14 research outputs found

    Electromagnetic and thermal analysis of a permanent magnet synchronous motor

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    The scope of this work is the evaluation of possible reduction power losses and the thermal behaviour of a Surface Permanent Magnet Synchronous Machines(SPMSM) The manuscript is organized as follows: first an introduction of PMs and some consideration regarding the Neodymium Iron Boron. Moreover, a mathematical model of PMSM is illustrated. Next, a geometrical, electrical and mechanical description of the motor is shown. Given that, the number of slots per pole per phase (q) is not an integer, an accurate study of the winding configuration is performed. Afterwards, the power budget analysis is executed and the reduction of iron losses by FEM model is evaluated. Finally, by a lumped parameter thermal network the thermal analysis is conducted and the steady-state temperature is calculated as a function of the current phase angle

    Pheochromocytoma in dogs undergoing adrenalectomy

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    Pheochromocytoma is frequent in dogs and carries a guarded prognosis. Current histological criteria may not predict malignant behavior in dogs, similar to humans. In humans, characterization of tumors has been refined using the pheochromocytoma of the adrenal gland scaled score (PASS) and by immunohistochemistry. The study aim was to investigate PASS and immunohistochemical markers used in humans in 24 dogs with pheochromocytoma that underwent adrenalectomy. Dogs with pheochromocytomas were reviewed and tumors collected. Histological sections were evaluated to apply the PASS and were single-labeled for chromogranin A, Ki-67, COX-2, p53, BCL-2, c-erbB-2, vascular endothelial growth factor, and S100. Survival, age, and vascular and capsular invasion were compared for PASS and immunohistochemical markers; results of PASS were also compared for each marker. Associations between markers were tested. PASS and immunohistochemical markers did not differ for survival, age, and vascular and capsular invasion. Tumors showing BCL-2 expression in >50% cells had lower PASS than those with lower expression (PASS: 7 ± 2 vs 9 ± 2; P = .011). Tumors positive for S100 had higher PASS than those that were negative (PASS: 10 ± 2 vs 7 ± 2; P = .001). Results of the different markers were not associated. In conclusion, in the context of canine pheochromocytoma, PASS and the selected immunohistochemical markers are not associated with survival, age, or vascular or capsular invasion. The higher PASS in S100-positive tumors may indicate that pheochromocytomas developing morphologic changes acquire S100 expression. The significance of lower PASS in tumors with elevated BCL-2 expression is uncertain. Overall, the use of PASS and the present immunohistochemical markers may not be useful in dogs with pheochromocytoma

    More accurate macro-models of solid oxide fuel cells through electrochemical and microstructural parameter estimation - Part II: Parameter estimation

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    This paper presents a systematic synergetic approach between experimental measurements, equivalent circuit modelling (described in Part I) and macro-scale modelling theory which has proved to be instrumental for the estimation of microstructural and electrochemical features of a Ni- YSZ|YSZ|Pr2NiO4+δ-GDC solid oxide fuel cell (SOFC). The aforementioned parameters have been used to generate a more accurate CFD macro-model which has been validated against the experimental results (presented in Part III)

    Cystic Echinococcosis in Spain: Current Situation and Relevance for Other Endemic Areas in Europe

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    Cystic echinococcosis (CE) remains an important health problem in many regions of the world, both where no control measures have been implemented, and where control programs have been incompletely successful with ensuing re-emergence of the disease. In Spain, official data on CE show an increase in the proportion of intermediate hosts with CE during the last few years, and autochthonous pediatric patients have been reported, a sign of active local transmission of disease. A similar picture emerges from data reported to the European Food Safety Authority by other European countries. Nevertheless, several crucial aspects related to CE that would help better understand and control the disease have not been tackled appropriately, in particular the emergence of infection in specific geographical areas. In this respect, while some data are missing, other data are conflicting because they come from different databases. We review the current situation of CE in Spain compared with areas in which similar problems in the CE field exist, and offer recommendations on how to overcome those limitations. Specifically, we believe that the introduction of national registries for CE with online data entry, following the example set by the European Registry for Alveolar Echinococcosis, would help streamline data collection on CE by eliminating the need for evaluating and integrating data from multiple regions, by avoiding duplication of data from patients who access several different health facilities over time, and by providing much needed clinical and epidemiological data that are currently accessible only to clinicians

    The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

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    The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR, browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters. Finally we briefly discuss on the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, and touch on communication and outreach activities, the consortium organisation, and finally on the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. (abridged).Comment: 48 pages, 29 figures, Accepted for publication in Experimental Astronomy with minor editin

    The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

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    The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory. Athena is a versatile observatory designed to address the Hot and Energetic Universe science theme, as selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), X-IFU aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over a hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR (i.e. in the course of its preliminary definition phase, so-called B1), browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters, such as the instrument efficiency, spectral resolution, energy scale knowledge, count rate capability, non X-ray background and target of opportunity efficiency. Finally, we briefly discuss the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, touch on communication and outreach activities, the consortium organisation and the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Poland, Spain, Switzerland, with additional contributions from the United States and Japan.The French contribution to X-IFU is funded by CNES, CNRS and CEA. This work has been also supported by ASI (Italian Space Agency) through the Contract 2019-27-HH.0, and by the ESA (European Space Agency) Core Technology Program (CTP) Contract No. 4000114932/15/NL/BW and the AREMBES - ESA CTP No.4000116655/16/NL/BW. This publication is part of grant RTI2018-096686-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This publication is part of grant RTI2018-096686-B-C21 and PID2020-115325GB-C31 funded by MCIN/AEI/10.13039/501100011033

    Natural merodiploidy involving duplicated rpoB alleles affects secondary metabolism in a producer actinomycete

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    Actinomadura sp. ATCC 39727 produces the glycopeptide antibiotic A40926, structurally similar to teicoplanin. Production of A40926 is governed by the stringent response at the transcriptional level. In fact, addition of an amino acid pool prevented the transcription of dbv cluster genes involved in the A40926 biosynthesis and the antibiotic production in chemically defined media, and a thiostrepton-resistant relaxed mutant was severely impaired in its ability to produce the antibiotic. The derivative strain rif19, highly resistant to rifampicin (minimal inhibitory concentration, MIC > 200 microg ml(-1)), was isolated from the wild type strain that exhibited low resistance to rifampicin (MIC < 25 microg ml(-1)). In this strain A40926 production started earlier than in the wild type, and reached higher final levels. Moreover, the antibiotic production was not subjected to the stringent control. Molecular analysis led to the identification of two distinct rpoB alleles, rpoBS and rpoBR, in both the wild type and the rif19. rpoBR harboured the H426N missense which is responsible for rifampicin-resistance in bacteria, in addition to other nucleotide substitutions affecting the primary structure of the RNA polymerase beta-chain. Transcript analysis revealed that rpoBR was expressed at a very low level in the wild type strain during the pseudo-exponential growth phase, and that the amount of rpoBR mRNA increased during the transition to the stationary phase. In contrast, expression of rpoBR was constitutive in the rif19. The results of mRNA half-life analysis did not support the hypothesis that post-transcriptional events are responsible for the different rpoB expression patterns in the two strains, suggesting a role of transcriptional mechanisms
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