472 research outputs found
Drilling polymeric matrix composites
This chapter presents the basics of drilling of polymeric matrix composites
(PMCs). PMCs are becoming widely used in the manufacturing of products where
a high mechanical strength must be accompanied by a low weight. However, the
machining of PMCs implies coping with problems that are not encountered when
machining other materials. Drilling is a particularly critical operation for PMCs
laminates because the large concentrated forces generated can lead to widespread
damage. This damage causes aesthetic problems but, more importantly, may compromise
the mechanical properties of the finished part
On quantitative analysis of interband recombination dynamics: Theory and application to bulk ZnO
The issue of the quantitative analysis of time-resolved photoluminescence
experiments is addressed by developing and describing two approaches for
determination of unimolecular lifetime, bimolecular recombination coefficient,
and equilibrium free-carrier concentration, based on a quite general
second-order expression of the electron-hole recombination rate. Application to
the case of band-edge emission of ZnO single crystals is reported, evidencing
the signature of sub-nanosecond second-order recombination dynamics for optical
transitions close to the interband excitation edge. The resulting findings are
in good agreement with the model prediction and further confirm the presence,
formerly evidenced in literature by non-optical methods, of near-surface
conductive layers in ZnO crystals with sheet charge densities of about
3{\div}5*10^13 cm^-2Comment: 4 pages, 5 figure
Mott Transition and Spin Structures of Spin-1 Bosons in Two-Dimensional Optical Lattice at Unit Filling
We study the ground state properties of spin-1 bosons in a two-dimensional
optical lattice, by applying a variational Monte Carlo method to the S=1
Bose-Hubbard model on a square lattice at unit filling. A doublon-holon binding
factor introduced in the trial state provides a noticeable improvement in the
variational energy over the conventional Gutzwiller wave function and allows us
to deal effectively with the inter-site correlations of particle densities and
spins. We systematically show how spin-dependent interactions modify the
superfluid-Mott insulator transitions in the S=1 Bose-Hubbard model due to the
interplay between the density and spin fluctuations of bosons. Furthermore,
regarding the magnetic phases in the Mott region, the calculated spin structure
factor elucidates the emergence of nematic and ferromagnetic spin orders for
antiferromagnetic () and ferromagnetic () couplings,
respectively.Comment: 5 pages, 5 figures, to appear in Journal of the Physical Society of
Japa
Commensurate lock-in and incommensurate supersolid phases of hardcore bosons on anisotropic triangular lattices
We investigate the interplay between commensurate lock-in and incommensurate
supersolid phases of the hardcore bosons at half-filling with anisotropic
nearest-neighbor hopping and repulsive interactions on triangular lattice. We
use numerical quantum and variational Monte Carlo as well as analytical
Schwinger boson mean-field analysis to establish the ground states and phase
diagram. It is shown that, for finite size systems, there exist a series of
jumps between different supersolid phases as the anisotropy parameter is
changed. The density ordering wavevectors are locked to commensurate values and
jump between adjacent supersolids. In the thermodynamic limit, however, the
magnitude of these jumps vanishes leading to a continuous set of novel
incommensurate supersoild phases.Comment: 5 pages, 5 figures, added new results, changed title and conclusio
UPO Biobank: The Challenge of Integrating Biobanking into the Academic Environment to Support Translational Research
Biobanks are driving motors of precision and personalized medicine by providing high-quality biological material/data through the standardization and harmonization of their collection, preservation, and distribution. UPO Biobank was established in 2020 as an institutional, disease, and population biobank within the University of Piemonte Orientale (UPO) for the promotion and support of high-quality, multidisciplinary studies. UPO Biobank collaborates with UPO researchers, sustaining academic translational research, and supports the Novara Cohort Study, a longitudinal cohort study involving the population in the Novara area that will collect data and biological specimens that will be available for epidemiological, public health, and biological studies on aging. UPO Biobank has been developed by implementing the quality standards for the field and the ethical and legal issues and normative about privacy protection, data collection, and sharing. As a member of the "Biobanking and Biomolecular Resources Research Infrastructure" (BBMRI) network, UPO Biobank aims to expand its activity worldwide and launch cooperation with new national and international partners and researchers. The objective of this manuscript is to report an institutional and operational experience through the description of the technical and procedural solutions and ethical and scientific implications associated with the establishment of this university research biobank
Istallazione di una stazione per la rivelazione continua Radon mediante spettrometria alfa nella Solfatara di Pozzuoli
INGV (Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Napoli - Osservatorio Vesuviano)Published1-221.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveN/A or not JCRrestricte
Persistence of neutralizing antibodies to SARS-CoV-2 in first wave infected individuals at ten months post-infection: The UnIRSA cohort study
Longitudinal mapping of antibody-based SARS-CoV-2 immunity is critical for public health control of the pandemic and vaccine development. We performed a longitudinal analysis of the antibody-based immune response in a cohort of 100 COVID-19 individuals who were infected during the first wave of infection in northern Italy. The SARS-CoV-2 humoral response was tested using the COVID-SeroIndex, Kantaro Quantitative SARS-CoV-2 IgG Antibody RUO Kit (R&D Systems, Bio-Techne, Minneapolis, USA) and pseudotype-based neutralizing antibody assay. Using sequential serum samples collected from 100 COVID-19 recovered individuals from northern Italy—mostly with mild disease—at 2 and 10 months after their first positive PCR test, we show that 93% of them seroconverted at 2 months, with a geometric mean (GeoMean) half-maximal neutralization titer (NT50) of 387.9. Among the 35 unvaccinated subjects retested at 10 months, 7 resulted seronegative, with an 80% drop in seropositivity, while 28 showed decreased anti-receptor binding domain (RBD) and anti-spike (S) IgG titers, with a GeoMean NT50 neutralization titer dropping to 163.5. As an NT50 > 100 is known to confer protection from SARS-CoV-2 re-infection, our data show that the neutralizing activity elicited by the natural infection has lasted for at least 10 months in a large fraction of subjects
Persistence of neutralizing antibodies to SARS-CoV-2 in first wave infected individuals at ten months post-infection: The UnIRSA cohort study
Longitudinal mapping of antibody-based SARS-CoV-2 immunity is critical for public health control of the pandemic and vaccine development. We performed a longitudinal analysis of the antibody-based immune response in a cohort of 100 COVID-19 individuals who were infected during the first wave of infection in northern Italy. The SARS-CoV-2 humoral response was tested using the COVID-SeroIndex, Kantaro Quantitative SARS-CoV-2 IgG Antibody RUO Kit (R&D Systems, Bio- Techne, Minneapolis, USA) and pseudotype-based neutralizing antibody assay. Using sequential serum samples collected from 100 COVID-19 recovered individuals from northern Italy—mostly with mild disease—at 2 and 10 months after their first positive PCR test, we show that 93% of them seroconverted at 2 months, with a geometric mean (GeoMean) half-maximal neutralization titer (NT50) of 387.9. Among the 35 unvaccinated subjects retested at 10 months, 7 resulted seronegative, with an 80% drop in seropositivity, while 28 showed decreased anti-receptor binding domain (RBD) and anti-spike (S) IgG titers, with a GeoMean NT50 neutralization titer dropping to 163.5. As an NT50 > 100 is known to confer protection from SARS-CoV-2 re-infection, our data show that the neutralizing activity elicited by the natural infection has lasted for at least 10 months in a large fraction of subjects
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