Pulse-front tilt for short-wavelength lasing by means of traveling-wave plasma-excitation

Generation of coherent short-wavelength radiation across a plasma column is dramatically improved under traveling-wave excitation (TWE). The latter is optimized when its propagation is close to the speed of light, which implies small-angle target-irradiation. Yet, short-wavelength lasing needs large irradiation angles in order to increase the optical penetration of the pump into the plasma core. Pulse-front back-tilt is considered to overcome such trade-off. In fact, the TWE speed depends on the pulse-front slope (envelope of amplitude), whereas the optical penetration depth depends on the wave-front slope (envelope of phase). Pulse-front tilt by means of compressor misalignment was found effective only if coupled with a high-magnification front-end imaging/focusing component. It is concluded that speed matching should be accomplished with minimal compressor misalignment and maximal imaging magnification

Structural features of laser ablation particulate from Si target, as revealed by focused ion beam technology

Heterogeneity in laser-induced particle structures was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of individual particles micro-machined using focused ion beam (FIB). The primary particle size distribution spanned over three orders of magnitude, i.e., in the range 10nm-10μm with few larger secondary objects. The particulate larger than 0.5μm often resulted from particle-particle aggregation, mostly upon a spherical core, seldom in chain-like structures. The core of these fractal aggregates was found to be polycrystalline. The heterogeneity of the particles with respect to structure and chemistry is surely of importance for elemental analysis using laser ablation as sample introduction techniqu

Systematic Investigations of Plastic Vials Concerning Their Suitability for Ultratrace Anion Analysis in High-Purity Industrial Applications

Abstract.: Ultratrace anion analysis in high-purity industrial applications is done using commercially available plastic vials to store the eluted liquid samples. Plastic vials are manufactured with materials containing several additives. Such additives might potentially release anionic contaminants, thus degrading the blank quality and determination limits (DL). The durability and thermal stability of several materials was found to be a function of anionic species. Fluorinated materials showed the best results for the majority of anions with the exception of fluoride. For the selective analysis of fluoride, polypropylene was found to be the best vial material, together with glass. Cold water extraction showed better results compared to hot water extraction. Over a long observation period, hot water extraction did not at all improve the performance, indicating that this type of supposedly efficient cleaning of the plastic containers to render them less prone to contaminant release does not hold tru

The formation of boundary clinopyroxenes and associated glass veins in type B1 CAIs

We used focused ion beam thin section preparation and scanning transmission electron microscopy (FIB/STEM) to examine the interfacial region between spinel and host melilite for spinel grains in type B1 inclusions from the Allende and Leoville carbonaceous chondrites. Boundary clinopyroxenes decorating spinel surfaces have compositions similar to those of coarser clinopyroxenes from the same region of the inclusion, suggesting little movement after formation. Host melilite displays no anomalous compositions near the interface and late-stage minerals are not observed, suggesting that boundary pyroxenes did not form by crystallization of residual liquid. Allende spinels display either direct spinel-melilite contact or an intervening boundary clinopyroxene between the two phases. Spinel-melilite interfacial regions in a Leoville B1 are more complex, with boundary clinopyroxene, as observed in Allende, but also variable amounts of glass, secondary calcite, perovskite, and an Mg-, Al-, OH-rich and Ca-, Si-poor crystalline phase that may be a layered double hydrate. One possible scenario of formation for the glass veins is that open system alteration of melilite produced a porous, hydrated aggregate of Mg-carpholite or sudoite + aluminous diopside that was shock melted and quenched to a glass. The hydrated crystalline phase we observed may have been a shocked remnant of the precursor phase assemblage, but is more likely to have formed later by alteration of the glass. In the mantle, boundary clinopyroxenes may have been crystallized from Ti-rich liquids formed by the direct dissolution of perovskite and an associated Sc-Zr-rich phase or as a reaction product between dissolving perovskite and liquid. In the core, any perovskite and associated Ti-enriched liquids that may have originally been present disappeared before the growth of boundary clinopyroxene, and the observed boundary clinopyroxene may have nucleated and grown from the liquid, along with the larger core clinopyroxene

CHanalysis 2022 - Back to the Future of Analytical Excellence: Conference Report

ISSN:0009-429

Edificio Híbrido de Comercio, Centro Cultural y Vivienda Social en Barrios Altos, Lima

La presente tesis nos sumerge en las problemáticas que existen en el Centro Histórico de Lima y de las consecuencias que genera el comercio invasivo para los habitantes que residen en esos espacios, como lo vemos en el Mercado Central en Barrios Altos, quien es catalogada como la cuna del criollismo y que ahora está en el abandono por las autoridades, necesitándose proyectos de regeneración urbana para mejorar la ciudad y a su vez la calidad de vida de sus habitantes, que ya han empezado a dejar ésta hermosa ciudad por el descontrol e inseguridad que se ha venido creando ante la construcción exagerada de almacenes que no respetan los parámetros urbano

The openBIS Digital Platform for Instrumentation and Data Workflow in the Analytical Laboratory

The management of scientific data plays a key role in all research areas and has increased in importance. Providing researchers with customizable data management tools is crucial for effectively managing data according to the FAIR principles. These principles have been defined by Wilkinson et al. in 2016, which describe how scientific data should be managed.[1] To support the specific needs of researchers at Empa, openBIS[2] was chosen as a FAIR compliant data management platform. OpenBIS is an Electronic Laboratory Notebook (ELN) and Laboratory Information Management System (LIMS) developed at ETH. The commissioning of this platform for the case of an analytical chemistry lab presented multiple challenges. In this paper, solutions to adapt openBIS as a digital platform to integrate the laboratory data workflow in chemical analysis and for spectroscopy instruments are presented. Two laboratory projects as case studies are described, consisting of a data pipeline and a complex dashboard for data collection, visualization and interaction. These examples show a successful integration of the data management platform in accordance with the FAIR data guidelines along with maximizing efficiency for laboratory personnel