Risk Sharing with Deep Neural Networks

We consider the problem of optimally sharing a financial position among agents with potentially different reference risk measures. The problem is equivalent to computing the infimal convolution of the risk metrics and finding the so-called optimal allocations. We propose a neural network-based framework to solve the problem and we prove the convergence of the approximated inf-convolution, as well as the approximated optimal allocations, to the corresponding theoretical values. We support our findings with several numerical experiments

Process simulation for the design and scale up of heterogeneous catalytic process: Kinetic modelling issues

Process simulation represents an important tool for plant design and optimization, either applied to well established or to newly developed processes. Suitable thermodynamic packages should be selected in order to properly describe the behavior of reactors and unit operations and to precisely define phase equilibria. Moreover, a detailed and representative kinetic scheme should be available to predict correctly the dependence of the process on its main variables. This review points out some models and methods for kinetic analysis specifically applied to the simulation of catalytic processes, as a basis for process design and optimization. Attention is paid also to microkinetic modelling and to the methods based on first principles, to elucidate mechanisms and independently calculate thermodynamic and kinetic parameters. Different case studies support the discussion. At first, we have selected two basic examples from the industrial chemistry practice, e.g., ammonia and methanol synthesis, which may be described through a relatively simple reaction pathway and the relative available kinetic scheme. Then, a more complex reaction network is deeply discussed to define the conversion of bioethanol into syngas/hydrogen or into building blocks, such as ethylene. In this case, lumped kinetic schemes completely fail the description of process behavior. Thus, in this case, more detailed\ue2\u80\u94e.g., microkinetic\ue2\u80\u94schemes should be available to implement into the simulator. However, the correct definition of all the kinetic data when complex microkinetic mechanisms are used, often leads to unreliable, highly correlated parameters. In such cases, greater effort to independently estimate some relevant kinetic/thermodynamic data through Density Functional Theory (DFT)/ab initio methods may be helpful to improve process description

Reservoir Computing with Charge-Trap Memory Based on a MoS2 Channel for Neuromorphic Engineering

Novel memory devices are essential for developing low power, fast, and accurate in-memory computing and neuromorphic engineering concepts that can compete with the conventional complementary metal-oxide-semiconductor (CMOS) digital processors. 2D semiconductors provide a novel platform for advanced semiconductors with atomic thickness, low-current operation, and capability of 3D integration. This work presents a charge-trap memory (CTM) device with a MoS2 channel where memory operation arises, thanks to electron trapping/detrapping at interface states. Transistor operation, memory characteristics, and synaptic potentiation/depression for neuromorphic applications are demonstrated. The CTM device shows outstanding linearity of the potentiation by applied drain pulses of equal amplitude. Finally, pattern recognition is demonstrated by reservoir computing where the input pattern is applied as a stimulation of the MoS2-based CTMs, while the output current after stimulation is processed by a feedforward readout network. The good accuracy, the low current operation, and the robustness to input random bit flip makes the CTM device a promising technology for future high-density neuromorphic computing concepts

Pure and Fe-doped mesoporous titania catalyse the oxidation of acid orange 7 by H2O2 under different illumination conditions: Fe doping improves photocatalytic activity under simulated solar light

A sample of mesoporous TiO2 (MT, specific surface area = 150 m2\uc2\ub7g\ue2\u88\u921) and two samples of MT containing 2.5 wt.% Fe were prepared by either direct synthesis doping (Fe2.5-MTd) or impregnation (Fe2.5-MTi). Commercial TiO2 (Degussa P25, specific surface area = 56 m2\uc2\ub7g\ue2\u88\u921) was used both as a benchmark and as a support for impregnation with either 0.8 or 2.5 wt.% Fe (Fe0.80-IT and Fe2.5-IT). The powders were characterized by X-ray diffraction, N2 isotherms at \ue2\u88\u92196\ue2\u97\ua6C, Energy Dispersive X-ray (EDX) Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Diffuse Reflectance (DR) ultra-violet (UV)-Vis and M\uc3\ub6ssbauer spectroscopies. Degradation of Acid Orange 7 (AO7) by H2O2 was the test reaction: effects of dark-conditions versus both UV and simulated solar light irradiation were considered. In dark conditions, AO7 conversion was higher with MT than with Degussa P25, whereas Fe-containing samples were active in a (slow) Fenton-like reaction. Under UV light, MT was as active as Degussa P25, and Fe doping enhanced the photocatalytic activity of Fe2.5-MTd; Fe-impregnated samples were also active, likely due to the occurrence of a photo-Fenton process. Interestingly, the Fe2.5-MTd sample showed the best performance under solar light, confirming the positive effect of Fe doping by direct synthesis with respect to impregnation

Efectos sobre el desempeño visual de dos filtros Longpass

Purpose: This study compared visual performance and optical properties of three filters. Method: Two groups of twenty adults were recruited: wearers of progressive addition lenses (PAL, 46–73 years) and wearers of single vision lenses (SVL, 26–55 years). Three spectacle filters (Hoya, Japan) were compared: clear control, Standard Drive (STD), and Professional Drive (PRO) lenses. Optical transmittance was measured by a Jasco V-650 spectrophotometer. Best corrected visual acuity (BCVA) was measured in photopic (BCVAphotopic) and mesopic (BCVAmesopic) conditions and under glare (BCVAglare). Photopic contrast sensitivity (CS) was also measured. Results: The three longpass filters show cutoff at 426 ± 2 nm (STD/PRO) and 405 ± 2 nm (clear lens). BCVAglare improved with Drive filters compared to the clear one (p < 0.05) from 0.03 to -0.02 (STD) and to -0.01 (PRO) for PAL and from -0.08 to -0.12 (STD and PRO) for SVL. For PAL, BCVAmesopic improved from 0.15 to 0.12 (STD, p < 0.05) and 0.13 (PRO), while no substantial difference was observed for SVL. CS showed some improvements with Drive lenses at some angular frequencies between 6 and 18 cycles/deg, mainly for the PAL group. No BCVAphotopic differences were found. After testing all filters, each for two weeks, 79% (PAL) and 60% (SVL) of participants preferred Drive lenses. Conclusions: Drive lenses are found to maintain or improve some visual functions compared to the clear lens. The improvement of mesopic visual acuity, visual acuity under glare, and contrast sensitivity is mainly attributed to the reduction of intraocular light scattering as a consequence of the total light attenuation in the spectral range below the cutoff

Liquid vs. Gas Phase CO2 Photoreduction Process: Which Is the Effect of the Reaction Medium?

The use of carbon dioxide, the most concerning environmental issue of the 21st century, as a feedstock for fuels productions still represents an innovative, yet challenging, task for the scientific community. CO2 photoreduction processes have the potential to transform this hazardous pollutant into important products for the energy industry (e.g., methane and methanol) employing a photocatalyst and light as the only energy input. In order to design an effective process, the high sustainability of this reaction should be matched with the perfect reaction conditions to allow the reactant, photocatalyst, and light source to come together: therefore, the choice of reaction conditions, and in particular its medium, is a crucial issue that needs to be investigated. Throughout this paper, a careful study of carbon dioxide photoreduction in liquid and vapour phases are reported, focusing on their effect on catalyst performances in terms of light harvesting, productivity, and selectivity. Different from most papers in the literature, catalytic tests were performed under extremely low light irradiance, in order to minimise the primary energy input, highlighting that this experimental variable has a great effect on the reaction pathway and, thus, product distribution

Surface probing by spectroscopy on titania-supported gold nanoparticles for a photoreductive application

The continuous increase in scientific reports concerning photocatalysis and in particular CO2 photoreduction in recent years reveals the high degree of interest around the topic. However, the adsorption and activation mechanisms of CO2 on TiO2, the most used photocatalyst, are poorly understood and investigated. Gold nanoparticles were prepared by a modified deposition-precipitation method using urea and a chemical reductant. Bare P25 was used as reference. Combined spectroscopic investigations of fresh and spent samples with photoactivity studies reported in this article provide new insights to the role of CO2 adsorption and carbonate formation on Au/TiO2 during CO2 photocatalytic reduction. The key intermediates’ and products’ adsorption (CO, methanol, ethanol) was studied, coupled with X-ray photoelectron microscopy (XPS) and UV-Visible spectroscopy. The adsorption of CO2 on fresh and spent catalysts changes radically considering the carbonate formation and the gold surface presence. Methanol and ethanol revealed new adsorbed species on Au with respect to bare titania. The characterisation of the spent catalysts revealed the good stability of these sample

Impact of work arrangements during the COVID-19 pandemic on mental health in France

• Symptoms of anxiety/depression were found in 28.8% of the participants at least once. • Unemployment and financial difficulties were associated with anxiety/depression. • Targeted mental health support could lessen mental health impact

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research