Static and dynamic properties of a two-dimensional charged Bose fluid

1997 ◽  
Vol 55 (1) ◽  
pp. 544-550 ◽  
Author(s):  
R. K. Moudgil ◽  
P. K. Ahluwalia ◽  
K. Tankeshwar ◽  
K. N. Pathak
Keyword(s):  
Dynamic Properties ◽  
Two Dimensional

scholarly journals Structural Transitions at Microtubule Ends Correlate with Their Dynamic Properties in Xenopus Egg Extracts

2000 ◽  
Vol 149 (4) ◽  
pp. 767-774 ◽  
Author(s):  
Isabelle Arnal ◽  
Eric Karsenti ◽  
Anthony A. Hyman
Keyword(s):  
Dynamic Instability ◽  
Dynamic Properties ◽  
Microtubule Assembly ◽  
Two Dimensional ◽  
Egg Extracts ◽  
Xenopus Egg ◽  
Xenopus Egg Extracts ◽  
First Time ◽  
The Relationship ◽  
Dynamic Populations

Microtubules are dynamically unstable polymers that interconvert stochastically between growing and shrinking states by the addition and loss of subunits from their ends. However, there is little experimental data on the relationship between microtubule end structure and the regulation of dynamic instability. To investigate this relationship, we have modulated dynamic instability in Xenopus egg extracts by adding a catastrophe-promoting factor, Op18/stathmin. Using electron cryomicroscopy, we find that microtubules in cytoplasmic extracts grow by the extension of a two- dimensional sheet of protofilaments, which later closes into a tube. Increasing the catastrophe frequency by the addition of Op18/stathmin decreases both the length and frequency of the occurrence of sheets and increases the number of frayed ends. Interestingly, we also find that more dynamic populations contain more blunt ends, suggesting that these are a metastable intermediate between shrinking and growing microtubules. Our results demonstrate for the first time that microtubule assembly in physiological conditions is a two-dimensional process, and they suggest that the two-dimensional sheets stabilize microtubules against catastrophes. We present a model in which the frequency of catastrophes is directly correlated with the structural state of microtubule ends.

Molecular and global structure and dynamics of membranes and lipid bilayers

1990 ◽  
Vol 68 (9) ◽  
pp. 999-1012 ◽  
Author(s):  
E. Sackmann
Keyword(s):  
Lipid Bilayers ◽  
Plasma Membranes ◽  
Mechanical Stability ◽  
Dynamic Properties ◽  
Composite Membranes ◽  
Two Dimensional ◽  
Molecular Architecture ◽  
Present Contribution ◽  
Cell Plasma ◽  
Low Dimensionality

The cell plasma is a composite type of material that is made up of a two-dimensional liquid crystal (lipid–protein bilayer) to which a macromolecular network (the cytoskeleton) is loosely coupled. The latter may be approximately two dimensional as in the case of the erythrocytes or may extend throughout the whole cell cytoplasm. Owing to this combination of two states of matter, the membrane combines the dynamics and flexibility of a fluid with the mechanical stability of a solid. Owing to its low dimensionality, the local structure of the bilayer or the global shape of cells may be most effectively controlled and modulated by biochemical signals such as macromolecular adsorption. The present contribution deals with comparative studies of the local and global dynamic properties of biological and artificial membranes. In the first part the question of the physical basis of selective lipid–protein interaction mechanisms is addressed and the outstanding viscoelastic properties of plasma membranes and their role for local instabilities shape fluctuations of cells and the cell–substrate interaction are described. The second part deals with the molecular architecture and dynamics of composite membranes prepared by combining monomeric and macromolecular lipids. These model membranes open new possibilities to mimick complex mechanical processes of cell plasma membranes and to prepare low-dimensionality macromolecular solutions and gels. Finally, the use of such compound systems by nature to prepare the semipermeable protective layers of plant leaves, the so-called cuticle, is discussed. In analogy to plasma membranes, the local transport properties are modulated by variation of the liquid-crystalline state of the monomeric waxes.

scholarly journals The Numerical Solutions of a Two-Dimensional Space-Time Riesz-Caputo Fractional Diffusion Equation

2011 ◽  
Vol 1 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Necati OZDEMIR ◽  
Derya AVCI ◽  
Beyza Billur ISKENDER
Keyword(s):  
Diffusion Equation ◽  
Anomalous Diffusion ◽  
Numerical Solutions ◽  
Fourier Transforms ◽  
Dynamic Properties ◽  
Dimensional Space ◽  
Space Time ◽  
Two Dimensional ◽  
Dimensional Space Time ◽  
Fractional Differential

This paper is concerned with the numerical solutions of a two dimensional space-time fractional differential equation used to model the dynamic properties of complex systems governed by anomalous diffusion. The space-time fractional anomalous diffusion equation is defined by replacing second order space and first order time derivatives with Riesz and Caputo operators, respectively. By using Laplace and Fourier transforms, a general representation of analytical solution is obtained as Mittag-Leffler function. Gr\"{u}nwald-Letnikov (GL) approximation is also used to find numerical solution of the problem. Finally, simulation results for two examples illustrate the comparison of the analytical and numerical solutions and also validity of the GL approach to this problem.

Nonlinear Dynamic Properties of Two-Dimensional Arrays of Magnetic Nanodots

2015 ◽  
pp. 97-116 ◽  
Author(s):  
Yuri Kobljanskyj ◽  
Denys Slobodianiuk ◽  
Gennady Melkov ◽  
Konstantin Guslienko ◽  
Valentyn Novosad ◽  
...  
Keyword(s):  
Nonlinear Dynamic ◽  
Dynamic Properties ◽  
Two Dimensional ◽  
Magnetic Nanodots ◽  
Nonlinear Dynamic Properties

scholarly journals Dynamic and static properties of stadium-shaped antidot arrays

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
E. Saavedra ◽  
R. M. Corona ◽  
N. Vidal-Silva ◽  
J. L. Palma ◽  
D. Altbir ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Numerical Analysis ◽  
Dynamic Properties ◽  
Dynamic Susceptibility ◽  
Two Dimensional ◽  
Static Properties ◽  
Micromagnetic Simulations ◽  
Circular Holes ◽  
Antidot Arrays

AbstractIn this work we performed a detailed numerical analysis on the static and dynamic properties of magnetic antidot arrays as a function of their geometry. In particular, we explored how by varying the shape of these antidot arrays from circular holes to stadium-shaped holes, we can effectively control the magnetic properties of the array. Using micromagnetic simulations we evidenced that coercivity is very sensitive to the shape of antidots, while the remanence is more robust to these changes. Furthermore, we studied the dynamic susceptibility of these systems, finding that it is possible to control both the position and the number of resonance peaks simply by changing the geometry of the holes. Thus, this work provides useful insights on the behavior of antidot arrays for different geometries, opening routes for the design and improvement of two-dimensional technologies.

Dynamic Properties of a Two-Dimensional Dense Electron Gas

2019 ◽  
Vol 128 (6) ◽  
pp. 932-938
Author(s):  
M. T. Keikimanova ◽  
G. I. Muratova ◽  
R. Zh. Nametkulova ◽  
M. N. Sarybekov ◽  
I. M. Tkachenko
Keyword(s):  
Dynamic Properties ◽  
Electron Gas ◽  
Two Dimensional
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