Electrical Resistivity of Noble Metals

1973 ◽  
Vol 51 (21) ◽  
pp. 2225-2232 ◽  
Author(s):  
Satya Pal
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Noble Metals ◽  
Secular Equation ◽  
Transport Coefficients ◽  
Boltzmann Transport ◽  
Dynamical Models ◽  
First Order ◽  
Experimental Values ◽  
Theoretical Results

The temperature variation of the electrical resistivity of copper, silver, and gold has been studied within the free electron approximation on the basis of the lattice dynamical models of Chéveau, and Bhatia and Horton. The first-order variational solution of the Boltzmann transport equation as developed by Ziman has been incorporated in the study for the calculation of the transport coefficients of noble metals. The force constants appearing in the secular equation for the lattice vibrations have been estimated with the help of the experimental values of the elastic constants of the noble metals. The phonon spectrum has been calculated by the modified Houston spherical six-term procedure as elaborated by Betts et al. The Normal and the Umklapp contributions to the electrical resistivity have been considered separately in the present study. A comparison of the theoretical results with the experimental data shows that the calculations are able to explain satisfactorily the temperature dependence of the electrical resistivity of the noble metals. However, as compared to the Bhatia–Horton model, the theoretical resistivity values of the noble metals as furnished by the Chéveau model give a better overall fit with the experimental data.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

scholarly journals Transport coefficients calculation using Inference the Momentum-Transfer and Inelastic-Collision Cross Sections of Electrons in Carbon Dioxide

2018 ◽  
Vol 29 (1) ◽  
pp. 174
Author(s):  
Jasim Mohammed salih Ali
Keyword(s):  
Transport Equation ◽  
Momentum Transfer ◽  
Drift Velocity ◽  
Cross Sections ◽  
Transport Coefficients ◽  
Boltzmann Transport Equation ◽  
Boltzmann Transport ◽  
Characteristic Energy ◽  
Rf Discharges ◽  
Experimental Values

Abstract: In this work, we were calculate the electron diffusion coefficients, such as, the drift velocity, characteristic energy, and collision frequencies using the cross sections of the momentum transfer and inelastic for electrons in CO2 from figure(1) after solving the Boltzmann transport equation numerically using the Finite-Difference Method in gas medium through applied electric field at 300 oK. The theoretical predictions were obtained in agreement with the experimental values was publishered. Keyword: CO2 lasers, Boltzmann Transport Equation, RF Discharges, Transport coefficients, Plasma discharge, Drift velocity. الخلاصة: في هذا العمل ، تم حساب معاملات انتشار الالكترونات مثل سرعة الانجراف، الطاقة الميزة و ترددات التصادم باستعمال المقاطع العرضية المرنة وغير مرنة للالكترونات في غاز ثاني أوكسيد الكاربون CO2 من شكل (1) خلال حل معادلة الانتقال لبولتزمان عددياً باستخدام طريقة التفريق المحدد في وسط غازي بعد تسليط مجال كهربائي عليه عند درجة حرارة 300 كلفن . النتائج التي تم الحصول عليها تنبأ بأنها متوافقة مع النتائج العملية المنشورة. الكلمات المفتاحية : ليزرات CO2 ، معادلة الانتقال لبولتزمان ، نموذج التفريغ ، معاملات الانتقال ، تفريغ البلازما ، سرعة الانجراف.

scholarly journals Lattice Vibrations and Ideal Electrical Resistivity of Noble Metals

1979 ◽  
Vol 34 (3) ◽  
pp. 310-314
Author(s):  
B. P. Singh ◽  
M. P. Hemkar
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Variation ◽  
Satisfactory Agreement ◽  
Noble Metals ◽  
Phonon Dispersion ◽  
Dynamical Model ◽  
Lattice Vibrations

Abstract The phonon dispersion in the three principal symmetry directions [ζ00], [ζζ0] and [ζζζ] and the temperature variation of the electrical resistivity of Cu, Ag and Au have been studied by using a lattice dynamical model which takes into account d shell-d shell central interactions up to second neighbours. The calculated results have been compared with the available experimental data and have been found to be in a satisfactory agreement.

Heats of vaporization of nonelectrolytes

1979 ◽  
Vol 44 (2) ◽  
pp. 307-312
Author(s):  
Petr Kyselka ◽  
Jiří Rameš ◽  
Karel Procházka
Keyword(s):  
Experimental Data ◽  
Chemical Properties ◽  
Approximate Expression ◽  
Maximum Deviation ◽  
First Order ◽  
Critical Data ◽  
Physico Chemical ◽  
Theory Of Liquids ◽  
Nonpolar Liquids ◽  
Experimental Values

The first-order perturbation theory of liquids was used for developing an approximate expression suitable for a rapid calculation of the heat of vaporization of nonpolar liquids formed by approximately spherical molecules. The calculation uses only available physico-chemical properties of substances, namely the critical data. The results are tested by a comparison with existing experimental data on a series of nonpolar substances. The agreement between calculated values and experimental data is relatively good. The maximum deviation between theoretical and experimental values does not exceed ±10%.

A calculation of the electron–electron scattering contribution to the electrical resistivity of copper

1978 ◽  
Vol 56 (6) ◽  
pp. 708-714 ◽  
Author(s):  
J. E. Black
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Plane Wave ◽  
Fermi Surface ◽  
Electron Scattering ◽  
Noble Metals ◽  
Electronic States ◽  
Cone Model ◽  
Wave States ◽  
Scattering Contribution

The contribution of electron–electron scattering to the electrical resistivity of copper has been calculated. Parts of the Fermi surface on which the initial and final electronic states contribute most heavily to the resistivity have also been determined. The calculations are based on two plane-wave states for the electrons and a Thomas–Fermi screened Coulomb interaction between electrons. The Fermi surface is approximated with the eight-cone model used in noble metals. The results of the calculations are presented here and compared with calculations and experimental data of other authors.

A Review on Vortex Streets, Periodic Wakes, and Induced Vibration Phenomena

1964 ◽  
Vol 86 (2) ◽  
pp. 185-193 ◽  
Author(s):  
A. W. Marris
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Vortex Pair ◽  
Present Knowledge ◽  
Number Range ◽  
First Order ◽  
Vortex Streets ◽  
Stationary Vortex ◽  
Theoretical Results

A survey is presented of recent experimental and theoretical researches on the problem of periodic wakes behind a cylinder in a stream. A synopsis is given of the present knowledge on the mechanics of wake formation and of the associated hydrodynamic forces for the full Reynolds number range from the first appearance of a stationary vortex pair behind the cylinder up to transition of the boundary layer on the cylinder. Experimental data are viewed in the light of the theoretical results of Birkhoff, which, it appears, may replace the classical theory based on the first order stability of a potential flow street of vortex filaments. The paper closes with a discussion of the problem of the induced vibration of a spring mounted cylinder in a stream.

A CONTRIBUTION TO THE QUALITATIVE GC ANALYSIS OF SOME NON-CHLORINATED XENOBIOTIC CHEMICALS IN WASTE WATERS

1994 ◽  
Vol 30 (3) ◽  
pp. 91-93 ◽  
Author(s):  
Biljana D. Škrbic ◽  
Mirjana B. Vojinovic-Miloradov
Keyword(s):  
Experimental Data ◽  
Stationary Phases ◽  
Retention Indices ◽  
Waste Waters ◽  
Gc Analysis ◽  
Experimental Values ◽  
Xenobiotic Chemicals

Gas chromatographic unified retention indices of some chlorinated xenobiotic chemicals, as pollutants in waste waters, on OV-101 and SE-30 stationary phases are presented. These values agree well with the corresponding experimental values used in the statistical treaunent of the experimental data.

scholarly journals Influence of the Porosity of Polymer Foams on the Performances of Capacitive Flexible Pressure Sensors

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1968 ◽  
Author(s):  
Sylvie Bilent ◽  
Thi Hong Nhung Dinh ◽  
Emile Martincic ◽  
Pierre-Yves Joubert
Keyword(s):  
Experimental Data ◽  
Linear Model ◽  
Dielectric Material ◽  
Pressure Sensors ◽  
Volume Ratio ◽  
Measurement Range ◽  
Polymer Foams ◽  
First Order ◽  
Non Linear ◽  
Flexible Pressure Sensors

This paper reports on the study of microporous polydimethylsiloxane (PDMS) foams as a highly deformable dielectric material used in the composition of flexible capacitive pressure sensors dedicated to wearable use. A fabrication process allowing the porosity of the foams to be adjusted was proposed and the fabricated foams were characterized. Then, elementary capacitive pressure sensors (15 × 15 mm2 square shaped electrodes) were elaborated with fabricated foams (5 mm or 10 mm thick) and were electromechanically characterized. Since the sensor responses under load are strongly non-linear, a behavioral non-linear model (first order exponential) was proposed, adjusted to the experimental data, and used to objectively estimate the sensor performances in terms of sensitivity and measurement range. The main conclusions of this study are that the porosity of the PDMS foams can be adjusted through the sugar:PDMS volume ratio and the size of sugar crystals used to fabricate the foams. Additionally, the porosity of the foams significantly modified the sensor performances. Indeed, compared to bulk PDMS sensors of the same size, the sensitivity of porous PDMS sensors could be multiplied by a factor up to 100 (the sensitivity is 0.14 %.kPa−1 for a bulk PDMS sensor and up to 13.7 %.kPa−1 for a porous PDMS sensor of the same dimensions), while the measurement range was reduced from a factor of 2 to 3 (from 594 kPa for a bulk PDMS sensor down to between 255 and 177 kPa for a PDMS foam sensor of the same dimensions, according to the porosity). This study opens the way to the design and fabrication of wearable flexible pressure sensors with adjustable performances through the control of the porosity of the fabricated PDMS foams.

scholarly journals An Additive Model to Predict the Rheological and Mechanical Properties of Polypropylene Blends Made by Virgin and Reprocessed Components

Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Francesco Paolo La Mantia ◽  
Maria Chiara Mistretta ◽  
Vincenzo Titone
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Additive Model ◽  
Industrial Process ◽  
Theoretical Predictions ◽  
Experimental Values ◽  
Polypropylene Blends ◽  
Polypropylene Sample

In this work, an additive model for the prediction of the rheological and mechanical properties of monopolymer blends made by virgin and reprocessed components is proposed. A polypropylene sample has been reprocessed more times in an extruder and monopolymer blends have been prepared by simulating an industrial process. The scraps are exposed to regrinding and are melt reprocessed before mixing with the virgin polymer. The reprocessed polymer is, then, subjected to some thermomechanical degradation. Rheological and mechanical experimental data have been compared with the theoretical predictions. The results obtained showed that the values of this simple additive model are a very good fit for the experimental values of both rheological and mechanical properties.

Analysis of a New Mixed Finite Volume Method

2003 ◽  
Vol 3 (1) ◽  
pp. 189-201 ◽  
Author(s):  
Ilya D. Mishev
Keyword(s):  
Finite Volume Method ◽  
Finite Volume ◽  
Elliptic Equations ◽  
Variable Pressure ◽  
Order Error ◽  
First Order ◽  
Scalar Variable ◽  
Volume Method ◽  
Well Posed ◽  
Theoretical Results

AbstractA new mixed finite volume method for elliptic equations with tensor coefficients on rectangular meshes (2 and 3-D) is presented. The implementation of the discretization as a finite volume method for the scalar variable (“pressure”) is derived. The scheme is well suited for heterogeneous and anisotropic media because of the generalized harmonic averaging. It is shown that the method is stable and well posed. First-order error estimates are derived. The theoretical results are confirmed by the presented numerical experiments.

Sign in / Sign up

Export Citation Format

Share Document