Chiral effects in the scattering of electrons by molecules

1996 ◽  
Vol 74 (11-12) ◽  
pp. 920-924 ◽  
Author(s):  
D. G. Thompson
Keyword(s):  
Physical Mechanism ◽  
Closed Shell ◽  
Spin Orbit ◽  
Polarized Electrons ◽  
Invariance Properties ◽  
Inversion Time ◽  
Consistent Manner ◽  
Chiral Effects ◽  
Set Up ◽  
Considerable Discussion

There are a number of scattering phenomena that depend on the "handedness" of the scattering system. In this paper we concentrate on the elastic scattering of polarized electrons by closed-shell molecules and consider mainly the property of electron optic dichroism. The effects can be fully analysed using the general invariance properties of the scattering matrix under spatial inversion, time reversal, and rotations. However, there is still considerable discussion about the physical mechanism causing the effects. Among the models proposed are two involving the spin–orbit interaction; in one the bound orbitals are perturbed, and in the other the incident electron. In this paper we show how these two approaches can be combined in a unified treatment. We set up the scattering equation including exchange and spin–orbit in a consistent manner and identify which terms contribute to the chiral effects.

scholarly journals Shot noise and spin-orbit coherent control of entangled and spin-polarized electrons

2005 ◽  
Vol 72 (23) ◽  
Author(s):  
J. Carlos Egues ◽  
Guido Burkard ◽  
D. S. Saraga ◽  
John Schliemann ◽  
Daniel Loss
Keyword(s):  
Shot Noise ◽  
Coherent Control ◽  
Spin Orbit ◽  
Polarized Electrons ◽  
Spin Polarized

Modeling the Systematic Uncertainty of Photogrammetric Tracking of Human Motion

1997 ◽  
Vol 119 (2) ◽  
pp. 358-361 ◽  
Author(s):  
S. B. Bortolami ◽  
P. O. Riley ◽  
D. E. Krebs
Keyword(s):  
Uncertainty Modeling ◽  
Human Locomotion ◽  
Human Motion ◽  
Tracking Data ◽  
Total Uncertainty ◽  
Rotation Matrices ◽  
Self Consistent ◽  
Consistent Manner ◽  
Set Up ◽  
Derivatives Of

We address bias errors of photogrammetric tracking of four SELSPOT-II® cameras using active marker photogrammetry in a 2 m × 2 m × 2 m viewing volume for human locomotion measurements. We present uncertainty modeling regarding the first stage of equipment set up, which provides the camera frame to global frame rotation matrices and the distances among cameras. We also characterize the uncertainty due to the camera distortions of the bare system as compared to published performances achieved with a camera correction procedure. The particular approach is to qualify performances of photogrammetric tracking during routine operation and to identify the nature and magnitude of the uncertainty due to equipment set up and camera distortions as part of the total uncertainty in a self-consistent manner. We found that uncertainty of the camera frame to global frame rotation matrices produced rotation of the image and uncorrected camera hardware uncertainty produced dilatation or compression of the image twice the magnitude of that seen with camera correction. However, camera resolution remains as an equally important factor limiting the accuracy of photogrammetric tracking that can not be easily reduced numerically. In conclusion, the analysis elucidates how uncertainty propagates to numerical derivatives of the tracking data and prepares the groundwork for future development.

Symmetry exploitation in closed-shell coupled-cluster theory with spin-orbit coupling

2011 ◽  
Vol 135 (3) ◽  
pp. 034115 ◽  
Author(s):  
Zheyan Tu ◽  
Dong-Dong Yang ◽  
Fan Wang ◽  
Jingwei Guo
Keyword(s):  
Closed Shell ◽  
Orbit Coupling ◽  
Coupled Cluster ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupled Cluster Theory ◽  
Cluster Theory

scholarly journals On the multi-fractal scaling properties of sea ice deformation

2019 ◽  
Author(s):  
Pierre Rampal ◽  
Véronique Dansereau ◽  
Einar Olason ◽  
Sylvain Bouillon ◽  
Timothy Williams ◽  
...  
Keyword(s):  
Sea Ice ◽  
Initial Conditions ◽  
Model Simulation ◽  
Winter Season ◽  
Scaling Properties ◽  
Scaling Invariance ◽  
Invariance Properties ◽  
Wide Range ◽  
Set Up ◽  
First Time

Abstract. In this paper, we evaluate the neXtSIM sea ice model with respect to the observed scaling invariance properties of sea ice deformation in the spatial and temporal domains. Using an Arctic set-up with realistic initial conditions, state-of-the-art atmospheric reanalysis forcing and geostrophic currents retrieved from satellite data, we show that the model is able to reproduce the observed properties of these scaling in both the spatial and temporal do- mains over a wide range of scales and, for the first time, their multi-fractality. The variability of these properties during the winter season are also captured by the model. We also show that the simulated scaling exhibit a space-time coupling, a suggested property of brittle deformation at geophysical scales. The ability to reproduce the multi-fractality of these scaling is crucial in the context of downscaling model simulation outputs to infer sea ice variables at the sub-grid scale, and also has implication in modeling the statistical properties of deformation-related quantities such as lead fractions, and heat and salt fluxes.

scholarly journals Dehydration-induced mechanical instabilities in active elastic spherical shells

2021 ◽  
Vol 477 (2254) ◽  
Author(s):  
M. Curatolo ◽  
G. Napoli ◽  
P. Nardinocchi ◽  
S. Turzi
Keyword(s):  
Analytical Model ◽  
Numerical Experiments ◽  
Water Concentration ◽  
Closed Shell ◽  
Natural World ◽  
Cavity Volume ◽  
Stress Diffusion ◽  
Elastic Instabilities ◽  
Simplifying Assumptions ◽  
Set Up

Active elastic instabilities are common phenomena in the natural world, where they have the character of sudden mechanical morphings. Frequently, the driving force of the instability mechanisms has a chemo-mechanical nature, which makes the instabilities very different from the standard elastic instabilities. In this paper, we describe and study the active elastic instability occurring in a swollen spherical closed shell, confining a water-filled cavity, during a dehydration process. We set up a few numerical experiments based on a stress-diffusion model to give an insight into the phenomenon. Then, we present a study that looks at the chemo-mechanical problem and, through a few simplifying assumptions, allows us to derive a semi-analytical model of the phenomenon. It takes into account both the stress state and the water concentration in the walls of the shell at the onset of the instability. Moreover, it considers the invariance of the cavity volume at the onset of instability, which is due to the impossibility of instantaneously changing the cavity volume filled with water. Eventually, it is shown that the semi-analytic model matches very well the outcomes of the numerical experiments far from the initial regime; the ranges of validity of the approximated analytical model are also discussed.

Closed-shell coupled-cluster theory with spin-orbit coupling

2008 ◽  
Vol 129 (6) ◽  
pp. 064113 ◽  
Author(s):  
Fan Wang ◽  
Jürgen Gauss ◽  
Christoph van Wüllen
Keyword(s):  
Closed Shell ◽  
Orbit Coupling ◽  
Coupled Cluster ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupled Cluster Theory ◽  
Cluster Theory
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