DISPERSION AND SELECTIVE ABSORPTION IN THE PROPAGATION OF ULTRASOUND IN LIQUIDS CONTAINED IN TUBES: Part I

1932 ◽  
Vol 6 (1) ◽  
pp. 102-118 ◽  
Author(s):  
R. W. Boyle ◽  
D. K. Froman ◽  
G. S. Field
Keyword(s):  
Critical Frequency ◽  
Ultrasonic Method ◽  
Selective Absorption ◽  
Frequency Curve ◽  
Frequency Shifts ◽  
Absorption Frequency ◽  
Longitudinal Waves ◽  
Thin Walls ◽  
Lateral Vibrations ◽  
First Time

An experimental study by the ultrasonic method of the phase velocity of longitudinal waves transmitted in liquids contained in tubes. Greatly augmented as well as largely decreased velocities may be obtained in any liquid by suitably adjusting the frequency of the wave or the diameter of the containing tube. This phenomenon, described here at length for the first time, is found to be caused by the selective absorption of energy of the longitudinal wave at certain frequencies, resulting in a velocity-frequency curve analogous to the "anomalous dispersion" curve of optics. In the experiments there is strong indication that the absorbing frequency depends inversely on the diameter of the tube.The fact that the absorption frequency does not depend on the material or length of the tube, or for thin walls on the wall thickness, indicates that it is neither longitudinal nor flexural (lateral) vibrations in the tube walls which causes the phenomenon; and the fact that for any liquid the critical frequency shifts with change of diameter indicates that it is in the column of liquid itself that the energy absorption or transference takes place.These experiments show that it is only at frequencies far removed from absorption i.e., on the regular and flat portions of the velocity-frequency curve some distance from the discontinuity, that the usual theories of sound transmission may safely be applied.

The Infrared Absorption Spectra of Some Samarium Diketo-ester Complexes

1970 ◽  
Vol 25 (2) ◽  
pp. 139-141 ◽  
Author(s):  
S. P. Tandon ◽  
P. C. Mehta
Keyword(s):  
Coordination Number ◽  
Absorption Spectra ◽  
Infrared Absorption ◽  
Relative Frequency ◽  
Methyl Acetoacetate ◽  
Frequency Shifts ◽  
Modes Of Vibration ◽  
Infrared Absorption Spectra ◽  
Stretching Vibrations ◽  
First Time

Infrared absorption spectra of some four- and five-coordinated (ethyl 1-methyl acetoacetate) complexes of trivalent samarium have been studied in the region 4000 - 250 cm-1 for the first time. About twenty bands in each chelate have been observed and assigned to different modes of vibration. A study of relative frequency shifts of CO stretching vibrations reveals that the metal-oxygen bonds in all the complexes are nearly of the same strength. The vibrational frequencies, with few exceptions, are found to be nearly independent of the coordination number of the metal.

scholarly journals Methods for evaluation of mechanical stress condition of materials

2018 ◽  
Vol 145 ◽  
pp. 05008 ◽  
Author(s):  
Yordan Mirchev ◽  
Pavel Chukachev ◽  
Mitko Mihovski
Keyword(s):  
Surface Waves ◽  
Mechanical Stress ◽  
Ultrasonic Method ◽  
Mechanical Stresses ◽  
Principal Stresses ◽  
Small Depth ◽  
Type Size ◽  
Cylindrical Holes ◽  
The One ◽  
First Time

Primary attention is given to the following methods: method by drilling cylindrical holes (drill method) and integrated ultrasonic method using volume (longitudinal and transverse), surface, and sub-surface waves. Drill method allows determination of residual mechanical stress in small depth of material surfaces, assessing type, size, and orientation of principal stresses. For the first time, parallel studies are carried out of mechanical stress in materials using the electroacoustic effect of volume, surface and sub-surface waves on the one hand, and effective mechanical stresses on the other. The experimental results present electroacoustic coefficients for different types of waves in the material of gas pipeline tube of 243 mm diameter and 14 mm thickness. These are used to evaluate mechanical stresses in pipelines, according to active GOST standards.

The Infra-Red Absorption Spectra of the Addition Complexes of Quinoline with Copper Salts

1964 ◽  
Vol 19 (3) ◽  
pp. 363-370
Author(s):  
C. S. Williams ◽  
K. F. Fouché
Keyword(s):  
Absorption Spectra ◽  
Copper Salts ◽  
Frequency Shifts ◽  
Infra Red ◽  
Halide Complexes ◽  
First Time

The infra-red spectra of a number of halide, acetate and thiocyanate quinoline and quinolinium complexes of copper have been recorded for the first time. The significance of the frequency shifts of the quinoline bands in the complexes and the influence of the electronegativity of the halide ion on the frequency shifts in the monoquinoline cuprous halide complexes are discussed. Evidence is presented that the Cu (NCS) 2.2 Q complex is probably binuclear.

scholarly journals Famennian ostracods from the Istanbul zone (Gebze, Kocaeli, NW Turkey) and their paleogeographical relations

2012 ◽  
Vol 63 (5) ◽  
pp. 355-363 ◽  
Author(s):  
Atike Nazik ◽  
Șenol Çapkinoğlu ◽  
Emine Șeker
Keyword(s):  
North Africa ◽  
Upper Devonian ◽  
Late Devonian ◽  
Rhenish Massif ◽  
Cantabrian Mountains ◽  
Holy Cross Mountains ◽  
Thin Walls ◽  
Nw Turkey ◽  
Conodont Zonation ◽  
First Time

Abstract Famennian (Late Devonian) ostracods of the Thuringian Mega-Assemblage were recovered for the first time from three incomplete sections of the Ayineburnu Member of the Büyükada Formation in the Denizliköy area (Gebze, NW Turkey), which were sampled for conodonts. Conodont faunas define an interval extending from the Upper rhomboidea? or Lower marginifera Zone into the Middle expansa Zone of the standard Upper Devonian conodont zonation. The ostracod faunas found here consist of species mainly with thin-walls, long spines and often smooth surfaces such as Rectonaria, Tricornina, Orthonaria, Triplacera, Beckerhealdia, Timorhealdia, Bohemina, Paraberounella and Acratia. These taxa indicate faunal relationship with Thuringia and the Rhenish Massif in Germany, the Cantabrian Mountains and Pyrenees in Spain, Holy Cross Mountains in Poland, North Africa and China.

scholarly journals The Raman spectrum of rock-salt

1946 ◽  
Vol 187 (1009) ◽  
pp. 188-196 ◽  
Keyword(s):  
Raman Spectrum ◽  
Rock Salt ◽  
Lattice Dynamics ◽  
Vibration Spectrum ◽  
Raman Effect ◽  
Frequency Shifts ◽  
Crystal Lattices ◽  
Absorption Frequency ◽  
Infra Red ◽  
Quartz Spectrograph

Using a non-luminescent crystal of rock-salt, a quartz spectrograph with a fine slit, and the 2536.5 A resonance radiations of mercury arc as exciter, the Raman effect in rock-salt has been studied. The spectrum exhibits nine distinct Raman lines with frequency shifts 135, 184, 202, 235, 258, 278, 314, 323 and 350 cm. -1 . The frequency shifts 235 and 184 cm. -1 representing conspicuous lines in the Raman spectrum agree as nearly as could be expected with the position of the two subsidiary infra-red absorption maxima observed by Barnes & Czerny with thin films of rock-salt. The principal infra-red absorption frequency of 163 cm. -1 is inactive in the Raman effect, but its octave is represented. The nature of the Raman spectrum to be expected is deduced on the basis of a theory due to Tamm, as also on the basis of another due to Fermi, the vibration spectrum of the rock-salt lattice being taken to be that worked out by Kellermann on the basis of the Born lattice dynamics. The results are altogether of a different nature from those actually observed experimentally in the present investigation. The conclusion is thus reached that the Born lattice dynamics does not correctly picture the vibration spectrum of the rock-salt lattice. On the other hand the observed facts, both in respect of Raman effect and infra-red absorption, fit into the theoretical picture provided by the dynamics of crystal lattices recently worked out by Sir C. V. Raman.

From Ag2S to luminescent Ag–In–S nanocrystals via an ultrasonic method – an in situ synthesis study in an NMR tube

2020 ◽  
Vol 8 (26) ◽  
pp. 8942-8952
Author(s):  
Patrycja Kowalik ◽  
Mateusz Penkala ◽  
Piotr Bujak ◽  
Angelika Kmita ◽  
Marta Gajewska ◽  
...  
Keyword(s):  
Ultrasonic Method ◽  
In Situ Synthesis ◽  
Preparation Conditions ◽  
First Time

Taking advantage of “mild” preparation conditions we have been able for the first time to perform the synthesis of Ag2S and luminescent AgInS2 nanocrystals in an NMR tube.

Sign in / Sign up

Export Citation Format

Share Document