1,720,994 research outputs found
The Impact of Fused Filament Fabrication (FFF) Printing Profiles on 17-4 PH Green and Sintered Parts
No full textThe aim of this research is to characterize parts from innovative hybrid printing method for obtaining dense metal components using affordable fused filament fabrication (FFF). The introduction of Desktop Metal technology in 2015 really attracts an increase in industrial interest in the FFF printing of highly metal-filled filament. Even though FFF is a well-known process, there are not many studies on how to optimize the printing parameters for these feedstocks. The effects of the printing setting on producing high-quality green parts and enhancing the mechanical properties of the finished 17-4 PH metallic parts are investigated in this work. The influence of four printing profiles provided by a BASF plugin for Ultimaker Cura slicing software, obtained by combining different printing parameters is investigated. The ASTM E8 tensile test is used to determine the mechanical characteristics of the finished metal components. To identify differences in morphology, optical and scanning electron microscopy (SEM) observations are made on both sections of green and sintered samples. The effect of printing parameters on shrinkage and density are also taken into consideration. The findings demonstrate the importance of optimizing the printing of the green parts in order to produce full metal components that are both strong and dense
Fused Filament Fabrication of Alumina/Polymer Filaments for Obtaining Ceramic Parts after Debinding and Sintering Processes
No full textA TYPOLOGICAL-MECHANICAL APPROACH TO ASSESS LARGE-SCALE SEISMIC FRAGILITY OF MASONRY BUILDINGS IN HISTORICAL CENTRES
No full textThe paper presents a mechanical approach for the assessment of large-scale seismic fragility for recurrent masonry building typologies in historical centres. Especially in the context of regional-scale analysis, the poor level of information drives analysts to develop suitable approaches to characterize in a synthetic way the seismic behaviour of the existing masonry building stock. Hence, the proposed framework arises from a matching between historical centres macro-classes and recurrent masonry building typologies defined by exploiting multisources data integration in GIS environment (e.g., census data, topographic cartographies, and information provided by the CARTIS form application). After, sets of mechanical models, which are sufficiently representative of the most widespread typologies on the regional territory, can be realized accounting for structural and morpho-typological features variability, as evincible from the available georeferenced database. Subsequently, nonlinear static analysis is adopted as analysis method where, for each model, Capacity/Demand ratio can be estimated for increasing levels of Peak Ground Acceleration. The obtained results are then processed according to Multiple Stripe Analysis method to derive typological fragility curves, which can be properly associated to historical centre macro-classes, covered by certain percentage of masonry building typologies. The proposed procedure was applied to the case study of Puglia region, allowing to investigate large portions of the building stock characterizing historical centres, by managing few information and by providing a methodology easily extendible to different context of applications
Investigation of architectural typological parameters influencing seismic vulnerability of masonry buildings in historical centres: the case of Puglia
No full textThe paper presents a systematical study on the main architectural features characterizing existing buildings in historical centres and influencing their vulnerability under seismic actions. In particular, the first step of the work reports a macro-classification of historical centres on regional scale, obtained through a combination of multisource data with different degrees of detail, such as data from regional landscape plans, public datasets on web GIS and quick virtual inspections. After, all gathered data have been collected and processed in a proper georeferenced database, in order to analyze specific features and their geographic distribution, releasing a new taxonomy. Therefore, a regional abacus of building typologies has been defined through the main architectural and morpho-typological features influencing seismic vulnerability. The starting dataset has been compared by means of other available urban-scale data as those derived from CARTIS (structural-typological characterization for urban compartments), the procedure proposed in Italy for an extensive classification at national scale of recurring building typologies in municipalities. The result is a homogeneous macro-classification of historical centres enriched by typological information also finalized to estimate seismic vulnerability in a given area. The above procedure has been applied on the case study of Puglia region, showing a GIS tool reporting the classification for Apulian historical centres and the resulting abacus for the recurring building typologies
A TYPOLOGICAL-MECHANICAL APPROACH TO ASSESS LARGE-SCALE SEISMIC FRAGILITY OF MASONRY BUILDINGS IN HISTORICAL CENTRES
Full text linkThe paper presents a mechanical approach for the assessment of large-scale seismic fragility for recurrent masonry building typologies in historical centres. Especially in the context of regional-scale analysis, the poor level of information drives analysts to develop suitable approaches to characterize in a synthetic way the seismic behaviour of the existing masonry building stock. Hence, the proposed framework arises from a matching between historical centres macro-classes and recurrent masonry building typologies defined by exploiting multi-sources data integration in GIS environment (e.g., census data, topographic cartographies, and information provided by the CARTIS form application). After, sets of mechanical models, which are sufficiently representative of the most widespread typologies on the regional territory, can be realized accounting for structural and morpho-typological features variability, as evincible from the available georeferenced database. Subsequently, nonlinear static analysis is adopted as analysis method where, for each model, Capacity/Demand ratio can be estimated for increasing levels of Peak Ground Acceleration. The obtained results are then processed according to Multiple Stripe Analysis method to derive typological fragility curves, which can be properly associated to historical centre macro-classes, covered by certain percentage of masonry building typologies. The proposed procedure was applied to the case study of Puglia region, allowing to investigate large portions of the building stock characterizing historical centres, by managing few information and by providing a methodology easily extendible to different context of applications
Are future teachers ready to integrate artificial intelligence into education? An evaluation of a training intervention on a sample of italian pre-service teachers.
Full text linkLo studio ha esaminato la percezione dell’IA da parte di futuri insegnanti dopo un training di 9 ore sulle sue applicazioni educative. Questionari pre/post hanno valutato cambiamenti in conoscenza, fiducia, facilità d’uso e intenzione d’uso. I risultati mostrano miglioramenti significativi, confermando l’efficacia della formazione mirata per l’integrazione dell’IA nella didattica.This study examined pre-service teachers’ perceptions of AI following a 9-hour training on its educational applications. Pre/post questionnaires assessed changes in knowledge, trust, perceived ease of use and intention to use. Results showed significant improvements, confirming the effectiveness of targeted training in promoting AI integration in education
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
