1,721,117 research outputs found
Contributions to Nonlinear PDEs arising in Conformal Geometry, Mean Field Games and Choquard models.
Full text linkThe goal of this thesis is to analyze certain nonlinear elliptic Partial Differential Equations (briefly PDEs) that arise in Conformal Geometry, Mean Field Games theory, and Choquard models. Our primary focus is on the study of the existence and nonexistence
of solutions, analyzing their asymptotic behavior, and examining the occurrence of concentrating phenomena. The contents of this manuscript have been organized into three distinct parts, each one focusing on a specific topic.
The first part of this work deals with some prescribed curvature problems. In particular, in Chapter 1 we address the problem of existence and compactness of entire solutions to the Gaussian curvature equation on R^2 in the case of power-type and sign-changing prescribed curvature; while in Chapter 2 we deal with the corresponding prescribed Q-curvature problem in R^4. While these two issues are undoubtedly interconnected, it is essential to recognize that each possesses distinct features that warrant in-depth analysis and attention. The content of Part I corresponds to the research papers [17, 18].
In the second part, we study second-order ergodic Mean-Field Games systems defined in the whole space R^N with a coercive potential V and aggregating nonlocal coupling, given in terms of a Riesz-type interaction kernel. In Chapter 3, we prove that the
strength of the attractive term and the behavior of the diffusive part interact to produce three distinct regimes for the existence and nonexistence of classical solutions in our MFG system. On the other hand, in Chapter 4, exploiting a variational approach and
a concentration-compactness argument, we show that in the vanishing viscosity limit, there is concentration of mass around minima of the potential V . This leads to proving the existence of solutions to the potential-free system. The content of Part II corresponds to
the research papers [19, 20].
The third part of this thesis focuses on boundary value problems for Choquard equations. More in detail, we investigate the existence of solutions when the domain is an annulus or an exterior domain, considering both Neumann and Dirichlet boundary conditions. The results of Chapter 5 are presented in the work [21]
Localization of serotonin transporter in the dog small intestine by western blot analysis
No full textThe image describes Western blot of Serotonin transporter in the dog small intestine and rat brain positive control. A Molecular Weight Marker has been used to check exact molecular weight of each bands
Sieve-element specific responses to phytoplasma infection: new insights about the role of occlusion proteins and callose
Full text linkPhytoplasma are phloem-limited, wall-less, uncultivable prokaryotes. They affect several economically important crops and fruit trees. Actually, no efficient treatments are available to directly control the diseases associated to these pathogens. The study of the molecular interaction between plant and phytoplasma could provide, in a close future, knowledge about the mechanism of host colonization and plant counteract, which is important to actuate new control approaches. Plants face mechanically phytoplasma infection by sealing the sieve elements by phloem protein and/or callose accumulation at the sieve pores, and activating several pathways involved in defense process. We used different mutant lines of Arabidopsis thaliana and a strain of the ‘Candidatus Phytoplasma asteris’ (the Chrysanthemum Yellows phytoplasma), as pathosystem, to give insight on the possible link occurring between mechanical site-specific plant responses and systemic defense signaling.
The first part of the study, dealing with the interaction between phytoplasmas and the sieve-element occlusion related (SEOR) proteins, underlined the involvement of AtSEOR2 protein with the pathway of phytohormones. Phytohormone accumulation (in particular jasmonic acid, indol-acetic acid and abscisic acid) was early activated at infection site in Atseor1ko mutants, an Arabidopsis line expressing the sole AtSEOR2 protein in the sieve tubes. The possible mechanism involved in the reduction of phytoplasma titre in Atseor1ko mutants was discussed.
The second part of the study regarded the role of phloem callose in the interaction. Also in this case, an important relation between the synthesis of callose at the sieve plate (by the phloem specific callose synthase 7) and the early activation of systemic defense responses, was shown. In particular, plant lacking the production of phloem callose, resulted able to unbalance sugar transport (at both the symplasmic and apoplasmic level) and metabolism, favoring the priming of sugar-related signaling processes. Taken together these results drive us to the conclusion that, in Arabidopsis following phytoplasma infection, site-specific mechanical responses trigger systemic signals, mediated by SEOR proteins and callose
Gli scavi sotto od. Dionysiou Areopaghitou e la cd. Casa di Proclo
No full textScheda descrittiva della cd. Casa di Proclo alle pendici meridionali dell'Acropoli di Aten
Influence of Slot Blowing Operating Parameters on Shock-Induced Separation in a Low-Pressure Turbine Cascade
No full textA numerical investigation is carried out to assess the effect of actuation parameters on flow field and losses in a transonic low-pressure turbine cascade subject to shock-induced separation. Active flow control is implemented through spanwise uniform steady slot blowing on the suction surface. The effect of slot blowing ratio and injection angle are studied by means of two-dimensional unsteady calculations performed using the in-house solver HybFlow. Slot blowing is studied at different blowing ratios and three injection angles, from 15° to 35° to the wall tangent. Slot blowing reduces separation height, but this does not coincide with loss reduction. Wake total pressure losses actually increase with higher blowing ratios because of the shock strengthening connected with increased passage diffusion. Unsteadiness is enhanced with blowing and the wake spans a larger pitchwise portion. The higher vorticity generated at the lambda shock triple point by the local shear interacts with the wake oscillation, enhancing the loss mechanism connected with the wake mixing and shear between vortices. The penetration of the jet depends on the injection angle but the positive effect of near-wall injection that fills the low-momentum portion of the boundary layer is outweighed by the higher losses connected to the increased shock intensity. The enhanced passage diffusion is independent of the injection angle, confirming that it is entirely a consequence of massflow injection rate
The Role of Urban Services, Climate Services and Insurance Services in Urban Climate Change Adaptation Processes
Full text linkThe increasing frequency and magnitude of extreme events associated with climate change represent a pressing issue on a global and local scale. While waiting for the desirable effects of mitigation measures, the scientific community, governments, and private businesses should increase their commitment to adaptation as a transition strategy. As a response to emerging risks, the adoption of non-structural (or “soft”) adaptation solutions—which concerns the organizational and intangible aspects of systems—represents a valid and complementary option to infrastructural (“hard”) interventions in contexts of high uncertainty. In line with this approach, the paper reports the results of ongoing research on the strategic role of Urban Facility Management (UFM) services in supporting cities in the adaptation process to climate change effects. It also highlights the potential contribution of insurance brokers and investigates competencies, responsibilities, and information flows in Urban service processes. The results of this analysis converge in a proposal for re-designed service delivery models
that meet emerging needs and make the integration between urban, climate, and insurance services operative to achieve an innovative “Adaptation services” system. The hypotheses and the proposals are tested by observing a case study—an Italian medium-sized municipality—where implementing Adaptation services models triggers new relationships between
public and private stakeholders and forms of collaboration with insurance suppliers
Determinazione immunoistochimica e western blot della caderina “E” nei tumori mammari della cagna
No full textTwenty-nine canine mammary samples (5 normal mammary glands, 3 atypical ductal hyperplasia, 8 benign and 13 malignant tumors) were tested by immunohistochemistry (IHC) and Western Blot (WB) for E-cadherin. Both methods revealed a reduction of protein expression as the most important finding. A significant reduction of expression was revealed in dysplastic as well in benign and malignant neoplastic samples. The two methods revealed a significant correlation and absence of IHC false negative evaluation when the data of WB were corrected for the amounts of epithelial cells of the sample
On the Assessment of an Unstructured Finite-Volume DES/LES Solver for Turbomachinery Applications
Full text linkImprovements in mean flow and performances simulation in turbomachinery has brought research to focus more demanding topics like turbulence effects on turbines. Although overall performances are well predicted by Unsteady-RANS, other phenomena such as aerodynamic noise or transition need more accurate prediction of turbulent flow features. Thus different kinds of equation modeling other than URANS are needed to cope with this issue. The success of Detached-Eddy Simulation and Large-Eddy Simulation applications in reproducing physical behavior of flow turbulence is well documented in literature. Despite that, LES simulations are still computationally very expensive and their use for investigating industrial configurations requires a careful assessment of both numerical and closure modeling techniques. Moreover LES solvers are usually developed on a structured mesh topology for sake of simplicity of high-order schemes implementation. Application to complex geometries like those of turbomachinery is therefore difficult. The present work addresses this issue considering the feasibility of converting an operative in-house URANS solver, widely validated for applicative purposes, into higher resolution DES and LES, in order to face turbulence computation of turbomachinery technical cases. The solver presents a 3D unstructured finite-volume formulation, which is kept in LES approach in order to handle complex geometries and it is developed to perform unsteady simulations on turbine stages. Preliminary assessment of the solver has been performed to evaluate and improve the accuracy of the convective fluxes discretization on an inviscid bump test case. First a DES-based approach has been implemented, as it is less computationally challenging and numerically demanding than LES. A square cylinder test case has been assessed and compared with experiments. Then, a pure LES with a Smagorinsky sub-grid scale model has been evaluated on the test case of incompressible periodic channel flow in order to assess the capability of the solver to correctly sustain a time developing turbulent field
Turbulence and Transition Modeling in Transonic Turbine Stages
No full textThis paper describes an in-house approach to the transition evaluation which is compared to conventional turbulence closures in test cases where steady and unsteady heat transfer evaluation is considered. The in-house URANS CFD code HybFlow has been used. The standard k-ω model by Wilcox, the SST model by Menter, the ν’2-f model, the k-ε-kl model of Walters and Leylek and the two equations models coupled with the transport of the intermittency function have been tested. The rationale of the work is to verify the accuracy of turbulence and transition models for heat transfer evaluation and by-pass transition when challenging applicative test cases are considered. The present work was carried out in the frame of the EU funded TATEF2 project
Time-Resolved Analysis of the Base Region in Cooled Transonic Turbine Airfoils
No full textHigh pressure turbine stages often work in the transonic regime. Hence the flow may be dominated by airfoil trailing edge shocks. In this paper, a detailed analysis of a test case representative of the trailing edge region of an airfoil is presented. The analysis has been performed reproducing the main characteristics of the flow field occurring at the blade trailing edge. The numerical campaign has been performed using the in-house HybFlow CFD code. Hybrid unstructured grids have been prepared for the selected configurations and special attention have been paid to the wake region discretization. The study started with the steady analysis with null and continuous blowing at several density ratios, on a round trailing edge representative of actual turbine blades. A main-flow Mach number of 1.5 have been initially considered to enhance the compressibility effects. The steady analyses allowed to evaluate the shock intensity variation increasing the coolant density ratio. Then, unsteady simulations have been conducted with both continuous and pulsating coolant at different frequencies. Frequency domain analyses have been performed and the results have been compared with each other. The obtained vortex structures have been also compared with the open literature results. Furthermore, shock intensity variations have been studied and their inclination monitored. For each frequency, the change in the shock intensity have been individuated and compared with the reference value obtained with continuous cooling. The results clarified the effect of continuous blowing on the flow field even far from the blade surface. Furthermore, uncommon vortex shedding structures have been individuated and discussed, depending on the coolant mass-flow rate
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