Meta-analysis of CO2 conversion, energy efficiency, and other performance data of plasma-catalysis reactors with the open access PIONEER database

This paper brings the comparison of performances of CO2 conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field, organised in an open access online database. This tool is open to all users to carry out their own analyses, but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made, and ultimately to improve the efficiency of CO2 conversion by plasma-catalysis. The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO2 conversion processes, be it methanation, dry reforming of methane, methanolisation, or others. As a result of this rapid increase, there is a need for a set of standard procedures to rigorously compare performances of different systems. However, this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures. Fortunately however, the accumulated data within the CO2 plasma-catalysis community has become large enough to warrant so-called “big data” studies more familiar in the fields of medicine and the social sciences. To enable comparisons between multiple data sets and make future research more effective, this work proposes the first database on CO2 conversion performances by plasma-catalysis open to the whole community. This database has been initiated in the framework of a H2020 European project and is called the “PIONEER DataBase”. The database gathers a large amount of CO2 conversion performance data such as conversion rate, energy efficiency, and selectivity for numerous plasma sources coupled with or without a catalyst. Each data set is associated with metadata describing the gas mixture, the plasma source, the nature of the catalyst, and the form of coupling with the plasma. Beyond the database itself, a data extraction tool with direct visualisation features or advanced filtering functionalities has been developed and is available online to the public. The simple and fast visualisation of the state of the art puts new results into context, identifies literal gaps in data, and consequently points towards promising research routes. More advanced data extraction illustrates the impact that the database can have in the understanding of plasma-catalyst coupling. Lessons learned from the review of a large amount of literature during the setup of the database lead to best practice advice to increase comparability between future CO2 plasma-catalytic studies. Finally, the community is strongly encouraged to contribute to the database not only to increase the visibility of their data but also the relevance of the comparisons allowed by this tool

PROPOSITIONS POUR UNE MÉTHODE D'ANALYSE DE L'INTONATION EN PAROLE SPONTANÉE

L'approche des méthodes traditionnelles en prosodie ne permet pas de rendre compte de l'intonation de la parole spontanée. Nous envisageons les causes de cette incapacité, et nous proposons une perspective phonologique devant nous permettre d'appréhender dans leur totalité les phénomènes intonatifs inhérents à la parole spontanée.The traditional methods of studying prosody don't permit to give an account of the intonation of spontaneous speech. We try to explain the causes of this inability and we expose a phonological perspective which may permit to apprehend in their totality the intonative phenomenons inherent in spontaneous speech

Optical Photothermal Infrared Microspectroscopy Discriminates for the First Time Different Types of Lung Cells on Histopathology Glass Slides.

The debate of whether a glass substrate can be used in Fourier transform infrared spectroscopy is strongly linked to its potential clinical application. Histopathology glass slides of 1 mm thickness absorb the mid-IR spectrum in the rich fingerprint spectral region. Thus, it is important to assess whether emerging IR techniques can be employed to study biological samples placed on glass substrates. For this purpose, we used optical photothermal infrared (O-PTIR) spectroscopy to study for the first time malignant and non-malignant lung cells with the purpose of identifying IR spectral differences between these cells placed on standard pathology glass slides. The data in this feasibility study showed that O-PTIR can be used to obtain good-quality IR spectra from cells from both the lipid region (3000-2700 cm-1) and the fingerprint region between 1770 and 950 cm-1 but with glass contributions from 1350 to 950 cm-1. A new single-unit dual-range (C-H/FP) quantum cascade laser (QCL) IR pump source was applied for the first time, delivering a clear synergistic benefit to the classification results. Furthermore, O-PTIR is able to distinguish between lung cancer cells and non-malignant lung cells both in the lipid and fingerprint regions. However, when these two spectral ranges are combined, classification accuracies are enhanced with Random Forest modeling classification accuracy results ranging from 96 to 99% across all three studied cell lines. The methodology described here for the first time with a single-unit dual-range QCL for O-PTIR on glass is another step toward its clinical application in pathology

CO2/CH4 Glow Discharge Plasma. Part II: Study of Plasma Catalysis Interaction Mechanisms on CeO2

International audienceA fundamental study of CO2/CH4 plasma is performed in a glow discharge at a few Torr. Experimentaland numerical results are compared to identify the main reaction pathways. OES-based techniques and FTIR(Fourier Transform Infrared) spectroscopy are used to determine molecules densities and gas temperature. Several conditions of pressure, initial mixture and residence time are measured. The main dissociation productsare found to be CO and H2. The LoKI simulation tool was used to build a simplified kinetic scheme to limit theuncertainties on rate coefficients, but sufficient to reproduce the experimental data. To this aim, only moleculescontaining at most one carbon atom are considered based on the experimental observations. Obtaining a goodmatch between the experimental data and the simulation requires the inclusion of reactions involving the excitedstate O(1D). The key role of CH3 radical is also emphasized. The good match obtained between the experimentand the simulation allows to draw the main reaction pathways of the low-pressure CO2-CH4 plasmas, in particular to identify the main back reaction mechanisms for CO2. The role of CH2O and H2O in the gas phaseis also discussed in depth as they appear to play an important role on catalytic surface studied in the part II ofthis stud

Optical-Feedback Cavity-Enhanced Absorption spectroscopy detects ppt traces of Formaldehyde for the validation of air plasma treatment system

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First Realistic validation of Plasma Air treatment with QCL-OFCEAS detection of formaldehyde below ppb range

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