2,421 research outputs found
Room- and High-Temperature Fatigue Strength of the T5 and Rapid T6 Heat-Treated AlSi10Mg Alloy Produced by Laser-Based Powder Bed Fusion
The AlSi10Mg alloy produced by laser-based powder bed fusion (L-PBF) is widely used to produce high-value-added structural parts subjected to cyclic mechanical loads at high temperatures. The paper aims to widen the knowledge of the room- and high-temperature (200 ◦C) fatigue behavior of the L-PBF AlSi10Mg alloy by analyzing the fully reversed rotating bending test results on mechanically polished specimens. Two heat-treated conditions are analyzed: T5 (direct artificial aging: 4 h at 160 ◦C) and novel T6R (rapid solution: 10 min at 510 ◦C, artificial aging: 6 h at 160 ◦C). The study highlights that (i) the T6R alloy is characterized by higher fatigue strength at room (108 MPa) and high temperatures (92 MPa) than the T5 alloy (92 and 78 MPa, respectively); (ii) thermal exposure at 200 ◦C up to 17 h does not introduce macroscopical microstructural variation; (iii) fracture surfaces of the room- and high-temperature-tested specimens show comparable crack initiation, mostly from sub-superficial gas and keyhole pores, and failure propagation mechanisms. In conclusion, the L-PBF AlSi10Mg alloy offers good cyclic mechanical performances
under various operating conditions, especially for the T6R alloy, and could be considered for structural components operating at temperatures up to 200 °
Fermi-LAT gamma-ray anisotropy and intensity explained by unresolved Radio-Loud Active Galactic Nuclei
Radio-loud active galactic nuclei (AGN) are expected to contribute
substantially to both the intensity and anisotropy of the isotropic gamma-ray
background (IGRB). In turn, the measured properties of the IGRB can be used to
constrain the characteristics of proposed contributing source classes. We
consider individual subclasses of radio-loud AGN, including low-,
intermediate-, and high-synchrotron-peaked BL Lacertae objects, flat-spectrum
radio quasars, and misaligned AGN. Using updated models of the gamma-ray
luminosity functions of these populations, we evaluate the energy-dependent
contribution of each source class to the intensity and anisotropy of the IGRB.
We find that collectively radio-loud AGN can account for the entirety of the
IGRB intensity and anisotropy as measured by the Fermi Large Area Telescope
(LAT). Misaligned AGN provide the bulk of the measured intensity but a
negligible contribution to the anisotropy, while high-synchrotron-peaked BL
Lacertae objects provide the dominant contribution to the anisotropy. In
anticipation of upcoming measurements with the Fermi-LAT and the forthcoming
Cherenkov Telescope Array, we predict the anisotropy in the broader energy
range that will be accessible to future observations.Comment: 27 pages, 29 figures. This version matches the published version,
minor changes onl
Black Hole - Neutron Star mergers: using kilonovae to constrain the equation of state
The merging of a binary system involving two neutron stars (NSs), or a black
hole (BH) and a NS, often results in the emission of an electromagnetic (EM)
transient. One component of this EM transient is the epic explosion known as a
kilonova (KN). The characteristics of the KN emission can be used to probe the
equation of state (EoS) of NS matter responsible for its formation. We predict
KN light curves from computationally simulated BH-NS mergers, by using the 3D
radiative transfer code \texttt{POSSIS}. We investigate two EoSs spanning most
of the allowed range of the mass-radius diagram. We also consider a soft EoS
compatible with the observational data within the so-called 2-families scenario
in which hadronic stars coexist with strange stars. Computed results show that
the 2-families scenario, characterized by a soft EoS, should not produce a KN
unless the mass of the binary components are small (, ) and the BH is rapidly spinning
(). In contrast, a strong KN signal potentially
observable from future surveys (e.g. VRO/LSST) is produced in the 1-family
scenario for a wider region of the parameter space, and even for non-rotating
BHs () when and . We also provide a fit that allows for the calculation of the
unbound mass from the observed KN magnitude, without running timely and costly
radiative transfer simulations. Findings presented in this paper will be used
to interpret light curves anticipated during the fourth observing run (O4), of
the advanced LIGO, advanced Virgo and KAGRA interferometers and thus to
constrain the EoS of NS matter.Comment: 14 pages, 16 figures, 2 table
Dermoscopy of Skin Adnexal Neoplasms: A Continuous Challenge
No abstract availabl
a conditional linear gaussian network to assess the impact of several agronomic settings on the quality of tuscan sangiovese grapes
Summary In this paper, a Conditional Linear Gaussian Network (CLGN) model is built for a two-year experiment on Tuscan Sangiovese grapes involving canopy management techniques (number of buds, defoliation and bunch thinning) and harvest time (technological and late harvest). We found that the impact of the considered treatments on the color of wine can be predicted still in the vegetative season of the grapevine; the best treatments to obtain wines with good structure are those with a low number of buds; the best treatments to obtain fresh wines suitable for young consumers are those with technological rather than late harvest, preferably with a high number of buds, and anyway with both defoliation and bunch thinning not performed
NTNU-SINTEF SolarNet: A solar irradiation monitoring network at high latitudes
This study presents a monitoring network for solar irradiation at high latitudes, called NTNU-SINTEF SolarNet. The network collects, with a time resolution ranging from seconds to hours, solar irradiance data, e.g. global horizontal irradiation, diffuse horizontal irradiation, direct normal irradiation, global tilted irradiation, solar energy generation, which are required in solar irradiation modelling in built environments. The network will be used for specific applications, such as (i) anomalies detection, (ii) influences of ground albedo, and (iii) ageing/degradation of solar modules, that are described in this paper. Some characteristics that make the NTNU-SINTEF SolarNet relevant for solar energy research at high latitudes are identified: short distances among the sensors, the ease of data accessibility, the use of the same sensor typologies, and different solar module technologies. The research holds the potential to boost the solar energy digitalization, impacting on several aspects such as predictive and adaptive control strategies for energy management, design of renewable energy system, multi-scale optimization and efficient exploitation of solar energy.publishedVersio
p53-sensitive epileptic behavior and inflammation in Ft1 hypomorphic mice
Epilepsy is a complex clinical condition characterized by repeated spontaneous seizures. Seizures have been linked to multiple drivers including DNA damage accumulation. Investigation of epilepsy physiopathology in humans imposes ethical and practical limitations, for this reason model systems are mostly preferred. Among animal models, mouse mutants are particularly valuable since they allow conjoint behavioral, organismal, and genetic analyses. Along with this, since aging has been associated with higher frequency of seizures, prematurely aging mice, simulating human progeroid diseases, offer a further useful modeling element as they recapitulate aging over a short time-window. Here we report on a mouse mutant with progeroid traits that displays repeated spontaneous seizures. Mutant mice were produced by reducing the expression of the gene Ft1 (AKTIP in humans). In vitro, AKTIP/Ft1 depletion causes telomere aberrations, DNA damage, and cell senescence. AKTIP/Ft1 interacts with lamins, which control nuclear architecture and DNA function. Premature aging defects of Ft1 mutant mice include skeletal alterations and lipodystrophy. The epileptic behavior of Ft1 mutant animals was age and sex linked. Seizures were observed in 18 mutant mice (23.6% of aged ≥ 21 weeks), at an average frequency of 2.33 events/mouse. Time distribution of seizures indicated non-random enrichment of seizures over the follow-up period, with 75% of seizures happening in consecutive weeks. The analysis of epileptic brains did not reveal overt brain morphological alterations or severe neurodegeneration, however, Ft1 reduction induced expression of the inflammatory markers IL-6 and TGF-β. Importantly, Ft1 mutant mice with concomitant genetic reduction of the guardian of the genome, p53, showed no seizures or inflammatory marker activation, implicating the DNA damage response into these phenotypes. This work adds insights into the connection among DNA damage, brain function, and aging. In addition, it further underscores the importance of model organisms for studying specific phenotypes, along with permitting the analysis of genetic interactions at the organismal level
Chemico-biological characterization of Torpedino Di Fondi® tomato fruits. A comparison with San Marzano cultivar at two ripeness stages
Torpedino di Fondi (TF) is a hybrid tomato landrace developed in Sicily and recently introduced in the south Lazio area along with the classical San Marzano (SM) cultivar. The present study aimed at characterizing TF tomatoes at both pink and red ripening stages, and at comparing them with traditional SM tomatoes. A multidisciplinary approach consisting of morphological, chemical (FT‐ICR MS, NMR, HPLC, and spectrophotometric methods), and biological (antioxidant and antifungal in vitro activity) analyses was applied. Morphological analysis confirmed the mini‐ San Marzano nature and the peculiar crunchy and solid consistency of TF fruits. Pink TF tomatoes displayed the highest content of hydrophilic antioxidants, like total polyphenols (0.192 mg/g), tannins (0.013 mg/g), flavonoids (0.204 mg/g), and chlorophylls a (0.344 mg/g) and b (0.161 mg/g), whereas red TF fruits were characterized by the highest levels of fructose (3000 mg/100 g), glucose (2000 mg/100 g), tryptophan (2.7 mg/100 g), phenylalanine (13 mg/100 g), alanine (25 mg/100 g), and total tri‐unsaturated fatty acids (13% mol). Red SM fruits revealed the greatest content of lipophilic antioxidants, with 1234 mg/g of total carotenoids. In agreement with phenolics content, TF cultivar showed the greatest antioxidant activity. Lastly, red TF inhibited Candida species (albicans, glabrata
and krusei) growth
Last improvements in the data assimilation scheme for the Mediterranean Analysis and Forecast system of the Copernicus Marine Service
The Mediterranean Forecasting System (MFS) is a numerical ocean prediction system
that produces analyses, reanalyses and short term forecasts for the entire Mediterranean
Sea and its Atlantic Ocean adjacent areas. The system is now part of the Copernicus
Marine Environment Monitoring Service (CMEMS) providing regular and systematic
information about the physical state and dynamics of the Mediterranean Sea through
the Med-MFC (Mediterranean Monitoring and Forecasting Center).
MFS has been implemented in the Mediterranean Sea with 1/16o horizontal resolution
and 72 vertical levels and is composed by the hydrodynamic model NEMO (Nucleus
for European Modelling of the Ocean) 2-way online coupled with the third generation
wave model WaveWatchIII (Clementi et al., 2017a) and forced by ECMWF atmospheric
fields at 1/8° horizontal resolution. The model solutions are corrected by the data
assimilation system (3D variational scheme, Dobricic and Pinardi, 2008) with a daily
assimilation cycle of along track satellite Sea Level Anomaly (SLA) and vertical profiles
of Temperature and Salinity from ARGO and gliders. In this study we present a new
estimate of the background error covariance matrix with vertical Empirical Orthogonal
Functions (EOFs) that are defined at each grid point of the model domain in order to
better account for the error covariance between temperature and salinity in the shelf and
open ocean areas. Moreover the Observational error covariance matrix is z-dependent
and varies in each month. This new dataset has been tested and validated for more
than 2 years against a background error correlation matrix varying only seasonally and
in thirteen sub-regions of the Mediterranean Sea (Dobricic et al. 2005).PublishedBergen, Norway3SR. AMBIENTE - Servizi e ricerca per la Societ
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