A critical point in the distribution of lepton energies from the decay of a spin-1 resonance

We consider a spin-$1$ resonance produced with an arbitrary spectrum of velocities and decaying into a pair of massless leptons, and we study the probability density function of the energy of the leptons in the laboratory frame. A special case is represented by the production of $W$ bosons in proton-proton collisions, for which the energy of the charged lepton from the decaying $W$ can be measured with sufficient accuracy for a high-precision measurement of $M_W$. We find that half of the resonance mass is a special value of the lepton energy, since the probability density function at this point is in general not analytic for a narrow-width resonance. In particular, the higher-order derivatives of the density function are likely to develop singularities, such as cusps or poles. A finite width of the resonance restores the regularity, for example by smearing cusps and poles into local stationary points. The quest for such points offers a handle to estimate the resonance mass with much reduced dependence on the underlying production and decay dynamics of the resonance.Comment: Revised version, 24 pages, 7 figure

Design guidelines for H-Darrieus wind turbines: Optimization of the annual energy yield

H-Darrieus wind turbines are gaining popularity in the wind energy market, particularly as they are thought to represent a suitable solution even in unconventional installation areas. To promote the diffusion of this technology, industrial manufacturers are continuously proposing new and appealing exterior solutions, coupled with tempting rated-power offers. The actual operating conditions of a rotor over a year can be, however, very different from the nominal one and strictly dependent on the features of the installation site. Based on these considerations, a turbine optimization oriented to maximize the annual energy yield, instead of the maximum power, is thought to represent a more interesting solution. With this goal in mind, 21,600 test cases of H-Darrieus rotors were compared on the basis of their energy-yield capabilities for different annual wind distributions in terms of average speed. The wind distributions were combined with the predicted performance maps of the rotors obtained with a specifically developed numerical code based on a Blade Element Momentum (BEM) approach. The influence on turbine performance of the cut-in speed was accounted for, as well as the limitations due to structural loads (i.e. maximum rotational speed and maximum wind velocity). The analysis, carried out in terms of dimensionless parameters, highlighted the aerodynamic configurations able to ensure the largest annual energy yield for each wind distribution and set of aerodynamic constraints

Valutazione microscopica della vitalita di blastocisti di cavallo dopo 6 o 24 ore di refrigerazione a 5°C in differenti media

The aim of this study was to compare the number of embryo dead cells after 6 and/or 24 h of cooled preservation in three different media. Day 8 embryos were collected by uterine flushing with Ringer Lactate at 37°C in an Ez-Way Filter (PETS, Canton, TX, USA) from 17 Standardbred mares artificially inseminated with fresh or frozen semen. Embryo quality, stage and diameter were evaluated before embryos were randomly allocated to one of these treatments: Emcare Holding Solution (ICPbio Repro- duction, USA), 24 h (EHS24; n = 6), using the standard protocol (control); Emcare Flushing Solution (ICPbio Reproduction, USA), 6 h (EFS6; n = 6) and 24 h (EFS24; n = 4); Ringer Lactate, 6 h (RL6; n = 7). In EFS’s and RL6 groups, the recovered embryos were kept in the filter and rinsed with 1 l of EFS or RL, which replaced the medium flushed from the uterus. Fluid filled filters were then placed in the Equitainer® and after cooling for the due time, the embryos were incubated with the cells stain DAPI and the dead cells were counted using epifluorescence UV- illumination on a Leica DM LB microscope. Embryo’s total cell number was estimated using the correlation: n = 0.0106d2 + 2.0542d-375.28 (n = cells number, d = embryo diameter in μm) (Moussa et al., 2004;160). The effects of treatment and diameter group (1000μ) on the percentages of dead cells/estimated total embryo cells were evaluated by ANOVA (GLM). All the recovered embryos were excellent or good quality blastocysts. No differences in proportion of dead cells were observed between diameter and treatment. Holding for 24 h or in RL for 6 h, 8 days old, good quality equine embryos in EFS didn’t increase the proportion of dead cells compared to cooling in EHS for 24 h. If in vivo studies will confirm the absence of major embryo damage, these protocols will simplify equine embryo cooling and shipping, before transfer

MATTER BECOMES ART

Il tema del progetto di questa Tesi di Laurea è situato sul Monte Corchia e prevede il recupero di una via di lizza, di alcuni edifici di cava (in località la Serretta) e la messa in sicurezza del ravaneto limitrofo, con creazione di un percorso espositivo-culturale, attraverso il quale sia possibile “percepire” il divenire della materia arte. La materia come punto di partenza, la materia come punto di arrivo, sublimata dall'azione dell'uomo

Critical Analysis of Dynamic Stall Models in Low-Order Simulation Models For Vertical-Axis Wind Turbines

Abstract The efficiency of vertical-axis wind turbines (VAWTs) still lacks from those of horizontal-axis rotors (HAWTs). To improve on efficiency, more accurate and robust aerodynamic simulation tools are needed for VAWTs, for which low-order methods have not reached yet a maturity comparable to that of HAWTs' applications. In the present study, the VARDAR research code, based on the BEM theory, is used to critically compare the predictiveness of some dynamic stall models for Darrieus wind turbines. Dynamic stall, connected to the continuous variation of the angle of attack on the airfoils, has indeed a major impact on the performance of Darrieus rotors. Predicted lift and drag coefficients of the airfoils in motion are reconstructed with the different dynamic stall models and compared to unsteady CFD simulations, previously validated by means of experimental data. The results show that low-order models are unfortunately not able to capture all the complex phenomena taking place during a VAWT functioning. It is however shown that the selection of the adequate dynamic stall model can definitely lead to a much better modelling of the real airfoils' behavior and then notably enhance the predictiveness of low-order simulation methods

Identification of a Common Pharmacophore for Binding to MMP2 and RGD Integrin: Towards a Multitarget Approach to Inhibit Cancer Angiogenesis and Metastasis

During tumor angiogenesis different growth factors, cytokines and other molecules interact closely with each other to facilitate tumor cell invasion and metastatic diffusion. The most intensively studied as molecular targets in anti-angiogenic therapies are vascular endothelial growth factor (VEGF) and related receptors, integrin receptors and matrix metalloproteinases (MMPs). Considering the poor efficacy of cancer angiogenesis monotherapies, we reasoned combining the inhibition of α(v)β(3) and MMP2 as a multitarget approach to deliver a synergistic blockade of tumor cell migration, invasion and metastasis. Accordingly, we identified a common pharmacophore in the binding cavity of MMP2 and α(v)β(3), demonstrating such approach with the design, synthesis and bioassays of tyrosine-derived peptidomimetics carrying the necessary functional groups to bind to key pharmacophoric elements of MMP2 and α(v)β(3) RGD integrin

Virtual incidence effect on rotating airfoils in Darrieus wind turbines

Small Darrieus wind turbines are one of the most interesting emerging technologies in the renewable energies scenario, even if they still are characterized by lower efficiencies than those of conventional horizontal-axis wind turbines due to the more complex aerodynamics involved in their functioning. In case of small rotors, in which the chord-to-radius ratios are generally high not to limit the blade Reynolds number, the performance of turbine blades has been suggested to be moreover influenced by the so-called "flow curvature effects". Recent works have indeed shown that the curved flowpath encountered by the blades makes them work like virtually cambered airfoils in a rectilinear flow. In the present study, focus is instead given to a further effect that is generated in reason of the curved streamline incoming on the blades, i.e. an extra-incidence seen by the airfoil, generally referred to as "virtual incidence". In detail, a novel computational method to define the incidence angle has been applied to unsteady CFD simulations of three airfoils in a Darrieus-like motion and their effective angles of attack have been compared to theoretical expectations. The analysis confirmed the presence of an additional virtual incidence on the airfoils and quantified it for different airfoils, chord-to-radius ratios and tip-speed ratios. A comparative discussion on BEM prediction capabilities is finally reported in the study

PSInSAR Analysis in the Pisa Urban Area (Italy): A Case Study of Subsidence Related to Stratigraphical Factors and Urbanization

Permanent Scatterer Interferometry (PSI) has been used to detect and characterize the subsidence of the Pisa urban area, which extends for 33 km2 within the Arno coastal plain (Tuscany, Italy). Two SAR (Synthetic Aperture Radar) datasets, covering the time period from 1992 to 2010, were used to quantify the ground subsidence and its temporal evolution. A geotechnical borehole database was also used to make a correspondence with the detected displacements. Finally, the results of the SAR data analysis were contrasted with the urban development of the eastern part of the city in the time period from 1978 to 2013. ERS 1/2 (European Remote-Sensing Satellite) and Envisat SAR data, processed with the PSInSAR (Permanent Scatterer InSAR) algorithm, show that the investigated area is divided in two main sectors: the southwestern part, with null or very small subsidence rates (<2 mm/year), and the eastern portion which shows a general lowering with maximum deformation rates of 5 mm/year. This second area includes deformation rates higher than 15 mm/year, corresponding to small groups of buildings. The case studies in the eastern sector of the urban area have demonstrated the direct correlation between the age of construction of buildings and the registered subsidence rates, showing the importance of urbanization as an accelerating factor for the ground consolidation process