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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Laser-induced plasma on polymeric materials and applications for the discrimination and identification of plastics / Plasma induit par laser sur des matériaux organiques et applications pour discrimination et identification de plastiques

Boueri, Myriam 18 October 2010 (has links)
La spectrométrie de plasma induit par laser, plus connue sous le nom de LIBS (l’acronyme du terme en anglais Laser-Induced Breakdown Spectroscopy) est une technique analytique qui permet la détection de l’ensemble des éléments du tableau périodique avec des limites de détection de l’ordre du ppm et ceci sur tous types d’échantillons qu’ils soient liquides, solides ou gazeux. Sa simplicité de mise en œuvre, sa rapidité et sa versatilité en font une technique très attractive avec un fort potentiel en termes d’applications que ce soit pour le contrôle en ligne, l’environnement ou l’exploration spatiale. Son point faible reste cependant son manque de fiabilité dans l’analyse quantitative, en particulier lors de l’étude d’échantillons hétérogènes ou de matrices complexes telles que les matrices organiques. Ce travail de thèse propose une étude des propriétés des plasmas induit par laser sur différentes familles de polymères. Une étude du plasma au temps court (~ns) par ombroscopie est tout d’abord présentée, ceci pour différents paramètres expérimentaux (énergie laser, durée d’impulsion, longueur d’onde). Un diagnostic complet du plasma par spectrométrie d’émission est ensuite détaillé pour différents délais de détection et montre que la mesure des températures des différentes espèces du plasma (atomique, ionique et moléculaire) permet de vérifier, dans certaines conditions, les hypothèses d’homogénéité et de l’équilibre thermodynamique local. Ceci permet alors la mise en place de procédures quantitatives telles que la méthode dite sans calibration (calibration free LIBS) tout en optimisant le rapport signal sur bruit de la mesure LIBS. Dans nos expériences cette optimisation est mise à profit pour l’identification de différentes familles de polymères en utilisant, pour le traitement des données de la spectroscopie LIBS, la méthode chimiométrique des réseaux de neurones artificiels. Les résultats obtenus, très prometteurs, permettent d’envisager l’utilisation de la LIBS pour l’identification en temps réel des matières plastiques sur chaine de tri. Par ailleurs et de manière plus générale, ce travail pourrait constituer une base solide pour aller étudier d’autres matériaux organiques plus complexes tels que des tissus biologiques. / Laser-Induced Breakdown Spectroscopy (LIBS) is an analytical technique that has the potential to detect all the elements present in the periodic table. The limit of detection can go below a few ppm and this regardless of the physical phase of the analyzed sample (solid, liquid or gas). Its simplicity of use, its rapidity to get results and its versatility provide this technique with attractive features. The technique is currently developed for applications in a large number of domains such as online control, spatial explorations and the environment. However the weakness of the LIBS technique, compared to other more conventional ones, is still its difficulty in providing reliable quantitative results, especially for inhomogeneous and complex matrix such as organic or biological materials. The work presented in this thesis includes a study of the properties of plasma induced from different organic materials. First, a study of the plasma induced on the surface of a Nylon sample at short time delays (~ns) was carried out using the time-resolved shadowgraph technique for different experimental parameters (laser energy, pulse duration, wavelength). Then, a complete diagnostics of the plasma was performed using the plasma emission spectroscopy. A detailed analysis of the emission spectra at different detection delays allowed us to determine the evolution of the temperatures of the different species in the plasma (atoms, ions and molecules). The homogeneity and the local thermodynamic equilibrium within the plasma was then experimentally checked and validated. We demonstrated that the optimisation of the signalto- noise ratio and a quantitative procedure, such as the calibration-free LIBS, can be put in place within a properly chosen detection window. In our experiments, such optimised detection configuration was further employed to record LIBS spectra from different families of polymer in order to identify and classify them. For this purpose, the chemometrics procedure of artificial neural networks (ANN) was used to process the recorded LIBS spectroscopic data. The promising results obtained in this thesis makes LIBS stand out as a potentially useful tool for real time identification of plastic materials. Finally, this work can also be considered as a base for the further studies of more complex materials such as biological tissues with LIBS.
172

Elemental Analysis and Forensic Comparison of Soils by Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS)

Jantzi, Sarah C. 12 November 2013 (has links)
The elemental analysis of soil is useful in forensic and environmental sciences. Methods were developed and optimized for two laser-based multi-element analysis techniques: laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS). This work represents the first use of a 266 nm laser for forensic soil analysis by LIBS. Sample preparation methods were developed and optimized for a variety of sample types, including pellets for large bulk soil specimens (470 mg) and sediment-laden filters (47 mg), and tape-mounting for small transfer evidence specimens (10 mg). Analytical performance for sediment filter pellets and tape-mounted soils was similar to that achieved with bulk pellets. An inter-laboratory comparison exercise was designed to evaluate the performance of the LA-ICP-MS and LIBS methods, as well as for micro X-ray fluorescence (μXRF), across multiple laboratories. Limits of detection (LODs) were 0.01-23 ppm for LA-ICP-MS, 0.25-574 ppm for LIBS, 16-4400 ppm for µXRF, and well below the levels normally seen in soils. Good intra-laboratory precision (≤ 6 % relative standard deviation (RSD) for LA-ICP-MS; ≤ 8 % for µXRF; ≤ 17 % for LIBS) and inter-laboratory precision (≤ 19 % for LA-ICP-MS; ≤ 25 % for µXRF) were achieved for most elements, which is encouraging for a first inter-laboratory exercise. While LIBS generally has higher LODs and RSDs than LA-ICP-MS, both were capable of generating good quality multi-element data sufficient for discrimination purposes. Multivariate methods using principal components analysis (PCA) and linear discriminant analysis (LDA) were developed for discriminations of soils from different sources. Specimens from different sites that were indistinguishable by color alone were discriminated by elemental analysis. Correct classification rates of 94.5 % or better were achieved in a simulated forensic discrimination of three similar sites for both LIBS and LA-ICP-MS. Results for tape-mounted specimens were nearly identical to those achieved with pellets. Methods were tested on soils from USA, Canada and Tanzania. Within-site heterogeneity was site-specific. Elemental differences were greatest for specimens separated by large distances, even within the same lithology. Elemental profiles can be used to discriminate soils from different locations and narrow down locations even when mineralogy is similar.
173

Separação e pré-concentração de metais : uma transferência do meio aquoso para fase sólida ou líquidos orgânicos

Souza, Rodrigo Papai de January 2018 (has links)
Orientadora: Profa. Dra. Ivanise Gaubeur / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia/Química, Santo André, 2018. / Dois novos procedimentos de extração que utilizam materiais extratores não-convencionais são apresentados nesta tese. A utilização de cera de parafina derretida como um extrator químico permitiu agregar as principais vantagens da extração em fase líquida (homogeneidade do extrato, curto tempo de extração e simplicidade de operação) na extração em fase sólida, delineando um procedimento inovador. O papel matte foi outro material estudado nesse trabalho e mostrou-se interessante como extrator químico, especialmente pelo baixo custo dessa fase sólida. Como prova de conceito, o íon metálico cobre (II) em solução aquosa foi utilizado para o desenvolvimento da metodologia. O extrato resultante de ambos os procedimentos de extração foi analisado diretamente por Espectrometria de Emissão Óptica com Plasma Induzido por LASER (LIBS). Os fatores que afetam a reação de complexação, a extração e a detecção do analito na fase sólida foram otimizados num estudo univariado. Nas melhores condições encontradas, foram construídas curvas de calibração numa faixa linear de 0,50 até 10,00 mg L-1 e alcançados limites inferiores de detecção de 0,12 mg L-1 e 0,08 mg L-1 de cobre (II) em solução aquosa, para os procedimentos com cera de parafina e com o papel matte, respectivamente. A precisão de ambos os métodos propostos mostrou-se inferior a 5% e a exatidão foi avaliada por: (i) análise de material de referência certificado de soro sanguíneo humano; (ii) ensaios de adição e recuperação do analito em amostras líquidas de composição química distintas (água mineral, água do mar, água de torneira, cachaça, refrigerante e urina humana) e (iii) comparação dos resultados obtidos com os fornecidos pelo método de Espectrometria de Absorção Atômica com Forno de Grafite. Ambos os procedimentos se destacaram pela: (i) elevada eficiência no processo de extração (>94%); (ii) facilidade de execução; (iii) baixo custo e inocuidade dos extratores; (iv) microhomogeneidade das fases sólidas obtidas; (v) possibilidade de préconcentração de íons metálicos e (vi) superação das dificuldades intrínsecas na análise de líquido por LIBS. / Two new extraction procedures that use non-conventional extractant materials are described in this thesis. The use of melted paraffin wax as a chemical extractant allowed to aggregate the main advantages of the liquid phase extraction (homogeneity of the extract, short extraction time and simplicity of operation) in solid phase extraction, delineating an innovative procedure. The matte paper was another material studied in this work and was interesting as a chemical extractant, especially for the low cost of this solid phase. As proof of concept, the copper (II) ion in aqueous solution was applied for the development of the methodology. The extract obtained from both extraction procedures was analyzed directly by LASER-Induced Breakdown Spectroscopy (LIBS). The parameters that affecting the complexation reaction, extraction and analyte detection in the solid phase were optimized in a univariate approach. Under the best conditions, calibration curves were constructed in a linear range of 0.50 to 10.00 mg L-1 and lower detection limits of 0.12 mg L-1 and 0.08 mg L-1 of copper (II) in aqueous solution were obtained, for the procedures with paraffin wax and matte paper, respectively. The precision of both methods was less than 5% and accuracy was assessed by: (i) analysis of certified reference material of human blood serum; (ii) spike and recovery analyte in liquid samples of different chemical compositions (seawater, tap water, mineral water, cachaça, soft drink and human urine) and (iii) comparison of the results obtained with those provided by the Graphite Furnace Atomic Absorption Spectrometry. Both procedures were highlighted by: (i) high efficiency in the extraction process (> 94%); (ii) ease of execution; (iii) low cost and safety of extractants; (iv) microhomogeneity of the solid phases obtained; (v) the ability of preconcentration metal ions and (vi) overcoming the intrinsic drawbacks in liquid analysis by LIBS.
174

Vliv atmosféry na laserovou ablaci materiálů / Impact of the atmosphere on laser ablation of matters

Černá, Svatava January 2020 (has links)
This thesis deals with a general overview of laser-induced breakdown spectroscopy - ablation of material and plasma formation when a change of the surrounding environment occurs. The aim is to establish ideal conditions for improving detection, which is difficult for some elements when the measurement takes place in the ambient atmosphere. This is the reason why we change the ambient conditions, the gas (air, helium, argon) and its pressure. Buffer gases (helium, argon) influence the development of the material ablation and quality of generated plasma. That is why we inspect the changes in the signal according to particular atmospheres (signal change in buffer gases compared to the ambient atmosphere). The first part of the thesis presents the principle and physical nature of laser ablation with a brief search of experiments performed so far for similar purposes. Based on this search we determine conclusions about the influence of buffer gasses and pressure on the detection used gasses. In the second part of the work, the controlled experiment is presented, which consisted of the detection of spectral lines of fluorine and potassium, see chapter 5.6 and molecular transitions of calcium fluoride, see chapter 5.10. In a controlled experiment, we established two assumptions. The first assumption is the influence of the inert gas atmosphere, which should significantly improve the detection of fluorine and potassium compared to the air atmosphere. We confirmed this finding only for the argon atmosphere. In contrast, in the helium atmosphere, the detection of none of the elements improved. The second assumption is the effect of reducing the ambient pressure, which in combination with an inert gas should allow the detection of fluorine even at low concentrations in the sample. We consider the measured glass disk in chapter 5.7 to be such a sample. This assumption is not confirmed, as the increased intensity of the fluorine spectral line does not manifest itself in any way when the pressure in the vacuum chamber decreases. Finally, in chapter 7 from the results of individual parts of the experiment, the most suitable conditions for the future detection of the measured substances were proposed: fluorine, potassium and calcium fluoride molecules.
175

Improving a Circular Electric Vehicle Battery Value Chain : A Case Study of Sustainable Waste Management of Lithium-Ion Batteries

Sithoumphalath, Sithiphone January 2024 (has links)
This master’s thesis aims to improve the circularity of the electric vehicle (EV) battery value chain, specifically focusing on sustainable waste management of Lithium-Ion Batteries (LIBs) in Europe, particularly Sweden. The research objectives include evaluating and proposing actionable recommendations to enhance circularity, addressing environmental impacts, and supporting the industry’s transition towards a sustainable business model aligned with the new European Union (EU) Battery Regulation, which aims to enhance recycling rates, reduce environmental impact, and secure the recovery of valuable materials. The key research questions addressed are: (1) What initiatives, technologies, or best practices are currently being developed to support circularity and sustainable waste management in the EV battery value chain? (2) How can the circularity of the EV battery value chain be enhanced, particularly in sustainable waste management for LIBs? (3) What environmental impacts, socio-economic opportunities, and challenges exist in a circular value chain in the EV battery industry? The methodology employed a mixed-methods approach, including a literature review and case study, stakeholder interviews, SWOT analysis and life cycle assessment (LCA) using Minviro LCA software to quantify and compare the environmental impacts of state-of-the-art industrial LIB recycling methods. Key findings indicate that several initiatives and technologies are being developed to support circularity, including advanced recycling technologies and second-life applications for batteries. Enhancing circularity requires regulatory support, technological advancements, and stakeholder collaborative efforts. The findings highlight significant potential for extending the lifecycle of EV batteries through re-use, re-purposing, and recycling strategies. The analysis reveals that advancements in recycling technologies and supportive regulatory frameworks can substantially reduce the environmental impact and improve LIB supply chain sustainability. Notably, the LCA results highlight that mechanical and hydrometallurgical recycling processes offer more favourable environmental outcomes than pyrometallurgical methods. Thus, it shows potential for lower environmental impact on greenhouse gas (GHG) emissions and resource depletion, alongside socio-economic opportunities like job creation and economic growth. However, challenges such as technological barriers, economic feasibility, regulatory compliance, and EV battery value chain complexities remain, and these must be addressed. The conclusions drawn from the findings recommend that a combination of regulatory support, technological innovation, and stakeholder collaboration is essential for improving the circularity of the EV battery value chain. The study recommends advancements in recycling technologies, developing efficient testing and certification processes for second-life batteries, and establishing clear regulatory frameworks to facilitate circular economy practices. These measures are crucial for supporting the industry’s shift towards a more sustainable and circular model, ultimately contributing to the EU’s climate neutrality goals by 2050.
176

Chimiométrie appliquée à la spectroscopie de plasma induit par laser (LIBS) et à la spectroscopie terahertz

El Haddad, Josette 13 December 2013 (has links) (PDF)
L'objectif de cette thèse était d'appliquer des méthodes d'analyse multivariées au traitement des données provenant de la spectroscopie de plasma induit par laser (LIBS) et de la spectroscopie térahertz (THz) dans le but d'accroître les performances analytiques de ces techniques.Les spectres LIBS provenaient de campagnes de mesures directes sur différents sites géologiques. Une approche univariée n'a pas été envisageable à cause d'importants effets de matrices et c'est pour cela qu'on a analysé les données provenant des spectres LIBS par réseaux de neurones artificiels (ANN). Cela a permis de quantifier plusieurs éléments mineurs et majeurs dans les échantillons de sol avec un écart relatif de prédiction inférieur à 20% par rapport aux valeurs de référence, jugé acceptable pour des analyses sur site. Dans certains cas, il a cependant été nécessaire de prendre en compte plusieurs modèles ANN, d'une part pour classer les échantillons de sol en fonction d'un seuil de concentration et de la nature de leur matrice, et d'autre part pour prédire la concentration d'un analyte. Cette approche globale a été démontrée avec succès dans le cas particulier de l'analyse du plomb pour un échantillon de sol inconnu. Enfin, le développement d'un outil de traitement par ANN a fait l'objet d'un transfert industriel.Dans un second temps, nous avons traité des spectres d'absorbance terahertz. Ce spectres provenaient de mesures d'absorbance sur des mélanges ternaires de Fructose-Lactose-acide citrique liés par du polyéthylène et préparés sous forme de pastilles. Une analyse semi-quantitative a été réalisée avec succès par analyse en composantes principales (ACP). Puis les méthodes quantitatives de régression par moindres carrés partiels (PLS) et de réseaux de neurons artificiels (ANN) ont permis de prédire les concentrations de chaque constituant de l'échantillon avec une valeur d'erreur quadratique moyenne inférieure à 0.95 %. Pour chaque méthode de traitement, le choix des données d'entrée et la validation de la méthode ont été discutés en détail.
177

Laser-induced breakdown spectroscopy (LIBS) on geological samples : compositional differentiation and relative hardness quantification

Panya panya, Sipokazi Ntombifikile 02 1900 (has links)
This master’s thesis is focused on the LIBS technique for compositional differentiation and relative hardness quantification of selected geological samples. The experimental part of this thesis was conducted at the National Institute of Laser Enhanced Sciences (NILES) in Cairo, Egypt where a simple LIBS system was constructed. In parallel to the experimental work, the literature review was surveyed with the aim to give a thorough view of the history, fundamentals and all the factors related to LIBS. LIBS is a developing analytical technique, which is used to perform qualitative and semi-quantitative elemental analysis of materials (solid, liquid and gas). The fast data collection and the lack of sample preparation made LIBS be an attractive technique to be used for geological samples. This study was done to improve analytical methods for geochemical analysis of samples during different exploration phases (Mining, filed analysis, etc.), as a real-time analysis method to save money and time spent in labs. For a generation of laser induced plasma, a Q-switched Nd: YAG laser operated at 10 Hz and wavelength of 1064 nm was employed on the surface of the samples. A spectrometer fitted with an intensified charge-coupled device (ICCD) was used to disperse and detect the spectrum; then fed to a computer for recording and further processing of the data. The sample set was compiled from samples collected from different areas (South Africa and Namibia). Using principal component analysis (PCA), it was found that LIBS was able to differentiate between the samples even those of the same area. The results from the LIBS technique were correlated with subsequent analysis of the same samples by Particle-induced X-ray emission (PIXE). The feasibility of relative hardness estimation using LIBS was done by measuring the plasma excitation temperature for different samples. LIBS with its advantages as an elemental analysis technique made it possible to estimate the hardness of geological samples. Based on theory and results, an analytical technique for compositional differentiation and quantification of relative hardness of geological samples is proposed. / National Research Foundation (South Africa) / Physics / M Sc. (Physics)
178

Using Laser-Induced Breakdown Spectroscopy (LIBS) for Material Analysis / Using Laser-Induced Breakdown Spectroscopy (LIBS) for Material Analysis

Pořízka, Pavel January 2014 (has links)
Tato doktorská práce je zaměřena na vývoj algoritmu ke zpracování dat naměřených zařízením pro spektrometrii laserem indukovaného plazmatu (angl. LIBS). Zařízení LIBS s tímto algoritmem by mělo být následně schopno provést třídění vzorků a kvantitativní analýzu analytu in-situ a v reálném čase. Celá experimentální část této práce byla provedena ve Spolkovém institutu pro materiálový výzku a testování (něm. BAM) v Berlíně, SRN, kde byl sestaven elementární LIBS systém. Souběžně s experimentílní prací byl vytvořen přehled literárních zdrojů s cílem podat ucelený pohled na problematiku chemometrických metod používaných k analýze LIBS měření. Použití chemometrických metod pro analýzu dat získaných pomocí LIBS měření je obecně doporučováno především tehdy, jsou-li analyzovány vzorky s komplexní matricí. Vývoj algoritmu byl zaměřen na kvantitativní analýzu a třídění vyvřelých hornin na základě měření pomocí LIBS aparatury. Sada vzorků naměřených použitím metody LIBS sestávala z certifikovaných referenčních materiálů a vzorků hornin shromážděných přímo na nalezištích mědi v Íránu. Vzorky z Íránu byly následně na místě roztříděny zkušeným geologem a množství mědi v daných vzorcích bylo změřeno na Univerzitě v Clausthalu, SRN. Výsledné kalibrační křivky byly silně nelineární, přestože byly sestaveny i z měření referenčních vzorků. Kalibrační křivku bylo možné rozložit na několik dílčích tak, že závislost intenzity měděné čáry na množství mědi se nacházela v jiném trendu pro jednotlivé druhy hornin. Rozdělení kalibrační křivky je zpravidla přisuzováno tzv. matričnímu jevu, který silně ovlivňuje měření metodou LIBS. Jinými slovy, pokud určujeme množství analytu ve vzorcích s různou matricí, je výsledná kalibrační křivka sestavená pouze z jedné proměnné (intenzity zvolené spektrální čáry analytu) nepřesná. Navíc, normalizace takto vytvořených kalibračních křivek k intenzitě spektrální čáry matrčního prvku nevedla k výraznému zlepšení linearity. Je obecně nemožné vybrat spektrální čáru jednoho matričního prvku pokud jsou analyzovány prvky s komplexním složením matric. Chemometrické metody, jmenovitě regrese hlavních komponent (angl. PCR) a regrese metodou nejmenších čtverců (angl. PLSR), byly použity v multivariační kvantitatvní analýze, tj. za použití více proměnných/spektrálních čar analytu a matričních prvků. Je potřeba brát v potaz, že PCR a PLSR mohou vyvážit matriční jev pouze do určité míry. Dále byly vzorky úspěšně roztříděny pomocí analýzy hlavních komponent (angl. PCA) a Kohonenových map na základě složení matričních prvků (v anglické literatuře se objevuje termín ‚spectral fingerprint‘) Na základě teorie a experimentálních měření byl navržen algoritmus pro spolehlivé třídění a kvantifikaci neznámých vzorků. Tato studie by měla přispět ke zpracování dat naměřených in-situ přístrojem pro dálkovou LIBS analýzu. Tento přístroj je v současnosti vyvíjen v Brně na Vysokém učení technickém. Toto zařízení bude nenahraditelné při kvantifikaci a klasifikaci vzorků pouze tehdy, pokud bude použito zároveň s chemometrickými metodami a knihovnami dat. Pro tyto účely byla již naměřena a testována část knihoven dat v zaměření na aplikaci metody LIBS do těžebního průmyslu.
179

Geological characterization of rock samples by LIBS and ME-XRT analytical techniques

Elvis Nkioh, Nsioh January 2022 (has links)
One of the major challenges in earth sciences and mineral exploration has been to determine with high accuracy and at a fast rate the elemental composition as well as the general chemistry of a rock sample. Many analytical techniques e.g., scanning electron microscopy (SEM) have been employed in the past with a certain degree of success, but their analyses usually require a lengthy sample preparation and time-consuming measurements which produce results at a much slower rate than techniques whichrequire less or do not require any sample preparation at all. SEM images the surface of a sample by scanning it with a high-energy beam of electrons in a raster scan pattern, where the primary electron beam produced under very low air pressure vacuum scans across the sample by striking it, and a variation of signals produce an image of the surface, or its elemental composition together with energy dispersive X-rays. Alternatively, laser induced breakdown spectrometry (LIBS) and multi energy X-ray transmission (ME-XRT) are non-contact measurement scanning techniques, capable of producing faster results than SEM-EDS which makes them suitable for real time measurements and analyses as they do not slow down the pace of a project being carried out. LIBS is a spectroscopic technique used to characterize and detect materials where a highly energetic laser pulse is focused onto the surfaces of solids, liquids or gases resulting in atomic and molecular species to emit light at specific wavelengths which is collected with a spectrometer and analysed using a computer. Comparably, ME-XRT is a sensor-based sorting technique involving the planar projection of X-ray attenuation of a particle stream, distributed on a fast conveyor belt, where they are scanned and evaluated while passing and an image is recorded by a line scan detector.      Eleven rock samples were analysed in this study. They include four rock type samples: granite, basalt, sandstone, and gneiss, all obtained from Luleå University of Technology (LTU) sample storage and seven ore type samples which include a porphyry Cu sulphide ore, a porphyry Cu oxide ore, a porphyry Cu-Au-Ag ore, an apatite iron ore (AIO), an iron-oxide copper gold ore (IOCG), an orogenic gold ore and a volcanogenic massive sulphide ore (VMS).       The SEM results give a semi-quantitative elemental composition of the rocks, which may be usedto discriminate mineralisation. Energy dispersive X-ray spectroscopy (EDS) maps may be used to identifygeological features and secondary electron (SE) images may be used to understand the topography of the rock samples. The SEM has a low penetration depth rate but produces moderate to high accuracy resultsdepending on the settings and calibrations. It requires a lengthy sample preparation, and its analytical time is often too long for routine industrial application. LIBS results also provide rock elemental compositions similar to the SEM, which may be quantitative if the same spectrometer is used for all elements and calibrated against a standard. It also produces element maps similar to the SEM-EDS maps. LIBS analyses yield high accuracy results but at a low penetration depth. There are no standard calibrations for the LIBS measurements, which limits quantification. LIBS measurements do not require any form of sample preparation. ME-XRT analyses result in rock chemical data portraying a light material fraction (aluminium-like) and a heavy material fraction (iron-like) which may be used to distinguish different rock samples based on the closeness of their effective atomic number Zeff to that of aluminium and iron respectively. It’s analysis also produces low-resolution images of the analysed rock samples. The image resolution is too low to allow interpretation of the data in the context of the structures and textures in the rock samples. It has a higher penetration depth than LIBS and SEM-EDS producing more volumetric data but with a lower accuracy in terms of the amount of information obtained. Only two elements are used for ME-XRT calibration measurements, if many elements of varying atomic numbers could be used, it would have the ability to provide a more reliable data. Samples must have a maximum and minimum thickness; thus, sample preparation is required to regulate the rock thickness.      SEM and LIBS provide element compositions of minerals and element distribution maps required by geologist in their daily activities during exploration and mining. This information can be considered the most useful obtained from all three techniques. However, LIBS analyses are faster, and its maps are of higher quality even at the same resolution as the SEM-EDS. This makes the LIBS preferable for real time measurements and analyses. Geological activities like drill core logging, mine mapping and sampling for grade control all require fast results for project continuity and LIBS is suitable for this purpose as it can keep up with the pace of these activities. SEM analytical technique provides semi-quantitative data which is more accurate than the LIBS data and thus, preferable for usage in research institutions and universities.ME-XRT can reveal information on the internal structures or different rock sample compositions. This makes it a suitable technique in distinguishing ore from waste material especially in iron ore mining and processing where the iron needs to be separated from the siliceous waste and sorting is also required prior to beneficiation to avoid equipment destruction by abrasive quartz. LIBS and ME-XRT analytical techniques complement each other in terms of analytical capabilities as LIBS has a low penetration depthrate but high accuracy results while the ME-XRT has a high penetration depth rate but low accuracy results. They are both fast scanning techniques that can be used for real time measurements and analyses and if their analytical prowess can be improved, the combination of these two fast analytical techniques may enable us to obtain high quality data and may as well be what is needed by geologists in the future.

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