A study of doping influences on transmission of large-diameter gallium antimonide substrates for long-wave (LWIR) to very long wavelength (VLWIR) infra-red applications

ABSTRACTThe interface between Hg1-xCdxTe(0 ≦ x ≦ 1) and Hg1-yCdyTe(0 ≦ y ≦ 1) epitaxial layers of different composition (x ≠ y) is unstable with regard to the intermixing of the Hg and Cd cations within the Group II sublattice. This phenomenon may give rise to long-term stability problems in HgTe-(Hg,Cd)Te superlattices and composition grading between (Hg,Cd)Te absorber layers and CdTe buffer or passivation layers in epitaxial infra red detectors. In this paper, a novel approach to the inhibition of interdiffusion in these systems is discussed. This involves the growth of an intervening ZnTe barrier layer at the heterointerface between two (Hg,Cd)Te layers. Initial results are presented which indicate the effectiveness of this technique in reducing interdiffusion in an experimental heterostructure grown by MOVPE. Some possible applications in a variety of HgTe-based long wavelength devices are discussed.

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The Abundances of Cobalt and Nickel in the Atmosphere of 78 Vir (A2p SrCrEu)

Research Notes of the AAS ◽

10.3847/2515-5172/ac48f0 ◽

2022 ◽

Vol 6 (1) ◽

pp. 9

Author(s):

Richard Monier

Keyword(s):

Convincing Evidence ◽

Ultraviolet Spectrum ◽

Rotational Period ◽

Solar Abundance ◽

Long Wavelength ◽

Chemically Peculiar ◽

Long Wave ◽

Cobalt And Nickel

Abstract Cobalt and nickel abundances are rarely available for normal and Chemically Peculiar A stars because the strongest transitions of Co ii and Ni ii fall in the mid-UV. The abundances of cobalt and nickel are derived for 78 Vir using a mean mid-ultraviolet spectrum constructed by coadding 10 spectra collected with the Long Wave Prime and Long wavelength Redundant cameras over the 18 yr of the IUE mission. The strong transitions of Co ii at 2286.16 Å, 2307.86 Å, 2324.32 Å and 2580.33 Å and that of Ni ii et 2287.09 Å are present and more or less affected by blends. The least blended, λ 2286.16 Å, yields a mean overabundance of cobalt of 5 times the solar abundance, the Ni ii line at 2287.09 Å yields a 3 times solar overabundance. There is no convincing evidence that these lines varied in the spectra analyzed. The rotational period of 78 Vir estimated from its recent TESS lightcurve is 3.723 ± 0.055 days.

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Beyond oxygen in-vivo long-wavelength near infra-red spectroscopy for hypoxia assessment

10.1117/12.2615210 ◽

2021 ◽

Author(s):

Shree Krishnamoorthy ◽

Ray Burke ◽

Fergus McCarthy ◽

Stefan Andersson-Engels

Keyword(s):

Long Wavelength ◽

Infra Red

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Long Wave-Length Buckling of Periodic Open-Cell Foams Subjected to Uniaxial Compression

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.345-346.81 ◽

2007 ◽

Vol 345-346 ◽

pp. 81-84

Author(s):

Dai Okumura ◽

Atsushi Okada ◽

Nobutada Ohno

Keyword(s):

Finite Element ◽

Uniaxial Compression ◽

Wave Length ◽

Elastic Buckling ◽

Element Analysis ◽

Open Cell ◽

Long Wavelength ◽

Onset Condition ◽

Long Wave ◽

Open Cell Foams

In this study, the elastic buckling strength of cubic open-cell foams subjected to uniaxial compression is investigated using the homogenization framework developed by the present authors (Ohno et al., JMPS 2002; Okumura et al., JMPS 2004). First of all, based on the framework, the microscopic bifurcation and macroscopic instability of cubic open-cell foams are numerically analyzed by performing finite element analysis. It is thus shown that long wavelength buckling is the primary mode and occurs just after the onset of macroscopic instability. Then, a solution for predicting the stress of long wavelength buckling is analytically derived from the onset condition of macroscopic instability. The validity of this analytical solution is demonstrated by the finite element results.

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Practical infra-red illumination and observation techniques for wildlife studies using ICI-962 perspex

Australian Mammalogy ◽

10.1071/am03201 ◽

2003 ◽

Vol 25 (2) ◽

pp. 201 ◽

Cited By ~ 3

Author(s):

C Marks ◽

F Busana ◽

F Gigliotti ◽

M Lindeman

Keyword(s):

Uv Light ◽

Ultra Violet ◽

Ir Radiation ◽

Long Wavelength ◽

Non Invasive ◽

Radiation Sources ◽

Infra Red ◽

Invaluable Tool ◽

Free Ranging ◽

Wavelength Light

MAMMALS do not normally visually perceive infrared (IR) or ultra-violet (UV) light that exists on either side of the visual spectrum from 390 to 760 nanometers (nm) (Wolken 1975). There is no evidence to suggest that nocturnal mammals have become more sensitive to long wavelength light as an adaptive response (Lythgoe 1979), although some reptiles can sense longer wavelength, thermal IR radiation (Barrett et al. 1970). Because it is not perceived, and is unlikely to affect animal behaviour, IR observation can be an invaluable tool for wildlife researchers. This paper describes the construction and use of simple IR radiation sources that can be used for non-invasive behavioural observations of captive and free-ranging mammals.

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Molded, wafer level optics for long wave infra-red applications

10.1117/12.2223872 ◽

2016 ◽

Author(s):

John Franks

Keyword(s):

Wafer Level ◽

Long Wave ◽

Infra Red

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Iceberg Detection in Low Visibility Conditions via Infra-Red Sensors: Processing and Modelling of Field Data

Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology ◽

10.1115/omae2017-61018 ◽

2017 ◽

Author(s):

Grégory Bouquet ◽

Helene Schulerud ◽

Francesco Scibilia

Keyword(s):

Optical Properties ◽

Numerical Modelling ◽

Field Data ◽

Radiation Transfer ◽

Short Wave ◽

Long Wave ◽

Infra Red ◽

Low Visibility ◽

Imaging Sensors ◽

Modelling Study

This article deals with Short Wave Infra-Red (SWIR) and Long Wave Infra-Red (LWIR) imaging sensors for detecting icebergs in harsh metocean conditions. Field data acquired during the Statoil Offshore Newfoundland Research Expedition 2015 (ONRE15) is analyzed. The analysis is supported by a numerical modelling study which aims at simulating the optical properties of ice and water combined with the radiation transfer in the Infra Red.

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Infra-red Radiation and Nasal Obstruction

Journal of Hygiene ◽

10.1017/s0022172400032204 ◽

1935 ◽

Vol 35 (2) ◽

pp. 185-198 ◽

Cited By ~ 15

Author(s):

H. A. E. van Dishoeck

Keyword(s):

Nasal Obstruction ◽

Short Wave ◽

Nasal Passage ◽

Surface Cooling ◽

Local Overheating ◽

Long Wave ◽

Infra Red ◽

The Hill ◽

Red Radiation ◽

Selection Of

For the investigation of the Hill phenomenon, viz. the antagonism of short-and long-wave infra-red radiation in their influence on nasal obstruction, the commonly used rhinomanometric technique is not well suited. In this paper a new procedure is described, in which an air current is blown through the nose. In this way the nasal passability may be estimated, independent of respiratory movements. It proved to be desirable to make a selection of suitable experimental subjects with the aid of adrenaline and histamine tests; only those persons in which the opening by adrenaline and the narrowing by histamine sprays were clearly demonstrable were chosen.Long-wave infra-red rays constantly caused nasal obstruction.The shorter waves were much weaker in their shutting effect, and also decreased the narrowing of the nose when they were given in combination with the long-wave rays of an electric fire.A nasal passage closed by long-wave infra-red radiation may be partly opened by the short-wave rays; the possibility of surface cooling being the opening factor was excluded.Artificial cooling of the skin has a very marked opening influence.It is suggested that nose-opening and nose-shutting are correlated with cooling and heating of the Malpighian layer. Long infra-red rays will be completely absorbed in the layer and cause capillary stasis with local overheating. The shorter waves for the greater part penetrate more deeply; the skin reacts by an active hyperaemia, which, by relatively cooling the overheated Malpighian layer, has the same effect as a cooling from without.

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On the stability of nonlinear waves coexisting with plasma beams

Journal of Plasma Physics ◽

10.1017/s0022377800025952 ◽

1975 ◽

Vol 13 (1) ◽

pp. 173-187 ◽

Cited By ~ 7

Author(s):

E. Infeld ◽

G. Rowlands

Keyword(s):

Nonlinear Wave ◽

Growth Rates ◽

Three Dimensional ◽

Stationary Waves ◽

One Dimensional ◽

Long Wavelength ◽

Long Wave ◽

Set Up ◽

The Stability ◽

The One

In this paper we consider the stability of one-dimensional stationary waves set up by two counter-streaming beams of electrons in a background of stationary ions. The perturbations considered are long-wave in a direction perpendicular to the wave. The presence of a uniform magnetic field in the direction of the wave and the effect of a perpendicular pressure are taken into account. In the long-wavelength limit growth rates are diminished by the nonlinear wave. When the amplitude of this wave tends to its maximum value, the growth rates tend to zero. Thus the wave has a stabilizing effect for long-wave perturbations. Three- dimensional effects lead to additional instabilities which are also quenched by the nonlinear wave, but not as fast as the one-dimensional calculation indicates.

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