High‐speed nanoindentation for fast mechanical property mapping and surface patterning

Nanoindentation represents a well established technique for the assessment of mechanical properties at the micro and nano scales. Nevertheless, the analysis of mechanical properties in highly heterogeneous materials still represents a major issue in the scientific community, because of due the high amount of time that is required to realize a large number of indentation tests over wide areas. Recently, this problem has been overcome by the introduction of a novel new High-Speed nanoindentation, which allows to realize a huge number of tests in a smaller time, thus improving statistical analysis of mechanical property distribution in heterogeneous materials. Two High-Speed nanoindentation applications are presented in this poster: an innovative tool for the mechanical characterization and high resolution mapping of highly heterogeneous materials and a new technique the surface patterning (N.I.H.L., Nanoindentation High-Speed Lithography). In the first one, two different and very high heterogeneous materials (LiMn2O4/polymer battery cathodes and cement pastes) were characterized combining high-speed nanoindentation tests with FIB microscopy and SEM-EDS maps. Please click Additional Files below to see the full abstract

Thermoresponsive Copolymers with Well-Defined Composition and Phase Separation Via Semi-Batch Free-Radical Polymerization in a Non-Polar Medium

Thermoresponsive polymers formulated in non-polar media are finding a plethora of applications in the oil and gas and lubricant sectors. Their great adaptability mainly comes from the possibility of tuning their cloud point (T-cp), which is achieved by copolymerizing two or more monomers. In this direction, good control over the copolymer composition is crucial to ensure a sharp phase separation and, as a consequence, a prompt and well-defined response. For this reason, controlled radical polymerizations (CRPs) are often used to synthesize these materials. However, these pseudoliving polymerization techniques are still far from industrial maturity because of their cost and low polymerization rate. On the other hand, free-radical polymerization (FRP) is notoriously affected by the compositional drift of the copolymer chains, which for thermoresponsive polymers is reflected in broad phase separations. To overcome the disadvantages of FRP and guarantee remarkable control of the copolymer composition typical of CRPs, in this work we develop a semibatch power feed process for the copolymerization of diethylene glycol methyl ether methacrylate (EG(2)MA) and lauryl methacrylate in Dectol (i.e., a mixture of decane/toluene 50:50 v/v). First, their reactivity ratios were determined by analyzing the variation in the residual monomer phase composition over time at different initial molar ratios of the two monomers. These were subsequently employed for designing the inlet flow rate of the power feed strategy. Through this approach, we demonstrated for the first time that semibatch FRP is a valuable strategy to afford compositionally well-defined copolymers with a controllable upper critical solution temperature and sharp phase separations while maintaining high productivity and avoiding CRPs

Effect of lithiation on micro-scale fracture toughness of LixMn2O4 cathode

An optimized nanoindentation pillar splitting technique is used for the fracture toughness measurement of spinel LixMn2O4 cathode material under different states of charge (SoC), along with the high-speed nanoindentation results for nanomechanical property mapping. High-speed nanoindentation enables for a robust and efficient evaluation of elastic modulus and hardness as a function of the SoC on strongly heterogeneous materials. The fracture toughness decreases linearly upon de-lithiation, with an overall reduction of 53% from 0% to 100% SoC. Decrease in fracture toughness is associated with the volume change, increase of defect density and stresses related to diffusion of lithium upon de-lithiation

Damage progression in thermal barrier coating systems during thermal cycling: A nano-mechanical assessment

This paper studies how the nano-mechanical properties of thermal barrier coatings (TBCs) vary during thermal cycling, as a way to shed new light on their failure mechanisms. In particular, high-throughput nanoindentation revealed the evolution of hardness and elastic modulus distributions of plasma-sprayed yttria-stabilized zirconia (YSZ) top layers. The evolution of fracture toughness of the YSZ layers and the thermally grown oxide (TGO) formed onto the vacuum plasma-sprayed NiCoCrAlY bond coat were investigated by nanoindentation micro-pillar splitting. The TGO fracture toughness increases up to ≈2.5–3.5 MPa√m at the early stages of thermal cycling, followed by a rapid decrease to ≈2.0 MPa√m after a critical TGO thickness of ≈5 μm is reached. Consequently, interface damage is initially limited to short cracks within the YSZ material. As TGO thickness exceeds the critical threshold, multiple cracks originate within the TGO and join through the YSZ to form long delamination cracks. Joining is favoured by a simultaneous loss in YSZ strength, testified by a decrease in the nanomechanical properties (hardness, elastic modulus) of both high- and low-porosity top coats. This is due to microstructural changes occurring because of the continuous interplay between sintering and thermal shock cracking in the YSZ layers

Molybdenum oxides coatings for high demanding accelerator components

Large electric gradients are required for a variety of new applications, notably including the extreme high brightness electron sources for X-ray free electron lasers (FELs), radio-frequency (RF) photo-injectors, industrial and medical accelerators, and linear accelerators for particle physics colliders. In the framework of the INFN-LNF, SLAC (USA), KEK (Japan), UCLA (Los Angeles) collaboration, the Frascati National Laboratories (LNF) are involved in the modelling, development, and testing of RF structures devoted to particles acceleration by high gradient electric fields of particles through metal devices. In order to improve the maximum sustainable gradients in normal-conducting RF-accelerating structures, both the RF breakdown and dark current should be minimized. To this purpose, studying new materials as well as manufacturing techniques are mandatory to identify better solutions to such extremely requested applications. In this contribution, we discuss the possibility of using a dedicated coating on a solid copper sample (and other metals) with a relatively thick film to improve and optimize breakdown performances and to minimize the dark current. We present here the first characterization of MoO3 films deposited on copper by pulsed-laser deposition (PLD)

Role of Management Strategies in Reducing Mortality From Invasive Fungal Disease in Children With Cancer or Receiving Hemopoietic Stem Cell Transplant

n/

Cardiovascular imaging research and innovation in 2023

© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.In 2023, cardiovascular imaging has made significant advancements, in terms of technology, pathophysiology, and clinical application. In this review, the most recent research findings in the field of cardiovascular imaging are discussed. Artificial intelligence and large population cohorts, together with several technical improvements, have had a crucial impact on the technological advancements of echocardiography, cardiovascular magnetic resonance, computed tomography (CT), and nuclear medicine. In the field of ischaemic heart disease, it has been demonstrated that appropriate non-invasive imaging strategies improve patients' management and reduce invasive procedures and the need for additional testing at follow-up. Moreover, improvements in plaque characterization with CT are an expanding field of research with relevant implications for the prediction of disease severity, evolution, and response to treatment. In the field of valvular heart disease, imaging techniques have advanced alongside improvements in transcatheter treatment for aortic stenosis, mitral, and tricuspid regurgitation. Finally, in the field of heart failure and cardiomyopathies, cardiovascular imaging has reinforced its crucial role in early diagnosis and risk evaluation, showcasing advanced techniques that outperform traditional methods in predicting adverse outcomes.publishersversionpublishe

Whole-genome sequencing of European autochthonous and commercial pig breeds allows the detection of signatures of selection for adaptation of genetic resources to different breeding and production systems

Background Natural and artificial directional selection in cosmopolitan and autochthonous pig breeds and wild boars have shaped their genomes and resulted in a reservoir of animal genetic diversity. Signatures of selection are the result of these selection events that have contributed to the adaptation of breeds to different environments and production systems. In this study, we analysed the genome variability of 19 European autochthonous pig breeds (Alentejana, Bísara, Majorcan Black, Basque, Gascon, Apulo-Calabrese, Casertana, Cinta Senese, Mora Romagnola, Nero Siciliano, Sarda, Krškopolje pig, Black Slavonian, Turopolje, Moravka, Swallow-Bellied Mangalitsa, Schwäbisch-Hällisches Schwein, Lithuanian indigenous wattle and Lithuanian White old type) from nine countries, three European commercial breeds (Italian Large White, Italian Landrace and Italian Duroc), and European wild boars, by mining whole-genome sequencing data obtained by using a DNA-pool sequencing approach. Signatures of selection were identified by using a single-breed approach with two statistics [within-breed pooled heterozygosity (HP) and fixation index (FST)] and group-based FST approaches, which compare groups of breeds defined according to external traits and use/specialization/type. Results We detected more than 22 million single nucleotide polymorphisms (SNPs) across the 23 compared populations and identified 359 chromosome regions showing signatures of selection. These regions harbour genes that are already known or new genes that are under selection and relevant for the domestication process in this species, and that affect several morphological and physiological traits (e.g. coat colours and patterns, body size, number of vertebrae and teats, ear size and conformation, reproductive traits, growth and fat deposition traits). Wild boar related signatures of selection were detected across all the genome of several autochthonous breeds, which suggests that crossbreeding (accidental or deliberate) occurred with wild boars. Conclusions Our findings provide a catalogue of genetic variants of many European pig populations and identify genome regions that can explain, at least in part, the phenotypic diversity of these genetic resources.info:eu-repo/semantics/publishedVersio

Survey of CT radiation doses and iodinated contrast medium administration: an international multicentric study

ObjectiveTo assess the relationship between intravenous iodinated contrast media (ICM) administration usage and radiation doses for contrast-enhanced (CE) CT of head, chest, and abdomen-pelvis (AP) in international, multicenter settings. MethodsOur international (n = 16 countries), multicenter (n = 43 sites), and cross-sectional (ConRad) study had two parts. Part 1: Redcap survey with questions on information related to CT and ICM manufacturer/brand and respective protocols. Part 2: Information on 3,258 patients (18-96 years; M:F 1654:1604) who underwent CECT for a routine head (n = 456), chest (n = 528), AP (n = 599), head CT angiography (n = 539), pulmonary embolism (n = 599), and liver CT examinations (n = 537) at 43 sites across five continents. The following information was recorded: hospital name, patient age, gender, body mass index [BMI], clinical indications, scan parameters (number of scan phases, kV), IV-contrast information (concentration, volume, flow rate, and delay), and dose indices (CTDIvol and DLP). ResultsMost routine chest (58.4%) and AP (68.7%) CECT exams were performed with 2-4 scan phases with fixed scan delay (chest 71.4%; AP 79.8%, liver CECT 50.7%) following ICM administration. Most sites did not change kV across different patients and scan phases; most CECT protocols were performed at 120-140 kV (83%, 1979/2685). There were no significant differences between radiation doses for non-contrast (CTDIvol 24 [16-30] mGy; DLP 633 [414-702] mGycm) and post-contrast phases (22 [19-27] mGy; 648 [392-694] mGycm) (p = 0.142). Sites that used bolus tracking for chest and AP CECT had lower CTDIvol than sites with fixed scan delays (p < 0.001). There was no correlation between BMI and CTDIvol (r2 <= - 0.1 to 0.1, p = 0.931). ConclusionOur study demonstrates up to ten-fold variability in ICM injection protocols and radiation doses across different CT protocols. The study emphasizes the need for optimizing CT scanning and contrast protocols to reduce unnecessary contrast and radiation exposure to patients. Clinical relevance statementThe wide variability and lack of standardization of ICM media and radiation doses in CT protocols suggest the need for education and optimization of contrast usage and scan factors for optimizing image quality in CECT

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe