5,390 research outputs found
Two-zero Majorana textures in the light of the Planck results
The recent results of the Planck experiment put a stringent constraint on the
sum of the light neutrino masses, m1+m2+m3 < 0.23 eV (95 % CL). On the other
hand, two-zero Majorana mass matrix textures predict strong correlations among
the atmospheric angle and the sum of the masses. We use the Planck result to
show that, for the normal hierarchy case, the texture with vanishing (2,2) and
(3,3) elements is ruled out at a high confidence level; in addition, we
emphasize that a future measurement of the octant of the atmospheric mixing
angle (or the one sigma determination of it based on recent fit to neutrino
data) will put severe constraint on the possible structure of the Majorana mass
matrix. The implication of the above mentioned correlations for neutrinoless
double beta-decay are also discussed, for both normal and inverted orderings.Comment: 9 pages, 8 figure
‘SOSpesa’–Service Design Leveraging Neighborhood Solidarity Networks to Tackle Food Poverty, Food Surplus, and Sustainability of Local Commerce
This paper illustrates a project to redesign a charitable initiative against food poverty into an innovative solution called "SOSpesa", implemented in a neighborhood of the city of Milan named NoLo - North of Loreto. The paper outlines approach, methodology and strategy to move from an activist initiative to a service with more than charitable purposes and outlines the new service configuration in its opportunities and limitations as emerged from the pilot project. It focuses on strategies to harness a network of neighborhood actors to achieve a goal of solidarity, combating food waste and supporting local shops. Based on the assumption that the local context is a strength of the service, the project activated a wide range of actors, from volunteers to third sector organizations and businesses, under the coordination of a team of researchers, to experiment with different service configurations in search of overall sustainability. Finally, the paper discusses design strategies for scaling up grassroots social innovation through replicability, not to distort its spirit and bottom-up engagement
Implementation of the Hierarchical Reference Theory for simple one-component fluids
Combining renormalization group theoretical ideas with the integral equation
approach to fluid structure and thermodynamics, the Hierarchical Reference
Theory is known to be successful even in the vicinity of the critical point and
for sub-critical temperatures. We here present a software package independent
of earlier programs for the application of this theory to simple fluids
composed of particles interacting via spherically symmetrical pair potentials,
restricting ourselves to hard sphere reference systems. Using the hard-core
Yukawa potential with z=1.8/sigma for illustration, we discuss our
implementation and the results it yields, paying special attention to the core
condition and emphasizing the decoupling assumption's role.Comment: RevTeX, 16 pages, 2 figures. Minor changes, published versio
Ultrasound-assisted synthesis of WOx-decorated ZnO photocatalysts for NOx abatement
Heterojunctions based on ZnO have numerous applications, such as water splitting, sensing and energy storage [1]. Recently, ZnO/WO3 composites have shown promising results in the sonocatalytic and photocatalytic degradation of aqueous and gas pollutants [2]. Several synthetic approaches have been reported, including chemical vapor deposition, magnetron sputtering, hydrothermal methods and high temperature annealing. Ultrasound-assisted synthesis can provide a scalable and cost-effective strategy to tailor the catalyst structural and morphological properties [3]. In the present work, pristine ZnO and ZnO/WOx composites were synthesized via a sonochemical method, studying the role of the ultrasound amplitude and mode (continuous/pulsed), metal precursor, WOx content and post-synthetic annealing. The resulting materials were extensively characterized, investigating their structural, morphological, optical, and surface properties. Samples were tested towards the photocatalytic removal of NOx under both UV and visible light irradiation in a batch reactor. A good degree of crystallinity is appreciable even before calcination and better morphological features are observed with respect to reference samples prepared without ultrasounds. The morphological properties can be further tuned by changing the metal precursor and adding a post-synthetic annealing step. Photocatalytic activity is promoted with respect to both benchmark samples (Figure 1)
Variational Approach to Hard Sphere Segregation Under Gravity
It is demonstrated that the minimization of the free energy functional for
hard spheres and hard disks yields the result that excited granular materials
under gravity segregate not only in the widely known "Brazil nut" fashion, i.e.
with the larger particles rising to the top, but also in reverse "Brazil nut"
fashion. Specifically, the local density approximation is used to investigate
the crossover between the two types of segregation occurring in the liquid
state, and the results are found to agree qualitatively with previously
published results of simulation and of a simple model based on condensation.Comment: 10 pages, 3 figure
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Measurement of geo-neutrinos from 1353 days of Borexino
We present a measurement of the geo--neutrino signal obtained from 1353 days
of data with the Borexino detector at Laboratori Nazionali del Gran Sasso in
Italy. With a fiducial exposure of (3.69 0.16) proton
year after all selection cuts and background subtraction, we detected
(14.3 4.4) geo-neutrino events assuming a fixed chondritic mass Th/U
ratio of 3.9. This corresponds to a geo-neutrino signal = (38.8
12.0) TNU with just a 6 probability for a null geo-neutrino
measurement. With U and Th left as free parameters in the fit, the relative
signals are = (10.6 12.7) TNU and =
(26.5 19.5) TNU. Borexino data alone are compatible with a mantle
geo--neutrino signal of (15.4 12.3) TNU, while a combined analysis with
the KamLAND data allows to extract a mantle signal of (14.1 8.1) TNU. Our
measurement of a reactor anti--neutrino signal =
84.5 TNU is in agreement with expectations in the presence of
neutrino oscillations.Comment: 9 pages, 6 figure
Prevalence and associated factors of COVID-19 across Italian regions: a secondary analysis from a national survey on physiotherapists
Background: Coronavirus disease 2019 (COVID-19) broke out in China in December 2019 and now is a pandemic all around the world. In Italy, Northern regions were hit the hardest during the first wave. We aim to explore the prevalence and the exposure characteristics of physiotherapists (PTs) working in different Italian regions during the first wave of COVID-19. Methods: Between April and May 2020 a structured anonymous online survey was distributed to all PTs registered in the National Professional Registry to collect prevalence data of a confirmed diagnosis of COVID-19 (i.e., nasopharyngeal swab and/or serological test). A bottom-up agglomerative nesting hierarchical clustering method was applied to identify groups of regions based on response rate. Multivariable logistic regression was used to explore personal and work-related factors associated with a confirmed diagnosis of COVID-19. Results: A total of 15,566 PTs completed the survey (response rate 43.3%). The majority of respondents (57.7%) were from Northern regions. Considering all respondents, the number of confirmed COVID-19 cases in Northern and Central Italy, was higher compared to those in Southern Italy (6.9% vs. 1.8%, P < 0.001); focusing the analysis on respondents who underwent nasopharyngeal swab and/or serological test led to similar findings (14.1% vs. 6.4%, P < 0.001). Working in Northern and Central regions was associated with a higher risk of confirmed diagnosis of COVID-19 compared to Southern regions (OR 3.4, 95%CI 2.6 to 4.3). PTs working in Northern and Central regions were more likely to be reallocated to a different unit and changing job tasks, compared to their colleagues working in the Southern regions (10.5% vs 3.7%, P < 0.001). Conclusions: Work-related risk factors were differently distributed between Italian regions at the time of first pandemic wave, and PTs working in the Northern and Central regions were more at risk of a confirmed diagnosis of COVID-19, especially when working in hospitals. Preventive and organizational measures should be applied to harmonize physiotherapy services in the national context. Registration: https://osf.io/x7ch
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Search for Solar Axions Produced in Reaction with Borexino Detector
A search for 5.5-MeV solar axions produced in the reaction was performed using the Borexino detector. The Compton
conversion of axions to photons, ; the
axio-electric effect, ; the decay of axions into
two photons, ; and inverse Primakoff conversion on
nuclei, , are considered. Model independent
limits on axion-electron (), axion-photon (), and
isovector axion-nucleon () couplings are obtained: and at 1 MeV (90% c.l.). These limits are
2-4 orders of magnitude stronger than those obtained in previous
laboratory-based experiments using nuclear reactors and accelerators.Comment: 11 pages, 7 figures, submitted to Phys.Rev.
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Solar neutrino with Borexino: results and perspectives
Borexino is a unique detector able to perform measurement of solar neutrinos
fluxes in the energy region around 1 MeV or below due to its low level of
radioactive background. It was constructed at the LNGS underground laboratory
with a goal of solar Be neutrino flux measurement with 5\% precision. The
goal has been successfully achieved marking the end of the first stage of the
experiment. A number of other important measurements of solar neutrino fluxes
have been performed during the first stage. Recently the collaboration
conducted successful liquid scintillator repurification campaign aiming to
reduce main contaminants in the sub-MeV energy range. With the new levels of
radiopurity Borexino can improve existing and challenge a number of new
measurements including: improvement of the results on the Solar and terrestrial
neutrino fluxes measurements; measurement of pp and CNO solar neutrino fluxes;
search for non-standard interactions of neutrino; study of the neutrino
oscillations on the short baseline with an artificial neutrino source (search
for sterile neutrino) in context of SOX project.Comment: 15 pages, 4 figure
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