Theoretical modeling and mechanical characterization at increasing temperatures under compressive loads of Al core and honeycomb sandwich

This work investigates the mechanical behavior under out-of-plane compression of the Al core and honeycomb sandwich at increasing temperatures of up to 300 ◦C. After the first introductive theoretical modeling on room-temperature compressive behavior, the experimental results at increasing temperatures up to 300 ◦C are presented and discussed. The analysis of the results shows that peak stress, plateau stress, and specific absorbed energy gradually decrease as the temperature increases. The final densification occurs always at the same strain level (around 75%). Sandwich honeycomb test temperatures have been limited to 200 ◦C for bonding problems of the skin to the sandwich due to the glue. The experimental and modeling results agree well at room temperature as well at increasing temperatures. The results can provide useful information to choose base materials for greater energy absorption at increasing temperatures

Effect of the Load Application Angle on the Compressive Behavior of Al Honeycomb under Combined Normal–Shear Stress

A comparison of the compressive behavior of Al honeycomb under pure normal stress and combined normal–shear stress was analyzed in this work. The typical working stress of honeycomb is a compressive load along the direction parallel to the axis of the cells. However, the component can also undergo shear stresses during operation, which can cause premature failure. This work analyzes the mechanical behavior in compression by normal stress (0 ) and in conditions of combined normal–shear stress (at 15 and 25 ) using a special pair of wedges. The samples were obtained from a 3000 series Al alloy sandwich panel and tested according to the ASTM C365/C365M-22 standard. The different deformation modes of the cells in the combined compression were examined for three angles (0, 15 , and 25 ). A theoretical model of combined compression was used to derive the normal and tangential components starting from the total stress–strain curves. A compression curve analysis was conducted at different angles , allowing for considerations regarding changes in strength, absorbed energy, and deformations. Overall, as the load application angle increased, both the shear resistance of the honeycomb and its tangential displacement up to densification increased, which is the opposite of what occurs in normal behavior. The cell rotation angle was calculated as the load angle varied. The rotation angle of the cell increased with the displacement of the crosshead and the application angle of the force

Chapter Dal ‘progetto assente’ alla ‘architettura interrotta’. Il ruolo della modellazione digitale 3D nell’analisi storico-critica. Un caso di studio

The 43rd UID conference, held in Genova, takes up the theme of ‘Dialogues’ as practice and debate on many fundamental topics in our social life, especially in these complex and not yet resolved times. The city of Genova offers the opportunity to ponder on the value of comparison and on the possibilities for the community, naturally focused on the aspects that concern us, as professors, researchers, disseminators of knowledge, or on all the possibile meanings of the discipline of representation and its dialogue with ‘others’, which we have broadly catalogued in three macro areas: History, Semiotics, Science / Technology. Therefore, “dialogue” as a profitable exchange based on a common language, without which it is impossible to comprehend and understand one another; and the graphic sign that connotes the conference is the precise transcription of this concept: the title ‘translated’ into signs, derived from the visual alphabet designed for the visual identity of the UID since 2017. There are many topics which refer to three macro sessions: - Witnessing (signs and history) - Communicating (signs and semiotics) - Experimenting (signs and sciences) Thanks to the different points of view, an exceptional resource of our disciplinary area, we want to try to outline the prevailing theoretical-operational synergies, the collaborative lines of an instrumental nature, the recent updates of the repertoires of images that attest and nourish the relations among representation, history, semiotics, sciences

Tecnologie avanzate per la rappresentazione dell'apparecchiatura costruttiva storica: HBIM e il rinnovarsi di un'istanza

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Transient Anomalous Diffusion MRI in Excised Mouse Spinal Cord: Comparison Among Different Diffusion Metrics and Validation With Histology

Neural tissue is a hierarchical multiscale system with intracellular and extracellular diffusion compartments at different length scales. The normal diffusion of bulk water in tissues is not able to detect the specific features of a complex system, providing nonlocal, diffusion measurement averaged on a 10-20 mm length scale. Being able to probe tissues with sub-micrometric diffusion length and quantify new local parameters, transient anomalous diffusion (tAD) would dramatically increase the diagnostic potential of diffusion MRI (DMRI) in detecting collective and sub-micro architectural changes of human tissues due to pathological damage. In DMRI, the use of tAD parameters quantified using specific DMRI acquisition protocols and their interpretation has often aroused skepticism. Although the derived formulas may accurately fit experimental diffusion-weighted data, the relationships between the postulated dynamical feature and the underlying geometrical structure remains elusive, or at most only suggestive. This work aimed to elucidate and validate the image contrast and information that can be obtained using the tAD model in white matter (WM) through a direct comparison between different diffusion metrics and histology. Towards this goal, we compared tAD metrics extracted from pure subdiffusion (a-imaging) and superpseudodiffusion (g-imaging) in excised mouse spinal cord WM, together with T2 and T2  relaxometry, conventional (normal diffusion-based) diffusion tensor imaging (DTI) and q-space imaging (QSI), with morphologic measures obtained by optical microscopy, to determine which structural and topological characteristics of myelinated axons influenced tAD contrast. Axon diameter (AxDiam), the standard deviation of diameters (SDax:diam), axonal density (AxDens) and effective local density (ELD) were extracted from optical images in several WM tracts. Among all the diffusion parameters obtained at 9.4 T, g-metrics confirmed a strong dependence on magnetic in-homogeneities quantified by R2  = 1/T2  and showed the strongest associations with AxDiam and ELD. On the other hand, a-metrics showed strong associations with SDax:diam and was significantly related to AxDens, suggesting its ability to quantify local heterogeneity degree in neural tissue. These results elucidate the biophysical mechanism underpinning tAD parameters and show the clinical potential of tAD-imaging, considering that both physiologic and pathologic neurodegeneration translate into alterations of WM morphometry and topology

AHBIM per l'analisi stratigrafica dell'architettura storica.

According to potentialities given by BIM (Building Information Modeling) procedures, in the last 10 years many experimentations have been conducted on BIM application to Architectural Heritage (AHBIM). BIM software are tools for information computing and management of buildings in the three-dimensional space. Aim of the paper is to study how BIM models can favor architectural stratigraphic analysis. A workflow for 3D modeling of Stratigraphic Units of the Masonry is proposed; this three-dimensional representation can aid the documentation and the analysis of the construction phases. The case study is the church of St. Vittorino near L’Aquila (4th-12th-18th centuries), characterized by important modification and stratification processes. The church has been surveyed by laser-scanning and digital photogrammetry, consequently a dedicated BIM model has been realized for Stratigraphic Units study

Isolation of Progenitors that Exhibit Myogenic/Osteogenic Bipotency In Vitro by Fluorescence-Activated Cell Sorting from Human Fetal Muscle

Summary Fluorescence-activated cell sorting (FACS) strategies to purify distinct cell types from the pool of fetal human myofiber-associated (hMFA) cells were developed. We demonstrate that cells expressing the satellite cell marker PAX7 are highly enriched within the subset of CD45−CD11b−GlyA−CD31−CD34−CD56intITGA7hi hMFA cells. These CD45−CD11b−GlyA−CD31−CD34−CD56intITGA7hi cells lack adipogenic capacity but exhibit robust, bipotent myogenic and osteogenic activity in vitro and engraft myofibers when transplanted into mouse muscle. In contrast, CD45−CD11b−GlyA−CD31−CD34+ fetal hMFA cells represent stromal constituents of muscle that do not express PAX7, lack myogenic function, and exhibit adipogenic and osteogenic capacity in vitro. Adult muscle likewise contains PAX7+ CD45−CD11b−GlyA−CD31−CD34−CD56intITGA7hi hMFA cells with in vitro myogenic and osteogenic activity, although these cells are present at lower frequency in comparison to their fetal counterparts. The ability to directly isolate functionally distinct progenitor cells from human muscle will enable novel insights into muscle lineage specification and homeostasis

Studies for the Historical-Critical Analysis of a Historical Center. The Case Study of Castel Camponeschi

[EN] Aim of the paper is the historical-critical study of Castel Camponeschi (aka Castello di Prata), a village at about 25 km from L’Aquila city (Italy), with peculiar urban characteristics –a herringbone pattern– probably founded in the thirteenth century and characterized by important phenomena of modification and stratification. The study roots on the direct analysis of the built heritage through the architectural surveying, realized at multiple scales from the urban settlement to the masonry structures. According to the morphology of the historic center, it could be traced to the process of new settlement foundation that characterized the territory –the border between the Papal State and the Frederic’s Empire first, and then the Angevin kingdom–. The analysis of the village requires both a correlation with the natural and anthropic historical context in which it is inserted and, a specific study of masonry equipments, characterized by the re-used of stone elements from the nearby Vestino-Roman town of Peltuinum.Trizio, I.; Brusaporci, S.; Continenza, R.; Maiezza, P.; Tata, A.; Ruggieri, A.; Giannageli, A. (2020). Studi per l’analisi storico-critica di un centro storico. Il caso di studio di Castel Camponeschi. Editorial Universitat Politècnica de València. 1449-1456. https://doi.org/10.4995/FORTMED2020.2020.11444OCS1449145

A multi-center validation study on the discrimination of Legionella pneumophila sg.1, Legionella pneumophila sg. 2-15 and Legionella non-pneumophila isolates from water by FT-IR spectroscopy

This study developed and validated a method, based on the coupling of Fourier-transform infrared spectroscopy (FT-IR) and machine learning, for the automated serotyping of Legionella pneumophila serogroup 1, Legionella pneumophila serogroups 2-15 as well as their successful discrimination from Legionella non-pneumophila. As Legionella presents significant intra- and inter-species heterogeneities, careful data validation strategies were applied to minimize late-stage performance variations of the method across a large microbial population. A total of 244 isolates were analyzed. In details, the method was validated with a multi-centric approach with isolates from Italian thermal and drinking water (n = 82) as well as with samples from German, Italian, French, and British collections (n = 162). Specifically, robustness of the method was verified over the time-span of 1 year with multiple operators and two different FT-IR instruments located in Italy and Germany. Moreover, different production procedures for the solid culture medium (in-house or commercial) and different culture conditions (with and without 2.5% CO2) were tested. The method achieved an overall accuracy of 100, 98.5, and 93.9% on the Italian test set of Legionella, an independent batch of Legionella from multiple European culture collections, and an extra set of rare Legionella non-pneumophila, respectively