334 research outputs found

    Lithium Diffusion & Magnetism in Battery Cathode Material LixNi1/3Co1/3Mn1/3O2

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    We have studied low-temperature magnetic properties as well as high-temperature lithium ion diffusion in the battery cathode materials LixNi1/3Co1/3Mn1/3O2 by the use of muon spin rotation/relaxation. Our data reveal that the samples enter into a 2D spin-glass state below TSG=12 K. We further show that lithium diffusion channels become active for T>Tdiff=125 K where the Li-ion hopping-rate [nu(T)] starts to increase exponentially. Further, nu(T) is found to fit very well to an Arrhenius type equation and the activation energy for the diffusion process is extracted as Ea=100 meV.Comment: Submitted to Journal of Physics: Conference Series (2014

    The Pfaffian quantum Hall state made simple--multiple vacua and domain walls on a thin torus

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    We analyze the Moore-Read Pfaffian state on a thin torus. The known six-fold degeneracy is realized by two inequivalent crystalline states with a four- and two-fold degeneracy respectively. The fundamental quasihole and quasiparticle excitations are domain walls between these vacua, and simple counting arguments give a Hilbert space of dimension 2n12^{n-1} for 2nk2n-k holes and kk particles at fixed positions and assign each a charge ±e/4\pm e/4. This generalizes the known properties of the hole excitations in the Pfaffian state as deduced using conformal field theory techniques. Numerical calculations using a model hamiltonian and a small number of particles supports the presence of a stable phase with degenerate vacua and quarter charged domain walls also away from the thin torus limit. A spin chain hamiltonian encodes the degenerate vacua and the various domain walls.Comment: 4 pages, 1 figure. Published, minor change

    Cryogenic and vacuum sectorisation of the LHC arcs

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    Following the recommendation of the LHC TC of June 20th, 1995 to introduce a separate cryogenic distribution line (QRL), which opened the possibility to have a finer cryogenic and vacuum sectorisation of the LHC machine than the original 8 arcs scheme, a working group was set up to study the implications: technical feasibility, advantages and drawbacks as well as cost of such a sectorisation (DG/DI/LE/dl, 26 July 1995). This report presents the conclusions of the Working Group. In the LHC Conceptual Design Report, ref. CERN/AC/95-05 (LHC), 20 October 1995, the so-called "Yellow Book", a complete cryostat arc (~ 2.9 km) would have to be warmed up in order to replace a defective cryomagnet. Even by coupling the two large refrigerators feeding adjacent arcs at even points to speed up the warm-up and cool down of one arc, the minimum down-time of the machine needed to replace a cryomagnet would be more than a full month (and even 52 days with only one cryoplant). Cryogenic and vacuum sectorisation of an arc into smaller sectors is technically feasible and would allow to reduce the down-times considerably (by one to three weeks with four sectors of 750 m in length, with respectively two or one cryoplants). In addition, sectorisation of the arcs may permit a more flexible quality control and commissioning of the main machine systems, including cold testing of small magnet strings. Sectorisation, described in detail in the following paragraphs, consists essentially of installing several additional cryogenic and vacuum valves as well as some insulation vacuum barriers. Additional cryogenic valves are needed in the return lines of the circuits feeding each half-cell in order to complete the isolation of the cryoline QRL from the machine, allowing intervention (i.e. venting to atmospheric pressure) on machine sectors without affecting the rest of an arc. Secondly, and for the same purpose, special vacuum and cryogenic valves must be installed, at the boundaries of machine sectors, for the circuits not passing through the cryoline QRL. Finally, some additional vacuum barriers must be installed around the magnet cold masses to divide the insulation vacuum of the magnet cryostats into independent sub-sectors, permitting to keep under insulating vacuum the cryogenically floating cold masses, while a sector (or part of it) is warmed up and opened to atmosphere. A reasonable scenario of sectorisation, namely with four 650-750 m long sectors per arc, and each consisting of 3 or 4 insulation vacuum sub-sectors with two to four half-cells, would represent an additional total cost of about 6.6 MCHF for the machine. It is estimated that this capital investment would be paid off by time savings in less than three long unscheduled interventions such as the change of a cryomagnet

    Bioclipse-R: integrating management and visualization of life science data with statistical analysis

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    SUMMARY: Bioclipse, a graphical workbench for the life sciences, provides functionality for managing and visualizing life science data. We introduce Bioclipse-R, which integrates Bioclipse and the statistical programming language R. The synergy between Bioclipse and R is demonstrated by the construction of a decision support system for anticancer drug screening and mutagenicity prediction, which shows how Bioclipse-R can be used to perform complex tasks from within a single software system. Availability and implementation: Bioclipse-R is implemented as a set of Java plug-ins for Bioclipse based on the R-package rj. Source code and binary packages are available from https://github.com/bioclipse and http://www.bioclipse.net/bioclipse-r, respectively. CONTACT: [email protected] SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online

    Estimating the marginal cost of railway track renewals using corner solution models

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    Economic theory advocates marginal cost pricing for efficient utilisation of transport infrastructure. A growing body of literature has emerged on the issue of rail marginal infrastructure wear and tear costs, but the majority of the work is focused on costs for infrastructure maintenance. Railway track renewals are a substantial part of an infrastructure manager’s budget, but in disaggregated statistical analyses they cause problems for traditional regression models since there is a piling up of values of the dependent variable at zero. Previous econometric work has sought to circumvent the problem by aggregation in some way. In this paper we instead apply corner solution models to disaggregate (track-section) data, including the zero observations. We derive track renewal cost elasticities with respect to traffic volumes and in turn marginal renewal costs using Swedish railway renewal data over the period 1999–2009. This paper is the first attempt in the literature to apply corner solution models, and in particular the two-part model, to disaggregate renewal cost data in railways. It is also the first paper that we are aware of to report usage elasticities specifically for renewal costs and therefore adds important new evidence to the previous literature where there is a paucity of studies on renewals and considerable uncertainty over the effects of rail traffic on renewal costs. In the Swedish context, we find that the inclusion of marginal track renewal costs in the track access pricing regime, which currently only reflects marginal maintenance costs, would add substantially to the existing track access charge. EU legislation requires that access charges reflect the ‘costs directly incurred as a result of operating the train service’, which should include a marginal renewal cost component. This change would also increase the cost recovery ratio of the Swedish infrastructure manager, thus meeting a policy objective of the national government

    Kinome-wide interaction modelling using alignment-based and alignment-independent approaches for kinase description and linear and non-linear data analysis techniques

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    <p>Abstract</p> <p>Background</p> <p>Protein kinases play crucial roles in cell growth, differentiation, and apoptosis. Abnormal function of protein kinases can lead to many serious diseases, such as cancer. Kinase inhibitors have potential for treatment of these diseases. However, current inhibitors interact with a broad variety of kinases and interfere with multiple vital cellular processes, which causes toxic effects. Bioinformatics approaches that can predict inhibitor-kinase interactions from the chemical properties of the inhibitors and the kinase macromolecules might aid in design of more selective therapeutic agents, that show better efficacy and lower toxicity.</p> <p>Results</p> <p>We applied proteochemometric modelling to correlate the properties of 317 wild-type and mutated kinases and 38 inhibitors (12,046 inhibitor-kinase combinations) to the respective combination's interaction dissociation constant (K<sub>d</sub>). We compared six approaches for description of protein kinases and several linear and non-linear correlation methods. The best performing models encoded kinase sequences with amino acid physico-chemical z-scale descriptors and used support vector machines or partial least- squares projections to latent structures for the correlations. Modelling performance was estimated by double cross-validation. The best models showed high predictive ability; the squared correlation coefficient for new kinase-inhibitor pairs ranging P<sup>2 </sup>= 0.67-0.73; for new kinases it ranged P<sup>2</sup><sub>kin </sub>= 0.65-0.70. Models could also separate interacting from non-interacting inhibitor-kinase pairs with high sensitivity and specificity; the areas under the ROC curves ranging AUC = 0.92-0.93. We also investigated the relationship between the number of protein kinases in the dataset and the modelling results. Using only 10% of all data still a valid model was obtained with P<sup>2 </sup>= 0.47, P<sup>2</sup><sub>kin </sub>= 0.42 and AUC = 0.83.</p> <p>Conclusions</p> <p>Our results strongly support the applicability of proteochemometrics for kinome-wide interaction modelling. Proteochemometrics might be used to speed-up identification and optimization of protein kinase targeted and multi-targeted inhibitors.</p

    Optimizing the bioenergy water footprint by selecting SRC willow canopy phenotypes: regional scenario simulations

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    © The Author(s) 2019. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Background and Aims: Bioenergy is central for the future energy mix to mitigate climate change impacts; however, its intricate link with the water cycle calls for an evaluation of the carbon–water nexus in biomass production. The great challenge is to optimize trade-offs between carbon harvest and water use by choosing cultivars that combine low water use with high productivity. Methods: Regional scenarios were simulated over a range of willow genotype × environment interactions for the major UK soil × climate variations with the process-based model LUCASS. Soil available water capacity (SAWC) ranged from 51 to 251 mm and weather represented the north-west (wet, cool), north-east (dry, cool), south-west (wet, warm) and south-east (dry, warm) of the UK. Scenario simulations were evaluated for small/open narrow-leaf (NL) versus large/closed broad-leaf (BL) willow canopy phenotypes using baseline (1965–89) and warmer recent (1990–2014) weather data. Key Results: The low productivity under baseline climate in the north could be compensated by choosing BL cultivars (e.g. ‘Endurance’). Recent warmer climate increased average productivity by 0.5–2.5 t ha−1, especially in the north. The modern NL cultivar ‘Resolution’ had the smallest and most efficient water use. On marginal soils (SAWC <100 mm), yields remained below an economic threshold of 9 t ha−1 more frequently under baseline than recent climate. In the drought-prone south-east, ‘Endurance’ yielded less than ‘Resolution’, which consumed on average 17 mm year−1 less water. Assuming a planting area of 10 000 ha, in droughty years between 1.3 and 4.5 × 106 m3 of water could be saved, with a small yield penalty, for ‘Resolution’. Conclusions: With an increase in air temperature and occasional water scarcities expected with climate change, high-yielding NL cultivars should be the preferred choice for sustainable use of marginal lands and reduced competition with agricultural food crops.Peer reviewedFinal Published versio

    The incentive gap: LULUCF and the Kyoto mechanism before and after Durban

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    To-date, forest resource-based carbon accounting in land use, land use change and forestry (LULUCF) under the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto Protocol (KP), European Union (EU) and national level emission reduction schemes considers only a fraction of its potential and fails to adequately mobilize the LULUCF sector for the successful stabilization of atmospheric greenhouse gas (GHG) concentrations. Recent modifications at the 2011 COP17 meetings in Durban have partially addressed this basic problem, but leave room for improvement. The presence of an Incentive Gap (IG) continues to justify reform of the LULUCF carbon accounting framework. Frequently neglected in the climate change mitigation and adaptation literature, carbon accounting practices ultimately define the nuts and bolts of what counts and which resources (forest, forest-based or other) are favored and utilized. For Annex I countries in the Kyoto Mechanism, the Incentive Gap under forest management (FM) is significantly large: some 75% or more of potential forestry-based carbon sequestration is not effectively incentivized or mobilized for climate change mitigation and adaptation (Ellison etal. 2011a). In this paper, we expand our analysis of the Incentive Gap to incorporate the changes agreed in Durban and encompass both a wider set of countries and a larger set of omitted carbon pools. For Annex I countries, based on the first 2years of experience in the first Commitment Period (CP1) we estimate the IG in FM at approximately 88%. Though significantly reduced in CP2, the IG remains a problem. Thus our measure of missed opportunities under the Kyoto and UNFCCC framework - despite the changes in Durban - remains important. With the exception perhaps of increased energy efficiency, few sinks or sources of reduced emissions can be mobilized as effectively and efficiently as forests. Thus, we wonder at the sheer magnitude of this underutilized resource

    Melanocortin receptors in GtoPdb v.2021.3

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    Melanocortin receptors (provisional nomenclature as recommended by NC-IUPHAR [41]) are activated by members of the melanocortin family (&#945;-MSH, &#946;-MSH and &#947;-MSH forms; &#948; form is not found in mammals) and adrenocorticotrophin (ACTH). Endogenous antagonists include agouti and agouti-related protein. ACTH(1-24) was approved by the US FDA as a diagnostic agent for adrenal function test, whilst NDP-MSH was approved by EMA for the treatment of erythropoietic protoporphyria. Several synthetic melanocortin receptor agonists are under clinical development
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