348 research outputs found

    Semiclassical methods in 2D QFT: spectra and finite-size effects

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    In this thesis, we describe some recent results obtained in the analysis of two-dimensional quantum field theories by means of semiclassical techniques. These achievements represent a natural development of the non-perturbative studies performed in the past years for conformally invariant and integrable theories, which have led to analytical predictions for several measurable quantities in the universality classes of statistical systems. Here we propose a semiclassical method to control analytically the spectrum and the finite-size effects in both integrable and non-integrable theories. The techniques used are appropriate generalizations of the ones introduced in seminal works during the Seventies by Dashen, Hasslacher and Neveu and by Goldstone and Jackiw. Their approaches, which do not require integrability and therefore can be applied to a large class of systems, are best suited to deal with those quantum field theories characterized by a non-linear interaction potential with different degenerate minima. In fact, these systems display kink excitations which generally have a large mass in the small coupling regime. Under these circumstances, although the results obtained are based on a small coupling assumption, they are nevertheless non-perturbative, since the kink backgrounds around which the semiclassical expansion is performed are non-perturbative too.Comment: PhD thesis, 117 pages, 40 figure

    Municipal Building Regulations for Energy Efficiency in Southern Italy

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    The building sector is still one of the most energy consuming sectors in Italy, like developed countries in Europe. At European level, the main policy driver related to the energy use in buildings is the Energy Performance of Buildings Directive (EPBD, 2002/91/EC) and its recast. Through the EPBD in- troduction, requirements for certification, inspections, training or renovation are now imposed in Member States. In order to fulfill the expected changes, local regulations are a key factor aiming at sustainable territorial planning. It is thus required support the issue of local rules at municipal level in order to guide local administrators and technicians and to limit discretional power of bureaucracy. In this paper, a review of the most common practices for building regulations in Europe and in Italy is proposed, then the role and the framework of a municipal building regulation for the Southern European area accounting for sustainability features is discussed

    Le acque sotterranee del Cansiglio

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    Il Cansiglio è un altipiano carsico, con un’estensione di circa 100 km2 e un’altitudine media di circa 1000 m; esso è situato al confine tra due regioni (Veneto e Friuli Venezia Giulia) e tre provincie (Treviso, Belluno e Pordenone). Questo importante sistema carsico non è mai stato oggetto di approfonditi studi idrogeologici, nonostante la presenza di rilevanti sorgenti alla sua base (Meschio, Molinetto, Santissima e Gorgazzo). L’occasione si è presentata con l’esplorazione, da parte del Gruppo Speleologico Ferrarese in collaborazione con altri gruppi speleologici, di quella che è tuttora la grotta più profonda della zona: l’Abisso Col de la Rizza (904/FR410) (circa 800 m di profondità per 4 km di sviluppo). Con la collaborazione del Dipartimento di Scienze della Terra dell’Università di Ferrara, è stato, quindi, progettato e realizzato un multi- tracciamento delle acque sotterranee, con due iniezioni in parallelo: fluoresceina sodica all’Abisso Col de la Rizza e tinopal CBS-X al Bus de la Genziana (V-TV1000) (la cavità più sviluppata della zona, con circa 5 km di sviluppo per 600 m di profondità). Il monitoraggio è stato eseguito alle sorgenti del Molinetto, Santissima e Gorgazzo, mediante campionatori di acqua automatici (alle sorgenti Molinetto e Gorgazzo) e con un impegnativo programma di prelievi manuali di campioni d’acqua e di fluocaptori (carboni attivi e garze di cotone) in 3-4 punti di ogni sorgente monitorata. Al termine del tracciamento risultavano positive alla fluoresceina sodica le sorgenti Molinetto e Santissima, mentre nessuna delle sorgenti monitorate era positiva al tinopal CBS-X. Le curve di arrivo del tracciante, permettevano il calcolo delle velocità medie di transito in entrambe le sorgenti positive alla fluoresceina sodica, pari a circa: 250 m giorno-1, in fase di magra, e 1100 m giorno-1, in fase di piena.Cansiglio is a limestone plateau with an extent of about 100 km2 and a mean altitude of 1000 m; it is located on the border between two regions (Veneto and Friuli Venezia Giulia) and three provinces (Treviso, Belluno and Pordenone). The hydrogeology of this important karst system is poorly known, despite it probably feeds three important springs located at its south-eastern border (Molinetto, Santissima and Gorgazzo) that form Livenza River. Gruppo Speleologico Ferrarese, in collaboration with other speleological team, explored the deepest cave of Cansiglio: Abisso Col de la Rizza (904/FR410) (about 800 m deep and with 4 km of extent), which provided the opportunity to perform a tracer test. In collaboration with the Earth Sciences Department of Ferrara University, a multi-tracer test was made with two contemporary injections of fluorescent dyes in groundwaters: uranine in Abisso Col de la Rizza and tinopal CBS-X in Bus de la Genziana (V-TV1000) (600 m deep and 5 km of extent). The monitoring at Molinetto, Santissima and Gorgazzo springs was performed by means of automated samplers (at Gorgazzo and Molinetto springs) and an intense discrete sampling survey, which included water samples, charcoal bags and cotton lints collection. Molinetto and Santissima springs resulted positive to uranine, while any springs was positive to tinopal CBS-X. The breakthrough curves make possible the determination of the mean velocity of uranine: about 250 m day-1, during low flow conditions, and 1100 m day-1, after an intense rainfall event

    Towards a better knowledge of Cansiglio karst system (Italy): results of the first successful groundwater tracer test

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    Cansiglio is a limestone plateau located on the border between the regions of Veneto and Friuli-Venezia Giulia, northeastern Italy. The eastern area is characterized by a thick succession of Cretaceous peritidal carbonates, while the central western part is characterized by slope breccia deposits. Even thoughPian Cansiglio is an important karst system, its hydrogeology is poorly known. Three important springs that form the Livenza River are located at its southeastern border and are thought to represent the majority of karst aquifer discharge, but no experimental data are available in the literature. Gruppo Speleologico Ferrarese explored an 800 m deep cave (Abisso Col de la Rizza) on Pian Cansiglio, whichprovided the opportunity to conduct tracer tests. Fluorescent dyes were injected in September 2008 in Abisso Col de la Rizza (uranine) and in Bus della Genziana (tinopal CBS-X). Over a period of three months, local cavers conducted an intense sampling programme, whichincluded collecting water samples, charcoal bags and cotton lints. Automated samplers were used for highfrequency monitoring at two of the springs. Tinopal was not detected, so the connection between Bus della Genziana and the springs was not demonstrated. The connection between Abisso Col de la Rizza and two of the springs was demonstrated by uranine. A mean velocity of 248 m/day results from the tracer concentration peaks; intense rainfall events increased the flow velocities four to five times. Different hypotheses are considered in order to explain the low mass recovery rate (32-40% of the injected mass). The uranine tracer test demonstrated that Pian Cansiglio aquifer contributes to the two Livenza springs; it also opens a question about the third spring, whichprobably originates from the Mount Cavallo area (another limestone massif close to Pian Cansiglio). The rapid response to rainfall recharge suggests a vulnerability of the spring system, further supporting the importance of conducting a detailed hydrogeological study. 

    CIGARETTE SMOKING HAS NO PRO-COGNITIVE EFFECT IN SUBJECTS WITH OBSESSIVE-COMPULSIVE DISORDER: A PRELIMINARY STUDY

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    Background: The prevalence of cigarette smoking in patients with different psychiatric disorders is higher than that in the general population, which is partly explained by the pro-cognitive effect of smoking on cognitive functions. In subjects with obsessive-compulsive disorder (OCD), the prevalence of smokers is lower than that in other psychiatric disorders. We hypothesized that cigarette smoking does not provide benefits and even worsen cognitive performance in OCD. Subjects and methods: We compared different executive function subdomains in 20 smoking and 20 non-smoking inpatients with OCD. At the beginning of hospitalization, we assessed visuo-spatial working memory, planning and set-shifting abilities (Cambridge Neuropsychological Test Automated Battery), smoking habits (standardized personal interviews), and the severity of obsessivecompulsive symptoms (Dimensional Yale-Brown Obsessive-Compulsive Scale). Results: The performance of smokers and non-smokers did not differ significantly in any cognitive subdomain. The smoking duration was significantly associated with poorer visuo-spatial working memory performance (P=0.001). Conclusions: Our results showed that cigarette smoking did not provide cognitive enhancement across various executive function subdomains in subjects with OCD. The lack of beneficial cognitive effects of smoking may make these subjects less prone to smoking and may partially explain the lower rate of smokers in OCD compared with other psychiatric conditions

    Bacterial community structure and diversity along the halocline of Tyro deep-sea hypersaline anoxic basin

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    Purpose: Tyro is a deep hypersaline anoxic basin (DHAB) located at the seafloor of the Eastern Mediterranean sea. Tyro hosts a stratified eukaryotic microbiome moving from seawater to the brine, but no reports are available on its prokaryotic community. We provide the first snapshot of the bacterial community structure in Tyro brine, seawaterbrine interface, and the overlaying deep seawater. Methods: In this study, we combined the use of molecular analyses, i.e., DNA fingerprinting and 16S rRNA pyrosequencing for the description of the bacterial community structure and taxonomy. PiCRUST2 was used to infer information on the prokaryotes functional diversity. A culture-dependent approach was applied to enrich bacteria of interest for marine biotechnology. Results: Bacterial communities sharply clustered moving from the seawater to the Tyro brine, in agreement with the abrupt increase of salinity values. Moreover, specific taxonomic groups inhabited the seawater-brine interface compared to the overlaying seawater and their identification revealed converging taxonomy with other DHABs in the Eastern Mediterranean sea. Functional traits inferred from the prokaryote taxonomy in the upper interface and the overlaying seawater indicated metabolic pathways for the synthesis of osmoprotectants, likely involved in bacterial adaptation to the steep increasing salinity. Metabolic traits related to methane and methylated compounds and to hydrocarbon degradation were also revealed in the upper interface of Tyro. The overall capability of the Tyro microbiome for hydrocarbon metabolism was confirmed by the isolation of hydrocarbonoclastic bacteria in the sediments. Conclusions: Our results suggest that Tyro seawater-brine interface hosts a specific microbiome adapted to the polyextreme condition typical of DHABs with potential metabolic features that could be further explored for the characterization of the metabolic network connecting the brine with the deep seawater through the chemocline. Moreover, Tyro could be a reservoir of culturable microbes endowed with functionalities of interest for biotechnological applications like hydrocarbon bioremediation
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