Optical and structural properties of the GaAs heterostructures grown using AlGaAs superlattice buffer layer on compliant Si(100) substrates with the preformed porous-Si (por-Si) layer

360 nm and 700 nm thick GaAs layers were grown by MO MOCVD growth technique directly on compliant Si (100) substrate and on supper-lattice (SL) AlGaAs buffer layer. The XRD study revealed better structural quality for the sample grown on SL / por-Si buffer. AFM study revealed a smoother sample surface with blocks of more regular rectangular shape and larger size as well. Photoluminescence spectra of the samples revealed an energy shift of PL maximum intensity for both samples. Sample grown on SL buffer also showed higher PL intensity corresponding to better crystalline perfection

Thermography of flame during diesel fuel combustion with steam gasification

The paper represents a study concerning the combustion of liquid hydrocarbon fuel in a perspective burner device with the controlled forced supply of overheated steam into the combustion zone, using diesel fuel. The thermal imaging measurements are conducted for the outer flame of the burner device in the wide range of regime parameters (flow rate and temperature of steam). A thermal imaging camera (FLIR, JADE J530SB) is used in the experiments. The effective emissivity coefficient of flame is obtained versus the flow rate of steam supplied. The steam parameters are found to influence on the temperature in the outer flame of the burner device

Porous nanostructured InP: technology, properties, application

We prepared porous InP (100) substrates with a nanostructured surface relief on which InP epitaxial films were grown. The structure, morphological, and photoluminescence properties of nanostructured substrates and InP epilayers grown on them were studied. These InP epilayers grown on the porous and standard InP substrates were used to make microwave diodes. We showed the advantages of the diodes made on the porous substrates (over those made on the standard ones) caused by higher structural perfection of the InP epilayers grown on the porous substrates

Vibration-induced phenomena in bulk granular materials

Vibration is one of the mechanisms affecting bulk granular materials behaviour in transportation and material separation efficiency in pharmaceutical, chemical, food, mineral processing and other industries. Understanding fundamentals of vibration and their influence on bulk materials handling is gaining an increasing importance in the economies of scale. However, at present there appears to be no accurate and sufficient description of various phenomena observed in a granular material affected by vibration. This paper presents a concise review of physical phenomena observed in bulk granular materials affected by vibration, taken here as mechanical oscillations of relatively low amplitude and relatively high frequency. This includes three main characteristic regimes of vibration defined as vibro-fluidisation, vibro-compaction and vibro-boiling. The analysis of other factors influencing bulk granular material behaviour under vibration including air resistance, wave effects and particle oscillations decay are also given. A new characteristic regime of vibration is introduced, defined as vibro-hovering. Description of main characteristic vibration-induced bulk granular material states combined with the analysis of other contributing factors result in a more complete classification of vibration phenomena and an improved understanding of vibration-induced bulk material behaviour. Analytical conclusions are supported by the results of experimental studies, with significant potential for improvement in material separation efficiency indicated. Prerequisite vibrational parameters for effective bulk granular material flow promotion are discussed with a specific focus on physical separation processes and optimum ranges of vibrational parameters for separation and flow promotion of dry particulate matter are recommended

Thermography of flame during diesel fuel combustion with steam gasification

The paper represents a study concerning the combustion of liquid hydrocarbon fuel in a perspective burner device with the controlled forced supply of overheated steam into the combustion zone, using diesel fuel. The thermal imaging measurements are conducted for the outer flame of the burner device in the wide range of regime parameters (flow rate and temperature of steam). A thermal imaging camera (FLIR, JADE J530SB) is used in the experiments. The effective emissivity coefficient of flame is obtained versus the flow rate of steam supplied. The steam parameters are found to influence on the temperature in the outer flame of the burner device