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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.
21

Current Business Models in Lithium Exploration / Aktuella affärsmodeller inom litiumprospektering

Henderson, Martha January 2022 (has links)
The world is facing the challenge of transforming from fossil fuel dependant to a zero-emission econ-omy. This results in multi-fold mineral requirements for technologies such as wind turbines, solar pan-els, and electric vehicles; an exorbitant amount that cannot be fulfilled by recycling alone. In Europe, this challenge is accelerated more by the current Russian conflict in Ukraine and the understanding that not only do we need to decarbonise the European economy, but also become independent from Russian energy and minerals. This transition requires many raw materials and the faster the transition occurs; the more minerals are required to be mined for these important technologies. Before mining can occur, mineral deposits must be discovered during the process of exploration. The success rate of exploration is less than 1 mine from 1000 exploration projects and projects can take decades to convert from discovery to producing mine. On top of this, we are currently searching for lower-grade deposits that are more difficult to find and technically complicated to extract. All this at a time, when environmental legislation is becoming more strict, there’s a requirement for decarbonisation in the mining industry, and the social license to operate is more difficult to obtain. This seemingly impossible task brings into question the efficiency of the business model of exploration companies to determine whether business model innovation can help achieve a more environmentally, socially, and economically sustainable industry. This study analyses companies working in lithium exploration, as lithium is a material that is re-quired in significant amounts for the green energy transition. The number of companies operating in this sector has increased significantly in the past few years. Through qualitative content analysis using web content, a cross sectional study of 55 companies listed on the Toronto Stock Exchange was com-pleted to identify themes relating to the business models of each company. Eight overlapping innova-tion categories were identified in 29 of the companies including Environment, Social, Economic, Cir-cular, Collaborative, Lean, Technology and Value Chain innovation.
22

Assessment of Drone-Borne Multispectral Mapping in the Exploration of Magmatic Ni-Cu Sulphides – an Example from Disko Island, West Greenland / Bedömning av multispektral kartläggning med drönare vid undersökning av magmatiska Ni-Cu sulfider – Disko Island, Västgrönland

Barnes, Ethan January 2020 (has links)
The senseFly eBeePlus fixed-wing drone is a market available UAV compatible with a range of sensors that includes the Parrot Sequoia+ multispectral camera. Commercial applications of the drone predominantly focus on agriculture, environmental management, and engineering applications. The Sequoia 4-band multispectral sensor with bands optimised for plant health analysis, has a spectral range that coincides with the absorption features of iron. Previous studies with the use of hyperspectral sensors on multicopter UAVs have proven successful in the detection and delineation of hydroxides and sulphates associated with weathering of sulphides at the surface. This study aims to evaluate the ability of the eBeePlus drone equipped with a Parrot Sequoia+ sensor to effectively detect and delineate surficial sulphide mineral expressions by testing its capability on a known nickel-copper mineralisation occurrence at Illukunnguaq, on the north-western coast of Disko Island, West Greenland. Formally hosting a 28-tonne nickeliferous pyrrhotite massive sulphide boulder, many companies have sought this region for a possible extension of the mineralisation or another local mineral occurrence. Iron-feature band ratios and Spectral Angle Mapping (SAM) are two methods tested to first characterise the known occurrence, then search the wider region for other features with a similar signature as the Illukunnguaq dyke. To assist the evaluation and fine tune the Sequoia sensor, it will be compared against the trialled and trusted Rikola hyperspectral sensor, proven to map iron features. In addition, eigen maxima as one of many geomorphological indices that utilise the co-product Digital Surface Model (DSM) of the spectral survey, is employed to assess whether the Illukunnguaq dyke and other features are structurally mappable.  Results show that the Sequoia multispectral sensor, albeit less spectrally resolved than the Rikola hyperspectral sensor was able to detect surficial sulphide mineral expressions both by applying iron-feature band ratios and SAM. The latter was performed using laboratory measured and open-access library spectra. To fine-tune the tools compatible with the Sequoia sensor, in-depth investigations into iron-feature band ratio index values and best-fit library spectra for SAM was conducted. Confidence was increased by the blind detection of another known exposure and permitted a regional search to find additional features with spectral similarities to the Illukunnguaq dyke for future ground truthing. This study demonstrates that the eBeePlus drone can be used for mineral exploration when iron-sulphides are a part of the mineral system and outcropping at the surface. Leading field programs with detailed multispectral mapping can improve the efficiency of geologists by generating or verifying targets prior to ‘boots-on-the-ground’ geological sampling or mapping.
23

‘Because It Was Hardcore and It Was Cool’: Masculinity as the Basis of Consent in Geochemical Sampling

Claus, Russell 06 1900 (has links)
Geochemical samplers carry out manual labour in difficult and dangerous conditions while largely unsupervised. This paper explores questions regarding the labour effort provided by these workers which often goes above and beyond the level necessary to maintain employment and at times endangers their personal safety. This extra effort is provided despite relatively high levels of worker autonomy, low levels of supervision, and little apparent economic incentive. Analysis of worker-level interviews using a number of possible theoretical frameworks indicates that more coercive factors such as direct managerial control and employment insecurity are unable to fully explain sampler behaviour and, instead, participant accounts indicate a form of active worker consent to increased labour effort and risk taking. This is a gendered worker consent based on a form of contingent upon the specific context of geochemical sampling. These specific contingent factors are: a working class masculinity derived from the hard manual labour of the work; the wilderness context that facilitates tropes of ‘man versus nature’ reinforcing the masculine workplace culture and obscuring the appropriation of surplus by more easily allowing the workplace to be interpreted as non-capitalist; and a fraternal masculinity resulting from the crew-based workplace organization and highly male dominated workforce composition, intensified by the conforming pressure of isolated camp life. This specific masculinity forms a basis of consent by which the autonomy afforded to workers by the labour process of geochemical sampling helps rather than hinders the imperative of management to encourage workers to exert the maximum effort. / Thesis / Master of Arts (MA)
24

Curvature Analysis of Aeromagnetic Data

Lee, Madeline 04 1900 (has links)
<p>Fundamentally the amplitude, sign, and frequency of a magnetic signal are inherently linked to curvature. This thesis employs curvature analysis as a semi-automated tool for source signal extraction from a magnetic field surface represented by a grid. The first step is to compute the full, profile, and plan curvatures from the magnetic grid. These values are used in two approaches to curvature analysis: statistical and lineament. The descriptive statistics mean, standard deviation, kurtosis, and skew are computed for quantitative analysis. Mean is used in conjunction with kurtosis and skew to assess frequency content of the signal, magnetization and source dip. Standard deviation characterizes low, moderate, and extreme curvatures. A rapid technique to statistical analysis is applied using a graphical approach with histograms and scatterplots. Histograms display frequency distribution and scatterplots display the relationship between different curvatures. Curvature in the maximum dip direction is used to systematically identify surficial lineaments characterized as continuous troughs or ridges. These lineaments may represent geological sources or remanent acquisition artefacts. Lineaments representing faults and dykes are used in conjunction with <em>a priori</em> knowledge to determine mineralization vectors since many ore deposits are structurally controlled. Quality control of the aeromagnetic grid levelling application may be assessed using spatial correlation of flight lines and magnetic lineaments. In this work curvature analysis is applied to simple synthetic models and two Canadian aeromagnetic data sets. Curvature analysis was applied to magnetic data from the Wopmay Orogen to identify bedrock contacts, fault configurations, and dyke swarms. The data was also used to show lineaments displayed as rose diagrams may be used as an alternative to standard Fourier power spectrums for assessment of levelling. Magnetic survey data from Southern Ontario was used to show a statistical approach to identify regional dip, dominant magnetization, and interference in anomalies.</p> / Doctor of Philosophy (PhD)
25

GEOPHYSICAL PROCESSING AND INTERPRETATION WITH GEOLOGIC CONTROLS: EXAMPLES FROM THE BATHURST MINING CAMP

Tschirhart, Peter 10 1900 (has links)
<p>With an ever-increasing consumption of natural resources new prospecting techniques are required to satisfy the demand. Geophysical methods are one tool commonly relied upon. New acquisition platforms or survey methodologies provide one way to expand the geophysical capabilities, but are expensive and slow to develop. New processing and interpretation techniques on the other hand provide a rapid means to reinterpret existing datasets with the goal of improving our geologic understanding of a project area. This thesis presents four new ways to extract additional geologic insights from a variety of geophysical datasets. All of the studies are based within the Bathurst Mining Camp, NB.</p> <p>A physical rock property database for the Bathurst Mining Camp is constructed and statistically analyzed in chapter two. Descriptive statistics include mean, standard deviation; first, second and third quartiles are calculated for density and magnetic susceptibility measurements and provided in tables for reference. Bivariate plots are then used to identify trends in the density-magnetic susceptibility relationship. We relate some of our findings to processes involved in the depositional and alteration history of the various lithologies. Comprehensive rock property databases provide valuable constraints for geophysical data processing and are essential for any subsequent geophysical modeling. This is demonstrated with two examples. A joint gravity-magnetic profile model is completed across the geologically complex Nine Mile Synform. The profile reveals deep structure in the Camp down to 5 km depth. A geologically constrained geophysical inversion model of the magnetic anomaly associated with the Armstrong B mineral deposit reveals this anomaly contains a strong magnetic remanence contribution. The influence of remanence is often ignored in magnetic interpretation and modeling, but vital to achieve a geologically correct solution. In this instance comparison of the calculated remanence direction with the expected Apparent Polar Wander Path defined direction suggests an age of mineralization that is compatible with geological evidence.</p> <p>A new approach to determine the optimum near surface residual magnetic signal is presented in chapter three. Additionally, a new way of locating remanently magnetized bodies is also introduced. This technique inverts frequency domain helicopter-borne electromagnetic data to yield apparent magnetic susceptibility. To locate those zones where the magnetic signal is dominated by remanence the inverted HFEM susceptibility is cross plot against the results of a traditional apparent susceptibility filter. The inverted HFEM susceptibility is independent of remanence while the apparent susceptibility assumes no remanence. Where remanence is present the TMI derived apparent susceptibility does not correlate with the HFEM. These differences are readily evident in a cross plot of the two susceptibilities. To determine a magnetic residual the inverted susceptibility is forward modeled as a series of vertical prisms with homogeneous susceptibility equal to the inverted susceptibility. This HFEM magnetic model is then used to reference the results of traditional wavelength separation methods. By design the HFEM information is restricted the near surface whereas all traditional regional / residual separation methods operate under wavelength assumptions. A case study using this methodology is presented on the western side of the Tetagouche Antiform.</p> <p>The use of a spatially variable density correction applied to ground gravity and gravity gradiometry in the BMC is examined in the fourth chapter. The influence of topography on gravity and gravity gradiometry measurements is profound and must be removed prior to interpretation. In geologic environments where there is a structural and/or stratigraphic control on the near surface mass distribution, using a single density value may introduce error into the reduced data. A regionally variable density correction is a means to compensate for this effect. Spectral information between the ground gravity and airborne gravity gradiometry is also compared in this chapter. Both systems are fundamentally recording the same geologic mass distribution albeit by different means. Where differences exist one system must be in error.</p> <p>The final chapter demonstrates a quantitative interpretative technique for geophysical data. Often interpretation of the geophysical data in a geological context is done qualitatively using total field and derivative maps. With this approach the resulting map product may reflect the interpreter’s bias. Source edge detection provides a quantitative means to map lateral physical property changes in potential and non-potential field data, but the field data must be transformed prior to SED computation. There are numerous transformation algorithms, all of which operate slightly differently. We demonstrate that by combining the output of several different SED computations through data stacking, the interpretable product of SED is improved. In two examples, a synthetic example and real world example from the Bathurst Mining Camp, a number of transformation algorithms are applied to gridded geophysical datasets and the resulting SED solutions combined. Edge stacking combines the benefits and nuances of each SED algorithm; coincident, or overlapping solutions are considered more indicative of a true edge, while isolated points are taken as being indicative of random noise or false solutions.</p> / Master of Science (MSc)
26

Winning Silver

Moncada de la Rosa, Jorge Daniel 12 June 2013 (has links)
The search for mineral deposits is a time consuming, risky and very expensive process. Applying new models and methods provides a competitive advantage in the search for mineral deposits because an explorationist can quickly evaluate potential targets and eliminate areas without good potential for mineralization. This dissertation presents a practical technique for prediction to finding precious metal mineralization at Guanajauato mining district (GMD) base on theoretical and experimental studies of fluids properties, mineral phase equilibrium, physical and chemical mechanisms. Making the technique highly transportable so that it can be applied in the field during an exploration program base on petrographic characteristics of mineral textures produced during boiling events in quartz, calcite and adularia, and fluid inclusions contained in these phases. While this work was conducted in GMD, the results should be applicable in exploration for epithermal deposits worldwide. The GMD is one of the largest silver producing districts in the world. Ore shoots are localized along three major northwest trending vein systems, the La Luz, Veta Madre and Vetas de la Sierra. More than 1200 samples were collected from surface outcrops, underground mine and historical and recent drill core. Traverses perpendicular to veins in all system were also conducted. Most of the samples (approximately 90%) were also assayed for Au, Ag, Cu, Pb, Zn, As, Sb. Samples from the GMD show a wide range in silica textures are indicative of rapid precipitation, such as occurs when fluids boil. Other mineral phases, including illite, rhombic adularia and bladed calcite are also indicative of rapid growth in a hydrothermal system and are characteristic of boiling systems. Because boiling is an effective mechanism for precipitating gold and silver from hydrothermal fluids, the presence of mineral textures indicative of boiling is a desirable feature in exploration. In many samples, textural evidence for boiling is supported by coexisting liquid-rich and vapor-rich fluid inclusions, or Fluid Inclusion Assemblages consisting of only vapor-rich inclusions, suggesting "flashing" of the hydrothermal fluids. Textural and fluid inclusion evidence for boiling has been observed in the deepest levels of the GMD, suggesting that additional precious metal resources may occur beneath these levels. / Ph. D.
27

Matriz de priorização aplicada à pesquisa mineral na pequena mineração. / Priority matrix applied to mineral exploration in small-scale mining.

Tichauer, Ricardo Marcelo 01 November 2016 (has links)
Na mineração, grande parte das incertezas e riscos estão associados à caracterização geológica. A adoção das melhores práticas na pesquisa mineral resulta em menor risco e maiores eficácia e eficiência à operação, agregando valor ao empreendimento. No Brasil, em geral, a mineração em pequena escala emprega poucos recursos para a pesquisa mineral, e as melhores práticas são frequentemente ignoradas. Este trabalho aborda a incerteza geológica na mineração e como as melhores práticas de pesquisa mineral podem ser aplicadas na pequena mineração para diminuir riscos e incorporar valor ao projeto. A aplicação da Matriz de Priorização CEBIm em três projetos de pesquisa mineral em pequenos depósitos mostra como essa ferramenta pode ser utilizada de forma simples, prática, rápida e econômica para avaliação do nível de aderência do programa de pesquisa mineral às melhores práticas, que pode indicar a magnitude da incerteza geológica associada ao projeto. / In mining, a large number of uncertainties and risks are associated with geological characterization. The adoption of best practices in mineral exploration results in lower risk and greater effectiveness and efficiency to the operation, adding value to the enterprise. In Brazil, in general, small-scale mining employs little resources for mineral exploration, and the best practices are often ignored. This work addresses the geological risks in mining and how best practices in mineral exploration can be applied in small mining to reduce risks and incorporate value to the project. The application of the CEBIm Priority Matrix in three projects of mineral exploration in small deposits shows how this tool can be utilized in a simple, practical, fast and economical way for assessment of the level of compliance of the mineral exploration program to the best practices, which can indicate the magnitude of geological uncertainty associated with the project.
28

Prospecção geofísica de detalhe em área potencialmente mineralizada em ouro em São Sepé (RS) /

Lima, Antônio Elton da Silva January 2019 (has links)
Orientador: César Augusto Moreira / Resumo: O potencial geológico do Brasil para mineralizações auríferas é mundialmente reconhecido, quer seja pelo seu passado histórico, como por conta do expressivo número de ocorrências, depósitos, minas e as centenas de áreas ativas e inativas distribuídas por todo o país. Na região em que presente estudo foi realizado, já foram detalhados uma série de jazimentos desta natureza, caracterizadas por associações de filões de quartzo e pequenas proporções de óxidos de ferro, pirita e calcopirita. Este trabalho apresenta, portanto, os resultados de um estudo de prospecção geofísica de detalhe realizado a partir da aplicação conjunta dos métodos da Eletrorresistividade e da Polarização Induzida, integrados a análise estrutural. O local estudado consiste numa área potencialmente mineralizada em ouro no Complexo Bossoroca, localizada na zona rural do município de São Sepé (RS). Para obtenção dos dados geofísicos foram realizadas cinco linhas de 400m de comprimento e 10m de espaçamento entre eletrodos, através da técnica de tomografia elétrica em arranjo Schlumberger. O levantamento estrutural, por sua vez, considerou medidas de lineamentos, extraídas a partir de imagem SRTM da área, assim como dados de acamamentos e de fraturas de litotipos pertencente ao Complexo Bossoroca, obtidos a partir de levantamento estrutural sistemático. Os resultados de resistividade não permitiram a definição de zonas mineralizadas, possivelmente devido ao pequeno contraste existente entre a rocha encaixante e ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil’s geological potential for auriferous mineralization is recognized worldwide for its historic past, as well as for the number of occurrences, deposits, mines and hundreds of active and inactive areas distributed throughout the country. In the region where the present study was carried out, series of such deposits have already been described, characterized by associations of quartz lodes and small proportions of iron oxides, pyrite and chalcopyrite. This work presents the results of a geophysical prospecting study obtained through the joint application of the DC resistivity and induced polarization methods, integrated to the structural analysis. The studied areas consists of a potentially gold mineralized area in the Bossoroca Complex located in the county of São Sepé (RS). In order to obtain the geophysical data, five lines with 400m in length and 10m of spacing between electrodes were made through the electrical tomography technique in a Schlumberger arrangement. The structural data collecting considered measures of lineaments, extracted from the SRTM image of the area, as well as data of bedding and fractures of lithotypes belonging to the Bossoroca Complex, obtained from a systematic structural data collecting. The results of resistivity did not allow the definition of mineralized zones, possibly due to the small contrast between the rock and the mineralized zone. The chargeability data indicated three zones with high values of load (≥ 4,4 mV / V) located to the eas... (Complete abstract click electronic access below) / Mestre
29

Design and Development of a Mineral Exploration Ontology

Sevindik Mentes, Hilal 18 December 2012 (has links)
In this thesis, an ontology for the mineral exploration domain is designed and developed applying the Protégé ontology editor. The MinExOnt ontology includes a formal and explicit representation of the terms describing real objects, activities, and processes in mineral exploration. The stages used for these activities have various vocabularies, which are semantically modeled in this ontology with Web Ontology Language (OWL). The aim of the thesis is to show how ontologies can be designed and developed to help manage and represent geological knowledge. In addition to providing a general workflow for building the ontology, this thesis presents a simple user guide for the used software, including Protégé, used for ontology development, and Knoodl-OntVis, used for OWL visualization.
30

Fingerprinting Quaternary Subglacial Processes on Hall Peninsula, Baffin Island, using Multiproxy Data

Johnson, Cassia January 2014 (has links)
It is important to study subglacial environments in northern Canada for many reasons, such as to develop a more comprehensive understanding of glacial landscape development and to aid in mineral exploration. The purpose of this research is improve understanding of the Quaternary Geology of north central Hall Peninsula, Baffin Island, the subglacial dynamics record in particular, in order to provide industry with new knowledge, maps and interpretations to aid in mineral exploration. The glacial history of north-central Hall Peninsula, Baffin Island is very complex. By studying the subglacial landscape using both remote- and field- based techniques it was possible to develop a subglacial landscape map and a flowset map which highlighted areas with different glacial histories and basal thermal regimes. The subglacial dynamics and how they changed spatially and temporally shaped the landscape to what it is today with a mixture of cold, intermediate, and warm-based ice. Through mapping using remote sensing and field methods, seven glacial landform and striation directions were found and grouped into four ice flow events. The identified ice flows include regional flows, northern and eastern fjord influenced areas, central deglacial flows, and modern icecap flows. Subglacial erosion was investigated using several proxies including streamlined hill elongation ratios, streamlined hill density, and bedrock controlled lake density studies. These proxies together with the subglacial landscape map were overlaid to select discrete zones, termed glacial terrain zones (GTZs), in an attempt to analyze the subglacial dynamics and how different basal thermal regimes interacted with the landscape. Five glacial terrain zones (GTZs) were identified, with different spatio-temporal basal ice regimes and landform assemblages. The first zone (GTZ 1) is characterized by an expansive flowset of parallel paleo-flow indicators trending northeast. This zone has the highest degree of areal scour with thin, discontinuous and relatively unweathered till. The second zone, GTZ 2, is an area where the broad northeast flowset is crosscut locally by ice flow indicators that converge into troughs that now form a series of north trending fjords in the north of the study area. This overprinted landscape is found to propagate inland forming a channelized system, leading way to linear erosion. The modern icecap resides in GTZ 3, which inherited the broad northeast flowset, but is overprinted in valleys by eastern flows funneling into the fjords to the east, as well as western flows flowing from the modern icecap. In the central area, there is a rolling terrain of thicker till (GTZ 4) that is distinguished by its lack of subglacial features. The final contrasting landscape (GTZ 5) is characterized by southeast trending bedrock features (most likely enhanced by southeast flowing ice) and associated perpendicular moraines. GTZ 5 is also characterized by highly weathered bedrock, and locally by landform assemblages recording late deglacial readvances of thin lobes including moraines and striated outcrops. Geochemical studies for each of these landscapes lead to additional insights, characterizing the five zones further. The geochemical studies took advantage of two till sample databases taken over the study area for exploration purposes by Peregrine Diamonds LTD. The chemical index of alteration (CIA) was applied to compare erosion in the different zones. High CIA values indicate high weathering, where low CIA values low weathering. GTZ 1 is characterized by low CIA values (low weathering footprint), and GTZ 5 is characterized by high CIA value (highly weathered). To study if the GTZs had a distinct geochemical signature, as well as a signature landscape, multivariate geochemical statistics (Principal Component Analysis and Linear Discriminant Analysis) were done over the study area. Interestingly, it was found that the GTZs have geochemical signatures, which reflect the role of underlying bedrock, weathering patterns, glacial dispersal, and the complex relationships between subglacial dynamics and landscape evolution. To determine if the GTZs could be predicted by the till geochemistry, linear discriminant analysis was subsequently applied. The results indicate that the till geochemical data has a predictive capacity with an accuracy of 83.78%, which brings insight into the relationship between glacial landscapes and till composition. With this multi-proxy approach and building from previous studies, a conceptual model was developed for the study area. During the Last Glacial Maximum (LGM), the study area was inundated by the Laurentide Ice Sheet (LIS), with the Hall Ice Divide parallel to the axis of the peninsula with ice flowing from the divide to the northeast and southwest. As ice thinned, GTZ 1, an area once inundated with warm-based ice, as shown by evidence of areal scour and low CIA values, switched to being cold-based ice preserving an older landscape. Though GTZ 1 was under cold-based ice, warm-based conditions still prevailed within the channelized flow zones, which characterize GTZ 2. Evidence of this is found in the striation record, as well as the low CIA value indicative of low weathering (or high erosion). This may reflect a transition from LGM (thick-based ice) to thinner, topographically controlled ice, with cold-based ice in interfluves and hilltops, during early deglaciation. The catchment zones of the channelized system locally extend near the central area (GTZ 4) which is reflected in dispersal patterns and the striation record. As the LIS retreated, it went through a series of southeastward readvances and surges (GTZ 5). Though the ice was warm-based near the moraines in GTZ 5, prevailing cold-based conditions prevailed during most of the last glacial cycle, and the late deglacial readvances had limited erosion capacity and did not overprint the cold-based landscape significantly. This is shown by the CIA values indicative of high weathering, and lack of subglacial landforms. Series of pro-glacial lakes also formed in front of the retreating lobe. Ice is needed over GTZ 1 to prevent these lakes from draining northward. This thin ice was most likely cold-based, preserving the older GTZ 1 landscape of areal scouring. The glacial landscape of Hall Peninsula appears to record a switch from uniform warm-based LGM ice, which was laterally extensive, to localized channel flows in the fjords during deglaciation and intervening cold-based ice. The change in the geometry and basal thermo-mechanical conditions may be the prologue to the separation of the modern day ice cap from the LIS.

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