Coupled vibrations of a varying length flexible cable transporter system with arbitrary axial velocity

2004 ◽  
Author(s):  
Yuhong Zhang ◽  
S. Agrawal
Keyword(s):  
Axial Velocity ◽  
Coupled Vibrations ◽  
Flexible Cable ◽  
Varying Length

A Lyapunov Controller for a Varying Length Flexible Cable System to Supress Transverse Vibration

2004 ◽  
Author(s):  
Yuhong Zhang ◽  
Sunil Agrawal
Keyword(s):  
Differential Equations ◽  
Transverse Vibration ◽  
Axial Velocity ◽  
Controller Design ◽  
Lyapunov Stability Theory ◽  
Lyapunov Theory ◽  
Governing Equations ◽  
Flexible Cable ◽  
Linear Partial Differential Equations ◽  
Lyapunov Controller

Modeling and controller design for a flexible cable transporter system, with arbitrarily varying cable length is presented using Hamilton’s principle and Lyapunov theory. The axial velocity of the system is assumed to be arbitrary in the model. This is different from existing literature where the axial velocity is assumed either constant or is prescribed. The governing equations are coupled non-linear partial differential equations (PDEs) and ordinary differential equations (ODEs), and boundary conditions. The interactions between the cables and the slider, pulleys, and motors are included in the model. Numerical solution of the governing equations is obtained using Galerkin’s method. Based on the Lyapunov stability theory, we propose boundary controllers and the control law for an actuator within the domain to suppress the transverse vibration of the cables, while achieving the slider goal. The proposed controllers dissipate the vibratory energy and guarantee asymptotic stability of the closed-loop system. Simulation results demonstrate the effectiveness of the proposed controllers.

Hierarchy of π-Stacking Determines the Conformational Preference of Bis-Squaraines

2020 ◽  
Author(s):  
Abhishek Singh ◽  
Reman K. Singh ◽  
G Naresh Patwari
Keyword(s):  
Hydrogen Bonding ◽  
Rational Design ◽  
Biological Molecules ◽  
Conformational Space ◽  
X Ray Crystallography ◽  
Simple Strategy ◽  
Induced Folding ◽  
Π Stacking ◽  
Varying Length ◽  
Dynamics Simulations

The rational design of conformationally controlled foldable modules can lead to a deeper insight into the conformational space of complex biological molecules where non-covalent interactions such as hydrogen bonding and π-stacking are known to play a pivotal role. Squaramides are known to have excellent hydrogen bonding capabilities and hence, are ideal molecules for designing foldable modules that can mimic the secondary structures of bio-molecules. The π-stacking induced folding of bis-squaraines tethered using aliphatic primary and secondary-diamine linkers of varying length is explored with a simple strategy of invoking small perturbations involving the length linkers and degree of substitution. Solution phase NMR investigations in combination with molecular dynamics simulations suggest that bis-squaraines predominantly exist as extended conformations. Structures elucidated by X-ray crystallography confirmed a variety of folded and extended secondary conformations including hairpin turns and 𝛽-sheets which are determined by the hierarchy of π-stacking relative to N–H···O hydrogen bonds.

Hierarchy of π-Stacking Determines the Conformational Preference of Bis-Squaraines

2020 ◽  
Author(s):  
Abhishek Singh ◽  
Reman K. Singh ◽  
G Naresh Patwari
Keyword(s):  
Hydrogen Bonding ◽  
Rational Design ◽  
Biological Molecules ◽  
Conformational Space ◽  
X Ray Crystallography ◽  
Simple Strategy ◽  
Induced Folding ◽  
Π Stacking ◽  
Varying Length ◽  
Dynamics Simulations

The rational design of conformationally controlled foldable modules can lead to a deeper insight into the conformational space of complex biological molecules where non-covalent interactions such as hydrogen bonding and π-stacking are known to play a pivotal role. Squaramides are known to have excellent hydrogen bonding capabilities and hence, are ideal molecules for designing foldable modules that can mimic the secondary structures of bio-molecules. The π-stacking induced folding of bis-squaraines tethered using aliphatic primary and secondary-diamine linkers of varying length is explored with a simple strategy of invoking small perturbations involving the length linkers and degree of substitution. Solution phase NMR investigations in combination with molecular dynamics simulations suggest that bis-squaraines predominantly exist as extended conformations. Structures elucidated by X-ray crystallography confirmed a variety of folded and extended secondary conformations including hairpin turns and 𝛽-sheets which are determined by the hierarchy of π-stacking relative to N–H···O hydrogen bonds.

Physical modeling and deformation simulation of flexible cable under the plane constraint

2017 ◽  
Vol 50 (4-6) ◽  
pp. 471-484
Author(s):  
Hongwang DU ◽  
Wei XIONG ◽  
Haitao WANG ◽  
Zuwen WANG
Keyword(s):  
Physical Modeling ◽  
Flexible Cable ◽  
Deformation Simulation

Аnticholinesterase and antioxidant activity of new binary conjugates of (с)-carbolines

2019 ◽  
Vol 484 (1) ◽  
pp. 104-108
Author(s):  
G. F. Makhaeva ◽  
E. F. Shevtsova ◽  
N. P. Boltneva ◽  
N. V. Kovaleva ◽  
E. V. Rudakova ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Antioxidant Activity ◽  
Anticholinesterase Activity ◽  
Amyloid Aggregation ◽  
Varying Length ◽  
Β Amyloid ◽  
New Compounds

This study presents the synthesis of binary tetrohydro-γ-carbolines with ditriazol spacers of varying length, which exhibit anticholinesterase and antioxidant activity, as compared to the original Dimebon prototype. Anticholinesterase activity suggests the potential ability of the new compounds to block β-amyloid aggregation induced by anticholinesterase, making them promising candidates for further research preparations for the treatment of Alzheimer's disease. Particular attention should be paid to the conjugate with an intertriazol hexamethylene spacer, which can be regarded as the leading compound in this series.

Axisymmetric flow near the critical point on the moving boundary

2010 ◽  
Vol 7 ◽  
pp. 182-190
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh. Nasibullaeva
Keyword(s):  
Fluid Flow ◽  
Finite Difference ◽  
Boundary Conditions ◽  
Numerical Solution ◽  
Axial Velocity ◽  
Moving Boundary ◽  
Axisymmetric Flow ◽  
Boundary Motion ◽  
Newton Raphson ◽  
Raphson Method

In this paper the investigation of the axisymmetric flow of a liquid with a boundary perpendicular to the flow is considered. Analytical equations are derived for the radial and axial velocity and pressure components of fluid flow in a pipe of finite length with a movable right boundary, and boundary conditions on the moving boundary are also defined. A numerical solution of the problem on a finite-difference grid by the iterative Newton-Raphson method for various velocities of the boundary motion is obtained.

Free Convective Mass Transfer at Isosceles Triangular Surfaces of Varying Inclination

2003 ◽  
Vol 68 (11) ◽  
pp. 2080-2092 ◽  
Author(s):  
Martin Keppert ◽  
Josef Krýsa ◽  
Anthony A. Wragg
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Mass Transfer Process ◽  
Sulfate Solution ◽  
Convective Mass Transfer ◽  
Varying Length ◽  
Inclined Surface ◽  
Vertical Case ◽  
Limiting Diffusion Current

The limiting diffusion current technique was used for investigation of free convective mass transfer at down-pointing up-facing isosceles triangular surfaces of varying length and inclination. As the mass transfer process, copper deposition from acidified copper(II) sulfate solution was used. It was found that the mass transfer rate increases with inclination from the vertical to the horizontal position and decreases with length of inclined surface. Correlation equations for 7 angles from 0 to 90° were found. The exponent in the ShL-RaL correlation ranged from 0.247 for the vertical case, indicating laminar flow, to 0.32 for inclinations of 60 to 90°, indicating mixed or turbulent flow. The general correlation ShL = 0.358(RaL sin θ)0.30 for the RaL sin θ range from 7 × 106 to 2 × 1011 and inclination range from 15 to 90° was obtained.

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