Input Parallel Output Series Structure of Planar Medium Frequency Transformers for 200 kW Power Converter: Model and Parameters Evaluation

Nowadays, the demand for high power converters for DC applications, such as renewable sources or ultra-fast chargers for electric vehicles, is constantly growing. Galvanic isolation is mandatory in most of these applications. In this context, the Solid State Transformer (SST) converter plays a fundamental role. The adoption of the Medium Frequency Transformers (MFT) guarantees galvanic isolation in addition to high performance in reduced size. In the present paper, a multi MFT structure is proposed as a solution to improve the power density and the modularity of the system. Starting from 20 kW planar transformer model, experimentally validated, a multi- transformer structure is analyzed. After an analytical treatment of the Input Parallel Output Series (IPOS) structure, an equivalent electrical model of a 200 kW IPOS (made by 10 MFTs) is introduced. The model is validated by experimental measurements and tests

100 kW Three-Phase Wireless Charger for EV: Experimental Validation Adopting Opposition Method

This paper presents the experimental validation, using the opposition method, of a high-power three-phase Wireless-Power-Transfer (WPT) system for automotive applications. The systemunder test consists of three coils with circular sector shape overlapped to minimize the mutualcross-coupling, a three-phase inverter at primary side and a three-phase rectifier at receiver side.In fact thanks to the delta configuration used to connect the coils of the electromagnetic structure,a three-phase Silicon Carbide (SiC) inverter is driving the transmitter side. The resonance tankcapacitors are placed outside of the delta configuration reducing in this way their voltage sizing. ThisWPT system is used as a 100 kW–85 kHz ultrafast battery charger for light delivery vehicle directlysupplied by the power grid of tramways. The adopted test-bench for the WPT charger consistsof adding circulating boost converter to the system under test to perform the opposition methodtechnique. The experimental results prove the effectiveness of the proposed structure together withthe validation of fully exploited simulation analysis. This is demonstrated by transferring 100 kWwith more than94Ü-to-DC efficiency over 50 mm air gap in aligned conditions. Furthermore,testing of Zero-Current and Zero-Voltage commutations are performed to test the performance of SiCtechnology employed

Losses and thermal considerations on an IPOS structure with 20kW high-frequency planar transformers

Nowadays power electronics is looking for more integrated and compact insulated DC/DC converters. Electrical machines, like transformers, have a fundamental role in those kinds of converters. One of the main integration issue is the thermal aspect due to the power losses. Moreover, in an insulated DC/DC converter the bulkiest device is the transformer. Based on the high frequency power application the adopted transformer could be planar or litz wounded technology. In this work a single phase planar transformer for high power application has been investigated. An IPOS structure connecting many planar transformers has been performed to cope with the limitations that a single component gives. An experimental set-up adopting a SiC H-bridge power module feeding the different transformer structure. A power losses comparison among different structures has been realized. Indeed, the comparison is made connecting the H-bridge to a: single phase planar transformer, IPOS with 2 transformers, IPOS with 5 transformers, IPOS with 6 trans- formers and IPOS with a 10 transformers. The paper proposes thermal simulations for the IPOS made by 10 transformers and experimental result

The Open Data Kit suite, Mobile Data Collection technology as an opportunity for forest mensuration practices

This paper examines the potential for using Mobile Data Collection (MDC) as an effective database supported technology to substantially improve forest mensuration practices. Open source Open Data Kit (ODK) procedures and tools were used during a survey campaign that initiated a local forest monitoring process in the Marganai forest (Sardinia). The ODK suite is practical to use and its procedures allow authoring and use of digital survey forms without users needing software development expertise. Form design enables a high degree of customization to be achieved by means of specifying a wide range of data flow control mechanisms. ODK has proved to be a valid tool for data coherence and completeness improvements. As forestry’s contribution to regional Gross Domestic Product has dramatically decreased, forest mensuration practices have been reduced. Meeting the increased need to monitor environmental assets such as forests requires these practices to be re-evaluated. If regional public institutions took an active part in the process of enhancing forest mensuration, by contributing with open database systems acting as repositories and knowledge engines, support for MDC tools like ODK would potentially be a great opportunity to disseminate the use of the system and boost its development

Idea moderna de universidad: de la torre de marfil al capitalismo académico

This article analyzes the evolution of discourses about the modernuniversity by presenting a reflexive reading of classical and contemporarytexts on the passage from a university conceived as an ivory tower to theentrepreneurial university, and the strains it creates in terms of formativeprinciples and knowledge organization. To do so, the article begins byarguing that the university becomes part of the Enlightenment and accesses to modernity when the Faculty of Philosophy ceases to be conceptualized as the handmaiden of the Faculty of Theology (philosophia theologiae ancilla) and grows to be understood as the mistress’  torchbearer, as ironically remarked by Kant. In the following decades, the new role that philosophy adopts in the division of academic labor changes the relationship of the institution with both the political and religious powers, opening the door on the road to the nation state and, further down, to the subordination of its activities to global academic capitalism. Consequently, traditional normative referents, as those proclaimed by Kant and Humboldt where universities were conceived as responsible for the evolution of modern society, lose plausibility and are subjected to the criticism of ideologies.The article concludes by examining future trends in education and researchconducted in contemporary universities and by arguing that the crisis ofthe modern idea of the university is, in fact, an expression of its moderncharacter that now turns against this very institution.                El presente artículo analiza la evolución de los discursos acerca de la universidad moderna a partir de la revisión reflexiva de textos clásicos y actuales sobre el tránsito desde la universidad como torre de marfil a la universidad emprendedora, examinando las tensiones que esta evolución genera en términos de principios formativos y organización del conocimiento. Para ello, este ensayo comienza argumentando que la universidad se hace parte de la Ilustración y accede a la modernidad cuando la Facultad de filosofía deja de ser conceptualizada como sierva de la Facultad de Teología y cuando deja, por lo tanto, de llevar su cola (philosophia theologiae ancilla), según ironiza Kant, para pasar en cambio a comprenderse como responsable de iluminar con una antorcha su camino. En las décadas siguientes el nuevo rol que asume la filosofía en la división del trabajo académico transforma las relaciones de la institución universitaria con el poder político y el poder religioso, abriendo las puertas, al mismo tiempo, hacia el Estado nacional y, más adelante, hacia la subordinación de sus actividades al capitalismo global. Consecuencia de lo anterior, los referentes normativos tradicionales de la universidad propiciados por Kant y Humboldt como responsable de la evolución de la sociedad moderna pierden plausibilidad y son sometidos a la crítica de las ideologías. El artículo concluye examinando futuras tendencias de la educación e investigación realizadas en las universidades contemporáneas y argumenta que la crisis de la idea moderna de la universidad es, de hecho, expresión de su carácter moderno que ahora se vuelve contra la misma institución

Forest Protection Unifies, Silviculture Divides: A Sociological Analysis of Local Stakeholders' Voices after Coppicing in the Marganai Forest (Sardinia, Italy)

Today, a forest is also understood as a real social actor with multiple-scale influences, capable of significantly conditioning the social, economic, and cultural system of a whole territory. The aim of this paper is to reconstruct and interpret the population's perception of the silvicultural activities related to traditional use of forest resources of the southwestern Sardinian Marganai State Forest. The "Marganai case" has brought to the attention of the mass media the role of this forest and its silviculture. The research was carried out via semi-structured interviews with the main stakeholders in the area. The qualitative approach in the collection and analysis of the information gathered has allowed us to reconstruct the historical-cultural and social cohesion function that the forest plays in rural communities. The results highlight that the main risks concern the erosion of the cultural forest heritage due to the abandonment of the rural dimension (mainly by the new generations, but not only), with the consequent spread of deep distortions in the perception, interpretation, and necessity of forestry activities and policy

Growing old in a transnational social field: belonging, mobility and identity among Italian migrants

This article focuses on ageing in transnationalism. Drawing on the experiences of Italians in the UK as a paradigmatic example of settled European migrants, it explores the lived experiences of this group of older migrants. Using Levitt and Glick Schiller’s framework,it concentrates first on migrants’ways of being and then on their ways of belonging. The article argues that a transnational lens is necessary to understand the experiences of older migrants and that a focus on older people needs to be incorporated into studies of transnationalism. Through a discussion of their narratives and experiences, the article offers a long view on the migration process and brings attention to the significance of gender, time and the life course to understand both migrants’transnationalism and their integration

Impact of safety-related dose reductions or discontinuations on sustained virologic response in HCV-infected patients: Results from the GUARD-C Cohort

BACKGROUND: Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice. METHODS: A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0-9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively. RESULTS: SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced 651 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with 651 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not 655. CONCLUSIONS: In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with peginterferon alfa-2a/ribavirin