Investigation into the cause of spontaneous emulsification of a free steel droplet : validation of the chemical exchange pathway

Small Fe-based droplets have been heated to a molten phase suspended within a slag medium to replicate a partial environment within the basic oxygen furnace (BOF). The confocal scanning laser microscope (CSLM) has been used as a heating platform to interrogate the effect of impurities and their transfer across the metal/slag interface, on the emulsification of the droplet into the slag medium. The samples were then examined through X-ray computer tomography (XCT) giving the mapping of emulsion dispersion in 3D space, calculating the changing of interfacial area between the two materials, and changes of material volume due to material transfer between metal and slag. Null experiments to rule out thermal gradients being the cause of emulsification have been conducted as well as replication of the previously reported study by Assis et al.[1] which has given insights into the mechanism of emulsification. Finally chemical analysis was conducted to discover the transfer of oxygen to be the cause of emulsification, leading to a new study of a system with undergoing oxygen equilibration

Ionic liquids at electrified interfaces

Until recently, “room-temperature” (<100–150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)–(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of “first-generation” room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the “later generation” RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in “cocktails” of one’s choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost “universal” solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) “sister-systems”.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules

ELECTRONIC CORRELATION AND THE M-NM TRANSITION IN FLUID ALKALIMETALS

Measurements of the magnetic susceptibility of cesium and rubidium are reported for both the expanded liquid and the dense vapour phase at saturation conditions. From the discussion of these results and the comparison with the electrical transport properties and structural investigations a suggestion is given for the type of M-NM transition in expanded fluid alkali metals. The corresponding change in the electronic structure is qualitatively described

Nanostructuring of Bi(0001) surfaces with the scanning tunneling microscope: Writing of periodic Bi structures by bias voltage pulsing

Turchanin A, Freyland W. Nanostructuring of Bi(0001) surfaces with the scanning tunneling microscope: Writing of periodic Bi structures by bias voltage pulsing. APPLIED PHYSICS LETTERS. 2005;87(17):173103.Employing the scanning-tunneling-microscope pulse technique with a tungsten tip, we studied the nanostructuring of Bi (0001) surfaces at room temperature. A controlled extraction of Bi and its reversible deposition is demonstrated by simply changing the pulse polarity. Periodic nanostructures of dots, holes, lines, and grooves were written in the point and line mode of the scanner which exhibit a relatively high stability over a period of up to 22 days. Our data indicate that during the nanostructuring a Bi nanobridge forms between tungsten tip and substrate on a time scale of similar to 100 mu s. (C) 2005 American Institute of Physics

Apparatus for neutron diffraction measurements on fluids up to 2 000 K and elevated pressures

The paper describes the principle set-up of a high temperature-high pressure apparatus for neutron diffraction on fluids. As an example the results of the static structure factor of expanded fluid rubidium up to 2 000 K near saturation conditions are briefly presented.Cette publication décrit le principe d'un appareillage pour l'étude de la diffraction des neutrons par des systèmes fluides, à hautes températures et hautes pressions. Comme exemple, les facteurs de structure du rubidium liquide à des températures allant jusqu'à 2 000 K et près de la saturation sont présentés