... The frequency of vibration was measured with a Frahm vibrating- reed tachometer, accurate to 0.5 percent of the frequency reading and with a ...
DTIC Science & Technology
... The laser radar was able to accurately measure a target's vibrational frequency and amplitude for amplitudes greater than 40 nim The theoretical ...
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...
National Technical Information Service (NTIS)
Non-uniform shafts can be used as accurate models for the analysis of missile vibrations. Digital programs that can calculate the upper and lower bounds to the torsional vibrations of such free, non-uniform shafts and can accept input data in standard eng...
Dense granular media, fluidized by a vibrating wall, is studied in the high-vibrating frequency limit, where the plate vibration frequency is much greater than the collision frequency, and the plate acceleration is much greater than gravity. Using kinetic theory, it is ...
PubMed
Accurate, contact-free measurement, outside the processing area, of the quantity of solid material in a centrifuge cylinder used in reprocessing nuclear fuel solutions. A mechanical vibration system consisting of the centrifuge cylinder and of a supplemental mass attached to the cylinder produces torsional vibrations by, for example, ...
Energy Citations Database
... Descriptors : *VIBRATION, *AUDIO FREQUENCY, FREQUENCY ... RESONANT FREQUENCY, RESONANCE, LOSSES, COMPRESSIVE ...
A review of the world literature dealing with the vibration of turbine blades describes the state-of-the-art and concludes that the basic mechanics of blade vibration are well understood. This knowledge had permitted the development of computer programs that can accurately predict blade and blade group natural ...
Octupole vibrntions of deformed even-mass nuclei are considered in terms of the collective model. The second quantization method is applied. It is shown that g-vibrations are accurately separnted from gamma vibrations for any frequency. The reduced probability for M2 transition from the g-band is ...
The presented research work, aimed at deeper understanding of vibrational process during high-frequency vibration cutting, is accomplished by treating cutting tool as an elastic structure which is characterized by several modes of natural vibrations. An approach for surface quality improvement is proposed in this ...
NASA Astrophysics Data System (ADS)
Relations between various values of the internal friction (tg{delta}, Q{sup -1}, Q{sup -1*}, and {lambda}/{pi}) measured by free decay and forced vibration are analyzed systemically based on a fundamental mechanical model in this paper. Additionally, relations between various natural frequencies, such as vibration ...
... Accession Number : ADA209391. Title : Computation of Vibrational Frequencies in Mercaptans, Alcohols, and Sulfides. ...
... of vibratory motion and mechanical impedance within ... to high-frequency vibrations and transient ... Low-frequency portable vibration measuring 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 ...
A versatile combination of hardware and software on the LLL T-DAC computer system has been developed that permits rapid and accurate modal analysis of complex mechanical structures under field conditions. Natural frequencies of vibration and values of dam...
State-of-the-art, calibrated ab initio quantum chemical calculations have been performed to obtain accurate structures, energies, and vibrational frequencies of the lowest singlet states of HNS and NSH, which are closed-shell states. Enthalpies of formati...
A simple, inexpensive, yet accurate method for measuring the dynamic complex modulus of elasticity is described. Using a 'free-free' bar selectively excited in three independent vibrational modes, the shear modulus is obtained by measuring the frequency o...
In this paper an interferometric setup called 'thermoelastic microscopy' has been used to measure the vibration response of the semiconductor cantilevers under modulated laser thermal source. The small vibration amplitude has been detected well below 10 pm magnitude in accurate adjustment conditions. The results ...
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 ...
... at known frequencies should be made to obtain definite calibration data0 As matters stand, determination of natural frequency of vibrations ...
Certain transition frequencies in the vibrational-rotational spectra of HD/sup +/, HT/sup +/, and DT/sup +/ have been calculated to a high degree of accuracy. For HD/sup +/ the differences between the calculated frequencies and the recently reported observed frequencies are less than those previously obtained and ...
The XCN and XNC (X = F, Cl) isomers have been investigated using the CCSD(T) method in conjunction with correlation consistent basis sets. Equilibrium geometries, harmonic frequencies, anharmonic constants, fundamental frequencies, and heats of formation ...
... developed procedure, in which the natural frequencies of a body ... OF REVOLUTION, *VIBRATION), RESONANT FREQUENCY, KINETIC ENERGY ...
... by an approximate method that yields the natural frequencies and mode ... ELASTIC PROPERTIES, WALLS, THICKNESS, FREQUENCY, VIBRATION ...
... a frequency that was the same as a natural vibrational frequency of the ... Reynolds number when coincidence of the two frequencies occur ...
Many aerospace structures must survive severe high frequency, hypersonic, random vibration during their flights. The random vibrations are generated by the turbulent boundary layer developed along the exterior of the structures during flight. These environments have not been simulated very well in the past using a fixed-based, single ...
DOE Information Bridge
An analytical model for predicting surface effects on the free vibration of fluid-conveying nanotubes is developed based on the non-local elasticity theory. In the new model, the effects of both inner and outer surface layers on the nanotubes are taken into consideration. The results show that the surface effects with positive elastic constant or positive residual surface ...
Halomethyl anions undergo a significant geometry change upon electron photodetachment, resulting in multiple extended vibrational progressions in the photoelectron spectra. The normal mode analysis that successfully models photoelectron spectra when geometry changes are modest is unable to reproduce the experimental data using physically reasonable parameters. A ...
1. In micro-electrode recordings from the human peroneal and tibial nerves, the responses of thirty-two primary spindle endings, thirteen secondary spindle endings and three Golgi tendon organs were studied during vibration of the tendons of the receptor-bearing muscles in the leg. The amplitude of the applied vibration was 1-5 mm and the ...
PubMed Central
... that shell-like behavior of Savannah is of ... Descriptors : *CARGO SHIPS, *NUCLEAR PROPERTIES, VIBRATION, VIBRATION, LOW FREQUENCY ...
... the laboratory and tested with both vibration and static load methods. The results indicated that the forced vibration ... ...
NBII National Biological Information Infrastructure
... Title : Design of Passive Vibration Absorber to Reduce Terrain-Induced Gun Barrel Vibration in the Frequency Domain. ...
... Title : ATOMIC VIBRATIONS IN STRESSED CRYSTAL LATTICES ... Descriptors : (*CRYSTAL LATTICES, VIBRATION), (*PHONONS, FREQUENCY ...
Based on the Rayleigh energy theory combining with Timoshenko beam model, the flexural vibration characteristics of piezoelectric tubes in ultrasonic micro-actuators are investigated. Additionally, the simplified formulae are derived to study the fundamental flexural resonance frequencies of the piezoelectric tubes with free-free ends and cantilevers. By ...
... MODELS, FREQUENCY, MECHANICAL PROPERTIES, VIBRATION, MODELS, INTERFACES, MATERIALS, COMPOSITE MATERIALS, BEAMS ...
... Title : VISUAL ACUITY DURING VIBRATION AS A FUNCTION OF FREQUENCY, AMPLITUDE AND SUBJECT DISPLAY RELATIONSHIP. ...
... intensities lends credence to the concept of asymmetric and symmetric vibrations. ... is the more intense, and the lower frequency vibration would be ...
... the method is not sensitive to vibrations, accelerations, or ... interferometer is the use of atomic samples with ... by the axial trap vibration frequency, and ...
... which relate circular frequencies to axial ... of vibration in composites of both ... Descriptors : (*COMPOSITE MATERIALS, VIBRATION), (*MECHANICAL ...
Monitoring the vibration behaviour of large rotating machinery is an effective way to reduce production losses and enhance safety, efficiency, reliability, availability and longevity in manufacturing processes. As large rotating machinery is increasingly employed in continuous operations at high speeds and with heavy loads, the vibration behaviour of the ...
... about the relationship between frequency and centershift ... As a result, the natural frequencies of bending ... Blade", Journal of Sound and Vibration, Vol ...
... sensitivity over a frequency band. Descriptors : *VIBRATION, *ACTUATORS, *TRUSSES, TEST ... MATERIALS, FREQUENCY BANDS, RESPONSE ...
... Accession Number : AD0163581. Title : High-Frequency Viscoelastic Vibrator. Descriptive Note : Patent,. Corporate Author ...
... period. The control hatch rate was 84 percent. Descriptors : * FREQUENCY, CHICKENS, EMBRYOS, VIBRATION. Subject ...
... Accession Number : ADA218840. Title : Computations of Vibrational Infrared Frequencies of Selected Amines. Descriptive Note : Contract rept. ...
The aim of this paper is to improve the phenomenological modeling of vortex-induced vibration of an elastically mounted cylinder in fluid flow. To this end an attempt is made to introduce a wake oscillator model that conforms to both the free and forced vibration experiments. This approach is new as in the past wake oscillator models have been tuned to the ...
Dynamic monitoring is part of bridge structural health monitoring. Real-time and online monitoring for bridge's dynamic performance is an important technology means for model updating, damage detection of structure and security evaluation of bridge. Nowadays dynamic monitoring system is generally installed on new long-span bridges. Vibration sensor is key part of the ...
... Abstract : The natural frequencies and mode shapes are ... The frequencies are found by ... PLATES, RESONANT FREQUENCY), (*VIBRATION, METAL ...
We recently presented very accurate calculations of the fundamental vibrational frequency of the (7)LiH(+) and (3)He(4)He(+) ions [Stanke et al. Phys. Rev. A 79, 060501(R) (2009)] performed without the Born-Oppenheimer approximation and included leading relativistic corrections. The accuracy of those calculations was estimated to be of ...
We recently presented very accurate calculations of the fundamental vibrational frequency of the 7LiH+ and 3He4He+ ions [Stanke et al. Phys. Rev. A 79, 060501(R) (2009)] performed without the Born-Oppenheimer approximation and included leading relativistic corrections. The accuracy of those calculations was estimated to be of the order ...
... thq static natural frequencies of reactionless vibration in ... reaction- less vibrations of frequencies 2n and 6n is shown in figure ...
Transition frequencies of cold molecules must be accurately evaluated to test the variance in the proton-to-electron mass ratio. Measuring the X2?(v,N)=(0,0)?(1,0) transition frequency of optically trapped 174Yb6Li molecules is a promising method for achieving this goal. The Stark shifts induced by trap and probe (for the Raman ...
The global minimum on the Si(2)CH(2) electronic singlet potential energy surface has been theoretically predicted to be a peculiar hydrogen bridged (Si���H���Si) disilacyclopropenylidene structure (Si(2)CH(2)). An accurate quartic force field for Si(2)CH(2) has been determined employing ab initio coupled-cluster theory with single and double excitations and a ...
The global minimum on the Si2CH2 electronic singlet potential energy surface has been theoretically predicted to be a peculiar hydrogen bridged (Si...H...Si) disilacyclopropenylidene structure (Si2CH2). An accurate quartic force field for Si2CH2 has been determined employing ab initio coupled-cluster theory with single and double excitations and a perturbative treatment for ...
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 ...
The objective of this study is to develop a numerical model of a stay cable interacted with deck, and to examine the vibration suppression technique of the stayed cable subject to external loading. First, a numerical model based on the finite difference method and the finite element method has been developed to simulate the effects of the bending stiffness and its ...
The free vibration characteristics of circular rings with sectorial cross-section are studied based on the three-dimensional (3-D), small strain, linear elasticity theory. The complete vibration spectrum has been obtained by using the Ritz method. A set of three-dimensional orthogonal coordinates composing of the polar coordinates (r,?) at the origin of ...
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 ...
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 ...
Spherical pressure vessels are used to fully contain the effects of high explosions. In this paper, the vibrations of a spherical containment vessel undergoing elastic response are investigated. Vibration modes of containment vessels are of particular interest, as it is the superposition and interaction of different modes of response with closely spaced ...
Vibration generated by underground railways transmits to nearby buildings causing annoyance to inhabitants and malfunctioning to sensitive equipment. Vibration can be isolated through countermeasures by reducing the stiffness of railpads, using floating-slab tracks and/or supporting buildings on springs. Modelling of vibration from ...
Vibrational spectra of liquid oxygen, shock compressed to several high-pressure/high-temperature states, were obtained using single-pulse multiplex coherent anti-stokes Raman scattering (CARS). The experimental spectra were compared to synthetic spectra calculated using a semiclassical model for the CARS intensities and best fit vibrational ...
... comprehensive rotorcraft analysis CAMRAD II ... accurate prediction of rotor-induced vibration ... VIBRATION, *HELICOPTER ROTORS, FLIGHT TESTING ...
... Title : THE COMPUTED FREQUENCY AND ANGULAR DISTRIBUTION OF THE NORMAL MODES OF VIBRATION IN RECTANGULAR ROOMS. ...
... Accession Number : AD0654710. Title : SIMPLIFIED ANALYSIS OF THE NATURAL FREQUENCIES FOR BENDING VIBRATIONS OF SHAFTS,. ...
... Descriptors : , ASSEMBLY, ENERGY, FOAM, LOW FREQUENCY, METALS, MOUNTS, NONMETALS, PATENT APPLICATIONS, RINGS ...
... Title : HIGH AND LOW FREQUENCY APPROACHES TO THE ACOUSTIC RADIATION PROBLEM, IN: JOURNAL OF SOUND AND VIBRATION ...
This patent describes a compound seismic source vibrator. It comprises: a housing having an upper section and a low frequency radiating section; a low frequency means for vibrating the low frequency radiating section; a high frequency radiating section flexibly connected to ...
... converge to the exact natural frequencies when the ... STRUCTURAL), VIBRATION), RESONANT FREQUENCY, OSCILLATION, DIFFERENTIAL ...
... Title : CALCULATED NATURAL FREQUENCIES AND NORMAL MODES OF VIBRATION OF THE USS OKINAWA (LPH-3),. ...
The vibrational frequencies of halogens adsorbed on Ag(100) are calculated. The frequency of a single adsorbed atom vibration perpendicular to the surface is obtained from AgX (X = F, Cl, Br, I) crystal frequencies. Interaction between dipoles consisting ...
A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant ...
DOEpatents
A decomposition scheme for the partitioning of normal-coordinate vibrational frequencies into individual internal-coordinate intrinsic frequencies is presented. This scheme assigns to each internal coordinate a frequency that is representative of a vibrat...
We report on accurate temperature control of size-selected sodium cluster cations by buffer gas thermalization in a temperature variable dodecapole radio frequency trap, which permits measurements of the cluster caloric behavior down to a temperature of T=6 K. For Na139+, a fit to the caloric curve obtained yields a Debye temperature of 163.5�10 K, which ...
The absorption sites and the low-lying rotational and vibrational (RV) energy states for H2 adsorbed within a metal-organic framework are calculated via van der Waals density-functional theory. The induced dipole due to bond stretching is found to be accurately given by a first-principles-driven approximation using maximally localized Wannier function ...
Due to the inherent flexibility of engineering structures, transient and residual vibrations occur when a motion command is applied, thus raising several practical restrictions concerning their fast, accurate and safe motion. Although various command-preconditioning techniques have been proposed for the effective suppression of the excited ...
Based on the Michelson interferometer, we use the circulator to realize the dual-path detection of the vibration signal, which reduce the intensity noise caused by laser source. Reflectors are connected to the terminal of the signal arm and reference arm respectively. The phase generated carrier (PGC) technology should use piezoelectric ceramic (PZT) to generate carrier signal ...
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 ...
... Abstract : The natural frequencies, nodal points and mode ... STRUCTURAL), *NODES, *RESONANT FREQUENCY, FUNCTIONS, VIBRATION ...
... Abstract : The natural frequencies of a thin, isotropic, simply ... VIBRATION), MODULUS OF ELASTICITY, RESONANT FREQUENCY, METAL PLATES ...
low frequency response in the Hz range was recorded as well as a resonance frequency at higher frequencies. A low peak of vibration amplitude is observed ...
NASA Website
Small IR probe molecules have been found to be useful to measure local electric fields in condensed phases and proteins and also to study nucleic acid and protein structure and dynamics by monitoring their vibrational couplings and frequency shifts. However, it is still difficult to accurately describe the ...
This study reviews experimental techniques, instrumentation requirements, safety considerations, and benefits of performing vibration tests on nuclear power plant containments and internal components. The emphasis is on testing to improve seismic structural models. Techniques for identification of resonant frequencies, damping, and mode shapes, are ...
Accurate anharmonic frequencies are provided for molecules of current research, i.e., diazirines, diazomethane, the corresponding fluorinated and deuterated compounds, their dioxygen analogs, and others. Vibrational-state energies were obtained from state-specific vibrational multiconfiguration self-consistent ...
The frequency range of interest for ground vibration from underground urban railways is approximately 20 to 100 Hz. For typical soils, the wavelengths of ground vibration in this frequency range are of the order of the spacing of train axles, the tunnel diameter and the distance from the tunnel to nearby building ...
The aim of this study was to analyse the behaviour of a hemi-spherical dome when vibrated under external water pressure, using the commercial computer package ANSYS 11.0. In order to achieve this aim, the dome was modelled and vibrated in air and then in water, before finally being vibrated under external water pressure. The results ...
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 extrapolation to the ...
... Accession Number : ADD200835. Title : An Accurate Prediction of Natural Frequencies of Laminated Plates by a Higher Order Theory. ...
Digital computer program for computing vibrational mode shapes and frequencies of linear orthotropic
NASA Technical Reports Server (NTRS)
... tool breakage, surface finish and machine chatter. ... sources, vibration signals, including low frequency vibrations of the machining system and ...
We report results of recent measurements of vibrations of the Tevatron collider elements and orbit movements over large diapason of frequencies.
Page 1. TITLE$ Theory of Human Vibration Response ... a qualitative basis. ... frequency spectrum analysis. The findings of this research ...
... Plate Vibration, Acoustic Radiation, Adaptive Control, Boundaries ... FREQUENCY, CONTROL, REDUCTION, PLATES, RESONANCE, ACOUSTICS ...
Applications of Holography to High Frequency Vibrations and Transient Response ... Abstract: Recent applications of holographic interferometry to vibration ...
... VIBRATION, *GEARS, *TRANSMISSIONS(MECHANICAL ... RESONANT FREQUENCY, HELICOPTERS, PLATES ... SEARCHING, WEIGHT, AIRCRAFT ...
Measurement of the vibrations the sensory neurons of the anterior lateral ... Frequency/response analysis of lateral line sense organs was determined by ...
... Descriptors : *VIBRATION, *LUNG, *UNDERWATER SOUND, MEASUREMENT, PHYSIOLOGICAL EFFECTS, ANIMALS, TRAVELING WAVE ...
... The new equations are applied to a case of forced thickness vibrations of a plate of sodium chloride crystal and the fundamental frequency, mode ...
... mechanical forces of vibration within the limits used. (Author). Descriptors : (*ESCHERICHIA COLI, VIBRATION), (*GENETICS, ESCHERICHIA COLI ...
... surface. (Rayleigh) waves generated by a vibrator at controlled frequencies. ... force) vibrator at several locations away Prom the tunnel and ruining ...
Panel flutter analysis via forced vibration technique noting frequency coalescence, flutter boundary
... The element is used to predict the vibrations of ... frequencies for the fan blade to within ... Descriptors : *GAS TURBINE BLADES, VIBRATION, SHELLS ...
Work aimed at finding out whether or not the methods of subjective evaluation established for sinusoidal vibration could be extended to mixtures of sinusoidal vibrations and random vibrations is outlined. Four main experiments are covered (1) detection le...
The study, along with results of other studies conducted by NIOSH, supports the importance of reducing job-related exposure to vibration. Ongoing research is evaluating the effectiveness of anti-vibration devices, such as anti-vibration gloves and tools.
NSDL National Science Digital Library
