44,415 research outputs found
Giant magnetoimpedance in crystalline Mumetal
We studied giant magnetoimpedance (GMI) effect in commercial crystalline
Mumetal, with the emphasis to sample thickness dependence and annealing
effects. By using appropriate heat treatment one can achieve GMI ratios as high
as 310%, and field sensitivity of about 20%/Oe, which is comparable to the best
GMI characteristics obtained for amorphous and nanocrystalline soft magnetic
materials.Comment: 8 pages, 3 figure
Suppressing longitudinal double-layer oscillations by using elliptically polarized laser pulses in the hole-boring radiation pressure acceleration regime
It is shown that well collimated mono-energetic ion beams with a large
particle number can be generated in the hole-boring radiation pressure
acceleration regime by using an elliptically polarized laser pulse with
appropriate theoretically determined laser polarization ratio. Due to the
effect, the double-layer charge separation region is
imbued with hot electrons that prevent ion pileup, thus suppressing the
double-layer oscillations. The proposed mechanism is well confirmed by
Particle-in-Cell simulations, and after suppressing the longitudinal
double-layer oscillations, the ion beams driven by the elliptically polarized
lasers own much better energy spectrum than those by circularly polarized
lasers.Comment: 6 pages, 5 figures, Phys. Plasmas (2013) accepte
Introduction of a spatiotemporal Life Cycle Inventory method using a wind energy example
This is the final version of the article. Available from the publisher via the DOI in this record.Life cycle assessment (LCA) is "primarily a steady-state-tool" and few studies to date have included dynamic temporal and spatial information in matrix-based LCA. Because of this many environmental impacts cannot be determined accurately in conventional LCA. We have integrated both temporal and spatial information in a novel dynamical life cycle inventory (LCI) framework that can produce detailed spatiotemporal results and thus offering more insights for sustainability assessment. This framework employs the existing Enhanced Structural Path Analysis (ESPA) method combined with spatial analysis to determine spatialised LCI over time. Previously we tested this new approach with a local spatial dispersion model using wheat production as an illustration. In this paper we demonstrate the new spatiotemporal LCI method over an entire life cycle, using wind energy as an example and a different approach to spatial analysis at a global scale.XY acknowledges financial support from the EU under Interreg project “ICE: Intelligent Community Energy”
Introducing a Localised Spatio-temporal LCI Method with wheat production as exploratory case study
The use of dynamical information, which is temporally and spatially explicit,
to quantify environmental impacts is gaining importance in recent years. Life
Cycle Assessment has been applied to identify environmental impacts of, for
example, wheat production. However, conventional Life Cycle Assessment is
typically limited by its static nature and cannot explicitly consider temporal
and spatial variability in its matrix-based mathematical structure. To address
this limitation, a novel dynamical Life Cycle Assessment framework that applies
spatio-temporal mathematical models in Life Cycle Inventory is introduced.
This framework employs the existing Enhanced Structural Path Analysis
(ESPA) method paired with a spatial dispersion model to determine the
localised emissions over time within the Life Cycle Inventory. The spatially
explicit calculations consider emissions to the surrounding area of an origin. A
case study was undertaken to demonstrate the developed framework using the
production of wheat at the Helford area in Cornwall, UK. Results show the
spatio-temporal dispersion for four example emissions atmosphere, soil, flowing
and groundwater. These outcomes show that it is possible to implement both
spatial and temporal information in matrix-based LCI. We believe this framework
could potentially transform the way LCA is currently performed, i.e., in
a static and spatially-generic way and will offer significantly improved understanding
of life cycle environmental impacts and better inform management of processes such as agricultural production that have high spatial and temporal
heterogeneity
Sub-TeV proton beam generation by ultra-intense laser irradiation of foil-and-gas target
A two-phase proton acceleration scheme using an ultra-intense laser pulse irradiating a proton foil with a tenuous heavier-ion plasma behind it is presented. The foil electrons are compressed and pushed out as a thin dense layer by the radiation pressure and propagate in the plasma behind at near the light speed. The protons are in turn accelerated by the resulting space-charge field and also enter the backside plasma, but without the formation of a quasistationary double layer. The electron layer is rapidly weakened by the space-charge field. However, the laser pulse originally behind it now snowplows the backside-plasma electrons and creates an intense electrostatic wakefield. The latter can stably trap and accelerate the pre-accelerated proton layer there for a very long distance and thus to very high energies. The two-phase scheme is verified by particle-in-cell simulations and analytical modeling, which also suggests that a 0.54 TeV proton beam can be obtained with a 10(23) W/cm(2) laser pulse. (C) 2012 American Institute of Physics. [doi:10.1063/1.3684658]Physics, Fluids & PlasmasSCI(E)EI0ARTICLE2null1
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