ultrasonic velocities
Recently Published Documents


TOTAL DOCUMENTS

322
(FIVE YEARS 26)

H-INDEX

30
(FIVE YEARS 2)

Warta Geologi ◽  
2021 ◽  
Vol 47 (1) ◽  
pp. 1-8
Author(s):  
John K. Raj

The main Beris Dam is founded on a sequence of thick bedded conglomerates and pebbly to fine grained sandstones with minor mudstone mapped as the Semanggol Formation of Triassic age. Ultrasonic pulse measurements show velocities of compressional and shear waves through the sandstones to increase with decreasing grain size; the pebbly sandstone with velocities of 2.210, and 5.171, km/s, and the coarse grained sandstone with velocities of 2.477, and 5.612, km/s, respectively. The medium grained sandstones have compressional and shear wave velocities of 2.457, and 5.793, km/s and the fine grained sandstones, velocities of 2.572, and 5.867 km/s, respectively. Dynamic elastic constants computed from the ultrasonic velocities also increase in values with decreasing grain size; Poisson’s ratio varying from 0.36 to 0.39, the modulus of elasticity from 35.076 to 48.210 GPa, the bulk modulus from 52.260 to 67.362 GPa and the modulus of rigidity from 12.637 to 17.468 GPa. Increasing velocities and elastic constants with decreasing grain size are considered to result from a denser arrangement of constituent grains as shown by increasing dry unit weights. Comparison with the results of an unconfined compression test on a fine grained sandstone indicate that the ultrasonic elastic constants are good approximations of static elastic constants.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohd Aftab Khan ◽  
Mahendra Kumar ◽  
Chandreshvar Prasad Yadav ◽  
Dharmendra Kumar Pandey

Abstract The present work is focused on the determination of elastic, mechanical, ultrasonic and thermal properties of ScRu intermetallic under the variation of pressure 0–60 GPa and particle size 5–40 nm. Initially, the second order elastic constants (SOECs) have been computed under a potential model approach, in which interaction potential is defined by Coulomb and Born–Mayer potentials. Later on, the estimation of mechanical, ultrasonic and thermo-physical parameters has been performed using SOECs. The ultrasonic velocities are estimated in the same pressure/particle size range for wave propagation along 〈100〉 crystallographic direction. It is found that elastic constants, ultrasonic velocities, Debye average velocity, specific heat at constant volume, thermal energy density, thermal conductivity and melting point enhance with increase in pressure and decay in particle size in chosen intermetallic. The analysis of the obtained results reveals that the elastic, mechanical and thermal properties of ScRu intermetallic shall enhance effectively under pressure in comparison to decay in particle size.


2021 ◽  
Vol 33 (8) ◽  
pp. 1776-1782
Author(s):  
Vivek Pathania ◽  
Manpreet Kaur ◽  
B.K. Vermani ◽  
Shrutila Sharma ◽  
Navya Grover

The ultrasonic velocities of solutions of Bu4NBPh4, Bu4NClO4, [Cu(AN)4]NO3, [Cu(BN)4]NO3, [Cu(Phen)2]NO3, [Cu(DMPhen)2]NO3, [Cu(Bipy)2]NO3 and [Cu(TU)4]NO3 (where AN = acetonitrile, BN = benzonitrile, Phen = 1,10-phenanthroline, DMPhen = 2,9-dimethyl-1,10-phenanthroline, Bipy = 2,2′-bipyridyl and TU = thiourea) were measured in the concentration range 0.03-0.27 M in dimethylsulfoxide (DMSO), nitromethane (NM) and binary mixtures of DMSO + NM containing 0, 20, 40, 60, 80 and 100 mol% NM at 298 K in the present studies. Using ultrasonic velocity and density data, isentropic compressibility (κs) and apparent molal isentropic compressibility (κs,φ) for electrolytes in DMSO + NM mixture have been calculated. Result shows that copper(I) electrolytes show less solvation in NM rich regions indicating structure breaking tendency of nitromethane. Extent of solvation in Cu(I) ions decreases in the order: [Cu(AN)4]+ > [Cu(BN)4]+ > [Cu(TU)4]+ > [Cu(DMPhen)2]+ > [Cu(Phen)2]+ > [Cu(Bipy)2]+.


Author(s):  
Yasmin Akhtar

Densities and ultrasonic velocities of Aniline in cyclohexane + Dimethyl ketone and Aniline in cyclohexane + ethyl methyl ketone of these ternary mixtures of different compositions have been determined experimentally at 303 and 313 K. The results obtained from density and ultrasonic velocity measurement have been used to calculate the acoustical parameters such as, adiabatic compressibility (Ks), free Length (Lf ) , and acoustic impedance (Z). The results are discussed in terms of the intermolecular hydrogen bonding and molecular association in these ternary systems.


2020 ◽  
Vol 10 ◽  
Author(s):  
Bhavi Patel ◽  
Bhavya Salvi ◽  
Vivekanand Mishra ◽  
Ritesh Yadav

Background: The Binary mixtures of the isopropanol/isobutanol/isoamylalcohol with equimolar mixture of ethanol and formamide consists of different ultrasonic properties have been studied at room temperature at a fixed frequency of 2 MHz. The ultrasonic related physical parameters like velocity (U), density (ρ), adiabatic compressibility (βad), intermolecular free length (Lf) ,acoustic impedance (Z) etc. have been studied. The theoretical evaluation of ultrasonic velocity in liquid mixtures offers a transparent method for the study of the nature of molecular interactions in the mixtures besides verifying the applicability of different theories such as Nomoto’s, Van Dael and Vangeel’s, Impedance Dependence relation, Junjie’s relation, Rao’s specific sound velocity relation and Jacobson’s relations, Percentage deviations of theoretical ultrasonic velocities from experimental values in the mixtures of all liquid mixture and also calculated values of ultrasonic velocity from polynomials of for all the schemes with mole fraction (x) of isopropanol/isobutanol/isoamyl alcohol. Objective: The main focus of the present work was to prepare the structural changes associated with the liquid mixtures having weakly interacting components as well as strongly interacting components. The study of molecular is association in mixtures having exact information of thermodynamic mixing properties such as adiabatic compressibility, intermolecular free length, free volume, internal pressure and molar volume and has a great importance in theoretical and applied areas of research. The ultrasonic study has been a subject of active interest during the past many years. This branch of physical sciences has played a great role in deciding the interactions between the molecules of compounds under study not only that, but also it exists a potential tool in evaluating energy exchange between various degrees of freedom and nonlinear properties in binary liquid mixtures. Methods: The binary liquid mixtures were prepared by mixing the two components, by weight, using an electronic analytical balance (Reptech RA2012) accurate to within ±0.0001 g. The average uncertainty in mole fraction of binary mixtures was estimated to be ±0.0001. To avoid losses of solvent due to evaporation, mixtures were stored in specially designed ground-glass airtight ampoules and placed in a dark place to avoid photolytic effects. Results: These empirical fittings of data are described qualitatively and quantitatively using experimental speed data even in the specific interaction predominant region where non-ideal behavior of the mixture is observed. The values of sound velocities and percentage deviation, (after determining the co-efficient in the polynomial equations by applying least squares method) have been compiled in the tables respectively. Conclusion: The ultrasonic velocities and densities for all the three mixtures are measured and the values of are calculated from these values.The observed trends of and indicate the presence of weak interactions and the strength of these interactions follow the order EMM+IPA>EMM+IBA>EMM+IAA. Besides, the ultrasonic velocities gauge from different velocity theories are correlated with the experimentally measured ultrasonic velocities. Among these theories the Jacobson’s velocity equation gives good result between the experimental and theoretical ultrasonic velocity values for all the binary mixtures occupied.


2020 ◽  
Vol 307 ◽  
pp. 321-326
Author(s):  
Nurhayati Mohd Nor ◽  
Halimah Mohamed Kamari ◽  
Amirah Abdul Latif ◽  
Nurisya Mohd Shah

Silica borotellurite glasses doped with different molar fraction of V2O5 have been prepared by melt quenching technique. The elastic properties of {[(TeO2)0.7 (B2O3)0.3]0.8(SiO2)0.2}(1-x)(V2O5)x glasses are investigated using ultrasonic pulse echo measurements and their elastic properties have been characterized at room temperature. The density of the glasses was measured by Archimedes method using distilled water as buoyant liquid. The ultrasonic wave velocities (longitudinal, vl and shear, vS) were recorded at 5 MHz. Elastic moduli, Poisson’s ratio (σ) and microhardness (H) were then calculated to obtain quantitative analysis regarding the structure of these glasses. The results obtained showed that the doping of V2O5 with silica borotellurite enhances the strengthening of glass network. Glass with 0.03 molar fraction of V205 shows low ultrasonic velocities and low elastic moduli. The variation of elastic properties is related to the change of structure in the vanadium doped silica-borotellurite glass system.


2020 ◽  
Vol 30 (2) ◽  
pp. 200-220
Author(s):  
Fatiha Boudjedra ◽  
Abdelhalim Benouis ◽  
Zineddine Boudaoud

AbstractThis experimental study aimed to use the ultrasonic pulse velocity method (UPV) in order to investigate the effect of rubber tire waste content and transducers’ diameters and frequencies on the evolution of ultrasonic velocities in time and to elucidate the correlations between UPV and the properties of various concrete mixtures. The incorporation of this waste involved volume substitution (0, 5, 10, 15 and 20%) of fine aggregates (sand) by rubber waste (RW) granulates. The dry unit weight, porosity, compressive and flexural strengths, and velocity of ultrasonic waves with different transducers - which presents the non-destructive technique - were evaluated. Rubberized concrete mixtures showed increases in porosity with lower dry unit weight compared to the control concrete. Compressive strength, flexural strength and ultrasonic velocity obtained by all transducers decreases with increasing RW content. These decreases are not influenced by the curing age of concretes. Decreases in the diameter and frequency of transducers caused reductions in ultrasonic velocity. These reductions are not influenced by the volume replacement of sand by RW. Correlations showed that ultrasonic velocity represents a reliable non-destructive technique for measuring the properties of rubberized concretes.


Sign in / Sign up

Export Citation Format

Share Document