The effects of the COVID-19 pandemic on the training of athletes with disabilities in the 7-a-side football championship

This study had as its main objective to investigate the difference in training programs carried out in athletes with disabilities practicing 7-a-side football before and after the Covid-19 pandemic. The two sporting seasons taken into consideration concerned the 2018/19 season and the 2020/2021 season. The study was conducted on ten disabled athletes belonging to a football school in Campania, Italy. The comparison between the two sports seasons is given in numerical terms by the statistical comparison of the results of the adapted motor tests concerning aerobic capacity and conditional capacities, which were administered to the athletes at the beginning and at the end of both sports seasons. From this comparison, in both seasons, minor improvements in the 2020/2021 season were found in athletes, between the entry and exit tests. It can be said that the consequences of the Covid-19 pandemic, concerning social distancing and the interruption of sports activities, have played a primary role in the decline in the improvement of athletes with disabilities for 7-a-side football in the 2020/2021 sports season

Damage assessment of different FDM-processed materials adopting Infrared Thermography

The use of components obtained through the additive manufacturing (AM) technique has become increasingly widespread in recent years, playing a central role in industrial production, and in particular in some fields such as automotive, biomedical, aerospace and electronics. Among all AM techniques, FDM (Fused Deposition Modelling) represents the most used printing technique to produce polymeric and composite components, thanks to the flexible printing process, the low cost and the diversity of the materials adopted. The aim of the present work concerns the comparison between the mechanical properties of three plastic materials printed with the FDM technique (polylactic acid PLA, polyethylene terephthalate glycol-modified PETG and Acrylonitrile-butadiene-styrene ABS) using an Original Prusa i3 MK3S, by varying the raster angle between 0°, 45° and 90° degrees. Infrared Thermography has been adopted to monitor the temperature evolution during static tensile tests and to assess stress level that can initiate damage within the material. Failure analysis was performed to correlate the mechanical behaviour with the microstructural characteristics of the materials

Dynamic analysis of a Drum Charger: Large amplitude vibrations of clamped circular thin plate on a linear foundation

n/

Artificial Neural Network Prediction of the Optimal Setup Parameters of a Seven Degrees of Freedom Mathematical Model of a Race Car: IndyCar Case Study

The aim of this paper is the development of a 7-DOF (Degrees Of Freedom) mathematical model of an IndyCar and the implementation of an Artificial Neural Network in order to predict the optimal setup parameters of the car, reducing time and costs for race teams. The mathematical model is created by using MATLAB(TM) and Simulink software starting from a telemetry acquisition at the Houston circuit and is based on Vertical Vehicle Dynamic equations. The optimal setup parameters have been predicted through an Artificial Neural Network (ANN) by using the NFTOOL Toolbox of MATLAB(TM) software. ANN is implemented in a Quarter Car model, firstly, in order to train the network and predict the parameters able to reduce tire deflection and suspension travel in the time domain and the resonance peaks amplitude in the frequency domain. Then, it is implemented in the 7-DOF model in order to predict the best setup parameters able to reduce body movements and the weight transfers of the car

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Modellierung der Streuung geladener gleich- und verschiedenartiger Teilchen zur Strömungssimulation in gepulsten Plasmatriebwerken

A better physical understanding of electrical space propulsion systems like Pulsed Plasma Thrusters requires the numerical modelling and simulation of highly rarefied plasma flows. Mathematically, such phenomena demand a kinetic description which is established by the complete, time-dependent Boltzmann equation. An attractive numerical approach to tackle this complex non-linear problem consists of a combination of the well-known Particle-in-Cell (PIC) and Monte Carlo methods extended by a PIC-based Fokker-Planck solver, on which we focus our attention in the following. This numerical model accommodates the physics of interaction of charged particles with electromagnetic fields, inelastic electron-neutral scattering as well as intra- and inter-species charged particle Coulomb collisions. To describe elastic intra- and inter-species charged particle Coulomb collisions it is convenient to start from the Boltzmann collision integral with the classical Rutherford differential cross section. A Taylor series expansion up to second order in velocity of the post-collision distribution functions and the adoption of a cut-off value for the impact parameter permits the final integration of the Boltzmann integral to obtain the Fokker-Planck equation. The central quantities appearing in the Fokker-Planck equation are the friction force vector and the diffusion tensor. The keys to compute the friction and diffusion coefficients are the Rosenbluth potentials which are in turn complicate integrals of the field particle distribution function and the relative velocity between test and field particles. Usually, strong assumptions like isotropic velocity distribution of the scatterer, are made to evaluate the Rosenbluth potentials. Observing that the Rosenbluth potentials are convolution intergrals addresses the use of fast Fourier transform techniques to calculate these quantities and their derivatives rapidly with the advantage of being free of any additional assumption. Furthermore, such a determination the Rosenbluth potentials is the basis to model collisional relaxation in a complete self-consistent manner. In order to fit the three-dimensional Fokker-Planck equation of the scattered distribution function into a particle-based method framework, the equivalence with the stochastic differential equation (SDE) is exploit. The stochastic variable C(t) which obeys the SDE is later identified with the charged particle velocity. Also in this context the friction force vector and a matrix derived from the diffusion tensor play the central role. By means of Ito-Taylor expansion and Ito calculus the stochastic differential equation is discretised and numerical schemes are derived. In this work, explicit weak schemes up to approximation order two have been applied to update the particles velocity. These weak Ito-Taylor schemes together with the Fourier transform method and particle-mesh interface techniques form a remarkable simulation tool to study collisional relaxation processes from first principles. For instance by means of this tool, a more realistic evaluation of the time scales can be provided since the classical test-particle approach is not necessary anymore thanks to self-consistency. The introduced intra-species charged particle modelling can be easily adapted for inter-species electron-ion particle collisions. Finally, the structure of the developed PIC-based method to solve the Fokker-Planck equation also allows to combine intra- and inter-species collisions to perform coupled simulations.Für ein besseres physikalisches Verständnis von elektrischen Antriebssystemen für die Raumfahrt, wie beispielsweise gepulste Plasma-Thruster, ist die numerische Modellierung und Simulation von hochverdünnten Plasmaströmungen unumgänglich. Die mathematische Formulierung solcher Phänomene basiert auf der kinetischen Beschreibung, wie sie durch die vollständige, zeitabhängige Boltzmanngleichung gegeben ist. Eine attraktive Strategie um das komplexe, nichtlineare Boltzmann-Problem numerisch anzugehen, besteht in der Kombination von bekannten Particle-in-Cell (PIC) und Monte Carlo Methoden, die durch einen PIC-basierten Fokker-Planck Löser erweitert werden müssen. Die Konstruktion und Entwicklung des PIC-basierten Fokker-Planck Lösers ist der Gegenstand der vorliegenden Arbeit.Das gesamte numerische Modell trägt der Physik der Wechselwirkung von geladenen Teilchen mit elektromagnetischen Feldern, der inelastischen Streuung von Elektronen mit Neutralteilchen als auch der Kollision zwischen gleichartigen (intraspezies) und verschiedenartigen (interspezies) geladenen Teilchen Rechnung. Zur Beschreibung der elastischen intra- und interspezies Coulomb Wechselwirkung geladener Teilchen ist es zweckmäßig vom Boltzmannschen Stoßintegral aus zu starten, wobei für den differentiellen Wirkungsquerschnitt die klassische Rutherfordformel benutzt wird. Eine Taylorentwicklung der gestreuten Verteilungsfunktionen nach der Geschwindigkeit bis zur zweiten Ordnung und die Annahme eines Grenzwertes des maximalen Stoßparameters erlauben es schließlich, das Boltzmannintegral zu integrieren, wodurch man zur Fokker-Planck Gleichung gelangt.Die zentralen physikalischen Größen, die in der Fokker-Planck Gleichung auftauchen sind der Vektor der Reibungskraft und der Diffusionstensor. Die Schlüsselelemente zur Berechnung dieser tensoriellen Koeffizienten sind die sogenannten Rosenbluthpotenziale. Diese sind ihrerseits komplizierte Integrale, die sich über den gesamten Geschwindigkeitsbereich erstrecken und deren Integranden aus dem Produkt der Verteilungsfunktion der Streuer-Teilchen und der Relativgeschwindigkeit der gestreuten und streuenden Partikel bestehen. Üblicherweise werden zur Berechnung dieser Potenziale oft sehr restriktive Annahmen gemacht: So wird gewöhnlich vorausgesetzt, dass die Geschwindigkeitsverteilung der Feldteilchen, wie die Streuer auch genannten werden, isotrop ist. Die Beobachtung, dass die Rosenbluthpotenziale Faltungsintegrale sind, legt das Vorgehen nahe, Techniken anzuwenden, die auf der Fouriertransformation basieren, um diese Potenziale und deren Ableitung zu bestimmen. Solch eine Vorgehensweise bringt den Vorteil mit sich, dass keinerlei Annahmen hinsichtlich der Gestalt der Verteilungsfunktion getroffen werden müssen.Es sei weiterhin erwähnt, dass diese Art der Bestimmung der Rosenbluthpotentiale den Grundstock für die selbstkonsistente Modellierung der Stoßrelaxation legt. Um die dreidimensionale Fokker-Planck Gleichung, welche die Entwicklung der gestreuten Verteilungsfunktion beschreibt, in den numerischen Rahmen der Teilchenmethoden einzubinden, wird die Äquivalenz dieser Gleichung zu den stochastischen Differentialgleichungen benutzt. Die stochastische Variable C(t), die solch einer Gleichung genügt, wird später mit der Geschwindigkeit der geladenen Teilchen identifiziert. Auch im Kontext der stochastischen Differentialgleichungen spielen die oben erwähnte Reibungskraft und eine Matrix, die von dem Diffusionstensor abgeleitet ist, eine zentrale Rolle. Mit Hilfe der Ito-Taylor Entwicklung und dem auf Ito zurückgehenden Rechenverfahren gelingt es, die stochastische Differentialgleichung zu diskretisieren und geeignete numerische Schemata abzuleiten. In der vorliegenden Arbeit wurden sogenannte explizite, schwache Schemata bis zur Verfahrensordnung zwei herangezogen, um die Geschwindigkeit der geladenen Simulationsteilchen zu bestimmen. Diese schwachen Ito-Taylor Verfahren stellen im Zusammenhang mit der verwendeten Fouriertransformationsmethode und den Teilchen-Gitter Kopplungstechniken ein bemerkenswertes Simulationswerkzeug dar, mit dessen Hilfe sich der Stoßrelaxationsprozess ohne spezielle Annahmen oder Modellen untersuchen läßt. Als Folge dieser selbstkonsistenten Berechnungmethode lassen sich beispielsweise unterschiedliche Zeitskalen des Relaxationsprozesses realistischer ermitteln als mit dem sogenannten Testteilchen-Ansatzes. Die vorgestellte Modellierung der Streuung gleichartiger geladener Teilchen läßt sich direkt auf die interspezies Wechselwirkung zwischen Elektronen und Ionen übertragen. Darüber hinaus erlaubt die Struktur der entwickelten, auf der PIC-Technik basierenden Methoden die numerische Simulation der gekoppelten Prozesse von intra- und interspezies Wechselwirkung

Football the performance level of athletes with disabilities for the "fourth category" 7-a-side championship

The work presented is important because it allows us to demonstrate the actual benefits, in this case concerning the physical sphere, of motor and sports practice on athletes with various disabilities. The study was conducted on 10 athletes belonging to a football school, each of whom has various types of diagnosed disabilities such as down syndrome, autism spectrum disorder, intellectual-cognitive disability, or motor disability, characterized by low functionality. Considering the problem, which is to adapt the performance level of the athletes to the performance model required for the "Fourth Category" 7-a-side football championship for disabled people, obtained by comparing it with the same, however, referred to 11-a-side football, they underwent an 8-week mesocycle of training, with the administration of motor evaluation tests both at the beginning and at the end of this period. The test results will then be compared with the statistical t test technique for dependent samples. From this comparison, significant differences emerged about endurance and sprint tests, and insignificant differences for the standing long jump. The conclusion therefore leads us to state that, through training, it is possible to increase the parameters of the performance level of disabled athletes to make them conform to the performance model and physiological commitment that the Fourth Category Championship requires

Fuel Consumption Reduction and Efficiency Improvement in Urban Street Sweeper Using Power Split with Lockup Clutch Transmission

The aim of this work is to design a power split transmission for an urban street sweeper in order to reduce fuel consumption. The design process starts with the comparison between a hydrostatic and a hydromechanical power split transmission. Both transmissions have been tested through an acceleration test considering 30, 50, 70 and 100 percent of the rated engine power. The results of both models developed in the Simcenter Amesim (TM) environment show that the power split transmission presents a higher efficiency, which justifies the adoption of this type of transmission with respect to the hydrostatic system. Then, a pure mechanical gear is added to the base concept of the power split transmission. The mechanical gear is managed by a lockup clutch, which can be engaged during the working phase of the street sweeper, similar to an adaptive cruise control. In this case, both transmissions are tested through a regulated cycle, UNI-EN 151429-2, highlighting the advantage of using a pure mechanical branch. At the end, both transmissions are tested with a driving cycle acquired through an experimental setup consisting of a control unit, a GPS and a tablet for the monitoring of the speed profile. The results show that the adoption of a lockup clutch allows an increase in the system efficiency during the working phase, hence reducing the average fuel consumption during the mission test