4,202 research outputs found

    A TDM synchronization system for multiple access satellite communication

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    Time Division Multiple Access /TDMA/ system for satellite communication with ground station syste

    Electromagnetic field angular momentum in condensed matter systems

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    Various electromagnetic systems can carry an angular momentum in their {\bf E} and {\bf B} fields. The electromagnetic field angular momentum (EMAM) of these systems can combine with the spin angular momentum to give composite fermions or composite bosons. In this paper we examine the possiblity that an EMAM could provide an explanation of the fractional quantum Hall effect (FQHE) which is complimentary to the Chern-Simons explanation. We also examine a toy model of a non-BCS superconductor (e.g. high TcT_c superconductors) in terms of an EMAM. The models presented give a common, simple picture of these two systems in terms of an EMAM. The presence of an EMAM in these systems might be tested through the observation of the decay modes of a charged, spin zero unstable particle inside one of these systems.Comment: 17 pages, no figures, to be published in Phys. Rev.

    A design of experiments approach for the rapid formulation of a chemically defined medium for metabolic profiling of industrially important microbes

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    This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: All relevant data are within the manuscript and its Supporting Information files.Geobacillus thermoglucosidans DSM2542 is an industrially important microbe, however the complex nutritional requirements of Geobacilli confound metabolic engineering efforts. Previous studies have utilised semi-defined media recipes that contain complex, undefined, biologically derived nutrients which have unknown ingredients that cannot be quantified during metabolic profiling. This study used design of experiments to investigate how individual nutrients and interactions between these nutrients contribute to growth. A mathematically derived defined medium has been formulated that has been shown to robustly support growth of G. thermoglucosidans in two different environmental conditions (96-well plate and shake flask) and with a variety of lignocellulose-based carbohydrates. This enabled the catabolism of industrially relevant carbohydrates to be investigated.Shell Global Solutions BVUniversity of Exete

    Cyclotron resonance in the layered perovskite superconductor Sr2RuO4

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    We report a detailed study of the magnetic-field-orientation dependence of the millimetre-wave magnetoconductivity of the superconductor Sr2RuO4 We find two harmonic series of cyclotron resonances. We assign the first, corresponding to a quasiparticle mass of 4.29±0.05me4.29 \pm 0.05 m_{\rm e}, where mem_{\rm e} is the free-electron mass, to the β\beta Fermi-surface section. We assign the second series, which contains only odd harmonics, to cyclotron resonance of the γ\gamma Fermi-surface section, yielding a quasiparticle mass of 12.35±0.20me12.35 \pm 0.20 m_{\rm e}. A third, single cyclotron resonance, corresponding to a quasiparticle mass of 5.60±0.03me5.60 \pm 0.03 m_{\rm e}, is attributed to the α\alpha Fermi-surface section. In addition, we find a very strong absorption mode in the presence of a magnetic field component parallel to the quasi-two-dimensional planes of the sample. Its dependence on the orientation of the magnetic field cannot be described in the context of conventional cyclotron resonance, and the origin of this mode is not yet clear.Comment: Submitted to J. Phys. Cond. Ma
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