Predicting loss in magnetic steels under arbitrary induction waveform and with minor hysteresis loops

We have studied ways of predicting power losses in soft magnetic laminations for generic time dependence of the periodic magnetic polarization J(t). We found that, whatever the frequency and the induction waveform, the loss behavior can be quantitatively assessed within the theoretical framework of the statistical loss model. The prediction requires a limited set of preemptive experimental data, depending on whether or not the arbitrary J(t) waveform is endowed with local slope inversions (i.e., minor hysteresis loops) in its periodic time behavior. In the absence of minor loops, such data reduce, for any peak polarization value Jp, to the loss figures obtained under sinusoidal J(t) at two different frequency values. In the presence of minor loops of semiamplitude Jm, the two-frequency loss experiment should be carried out for both peak polarization values Jp and Jm. Additional knowledge of the quasi-static major loop, to be used for modeling hysteresis loss, does improve the accuracy of the prediction method. A more general approach to loss in soft magnetic laminations is obtained in this way, the only limitation apparently being the onset of skin effect at high frequencie

Alternating and Rotational Losses up to Magnetic Saturation in Non-Oriented Steel Sheets

partially_open5sìpartially_openAppino, Carlo; Khan, Mahmood; de la Barrière, Olivier; Ragusa, Carlo; Fiorillo, FaustoAppino, Carlo; Khan, Mahmood; de la Barrière, Olivier; Ragusa, Carlo; Fiorillo, Faust

Optimum Air Gap Selection in Powder Core Inductors

The requirements of magnetics for power electronics are high power density and low power losses, driven by the need for more compact and more efficient power converters. Metal powder materials are a common choice for high power and high frequency inductors subject to a magnetic field bias applied because of the high saturation flux density and their "distributed" air gap property that allows adopting these materials in un-gapped core configurations. Nevertheless, in certain conditions, a concentrated air gap could maximize the overall inductance factor for a given winding configuration (i.e. the number of turns). Therefore, this paper proposes a straightforward procedure to maximize the inductance factor of metal powder magnetic cores by selecting the optimum air gap length for a specified design operating point. The proposed methodology is theoretically described and then experimentally validated on an XFlux 60 core from Magnetics ®

SISTEMA DI PROPULSIONE PER VELIVOLO E METODO DI CONTROLLO DEL SISTEMA DI PROPULSIONE PER VELIVOLO

Brevetto per invenzione industriale intitolato "Sistema di propulsione per velivolo e metodo di controllo di sistema di propulsione per velivolo". Titolari: Politecnico di Torino, Torino; Alenia Aermacchi S.P.A., Venegono Superiore (VA). Inventori: Ronchetto Davide, Chiesa Sergio, Ragusa Carlo Stefano, Armando Eric Giacomo, Farfaglia Salvatore

Broadband magnetic losses of nanocrystalline ribbons and powder cores

partially_open7sìFinemet type alloys have been investigated from DC to 1 GHz at different induction levels upon different treatments: as amorphous precursors, as ribbons nanocrystallized with and without an applied saturating field, as consolidated powders. The lowest energy losses at all frequencies and maximum Snoek's product are exhibited by the transversally field-annealed ribbons. This is understood in terms of rotation-dominated magnetization process in the low-anisotropy material. Intergrain eddy currents are responsible for the fast increase of the losses with frequency and for early permeability relaxation of the powder cores. Evidence for resonant phenomena at high frequencies and for the ensuing inadequate role of the static magnetic constitutive equation of the material in solving the magnetization dynamics via the Maxwell's diffusion equation of the electromagnetic field is provided. It is demonstrated that, by taking the Landau–Lifshitz–Gilbert equation as a constitutive relation, the excellent frequency response of the transverse anisotropy ribbons can be described by analytical method.partially_openBeatrice, Cinzia; Dobák, Samuel; Ferrara, Enzo; Fiorillo, Fausto; Ragusa, Carlo; Füzer, Ján; Kollár, PeterBeatrice, Cinzia; Dobák, Samuel; Ferrara, Enzo; Fiorillo, Fausto; Ragusa, Carlo; Füzer, Ján; Kollár, Pete

AdvManuNet: a networking project on metrology for advanced manufacturing

The networking project AdvManuNet has been started recently to accelerate the process of establishing an European Metrology Network (EMN) on Advanced Manufacturing. EMNs are intended by EURAMET, the association of metrology institutes in Europe, to provide a sustainable structure for ongoing stakeholder interaction in different thematic areas. Advanced manufacturing has been identified by the European Commission (EC) as one of six Key Enabling Technologies (KETs) with applications in multiple industries. Various EURAMET projects have partly addressed metrology needs for advanced manufacturing. However, a high-level coordination of the metrology community is currently absent and limits the impact of metrology developments on advanced manufacturing. AdvManuNet will address these limits by establishing a single hub for stakeholder consultation, a knowledge base on research results, and a strategic agenda for research and training to push forward advanced manufacturing and related KETs and strengthen Europe’s position in advanced manufacturing via the EMN

New European Metrology Network for advanced manufacturing

Advanced manufacturing has been identified as one of the key enabling technologies with applications in multiple industries. The growing importance of advanced manufacturing is reflected by an increased number of publications on this topic in recent years. Advanced manufacturing requires new and enhanced metrology methods to assure the quality of manufacturing processes and the resulting products. However, a high-level coordination of the metrology community is currently absent in this field and consequently this limits the impact of metrology developments on advanced manufacturing. In this article we introduce the new European Metrology Network (EMN) for Advanced Manufacturing within EURAMET, the European Association of National Metrology Institutes (NMIs). The EMN is intended to be operated sustainably by NMIs and Designated Institutes in close cooperation with stakeholders interested in advanced manufacturing. The objectives of the EMN are to set up a permanent stakeholder dialogue, to develop a Strategic Research Agenda for the metrology input required for advanced manufacturing technologies, to create and maintain a knowledge sharing programme and to implement a web-based service desk for stakeholders. The EMN development is supported by a Joint Network Project within the European Metrology Programme for Innovation and Research

A Knowledge, Attitude, and Perception Study on Flu and COVID-19 Vaccination during the COVID-19 Pandemic: Multicentric Italian Survey Insights

In January 2020, Chinese health authorities identified a novel coronavirus strain never before isolated in humans. It quickly spread across the world, and was eventually declared a pandemic, leading to about 310 million confirmed cases and to 5,497,113 deaths (data as of 11 January 2022). Influenza viruses affect millions of people during cold seasons, with high impacts, in terms of mortality and morbidity. Patients with comorbidities are at a higher risk of acquiring severe problems due to COVID-19 and the flu-infections that could impact their underlying clinical conditions. In the present study, knowledge, attitudes, and opinions of the general population regarding COVID-19 and influenza immunization were evaluated. A multicenter, web-based, cross-sectional study was conducted between 10 February and 12 July 2020, during the first wave of SARS-CoV-2 infections among the general population in Italy. A sample of 4116 questionnaires was collected at the end of the study period. Overall, 17.5% of respondents stated that it was unlikely that they would accept a future COVID-19 vaccine (n = 720). Reasons behind vaccine refusal/indecision were mainly a lack of trust in the vaccine (41.1%), the fear of side effects (23.4%), or a lack of perception of susceptibility to the disease (17.1%). More than 50% (53.8%; n = 2214) of the sample participants were willing to receive flu vaccinations in the forthcoming vaccination campaign, but only 28.2% of cases had received it at least once in the previous five seasons. A higher knowledge score about SARS-CoV-2/COVID-19 and at least one flu vaccination during previous influenza seasons were significantly associated with the intention to be vaccinated against COVID-19 and influenza. The continuous study of factors, determining vaccination acceptance and hesitancy, is fundamental in the current context, in regard to improve vaccination confidence and adherence rates against vaccine preventable diseases

Dupilumab in the treatment of severe uncontrolled chronic rhinosinusitis with nasal polyps (CRSwNP): A multicentric observational Phase IV real-life study (DUPIREAL)

Background Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with significant morbidity and reduced health-related quality of life. Findings from clinical trials have demonstrated the effectiveness of dupilumab in CRSwNP, although real-world evidence is still limited. Methods This Phase IV real-life, observational, multicenter study assessed the effectiveness and safety of dupilumab in patients with severe uncontrolled CRSwNP (n = 648) over the first year of treatment. We collected data at baseline and after 1, 3, 6, 9, and 12 months of follow-up. We focused on nasal polyps score (NPS), symptoms, and olfactory function. We stratified outcomes by comorbidities, previous surgery, and adherence to intranasal corticosteroids, and examined the success rates based on current guidelines, as well as potential predictors of response at each timepoint. Results We observed a significant decrease in NPS from a median value of 6 (IQR 5–6) at baseline to 1.0 (IQR 0.0–2.0) at 12 months (p < .001), and a significant decrease in Sino-Nasal Outcomes Test-22 (SNOT-22) from a median score of 58 (IQR 49–70) at baseline to 11 (IQR 6–21; p < .001) at 12 months. Sniffin' Sticks scores showed a significant increase over 12 months (p < .001) compared to baseline. The results were unaffected by concomitant diseases, number of previous surgeries, and adherence to topical steroids, except for minor differences in rapidity of action. An excellent-moderate response was observed in 96.9% of patients at 12 months based on EPOS 2020 criteria. Conclusions Our findings from this large-scale real-life study support the effectiveness of dupilumab as an add-on therapy in patients with severe uncontrolled CRSwNP in reducing polyp size and improving the quality of life, severity of symptoms, nasal congestion, and smell

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements