No abstract

To measure the bulk flow of liquid foam, we introduce an X-ray radiographic technique utilizing purposely shaped 3D-printed steel tracers.

in the range of 200-4000 mAh g À1 , and their highly negative redox potential below À2.5 V versus standard hydrogen electrode (SHE) can lead to a high cell operating voltage. These characteristics can enable high specific energies, which are generally given in the unit Wh kg À1 for expressing the energy-storage performance per mass of active materials or the system's total mass. However, the development of rechargeable batteries with alkali and alkaline earth metals has been extremely challenging due to the formation of dendrites, causing safety, stability, and efficiency issues. [1,4,5] As a solution to dendrite formation, solid-state electrolytes can be used as an alternative to conventional electrolytes dissolved in aqueous or organic solvents. However, according to recent studies, [5][6][7][8] dendrites can still penetrate the solid-state electrolytes, and the solid-solid interface of such energy-storage systems may cause other issues such as limited electrochemical stability window and physical contact loss between the electrolyte and the metal.Another effective approach for handling the dendrite formation is to employ liquid metal anodes. [9][10][11][12][13][14] At temperatures above 25 °C, the redox reactions of alkali and alkaline earth metals can be utilized in a molten state either in its pure metal form [13,15] or

The liquid fraction of foam is an important quantity in engineering process control and essential to interpret foam rheology. Established measurement tools for the liquid fraction of foam, such as optical measurement or radiography techniques as well as weighing the foam, are mostly laboratory-based, whereas conductivity-based measurements are limited to the global measurement without detailed spatial information of liquid fraction. In this work, which combines both types of measurement techniques, the conductivity-based wire-mesh sensor is compared with neutron radiography. We found a linear dependency between the liquid fraction of the foam and the wire-mesh readings with a statistical deviation less than 15%. However, the wire-mesh sensor systematically overestimates the liquid fraction, which we attribute to liquid bridge formation between the wires.

The movement of hydrophobic particles in a rising froth column is investigated. Gadolinium particles are hydrophobized and floated by means of small air bubbles. The generated froth is investigated by neutron imaging. Particles are identified by correlating the resulting radiographs with an artificial template of a typical particle and subsequent scanning for local maxima. The movement of the particles in the froth was analyzed for different froth stabilities, which resulted from various concentrations of the frother sodium oleate. Decreasing froth stability leads to lower superficial vertical particle velocity and to higher horizontal diffusion of particles due to bubble rupture.