Computational Fluid Dynamics of Reacting Flows at Surfaces: Methodologies and Applications

This review presents the numerical algorithms and speed-up strategies developed to couple continuum macroscopic simulations and detailed microkinetic models in the context of multiscale approaches to chemical reactions engineering. CFD simulations and hierarchical approaches are discussed both for fixed and fluidized systems. The foundations of the methodologies are reviewed together with specific examples to show the applicability of the methods. These concepts play a pivotal role to enable the first-principles multiscale approach to systems of technological relevance

Transport Properties and Exponential n-values of Fe/MgB2 Tapes With Various MgB2 Particle Sizes

Fe/MgB2 tapes have been prepared starting with pre-reacted binary MgB2 powders. As shown by resistive and inductive measurements, the reduction of particle size to a few microns by ball milling has little influence on Bc2, while the superconducting properties of the individual MgB2 grains are essentially unchanged. Reducing the particle size causes an enhancement of Birr from 14 to 16 T, while Jc has considerably increased at high fields, its slope Jc(B) being reduced. At 4.2K, values of 5.3*10^4 and 1.2*10^3 A/cm^2 were measured at 3.5 and 10 T, respectively, suggesting a dominant role of the conditions at the grain interfaces. A systematic variation of these conditions at the interfaces is undertaken in order to determine the limit of transport properties for Fe/MgB2 tapes. The addition of 5% Mg to MgB2 powder was found to affect neither Jc nor Bc2. For the tapes with the highest Jc values, very high exponential n factors were measured: n = 148, 89 and 17 at 3.5, 5 and 10T, respectively and measurements of critical current versus applied strain have been performed. The mechanism leading to high transport critical current densities of filamentary Fe/MgB2 tapes based on MgB2 particles is discussed.Comment: Presented at ICMC 2003, 25-28 May 200

Proven intra and interobserver reliability in the echographic assessments of body fat changes related to HIV associated Adipose Redistribution Syndrome (HARS)

OBJECTIVE: To prove intra- and inter-observer's reliability of ultrasound (US) in the assessment of lipoatrophic findings related to the HIV associated Adipose Redistribution Syndrome (HARS). PATIENTS AND METHODS: In two separated sessions, 2 consecutive measurements of subcutaneous fat thickness (SFT) were performed by each observer at the deepest point of Bichat pad, the dorsal face of arm and the mid thigh for the assessment of facial, brachial and crural lipoatrophy, respectively. We enrolled 20 HIV patients, rotating an experienced and untrained sonologist. The assessments were performed avoiding any stand off pads in the skin and excluding artefacts due to the too abundant quantity of gel to obtaining, with minimal transducer pressure, the best resolution of the reference points. RESULTS: Means of facial, brachial and crural SFT showed no significant differences between the workers. Coefficients of variability (SD/mean x100) were similar for facial (ranges: 4.7-5.2% vs 4.9-5.6%, respectively), brachial (ranges: 5.8-8.4% vs 9.7-11.2%) and crural SFTs (ranges: 5.9-6% vs 6.2-8.7%). There was greater consistency in the measurements performed by the experienced vs the untrained worker. Inter-observer agreement, assessed through kappa statistic (k) analysis, confirmed increased measurement's agreement in the facial (k ranged from 0.40 to 0.60), brachial (k: 0.23-0.63) and crural SFT assessments (k: 0.58-0.70) from the 1(st) to 2(nd) session. CONCLUSIONS: US shows low intra observer variability and good inter observer reliability in the assessment of body fat changes related to the HARS. The different degree of consistency by the workers and the improvement of interobserver agreement, suggest to stating a well defined period of training to obtain better US reliabilit

Efficacy and Safety of Rilpivirine-Based Antiretroviral Therapy in Treatment-Naïve and Treatment-Experienced HIV-1-Positive Patients: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

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Outcome of Darunavir–Cobicistat-Based Regimens in HIV-Infected People Who Have Experienced Virological Failure

Francesca Alberton,1 Laura Galli,2 Riccardo Lolatto,2 Caterina Candela,1 Nicola Gianotti,2 Matteo Chiurlo,2 Martina Ranzenigo,2 Martina Strano,2 Alessia Uglietti,3 Antonella Castagna1,2 1Infectious Diseases Unit, Vita Salute San Raffaele University, Milan, Italy; 2Infectious Diseases Unit, San Raffaele Scientific Institute, Milan, Italy; 3Medical Affairs Department, Infectious Diseases and Vaccines & Rare Diseases, Johnson&Johnson, Milan, ItalyCorrespondence: Alessia Uglietti, Medical Affairs Department, Infectious Disease and Vaccines & Rare Diseases, Johnson&Johnson, viale Fulvio Testi 280/6, Milan, 20126, Italy, Tel +39-344 2665502, Email [email protected]: To evaluate the virological outcome of darunavir–cobicistat (DRVc)‐based regimens in adults living with HIV who had experienced virological failure (VF) on any previous drug combination.Methods: This was a retrospective cohort study (CSLHIV Cohort) of adults living with HIV who started a DRVc‐based regimen with HIV‐RNA > 50 copies/mL after VF on any previous drug combination. Data on demographics, antiretroviral treatment since HIV diagnosis, and immunological and metabolic parameters from baseline (start of DRVc) to 48 weeks were analyzed in order to assess the cumulative proportion of those who achieved virological success (VS), defined as at least one instance of HIV‐RNA < 50 copies/mL within 12 months from baseline. Follow-up lasted from the start of the DRVc-based regimen (baseline) to the first instance of HIV-RNA < 50 copies/mL, last available visit, or loss to follow‐up or death, whichever occurred first. Univariate and multivariate Cox proportional-hazard regression models were used to identify baseline factors associated with VS.Results: A total of 176 individuals were included, and 120 (68.2%) achieved < 50 HIV‐RNA copies/mL within 12 months since baseline. On multivariate analysis, baseline HDL cholesterol was independently associated with the occurrence of VS (adjusted HR 1.021, 95% CI 1.004– 1.038; p=0.014). Among the 120 subjects with VS, 27 (22.5%) had had VF during a median follow-up of 20.8 months since the first undetectable HIV-RNA. Resistance testing after VF was available in two cases, which harboured the HIV variant–bearing protease inhibitor–resistance mutations D30N, I50V, and N88D. During a median follow-up of 38.4 months, 65 of 176 (36.9%) individuals discontinued DRVc for any reason (37 of 120, 30.8%) and achieved VS vs. 28 of 56 (50%) without VS (p=0.019). Time to discontinuation was longer in people with VS (41.5 vs. 23.0 months, p=0.0007). No statistically significant changes were observed in immunological or lipid profiles during follow-up.Conclusion: Most individuals in this study achieved VS within 12 months from the beginning of a DRVc-based regimen; therefore, this treatment represent a viable option for people who have experienced VF on other regimens.Keywords: HIV infection, antiretroviral therapy, ART, darunavir–cobicistat, DRVc, virological failure, V

TCV divertor upgrade for alternative magnetic configurations

The Swiss Plasma Center (SPC) is planning a divertor upgrade for the TCV tokamak. The upgrade aims at extending the research of conventional and alternative divertor configurations to operational scenarios and divertor regimes of greater relevance for a fusion reactor. The main elements of the upgrade are the installation of an in-vessel structure to form a divertor chamber of variable closure and enhanced diagnostic capabilities, an increase of the pumping capability of the divertor chamber and the addition of new divertor poloidal field coils. The project follows a staged approach and is carried out in parallel with an upgrade of the TCV heating system. First calculations using the EMC3-Eirene code indicate that realistic baffles together with the planned heating upgrade will allow for a significantly higher compression of neutral particles in the divertor, which is a prerequisite to test the power dissipation potential of various divertor configurations

The DEMO magnet system – Status and future challenges

We present the pre-concept design of the European DEMO Magnet System, which has successfully passed the DEMO plant-level gate review in 2020. The main design input parameters originate from the so-called DEMO 2018 baseline, which was produced using the PROCESS systems code. It defines a major and minor radius of 9.1 m and 2.9 m, respectively, an on-axis magnetic field of 5.3 T resulting in a peak field on the toroidal field (TF) conductor of 12.0 T. Four variants, all based on low-temperature superconductors (LTS), have been designed for the 16 TF coils. Two of these concepts were selected to be further pursued during the Concept Design Phase (CDP): the first having many similarities to the ITER TF coil concept and the second being the most innovative one, based on react-and-wind (RW) Nb3Sn technology and winding the coils in layers. Two variants for the five Central Solenoid (CS) modules have been investigated: an LTS-only concept resembling to the ITER CS and a hybrid configuration, in which the innermost layers are made of high-temperature superconductors (HTS), which allows either to increase the magnetic flux or to reduce the outer radius of the CS coil. Issues related to fatigue lifetime which emerged in mechanical analyses will be addressed further in the CDP. Both variants proposed for the six poloidal field coils present a lower level of risk for future development. All magnet and conductor design studies included thermal-hydraulic and mechanical analyses, and were accompanied by experimental tests on both LTS and HTS prototype samples (i.e. DC and AC measurements, stability tests, quench evolution etc.). In addition, magnet structures and auxiliary systems, e.g. cryogenics and feeders, were designed at pre-concept level. Important lessons learnt during this first phase of the project were fed into the planning of the CDP. Key aspects to be addressed concern the demonstration and validation of critical technologies (e.g. industrial manufacturing of RW Nb3Sn and HTS long conductors, insulation of penetrations and joints), as well as the detailed design of the overall Magnet System and mechanical structures

Aerosols in the Pre-industrial Atmosphere

Purpose of Review: We assess the current understanding of the state and behaviour of aerosols under pre-industrial conditions and the importance for climate. Recent Findings: Studies show that the magnitude of anthropogenic aerosol radiative forcing over the industrial period calculated by climate models is strongly affected by the abundance and properties of aerosols in the pre-industrial atmosphere. The low concentration of aerosol particles under relatively pristine conditions means that global mean cloud albedo may have been twice as sensitive to changes in natural aerosol emissions under pre-industrial conditions compared to present-day conditions. Consequently, the discovery of new aerosol formation processes and revisions to aerosol emissions have large effects on simulated historical aerosol radiative forcing. Summary: We review what is known about the microphysical, chemical, and radiative properties of aerosols in the pre-industrial atmosphere and the processes that control them. Aerosol properties were controlled by a combination of natural emissions, modification of the natural emissions by human activities such as land-use change, and anthropogenic emissions from biofuel combustion and early industrial processes. Although aerosol concentrations were lower in the pre-industrial atmosphere than today, model simulations show that relatively high aerosol concentrations could have been maintained over continental regions due to biogenically controlled new particle formation and wildfires. Despite the importance of pre-industrial aerosols for historical climate change, the relevant processes and emissions are given relatively little consideration in climate models, and there have been very few attempts to evaluate them. Consequently, we have very low confidence in the ability of models to simulate the aerosol conditions that form the baseline for historical climate simulations. Nevertheless, it is clear that the 1850s should be regarded as an early industrial reference period, and the aerosol forcing calculated from this period is smaller than the forcing since 1750. Improvements in historical reconstructions of natural and early anthropogenic emissions, exploitation of new Earth system models, and a deeper understanding and evaluation of the controlling processes are key aspects to reducing uncertainties in future