THEORY FOR THE ELECTRONIC SHELL STRUCTURE IN MESOSCOPIC SYSTEMS: SPHERES, DISCS, AND RINGS

1996 ◽  
Vol 03 (01) ◽  
pp. 293-297
Author(s):  
P. STAMPFLI ◽  
K.H. BENNEMANN ◽  
B. TATIEVSKI
Keyword(s):  
Shell Structure ◽  
Size Dependence ◽  
Numerical Solutions ◽  
Quantum Mechanical ◽  
Semiclassical Theory ◽  
Electronic Shell ◽  
Asymptotic Size ◽  
Quantum Mechanical Effects ◽  
Analytical Expressions ◽  
Good Agreement

The electronic shell structure resulting from the interference of closed orbital paths is determined for spheres, discs, and rings using the semiclassical theory of Balian and Bloch. The effect of finite surface potentials and magnetic fields is discussed. We obtain analytical expressions for the oscillating structure in the density of states, which are in good agreement with numerical solutions of the Schrödinger equation. These results can be applied to the electronic shell structure of metallic clusters, including the asymptotic size dependence of the structure in the ionization potential and the cohesive energy. Dimensional quantum-mechanical effects are examined.

Electronic shell structure in clusters as reflected in mass abundance spectra

1999 ◽  
Vol 79 (9) ◽  
pp. 1321-1342
Author(s):  
Svenbjo Rnholm, Jo Rnborggreen
Keyword(s):  
Shell Structure ◽  
Electronic Shell

Thermal Performance Analysis of a Rectangular Longitudinal Finned Solar Air Heater With Semicircular Absorber Plate

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Satyender Singh ◽  
Prashant Dhiman
Keyword(s):  
Thermal Performance ◽  
Numerical Solutions ◽  
Solar Air Heater ◽  
Duct Flow ◽  
Balance Equations ◽  
Absorber Plate ◽  
Ansys Fluent ◽  
Air Heater ◽  
Glass Cover ◽  
Good Agreement

Thermal performance of a single-pass single-glass cover solar air heater consisting of semicircular absorber plate finned with rectangular longitudinal fins is investigated. The analysis is carried out for different hydraulic diameters, which were obtained by varying the diameter of the duct from 0.3–0.5 m. One to five numbers of fins are considered. Reynolds number ranges from 1600–4300. Analytical solutions for energy balance equations of different elements and duct flow of the solar air heater are presented; results are compared with finite-volume methodology based numerical solutions obtained from ansys fluent commercial software, and a fairly good agreement is achieved. Moreover, analysis is extended to check the effect of double-glass cover and the recycle of the exiting air. Results revealed that the use of double-glass cover and recycle operation improves the thermal performance of solar air heater.

scholarly journals Experimental and Numerical Buckling Analyses of Laminated Composite Plates under Temperature Effects

2010 ◽  
Vol 19 (4) ◽  
pp. 096369351001900 ◽  
Author(s):  
Emin Ergun
Keyword(s):  
Composite Plate ◽  
Numerical Solutions ◽  
Laminated Composite ◽  
Composite Plates ◽  
Buckling Load ◽  
Fibre Reinforcement ◽  
Stacking Sequence ◽  
Laminated Composite Plates ◽  
Different Temperatures ◽  
Good Agreement

The aim of this study is to investigate, experimentally and numerically, the change of critical buckling load in composite plates with different ply numbers, orientation angles, stacking sequences and boundary conditions as a function of temperature. Buckling specimens have been removed from the composite plate with glass-fibre reinforcement at [0°]i and [45°]i (i= number of ply). First, the mechanical properties of the composite material were determined at different temperatures, and after that, buckling experiments were done for those temperatures. Then, numerical solutions were obtained by modelling the specimens used in the experiment in the Ansys10 finite elements package software. The experimental and numerical results are in very good agreement with each other. It was found that the values of the buckling load at [0°] on the composite plates are higher than those of other angles. Besides, symmetrical and anti-symmetrical conditions were examined to see the effect of the stacking sequence on buckling and only numerical solutions were obtained. It is seen that the buckling load reaches the highest value when it is symmetrical in the cross-ply stacking sequence and it is anti-symmetrical in the angle-ply stacking sequence.

scholarly journals Quantum resources for energy storage

2020 ◽  
Vol 230 ◽  
pp. 00003 ◽  
Author(s):  
Dario Ferraro ◽  
Michele Campisi ◽  
Gian Marcello Andolina ◽  
Vittorio Pellegrini ◽  
Marco Polini
Keyword(s):  
Energy Storage ◽  
Cavity Mode ◽  
Quantum Mechanical ◽  
Double Quantum ◽  
Level System ◽  
Close Proximity ◽  
Two Level Systems ◽  
Quantum Mechanical Effects ◽  
The One ◽  
Superradiant Phase

Recently the possibility to exploit quantum-mechanical effects to increase the performance of energy storage has raised a great interest. It consists of N two-level systems coupled to a single photonic mode in a cavity. We demonstrate the emergence of a quantum advantage in the charging power on this collective model (Dicke Quantum Battery) with respect to the one in which each two-level system is coupled to its own separate cavity mode (Rabi Quantum Battery). Moreover, we discuss the model of a Quantum Supercapacitor. This consists of two chains, one containing electrons and the other one holes, hosted by arrays of double quantum dots. The two chains are in close proximity and embedded in the same photonic cavity, in the same spirit of the Dicke model. We find the phase diagram of this model showing that, when transitioning from the ferro/antiferromagnetic to the superradiant phase, the quantum capacitance of the model is greatly enhanced.

A Compact Model for Spherical Rough Contacts

2004 ◽  
Author(s):  
M. Bahrami ◽  
M. M. Yovanovich ◽  
J. R. Culham
Keyword(s):  
Pressure Distribution ◽  
Entire Range ◽  
Present Model ◽  
Numerical Solutions ◽  
Contact Radius ◽  
Bulk Deformation ◽  
Dimensional Parameters ◽  
Maximum Contact ◽  
Good Agreement ◽  
Key Parameter

The contact of rough spheres is of high interest in many tribological, thermal, and electrical fundamental analyses. Implementing the existing models is complex and requires iterative numerical solutions. In this paper a new model is presented and a general pressure distribution is proposed that encompasses the entire range of spherical rough contacts including the Hertzian limit. It is shown that the non-dimensional maximum contact pressure is the key parameter that controls the solution. Compact expressions are proposed for calculating the pressure distribution, radius of the contact area, elastic bulk deformation, and the compliance as functions of the governing non-dimensional parameters. The present model shows the same trends as those of the Greenwood and Tripp model. Correlations proposed for the contact radius and the compliance are compared with experimental data collected by others and good agreement is observed.

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