Structure and nanostructure in ionic liquids.

This review gives a survey on the latest most representative developments and progress concerning ionic liquids, from their fundamental properties to their applications in catalytic processes. It also highlights their emerging use for biomass treatment and transformation.

Ionic liquids and catalysis: Recent progress from knowledge to applications

Preface 1.General Considerations 2.Basic Processes in Atomization 3.Drop Size Distributions of Sprays 4.Atomizers 5.Flow in Atomizers 6.Atomizer Performance 7.External Spray Charcteristics 8.Drop Evaporation 9.Drop Sizing Methods Index

Atomization and Sprays

The first part of this two-part review focused on the fundamental and diagnostics aspects of laser-induced plasmas, only touching briefly upon concepts such as sensitivity and detection limits and largely omitting any discussion of the vast panorama of the practical applications of the technique. Clearly a true LIBS community has emerged, which promises to quicken the pace of LIBS developments, applications, and implementations. With this second part, a more applied flavor is taken, and its intended goal is summarizing the current state-of-the-art of analytical LIBS, providing a contemporary snapshot of LIBS applications, and highlighting new directions in laser-induced breakdown spectroscopy, such as novel approaches, instrumental developments, and advanced use of chemometric tools. More specifically, we discuss instrumental and analytical approaches (e.g., double- and multi-pulse LIBS to improve the sensitivity), calibration-free approaches, hyphenated approaches in which techniques such as Raman and fluorescence are coupled with LIBS to increase sensitivity and information power, resonantly enhanced LIBS approaches, signal processing and optimization (e.g., signal-to-noise analysis), and finally applications. An attempt is made to provide an updated view of the role played by LIBS in the various fields, with emphasis on applications considered to be unique. We finally try to assess where LIBS is going as an analytical field, where in our opinion it should go, and what should still be done for consolidating the technique as a mature method of chemical analysis.

https://journals.sagepub.com/doi/pdf/10.1366/11-06574

Laser-induced breakdown spectroscopy (LIBS), part II: review of instrumental and methodological approaches to material analysis and applications to different fields.

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.

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Ionic Liquids at Electrified Interfaces

Characterization of Internal flow and Spray of Multihole DI Gasoline Spray using X-ray Imaging and CFD

A main topic for the further development of direct injection diesel engines is the optimization of mixture formation, as all subsequent processes like ignition, combustion, and pollutant formation are mainly influenced by the local air/fuel ratio inside the cylinder. Especially for passenger-car engines, the interaction between spray and combustion chamber walls is an important issue for mixture formation. Therefore, this interaction was the subject of the investigations described. The investigations were carried out in a heatable high-pressure high-temperature chamber under typical diesel engine conditions of 450°C temperature and 50 bar pres'sure. A passenger-car common rail system was used as injection system which could be equipped with two different six-hole nozzles, both with common rail specific seat geometry, mini sac hole geometry, and double needle guide. In order to allow a detailed evaluation of the quality of mixture formation, a measurement technique based on spontaneous Raman scattering was applied, enabling quatitative measurements of the local air/fuel ratio along a line of a few milimeters. The careful adaptation of the optical setup made it possible to separate the weak Raman signals from background contributions, and this allowed a distinct determination of air and fuel density in the vapor phase. The measurements were carried out at a distance of 2 mm from the wall, directly above the impact location of the spray jet, as well as inside the wall jet region. The results obtained indicate the improvement of the mixture formation inside the wall jet as-consequence of the increased air entrainment. Additionally, for the investigation of the temporal development of mixture formation, the influences of injection pressure, nozzle orifice geometry, and wall surface temperature on mixture formation have been studied.

Spray/wall interaction influences on the diesel engine mixture formation process investigated by spontaneous Raman scattering

Mass transfer has been investigated quantitatively in the compressible ternary multi-phase system composed of the oil component ethyl acetate, water and carbon dioxide at the elevated pressure of 8.5 MPa and at temperatures of 298 K and 310.5 K. The multi-phase system has been generated inside a micro capillary. Each of the involved mass transfer paths could be quantified though taking place simultaneously between the three phases: oil, water and CO2. The quantification is based experimentally on the application of an optical long distance microscopy technique which provides information about the CO2 volume shrinkage and the refractive index of the oil phase. Both parameters allowed the solution of the mass transfer model which considers the mutual interaction of the involved transfer paths.

Microfluidic investigation into mass transfer in compressible multi-phase systems composed of oil, water and carbon dioxide at elevated pressure

Quantification of the mass transport in a two phase binary system at elevated pressures applying Raman spectroscopy: Pendant liquid solvent drop in a supercritical carbon dioxide environment

The combustion process inside a direct injection spark ignition engine with charge stratification is a very complex process with a large number of variables existing for the definition of t...

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Alfred Leipertz

Papers

Characterization of Internal flow and Spray of Multihole DI Gasoline Spray using X-ray Imaging and CFD

Spray/wall interaction influences on the diesel engine mixture formation process investigated by spontaneous Raman scattering

Microfluidic investigation into mass transfer in compressible multi-phase systems composed of oil, water and carbon dioxide at elevated pressure

Quantification of the mass transport in a two phase binary system at elevated pressures applying Raman spectroscopy: Pendant liquid solvent drop in a supercritical carbon dioxide environment

Study of the mixture formation processes inside a modern direct-injection gasoline engine: