296 research outputs found
Il piatto argenteo di Cesena. Note a margine su una scena di banchetto all'aperto della Tarda Antichità
No full textNovel Magnesium Elektron21-AlN Nanocomposites Produced by Ultrasound-Assisted Casting; Microstructure, Thermal and Electrical Conductivity
No full textIn the current work, a novel magnesium alloy Elektron21 reinforced by ceramic AlN nanoparticles were produced by an ultrasound-assisted casting. The fabricated nanocomposites were investigated to evaluate their microstructure, hardness, physical, thermal and electrical conductivity. The microstructural evolutions show that a uniform dispersion of the ceramic particles within the matrix can be achieved by employing the ultrasound-assisted stirring. However, some nanoparticles were found to be pushed by the solidification front. According to the Vickers hardness results, the addition of AlN nanoparticles results in a slight improvement of the mechanical properties of the nanocomposites. What is surprising is that both electrical and thermal conductivity of the nanocomposite were improved significantly as a consequence of AlN addition. This improvement in the conductivity characteristics of the nanocomposite is mainly corresponding to the structural effect of nanoparticles within the matrix
The East Variscan Shear Zone:geochronological constraints from the Capo Ferro area (NE Sardinia, Italy)
No full textThe exhumation of the Variscan High Grade Metamorphic Complex of Sardinia has been driven by a wide dextral shearing which reached middle crustal levels at 325 ±1.3 Ma and caused partial melting. The migmatization process has been followed by the emplacement of syn-tectonic granites dated at 316 ±2 Ma, 318 ±3 Ma and 317 ±2 Ma which produced contact metamorphism at 315 ±1.3 Ma in mylonitic Silurian orthogneiss. The NW-SE dextral shear zone of the Capo Ferro area (NE Sardinia) shows remarkable petro-tectonic analogies and can thus be related to the East Variscan Shear Zone, a major intra-continental shear zone which was active in the southern European Variscides from 325 Ma to 315 Ma and that is precisely dated with the U-Pb monazite system. The emplacement of migmatitic gneisses along large shear zones within this time interval is not restricted to Sardinia, but has also been observed in southern Corsica, in the French Massif Central, in the Western Alps and in central Spain. This pattern of shear zones is related to a complex geodynamic scenario, linked to the oblique convergence between Gondwana and Laurussia plates during the Middle-Upper Carboniferous
The East Variscan Shear Zone: geochronological constaints from the Capo Ferro area (NE Sardinia, Italy)
No full textThe exhumation of the Variscan High Grade Metamorphic Complex of Sardinia was driven by large-scale asymmetric shear zones which reached middle crustal levels at 325 ± 1.3 (U–Pb, monazite) Ma. Exhumation was
accompanied by heating and partial melting. The migmatization process was followed by the emplacement of
syntectonic granites dated with U–Pb on zircon at 318 ± 3 Ma and 317 ± 2 Ma, which produced contact metamorphism at 315 ± 1.3 Ma (U–Pb, monazite) in mylonitic Silurian orthogneisses. The NW–SE dextral shear zone
of the Capo Ferro area (NE Sardinia) is affected by partial melting, by granite emplacement and shows remarkable
petrotectonic analogies to, and can thus be related to the East Variscan Shear Zone, a major intra-continental
shear zone which was active in the southern European Variscides from 325 Ma to 315 Ma and that has been precisely dated with the U–Pb monazite system. The emplacement of migmatitic gneisses along large shear zones
within this time interval is not restricted to Sardinia, but has also been observed in southern Corsica, in the French
Massif Central, in the Western Alps and in central Spain. This pattern of shear zones is related to a complex
geodynamic scenario, linked to the oblique convergence of the Gondwana and Laurussia plates during the
Middle–Upper Carboniferous
Fat embolism: a systematic review to facilitate the development of standardised procedures in pathology
No full textFat embolism (FE) is a historically recognised but still actively researched topic in forensic pathology. Several aspects remain not fully elucidated, such as its aetiopathogenesis, its causal role in death determination, the impact of interfering factors (e.g. cardiopulmonary resuscitation or other medical procedures) and both qualitative and quantitative diagnostic methodologies in clinical and forensic contexts. These issues are further underscored by the potential involvement of FE in the causal determination of non-traumatic deaths, which often raises questions of professional liability. The present study aims to provide a comprehensive and up-to-date overview of the most recent scientific evidence relevant to forensic pathology. Our systematic research has included 58 articles from 1990 to the present on the topic of FE and fat embolism syndrome (FES). From these articles, we identified 45 case reports, from which the authors’ descriptions were extracted to provide information on individual cases and the operational methods of forensic pathologists. Additionally, 21 experimental studies were identified, and their key findings have been summarised narratively. It has emerged that both traumatic and non-traumatic cases are frequently reported in the forensic context, with orthopaedic and cosmetic surgery being among the highest-risk specialities. Experimental studies have re-evaluated the role of a patent foramen ovale in the pathogenesis of FE, as well as the impact of cardiopulmonary resuscitation in causing FE severe enough to result in death. Additionally, there are new findings regarding diagnostic techniques, including radiological and immunohistological methods; however, they have not yet fully bridged the reliability gap compared to an accurate autopsy–histological evaluation. The major critical points that emerged include the lack of complete and detailed information on premortem clinical conditions, the underutilisation of grading systems and the methodological heterogeneity applied, resulting in considerable variability regarding the organs studied histologically and the diagnostic techniques used. Despite the limitations associated with the analysis of case reports and the heterogeneity of included experimental studies, we believe that this study can provide a comprehensive overview of the FE topic. It furnishes pathologists with an updated overview useful for clinical practice and guiding future research trends, as well as facilitating the development of standardised procedures
Effect of Solution Treatment on Precipitation Behaviors, Age Hardening Response and Creep Properties of Elektron21 Alloy Reinforced by AlN Nanoparticles
No full textIn the present study, the solution and ageing treatments behavior of Mg-RE-Zr-Zn alloy (Elektron21) and its nano-AlN reinforced nanocomposites have been evaluated. The properties of the thermal-treated materials were investigated in terms of Vickers hardness, the area fraction of precipitates, microstructure and phase composition. The solution treatments were performed by treating at 520 ◦C, 550 ◦C and 580 ◦C in argon atmosphere. The outcomes show that the hardness of the solutionized alloys was slightly affected by the solution temperature. X-ray diffraction and image analysis revealed that the complete dissolution of precipitates was not possible, neither for Elektron21 (El21) nor for its AlN containing nanocomposites. The ageing treatment of El21 led to a significant improvement in hardness after 20 h, while for longer times, it progressively decreased. The effect of ageing on the hardness of El21-AlN composites was found to be much less than this effect on the hardness of the host alloy. Electron backscatter diffraction (EBSD) analysis of El21 and El21-1%AlN after solution treatment confirm the random orientation of grains with a typical texture of random distribution. The as-cast creep results showed that the incorporation of nanoparticles could effectively improve the creep properties, while the results after solution treatment at 520 ◦C for 12 h followed by ageing treatment at 200 ◦C for 20 h confirmed that the minimum creep rate of T6-El21 was almost equal to the as-cast El21-AlN
Shaken Baby Syndrome: Magnetic Resonance Imaging Features in Abusive Head Trauma
No full textIn the context of child abuse spectrum, abusive head trauma (AHT) represents the leading cause of fatal head injuries in children less than 2 years of age. Immature brain is characterized by high water content, partially myelinated neurons, and prominent subarachnoid space, thus being susceptible of devastating damage as consequence of acceleration–deceleration and rotational forces developed by violent shaking mechanism. Diagnosis of AHT is not straightforward and represents a medical, forensic, and social challenge, based on a multidisciplinary approach. Beside a detailed anamnesis, neuroimaging is essential to identify signs suggestive of AHT, often in absence of external detectable lesions. Magnetic resonance imaging (MRI) represents the radiation-free modality of choice to investigate the most typical findings in AHT, such as subdural hematoma, retinal hemorrhage, and hypoxic-ischemic damage and it also allows to detect more subtle signs as parenchymal lacerations, cranio-cervical junction, and spinal injuries. This paper is intended to review the main MRI findings of AHT in the central nervous system of infants, with a specific focus on both hemorrhagic and non-hemorrhagic injuries caused by the pathological mechanisms of shaking. Furthermore, this review provides a brief overview about the most appropriate and feasible MRI protocol to help neuroradiologists identifying AHT in clinical practice
Improving the Laser Powder Bed Fusion Processability of A2618 alloy: Investigation on TiB2 Addition Strategies via Single Scan Track Approach
No full textProcessing aluminum alloys by Laser Powder Bed Fusion (L-PBF) is of great interest for components production in various industries; however, their processability is
quite challenging due to their susceptibility to solidification cracking. One effective strategy to overcome this problem is the addition of inoculants to modify their
solidification mechanism and to prevent crack initiation. In this context, this study focuses on the processability of the A2618 alloy with the addition of TiB2 as an
inoculant using different ex situ strategies: low- and high-energy mechanical mixing and plasma coating respectively. The Single Scan Tracks (SSTs) approach was
used to investigate the quality and stability of tracks that greatly influence the quality of printed parts and optimize the process parameters for the three feedstocks.
The comparison between the systems enabled the identification of slight differences between powders in terms of the processability window, revealing the influence
of the inoculant dispersion method on the processability of the A2618 alloy. Electron Backscatter Diffraction (EBSD) analysis carried out on the SST cross-sections
confirmed significant differences between the three powders in terms of grain refinement. In addition to the microstructure refinement and the absence of solidification cracks, the analysis revealed the effectiveness of the plasma coating method which allows for obtaining a uniform and homogeneous distribution of the
reinforcement on the aluminum particles’ surface. Bulk samples were then produced to validate the optimization study results: the characterization of the cubic
samples revealed a dense (99.9%) and crack-free microstructure, with a homogeneous distribution of the reinforcement phase
Thermophysical Properties of Short Carbon Fiber/SiC Multilayer Composites Prepared by Tape Casting and Pressureless Sintering
No full textIdentification of 5F-Cumyl-PINACA, a Synthetic Cannabinoid, in the Herbal Material Used for Recreational Purposes in the Province of Trieste: Public Health Implications
No full textIn recent years, the phenomenon of the production and trade of synthetic cannabinoids has grown, becoming a public health issue worldwide. The recent accesses - to the ED of the hospital of Trieste - of people who complained episodes of hallucinations, sensation of poisoning, tachycardia, and air hunger following the inhalation of "Che Sballo platinum", have highlighted the need to perform further analysis on the contents of the packet sold as an air freshener, produced in Koper (Slovenia)
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