Outdoor and indoor noise levels resulting from aircraft flyovers and certain nonaircraft events were recorded at eight homesites and a school along with the associated vibration levels in the walls, windows, and floors at these test sites. Limited subjective tests were conducted to examine the human detection and annoyance thresholds ...

Using a U (2) algebraic model the fundamental stretching vibrations of copper octaethyl porphyrin and magnesium octaethyl porphyrin are calculated for 24 vibrational bands. The locality parameter ? confirms the highly local behavior of the stretching modes of these porphyrin molecules. The model Hamiltonian so constructed appears to describe the ...

... repeatability of octave band vibration measurements of ... relationship between bearing vibration level measured in octave bands and the ...

... to. FAR FIELD NOISE AND VIBRATION LEVELS PRODUCED ... FAR FIELD NOISE AND VIBRATION LEVELS PRODUCED ...

An accurate potential energy curve for the BeF molecule in the X(sup 2)(Sigma) (sup +) state is calculated within the MRSDCI approach. Vibrational level spacings and the dissociation energy are reported. Agreement with the available experimental spacings ...

The purpose of the present study was to determine if the administration of low-level sensory stimuli (odor or vibration) enhances a soldier's speed and ability to detect targets, discriminate friend from foe and accurately shoot at enemy targets during 3 ...

An accurate characterization of the vibration environment and a vibration qualification test derived from it will be a very useful tool for manufacturers of instrumentation for use on underground coal mining equipment. Recognizing this, the Bureau of Mines sponsored a study wherein vibration ...

A computational approach is presented for prediction and interpretation of core-level spectra of complex molecules. Applications are presented for several isolated organic molecules, sampling a range of chemical bonding and structural motifs. Comparison with gas phase measurements indicate that spectral lineshapes are accurately reproduced both above and ...

The pump--probe threshold ionization photoelectron spectra of pyrazine have been recorded using nine different vibrations of [ital S][sub 1] as intermediate resonances. The extensive vibrational structure in these spectra of the ionic ground state have enabled the measurement of 12 of its vibrational frequencies and their assignments. ...

... The frequency of vibration was measured with a Frahm vibrating- reed tachometer, accurate to 0.5 percent of the frequency reading and with a ...

A recently developed implementation of photofragment spectroscopy, based on specific properties of infrared multiphoton dissociation, has been applied for overtone spectroscopy of the CH stretch vibration in CF3H. The selectivity and sensitivity of this detection technique, called infrared laser assisted photofragment spectroscopy (IRLAPS), is high enough to combine it with ...

An accurate potential surface of 68 grid points for the H/sub 3//sup +/ system is given. The surface was calculated at the level of a full configuration expansion using a large basis set of 63 contracted Gaussian functions. This surface should be suitable for extremely accurate predictions of the ...

... comprehensive rotorcraft analysis CAMRAD II ... accurate prediction of rotor-induced vibration ... VIBRATION, *HELICOPTER ROTORS, FLIGHT TESTING ...

Estimates of the absorption and emission characteristics of molecules required to develop materials for solar-pumped lasers are addressed. These characteristics are described in terms of the Franck Condon factors, which are calculated from the molecular wave functions. Wave functions for vibrational levels in the lower and upper electronic states of I2 and ...

We have demonstrated the use of ab initio molecular dynamics (AIMD) trajectories to compute the vibrational energy levels of molecular systems in the context of the semiclassical initial value representation (SC-IVR). A relatively low level of electronic structure theory (HF/3-21G) was used in this proof-of-principle study. ...

We have demonstrated the use of ab initio molecular dynamics (AIMD) trajectories to compute the vibrational energy levels of molecular systems in the context of the semiclassical initial value representation (SC-IVR). A relatively low level of electronic structure theory (HF/3-21G) was used in this proof-of-principle study. ...

The goal of this work is to characterize the intermolecular vibrations of small water clusters. Using tunable far infrared laser absorption spectroscopy, large amplitude vibration-rotation-tunneling (VRT) dynamics in vibrationally excited states of the water dimer and the water trimer are investigated. This study begins with the ...

The goal of this work is to characterize the intermolecular vibrations of small water clusters. Using tunable far infrared laser absorption spectroscopy, large amplitude vibration-rotation-tunneling (VRT) dynamics in vibrationally excited states of the water dimer and the water trimer are investigated. This study begins with the ...

A set of Direct Simulation Monte Carlo (DSMC) chemical-reaction models recently proposed by Bird and based solely on the collision energy and the vibrational energy levels of the species involved is applied to calculate nonequilibrium chemical-reaction rates for atmospheric reactions in hypersonic flows. The DSMC non-equilibrium model predictions are in ...

A set of Direct Simulation Monte Carlo (DSMC) chemical-reaction models recently proposed by Bird and based solely on the collision energy and the vibrational energy levels of the species involved is applied to calculate non-equilibrium chemical-reaction rates for atmospheric reactions in hypersonic flows. The DSMC non-equilibrium model predictions are in ...

We investigated transition strengths from ultracold weakly bound K41Rb87 molecules produced via the photoassociation of laser-cooled atoms. An accurate potential energy curve of the excited state (3)1?+ was constructed by carrying out direct potential fit analysis of rotational spectra obtained via depletion spectroscopy. Vibrational energies and ...

... those factors (mechanical and electrical ... of the vibrations and the ... MOTOR GENERATORS, SHIPBOARD, VIBRATION, OPTIMIZATION, MAGNETIC ...

The study of vibration resonance physics in propyne is based on experimental measurements of about 600 new rotational transitions between 495-590 and 700-760 GHz in excited vibrational levels v5 = 1, v8 = 1, v10 = 3 and v9 = v10 = 1 with vibrational energies around 1000 cm?1. The limits to the assignments and ...

Jun 20, 2001 ... The most severe test was a 12.3grms random vibration test (peak vibration ... The random vibration test levels were chosen to simulate, ...

The GEVS random vibration requirements have a lower ... The next vibration level tested is 14.1 G,, as derived from the GEVS requirements for random vibration ...

Propadienylidene (H(2)CCC), a reactive carbene of interest to combustion processes and astrochemistry, has been studied by explicitly correlated coupled cluster theory at the CCSD(T)-F12x (x = a, b) level. Vibrational configuration interaction (VCI) has been employed to calculate accurate wavenumbers for the fundamental ...

We treat vibrational excitation of hydrogen by low-energy electrons using an improved nonlocal resonance model. The model is based on accurate ab initio data for the {sup 2}{sigma}{sub u}{sup +} shape resonance and takes full account of the nonlocality of the effective potential for nuclear motion. Integral vibrational excitation cross ...

We propose a process to convert ultracold metastable Cs2 molecules in their lowest triplet state into (singlet) ground-state molecules in their lowest vibrational levels. Molecules are first pumped into an excited triplet state, and the triplet-singlet conversion is facilitated by a two-step spontaneous decay through the coupled A1?u+-b3?u states. Using ...

Understanding the stability of fluid interfaces subjected to small vibrations under microgravity conditions is important for designing future materials science experiments to be conducted aboard orbiting spacecraft. During the STS-85 mission, experiments investigating the motion of a large bubble resulting from small, controlled vibrations were performed ...

An analytical expression is found for the accurate ab initio potential energy curve of the fluorine molecule that has been determined in the preceding two papers. With it, the vibrational and rotational energy levels of F(2) are calculated using the discrete variable representation. The comparison of this theoretical spectrum with the ...

... Accession Number : ADA108131. Title : Vibration Levels in Army Helicopters--Measurement Recommendations and Data. ...

... Accession Number : AD0609678. Title : VIBRATIONAL LEVELS IN LIQUID BROMINE BY NEUTRON INELASTIC SCATTERING,. ...

... Effects on Vibrational Level Populations. ... induced fluorescence techniques to number density measurements of ... of deviation of the population in the ...

... ADA136238. Title : Rates of Relaxation in the Upper Vibrational Levels of HF (Hydrogen Fluoride) and DF (Deuterium Fluoride). ...

sound pressure radiation to differ markedly from the vibration spectrum, Fig. 12 is cited. This figure shows the vibration levels and sound pressure levels ...

By means of near Hartree-Fock quality Slater basis sets, and the incorporation of electron correlation through the coupled-pair formalism, theoretical potentials are obtained for the X1Sigma(+) states of NaH, KH, and RbH. Electric dipole moment functions are given for NaH-RbH, as well as vibrationally averaged dipole moments, Einstein coefficients, and radiative lifetimes for ...

The pure rotational spectrum of chlorine nitrate in its v6 = 1 excited vibrational state has been studied. A total of 2901 lines, with Ka extending to 33 in the 35Cl isotopologue and 30 in the 37Cl isotopologue, respectively, have been recorded and assigned. This analysis, along with our recently reported study of the ?5/?6?9 dyad and the improved energy ...

The aim of the study was to explore the limits of initio methods towards the description of excited vibrational levels up to the dissociation limit for molecules having more than two electrons. To this end a high level ab initio potential energy function was constructed for the four-electron LiH molecule in order to ...

Successful operation of the APS facility requires a very stable particle beam. Vibration coupled through mechanical systems, such as magnet supports, beam tube supports, and other paths can cause deterioration of the particle beam. There are two sources of vibration: external, or far field, which is generated external to the APS site and internal, or near ...

... Title : Ab Initio Calculation of Vibrational Circular Dichroism Spectra Using Accurate Post-Self-Consistent-Field Force Fields: trans-2,3 ...

The objective of this research is to detail the development of a simple and unique instrumentation for precise micro-measurement as well as vibration measurement in an integrated manufacturing set up that can be demonstrated in a student laboratory. Based on this we propose new research for a smaller embedded measurement unit. All machines have some amount of forced ...

An experimental system has been designed and tested for the spectrophotometric study of low pressure fluorine supported flames. Fluorine gas flowrates of 5 to 500 cc/sec can be accurately measured and easily controlled. A multidiffusion burner and vacuum ...

The adaptation of standard techniques to operational amplifiers resulted in the construction of current sources capable of supplying currents down to 10/ sup -13/ amp with stabilities of 0.1%. Such sources were used for checking the current sensitivity of various devices and, in conjunction with a vibrating-reed electrometer, were used for direct measurements of ...

, construct, and test a High Powered Rocket, which carries a useful scientific payload. The teams of payload deployment. CySLI's design will be to construct a rocket to reach 5,280ft (Above Ground Level vibrations in the airframe that are caused by uneven burning in the solid motor. In order to accurately

Vibration-electronic spectroscopy of I2 vapor is a common, important experiment in physical chemistry lab courses. We use narrow bandwidth diode-pumped solid state (DPSS) lasers to excite specific rotational levels; these lasers are surprisingly stable and are now available at low cost. We also use efficient miniature fiber-optic spectrometers to resolve ...

Improvements in the manner in which the potential energy surface (PES) is generated in the vibrational self-consistent field (VSCF) method have been implemented. The PES can now be computed over a flexible range of displacements and following normal mode displacement vectors expressed in internal rather than Cartesian coordinates, leading to higher accuracy of the calculated ...

A mid-infrared high-resolution spectral survey of the source IRC+10216 (CW Leo) has been carried out between 11 and 14 ?m. A large number of lines of C_2H_2 and HCN and their most abundant isotopologues, have been identified. Lines involving high-energy ro-vibrational levels allow an accurate derivation of the physical and chemical ...

The results of microwave spectrum investigation of the excited vibrational states of furfural in the frequency range between 49 and 149 GHz are reported. In total 15 excited vibrational states (9 for trans-furfural and 6 for cis-furfural) were assigned and analyzed. Six of the 15 investigated states were assigned for the first time. ...

A configuration selection scheme has been used to speed up vibrational multiconfiguration self-consistent field calculations. Deviations with respect to reference calculations were found to be negligible while yielding an acceleration of about two orders of magnitude. Its application to bridged lithium compounds (Li(2)H(2), Li(2)F(2), Li(2)O(2), and Li(3)F(3)) based on ...

A configuration selection scheme has been used to speed up vibrational multiconfiguration self-consistent field calculations. Deviations with respect to reference calculations were found to be negligible while yielding an acceleration of about two orders of magnitude. Its application to bridged lithium compounds (Li2H2, Li2F2, Li2O2, and Li3F3) based on ...

Vibrational fine structure has been observed in the C1s and O1s photoelectron lines of CO adsorbed on Ni(100). This allows a detailed separation of vibrational and electronic contributions to the line profile. The main line is found to represent the fully screened final state. The width of the photoelectron lines is dominated by the intramolecular stretch ...

We determine the energies of twelve vibrational levels lying within 20 GHz of the lowest dissociation limit of 85Rb2 with two-color photoassociation spectroscopy of ultracold 85Rb atoms. The levels lie in an energy range for which singlet and triplet states are mixed by the hyperfine interaction. We carry out a coupled channels bound ...

Efficient, novel design and analysis methods are presented for improving the structural performance of turbine engine rotors with respect to blade vibration response. For a bladed disk, the blades are intended to be identical; however, blade-to-blade structural irregularities, known as blade mistuning, in practice are unavoidable due to manufacturing tolerances and in-service ...

The effect of an adiabatic approximation, named adiabatic Jacobi correction (AJC) and introduced in J. Chem. Phys. 126, 024102 (2007), was investigated on the complete set of vibrational levels of H(2)(+) and its isotopologues, most importantly on the highest-lying vibrational states of HD(+). In order to perform clamped nuclei ...

In this paper, we present a neural adaptive control scheme for active vibration suppression of a composite aircraft fin tip. The mathematical model of a composite aircraft fin tip is derived using the finite element approach. The finite element model is updated experimentally to reflect the natural frequencies and mode shapes very accurately. ...

The N2 Lyman-Birge-Hopfield (LBH) bands (a-X transition) extend throughout the Earth's far-ultraviolet spectrum in the dayglow and aurora. LBH band emissions are important for remote sensing of the Earth's thermosphere, used in both limb-scanning techniques that retrieve N2 and O2 densities and in nadir-viewing techniques for retrieving the O/N2 column density ratios. There is significant ...

Measured vibration levels from trains have been used to determine the distance dependence of ground-borne vibrations and a reference vibration level for each train type. Using the results of a Norwegian study, an empirical prediction formula has been made...

Accurate calibration of accelerometers requires that accurate measurement techniques be developed and maintained. Calibrations of vibration exciters and pickups are performed by comparison with the response characteristics of NBS standard accelerometers o...

The book represents a survey of the contemporary methods of balancing the rotors of aircraft engines and lists the factors which influence the level of vibrations of engines. It is noted that one of the basic reasons for vibrations is the imbalance of ela...

... Programme with a Finite Number of Strain Levels; Fatigue Analysis of Multi-Degree-of-Freedom Systems under Random Vibration; A Mathematical ...

An accurate characterization of the vibration environment and a vibration qualification test derived from it will be a very useful tool for manufacturers of instrumentation for use on underground coal mining equipment. Recognizing this, the Bureau of Mine...

Vibration analyses of structural systems are concerned with accurately predicting the natural frequencies and mode shapes of the vibrating system. This analysis process involves two general parts: the dynamic finite element model of the physical system an...

Vibration potentials are generated when sound waves are propagated through an ionic solution, polyelectrolyte, or colloidal suspension in an electrolyte. Accurate measurements of vibration potential can be now performed on a routine basis, using pulse mod...

... ELECTRON TRANSITIONS), (*DIATOMIC MOLECULES, *MOLECULAR ENERGY LEVELS), VIBRATION, ROTATION, BAND SPECTRA. ...

... The effect of axial load on the octave band vibration level of 23256 spherical roller bearings was investigated in the range above 50 cps. (Author). ...

goals will be significantly enhanced by increasing its vibrational damping at ... the damping levels of various materials at cryogenic temperatures and to search ...

... 18) which correlate third-octave bond noise and vibration levels for a "reference" structure, with corrections (Figures 19 ...

... precision, which enabled one to determine the dipole moments accurately and to observe a non linear variation of dipole moment with vibration al ...

membrane theory. Hence, it appears that the state of prestress determined according to the linear membrane theory is adequately accurate for the ...

... The laser radar was able to accurately measure a target's vibrational frequency and amplitude for amplitudes greater than 40 nim The theoretical ...

Hybrid (quantum mechanics/molecular mechanics) theoretical techniques will be discussed that may allow to obtain accurate vibrational spectra of ...

This paper is a critical review of information pertinent to the behaviour of stadia structures subjected to dynamic crowd loading. It is intended to introduce and explain key concepts in the field as well as summarise the development of current guidance and methods for modelling and assessing crowd occupancy.The review is structured by presenting a field overview and then rationalising the ...

The vibrational levels associated with the HeitlerLondon potertial of H/ sub 2/ were found through use of the firstorder WBK approximation. The vibrational energies G as a function of quantum number nu are accurately represented by G = --D/sub o/(1--A nu -- B nu /sup 2/)/sup n/, where D/sup o/ is the ...

The nu(4) + nu(5) combination band, which appears relatively weak in the IR absorption spectrum, has been identified with exceptionally high intensity in the IR emission spectra from highly vibrationally excited acetylene, which is produced with approximately 71 kcal mol(-1) of vibrational energy from the 193 nm photolysis of vinyl bromide. The ...

Foam damping materials judiciously placed in automotive structures efficiently reduce the vibration amplitudes of large, relatively flat exterior body panels such as the hood, roof, deck lid (trunk) and door skin. These polymer foams (typically epoxy or vinyl) have mechanical properties that depend on the foam homogeneity, degree of expansion, temperature and frequency of ...

Development of the design selected for the 10 degree K cryogenic cooler in the Phase I study was continued in this second phase of the program. The configuration arrived at in Phase 1 was a triple-expansion, free-displacer Stirling-cycle refrigerator driven by a linear motor. Vibrations are attenuated with a passive vibration absorber. Electromagnetic ...

Helicopter flight, relying on rotary motion of a complex mechanical system, is predisposed to vibration. While the helicopter has many sources of vibrations the main rotor system generates by far the largest magnitude vibrations, and can render the vehicle inoperable if left unaddressed. Thus, proper maintenance to reduce ...

... Descriptors : *ATOMIC ENERGY LEVELS, *MOLECULAR ROTATION, VIBRATION ... URANYL RADICALS, TRANSITION METALS, MOLECULES ...

Cabin noise reduction may be achieved by modification to the source levels, ..... Cabin window vibration levels - computed contribution of ...

From accurate spectroscopic constants one finds that the thermal dissociative-attachment process (DA) in DI should be exothermic only for rotational levels {ital J}{gt}8 in {ital v}=0. We report herein measurement of an enhancement of DA with rotational temperature {ital T} in the range 298--468 K. The effect is easily accounted for by the increase in ...

We experimentally present a technique for sensitively determining the laser-induced frequency shifts of the long-range molecular vibrational and rotational levels. The scheme relies on an optical frequency shifter, leading to two laser beams with a precise and adjustable frequency interval. A series of photoassociation spectra are recorded with both beams ...

The possibility of satisfactory modeling of the vibratory stress level history of a vertical axis wind turbine (VAWT) is considered. Fatigue life prediction is expressed as a function of the vibratory stress level, the wind speed, and the wind speed distribution on-site. A statistical distribution of stress levels is asserted to more ...

Ground- and excited-state diatomic bond lengths, vibrational levels, and potential-energy curves are determined using conventional and localized Hartree-Fock (LHF)-based density-functional theory. Exchange only and hybrid functionals (with various fractions of exchange) are considered, together with a standard generalized gradient approximation (GGA). ...

Ground- and excited-state diatomic bond lengths, vibrational levels, and potential-energy curves are determined using conventional and localized Hartree-Fock (LHF)-based density-functional theory. Exchange only and hybrid functionals (with various fractions of exchange) are considered, together with a standard generalized gradient approximation (GGA). ...

Calculations of the second virial coefficients and their derivatives for the Hulburt-Hirschfelder (HH) and other accurate interaction potentials are used to determine the thermodynamic properties of nitrogen at high temperatures. Unlike the usual methods employing partition functions, which are most accurate at low temperatures where the energy ...

Calculating accurate forces within variational and diffusion Monte Carlo (VMC and DMC) methods is a very challenging problem. We derive expressions for the contribution to the Hellmann-Feynman force from nonlocal pseudopotentials for use within the VMC and DMC methods. Equilibrium bond lengths and harmonic vibrational frequencies are calculated from the ...

Electron excitation cross sections to produce vibrationally excited H/sub 2/ molecules are calculated for molecules initially in the first and second vibrational levels. The pattern of excitation cross sections as a function of final vibrational level v'' differs from that ...

The infrared spectrum of the T-shaped 52Cr+-D2 complex is measured over the 2742-2820 cm-1 range by detecting Cr+ photofragments. The main band, due to the D-D stretch excitation, is shifted at 215 cm-1 to lower energy from the Q01 transition of the free D2 molecule and displays clearly resolved rovibrational transitions. Observation of a photodissociation onset for the N'=8 rotational ...

The infrared spectrum of the T-shaped (52)Cr(+)-D(2) complex is measured over the 2742-2820 cm(-1) range by detecting Cr(+) photofragments. The main band, due to the D-D stretch excitation, is shifted at 215 cm(-1) to lower energy from the Q(0) (1) transition of the free D(2) molecule and displays clearly resolved rovibrational transitions. Observation of a photodissociation onset for the N(')=8 ...

Alkali-metal hydride molecules have large dipole moments in their ground electronic states. We explore the possibility of forming such molecules from a mixture of the ultracold atomic gases, employing a one-photon stimulated radiative association process. Using accurate molecular potential-energy curves and dipole moments, we have calculated the rate coefficients for ...

First and second derivative of the nonadiabatic coupling between the several 1?+ adiabatic states of the KH molecule considered from accurate diabatic and adiabatic data have been evaluated. Such derivatives of the electronic wave function are determined through a numerical differentiation of the rotational matrix connecting the diabatic and adiabatic representations. The ...

The first and second vibrational levels of the Br-Br molecule have been measured directly for the first time in the liquid state. The beryllium filter technique of neutron inelastic scattering was employed to excite the vibrational levels and measure thei...

Simple methods to calculate a vibrational enhancement factor of a nuclear level density with allowance for damping of collective state are considered. The results of the phenomenological approach and the microscopic quasiparticle-phonon model are compared. The practical method of calculation of a vibrational enhancement factor and ...

Relative importance of anharmonic corrections to molecular vibrational energies, nuclear magnetic resonance (NMR) chemical shifts, and J-coupling constants was assessed for a model set of methane derivatives, differently charged alanine forms, and sugar models. Molecular quartic force fields and NMR parameter derivatives were obtained quantum mechanically by a numerical ...

Vibrational coupled cluster (VCC) calculations of molecular vibrational energy levels can be characterized by the number of modes coupled in the Hamiltonian operator and the number of modes simultaneously excited in the parameter space. We propose a VCC model which includes all two-mode couplings in the Hamiltonian and excitation space ...

Instructors and students can use this spreadsheet to quickly and easily observe how the shape of a one-dimensional vibrational potential energy curve and its associated vibrational quantum energy levels depend on the anharmonicity. This illustrates the connection between the harmonic (approximation) and anharmonic descriptions of ...

A vibration isolation system for a payload. The vibration isolation system provides a level of vibration isolation for all vibration translational and rotational components, while minimizing the moment of the payload mass relative to the isolation system....

Payloads delivered to orbit by expendable launch vehicles experience high levels of vibration. This vibration can cause component failures, or more frequently, lead to extra weight that would otherwise be useful for added functions on orbit. Vibration iso...

... Accession Number : ADD257066. Title : Stability of PZT Piezoelectric Ceramics Under Vibration Level Change. Descriptive Note : Journal article,. ...

... Vibrational Level Relaxation Effects on Laser-Induced Fluorescence Number Density Measurements of Hydroxide in a Combustion Environment. ...

... Accession Number : AD0273666. Title : FAR FIELD NOISE AND VIBRATION LEVELS PRODUCED DURING THE SATURN SA-1 LAUNCH. ...

... Accession Number : ADA140853. Title : Deactivation of Higher Vibrational Levels of HF by F Atoms. Descriptive Note : Technical rept.,. ...

The infrared gas phase spectra of 12CH2Cl2, 13CH2Cl2, and 12CD2Cl2 have been studied in the region below 6200 cm-1 under conditions of high resolution. Some 30 vibrational levels can be identified for each isotopic species and assigned unequivocally in terms of the band contours displayed. Direct observation has been made of the very weak ?2 fundamentals ...

In preliminary work, we explore using a temperature-jump method, similar to what has been used in our ongoing CO2(?2)-O energy transfer studies, to measure vibrational energy transfer efficiencies in O3-M encounters, where M=O2, N2, or O. A lingering concern in the analysis of NASA`s TIMED/SABER data involves the 9.6 micron channel, where the observed radiance is dominated ...

Alkali hydride molecules are very polar, exhibiting large ground-state dipole moments. Ultracold sources of alkali atoms and hydrogen have been created in the laboratory. We explore theoretically the feasibility of forming such molecules from a mixture of the ultracold atomic gases, employing a two-photon stimulated radiative association process -- Raman excitation. The triplet ground state for ...

The phonon spectra of niobium diselenide nanofilms, consisting of several structural elements of this compound, as well as graphite nanofilms starting with bigraphene are analyzed at the microscopic level. The partial contributions of the displacements of atoms along the strong and weak coupling directions (i.e. along and perpendicular to the layers) to the phonon density of ...

Variational results of the vibrational states up to 8500 cm{sup {minus}1} for {ital X} {sup 1}{ital A}{sub 1} formaldehyde at {ital J}=0 are presented. Our results agree reasonably well with perturbation results and with experimental results. Our calculations show additional {ital b}{sub 1} and {ital b}{sub 2} states in the energy region of the 2{sub 2}4{sub 4} ...

A Fabry-Perot interferometer on the DE-2 satellite measured a surface glow near 732 nm at an altitude of 250 km. By comparison with the mesospheric nightglow, the hydroxyl radical was implicated as the fluorescing species. Unfortunately, the identification was not clear cut, since the spectrum showed an additional feature not observed in the nightglow. Calculations indicated that this feature ...

High-order many-mode terms in the expansion of multidimensional potential energy surfaces were modeled by a fully automated molecule-specific fitting of parameters within semiempirical molecular orbital theory to low-order grid representations of high-level ab initio potentials. Analytical derivatives of the total energy with respect to the fitting parameters in combination ...

High-order many-mode terms in the expansion of multidimensional potential energy surfaces were modeled by a fully automated molecule-specific fitting of parameters within semiempirical molecular orbital theory to low-order grid representations of high-level ab initio potentials. Analytical derivatives of the total energy with respect to the fitting parameters in combination ...

We recently reported the formation of ultracold LiCs molecules in the rovibrational ground state X1sigma+, v" = 0,J" = 0 (J. Deiglmayr et al., Phys. Rev. Lett., 2008, 101, 133004). Here we discuss details of the experimental setup and present a thorough analysis of the photoassociation step including the photoassociation line shape. We predict the distribution of produced ground state molecules ...

Accurate predictions of a structure dynamics require precise modeling of its boundary conditions including any nonlinear effects. This paper investigates the behavior of frictional supports that are examples of boundary conditions exhibiting nonlinear effects, such as stiction and slip phenomena, depending on the structure vibration amplitudes. The ...

The accurate detection and characterization of nonlinearities associated with damage in structural systems is an area of vibration analysis that is being widely researched. In this paper, nonlinear behavior is considered a potential indicator of damage. Most conventional damage detection methods, such as those based on resonant frequencies and mode shapes, ...

The available theoretical analyses relating to the vibrational excitation of a dissociating gas that assume that the gas dissociates from vibrational level populations given by the Maxwell- Boltzmann distribution law are questioned. The two theories of thermal dissociation are briefly outlined and it is shown that either ...

The terahertz (THz) spectrum of phencyclidine hydrochloride from 7.0 to 100.0 cm-1 has been measured at cryogenic (78.4 K) temperature. The complete structural analysis and vibrational assignment of the compound have been performed employing solid-state density functional theory utilizing eight generalized gradient approximation density functionals and both solid-state and ...

The aim of this paper is to present the model of a complete system, consisting of a variable damping shock absorber and a specialized servo-hydraulic tester, used to evaluate the vibration levels produced by a shock absorber. This kind of evaluation is used within the automotive industry to investigate shock absorbers, as an alternative to ...

The behavior of IR absorption bands with temperature has been examined systematically in the laboratory for three representative polycyclic aromatic hydrocarbon molecules: coronene, chrysene, and 1-methylcoronene. A careful description of both intensity and profile measured for most of the bands is reported. A tentative interpretation of the observed variations is given in terms of extra-molecular ...

We present an accurate potential energy curve of the B (1)Pi state in the LiCs molecule for which vibrational levels between v(') = 0 and v(') = 35 (bound by 11.4 GHz) were measured by photoassociation spectroscopy in an ultracold ensemble of (7)Li and (133)Cs atoms. By the combination of conventional spectroscopic data of the B-X ...

The coupled cluster singles and doubles method with perturbative treatment of triple excitations is applied to calculate the potentials of Mz-X complexes (M = Cu, Ag, and Au; X = He, Ne, and Ar; and z = +/-1). The bond functions and the basis set superposition errors are considered to obtain accurate interaction energies. The potential energy curves of all complexes are ...

We present here a detailed calculation of the vibrational transitions of the water molecule in its electronic ground state. The results have been obtained through approximately 5000 hr of computing (CPU) time and constitute the most complete and accurate calculation that exists for water. We locate 412 vibrational energy ...

Equilibrium internuclear separations, harmonic frequencies and potential energy curves (PECs) of HC1(X1?+) molecule are investigated by using the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach in combination with a series of correlation-consistent basis sets in the valence range. The PECs are all fitted to the ...

For more than a decade the B isotopic compositions of marine carbonates have been used as paleo-pH proxies for seawater and to reconstruct paleo-[CO2] concentrations in the atmosphere. A necessary step is this process is the accurate determination of the equilibrium constant, K, for the reaction shown in the title above. This equilibrium constant has been recently calculated ...

This document describes the procedures for determining the mechanical shock and vibration levels of tracked vehicles, including on-board equipment during operation over selected courses. Shock and vibration levels of tracked vehicles, components and tank ...

Room temperature quenching rate coefficients for relaxation from the upper vibrational levels of HF and DF have been successfully duplicated with good agreement with available experimental data. This agreement was obtained with the use of a rotational non...

Basing on a phenomenological approach accounting for the shell structure, pair correlations and coherent excitations of vibrational type, the energy dependence is discussed of the coefficient of vibrational level density increase for spherical nuclei with...

A series of studies were conducted to assess the noise-induced building vibrations associated with Concorde operations. The vibration levels of windows, walls, and floors were measured along with the associated noise levels of Concorde, subsonic aircraft ...

Compares the similar mathematical problems of molecular vibrational calculations (at any intermediate level of sophistication) and molecular orbital calculations (at the Huckel level). Discusses how the generalizations of Huckel treatment of molecular orbitals apply to vibrational theory. (TW)

Glyoxylic acid is a possible candidate for interstellar detection. Many transitions of the submillimeter wave spectrum of the ground vibrational state of its most stable conformer have been measured for the first time. These transitions have been used together with microwave transitions measured previously to obtain accurate spectroscopic constants that ...

High-accuracy absorption spectroscopy of CH3OH in the far infrared is discussed. In addition to 22 transitions in the ground state, the frequency of the (n, tau, J, K), (0, 1, 16, 8) to (0, 2, 15, 7) transition in the nu5 excited vibrational level, which is responsible for the laser emission at 119 microns, was measured. The measured frequency is ...

Rotationally resolved photoelectron spectroscopy is used to elucidate the mechanism for vibrational autoionization via the nontotally symmetric umbrella vibration of ammonia (NH{sub 3} ). This mechanism depends strongly on the character of the autoionizing level, and the data demonstrate that both the electronic and rotational degrees ...

High level ab initio potential energy functions have been constructed for LiH in order to predict vibrational levels up to dissociation. After careful tests of the parameters of the calculation, the final adiabatic potential energy function has been composed from: (a) an ab initio nonrelativistic potential obtained at the ...

High level ab initio potential energy functions have been constructed for LiH in order to predict vibrational levels up to dissociation. After careful tests of the parameters of the calculation, the final adiabatic potential energy function has been composed from: (a) an ab initio nonrelativistic potential obtained at the ...

We investigate the feasibility of forming ultracold LiH from a mixture of the ultracold atomic gases, by using B1? as an intermediate state in the photoassociation process. Using accurate molecular potential energy curves and dipole transition moments, we calculate and compare two possible schemes to populate vibrational levels of the ...

High levels of theory have been used to compute quartic force fields (QFFs) for the cyclic and linear forms of the C(3)H(3)(+) molecular cation, referred to as c-C(3)H(3)(+) and l-C(3)H(3)(+). Specifically, the singles and doubles coupled-cluster method that includes a perturbational estimate of connected triple excitations, CCSD(T), has been used in conjunction with ...

High levels of theory have been used to compute quartic force fields (QFFs) for the cyclic and linear forms of the C{_3}H{_3}+ molecular cation, referred to as c-C{_3}H{_3}+ and l-C{_3}H{_3}+. Specifically the singles and doubles coupled-cluster method that includes a perturbational estimate of connected triple excitations, CCSD(T), has been used in conjunction with ...

The OH radical is an important species in the chemistry of atmospheric and combustion environments, where an understanding of OH concentration and chemistry is necessary to create and validate chemical models. Laser-induced fluorescence (LIF) is used with great success in OH detection, but OH LIF measurements require a vast knowledge of the collisional and spectroscopic properties of OH. ...

The Breit-Wigner formula for the cross section for the excitation of a molecule by electron impact via formation of an intermediate autoionization state of a negative ion is generalized to include the case when the width of the autoionization level is small in comparison with the vibrational quantum of the negative ion. Use is made of the absence of ...

Interest in the analysis of random vibrations of mechanical systems started to grow about a half century ago in response to the need for a theory that could accurately predict structural response to jet engine noise and missile launch-induced environments. However, the work that enabled development of the theory of random vibrations ...

... MODIFICATIONS THE PULSATIONS ARE WITHIN OR SLIGHTLY EXCEED THE ALLOWABLE LEVEL. THE PULSATION INDUCED VIBRATION ...

... (Author). Descriptors : (*PHOTOLYSIS, *NITROGEN HETEROCYCLIC COMPOUNDS), VIBRATION, MOLECULAR ENERGY LEVELS, EXCITATION ...

... SPECTROSCOPY, *WATER, *WATER VAPOR, MODELS, MOLECULAR VIBRATION, MOLECULES, MOLECULAR ROTATION, ENERGY LEVELS ...

... VAPOR, *MOLECULAR ENERGY LEVELS, COMPUTATIONS, MODELS, MOLECULAR VIBRATION, MOLECULES, WATER, QUANTUM THEORY ...