10 research outputs found
Il Battistero di San Giovanni in Pisa
In 2013, the movement of one of the blocks of northwestern arcs triggered the studies presented in this paper. Although the monuments of Piazza dei Miracoli appear, with the exception of the Tower, solid and stable in time, they reveal the need for continuous maintenance and restoring. In the case of the Baptistery of San Giovanni, the 2013 event provided the opportunity to deepen the knowledge of the monument. In order to obtain more information, a series of investigation activities have been initiated. At first, some information about history of construction has been collected. The information were accurate for the period covering the first 50 years of the construction. After this period the information became poor and in some cases not consistent.
In addition to historical information, some investigation regarded the masonry of foundation, the subsoil and the geometry of the whole structure. About the foundation, a specially developed drilling machine has been used to obtain information about geometry of foundation (mainly foundation plan depth) and solidity of masonry.
The instrumented perforation confirmed the presence of a sort of reclamation stratum as reported in some chronicles of that time. Investigation of geometry, carried out by means of laser scanner, provided a reliable support for further structural studies and provided some additional elements to clarify construction sequence.
In fact, one of uncertainties concerns the construction of floor of first gallery. The measurement of difference in level of floor indicates that the construction of floor occurred after the completion of building.
A two-year monitoring of structure allowed a better understanding of structure behaviour as a consequence of environmental conditions changing. Thermal effects seem to be dominant and some movements are not reversible.
A specially designed instrumented drilling machine has been used for the investigation of the foundations. The instrumented drilling machine provided the definition of geometry of foundation masonry. It is finally outlined a program for the new surveys and measurements
Early outcomes of colon laparoscopic resection in the elderly patients compared with the younger
Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study
: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI
Effects of Environmental Conditions on Historic Buildings: Interpretable Versus Accurate Exploratory Data Analysis
The goal of structural health monitoring is to continuously assess the structural integrity and performance of a building or structure over time. This is achieved by collecting data on various structural parameters and using this data to identify potential areas of concern or damage. A critical challenge involves some properties being severely damaged by recurrent variations of external factors. These variations in environmental and operational conditions (such as humidity, temperature, and traffic) can deflect the variability in structural behavior caused by structural damage and make it difficult to identify the damage of interest. In this paper, we present a study on how regression analysis and deep learning can be used to measure the influence of environmental factors on the structural behavior of the Leaning Tower of Pisa. Transparent linear regressors offer the benefit of being simple to understand and interpret. They can provide insights about the relationship between input an d target variables, as well as the relative importance of each input in forecasting the outcome. On the other hand, deep learning models are capable of learning nonlinear relationships between input and target variables. Definitively, in this work the accuracy-interpretability trade-off for structural health monitoring is discussed
Rilievi integrati per l’analisi dei dissesti strutturali del Battistero di San Giovanni a Pisa. Integrated Surveys for the Snalysis of the Structural Instabilities of the Baptistery of Pisa
Il Battistero è uno dei principali monumenti della piazza dei Miracoli a Pisa. Iniziati nel 1152, i lavori di costruzione durarono fino alla fine del XIV sec.. Significative modificazioni sono da riferirsi, inoltre, alla stagione dei restauri che ha interessato la piazza nel XIX secolo. Dal 2013, il monumento manifesta alcuni fenomeni di dissesto. Il contributo intende presentare i primi risultati di uno studio condotto in collaborazione con l’Opera della Primaziale Pisana, volto alla comprensione dei fenomeni di dissesto in una prospettiva storico-critica.The Baptistery is one of the most important monuments of the Piazza dei Miracoli in Pisa. Its construction started in 1152 and lasted until the end of the 14th century. The monument was subjected to significant modifications during the restoration works that affected all the square in the 19th century. Since 2013, the Baptistery has manifested some structural instability phenomena. The paper aims to present the first results of a study developed in collaboration with the Opera della Primaziale Pisana finalized to understand the phenomena of instability in a historical-critical perspective
Deep learning of structural changes in historical buildings: the case study of the Pisa tower
Structural health monitoring of buildings via agnostic approaches is a research challenge. However, due to the recent advent of pervasive multi-sensor systems, historical data samples are still limited. Consequently, datadriven methods are often unfeasible for long-term assessment. Nevertheless, some famous historical buildings have been subject to monitoring for decades, before the development of smart sensors and Deep Learning (DL). This paper presents a DL approach for the agnostic assessment of structural changes. The proposed approach has been experimented to the stabilizing intervention carried out in 2000-2002 on the leaning tower of Pisa (Italy). The data set is made by operational and environmental measures collected from 1993 to 2006. Both conventional and recent approaches are compared: Multiple Linear regression, LSTM and Tansformer. Experimental results are promising, and clearly shows a better change sensitivity of the LSTM, as well as a better modeling accuracy of the Transformer
Contact resonance atomic force microscopy (CR-AFM) in applied mineralogy: the case of natural and thermally treated diaspore
Contact resonance atomic force microscopy (CR-AFM) is a nondestructive technique based on atomic force microscopy (AFM) that allows one to perform single-point measurements as well as surface mapping of the indentation modulus of a material. In this work, we demonstrate the potential of CR-AFM in applied mineralogy research. As a case study, we report the characterization of natural and thermally treated diaspore. Natural diaspore samples from the Ilbirdagi diasporic metabauxite (diasporite) deposit in the Milas (Muǧla) region in Turkey were heat treated in a muffle furnace causing them to transform from diaspore to corundum. After the treatment, the samples had a polycrystalline structure with ordered micrometer-size rectangular grains of uniform crystallographic orientation. Nanomechanical characterization by CR-AFM allowed us to visualize inclusions with different mechanical properties and to determine the average indentation modulus of the surface of the thermally treated diaspore. Quantitative maps of the indentation modulus reveal the variation of the indentation modulus on the surface of single micro-grains with nanometer spatial resolution
A knowledge-based approach for the structural assessment of cultural heritage, a case study: La Sapienza Palace in Pisa
The full knowledge of the morphological evolution of an historical masonry building, defined more as ‘structural aggregate’ than as ‘single construction’, together with the analysis of the architectural, structural, geological and geotechnical aspects, allow the assessment of the static safety and seismic vulnerability of the complex and the design of retrofit interventions. In the present paper, a Knowledge-Based-Approach is applied to the historical building ‘Palazzo La Sapienza’ in Pisa, allowing to provide reliable results concerning the actual structural condition of the building avoiding the strong computational effort usually associated to the execution of refined numerical analyses. In case of complex buildings, characterized by a high heterogeneity of materials, structural typologies, geometries and so on, the adoption of a global model is not always useful to represent the effective structural behaviour. The proposed approach shows how a deep multidisciplinary knowledge of the construction can limit the use of cumbersome numerical modelling and analysis, however reaching reliable and accurate results usable also in the current practice