Superfluid high REynolds von Kármán experiment.

The Superfluid High REynolds von Kármán experiment facility exploits the capacities of a high cooling power refrigerator (400 W at 1.8 K) for a large dimension von Kármán flow (inner diameter 0.78 m), which can work with gaseous or subcooled liquid (He-I or He-II) from room temperature down to 1.6 K. The flow is produced between two counter-rotating or co-rotating disks. The large size of the experiment allows exploration of ultra high Reynolds numbers based on Taylor microscale and rms velocity [S. B. Pope, Turbulent Flows (Cambridge University Press, 2000)] (Rλ > 10000) or resolution of the dissipative scale for lower Re. This article presents the design and first performance of this apparatus. Measurements carried out in the first runs of the facility address the global flow behavior: calorimetric measurement of the dissipation, torque and velocity measurements on the two turbines. Moreover first local measurements (micro-Pitot, hot wire,…) have been installed and are presented.

Laminar and intermittent flow in a tilted heat pipe.

Heat transfer measurements performed by Riedinger et al. (Phys. Fluids, 25, 015117 (2013)) showed that in an inclined channel, heated from below and cooled from above with adiabatic walls, the flow is laminar or intermittent (local bursts can occur in the laminar flow) when the inclination angle is sufficiently high and the applied power sufficiently low. In this case, gravity plays a crucial role in the characteristics of the flow. In this paper, we present velocity measurements, and their derived tensors, obtained with Particle Image Velocimetry inside the channel. We, also, propose a model derived from a jet interpretation of the flow. Comparison between experiment and model shows a fair agreement.

Cantilever anemometer based on a superconducting micro-resonator: application to superfluid turbulence.

We present a new type of cryogenic local velocity probe that operates in liquid helium (1 K < T < 4.2 K) and achieves a spatial resolution of ≈ 0.1 mm. The operating principle is based on the deflection of a micro-machined silicon cantilever which reflects the local fluid velocity. Deflection is probed using a superconducting niobium micro-resonator sputtered on the sensor and used as a strain gauge. We present the working principle and the design of the probe, as well as calibration measurements and velocity spectra obtained in a turbulent helium flow above and below the superfluid transition.

[Allergic drug reactions in children]. / Reacciones alérgicas a medicamentos en niños.

We present a retrospective study of allergic drug reactions seen in our pediatric allergy consulting room during the last 6 years. During this time, 840 patients were examined for suspected adverse drug reactions. Drug allergy was confirmed in 72 cases (8.5%). Of these cases, 29 (40.2%) were considered to be IgE mediated, or immediate hypersensitivity reactions. We have not found significant differences with regards to age, sex, atopic family history or atopia between patients with IgE mediated reactions compared to patients with allergic drug reactions of different mechanisms or to patients without drug allergies. Sulfonamides, streptomycin, beta-lactam and analgesics were the drugs most frequently involved in immediate type reactions. Among non-immediate reactions, fixed eruption by sulfonamides and contact dermatitis due to Mercurochrome were the most frequent.