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

Plasmon transmissivity and reflectivity of narrow grooves in a silver film

Bouhelier A, Huser T, Freyland JM, Güntherodt HJ, Pohl DW. Plasmon transmissivity and reflectivity of narrow grooves in a silver film. Journal of Microscopy. 1999;194:571-573.Surface plasmon (SP) reflectivity and transmissivity of narrow grooves in silver films are studied. The SP source is the probe of a scanning near-field optical microscope. Locally detected leakage radiation from the SP provides detailed information on the paths of SP propagation, in particular the influence of perturbations, Global detection provides representative average data on the SP properties of a given metal film and its structures, A groove of 200 nm width, for instance, reflects/transmits about 15%/80% of 'blue-green' SP radiation at normal incidence

Resonant Raman scattering from phonons in GaAs/(GaAs)(m)(AlAs)(n) quantum wire structures

Raman spectroscopy has been used to measure phonons in GaAs v-groove quantum wire structures containing (001) and (111) GaAs/AlAs superlattice barrier regions. Resonance enhancement permits the identification of modes in different regions of the structure, and the measured phonon frequencies provide structural information which shows clear evidence of GaAs migration during growth from (001) surfaces into the grooves. Confined and interface phonons with large in-(111) plane wavevectors are observed. (C) 1996 American Institute of Physics