Analysis of a two-crystal delay line for femtosecond pulses of the X-ray free electron laser

Using the methods of statistical optics the formation of delayed X-ray pulses in the diffraction reflection of an incident pulse with an arbitrary degree of temporal coherence from a system of parallel crystals with different lattice periods is considered. The results are of interest for constructing delay lines in experiments with a time resolution of the pump-and-probe type and realizing of the self-seeding mode to increase the degree of temporal coherence of the X-ray free-electron laser radiation. A rigorous theory of dynamic diffraction in Bragg geometry is applied to the diffraction reflection of short X-ray pulses from a system of two parallel crystals with arbitrary thicknesses, and also, for a system of two pairs of parallel crystals. The dependence of the delay time and the intensity of the delayed pulses on the thickness of the crystals and the distances between them are analyzed. Since the pulses from the X-ray free electron laser have high spatial coherence, i. e. a small angular divergence, but very poor temporal coherence, special attention is paid to the effect of the degree of temporal coherence on the width of the energyspectrum of the incident pulses and on the influence of this width on the intensity of the delayed pulse

Effect of the Topology on Wetting and Drying of Hydrophobic Porous Materials

Establishing molecular mechanisms of wetting and drying of hydrophobic porous materials is a general problem for science and technology within the subcategories of the theory of liquids, chromatography, nanofluidics, energy storage, recuperation, and dissipation. In this article, we demonstrate a new way to tackle this problem by exploring the effect of the topology of pure silica nanoparticles, nanotubes, and zeolites. Using molecular dynamics simulations, we show how secondary porosity promotes the intrusion of water into micropores and affects the hydrophobicity of materials. It is demonstrated herein that for nano-objects, the hydrophobicity can be controlled by changing the ratio of open to closed nanometer-sized lateral pores. This effect can be exploited to produce new materials for practical applications when the hydrophobicity needs to be regulated without significantly changing the chemistry or structure of the materials. Based on these simulations and theoretical considerations, for pure silica zeolites, we examined and then classified the experimental database of intrusion pressures, thus leading to the prediction of any zeolite’s intrusion pressure. We show a correlation between the intrusion pressure and the ratio of the accessible pore surface area to total pore volume. The correlation is valid for some zeolites and mesoporous materials. It can facilitate choosing prospective candidates for further investigation and possible exploitation, especially for energy storage, recuperation, and dissipation

Development of a Wireless Pressure Transmitter with Diagnostics

The Industrial Internet of Things (IIoT) and Industry 4.0 require new intelligent sensor designs with enhanced functionality, including local diagnostics. In previous work, we have experimentally investigated an important fault mode of a commercial pressure sensor, working in partnership with the sensor manufacturer who has provided modified sensors with calibrated levels of the fault condition. We have further developed simple signal processing techniques to detect the fault condition, based on a low cost noise analysis. In the current paper, we describe the development of a prototype wireless pressure transmitter. This transmitter monitors the analogue output of the pressure sensor, and applies the diagnostic procedures in real time. The resulting pressure measurement in engineering units, together with diagnostic information, are both communicated wirelessly to a receiving system

Subnanometer Topological Tuning of the Liquid Intrusion/Extrusion Characteristics of Hydrophobic Micropores

Intrusion (wetting)/extrusion (drying) of liquids in/from lyophobic nanoporous systems is key in many fields, including chromatography, nanofluidics, biology, and energy materials. Here we demonstrate that secondary topological features decorating main channels of porous systems dramatically affect the intrusion/extrusion cycle. These secondary features, allowing an unexpected bridging with liquid in the surrounding domains, stabilize the water stream intruding a micropore. This reduces the intrusion/extrusion barrier and the corresponding pressures without altering other properties of the system. Tuning the intrusion/extrusion pressures via subnanometric topological features represents a yet unexplored strategy for designing hydrophobic micropores. Though energy is not the only field of application, here we show that the proposed tuning approach may bring 20–75 MPa of intrusion/extrusion pressure increase, expanding the applicability of hydrophobic microporous materials