52 research outputs found

    How to scrutinise a Production Sharing Agreement: A guide for the oil and gas sector based on experience from the Caspian region

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    This guide discusses the provisions of a particular type of oil and gas contract, the Production Sharing Agreement (PSA). While the guide is aimed at a general civil society readership, it draws particularly on experience from Kazakhstan. The purpose of this guide is to give an accessible account of some key characteristics of PSAs, with a focus on revenue issues, and to suggest action points for civil society organisations involved with monitoring extractive industries. Indeed, in recent years the public in resource-rich states has become increasingly concerned about the management of extractive industry revenues

    Doppler confirmation of TESS planet candidate TOI1408.01: grazing transit and likely eccentric orbit

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    We report an independent Doppler confirmation of the TESS planet candidate orbiting an F-type main sequence star TOI-1408 located 140 pc away. We present a set of radial velocities obtained with a high-resolution fiber-optic spectrograph FFOREST mounted at the SAO RAS 6-m telescope (BTA-6). Our self-consistent analysis of these Doppler data and TESS photometry suggests a grazing transit such that the planet obscures its host star by only a portion of the visible disc. Because of this degeneracy, the radius of TOI-1408.01 appears ill-determined with lower limit about \sim1 RJup_{\rm Jup}, significantly larger than in the current TESS solution. We also derive the planet mass of 1.69±0.201.69\pm0.20~MJupM_{\rm Jup} and the orbital period 4.425\sim4.425 days, thus making this object a typical hot Jupiter, but with a significant orbital eccentricity of 0.259±0.0260.259\pm0.026. Our solution may suggest the planet is likely to experience a high tidal eccentricity migration at the stage of intense orbital rounding, or may indicate possible presence of other unseen companions in the system, yet to be detected.Comment: 5 pages, 3 figure

    Electronic properties and phase transitions in low-dimensional semiconductors

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    We present the first review of the current state of the literature on electronic properties and phase transitions in TlX and TlMX2 (M = Ga, In; X = Se, S, Te) compounds. These chalcogenides belong to a family of the low-dimensional semiconductors possessing chain or layered structure. They are of significant interest because of their highly anisotropic properties, semi- and photoconductivity, non-linear effects in their I-V characteristics (including a region of negative differential resistance), switching and memory effects, second harmonic optical generation, relaxor behavior and potential applications for optoelectronic devices. We review the crystal structure of TlX and TlMX2 compounds, their transport properties under ambient conditions, experimental and theoretical studies of the electronic structure, transport properties and semiconductor-metal phase transitions under high pressure, and sequences of temperature-induced structural phase transitions with intermediate incommensurate states. Electronic nature of the ferroelectric phase transitions in the above-mentioned compounds, as well as relaxor behavior, nanodomains and possible occurrence of quantum dots in doped and irradiated crystals is discussed.Comment: 70 pages, 38 figure

    Surface-Initiated Polymer Brushes in the Biomedical Field: Applications in Membrane Science, Biosensing, Cell Culture, Regenerative Medicine and Antibacterial Coatings

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    Non-ionic Thermoresponsive Polymers in Water

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