In both Upper Secondary School and first-level university courses, Newtonian gravitation is typically taught with a primary focus on theoretical aspects, particularly on solving the two-body problem. The solution is c...
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In both Upper Secondary School and first-level university courses, Newtonian gravitation is typically taught with a primary focus on theoretical aspects, particularly on solving the two-body problem. The solution is claimed reproduce Kepler's empirical laws, but little attention is given to the details of its validation. In the past, the emphasis on theory could be justified by the technical difficulties associated with accessing and analyzing data. Today, however, the availability of open-access data and advanced computational tools makes it feasible to construct empirical evidence for Newtonian gravitation, even within classroom settings. This work revisits the arguments Newton himself used to support his theory and replicate the validation process through a series of activities designed for educational purposes. This approach includes analyzing astrophotographic and mareographic data, along with revisiting Aristarchus of Samos's method for measuring the distance to the Moon through eclipse analysis.
Malaria is a disease caused by blood infection with Plasmodium parasites imposing a heavy toll on global public health. The gold standard diagnostic method is the microscopy analysis of a blood smear, but the method i...
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Malaria is a disease caused by blood infection with Plasmodium parasites imposing a heavy toll on global public health. The gold standard diagnostic method is the microscopy analysis of a blood smear, but the method is difficult to implement in low-resource settings due to the lack of equipment and skilled personnel. In this paper, an open-source image acquisition tool is presented in combination with a pipeline for image analysis of thin blood smears to assess sample quality, a critical aspect of the preparatory procedure which is often overlooked. Quantitative parameters on red blood cell morphology and distribution were extracted and correlated with the quality of the thin blood smear. Images acquired from healthy donor samples were used to test the pipeline. The pipeline proved capable of correctly extracting sample quality parameters and will be used in future developments as the basis for an artificial intelligence algorithm for an automatic classification between samples of low and high quality in diagnosis process.
Climate change has raised outdoor surface temperatures, increasing pedestrians' vulnerability to heat stress. In this context, there is a lack of a methodology that captures the effects of directional radiation fr...
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Climate change has raised outdoor surface temperatures, increasing pedestrians' vulnerability to heat stress. In this context, there is a lack of a methodology that captures the effects of directional radiation from urban environments on the human body, considering the relative positioning of pedestrians and surfaces. This paper proposes a methodology to evaluate the effects of surface temperatures on urban microclimate and pedestrian thermal comfort using infrared thermography. A 3D model of the urban environment was generated with projected thermographic images, also including a human body model to calculate view factors between each body segment and the surrounding surfaces. These view factors, combined with the surrounding temperatures, allow the determination of radiative heat flux from urban surfaces to each body part. The methodology was applied to three scenarios in pisa using an AVIO TVS-600 thermal camera (320 x 240 pixels, IFOV 1.4 mrad, resolution 0.15 degrees C): an open field, an urban canyon, and a semi-open area. Temperatures ranged from 15.0 degrees C to 54.6 degrees C, with longwave radiation fluxes to pedestrians varying due to view factors and solar radiation exposure of surfaces, peaking at around 500 W/m2, especially those impacting the head section. The results are valuable for mapping longwave radiation and assessing pedestrian exposure to improve urban planning. They are also useful to evaluate the impact of longwave radiation on thermal comfort, analysing radiant asymmetries and variations in thermal perception across different body parts. Future studies should apply this methodology to enhance urban planning by addressing pedestrian thermal stress, including measurement campaigns with participants.
In this paper, we consider the incompressible 3D Euler and Navier-Stokes equations in a smooth bounded domain. First, we study the 3D Euler equations endowed with slip boundary conditions and we prove the same criteri...
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In this paper, we consider the incompressible 3D Euler and Navier-Stokes equations in a smooth bounded domain. First, we study the 3D Euler equations endowed with slip boundary conditions and we prove the same criteria for energy conservation involving the gradient, already known for the Navier-Stokes equations. Subsequently, we utilize this finding, which is based on a proper approximation of the velocity (and does not require any estimate or additional assumption on the pressure), to explore energy conservation for Beltrami flows. Finally, we explore Beltrami solutions to the Navier-Stokes equations and demonstrate that conditions leading to energy conservation are significantly distinct from those implying regularity. This remains true even when making use of the bootstrap regularity improvement, stemming from the solution being a Beltrami vector field.
The Tile Calorimeter (TileCal) is the hadron calorimeter covering the central region of the ATLAS experiment alternating layers of steel and plastic scintillators. The scintillators are read-out by wavelength shifting...
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The Tile Calorimeter (TileCal) is the hadron calorimeter covering the central region of the ATLAS experiment alternating layers of steel and plastic scintillators. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMTs). The analog signals from similar to 10000 PMTs are amplified, shaped, sampled, digitized and stored on detector until a trigger decision is received. Each stage of the signal production from scintillation light to the PMT signal reconstruction is monitored and calibrated. This contribution focuses on the TileCal calibration systems including a Cesium radioactive source, a laser and its upgrade for High Luminosity LHC, a charge injection system, and an integrator-based readout system. A summary of the latest calibration results during LHC Run 3 and a description of the new components of the laser system will be presented.
The integration of AI in archaeology poses several risks due to the oversimplification of complex archaeological data for computational ease. This reductionist approach fosters a deterministic view, treating provision...
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The integration of AI in archaeology poses several risks due to the oversimplification of complex archaeological data for computational ease. This reductionist approach fosters a deterministic view, treating provisional classifications as definitive truths and influencing subsequent interpretations. The reliance on legacy data and Big Data for AI training risks perpetuating outdated ideas and frameworks. As AI expands from automating tasks to interpreting and creating reconstructions, archaeologists must adopt a critical approach to avoid biased and harmful outputs. The deterministic view of AI hinders informed debate. Archaeologists should engage in discussions that address the classificatory, and ethical aspects as well as the materiality of AI. The accumulation of data in AI mimics storytelling but lacks the interpretative depth needed to understand historical human perspectives. Developing theories and narrative practices is essential to making archaeological data meaningful. The shift from a representational to a co-creative view of data is necessary to understand its re-use and the power dynamics involved. Finally, to normalise AI in archaeology, a critical and sceptical approach is needed to integrate AI into the real world and understand its implications and ethical considerations. (c) 2024 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license ( http://***/licenses/by/4.0/ )
In this paper we consider a very general form of a non-local energy in integral form, which covers most of the usual ones (for instance, the sum of a positive and a negative power). Instead of admitting only sets, or ...
In this paper we consider a very general form of a non-local energy in integral form, which covers most of the usual ones (for instance, the sum of a positive and a negative power). Instead of admitting only sets, or L infinity\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$L<^>\infty $$\end{document} functions, as admissible objects, we define the energy for all the Radon measures. We prove the existence of optimal measures in a wide generality, and we show that in several cases the optimal measures are actually L infinity\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$L<^>\infty $$\end{document} functions, providing an a priori bound on their norm. We also derive a uniqueness result for minimizers.
The concept of a self-deployable Pulsating Heat Pipe (PHP) actuated by Shape Memory Alloy (SMA) is shown in the present paper. The system exploits the heat source to activate both the two-phase flow in the PHP and the...
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The concept of a self-deployable Pulsating Heat Pipe (PHP) actuated by Shape Memory Alloy (SMA) is shown in the present paper. The system exploits the heat source to activate both the two-phase flow in the PHP and the shape memory effect in the actuator to passively fold and unfold the device. The PHP acts as a torsional spring in the adiabatic section, and a shape memory wire unfolds it. The authors propose a mechanical model that outlines the size/material (spring/Al6063) and number of coils (3.5) to design the PHP adiabatic section and the actuator (7 Nickel-Titanium parallel wires). Two strategies are adopted to simulate active (Joule effect) and passive (heat conduction) heating. Joule heating uniformly warms the SMA wire to 120 degrees C, allowing the device to deploy up to 80 deg. Despite, under the passive heating, the shape memory effect is limited (deployment 16.5 deg) due to poor heat conduction, this is a breakthrough starting point for further implementation. For such purpose, the shape memory effect at non-uniform heating is simulated and predicted via a thermomechanical analytical model. Simulations are then validated with good accuracy with the experimental results obtained (error between 12 %-15 %).
ContextIdentifying the possible root causes of observed failures is crucial in microservice applications, as much as explaining how such possible root failures propagated across the microservices forming an applicatio...
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ContextIdentifying the possible root causes of observed failures is crucial in microservice applications, as much as explaining how such possible root failures propagated across the microservices forming an application. This can indeed help pick countermeasures avoiding observed failures to happen again, e.g., by introducing circuit breakers or bulkheads avoiding the root failures to propagate and cause those *** paper aims at enabling to explain observed failures in microservice applications, either searching for all possible cascading failures or focusing only on those starting in a known root *** propose a log-based root cause analysis technique, which declaratively determines the cascading failures that possibly caused an observed failure. We also enable exploiting our proposed technique in practice, by introducing a logging methodology to instrument applications to log their failures and service interactions, and by enabling to analyse such logs through yRCA, a prototype implementation of our proposed root cause analysis *** practical usability of our proposed technique is assessed by means of a case study and controlled experiments. The case study shows the low effort for instrumenting a third-party application to produce the logs needed by our technique and its effectiveness in explaining injected failures. The controlled experiments further assess our technique's effectiveness and performances in explaining failures obtained with an existing chaos *** proposed technique can help to identify the cascading failures that possibly caused an observed failure in a microservice application. It can be used to determine all possible cascading failures, or to explain how cascading failures propagated from a known root cause (e.g., identified with some other existing root cause analyser).
The Digital Product Passport (DPP), introduced by the European Green Deal in 2022, is a key innovation designed to improve product sustainability and circularity by enabling secure and transparent communication among ...
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The Digital Product Passport (DPP), introduced by the European Green Deal in 2022, is a key innovation designed to improve product sustainability and circularity by enabling secure and transparent communication among stakeholders. Despite its potential, existing blockchain-based implementations of the DPP face significant limitations, such as scalability challenges and usability issues, which hinder widespread adoption. To address these shortcomings, this paper proposes a hybrid blockchain-based implementation of the DPP that enhances data transparency, integrity, and accessibility while minimizing common drawbacks. The proposed solution utilizes a hybrid blockchain architecture, where data is collected and managed within a private blockchain network and notarized on a public blockchain. Additionally, the central problem of authenticated blockchain data visualization is addressed by proposing a new solution that not only ensures the provenance, integrity, and history consistency of DPP data, but also preserves these properties throughout data processing and visualization. Our experiments demonstrates the effectiveness of our approach, achieving low time consumption and storage overhead. To further promote transparency and collaboration, a selection of the implementation has been made available as open-source projects. We show that hybrid blockchains offer a promising path for realizing the full potential of the Digital Product Passport.
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