70 research outputs found
Electrical and optical properties of Transparent Oxide/Metal/Oxide MultilayerFilms Deposited on Glass and PET substrates
Date du colloque : 10/2012International audienc
Reversible Martensitic Phase Transition in Yttrium-Stabilized ZrO2 Nanopowders by Adsorption of Water
Funding: This work was supported by H2020/MSCA/RISE/SSHARE number 871284 project and the RO-JINR Grant No. 367/2021 item 27 and RO-JINR Projects № 366/2021 items 57, 61, 83, 85.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.The present study was aimed at revealing the influence of the mechanical stress induced by water molecule adsorption on the composition of crystalline phases in the ZrO2 + 3 mol% Y2O3-nanoparticles. Three basic methods were used to determine the phase transition: Neutron diffraction, Raman microspectroscopic scanning, and X-ray diffraction. The fact of reversible phase-structural β → α transformation and the simultaneous presence of two polymorphic structural modifications (β is the phase of the tetragonal syngony and α of monoclinic syngony in nanosized particles (9 nm)) under normal physical conditions was established by these methods. An assumption was made regarding the connection of the physical mechanism of transformation of the extremely nonequilibrium surface of nanoparticles with electronic exchange of the material of the near-surface layer of nanoparticles with the adsorption layer through donor-acceptor interaction. The principal possibility of creating direct-acting hydroelectric converters based on nanoscale YSZ (Yttria-Stabilized Zirconia) systems due to the reversible character of the considered effect was shown.publishersversionpublishe
Efficient CSL Model Checking Using Stratification
For continuous-time Markov chains, the model-checking problem with respect to
continuous-time stochastic logic (CSL) has been introduced and shown to be
decidable by Aziz, Sanwal, Singhal and Brayton in 1996. Their proof can be
turned into an approximation algorithm with worse than exponential complexity.
In 2000, Baier, Haverkort, Hermanns and Katoen presented an efficient
polynomial-time approximation algorithm for the sublogic in which only binary
until is allowed. In this paper, we propose such an efficient polynomial-time
approximation algorithm for full CSL. The key to our method is the notion of
stratified CTMCs with respect to the CSL property to be checked. On a
stratified CTMC, the probability to satisfy a CSL path formula can be
approximated by a transient analysis in polynomial time (using uniformization).
We present a measure-preserving, linear-time and -space transformation of any
CTMC into an equivalent, stratified one. This makes the present work the
centerpiece of a broadly applicable full CSL model checker. Recently, the
decision algorithm by Aziz et al. was shown to work only for stratified CTMCs.
As an additional contribution, our measure-preserving transformation can be
used to ensure the decidability for general CTMCs.Comment: 18 pages, preprint for LMCS. An extended abstract appeared in ICALP
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Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700
High throughput growth, modification and characterization of thin anodic oxides on valve metals
Modifizierte anodische Oxide wurden durch Einbindung von Nanopartikeln in reine anodische Oxide und durch Anodisierung von Metalllegierungen hergestellt, die durch kombinatorische Abscheidung als dünne Filme hergestellt wurden. Die Nanopartikel wurden durch Ionenimplantation oder Molekularstrahlabscheidung hergestellt. Die Repassivierung der Oxidoberfläche nach der Modifikation wurde diskutiert und der Einfluss der Nanopartikel auf die elektrochemischen Eigenschaften wurde untersucht. Al, Hf, Nb, Ta, Ti-Oxide und ihre binären und ternären Oxide wurden mit einer Rastertropfenzelle hergestellt und charakterisiert. Die elektrischen Widerstände und Dielektrizitätskonstanten der Oxide wurden in situ mittels Impedanzspektroskopie als Funktion der Legierung abgebildet. Die Halbleitereigenschaften der modifizierten Oxide wurden mit Mott-Schottky-Diagrammen analysiert, die chemische Zusammensetzung wurde mit XPS Tiefenprofilen untersucht und mit den ursprünglichen Metalllegierungen verglichen.Modified anodic oxides were obtained in two modes: by nanoparticle incorporation in pure anodic oxides and by anodization of metallic alloys previously fabricated using combinatorial thin film depositions. The nanoparticle synthesis was achieved by ion implantation or by molecular beam deposition methods. The repassivation of the oxide surface after modification was discussed and the effect of the nanoparticles on the electrochemical properties were analysed. A scanning droplet cell was used for growth and characterization of anodic oxides on Al, Hf, Nb, Ta, Ti and their binary and ternary alloys. The electrical resistivities and dielectric constants of the oxides were mapped in situ as a function of the alloy compositions using impedance spectroscopy. The semiconducting properties of the modified oxides were analysed using Mott-Schottky plots. Their compositions were studied by depth profile XPS analysis and were compared with the compositions of the parent metal alloys
Pulsed laser deposition of barium metaplumbate thin films for ferroelectric capacitors
Barium metaplumbate thin films were deposited in situ by pulsed laser deposition
on Si/SiO2/Ti/Pt substrates with a high deposition rate. The temperatures used ranged
between 400 °C and 700 °C. As the deposition temperature was increased, the films
assumed a strong (222) preferential orientation. This orientation of the electrodes was
reflected on the PZT films, having a very big influence on their ferroelectric behavior.
The PZT films made over BPO deposited at high temperature presented high values of
remanent polarization (43 μC/cm2) but indications of high leakage currents could be
observed in the hysteresis loops. By using BPO bottom electrodes, a 30% improvement
in the fatigue behavior of PZT capacitors when compared with the normal platinum
electrodes was observed
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