Critical temperature with paramagnetic and normal impurities under the square well model

1984 ◽  
Vol 62 (2) ◽  
pp. 158-166 ◽  
Author(s):  
J. W. Blezius ◽  
J. P. Carbotte
Keyword(s):  
Energy Gap ◽  
Mean Square ◽  
Electron Phonon Interaction ◽  
The Past ◽  
Paramagnetic Impurities ◽  
Well Model ◽  
Gap Anisotropy ◽  
The Mean ◽  
Square Well ◽  
Pairing Potential

In the past, it has been shown that in superconductors where paramagnetic impurities are not involved, the results obtained from an analysis in the Eliashberg model with a square well approximation to the electron–phonon interaction are related simply to the analogous results of the Bardeen–Cooper–Schrieffer (BCS) model. The relation consists of a substitution of the mean square energy gap anisotropy for the mean square pairing potential anisotropy and of adding a (1 + λ) mass renormalization factor. The present paper considers a paramagnetic case in the same model and it is found that the relation to the BCS result is different from that of previously studied cases.

Structure factors of binary liquid metal alloys within the square-well model

Open Physics ◽  
2009 ◽  
Vol 7 (3) ◽  
Author(s):  
Nikolay Dubinin ◽  
Vladimir Filippov ◽  
Olga Malkhanova ◽  
Nikolay Vatolin
Keyword(s):  
Random Phase Approximation ◽  
Random Phase ◽  
Spherical Approximation ◽  
Mean Spherical Approximation ◽  
Structure Factors ◽  
Well Model ◽  
The Mean ◽  
Square Well ◽  
Experimental Structure ◽  
Good Agreement

AbstractThe procedure suggested previously for the description of the square-well (SW) fluid within the framework of the mean spherical approximation is applied to calculate the structure factors of pure Na, pure K, and 0.5Na-0.5K alloy in liquid state. It is shown that our variations of the SW depth and SW width enable us to achieve a good agreement between calculated and experimental structure factors. The procedure under consideration gives more accurate results than the random phase approximation for the same values of the SW parameters.

Evaluation of the internal field produced by longitudinal optic phonons in ZnSe crystals

1983 ◽  
Vol 61 (7) ◽  
pp. 1017-1020 ◽  
Author(s):  
J. Daunay ◽  
Jac. Daunay ◽  
P. Bugnet
Keyword(s):  
Room Temperature ◽  
Internal Field ◽  
Mean Square ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Longitudinal Optic ◽  
The Mean ◽  
Increasing Temperature ◽  
Franz Keldysh Effect ◽  
Longitudinal Optic Phonons

Measurements of light absorption on ZnSe single crystals, conducted from 80 K to room temperature, show that the forbidden band gap decreases with increasing temperature because of the electron–phonon interaction. It is established for temperatures ranging from 140 to 320 K that longitudinal optic (LO) and acoustic (A) phonons operate simultaneously and exclusively so that [Formula: see text]. The first term, resulting from the Franz–Keldysh effect applied to the mean square field produced by LO phonons, provides the value of this field. It reaches 105 V cm−1 at room temperature.

scholarly journals Self-Diffusion in Liquid Copper, Silver, and Gold

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1651
Author(s):  
Nikolay Dubinin
Keyword(s):  
Liquid Copper ◽  
Spherical Approximation ◽  
Mean Spherical Approximation ◽  
Self Diffusion ◽  
Well Model ◽  
Different Temperatures ◽  
The Mean ◽  
Square Well ◽  
Theoretical Results ◽  
Good Agreement

The recently developed by us semi-analytical representation of the mean spherical approximation in conjunction with the linear trajectory approximation is applied to the quantitative study of self-diffusivities in liquid Cu, Ag and Au at different temperatures. The square-well model is employed for the description of the interatomic pair interactions in metals under study. It is found that our theoretical results are in good agreement with available experimental and computer-simulation data and can be considered as a prediction when such data are absent.

Superconductivity in Single Crystal Tl

1974 ◽  
Vol 52 (16) ◽  
pp. 1504-1509 ◽  
Author(s):  
P. T. Truant ◽  
J. P. Carbotte
Keyword(s):  
Single Crystal ◽  
Phonon Dispersion ◽  
Scattering Data ◽  
Electron Mass ◽  
Phonon Dispersion Curves ◽  
Electron Phonon Interaction ◽  
Gap Anisotropy ◽  
Crystal Transition ◽  
The Mean ◽  
Pure Single Crystal

We have used a model of the electron–phonon interaction in Tl which is consistent with neutron scattering data on the phonon dispersion curves as well as the superconducting tunneling data on the isotropic electron–phonon function α2(ω)F(ω) to explore the amount of anisotropy that can be expected in select properties of Tl. First the Fermi surface (FS) variation of the electron mass renormalization parameter λ(k) is determined. Then the superconducting gap Δ(k) is obtained for many k's on the FS. The mean square gap anisotropy is calculated. The pure single crystal transition temperature is obtained and compared with the dirty limit.

The Bordeaux Automatic Meridian Circle

1978 ◽  
Vol 48 ◽  
pp. 227-228
Author(s):  
Y. Requième
Keyword(s):  
Mean Square Error ◽  
Mean Square ◽  
Meridian Circle ◽  
The Mean ◽  
Full Automation

In spite of important delays in the initial planning, the full automation of the Bordeaux meridian circle is progressing well and will be ready for regular observations by the middle of the next year. It is expected that the mean square error for one observation will be about ±0.”10 in the two coordinates for declinations up to 87°.

The mean-square generalized delayed decision feedback sequence detector

2003 ◽  
Vol 14 (3) ◽  
pp. 265-268 ◽  
Author(s):  
Maurizio Magarini ◽  
Arnaldo Spalvieri ◽  
Guido Tartara
Keyword(s):  
Decision Feedback ◽  
Mean Square ◽  
The Mean

Scrub typhus (Orientia tsutsugamushi), A rapidly spreading epidemic in Chennai - A standalone lab experience

2016 ◽  
Vol 5 (09) ◽  
pp. 4896
Author(s):  
Sripriya C.S.* ◽  
Shanthi B. ◽  
Arockia Doss S. ◽  
Antonie Raj I. ◽  
Mohana Priya
Keyword(s):  
Scrub Typhus ◽  
Clinical Symptoms ◽  
Clinical Manifestations ◽  
Febrile Illness ◽  
Orientia Tsutsugamushi ◽  
The Past ◽  
Igm Elisa ◽  
The Mean ◽  
Specific Symptoms ◽  
Symptoms And Signs

Scrub typhus (Orientia tsutsugamushi), is a strict intracellular bacterium which is reported to be a recent threat to parts of southern India. There is re-emergence of scrub typhus during the past few years in Chennai. Scrub typhus is an acute febrile illness which generally causes non-specific symptoms and signs. The clinical manifestations of this disease range from sub-clinical disease to organ failure to fatal disease. This study documents our laboratory experience in diagnosis of scrub typhus in patients with fever and suspected clinical symptoms of scrub typhus infection for a period of two years from April 2014 to April 2016 using immunochromatography and IgM ELISA methods. The study was conducted on 648 patients out of whom 188 patients were found to be positive for scrub typhus. Results also showed that pediatric (0 -12 years) and young adults (20 – 39 years) were more exposed to scrub typhus infection and female patients were more infected compared to male. The study also showed that the rate of infection was higher between September to February which also suggested that the infection rate is proportional to the climatic condition. Statistical analysis showed that the mean age of the patients in this study was 37.6, standard deviation was 18.97, CV % was 50.45. 

Limit tolerances for sums of measurement errors

2018 ◽  
Vol 934 (4) ◽  
pp. 59-62
Author(s):  
V.I. Salnikov
Keyword(s):  
Normal Distribution ◽  
Mean Square Error ◽  
Gaussian Distribution ◽  
Measurement Errors ◽  
Theory And Practice ◽  
Mean Square ◽  
The Mean ◽  
Limiting Values ◽  
Limiting Value

The question of calculating the limiting values of residuals in geodesic constructions is considered in the case when the limiting value for measurement errors is assumed equal to 3m, ie ∆рred = 3m, where m is the mean square error of the measurement. Larger errors are rejected. At present, the limiting value for the residual is calculated by the formula 3m√n, where n is the number of measurements. The article draws attention to two contradictions between theory and practice arising from the use of this formula. First, the formula is derived from the classical law of the normal Gaussian distribution, and it is applied to the truncated law of the normal distribution. And, secondly, as shown in [1], when ∆рred = 2m, the sums of errors naturally take the value equal to ?pred, after which the number of errors in the sum starts anew. This article establishes its validity for ∆рred = 3m. A table of comparative values of the tolerances valid and recommended for more stringent ones is given. The article gives a graph of applied and recommended tolerances for ∆рred = 3m.

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