ELASTIC BEHAVIOR OF Pr SUBSTITUTED Y-123 SUPERCONDUCTING MATERIALS

2006 ◽  
Vol 20 (14) ◽  
pp. 843-847 ◽  
Author(s):  
B. N. DOLE ◽  
Y. PURUSHOTHAM ◽  
P. VENUGOPAL REDDY ◽  
S. S. SHAH
Keyword(s):  
High Temperature ◽  
Linear Relationship ◽  
Sound Velocity ◽  
Room Temperature ◽  
Elastic Moduli ◽  
High Temperature Superconductors ◽  
Elastic Behavior ◽  
Wave Velocities ◽  
Pulse Transmission ◽  
Transmission Technique

The longitudinal (Vl) and shear (Vs) wave velocities of Praseodymium substituted YB 2 Cu 3 O 7-δ high temperature superconductors were determined at room temperature by the pulse transmission technique. The values of Young's (E), rigidity (n) and bulk (k) moduli have been corrected to zero porosity. The zero porous corrected values of the elastic moduli are found to increase with increasing Praseodymium concentration. A linear relationship between the Debye temperature (θD) and average sound velocity (Vm) has also been observed and the behavior is explained qualitatively.

ELASTIC BEHAVIOR OF SOME SUBSTITUTED Sr–Zn W-TYPE HEXAGONAL FERRITES

1999 ◽  
Vol 13 (27) ◽  
pp. 991-998 ◽  
Author(s):  
Y. PURUSHOTHAM ◽  
P. VENUGOPAL REDDY
Keyword(s):  
Linear Relationship ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Dopant Concentration ◽  
Elastic Behavior ◽  
Hexagonal Ferrites ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission ◽  
Transmission Technique

In the present work, we investigate the elastic behavior of monovalent and divalent doped Sr–Zn W-type hexagonal ferrites at room temperature by measuring their longitudinal and shear wave velocities using a pulse transmission technique. The values of Young (E) and rigidity (G) moduli have been corrected to the theoretical density. The zero porosity values of both the elastic moduli are found to increase with increasing dopant concentration. Further, a linear relationship between the Debye temperature and the average sound velocity has also been observed and the behavior is explained qualitatively.

ELASTIC BEHAVIOR OF GERMANIUM-SUBSTITUTED LITHIUM FERRITES

1995 ◽  
Vol 09 (01) ◽  
pp. 39-44 ◽  
Author(s):  
Y. PURUSHOTHAM ◽  
P. VENUGOPAL REDDY ◽  
PRAN KISHAN ◽  
NITENDAR KUMAR
Keyword(s):  
Room Temperature ◽  
Elastic Moduli ◽  
Elastic Behavior ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission ◽  
Power Equation ◽  
Lithium Ferrites ◽  
Transmission Technique ◽  
Germanium Concentration

The longitudinal and shear wave velocities of germanium-substituted lithium ferrites were determined at room temperature by the pulse transmission technique. Young's (E) and rigidity (n) moduli have been corrected to theoretical density by a power equation. The zero porous corrected values of both the elastic moduli (Young's and rigidity) are found to increase with increasing germanium concentration. A linear relationship between the Debye temperature and the average sound velocity has also been observed.

Electrical and Elastic Behavior of In and Al Substituted Mg-Mn Ferrites

1998 ◽  
Vol 12 (22) ◽  
pp. 2247-2262 ◽  
Author(s):  
Y. Purushotham ◽  
Mahavir Singh ◽  
S. P. Sud ◽  
P. Venugopal Reddy
Keyword(s):  
Electrical Conductivity ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Ultrasonic Pulse ◽  
Elastic Behavior ◽  
Pulse Transmission ◽  
Transmission Technique ◽  
Ultrasonic Pulse Transmission ◽  
Curie Temperatures ◽  
Suitable Explanation

Thermopower and electrical conductivity studies of polycrytslline In 3+ and Al 3+ substituted Mg-Mn ferrites having different compositions were undertaken in the temperature range 300–700 K, using differential and two-probe methods respectively. It has been observed that all the ferrites are found to exhibit clear and well-defined transtions near their respective Curie temperatures in both Seebeck coefficient and electrical conductivity versus temperature behavior. The elastic behavior of these ferrites has also been studied as a function of composition at room temperature using ultrasonic pulse transmission technique and it has been found that the elastic moduli decrease continuously with increasing Indium concentration and increase with increasing Aluminium dopants. Suitable explanation for the observed phenomena are given.

EFFECT OF Nb2O5 ON THE ELASTIC BEHAVIOR OF PZT FERROELECTRIC MATERIALS

2002 ◽  
Vol 16 (03) ◽  
pp. 79-85
Author(s):  
Y. PURUSHOTHAM ◽  
O. P. THAKUR ◽  
CHANDRA PRAKASH ◽  
P. VENUGOPAL REDDY
Keyword(s):  
Elastic Moduli ◽  
Solid State Reaction Method ◽  
Ferroelectric Materials ◽  
Ferroelectric Ceramics ◽  
Elastic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission

A series of ferroelectric ceramics with the compositional formula PbZr0.52Ti0.48O3 + x wt% of Nb2O5 were prepared by the solid state reaction method. Samples were characterized by studying their X-ray diffraction and dielectric measurements. The longitudinal and shear wave velocities and corresponding elastic moduli were determined at room temperature by using the pulse transmission technique. The values of Young's modulus (E), and the rigidity (n) and bulk (k) moduli were corrected to theoretical density and were found to increase with increasing dopant concentration. The variation of elastic moduli and other elastic parameters such as Debye temperature (θ D ) with composition are explained qualitatively.

Experimental Research and Application of UT Inspection Method for Detection of Defects on Pressure Vessels and Pipelines Under High-Temperature Environment

2006 ◽  
Author(s):  
Weihe Guan ◽  
Changzhou Yan ◽  
Yuanhong Tao ◽  
Xuedong Chen
Keyword(s):  
High Temperature ◽  
Sound Velocity ◽  
Shear Wave ◽  
Room Temperature ◽  
Pressure Vessels ◽  
Inspection Time ◽  
Inspection Method ◽  
Temperature Environment ◽  
Ultrasonic Shear ◽  
High Temperature Environment

High temperature UT inspection techniques can be used to conduct random inspection on line on the key locations of pressure vessels and pipelines in operation so as to find out fresh defects in time and determine inspection time. It can also be used for real-time monitoring and control of defect-containing pressure vessels and pipelines and provide a basis for safety assessment of equipment so as to ensure safe operation of pressure vessels and pipelines. The propagation velocity of ultrasonic wave in metallic pressure-bearing equipment and its amplitude vary with temperature, therefore, the factors that influence UT inspection ability and measuring accuracy will be increased. In this paper the variation in sound velocity and attenuation law of ultrasonic shear wave in common pressure vessels and pipelines in the range of room temperature ∼ 450 °C is studied, the sound velocity decreases linearly as temperature rises and the attenuation coefficient α decreases as temperature rises, from 0.006 dB/mm at room temperature to 0.08dB/mm at 450 °C. The factors that influence inspection accuracy of ultrasonic shear wave are discussed, including variation in sound velocity, loss in interface sound pressure, thermal expansion, and so forth. The method for detection of weld defects within above temperature range using the ultrasonic shear wave is established, including scanning manner, measurement of defect height and length and their position correction, and so forth. The present situation of online high-temperature UT inspection technology for pressure vessels and pipelines in China is summarized through online UT inspection examples of petrochemical equipment under local high-temperature environment.

LOW TEMPERATURE ELASTIC BEHAVIOR OF POTASSIUM-DOPED Bi-2212 SINGLE PHASE HIGH Tc SUPERCONDUCTORS

1994 ◽  
Vol 08 (18) ◽  
pp. 1097-1106 ◽  
Author(s):  
B. GOPALA KRISHNA ◽  
R. RAVINDER REDDY ◽  
P. VENUGOPAL REDDY ◽  
S. V. SURYANARAYANA
Keyword(s):  
Single Phase ◽  
Longitudinal Velocity ◽  
Solid State Reaction Method ◽  
Elastic Behavior ◽  
Velocity Measurements ◽  
High Tc Superconductors ◽  
Qualitative Explanation ◽  
High Tc ◽  
Pulse Transmission ◽  
Transmission Technique

A single phase Bi-2212 and two potassium-doped Bi-2212 samples have been prepared by the solid state reaction method. After the usual characterisation, the ultrasonic longitudinal velocity measurements of all the samples over a temperature range of 80–300 K were undertaken by the pulse transmission technique. The longitudinal velocity of the undoped sample is found to vary in an anomalous way followed by a maximum at 140 K. On the other hand, in the case of the two K-doped ones, the velocity is found to vary with temperature in a normal way up to 120 K followed by a maximum at 105 and 100 K respectively. A qualitative explanation for the observed behavior in all the three cases is given.

Acoustic and Elastic Properties of Cu3Au Alloyin in the Field of High Temperature

2015 ◽  
Vol 770 ◽  
pp. 179-184
Author(s):  
Elena P. Tesleva
Keyword(s):  
High Temperature ◽  
Sound Velocity ◽  
Elastic Properties ◽  
Temperature Interval ◽  
Elastic Waves ◽  
Elastic Moduli ◽  
Temperature Changes ◽  
Two Component ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

The article studies the elastic properties of anisotropy and interatomic anharmonicity in a two-component Cu3Au alloy with positional order-disorder within the high temperature interval of 300 К and 725 К. It provides calculations on velocities of purely transverse and longitudinal elastic waves, elastic moduli (Young’s, shear, adiabatic bulk moduli) and Poisson’s ratios based on the stiffness constants сij(T) of the crystal. Sound velocity values were employed for determining the temperature changes of Grüneisen parameter along the crystallographic directions [100], [110] and [111].

Elastic Properties of Vanadium Doped Silica-Borotellurite Glasses

2020 ◽  
Vol 307 ◽  
pp. 321-326
Author(s):  
Nurhayati Mohd Nor ◽  
Halimah Mohamed Kamari ◽  
Amirah Abdul Latif ◽  
Nurisya Mohd Shah
Keyword(s):  
Elastic Properties ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Molar Fraction ◽  
Glass Network ◽  
Ultrasonic Pulse ◽  
Ultrasonic Velocities ◽  
Wave Velocities ◽  
Network Glass ◽  
Pulse Echo

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.

Sign in / Sign up

Export Citation Format

Share Document