POPULATION DYNAMICS FOR SPIN-POLARON-PAIRS IN HIGH-Tc SUPERCONDUCTORS

1993 ◽  
Vol 07 (05) ◽  
pp. 325-330
Author(s):  
RONALDO MOTA
Keyword(s):  
Experimental Data ◽  
Population Dynamics ◽  
Critical Temperature ◽  
Growth Model ◽  
Logistic Growth ◽  
Spin Polaron ◽  
High Tc Superconductors ◽  
High Tc ◽  
Logistic Growth Model ◽  
Good Concordance

A study of the population dynamics for spin-polaron-pairs in high-T c superconductors is presented. A particular population dynamical model and its appropriateness is discussed. Numerical results are obtained for the x-dependence of the critical temperature using the logistic growth model and a good concordance with experimental data has been obtained for T c as a function of x for La 2 − x Sr x CuO 4. A discussion of various aspects and implications of the model is given.

A Neoclassical Growth Model for Population Dynamics in a Homogeneous Habitat

2001 ◽  
Author(s):  
Peter Vadasz ◽  
Alisa S. Vadasz
Keyword(s):  
Experimental Data ◽  
Growth Model ◽  
Logistic Growth ◽  
Lag Phase ◽  
Growth Stages ◽  
Initial Growth ◽  
Neoclassical Model ◽  
Wide Range ◽  
Logistic Growth Model ◽  
Special Case

Abstract A neoclassical model is proposed for the growth of cell and other populations in a homogeneous habitat. The model extends on the Logistic Growth Model (LGM) in a non-trivial way in order to address the cases where the Logistic Growth Model (LGM) fails short in recovering qualitative as well as quantitative features that appear in experimental data. These features include in some cases overshooting and oscillations, in others the existence of a “Lag Phase” at the initial growth stages, as well as an inflection point in the “In curve” of the population size. The proposed neoclassical model recovers also the Logistic Growth Curve as a special case. Comparisons of the solutions obtained from the proposed neoclassical model with experimental data confirm its quantitative validity, as well as its ability to recover a wide range of qualitative features captured in experiments.

A GINZBURG-LANDAU THEORY FOR CRITICAL TEMPERATURE OF LAYERED HIGH-Tc SUPERCONDUCTORS

1989 ◽  
Vol 03 (18) ◽  
pp. 1393-1400
Author(s):  
TATSUYA NAGAO ◽  
HIROYUKI MORI ◽  
FUMIKO YONEZAWA
Keyword(s):  
Experimental Data ◽  
Critical Temperature ◽  
Layered Structure ◽  
Phenomenological Model ◽  
Landau Theory ◽  
Single Layer ◽  
High Tc Superconductors ◽  
Ginzburg Landau ◽  
High Tc ◽  
Periodic Layered Structure

Using a phenomenological model for layered superconductors, we derive a formalism for the critical temperature T c in terms of the layer numbers. We show that T c of a system of n identical layers is the same as that of a single layer for all values of n. In a periodic layered structure composed of two kinds of layers, T c increases monotonically with the number of higher-T c layers. When the carrier number depends on structure, T c shows a behavior consistent with the experimental data on some high-T c superconductors such as Tl and Bi families. We make a suggestion to achieve a higher T c .

scholarly journals Extended logistic growth model for heterogeneous populations

2017 ◽  
Author(s):  
Wang Jin ◽  
Scott W McCue ◽  
Matthew J Simpson
Keyword(s):  
Cell Proliferation ◽  
Growth Model ◽  
Numerical Solutions ◽  
Cellular Level ◽  
Logistic Growth ◽  
Logistic Growth Model ◽  
Living Tissues ◽  
Discrete Mathematical Model ◽  
The Continuum

AbstractCell proliferation is the most important cellular-level mechanism responsible for regulating cell population dynamics in living tissues. Modern experimental procedures show that the proliferation rates of individual cells can vary significantly within the same cell line. However, in the mathematical biology literature, cell proliferation is typically modelled using a classical logistic equation which neglects variations in the proliferation rate. In this work, we consider a discrete mathematical model of cell migration and cell proliferation, modulated by volume exclusion (crowding) effects, with variable rates of proliferation across the total population. We refer to this variability as heterogeneity. Constructing the continuum limit of the discrete model leads to a generalisation of the classical logistic growth model. Comparing numerical solutions of the model to averaged data from discrete simulations shows that the new model captures the key features of the discrete process. Applying the extended logistic model to simulate a proliferation assay using rates from recent experimental literature shows that neglecting the role of heterogeneity can, at times, lead to misleading results.

scholarly journals Outbreak analysis with a logistic growth model shows COVID-19 suppression dynamics in China

PLoS ONE ◽  
2020 ◽  
Vol 15 (6) ◽  
pp. e0235247 ◽  
Author(s):  
Yi Zou ◽  
Stephen Pan ◽  
Peng Zhao ◽  
Lei Han ◽  
Xiaoxiang Wang ◽  
...  
Keyword(s):  
Growth Model ◽  
Logistic Growth ◽  
Logistic Growth Model

PREDATION AND STEADY STATES IN HIGH-TC SUPERCONDUCTORS

1993 ◽  
Vol 07 (12) ◽  
pp. 829-833
Author(s):  
RONALDO MOTA
Keyword(s):  
Steady State ◽  
Steady States ◽  
Dynamical Model ◽  
Stable Steady State ◽  
Spin Polaron ◽  
High Tc Superconductors ◽  
High Tc ◽  
Practical Model

A study of the role played by predation in a population dynamical model previously considered for spin-polaron-pairs in high-Tc superconductors is presented. A practical model which exhibits two positive linearly stable steady state populations is considered. A discussion of various aspects and implications of the model is given.

Electrical resistivity and critical temperature of Bi-based High-TC superconductors to 1 GPa

1990 ◽  
Vol 3 (1-6) ◽  
pp. 120-122 ◽  
Author(s):  
B. M. Andersson ◽  
K. E. Easterling ◽  
S. J. Guo ◽  
B. Sundqvist
Keyword(s):  
Electrical Resistivity ◽  
Critical Temperature ◽  
High Tc Superconductors ◽  
High Tc
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