42 research outputs found

    Impact of Gamma Radiation on Dynamic RDSON Characteristics in AlGaN/GaN Power HEMTs

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    GaN high-electron-mobility transistors (HEMTs) are promising next-generation devices in the power electronics field which can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters, where high frequencies and voltages are also needed. Its wide band gap (WBG), large breakdown electric field, and thermal stability improve actual silicon performances. However, at the moment, GaN HEMT technology suffers from some reliability issues, one of the more relevant of which is the dynamic on-state resistance (RON_dyn) regarding power switching converter applications. In this study, we focused on the drain-to-source on-resistance (RDSON) characteristics under 60Co gamma radiation of two different commercial power GaN HEMT structures. Different bias conditions were applied to both structures during irradiation and some static measurements, such as threshold voltage and leakage currents, were performed. Additionally, dynamic resistance was measured to obtain practical information about device trapping under radiation during switching mode, and how trapping in the device is affected by gamma radiation. The experimental results showed a high dependence on the HEMT structure and the bias condition applied during irradiation. Specifically, a free current collapse structure showed great stability until 3.7 Mrad(Si), unlike the other structure tested, which showed high degradation of the parameters measured. The changes were demonstrated to be due to trapping effects generated or enhanced by gamma radiation. These new results obtained about RON_dyn will help elucidate trap behaviors in switching transistors

    Near edge x-ray absorption fine structure spectroscopy study of atomic nitrogen implanted in Al2O3 by low energy N2+ bombardment

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    N2+ bombardment of Al2O3 has been investigated by near edge x-ray absorption fine structure spectroscopy. Two kinds of species were detected and were attributed to implanted nitrogen atoms and nitride species. These results are discussed in relation to previous attributions in the literature of these species to AlNO and AlN.Comisión Interministerial de Ciencia y Tecnología (CICYT) MAT97-068

    How the analysis of archival data could provide helpful information about TID degradation. Case study: Bipolar transistors

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    A critical step of radiation hardness assurance (RHA) for space systems is given by the parts selection in accordance with the observed (or estimated) radiation effects. Although radiation testing is the most decisive way of studying the radiation degradation of electronic components, the increasing use of commercial off-the-shelf (COTS) devices and the challenges posed by NewSpace are pushing the need of finding new approaches to assess the risk associated with radiation environments. This work tries to evaluate if valuable information might be extracted from archival data to carry out this assessment despite the well-known and dramatic lot-to-lot, or even part-to-part, variability for some technologies and the impact of the different test conditions, such as the bias conditions and the dose rate in enhanced low dose rate sensitivity (ELDRS). These factors are briefly analyzed for some examples. A new radiation database is briefly introduced, and some statistical approaches are cited, apart from the analysis herein followed. To finish, a first analysis on three families of bipolar transistors is presented together with the independent results from three external reports, with a good agreement between the experimental results and the expected ones.10.13039/501100002878-Junta de Andalucia and Fondo Europeo de Desarrollo Regional (FEDER) Funds through the Singular Project Predicción del Comportamiento Eléctrico de Dispositivos Electrónicos bajo Radiación (PRECEDER) (Grant Number: CEI-5-RNM138). 10.13039/501100004837-Spanish Ministry of Science and Innovation under Project (Grant Number: PID2019-108377RB-C32)Peer reviewe

    Evaluation of a COTS 65-nm SRAM Under 15 MeV Protons and 14 MeV Neutrons at Low VDD

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    This article presents an experimental study on the sensitivity of a commercial-off-the-shelf (COTS) bulk 65-nm static random access memory (SRAM) under 15.6 MeV proton irradiation when powered up at ultralow bias voltage. Tests were run on standby and while reading the memory. Results show obvious evidence indicating that decreasing the bias voltage below 1 V exponentially increases the number of observed errors. Single-bit upsets (SBUs) and multiple-cell upsets (MCUs) (mostly with vertical shapes according to the manufacturers' layout) are reported and their behavior is analyzed in this article. Predictions on the single-event upset (SEU) sensitivity obtained with the multiscales single-event phenomena predictive platform (MUSCA-SEP3) modeling tool are also provided and compared with the experimental results. These are also compared with 14.2 MeV neutrons, showing a significant difference in the cross sections for both irradiation sources. Total ionizing dose (TID) tests and GEANT4 simulations were also run to check for the reason behind the difference in the cross section between these two particles

    TEDH y gestación por sustitución

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    Grado en Derecho. Derecho Internacional Privado Grupo II, 2020-201[ES]Cuando hablamos de gestación por sustitución, observamos que existe una denominación muy variada acerca del tema que hacen referencia a un mismo fenómeno: gestación por sustitución, maternidad subrogada, gestación subrogada, etc. Si bien, de conformidad con la Real Academia Española la gestación por sustitución es definida como el embarazo en el que media un contrato en virtud del cual, la gestante renuncia a la declaración de maternidad del hijo en favor del reconocimiento de la filiación biológica de otras personas, los padres comitentes o intencionales. Si observamos las definiciones que da la doctrina acerca de la gestación por sustitución, todas ellas van a coincidir en la existencia de una serie de aspectos: de un contrato entre las partes, de una gestante, de un progenitor o unos progenitores legales, y de una entrega del bebé cuando finaliza el proceso. Por lo tanto, podemos considerar que estos elementos encuadran la base de la gestación por sustitución

    Deficits of entropy modulation of the EEG: A biomarker for altered function in schizophrenia and bipolar disorder?

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    peer reviewed[en] BACKGROUND: The synchronized activity of distributed neural assemblies — reflected in the electroencephalogram (EEG) — underpins mental function. In schizophrenia, modulation deficits of EEG spectral content during a P300 task have been replicated. The effects of treatment, chronicity and specificity in these deficits and their possible relationship with anatomic connectivity remain to be explored. METHODS: We assessed spectral entropy modulation of the EEG during a P300 task in 79 patients with schizophrenia (of those, 31 werein their first episode), 29 patients with bipolar disorder and 48 healthy controls. Spectral entropy values summarize EEG characteristics by quantifying the irregularity of spectral content. In a subsample, we calculated the network architecture of structural connectivity using diffusion tensor imaging and graph-theory parameters. RESULTS: We found significant spectral entropy modulation deficits with task performance in patients with chronic or first-episode schizophrenia and in patients with bipolar disorder, without significant pre-stimulus spectral entropy differences. The deficits were unrelated to treatment doses, and spectral entropy modulation did not differ between patients taking or not taking antipsychotics, lithium, benzodiazepines or antidepressants. Structural connectivity values were unrelated to spectral entropy modulation. In patients with schizophrenia, spectral entropy modulation was inversely related to negative symptoms and directly related to verbal memory. LIMITATIONS: All patients were taking medication. Patients with bipolar disorder were euthymic and chronic. The cross-sectional nature of this study prevented a more thorough analysis of state versus trait criteria for spectral entropy changes. CONCLUSION: Spectral entropy modulation with task performance is decreased in patients with schizophrenia and bipolar disorder. This deficit was not an effect of psychopharmacological treatment or structural connectivity and might reflect a deficit in the synchronization of the neural assemblies that underlie cognitive activity

    Intermediate Molecular Phenotypes to Identify Genetic Markers of Anthracycline-Induced Cardiotoxicity Risk.

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    Cardiotoxicity due to anthracyclines (CDA) affects cancer patients, but we cannot predict who may suffer from this complication. CDA is a complex trait with a polygenic component that is mainly unidentified. We propose that levels of intermediate molecular phenotypes (IMPs) in the myocardium associated with histopathological damage could explain CDA susceptibility, so variants of genes encoding these IMPs could identify patients susceptible to this complication. Thus, a genetically heterogeneous cohort of mice (n = 165) generated by backcrossing were treated with doxorubicin and docetaxel. We quantified heart fibrosis using an Ariol slide scanner and intramyocardial levels of IMPs using multiplex bead arrays and QPCR. We identified quantitative trait loci linked to IMPs (ipQTLs) and cdaQTLs via linkage analysis. In three cancer patient cohorts, CDA was quantified using echocardiography or Cardiac Magnetic Resonance. CDA behaves as a complex trait in the mouse cohort. IMP levels in the myocardium were associated with CDA. ipQTLs integrated into genetic models with cdaQTLs account for more CDA phenotypic variation than that explained by cda-QTLs alone. Allelic forms of genes encoding IMPs associated with CDA in mice, including AKT1, MAPK14, MAPK8, STAT3, CAS3, and TP53, are genetic determinants of CDA in patients. Two genetic risk scores for pediatric patients (n = 71) and women with breast cancer (n = 420) were generated using machine-learning Least Absolute Shrinkage and Selection Operator (LASSO) regression. Thus, IMPs associated with heart damage identify genetic markers of CDA risk, thereby allowing more personalized patient management.J.P.L.’s lab is sponsored by Grant PID2020-118527RB-I00 funded by MCIN/AEI/10.13039/ 501100011039; Grant PDC2021-121735-I00 funded by MCIN/AEI/10.13039/501100011039 and by the “European Union Next Generation EU/PRTR”, the Regional Government of Castile and León (CSI144P20). J.P.L. and P.L.S. are supported by the Carlos III Health Institute (PIE14/00066). AGN laboratory and human patients’ studies are supported by an ISCIII project grant (PI18/01242). The Human Genotyping unit is a member of CeGen, PRB3, and is supported by grant PT17/0019 of the PE I + D + i 2013–2016, funded by ISCIII and ERDF. SCLl is supported by MINECO/FEDER research grants (RTI2018-094130-B-100). CH was supported by the Department of Defense (DoD) BCRP, No. BC190820; and the National Cancer Institute (NCI) at the National Institutes of Health (NIH), No. R01CA184476. Lawrence Berkeley National Laboratory (LBNL) is a multi-program national laboratory operated by the University of California for the DOE under contract DE AC02-05CH11231. The Proteomics Unit belongs to ProteoRed, PRB3-ISCIII, supported by grant PT17/0019/0023 of the PE I + D +i, 2017–2020, funded by ISCIII and FEDER. RCC is funded by fellowships from the Spanish Regional Government of Castile and León. NGS is a recipient of an FPU fellowship (MINECO/FEDER). hiPSC-CM studies were funded in part by the “la Caixa” Banking Foundation under the project code HR18-00304 and a Severo Ochoa CNIC Intramural Project (Exp. 12-2016 IGP) to J.J.S

    Fuentes orales y archivos: Modelos de Syllabus de clases prácticas para Grados de Historia, Historia del Arte y Arqueología

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    Este documento contiene la memoria final del proyecto de innovación docente nº. 11 de la convocatoria para el curso académico 2022-2023. En ella se contiene modelos de clases prácticas para aquellos profesores de los Grados de Historia, Historia del Arte o Arqueología que pudieran impartir asignaturas de dichos Grados.Depto. de Historia Moderna y ContemporáneaFac. de Geografía e HistoriaFALSEsubmitte

    Search for pair-produced vector-like leptons in final states with third-generation leptons and at least three b quark jets in proton-proton collisions at √s = 13 TeV

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