19,692 research outputs found
Isothiazolo[5,4-d]isoxazole S,S-dioxides and pyrazolo [3,4-d]-isothiazole S,S-dioxides through cycloaddition reaction on 3-benzylaminoisothiazole S,S-dioxides
No full textBy reacting 4,5-unsubstituted isothiazole dioxides with diazoalkanes and nitrile oxides bicyclic pyrazolo[3,4-d]isothiazole and isothiazolo[5,4-d]isoxazole S,S-dioxides were obtained in good yield through a regioselective cycloaddn. reaction. Through cycloaddn. reaction of 3-benzylamino-4-bromo-isothiazole S,S-dioxide labile cycloadducts were formed that underwent in situ dehydrobromination affording the corresponding aromatized compd
Protecting and restoring the salt marshes and seagrasses in the lagoon of Venice.
No full textThe Lagoon of Venice is one of the largest and important Coastal Transitional Ecosystems of the Mediterranean (Tagliapietra et al. 2009). Human presence has constantly modified the original estuarine structure so that the lagoon can be nowadays considered as a human-oriented ecosystem, still maintaining strong natural traits. It is located at the north-western part of the Adriatic Sea between the current mouths of the Sile and Brenta rivers, ranging in latitude between 45,18 - 45,57 N and 12,12 - 12,63 E in Longitude (Fig. 1).
The lagoon is connected to the sea by three lagoon-inlets and the physical separation between the lagoon and the Adriatic Sea is constituted by two barrier islands and the two spits.
The lagoon is about 50 km long and 10 km wide. accounting for a surface of about 540 km2. Out of them the 36 km2 are saltmarshes, 30 km2 islands (excluding the barrier islands) and the rest is covered by water. The mean depth of the water column is about 1.2 m, with only 5% of the lagoon deeper than 5 m (Molinaroli et al. 2009). The maximum depth is 47 m, at a scour located at the lagoon side of the Malamocco Inlet. The volume of water contained in the lagoon is about 628 million m3. According to Kjerfve (1994), the Lagoon of Venice can be defined as a "restricted" coastal lagoon. The basin is connected to the Adriatic Sea through three inlets (Lido, Malamocco and Chioggia) which allow tidal flushing twice a day. Every day the Venice lagoon exchanges with the Adriatic Sea about 400 million m3 of water while the inflow from the inland through the rivers and subsoil about 3.7 million m3 (Bernstein and Montobbio 2011). Tides are a main factor in shaping the morphology of the lagoon and driving water exchange, dissolved oxygen, salinity, nutrients and sediment distribution. The North Adriatic tides are the largest in the Mediterranean. In the Lagoon of Venice tides are mixed, predominantly semidiurnal, and microtidal (Tagliapietra and Ghirardini 2006) with a mean tidal range of 61 cm , and an intertidal range of 121 cm from the Highest to the Lowest Astronomical Tidal Level (calculated for 1986-2004).
The drainage basin is about 1850 km2, 40% of which is reclaimed land laying under the sea level. According to the Koeppen–Geiger–Pohl Climatic Classification (Geiger and Pohl 1953) the lagoon experience a Cfa climate i.e. humid subtropical climate, hot summers. Due to the shallowness of the lagoon, water temperature follows strictly the seasonal trends of air temperature, ranging from zero (seldom freezing) to above 30°C.
Precipitations distributed throughout the year contribute to an average freshwater input of about 35.5 m3 s-1 as recorded in 1999 (Zuliani et al. 2005), with the most important tributaries located in the northern basin. Freshwater input and tides produce a salinity gradient, ranging from marine (ca 37 psu) to almost freshwater near the bay-head estuaries and freshwater inlets. The salinity gradient is compressed toward the mainland, due to the preponderant tidal contribution resulting in an average value of ca 30 psu. Therefore the majority of the lagoon can be classified as Mixoeuhaline/(Mixo-)polyhaline according to the Venice System (D’ancona 1959).
Some socio-environmental contexts are particularly sensitive to the use of traditional materials or compatible with the landscape in which they are placed. Venice and its lagoon are all about it. Due to the uniqueness and peculiarity of its cultural values, which are made up of an exceptional cultural heritage and, above all, integrated into an extraordinary environmental context, "Venice and its Lagoon" is a UNESCO World Heritage List since 1987. The Venice Lagoon can be considered as a "cultural landscape" where over time the work of man and nature is intertwined under the influence of environmental, social and economic constraints and opportunities (Fig. 2). The lagoon of Venice is one of the most studied coastal sites in the world, both ecologically and culturally, it is a site belonging to the international Long-Term Ecological Research network (https://data.lter-europe.net/deims / site / lter_eu_it_016
The Sala delle Asse in the Sforza Castle in Milan
No full textThis dissertation deals with two periods in the history of a room in the Sforza Castle known as the Sala delle Asse: the fifteenth-century, when Ludovico Sforza (1452-1508) commissioned Leonardo da Vinci (1452-1519) to paint it and the late-nineteenth-to-early-twentieth century when the Sala was re-discovered and subjected to a major restoration by the Italian architectural historian Luca Beltrami (1854-1933). Beltrami's participation in the Sala's re-discovery in 1893, the architectural and pictorial alterations he ordered in preparing the room for public view, and his monographic presentation of the Sala's fifteenth-century history will be discussed here using new archival evidence. The author will argue that Beltrami's interventions ultimately shifted attention away from the Sala's fifteenth-century circumstances and transformed it into a key component of the ambitious restoration scheme that Beltrami had formulated for the Sforza Castle as whole. This was a scheme that supported certain political and cultural ideologies about Milan at the turn of the twentieth-century. In an effort to provide an alternative voice for the Sala to that of Beltrami, the author will use new archival documentation to discuss the participation of Paul Müller-Walde, a German art historian who is credited with the actual re-discovery of the Sala but whose contributions remained curiously absent from all modern art-historical literature dealing with the Sala. Acting on the premise that a more plausible and much needed interpretation for the Sala's fifteenth-century history is needed, the author will offer a reconsideration of some of the Sala's most basic problems such as dating, location and possible uses. The author will also deal with Leonardo's contributions and the perils of characterizing the Sala as yet another work that sprang fully from Leonardo's imagination, with little interference or direction from outside sources. Finally, the author will deal with Ludovico Sforza's reasons for commissioning the Sala and lay the groundwork for an expanded and alternative interpretative discourse intended to broaden the avenue of investigation of this important and unique commission in Renaissance art. This dissertation concludes with an extensive Register of Documents containing reproductions or transcriptions of important fifteenth-, nineteenth- and twentieth-century documents for the Sala delle Asse
Flavour physics and flavour symmetries after the first LHC phase
No full textBased on flavour symmetries only, there are two ways to give rise to an effective description of flavour physics in the quark sector close to the CKM picture: one is based on U(3) q × U(3) u × U(3) d (or equivalent) and the other on U(2) q × U(2) u × U(2) d (or equivalent). In this context we analyze the current status of flavour physics measurements and we compare their impact, in the specific case of supersymmetry, with the direct searches of new particles at the LHC, present or foreseen. © 2014 The Author(s)
3-Amminoisotiazol S-ossido : un efficiente e selettivo dienofilo in reazioni di cicloaddizione di Diels-Alder
No full text3-Amminoisotiazol S-ossido: un efficiente e selettivo dienofilo in reazioni di cicloaddizione di Diels-AlderLe reazioni di Diels-Alder rappresentano uno dei mezzi più efficaci per la costruzione di sistemi carbociclici od eterociclici esatomici ed offrono la possibilità di realizzare processi sintetici stereocontrollati. Sulla base di questa considerazione e del nostro interesse nei confronti dei sistemi isotiazolici,1 abbiamo studiato le potenzialità del sistema 3-amminoisotiazol S-ossido in reazioni di Diels-Alder, valutando la sua efficienza come dienofilo e l’efficacia del gruppo sulfinilico come induttore di stereoselettività. Per la realizzazione delle cicloaddizioni sono state studiate metodologie eco-compatibili.2 In particolare, abbiamo utilizzato due approcci: 1) eliminazione del solvente; 2) sostituzione con solventi a basso impatto ambientale.
Il gruppo SO induce la formazione esclusiva dell’addotto endo e, a seconda delle condizioni adottate, è possibile osservare una variazione nel rapporto percentuale tra i due addotti endo sin ed endo anti.
1. F. Clerici, “Thiazole and Thiadiazole S-oxides” Advances in Heterocyclic Chemistry, A. R. Katritzky ed., Pergamon Press, vol. 83, 72-116, 2002
2.G.Imperato, B. Koenig, A. Sala. Sweet Solutions – Low melting mixtures of carbohydrates and inorganic salts as new media for organic reaction, German, Degussa, January 200
Evolution of the Magnetic Excitations in NaOsO3 through its Metal-Insulator Transition
No full textThe temperature dependence of the excitation spectrum in
NaOsO
3
through its metal-to-insulator transition (MIT) at 410 K has been investigated using resonant inelastic x-ray scattering at the Os
L
3
edge. High-resolution (
Δ
E
∼
56
meV
) measurements show that the well-defined, low-energy magnons in the insulating state weaken and dampen upon approaching the metallic state. Concomitantly, a broad continuum of excitations develops which is well described by the magnetic fluctuations of a nearly antiferromagnetic Fermi liquid. By revealing the continuous evolution of the magnetic quasiparticle spectrum as it changes its character from itinerant to localized, our results provide unprecedented insight into the nature of the MIT in
NaOsO
3
[J. G. Vale, S. Calder, C. Donnerer, D. Pincini, Y. G. Shi, Y. Tsujimoto, K. Yamaura, M. M. Sala, J. van den Brink, A. D. Christianson, and D. F. McMorrow, Phys. Rev. B 97, 184429 (2018)]
3-Amino-substituted isothiazole S,S-dioxides as dienophiles in Diels-Alder cycloaddition reactions with cyclic, acyclic and heterocyclic dienes
No full textThe Diels-Alder reactions of two 3-aminoisothiazole S,S-dioxides with various dienes, such as 2,3-dimethylbutadiene, cyclopentadiene or furan, under diverse reaction conditions are investigated. Differences of reactivity and selectivity between the studied isothiazoles and the influence of the reaction conditions on the outcome of the reactions are discusse
Chemoselective and enantioselective synthesis of 3-aminoisothiazolo S-oxides
No full textChemoselective and enantioselective synthesis of 3-aminoisothiazolo S-oxidesThe main scope of our project is the chemoselective oxidation of 3-amino-isothiazoles 1 affording the new 3-amino-isothiazole S-oxides 3. The number of oxidizing reagent used for the oxidation of sulfides to sulfoxides are many and varied but few have general or broad application. Many oxidizing reagents are too reactive over-oxidizing sulfoxides to sulfones, with other the chemoselectivity is poor or they give undesiderable side reactions. Additional limitations include slow reaction rates, the necessity for careful control of the reaction parameters, instability and expense. Among the oxidizing reagents available we found N-sulfonyloxaziridines 2 as the more effective and selective reagents affording 3 in satisfactory yield (61-64%) together with minor amount of the corresponding sulfones 4 (10-15%)
Much efforts has also been devoted to the development of methodology for the preparation of optically active sulfoxides. Several kind of chiral sulfonyloxazirides have been tested affording optically active sulfoxides with satisfactory yield and ee% depending on the hindrance of oxaziridines. As an example the reaction between 1 and 4a or 4b is reported
Lympha technique for primary and early secondary prevention of lymphedema following cancer treatment
No full textLYMPHA proved to be an effective preventive procedure that contributes in giving our oncological patients a good quality of life. In this presentation, the author will report indications, technical aspects and benefits of LYMPHA technique
Mechanical Characterization of Traditional Masonry in an Homogeneous Territory: Valtellina
No full textThe current Italian Building Code provides tables with standard values of the mechanical characteristics of existing masonry. These tables refer to specific typologies, as described, according to masonry texture. As experience suggests, the way in which the masonry is built up could really affect its structural behaviour, both in terms of mechanical properties and failure mechanisms. Furthermore, the code entrusts each Region to improve and better define these mechanical characteristics, specifically in areas where they could be regarded as homogeneous, in order to improve definitions of the quality, the behaviour and the mechanical properties with a higher degree of precision and knowledge.
Valtellina, located in the north of the Lombardy region and in the middle of the Alps, can be regarded as a homogeneous area because of its specific masonry, built up with hard rock stones and weak lime mortar. The available in–situ experimental data about this masonry typology, achieved through MDTs and NDTs, was collected, implemented and improved with additional tests to identify the relevant mechanical properties. This was aimed to classify and structurally identify this specific regional masonry typology, never analysed before
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