43,453 research outputs found
Vibration damping system Patent
Vibration damping system operating in low vacuum environment for spacecraft mechanism
Non-isothermal modelling of the all-vanadium redox flow battery
An non-isothermal model for the all-vanadium redox flow battery (RFB) is presented. The two-dimensional model is based on a comprehensive description of mass, charge, energy and momentum transport and conservation, and is combined with a global kinetic model for reactions involving vanadium species. Heat is generated as a result of activation losses, electrochemical reaction and ohmic resistance. Numerical simulations demonstrate the effects of changes in the operating temperature on performance. It is shown that variations in the electrolyte flow rate and the magnitude of the applied current substantially alter the charge/discharge characteristics, the temperature rise and the distribution of temperature. The influence of heat losses on the charge/discharge behaviour and temperature distribution is investigated. Conditions for localised heating and membrane degradation are discusse
Electronic chemical potentials of porous metal-organic frameworks
The binding energy of an electron in a material is a fundamental
characteristic, which determines a wealth of important chemical and physical
properties. For metal-organic frameworks this quantity is hitherto unknown. We
present a general approach for determining the vacuum level of porous
metal-organic frameworks and apply it to obtain the first ionisation energy for
six prototype materials including zeolitic, covalent and ionic frameworks. This
approach for valence band alignment can explain observations relating to the
electrochemical, optical and electrical properties of porous frameworks
Global bifurcation for monotone fronts of elliptic equations
In this paper, we present two results on global continuation of monotone
front-type solutions to elliptic PDEs posed on infinite cylinders. This is done
under quite general assumptions, and in particular applies even to fully
nonlinear equations as well as quasilinear problems with transmission boundary
conditions. Our approach is rooted in the analytic global bifurcation theory of
Dancer and Buffoni--Toland, but extending it to unbounded domains requires
contending with new potential limiting behavior relating to loss of
compactness. We obtain an exhaustive set of alternatives for the global
behavior of the solution curve that is sharp, with each possibility having a
direct analogue in the bifurcation theory of second-order ODEs.
As a major application of the general theory, we construct global families of
internal hydrodynamic bores. These are traveling front solutions of the full
two-phase Euler equation in two dimensions. The fluids are confined to a
channel that is bounded above and below by rigid walls, with incompressible and
irrotational flow in each layer. Small-amplitude fronts for this system have
been obtained by several authors. We give the first large-amplitude result in
the form of continuous curves of elevation and depression bores. Following the
elevation curve to its extreme, we find waves whose interfaces either overturn
(develop a vertical tangent) or become exceptionally singular in that the flow
in both layers degenerates at a single point on the boundary. For the curve of
depression waves, we prove that either the interface overturns or it comes into
contact with the upper wall.Comment: 60 pages, 6 figure
European Paediatric Formulation Initiative (EuPFI)-Formulating Ideas for Better Medicines for Children.
Ā© American Association of Pharmaceutical Scientists 2016, published by Springer US, available online at doi: https://doi.org/10.1208/s12249-016-0584-1The European Paediatric Formulation Initiative (EuPFI), founded in 2007, aims to promote and facilitate the preparation of better and safe medicines for children through linking research and information dissemination. It brings together the capabilities of the industry, academics, hospitals, and regulators within a common platform in order to scope the solid understanding of the major issues, which will underpin the progress towards the future of paediatric medicines we want.The EuPFI was formed in parallel to the adoption of regulations within the EU and USA and has served as a community that drives research and dissemination through publications and the organisation of annual conferences. The membership and reach of this group have grown since its inception in 2007 and continue to develop and evolve to meet the continuing needs and ambitions of research into and development of age appropriate medicines. Five diverse workstreams (age-appropriate medicines, Biopharmaceutics, Administration Devices, Excipients and Taste Assessment & Taste Masking (TATM)) direct specific workpackages on behalf of the EuPFI. Furthermore, EuPFI interacts with multiple diverse professional groups across the globe to ensure efficient working in the area of paediatric medicines. Strong commitment and active involvement of all EuPFI stakeholders have proved to be vital to effectively address knowledge gaps related to paediatric medicines, discuss potential areas for further research and identify issues that need more attention and analysis in the future.Peer reviewedFinal Accepted Versio
The light ion trough, the main trough, and the plasmapause
Extensive observations of mid-latitude depletions in electron and total ion density by both direct and indirect techniques, have prompted numerous studies of the possible association between these troughs, observed in the F-region, the topside ionosphere, and the plasmapause. One basic problem arises, in that while the plasmapause was detected as a global phenomenon both by VLF and ion composition measurements, the electron and ion density troughs were identified primarily as nightside features. This problem, as well as the difficulty in explaining various inconsistencies in relating the position of the plasmapause and the ionization trough, is explained by a close examination of the ion composition. In particular, ion composition results from the polar orbiting OGO satellites identify the persistence of a pronounced light ion trough in H(+) and He(+) identified by order of magnitude decreases in the light ion concentrations
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