578 research outputs found
DEL British Dashboard October 2020
Overall, the profile of public engagement with development has not changed significantly since June 2020. Changes in overall engagement between June and October with the 10 actions DEL tracks are small and/or insignificant
New Neighbours: Modelling the Growing Population of Gamma-ray Millisecond Pulsars
The Fermi Large Area Telescope, in collaboration with several groups from the
radio community, have had marvellous success at uncovering new gamma-ray
millisecond pulsars (MSPs). In fact, MSPs now make up a sizable fraction of the
total number of known gamma-ray pulsars. The MSP population is characterized by
a variety of pulse profile shapes, peak separations, and radio-to-gamma phase
lags, with some members exhibiting nearly phase-aligned radio and gamma-ray
light curves (LCs). The MSPs' short spin periods underline the importance of
including special relativistic effects in LC calculations, even for emission
originating from near the stellar surface. We present results on modelling and
classification of MSP LCs using standard pulsar model geometries.Comment: 4 pages, 2 figures, proceedings of the ICREA Workshop on The
High-Energy Emission from Pulsars and their Systems (HEEPS), Sant Cugat,
Spai
Optimal design of multi-channel microreactor for uniform residence time distribution
Multi-channel microreactors can be used for various applications that require chemical or electrochemical reactions in either liquid, gaseous or multi phase. For an optimal control of the chemical reactions, one key parameter for the design of such microreactors is the residence time distribution of the fluid, which should be as uniform as possible in the series of microchannels that make up the core of the reactor. Based on simplifying assumptions, an analytical model is proposed for optimizing the design of the collecting and distributing channels which supply the series of rectangular microchannels of the reactor, in the case of liquid flows. The accuracy of this analytical approach is discussed after comparison with CFD simulations and hybrid analytical-CFD calculations that allow an improved refinement of the meshing in the most complex zones of the flow. The analytical model is then extended to the case of microchannels with other cross-sections (trapezoidal or circular segment) and to gaseous flows, in the continuum and slip flow regimes. In the latter case, the model is based on second-order slip flow boundary conditions, and takes into account the compressibility as well as the rarefaction of the gas flow
Low-Power consumption Franz-Keldysh effect plasmonic modulator
In this paper we report on a low energy consumption CMOS-compatible plasmonic modulator based on Franz-Keldysh effect in germanium on silicon. We performed integrated electro-optical simulations in order to optimize the main characteristics of the modulator. A 3.3 dB extinction ratio for a 30 ”m long modulator is demonstrated under 3 V bias voltage at an operation wavelength of 1647 nm. The estimated energy consumption is as low as 20 fJ/bit
A survey of Italian and Spanish neonatologists and paediatricians regarding awareness of the diagnosis of FAS and FASD and maternal ethanol use during pregnancy
<p>Abstract</p> <p>Background</p> <p>Ethanol is the most widely used drug in the world and a human teratogen whose consumption among women of childbearing age has been steadily increasing. There are no Italian or Spanish statistics on ethanol consumption during pregnancy nor any information regarding prevalence of fetal alcohol syndrome (FAS) and fetal alcohol spectrum disorders (FASD). There is also a reasonable suspicion that these two diseases are underdiagnosed by professionals from the above-reported countries. The objectives of this study were: 1) to evaluate the experience, knowledge and confidence of Italian and Spanish neonatologists and paediatricians with respect to the diagnosis of FAS and FASD, and 2) to evaluate professionals awareness of maternal drinking patterns during pregnancy.</p> <p>Methods</p> <p>A multiple-choice anonymous questionnaire was e-mailed to Italian neonatologists registered in the mailing list of the corresponding Society and administered to Italian and Spanish paediatricians during their National Congress.</p> <p>Results</p> <p>The response rate was 16% (63/400) for the Italian neonatologists of the National Society while a total of 152 Spanish and 41 Italian paediatricians agreed to complete the questionnaire during National Congress. Over 90% of the surveyed physicians declared that FAS is an identifiable syndrome and over 60% of them identified at least one of the most important features of FAS. Although over 60% Italian responders and around 80% Spanish responders were aware that ethanol use in pregnancy is dangerous, approximately 50% Italian responders and 40% Spanish ones allowed women to drink sometimes a glass of wine or beer during pregnancy.</p> <p>Neonatologists and paediatricians rated confidence in the ability to diagnosis FAS and FASD as low, with over 50% responders feeling they needed more information regarding FAS and FASD identification in newborn and child.</p> <p>Conclusions</p> <p>Italian and Spanish neonatologists and paediatricians do not feel confident about diagnosing FAS and FASD. More training is needed in order to accurately diagnose ethanol use during pregnancy and correctly inform pregnant women on the consequences on the newborn.</p
Discovery of Pulsed -rays from PSR J0034-0534 with the Fermi LAT: A Case for Co-located Radio and -ray Emission Regions
Millisecond pulsars (MSPs) have been firmly established as a class of
gamma-ray emitters via the detection of pulsations above 0.1 GeV from eight
MSPs by the Fermi Large Area Telescope (LAT). Using thirteen months of LAT data
significant gamma-ray pulsations at the radio period have been detected from
the MSP PSR J0034-0534, making it the ninth clear MSP detection by the LAT. The
gamma-ray light curve shows two peaks separated by 0.2740.015 in phase
which are very nearly aligned with the radio peaks, a phenomenon seen only in
the Crab pulsar until now. The 0.1 GeV spectrum of this pulsar is well
fit by an exponentially cutoff power law with a cutoff energy of 1.80.1 GeV and a photon index of 1.50.1, first errors are
statistical and second are systematic. The near-alignment of the radio and
gamma-ray peaks strongly suggests that the radio and gamma-ray emission regions
are co-located and both are the result of caustic formation.Comment: 20 pages, 3 figures, 2 tables. Accepted for publication in Ap
The Relation Between the Surface Brightness and the Diameter for Galactic Supernova Remnants
In this work, we have constructed a relation between the surface brightness
() and diameter (D) of Galactic C- and S-type supernova remnants
(SNRs). In order to calibrate the -D dependence, we have carefully
examined some intrinsic (e.g. explosion energy) and extrinsic (e.g. density of
the ambient medium) properties of the remnants and, taking into account also
the distance values given in the literature, we have adopted distances for some
of the SNRs which have relatively more reliable distance values. These
calibrator SNRs are all C- and S-type SNRs, i.e. F-type SNRs (and S-type SNR
Cas A which has an exceptionally high surface brightness) are excluded. The
Sigma-D relation has 2 slopes with a turning point at D=36.5 pc: (at 1
GHz)=8.4 D
WmHzster (for
WmHzster and D36.5 pc) and (at 1
GHz)=2.7 10 D
WmHzster (for
WmHzster and D36.5 pc). We discussed the theoretical
basis for the -D dependence and particularly the reasons for the change
in slope of the relation were stated. Added to this, we have shown the
dependence between the radio luminosity and the diameter which seems to have a
slope close to zero up to about D=36.5 pc. We have also adopted distance and
diameter values for all of the observed Galactic SNRs by examining all the
available distance values presented in the literature together with the
distances found from our -D relation.Comment: 45 pages, 2 figures, accepted for publication in Astronomical and
Astrophysical Transaction
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