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Yadav, R. R.
- Characterization of Cu-PVA Nanofluids:Ultrasonic and Thermal Properties
Abstract Views :156 |
PDF Views:9
Authors
Vimal Pandey
1,
Giridhar Mishra
2,
Meher Wan
3,
Devraj Singh
2,
A. K. Tiwari
4,
R. R. Yadav
3,
Bharat Mishra
5
Affiliations
1 Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalaya, Satna-485334, IN
2 Amity School of Engineering and Technology (Affiliated to GGSIP University), Bijwasan, New Delhi-110061, IN
3 University of Allahabad, Allahabad-211002, IN
4 B.S.N.V.P.G. College (University of Lucknow) Charbagh, Lucknow-226001, IN
5 Mahatma Gandhi Chitrakoot Gramoday Vishwavidyalaya, Satna-485334, IN
1 Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalaya, Satna-485334, IN
2 Amity School of Engineering and Technology (Affiliated to GGSIP University), Bijwasan, New Delhi-110061, IN
3 University of Allahabad, Allahabad-211002, IN
4 B.S.N.V.P.G. College (University of Lucknow) Charbagh, Lucknow-226001, IN
5 Mahatma Gandhi Chitrakoot Gramoday Vishwavidyalaya, Satna-485334, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 37, No 2-3 (2015), Pagination: 33-38Abstract
Nanofluids have unique features different from conventional solid-liquid mixtures which have millimeter or micrometer sized particles dispersed in some base fluid. Due to their excellent characteristics, these new types of fluids have attracted wide interest in recent years. It is found that nanofluids have significantly higher thermal conductivity than the base fluids. In this work we focus on the ultrasonic and thermal properties of nanofluids. Nanofluids containing copper nanoparticles with base fluid polyvinyl alcohol (PVA) have been developed in our laboratory. These nanofluids are characterized by UV-Visible spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). Temperature dependent ultrasonic velocity and ultrasonic attenuation measurements are performed for different concentration of the copper nanoparticles in the PVA. Hot Disk Thermal Constant Analyser is used for the measurement of the thermal conductivity of synthesized nanofluids. Experimental results show that the thermal conductivities of the nanofluids are higher than that of base fluid PVA. The obtained results were analyzed taking into account the ultrasonic and thermal behavior of matrix and particles. Possible mechanism for the enhancement of thermal conductivity of the nanofluids using theoretical model is also discussed.Keywords
Nanofluids, Ultrasonic Properties, Enhanced Heat Transfer, Effective Thermal Conductivity, Brownian Motion.Full Text
- Non Linear Elastic Properties and Ultrasonic Attenuation in Ni-Al-Cr Alloy
Abstract Views :194 |
PDF Views:0
Authors
Affiliations
1 Physics Department, University of Allahabad, Allahabad-211002, IN
2 Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN
1 Physics Department, University of Allahabad, Allahabad-211002, IN
2 Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 33, No 3 (2011), Pagination: 54-58Abstract
The single crystal higher order elastic constants of Ni-Al-Cr ternary alloy at different temperatures have been calculated with the help of interaction potential model. Ultrasonic attenuation in the ternary alloy is determined using higher order elastic constants. Other ultrasonic parameters such as Gruneisen numbers, acoustic coupling constants and acoustical anisotropy have been also calculated to discuss the ultrasonic properties of the ternary alloys. The ultrasonic wave propagation behavior at different temperatures for Ni-Al-Cr alloy have been investigated and correlated with respect to the microstructural phenomena during the wave propagation and thermal behavior of the ternary alloy. An ultrasonic mechanism has been developed to correlate the temperature dependent ultrasonic properties with the thermophysical properties particularly the thermal conductivity of the alloy. The results are compared with earlier studies of the elastic constants and are found to be in good agreement. We find that the thermal conductivity of Ni-Al-Cr alloy plays important role in the ultrasonic wave propagation behavior inside the alloy.Keywords
Ternary Alloy, Elastic Constants, Ultrasonic Attenuation, Thermal Properties.Full Text
- Nondestructive Characterization of a Lyotropic Liquid Crystalline System
Abstract Views :170 |
PDF Views:0
Authors
Affiliations
1 Physics Department, University of Allahabad, Allahabad-211002, IN
1 Physics Department, University of Allahabad, Allahabad-211002, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 31, No 1 (2009), Pagination: 31-35Abstract
In the present work, the characterization of a calamitic liquid crystal mixture-sodium lauryl sulphate (SLS)/decanol/water-has been reported using ultrasonic velocity and absorption measurements as a function of temperature and concentration. The experimental tools used were, ultrasonic interferometry for the velocity and pulse-echo technique for the absorption measurements. The results are discussed in terms of the temperature and concentration dependent lyotropic liquid crystal formed in the material system.Keywords
Ultrasonic Velocity, Ultrasonic Absorption, Lyotropic Liquid Crystals, Pulse-Echo Technique.Full Text
- Ultrasonic Properties of CuO Nanoparticles Based Nanofluids
Abstract Views :157 |
PDF Views:2
Authors
Affiliations
1 Department of Physical Sciences, Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalaya, Chitrakoot, Satna (M.P.), IN
2 Department of Physics, University of Allahabad, Allahabad-211002, IN
1 Department of Physical Sciences, Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalaya, Chitrakoot, Satna (M.P.), IN
2 Department of Physics, University of Allahabad, Allahabad-211002, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 34, No 4 (2012), Pagination: 72-75Abstract
Study of nanofluids is important for different types of heat transfer management systems. Three different samples of CuO nanoparticles-PVA nanofluids are prepared through the chemical routes using ultrasonication. Temperature dependent ultrasonic velocity in the samples is measured and the behavior is correlated to extract the important information about thermal conduction at different temperatures. The results are applicable for the heat management in microelectronic industries.Keywords
Nanofluid, Ultrasonic Attenuation, Ultrasonic Velocity.Full Text
- Ultrasonic Properties of β-Phase Nickel Aluminide
Abstract Views :126 |
PDF Views:0
Authors
R. R. Yadav
1,
D. K. Pandey
1
Affiliations
1 Physics Department, Allahabad University, Allahabad-211002, IN
1 Physics Department, Allahabad University, Allahabad-211002, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 28, No 1 (2006), Pagination: 4-11Abstract
The ultrasonic attenuation due to phonon-phonon interaction has been evaluated in β-phase NiAl in high temperature interval 300-1400K along the crystallographic directions <100>, <110> and <111> for longitudinal and shear waves. For this evaluation we have calculated second and third order elastic constants (SOEC and TOEC) at the different temperatures using only two basic parameters. Ultrasonic velocities and Non-linearity parameters are calculated using the elastic constants. Structural stability, abrupt change in ductility, disordering at TC may be predicted on the basis of temperature variation of the elastic constants and the ultrasonic attenuation.Full Text
- The Thermal Conductivity and Ultrasonic Absorption in Dielectric Crystals
Abstract Views :181 |
PDF Views:0
Authors
Devraj Singh
1,
R. R. Yadav
1
Affiliations
1 Department of Physics, University of Allahabad, Allahabad-211002, IN
1 Department of Physics, University of Allahabad, Allahabad-211002, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 25, No 3 (2003), Pagination: 82-87Abstract
In this paper ultrasonic absorption and other associated parameters have been evaluated in AgCl, LiF and MnO along different directions as a function of higher temperatures. We have also calculated the second and third order elastic constants of these materials for the evaluations. The results are compared with experimental values. It is concluded that the lattice thermal conductivity played an important role in temperature dependence of the ultrasonic absorption in these dielectrics.Full Text
- Effect of Electrical Resistivity on Ultrasonic Attenuation in FeSe Single Crystal at Low Temperature
Abstract Views :233 |
PDF Views:0
Authors
Affiliations
1 Department of Physics, University of Allahabad, Allahabad-211002, IN
2 Department of Physics, Prof. Rajendra Singh (Rajju Bhaiya) Institute of Physical Sciences for Study and Research, V.B.S. Purvanchal University, Jaunpur- 222003, IN
1 Department of Physics, University of Allahabad, Allahabad-211002, IN
2 Department of Physics, Prof. Rajendra Singh (Rajju Bhaiya) Institute of Physical Sciences for Study and Research, V.B.S. Purvanchal University, Jaunpur- 222003, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 41, No 3 (2019), Pagination: 69-73Abstract
The ultrasonic attenuation and velocities following electron viscosity mechanism has been computed in semi-metallic, superconducting single crystal Iron Selenide(FeSe) in low temperatures 10-70K. We have also calculated the electron-viscosity at different low temperature needed for the calculation of ultrasonic attenuation. The behaviour of ultrasonic attenuation is quite similar to its inverse electrical resistivity. The ultrasonic attenuation due to electron viscosity mechanism is most significant at 15 K. Computed results of ultrasonic parameters have been discussed.Keywords
Elastic Constant, Electrical Resistivity, Superconductor, Ultrasonic Attenuation.Full Text
References
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