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In this study, the localized corrosion susceptibility of AA2050‐T84, AA2198‐T851, and AA2024‐T3 alloys was compared by immersion in three test solutions, specifically sodium chloride solution (3.5% NaCl), EXCO solution, according to ASTM G34‐18, and a solution for intergranular corrosion (IGC) test recommended by ASTM G110‐15 and via scanning vibrating electrode technique (SVET). The results showed higher susceptibility of AA2050‐T84 alloy to all types of corrosion tested compared to the other studied 2XXX series alloys. Corrosion penetration was deeper in the AA2050‐T84 due to its microstructural characteristics as a difference in the micrometric Cu‐Rich intermetallic particle distribution on the surface and related to the distribution of the T1 (Al2CuLi) phase. [ABSTRACT FROM AUTHOR]

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Copyright of Zeitschrift für Bildungsforschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article studies deep neural network expression rates for optimal stopping problems of discrete-time Markov processes on high-dimensional state spaces. A general framework is established in which the value function and continuation value of an optimal stopping problem can be approximated with error at most ε by a deep ReLU neural network of size at most κ d q ε − r . The constants κ , q , r ≥ 0 do not depend on the dimension d of the state space or the approximation accuracy ε . This proves that deep neural networks do not suffer from the curse of dimensionality when employed to approximate solutions of optimal stopping problems. The framework covers for example exponential Lévy models, discrete diffusion processes and their running minima and maxima. These results mathematically justify the use of deep neural networks for numerically solving optimal stopping problems and pricing American options in high dimensions. [ABSTRACT FROM AUTHOR]

Background: Computed tomography (CT) offers pulmonary volumetric quantification but is not commonly used in healthy individuals due to radiation concerns. Chronic airflow limitation (CAL) is one of the diagnostic criteria for chronic obstructive pulmonary disease (COPD), where early diagnosis is important. Our aim was to present reference values for chest CT volumetric and radiodensity measurements and explore their potential in detecting early signs of CAL. Methods: From the population‐based Swedish CArdioPulmonarybioImage Study (SCAPIS), 294 participants aged 50–64, were categorized into non‐CAL (n = 258) and CAL (n = 36) groups based on spirometry. From inspiratory and expiratory CT images we compared lung volumes, mean lung density (MLD), percentage of low attenuation volume (LAV%) and LAV cluster volume between groups, and against reference values from static pulmonary function test (PFT). Results: The CAL group exhibited larger lung volumes, higher LAV%, increased LAV cluster volume and lower MLD compared to the non‐CAL group. Lung volumes significantly deviated from PFT values. Expiratory measurements yielded more reliable results for identifying CAL compared to inspiratory. Using a cut‐off value of 0.6 for expiratory LAV%, we achieved sensitivity, specificity and positive/negative predictive values of 72%, 85% and 40%/96%, respectively. Conclusion: We present volumetric reference values from inspiratory and expiratory chest CT images for a middle‐aged healthy cohort. These results are not directly comparable to those from PFTs. Measures of MLD and LAV can be valuable in the evaluation of suspected CAL. Further validation and refinement are necessary to demonstrate its potential as a decision support tool for early detection of COPD. [ABSTRACT FROM AUTHOR]

Objectives: Despite their efficacy, some immunotherapies have been shown to induce immune-related adverse events, including the potentially life-threatening cytokine release syndrome (CRS), calling for reliable and translational preclinical models to predict potential safety issues and investigate their rescue. Here, we tested the reliability of humanized BRGSF mice for the assessment of therapeutics-induced CRS features in preclinical settings. Methods: BRGSF mice reconstituted with human umbilical cord blood CD34+ cells (BRGSF-CBC) were injected with anti-CD3 antibody (OKT3), anti-CD3/CD19 bispecific T-cell engager Blinatumomab, or VISTA-targeting antibody. Human myeloid and dendritic cells' contribution was investigated in hFlt3Lboosted BRGSF-CBC mice. OKT3 treatment was also tested in human PBMCreconstituted BRGSF mice (BRGSF-PBMC). Cytokine release, immune cell distribution, and clinical signs were followed. Results: OKT3 injection in BRGSF-CBC mice induced hallmark features of CRS, specifically inflammatory cytokines release, modifications of immune cell distribution and activation, body weight loss, and temperature drop. hFlt3Lboosted BRGSF-CBC mice displayed enhanced CRS features, revealing a significant role of myeloid and dendritic cells in this process. Clinical CRSmanaging treatment Infliximab efficiently attenuated OKT3-induced toxicity. Comparison of OKT3 treatment's effect on BRGSF-CBC and BRGSF-PBMC mice showed broadened CRS features in BRGSF-CBC mice. CRS-associated features were also observed in hFlt3L-boosted BRGSF-CBC mice upon treatment with other T-cell or myeloid-targeting compounds. Conclusions: These data show that BRGSF-CBC mice represent a relevant model for the preclinical assessment of CRS and CRS-managing therapies. They also confirm a significant role of myeloid and dendritic cells in CRS development and exhibit the versatility of this model for therapeutics-induced safety assessment. [ABSTRACT FROM AUTHOR]

Political actors pay attention to newspapers because they stimulate them to address a topic, reflect public opinion, provide feedback to their decisions, and help them to generate effective messages. Previous surveys showed that this is true for scientific issues. It follows that the newspaper coverage of scientific issues should appear as politically oriented, as observed regarding climate change. Here, we tested this prediction regarding educational neuroscience. This scientific issue is interesting because it implies no major economic interest and because the relevance of neuroscience regarding teaching in the classroom is still highly controversial. As hypothesized, we observed that the French press appeared strongly polarized: the right-leaning press was mostly favorable to educational neuroscience, whereas critical opinions were mainly found in the social-democrat press. Although the relevance of neuroscience toward teaching was rarely discussed in scientific arguments, political actors often invoked educational neuroscience in the press to legitimate their decision. [ABSTRACT FROM AUTHOR]

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Purpose: The years 1960-1970 were decisive years in the development of Swiss vocational education and training (VET). The post-World War II economic boom, technological innovations and the debate concerning equal opportunities and the democratisation of education put the VET system under pressure. Reforms were thus undertaken to increase the attractiveness of the system and to respond to the shortage of qualified workers at the time. At the same time, reforms were adopted increasing the theoretical and general knowledge content of VET and improving the quality of training. The aim of our article is to describe these reforms and to show how they relate to a certain image of the future of society. Method: Our article is based on an analysis of historical documents written between 1962 and 1972 in Switzerland on the subject of VET. These documents will, firstly, be used for a historical reconstruction of the situation and of the major challenges of the time; and secondly, they will be subjected to a discourse analysis in order to identify the main arguments that characterised the public debate at the time. Results: Our article shows how the reforms undertaken take shape on the basis of a certain image of the future of society and of VET held at the time: An image characterised by constant and rapid changes, increasing insecurity, need for adaptation and flexibility, complexification and specialisation of work tasks. Conclusion: The article will also underline how the responses to the challenges posed by this image of the future will be at the origin of new VET policy orientations that will characterise the evolution of Swiss VET up to the present day: A trend towards academisation, with more academic and general content; a trend towards pedagogisation, with increased pedagogical attention to curricula and teacher training; differentiation, with the creation of new certifications; permeability, with the opening of vocational tracks to higher education; and "learnerisation", with the gradual change of the figure of the apprentice from a "worker" to a "learner". Far from being limited to the evolution of Swiss VET, these five orientations describe movements that recent studies show also at the European level. [ABSTRACT FROM AUTHOR]

The electronic structure and optical properties of monoclinic HfO2 (m-HfO2) and HfO2:Al2O3 alloys, from the density functional theory (DFT), are investigated. The calculated lattice parameters and optical properties of m-HfO2 are consistent with the experimental data. Upon alloying with Al2O3 (more than 25%), we observe that the bandgap of Hf-aluminate (HfAlO) increases. Moreover, some doping states in the top and bottom valence bands are induced, which enhance the visible absorption of HfO2. From the impedance spectroscopy analysis, it is observed that 90% of the Al2O3 content in HfO2 induces a reduction of oxygen vacancies (and ac conductivity) as well as an increase in the dielectric constant as compared to pure HfO2. In addition, from the J–V and C–V variations, both current density and capacitance voltage nonlinearities are reduced. The conduction mechanisms of HfO2 and HfAlO dielectrics are systematically investigated. According to the J–E plots, parameters like the optical dielectric constant and the effective barrier height are extracted. Results are consistent with the DFT calculations and show that the Hf0.1Al0.9O device may constitute a potential candidate for metal–insulator–metal capacitor applications. [ABSTRACT FROM AUTHOR]

Doped hafnium oxide was shown to exhibit a strong ferroelectric behavior. It was implied that doping allows the stabilization of a HfO2 non-centrosymmetric orthorhombic phase, a prerequisite for ferroelectric behavior. However, a number of reports showed comparable ferroelectric properties in undoped HfO2, although with different behaviors of the remanent polarization upon layer thickness. In this work, the ferroelectric properties and crystalline structure of doped and undoped HfO2 layers as a function of the layer thickness were studied. The results show similar properties for ultrathin layers. Indeed, both show a linear increase in the orthorhombic/tetragonal crystalline phase amount and of remanent polarization as a function of thickness up to 7 nm. For higher thicknesses, a strong increase in the monoclinic phase is observed in undoped layers alongside a strong decrease in the remanent polarization whereas, for doped layers, the remanent polarization continues to increase with thickness. The experimental results suggest that the stabilization of the undoped HfO2 orthorhombic ferroelectric phase is due to mechanical stress, which is particularly high in ultrathin layers but relaxes for thicker layers. [ABSTRACT FROM AUTHOR]

The corrosion behavior and corrosion products of three zinc alloy‐coated steel substrates with different Al and Mg contents such as hot‐dip galvanized steel (HDG), Zn–Al‐coated steel (ZA), and Zn–Al–Mg‐coated steel (ZM) substrates were investigated during 168 h of immersion in 0.1 M NaCl solution. The characteristics and morphology of corrosion products on all the substrates formed during exposure to electrolyte solution were observed by X‐ray diffraction, X‐ray photoelectron spectroscopy, and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy. Their electrochemical behavior was investigated by open‐circuit potential, polarization curves, and electrochemical impedance spectroscopy. The addition of Al and Mg alloying elements affected the corrosion mechanism as well as the anticorrosion properties. The main crystalline corrosion products on the HDG surface were simonkolleite and zincite, while the ZnAl hydrotalcite was identified as the main corrosion product on ZA and ZM surfaces. The corrosion resistance of ZA and ZM substrates was improved compared to the HDG substrate due to the enhanced adhesion of the corrosion product layer. [ABSTRACT FROM AUTHOR]

Purpose: The assumption that traversal of the cell nucleus by ionizing radiation is a prerequisite to induce genetic damage, or other important biological responses, has been challenged by studies showing that oxidative alterations extend beyond the irradiated cells and occur also in neighboring bystander cells. Cells and tissues outside the radiation field experience significant biochemical and phenotypic changes that are often similar to those observed in the irradiated cells and tissues. With relevance to the assessment of long-term health risks of occupational, environmental and clinical exposures, measurable genetic, epigenetic, and metabolic changes have been also detected in the progeny of bystander cells. How the oxidative damage spreads from the irradiated cells to their neighboring bystander cells has been under intense investigation. Following a brief summary of the trends in radiobiology leading to this paradigm shift in the field, we review key findings of bystander effects induced by low and high doses of various types of radiation that differ in their biophysical characteristics. While notable mechanistic insights continue to emerge, here the focus is on the many means of intercellular communication that mediate these effects, namely junctional channels, secreted molecules and extracellular vesicles, and immune pathways. Conclusions: The insights gained by studying radiation bystander effects are leading to a basic understanding of the intercellular communications that occur under mild and severe oxidative stress in both normal and cancerous tissues. Understanding the mechanisms underlying these communications will likely contribute to reducing the uncertainty of predicting adverse health effects following exposure to low dose/low fluence ionizing radiation, guide novel interventions that mitigate adverse out-of-field effects, and contribute to better outcomes of radiotherapeutic treatments of cancer. In this review, we highlight novel routes of intercellular communication for investigation, and raise the rationale for reconsidering classification of bystander responses, abscopal effects, and expression of genomic instability as non-targeted effects of radiation. [ABSTRACT FROM AUTHOR]

This work focuses on the impact of sulfonated poly(ether ether ketone) (sPEEK) membrane pretreatments on fuel cell performance, starting from two different batches of Fumapem E730 from Fumatech, acquired in 2019 and in 2020. sPEEK membranes are possible lower cost alternatives to perfluorosulfonic acid (PFSA) membranes for proton exchange membrane fuel cells (PEMFC) applications. Before use, they must be pretreated to ensure a complete protonic substitution and removal of residual reagents/solvent: the simplest protocol consists in soaking the membrane in an acid solution followed by a rinsing step in water. In addition to this acidification step, hydrothermal (HT) treatments in water at high temperature for a few hours to a few days were also considered herein, as well as a hydro‐alcoholic (HA) step, because of their expected effects on membrane nanostructure. Overall, four different protocols were used. The membrane water uptake, water self‐diffusion, proton conductivity, and fuel cell performance—under H2/O2—were measured. It was found that in the best case—membranes from the 2020 batch subjected to HA followed by 72 h HT pretreatments—the fuel cell performances exceeded those obtained with a PFSA membrane (Nafion XL). This is explained by a higher protonic conductivity, probably resulting from a better sPEEK nano‐structuration. [ABSTRACT FROM AUTHOR]

Glass-ceramics containing pyroelectric Sr2TiSi2O8 (STS) crystals are produced from parent glasses of compositions STS + 0.8 SiO2 + (0.2 − x) Na2O + x CaO, with x = 0; 0.05; 0.10; and 0.15. The aim of this work is to investigate the effect of the additions to the stoichiometric STS composition on the crystallization mechanisms and on the piezoelectric properties of the glass-ceramic. The DSC analyses evidence that the glass transition temperatures Tg, the onset temperature of the crystallization peak To and the temperature Tc of the maximum of this peak increase with the CaO/Na2O ratio. On the basis of the DSC data, the crystallization of the parent glass samples was operated by thermal treatment. The observation of the cross-sections of the heat-treated samples highlights that the competition between the surface and volume crystallization mechanisms is influenced by the CaO/Na2O ratio and the temperature. For all the samples, the XRD analyses performed on the surfaces as obtained after the crystallization treatment evidenced a preferential orientation of the STS crystals with the plans (00l) parallel to the surface. The XRD analyses performed after grinding the surface show that only the surface crystallized layers are preferentially oriented. Moreover, changes in preferential orientation to plans (202) or (201) are observed over the depth, depending on the composition and the temperature of the thermal treatment. These changes influence the polarization of the surface crystallized layer and, consequently, its piezoelectric charge coefficient d33. The highest values of d33 were measured on the glass-ceramic samples exhibiting mainly a (202) preferential orientation over their thickness. [ABSTRACT FROM AUTHOR]

In the present study, Mg-Al layered double hydroxide (Mg-Al/LDH) was synthesized on the surface of AZ31 Mg alloy substrate via in-situ hydrothermal treatment. Synthesis parameters were changed to determine their effect on the lateral size of LDH. For this purpose, etching in nitric acid and anodizing in sodium hydroxide solution were performed as surface pretreatments. Moreover, the influence of LDH solution pH (10 and 11) on the lateral size of LDH coating was investigated. Morphology, chemical composition, and crystalline structure were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The corrosion resistance of the coatings was investigated by H2 measurements, salt spray, and electrochemical impedance spectroscopy (EIS). Moreover, the epoxy coating was applied on the best anti-corrosive LDH sample for assessing the compatibility and effectiveness of LDH on the corrosion properties of the substrate with the epoxy layer. At pH = 11, the lateral size of LDH was smaller than samples at pH = 10. In addition, small-sized LDH, as well as LDH/epoxy coating, revealed enhanced corrosion protection. [ABSTRACT FROM AUTHOR]

We present a model for the lowest two potential energy surfaces (PESs) that describe the photoinduced ring-opening reaction of benzopyran taken as a model compound to study the photochromic ring-opening reaction of indolinobenzospiropyran and its evolution toward its open-chain analog. The PESs are expressed in terms of three effective rectilinear coordinates. One corresponds to the direction between the equilibrium geometry in the electronic ground state, referred to as the Franck-Condon geometry, and the minimum of conical intersection (CI), while the other two span the two-dimensional branching space at the CI. The model correctly reproduces the topography of the PESs. The ab initio calculations are performed with the extended multiconfiguration quasidegenerate perturbation theory at second order method. We demonstrate that accounting for electron dynamic correlation drastically changes the global energy landscape since some zwitterionic states become strongly stabilized. Quantum dynamics calculations using this PES model produce an absorption spectrum that matches the experimental one to a good accuracy. [ABSTRACT FROM AUTHOR]

This article examines neural network‐based approximations for the superhedging price process of a contingent claim in a discrete time market model. First we prove that the α‐quantile hedging price converges to the superhedging price at time 0 for α tending to 1, and show that the α‐quantile hedging price can be approximated by a neural network‐based price. This provides a neural network‐based approximation for the superhedging price at time 0 and also the superhedging strategy up to maturity. To obtain the superhedging price process for t>0$t>0$, by using the Doob decomposition, it is sufficient to determine the process of consumption. We show that it can be approximated by the essential supremum over a set of neural networks. Finally, we present numerical results. [ABSTRACT FROM AUTHOR]

Deep neural networks (DNNs) with ReLU activation function are proved to be able to express viscosity solutions of linear partial integrodifferential equations (PIDEs) on state spaces of possibly high dimension d. Admissible PIDEs comprise Kolmogorov equations for high-dimensional diffusion, advection, and for pure jump Lévy processes. We prove for such PIDEs arising from a class of jump-diffusions on ℝ d , that for any suitable measure μ d on ℝ d , there exist constants C , , > 0 such that for every ∈ (0 , 1 ] and for every d ∈ ℕ the DNN L 2 (μ d) -expression error of viscosity solutions of the PIDE is of size with DNN size bounded by C d − . In particular, the constant C > 0 is independent of d ∈ ℕ and of ∈ (0 , 1 ] and depends only on the coefficients in the PIDE and the measure used to quantify the error. This establishes that ReLU DNNs can break the curse of dimensionality (CoD for short) for viscosity solutions of linear, possibly degenerate PIDEs corresponding to suitable Markovian jump-diffusion processes. As a consequence of the employed techniques, we also obtain that expectations of a large class of path-dependent functionals of the underlying jump-diffusion processes can be expressed without the CoD. [ABSTRACT FROM AUTHOR]

The direct integration of performant permanent magnets (PMs) within miniaturized circuits remains both a scientific and a technological challenge. Magnetophoresis‐driven capillary assembly of hard magnetic nanoparticles is a promising approach to fabricate 3D rare‐earth‐free PMs. However, this process implies the use of soft magnetic blocks to generate the magnetic field gradients required to localize the assembly directly onto silicon substrates. The impact of these soft elements onto the overall magnetic properties is evaluated using Co nanorods as hard material and 150 μm–thick Ni blocks. As expected, the presence of Ni softens the overall properties of the hybrid magnet obtained, but PM properties are preserved for reduced Ni volumes. Magnetic induction as high as 19 mT at a distance of 200 μm is generated by the hybrid Ni–Co–Ni structures, allowing for the electromagnetic actuation of a microelectromechanical resonant sensor. [ABSTRACT FROM AUTHOR]

B Electrocardiogram (ECG) with reversed leads showing right bundle branch block and left anterior hemiblock Graph: Figure 2 SPECT/CT of the patient demonstrating dextrocardia with situs inversus. Dextrocardia with situs inversus is a rare congenital condition with a prevalence of 1:10,000. [Extracted from the article]

A simple approach towards the compatibilization of polylactide (PLA) and hydroxyapatite (HAp) nanoparticles nanocomposites is here presented. An amphiphilic diblock copolymer, consisting of poly(ethylene glycol) (PEG) and PLA block was prepared and used to form an interphase between PLA matrix and HAp nanofiller. This copolymer was next mixed with HAp to intimly deposit PEG block on the HAp surface. Effective hydrophobization via PLA chains presence on the surface of the modified nanoparticles was attested via dispersion test in chloroform. Finally, the as modified HAp nanoparticles were blended in PLA. Thermal analyses showed a Tg superior to human body temperature. Dynamic mechanical and morphological analysis attested for improved dispersion and deagglomeration state of the nanoparticles in PLA. Interfacial mechanical properties studies recorded an increase of 150% in compressive modulus compared with neat PLA. In vitro bioactivity assay showed beneficial effect on the mineralization process in simulated body fluid when the interphase is created. This improvement of mechanical properties and bioactivity combined with a simple production process as extrusion make these materials suitable choice for potential load bearing applications. [ABSTRACT FROM AUTHOR]

Recently, artificial neural networks (ANNs) in conjunction with stochastic gradient descent optimization methods have been employed to approximately compute solutions of possibly rather high-dimensional partial differential equations (PDEs). Very recently, there have also been a number of rigorous mathematical results in the scientific literature, which examine the approximation capabilities of such deep learning-based approximation algorithms for PDEs. These mathematical results from the scientific literature prove in part that algorithms based on ANNs are capable of overcoming the curse of dimensionality in the numerical approximation of high-dimensional PDEs. In these mathematical results from the scientific literature, usually the error between the solution of the PDE and the approximating ANN is measured in the |$L^p$| -sense, with respect to some |$p \in [1,\infty)$| and some probability measure. In many applications it is, however, also important to control the error in a uniform |$L^\infty $| -sense. The key contribution of the main result of this article is to develop the techniques to obtain error estimates between solutions of PDEs and approximating ANNs in the uniform |$L^\infty $| -sense. In particular, we prove that the number of parameters of an ANN to uniformly approximate the classical solution of the heat equation in a region |$ [a,b]^d $| for a fixed time point |$ T \in (0,\infty) $| grows at most polynomially in the dimension |$ d \in {\mathbb {N}} $| and the reciprocal of the approximation precision |$ \varepsilon> 0 $|⁠. This verifies that ANNs can overcome the curse of dimensionality in the numerical approximation of the heat equation when the error is measured in the uniform |$L^\infty $| -norm. [ABSTRACT FROM AUTHOR]

The primal definition of first-order non-adiabatic couplings among electronic states relies on the knowledge of how electronic wavefunctions vary with nuclear coordinates.However, the non-adiabatic coupling between two electronic states can be obtained in the vicinity of a conical intersection from energies only, as this vector spans the branching plane along which degeneracy is lifted to first order. The gradient difference and derivative coupling are responsible of the two-dimensional cusp of a conical intersection between both potential-energy surfaces and can be identified to the non-trivial eigenvectors of the second derivative of the square energy difference, as first pointed out in Köppel and Schubert [Mol. Phys. 104(5-7), 1069 (2006)]. Such quantities can always be computed in principle for the cost of two numerical Hessians in the worst-case scenario. Analytic-derivative techniques may help in terms of accuracy and efficiency but also raise potential traps due to singularities and illdefined derivatives at degeneracies.We compare here two approaches, one fully numerical, the other semianalytic, where analytic gradients are available but Hessians are not, and investigate their respective conditions of applicability. Benzene and 3-hydroxychromone are used as illustrative application cases. It is shown that non-adiabatic couplings can thus be estimated with decent accuracy in regions of significant size around conical intersections. This procedure is robust and could be useful in the context of on-the-fly non-adiabatic dynamics or be used for producing model representations of intersecting potential energy surfaces with complete obviation of the electronic wavefunctions. [ABSTRACT FROM AUTHOR]

Sub-10 nm thick gadolinium-doped hafnia (Gd:HfO2) layers were grown in metal–insulator–metal (TiN/Gd:HfO2/TiN) stacks using a plasma-enhanced atomic layer deposition process. Thermally annealed Gd:HfO2 layers with a thickness of 8.8, 6.6, and 4.4 nm exhibited orthorhombic crystalline structure and showed ferroelectric properties. Indeed, polarization vs electric field hysteresis loops were recorded with 2Pr polarization ranging from 2 to 20 μC/cm2. The studied layers showed the same coercive electric field (∼2 MV/cm). Consequently, polarization switching voltage between +Pr and −Pr decreased down to 0.9 V for the thinnest layer. Remanent polarization cycling showed a strong wake-up effect, with no fatigue, up to 109, followed by a stabilization up to 1010 cycles, where 2Pr reached 33 μC/cm2 for 8.8 nm Gd:HfO2. This endurance result and the absence of noticeable remanent polarization fatigue can be attributed to the optimal chemical composition of the TiN/Gd:HfO2 interface, which is supposed to be at the origin of defect generation, mostly oxygen vacancies, that leads to ferroelectric polarization fatigue. [ABSTRACT FROM AUTHOR]

Copyright of Douleur et Analgésie is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, TiO2 layers grown on RuO2 by atomic layer deposition (ALD) using tetrakis (dimethyla-mino) titanium (TDMAT) and either oxygen plasma or H2O as oxygen source were analyzed using X-ray diffraction (XRD), Raman spectroscopy, and depth-resolved X-ray Photoelectron spectroscopy (XPS). The main objective is to investigate the surface chemical reactions mechanisms and their influence on the TiO2 film properties. The experimental results using XRD show that ALD deposition using H2O leads to anatase TiO2 whereas a rutile TiO2 is obtained when oxygen-plasma is used as oxygen source. Depth-resolved XPS analysis allows to determine the reaction mechanisms at the RuO2 substrate surface after growth of thin TiO2 layers. Indeed, the XPS analysis shows that when H2O assisted ALD process is used, intermediate Ti2O3 layer is obtained and RuO2 is reduced into Ru as evidenced by high resolution transmission electron microscopy. In this case, there is no possibility to re-oxidize the Ru surface into RuO2 due to the weak oxidation character of H2O and an anatase TiO2 layer is therefore grown on Ti2O3. In contrast, when oxygen plasma is used in the ALD process, its strong oxidation character leads to the re-oxidation of the partially reduced RuO2 following the first Ti deposition step. Consequently, the RuO2 surface is regenerated, allowing the growth of rutile TiO2. A surface chemical reaction scheme is proposed that well accounts for the observed experimental results. [ABSTRACT FROM AUTHOR]

Dielectric spectroscopy is carried out for intrinsic and aluminum-doped TiO2 rutile films which are deposited on RuO2 by the atomic layer deposition technique. Capacitance and conductance are measured in the 0.1 Hz-100 kHz range, for ac electric fields up to 1 MVrms/cm. Intrinsic films have a much lower dielectric constant than rutile crystals. This is ascribed to the presence of oxygen vacancies which depress polarizability. When Al is substituted for Ti, the dielectric constant further decreases. By considering Al-induced modification of polarizability, a theoretical relationship between the dielectric constant and the Al concentration is proposed. Al doping drastically decreases the loss in the very low frequency part of the spectrum. However, Al doping has almost no effect on the loss at high frequencies. The effect of Al doping on loss is discussed through models of hopping transport implying intrinsic oxygen vacancies and Al related centers. When increasing the ac electric field in the MVrms/cm range, strong voltage non-linearities are evidenced in undoped films. The conductance increases exponentially with the ac field and the capacitance displays negative values (inductive behavior). Hopping barrier lowering is proposed to explain highfield effects. Finally, it is shown that Al doping strongly improves the high-field dielectric behavior. [ABSTRACT FROM AUTHOR]

Resistance switching is studied in HfO2 as a function of the anode metal (Au, Cu, and Ag) in view of its application to resistive memories (resistive random access memories, RRAM). Current-voltage (I-V) and current-time (I-t) characteristics are presented. For Au anodes, resistance transition is controlled by oxygen vacancies (oxygen-based resistive random access memory, OxRRAM). For Ag anodes, resistance switching is governed by cation injection (Conducting Bridge random access memory, CBRAM). Cu anodes lead to an intermediate case. I-t experiments are shown to be a valuable tool to distinguish between OxRRAM and CBRAM behaviors. A model is proposed to explain the high-to-low resistance transition in CBRAMs. The model is based on the theory of low-temperature oxidation of metals (Cabrera-Mott theory). Upon electron injection, oxygen vacancies and oxygen ions are generated in the oxide. Oxygen ions are drifted to the anode, and an interfacial oxide is formed at the HfO2/anode interface. If oxygen ion mobility is low in the interfacial oxide, a negative space charge builds-up at the HfO2/oxide interface. This negative space charge is the source of a strong electric field across the interfacial oxide thickness, which pulls out cations from the anode (CBRAM case). Inversely, if oxygen ions migration through the interfacial oxide is important (or if the anode does not oxidize such as Au), bulk oxygen vacancies govern resistance transition (OxRRAM case). [ABSTRACT FROM AUTHOR]

The operation speed of dynamic random access memory devices has been increasing with respect to the evolution of electronic devices. This in turn has induced a decrease in the allowed time for the operation. Therefore, the effective capacitance degradation in which the capacitance gradually decreases with increasing frequency of applied ac voltage is a severe concern for decreasing capacitance during fast operation, in addition to inducing reliability degradation. Hence, in this article, the origin of capacitance degradation depending on operation frequency, also called “frequency dependence” of the capacitance, was revealed. By performing dc and ac nonlinearity analyses, the effect of defects, especially oxygen vacancies, on the electrical properties of metal-insulator-metal (MIM) capacitors was investigated. Eventually, the mechanism of frequency dependence related to oxygen vacancy in the insulator of the MIM capacitor was identified. [ABSTRACT FROM AUTHOR]

Formale Qualifikation gilt als zentrale Voraussetzung für Beschäftigungsfähigkeit. Anhand von Erwerbsverläufen von gering qualifizierten Arbeitskräften in der Schweiz untersucht dieser Beitrag Beschäftigungsfähigkeit als dynamische Wechselwirkung zwischen Orientierungen und Erwerbshandeln des Subjekts und institutionellen Regulierungen und Praktiken von Betrieben, Branchen und Sozialstaat. Die Analyse beruht auf qualitativen Interviews mit Arbeitskräften, Betrieben und Personalvermittlern. Die Mehrheit der befragten Arbeitskräfte war ein- oder mehrmals arbeitslos, aber nur ein Drittel der Erwerbsverläufe war insgesamt prekär. Vielmehr waren stabile Verläufe am häufigsten, und es gab auch Aufstiegskarrieren. Branche, betriebliche Personalstrategien und außerberufliche Faktoren erwiesen sich als ebenso entscheidend für die Beschäftigungsfähigkeit wie individuelles Erwerbshandeln und Bildungsbemühungen. Formal occupational qualification is regarded as a key factor of employability. Using employment trajectories of low-skilled workers in Switzerland this paper analyses employability as a dynamic interaction between individual orientations and strategies on the one hand, and institutional regulations and practices of firms, industry sector and the welfare state on the other hand. The empirical database consists of qualitative interviews with low-skilled workers, employers and labour market intermediaries. The majority of the 39 low-skilled workers experienced one or more unemployment spells. Yet, only a third of the employment trajectories were precarious. Rather, stable trajectories formed the largest group and there were also upward careers. Employers' personnel strategies and extra-occupational personal factors (e.g., family or health) proved just as decisive for the development or erosion of employability as individual educational and training efforts. [ABSTRACT FROM AUTHOR]

We study the expression rates of deep neural networks (DNNs for short) for option prices written on baskets of d risky assets whose log-returns are modelled by a multivariate Lévy process with general correlation structure of jumps. We establish sufficient conditions on the characteristic triplet of the Lévy process X that ensure ε error of DNN expressed option prices with DNNs of size that grows polynomially with respect to O (ε − 1) , and with constants implied in O (⋅) which grow polynomially in d , thereby overcoming the curse of dimensionality (CoD) and justifying the use of DNNs in financial modelling of large baskets in markets with jumps. In addition, we exploit parabolic smoothing of Kolmogorov partial integro-differential equations for certain multivariate Lévy processes to present alternative architectures of ReLU ("rectified linear unit") DNNs that provide ε expression error in DNN size O (| log (ε) | a) with exponent a proportional to d , but with constants implied in O (⋅) growing exponentially with respect to d . Under stronger, dimension-uniform non-degeneracy conditions on the Lévy symbol, we obtain algebraic expression rates of option prices in exponential Lévy models which are free from the curse of dimensionality. In this case, the ReLU DNN expression rates of prices depend on certain sparsity conditions on the characteristic Lévy triplet. We indicate several consequences and possible extensions of the presented results. [ABSTRACT FROM AUTHOR]

The Feynman–Kac formula implies that every suitable classical solution of a semilinear Kolmogorov partial differential equation (PDE) is also a solution of a certain stochastic fixed point equation (SFPE). In this article we study such and related SFPEs. In particular, the main result of this work proves existence of unique solutions of certain SFPEs in a general setting. As an application of this main result we establish the existence of unique solutions of SFPEs associated with semilinear Kolmogorov PDEs with Lipschitz continuous nonlinearities even in the case where the associated semilinear Kolmogorov PDE does not possess a classical solution. [ABSTRACT FROM AUTHOR]

Copyright of Industrielle Beziehungen is the property of Rainer Hampp Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Referring to historical debates and theories on vocational education and training (VET) since the 19th century and developments up to the present day, this paper considers the cultural conditions that were relevant for the emergence and legitimisation of vocational education and training and, in particular, the dual principle of apprenticeships in Germany and Switzerland. With reference to the theories of German Vocational Education Theory that emerged at the beginning of the 20th century and the concept of vocation (Beruf), i.e. the merging of occupation-based work and education, as it was propagated in particular by Georg Kerschensteiner, the development and establishment of dual vocational training in Germany and Switzerland is reconstructed, in line with what became the institutional framework of apprenticeships in the two countries. It is above all the focus on education in schools through Bildung as a pedagogical concept reaching beyond what may technically be associated with skill formation for jobs, but also the understanding that VET should be given a reliable institutional framework, that were crucial for the emergence and establishment of the modern VET system in both countries. [ABSTRACT FROM AUTHOR]

We study risk‐sharing equilibria with general convex costs on the agents' trading rates. For an infinite‐horizon model with linear state dynamics and exogenous volatilities, we prove that the equilibrium returns mean‐revert around their frictionless counterparts—the deviation has Ornstein‐Uhlenbeck dynamics for quadratic costs whereas it follows a doubly‐reflected Brownian motion if costs are proportional. More general models with arbitrary state dynamics and endogenous volatilities lead to multidimensional systems of nonlinear, fully‐coupled forward‐backward SDEs. These fall outside the scope of known well‐posedness results, but can be solved numerically using the simulation‐based deep‐learning approach of Han, Jentzen, and E (2018). In a calibration to time series of prices and trading volume, realistic liquidity premia are accompanied by a moderate increase in volatility. The effects of different cost specifications are rather similar, justifying the use of quadratic costs as a proxy for other less tractable specifications. [ABSTRACT FROM AUTHOR]

Copyright of Sozialer Fortschritt is the property of Duncker & Humblot GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We prove existence and uniqueness of solutions to Fokker–Planck equations associated with Markov operators multiplicatively perturbed by degenerate time-inhomogeneous coefficients. Precise conditions on the time-inhomogeneous coefficients are given. In particular, we do not necessarily require the coefficients to be either globally bounded or bounded away from zero. The approach is based on constructing random time-changes and studying related martingale problems for Markov processes with values in locally compact, complete and separable metric spaces. [ABSTRACT FROM AUTHOR]

Capacitance nonlinearities were studied in atomic layer deposited HfO2 films using two types of signals: a pure ac voltage of large magnitude (ac nonlinearities) and a small ac voltage superimposed to a large dc voltage (dc nonlinearities). In theory, ac and dc nonlinearities should be of the same order of magnitude. However, in practice, ac nonlinearities are found to be an order of magnitude higher than dc nonlinearities. Besides capacitance nonlinearities, hopping conduction is studied using low-frequency impedance measurements and is discussed through the correlated barrier hopping model. The link between hopping and nonlinearity is established. The ac nonlinearities are ascribed to the polarization of isolated defect pairs, while dc nonlinearities are attributed to electrode polarization which originates from defect percolation paths. Both the ac and dc capacitance nonlinearities display an exponential variation with voltage, which results from field-induced lowering of the hopping barrier energy. [ABSTRACT FROM AUTHOR]

Summary: Iron (Fe) is a major micronutrient and is required for plant growth and development. Nongrass species have evolved a reduction‐based strategy to solubilize and take up Fe. The secretion of Fe‐mobilizing coumarins (e.g. fraxetin, esculetin and sideretin) by plant roots plays an important role in this process. Although the biochemical mechanisms leading to their biosynthesis have been well described, very little is known about their cellular and subcellular localization or their mobility within plant tissues.Spectral imaging was used to monitor, in Arabidopsis thaliana, the in planta localization of Fe‐mobilizing coumarins and scopolin. Molecular, genetic and biochemical approaches were also used to investigate the dynamics of coumarin accumulation in roots.These approaches showed that root hairs play a major role in scopoletin secretion, whereas fraxetin and esculetin secretion occurs through all epidermis cells. The findings of this study also showed that the transport of coumarins from the cortex to the rhizosphere relies on the PDR9 transporter under Fe‐deficient conditions. Additional experiments support the idea that coumarins move throughout the plant body via the xylem sap and that several plant species can take up coumarins present in the surrounding media.Altogether, the data presented here demonstrate that coumarin storage and accumulation in roots is a highly complex and dynamic process. [ABSTRACT FROM AUTHOR]