Indagini termografiche, trasformazioni architettoniche e degrado dei materiali nelle chiese del centro storico di Siliqua (Sardegna S-W)

La termografia a raggi infrarossi, come noto, consente l’analisi strutturale di manufatti edilizi sulla base dell’individuazione di zone a differente temperatura e di possibili processi di scambio termico in stretta relazione con la risposta dei materiali utilizzati alle sollecitazioni termiche a cui sono interessati. Le immagini termiche, soprattutto se acquisite mediante strumentazione caratterizzata da elevata risoluzione e sensibilità, consentono di mettere in evidenza, oltre alla presenza di anomalie legate a processi di alterazione e degradazione dei materiali utilizzati, eventuali trasformazioni architettoniche avvenute nella storia del manufatto e, in particolare, caratteri costruttivi originari nascosti da interventi posteriori. Sulla base di questi presupposti, vengono esposti i risultati di una indagine applicata per lo studio di alcuni tra gli edifici storico-religiosi presenti nel paese di Siliqua (Sardegna sud-occidentale): la Chiesa di San Giorgio, la Chiesa di Sant’Anna e la Chiesa di Santa Margherita. La ricerca, in particolare, ha consentito di mettere in evidenza la struttura e la tessitura muraria dei prospetti principali, oggi coperta dall’intonaco e, sulla base di documenti storici e delle immagini fotografiche del passato, tarare la risposta termica acquisita in base alle specifiche caratteristiche dei materiali utilizzati. Lo studio è stato condotto mediante l’utilizzo della Termocamera IR Thermo Tracer TH9260 (NEC Avio Infrared Technologies Co., Ltd).Infrared thermography, as known, allows the analysis of structural building elements on the basis of the identification of areas at different temperatures and possible heat transfer processes in close relationship with the response of the materials used to thermal stresses to which they are interested. The thermal images, especially if acquired through instrumentation characterized by high resolution and sensitivity, allow to put in evidence, in addition to the presence of anomalies associated with processes of alteration and degradation of the materials used, any architectural transformations occurred in the history of the article and, in particular, original characters constructive hidden by later interventions. Based on these assumptions, the thermographic method has been applied to the study of some of the historical and religious buildings in the country of Siliqua (south-western Sardinia): the Church of San Giorgio, the Church of Sant’Anna and the Church of Santa Margherita. The research, in particular, has made it possible to highlight the structure and texture of the main elevations of walls, now covered by plaster, and, on the basis of historical documents and photographs of the past, adjust the thermal response acquired with the specific materials used. The study has been carried through non-destructive telemetry investigations through the use of Thermal Imaging Camera IR Thermo Tracer TH9260 (NEC Avio Infrared Technologies Co., Ltd)

Stereocontrolled synthesis and functionalization of cyclobutanes and cyclobutanones

In the last decade a certain number of new cyclobutane and cyclobutanone synthesis and functionalization protocols have been published. Organo- and biocatalyzed eco-friendly approaches to cyclobutane-containing molecules have been developed with interesting results. Also, successful new total synthesis of bioactive compounds and drugs have been recently reported where a four membered ring represented the key intermediate. Therefore, the rising interest in this field represents a great point of discussion for the scientific community, disclosing the synthetic potential of strained four membered ring carbocyclic compounds. Herein we report a critical survey on the literature concerning the enantiocontrolled synthesis and functionalization of cyclobutane derivatives, with particular attention to metal-free, low impact methodologies, published during the period 2000–2013

Flood damage risk assessment optimizing a flood mitigation system

Flood risk management plan for potentially damaged areas is a main requirement from the European Directive 2007/60. Therefore, assessment and evaluation of the potential flood damages in quantitative terms need to be defined in mapped flood risk areas. Quantitative evaluation should be in agreement with the required cost-benefit analysis as a rational decision-making tool optimizing the flood mitigation system. In the first part of the paper, analyses are reported, based on recent flood events that had taken place in the Europe, in order to obtain depth-damage functions to apply in the Sardinia region (Italy). Flood damage functions are not still available for every European country and the paper analysed previous studies to define depth-damage functions for this region. The paper focuses then on the validation of the proposed depth-damage functions. The available flood data and reported damages of the massive storm happened in South-Est Sardinia the 22nd of October 2008 are analysed. Data analysis allows to compute the total economic losses for different land uses conditions and to compare with the evaluated ones. In the last part of the paper, expected damages evaluated using depth-damages functions are used for the Coghinas river lowlands valley. The regional Water District Authority defining the flood risk management plan considers this river basin as a pilot area. Applying hydraulic models to floodplain river flow allows evaluation of the expected flood damages using the depth-damage functions. Moreover, the procedure allows developing the cost-benefit analysis in order to justify different design scenarios and gives a rational decision-making tool optimizing the flood mitigation syste

Occhio quadrato di Alberto Lattuada (1941): un libro fotografico alla verifica delle fonti d’archivio

Alberto Lattuada’s book Occhio quadrato (1941) has come to be considered as a depiction of urban poverty in the outskirts of Milan during the fascist regime, a forerunner of Italian ‘neorealist’ photography, and an early response to the American documentary approach of the 1930s. Underscoring the limits of such narratological and stylistic readings of the photographic sequence, this essay argues for the importance of cross-analysis and philological research as a way to deconstruct the supposed self-referentiality of the book and to investigate the complex connections with the photographer’s archive from which it takes shape

Studio delle problematiche delle infiltrazioni e perdite della diga di Medau Zirimilis (Sardegna SW)

The costruction earthfill dam Medau Zirimilis, in the territory of Siliqua (SW Sardinia), began in 1989 and ended in 1991. Over the years, a time series of experimental basins, showed several problems of leakage and filtration in dam body. In the present work, through the application of classical methods of hydrogeology and applied, we have studied the problems of infiltration and loss of earth dam of Medau Zirimilis. The research has tried to examine the causes of the existing problems and identify possible solutions. The work of investigation has been developed from the acquisition of a basic knowledge of the geological characteristics of the tax of the dam and its surroundings. The understanding of its technical and constructional features and behavior had the objective to increase the level of reservoir . For this purpose, during the research have been acquired experimental data on levels in various types of water wells and drainage of the dam. Through the elaboration and interpretation with GIS methodologies and software, the attempt of this research was to reconstruct the model of the aquifer and to identify possible preferential of flow paths. Always with the purpose of identifying pathways of water, we have been carried out a study on the mantle of coating internal hangings of the bank barrage made in bituminous conglomerate, applying innovative methodologies, techniques by such as non-destructive surveys to infrared thermography

Recensione di Clément Chéroux (a cura di), Walker Evans, Paris, Éditions du Centre Pompidou, 2017

Recensione di Clément Chéroux (a cura di), Walker Evans, Paris, Éditions du Centre Pompidou, 201

Ambiente, agricoltura e sviluppo: il sistema Arborea

Starting from the assumption that contemporary society is characterized by "complexity”, the aim of this work is to go beyond the dualistic view of society and nature, to argue that the two dimensions are now indispensable of each other in terms of reciprocal relationships. As Edgar Morin says "the principle of complexity is to keep the plot intact objects: differentiating, but keeping them together" (Morin, 2007, p.23). The theoretical framework used for this survey is the theory of complex systems, with specific reference to the Maturana and Varela’s autopoiesis theory, which has its origins in the observation of biological systems and at the same time is a theory of knowledge and its possible application to the social system. The starting conceptual category of this survey is the definition of the social system and the analysis of the historical and relational dimension of it, which focuses on the action of individuals, without forgetting the influence of cultural values and shared meanings. A second category is that of environment, in its meaning and its systemic interrelation with the social system, and the characteristics of this interrelation that emerge from the theory developed by Maturana and Varela . The empirical part of the work is a case study on "Arborea System", a specific case in which the relationship between man and environment footprint is strongly interrelated. From the definition of Arborea as a closed system, we will see if this definition truly reflects the characteristics of closed systems with the emergence of potential risks that would entail

Fotografia documentaria e modernismo “transatlantico”: influenze europee e americane in Changing New York di Berenice Abbott

One of the most significant photo-books of the 1930s, Berenice Abbott’s Changing New York has increasingly been understood as a critical study of the American metropolis modelled on Atget’s survey of Old Paris. This essay relies on the notion of “transatlantic modernism” to uncover the influence of European as well as American visual culture on Abbott’s work, suggesting a dialectical exchange between documentary and modernist art in her visual language and selection of subjects

Tandem Baeyer–Villiger/Wittig/oxa-Michael addition: One-step to 5-substituted γ-lactones

The results reported in this study provide a practical protocol for the construction, in one single step of synthetically important γ-lactones in good yields starting from α-hydroxy cyclobutanone, H2O2 and several stabilized phosphonium ylides. Our synthetic strategy relies on a tandem Baeyer–Villiger oxidation/Wittig reaction/oxa-Michael addition