A New High-intensity, Low-momentum Muon Beam for the Generation of Low-energy Muons at PSI

At the Paul Scherrer Institute (PSI, Villigen, Switzerland) a new high-intensity muon beam line with momentum p < 40MeV/c is currently being commissioned. The beam line is especially designed to serve the needs of the low-energy, polarized positive muon source (LE-μ+) and LE-μ SR spectrometer at PSI. The beam line replaces the existing μ E4 muon decay channel. A large acceptance is accomplished by installing two solenoidal magnetic lenses close to the muon production target E that is hit by the 590-MeV PSI proton beam. The muons are then transported by standard large aperture quadrupoles and bending magnets to the experiment. Several slit systems and an electrostatic separator allow the control of beam shape, momentum spread, and to reduce the background due to beam positrons or electrons. Particle intensities of up to 3.5 × 108 μ+/s and 107 μ−/s are expected at 28MeV/c beam momentum and 1.8mA proton beam current. This will translate into a LE-μ+ rate of 7,000/s being available at the LE-μ SR spectrometer, thus achieving μ+ fluxes, that are comparable to standard μ SR facilitie

Towards a Greener and Scalable Synthesis of Na2_{2}Ti6_{6}O13_{13} Nanorods and Their Application as Anodes in Batteries for Grid-Level Energy Storage

Grid applications require high power density (for frequency regulation, load leveling, and renewable energy integration), achievable by combining multiple batteries in a system without strict high capacity requirements. For these applications however, safety, cost efficiency, and the lifespan of electrode materials are crucial. Titanates, safe and longevous anode materials providing much lower energy density than graphite, are excellent candidates for this application. The innovative molten salt synthesis approach proposed in this work provides exceptionally pure Na$_{2}$Ti$_{6}$O$_{13}$ nanorods generated at 900–1100 °C in a yield ≥80 wt%. It is fast, cost‐efficient, and suitable for industrial upscaling. Electrochemical tests reveal stable performance providing capacities of ≈100 mA h g$^{-1}$ (Li) and 40 mA h g$^{-1}$ (Na). Increasing the synthesis temperature to 1100 °C leads to a capacity decrease, most likely resulting from 1) the morphology/volume change with the synthesis temperature and 2) distortion of the Na$_{2}$Ti$_{6}$O$_{13}$ tunnel structure indicated by electron energy‐loss and Raman spectroscopy. The suitability of pristine Na$_{2}$Ti$_{6}$O$_{13}$ as the anode for grid‐level energy storage systems has been proven a priori, without any performance‐boosting treatment, indicating considerable application potential especially due to the high yield and low cost of the synthesis route

The clinical relevance of oliguria in the critically ill patient : Analysis of a large observational database

Funding Information: Marc Leone reports receiving consulting fees from Amomed and Aguettant; lecture fees from MSD, Pfizer, Octapharma, 3 M, Aspen, Orion; travel support from LFB; and grant support from PHRC IR and his institution. JLV is the Editor-in-Chief of Critical Care. The other authors declare that they have no relevant financial interests. Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Urine output is widely used as one of the criteria for the diagnosis and staging of acute renal failure, but few studies have specifically assessed the role of oliguria as a marker of acute renal failure or outcomes in general intensive care unit (ICU) patients. Using a large multinational database, we therefore evaluated the occurrence of oliguria (defined as a urine output 16 years) patients in the ICON audit who had a urine output measurement on the day of admission were included. To investigate the association between oliguria and mortality, we used a multilevel analysis. Results: Of the 8292 patients included, 2050 (24.7%) were oliguric during the first 24 h of admission. Patients with oliguria on admission who had at least one additional 24-h urine output recorded during their ICU stay (n = 1349) were divided into three groups: transient - oliguria resolved within 48 h after the admission day (n = 390 [28.9%]), prolonged - oliguria resolved > 48 h after the admission day (n = 141 [10.5%]), and permanent - oliguria persisting for the whole ICU stay or again present at the end of the ICU stay (n = 818 [60.6%]). ICU and hospital mortality rates were higher in patients with oliguria than in those without, except for patients with transient oliguria who had significantly lower mortality rates than non-oliguric patients. In multilevel analysis, the need for RRT was associated with a significantly higher risk of death (OR = 1.51 [95% CI 1.19-1.91], p = 0.001), but the presence of oliguria on admission was not (OR = 1.14 [95% CI 0.97-1.34], p = 0.103). Conclusions: Oliguria is common in ICU patients and may have a relatively benign nature if only transient. The duration of oliguria and need for RRT are associated with worse outcome.publishersversionPeer reviewe

Synthesis of 3D silicon with tailored nanostructure: Influence of morphology on the electrochemical properties

Within this work, monodisperse porous silicon nanospheres have been derived from monodisperse silica nanospheres via two different magnesiothermic reduction routes, namely (i) magnesiothermic reduction using a two-chamber set-up, and (ii) magnesiothermic reduction using NaCl as heat scavenger. Both methods allow a size- and shape-preserving preparation of mesoporous silicon. Crystalline silicon with a particle size of 56 nm and a specific surface area of 198 m2 g− 1 and amorphous silicon with a particle size of 35 nm and a specific surface area of 623 m2 g− 1 are synthesized using the two chamber and salt assisted routes, respectively. TEM micrographs confirm enhanced porous character of silicon from NaCl assisted route. An unstable electrochemical performance of the crystalline silicon is found, whereas the amorphous Si presents a stable electrochemical behavior

Design study of a large-gap superconducting spectrometer dipole

The conceptual design of the large gap spectrometer dipole for the LHCb experiment is presented here. The required acceptance implies a gap height of 3.6 m and a width of 4.3 m. Although the magnetic induction of the 1.92 m long magnet is only 1.1 T, it turns out that a superconducting (SC) coil is the most economic solution. The design considerations for the yoke and the SC-coil are explained, the parameters of the conductor, coil, cooling system are presented and the quench behavior estimated.

Novel 3D Si/C/SiOC nanocomposites: Toward electrochemically stable lithium storage in silicon

In this work, we present an easy and environmentally friendly approach to stabilize nanostructured, porous crystalline (Sitc) and amorphous (Sisa) silicon synthesized via magnesiothermic reduction. As matrix, fructose-derived carbon, polymer-derived SiOC ceramic or both, carbon and SiOC, are used. By means of X-ray diffraction and Raman spectroscopy it is found that the crystallinity of Sitc as well as the amorphous character of Sisa is preserved in the final composites. Embedding of crystalline silicon into carbon leads to high initial capacities of ~ 600–650 mAh·g− 1, but only the matrix consisting of carbon and SiOC results in a stable cycling behaviour over 50 cycles with a final capacity of 575 mAh·g− 1. All composites derived from amorphous Sisa show a stable cycling behaviour; the highest, stable capacity of ~ 500 mAh·g− 1 is observed when silicon is covered with carbon and SiOC

Design study of a large-gap superconducting spectrometer dipole

The conceptual design of the large gap Spectrometer Dipole for the LHC-b experiment is presented here. The required acceptance implies a gap height of 3.6 m and a width of 4.3 m. Although the magnetic induction of the 1.92 m long magnet is only 1.1 T, it turns out that a superconducting (SC) coil is the most economic solution. The design considerations for the yoke and the SC-coil are explained, the parameters of the conductor, coil, cooling system are presented and the quench behavior is estimated

Influence of external compressive stress on the ionic conductivity of melt-quenched lithium silicate (15Li2O-85SiO2) glass

This paper reports measurements of the electrical resistances of bulk and milled amorphous lithium silicate (15Li2O-85SiO2) under uniaxial load at 200 °C. With imposed load up to 700 MPa, the resistance of the melt-quenched glass increases from 1.56 to 1.95 MΩ cm. This change is reversible, namely after releasing the load the initial electrical resistance is recovered. Milled and compacted glass consists of the bulk and particle contacts resistances. Both of them increase when the external compression up to 200 MPa. For the bulk element, when compression is released, the initial resistance is recovered, whereas the resistance changes within the particles contacts are irreversible

Observation of positronium annihilation in the 2S state: towards a new measurement of the 1S-2S transition frequency

We report the first observation of the annihilation of positronium from the 2S state. Positronium (Ps) is excited with a two-photon transition from the 1S to the 2S state where its lifetime is increased by a factor of eight compared to the ground state due to the decrease in the overlap of the positron electron wavefunction. The yield of delayed annihilation photons detected as a function of laser frequency is used as a new method of detecting laser-excited Ps in the 2S state. This can be considered the first step towards a new high precision measurement of the 1S-2S Ps line.Comment: 6 pages, 3 Figures, proceedings EXA 2014, accepted for publication in Hyperfine Interaction