MULTIRESONANCE AND ENHANCED SYNCHRONIZATION IN STOCHASTICALLY COUPLED RATCHETS

We investigate the dynamics and synchronization of two inertia ratchets interacting indirectly through a stochastic dynamical environment. We examine resonant oscillations in their synchronous and asynchronous modes; and we determine the effects of the interaction with the environment on the system's response and synchronization. We show the occurrence of noise-induced multiresonance and noise-enhanced synchronization emerging from the ratchets' interaction with the noisy environment. The simultaneous quenching of the chaotic regimes, and the domain of gain parameters for efficient control, are identified. It is shown that optimal transport can be achieved, implying that an inertia ratchet can take advantage of its noisy environment to enhance its rich dynamical and transport properties.

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Novel Composite Membranes Based on Chitosan Copolymers with Polyacrylonitrile and Polystyrene: Physicochemical Properties and Application for Pervaporation Dehydration of Tetrahydrofuran

Membranes ◽

10.3390/membranes9030038 ◽

2019 ◽

Vol 9 (3) ◽

pp. 38 ◽

Cited By ~ 7

Author(s):

Ksenia Otvagina ◽

Anastasia Penkova ◽

Maria Dmitrenko ◽

Anna Kuzminova ◽

Tatyana Sazanova ◽

...

Keyword(s):

Transport Properties ◽

Optimal Transport ◽

Mechanical Stability ◽

Evolved Gas Analysis ◽

Composite Membranes ◽

Gas Analysis ◽

Vinyl Monomers ◽

Porous Support ◽

Selective Layer ◽

Force Microscopy

Pervaporation has been applied for tetrahydrofuran (THF) dehydration with novel composite membranes advanced by a thin selective layer composed of chitosan (CS) modified by copolymerization with vinyl monomers, acrylonitrile (AN) and styrene, in order to improve the chemical and mechanical stability of CS-based membranes. Composite membranes were developed by depositing a thin selective layer composed of CS copolymers onto a commercially-available porous support based on aromatic polysulfonamide (UPM-20®). The topography and morphology of the obtained materials were studied by atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). Thermal properties and stability were determined by coupled evolved gas analysis (EGA-MS). Transport properties were estimated in pervaporation dehydration of THF. The effect of operating parameters for the pervaporation dehydration of THF such as feed compositions and temperatures (295, 308 and 323 K) was evaluated. It was shown that CS modification with different vinyl monomers led to a difference in physical and transport properties. The composite membrane with the thin selective layer based on CS-PAN copolymer demonstrated optimal transport properties and exhibited the highest water content in the permeate with a reasonably high permeation flux.

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Structural inhomogeneities observed inYBa2Cu3O7−δcrystals with optimal transport properties

Physical Review B ◽

10.1103/physrevb.56.2860 ◽

1997 ◽

Vol 56 (5) ◽

pp. 2860-2870 ◽

Cited By ~ 19

Author(s):

V. M. Browning ◽

E. F. Skelton ◽

M. S. Osofsky ◽

S. B. Qadri ◽

J. Z. Hu ◽

...

Keyword(s):

Transport Properties ◽

Optimal Transport ◽

Structural Inhomogeneities

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Novel Pervaporation Membranes Based on Biopolymer Sodium Alginate Modified by FeBTC for Isopropanol Dehydration

Sustainability ◽

10.3390/su13116092 ◽

2021 ◽

Vol 13 (11) ◽

pp. 6092

Author(s):

Anna Kuzminova ◽

Mariia Dmitrenko ◽

Anton Mazur ◽

Sergey Ermakov ◽

Anastasia Penkova

Keyword(s):

Citric Acid ◽

Transport Properties ◽

Sodium Alginate ◽

Optimal Transport ◽

Metal Organic Framework ◽

Modern Society ◽

Ease Of Use ◽

Spectroscopic Techniques ◽

Environmental Friendliness ◽

Isopropanol Dehydration

Modern society strives for the development of sustainable processes that are aimed at meeting human needs while preserving the environment. Membrane technologies satisfy all the principles of sustainability due to their advantages, such as cost-effectiveness, environmental friendliness, absence of additional reagents and ease of use compared to traditional separation methods. In the present work, novel green membranes based on sodium alginate (SA) modified by a FeBTC metal–organic framework were developed for isopropanol dehydration using a membrane process, pervaporation. Two kinds of SA-FeBTC membranes were developed: (1) untreated membranes and (2) cross-linked membranes with citric acid or phosphoric acid. The structural and physicochemical properties of the developed SA-FeBTC membranes were studied by spectroscopic techniques (FTIR and NMR), microscopic methods (SEM and AFM), thermogravimetric analysis and swelling experiments. The transport properties of developed SA-FeBTC membranes were studied in the pervaporation of water–isopropanol mixtures. Based on membrane transport properties, 15 wt % FeBTC was demonstrated to be the optimal content of the modifier in the SA matrix for the membrane performance. A membrane based on SA modified by 15 wt % FeBTC and cross-linked with citric acid possessed optimal transport properties for the pervaporation of the water–isopropanol mixture (12–100 wt % water): 174–1584 g/(m2 h) permeation flux and 99.99 wt % water content in the permeate.

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Spectroscopic Diagnostics of Tokamaks

International Astronomical Union Colloquium ◽

10.1017/s0252921100107638 ◽

1988 ◽

Vol 102 ◽

pp. 165-174

Author(s):

C. de Michelis

Keyword(s):

Transport Properties ◽

Power Losses ◽

Spectroscopic Diagnostics ◽

Important Concern

AbstractImpurities being an important concern in tokamaks, spectroscopy plays a key role in their understanding. Techniques for the evaluation of concentrations, power losses and transport properties are surveyed, and a few developments are outlined.

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Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088816 ◽

1991 ◽

Vol 49 ◽

pp. 900-901 ◽

Cited By ~ 1

Author(s):

Alain Claverie ◽

Zuzanna Liliental-Weber

Keyword(s):

Transport Properties ◽

Layer Thickness ◽

Growth Temperature ◽

Low Temperatures ◽

Lattice Parameter ◽

Crystalline Quality ◽

Insulating Properties ◽

Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

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