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Stars provide an enormous gain for interstellar communications at their gravitational focus, perhaps as part of an interstellar network. If the Sun is part of such a network, there should be probes at the gravitational foci of nearby stars. If there are probes within the solar system connected to such a network, we might detect them by intercepting transmissions from relays at these foci. Here, we demonstrate a search across a wide bandwidth for interstellar communication relays beyond the Sun's innermost gravitational focus at 550 AU using the Green Bank Telescope (GBT) and Breakthrough Listen (BL) backend. As a first target, we searched for a relay at the focus of the Alpha Centauri AB system while correcting for the parallax due to Earth's orbit around the Sun. We searched for radio signals directed at the inner solar system from such a source in the L and S bands. Our analysis, utilizing the turboSETI software developed by BL, did not detect any signal indicative of a non-human-made artificial origin. Further analysis excluded false negatives and signals from the nearby target HD 13908. Assuming a conservative gain of 10^3 in L-band and roughly 4 times that in S-band, a ~1 meter directed transmitter would be detectable by our search above 7 W at 550 AU or 23 W at 1000 AU in L-band, and above 2 W at 550 AU or 7 W at 1000 AU in S-band. Finally, we discuss the application of this method to other frequencies and targets., Comment: 20 pages, 9 figures, accepted to AJ

The Breagh tight gas field is located in the Southern North Sea and currently delivers gas from 8 wells via a normally unmanned installation (NUI) to a processing facility in Teesside. In the coming years there is scope to install a second NUI and drill an additional nine wells. Platform and onshore sensors deliver high-frequency pressure, temperature, and flow rate data for each well, in addition to key facility data. The high volume and variable quality of this high frequency and real time data directly affects the way in which daily engineering activities are performed. Originally, the engineering team used conventional methods of data handling, storage and management, including manual manipulation, and spreadsheet computations. This was a time consuming exercise which led to excessive replication of data and a lack of audit trail behind the data used for any analysis. Allocation of field production to individual wells is a key production engineering workflow. The flow rate data is the prime input for every piece of analysis conducted by the reservoir engineering team; decline curve analysis, rate and pressure transient analysis, material balance and history matching the numerical simulation model. The results of this analysis directly impacts upon routine production strategy & optimisation, workovers, well planning, future development strategy and reserves. The platform Venturi flow meters have proven unreliable throughout the production life of Breagh, leading to the evaluation of several alternative allocation methods, all of which are manual and time intensive. This paper presents workflows for production data management and production allocation. Various production allocation methods are used and this paper demonstrates the impact of data accuracy on long-term development decisions, and short term interventions due to flow assurance issues. Thereby, the asset team can shift from a reactive, to a proactive position and generate value for the business.

To obtain good dispersion of nanofillers in nanodielectrics, the surface of nanopowders or colloidal particles can be chemically treated to make them more compatible with the matrix. Epoxy nanocomposites that contain surface functionalized nanosilica, either colloidal or powdered, show higher breakdown strengths than the reference epoxy material. For nanodielectric composites containing 2 wt % of nanosilica, a breakdown strength some 25% higher than that of the unfilled epoxy was obtained. Spectroscopic measurements were obtained from all samples and multi variate statistical analysis was applied to enable selected material properties to be regressed allowing molecular associations of these properties to be identified. Electrical breakdown strength was found to be related to the presence of silica and the degree of curing whereas space charge accumulation was found to be related to a reduction in polar ester formation. In contrast we find clear evidence of space charge accumulation being related to more shallow charge trapping centers.

There is a need to develop materials with controlled electrical resistivity, reduced space charge accumulation, higher thermal conductivity, higher dielectric strength and enhanced voltage endurance to cope with DC stresses in High Voltage Direct Current (HVDC) transmission systems in addition to HVAC requirements. If the balance of properties, performance and process requirements are achieved this may lead to HVDC insulation systems and equipment having a reduced footprint, larger power densities, and greater multi-stress resilience with longer service lifetimes. It reports findings of a project that is engaging this challenge and investigates the development and scaling of new thermoset based nanocomposite electrical insulation materials for HVDC power transmission applications. Some of the results such as increased electrical breakdown strength and reduced electrical conductivity for reactively surface functionalised nanosilica, and increased thermal conductivity for nano boron nitride and their significance in regard to the wider application of these electrical insulation materials are also discussed. With sufficient understanding of these properties, their trade-offs and process requirements it is possible to tailor balanced materials for specific use in HVAC or HVDC components.

To lock in progress over the last three years, Southeast Europe needs to take steps now to develop effective cross-border cooperation at both the practical and political levels. It also needs to demonstrate that it can speak out on major issues of concern with a single, coordinated voice. Not only does meaningful regional cooperation build local confidence and reflect full regional buy-in on tough, challenging economic and political issues, it also helps form crucial regional networks in political, diplomatic and specialist areas. This in turn leads crucially to standard setting at the regional level, which can significantly enhance the durability of national commitments. The Southeast European Cooperation Process (SEECP) is starting to take on this role in important areas. It has progressively become more focused in its goals and objectives. It now needs to begin to exert the leadership necessary to craft workable solutions to persistent regional challenges. This means developing an indigenous capacity t...

The paper reports and discusses the properties of carbon and silicon carbide fibre reinforced ceramic matrix composites (CMCs) and relates to these to their potential applications. These materials are attractive for applications requiring zero or controlled thermal expansion, low density, high stiffness, refractoriness, damage tolerance and high strength to low mass ratio. The development of CMCs and component fabrication technology at GEC ALSTHOM Engineering Research Centre is reported. This development encompassed design methods, component performance, production routes and materials. The fabrication of large complex geometry, multidirectional fibre, reinforced CMCs to near-net size and shape is discussed.

The properties of continuous fibre, whisker, platelet and particulate reinforced ceramic matrix composite (CMCs) are discussed with emphasis upon their improved strength, fracture toughness and reliability in comparison with glass, glass-ceramic and ceramic materials. Fabrication of composites to component shape is discussed. Finally, potential applications of CMCs in a variety of applications are identified and discussed with particular attention to cost and performance.

More "green" power provided by Distributed Generation will enter into the European electricity network in the near future. hi order to control the powerflow and to ensure proper and secure operation of this future grid, with an increased level of the renewable power, new power electronic converters for grid connection of renewable sources are needed. These power converters must be able to provide intelligent power management as well as ancillary services. This paper presents an overview of an advanced power converter for universal and flexible power management that can enable the large scale-integration of dispersed generation into these future networks. The overall structure and the control requirements that are to be placed upon this converter are given. Furthermore, some possible applications as well as the bene,fits of using this converter are presented.