Aerodynamic control capability of a wing-flap in hypersonic, rarefied regime: Part II

The attitude control of an aircraft is usually fulfilled by means of thrusters at high altitudes. Therefore, the possibility of using also aerodynamic surfaces would produce the advantage of reducing the amount of fuel for the thrusters to be loaded on board. For this purpose, Zuppardi already considered some aerodynamic problems linked to the use of a wing flap in a previous paper. A NACA 0010 airfoil with a trailing edge flap of 35% of the chord, in the range of angle of attack 0-40 deg and flap deflections up to 30 deg was investigated. Computer tests were carried out in hypersonic, rarefied flow by a direct simulation Monte Carlo code at the altitudes of 65 and 85 km of Earth Atmosphere. The present work continues this subject, considering the same airfoil and free stream conditions but two flap extensions of 45% and 25% of the chord and two flap deflections of 15 and 30 deg. The main purpose is to compare the influence of the flap dimension with that of the flap deflection. The present analysis is carried out in terms of: 1) percentage variation of the global aerodynamic coefficients with respect to the no-flap configuration, 2) increment of pressure and heat flux on the airfoil lower surface due to the shock wave-shock wave interaction with respect to the same quantities in no-flap configuration, 3) flap hinge moment. Issues 2) and 3) are important for the design of the mechanical and thermal protection system and of the flap actuator. Even though the flap deflection is aerodynamically more effective than the flap extension, tests verify that using a smaller deflection angle involves the advantage of a smaller increment of pressure and heat flux on the airfoil lower surface as well as a smaller hinge moment

Breaking a 'Taboo': the case for a dynamic approach to secessionist claims

The essay deals with secession, that from a legal point of view presents a number of difficulties common to both the national dimension and the global one. Moving from a recognition of the evidences coming from a static and legalistic approach, relevant cases are analyzed in order to demonstrate the necessity in adopting alternative, dynamic approaches to secessionist phenomena in the academic debate

Are Regional Policies Effective? An Empirical Evaluation on the Diffusion of the Effects of R&D Incentives

This paper provides evidence on the effectiveness of R&D incentives to private firms allocated by Region Umbria in the period between 2004 and 2009. The methodological innovation proposed in this paper is a novel spatial Difference-in-Difference estimator. Our approach compares distinct treatment effects on the basis of the localization in the main local market areas of Umbria (Perugia and Terni), controlling for the presence of technological spillovers due to geographical and economic proximity. The results show a positive and statistically significant impact of the subsidies, especially for innovative outputs and for small firms. The impact is higher for the firms located in less concentrated areas, suggesting the presence of significant local technological and economical spillovers due to the conjunct action of regional policies and spatial diffusion of the activities. Finally, this paper provides some empirical evidence in favour of the effectiveness of «place-based» innovation policies which constitutes the «core» of the recent smart specialization strategy

Long Time Behaviour of the Discrete Volume Preserving Mean Curvature Flow in the Flat Torus

We show that the discrete approximate volume preserving mean curvature flow in the flat torus $\mathbb{T}^N$ starting near a strictly stable critical set $E$ of the perimeter converges in the long time to a translate of $E$ exponentially fast. As an intermediate result we establish a new quantitative estimate of Alexandrov type for periodic strictly stable constant mean curvature hypersurfaces. Finally, in the two dimensional case a complete characterization of the long time behaviour of the discrete flow with arbitrary initial sets of finite perimeter is provided.Comment: 38 pages, 2 figure. arXiv admin note: text overlap with arXiv:2004.04799 by other author

The role of bevacizumab in breast cancer

AbstractNeoangiogenesis and expression of the main angiogenic factor Vascular endothelial growth factor (VEGF) are critical steps already present at an early stage of breast cancer development. As tumor growth progresses other pro-angiogenic factors, including bFGF, TGFa and IL-8, are overexpressed and act in addition to VEGF. VEGF expression has been associated to poor prognosis and therapy outcome in breast cancer. Moreover, several studies have documented that HER-2 overexpression induces VEGF expression/secretion and neovascularization and that VEGF expression increases when tumors become resistant to treatment. On these bases the anti-VEGF drug Bevacizumab has been evaluated in the clinical setting in breast cancer patients. Recently, phase III studies have demonstrated that Bevacizumab in combination with taxanes produces a high rate of responses and increases the Progression Free survival of breast cancer patients. A large array of studies is currently ongoing with Bevacizumab in combination with chemotherapy and hormone-therapy in the metastatic, neoadjuvant and adjuvant setting

Minimizing Movements for Anisotropic and Inhomogeneous Mean Curvature Flows

In this paper we address anisotropic and inhomogeneous mean curvature flows with forcing and mobility, and show that the minimizing movements scheme converges to level set/viscosity solutions and to distributional solutions \textit{\`a la} Luckhaus-Sturzenhecker to such flows, the latter holding in low dimension and conditionally to a convergence of the energies. By doing so we generalize recent works concerning the evolution by mean curvature by removing the hypothesis of translation invariance, which in the classical theory allows to simplify many arguments

Policy evaluation and spillover effects

This paper provides evidence on the effectiveness of R&D incentives to private firms allocated by Region Umbria in the period between 2004 and 2009. The methodological innovation proposed in this paper is a novel spatial Difference-in-Difference estimator. Our approach compares distinct treatment effects on the basis of the localization in the main local market areas of Umbria (Perugia and Terni), controlling for the presence of technological spillovers due to geographical and economic proximity. The results show a positive and statistically significant impact of the subsidies, especially for innovative outputs and for small firms. The impact is higher for the firms located outside the main labour market areas, suggesting the presence of significant local technological spillovers due to the conjunct action of regional policies and geographical concentration. Finally, this paper provides some empirical evidence in favour of the effectiveness of ”place-based” innovation policies which constitutes the ”core" of the recent smart specialization strategy. During the last decades SUTVA has represented the "gold standard" for the identification and evaluation of causal effects. However, the presence of interferences in causal analysis requires a substantial review of the SUTVA hypothesis. This paper proposes a framework for causal inference in presence of spatial interactions within a new spatial hierarchical Differencein-Differences model (SH-DID). The novel approach decomposes the ATE (Average Treatment Effect), allowing the identification of direct (ADTE) and indirect treatment effects. In addition, our approach permits the identification of different indirect causal impact both on treated (AITET) and on controls (AITENT). The performance of the SH-DID are evaluated by a Montecarlo Simulation. The results confirm how omitting the presence of interferences produces biased parameters of direct and indirect effects, even though the estimates of the ATE in the traditional model are correct. Conversely, the SH-DID provides unbiased estimates of both total, direct and indirect effects. In addition, this model is the more efficient compared both to the traditional and a Spatial modified Difference-in-Differences estimator. Rubin Causal Model explicitly rule out the presence of spatial interferences in the definition and estimation of causal impact. In this way, the traditional approach provide unbiased estimates of the average total effect of the treatment (ATE), but it makes impossible the distinction between direct and indirect (spillover) effects. Di Gennaro and Pellegrini (forthcoming) propose an alternative specification of a Difference-in-Difference estimator, which includes the presence of spatial interaction, and define three different causal effect: the direct (ADTE) and the indirect for both the treated and control group (AITET and AITENT respectively). In this paper we follow the intuition behind the novel methodology in order to find empirical evidences of the diffusion of spillover effects due to the policy in the Italian case

The Relevance of Polarity for the Online Interpretation of Scalar Terms

The interpretation of scalar terms (like, e.g., some vs. all; the numerals) has been at the center of much theoretical debate. Recently, this debate has focused on whether Scalar Implicature (SI) computation is grammatically or post grammatically driven (cf., e.g., Russell, 2006 vs. Chierchia, Fox and Spector, 2008 and references therein). In the present work, we address these issues through experimental means arguing, specifically, for two theses: Thesis 1: The interpretation of both numerals and determiners like some/all are systematically affected by the polarity (Downward monotone or DE vs. Upward monotone or UE) of the local context in which they are embedded. Thesis 2: Numerals and Determiners differ in how the ‘exact’ interpretation comes about: for numerals such interpretation is much faster. Thesis 1, if true, provides evidence against the thesis that scalar items are lexically ambiguous (for no lexical ambiguity is polarity sensitive in such a way) and in favor of the view that the ‘exact’ vs. the ‘at least’ interpretation of both types of scalar items is an implicature. Thesis 2, if true, shows that the way in which the ‘exact’ interpretation comes about for numerals vs. determiners is partly similar and partly different. This can be construed as an argument against the thesis that these elements are ‘underspecified’ in similar ways (cf., e.g., Musolino, 2003).LinguisticsPhilosophyPsycholog

Epidermal inclusion cyst of the breast . A literature review

An epidermal inclusion cyst (EIC) of the breast is a rare, benign condition that may potentially be malignant. The present study conducted a systematic review of the literature in order to identify pathological hypotheses, clinical characteristics, and diagnostic and treatment options. A search for relevant studies was conducted through the Scopus, Embase and Medline databases during September 2014. The search term employed was ῾epidermal inclusion cyst breast᾽. Studies were selected if they contained adequate information regarding symptoms at presentation, diagnostic tools, pathology, characteristics, type of procedure performed and follow-up routines. A total of 35 papers describing 91 patients affected by EIC of the breast were identified. Following this, a total of 82 patients, including an additional case supplied from the present study, were selected for further analysis. EIC of the breast typically occurs during the fifth decade of life. A palpable mass of the breast was present in 65 (79%) patients. Ultrasonographic imaging was consistently utilized as a diagnostic tool in all the cases analyzed, whereas fine-needle aspiration cytology was used in 70% of the cases and mammography in 65%. No tumor recurrence was reported at a mean follow-up time of 53 months. The present study demonstrated that elliptical excision is the preferred treatment for EIC of the breast, with pathological analysis required to exclude malignancy