Non-linear temperature dependence of Bragg gratings written in different fibres, optimised for sensor applications over a wide range of temperatures

2004 ◽  
Vol 112 (2-3) ◽  
pp. 211-219 ◽  
Author(s):  
Suchandan Pal ◽  
Tong Sun ◽  
Kenneth T.V. Grattan ◽  
Scott A. Wade ◽  
Stephen F. Collins ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Bragg Gratings ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Sensor Applications ◽  
Wide Range ◽  
Non Linear

Parametric Models of Ultrasonic Piezoelectric Transducers over a Wide Temperature Range

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000266-000272 ◽  
Author(s):  
Steven A. Morris ◽  
Jeremy Townsend
Keyword(s):  
Dielectric Constant ◽  
Temperature Dependence ◽  
Coupling Coefficient ◽  
Thin Disk ◽  
Piezoelectric Transducers ◽  
Parametric Models ◽  
Model Parameters ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Wide Range

Piezoelectric ultrasonic transducers are used extensively in well logging and logging-while-drilling applications for pulse-echo operation. We present a method of modeling the operation of ultrasonic thin-disk piezoelectric transducers over a wide range of temperatures. The model is based on using Redwood's version of Mason's model of thin-disk transducers. Laboratory measurements in the oven of non-backed transducers in air are used to extract the Mason model parameters as a function of temperature. Derived parameters are frequency-thickness constant, dielectric constant, and thickness mode coupling coefficient. A fourth parameter, bulk density, is measured independently and assumed constant over temperature. Temperature dependence of frequency thickness constant and coupling coefficient are modeled as linear temperature coefficients. Temperature dependence of the dielectric constant must be specified as a table because of the non-linear temperature dependence of that parameter.

Electrical Transport and Oxygen Disorder in YBCO

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3465-3469 ◽  
Author(s):  
J. Jung ◽  
M. M. Abdelhadi
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Electrical Transport ◽  
Linear Component ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Low Temperature Annealing ◽  
Non Linear

We investigated the origin of a non-linear temperature dependence of resistivity ρab(T) in the a-b planes of YBCO, frequently observed in optimally doped twinned YBCO single crystals and thin films and in untwinned YBCO crystals along the chain direction. We performed the measurements of ρab(T) in c-axis oriented YBCO thin films that were subjected to low temperature annealing at 120–140°C (400–420 K) in argon. Our results have shown that redistribution of oxygen at a fixed oxygen content in the chain layers of YBCO with a non-linear ρab(T), leads to an increase of Tc, an increase of resistivity and a reduction of the non-linear component in ρab(T).

Non-linear temperature dependence of Hg–O and Cu–O distances in Hg-1212 superconductor

2000 ◽  
Vol 340 (2-3) ◽  
pp. 133-140 ◽  
Author(s):  
Kouji Yamawaki ◽  
Satoshi Sasaki ◽  
Masato Kakihana ◽  
Masahiko Tanaka
Keyword(s):  
Temperature Dependence ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Non Linear

Temperature Dependent Phononic Response of Few Layered MoS2 Nanosheets

2018 ◽  
Vol 4 (5) ◽  
pp. 546-548
Author(s):  
Sneha Sinha ◽  
Vasant Sathe ◽  
Sunil K. Arora
Keyword(s):  
Temperature Dependence ◽  
Phonon Scattering ◽  
Linear Temperature Dependence ◽  
Mos2 Nanosheets ◽  
Temperature Dependent ◽  
Linear Temperature ◽  
First Order ◽  
Non Linear ◽  
Out Of Plane ◽  
Raman Modes

From the temperature dependent phononic studies of few layered liquid phase exfoliated MoS2 nanosheets we find that the E12g (in-plane) and A1g (out-of-plane) Raman modes follow red shift with increase in temperature and exhibits non-linear temperature dependence in the entire temperature range (80 to 600 K). The first-order temperature coefficients for E12g and A1g modes are found to be -0.0133 cm-1K-1 and -0.0092 cm-1K-1, respectively. The physical origin of the non-linear temperature dependence is analyzed using an analytical model that includes contribution of the thermal expansion and an-harmonic effects to the lattice potential. Our analysis suggests that the non-linear temperature dependence of E12g and A1g modes mainly originates from the an-harmonic contributions from three-phonon and four-phonon scattering.

Non linear temperature dependence of the resistivity of LaSrCuO: Effects of Sr content

1989 ◽  
Vol 69 (4) ◽  
pp. 355-357 ◽  
Author(s):  
R. Decca ◽  
E. Osquiguil ◽  
F. de la Cruz ◽  
C. D'Ovidio ◽  
M.T. Malachevski ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Non Linear
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