Plasma oscillations in porous samples

The influence of the shape of a sample on the type of uniform dipole collective electrons oscillations is discussed. In samples of a bulk shape uniform bulk dipole oscillations cannot exist. They exist in samples of a thin slab shape only. However in essentially porous materials the electrostatic energy of the oscillation in a sample is considerably larger thus leading to stronger restoring force and higher frequency of the oscillation. When this frequency exceeds the Langmuir frequency, the oscillation becomes of a bulk type. .

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Uniform plasma oscillations in ellipsoid of conductive material

Facta universitatis - series Physics Chemistry and Technology ◽

10.2298/fupct0401035k ◽

2004 ◽

Vol 3 (1) ◽

pp. 35-39 ◽

Cited By ~ 2

Author(s):

Yuri Kornyushin

Keyword(s):

Surface Layer ◽

Thin Slab ◽

Plasma Oscillations ◽

Conductive Material ◽

Langmuir Oscillation ◽

Dipole Oscillation ◽

Uniform Plasma

The influence of the shape of a sample on the type of uniform dipole collective electrons oscillations is discussed. In samples of a bulk shape uniform bulk dipole oscillation (Langmuir oscillation) cannot exist. It exists in samples of a thin slab shape only. As uniform bulk dipole oscillations cannot penetrate ellipsoidal samples of conductive material they exist in the surface layer of a sample only (Mie oscillations). Frequencies of Mie oscillations are calculated for a sample of the shape of an arbitrary ellipsoid.

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Introduction to low frequency local plasmons in bulk extrinsic semiconductors

Facta universitatis - series Physics Chemistry and Technology ◽

10.2298/fupct0305253k ◽

2003 ◽

Vol 2 (5) ◽

pp. 253-258

Author(s):

Yuri Kornyushin

Keyword(s):

Ground State ◽

Low Frequency ◽

Charged Impurity ◽

Free Electrons ◽

Restoring Force ◽

Plasma Oscillations ◽

Impurity Atoms ◽

Dispersion Law ◽

First Excited State ◽

Conductivity Band

It is shown that restoring force acts on the electronic cloud of the outer electrons of a neutral or charged impurity atom when it is shifted relative to the inner charged core (or expanded). Because of this the dipole oscillations arise which influence considerably the dispersion law of the plasma oscillations in bulk extrinsic semiconductors. Assuming that only one transition of electron from the ground state to the first excited state is essential, the dispersion law is calculated. It is shown that the calculated dispersion law consists of two separate branches, one of them originates from the regular plasma oscillations of the free electrons of a conductivity band, and the other one stems from the local oscillations of the outer electrons bounded to the impurity atoms.

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Effect of energy filtering on micro-diffraction in the SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017075x ◽

1994 ◽

Vol 52 ◽

pp. 604-605

Author(s):

James F. Mancuso ◽

Leo A. Fama ◽

William B. Maxwell ◽

Jerry L. Lehman ◽

Hasso Weiland ◽

...

Keyword(s):

Detection Efficiency ◽

Ccd Camera ◽

High Gain ◽

Microchannel Plate ◽

Electrostatic Energy ◽

Energy Filtering ◽

Electron Channelling ◽

Low Energy Electrons ◽

Low Sensitivity ◽

Angular Field Of View

Micro-diffraction based crystallography is essential to the design and development of many classes of ‘crafted materials’. Although the scanning electron microscope can provide crystallographic information with high spatial resolution, its current utility is severely limited by the low sensitivity of existing diffraction techniques (ref: Dingley). Previously, Joy showed that energy filtering increased contrast and pattern visibility in electron channelling. This present paper discribes the effect of energy filtering on EBSP sensitivity and backscattered SEM imaging.The EBSP detector consisted of an electron energy filter, a microchannel plate detector, a phosphor screen, optical coupler, and a slow scan CCD camera. The electrostatic energy filter used in this experiment was constructed as a cone with 5 coaxial electrodes. The angular field-of-view of the filter was approximately 38°. The microchannel plate, which was the initial sensing component, had high gain and had 50% to 80% detection efficiency for the low energy electrons that passed through the retarding field filter.

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Porous materials from cellulose nanocrystal and mxene surfactants at the oil/water interface

10.1021/scimeetings.0c07366 ◽

2020 ◽

Author(s):

Bingqing qian ◽

Haiqiao Wang ◽

Dong Wang ◽

Hao-Bin Zhang ◽

Jessica Wu ◽

...

Keyword(s):

Porous Materials ◽

Cellulose Nanocrystal ◽

Water Interface ◽

Oil Water

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Porous materials: Magic foam

Nature China ◽

10.1038/nchina.2013.74 ◽

2013 ◽

Author(s):

Felix Cheung

Keyword(s):

Porous Materials

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ELECTROSTATIC ENERGY AND LATTICE VIBRATIONS IN THIN IONIC SLABS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19816100 ◽

1981 ◽

Vol 42 (C6) ◽

pp. C6-341-C6-343

Author(s):

G. Kanellis ◽

J. F. Morhange ◽

M. Balkanski

Keyword(s):

Electrostatic Energy ◽

Lattice Vibrations

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Numerical analysis of local heat flux and thin-slab solidification in a CSP funnel-type mold with electromagnetic braking

Metallurgical Research & Technology ◽

10.1051/metal/2020044 ◽

2020 ◽

Vol 117 (6) ◽

pp. 602

Author(s):

Heping Liu ◽

Jianjun Zhang ◽

Hongbiao Tao ◽

Hui Zhang

Keyword(s):

Heat Flux ◽

Casting Speed ◽

Shell Growth ◽

Local Heat ◽

Operating Conditions ◽

Thin Slab ◽

Wide Face ◽

Slab Width ◽

Steel Grades ◽

Local Heat Flux

In this article, based on the actual monitored temperature data from mold copper plate with a dense thermocouple layout and the measured magnetic flux density values in a CSP thin-slab mold, the local heat flux and thin-slab solidification features in the funnel-type mold with electromagnetic braking are analyzed. The differences of local heat flux, fluid flow and solidified shell growth features between two steel grades of Q235B with carbon content of 0.19%C and DC01 of 0.03%C under varying operation conditions are discussed. The results show the maximum transverse local heat flux is near the meniscus region of over 0.3 m away from the center of the wide face, which corresponds to the upper flow circulation and the large turbulent kinetic energy in a CSP funnel-type mold. The increased slab width and low casting speed can reduce the fluctuation of the transverse local heat flux near the meniscus. There is a decreased transverse local heat flux in the center of the wide face after the solidified shell is pulled through the transition zone from the funnel-curve to the parallel-cure zone. In order to achieve similar metallurgical effects, the braking strength should increase with the increase of casting speed and slab width. Using the strong EMBr field in a lower casting speed might reverse the desired effects. There exist some differences of solidified shell thinning features for different steel grades in the range of the funnel opening region under the measured operating conditions, which may affect the optimization of the casting process in a CSP caster.

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