Non-uniform carrier density in Cd3_3As2_2 evidenced by optical spectroscopy

We report the detailed optical properties of Cd$_3$As$_2$ crystals in a wide parameter space: temperature, magnetic field, carrier concentration and crystal orientation. We investigate high-quality crystals synthesized by three different techniques. In all the studied samples, independently of how they were prepared and how they were treated before the optical experiments, our data indicate conspicuous fluctuations in the carrier density (up to 30%). These charge puddles have a characteristic scale of 100 $\mu$m, they become more pronounced at low temperatures, and possibly, they become enhanced by the presence of crystal twinning. The Drude response is characterized by very small scattering rates ($\sim 1$ meV) for as-grown samples. Mechanical treatment, such as cutting or polishing, influences the optical properties of single crystals, by increasing the Drude scattering rate and also modifying the high frequency optical response. Magneto-reflectivity and Kerr rotation are consistent with electron-like charge carriers and a spatially non-uniform carrier density.Comment: Accepted in Physical Review

Continuous infusion of recombinant factor VIII formulated with sucrose in surgery : non-interventional, observational study in patients with severe haemophilia A

In haemophilia A, continuous infusion (CI) of FVIII perioperatively provides a more constant FVIII level than conventional bolus injections, avoiding low trough levels that could increase bleeding risk. Due to the low number of surgical cases in clinical trials, especially in haemophilia, more information on the clinical practice of CI from observational studies is helpful. We aimed to evaluate the effectiveness and safety of CI with recombinant factor VIII formulated with sucrose (rFVIII-FS) in a typical surgery practice setting. This was a non-interventional study in 12 centres. Patients with severe haemophilia A who received rFVIII-FS by CI during and after surgery were included in this study if they had more than 150 exposure days (EDs) to any FVIII product and had no history of inhibitors before CI. Patients were observed during the entire course of CI, with monitoring up to 3 months thereafter. Twenty-five patients with 28 surgeries were included in the analysis. Median age was 51.7 (range 10-75). Most (75%; 21/25) patients underwent orthopaedic surgeries. The median dose of rFVIII-FS consumed during CI was 376 IU kg(-1) (range 157.9-3605.6 IU kg(-1)) with a greater median dose for orthopaedic surgeries (424.0 IU kg(-1)) compared to non-orthopaedic surgeries (278.5 IU kg(-1)). 95% of all FVIII measurements (214/224) were on target. Efficacy and tolerability were rated as good/excellent in 89.3% (25/28) of surgeries. No inhibitors were observed during or after surgery. This study demonstrates the effectiveness of CI with rFVIII-FS during surgery in patients with severe haemophilia A in a clinical practice setting

Letter of Intent for a Demonstration Experiment in Proton-Driven Plasma Wakefield Acceleration

We propose an experiment on proton-driven plasma wakefield acceleration (PDPWA) which could lead to a future TeV-scale e+- collider of much reduced length compared to conventional designs. Proton bunches are ideal drivers for high energy lepton accelerators, with the potential of reducing drastically the number of required driver stages. By using a plasma to modulate a long proton bunch, a strong plasma wave can be generated by a series of ‘micro-bunches’, so that an experimental program can start today with the existing proton beams. In this letter of intent, we propose a demonstration experiment using the existing CERN SPS beam. This project would be the first beam-driven wakefield acceleration experiment in Europe, and the first proton-driven plasma-wakefield acceleration experiment worldwide. We have set as an initial goal the demonstration of 1 GeV energy gain for electrons in 10 m of plasma. A proposal for reaching 100 GeV within 100 m of plasma will be developed using results from the initial round of experimentation. It is envisaged that the proposed experimental setup can be extended in the future to perform additional advanced accelerator research at CERN. The proposed location of the experiment in TT4/TT5 is compatible with such future usages. The proto-collaboration is already significant in size, and includes expertise from previous PWA experiments

Permeability of rock discontinuities and faults in the Triassic Sherwood Sandstone Group (UK): insights for management of fluvio-aeolian aquifers worldwide

Fluvio-aeolian sedimentary successions host groundwater aquifers at shallow depths (<~0.15 km), which overlie geothermal and shale-gas reservoirs, and nuclear waste repositories at intermediate depths (~0.15–2.0 km). Additionally, such deposits represent petroleum reservoirs at greater depths (~2.0–4.0 km). The need to improve conceptual understanding of the hydraulic behaviour of fluvial-aeolian sandstone successions over a large depth interval (~0–4 km) is important for socio-economic reasons. Thus, the hydraulic properties of the Triassic Sherwood Sandstone aquifer in the UK have been reviewed and compared to similar fluvio-aeolian successions. The ratio between well-scale and core-plug-scale permeability (Kwell-test/Kcore-plug) acts as a proxy for the relative importance of fracture versus intergranular flow. This ratio (which typically varies from ~2 to 100) indicates significant contribution of fractures to flow at relatively shallow depths (<~0.15 km). Here, permeability development is controlled by dissolution of calcite-dolomite in correspondence of fractures. The observed ratio (Kwell-test/Kcore-plug) decreases with depth, approaching unity, indicating that intergranular flow dominates at ~1 km depth. At depths ≥ ~1 km, dissolution of carbonate cement by rock alteration due to groundwater flow is absent and fractures are closed. Aeolian and fluvial deposits behave differently in proximity to normal faults in the Sherwood Sandstone aquifer. Deformation bands in aeolian dune deposits strongly compartmentalize this aquifer. The hydro-structural properties of fluvio-aeolian deposits are also controlled by mineralogy in fault zones. A relative abundance of quartz vs. feldspar and clays in aeolian sandstones favours development of low-permeability deformation bands