A numerical methodology is presented which is based on Topology Optimization (TO) approach for designing continuous heterogeneous structures. This method is then exploited to reduce weight and to ...increase stiffness in mechanical components. Useful guidelines for the evaluation of equivalent material properties of metallic cellular structures are discussed, and they are applied for the optimization process of an engine mounting bracket under realistic loading and boundary conditions. The outcome of TO, which is related to the material density distribution into the design space, is critically reviewed for the definition of bulk, lattice and void regions within the component.
Various experiments are searching for detectors that can cover large areas (as in the present LHC experiments) with excellent timing performances and insensitivity to magnetic field. A detector based ...on scintillators coupled to SiPM can fulfil these requirements. SiPMs are indeed replacing the standard PhotoMultiplier technology thanks to the many advantages, with the corresponding possibility to achieve also higher segmentations in calorimetry or other applications. Also in view of future colliders experiments like HL-LHC or FCC or medical applications like TOF-PET, an important R&D on timing performances of SiPMs-scintillator detectors has begun, with the goal of including them in the list of possible 4-D tracking-timing devices.
An R&D on SiPM coupled to scintillator time resolution has been performed in a cosmic ray setup. Different kind of SiPMs, geometries of SiPMs coupled to the scintillator and different size of scintillator have been also studied. A time resolution of ∼69 ps, comprehensive of the full electronic chain, from the front-end to the readout electronics, has been achieved with SiPMs coupled to a 2x2x3 cm3 plastic scintillator.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
The direct response of Silicon PhotoMultipliers being
traversed by a MIP charged particle have been studied in a
systematic way for the first time. Using beam test data, time
resolution and ...the crosstalk probability have been measured. A
characterization of the SiPM by means of a laser beam is also
reported. The results obtained for different sensors indicate a
measured time resolution around 40–70 ps. Although particles are
expected to traverse only one SPAD per event, crosstalk measurements
on different sensors indicate an unexpected higher value with
respect to the one related to the sensor noise.
Seagrasses' ability to store information after exposure to stress (i.e. stress memory) and to better respond to further stress (i.e. priming) have recently been observed, although the temporal ...persistence of the memory and the mechanisms for priming induction remain to be defined. Here, we explored three priming strategies in Posidonia oceanica seedlings, each inducing a different level of stress, for temperature and salinity. We investigated changes in morphometry, growth rate and biomass between primed and non-primed seedlings. The results showed similar behaviour of seedlings when exposed to an acute stress event, regardless of whether they had been primed or not and of the priming strategy received. This opens the debate on the level of stress necessary for inducing a priming status and the persistence of the stress memory in P. oceanica seedlings. Although no priming-induced stress resistance was observed, seedlings showed unexpectedly high resilience to extreme levels of both abiotic stressors.
•The induction of a priming status is dependent on the level of stress.•The persistence of stress memory could depend on the duration of the lag phase.•Posidonia oceanica seedlings are highly resilient to strong thermal and saline stress.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, different Silicon PhotoMultiplier (SiPM) sensors have been tested with charged particles to characterize the Cherenkov light produced in the sensor protection layer. A careful position ...scan of the SiPM response has been performed with different prototypes, confirming the large number of firing cells and proving almost full efficiency, with the SiPM filling factor essentially negligible. This study also allowed us to study the time resolution of such devices as a function of the number of firing cells, reaching values below 20 ps. These measurements provide significant insight into the capabilities of SiPM sensors in direct detection of charged particles and their potential for several applications.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper presents the results of the application of an ultrasonic telemetry system to the investigation of short‐term movements in the European spiny lobster, Palinurus elephas, in a coastal area ...of NW Sicily (Central Mediterranean Sea). Ten lobsters were tagged with miniaturized transmitters and released over a favourable habitat and their movements then recorded by means of nine automated receivers with the objective of investigating post‐release displacement, home‐range extension, movement patterns, activity rhythm and the influence of lunar light intensity on lobster activity. Acoustic detection data were used to assess activity and home range using estimates of horizontal and vertical movements and minimum convex polygons, respectively. Continuous wavelet transform (CWT) analysis was applied to time series of position data. Acoustic data from five of 10 lobsters were successfully recorded across a 78‐day study period between April and June 2008. All of them displayed an activity pattern characterized by diurnal sheltering and nocturnal foraging, with higher activity (i.e., longer distances travelled) at night. Their home range measured between 1629 and 8641 m2, and all lobsters relocated every 4.6 days on average, probably in search of unexploited feeding grounds. For this reason we hypothesize a nomadic movement pattern for our tagged lobsters. CWT analyses highlighted a 24‐h periodicity in lobster activity, with higher activity from sunset to sunrise. No clear influence of moon phase on lobster activity was detected.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Purpose
Traumatic diaphragm rupture (TDR) is a rare complication of trauma in pediatric age and may be easily missed by the severity of associated injuries so that delayed emergent presentation can ...occur with increased rate of morbidity and mortality. No review has been available to guide clinicians through the pitfalls and the initial diagnostic approach to pediatric TDR.
Methods
A Medline thorough search on TDR was conducted using different queries. English language citations were identified during the period of January 2000 through December 2014 limiting the search to pediatric age (0–18 years). Abstracts were reviewed to determine eligibility and texts were obtained for further review. Differences were resolved by consensus and only reliable data were included.
Results
Most frequently reported presenting symptoms of TDR are respiratory and abdominal. While respiratory symptoms are among the most frequently described at the onset in pediatric and adult series, abdominal symptoms result to be more frequent in adult than pediatric patients. Chest X-ray (CXR) is the first-line imaging exam which is reported to show pathognomonic or suspect findings in 85 %. CT was the second main radiological technique used, in particular to confirm the suspicion of TDR.
Conclusions
A high clinical index of suspicion is needed to diagnose and effectively manage diaphragmatic rupture. TDR should be kept in mind while dealing with patients assessed for abdominal or respiratory symptoms whenever there is history of trauma or blunt injury especially in children as the increasing of non-operative management of blunt abdominal trauma could result in missing important injuries as TDR.
In this paper, evidence that the increased response of SiPM sensors to the passage of charged particles is related mainly to Cherenkov light produced in the protection layer is reported. The response ...and timing properties of sensors with different protection layers have been studied.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper presents the results of an application of ultrasonic telemetry on white seabream, Diplodus sargus inhabiting an artificial reef (AR) in NW Sicily (western Mediterranean Sea). The objective ...of the study was to investigate the movement pattern of seabreams, verify their homing behaviour and site fidelity, determine their home range and describe their use of the habitat. Four seabreams were tagged and released, and their movements were recorded with automated and manual acoustic receivers. The spatial and temporal distribution of positional data suggest that the tagged seabreams hide inside the AR during the day, staying out of their shelter at night. The nocturnal movements of the tagged fishes are suggested to be a search for food in the seagrass patches surrounding the ARs. The monitored seabreams showed clear homing behaviour and strong site fidelity. Their home range extended from 0.01 to 0.17 km and included the AR and the surrounding sandy area with seagrass patches. Home range areas increased proportionally to the distance between the refuge on AR and the foraging areas on seagrass patches. The higher activity of seabreams during the night was interpreted as a result of a trade-off between predation risk and foraging needs.
This paper develops a new time series clustering procedure allowing for heteroskedasticity, non-normality and model's non-linearity. At this aim, we follow a fuzzy approach. Specifically, considering ...a Dynamic Conditional Score (DCS) model, we propose to cluster time series according to their estimated conditional moments via the Autocorrelation-based fuzzy C-means (A-FCM) algorithm. The DCS parametric modeling is appealing because of its generality and computational feasibility. The usefulness of the proposed procedure is illustrated using an experiment with simulated data and several empirical applications with financial time series assuming both linear and nonlinear models' specification and under several assumptions about time series density function.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF