527 research outputs found
Phytoplasmas: An Introduction
No full textPhytoplasmas are among the most recently discovered plant pathogens. They are wall-less prokaryotes
restricted to phloem tissue, associated with diseases affecting several hundred plant species. The impact of
phytoplasma diseases on agriculture is impressive and, at the present day, no effective curative strategy has
been developed. The availability of rapid and sensitive techniques for phytoplasma detection as well as the
possibility to study their relationship with the host plants is a prerequisite for the management of
phytoplasma-associated diseases
USE OF FISHEYE PARROT BEBOP 2 IMAGES FOR 3D MODELLING USING COMMERCIAL PHOTOGRAMMETRIC SOFTWARE
No full textFisheye camera installed on-board mass market UAS are becoming very popular and it is more and more frequent the use of such platforms for photogrammetric purposes. The interest of wide-angles images for 3D modelling is confirmed by the introduction of fisheye models in several commercial software packages. The paper exploits the different mathematical models implemented in the most famous commercial photogrammetric software packages, highlighting the different processing pipelines and analysing the achievable results in terms of checkpoint residuals, as well as the quality of the delivered 3D point clouds. A two-step approach based on the creation of undistorted images has been tested too. An experimental test has been carried out using a Parrot Bebop 2 UAS by performing a flight over an historical complex located near Piacenza (Northern Italy), which is characterized by the simultaneous presence of horizontal, vertical and oblique surfaces. Different flight configurations have been tested to evaluate the potentiality and possible drawbacks of the previously mentioned UAS platform. Results confirmed that the fisheye images acquired with the Parrot Bebop 2 are suitable for 3D modelling, ensuring accuracies of the photogrammetric blocks of the order of the GSD (about 0.05 m normal to the optic axis in case of a flight height equal to 35 m). The generated point clouds have been compared to a reference scan, acquired by means of a MS60 MultiStation, resulting in differences below 0.05 in all directions
Seeing the unseen: uncovering networks of informal coordination among interest groups
No full textInterest groups interact with one another and frequently coordinate their activities, but much of this communication takes place behind closed doors. Drawing on a new study, Stefano Pagliari and Kevin L Young present a novel approach for uncovering networks of interest groups by using ‘text reuse’ analysis
“Prime note” sulla l. 20 novembre 2017, n. 168 (“norme in materia di domini collettivi”)
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PARTICLE SIZE EFFECT ON KINETICS AND THERMODYNAMICS OF PHASE TRANSITIONS IN MINERALS
No full textPhase transitions in minerals are transformations naturally occurring when environmental conditions, such as pressure and temperature, change. So, studying their evolution means to understand the modifications of the physical and structural properties of a compound, which can be controlled through industrial processes and exploited in technological applications.
On this ground, the present thesis is divided into two big sectors of material science: after a short overview on the basic theory of thermodynamics and kinetics (Part I), the first branch deals with traditional ceramics (Part II), where interest is focused on quartz-cristobalite-tridymite-involving reactions; after that, the field of functional ceramics is discussed in Part III, analysing the behaviour at the nano scale of two widely studied technological materials: the half-doped La and Ca manganite and the tetragonal zirconia stabilized at room temperature by size reduction.
All these subjects of study are treated considering the effect of varying the particle size. It is well known,
indeed, that reactions are promoted when particles have a greater surface to volume ratio. Therefore, when investigating phase transitions, solid state reactivity and kinetics must reflect the effect of the reduction of grain size. Knowing the mechanisms and the behaviour of materials undergoing high or low temperature processes is essential for industrial procedures to be developed. Thus, phase transitions of the cited compounds are here discussed, in the light of three completely different but complementary approaches: X-Ray Powder Diffraction, performing both reciprocal-space and real-space refinements, and Resonant Ultrasound Spectroscopy, investigating the elastic and anelastic properties of the material of interest
Efficacia, esecutività ed esecutorietà dei provvedimenti amministrativi
No full textIl lavoro esamina i temi dell’efficacia, dell’esecutività e dell’esecutorietà dei provvedimenti amministrativi alla luce della disciplina dettata dagli artt. 21 bis e 21 ter L. 7.08.1990 n. 241 introdotti dalla L. 11 febbraio 2005 n. 15.
I temi suddetti vengono trattati con attenzione all’inquadramento dogmatico delle fattispecie e alla disamina critica della disciplina di diritto positivo.
Quanto al tema dell’efficacia, vengono toccati i profili della portata dell’art. 21 bis con specifico riferimento alla sua applicazione anche per i provvedimenti ampliativi, all’obbligo o meno della comunicazione al controinteressato, alla forma e alla prova della comunicazione, alle conseguenze di diritto sostanziale e processuale della mancata comunicazione nonché, infine, alle eccezioni legali al principio della recettizietà dei provvedimenti limitativi della sfera giuridica del privato,
La riflessione sulla esecutorietà affronta, in particolare, i seguenti profili: (a) l’esecutorietà tra principio di (stretta) legalità, tipicità e nominatività, (b) l’esecutorietà come potere tipico e nominato, (c) le conseguenze dell’esercizio dell’esecutorietà al di fuori dei casi e delle modalità indicate dalla legge, (d) il potere esecutorio, sua discrezionalità e limiti di questa e (e) il significato di “provvedimento costitutivo di obblighi”
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