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Textured Tools and Cryogenic Cooling for Modifying Chip Morphology in PEEK Machining
No full textPEEK is a high-performance polymer widely used for biomedical applications, but its
machinability remains a critical issue. Traditional coolants are unsuitable for biomedical use, and
dry machining produces long, entangled chips that hinder surface quality. Cryogenic machining
has been recently introduced for PEEK chip breaking. Textured tools can be exploited to modify
the chip formation further. In this context, the study examines the effects of tool rake face texturing
on chip formation in cryogenic and dry cutting conditions. Turning trials were conducted with
plain and laser-textured tools with grooves of different geometry at varying depths of cut. The
results indicate that cryogenic cooling promotes chip breakage, with textured tools enhancing the
fragmentation process. A correlation was observed between groove design and chip morphology,
highlighting the potential of these solutions to improve machining efficiency
Engineering morphological features and surface steps in ultrathick penta-twinned copper nanowires
No full text
Editorial: Fundamentals of luminescence and electroluminescence in particle detection technologies relying on noble-gas media
Get PDFDesign of a Latent Thermal Energy Storage System Using Ice and Roll-Bond Heat Exchangers
No full textThis work is developed in the framework of the EU project AGRI-COOL,
which aims at deploying innovative off-grid cold rooms in Africa. The core of the
system is a latent heat thermal energy storage (LTES) system which uses ice as
phase change material and the roll-bond heat exchangers. The LTES is designed to
store energy during the daily hours, when an excess of electricity is produced by a
suitable solar array that powers a chiller also used to refrigerate the positive cold
room. During the night, when the solar system does not work, the LTES supplies
the cooling load. Two different tank configurations were investigated: rectangular
and cylindrical to understand the effects on the layout on the performance of the
LTES. A numerical framework is developed using ANSYS Fluent. The roll- bond HXs
are modelled as isothermal 7lat plates with different sizes. The effects of the roll-
bond HXs layout is also studied to identify the best performance of the system in
terms of lower solidification time and volume allocation. The results are shown in
terms of temperature, liquid fraction, energy storage density, and solidification
time
Characterizing Aquifer Properties Through a Sparse‐Grids‐Based Bayesian Framework and InSAR Measurements: A Basin‐Scale Application to Alto Guadalentín, Spain
No full textA Machine Learning Model Integrating Remote Sensing, Ground Station, and Geospatial Data to Predict Fine-Resolution Daily Air Temperature for Tuscany, Italy
Get PDF: Heat-related morbidity and mortality are increasing due to climate change, emphasizing the need to identify vulnerable areas and people exposed to extreme temperatures. To improve heat stress impact assessment, we developed a replicable machine learning model that integrates remote sensing, ground station, and geospatial data to estimate daily air temperature at a spatial resolution of 100 m × 100 m across the region of Tuscany, Italy. Using a two-stage approach, we first imputed missing land surface temperature data from MODIS using gradient-boosted trees and spatio-temporal predictors. Then, we modeled daily maximum and minimum air temperatures by incorporating monitoring station observations, satellite-derived data (MODIS, Landsat 8), topography, land cover, meteorological variables (ERA5-land), and vegetation indices (NDVI). The model achieved high predictive accuracy, with R2 values of 0.95 for Tmax and 0.92 for Tmin, and root mean square errors (RMSE) of 1.95 °C and 1.96 °C, respectively. It effectively captured both temporal (R2: 0.95; 0.94) and spatial (R2: 0.92; 0.72) temperature variations, allowing for the creation of high-resolution maps. These results highlight the potential of integrating Earth Observation and machine learning to generate high-resolution temperature maps, offering valuable insights for urban planning, climate adaptation, and epidemiological studies on heat-related health effects
INTUITY and INSPIRIS Aortic Valves
No full textAortic valve pathologies, including both stenosis and regurgitation, are among the most common valvular heart diseases. According to current guidelines, surgical aortic valve replacement (SAVR) remains the gold standard treatment for young, low-risk patients with these conditions. SAVR is a well-established procedure with continuous advancements in valve prosthesis design. In particular, biological prostheses offer a range of options, such as stented, stentless, sutureless, and rapid-deployment valves, allowing for patient-specific customization that enhances surgical efficiency and long-term durability.
This project aimed to assess two next-generation valves: the Intuity and Inspiris Resilia valves.
We compared the clinical and hemodynamic outcomes of the Intuity and Inspiris Resilia valves with the historically well-established Magna Ease valve. Data were collected from 2589 patients across two national multicenter registries and one institutional database. A propensity score weighting approach was employed to minimize confounding factors. Our analysis revealed that in isolated SAVR, aortic cross-clamp time was significantly shorter with the Intuity valve. Mortality rates were similar but permanent pacemaker implantation rates were notably lower with the Inspiris valve. Hemodynamic evaluation showed lower trans-prothesis gradients in Intuity and Inspiris group.
We also investigated two critical issues: managing patients with a small aortic annulus and prosthesis-patient mismatch (PPM).
In the small annulus study, we included patients undergoing isolated or combined SAVR with Magna Ease and Intuity valves (sizes 19 and 21) at our institution. After propensity score weighting, we analyzed 666 patients (367 Magna Ease and 299 Intuity). There were no significant differences in postoperative complications and also mid-term survival and re-hospitalization rates were similar. However, Intuity valves demonstrated significantly lower mean gradients overall and for size 21.
In the PPM study, we analyzed 1323 patients who underwent SAVR, with complete hemodynamic data available for 872 at our insitutition. We evaluated both measured PPM (PPMm) and predicted PPM (PPMp), assessing sensitivity, specificity, and overall accuracy. We concluded that PPMp should be used cautiously when implanting small valves to avoid unexpected PPMm.
Lastly, a detailed review of current European and American guidelines was conducted to assess the optimal treatment strategy (SAVR vs. TAVR) and the appropriate prosthesis for individual patients. We analyzed 1227 patients from 35 Italian centers, dividing them based on guideline recommendations. About 60% of the patients fell into a grey zone (65-80 years) according to American guidelines. Despite differing baseline characteristics, 30-day outcomes (mortality and stroke) were similar across groups. Finally, we concluded that despite variations in guideline recommendations, outcomes for SAVR patients were comparable across all groups, supporting the need for harmonized guidelines.
In conclusion, this study confirms the excellent clinical and hemodynamic performance of both analyzed devices, the Intuity and Inspiris Resilia valves. The Intuity valve may be a more favorable choice in patients with smaller body size or during minimally invasive procedures, whereas the Inspiris Resilia valve could be preferred in younger patients with preoperative conduction disorders
When Does the Clock Start Ticking? The Court of Justice’s Judgment in Nissan Iberia (C-21/24)
No full textThis article examines the Court of Justice’s judgment in Nissan Iberia (C-21/24), which clarifies the commencement of the limitation period for damages actions under EU competition law. The Court held that the publication of a sufficiently detailed decision by a national competition authority can provide claimants with the knowledge necessary to initiate a claim, without waiting for the decision to become final. The judgment also emphasizes that national courts may suspend proceedings pending appeals, reflecting a careful balance between the effective enforcement of competition law and the principles of procedural fairness
Textiles for storage: A twined fabric grain sack from a Bronze Age (Catacomb Culture) burial in Bolotne, Crimea
No full textThe aim of this contribution is to bring scholarly attention to an important early textile find, excavated in the northern Crimea in 1978 and published in Russian in 1990. The Catacomb Culture (c. 2500-1950 BCE) burial discovered near the village of Bolotne of Dzhankoi region in the north of the Crimea, contained two individuals accompanied by four wooden wagon wheels, bronze, ceramic and stone burial goods, and a cloth sack containing grain. Relatively large fragments of the sack fabric survive due to unusual preservation conditions. The fabric was created using weft-twining technique using plied threads made of locally available plants. In addition to the overview of the find itself, we present the new Scanning Electron Microscope analyses of the fibre and place the find within a broader chronological and geographical context