Determination of the Hydrodynamic Vibration Frequencies in the Main Pump Pipings

A secular determinant for the determination of vibration frequencies of lithium has been set up by Launay’s method which takes the electron gas into account. Theoretical elastic constants have been used in the calculation of the force constants. Frequencies have been calculated for 47 points of the first Brillouin zone which gives the value of 3 x 1000 = 3000 frequencies by symmetry. Specific heats have been calculated by numerical computation in the range 300 to 6°K and show good agreement with the experimental data. The agreement below liquid-air temperatures is surprising in view of the known phase transformation of lithium.

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The use of electron gas modification in the evaluation of the vibration frequencies and the specific heats of sodium and potassium

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1961.0108 ◽

1961 ◽

Vol 262 (1308) ◽

pp. 136-144 ◽

Cited By ~ 23

Keyword(s):

Low Temperatures ◽

Electron Gas ◽

Outer Region ◽

Low Density ◽

Vibration Frequencies ◽

Specific Heats ◽

A New Technique ◽

Experimental Values ◽

Sodium And Potassium

The earlier work on the determination of the specific heats of lithium by the use of deLaunay’s model has been extended to sodium and potassium. A new technique has been introduced in which the contributions of the central and the outer parts of the Brillouin zone to C v are calculated separately from different distribution densities of 8000 and 1000 points per zone, respectively. The agreement between the calculated and the experimental values of C v has been found to be very good except at very low temperatures where the deviations can be ascribed to the presence of phase transformation. The effect of using a finer mesh of points on C v has been examined. In order to get accurate values of C v the density of points in the central region has to be increased considerably. In the outer region, however, a low density of eight points per zone as in Raman’s theory is found to be reasonably satisfactory.

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Quasi-classical Determination of Electronic Energies and Vibration Frequencies in Boron Compounds

Journal of Solid State Chemistry ◽

10.1006/jssc.2000.8826 ◽

2000 ◽

Vol 154 (1) ◽

pp. 148-152 ◽

Cited By ~ 20

Author(s):

Levan Chkhartishvili ◽

David Lezhava ◽

Otar Tsagareishvili

Keyword(s):

Vibration Frequencies ◽

Boron Compounds

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Semiempirische Rechnungen zur Bestimmung der Konformation des 4,5-Dihydro-1,3-dioxepins und seines 2-Methyl-Derivats

Zeitschrift für Naturforschung A ◽

10.1515/zna-1994-0610 ◽

1994 ◽

Vol 49 (6) ◽

pp. 714-718 ◽

Cited By ~ 3

Author(s):

Josef Esser ◽

Jörg Fleischhauer ◽

Herbert Frauenrath ◽

Christoph Jansen ◽

Bernd Kramer ◽

...

Keyword(s):

Equilibrium Concentration ◽

Chair Conformation ◽

Experimental Results ◽

Semiempirical Methods ◽

Equatorial Position ◽

Vibration Frequencies ◽

Local Minima ◽

Free Enthalpy ◽

Methyl Derivative

Abstract Semiempirical Calculations for the Determination of the Conformation of 4,5-dihydro-1,3-dioxepine and its 2-methyl derivative The possible conformations of the title compounds have been studied with the semiempirical methods MNDO and AM1. In the local minima, the vibration frequencies have been calculated to get the free enthalpy of each conformer and its equilibrium concentration. The energy minimized structures and the calculated thermodynamical values are compared with experimental results. From our investigations we conclude that the chair conformation is preferred. In the case of the methyl derivative, the substituent favours the equatorial position.

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Schwingungsspektrum von CSFCl Vollständiger Satz von Anharmonizitätskonstanten; harmonische Schwingungsfre- quenzen ; korrigiertes harmonisches inneres Kraftfeld / Vibration Spectrum of CSFCl

Zeitschrift für Naturforschung A ◽

10.1515/zna-1979-0308 ◽

1979 ◽

Vol 34 (3) ◽

pp. 325-332

Author(s):

R. Hamm

Keyword(s):

Infrared Spectrum ◽

Force Field ◽

Path Length ◽

Vibration Spectrum ◽

Vibration Frequencies ◽

Harmonic Force ◽

Isotopic Species ◽

Correction Terms ◽

Anharmonicity Constants

Abstract The measurement of the infrared spectrum of CSFCl over a large spectral range from 300 cm -1 to 4000 cm -1 was done with a special cell allowing a path-length of up to 20 m. In that way it was possible to obtain a full set of anharmonicity constants by exploring combination and over-tone bands. Hereby the vibration frequencies of the fundamentals could be corrected for anharmonicity. The corrected values of the main species and of a further isotopic species were used to calculate the internal harmonic force field. The harmonic vibration correction terms needed for the determination of the rz-structure turned out to be changed only by 1% as com-pared with those values that were infered from a preliminary force field formerly.

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Non-destructive determination of concrete elastic constants from vibration frequencies of cylinders

10.1063/1.1306235 ◽

2000 ◽

Author(s):

J. S. Popovics

Keyword(s):

Elastic Constants ◽

Vibration Frequencies ◽

Non Destructive

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Research on Dynamic Properties of Concrete Steel Tubular Arch Bridge Based on ANSYS

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.71-78.3233 ◽

2011 ◽

Vol 71-78 ◽

pp. 3233-3236 ◽

Cited By ~ 1

Author(s):

Rong He ◽

Wei He ◽

Guo Hua Geng

Keyword(s):

Dynamic Response ◽

Dynamic Characteristics ◽

Dynamic Properties ◽

Superposition Method ◽

Vibration Frequencies ◽

Fem Model ◽

Arch Bridge ◽

Mode Superposition Method ◽

Definition Of

Based on ANSYS for modal analysis of bridges, the basic steps includes: building up the FEM model, applying the load and solving the model, expanding the mode, observing the results and so on. Taking the Friendship Avenue Arch Bridge as an example, the building procedures of FEM model were described from the definition of member section, element selection, and the determination of relevant attributes. At last, the dynamic characteristics of the bridge were analyzed based on ANSYS. The results showed that the first 10th order vibration frequencies of the Friendship Avenue Arch Bridge ranged from 1.3Hz to 3.1Hz, and the more order modes should be considered when calculated the dynamic response based on the mode superposition method.

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