260 research outputs found
Paying the price for body evolution:The role of evolution in disorders of body representation
Wake control of a 3D bluff body
Bluff bodies are characterized by massive flow separation responsible of most of the pressure drag.
Three main contributions roughly determine the total amount of the body drag : 30% is due to the rolling tire, 45% derive from the rear base and 25% comes from the underbody flow and interferences. In the case of large and medium size trucks employed for short and long distance of transportations the fuel consumption can be considerable reduced through the control of the flow separation from the base. The afterbody geometry plays a key role for the drag contributions as showed by Ahmed [1]. Aider et al. [2] used passive vortex generators while piezoelectric vortex generators were investigated by Orazi et al. [3]. Continuous blowing slots as done by Rouméas et al. [4] have been also used on a semi-infinite body. The present investigation considers a simplified 3D car with square-back rear shape. The wake control consist in the injection of continuous jets through four rectangular slots mounted around the perimeter of the rear part. Furthermore, four curved slots are disposed near the wheel to control the flow separation in this region. The flow analysis is performed by means of CFD commercial code (STAR CCM+® by Cd-Adapco). Results of this preliminary investigation will be presented. The effects of the independent rear slots orientation (i) and of the jet velocity (Vi) are analyzed as well as the effects of the jets around the wheels. The study will be also carry out on a physical model that will be tested in a wind tunnel. In figure 1 the expanded model and a portion of the longitudinal section of the rear part of the body are shown
Dermatological high-dose-rate brachytherapy for the treatment of basal and squamous cell carcinoma
Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are among the most common cancers in humans. Various therapies are currently being used to treat these tumours including surgery, topical treatments and radiotherapy. We describe a new treatment for BCC and SCC. This consists of superficial radiotherapy, using synthetic resin containing a radioactive beta-emitting isotope. The resin is applied to the lesion to perform a selective beta-irradiation brachytherapy treatment
The origin of the first neutron star -- neutron star merger
The first neutron star-neutron star (NS-NS) merger was discovered on August
17, 2017 through gravitational waves (GW170817) and followed with
electromagnetic observations. This merger was detected in an old elliptical
galaxy with no recent star formation. We perform a suite of numerical
calculations to understand the formation mechanism of this merger. We probe
three leading formation mechanisms of double compact objects: classical
isolated binary star evolution, dynamical evolution in globular clusters and
nuclear cluster formation to test whether they are likely to produce NS-NS
mergers in old host galaxies. Our simulations with optimistic assumptions show
current NS-NS merger rates at the level of 10^-2 yr^-1 from binary stars, 5 x
10^-5 yr^-1 from globular clusters and 10^-5 yr^-1 from nuclear clusters for
all local elliptical galaxies (within 100 Mpc^3). These models are thus in
tension with the detection of GW170817 with an observed rate 1.5 yr^-1 (per 100
Mpc^3; LIGO/Virgo estimate). Our results imply that either (i) the detection of
GW170817 by LIGO/Virgo at their current sensitivity in an elliptical galaxy is
a statistical coincidence; or that (ii) physics in at least one of our three
models is incomplete in the context of the evolution of stars that can form
NS-NS mergers; or that (iii) another very efficient (unknown) formation channel
with a long delay time between star formation and merger is at play.Comment: A&A: accepte
Using Virtual Reality to Rehabilitate Neglect
Purpose: Virtual Reality (VR) platforms gained a lot of attention in the rehabilitation field due to their ability to engage patients and the opportunity they offer to use real world scenarios. As neglect is characterized by an impairment in exploring space that greatly affects daily living, VR could be a powerful tool compared to classical paper and pencil tasks and computer training. Nevertheless, available platforms are costly and obstructive. Here we describe a low cost platform for neglect rehabilitation, that using consumer equipments allows the patient to train at home in an intensive fashion.
Method: We tested the platform on IB, a chronic neglect patient, who did not benefit from classical rehabilitation.
Results: Our results show that IB improved both in terms of neglect and attention. Importantly, these ameliorations lasted at a follow up evaluation 5 months after the last treatment session and generalized to everyday life activities.
Conclusions: VR platforms built using equipment technology and following theoretical principles on brain functioning may induce greater ameliorations in visuo-spatial deficits than classical paradigms possibly thanks to the real world scenarios in association with the "visual feedback" of the patient's own body operating in the virtual environmen
Trapped vortex cell for aeronautical applications: flow analysis through PIV and Wavelet transform tools.
Abstract Results of the application of a trapped vortex cell to an airfoil with the aim of improving the
aerodynamic performances are presented for two complementary experiments arranged at CIRA and at
Politecnico di Torino. In the CIRA experiments, PIV measurements on a simplified configuration were carried
out to characterize the trapped vortical structure and its effect on the separating flow downstream of the cell. In
the experimental investigation at Politecnico di Torino, static pressure distributions were measured around a
complete airfoil model, to yield lift and pitching moment coefficients. Wake surveys were also carried out to
measure the drag. To study the unsteady phenomena inside the cavity pressure fluctuations signals were also
investigated using Kulite sensors. In both experiments, the angle of attack of the airfoil and the Reynolds number
were varied. It is shown that the flow inside the cell is highly unsteady with significant shedding of flow
structures downstream. This phenomenon results in a large region of separated flow, in higher drag and lower
lift. By contrast, the cell flow is considerably stabilized and regularized by applying distributed suction over the
cell wall. As a result, the flow downstream of the cell reattaches and lower drag and larger lift are observed
FOOD SAFETY AND PROCESS HYGIENE CRITERIONS ON SHEEP CARCASSES
The hygienic status and the presence of some pathogens (Staphylococcus aureus, Listeria monocytogenes e Salmonella spp.) at slaughterhouses was evaluated in different matrix of sheep and lambs (carcass surface, faeces, fleeces and mesenteric lymph nodes) according to the Com. Reg. (EC) No 2073/2005. The 48% of sheep and 68.9% of lamb sampled carcasses resulted allocated into the marginal category for Aerobic colony count, while the 28% and 42.2% respectively were allocated into unacceptable category for Enterobacteriaceae. S.aureus was isolated more frequently in fleeces (11.5%), carcasses (12.6%) of lambs than sheep. L. monocytogenes was found in fleeces and carcass of two sheep and in faeces of four lambs, while Salmonella spp. was detected only in sheep carcasses of a single plant
From mining wastes to mineral sources - investigating the REE-bearing occurrences in the Arburèse District (SW Sardinia)
In recent years, the search for possible sources of REE minerals in Europe involved numerous old mine
areas with high volumes of mining wastes that may offer significant amounts of Critical Raw Materials
(CRMs). In some cases, strong evidence of CRMs anomalous concentrations arises from environmental
characterization of wastes, so that an interesting problem is that of finding their sources, i.e., the original
CRMs - rich mineral phases in the residual ore. An excellent example is provided by the Arburèse district of
SW Sardinia, for about 150 years a major Pb-Zn source in Italy, now an area under study for remediation of
its severe environmental problems, including >10 Mt of waste deposits. The district exploited a large system
(>10 km) of low-temperature polymetallic veins hosted in Lower Paleozoic siliciclastic rocks belonging to
the Variscan Nappe zone, arranged in two main geometrical trends relative to the late Variscan Arbus pluton:
“peripheral” and “intersecting”. Recent investigations in the Montevecchio mine area discovered high Zn (up
to 2.65 wt.%) and Pb (1.23 wt.%) grades in stratified tailing materials belonging to the Sanna old processing
plant. Remarkably, ICP-MS analyses on the same materials revealed total REE+ Y contents attaining about
600 ppm. XRD studies confirmed a tailing composition essentially made of gangue minerals (quartz, siderite
and micas) with goethite, baryte and traces of Zn carbonates and Pb sulfates. Chondrite-normalized REE
patterns are coherent with the hydrothermal character of the source: however, both the REE mineralogical
host(s) in tailings and in the Montevecchio ore are still undetermined. In the search of REE-bearing phases
in the ores, some relevant insights are provided by studies on the southern branch of the Arburèse system,
where the veins of “peripheral” system are hosted in late Ordovician-Silurian sedimentary sequences. In this
part of the district the polymetallic veins assume the character of five-elements (Ni-Co-As-Bi-Ag) veins,
with a rich Ni-Co-Fe arsenide – quartz association (1) overprinted by a Zn-Pb-Cu sulfide – siderite – quartz
association (2), very similar to that dominating in Montevecchio. Investigations in the Pira Inferida mine
sector highlighted the presence of LREE fluorocarbonates (synchysite-Ce and bastnaesite-Ce) and phosphates
(monazite) associated with rutile and apatite. LREE minerals have been detected by SEM-EDS as tiny crystals
in the quartz-sericitic gangue of the Montevecchio-type (2) mineral association. The same minerals are found
in millimetric aggregates in the oxide zone of the veins, sporadically reported by mineral collectors in other
mine sites of the same system. Overall, these occurrences, similar to those found in other low-temperature vein
systems of Sardinia (e.g., Silius vein system), appear reliable mineral REE sources for Montevecchio mine
wastes; they may be therefore used as proxies for REE exploration and assessment in the district
- …