419 research outputs found

    Risk Analysis for Smart Cities Urban Planners: Safety and Security in Public Spaces

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    Christopher Alexander in his famous writings "The Timeless Way of Building" and "A pattern language" defined a formal language for the description of a city. Alexander developed a generative grammar able to formally describe complex and articulated concepts of architecture and urban planning to define a common language that would facilitate both the participation of ordinary citizens and the collaboration between professionals in architectural and urban planning. In this research, a similar approach has been applied to let two domains communicate although they are very far in terms of lexicon, methodologies and objectives. These domains are urban planning, urban design and architecture, seen as the first domain both in terms of time and in terms of completeness of vision, and the one relating to the world of engineering, made by innumerable disciplines. In practice, there is a domain that defines the requirements and the overall vision (the first) and a domain (the second) which implements them with real infrastructures and systems. To put these two worlds seamlessly into communication, allowing the concepts of the first world to be translated into those of the second, Christopher Alexander’s idea has been followed by defining a common language. By applying Essence, the software engineering formal descriptive theory, using its customization rules, to the concept of a Smart City, a common language to completely trace the requirements at all levels has been defined. Since the focus was on risk analysis for safety and security in public spaces, existing risk models have been considered, evidencing a further gap also within the engineering world itself. Depending on the area being considered, risk management models have different and siloed approaches which ignore the interactions of one type of risk with the others. To allow effective communication between the two domains and within the engineering domain, a unified risk analysis framework has been developed. Then a framework (an ontology) capable of describing all the elements of a Smart City has been developed and combined with the common language to trace the requirements. Following the philosophy of the Vienna Circle, a creative process called Aufbau has then been defined to allow the generation of a detailed description of the Smart City, at any level, using the common language and the ontology above defined. Then, the risk analysis methodology has been applied to the city model produced by Aufbau. The research developed tools to apply such results to the entire life cycle of the Smart City. With these tools, it is possible to understand how much a given architectural, urban planning or urban design requirement is operational at a given moment. In this way, the narration can accurately describe how much the initial requirements set by architects, planners and urban designers and, above all, the values required by stakeholders, are satisfied, at any time. The impact of this research on urban planning is the ability to create a single model between the two worlds, leaving everyone free to express creativity and expertise in the appropriate forms but, at the same time, allowing both to fill the communication gap existing today. This new way of planning requires adequate IT tools and takes the form, from the engineering side, of harmonization of techniques already in use and greater clarity of objectives. On the side of architecture, urban planning and urban design, it is instead a powerful decision support tool, both in the planning and operational phases. This decision support tool for Urban Planning, based on the research results, is the starting point for the development of a meta-heuristic process using an evolutionary approach. Consequently, risk management, from Architecture/Urban Planning/Urban Design up to Engineering, in any phase of the Smart City’s life cycle, is seen as an “organism” that evolves.Christopher Alexander nei suoi famosi scritti "The Timeless Way of Building" e "A pattern language" ha definito un linguaggio formale per la descrizione di una città, sviluppando una grammatica in grado di descrivere formalmente concetti complessi e articolati di architettura e urbanistica, definendo un linguaggio comune per facilitare la partecipazione dei comuni cittadini e la collaborazione tra professionisti. In questa ricerca, un approccio simile è stato applicato per far dialogare due domini sebbene siano molto distanti in termini di lessico, metodologie e obiettivi. Essi sono l'urbanistica, l'urban design e l'architettura, visti come primo dominio sia in termini di tempo che di completezza di visione, e quello del mondo dell'ingegneria, con numerose discipline. In pratica, esiste un dominio che definisce i requisiti e la visione d'insieme (il primo) e un dominio (il secondo) che li implementa con infrastrutture e sistemi reali. Per metterli in perfetta comunicazione, permettendo di tradurre i concetti del primo in quelli del secondo, si è seguita l'idea di Alexander definendo un linguaggio. Applicando Essence, la teoria descrittiva formale dell'ingegneria del software al concetto di Smart City, è stato definito un linguaggio comune per tracciarne i requisiti a tutti i livelli. Essendo il focus l'analisi dei rischi per la sicurezza negli spazi pubblici, sono stati considerati i modelli di rischio esistenti, evidenziando un'ulteriore lacuna anche all'interno del mondo dell'ingegneria stessa. A seconda dell'area considerata, i modelli di gestione del rischio hanno approcci diversi e isolati che ignorano le interazioni di un tipo di rischio con gli altri. Per consentire una comunicazione efficace tra i due domini e all'interno del dominio dell'ingegneria, è stato sviluppato un quadro di analisi del rischio unificato. Quindi è stato sviluppato un framework (un'ontologia) in grado di descrivere tutti gli elementi di una Smart City e combinato con il linguaggio comune per tracciarne i requisiti. Seguendo la filosofia del Circolo di Vienna, è stato poi definito un processo creativo chiamato Aufbau per consentire la generazione di una descrizione dettagliata della Smart City, a qualsiasi livello, utilizzando il linguaggio comune e l'ontologia sopra definita. Infine, la metodologia dell'analisi del rischio è stata applicata al modello di città prodotto da Aufbau. La ricerca ha sviluppato strumenti per applicare tali risultati all'intero ciclo di vita della Smart City. Con questi strumenti è possibile capire quanto una data esigenza architettonica, urbanistica o urbanistica sia operativa in un dato momento. In questo modo, la narrazione può descrivere con precisione quanto i requisiti iniziali posti da architetti, pianificatori e urbanisti e, soprattutto, i valori richiesti dagli stakeholder, siano soddisfatti, in ogni momento. L'impatto di questa ricerca sull'urbanistica è la capacità di creare un modello unico tra i due mondi, lasciando ognuno libero di esprimere creatività e competenza nelle forme appropriate ma, allo stesso tempo, permettendo ad entrambi di colmare il gap comunicativo oggi esistente. Questo nuovo modo di progettare richiede strumenti informatici adeguati e si concretizza, dal lato ingegneristico, in un'armonizzazione delle tecniche già in uso e in una maggiore chiarezza degli obiettivi. Sul versante dell'architettura, dell'urbanistica e del disegno urbano, è invece un potente strumento di supporto alle decisioni, sia in fase progettuale che operativa. Questo strumento di supporto alle decisioni per la pianificazione urbana, basato sui risultati della ricerca, è il punto di partenza per lo sviluppo di un processo meta-euristico utilizzando un approccio evolutivo

    Effectiveness, compatibility and durability of consolidants for marble: a review of the last ten year of researches

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    The choice of suitable consolidant treatment for cultural stones is one of the main challenging issue for conservation and protection of ancient masonry. Among building materials, marble is one of the most used for building and sculptures. Due to its low porosity, the assessment of suitable treatment for marble consolidation is not trivial; beside, the type of product, treatment methodology, effectiveness and compatibility investigation and durability monitoring have to be taken in great account. Recently, researchers have extensively tested and proposed new products for consolidating carbonate stones, including organic and inorganic products, nanoparticles, biological organisms (De Muynck et al., 2010). Nevertheless, no entirely satisfactory treatment is currently available for marble consolidation. At the same time, no unique evaluation criteria to use as laboratory estimators of consolidating performances have been assessed . The present paper aims to carry out a review of the state of art, based on the last ten years of researches, on consolidants for marble substrate. We summarize the different type of commercial and research products proposed for marble consolidation, by comparing also effectiveness, compatibility and durability of each proposed product, in function of consolidant features (i.e., product concentration, solvent type) and treatment methodology (application process, and contact time)

    X-ray fluorescence analysis of trace elements in silicate rocks using fused glass discs

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    X-ray fluorescence analysis of twelve trace elements in silicate rocks (V, Cr, Co, Ni, Rb, Sr, Y, Zr, Nb, Ba, La, Ce) was carried out by using fused glass discs prepared by mixing 0.700 g of powder rock samples with 3.150 g of lithium tetraborate and 3.150 g of lithium metaborate. The method was calibrated using one hundred and twenty-one in-house rock standards and the accuracy was tested using sixteen international rock standards. The errors range from 3 to 10% for abundances ranging from 0 to 2300 ppm. Overall, the quality of the analytical data obtained by the proposed method is similar to that one obtained by processing powder pellets. Since the samples prepared through this technique allows the determination of major elements too, with a high degree of accuracy, the proposed methodology is characterized by an excellent ratio of analytical quality and operating time

    Calibration of XRF data on silicate rocks using chemicals as in-house standards

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    X-ray fluorescence (XRF) is an accurate, rapid spectroscopic technique for chemical element determinations on rock samples. The aim of this research was to evaluate a calibration method based on the use of suitable mixtures of chemicals. X-ray fluorescence analysis of major elements (Na, Mg, Al, Si, K, Ca, Fe) was carried out using sample-lithium borate fusion mixtures (with a 1:9 sample/borate dilution). The accuracy of the proposed calibration method was tested on twenty-four international rock standards. Results are in good or excellent agreement with the literature recommended value

    The building stones of the apsidal walls of the Pisa’s Cathedral

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    This paper reports the preliminary data about the stones used in the apsidal walls of the Cathedral of Pisa. The research was made during the study and restoration works of the monument, under the supervision of the Opera della Primaziale Pisana. The collected data shows the prevalence of stones commonly used in the historical buildings of the city. The main lithotypes are the marbles from the Monte Pisano and from the Apuan Alps. Moreover, there are numerous ashlars of Proconnesian marble and two capitals of Pentelic and one of Paros marbles, three lithotypes used during the Roman Age and coming from the Eastern Mediterranean. The wall of the loggia of the third storey is almost entirely made up of a calcarenite (Panchina) coming from the area South of Livorno. Black limestone from the Monti d’Oltre Serchio, and serpentinite and red marly limestone outcropping in different areas of Tuscany, were also identified

    A contribution to the mineralogy of the Larderello geothermal field. X-ray crystallographic studies on borate minerals "bechilite" and "lagonite" and crystal structure determination of ginorite

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    This work reports the results of mineralogical studies on some borate minerals from the Larderello geothermal field. XRD patterns of “bechilite” and “lagonite” confirmed they actually are respectively admixtures of sassolite and ammonioborite, and of sassolite with minor santite, gypsum and larderellite. Single crystal structural study of ginorite from the type locality, Sasso Pisano (Castelnuovo val di Cecina, Pisa) confirmed its isotypism with strontioginorite. Ginorite is monoclinic, space group P21/a, with unit cell parameters a =12.7673(1) Å, b = 14.3112(11), c = 12.7298(9), β= 101.055(5)° V=2282.8(2) Å3. The refinement of its crystal structure converged to R1 = 0.058 on the basis of 3387 reflections with Fo > 4σ (Fo). Analogously to strontioginorite, ginorite crystal structure can be described in terms of complex “sheets” parallel to (010), made up by borate groups and Ca coordination polyhedra, with interlayer linkage assured by Ca cations and hydrogen bonds. The cell volume contraction of ginorite respect to strontioginorite is related to the shrinkage of Ca coordination polyhedra present in the complex Me-borate sheets

    Thermal behaviour of Al-rich tobermorite

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    The tobermorite supergroup is composed by a number of calcium-silicate-hydrate (C-S-H) minerals characterized by different hydration states and sub-cell symmetries. Taking into account their basal spacing, closely related to the hydration state, phases having a 14 Å (plombierite), 11 Å (tobermorite, kenotobermorite, and clinotobermorite), and 9 Å (riversideite) basal spacing have been described. Tobermorite and kenotobermorite belong to the so-called tobermorite group and differ for their thermal behaviour which can be "normal" (the phase shrinks to a 9 Å phase at 300 °C) or "anomalous" (the phase preserves its 11 Å basal spacing at 300 °C). Specimens of Al-rich tobermorite from Montalto di Castro and Vallerano, Latium, Central Italy, showing a "normal" thermal behaviour, were studied in order to describe the transition from the 11 Å to the 9 Å phase by means of thermogravimetric-differential scanning calorimetry (TG-DSC) analyses as well as in situ and ex situ X-ray diffraction experiments. The TG-DSC analyses showed a continuous mass loss from 100 °C up to 700 °C, with different mass loss gradients between 100 °C up to 300 °C and between 300 °C up to 700 °C, corresponding to the dehydration of tobermorite and dehydroxylation of "tobermorite 9 A", respectively. Above 700 °C, "tobermorite 9 Å" is replaced by wollastonite. The X-ray powder diffraction data were collected at the GILDA beamline of the ESRF, Grenoble, France, from room temperature up to ca. 840 °C. Tobermorite is completely replaced by the 9 A phase at ca. 300 °C, whereas the latter is transformed into wollastonite at ca. 700 °C. The transition from the 11 Å to the 9 Å phase seems to be favoured by the transient appearance of a clinotobermorite-like compound

    A fast and user-friendly software for quantitative chemical analysis through XRF

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    X-ray fluorescence (XRF) spectroscopy is a technique widely used for the study and conservation of cultural heritage materials. A Microsoft Excel spreadsheet to determine major (Na, Mg, Al, Si, K, Ca, Fe) and minor (P, Ti, Mn) elements in rocks and other materials by XRF is presented. The code is based on the analytical method proposed a few decades ago by Franzini et al., which is based on the algorithm: Ci = Ii ⋅ ΣKi,j Cj, where Ci is the concentration (expressed as wt%) of the chemical element “i”, Ii is the intensity of the characteristic line, Cj is the concentration of interfering elements, and Ki,j are experimental coefficients that account for the matrix effects (absorption and enhancement). Ki,j have the dimension of mass absorption coefficients and they may be calculated from a set of N reference samples using multivariate regression methods. The algorithm proposed by these authors is particularly suitable for processing samples prepared in the form of pressed powders. The Microsoft Excel spreadsheet allows you to: a) choose a set of reference samples (international or interlaboratory standards); b) evaluate the expected matrix effects on the basis of the XRF total mass absorption coefficients; c) calculate the correction coefficients Ki,j through multivariable regression; d) calculate the analytical accuracy and graphically represent the results; e) choose five samples (monitors) for the correction of instrumental drift. Based on these steps, the software allows you to: i) enter the analytical intensities of major and minor elements measured on the monitors and on unknown samples (the loss on ignition must be determined separately); ii) calculate the correction of the instrumental drift; iii) determine the concentration of elements and express them as wt%

    Mineralogical-chemical Alteration and Origin of Ignimbritic Stones Used in the Old Cathedral of Nostra Signora di Castro (Sardinia, Italy)

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    The pyroclastic rocks belonging to the Late Eocene-Miocene volcanic activity that occurred in Sardinia between 38 and 15 Ma ago were widely used as construction materials in several Romanesque churches of the easternmost Logudoro area, as well as in large parts of the Sardinia territory. In this work, the ancient Cathedral of Nostra Signora di Castro (twelfth century) was taken as a representative case study. There is no historical or archaeological evidence of ancient quarries. Based on the geochemical, petrographic, and volcanological data on several samples from an extensive field area (approximately 150km2), a geographical zoning of the volcanics has been recognised. In the Oschiri sector, there are three different sub-zones, which can be identified with different volcanic rocks: less fractionated rocks (Differentation Index ∼70–78); intermediately fractionated rocks (D.I. ∼76– 79); and more fractionated rocks (D.I. ∼77–82). To identify the origin of the ignimbrite rocks of the Church of Nostra Signora di Castro, two statistical methods were used: stepwise linear discriminant and canonical analysis. Moreover, to define the geochemical transformation processes induced by the alteration, a comparative study of concentrations of major and trace elements measured by XRF and SEM-EDX analyses on the surface portion and the innermost areas of the stone was made
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