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.

/pdf/ionic-liquids-at-electrified-interfaces-4n93eaytys.pdf

Ionic Liquids at Electrified Interfaces

Abstract Die Charakterisierung gasgetragener Nanoteilchen ist für eine Vielzahl industrieller und natürlicher Prozesse von entscheidender Bedeutung. Insbesondere die Überwachung von in Verbrennungssystemen erzeugten Rußteilchen und die für die Nanoteilchentechnologie notwendige Produktcharakterisierung und Prozesssteuerung benötigen in zunehmendem Maße geeignete Analysenmesstechniken, die schnelle, empfindliche und zuverlässige Aussagen über eine Vielzahl von Messgrößen zulässt. Mit der laserinduzierten Glühtechnik (laser-induced incandescence, LII) steht ein nicht-invasives laseroptisches Online-Verfahren zur Verfügung, das neben einer hochempfindlichen Konzentrationsbestimmung auch dazu in der Lage ist, die spezifische Oberfläche bzw. die Primärteilchengröße der Partikel zu bestimmen.

Laseroptische Charakterisierung von gasgetragenen Nanoteilchen mit der zeitaufgelösten laserinduzierten Glühtechnik (TIRE-LII) (Laser-Optical Characterization of Air-Borne Nanoparticles by Time-Resolved Laser-Induced Incandescence (TIRE-LII))

Coherent anti-Stokes Raman scattering technique combined with a single pulsed Nd3+:YAG laser is proposed and demonstrated for simultaneous measurement of CO 2 and CH 4 . The technique can be used in combustion measurement consisting of gas mixture.

Simultaneous measurement of multiple gas species using a Nd 3+ :YAG laser combined with Raman scattering

Dual-pump vibrational and dual-broadband rotational coherent anti-Stokes Raman scattering is applied to a porous burner with limited optical access. Temperature and species concentration were determined inside the burner ceramic.

Application of a Dual-Pump Vibrational and Pure Rotational CARS System for Temperature and Multi-Species Measurements inside a Porous Burner

We present polarization-resolved shifted excitation Raman difference spectroscopy (pol-SERDS) and its application to monitor a bioreactor in which the microalga Porphyridium purpureum produces antiviral exopolysaccharides and pigments.

Raman difference spectroscopy approach for monitoring of a bioreactor

In order to improve air/fuel mixture, fulfilling the European Emission Standard and to reduce fuel consumption, injection and combustion systems have to be improved. The understanding of spray formation and evaporation has been the great challenge of last years in modern gasoline direct-injection (GDI) and Diesel engine as well as aerospace technology. For engine development, the most essential spray data are the cone angle, axial and radial penetration under various injection conditions. The purpose of this work is developing a semi-empiric spray model which is able to predict a single jet penetration of a plain orifice injector, typically from a Diesel or GDI atomizer by different temperatures and pressures based on dimensional analysis theorem. Equations were found to prognosticate the spray penetration and an exponent factor which is able to correct the evaporation effect. The results are satisfactory and the improvement of calculation is possible by adding phenomena such as drag force and air entrainment.

/pdf/semi-empirical-model-to-calculate-spray-length-considering-24tzq6w8v4.pdf

Alfred Leipertz

Papers

Laseroptische Charakterisierung von gasgetragenen Nanoteilchen mit der zeitaufgelösten laserinduzierten Glühtechnik (TIRE-LII) (Laser-Optical Characterization of Air-Borne Nanoparticles by Time-Resolved Laser-Induced Incandescence (TIRE-LII))

Simultaneous measurement of multiple gas species using a Nd 3+ :YAG laser combined with Raman scattering

Application of a Dual-Pump Vibrational and Pure Rotational CARS System for Temperature and Multi-Species Measurements inside a Porous Burner

Raman difference spectroscopy approach for monitoring of a bioreactor

Semi-Empirical Model to Calculate Spray Length Considering Evaporation Effect