664 research outputs found
D3.4 + D3.6: Annex 2 Results logistical case studies Aragon
In the S2Biom project the logistical case study in Burgundy was the first that wasperformed. The data were based on the results of the LogistEC project, which had already performed a thorough assessment of the case. Therefore, the S2Biom case study was especially used to develop the new tool LocaGIStics, and to illustrate the possibilities of such a new logistical tool in combination with an existing tool, the BeWhere model. So the results of the case study were not primarily intended to further assess the real life case or to advise an actual company for taking decisions on their biomass supply chain yet.The BeWhere model has been applied for the case study of Burgundy in order toidentify the optimal locations of bioenergy production plants. It should be emphasized that the locations of the plants were highly driven by the location and amount of the demand of heat over the transport collection of the feedstock at least for this particular case study. The collection points of the biomass are nevertheless very well concentrated around the production plants. Anyhow to validate those results, LocaGIStics is a valuable tool for the simulation of the feedstock collection from the plants determined from BeWhere. The quality check controls the feedstock collection, capacity and therefore the validity of the chosen location.The LocaGIStics model has especially been developed using the Burgundy casestudy. Several logistical concepts have been tested in the Burgundy case. These are:i) mixing different biomass types (straw as a biomass residue and Miscanthus as an energy crop), ii) applying pretreatment technology (pelletizing) to densify the material in order to lower the transportation costs and increase handling properties, iii) switching between different types of transport means (truck and walking floor vehicle)and iv) direct delivery to a power plant versus putting an intermediate collection point in the value chain. Due to the nature of this development case less value should be given to the exact results of the five variants that are described in this report. However, these variants are perfect examples of what effects can be achieved if the set-up of a lignocellulosic biomass value chain is changed, even if that change is only slightly. So the case was used successfully to build a first version of the locaGIStics tool. However, many improvements are still possible and could be achieved in future project cases
Redox transformations of adsorbed NO molecules on a Pt(100) electrode
The electrochemical behavior of adsorbed NO molecules on a Pt(100) electrode has been studied in perchloric acid solutions by means of cyclic voltammetry. According to the literature data, a saturated NO adlayer with a coverage of âŒ0.5 monolayers (MLs) is formed under open circuit conditions in an acidic nitrite solution as a result of a disproportionation reaction. The saturated adlayer is stable in the potential range of 0.4â0.9 V vs. a reversible hydrogen electrode in 0.1 M HClO4. NO molecules are oxidized at 0.9â1.1 V with the formation of adsorbed nitrite anions, and they can be reduced to ammonia at potentials less than 0.4 V. In this paper it has been shown that the adlayer stability depends on the surface coverage and extent of ordering. An unsaturated NO adlayer demonstrates NO â NH3 redox transformations at 0.5â0.8 V.Financial support from the Russian Foundation for Basic Research (project no. 10-03-00427), MICINN (CTR2010-1624)(Feder), and Generalitat Valenciana (Prometeo/2009/045)(Feder, Spain) is gratefully acknowledged
Sensitivity plots for WIMP direct detection using the annual modulation signature
Annual modulation due to the Earth's motion around the Sun is a well known
signature of the expected WIMP signal induced in a solid state underground
detector. In the present letter we discuss the prospects of this technique on
statistical grounds, introducing annual-modulation sensitivity plots for the
WIMP-nucleon scalar cross section for different materials and experimental
conditions. The highest sensitivity to modulation is found in the WIMP mass
interval 10 GeV< m_W < 130 GeV, the actual upper limit depending from the
choice of the astrophysical parameters, while the lowest values of the
explorable WIMP-nucleon elastic cross-sections fall in most cases within one
order of magnitude of the sensitivities of present direct detection WIMP
searches.Comment: 24 pages, ReVTeX, 9 figures, submitted to Astroparticle Physic
Lowering the background level and the energy threshold of Micromegas x-ray detectors for axion searches
Axion helioscopes search for solar axions by their conversion in x-rays in
the presence of high magnetic fields. The use of low background x-ray detectors
is an essential component contributing to the sensitivity of these searches. In
this work, we review the recent advances on Micromegas detectors used in the
CERN Axion Solar Telescope (CAST) and proposed for the future International
Axion Observatory (IAXO). The actual setup in CAST has achieved background
levels below 10 keV cm s, a factor 100 lower than
the first generation of Micromegas detectors. This reduction is based on active
and passive shielding techniques, the selection of radiopure materials, offline
discrimination techniques and the high granularity of the readout. We describe
in detail the background model of the detector, based on its operation at CAST
site and at the Canfranc Underground Laboratory (LSC), as well as on Geant4
simulations. The best levels currently achieved at LSC are low than 10
keV cm s and show good prospects for the application of
this technology in IAXO. Finally, we present some ideas and results for
reducing the energy threshold of these detectors below 1 keV, using
high-transparent windows, autotrigger electronics and studying the cluster
shape at different energies. As a high flux of axion-like-particles is expected
in this energy range, a sub-keV threshold detector could enlarge the physics
case of axion helioscopes.Comment: Proceedings of 3rd International Conference on Technology and
Instrumentation in Particle Physics (TIPP 2014
Characteristic properties of Planacon MCP-PMTs
A systematic investigation of Planacon MCP-PMTs was performed using 64 XP85002/ FIT-Q photosensors. These devices are equipped with microchannel plates of reduced resistance. Results of a study of their gain stability over time and saturation level in terms of the average anode current are presented. This information allows one to determine the lower limit of the MCP resistance for stable Planacon operation. The spread of the electron multiplication characteristics for the entire production batch is also presented, indicating the remarkably low voltage requirements of these MCP-PMTs. Detection efficiency and noise characteristics, such as dark count rate and afterpulsing level, are also reviewed.Peer reviewe
Glucocerebrosidase expression patterns in the non-human primate brain
Glucocerebrosidase (GCase) is a lysosomal
enzyme encoded by the GBA1 gene. Mutations in GBA1
gene lead to Gaucherâs disease, the most prevalent lysosomal storage disorder. GBA1 mutations reduce GCase
activity, therefore promoting the aggregation of alphasynuclein, a common neuropathological finding underlying
Parkinsonâs disease (PD) and dementia with Lewy bodies.
However, it is also worth noting that a direct link between
GBA1 mutations and alpha-synuclein aggregation indicating cause and effect is still lacking, with limited experimental evidence to date. Bearing in mind that a number of
strategies increasing GCase expression for the treatment of
PD are currently under development, here we sought to
analyze the baseline expression of GCase in the brain of
Macaca fascicularis, which has often been considered as
the gold-standard animal model of PD. Although as with
other lysosomal enzymes, GCase is expected to be ubiquitously expressed, here a number of regional variations
have been consistently found, together with several specific
neurochemical phenotypes expressing very high levels of
GCase. In this regard, the most enriched expression of
GCase was constantly found in cholinergic neurons from
the nucleus basalis of Meynert, dopaminergic cells in the
substantia nigra pars compacta, serotoninergic neurons
from the raphe nuclei, as well as in noradrenergic neurons
located in the locus ceruleus. Moreover, it is also worth
noting that moderate levels of expression were also found
in a number of areas within the paleocortex and archicortex, such as the entorhinal cortex and the hippocampal
formation, respectively
Micromegas for dark matter searches: CAST/IAXO & TREX-DM experiments
The most compelling candidates for Dark Matter to day are WIMPs and axions. The applicability of gasesous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) to the search of these particles is explored within this work. Both particles would produce an extremely low rate at very low energies in particle detectors. Micromegas detectors can provide both low background rates and low energy threshold, due to the high granularity, radiopurity and uniformity of the readout. Small (few cm wide) Micromegas detectors are used to image the ax ion-induced x-ray signal expected in the CERN Axion Solar Telescope (CAST) experiment. We show the background levels obtained in CAST and the prospects to further reduce them to the values required by the Internation Axion Observatory (IAXO). We also present TREX-DM. a scaled-up version of the Micromegas used in axion research, but this time dedicated to the low-mass WIMP detection. TREX-DM is a high-pressure Micromegas-based TPC designed to host a few hundreds of grams of light nuclei (argon or neon) with energy thresholds potentially at the level of 100 eV. The detector is described in detail, as well as the results of the commissioning and characterization phase on surface. Besides, the background model of TREX-DM is presented, along with the anticipated sensitivity of this search, which could go beyond current experimental limits
Resonant structure of space-time of early universe
A new fully quantum method describing penetration of packet from internal
well outside with its tunneling through the barrier of arbitrary shape used in
problems of quantum cosmology, is presented. The method allows to determine
amplitudes of wave function, penetrability and reflection relatively the barrier (accuracy of the method: ), coefficient of penetration (i.e. probability of
the packet to penetrate from the internal well outside with its tunneling),
coefficient of oscillations (describing oscillating behavior of the packet
inside the internal well). Using the method, evolution of universe in the
closed Friedmann--Robertson--Walker model with quantization in presence of
positive cosmological constant, radiation and component of generalize Chaplygin
gas is studied. It is established (for the first time): (1) oscillating
dependence of the penetrability on localization of start of the packet; (2)
presence of resonant values of energy of radiation , at which the
coefficient of penetration increases strongly. From analysis of these results
it follows: (1) necessity to introduce initial condition into both
non-stationary, and stationary quantum models; (2) presence of some definite
values for the scale factor , where start of expansion of universe is the
most probable; (3) during expansion of universe in the initial stage its radius
is changed not continuously, but passes consequently through definite discrete
values and tends to continuous spectrum in latter time.Comment: 18 pages, 14 figures, 4 table
A Quantitative Model of Energy Release and Heating by Time-dependent, Localized Reconnection in a Flare with a Thermal Loop-top X-ray Source
We present a quantitative model of the magnetic energy stored and then
released through magnetic reconnection for a flare on 26 Feb 2004. This flare,
well observed by RHESSI and TRACE, shows evidence of non-thermal electrons only
for a brief, early phase. Throughout the main period of energy release there is
a super-hot (T>30 MK) plasma emitting thermal bremsstrahlung atop the flare
loops. Our model describes the heating and compression of such a source by
localized, transient magnetic reconnection. It is a three-dimensional
generalization of the Petschek model whereby Alfven-speed retraction following
reconnection drives supersonic inflows parallel to the field lines, which form
shocks heating, compressing, and confining a loop-top plasma plug. The
confining inflows provide longer life than a freely-expanding or
conductively-cooling plasma of similar size and temperature. Superposition of
successive transient episodes of localized reconnection across a current sheet
produces an apparently persistent, localized source of high-temperature
emission. The temperature of the source decreases smoothly on a time scale
consistent with observations, far longer than the cooling time of a single
plug. Built from a disordered collection of small plugs, the source need not
have the coherent jet-like structure predicted by steady-state reconnection
models. This new model predicts temperatures and emission measure consistent
with the observations of 26 Feb 2004. Furthermore, the total energy released by
the flare is found to be roughly consistent with that predicted by the model.
Only a small fraction of the energy released appears in the super-hot source at
any one time, but roughly a quarter of the flare energy is thermalized by the
reconnection shocks over the course of the flare. All energy is presumed to
ultimately appear in the lower-temperature T<20 MK, post-flare loops
Lorentz breaking Effective Field Theory and observational tests
Analogue models of gravity have provided an experimentally realizable test
field for our ideas on quantum field theory in curved spacetimes but they have
also inspired the investigation of possible departures from exact Lorentz
invariance at microscopic scales. In this role they have joined, and sometime
anticipated, several quantum gravity models characterized by Lorentz breaking
phenomenology. A crucial difference between these speculations and other ones
associated to quantum gravity scenarios, is the possibility to carry out
observational and experimental tests which have nowadays led to a broad range
of constraints on departures from Lorentz invariance. We shall review here the
effective field theory approach to Lorentz breaking in the matter sector,
present the constraints provided by the available observations and finally
discuss the implications of the persisting uncertainty on the composition of
the ultra high energy cosmic rays for the constraints on the higher order,
analogue gravity inspired, Lorentz violations.Comment: 47 pages, 4 figures. Lecture Notes for the IX SIGRAV School on
"Analogue Gravity", Como (Italy), May 2011. V.3. Typo corrected, references
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