933 resultados para Nuclear energy and meteorology.


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The effects of feeding level on growth, retention efficiency, faeces production and energy partitioning of redlip mullet were studied. A practical diet was used and fed at six levels from starvation, 1%, 2%, 3%, 4% of body weight (BW) to satiation for 3 weeks. The temperature was kept at 24 +/- 1 degrees C. Reducing the feeding amount resulted in significantly lower weight gain, and retention efficiency was significantly affected by feeding levels and attained the maximum at maximum feeding intake. Feeding 2% BW was the minimum required for fish to maintain growth. Fish carcass composition under different feeding levels could be divided into three groups: (1) starvation and FL1; (2) FL2 and FL3 and (3) FL4 and satiation, with significant differences among the groups but no differences in the groups except that ash content remained at constant value. Body composition of fish of group 2 was close to initial fish. The thermal-unit coefficient was 0.0381 at satiation, and significantly increased with increasing feeding levels. In order to accurately estimate basal metabolism (HeE), another trial on the relationship between HeE (kJ) and BW (g) was carried out. An exponential curve as HeE=0.1255BW(0.8386) explained this relationship. Intake energy (IE) increased from 11.30 to 63.08 kJ per fish, matching with different feeding levels. Energy allocated to growth of IE decreased with reducing feeding amount. There was a linear relationship between metabolism energy and retention energy in percentage.

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Copper phthalocyanine on InSb(111)A?interface bonding, growth mode and energy band alignment, D.A. Evans, H.J. Steiner, S. Evans, R. Middleton, T.S. Jones, S. Park, T.U. Kampen, D.R.T. Zahn, G. Cabailh and I.T. McGovern, J. Phys.: Condens. Matter, 15, S2729?S2740, (2003)

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R. Zwiggelaar, C.R. Bull, M.J. Mooney and S. Czarnes, 'The detection of 'soft' materials by selective energy xray transmission imaging and computer tomography', Journal of Agricultural Engineering Research 66 (3), 203-212 (1997)

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Scott, Len, The Cuban Missile Crisis And The Threat Of Nuclear War: Lessons From History (London: Continuum, 2007), pp.xii+222 RAE2008

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Buildings consume 40% of Ireland's total annual energy translating to 3.5 billion (2004). The EPBD directive (effective January 2003) places an onus on all member states to rate the energy performance of all buildings in excess of 50m2. Energy and environmental performance management systems for residential buildings do not exist and consist of an ad-hoc integration of wired building management systems and Monitoring & Targeting systems for non-residential buildings. These systems are unsophisticated and do not easily lend themselves to cost effective retrofit or integration with other enterprise management systems. It is commonly agreed that a 15-40% reduction of building energy consumption is achievable by efficiently operating buildings when compared with typical practice. Existing research has identified that the level of information available to Building Managers with existing Building Management Systems and Environmental Monitoring Systems (BMS/EMS) is insufficient to perform the required performance based building assessment. The cost of installing additional sensors and meters is extremely high, primarily due to the estimated cost of wiring and the needed labour. From this perspective wireless sensor technology provides the capability to provide reliable sensor data at the required temporal and spatial granularity associated with building energy management. In this paper, a wireless sensor network mote hardware design and implementation is presented for a building energy management application. Appropriate sensors were selected and interfaced with the developed system based on user requirements to meet both the building monitoring and metering requirements. Beside the sensing capability, actuation and interfacing to external meters/sensors are provided to perform different management control and data recording tasks associated with minimisation of energy consumption in the built environment and the development of appropriate Building information models(BIM)to enable the design and development of energy efficient spaces.

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Due to growing concerns regarding the anthropogenic interference with the climate system, countries across the world are being challenged to develop effective strategies to mitigate climate change by reducing or preventing greenhouse gas (GHG) emissions. The European Union (EU) is committed to contribute to this challenge by setting a number of climate and energy targets for the years 2020, 2030 and 2050 and then agreeing effort sharing amongst Member States. This thesis focus on one Member State, Ireland, which faces specific challenges and is not on track to meet the targets agreed to date. Before this work commenced, there were no projections of energy demand or supply for Ireland beyond 2020. This thesis uses techno-economic energy modelling instruments to address this knowledge gap. It builds and compares robust, comprehensive policy scenarios, providing a means of assessing the implications of different future energy and emissions pathways for the Irish economy, Ireland’s energy mix and the environment. A central focus of this thesis is to explore the dynamics of the energy system moving towards a low carbon economy. This thesis develops an energy systems model (the Irish TIMES model) to assess the implications of a range of energy and climate policy targets and target years. The thesis also compares the results generated from the least cost scenarios with official projections and target pathways and provides useful metrics and indications to identify key drivers and to support both policy makers and stakeholder in identifying cost optimal strategies. The thesis also extends the functionality of energy system modelling by developing and applying new methodologies to provide additional insights with a focus on particular issues that emerge from the scenario analysis carried out. Firstly, the thesis develops a methodology for soft-linking an energy systems model (Irish TIMES) with a power systems model (PLEXOS) to improve the interpretation of the electricity sector results in the energy system model. The soft-linking enables higher temporal resolution and improved characterisation of power plants and power system operation Secondly, the thesis develops a methodology for the integration of agriculture and energy systems modelling to enable coherent economy wide climate mitigation scenario analysis. This provides a very useful starting point for considering the trade-offs between the energy system and agriculture in the context of a low carbon economy and for enabling analysis of land-use competition. Three specific time scale perspectives are examined in this thesis (2020, 2030, 2050), aligning with key policy target time horizons. The results indicate that Ireland’s short term mandatory emissions reduction target will not be achieved without a significant reassessment of renewable energy policy and that the current dominant policy focus on wind-generated electricity is misplaced. In the medium to long term, the results suggest that energy efficiency is the first cost effective measure to deliver emissions reduction; biomass and biofuels are likely to be the most significant fuel source for Ireland in the context of a low carbon future prompting the need for a detailed assessment of possible implications for sustainability and competition with the agri-food sectors; significant changes are required in infrastructure to deliver deep emissions reductions (to enable the electrification of heat and transport, to accommodate carbon capture and storage facilities (CCS) and for biofuels); competition between energy and agriculture for land-use will become a key issue. The purpose of this thesis is to increase the evidence-based underpinning energy and climate policy decisions in Ireland. The methodology is replicable in other Member States.

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Wind power generation differs from conventional thermal generation due to the stochastic nature of wind. Thus wind power forecasting plays a key role in dealing with the challenges of balancing supply and demand in any electricity system, given the uncertainty associated with the wind farm power output. Accurate wind power forecasting reduces the need for additional balancing energy and reserve power to integrate wind power. Wind power forecasting tools enable better dispatch, scheduling and unit commitment of thermal generators, hydro plant and energy storage plant and more competitive market trading as wind power ramps up and down on the grid. This paper presents an in-depth review of the current methods and advances in wind power forecasting and prediction. Firstly, numerical wind prediction methods from global to local scales, ensemble forecasting, upscaling and downscaling processes are discussed. Next the statistical and machine learning approach methods are detailed. Then the techniques used for benchmarking and uncertainty analysis of forecasts are overviewed, and the performance of various approaches over different forecast time horizons is examined. Finally, current research activities, challenges and potential future developments are appraised.

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This paper presents simulated computational fluid dynamics (CFD) results for comparison against experimental data. The performance of four turbulence models has been assessed for electronic application areas considering both fluid flow and heat transfer phenomenon. CFD is vast becoming a powerful and almost essential tool for design, development and optimization in engineering problems. However turbulence models remain to be the key problem issue when tackling such flow phenomena. The reliability of CFD analysis depends heavily on the performance of the turbulence model employed together with the wall functions implemented. To be able to resolve the abrupt changes in the turbulent energy and other parameters near the wall a particularly fine mesh is necessary which unfortunately increases the computer storage capacity requirements. The objective of turbulence modelling is to enhance computational procdures of sufficient acccuracy and generality for engineers to anticipate the Reynolds stresses and the scalar transport terms.

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The scattering of electrons with kinetic energies down to a few meV by para-xylene and para-difluorobenzene has been observed experimentally with an electron beam energy resolution of 0.95 to 1.5 meV (full width half maximum). At low electron energies the collisions can be considered as cold scattering events because the de Broglie wavelength of the electron is considerably larger than the target dimensions. The scattering cross sections measured rise rapidly at low energy due to virtual state scattering. The nature of this scattering process is discussed using s- and p-wave phase shifts derived from the experimental data. Scattering lengths are derived of, respectively, -9.5+/-0.5 and -8.0+/-0.5 a.u. for para-xylene and para-difluorobenzene. The virtual state effect is interpreted in terms of nuclear diabatic and partially adiabatic models, involving the electronic and vibronic symmetries of the unoccupied orbitals in the target species. The concept of direct and indirect virtual state scattering is introduced, through which the present species, in common with carbon dioxide and benzene, scatter through an indirect virtual state process, whereas other species, such as perfluorobenzene, scatter through a direct process. (C) 2005 American Institute of Physics.

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The past few years have seen remarkable progress in the development of laser-based particle accelerators. The ability to produce ultrabright beams of multi-megaelectronvolt protons routinely has many potential uses from engineering to medicine, but for this potential to be realized substantial improvements in the performances of these devices must be made. Here we show that in the laser-driven accelerator that has been demonstrated experimentally to produce the highest energy protons, scaling laws derived from fluid models and supported by numerical simulations can be used to accurately describe the acceleration of proton beams for a large range of laser and target parameters. This enables us to evaluate the laser parameters needed to produce high-energy and high-quality proton beams of interest for radiography of dense objects or proton therapy of deep-seated tumours.

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The damage induced in supercoiled plasmid DNA molecules by 1-6 keV carbon ions has been investigated as a function of ion exposure, energy and charge state. The production of short linear fragments through multiple double strand breaks has been demonstrated and exponential exposure responses for each of the topoisomers have been found. The cross section for the loss of supercoiling was calculated to be (2.2 +/- 0.5) x 10(-14) cm(2) for 2 keVC(+) ions. For singly charged carbon ions, increased damage was observed with increasing ion energy. In the case of 2 keV doubly charged ions, the damage was greater than for singly charged ions of the same energy. These observations demonstrate that ion induced damage is a function of both the kinetic and potential energies of the ion.

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Throughout Earth's history there have been temporal and spatial variations in the amount of visible and ultraviolet radiation received by ecosystems. This paper examines if temporal changes in these forms of energy receipt could have influenced the tempo and mode of plant diversity and speciation, focusing in particular upon Cenozoic time-scales. Evidence for changing patterns of plant diversity and speciation apparent in various fossil records and molecular phylogenies are considered alongside calculated changes in thermal and solar ultraviolet energy (specifically UV-B) over the past 50 Myr. We suggest that changes in thermal energy influx (amount and variability) affected the tempo of evolution through its influence upon community dynamics (e.g. population size, diversity, turnover, extinctions). It was not only the amount of thermal energy but also variability in its flux that may have influenced these processes, and ultimately the rate of diversification. We suggest that variations in UV-B would have influenced the mode and tempo of speciation through changes to genome stability during intervals of elevated UV-B. We argue, therefore, that although variability in thermal energy and UV-B fluxes through time may lead to the same end-point (changing the rate of diversification), the processes responsible are very different and both need to be considered when linking evolutionary processes to energy flux.

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Energy intake in 15-20% of the UK older population is currently thought to be inadequate for health. Based on the suggestion that increases in food pleasantness and familiarity can increase intake, this study investigated the impact of the addition of sauce to an older person's meal on subsequent intake. Twenty-eight older people consumed two meals with sauce and the same two meals without sauce on different occasions, and amount consumed in terms of weight, energy and energy consumed from carbohydrate, fat and protein were compared. Pre-meal hunger and desire to eat, post-meal pleasantness and familiarity and participants' expectations of the effects of sauces were also measured. Compared to meals without sauce, meals with sauce were found to result in greater intakes of energy, energy consumed from protein and energy consumed from fat (smallest t(27)=2.13, p=0.04). No differences between conditions were found in measures of pre-meal hunger and desire to eat, or post-meal pleasantness and familiarity (largest t(27) = 1.47, p = 0.15). Similar effects were also found when participant expectations were taken into account, and no differences between participants who expected sauces to affect intake vs. those who did not expect sauces to affect intake were found (largest F(1, 26) = 1.70, p=0.20). These findings suggest that the addition of sauce to an older person's meal can result in increases in intake and may be beneficial for preventing or treating under-nutrition in these individuals, although the mechanisms by which sauces can increase intake are unlikely to be related to pleasantness and familiarity. (c) 2008 Elsevier Ltd. All rights reserved.

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The results of an investigation into the damage caused to dry plasmid DNA after irradiation by fast (keV) hydrogen atoms are presented. Agarose gel electrophoresis was used to assess single and double strand break yields as a function of dose in dry DNA samples deposited on a mica substrate. Damage levels were observed to increase with beam energy. Strand break yields demonstrated a considerable dependence on sample structure and the method of sample preparation. Additionally, the effect of high-Z nanoparticles on damage levels was investigated by irradiating DNA samples containing controlled amounts of gold nanoparticles. In contrast to previous (photonic) studies, no enhancement of strand break yields was observed with the particles showing a slight radioprotective effect. A model of DNA damage as a function of dose has been constructed in terms of the probability for the creation of single and double strand breaks, per unit ion flux. This model provides quantitative conclusions about the effects of both gold nanoparticles and the different buffers used in performing the assays and, in addition, infers the proportion of multiply damaged fragments.