38 resultados para energy and resources


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When the dominant mechanism for ion acceleration is the laser radiation pressure, the conversion efficiency of the laser energy into the energy of relativistic ions may be very high. Stability analysis of a thin plasma layer accelerated by the radiation pressure shows that Raleigh-Taylor instability may enhance plasma inhomogeneity. In the linear stage of instability, the plasma layer decays into separate bunches, which are accelerated by the radiation pressure similarly to clusters accelerated under the action of an electromagnetic wave. The energy and luminosity of an ion beam accelerated in the radiation-pressure-dominated regime are calculated.

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Purpose: To measure action spectra for the induction of single- strand breaks (SSB) and double-strand breaks (DSB) in plasmid DNA by low-energy photons and provide estimates for the energy dependence of strand-break formation important for track-structure simulations of DNA damage.

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The deployment of biofuels is significantly affected by policy in energy and agriculture. In the energy arena, concerns regarding the sustainability of biofuel systems and their impact on food prices led to a set of sustainability criteria in EU Directive 2009/28/EC on Renewable Energy. In addition, the 10% biofuels target by 2020 was replaced with a 10% renewable energy in transport target. This allows the share of renewable electricity used by electric vehicles to contribute to the mix in achieving the 2020 target. Furthermore, only biofuel systems that effect a 60% reduction in greenhouse gas emissions by 2020 compared with the fuel they replace are allowed to contribute to meeting the target. In the agricultural arena, cross-compliance (which is part of EU Common Agricultural Policy) dictates the allowable ratio of grassland to total agricultural land, and has a significant impact on which biofuels may be supported. This paper outlines the impact of these policy areas and their implications for the production and use of biofuels in terms of the 2020 target for 10% renewable transport energy, focusing on Ireland. The policies effectively impose constraints on many conventional energy crop biofuels and reinforce the merits of using biomethane, a gaseous biofuel. The analysis shows that Ireland can potentially satisfy 15% of renewable energy in transport by 2020 (allowing for double credit for biofuels from residues and ligno-cellulosic materials, as per Directive 2009/28/EC) through the use of indigenous biofuels: grass biomethane, waste and residue derived biofuels, electric vehicles and rapeseed biodiesel. © 2010 Elsevier Ltd. All rights reserved.

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Thermal stability is of major importance in polymer extrusion, where product quality is dependent upon the level of melt homogeneity achieved by the extruder screw. Extrusion is an energy intensive process and optimisation of process energy usage while maintaining melt stability is necessary in order to produce good quality product at low unit cost. Optimisation of process energy usage is timely as world energy prices have increased rapidly over the last few years. In the first part of this study, a general discussion was made on the efficiency of an extruder. Then, an attempt was made to explore correlations between melt thermal stability and energy demand in polymer extrusion under different process settings and screw geometries. A commodity grade of polystyrene was extruded using a highly instrumented single screw extruder, equipped with energy consumption and melt temperature field measurement. Moreover, the melt viscosity of the experimental material was observed by using an off-line rheometer. Results showed that specific energy demand of the extruder (i.e. energy for processing of unit mass of polymer) decreased with increasing throughput whilst fluctuation in energy demand also reduced. However, the relationship between melt temperature and extruder throughput was found to be complex, with temperature varying with radial position across the melt flow. Moreover, the melt thermal stability deteriorated as throughput was increased, meaning that a greater efficiency was achieved at the detriment of melt consistency. Extruder screw design also had a significant effect on the relationship between energy consumption and melt consistency. Overall, the relationship between the process energy demand and thermal stability seemed to be negatively correlated and also it was shown to be highly complex in nature. Moreover, the level of process understanding achieved here can help to inform selection of equipment and setting of operating conditions to optimise both energy and thermal efficiencies in parallel. 

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Following the collapse of the Soviet Union in 1991, the newly independent oil-rich country of Kazakhstan has become a major recipient of foreign direct investment (FDI). Although international organisations such as the IMF and UNCTAD have claimed that FDI could be considered an engine in the transition from state socialism and as a powerful force for integration of this region into the global economy; this investment also poses significant risks to Kazakhstan. These risks fall into two broad categories: The first category can be broadly described as issues associated with the “resource curse” or the “Dutch Disease”. The term Dutch Disease describes a situation where booming demand in oil exporting countries, due to high oil revenues, leads to shift of an economy’s productive resources from the tradeable sector to the non-tradeable sector. The second category is associated with the over-dependency of oil exporting countries on a relatively small number of large multinational corporations (MNCs). This over-dependency can lead to a situation where licenses and concessions are granted at less favourable conditions than if they were auctioned in an efficient market. Examining the licensing policy of the Kazakhstani Energy and Mineral Resource Ministry, this paper notes that the latter issue of over-dependency has become less of a risk due to deliberate efforts to diversify investment relationships. Notwithstanding this situation there is some evidence that it remains difficult for oil exporting nations such as Kazakhstan to ensure that oil revenues are channelled into sustainable economic development.

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Despite a focus in the UK on providing sustainable housing in recent years, it is unlikely that targets set to reduce resource consumption in housing will be achieved without a greater focus on human behaviour. It is necessary to understand the actions of people occupying dwellings, as it is invariably the occupants rather than the buildings that decided whether or not to consume resources. In this paper the authors present a pilot study where 53 social housing tenant households in Northern Ireland were interviewed to ascertain their perceptions of Climate Change, their current behaviours and their willingness to reduce energy and water consumption in the home. The intention was to explore links between perceptions and reported behaviour as well as perceptions and willingness to reduce resource consumption. Results show that 77% of tenants believed Climate Change to be an important issue; 57% accepted that it is up to the individual to take responsibility for tackling Climate Change; and demonstrated a strong desire to make a difference to reduce their impact. The researchers identified both passive (devices) and active (behaviours) resource savings currently in place and established where further resource reduction was feasible based on tenants' willingness to alter their behaviours.

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Wind energy projects face increasing opposition from host communities throughout the western world. Governments have responded in a range of ways, including enhanced local control over consenting (England), reform of planning regulations (Australia) or community ownership (Denmark). However, there is no effective mechanism for monitoring levels of social acceptance and thus, no means of evaluating the effectiveness of these approaches. There have been attempts to understand how social framing of wind energy in the media (e.g. Van de Velde et al 2010, Barry and Ellis, 2008, Hindmarsh 2014), highlighting how this changes over time. However, no research has focussed on Ireland and critically, none have examined whether this can help monitor overall levels of social acceptance. In order to explore this, this paper will present a media analysis of wind energy in the Republic of Ireland, which witnessed a rapid increase in wind energy capacity and has the highest energy penetration of wind in the world (19%). However, this has been accompanied by increasing public opposition and (assumed) declining levels of social acceptance.

This paper will describe the results of analysing over 8000 articles on wind energy that have appeared in three Irish newspapers. These are assessed through historical-diachronic (over time) and comparative –synchronic (differences between newspapers) analyses (Carvalho 2007) to highlight changing trends in framing wind energy and changing concerns over wind energy in Ireland. The paper will consider whether such media analysis could form a tool for monitoring the trends in social acceptance of wind energy.

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As a leading facility in laser-driven nuclear physics, ELI-NP will develop innovative research in the fields of materials behavior in extreme environments and radiobiology, with applications in the development of accelerator components, new materials for next generation fusion and fission reactors, shielding solutions for equipment and human crew in long term space missions and new biomedical technologies. The specific properties of the laser-driven radiation produced with two lasers of 1 PW at a pulse repetition rate of 1 Hz each are an ultra-short time scale, a relatively broadband spectrum and the possibility to provide simultaneously several types of radiation. Complex, cosmic-like radiation will be produced in a ground-based laboratory allowing comprehensive investigations of their effects on materials and biological systems. The expected maximum energy and intensity of the radiation beams are 19 MeV with 10^9 photon/pulse for photon radiation, 2 GeV with 108 electron/pulse for electron beams, 60 MeV with 10^12 proton/pulse for proton and ion beams and 60 MeV with 107 neutron/pulse for a neutron source. Research efforts will be directed also towards measurements for radioprotection of the prompt and activated dose, as a function of laser and target characteristics and to the development and testing of various dosimetric methods and equipment.