186,910 research outputs found
Le trasformazioni del movimento ambientalista in Italia tra istituzionalizzazione e conflitto
No full textThis paper aims at exploring the current Italian ecologist archipelago by focusing on three main dimensions: organization, «frame» and action repertoire. By investigating these dimensions, we would like to address some fundamental questions: a) how does the environmental movement in Italy look like today? Who are the protagonists? What are their patterns of action and their claims? b) How the relationships between protest and ecologist groups are? c) Where environmental claims can be placed between materialist and post-materialist
perspectives? By drawing on a mixed qualitative/quantitative methodology, we aim to provide an updated overview about Italian environmentalism. We first use the Protest Event Analysis (PEA) to trace the main trends in terms of institutionalization/radicalization, territorialisation, alliance structure and other aspects of the environmental protest, and eventually further explore the issue through the frame analysis approach based mainly on in-depth interviews and the analysis of documents drafted by social movement actors
SAR Radiometric Calibration Based on Differential Geometry: From Theory to Experimentation on SAOCOM Imagery
No full textThe modeling and simulation of topography-induced imaging distortions are crucial for consistent radiometric information exploitation in current and forthcoming SAR-based Earth observation missions with a high spatial and temporal resolution, with relevance in several applications. In this paper, for the first time, we specifically investigate the compensation of topography-induced radiometric distortions affecting SAR images acquired by the L-band Argentinian satellite SAOCOM. We adopt a recently developed calibration method relying on an analytical formulation derived in the rigorous framework of the differential geometry of surfaces. We first provide an original interpretation of the analytical formulation, thus providing further insights into the relevant area-stretching-based formalism. Then, the numerical implementation of the method is specialized to systematically process the data acquired by SAOCOM sensors; hence, the resulting sensor-specific prototype solution processor is employed in this study. Finally, experiments performed over a real scenario in the southern part of Italy, characterized by large topography variations, are presented and discussed, thus elucidating the effectiveness of the adopted method applied to SAOCOM images. The adopted effective SAR calibration strategy opens up the way to its operational use in large-scale SAOCOM data processing
Poteri religiosi e istituzioni: il culto di San Costantino Imperatore tra Oriente e Occidente II
No full textIn occasione del IX Seminario internazionale di studi su “Il culto di San
Costantino Imperatore tra Oriente e Occidente”, Sassari-Sedilo 4-6 luglio,
si è ritenuto opportuno pubblicare in formato elettronico e distribuire fra i
partecipanti le relazioni, presentate nei precedenti Seminari, non incluse
(per varie ragioni) nel volume edito nel 2003
Gentili (Bruno) éd. Giuliano imperatore
No full textLambrechts P. Gentili (Bruno) éd. Giuliano imperatore. In: Revue belge de philologie et d'histoire, tome 66, fasc. 1, 1988. Antiquité - Oudheid. pp. 165-166
PERTURBATION THEORY FOR ELECTROMAGNETIC WAVE SCATTERING IN RANDOM LAYERED STRUCTURES
No full textThe problem of electromagnetic wave scattering in 3-D random layered structures, is analytical treated by relying on original results of the Boundary Perturbation Theory (BPT) and Volumetric-Perturbative Reciprocal Theory (VPRT), whose structured presentation of the pertinent theoretical body of innovative results is proposed and developed in this thesis.
The systematic formulation of Boundary Perturbation Theory (BPT) is here introduced to deal with the analysis of a layered structure with an arbitrary number of gently rough interfaces: in this case the proposed theoretical construct is based on a suitable perturbation pertinent to the geometry of the problem and the scattering problem is treated by adopting a proper perturbation of boundary conditions. Specifically, it is demonstrated that, in the first-order approximation, BPT leads to fully polarimetric, formally symmetric and physical revealing closed form solution: the relevant innovative scattering models obtained in this perturbation framework permit to deal with bistatic scattering, from and through three-dimensional layered structures with an arbitrary number of gently rough interfaces.
Furthermore, Volumetric-Perturbative Reciprocal Theory (VPRT) is also formulated in this thesis. VPRT methodologically adopts a different approach, which is based on two key elements: the use of the Reciprocity Theorem and an appropriate description of the scattering structure in terms of space-variant volumetric perturbation of the dielectric constant distribution. The VPRT construct also provides meaningful reaction-based expressions for the scattering field, which are straightforward and rich in descriptive power.
It is important to emphasize that VPRT, which is methodologically conceived to consistently treat both interfacial and volumetric random inhomogeneities (so providing a unified mathematical formulation and conceptual understanding of two inherent scattering mechanisms), is also fully consistent with the results of BPT. Accordingly, within VPRT framework, both rough-interface and volume scattering are take into account methodologically.
Furthermore, within this new theoretical framework, a new look at the classical SPM solution for rough surface is also offered: even such a specific solution (whose derivation hitherto obtained via unnecessary, involved and obscure algebraic manipulations) is derived a surprisingly simple way, clarifying all the same the lacking inherent physical meaning.
Beyond a certain compactness of the pertinent closed-form solutions, the fundamental scattering interactions can be revealed, gaining a coherent explanation and a neat picture of the physical meaning of the proposed theoretical constructs. In fact, it is important to note that a deep comprehension of the physical phenomena involved in the electromagnetic wave scattering interaction with such kind of complex structures would have been a rather hopeless task before the introduction of these theories.
Finally, it is noteworthy that this theoretical body of results enables a new way to systematically construct meaningful and general expressions for the scattering field pertinent to wide class of scattering configurations, involving complex structures that can be arranged in a perturbation framework, and it is successful in that it exhibit: conceptual clearness, descriptive power and general applicability to random layered structures
Path loss measurements at 3.5 GHz: A trial test WiMAX based in rural environment
No full textAbstract:
This paper addresses the dimensioning of the emerging wireless broadband networks operating in 3.5 GHz band by focusing on the key problem of propagation loss. The characteristics of the path loss in the 3.5 GHz band measured in a rural macro-cellular environment are presented. The existing empirical prediction models are compared with the measured data and a comparative analysis is carried out. The measurements are performed within the experimental activities developed on a WiMAX based platform located in an Italian rural area
Abitare, spazio condiviso, progetto urbano. Il caso del complesso residenziale di Giustiniano Imperatore a Roma di ABDR Architetti associati
No full textThe paper proposes a reinterpretation of the residential and urban redevelopment case in viale Giustiniano Imperatore in Rome, which has proved successful even after its completion, becoming an exemplary case of public design of residences and urban spaces, as well as one of the first demolition and reconstruction projects undertaken in Italy. The initiative was undertaken by Department VI of the Municipality of Rome and the complex was designed by ABDR studio (M.L. Arlotti, M. Beccu, P. Desideri, F. Raimondo) based in Rome
Experimental behaviour of reinforced concrete tie-rods damaged by corrosion
No full textExisting reinforced concrete elements are subjected to the ageing and to corrosion phenomena, that can lead to a significant decay of the material and structural properties. The researches on the influence of the corrosion on the bond properties of reinforced concrete elements are numerous in the technical literature, and both theoretical and experimental surveys may be found. Nevertheless, small specimens (for which only the local bond-slip behaviour can develop) are typically employed. To evaluate the influence of the corrosion on the global tensile behaviour of reinforced concrete elements, three tie rods were cast, artificially corroded and tested at the Laboratory of Materials and Structures of the University of Rome Tor Vergata. Each specimen was characterized by a 150x150mm2 cross-section and a length of 3000 mm and reinforced with a 016 steel bar placed at the centerline of the element. The specimens were artificially corroded up to about 5% corrosion level (in terms of mass loss). The obtained results clearly highlight the influence of the corrosion of the bond transmission mechanism
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