3,218 research outputs found

    Geometria e costruzione. La teoria delle linee di curvatura nella stereotomia della pietra

    Get PDF
    Il contributo illustra lo studio teorico e pratico della teoria delle linee di curvatura delle superfici elaborata da Gaspard Monge alla fine del Settecento, e la sua applicazione alle costruzioni in pietra da taglio, con particolare riferimento al caso di studio (proposto da Monge e rivisitato da Hachette e Leroy) di una volta ellissoidale. L’intento è quello di ottimizzare la costruzione di queste linee nel metodo della rappresentazione matematica, almeno per il caso specifico di studio. Il legame che sussiste fra la le teorie geometrico descrittive e i principi della progettazione stereotomica è significativo. Costruzioni geometriche teoriche, apparentemente astratte, trovano riscontri e applicazioni nella pratica delle costruzioni e diventano, a volte, condizione indispensabile alla soluzione di casi complessi come quello presentato

    new methodologies for the documentation of fortifiedarchitecture in the state of ruins

    Get PDF
    Fortresses and castles are important symbols of social and cultural identity providing tangible evidence of cultural unity in Europe. They are items for which it is always difficult to outline a credible prospect of reuse, their old raison d'ĂŞtre- namely the military, political and economic purposes for which they were built- having been lost. In recent years a Research Unit of the University of Bologna composed of architects from different disciplines has conducted a series of studies on fortified heritage in the Emilia Romagna region (and not only) often characterized by buildings in ruins. The purpose of this study is mainly to document a legacy, which has already been studied in depth by historians, and previously lacked reliable architectural surveys for the definition of a credible as well as sustainable conservation project. Our contribution will focus on different techniques and methods used for the survey of these architectures, the characteristics of which- in the past- have made an effective survey of these buildings difficult, if not impossible. The survey of a ruin requires, much more than the evaluation of an intact building, reading skills and an interpretation of architectural spaces to better manage the stages of documentation and data processing. Through a series of case studies of fortified buildings in ruins, we intend to describe the reasons that guided the choice of the methods and tools used and to highlight the potentials and the limits of these choices in financial terms

    The Critical Digital Model and Two Case Studies: the Churches of Santa Margherita and Santo Spirito in Bologna

    Get PDF
    Two case studies of hypothetical reconstruction are presented according to the principles of the Critical Digital Model [Apollonio et al. 2019]. One of the case studies is an architecture that was designed but never realized, and the other is the reconstruction of a historical art exhibition hosted into an architecture still existing today. This study is part of a wider research which is being currently carried out in the international Erasmus+project CoVHer. The main objective of the CoVHer project is to identify shared standards for the construction, evaluation and sharing of 3D hypothetical reconstructions. This research exploits the diversities of the two case studies to classify and re-defne the methods of digital representation, which deal with the geometrical/mathematical nature of the models themselves and tries to defne good practices to produce scientifcally valid, sharable, and reusable 3D reconstructions


    Get PDF
    The modern city of Urbisaglia, Roman Urbs Salvia, features many traces of its ancient origins. One of the most noteworthy is the theater, dated at around 23 d.C. The article presents a new, hypothetical virtual reconstruction of the structure, which was carried out based on the recent research of the geometric framework used by Roman architects in design. The principal intention of the article is to demonstrate the methodology of the study, in the case of a monument characterized by poor state of preservation


    Get PDF
    The sixteenth-century Fountain of Neptune is one of Bologna's most renowned landmarks. During the recent restoration activities of the monumental sculpture group, consisting in precious marbles and highly refined bronzes with water jets, a photographic campaign has been carried out exclusively for documentation purposes of the current state of preservation of the complex. Nevertheless, the highquality imagery was used for a different use, namely to create a 3D digital model accurate in shape and color by means of automated photogrammetric techniques and a robust customized pipeline. This 3D model was used as basic tool to support many and different activities of the restoration site. The paper describes the 3D model construction technique used and the most important applications in which it was used as support tool for restoration: (i) reliable documentation of the actual state; (ii) surface cleaning analysis; (iii) new water system and jets; (iv) new lighting design simulation; (v) support for preliminary analysis and projectual studies related to hardly accessible areas; (vi) structural analysis; (vii) base for filling gaps or missing elements through 3D printing; (viii) high-quality visualization and rendering and (ix) support for data modelling and semantic-based diagrams

    Revascularization of Chronic Hibernating Myocardium Stimulates Myocyte Proliferation and Partially Reverses Chronic Adaptations to Ischemia

    Get PDF
    AbstractBackgroundThe time course and extent of recovery after revascularization of viable dysfunctional myocardium are variable. Although fibrosis is a major determinant, myocyte structural and molecular remodeling may also play important roles.ObjectivesThis study sought to determine whether persistent myocyte loss and/or irreversibility of protein changes that develop in hibernating myocardium have an impact on functional recovery in the absence of infarction.MethodsSwine implanted with a chronic left anterior descending artery (LAD) stenosis to produce hibernating myocardium underwent percutaneous revascularization, with serial functional recovery evaluated for 1 month (n = 12). Myocardial tissue was evaluated to assess myocyte size, nuclear density, and proliferation indexes in comparison with those of normal animals and nonrevascularized controls. Proteomic analysis by 2-dimensional differential in-gel electrophoresis was used to determine the reversibility of molecular adaptations of hibernating myocytes.ResultsAt 3 months, physiological features of hibernating myocardium were confirmed, with depressed LAD wall thickening and no significant infarction. Revascularization normalized LAD flow reserve, with no immediate change in LAD wall thickening. Regional LAD wall thickening slowly improved but remained depressed 1 month post–percutaneous coronary intervention. Surprisingly, revascularization was associated with histological evidence of myocytes re-entering the growth phase of the cell cycle and increases in the number of c-Kit+ cells. Myocyte nuclear density returned to normal, whereas regional myocyte hypertrophy regressed. Proteomic analysis demonstrated heterogeneous effects of revascularization. Up-regulated stress and cytoskeletal proteins normalized, whereas reduced contractile and metabolic proteins persisted.ConclusionsDelayed recovery of hibernating myocardium in the absence of scar may reflect persistent reductions in the amounts of contractile and metabolic proteins. Although revascularization appeared to stimulate myocyte proliferation, the persistence of small immature myocytes may have contributed to delayed functional recovery

    Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade

    Get PDF
    The CMS Collaboration has been developing large-area triple-gas electron multiplier (GEM) detectors to be installed in the muon Endcap regions of the CMS experiment in 2019 to maintain forward muon trigger and tracking performance at the High-Luminosity upgrade of the Large Hadron Collider (LHC); 10 preproduction detectors were built at CERN to commission the first assembly line and the quality controls (QCs). These were installed in the CMS detector in early 2017 and participated in the 2017 LHC run. The collaboration has prepared several additional assembly and QC lines for distributed mass production of 160 GEM detectors at various sites worldwide. In 2017, these additional production sites have optimized construction techniques and QC procedures and validated them against common specifications by constructing additional preproduction detectors. Using the specific experience from one production site as an example, we discuss how the QCs make use of independent hardware and trained personnel to ensure fast and reliable production. Preliminary results on the construction status of CMS GEM detectors are presented with details of the assembly sites involvement
    • …