A Simple Approach to Compute Interatomic Force Constant for Mono and Diatomic Semiconductors

Cliff and Lorimer (1) have proposed a simple approach to thin foil x-ray analy sis based on the ratio of x-ray peak intensities. However, there are several experimental pitfalls which must be recognized in obtaining the desired x-ray intensities. Undesirable x-ray induced fluorescence of the specimen can result from various mechanisms and leads to x-ray intensities not characteristic of electron excitation and further results in incorrect intensity ratios.In measuring the x-ray intensity ratio for NiAl as a function of foil thickness, Zaluzec and Fraser (2) found the ratio was not constant for thicknesses where absorption could be neglected. They demonstrated that this effect originated from x-ray induced fluorescence by blocking the beam with lead foil. The primary x-rays arise in the illumination system and result in varying intensity ratios and a finite x-ray spectrum even when the specimen is not intercepting the electron beam, an ‘in-hole’ spectrum. We have developed a second technique for detecting x-ray induced fluorescence based on the magnitude of the ‘in-hole’ spectrum with different filament emission currents and condenser apertures.

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Complex Subject : Simple Approach

Contemporary Psychology ◽

10.1037/004370 ◽

2004 ◽

Vol 49 (4) ◽

pp. 401-403

Author(s):

Richard B. Makover

Keyword(s):

Simple Approach ◽

Complex Subject

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Effect of Inner and Outer Wheels Driving Force Control on Small Electric Vehicle

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.17.4.2020.02.0622 ◽

2020 ◽

Vol 17 (4) ◽

pp. 8246-8254

Author(s):

K. Shibazaki ◽

H. Nozaki

Keyword(s):

Control System ◽

Angular Velocity ◽

Electric Vehicle ◽

Force Constant ◽

Force Control ◽

Driving Force ◽

Vehicle Control ◽

Steering Angle ◽

Force Control System ◽

The Difference

In this study, in order to improve steering stability during turning, we devised an inner and outer wheel driving force control system that is based on the steering angle and steering angular velocity, and verified its effectiveness via running tests. In the driving force control system based on steering angle, the inner wheel driving force is weakened in proportion to the steering angle during a turn, and the difference in driving force is applied to the inner and outer wheels by strengthening the outer wheel driving force. In the driving force control (based on steering angular velocity), the value obtained by multiplying the driving force constant and the steering angular velocity, that differentiates the driver steering input during turning output as the driving force of the inner and outer wheels. By controlling the driving force of the inner and outer wheels, it reduces the maximum steering angle by 40 deg and it became possible to improve the cornering marginal performance and improve the steering stability at the J-turn. In the pylon slalom it reduces the maximum steering angle by 45 deg and it became possible to improve the responsiveness of the vehicle. Control by steering angle is effective during steady turning, while control by steering angular velocity is effective during sharp turning. The inner and outer wheel driving force control are expected to further improve steering stability.

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Bonded Force Constant Derivation of Lysine-Arginine Cross-linked Advanced Glycation End-Products

10.26434/chemrxiv.5891602.v2 ◽

2018 ◽

Author(s):

Anthony Nash ◽

Nora H de Leeuw ◽

Helen L Birch

Keyword(s):

Molecular Dynamics ◽

Force Constant ◽

Computational Study ◽

Force Constants ◽

Quantum Mechanical ◽

Advanced Glycation ◽

Partial Charges ◽

Cross Links ◽

Complete Set ◽

Dynamics Simulations

<div> <div> <div> <p>The computational study of advanced glycation end-product cross- links remains largely unexplored given the limited availability of bonded force constants and equilibrium values for molecular dynamics force fields. In this article, we present the bonded force constants, atomic partial charges and equilibrium values of the arginine-lysine cross-links DOGDIC, GODIC and MODIC. The Hessian was derived from a series of <i>ab initio</i> quantum mechanical electronic structure calculations and from which a complete set of force constant and equilibrium values were generated using our publicly available software, ForceGen. Short <i>in vacuo</i> molecular dynamics simulations were performed to validate their implementation against quantum mechanical frequency calculations. </p> </div> </div> </div>

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