518 research outputs found
From Problems to Potentials - The Urban Energy Transition of Gruž, Dubrovnik
In the challenge for a sustainable society, carbon-neutrality is the critical objective for all cities in the coming decades. In the EU City-zen project, academic partners collaborate to develop an urban energy transition methodology, which supports cities in making the energy transition to sustainable lifestyles and carbon neutrality. As part of the project, so-called Roadshows are organised in cities that wish to take the first step toward zero-energy living. Each Roadshow being methodologically composed to allow sustainability experts from across Europe to co-create designs, strategies and timelines with local stakeholders in order to reach this vital goal. Following a precursory investigative student workshop (the SWAT Studio) Dubrovnik would be third city to host the Roadshow in November 2016.
During these events the characteristics of Dubrovnik, and the district of Gruž in particular, were systematically analysed, leading to good insights into the current problems and potentials of the city. In close collaboration with local stakeholders, the team proposed a series of interventions that would help make Gruž, and in its wake the whole city of Dubrovnik, net zero energy and zero carbon, by validation of carbon emission calculations. The vision presented to the inhabitants and its key city decision makers encompassed a pathway towards an attainable sustainable future. The strategies and solutions proposed for the Dubrovnik district of Gruž turned out to be capable of reducing the current carbon sequestration compensation of 1,200 hectares of forestland to 67 hectares only, an area achievable by urban reforestation projects.
This paper presents the City-zen methodology of urban energy transition and that of the City-zen Roadshow, the analysis of the city of Dubrovnik, proposed interventions and the carbon impact, as calculated by means of a carbon accounting method discussed in the paper
First order optical potentials and 25 to 40 MeV proton elastic scattering
The differential cross sections and analyzing powers from the elastic
scattering of 25 and 40 MeV protons from many nuclei have been studied.
Analyses have been made using a fully microscopic model of proton-nucleus
scattering seeking to establish a means appropriate for use in analyses of
radioactive beam scattering from hydrogen with ion energies 25A and 40A MeV.Comment: 9 pages, RevTeX, 4 figure
Adding value? A review of the international literature on the role of higher education in police training and education
This paper reviews the current English-language literature on developments in police
training and education in order to identify common areas where higher education ‘adds
value’ to police learning and development. Reforms in training and education are
constituent parts of the ongoing shift to a service-oriented professional police in a
number of countries. A comparative analysis of the literature on police training and
education is provided here which focuses primarily on the USA, the European Union,
Australia and India. The review provides a contribution to international policy debates
about future developments in this area
Generalized Quantum Theory of Recollapsing Homogeneous Cosmologies
A sum-over-histories generalized quantum theory is developed for homogeneous
minisuperspace type A Bianchi cosmological models, focussing on the particular
example of the classically recollapsing Bianchi IX universe. The decoherence
functional for such universes is exhibited. We show how the probabilities of
decoherent sets of alternative, coarse-grained histories of these model
universes can be calculated. We consider in particular the probabilities for
classical evolution defined by a suitable coarse-graining. For a restricted
class of initial conditions and coarse grainings we exhibit the approximate
decoherence of alternative histories in which the universe behaves classically
and those in which it does not. For these situations we show that the
probability is near unity for the universe to recontract classically if it
expands classically. We also determine the relative probabilities of
quasi-classical trajectories for initial states of WKB form, recovering for
such states a precise form of the familiar heuristic "J d\Sigma" rule of
quantum cosmology, as well as a generalization of this rule to generic initial
states.Comment: 41 pages, 4 eps figures, revtex 4. Modest revisions throughout.
Physics unchanged. To appear in Phys. Rev.
Description of the inelastic collision of two solitary waves for the BBM equation
We prove that the collision of two solitary waves of the BBM equation is
inelastic but almost elastic in the case where one solitary wave is small in
the energy space. We show precise estimates of the nonzero residue due to the
collision. Moreover, we give a precise description of the collision phenomenon
(change of size of the solitary waves).Comment: submitted for publication. Corrected typo in Theorem 1.
Review article: MHD wave propagation near coronal null points of magnetic fields
We present a comprehensive review of MHD wave behaviour in the neighbourhood
of coronal null points: locations where the magnetic field, and hence the local
Alfven speed, is zero. The behaviour of all three MHD wave modes, i.e. the
Alfven wave and the fast and slow magnetoacoustic waves, has been investigated
in the neighbourhood of 2D, 2.5D and (to a certain extent) 3D magnetic null
points, for a variety of assumptions, configurations and geometries. In
general, it is found that the fast magnetoacoustic wave behaviour is dictated
by the Alfven-speed profile. In a plasma, the fast wave is focused
towards the null point by a refraction effect and all the wave energy, and thus
current density, accumulates close to the null point. Thus, null points will be
locations for preferential heating by fast waves. Independently, the Alfven
wave is found to propagate along magnetic fieldlines and is confined to the
fieldlines it is generated on. As the wave approaches the null point, it
spreads out due to the diverging fieldlines. Eventually, the Alfven wave
accumulates along the separatrices (in 2D) or along the spine or fan-plane (in
3D). Hence, Alfven wave energy will be preferentially dissipated at these
locations. It is clear that the magnetic field plays a fundamental role in the
propagation and properties of MHD waves in the neighbourhood of coronal null
points. This topic is a fundamental plasma process and results so far have also
lead to critical insights into reconnection, mode-coupling, quasi-periodic
pulsations and phase-mixing.Comment: 34 pages, 5 figures, invited review in Space Science Reviews => Note
this is a 2011 paper, not a 2010 pape
Preparation of chalcogenide materials for next generation optoelectronic devices
Chalcogenide materials are finding increasing interest as an active material in next generation optical and electronic devices. There wide range of properties, ranging from photosensitivity, ability to host rare earth ions, electrical conductivity, phase change, exceptional optical non-linearities to name only a few are fueling this interest. Moreover, the ability to synthesize these materials in numerous forms as diverse as 2D monolayers, microspheres, optical fibres, nanowires, thin films as well as bulk glass ingots of over a kilogram in size ensures their application space is vast. We began preparation of chalcogenides, largely based on sulphides, in 1992 and since then have built up an extensive capability for their purification, synthesis and fabrication in various forms. A key aspect of this facility is the ability to process in a flowing atmosphere of hydrogen sulphide which provided the capability of synthesis from elemental, oxide or halide precursors, processing through various chemical vapour deposition reactions as well as post purification.In this talk we describe recent additions to the range of materials we synthesize highlighting transition metal di-chalcogenides for electronic applications, an example of which is shown below, crystalline semiconductors for solar cell applications, ion implanted thin films which provide carrier type reversal, low power phase change memory devices, switchable metamaterial devices as well as traditional chalcogenides glass and optical fibre
Early sustained recovery following first episode psychosis:Evidence from the AESOP10 follow-up study
Objective: To describe the characteristics of individuals with early sustained recovery following first episode psychosis. Methods: Individuals with a first episode psychosis were followed-up for ten years. Comparisons were made between those with Early Sustained Recovery and those with Other Course types. Results: Of 345 individuals, n=43 (12.5%) had Early Sustained Recovery. They were more likely than those with Other Course types to be female (OR=2.45; 95% CI: 1.25-4.81); employed (OR=2.39; 95% CI: 1.22-4.69); in a relationship (OR=2.68; 95% CI: 1.35-5.32); have a short DUP (OR=2.86; 95% CI: 1.37-5.88); and have a diagnosis other than schizophrenia, particularly mania (OR=6.39; 95% CI: 2.52-16.18) or brief psychosis (OR=3.64; 95% CI: 1.10-12.10). Conclusions: Sustained recovery from first episode psychosis occurs in a minority. (c) 2018 Elsevier B.V. All rights reserved
The Number Of Magnetic Null Points In The Quiet Sun Corona
The coronal magnetic field above a particular photospheric region will vanish
at a certain number of points, called null points. These points can be found
directly in a potential field extrapolation or their density can be estimated
from Fourier spectrum of the magnetogram. The spectral estimate, which assumes
that the extrapolated field is random, homogeneous and has Gaussian statistics,
is found here to be relatively accurate for quiet Sun magnetograms from SOHO's
MDI. The majority of null points occur at low altitudes, and their distribution
is dictated by high wavenumbers in the Fourier spectrum. This portion of the
spectrum is affected by Poisson noise, and as many as five-sixths of null
points identified from a direct extrapolation can be attributed to noise. The
null distribution above 1500 km is found to depend on wavelengths that are
reliably measured by MDI in either its low-resolution or high-resolution mode.
After correcting the spectrum to remove white noise and compensate for the
modulation transfer function we find that a potential field extrapolation
contains, on average, one magnetic null point, with altitude greater than 1.5
Mm, above every 322 square Mm patch of quiet Sun. Analysis of 562 quiet Sun
magnetograms spanning the two latest solar minimum shows that the null point
density is relatively constant with roughly 10% day-to-day variation. At
heights above 1.5 Mm, the null point density decreases approximately as the
inverse cube of height. The photospheric field in the quiet Sun is well
approximated as that from discrete elements with mean flux 1.0e19 Mx
distributed randomly with density n=0.007 per square Mm
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