974 resultados para ENERGY ANALYSIS


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Background: The bioenergetic status of non-small cell lung cancer correlates with tumour aggressiveness. The voltage dependent anion channel type 1 (VDAC1) is a component of the mitochondrial permeability transition pore, regulates mitochondrial ATP/ADP exchange suggesting that its over-expression could be associated with energy dependent processes including increased proliferation and invasiveness. To test this hypothesis, we conducted an in vivo gene-expression meta-analysis of surgically resected non-small cell lung cancer (NSCLC) using 602 individual expression profiles, to examine the impact of VDAC1 on survival.

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Guanine-rich DNA repeat sequences located at the terminal ends of chromosomal DNA can fold in a sequence-dependent manner into G-quadruplex structures, notably the terminal 150–200 nucleotides at the 3' end, which occur as a single-stranded DNA overhang. The crystal structures of quadruplexes with two and four human telomeric repeats show an all-parallel-stranded topology that is readily capable of forming extended stacks of such quadruplex structures, with external TTA loops positioned to potentially interact with other macromolecules. This study reports on possible arrangements for these quadruplex dimers and tetramers, which can be formed from 8 or 16 telomeric DNA repeats, and on a methodology for modeling their interactions with small molecules. A series of computational methods including molecular dynamics, free energy calculations, and principal components analysis have been used to characterize the properties of these higher-order G-quadruplex dimers and tetramers with parallel-stranded topology. The results confirm the stability of the central G-tetrads, the individual quadruplexes, and the resulting multimers. Principal components analysis has been carried out to highlight the dominant motions in these G-quadruplex dimer and multimer structures. The TTA loop is the most flexible part of the model and the overall multimer quadruplex becoming more stable with the addition of further G-tetrads. The addition of a ligand to the model confirms the hypothesis that flat planar chromophores stabilize G-quadruplex structures by making them less flexible.

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Polyphosphate is a ubiquitous linear homopolymer of phosphate residues linked by high-energy bonds similar to those found in ATP. It has been associated with many processes including pathogenicity, DNA uptake and multiple stress responses across all domains. Bacteria have also been shown to use polyphosphate as a way to store phosphate when transferred from phosphate-limited to phosphate-rich media - a process exploited in wastewater treatment and other environmental contaminant remediation. Despite this, there has, to date, been little research into the role of polyphosphate in the survival of marine bacterioplankton in oligotrophic environments. The three main proteins involved in polyphosphate metabolism, Ppk1, Ppk2 and Ppx are multi-domain and have differential inter-domain and inter-gene conservation, making unbiased analysis of relative abundance in metagenomic datasets difficult. This paper describes the development of a novel Isofunctional Homolog Annotation Tool (IHAT) to detect homologs of genes with a broad range of conservation without bias of traditional expect-value cutoffs. IHAT analysis of the Global Ocean Sampling (GOS) dataset revealed that genes associated with polyphosphate metabolism are more abundant in environments where available phosphate is limited, suggesting an important role for polyphosphate metabolism in marine oligotrophs.

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The European Union has set a target for 10% renewable energy in transport by 2020, which will be met using both biofuels and electric vehicles. In the case of biofuels, for the purposes of meeting the target, the biofuel must achieve greenhouse gas savings of 35% relative to the fossil fuel replaced. For biofuels, greenhouse gas savings can be calculated using life cycle analysis, or the European Union default values. In contrast, all electricity used in transport is considered to be the same, regardless of the source or the type of electric vehicle. However, the choice of the electric vehicle and electricity source will have a major impact on the greenhouse gas savings. This paper examines different electric-vehicle scenarios in terms of greenhouse gas savings, using a well-to-wheel life cycle analysis.

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To meet European Union renewable energy and greenhouse gas emissions reduction targets the Irish government set a target in 2008 that 10% of all vehicles in the transport fleet be powered by electricity by 2020. Similar electric vehicle targets have been introduced in other countries. However, reducing energy consumption and decreasing greenhouse gas emissions in transport is a considerable challenge due to heavy reliance on fossil fuels. In fact, transport in the Republic of Ireland in 2009 accounted for 29% of non-emissions trading scheme greenhouse gas emissions, 32% of energy-related greenhouse gas emissions, 21% of total greenhouse gas emissions and approximately 50% of energy-related non-emission trading scheme greenhouse gas emissions. In this paper the effect of electric vehicle charging on the operation of the single wholesale electricity market for the Republic of Ireland and Northern Ireland is analysed. The energy consumed, greenhouse gas emissions generated and changes to the wholesale price of electricity under peak and off-peak charging scenarios are quantified and discussed. Results from the study show that off-peak charging is more beneficial than peak charging.

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Laser-driven proton and ion acceleration is an area of increasing research interest given the recent development of short pulse-high intensity lasers. Several groups have reported experiments to understand whether a laser-driven beam can be applied for radiobiological purposes and in each of these, the method to obtain dose and spectral analysis was slightly different. The difficulty with these studies is that the very large instantaneous dose rate is a challenge for commonly used dosimetry techniques, so that other more sophisticated procedures need to be explored. This paper aims to explain a method for obtaining the energetic spectrum and the dose of a laser-driven proton beam irradiating a cell dish used for radiobiology studies. The procedure includes the use of a magnet to have charge and energy separation of the laser-driven beam, Gafchromic films to have information on dose and partially on energy, and a Monte Carlo code to expand the measured data in order to obtain specific details of the proton spectrum on the cells. Two specific correction factors have to be calculated: one to take into account the variation of the dose response of the films as a function of the proton energy and the other to obtain the dose to the cell layer starting from the dose measured on the films. This method, particularly suited to irradiation delivered in a single laser shot, can be applied in any other radiobiological experiment performed with laser-driven proton beams, with the only condition that the initial proton spectrum has to be at least roughly known. The method was tested in an experiment conducted at Queen's University of Belfast using the TARANIS laser, where the mean energy of the protons crossing the cells was between 0.9 and 5 MeV, the instantaneous dose rate was estimated to be close to 10(9) Gy s(-1) and doses between 0.8 and 5 Gy were delivered to the cells in a single laser shot. The combination of the applied corrections modified the initial estimate of dose by up to 40%.

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A description of the radiation emitted by impurities from within a plasma is crucial if spectral line intensities are to be used in detailed studies, such as the analysis of impurity transport. The simplest and most direct check that can be made on measurements of line intensities is to analyse their ratios with other lines from the same ion. This avoids uncertainties in determining the volume of the emitting plasma and the absolute sensitivity calibration of the spectrometer and, in some cases, the need even for accurate measurements of parameters such as electron density. Consistency is required between the measured line intensity ratios and the theoretical values. The expected consistency has not been found for radiation emitted from the JET scrape-off layer (e.g. Lawson et al 2009a JINST 4 P04013), meaning that the description of the spectral line intensities of impurity emission from the plasma edge is incomplete. In order to gain further understanding of the discrepancies, an analysis has been carried out for emission from the JET divertor plasma and this is reported in this paper. Carbon was the main low Z intrinsic impurity in JET and an analysis of spectral line intensity ratios has been made for the C (IV) radiation emitted from the JET divertor. In this case, agreement is found between the measured and theoretical ratios to a very high accuracy, namely to within the experimental uncertainty of similar to +/- 10%. This confirms that the description of the line intensities for the present observations is complete. For some elements and ionization stages, an analysis of line intensity ratios can lead to the determination of parameters such as the electron temperature of the emitting plasma region and estimates of the contribution of recombination to the electron energy level populations. This applies to C (IV) and, to show the value and possibilities of the spectral measurements, these parameters have been calculated for a database of Ohmic and additionally heated phases of a large number of pulses. The importance of dielectronic, radiative and charge-exchange recombination as well as ionization has been investigated. In addition, the development of T-e throughout two example discharges is illustrated. The presented results indicate a number of areas for further investigation.

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Two manganese steels were investigated: Fe-19.7%Mn (VM339A) and Fe-19.7%Mn stabilized with 0.056%C, 0.19%Ti and 0.083%Al (VM339B). The toughness of VM339A was higher than VM339B, but VM339B had higher hardness. Tempering does not affect the toughness of the alloys. SEM images of the fracture surface for both the alloys revealed ductile fractures. A further alloy with a lower manganese content, Fe-8.46%Mn-0.24%Nb-0.038%C, and thus even lower cost than the conventional 3.5Ni cryogenic steel, was tested for its impact toughness after heat treatment at 600°C, giving promising results.

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Non-resonant multiphoton ionization combined with quadrupole and time-of-flight analysis has been used to study sputtering by both atomic and molecular ion beams. The mass spectra and energy distributions of both sputtered atoms and secondary ions produced by 3.6 keV Ar+, N+, N-2(+), CF2+ and CF3+ ion bombardment at 45 degrees to a polycrystalline copper target have been measured. The energy distributions of the copper ions and atoms are found to be different and quite complex. The ion distributions can generally be described by a linear collision cascade model, with possible evidence for a knock-on contribution. The sputtered atom distributions are partially described by a combination of linear collision cascade and dense cascade (thermal spike) models. This is interpreted as support for a time-evolving sputtering mechanism.

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Installed wind capacity in the European Union is expected to continue to increase due to renewable energy targets and obligations to reduce greenhouse gas emissions. Renewable energy sources such as wind power are variable sources of power. Energy storage technologies are useful to manage the issues associated with variable renewable energy sources and align non-dispatchable renewable energy generation with load demands. Energy storage technologies can play different roles in electric power systems and can be used in each of the steps of the electric power supply chain. Moreover, large scale energy storage systems can act as renewable energy integrators by smoothening the variability of large penetrations of wind power. Compress Air Energy Storage is one such technology. The aim of this paper is to examine the technical and economic feasibility of a combined gas storage and compressed air energy storage facility in the all-island Single Electricity Market of Northern Ireland and the Republic of Ireland in order to optimise power generation and wind power integration. This analysis is undertaken using the electricity market software PLEXOS ® for power systems by developing a model of a combined facility in 2020.

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Turbulence characteristics in the Indonesian seas on the horizontal scale of order of 100 km were calculated with a regional model of the Indonesian seas circulation in the area based on the Princeton Ocean Model (POM). As is well known, the POM incorporates the Mellor–Yamada turbulence closure scheme. The calculated characteristics are: twice the turbulence kinetic energy per unit mass, <i>q</i><sup>2</sup>; the turbulence master scale, &ell;; mixing coefficients of momentum, <i>K</i><sub>M</sub>; and temperature and salinity, <i>K</i><sub>H</sub>; etc. The analyzed turbulence has been generated essentially by the shear of large-scale ocean currents and by the large-scale wind turbulence. We focused on the analysis of turbulence around important topographic features, such as the Lifamatola Sill, the North Sangihe Ridge, the Dewakang Sill, and the North and South Halmahera Sea Sills. In general, the structure of turbulence characteristics in these regions turned out to be similar. For this reason, we have carried out a detailed analysis of the Lifamatola Sill region because dynamically this region is very important and some estimates of mixing coefficients in this area are available. <br><br> Briefly, the main results are as follows. The distribution of <i>q</i><sup>2</sup> is quite adequately reproduced by the model. To the north of the Lifamatola Sill (in the Maluku Sea) and to the south of the Sill (in the Seram Sea), large values of <i>q</i><sup>2</sup> occur in the deep layer extending several hundred meters above the bottom. The observed increase of <i>q</i><sup>2</sup> near the very bottom is probably due to the increase of velocity shear and the corresponding shear production of <i>q</i><sup>2</sup> very close to the bottom. The turbulence master scale, &ell;, was found to be constant in the main depth of the ocean, while &ell; rapidly decreases close to the bottom, as one would expect. However, in deep profiles away from the sill, the effect of topography results in the &ell; structure being unreasonably complicated as one moves towards the bottom. Values of 15 to 20 × 10<sup>&minus;4</sup> m<sup>2</sup> s<sup>-1</sup> were obtained for <i>K</i><sub>M</sub> and <i>K</i><sub>H</sub> in deep water in the vicinity of the Lifamatola Sill. These estimates agree well with basin-scale averaged values of 13.3 × 10<sup>&minus;4</sup> m<sup>2</sup> s<sup>-1</sup> found diagnostically for <i>K</i><sub>H</sub> in the deep Banda and Seram Seas (Gordon et al., 2003) and a value of 9.0 × 10<sup>&minus;4</sup> m<sup>2</sup> s<sup>-1</sup> found diagnostically for <i>K</i><sub>H</sub> for the deep Banda Sea system (van Aken et al., 1988). The somewhat higher simulated values can be explained by the presence of steep topography around the sill.

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Increasing fruit and vegetable (FV) consumption is associated with reduced risk of major diseases. However, it is unclear if health benefits are related to increased micronutrient intake or to improvements in overall diet profile. This review aimed to assess if increasing FV consumption had an impact on diet profile. In the systematic review, twelve studies revealed increases in micronutrient intakes, whilst the meta-analysis confirmed macronutrient findings from the systematic review showing no significant difference between the intervention and control groups in energy (kcals) in seven studies (mean difference = 1 kcals [95% CI = -115, 117]; P = 0.98), significant decreases in total fat (% energy) in 5 studies (Mean difference = -4% [95% CI = -5, -3]; P = <0.00001) and significant increases in fibre in 6 studies (Mean difference = 5.36 grams [95% CI = 4, 7]; P = <0.00001) and total carbohydrate (% energy) in 4 studies (Mean = 4% [95% CI = 2, 5]; P = <0.00001). In conclusion, results indicate that increased FV consumption increases micronutrient, carbohydrate and fibre intakes and possibly reduces fat intake, with no overall effect on energy intake. Therefore health benefits may act through an improvement in overall diet profile alongside increased micronutrient intakes.

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This paper analyzes data captured by a phasor measurement unit at a wind farm, employing two-speed induction generators, and investigates aspects of the control system's interaction with the power system. Composite superimposed transient events are proposed as a method to improve the quality of the analysis and reduce errors caused by unknowns, such as wind speed variation. A Mathworks SimPowerSystems model validates the inertia contribution of the wind farm, which is an important parameter in power systems with high wind penetration. Transients caused by turbine speed transitions are identified and explained. The analysis also highlights areas where wind farm control should be improved if useful inertia contribution is to be provided.

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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.