Search results for "brea"
showing 10 items of 4298 documents
Kulinaria w przestrzeni miasta : nowe trendy, nowe potrzeby mieszkańców
2015
The subject of this article is culinary trends observable in Polish cities during the past few years. They include both the rediscovered practices, directly related to the cultural (culinary) heritage of a particular area, and these which have become popular only recently. According to the author, characteristic culinary fads are: the promotion of local delicacies on a large scale, growing interest in shopping in farmers’ markets offering organic produce (bio-markets) and traditional goods, growing popularity of street food (including street food festivals and picnics), and organizing the so called “breakfast on the grass” events.
SARS-CoV-2 vaccine response and rate of breakthrough infection in patients with hematological disorders
2022
Abstract Background The clinical efficacy of SARS-CoV-2 vaccines according to antibody response in immunosuppressed patients such as hematological patients has not yet been established. Patients and methods A prospective multicenter registry-based cohort study conducted from December 2020 to December 2021 by the Spanish transplant and cell therapy group was used to analyze the relationship of antibody response at 3–6 weeks after full vaccination (2 doses) with breakthrough SARS-CoV-2 infection in 1394 patients with hematological disorders. Results At a median follow-up of 165 days after complete immunization, 37 out of 1394 (2.6%) developed breakthrough SARS-CoV-2 infection at median of 77 …
High-Power Multicarrier Generation for RF Breakdown Testing
2017
Testing of satellite components for high RF power breakdown effects, such as multipactor and corona or passive-intermodulation, is a topic of growing interest in the aerospaceindustry. Switching fromthe classical single carrier approach to the more realisticmulticarrier scenario is very challenging from the experimental point of view. Themulticarrier signals, amplifiedby several RF power amplifiers, need to have controlled phase, amplitude, and frequency in each carrier. Fine tuning of the signal generator phases is required in order to compensate the phase drift occurring in the active elements of the test bed. This paper presents an efficient and low-cost technique to generate multicarrie…
SiC MOSFET vs SiC/Si Cascode short circuit robustness benchmark
2019
Abstract Nowadays, MOSFET SiC semiconductors short circuit capability is a key issue. SiC/Si Cascodes are compound semiconductors that, in some aspects, show a similar MOSFET behaviour. No interlayer dielectric insulation suggests, in theory, Cascode JFETs as more robust devices. The purpose of this paper is to compare the drift and degradation of two commercial devices static parameters by exposing them to different levels of repetitive 1.5 μs short-circuit campaigns at 85% of its breakdown voltage. Short-circuit time has been set experimentally, and longer times result in catastrophic failure of MOSFET devices due to over self-heating. For this purpose, pre- and post-test short circuit ch…
Multi-pulse characterization of trapping/detrapping mechanisms in AlGaN/GaN high electromobility transistors
2019
GaN high-electro mobility transistors (HEMTs) are among the most promising candidates for use in high-power, high-frequency, and high-temperature electronics owing to their high electrical breakdown threshold and their high saturation electron velocity. The applications of these AlGaN/GaN HEMTs in power converters are limited by the surface trapping effects of drain-current collapse. Charge-trapping mechanisms affect the dynamic performance of all GaN HEMTs used in power switching applications. This study analyzes the dynamic resistance of GaN HEMTs and finds that the effects of dynamic resistance can be suppressed by controlling switching conditions and on-off cycles.
Radiation resistance of nanolayered silicon nitride capacitors
2020
Abstract Single-layered and multi-layered 20–60 nm thick silicon nitride (Si3N4) dielectric nanofilms were fabricated using a low-pressure chemical vapour deposition (LPCVD) method. The X-ray photoelectron spectroscopy (XPS) confirmed less oxygen content in the multi-layered nanofilms. The capacitors with Si3N4 multilayer demonstrated a tendency to a higher breakdown voltage compared to the capacitors with Si3N4 single layer. Si3N4 nanofilms and capacitors with Si3N4 dielectric were exposed to 1 kGy dose of gamma photons. Fourier transform infrared (FTIR) spectroscopy analysis showed that no modifications of the chemical bonds of Si3N4 were present after irradiation. Also, gamma irradiation…
On the N1-H and N3-H Bond Dissociation in Uracil by Low Energy Electrons: A CASSCF/CASPT2 Study.
2015
The dissociative electron-attachment (DEA) phenomena at the N1-H and N3-H bonds observed experimentally at low energies (<3 eV) in uracil are studied with the CASSCF/CASPT2 methodology. Two valence-bound π(-) and two dissociative σ(-) states of the uracil anionic species, together with the ground state of the neutral molecule, are proven to contribute to the shapes appearing in the experimental DEA cross sections. Conical intersections (CI) between the π(-) and σ(-) are established as the structures which activate the DEA processes. The N1-H and N3-H DEA mechanisms in uracil are described, and experimental observations are interpreted on the basis of two factors: (1) the relative energy of …
Selective Metal–Ligand Bond-Breaking Driven by Weak Intermolecular Interactions: From Metamagnetic Mn(III)-Monomer to Hexacyanoferrate(II)-Bridged Me…
2020
Metal–ligand coordination interactions are usually much stronger than weak intermolecular interactions. Nevertheless, here, we show experimental evidence and theoretical confirmation of a very rare...
The Synergistic Impacts of Anthropogenic Stressors and COVID-19 on Aquaculture: A Current Global Perspective
2021
13 pages, 6 figures, 2 tables.-- This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License
Effects of host abundance on larch budmoth outbreaks in the European Alps
2017
Outbreaks of the larch budmoth (LBM) in the European Alps are among the most documented population cycles and their historical occurrence has been reconstructed over 1200 years. Causes and consequences of cyclic LBM outbreaks are poorly understood and little is known about populations near the margin of the host's distribution range. In the present study, we quantify historical LBM outbreaks and associated growth reductions in host trees (European larch). Tree-ring data collected from 18 sites between approximately 500 and 1700 m a.s.l. in the Northern pre-Alps are compared with data from the Western Alps and Tatra Mountains, as well as with nonhost Norway spruce. Highly synchronized host a…