Backward-mode photoacoustic transducer for sensing optical scattering and ultrasonic attenuation: determining fraction consistencies in pulp suspensions

A simple, laser-based reflectometer is described for the measurement of water turbidity via 180° optical scattering. Applications exist both in clean source waters (0-1000NTU) with a minimum detectable turbidity better than 1NTU, and in dense wastewater primary-clarifier sludges. The non-contact measurement is performed from a distance at least up to 10m, substantially avoiding the usual window fouling problems of optical instruments. By measuring directly in the process, through a free water surface or on the side of a flowing water stream, the difficulties of transporting sample to the instrument are also avoided. Extensions to be described allow measurement also of water colour.

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Investigation of zirconium nanowire by elastic, thermal and ultrasonic analysis

Zeitschrift für Naturforschung A ◽

10.1515/zna-2020-0167 ◽

2020 ◽

Vol 75 (12) ◽

pp. 1077-1084

Author(s):

Bhawan Jyoti ◽

Shakti Pratap Singh ◽

Mohit Gupta ◽

Sudhanshu Tripathi ◽

Devraj Singh ◽

...

Keyword(s):

Ultrasonic Attenuation ◽

Thermal Relaxation ◽

Coupling Constants ◽

Physical Parameters ◽

Third Order ◽

Jones Potential ◽

Acoustic Coupling ◽

Anisotropic Factor ◽

Third Order Elastic Constants ◽

Ultrasonic Analysis

AbstractThe elastic, thermal and ultrasonic properties of zirconium nanowire (Zr-NW) have been investigated at room temperature. The second and third order elastic constants (SOECs and TOECs) of Zr-NW have been figured out using the Lennard–Jones Potential model. SOECs have been used to find out the Young’s modulus, bulk modulus, shear modulus, Poisson’s ratio, Pugh’s ratio, Zener anisotropic factor and ultrasonic velocities. Further these associated parameters of Zr-NW have been utilized for the evaluation of the Grüneisen parameters, thermal conductivity, thermal relaxation time, acoustic coupling constants and ultrasonic attenuation. On the basis of the above analyzed properties of Zr-NW, some characteristics features of the chosen nanowire connected with ultrasonic and thermo-physical parameters have been discussed.

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Pressure dependent ultrasonic properties of hcp hafnium metal

Zeitschrift für Naturforschung A ◽

10.1515/zna-2021-0013 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Ramanshu P. Singh ◽

Shakti Yadav ◽

Giridhar Mishra ◽

Devraj Singh

Keyword(s):

Elastic Constants ◽

Pressure Range ◽

Room Temperature ◽

Ultrasonic Attenuation ◽

Coupling Constants ◽

Ultrasonic Properties ◽

Acoustic Coupling ◽

Third Order Elastic Constants ◽

The Stability ◽

The Given

Abstract The elastic and ultrasonic properties have been evaluated at room temperature between the pressure 0.6 and 10.4 GPa for hexagonal closed packed (hcp) hafnium (Hf) metal. The Lennard-Jones potential model has been used to compute the second and third order elastic constants for Hf. The elastic constants have been utilized to calculate the mechanical constants such as Young’s modulus, bulk modulus, shear modulus, Poisson’s ratio, and Zener anisotropy factor for finding the stability and durability of hcp hafnium metal within the chosen pressure range. The second order elastic constants were also used to compute the ultrasonic velocities along unique axis at different angles for the given pressure range. Further thermophysical properties such as specific heat per unit volume and energy density have been estimated at different pressures. Additionally, ultrasonic Grüneisen parameters and acoustic coupling constants have been found out at room temperature. Finally, the ultrasonic attenuation due to phonon–phonon interaction and thermoelastic mechanisms has been investigated for the chosen hafnium metal. The obtained results have been discussed in correlation with available findings for similar types of hcp metals.

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