EvalHyd v0.1.2: a polyglot tool for the evaluation of deterministic and probabilistic streamflow predictions

The evaluation of streamflow predictions forms an essential part of most hydrological modelling studies published in the literature. The evaluation process typically involves the computation of some evaluation metrics, but it can also involve the preliminary processing of the predictions as well as the subsequent processing of the computed metrics. In order for published hydrological studies to be reproducible, these steps need to be carefully documented by the authors. The availability of a single tool performing all of these tasks would simplify not only the documentation by the authors but also the reproducibility by the readers. However, this requires such a tool to be polyglot (i.e. usable in a variety of programming languages) and openly accessible so that it can be used by everyone in the hydrological community. To this end, we developed a new tool named evalhyd that offers metrics and functionalities for the evaluation of deterministic and probabilistic streamflow predictions. It is open source, and it can be used in Python, in R, in C++, or as a command line tool. This article describes the tool and illustrates its functionalities using Global Flood Awareness System (GloFAS) reforecasts over France as an example data set.</p

E×B probe measurements in the plasma plume of a 100 W-class Hall thruster

International audienceThe ion far-field plume of the 100 W-class ISCT100-v2 Hall Thruster (HT) has been characterized by means of an E×B probe. The influence of operating parameters on both velocities and fraction of different ion species was investigated over a 40 • circular arc. E×B spectra were thus recorded for different background gas pressures, discharge voltages, angular positions and propellants (namely xenon and krytpon). The probe alignment is also discussed in this contribution, since measurements were recorded for the probe aligned with both the thruster centerline and the thruster mid-channel

Effects of the α-ε phase transition on wave propagation and spallation in laser shock-loaded iron

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Response of iron to two symmetric laser shocks

–Laser-driven shocks provide a means of studying the dynamic behaviour of solid materials at very high strain rates. Here, we investigate the effects of a new pulsed load, generated by the crossing of two symmetric laser shocks. Both surfaces of thin iron foils are irradiated simultaneously by two high-power laser beams, producing two compressive pulses of duration about 3 ns and amplitude about 10 to 60 GPa. When they cross each other in the central region of the sample, considerable increases of the pressure and the temperature are induced, leading to twin formation and phase transition. Then, the interactions of all the incident and reflected release waves which propagate inside the sample result in various types of spall damage, depending strongly on the sample thickness and on the shock pressure. All those effects have been observed in the recovered targets, and explained by a phenomenological analysis of wave propagation. The influences of various experimental parameters have been investigated. Finally, one-dimensional computations have been performed to test the ability of a simple constitutive model, including twin formation, phase transformation and spallation, to predict the observed results. A rough agreement between computations and experiments, better at lower shock pressure, bas been obtained

Laser shock techniques to investigate shock-induced phase transitions in quartz

The very short duration of laser shocks and their low-destructive character provide new means of studying the kinetics of phase transitions. Here, we investigate the phase transformation behavior of quartz under dynamic compression of short duration (nanosecond order) generated by various laser shock techniques. VISAR measurements have been performed to characterize the stress history induced in the targets. Recovered samples have been analyzed by micro-Raman spectroscopy. The influences of several experimental parameters (pulse duration, tensile and shear stresses...) have been investigated. The results, which differ notably from observations reported under quasi-static compression or longer pulsed loads (microsecond order), suggest a partial amorphization of the shocked samples, as well as the formation of a new structure that can be compared to known orthorhombic high pressure phases

Laser-driven shocks to study phase transformations in materials of geophysical interest

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