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Chapter and Conference Paper
The nucleation structure for cracks in AlGaN epitaxial layers
When an epitaxial layer is under tensile strain due to lattice mismatch, cracks are expected to form above a critical thickness. In the case of Group III nitrides grown on the sapphire (0001) plane, the epitax...
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Chapter
The Stark Effect and Electron-Hole Wavefunctions in InAs-GaAs Self-Assembled Quantum Dots
New information on the electron-hole wavefunctions in InAs-GaAs self-assembled quantum dots is obtained from study of the quantum confined Stark effect. From the sign of asymmetry observed in the Stark effect,...
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Chapter
Intersubband Electroluminescence from GaAs/AIGaAs Triple Barrier and Quantum Cascade Structures
This paper reports: (1) the first observation of intersubband electroluminescence from a single period resonant tunnelling structure; and (2) the observation of intersubband electroluminescence from GaAs/AlGaAs-b...
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Chapter
Close Binary Stars (Étoiles Doubles Serrées)
The pervasive connection of Close Binary Stars (CBS) with essentially every fundamental field of astronomy and astrophysics has required a huge number of papers on many topics to be considered for this report....
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Chapter
Identification of Tunneling Mechanisms through GaAs/AlAs/GaAs Single Barrier Structires
We have identified the Γ-X and X-Γ intervalley tunneling mechanisms in GaAs/AlAs/GaAs single barrier p-i-n structures by employing electroluminescence and transfort techniques. We show that the Γ-X-Γ tunneling...
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Chapter
Magnetic and Electric Field Effects in Semiconductor Quantum Microcavity Structures
The effects of magnetic and electric field on the vacuum Rabi exciton-photon coupling in semiconductor quantum microcavity structures are presented. A number of phenomena are described including marked increas...
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Chapter
Preservation of cosmetics and toiletries
With the manufacture of cosmetics and toiletries on an industrial scale it became from the commercial point of view very important to maintain the integrity of the products released for sale. Manufacturers, th...
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Chapter
Resonant Tunnelling via the Bound States of Shallow Donors
We have performed a systematic study of GaAs/(AlGa)As resonant tunnelling diodes in which the quantum well is intentionally δ-doped with Si donors. By comparing the I(V) of such devices with control samples we...
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Chapter
Excited State Populations of the Quantum Wells of Double Barrier Resonant Tunneling Structures
The observation of electroluminescence recombination from electrons in both ground (El) and excited states (E2) of the quantum wells of double barrier resonant tunneling structures is reported. Analysis of the...
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Chapter and Conference Paper
Magnetotunnelling Spectroscopy to Measure the Electron and Hole ε(k) Dispersion Curves in the Quantum Well of Resonant Tunnelling Structures
We investigate the effect of a large magnetic field, B, applied parallel to the plane of the barriers on the resonant I(V) currents of n- and p-type double barrier structures. The shifts in the electron resona...
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Chapter
Pressure Dependence of Negative Differential Resistance in AlGaAs/GaAs Double Barrier Resonant Tunnelling Devices up to 20 Kbar
We have investigated the pressure dependence of Negative Differential Resistance (NDR) features observed in the DC current-voltage (I-V) characteristics of AlxGa1-xAs/GaAs Double Barrier Resonant Tunnelling Devic...
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Chapter and Conference Paper
Resonant Tunnelling Devices in a Quantising Magnetic Field
High magnetic fields, applied either parallel or perpendicular to the barriers, are extremely useful for investigating the electrical properties of resonant tunnelling structures [1–11]. By considering the cur...
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Chapter and Conference Paper
Magnetic Field Studies of Resonant and Non-resonant Tunnelling in n-(AlGa)As/GaAs Double Barrier Structures
The electrical properties of a series of double barrier tunnelling devices with well widths between 5 and 60 nm are investigated. It is shown that the bistability effect in the current-voltage characteristics ...
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Chapter and Conference Paper
Resonant Magnetotransport in Short (0.25 – 9 μm) n+nn+ GaAs Structures
Magnetophonon resonance in thin (0.25 – 9 μm) n+nn+ GaAs structures is used to study quasi-elastic inter-Landau level scattering which is induced in the high electric fields (up to 20 kV/cm) achievable in structu...
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Chapter
Primary production in the Amazonian aquatic ecosystem
The incomparable beauty of the energy/biomass exchange has its finest expression in the lakes of the Central Amazon. Blackwater, whitewater and clearwater rivers and streams flood the myriad ria and várzea lakes ...
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Chapter
Microbiology of Amazonian waters
The relation between river and lake in the Central Amazon is one that reflects evolutionary adaptation to the environment. Down through the millenia, a grand design has evolved. This design, or structure, has ...
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Chapter and Conference Paper
Close Binary Stars
Commission 42 convened for two business meetings and two scientific sessions. In the following, the minutes of the business meetings and a summary of the scientific meetings are presented, with the abstracts o...
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Chapter
Classification of Early Type Stars on the Dominion Astrophysical Observatory Photometric System
A classification method has been developed for early—type stars observed on the Dominion Astrophysical Observatory photometric system. Two reddening—independent parameters, Q(35) and Q(38), are used. Q(35) is a m...
