses about various developments and energization of the IOT based RF amplifier with high power dummy load. (author)

  16. Re-energizing enquiry among our young professionals

    Science.gov (United States)

    Roychoudhuri, ChandraSekhar

    2017-08-01

    Children are born with enquiring mindset. They keep on asking questions to explore, understand and take part in their environment. However, modern educational systems discourage persistent enquiring questions. Most students, graduating from college, can use their enquiring faculties only to solve problems at hand. They accept the theories taught as the final models for the laws of nature. They safely assume that no further deeper enquiry is needed. This is a disturbing collective tendency counter to our continuously evolving nature. We should also consciously train our minds to evolve continuously by persistently asking enquiring questions. Therefore, we suggest that we take pro-active steps to re-energize the enquiring mindset among our young professionals by organizing enquiry forums for students from all international Student Chapters during most of our optical society meetings. Panels of volunteer senior scientists should encourage deep enquiring questions from the students. In this paper, as examples, I will present a set of enquiring questions in the field of optics that we have been underscoring to students. This is one of the three papers by this author for this conference, ETOP 100-43. Since scientific content-wise they complement each other, the readers should consult the others. They are: ETP100-36, "Consequences of repeated discovery and benign neglect of non-interaction of waves" and ETP100-83, and "Demonstration and implications when 50% beam combiners can behave as 0 or 100% reflector/transmitter inside some interferometers."

  17. Vibrations and waves

    CERN Document Server

    Kaliski, S

    2013-01-01

    This book gives a comprehensive overview of wave phenomena in different media with interacting mechanical, electromagnetic and other fields. Equations describing wave propagation in linear and non-linear elastic media are followed by equations of rheological models, models with internal rotational degrees of freedom and non-local interactions. Equations for coupled fields: thermal, elastic, electromagnetic, piezoelectric, and magneto-spin with adequate boundary conditions are also included. Together with its companion volume Vibrations and Waves. Part A: Vibrations this work provides a wealth

  18. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 2nd edition of this textbook on linear stochastic vibration th...... theory is basically unchanged in comparison to the 1st edition. Only section 4.2 on single input - single output systems and chapter 6 on offshore structures have been modified in order to enhance the clearness....

  19. Low-energy positron interactions with atoms and molecules

    International Nuclear Information System (INIS)

    Surko, C M; Gribakin, G F; Buckman, S J

    2005-01-01

    This paper is a review of low-energy positron interactions with atoms and molecules. Processes of interest include elastic scattering, electronic and vibrational excitation, ionization, positronium formation and annihilation. An overview is presented of the currently available theoretical and experimental techniques to study these phenomena, including the use of trap-based positron beam sources to study collision processes with improved energy resolution. State-resolved measurements of electronic and vibrational excitation cross sections and measurement of annihilation rates in atoms and molecules as a function of incident positron energy are discussed. Where data are available, comparisons are made with analogous electron scattering cross sections. Resonance phenomena, common in electron scattering, appear to be less common in positron scattering. Possible exceptions include the sharp onsets of positron-impact electronic and vibrational excitation of selected molecules. Recent energy-resolved studies of positron annihilation in hydrocarbons containing more than a few carbon atoms provide direct evidence that vibrational Feshbach resonances underpin the anomalously large annihilation rates observed for many polyatomic species. We discuss open questions regarding this process in larger molecules, as well as positron annihilation in smaller molecules where the theoretical picture is less clear. (topical review)

  20. Global bending quantum number and the absence of monodromy in the HCN-CNH molecule

    NARCIS (Netherlands)

    Efstathiou, K; Joyeux, M; Sadovskií, D. A.

    We introduce and analyze a model system based on a deformation of a spherical pendulum that can be used to reproduce large amplitude bending vibrations of flexible triatomic molecules with two stable linear equilibria. On the basis of our model and the recent vibrational potential [ J. Chem. Phys.

  1. Formation of ultracold NaRb Feshbach molecules

    International Nuclear Information System (INIS)

    Wang, Fudong; He, Xiaodong; Li, Xiaoke; Zhu, Bing; Chen, Jun; Wang, Dajun

    2015-01-01

    We report the creation of ultracold bosonic 23 Na 87 Rb Feshbach molecules via magneto-association. By ramping the magnetic field across an interspecies Feshbach resonance (FR), at least 4000 molecules can be produced out of the near degenerate ultracold mixture. Fast loss due to inelastic atom–molecule collisions is observed, which limits the pure molecule number, after residual atoms removal, to 1700. The pure molecule sample can live for 21.8(8) ms in the optical trap, long enough for future molecular spectroscopy studies toward coherently transferring to the singlet ro-vibrational ground state, where these molecules are stable against chemical reaction and have a permanent electric dipole moment of 3.3 Debye. We have also measured the Feshbach molecule’s binding energy near the FR by the oscillating magnetic field method and found these molecules have a large closed-channel fraction. (paper)

  2. Composite Struts Would Damp Vibrations

    Science.gov (United States)

    Dolgin, Benjamin P.

    1991-01-01

    New design of composite-material (fiber/matrix laminate) struts increases damping of longitudinal vibrations without decreasing longitudinal stiffness or increasing weight significantly. Plies with opposing chevron patterns of fibers convert longitudinal vibrational stresses into shear stresses in intermediate viscoelastic layer, which dissipate vibrational energy. Composite strut stronger than aluminum strut of same weight and stiffness.

  3. Development of vibrating insoles

    NARCIS (Netherlands)

    Hijmans, J.M.; Geertzen, J.H.B.; Schokker, B.; Postema, K.

    2007-01-01

    The objective of this study was to describe the development of vibrating insoles. Insoles, providing a subsensory mechanical noise signal to the plantar side of the feet, may improve balance in healthy young and older people and in patients with stroke or diabetic neuropathy. This study describes

  4. Structural Stability and Vibration

    DEFF Research Database (Denmark)

    Wiggers, Sine Leergaard; Pedersen, Pauli

    This book offers an integrated introduction to the topic of stability and vibration. Strikingly, it describes stability as a function of boundary conditions and eigenfrequency as a function of both boundary conditions and column force. Based on a post graduate course held by the author...

  5. Vibrations and Eigenvalues

    Indian Academy of Sciences (India)

    rical or mechanical reasonings, but solely algebraic [analytic] operations subjected to a uniform and regular procedure. Those. Keywords. Vibrations, eigenvalues .... Suggested Reading. [1] R Bhatia, Fourier Series, Hindustan Book Agency, Second Edition, 2003. [2] G Strang, Essays in Linear Algebra, SIAM, 2012. 872.

  6. Compact Vibration Damper

    Science.gov (United States)

    Ivanco, Thomas G. (Inventor)

    2014-01-01

    A vibration damper includes a rigid base with a mass coupled thereto for linear movement thereon. Springs coupled to the mass compress in response to the linear movement along either of two opposing directions. A converter coupled to the mass converts the linear movement to a corresponding rotational movement. A rotary damper coupled to the converter damps the rotational movement.

  7. Blade Vibration Measurement System

    Science.gov (United States)

    Platt, Michael J.

    2014-01-01

    The Phase I project successfully demonstrated that an advanced noncontacting stress measurement system (NSMS) could improve classification of blade vibration response in terms of mistuning and closely spaced modes. The Phase II work confirmed the microwave sensor design process, modified the sensor so it is compatible as an upgrade to existing NSMS, and improved and finalized the NSMS software. The result will be stand-alone radar/tip timing radar signal conditioning for current conventional NSMS users (as an upgrade) and new users. The hybrid system will use frequency data and relative mode vibration levels from the radar sensor to provide substantially superior capabilities over current blade-vibration measurement technology. This frequency data, coupled with a reduced number of tip timing probes, will result in a system capable of detecting complex blade vibrations that would confound traditional NSMS systems. The hardware and software package was validated on a compressor rig at Mechanical Solutions, Inc. (MSI). Finally, the hybrid radar/tip timing NSMS software package and associated sensor hardware will be installed for use in the NASA Glenn spin pit test facility.

  8. Man-Induced Vibrations

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Hansen, Lars Pilegaard

    1994-01-01

    work has been done on the measurement of the exact load functions and related reponse analysis. A recent work using a spectral description has been performed by Per-Erik Erikson and includes a good literature survey. Bachmann and Ammann give a good overview of vibrations caused by human activity. Other...

  9. Vibration characteristics of ultrasonic complex vibration for hole machining

    Science.gov (United States)

    Asami, Takuya; Miura, Hikaru

    2012-05-01

    Complex vibration sources that use diagonal slits as a longitudinal-torsional vibration converter have been applied to ultrasonic motors, ultrasonic rock drilling, and ultrasonic welding. However, there are few examples of the application of these sources to ultrasonic machining in combination with an abrasive. Accordingly, a new method has been developed for machining of holes in brittle materials by using the ultrasonic longitudinal and torsional vibration of a hollow-type stepped horn with a diagonal slit vibration converter. In this paper, we compared vibration of a uniform rod and a hollow-type stepped horn, both with diagonal slits, when the conditions of the diagonal slits are constant.

  10. Stabilizing photoassociated Cs2 molecules by optimal control

    International Nuclear Information System (INIS)

    Zhang Wei; Xie Ting; Huang Yin; Wang Gao-Ren; Cong Shu-Lin

    2013-01-01

    We demonstrate theoretically that photoassociated molecules can be stabilized to deeply bound states. This process is achieved by transferring the population from the outer well to the inner well using the optimal control theory, the Cs 2 molecule is taken as an example. Numerical calculations show that weakly bound molecules formed in the outer well by a pump pulse can be compressed to the inner well via a vibrational level of the ground electronic state as an intermediary by an additionally optimized laser pulse. The positively chirped pulse can enhance the population of the target state. With a transform-limited dump pulse, nearly all the photoassociated molecules in the inner well of the excited electronic state can be transferred to the deeply vibrational level of the ground electronic state. (atomic and molecular physics)

  11. Layers of Cold Dipolar Molecules in the Harmonic Approximation

    DEFF Research Database (Denmark)

    R. Armstrong, J.; Zinner, Nikolaj Thomas; V. Fedorov, D.

    2012-01-01

    We consider the N-body problem in a layered geometry containing cold polar molecules with dipole moments that are polarized perpendicular to the layers. A harmonic approximation is used to simplify the hamiltonian and bound state properties of the two-body inter-layer dipolar potential are used...... to adjust this effective interaction. To model the intra-layer repulsion of the polar molecules, we introduce a repulsive inter-molecule potential that can be parametrically varied. Single chains containing one molecule in each layer, as well as multi-chain structures in many layers are discussed...... and their energies and radii determined. We extract the normal modes of the various systems as measures of their volatility and eventually of instability, and compare our findings to the excitations in crystals. We find modes that can be classified as either chains vibrating in phase or as layers vibrating against...

  12. Interactions Between Ground-State Nitrogen Atoms and Molecules

    Science.gov (United States)

    Vanderslice, Joseph T.; Mason, Edward A.; Lippincott, Ellis R.

    1959-01-01

    Potential-energy curves for nitrogen atom (N-N) interactions corresponding to the X (1)Sigma(sup +, sub g), A (3)Sigma(sup +, sub u), (5)Sigma(sup +, sub g), (7)Sigma(sup +, sub u), B (3) Pi(sub g), C (3)(Pi(su u)and a (1)Pi(sub g) states of the nitrogen molecule N2 as well as curves for the atom-molecules (N-N2) and molecule-molecule (N2-N2) interactions have been calculated. All calculations have been based as nearly as possible on experimental data, including spectroscopically determined vibrational energy levels, scattering cross sections of atomic beams in gases, and measured vibrational relaxation times. In cases where experimental data were not available, approximate quantum-mechanical calculations have been made. Results obtained by these various methods are remarkably consistent with one another and are believed to have good accuracy.

  13. Long-Lived Feshbach Molecules in a Three-Dimensional Optical Lattice

    International Nuclear Information System (INIS)

    Thalhammer, G.; Winkler, K.; Lang, F.; Schmid, S.; Denschlag, J. Hecker; Grimm, R.

    2006-01-01

    We have created and trapped a pure sample of 87 Rb 2 Feshbach molecules in a three-dimensional optical lattice. Compared to previous experiments without a lattice, we find dramatic improvements such as long lifetimes of up to 700 ms and a near unit efficiency for converting tightly confined atom pairs into molecules. The lattice shields the trapped molecules from collisions and, thus, overcomes the problem of inelastic decay by vibrational quenching. Furthermore, we have developed an advanced purification scheme that removes residual atoms, resulting in a lattice in which individual sites are either empty or filled with a single molecule in the vibrational ground state of the lattice

  14. La Seguridad Energética y la Estrategia Global de Seguridad de la Unión Europea

    Directory of Open Access Journals (Sweden)

    Ruben Herrero

    2016-10-01

    Full Text Available El presente artículo plantea una definición ampliada del concepto de seguridad energética, yendo más allá del concepto clásico establecido por la Agencia Internacional de la Energía, incorporando cuestiones relativas a la eficiencia energética, la aceptabilidad del modelo energético y los retos que impone el cambio climático, pero sin perder de perspectiva las exigencias y las dinámicas competitivas económicas globales. Sobre la base de este concepto ampliado, se examina la evolución de la seguridad energética en el marco de la Unión Europea, con una atención particular a cómo se concibe la seguridad energética en la Estrategia Global de Seguridad de 2016.

  15. Resonant inelastic collisions of electrons with diatomic molecules

    International Nuclear Information System (INIS)

    Houfek, Karel

    2012-01-01

    In this contribution we give a review of applications of the nonlocal resonance theory which has been successfully used for treating the nuclear dynamics of low-energy electron collisions with diatomic molecules over several decades. We give examples and brief explanations of various structures observed in the cross sections of vibrational excitation and dissociative electron attachment to diatomic molecules such as threshold peaks, boomerang oscillations below the dissociative attachment threshold, or outer-well resonances.

  16. Patterns of energy levels and spectra for polyatomic molecules

    International Nuclear Information System (INIS)

    Harter, W.G.

    1983-01-01

    Laser spectroscopy has revealed a remarkable intricacy in the rotational, vibrational, and electronic energy levels for polyatomic molecules. The infrared spectra of SF 6 , CF 4 , and related molecules contain several levels of structure on top of structure which resembles a fractal in some ways. The purpose of this article will be to exhibit some of this structure and introduce the simplest theoretical interpretations of it which are presently available

  17. Examining the impact of harmonic correlation on vibrational frequencies calculated in localized coordinates

    Science.gov (United States)

    Hanson-Heine, Magnus W. D.

    2015-10-01

    Carefully choosing a set of optimized coordinates for performing vibrational frequency calculations can significantly reduce the anharmonic correlation energy from the self-consistent field treatment of molecular vibrations. However, moving away from normal coordinates also introduces an additional source of correlation energy arising from mode-coupling at the harmonic level. The impact of this new component of the vibrational energy is examined for a range of molecules, and a method is proposed for correcting the resulting self-consistent field frequencies by adding the full coupling energy from connected pairs of harmonic and pseudoharmonic modes, termed vibrational self-consistent field (harmonic correlation). This approach is found to lift the vibrational degeneracies arising from coordinate optimization and provides better agreement with experimental and benchmark frequencies than uncorrected vibrational self-consistent field theory without relying on traditional correlated methods.

  18. Rotational dependence of Fermi-type resonance interactions in molecules

    Science.gov (United States)

    Mikhailov, Vladimir M.; Smirnov, M. A.

    1997-03-01

    In Pasadena, (Milliken Lab., USA, 1930) F. Rossetti has observed in Raman spectrum of carbon-dioxide molecule the full symmetric vibration of carbon dioxide appeared as the group of four near lying lines instead of the waited single line. The true interpretation of this enigmatic effect (in that time) was given by E. Fermi -- accidental degeneration of the first excited state of the full symmetric vibration in carbon dioxide. It was the first example of the event observed later in various organic molecules. This event was named as resonance Fermi. The rotational dependence of Fermi type resonance interactions in quasirigid molecules in dominant approximation can be selected in an expansion of the effective vibration-rotation Hamiltonian Hvib- roteff by the operator H(g)(Fermi) equals H30 plus (Sigma) nH3n(g). Let us consider in detail the problem of the construction of the effective vibration-rotational Hamiltonian HVR yields Heff from the point of view of various ordering schemes (grouping) of the vibrational-rotational interactions with sequential analysis of the choice of the convenient grouping adequate to the spectroscopic problem.

  19. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    RESONANCE. February 2015. GENERAL ARTICLE. Single-Molecule Spectroscopy. Every Molecule is Different! Kankan Bhattacharyya. Keywords. Single-molecule ..... Resonance Energy. Transfer (FRET) is an elegant technique to measure the distance between a donor and an acceptor molecule. FRET refers to the.

  20. Molecule of the Month.

    Indian Academy of Sciences (India)

    Molecule of the Month. Corannulene - A Bucky Bowl. H Surya Prakash Rao. The structure, properties and synthesis of a bowl shaped molecule, which resembles a fragment of fullerene, are described here. Chemistry of aromatic molecules has a long history. Many molecules made up of multiple benzene-like rings have ...

  1. Apparatus for deploying and energizing submersible electric motor downhole

    International Nuclear Information System (INIS)

    Conner, S.E.; Dwiggins, J.L.; Brookbank, E.B.

    1991-01-01

    This patent describes an apparatus for deploying and energizing a submergible electric motor downhole. It comprises a cable socket assembly and a cable connecting-and-sealing chamber assembly adapted to be arranged seriatim in the path of cable means and the motor, the assemblies having first and second housings, respectively, means for connecting a lower end of the first housing to an upper end of the second housing, a lower end of the second housing being adapted for connection to the motor, the cable socket assembly having an attachment portion including means for attaching a weight-bearing cable of the cable means to the first housing via a breakaway connection, the first housing having a passage therein adapted to pass an electrical cable of the cable means to the second housing, the second housing being divided by a body therein into first and second chambers sealed from each other, the first chamber being adapted to communicate sealingly with the passage and the second chamber being adapted to communicate sealingly with the interior of the motor, a first set of electrical conductors in the first chamber and a second set of electrical conductors in the second chamber, the body having feed-through means for electrically interconnecting conductors of the first set with corresponding conductors of the second set, the conductors of the first set having electrical connector parts adapted to connect releasably with corresponding electrical connector parts of the electrical cable, and the conductors of the second set having electrical connector parts adapted to connect with corresponding electrical connector parts of the motor, each of the chambers being adapted to be filled with fluid to exclude well fluid therefrom

  2. The effects of vibration-reducing gloves on finger vibration

    Science.gov (United States)

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2015-01-01

    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration can cause hand-arm vibration syndrome. Vibration-reducing gloves have been used as an alternative approach to reduce the vibration exposure. However, their effectiveness for reducing finger-transmitted vibrations remains unclear. This study enhanced the understanding of the glove effects on finger vibration and provided useful information on the effectiveness of typical VR gloves at reducing the vibration transmitted to the fingers. The new

  3. Costo energético de muros y techos utilizados en la zona sur de Tamaulipas

    Directory of Open Access Journals (Sweden)

    Mireya Alicia Rosas Lusett

    2015-01-01

    Full Text Available El presente trabajo muestra los procedimientos y resultados obtenidos del análisis de la energía trasmitida en techos y muros de las viviendas seleccionadas de la zona sur del estado de Tamaulipas, una de las cinco áreas establecidas dentro del proyecto “Desarrollo y validación de una metodología para estimar los impactos en el ahorro de energía por el uso de sistemas pasivo-constructivos en la edificación para diferentes climas de México”. Este proyecto fue financiado por la Convocatoria S0019-2009-01 del Fondo Sectorial de Sustentabilidad Energética SENER-CONACYT con registro Nº 118665, cuyo objetivo en su tercera etapa de ejecución, consistió en hacer uso de la herramienta Ener-Habitat, la cual fue desarrollada durante la segunda fase del proyecto. Con dicho programa de cálculo se determinaron los gastos de energía, comparativa de cuatro sistemas constructivos para muros y tres sistemas constructivos para losas utilizadas en la zona sur de Tamaulipas. Con la información obtenida y mediante el uso de la metodología desarrollada para estimar los impactos en el ahorro de energía, se evaluó el costo energético de cada uno de los sistemas constructivos. Con los resultados obtenidos se pudo determinar cuál era el muro y techo de menor gasto de energía para la zona de estudio. Adicionalmente se realizó un estudio de la influencia de la absortancia solar de la superficie exterior de los muros, cuyos resultados darán la pauta para diseñar una vivienda que pretende sea adecuada y cómoda al clima cálido húmedo que prevalece en el área.

  4. Estudio para el ahorro de energía en alumbrado público de la base naval sur

    OpenAIRE

    Cazco Arizaga, Alex; Aragundi Rodriguez, Jorge

    2009-01-01

    El costo elevado de la energía eléctrica en nuestro país produce la necesidad de buscar alternativas para conseguir el ahorro energético, en cuanto a esto, el consumo de energía por concepto de alumbrado público tiene un valor considerable dentro de los sistemas eléctricos. Con el fin de alcanzar el ahorro de energía en alumbrado público en la Base Naval Sur, se elabora el presente trabajo, el mismo que inicia con la determinación del consumo real de las luminarias, de ahí se obtuvo ...

  5. La Seguridad Energética y la Estrategia Global de Seguridad de la Unión Europea

    OpenAIRE

    Herrero Castro, Rubén

    2016-01-01

    El presente artículo plantea una definición ampliada del concepto de seguridad energética, yendo más allá del concepto clásico establecido por la Agencia Internacional de la Energía, incorporando cuestiones relativas a la eficiencia energética, la aceptabilidad del modelo energético y los retos que impone el cambio climático, pero sin perder de perspectiva las exigencias y las dinámicas competitivas económicas globales. Sobre la base de este concepto ampliado, se examina la evolución de la se...

  6. Estudio de la energía del mar y posibles aplicaciones en las costas Españolas

    OpenAIRE

    Dolgov, Viktor

    2015-01-01

    El objetivo principal de este trabajo es analizar el método o sistema que mejor se adapta a las costas españolas para aprovechar la energía del mar. La postura filosófica adoptada a la hora de realizar el siguiente proyecto se orienta hacia el racionalismo. Una vez analizadas las diferentes posibilidades, se han excluido las menos rentables y eficientes. En este trabajo se han estudiado 5 maneras de aprovechar la energía del mar: 1. Energía mareomotriz 2. Energía de las corrientes marinas 3. ...

  7. Cuantificación del potencial energético undimotriz en las costas del Caribe colombiano

    OpenAIRE

    Jaime P; Wilson Becerra Colpas

    2017-01-01

    En este documento se describen los avances en la cuantificación de la energía de las olas de la costa caribeña colombiana. La metodología utilizada servirá como punto de partida para establecer el potencial energético en Colombia para este tipo de suministro energético. En la actualidad, el potencial energético teórico estimado en las ondas de la costa cercana en la costa atlántica es de aproximadamente 1107 MW y esto fue posible con datos que se han recogido y procesado desde enero de 2014. ...

  8. Uso de dispositivos móviles en zonas rurales aisladas abastecidas con energía solar fotovoltaica

    OpenAIRE

    Rocabado Moreno, Sergio Hernán; Díaz, Francisco Javier; Cadena, Carlos

    2015-01-01

    En el presente trabajo se propone el uso de dispositivos móviles, con recarga basada en energía solar fotovoltaica, para acceder a información digital desde zonas rurales que se encuentren fuera del alcance de los centros de distribución de energía. Se realizaron mediciones de la potencia utilizada por un dispositivo móvil ubicado en una zona rural aislada, inicialmente se determinó el consumo de energía del celular sin carga de trabajo (e0), luego se midió el consumo adicional de energía (e1...

  9. Simulations of vibrational relaxation in dense molecular fluids

    International Nuclear Information System (INIS)

    Holian, B.L.

    1985-07-01

    In the understanding of high-temperatre and -pressure chemistry in explosives, first step is the study of the transfer of energy from translational degrees of freedom into internal vibrations of the molecules. We present new methods using nonequilibrium molecular dynamics (NEMD) for measuring vibrational relaxation in a diatomic fluid, where we expect a classical treatment of many-body collisions to be relevant because of the high densities (2 to 3 times compressed compared to the normal fluid) and high temperatures (2000 to 4000 K) involved behind detonation waves. NEMD techniques are discussed, including their limitations, and qualitative results presented

  10. Ultrafast Dynamics of Vibration-Cavity Polariton Modes

    Science.gov (United States)

    Owrutsky, Jeff; Dunkelberger, Adam; Fears, Kenan; Simpkins, Blake; Spann, Bryan

    Vibrational modes of polymers, liquids, and solvated compounds can couple to Fabry-Perot optical cavity modes, creating vibration-cavity polariton modes whose energy tunes with the cavity length and incidence angle. Here we report the pump-probe infrared spectroscopy of vibration-cavity polaritons in cavity-coupled W(CO)6. At very early times, we observe quantum beating between the two polariton states find an anomalously low degree of excitation. After the quantum beating, we directly observe spectroscopic signatures of excited-state absorption from both polariton modes and uncoupled reservoir modes. An analytical expression for cavity transmission reproduces these signatures. The upper polariton mode relaxes ten times more quickly than the uncoupled vibrational mode and the polariton lifetime depends on the angle of incidence of the infrared pulses. Coupling to an optical cavity gives a means of control of the lifetime of vibration-cavity polaritons and could have important implications for chemical reactivity in vibrationally excited molecules.

  11. Vibration Attenuation of Plate Using Multiple Vibration Absorbers

    Directory of Open Access Journals (Sweden)

    Zaman Izzuddin

    2014-07-01

    Full Text Available Vibrations are undesired phenomenon and it can cause harm, distress and unsettling influence to the systems or structures, for example, aircraft, automobile, machinery and building. One of the approach to limit this vibration by introducing passive vibration absorber attached to the structure. In this paper, the adequacy of utilizing passive vibration absorbers are investigated. The vibration absorber system is designed to minimize the vibration of a thin plate fixed along edges. The plate’s vibration characteristics, such as, natural frequency and mode shape are determined using three techniques: theoretical equations, finite element (FE analysis and experiment. The results demonstrate that the first four natural frequencies of fixed-fixed ends plate are 48, 121, 193 and 242 Hz, and these results are corroborated well with theoretical, FE simulation and experiment. The experiment work is further carried out with attached single and multiple vibration absorbers onto plate by tuning the absorber’s frequency to match with the excitation frequency. The outcomes depict that multiple vibration absorbers are more viable in lessening the global structural vibration.

  12. Theory of the (e,2e) reaction on molecules II

    International Nuclear Information System (INIS)

    McCarthy, I.E.

    1975-01-01

    The theory of (e,2e) reactions given in a previous publication is modified in the light of experience with fitting data for atoms and molecules. The molecular orbitals are linear combinations of atomic orbitals in spherical polar coordinates. The general formulation is greatly simplified by using closure over unresolved rotational and vibrational states. Concrete examples of interest are formulated and discussed. (author)

  13. Intense field non-resonant multiphoton absorption of diatomic molecules

    International Nuclear Information System (INIS)

    We report on the results of nonlinear ionization and dissociation of gas-phase diatomic molecules, H 2 , D 2 , O 2 , and Cl 2 , in an intense (10 11-14 W/cm 2 ) laser field. Measurements include energy and angularly resolved vibrational photoelectron spectroscopy, as well as mass spectroscopy. 5 refs., 2 figs

  14. Double ionization of molecule H2 in intense ultrashort laser fields

    International Nuclear Information System (INIS)

    Le, Thu-Thuy; Nguyen, Ngoc-Ty

    2015-01-01

    By solving numerically the time-dependent Schrödinger equation (TDSE), we have calculated the double ionization probability when a vibrating hydrogen molecule interacts with intense ultrashort laser pulses. The results show that in the case of vibrating nuclei the double ionization probability is higher than that of the fixed nuclei. Additionally, the double ionization probability is larger if the molecule is vibrating in a higher level. This is due to the decreasing of ionization potential when the inter-nuclei separation increases. (paper)

  15. Energy-resolved positron annihilation for molecules

    International Nuclear Information System (INIS)

    Barnes, L.D.; Gilbert, S.J.; Surko, C.M.

    2003-01-01

    This paper presents an experimental study designed to address the long-standing question regarding the origin of very large positron annihilation rates observed for many molecules. We report a study of the annihilation, resolved as a function of positron energy (ΔE∼25 meV, full width at half maximum) for positron energies from 50 meV to several eV. Annihilation measurements are presented for a range of hydrocarbon molecules, including a detailed study of alkanes, C n H 2n+2 , for n=1-9 and 12. Data for other molecules are also presented: C 2 H 2 , C 2 H 4 ; CD 4 ; isopentane; partially fluorinated and fluorinated methane (CH x F 4-x ); 1-fluorohexane (C 6 H 13 F) and 1-fluorononane (C 9 H 19 F). A key feature of the results is very large enhancements in the annihilation rates at positron energies corresponding to the excitation of molecular vibrations in larger alkane molecules. These enhancements are believed to be responsible for the large annihilation rates observed for Maxwellian distributions of positrons in molecular gases. In alkane molecules larger than ethane (C 2 H 6 ), the position of these peaks is shifted downward by an amount ∼20 meV per carbon. The results presented here are generally consistent with a physical picture recently considered in detail by Gribakin [Phys. Rev. A 61, 022720 (2000)]. In this model, the incoming positron excites a vibrational Feshbach resonance and is temporarily trapped on the molecule, greatly enhancing the probability of annihilation. The applicability of this model and the resulting enhancement in annihilation rate relies on the existence of positron-molecule bound states. In accord with this reasoning, the experimental results presented here provide the most direct evidence to date that positrons bind to neutral molecules. The shift in the position of the resonances is interpreted as a measure of the binding energy of the positron to the molecule. Other features of the results are also discussed, including large

  16. The Roles of Fluid Compression and Shear in Electron Energization during Magnetic Reconnection

    Science.gov (United States)

    Li, Xiaocan; Guo, Fan; Li, Hui; Birn, Joachim

    2018-03-01

    Particle acceleration in space and astrophysical reconnection sites is an important unsolved problem in studies of magnetic reconnection. Earlier kinetic simulations have identified several acceleration mechanisms that are associated with particle drift motions. Here, we show that, for sufficiently large systems, the energization processes due to particle drift motions can be described as fluid compression and shear, and that the shear energization is proportional to the pressure anisotropy of energetic particles. By analyzing results from fully kinetic simulations, we show that the compression energization dominates the acceleration of high-energy particles in reconnection with a weak guide field, and the compression and shear effects are comparable when the guide field is 50% of the reconnecting component. Spatial distributions of those energization effects reveal that reconnection exhausts, contracting islands, and island-merging regions are the three most important regions for compression and shear acceleration. This study connects particle energization by particle guiding-center drift motions with that due to background fluid motions, as in the energetic particle transport theory. It provides foundations for building particle transport models for large-scale reconnection acceleration such as those in solar flares.

  17. Perspectivas del potencial energético de la biomasa en el marco global y latinoamericano

    Directory of Open Access Journals (Sweden)

    Julián Rodrigo Quintero González

    2015-06-01

    Full Text Available El calentamiento global y los cambios climáticos que éste conlleva han fomentado desde hace algunos años la exploración de otros tipos de obtención energética para disminuir el uso del combustible fósil, siendo éste último uno de los principales causantes de dicho problema ambiental. El presente artículo expone algunas investigaciones recientes sobre la bioenergía u obtención de energía a partir de biomasa, considerada como energía limpia. Se abarcan temáticas como la bioenergía y sus posibilidades desde el punto de vista energético, teniendo en cuenta las expectativas de producción según su potencial o productividad energética, además del aporte que este tipo de tecnología hace a la disminución de la huella ecológica.

  18. Rotational excitation of molecules by electron collisions

    International Nuclear Information System (INIS)

    Itikawa, Yukikazu; Mason, Nigel

    2005-01-01

    The anisotropic charge distribution of a molecule can easily induce a rotational transition in the molecule during an electron collision. Further, since the level spacing of the rotational states is very small, the transition can take place over a wide range of electron energies. The rotational excitation is the dominant energy-loss process for an electron in a molecular gas, when the electron energy lies below the vibrational threshold of the molecule. In the case of polar molecules, the rotationally excited molecule promptly emits microwave (or far infrared) radiation. In this way, the rotational excitation effectively cools electrons. The present paper reviews theoretical and experimental studies of the electron-impact rotational excitation of molecules. After a general introduction of the relevant theory and experiment, case studies of five different molecular species (H 2 , N 2 , CH 4 , HCl, and H 2 O) are presented to show the characteristics of rotational cross sections. From those studies, common features of the cross sections are discussed

  19. Evaluación del potencial energético del oleaje en la costa sur del Golfo de México

    OpenAIRE

    Alejandro González-Carrillo; Raziel Ruiz-Cabrera; Quetzalcoatl Hernández-Escobedo; Aránzazu Fernández-García; Francisco Manzano-Agugliaro

    2015-01-01

    Hallar nuevas fuentes de energía es uno de los retos que trajo consigo el siglo XXI. En este tr abajo se hace un análisis sobre la energía de las olas, la cual presenta varia s ventajas significativas con r especto a otras fuentes de energ ías basadas en combustibles fós iles e, inclusive, otras fuentes renovables de energía. De entre estas ventajas de stacan el bajo impacto ambiental y su alta densidad energética, respectivamente. La energía de las olas del mar se consi...

  20. Vibrational stability of graphene

    Directory of Open Access Journals (Sweden)

    Yangfan Hu

    2013-05-01

    Full Text Available The mechanical stability of graphene as temperature rises is analyzed based on three different self-consistent phonon (SCP models. Compared with three-dimensional (3-D materials, the critical temperature Ti at which instability occurs for graphene is much closer to its melting temperature Tm obtained from Monte Carlo simulation (Ti ≃ 2Tm, K. V. Zakharchenko, A. Fasolino, J. H. Los, and M. I. Katsnelson, J. Phys. Condens. Matter 23, 202202. This suggests that thermal vibration plays a significant role in melting of graphene while melting for 3-D materials is often dominated by topologic defects. This peculiar property of graphene derives from its high structural anisotropy, which is characterized by the vibrational anisotropic coefficient (VAC, defined upon its Lindermann ratios in different directions. For any carbon based material with a graphene-like structure, the VAC value must be smaller than 5.4 to maintain its stability. It is also found that the high VAC value of graphene is responsible for its negative thermal expansion coefficient at low temperature range. We believe that the VAC can be regarded as a new criterion concerning the vibrational stability of any low-dimensional (low-D materials.

  1. Pickin’ up good vibrations

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    In preparation for the civil engineering work on the HL-LHC, vibration measurements were carried out at the LHC’s Point 1 last month. These measurements will help evaluate how civil engineering work could impact the beam, and will provide crucial details about the site’s geological make-up before construction begins.   A seismic truck at Point 1 generated wave-like vibrations measured by EN/MME. From carrying out R&D to produce state-of-the-art magnets to developing innovative, robust materials capable of withstanding beam impact, the HL-LHC is a multi-faceted project involving many groups and teams across CERN’s departments. It was in this framework that the project management mandated CERN's Mechanical and Materials Engineering (EN/MME) group to measure the propagation of vibrations around Point 1. Their question: can civil engineering work for the HL-LHC – the bulk of which is scheduled for LS2 – begin while the LHC is running? Alth...

  2. Thermo-dynamical contours of electronic-vibrational spectra simulated using the statistical quantum-mechanical methods

    DEFF Research Database (Denmark)

    Pomogaev, Vladimir; Pomogaeva, Anna; Avramov, Pavel

    2011-01-01

    Three polycyclic organic molecules in various solvents focused on thermo-dynamical aspects were theoretically investigated using the recently developed statistical quantum mechanical/classical molecular dynamics method for simulating electronic-vibrational spectra. The absorption bands of estradi...

  3. Vibrational Spectroscopy of the CCl[subscript 4] v[subscript 1] Mode: Theoretical Prediction of Isotopic Effects

    Science.gov (United States)

    Gaynor, James D.; Wetterer, Anna M.; Cochran, Rea M.; Valente, Edward J.; Mayer, Steven G.

    2015-01-01

    Raman spectroscopy is a powerful experimental technique, yet it is often missing from the undergraduate physical chemistry laboratory curriculum. Tetrachloromethane (CCl[subscript 4]) is the ideal molecule for an introductory vibrational spectroscopy experiment and the symmetric stretch vibration contains fine structure due to isotopic variations…

  4. The status of molecules

    International Nuclear Information System (INIS)

    Barnes, T.

    1994-01-01

    The experimental and theoretical status of hadronic molecules, which are weakly-bound states of two or more hadrons are summarized. A brief history of the subject is given, and a few good candidates are discussed. Some signatures for molecules which may be of interest in the classification of possible molecule states are studied. It is shown that a more general understanding of 2 → 2 hadron-hadron scattering amplitudes will be crucial for molecule searches. A few more recent molecule candidates which are not well established as molecules but satisfy some of the expected signatures are also discussed. (author). 50 refs

  5. Metastable Helium Molecules as Tracers in Superfluid 4He

    International Nuclear Information System (INIS)

    Guo, W.; Wright, J. D.; Cahn, S. B.; Nikkel, J. A.; McKinsey, D. N.

    2009-01-01

    Metastable helium molecules generated in a discharge near a sharp tungsten tip immersed in superfluid 4 He are imaged using a laser-induced-fluorescence technique. By pulsing the tip, a small cloud of He 2 * molecules is produced. We can determine the normal-fluid velocity in a heat-induced counterflow by tracing the position of a single molecule cloud. As we run the tip in continuous field-emission mode, a normal-fluid jet from the tip is generated and molecules are entrained in the jet. A focused 910 nm pump laser pulse is used to drive a small group of molecules to the first excited vibrational level of the triplet ground state. Subsequent imaging of the tagged molecules with an expanded 925 nm probe laser pulse allows us to measure the flow velocity of the jet. The techniques we developed provide new tools in quantitatively studying the normal fluid flow in superfluid helium.

  6. Las cuestiones energéticas en la Estrategia de Seguridad Nacional 2013

    Directory of Open Access Journals (Sweden)

    Rubén Herrero

    2014-05-01

    Full Text Available La energía se torna en un aspecto capital de la sociedad global de hoy en día. Conseguir un combo energético diverso y eficiente es un factor esencial para la promoción y defensa de los intereses nacionales de España, así como de los de la Unión Europea. Este artículo analiza el cambiante escenario energético internacional, sus retos, amenazas e impacto sobre España y la Unión Europea, así como incluye diversas recomendaciones para conseguir una adecuada salvaguarda de nuestros intereses nacionales.

  7. Medidas de eficiencia energética en alumbrado público exterior

    OpenAIRE

    Madrigal Bayonas, Maria Ángeles

    2013-01-01

    En los últimos años se ha puesto de manifiesto que la energía es un bien escaso y caro, además de ser un factor determinante de la actividad económica, lo cual ha hecho que las administraciones públicas dediquen un esfuerzo importante para conseguir una utilización más racional y el desarrollo de nuevas fuentes de energía. Esta preocupación queda ya recogida en el Libro Blanco de la Comunidad Europea, donde se señalan como objetivos fundamentales de la política energética a nivel europeo, ...

  8. Los balances energéticos en la producción agropecuaria.

    OpenAIRE

    Yepes Jaramillo, Guillermo; Martínez Bustamante, Enrique

    2011-01-01

    A través de este ensayo se presenta otro enfoque de análisis de la energía utilizada por los vegetales para la producción agraria. Se parte de los conceptos fundamentales relacionados con la termodinámica y la manera como el flujo de energía incide sobre el follaje de la vegetación y se distribuye, a través de las hojas, en todo el dosel de comunidades de plantas. La vida en la tierra es mantenida por el flujo de energía radiado por el sol y que entra en la biosfera. Por medio de la fotosínte...

  9. El hidrógeno y la energía

    OpenAIRE

    Aurelio Mendoza Medellín

    2006-01-01

    El hidrógeno es el elemento más simple, pero es fundamental para la vida. En el futuro sustituirá a los combustibles fósiles como fuente de energía para las máquinas hechas por el hombre. Hoy en día su uso es muy caro, pero ya existen motores que trabajan quemando este gas. En el sol la fusión de hidrógeno libera cantidades inconmensurables de energía, que en parte es captada por los cloroplastos, que la transforman en la energía química contenida en los carbohidratos resultantes de la fotosí...

  10. El hidrógeno y la energía

    OpenAIRE

    Aurelio Mendoza Medellín

    2006-01-01

    El hidrógeno es el elemento más simple, pero es fundamental para la vida. En el futuro sustituirá a los combustibles fósiles como fuente de energía para las máquinas hechas por el hombre. Hoy en día su uso es muy caro, pero ya existen motores que trabajan quemando este gas. En el sol la fusión de hidrógeno libera cantidades inconmensurables de energía, que en parte es captada por los cloroplastos, que la transforman en la energía química contenida en los carbohidratos resultantes ...

  11. Estudio de un Motor Stirling con Absorbedor Interno Alimentado con Energía Solar

    OpenAIRE

    Santos Ráez, Isidro María

    2016-01-01

    La importancia de la energía desde un punto de vista socioeconómico es indiscutible, siendo la energía solar una de las fuentes renovables más atractiva e interesante. Dentro de las múltiples aplicaciones del motor Stirling, cabe destacar su empleo en instalaciones solares de concentración (CSP - Sistemas Dish Stirling), donde se ha demostrado que el diseño del mismo juega un papel relevante en la producción de energía eléctrica. En este trabajo se ha realizado un análisis térmico del diseño ...

  12. Control digital para convertidor multinivel alimentado con energía solar

    OpenAIRE

    Martínez Hernández, Domitilo

    2006-01-01

    Hoy en día la obtención de formas alternativas de energía eléctrica es un tema que preocupa al ámbito mundial, ya que la dependencia de los recursos no renovables como los hidrocarburos, el carbón mineral y el uranio para la generación de la misma, cada día resulta más costoso debido al agotamiento de los mismos. Una alternativa de solución es la generación de energía eléctrica mediante el aprovechamiento de la energía solar, utilizando paneles solares para la captación ...

  13. Eficiencia energética de los edificios: repercusión medioambiental

    Directory of Open Access Journals (Sweden)

    Maria Nieves Pacheco Jiménez

    2009-06-01

    Full Text Available Los recientes Planes, Estrategias y normas atinentes al fomento de la eficiencia energética en los edificios1 nacen en un contexto de preocupación por el cambio climático y sus consecuencias. Todos ellos persiguen la reducción de costes energéticos y la promoción de la sostenibilidad económica, política y ambiental. Un reflejo de esta inquietud por el bajo impacto ambiental puede observarse en el sector de la vivienda, cuyo consumo final de energía es muy elevado, y en la consiguiente intención de construir edificios bioclimáticos que aprovechen la energía del entorno. En aras a la consecución de estos objetivos, el Plan de Acción 2008-2012 impulsa una serie de medidas que recaen sobre el sector transporte, la industria, el sector residencial y el sector terciario, articulándose en torno a cuatro líneas de actuación: transversal, de movilidad, de edificios y de ahorro eléctrico. Este estudio aborda las pautas de ahorro y eficiencia energética propuestas para los edificios, tanto existentes como de nueva construcción, así como residenciales y del sector terciario. Para ello se hace imprescindible la remisión al concepto de “calidad” de los edificios, contemplado en la propia Exposición de Motivos de la Ley 38/1999, de Ordenación de la Edificación, y ligado estrechamente a la eficiencia energética de aquéllos.

  14. Random vibrations theory and practice

    CERN Document Server

    Wirsching, Paul H; Ortiz, Keith

    1995-01-01

    Random Vibrations: Theory and Practice covers the theory and analysis of mechanical and structural systems undergoing random oscillations due to any number of phenomena— from engine noise, turbulent flow, and acoustic noise to wind, ocean waves, earthquakes, and rough pavement. For systems operating in such environments, a random vibration analysis is essential to the safety and reliability of the system. By far the most comprehensive text available on random vibrations, Random Vibrations: Theory and Practice is designed for readers who are new to the subject as well as those who are familiar with the fundamentals and wish to study a particular topic or use the text as an authoritative reference. It is divided into three major sections: fundamental background, random vibration development and applications to design, and random signal analysis. Introductory chapters cover topics in probability, statistics, and random processes that prepare the reader for the development of the theory of random vibrations a...

  15. CD molecules 2005: human cell differentiation molecules

    Czech Academy of Sciences Publication Activity Database

    Zola, H.; Swart, B.; Nicholson, I.; Aasted, B.; Bensussan, A.; Boumsell, L.; Buckley, C.; Clark, G.; Drbal, Karel; Engel, P.; Hart, D.; Hořejší, Václav; Isacke, C.; Macardle, P.; Malavasi, F.; Mason, D.; Olive, D.; Saalmüller, A.; Schlossman, S.F.; Schwartz-Albiez, R.; Simmons, P.; Tedder, T.F.; Uguccioni, M.; Warren, H.

    2005-01-01

    Roč. 106, č. 9 (2005), s. 3123-3126 ISSN 0006-4971 Institutional research plan: CEZ:AV0Z5052915 Keywords : CD molecules * leukocyte antigen Subject RIV: EC - Immunology Impact factor: 10.131, year: 2005

  16. On selection rules in vibrational and rotational molecular spectroscopy

    International Nuclear Information System (INIS)

    Guichardet, A.

    1986-01-01

    The aim of this work is a rigorous proof of the Selection Rules in Molecular Spectroscopy (Vibration and Rotation). To get this we give mathematically rigorous definitions of the (tensor) transition operators, in this case the electric dipole moment; this is done, firstly by considering the molecule as a set of point atomic kernels performing arbitrary motions, secondly by limiting ourselves either to infinitesimal vibration motions, or to arbitrary rotation motions. Then the selection rules follow from an abstract formulation of the Wigner-Eckart theorem. In a last paragraph we discuss the problem of separating vibration and rotation motions; very simple ideas from Differential Geometry, linked with the ''slice theorem'', allow us to define the relative speeds, the solid motions speeds, the Coriolis energies and the moving Eckart frames [fr

  17. Eficiencia energética en escuela rural de Pellegrini, Santiago del Estero

    OpenAIRE

    Giuliano, Gabriela; Garzón, Beatriz

    2016-01-01

    El presente trabajo tiene como objeto estudiar el rediseño arquitectónico para la adecuación térmico-energética de una escuela rural en Santiago del Estero, Argentina; con el propósito de contribuir a mejorar las condiciones de confort de los usuarios de este hábitat educativo, a través del empleo racional de la energía convencional. Los resultados alcanzados fueron: 1) Definición de condicionantes geográficas y climáticas, 2) Determinación de estrategias y selección de pautas bioambientales,...

  18. Limitaciones para el desarrollo de energías renovables en Argentina

    OpenAIRE

    Marina Yesica Recalde; Daniel Hugo Bouille; Leónidas Osvaldo Girardin

    2015-01-01

    En las últimas décadas las energías renovables han cobrado impulso a nivel mundial con un significativo impacto sobre el desarrollo sustentable de las naciones. Si bien diferentes trabajos analizan la eficiencia de políticas e instrumentos para la promoción de dichas fuentes, la mayoría de las veces se deja de lado el análisis de cómo el contexto en el cual las políticas son implementadas determina su performance. En este trabajo se analiza el desarrollo de las energías renovables en el merca...

  19. Posibilidades de integración de sistemas energéticos renovables en infraestructuras portuarias

    OpenAIRE

    Perdomo Feo, Alejandro José

    2014-01-01

    El presente TFG en Ingeniería Marítima es una prospección para identificar las posibilidades tanto técnicas como legales, que existen a día de hoy para integrar sistemas energéticos renovables marinos en infraestructuras portuarias. Se trata de dar respuesta a la pregunta de si es posible producir energía en los espacios portuarios y haciendo un repaso histórico de cómo se han aprovechado a lo largo de la historia el recurso marea, el recurso ola, el recurso gradiente térmico, el recurso grad...

  20. Cálculo de la eficiencia energética en centros de procesos de datos

    OpenAIRE

    Vila López, Manuel

    2012-01-01

    RESUMEN: El objetivo del presente Proyecto Fin de Carrera es crear una herramienta software para la medida y monitorización de la eficiencia energética en centros de procesos de datos. Esta herramienta se realizará en la empresa CIC Consulting Informático, realizando las medias y las pruebas sobre el data center de la citada empresa. La métrica estándar para obtener la eficiencia energética es el PUE que es una variable definida por el consorcio ‘The Green Grid’. El PUE se calcula como la ...

  1. Regulación central del balance energético por hormonas tiroideas

    OpenAIRE

    Martínez Sánchez, Noelia

    2016-01-01

    La Obesidad y sus comorbilidades asociadas están alcanzando unas proporciones pandémicas, lo que supone un empeoramiento de la calidad de vida y un incremento de los costes sociales. Es por tanto demandante investigar y comprender los mecanismos fisiopatológicos que regulan el balance energético. Lograr comprender las interacciones entre las diferentes vías específicas implicadas en esta enfermedad (regulación de la ingesta, el gasto energético y el metabolismo) es actualmente,...

  2. Estudio comparativo de eficiencia energética: Fachada ventilada frente a fachada vegetal

    OpenAIRE

    Azkorra Larrinaga, Zaloa

    2016-01-01

    398 p. + anexos En la actualidad se desarrollan multitud de investigaciones relacionadas con la rehabilitación energética lo que la ha convertido en un campo emergente en el sector de la construcción y de la arquitectura.El objetivo general de la tesis es evaluar la aplicabilidad de diferentes sistemas pasivos de rehabilitación de fachadas (fachada ventilada y fachada vegetal) y analizar los beneficios de la incorporación de dichos sistemas en el ahorro energético de edificios.Para ello, s...

  3. Problemas institucionales de las energías renovables en México

    Directory of Open Access Journals (Sweden)

    Samuel Brugger

    2011-09-01

    Full Text Available Este ensayo trata de explicar los problemas institucionales y jurídicos que han limitado el aprovechamiento de dichas energías alternativas. El trabajo presenta la situación actual de México; después analiza el potencial que tiene el país. De ahí se pasa al estudio de la problemática institucional y jurídica que no ha logrado fomentar la promoción de energías renovables en México.

  4. Estado y reforma energética en México

    OpenAIRE

    Marco A. Merchand

    2015-01-01

    Este ensayo analiza, cómo las reformas en el sector energético emprendidas por el gobierno de Enrique Peña Nieto (2012-2018) representan la culminación de un Estado, que no está interesado en salvaguardar el patrimonio territorial. Es el propio Estado, que aplica la acumulación por despojo para beneficio de los particulares, sobre todo de las transnacionales que ganan licitaciones en megaproyectos energéticos –termoeléctricas– (petroleras, mineras, telecomunicaciones, etcétera). El Estado fav...

  5. Clusters minero energéticos en Colombia: Desarrollo, hallazgos y propuestas

    OpenAIRE

    Ángela Inés Cadena; William Pinzón

    2011-01-01

    En este artículo se presenta un resumen del Proyecto DNP- Universidad de los Andes sobre "Clusters" en la industria minero energética, que la Universidad de los Andes realizó para el Departamento Nacional de Planeación. Para comenzar, se hace una síntesis de la metodología empleada, que combinó análisis de tipo macro con análisis de detalle. Más adelante se exponen los hallazgos en cuanto a la caracterización y localización de las industrias minero energéticas y aquellas relacionadas. Se pres...

  6. Cómo producen energía las células

    OpenAIRE

    Carlos Alberto Ordoñez

    2014-01-01

    El adenosín trifosfato (ATP), es la moneda energética de los seres vivos. Para poder ser sintetizado, los organismos requieren oxidar los sustratos energéticos de la dieta, proteínas, grasas y carbohidratos. Inicialmente estas sustancias tienen vías metabólicas separadas hasta alcanzar en su degradación un metabolito común que es el acetil CoA. A partir de este punto entran al ciclo de Krebs, con producción de CO2 e hidrogeniones, estos últimos se transportan por óxido reducción a la cadena r...

  7. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    GENERAL ARTICLE. Single-Molecule Spectroscopy. Every Molecule is Different! Kankan Bhattacharyya. Keywords. Single-molecule spectroscopy. (SMS), confocal microscopy,. FCS, sm-FRET, FLIM. 1 High-resolution spectrum re- fers to a spectrum consisting of very sharp lines. The sharp lines clearly display transitions to ...

  8. Decelerating and Trapping Large Polar Molecules.

    Science.gov (United States)

    Patterson, David

    2016-11-18

    Manipulating the motion of large polyatomic molecules, such as benzonitrile (C 6 H 5 CN), presents significant difficulties compared to the manipulation of diatomic molecules. Although recent impressive results have demonstrated manipulation, trapping, and cooling of molecules as large as CH 3 F, no general technique for trapping such molecules has been demonstrated, and cold neutral molecules larger than 5 atoms have not been trapped (M. Zeppenfeld, B. G. U. Englert, R. Glöckner, A. Prehn, M. Mielenz, C. Sommer, L. D. van Buuren, M. Motsch, G. Rempe, Nature 2012, 491, 570-573). In particular, extending Stark deceleration and electrostatic trapping to such species remains challenging. Here, we propose to combine a novel "asymmetric doublet state" Stark decelerator with recently demonstrated slow, cold, buffer-gas-cooled beams of closed-shell volatile molecules to realize a general system for decelerating and trapping samples of a broad range of volatile neutral polar prolate asymmetric top molecules. The technique is applicable to most stable volatile molecules in the 100-500 AMU range, and would be capable of producing trapped samples in a single rotational state and at a motional temperature of hundreds of mK. Such samples would immediately allow for spectroscopy of unprecedented resolution, and extensions would allow for further cooling and direct observation of slow intramolecular processes such as vibrational relaxation and Hertz-level tunneling dynamics. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Digital analysis of vibrations

    International Nuclear Information System (INIS)

    Bohnstedt, H.J.; Walter, G.

    1982-01-01

    Vibrational measurements, e.g. on turbomachinery, can be evaluated rapidly and economically with the aid of a combination of the following instruments: a desk-top computer, a two-channel vector filter and a FFT spectral analyzer. This equipment combination is available within the Allianz Centre for Technology and has also been used for mobile, on-site investigations during the last year. It enables calculation and display of time functions, kinetic shaft orbits, displacement diagrams. Bode plots, polar-coordinate plots, cascade diagrams and histograms. (orig.) [de

  10. Fiabilidad de un sistema eléctrico con energía eólica : credito de capacidad

    OpenAIRE

    Casado Rodríguez, Alejandro

    2012-01-01

    En los últimos años ha habido un aumento del nivel de integración de energía eólica en las redes de energía. Sin embargo, debido al carácter intermitente de la energía eólica, por lo general es difícil determinar la penetración compatible para un nivel admisible de fiabilidad de la red. Para ello, el cálculo correcto del crédito de capacidad de la energía eólica (CC) ha tomado relevancia en las fases de planificación y operación de sistemas de energía que contenga distintos tipos de producció...

  11. Modelling the spectroscopic behaviour of hot molecules

    Science.gov (United States)

    Tennyson, Jonathan

    2010-05-01

    At elevated temperatures the molecules absorb and emit light in a very complicated fashion which is hard to characterise on the basis of laboraroty measurement. Computed line lists of molecule transitions therefore provide a vital input for models of hot atmospheres. I will describe the calculation and use of such line lists including the BT2 water line list [1], which contains some 500 million distinct rotation-vibration transitions. This linelist proved crucial in the detection of water in extrasolar planet HD189733b and has been used extensively in atmospheric modelling. Illustrations will be given at the meeting. A new linelist for the ammonia molecule has just been completed [2] which shows that standard compilations for this molecule need to be improved. Progress on a more extensive linelist for hot ammonia and linelists for other molecules will be discussed at the meeting. [1] R.J. Barber, J. Tennyson, G.J. Harris and R.N. Tolchenov, Mon. Not. R. Astr. Soc., 368, 1087-1094 (2006) [2] S.N. Yurchenko, R.J. Barber, A. Yachmenev, W. Theil, P. Jensen and J. Tennyson, J. Phys. Chem. A, 113, 11845-11855 (2009).

  12. Advances in molecular vibrations and collision dynamics molecular clusters

    CERN Document Server

    Bacic, Zatko

    1998-01-01

    This volume focuses on molecular clusters, bound by van der Waals interactions and hydrogen bonds. Twelve chapters review a wide range of recent theoretical and experimental advances in the areas of cluster vibrations, spectroscopy, and reaction dynamics. The authors are leading experts, who have made significant contributions to these topics.The first chapter describes exciting results and new insights in the solvent effects on the short-time photo fragmentation dynamics of small molecules, obtained by combining heteroclusters with femtosecond laser excitation. The second is on theoretical work on effects of single solvent (argon) atom on the photodissociation dynamics of the solute H2O molecule. The next two chapters cover experimental and theoretical aspects of the energetics and vibrations of small clusters. Chapter 5 describes diffusion quantum Monte Carlo calculations and non additive three-body potential terms in molecular clusters. The next six chapters deal with hydrogen-bonded clusters, refle...

  13. Vibrational quasi-continuum in unimolecular multiphoton dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Fernandez, P.; Gonzalez-Diaz, P.F.

    1987-04-01

    The vibrational quasi-continuum of the boron trifluoride molecule has been qualitatively studied and the formalism extended to treat N-normal-mode molecules. The anharmonic potential curves for the BF/sub 3/ normal modes have been calculated, and the computed anharmonicity constants have been tested against the fundamental frequencies. The potential curve of the wagging mode has been simulated by an internal rotation of one of the fluoride atoms. The vibrational-energy levels and wave functions have been calculated applying second-order perturbation theory. The quasi-continuum energy levels of BF/sub 3/ have been obtained by means of a method based in forming adequate linear combinations of wave functions belonging to the N-1 modes resulting from removing the i.r.-active mode;the associated energies have been minimized using a constrained minimization procedure. It has been found that the energy pattern of the N-1 vibrational modes possesses an energy density high enough for constituting a vibrational heat bath and, finally, it has been verified that the ''fictitious'' pattern of the active mode is included in the pattern of the N-1 modes.

  14. Quantum dynamics of vibrational excitations and vibrational charge ...

    Indian Academy of Sciences (India)

    Administrator

    Dedicated to the memory of the late Professor S K Rangarajan. *For correspondence. Quantum dynamics of vibrational excitations and vibrational charge transfer processes in H. +. + O2 collisions at collision energy 23 eV. †. SAIESWARI AMARAN# and SANJAY KUMAR*. Department of Chemistry, Indian Institute of ...

  15. Off-axis Modal Active Vibration Control Of Rotational Vibrations

    NARCIS (Netherlands)

    Babakhani, B.; de Vries, Theodorus J.A.; van Amerongen, J.

    Collocated active vibration control is an effective and robustly stable way of adding damping to the performance limiting vibrations of a plant. Besides the physical parameters of the Active Damping Unit (ADU) containing the collocated actuator and sensor, its location with respect to the

  16. Action spectroscopy for single-molecule reactions - Experiments and theory

    Science.gov (United States)

    Kim, Y.; Motobayashi, K.; Frederiksen, T.; Ueba, H.; Kawai, M.

    2015-05-01

    We review several representative experimental results of action spectroscopy (AS) of single molecules on metal surfaces using a scanning tunneling microscope (STM) by M. Kawai's group over last decade. The experimental procedures to observe STM-AS are described. A brief description of a low-temperature STM and experimental setup are followed by key experimental techniques of how to determine an onset bias voltage of a reaction and how to measure a current change associated with reactions and finally how to observe AS for single molecule reactions. The experimental results are presented for vibrationally mediated chemical transformation of trans-2-butene to 1.3-butadiene molecule and rotational motion of a single cis-2-butene molecule among four equivalent orientations on Pd(1 1 0). The AS obtained from the motion clearly detects more vibrational modes than inelastic electron tunneling spectroscopy with an STM. AS is demonstrated as a useful and novel single molecule vibrational spectroscopy. The AS for a lateral hopping of water dimer on Pt(1 1 1) is presented as an example of novelty. Several distinct vibrational modes are detected as the thresholds in the AS. The assignment of the vibrational modes determined from the analysis of the AS is made from a view of the adsorption geometry of hydrogen-bond donor or acceptor molecules in water dimer. A generic theory of STM-AS, i.e., a reaction rate or yield as a function of bias voltage, is presented using a single adsorbate resonance model for single molecule reactions induced by the inelastic tunneling current. Formulas for the reaction rate R (V) and Y (V) , i.e., reaction yield per electron Y (V) = eR (V) / I are derived. It provides a versatile framework to analyze any vibrationally mediated reactions of single adsorbates on metal surfaces. Numerical examples are presented to demonstrate generic features of the vibrational generation rate and Y (V) at different levels of approximations and to show how the effective

  17. Vibrational spectra of solid HNFX (C6H8F8N8O4): Experiments and theory

    Science.gov (United States)

    Nicol, Malcolm; Gobin, Cedric; Kim, Eunja

    2007-03-01

    Assignment of the vibrational spectra of molecular solids such as HNFX is very complex. We have made a combined experimental and modeling study of the vibrational spectra of solid HNFX. Crystalline HFNX consists of unit cell with 9 HNFX molecules in Ci symmetry. Vibrational modes were calculated by using the PCFF force field method and were directly compared to measured IR and Raman spectra. A complimentary calculation for molecular HNFX allows us to identify the intramolecular motions measured in experiments. Intermolecular motion by F--H bonds between HNFX molecules will be discussed in this talk.

  18. Algebraic descriptions of nuclear and molecular rotation-vibration spectra

    International Nuclear Information System (INIS)

    Roosmalen, O.S. van.

    1982-01-01

    The application of algebraic models to the description of rotational and vibrational degrees of freedom of nuclei and molecules are discussed. Simple model Hamiltonians are shown to give good agreement with the energy spectra of diatomic molecules and nuclei. Some formal aspects of path integral methods for many-boson systems are treated. The two representations for the quantum mechanical propagator are compared and appear to be identical in leading order in 1/N (N is the number of bosons). Approximations for both are static and dynamic problems are discussed. Applications of mean field techniques are also treated. A description of tri- and tetra-atomic molecules in terms of a U(4)xU(4) and U(4)xU(4)xU(4) group structure is given. Linear molecules appear to correspond with symmetries of O(4) type. S-matrix elements are calculated to test mean field methods, and the results compared with exact calculations. (Auth.)

  19. MECHANICAL VIBRATION INHIBITS OSTEOCLAST FORMATION BY REDUCING DC-STAMP RECEPTOR EXPRESSION IN OSTEOCLAST PRECURSOR CELLS

    OpenAIRE

    Kulkarni, R.N.; Voglewede, P.A.; Liu, D.

    2013-01-01

    It is well known that physical inactivity leads to loss of muscle mass, but it also causes bone loss. Mechanistically, osteoclastogenesis and bone resorption have recently been shown to be regulated by vibration. However, the underlying mechanism behind the inhibition of osteoclast formation is yet unknown. Therefore, we investigated whether mechanical vibration of osteoclast precursor cells affects osteoclast formation by the involvement of fusion-related molecules such as dendritic cell-spe...

  20. Theory of vibrational excitation and dissociative attachment: an R-matrix approach

    International Nuclear Information System (INIS)

    Schneider, B.I.; LeDourneuf, M.; Burke, P.G.

    1979-01-01

    The R-matrix method for electron scattering by diatomic molecules, developed in our earlier papers, is extended to describe vibrational excitation and dissociative attachment. The resultant expressions involve quantities which can be obtained with only small extensions of our existing fixed-nuclei codes. The connection with frame transformation theory is demonstrated and it is shown that structure in resonant vibrational excitation arises naturally from the theory. (author)

  1. Photochromism of Composite Organometallic Nanostructures Based on Diarylethenes. II. Vibrational Spectroscopy and Quantum Chemistry Studies

    Science.gov (United States)

    Vasilyuk, G. T.; Askirka, V. F.; Lavysh, A. V.; Kurguzenkov, S. A.; Yasinskii, V. M.; Kobeleva, O. I.; Valova, T. M.; Ayt, A. O.; Barachevsky, V. A.; Yarovenko, V. N.; Krayushkin, M. M.; Maskevich, S. A.

    2017-11-01

    The structure and photochromic transformations of nanostructured organometallic composites consisting of Ag nanoparticles with shells of photochromic diarylethenes (DAEs) deposited from various solutions onto the nanoparticles were studied using infrared absorption and surface enhanced Raman scattering (SERS) vibrational spectroscopy and quantum chemistry. The studied nanostructures exhibited photochromic properties manifested as reversible photoinduced changes of the relative intensities of SERS bands related to vibrations of bonds participating in the reversible photoisomerization. Spectral manifestations of chemical interaction between metal nanoparticles and DAE molecules were detected.

  2. 14 CFR 33.33 - Vibration.

    Science.gov (United States)

    2010-01-01

    ... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Reciprocating Aircraft Engines § 33.33 Vibration. The... vibration and without imparting excessive vibration forces to the aircraft structure. ...

  3. Melt Stirring by Horizontal Crucible Vibration

    Science.gov (United States)

    Wolf, M. F.; Elwell, D.; Feigelson, R. S.

    1985-01-01

    Horizontal vibration suggested as technique for more effective stirring of melts in crystal-growth apparatus. Vibrational technique may replace accelerated crucible rotation. Potential superiority of vibrational technique shown by preliminary experiments in which ink stirred into water.

  4. Tensor-decomposed vibrational coupled-cluster theory: Enabling large-scale, highly accurate vibrational-structure calculations

    Science.gov (United States)

    Madsen, Niels Kristian; Godtliebsen, Ian H.; Losilla, Sergio A.; Christiansen, Ove

    2018-01-01

    A new implementation of vibrational coupled-cluster (VCC) theory is presented, where all amplitude tensors are represented in the canonical polyadic (CP) format. The CP-VCC algorithm solves the non-linear VCC equations without ever constructing the amplitudes or error vectors in full dimension but still formally includes the full parameter space of the VCC[n] model in question resulting in the same vibrational energies as the conventional method. In a previous publication, we have described the non-linear-equation solver for CP-VCC calculations. In this work, we discuss the general algorithm for evaluating VCC error vectors in CP format including the rank-reduction methods used during the summation of the many terms in the VCC amplitude equations. Benchmark calculations for studying the computational scaling and memory usage of the CP-VCC algorithm are performed on a set of molecules including thiadiazole and an array of polycyclic aromatic hydrocarbons. The results show that the reduced scaling and memory requirements of the CP-VCC algorithm allows for performing high-order VCC calculations on systems with up to 66 vibrational modes (anthracene), which indeed are not possible using the conventional VCC method. This paves the way for obtaining highly accurate vibrational spectra and properties of larger molecules.

  5. The SPASIBA force field of aldehydes. Part II: structure and vibrational wavenumbers of ethandial, propenal and 2-methylpropenal

    Science.gov (United States)

    Durier, V.; Zanoun a, A.; Belaidi, A.; Vergoten, G.

    1999-02-01

    The SPASIBA potential energy function has been extended to conjugated aldehydes. Molecular structures, conformational energies, moments of inertia, dipole moments and vibrational wavenumbers have all been examined. The tested molecules are ethandial (glyoxal), propenal (acrolein), 2-methylpropenal (methacrolein) and some of their deuterated analogs. The parameters of the force field were developed in order to reproduce experimental values: structures, conformational energies and vibrational wavenumbers (minimization of the standard deviation between observed and calculated vibrational wavenumbers). A set of 30 independent force constants was found to be sufficient to describe correctly the structure and vibrational wavenumbers. The average r.m.s errors is 15.25 cm -1.

  6. How Far Does a Receptor Influence Vibrational Properties of an Odorant?

    DEFF Research Database (Denmark)

    Reese, Anna; List, Nanna Holmgaard; Kongsted, Jacob

    2016-01-01

    -assisted electron transfer reaction. We consider this controversy by studying the influence of a receptor on the vibrational properties of an odorant in atomistic details as the coupling between electronic degrees of freedom of the receptor and the vibrations of the odorant is the key parameter of the vibrationally......The biophysical mechanism of the sense of smell, or olfaction, is still highly debated. The mainstream explanation argues for a shape-based recognition of odorant molecules by olfactory receptors, while recent investigations suggest the primary olfactory event to be triggered by a vibrationally......-assisted electron transfer. Through molecular dynamics simulations we elucidate the binding specificity of a receptor towards acetophenone odorant. The vibrational properties of acetophenone inside the receptor are then studied by the polarizable embedding density functional theory approach, allowing to quantify...

  7. How Far Does a Receptor Influence Vibrational Properties of an Odorant?

    Science.gov (United States)

    Reese, Anna; List, Nanna Holmgaard; Kongsted, Jacob; Solov'yov, Ilia A

    2016-01-01

    The biophysical mechanism of the sense of smell, or olfaction, is still highly debated. The mainstream explanation argues for a shape-based recognition of odorant molecules by olfactory receptors, while recent investigations suggest the primary olfactory event to be triggered by a vibrationally-assisted electron transfer reaction. We consider this controversy by studying the influence of a receptor on the vibrational properties of an odorant in atomistic details as the coupling between electronic degrees of freedom of the receptor and the vibrations of the odorant is the key parameter of the vibrationally-assisted electron transfer. Through molecular dynamics simulations we elucidate the binding specificity of a receptor towards acetophenone odorant. The vibrational properties of acetophenone inside the receptor are then studied by the polarizable embedding density functional theory approach, allowing to quantify protein-odorant interactions. Finally, we judge whether the effects of the protein provide any indications towards the existing theories of olfaction.

  8. The influence of vibrational state-resolved transport coefficients on the wave propagation in diatomic gases

    Science.gov (United States)

    Kremer, Gilberto M.; Kunova, Olga V.; Kustova, Elena V.; Oblapenko, George P.

    2018-01-01

    A detailed kinetic-theory model for the vibrationally state-resolved transport coefficients is developed taking into account the dependence of the collision cross section on the size of vibrationally excited molecule. Algorithms for the calculation of shear and bulk viscosity, thermal conductivity, thermal diffusion and diffusion coefficients for vibrational states are proposed. The transport coefficients are evaluated for single-component diatomic gases N2, O2, NO, H2, Cl2 in the wide range of temperature, and the effects of molecular diameters and the number of accounted states are discussed. The developed model is applied to study wave propagation in diatomic gases. For the case of initial Boltzmann distribution, the influence of vibrational excitation on the phase velocity and attenuation coefficient is found to be weak. We expect more significant effect in the case of initial thermal non-equilibrium, for instance in gases with optically pumped selected vibrational states.

  9. Implicaciones ambientales de las tecnologías de energía renovable

    Directory of Open Access Journals (Sweden)

    Jan Mahirt-Smith

    2011-12-01

    Full Text Available Las tecnologías de energía renovable como la eólica, la solar y la biomasa, hacen un uso del suelo más intenso que las de combustibles fósiles tradicionales y, geográficamente, sus implicaciones ambientales son más heterogéneas, por lo que presentan un gran desafío para las técnicas de evaluación de su ciclo de vida. Este trabajo presenta los resultados de una investigación bibliográfica alrededor de los siguientes temas: 1 cambios en el uso del suelo debido a la mayor producción de energía renovable; 2 impactos del uso de suelo; 3 variabilidad geográfica en el inventario de datos; y 4 efectos de la distribución de energía. Además, se revisa el grado de investigación que actualmente se aplica acerca de las tecnologías de energía renovable en campos como el eólico, el solar y la bioenergía y en la evaluación del ciclo de vida en general.

  10. Proyecto Energético Palmdale; Decisión del Permiso Final

    Science.gov (United States)

    Proyecto Energético Palmdale: EPA Región 9 por el presente emite aviso de su decisión final, el cumplimiento con la Ley Federal de Aire Limpio, para la construcción de una planta generadora de electricidad de ciclo combinado y alimentada por gas natural

  11. Gas exchange and leaf contents in bell pepper under energized water and biofertilizer doses

    Directory of Open Access Journals (Sweden)

    Francisca R. M. Borges

    2016-06-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the effect of energized water and bovine biofertilizer doses on the gas exchange and NPK contents in leaves of yellow bell pepper plants. The experiment was conducted at the experimental area of the Federal University of Ceará, in Fortaleza-CE, Brazil, from June to November 2011. The experiment was set in a randomized block design, in a split-plot scheme; the plots were composed of treatments with energized and non-energized water and the subplots of five doses of liquid biofertilizer (0, 250, 500, 750 and 1000 mL plant-1 week-1. The following variables were analyzed: transpiration, stomatal conductance, photosynthesis and leaf contents of nitrogen (N, phosphorus (P and potassium (K. Water energization did not allow significant increases in the analyzed variables. The use of biofertilizer as the only source of fertilization was sufficient to provide the nutrients N, P and K at appropriate levels for the bell pepper crop.

  12. El hidrógeno y la energía

    Directory of Open Access Journals (Sweden)

    Aurelio Mendoza Medellín

    2006-01-01

    Full Text Available El hidrógeno es el elemento más simple, pero es fundamental para la vida. En el futuro sustituirá a los combustibles fósiles como fuente de energía para las máquinas hechas por el hombre. Hoy en día su uso es muy caro, pero ya existen motores que trabajan quemando este gas. En el sol la fusión de hidrógeno libera cantidades inconmensurables de energía, que en parte es captada por los cloroplastos, que la transforman en la energía química contenida en los carbohidratos resultantes de la fotosíntesis. Esto implica la transferencia del hidrógeno del agua al dióxido de carbono. Los animales liberan la energía de los combustibles biológicos revirtiendo dicha reacción a través del metabolismo oxidativo, la cadena respiratoria y la fosforilación oxidativa. El hidrógeno es vital para producir ATP y por lo tanto para la vida.

  13. Procesos de urbanización y problemas energéticos

    Directory of Open Access Journals (Sweden)

    RAMIRO CIBRIAN

    1980-01-01

    Full Text Available Se presenta una discusión en torno a la necesidad de desarrollar energías alternativas, preferiblemente renovables, para los futuros centros urbanos. Actualmente, el consumo mundial de energía se sitúa en 8 terawatios-año por año. Se espera que en 2030 el consumo ascenderá a 20-40 terawatios-año por año. Los datos disponibles para la mayor parte de los centros metropolitanos del mundo muestran que, si bien comparando las zonas rurales se puede observar que los países desarrollados emplean más energías que los países no-desarrollados, esta diferencia no resulta perceptible cuando tomamos como referencia los centros urbanos. Se enfatiza que la demanda creciente de petróleo agrava la crisis energética mediante el incremento de las tensiones políticas y del mercado.

  14. Aspectos energéticos da teoria cinética dos gases

    Directory of Open Access Journals (Sweden)

    Robert Saraiva Matos

    2014-12-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE Neste artigo, discutem-se aspectos energéticos relacionados à Teoria Cinética dos Gases (TCG. Trata-se de um estudo de revisão bibliográfica. Os dados foram coletados através do levantamento das fontes, por meio de textos técnicos, publicações científicas e livros didáticos. Através da interpretação energética da TCG foi possível discutir a rota para o equilíbrio térmico, a transferência de partículas entre níveis de energia devido à variação na temperatura e também demonstrar a distribuição de Maxwell-Boltzmann-Gibbs. Além disso, notou-se que a visão energética das TCG fornece uma ponte entre colisões e transações financeiras. Conclui-se que a abordagem energética da TCG possui importância crucial para o entendimento dos fundamentos da Física Térmica, sobretudo no Ensino Médio, onde estes estudos possuem uma demanda significativa na disciplina de Física

  15. Effectiveness of the Energize Elementary School Program to Improve Diet and Exercise

    Science.gov (United States)

    Herbert, Patrick C.; Lohrmann, David K.; Seo, Dong-Chul; Stright, Anne D.; Kolbe, Lloyd J.

    2013-01-01

    Background: The rate of childhood obesity has more than tripled during the past 30?years. Research shows that prevention at an early age is more effective than treatment later in life. Energize is a multicomponent intervention incorporated into the school day that combines nutrition education and physical activity aimed at maintaining healthy…

  16. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  17. Single Molecule Raman Detection of Enkephalin on Silver Colloidal Particles

    DEFF Research Database (Denmark)

    Kneipp, Katrin; Kneipp, Holger; Abdali, Salim

    2004-01-01

    Enkephalin, an endogeneous substance in the human brain showing morphine-like biological functions, has been detected at the single molecule level based on the surface-enhanced Raman signal of the ring breathing mode of phenylalanine, which is one building block of the molecule. For enhancing...... the Raman signal the enkephalin molecules have been attached to silver colloidal cluster structures. The experiments demonstrate that the SERS signal of the strongly enhanced ring breathing vibration of phenylalanine at 1000 cm-1 can be used as “intrinsic marker” for detecting a single enkephalin molecule...... and for monitoring its diffusion on the surface of the silver colloidal cluster without using a specific label molecule....

  18. Augmented-plane-wave calculations on small molecules

    International Nuclear Information System (INIS)

    Serena, P.A.; Baratoff, A.; Soler, J.M.

    1993-01-01

    We have performed ab initio calculations on a wide range of small molecules, demonstrating the accuracy and flexibility of an alternative method for calculating the electronic structure of molecules, solids, and surfaces. It is based on the local-density approximation (LDA) for exchange and correlation and the nonlinear augmented-plane-wave method. Very accurate atomic forces are obtained directly. This allows for implementation of Car-Parrinello-like techniques to determine simultaneously the self-consistent electron wave functions and the equilibrium atomic positions within an iterative scheme. We find excellent agreement with the best existing LDA-based calculations and remarkable agreement with experiment for the equilibrium geometries, vibrational frequencies, and dipole moments of a wide variety of molecules, including strongly bound homopolar and polar molecules, hydrogen-bound and electron-deficient molecules, and weakly bound alkali and noble-metal dimers, although binding energies are overestimated

  19. Assessing potential impacts of energized submarine power cables on crab harvests

    Science.gov (United States)

    Love, Milton S.; Nishimoto, Mary M.; Clark, Scott; McCrea, Merit; Bull, Ann Scarborough

    2017-12-01

    Offshore renewable energy facilities transmit electricity to shore through submarine power cables. Electromagnetic field emissions (EMFs) are generated from the transmission of electricity through these cables, such as the AC inter-array (between unit) and AC export (to shore) cables often used in offshore energy production. The EMF has both an electric component and a magnetic component. While sheathing can block the direct electric field, the magnetic field is not blocked. A concern raised by fishermen on the Pacific Coast of North America is that commercially important Dungeness crab (Metacarcinus magister Dana, 1852)) might not cross over an energized submarine power cable to enter a baited crab trap, thus potentially reducing their catch. The presence of operating energized cables off southern California and in Puget Sound (cables that are comparable to those within the arrays of existing offshore wind energy devices) allowed us to conduct experiments on how energized power cables might affect the harvesting of both M. magister and another commercially important crab species, Cancer productus Randall, 1839. In this study we tested the questions: 1) Is the catchability of crabs reduced if these animals must traverse an energized power cable to enter a trap and 2) if crabs preferentially do not cross an energized cable, is it the cable structure or the EMF emitted from that cable that deters crabs from crossing? In field experiments off southern California and in Puget Sound, crabs were given a choice of walking over an energized power cable to a baited trap or walking directly away from that cable to a second baited trap. Based on our research we found no evidence that the EMF emitted by energized submarine power cables influenced the catchability of these two species of commercially important crabs. In addition, there was no difference in the crabs' responses to lightly buried versus unburied cables. We did observe that, regardless of the position of the cable

  20. Redes de energía en la Argentina del siglo XXI. Proyectos locales innovadores

    Directory of Open Access Journals (Sweden)

    Silvina Carrizo

    2015-04-01

    Full Text Available En Argentina se construyeron de forma pionera, extensas redes de electricidad, gas y combustibles. El 98% de los hogares están conectados a la red eléctrica y el 51% de la población tiene acceso al gas natural por red (INDEC 2012. A pesar de la cobertura energética amplia, aún persisten en el país algunas regiones -como el Noroeste de la Provincia de Buenos Aires NOBAdonde las redes no llegan o tienen menor densidad. La región NOBA, situada entre las ciudades de Rosario y Buenos Aires, que cuentan con infraestructura considerable para su aprovisionamiento, presenta redes eléctricas y gasíferas poco densas -especialmente hacia el interior- y escaso desarrollo de fuentes de energías alternativas. En materia de gas, faltan gasoductos troncales o regionales. En el sistema eléctrico, hay poca capacidad de generación y se necesita mayor interconexión. Desde distintos niveles se han promovido alternativas en materia de producción, transporte y distribución de energía, pero los avances aún no alcanzan para asegurar la resiliencia energética enla región NOBA. En un contexto de esta índole, actores locales se han organizado para satisfacer sus necesidades energéticas con proyectos nuevos de transporte de gas y de aprovechamiento de recursos locales renovables, con un potencial que aún no ha sido puesto en valor. Abordando proyectos energéticos locales y regionales, este trabajo propone reflexionar acerca de la nueva geografía que podría delinearse en la producción y circulación de la energía, más flexible, fiable y sustentable, fomentando la innovación y la productividad, así como la equidad regional.

  1. Rotational and vibrational population of D2 desorbing from sulfur-covered Pd(100)

    Science.gov (United States)

    Rutkowski, M.; Wetzig, D.; Zacharias, H.; Groß, A.

    2002-09-01

    We report rovibrational populations of D2 desorbing recombinatively from sulfur-covered Pd(100). The palladium surface is poisoned with an ordered c(2×2) overlayer corresponding to a coverage of ΘS~0.5 ML. Desorbing D2 molecules are detected with (1+1') REMPI via various B1Σ+uradiation for the excitation step. Rotational quantum states J''=0-12 in the vibrational ground and J''=0 to 8 in the first vibrational excited state are measured. Experiments are performed for surface temperatures in the range from TS=500-800 K. Rotational energies lower and vibrational energies higher than the corresponding surface temperature are observed. The vibrational energies are higher than those of molecules desorbing from a clean Pd surface. The experimental results are compared with quantum dynamical calculations for the desorption of H2 from a p(2×2) sulfur-covered Pd(100) surface, based on a potential energy surface derived from density functional calculations. While the observed rotational cooling for molecules in the vibrational ground state is reproduced by the calculations, the vibrational effects are underestimated.

  2. Towards a scalable and accurate quantum approach for describing vibrations of molecule–metal interfaces

    Directory of Open Access Journals (Sweden)

    David M. Benoit

    2011-08-01

    Full Text Available We present a theoretical framework for the computation of anharmonic vibrational frequencies for large systems, with a particular focus on determining adsorbate frequencies from first principles. We give a detailed account of our local implementation of the vibrational self-consistent field approach and its correlation corrections. We show that our approach is both robust, accurate and can be easily deployed on computational grids in order to provide an efficient computational tool. We also present results on the vibrational spectrum of hydrogen fluoride on pyrene, on the thiophene molecule in the gas phase, and on small neutral gold clusters.

  3. Solvent effects on first-order molecular hyperpolarizability: A study based on vibrational observables

    Science.gov (United States)

    Zuliani, P.; Del Zoppo, M.; Castiglioni, C.; Zerbi, G.; Marder, S. R.; Perry, J. W.

    1995-12-01

    Using a recently developed method, we show here that solvent effects on the first molecular hyperpolarizabilities of push-pull polyenes can be predicted by evaluation of the relaxation contribution βr to the hyperpolarizability from vibrational infrared and Raman intensities and vibrational frequencies. The molecules studied in this work are a few organic polymethine dyes with different donor and acceptor groups. The analysis of their vibrational spectra confirms the key role played by the structural parameters of the polyene chain in determining the nonlinear optical response.

  4. The Possible Interstellar Anion CH2CN-: Spectroscopic Constants, Vibrational Frequencies, and Other Considerations

    Science.gov (United States)

    Fortenberry, Ryan C.; Crawford, T. Daniel; Lee, Timothy J.

    2012-01-01

    The A 1B1 interstellar band. However, this particular molecular system has not been detected in the interstellar medium even though the related cyanomethyl radical and the isoelectronic ketenimine molecule have been found. In this study we are employing the use of proven quartic force elds and second-order vibrational perturbation theory to compute accurate spectroscopic constants and fundamental vibrational frequencies for X 1A0 CH2CN?? in order to assist in laboratory studies and astronomical observations. Keywords: Astrochemistry, ISM: molecular anions, Quartic force elds, Rotational constants, Vibrational frequencies

  5. The status of molecules

    International Nuclear Information System (INIS)

    Barnes, T.; Oak Ridge National Lab., TN; Tennessee Univ., Knoxville, TN

    1994-06-01

    This report summarizes the experimental and theoretical status of hadronic molecules, which are weakly-bound states of two or more hadrons. We begin with a brief history of the subject and discuss a few good candidates, and then abstract some signatures for molecules which may be of interest in the classification of possible molecule states. Next we argue that a more general understanding of 2 → 2 hadron-hadron scattering amplitudes will be crucial for molecule searches, and discuss some of our recent work in this area. We conclude with a discussion of a few more recent molecule candidates (notably the f o (1710)) which are not well established as molecules but satisfy some of the expected signatures. (Author)

  6. Ultracold Polar Molecules

    Science.gov (United States)

    2016-04-01

    AFRL-AFOSR-UK-TR-2016-0005 Ultracold Polar Molecules Jeremy Hutson UNIVERSITY OF DURHAM Final Report 04/01/2016 DISTRIBUTION A: Distribution approved...DATES COVERED (From - To) 15-Jan-2010 to 14-Jul-2015 4. TITLE AND SUBTITLE Final Report on Grant FA8655-10-1-3033 on Ultracold Polar Molecules 5a...formation of ultracold 87RbCs molecules in their rovibrational ground state by magnetoassociation followed by STIRAP, resulting in 14 papers acknowledging

  7. Quantum interference experiments with complex organic molecules

    International Nuclear Information System (INIS)

    Eibenberger, S. I.

    2015-01-01

    Matter-wave interference with complex particles is a thriving field in experimental quantum physics. The quest for testing the quantum superposition principle with highly complex molecules has motivated the development of the Kapitza-Dirac-Talbot-Lau interferometer (KDTLI). This interferometer has enabled quantum interference with large organic molecules in an unprecedented mass regime. In this doctoral thesis I describe quantum superposition experiments which we were able to successfully realize with molecules of masses beyond 10 000 amu and consisting of more than 800 atoms. The typical de Broglie wavelengths of all particles in this thesis are in the order of 0.3-5 pm. This is significantly smaller than any molecular extension (nanometers) or the delocalization length in our interferometer (hundreds of nanometers). Many vibrational and rotational states are populated since the molecules are thermally highly excited (300-1000 K). And yet, high-contrast quantum interference patterns could be observed. The visibility and position of these matter-wave interference patterns is highly sensitive to external perturbations. This sensitivity has opened the path to extensive studies of the influence of internal molecular properties on the coherence of their associated matter waves. In addition, it enables a new approach to quantum-assisted metrology. Quantum interference imprints a high-contrast nano-structured density pattern onto the molecular beam which allows us to resolve tiny shifts and dephasing of the molecular beam. I describe how KDTL interferometry can be used to investigate a number of different molecular properties. We have studied vibrationally-induced conformational changes of floppy molecules and permanent electric dipole moments using matter-wave deflectometry in an external electric field. We have developed a new method for optical absorption spectroscopy which uses the recoil of the molecules upon absorption of individual photons. This allows us to

  8. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    D)> HBr (0.83 D) > HI (0.45 D) [8]. Hence, these molecules can and do induce a dipole moment in the rare gas atoms when the two interact. The induced dipole moment is proportional to the inducing field E and the proportionality constant is the polariz- ability, i.e., μ i. = αE. However, as mentioned above, dispersion.

  9. Cold Rydberg molecules

    Science.gov (United States)

    Raithel, Georg; Zhao, Jianming

    2017-04-01

    Cold atomic systems have opened new frontiers at the interface of atomic and molecular physics. These include research on novel types of Rydberg molecules. Three types of molecules will be reviewed. Long-range, homonuclear Rydberg molecules, first predicted in [1] and observed in [2], are formed via low-energy electron scattering of the Rydberg electron from a ground-state atom within the Rydberg atom's volume. The binding mostly arises from S- and P-wave triplet scattering. We use a Fermi model that includes S-wave and P-wave singlet and triplet scattering, the fine structure coupling of the Rydberg atom and the hyperfine structure coupling of the 5S1/2 atom (in rubidium [3]). The hyperfine structure gives rise to mixed singlet-triplet potentials for both low-L and high-L Rydberg molecules [3]. A classification into Hund's cases [3, 4, 5] will be discussed. The talk further includes results on adiabatic potentials and adiabatic states of Rydberg-Rydberg molecules in Rb and Cs. These molecules, which have even larger bonding length than Rydberg-ground molecules, are formed via electrostatic multipole interactions. The leading interaction term of neutral Rydberg-Rydberg molecules is between two dipoles, while for ionic Rydberg molecules it is between a dipole and a monopole. NSF (PHY-1506093), NNSF of China (61475123).

  10. Desarrollo de sistema autónomo innovador para la generación de energía eléctrica a partir de energía eólica y fotovoltaica

    OpenAIRE

    Cáceres Chiquillo, Juan José

    2013-01-01

    Este proyecto forma parte del Programa Integral de Investigación en Energías Renovables. Se construyó en la Sede Central Santa Tecla un sistema de generación de energía renovable híbrido y en disposición tipo isla, conformado por ocho paneles solares policristalinos y un aerogenerador de eje horizontal. Se determinaron los ángulos mínimos y máximos de inclinación para los paneles fotovoltaicos, tomando como base la latitud de Santa Tecla. La energía generada se acumula en un banco de baterías...

  11. Proyecto de construcción de invernadero para producción de cultivos ecológicos, con incorporación de energías renovables para autoabastecimiento energético.

    OpenAIRE

    Antón Corredor, Tatiana

    2017-01-01

    El proyecto consiste en la construcción de un invernadero para producción hortícola de tipo ecológico, incorporando la energía solar fotovoltaica como fuente de energía para practicar el autoabastecimiento energético. La explotación se encuentra en un sistema aislado por lo que el autoabastecimiento está permitido. El invernadero proyectado está muy tecnificado, disponiendo de un sistema de calefacción por agua caliente, calentado mediante caldera de pellets, sistema de ventilación automat...

  12. Cuantificación del potencial energético undimotriz en las costas del Caribe colombiano

    Directory of Open Access Journals (Sweden)

    Jaime P

    2017-11-01

    Full Text Available En este documento se describen los avances en la cuantificación de la energía de las olas de la costa caribeña colombiana. La metodología utilizada servirá como punto de partida para establecer el potencial energético en Colombia para este tipo de suministro energético. En la actualidad, el potencial energético teórico estimado en las ondas de la costa cercana en la costa atlántica es de aproximadamente 1107 MW y esto fue posible con datos que se han recogido y procesado desde enero de 2014. Las ecuaciones que tienen en cuenta variables tales como: la densidad del agua de mar, la temperatura y la velocidad del viento en la zona. También muestra el progreso del diseño del sistema Near Shore para la verificación del potencial de energía de las olas que consiste en un dispositivo que transforma la energía cinética de las ondas del mar en energía potencial gravitacional que se va a usar para mover un generador de corriente alterna.

  13. La utilización eficaz del hormigón térmico en rehabilitación energética de edifcios

    OpenAIRE

    Moraño Rodríguez, Alfonso Javier

    2016-01-01

    Como sabrá el lector, se ha establecido en España por consecuencia de la Directiva 2012/27/ UE, un Programa de Ayudas para la Rehabilitación Energética de Edificios existentes (Programa PAREER-CRECE) con el fin de incentivar y promover la realización de actuaciones de reforma que favorezcan el ahorro energético, la mejora de la eficiencia energética, el aprovechamiento de las energías renovables y la reducción de emisiones de dióxido de carbono. El Ministerio de Industria, Energía y Turismo, ...

  14. Theoretical studies on the molecular structure, conformational preferences, topological and vibrational analysis of allicin

    Science.gov (United States)

    Durlak, Piotr; Berski, Sławomir; Latajka, Zdzisław

    2016-01-01

    The molecular structure, conformational preferences, topological and vibrational analysis of allicin has been investigated at two different approaches. Calculations have been carried out on static (DFT and MP2) levels with an assortment of Dunning's basis sets and dynamic CPMD simulations. In this both case within the isolated molecule approximation. The results point out that at least twenty different conformers coexist on the PES as confirmed by the flexible character of this molecule. The topological analysis of ELF showed very similar nature of the Ssbnd S and Ssbnd O bonds. The infrared spectrum has been calculated, and a comparative vibrational analysis has been performed.

  15. Vibration response of misaligned rotors

    Science.gov (United States)

    Patel, Tejas H.; Darpe, Ashish K.

    2009-08-01

    Misalignment is one of the common faults observed in rotors. Effect of misalignment on vibration response of coupled rotors is investigated in the present study. The coupled rotor system is modelled using Timoshenko beam elements with all six dof. An experimental approach is proposed for the first time for determination of magnitude and harmonic nature of the misalignment excitation. Misalignment effect at coupling location of rotor FE model is simulated using nodal force vector. The force vector is found using misalignment coupling stiffness matrix, derived from experimental data and applied misalignment between the two rotors. Steady-state vibration response is studied for sub-critical speeds. Effect of the types of misalignment (parallel and angular) on the vibration behaviour of the coupled rotor is examined. Along with lateral vibrations, axial and torsional vibrations are also investigated and nature of the vibration response is also examined. It has been found that the misalignment couples vibrations in bending, longitudinal and torsional modes. Some diagnostic features in the fast Fourier transform (FFT) of torsional and longitudinal response related to parallel and angular misalignment have been revealed. Full spectra and orbit plots are effectively used to reveal the unique nature of misalignment fault leading to reliable misalignment diagnostic information, not clearly brought out by earlier studies.

  16. Towards ultracold RbCa molecules

    Science.gov (United States)

    Kleinert, Michaela; Whitson, Hayley; Parsagian, Alexandria

    2012-06-01

    Ultracold heteronuclear molecules have seen increasing interest in the scientific community over the last few years. By controlling their ro-vibrational energy levels, ultracold molecules can be used for high precision spectroscopy, to study cold collisions with rich internal dynamics, as model systems for condensed matter physics, and as qubits in quantum information processing. We study the novel combination RbCa. In addition to a permanent electric dipole moment, it also possesses a permanent magnetic dipole moment. This makes it an ideal candidate to study strong long-range dipole-dipole interactions. We are currently in the process of adding a Ca MOT to our existing Rb MOT and will discuss our current and future efforts toward our goal of creating, for the first time, ultracold RbCa molecules. Molecules, once created, will be detected through resonantly enhanced multi-photon ionization (REMPI). We have also performed ab initio calculations to determine the electronic energy levels of RbCa, and calculated Franck-Condon factors between the ground and several excited states

  17. Liga de magnésio como material para bateria de alta densidade energética

    OpenAIRE

    Munhoz, Igor Polezi

    2014-01-01

    Orientador: Prof. Dr. Jorge Tomioka Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Elétrica, 2014. No contexto energético, as mudanças climáticas e as crescentes crises energéticas aumentaram as preocupações e as pesquisas na área de acumuladores de energia, visando alcançar melhorias no cenário energético e ambiental global. Ao mesmo tempo, a sociedade tornou-se dependente do consumo de energia elétrica, sendo que falhas no fornec...

  18. Unidad experimental eólico-solar con almacenaje de energía térmica en parafinas

    OpenAIRE

    Monzón Verona, José Miguel

    2016-01-01

    [ES]El presente estudio ha utilizado un sistema combinado eólico-solar y un sistema de almacenamiento de energía por medio de calor latente. La unidad experimental consta de las siguientes partes: paneles solares, aerogeneradores y almacén de energía. Entre las conclusiones de la tesis cabe destacar: 1. se ha conseguido una reducción del volumen de almacenamiento de energía. 2. se consigue una mejora en el coeficiente de utilización mediante el...

  19. La dependencia energética en España por sectores y su impacto económico

    OpenAIRE

    Galdón-Ruiz, Jose Antonio; Marí, B.; Guaita Pradas, Inmaculada

    2016-01-01

    Este artículo describe la situación histórica de España frente a la dependencia energética y la evolución en los últimos años. Se analiza la dependencia energética en función de los diferentes sectores, en concreto el sector industrial, el transporte y el de usos diversos donde estarán incluidos la Agricultura, Pesca, Comercio, Servicios y Administraciones Públicas, el Residencial y otros. A partir del análisis del mix de consumo energético de cada uno de los tres sectores objeto del estud...

  20. Molecule of the Month

    Indian Academy of Sciences (India)

    Atoms in a molecule generally prefer, particularly among the neighbouring ones, certain optimmn geometrical relationships. These are manifested in specific ranges of bond lengths, bond angles, torsion angles etc. As it always happens, chemists are interested in making molecules where these 'standard relationships' are ...

  1. Molecule of the Month

    Indian Academy of Sciences (India)

    Cyclo bu tadiene (1) has been one of the most popular molecules for experimentalists and theoreticians. This molecule is unstable as . it is antiaromatic ( 4,n electrons in a cyclic array). Even though some highly substituted cyclobutadienes, for example, compound 2 and the Fe(CO)3 complex of cyclobutadiene (3) are ...

  2. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 2. Single-Molecule Spectroscopy: Every Molecule is Different! Kankan Bhattacharyya. General Article Volume 20 Issue 2 February 2015 pp 151-164. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. Algebraic theory of molecules

    CERN Document Server

    Iachello, F

    1995-01-01

    1. The Wave Mechanics of Diatomic Molecules. 2. Summary of Elements of Algebraic Theory. 3. Mechanics of Molecules. 4. Three-Body Algebraic Theory. 5. Four-Body Algebraic Theory. 6. Classical Limit and Coordinate Representation. 8. Prologue to the Future. Appendices. Properties of Lie Algebras; Coupling of Algebras; Hamiltonian Parameters

  4. Molecule of the Month.

    Indian Academy of Sciences (India)

    described here. Chemistry of aromatic molecules has a long history. Many molecules made up of multiple benzene-like rings have been isolated or made in the laboratory over the years. These are called polycondensed aromatic hydrocarbons (PAH for short). ... a bowl like symmetric polycyclic aromatic hydrocarbon of the.

  5. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 2. Single-Molecule Spectroscopy: Every Molecule is Different! ... Author Affiliations. Kankan Bhattacharyya1. Department of Physical Chemistry, Indian Association for the Cultivation of Science Jadavpur, Kolkata 700 032 India.

  6. Electrons in Molecules

    Indian Academy of Sciences (India)

    “What are electrons doing in molecules?” This is a deceptively simple question that scientists have been trying to answer for more than eighty years. With the advent of quantum mechanics in 1926, it became clear that we must understand the dynamics of electronic motion in atoms, molecules and solids in order to explain ...

  7. ISOLATED MOLECULES IN METALS

    NARCIS (Netherlands)

    1992-01-01

    In this paper, some results obtained on the formation of isolated molecules of composition SnOx in silver and SnFx in copper-are reviewed. Hyperfine interaction and ion beam interaction techniques were used for the identification of these molecules.

  8. Molecule of the Month

    Indian Academy of Sciences (India)

    Nature is an excellent synthetic organic chemist. Using mild reaction conditions and a few elemental combinations, a large variety of complex molecules are made in and around us. The atoms are put together in precise arrangements to enable the molecules to carry out different tasks with remarkable specificity.

  9. Marketing online, bebidas energ??ticas y la aportaci??n de energ??a e hidrataci??n al consumidor en un mismo envase

    OpenAIRE

    Corral Saludes, V??ctor Hugo

    2015-01-01

    Las bebidas energ??ticas tambi??n conocidas con el nombre de hipert??nicas, son bebidas analcoh??licas, compuestas b??sicamente por cafe??na e hidratos de carbono y az??cares. Estas bebidas se introdujeron en el mercado ofreciendo a los consumidores supuestas virtudes regeneradoras de la fatiga y el agotamiento, as?? como aumentar la habilidad mental, incrementar la resistencia f??sica, evitar el sue??o y obtener una mayor concentraci??n. Estas bebidas van destinadas principalmente a estudian...

  10. 49 CFR 178.819 - Vibration test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vibration test. 178.819 Section 178.819... Testing of IBCs § 178.819 Vibration test. (a) General. The vibration test must be conducted for the... vibration test. (b) Test method. (1) A sample IBC, selected at random, must be filled and closed as for...

  11. Flexural vibrations of finite composite poroelastic cylinders

    Indian Academy of Sciences (India)

    If the wavelength is infinite, frequency equations are degenerated as product of two determinants pertaining to extensional vibrations and shear vibrations. In this case, it is seen that the nature of the surface does not have any influence over shear vibrations unlike in the case of extensional vibrations. For illustration purpose ...

  12. Theoretical studies on CH+ ion molecule using configuration interaction method and its spectroscopic properties

    International Nuclear Information System (INIS)

    Machado, F.B.C.

    1985-01-01

    The use of the configuration (CI) method for the calculation of very accurate potential energy curves and dipole moment functions, and then their use in the comprehension of spectroscopic properties of diatomic molecules is presented. The spectroscopic properties of CH + and CD + such as: vibrational levels, spectroscopic constants, averaged dipole moments for all vibrational levels, radiative transition probabilities for emission and absorption, and radiative lifetimes are verificated. (M.J.C.) [pt

  13. Hydrogen molecules in the divertor of ASDEX Upgrade

    International Nuclear Information System (INIS)

    Fantz, U.; Reiter, D.; Heger, B.; Coster, D.

    2001-01-01

    In order to reduce the power load onto the target plates detached divertor conditions are often preferred. These are characterized by volume recombination, i.e. three-body and radiative recombination. Due to low T e (few eV) hydrogen molecules can penetrate into the plasma and may play a role in divertor dynamics. In particular, it was suggested, that molecules may assist the volume recombination process. The role of molecules in the divertor is examined here by a combination of experimental results with plasma edge simulations (B2-EIRENE) and a collisional-radiative model for hydrogen molecules. Spectroscopic diagnostics of the Fulcher transition carried out at the divertor of ASDEX Upgrade yield estimates of molecular hydrogen fluxes and the vibrational population in the ground state in detached and attached hydrogen plasmas. Good agreement with B2-EIRENE is achieved only if vibrational levels are treated as distinct (metastable) particles in the model and if the collisional-radiative model is applied to the electronically excited levels. On this basis the contribution of molecules to plasma recombination was determined to be in the order of a few 10%. The dominant molecular process is the dissociation process via H 2 + . As a consequence initially detached divertor plasmas can even re-attach if vibrationally resolved molecules are properly included in plasma edge models. A set of B2-EIRENE calculations carried out for ASDEX Upgrade is discussed. In particular the threshold upstream density for detachment was found to be up to a factor 1.5 higher than that originally expected due to these molecular effects. The transferability of the results to deuterium will be discussed

  14. Vibration Theory, Vol. 1B

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Nielsen, Søren R. K.

    The present collection of MATLAB exercises has been published as a supplement to the textbook, Svingningsteori, Bind 1 and the collection of exercises in Vibration theory, Vol. 1A, Solved Problems. Throughout the exercise references are made to these books. The purpose of the MATLAB exercises...... is to give a better understanding of the physical problems in linear vibration theory and to surpress the mathematical analysis used to solve the problems. For this purpose the MATLAB environment is excellent....

  15. Final Report: Vibrational Dynamics in Photoinduced Electron Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth G. Spears

    2006-04-19

    The objective of this grant was to understand how molecular vibrational states (geometry distortions) are involved in photoinduced electron transfer rates of molecules. This subject is an important component of understanding how molecular absorbers of light convert that energy into charge separation. This is important because the absorption usually excites molecular vibrations in a new electronic state prior to electron transfer to other molecules or semiconductor nanoparticles, as in some types of solar cells. The speeds of charge separation and charge recombination are key parameters that require experiments such as those in this work to test the rules governing electron transfer rates. Major progress was made on this goal. Some of the molecular structures selected for developing experimental data were bimolecular charge transfer complexes that contained metals of cobalt or vanadium. The experiments used the absorption of an ultrafast pulse of light to directly separate charges onto the two different molecular parts of the complex. The charge recombination then proceeds naturally, and one goal was to measure the speed of this recombination for different types of molecular vibrations. We used picosecond and femtosecond duration pulses with tunable colors at infrared wavelengths to directly observe vibrational states and their different rates of charge recombination (also called electron transfer). We discovered that different contact geometries in the complexes had very different electron transfer rates, and that one geometry had a significant dependence on the amount of vibration in the complex. This is the first and only measurement of such rates, and it allowed us to confirm our interpretation with a number of molecular models and test the sensitivity of electron transfer to vibrational states. This led us to develop a general theory, where we point out how molecular distortions can change the electron transfer rates to be much faster than prior theories

  16. Modelo económica de demanda de energía eléctrica en la industria colombiana

    OpenAIRE

    Elkin Castaño; Jesús Botero; Carlos Eduardo Vélez

    1990-01-01

    Este artículo busca encontrar los determinantes económicos de la demanda industrial de energía eléctrica en Colombia durante el período 1970-1983. La estimación de las ecuaciones de demanda derivadas de la función translogarítmica de costos muestra la complementariedad o sustituibilidad entre energía y otros insumos de la función de producción industrial. Tras constatar la complementariedad entre energía y capital, se estima la demanda de energía en función del stock de capital de la industri...

  17. Otimização energética na empresa Simoldes Plásticos S.A.

    OpenAIRE

    Lages, Sara Maria De Bastos Peixoto

    2011-01-01

    Mestrado em Engenharia Química - Ramo Optimização Energética na Indústria Química A empresa Simoldes Plásticos, S.A. tem como atividade a injeção de peças plásticas para o ramo automóvel. O objectivo deste projeto foi sugerir a aplicação de medidas que permitam diminuir o consumo energético na empresa Simoldes Plásticos, S.A. Realizou-se um levantamento das ineficiências energéticas. Foram sugeridas três soluções com vista à redução energética. A primeira opção corresponde à colocaçã...

  18. Aplicación de la energía geotérmica en el sector agroalimentario

    OpenAIRE

    Pacheco Naranjo, Alejandro

    2015-01-01

    La introducción de energías renovables para el ahorro energético cobra cada vez más importancia, por lo que se hace especialmente relevante la utilización de sistemas de generación de calefacción y refrigeración a través de fuentes de energías renovables. Una de ellas, la geotermia de muy baja entalpía, presenta unos bajos costes de mantenimiento y operación, y consigue reducir la dependencia de recursos energéticos exteriores, así como la disminución del impacto medioambiental producido y la...

  19. Electron correlation in molecules

    CERN Document Server

    Wilson, S

    2007-01-01

    Electron correlation effects are of vital significance to the calculation of potential energy curves and surfaces, the study of molecular excitation processes, and in the theory of electron-molecule scattering. This text describes methods for addressing one of theoretical chemistry's central problems, the study of electron correlation effects in molecules.Although the energy associated with electron correlation is a small fraction of the total energy of an atom or molecule, it is of the same order of magnitude as most energies of chemical interest. If the solution of quantum mechanical equatio

  20. Comparisons of the Structure of Water at Neat Oil/Water and Air/Water Interfaces as Determined by Vibrational Sum Frequency Generation

    National Research Council Canada - National Science Library

    Gragson, D

    1997-01-01

    We have employed vibrational sum frequency generation (VSFG) to investigate the structure of water at neat oil/water and air/water interfaces through the OH stretching modes of the interfacial water molecules...

  1. Eficiencia energética en sistemas de bombeo de hidromezclas

    Directory of Open Access Journals (Sweden)

    Gabriel Hernández-Ramírez

    2015-10-01

    Full Text Available Las hidromezclas lateríticas presentan características no newtonianas debido a sus propiedades físico-químicas y al contenido de sólidos requerido para su procesamiento industrial, que ocasionan problemas de transportación por su alta viscosidad a causa de la sedimentación dentro de las tuberías, lo cual demanda una mayor carga de bombeo y, por consiguiente, un elevado consumo energético. Durante las mediciones realizadas para diferentes concentraciones de sólidos se demostró que las hidromezclas provocan un gasto energético cuando se incrementa el tiempo de bombeo por no corregirse la potencia eléctrica y la velocidad de giro al cambiar las propiedades reológicas de la pulpa.

  2. Comportamiento termico-energético de una vivienda social de la ciudad de Mendoza, Argentina

    OpenAIRE

    Mercado,María Victoria; Esteves,Alfredo; Filippín,Celina

    2010-01-01

    El estado hace entrega del 30% de las viviendas que se habitan por año en la ciudad de Mendoza, Argentina. El presente trabajo evalúa: (a) la calidad térmico-energética de una vivienda social, por medio de mediciones in-situ en condiciones de uso real; (b) el requerimiento energético necesario por medio de un balance; (c) la simulación de la vivienda en el programa SIMEDIF, donde se ajustó el modelo y se ensayaron mejoras de aplicación fácil y económica; y (d) un sondeo cualitativo de las sen...

  3. Eficiencia energética del alumbrado exterior en España

    OpenAIRE

    Gutiérrez Escolar, A.; Castillo Martínez, A.; Gómez Pulido, José Manuel; Gutiérrez Martínez, J. M.; García-Cabot, Antonio

    2013-01-01

    El alumbrado público en España representa entre un 40% y 60 % del total del consumo eléctrico de las ciudades, lo que supone unos gastos de electricidad y mantenimiento en torno a los 1.200 millones de euros al año. Sin embargo, los avances realizados en esta materia pueden ayudar a reducir este consumo energético hasta en un 45%. Si echamos un vistazo al resto de los países de la Unión Europea, podemos comprobar como España es el país que presenta un mayor consumo energético en alumbrado ext...

  4. Programación por metas Energía alternativa mediante biomasa.

    Directory of Open Access Journals (Sweden)

    Guerrero Casas, Flor María

    2003-01-01

    Full Text Available En este trabajo se presenta un modelo multicriterio de localización de centrales de generación de energía eléctrica mediante biomasa. Los objetivos considerados son: (1 minimizar el coste total de la operación, (2 maximizar la producción de electricidad obtenida, (3 maximizar la distancia entre plantas, (4 maximizar la aceptación social y (5 establecer las plantas o ampliaciones en aquellos lugares donde exista una mayor predisposición por parte de las administraciones locales. Finalmente, se concluye con una aplicación práctica mediante programación por metas ponderadas para la región andaluza, considerando los residuos procedentes del olivar como fuente de energía.

  5. Mechanism of Occurring Over-Voltage Phenomena in Distributed Power System on Energization of Transformers

    Science.gov (United States)

    Nakachi, Yoshiki; Ueda, Fukashi; Kajikawa, Takuya; Amau, Tooru; Kameyama, Hirokazu; Ito, Hisanori

    This paper verifies the mechanism of occurring over voltage phenomena in the distributed power system on energizing the transformer. This over-voltage, which is observed at the actual distributed power system, with heavy inrush current is found to occur at about 0.1-0.2sec after the energizing and continue for a duration of more than 0.1[sec]. There is a concern that this over-voltage may operate the protection relay and deteriorate the insulation of apparatus. It is basically caused by the resonance between the shunt capacitors and saturated/unsaturated magnetizing inductance of transformer, system inductance. By using analytical formulation of a simple equivalent circuit, its mechanism has been verified through simulations carried out by using EMTP. Moreover, the sympathetic interaction between transformers is prolonged the duration of the over-voltage by the field test data is discussed in this paper.

  6. Integración energética: una incertidumbre regulatoria

    Directory of Open Access Journals (Sweden)

    María de la Cruz Bayá C.

    2006-01-01

    Full Text Available Este artículo pretende introducir en la reflexión de los elementos que están insertos hoy por hoy en la agenda de la integración energética, como uno de los baluartes más importantes para la consolidación de los procesos subregionales ya que establece, per se, la base de la nueva configuración de las relaciones interestatales a partir de la relación de oferta y demanda energética. En este sentido, los métodos utilizados en la presente investigación han sido el exegético, comparado, estudio de caso y bibliográfico, lo cual ha permitido concluir que se requiere de la generación de un marco regulatorio comunitario armonizado, vinculado a los principios de supranacionalidad y de sustentabilidad.

  7. D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Initial Validation Procedures

    International Nuclear Information System (INIS)

    Jaskierny, W.; Hance, R.

    1998-01-01

    This note presents the inspection and tests to be performed on the DZERO solenoid energization, controls, interlocks and quench protection system before it is energized for the first time. This test is to be performed with a 5000A jumper at the end of the bus instead of the solenoid. This system is based in DZERO room 511. A copy of this note shall be annotated, signed and dated by the person coordinating the procedure; and filed with the system maintenance records. Annotations shall include comments about any aspect of the procedure that is abnormal or unsuccessful. The following inspections and tests shall be performed by persons knowledgeable about the system. Each individual test step should be reviewed and understood before proceeding with that step.

  8. Design and Implementation of Energized Fracture Treatment in Tight Gas Sands

    Energy Technology Data Exchange (ETDEWEB)

    Mukul Sharma; Kyle Friehauf

    2009-12-31

    Hydraulic fracturing is essential for producing gas and oil at an economic rate from low permeability sands. Most fracturing treatments use water and polymers with a gelling agent as a fracturing fluid. The water is held in the small pore spaces by capillary pressure and is not recovered when drawdown pressures are low. The un-recovered water leaves a water saturated zone around the fracture face that stops the flow of gas into the fracture. This is a particularly acute problem in low permeability formations where capillary pressures are high. Depletion (lower reservoir pressures) causes a limitation on the drawdown pressure that can be applied. A hydraulic fracturing process can be energized by the addition of a compressible, sometimes soluble, gas phase into the treatment fluid. When the well is produced, the energized fluid expands and gas comes out of solution. Energizing the fluid creates high gas saturation in the invaded zone, thereby facilitating gas flowback. A new compositional hydraulic fracturing model has been created (EFRAC). This is the first model to include changes in composition, temperature, and phase behavior of the fluid inside the fracture. An equation of state is used to evaluate the phase behavior of the fluid. These compositional effects are coupled with the fluid rheology, proppant transport, and mechanics of fracture growth to create a general model for fracture creation when energized fluids are used. In addition to the fracture propagation model, we have also introduced another new model for hydraulically fractured well productivity. This is the first and only model that takes into account both finite fracture conductivity and damage in the invaded zone in a simple analytical way. EFRAC was successfully used to simulate several fracture treatments in a gas field in South Texas. Based on production estimates, energized fluids may be required when drawdown pressures are smaller than the capillary forces in the formation. For this field

  9. Back-to-Back Energization of a 60kV Cable Network - Inrush Currents Phenomenon

    DEFF Research Database (Denmark)

    Faria da Silva, Filipe; Bak, Claus Leth; Hansen, M. Lind

    2010-01-01

    On November 2008 the Danish government decided that all Danish transmission lines with a rated voltage equal to and below 150kV must be put underground, in order to reduce the visual pollution caused by Overhead Lines. This decision will lead to a massive use of underground cables in the Danish...... Network, and force a change in the approach used until now when planning, analyzing and operating electrical power systems. One problem that might arise is the energization of cables in parallel, as this operation may originate high inrush currents, which represent a risk to the circuit breakers connected...... to the cables. The Danish utility ENV plans to install a new cable on its 60kV network, which will be installed in parallel with other cables already installed in the network. This paper summarizes the study made to calculate the inrush currents during the cable's energization, and its importance...

  10. An exactly solvable model for multiphoton excitation of polyatomic molecules in the presence of collisions

    International Nuclear Information System (INIS)

    Strekalov, M L

    2013-01-01

    A theoretical study has been made on the non-stationary phenomena in the relaxation of highly vibrationally excited molecules under laser radiation giving rise to these molecules. An exact analytical solution to the master equation has been obtained in terms of Meixner polynomials with regard to VV and VT processes. The time-dependent vibrational distribution is used to obtain analytical expressions for the mean number of photons, stored on the vibrational degrees of freedom and transferred to a thermal bath. Using the latter result, an explicit expression is given for the average energy transfer as a function of time. Its dependence on the partial pressure of absorbing molecules has also been established. (paper)

  11. [Research on the emission spectrum of NO molecule's γ-band system by corona discharge].

    Science.gov (United States)

    Zhai, Xiao-dong; Ding, Yan-jun; Peng, Zhi-min; Luo, Rui

    2012-05-01

    The optical emission spectrum of the gamma-band system of NO molecule, A2 sigma+ --> X2 pi(r), has been analyzed and calculated based on the energy structure of NO molecule' doublet states. By employing the theory of diatomic molecular Spectra, some key parameters of equations for the radiative transition intensity were evaluated theoretically, including the potentials of the doublet states of NO molecule's upper and lower energy levels, the electronic transition moments calculated by using r-centroid approximation method, and the Einstein coefficient of different vibrational and rotational levels. The simulated spectrum of the gamma-band system was calculated as a function of different vibrational and rotational temperature. Compared to the theoretical spectroscopy, the measured results were achieved from corona discharge experiments of NO and N2. The vibrational and rotational temperatures were determined approximately by fitting the measured spectral intensities with the calculated ones.

  12. Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

    Directory of Open Access Journals (Sweden)

    Xiaoqing Zhang

    2015-07-01

    Full Text Available Piezoelectret films are prepared by modification of the microstructure of polypropylene foam sheets cross-linked by electronic irradiation (IXPP, followed by proper corona charging. Young’s modulus, relative permittivity, and electromechanical coupling coefficient of the fabricated films, determined by dielectric resonance spectra, are about 0.7 MPa, 1.6, and 0.08, respectively. Dynamic piezoelectric d33 coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d33 ⋅ g33 for a more typical d33 value of 400 pC/N is about 11.2 GPa−1. Vibration-based energy harvesting with one-layer and two-layer stacks of these films is investigated at various frequencies and load resistances. At an optimum load resistance of 9 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, referred to the acceleration g due to gravity, is obtained for an energy harvester consisting of a one-layer IXPP film with an area of 3.14 cm2 and a seismic mass of 33.7 g. The output power can be further improved by using two-layer stacks of IXPP films in electric series. IXPP energy harvesters could be used to energize low-power electronic devices, such as wireless sensors and LED lights.

  13. Energy harvesting from vibration with cross-linked polypropylene piezoelectrets

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoqing [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology & School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Institute for Telecommunications Technology, Merckstrasse 25, 64283 Darmstadt (Germany); Wu, Liming [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology & School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Sessler, Gerhard M., E-mail: g.sessler@nt.tu-darmstadt.de [Institute for Telecommunications Technology, Merckstrasse 25, 64283 Darmstadt (Germany)

    2015-07-15

    Piezoelectret films are prepared by modification of the microstructure of polypropylene foam sheets cross-linked by electronic irradiation (IXPP), followed by proper corona charging. Young’s modulus, relative permittivity, and electromechanical coupling coefficient of the fabricated films, determined by dielectric resonance spectra, are about 0.7 MPa, 1.6, and 0.08, respectively. Dynamic piezoelectric d{sub 33} coefficients up to 650 pC/N at 200 Hz are achieved. The figure of merit (FOM, d{sub 33} ⋅ g{sub 33}) for a more typical d{sub 33} value of 400 pC/N is about 11.2 GPa{sup −1}. Vibration-based energy harvesting with one-layer and two-layer stacks of these films is investigated at various frequencies and load resistances. At an optimum load resistance of 9 MΩ and a resonance frequency of 800 Hz, a maximum output power of 120 μW, referred to the acceleration g due to gravity, is obtained for an energy harvester consisting of a one-layer IXPP film with an area of 3.14 cm{sup 2} and a seismic mass of 33.7 g. The output power can be further improved by using two-layer stacks of IXPP films in electric series. IXPP energy harvesters could be used to energize low-power electronic devices, such as wireless sensors and LED lights.

  14. Single-molecule electron tunnelling through multiple redox levels with environmental relaxation

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Ulstrup, Jens

    2004-01-01

    We present an analytical theory for electron flow through a molecule with several redox levels, enclosed between a pair of metallic electrodes. The levels can be electronic or electronic-vibrational levels. Vibrational energy spacing characterises the latter sets. The levels are further coupled...... can be only achieved when the latter are located between the Fermi levels of the substrate and tip or source and drain electrodes. The redox levels can be brought into this "energy window", either by the overpotential or bias and gate voltages, or by vibrational relaxation of (a) given (set of) redox...

  15. Resonant R-matrix theory of inelastic processes in collisions of electrons with HF molecules

    International Nuclear Information System (INIS)

    Fabrikant, I.I.; Kalin, S.A.; Kazansky, A.K.

    1992-01-01

    The resonant R-matrix theory is applied to the calculation of vibrational excitation and dissociative attachment cross sections in collisions of electrons with HF molecules. The parameters of our model were chosen by fitting our eigenphase sums for e-HF scattering to the results of ab initio R-matrix calculations by previous authors. Another set of parameters was chosen to get a better agreement with experimental results on vibrational excitation. Dissociative attachment cross sections calculated with these parameters are in good agreement with experimental results. We also calculated cross sections for vibrational excitation from excited states and angular distribution of the scattered electrons. (author)

  16. Far-Infrared Spectroscopy of Weakly Bound Hydrated Cluster Molecules

    DEFF Research Database (Denmark)

    Andersen, Jonas

    -sized molecular clusters with water by means of far-infrared and terahertz neon matrix isolation spectroscopy. The embedding of non-covalent cluster molecules in solid cryogenic neon matrices at 2.8 K ensures a high sensitivity for direct spectroscopic observations of the large-amplitude intermolecular...... vibrational bands of the cluster molecules in the challenging far-infrared and terahertz spectral regions.A key parameter in the validation of the performance of theoretical predictions for weak non-covalent intermolecular interactions is the dissociation energy D0 that depends heavily on the class of large...

  17. Conteúdo energético das operárias da formiga cortadeira, Atta sexdens

    Directory of Open Access Journals (Sweden)

    Roberto da Silva Camargo

    2013-11-01

    Full Text Available O conhecimento do conteúdo energético das operárias é essencial para mensurar a disponibilidade energética, responsável pela manutenção e execução de atividades essenciais para o crescimento da colônia de formigas. Mas pouco se conhece sobre o conteúdo energético das operárias e quanto estará disponível para realizar atividades de, por exemplo, escavar do ninho. O presente estudo determinou o teor de lipídeo e o conteúdo energético das operárias de formigas cortadeiras inativas, antes e pós atividade de escavação. Por meio da determinação do teor de lipídeos, pode-se calcular o conteúdo energético das operárias em repouso (paradas e compará-las com as que escavaram. O teor de lipídeo e conteúdo energético das operárias foram em média 9,1±0,8% e 111,31±54,71J, respectivamente, entretanto, as séries experimentais não diferiram significativamente. Adicionalmente, a taxa do fluxo catabólico, embasado na massa corporal das operárias foi de 14,76±10,11µW. Conclui-se que o recurso energético para a escavação do ninho não é proveniente de reserva de lipídeos corporal e, dessa forma, o conteúdo energético das operárias não alterou antes e pós-atividade de escavação.

  18. Investigation of Prevalence of Energizer Drugs and Supplements Consumption and Effective Factors Among Bodybuilder Men in Karaj (2011)

    OpenAIRE

    F. Shoshtarizadeh; F. Bahramian; A.A. Safari; M. Pourghaderi; H. Barati

    2013-01-01

    Background: Body builder athletes’ high attention to form of body can result in high prevalence of nutritional disorders and habit to energizer drugs consumption. With notice to abuse problems of these drugs, this research was carried out to estimate prevalence of energizer drugs and supplements consumption in Karaj body builder men in 2011. Method: In cross-sectional (description- analytical) research 780 Karaj body builder men were selected randomly. Data were collected through interv...

  19. Energizing the Enterprise: An Incentive-Based Approach to Homeland Security

    Science.gov (United States)

    2010-12-01

    happen, but so far, they have not. To assume that Americans live in a vacuum—that they will only understand what we spoon - feed them—is naive...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited ENERGIZING THE...S) Jason B. Porter 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 8

  20. Concepción energética y universal de la vida

    OpenAIRE

    Morales Macedo, Carlos

    2010-01-01

    La vida es independiente de la materia; La vida es consubstancial con el universo; La vida actúa como una energía superior; Difusión, circulación y continuidad de la vida; Universalidad de la vida; El nuevo concepto ante las clásicas doctrinas fundamentales de la vida; La nueva concepción de la vida ante las modernas teorías organicistas; Resumen y conclusiones.