Spin‐dependent force model of molecular liquids. III. Orbital and spin angular momenta degrees of freedom

1989 ◽  
Vol 91 (12) ◽  
pp. 7854-7860 ◽  
Author(s):  
J. Juanós i Timoneda ◽  
A. D. J. Haymet
Keyword(s):  
Degrees Of Freedom ◽  
Force Model ◽  
Molecular Liquids ◽  
Angular Momenta

scholarly journals Integrated structured light architectures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Randy Lemons ◽  
Wei Liu ◽  
Josef C. Frisch ◽  
Alan Fry ◽  
Joseph Robinson ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Temporal Distribution ◽  
Multiple Degrees Of Freedom ◽  
Beam Combination ◽  
Angular Momenta ◽  
Field Control ◽  
Topological States ◽  
Spatio Temporal ◽  
Temporal Field ◽  
Structural Versatility

AbstractThe structural versatility of light underpins an outstanding collection of optical phenomena where both geometrical and topological states of light can dictate how matter will respond or display. Light possesses multiple degrees of freedom such as amplitude, and linear, spin angular, and orbital angular momenta, but the ability to adaptively engineer the spatio-temporal distribution of all these characteristics is primarily curtailed by technologies used to impose any desired structure to light. We demonstrate a laser architecture based on coherent beam combination offering integrated spatio-temporal field control and programmability, thereby presenting unique opportunities for generating light by design to exploit its topology.

Spin dependent force model of molecular liquids: Theory and simple applications

1988 ◽  
Vol 88 (1) ◽  
pp. 342-350 ◽  
Author(s):  
A. D. J. Haymet ◽  
Marc R. Kramer ◽  
Christopher Marshall
Keyword(s):  
Force Model ◽  
Molecular Liquids

scholarly journals Realization of acoustic spin transport in metasurface waveguides

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Long ◽  
Danmei Zhang ◽  
Chenwen Yang ◽  
Jianmin Ge ◽  
Hong Chen ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Degrees Of Freedom ◽  
Transport Processes ◽  
Angular Momenta ◽  
Transverse Electromagnetic ◽  
Spin Texture ◽  
Momentum Coupling ◽  
Practical Implications ◽  
Spin Momentum

Abstract Spin angular momentum enables fundamental insights for topological matters, and practical implications for information devices. Exploiting the spin of carriers and waves is critical to achieving more controllable degrees of freedom and robust transport processes. Yet, due to the curl-free nature of longitudinal waves distinct from transverse electromagnetic waves, spin angular momenta of acoustic waves in solids and fluids have never been unveiled only until recently. Here, we demonstrate a metasurface waveguide for sound carrying non-zero acoustic spin with tight spin-momentum coupling, which can assist the suppression of backscattering when scatters fail to flip the acoustic spin. This is achieved by imposing a soft boundary of the π reflection phase, realized by comb-like metasurfaces. With the special-boundary-defined spin texture, the acoustic spin transports are experimentally manifested, such as the suppression of acoustic corner-scattering, the spin-selected acoustic router with spin-Hall-like effect, and the phase modulator with rotated acoustic spin.

scholarly journals Chaos phenomenon and stability analysis of RU-RPR parallel mechanism with clearance and friction

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774625 ◽  
Author(s):  
Yulei Hou ◽  
Yi Wang ◽  
Guoning Jing ◽  
Yunjiao Deng ◽  
Daxing Zeng ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Contact Force ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Force Model ◽  
Obvious Effect ◽  
Normal Contact ◽  
Rotational Degrees Of Freedom ◽  
The Stability ◽  
Baumgarte Stabilization

The chaos phenomenon often exists in the dynamics system of the mechanism with clearance and friction, which has obvious effect on the stability of the mechanism, then it is worthy of attention for identifying the relationship between the friction coefficient and the stability of the mechanism. Two rotational degrees of freedom decoupled parallel mechanism RU-RPR is taken as the research object. Considering the clearance existing in the revolute pair, Lankarani–Nikravesh contact force model is used to calculate the normal contact force, and the Coulomb friction force model is used to calculate the tangential contact force. The dynamics model is established using Newton–Euler equations, and the Baumgarte stabilization method is used to keep the stability of the numerical analysis. Then, the equations are solved using the fourth adaptive Runge–Kutta method, and the effect of the revolute pair’s clearance on the dynamic behavior is analyzed. Poincare mapping is plotted, and the bifurcation diagrams are analyzed with varying the friction coefficient corresponding to different values of clearance size. The research contents possess a certain theoretical guidance significance and practical application value on the analysis of the chaotic motion and its stability in the dynamics of the parallel mechanism.

scholarly journals On the evolution of a binary system with arbitrarily misaligned orbital and stellar angular momenta due to quasi-stationary tides

2020 ◽  
Vol 500 (3) ◽  
pp. 3335-3367
Author(s):  
P B Ivanov ◽  
J C B Papaloizou
Keyword(s):  
Energy Dissipation ◽  
Binary System ◽  
Coriolis Force ◽  
Degrees Of Freedom ◽  
Orbital Plane ◽  
Phenomenological Approach ◽  
Orbital Eccentricity ◽  
Tidal Effects ◽  
Radiative Processes ◽  
Angular Momenta

ABSTRACT We consider the evolution of a binary system interacting due to tidal effects without restriction on the orientation of the orbital, and where significant, spin angular momenta, and orbital eccentricity. We work in the low tidal forcing frequency regime in the equilibrium tide approximation. Internal degrees of freedom are fully taken into account for one component, the primary. In the case of the companion the spin angular momentum is assumed small enough to be neglected but internal energy dissipation is allowed for as this can be significant for orbital circularization in the case of planetary companions. We obtain a set of equations governing the evolution of the orbit resulting from tidal effects. These depend on the masses and radii of the binary components, the form and orientation of the orbit, and for each involved component, the spin rate, the Coriolis force, the normalized rate of energy dissipation associated with the equilibrium tide due to radiative processes and viscosity, and the classical apsidal motion constant, k2. These depend on stellar parameters with no need of additional assumptions or a phenomenological approach as has been invoked in the past. They can be used to determine the evolution of systems with initial significant misalignment of spin and orbital angular momenta as hypothesized for systems containing Hot Jupiters. The inclusion of the Coriolis force may lead to evolution of the inclination between orbital and spin angular momenta and precession of the orbital plane which may have observational consequences.

Trajectory Prediction of Moored Vessels With Reduced Station Keeping Capability due to Exceeded Anchor Load Limits

2019 ◽  
Author(s):  
Michał Josten
Keyword(s):  
Degrees Of Freedom ◽  
System Analysis ◽  
Equations Of Motion ◽  
Weather Conditions ◽  
Mooring Line ◽  
Force Model ◽  
Station Keeping ◽  
Design Environment ◽  
Trajectory Prediction ◽  
The Time Domain

Abstract This paper presents the development and application of an in-house manoeuvring method for the prediction of the track of a moored vessel in the case of a temporary or total loss of station keeping capability as a result of exceeded permissible anchor loads. The described method is implemented in the in-house ship design environment E4, which already contains a method for manoeuvring simulations. The equations of motion are solved for three degrees of freedom: surge, sway and yaw. Any effects due to dynamic heel are considered quasi-statically. The method is based on a force model with components for environmental and body forces as well as propeller, rudder and steering forces for dynamic positioning applications. For the purpose of mooring system analysis an additional force component for the mooring line loads is introduced by using load-deflection curves. These curves can be calculated within E4 or imported from other sources. The resulting method allows detailed response calculations in the time-domain and can be used in various applications due to its great computational efficiency. In the presented paper the method is used for the analysis of a marine casualty due to harsh weather conditions.

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