71 research outputs found
Electrophoretic impregnation of porous anodic aluminum oxide film by silica nanoparticles
In this paper, it is proposed to study the deposition of nanoparticles by electrophoretic deposition (EPD) inside a porous anodic aluminum oxide film. Despite the presence of a highly resistive barrier layer at the metal-anodic film interface, porous anodic films on AA 1050A were successfully filled by 16-nm, surface modified silica particles. During this study it was shown that both the colloidal suspension conductivity and the applied electric field drive the penetration into the porous film. FEG-SEM observations showed that large (130-nm diameter), linear pores of 10 μm in length can be completely filled in 1 min. These results attest that porous anodic films can be efficiently filled with nanoparticles by EPD despite the presence of the barrier layer
Caracterisation Geochimique des Deblans de la Baie du Banco, Abidjan, Basse Cote d’Ivoire
L’étude géochimique réalisée s’est éffectuée sur les déblais du substratum de la baie du Banco situé au sud est du bassin sédimentaire côtier de la Côte d’Ivoire. Cette étude vise à caractériser le substratum de la baie du Banco à partir des éléments chimiques ainsi que la détermination des paléoconditions des environnements de dépôt. La spectrométrie par fluorescence à rayon x (XRF) a permis de déterminer des éléments traces ainsi que les éléments majeurs présents dans les lutites sombres du substratum. Les éléments majeurs identifiés dans les lutites sombres sont par ordre décroissant le Silicium (45,33 %), le Fer (35,56 %), l’Aluminium (9,24 %), le potassium (2,31 %), le Calcium (2,22 %), le Titane (2 ,15 %), le Chlore (2,04 %) et le Phosphore (1,12 %). L’analyse géostatistique a permis de mettre en évidence de fortes corrélations entre la matière organique et Fe 2+, Sn, As, S. Le substratum de la baie du Banco est caractérisé par une forte concentration en soufre et une bioproductivité primaire plus importante en profondeur qu’en surface. Les éléments traces U, V et Mo ont permis d’identifier un milieu euxinique à interface eau-sédiment en subsurface du substratum tandis qu’au fond précisément en fin de forage, on distingue un milieu suboxique à anoxique.
The geochemical study was carried out on Banco Bay bedrock cuttings located in the south-eastern part of the Côte d'Ivoire coastal sedimentary basin. The aim of the study was to characterize the Banco Bay bedrock using chemical elements and to determine the paleoconditions of the depositional environments. X-ray fluorescence spectrometry (XRF) was used to determine the trace elements and major elements present in the dark lutites of the bedrock. The major elements identified in the dark lutites are, in descending order, Silicon (45.33%), Iron (35.56%), Aluminium (9.24%), Potassium (2.31%), Calcium (2.22%), Titanium (2.15%), Chlorine (2.04%) and Phosphorus (1.12%). Geostatistical analysis revealed strong correlations between organic matter and Fe 2+, Sn, As, S. The Banco Bay bedrock is characterized by a high sulfur concentration and greater primary bioproductivity at depth than at surface. The trace elements U, V and Mo identified an euxinic environment at the water-sediment interface in the subsurface of the bedrock, while at the bottom, precisely at the end of the borehole, a suboxic to anoxic environment can be distinguished
Reconstitution Paléoenvironnementale des Formations Maastrichtiennes, Cénomaniennes et Albiennes Basée sur les Données Sédimentologiques et Ichnologiques Issues des Carottes du Puits FIM-1X dans le Bassin Sédimentaire Offshore de la Cote d’Ivoire
Les études sédimentologiques et ichnologiques détaillées du puits FIM-1X ont été effectuées. Les analyses physiques ont été réalisées sur les échantillons de carottes. L'objectif principal est de caractériser la diversité de faciès rencontrés dans les formations maastrichtiennes, cénomaniennes et albiennes afin de déterminer les différents paléoenvironnement rencontrés dans le puits FIM-1X du bassin offshore de Côte d’Ivoire. Les résultats sédimentologiques indiquent que les successions lithologiques des échantillons de carottes comprennent quatre grands groupes de lithofaciès : galets (PS), grès propre (S), sable argileux (SM) et argile (HM, ML, MJ & M). Ces groupes de lithofaciès ont ensuite été subdivisés en faciès constitutifs basés principalement sur des structures sédimentaires. Le groupe des galets comprend uniquement les granules. Le groupe de grès propre comprend trois faciès : grès massif, grès laminé et grès à rides. Le groupe de sable argileux comprend deux faciès à savoir les sables argileux laminés et déformés. Le groupe d’argile comprend trois faciès principaux, à savoir les structures hétérolithiques à dominance argileuses, les argiles calcareuses, et les argiles pures. Une diversité d'ichnofossiles a été identifiée dans les carottes, notamment : Ophiomorpha, Palaeophycus, Thalassinoides, Spyrophyton et Scolicia. L’intégration des données sédimentaires (faciès de granules, grès, sable argileux et argile) et des ichnofossiles reconnues a permis de caractériser des environnements de chenaux du front deltaïque, de complexe chenaux – levées et de milieux marins côtiers (Shoreface) dans ces formations carottés d’âge Maastrichtien, Cénomanien at Albiens. Ces conditions d'environnements bien préservés pourraient constituer de possibles bons réservoirs d'hydrocarbures.
Detailed sedimentological and ichnological studies of FIM-1X well were performed. Physical analyses were carried out on the core samples. The main target is to characterize the diversity of facies encountered in the Maastrichtian, Cenomanian and Albian formations in order to determine the different paleoenvironments encountered in the FIM-1X well of the Côte d'Ivoire offshore basin. The sedimentological results indicate that the lithological successions of the core samples include four major groups of lithofacies: pebbles (PS), clean sandstone (S), muddy sandstone (SM) and mudstone (HM, ML, MJ & M). These lithofacies groups were then subdivided into constituent facies based mainly on sedimentary structures. The group of pebbles includes only the granules. The clean sandstone group includes three facies: massive sandstone, laminated sandstone and ripple sandstone. The muddy sandstone group includes two facies namely the laminated and deformed muddy sandstone. The mudstone group includes three main facies, namely heterolithic structures predominantly mudstone, calcareous mudstone, and pure mudstone. A variety of ichnofossils have been identified in cores, including: Ophiomorpha, Palaeophycus, Thalassinoides, Spyrophyton and Scolicia. The integration of sedimentary data (granule, sandstone, muddy sandstone and mudstone facies) and recognized ichnofossils made it possible to characterize the environments of delta front channels, complex channels - levees and shallow marine environments (Shoreface) in these Maastrichtian, Cenomanian and Albian formations. These well preserved environments conditions could be a possible good hydrocarbon reservoirs
Nucleation and growth mechanisms of trivalent chromium conversion coatings on 2024-T3 aluminium alloy
Nucleation and growth mechanisms of trivalent chromium conversion coatings on 2024 aluminium alloy (AA 2024) were studied. Nucleation of 25 nm diameter nodules was observed on the ridges of the scalloped structure of degreased and desmutted AA 2024 after very short time of conversion treatment corresponding to the formation of a 12 nm thick precursor layer. Then, the composition of this layer evolved and concomitantly a chromium and zirconium outer layer deposited on top of it. Rather long-lasting anticorrosive properties were measured even for conversion coatings formed after short exposure to the conversion bath, except for the precursor layer
Caractérisation Sédimentologique Et Minéralogique Des Formations Du Tertiaire-Quaternaire De La Région D’anyama Au Sud De La Côte d’Ivoire
Anyama is located on the onshore of the sedimentary basin of Côte d’Ivoire. It is to the east of the basin and the formations, particularly those dating back to the Quaternary may have been studied. Based on samples, collected from two drill holes (An1 and An2), each 114 m deep, a sedimentology and mineralogy characterization of Plio-Quaternary formations was carried out. The sedimentological study was assessed by taking account the lithology, the grain size, the transport model and the environment deposit of the sediments, the morphoscopy and the exoscopy of the quartz grain. The mineralogy study was made on clays through X-Ray Diffraction (XRD). Lithological characterization, revealed the presence of clay facies (kaolinite), sandy facies and mixed sediments, all covered with the earth bar. As for the size, it indicates coarse to medium sands with a positive asymmetry to almost positive, sands moderately classified to fairly classify. The relative mineralogy reveals the presence of silicon, aluminum and iron oxides. XRD indicates that quartz and kaolinite prevail and gypsum, rutile or anatase, illite and calcium sulfate hydrate are associated minerals
Caracterisasion Geochimique des Deblais du Substratum de la Baie du Banco, Abidjan, Basse Cote d‘Ivoire
L’étude géochimique réalisée s’est éffectuée sur les déblais du substratum de la baie du Banco situé au Sud-est du bassin sédimentaire côtier de la Côte d’Ivoire. Cette étude vise à caractériser le substratum de la baie du Banco à partir des éléments chimiques ainsi que la détermination des paléoconditions des environnements de dépôt. La spectrométrie par fluorescence à rayon x (XRF) a permis de déterminer les éléments majeurs ainsi que des éléments traces présents dans les lutites noirâtres du substratum de la baie. Les éléments majeurs identifiés sont par ordre décroissant le Silicium (45,33 %), le Fer (35,56 %), l’Aluminium (9,24 %), le Potassium (2,31 %), le Calcium (2,22 %), le Titane (2 ,15 %), le Chlore (2,04 %) et le Phosphore (1,12 %). L’analyse géostatistique a permis de mettre en évidence de fortes corrélations entre la matière organique et le fer réduit (Fe 2+), l’étain (Sn), l’arsenic (As) et le soufre (S). Le substratum de la baie du Banco est caractérisé par une forte concentration en soufre variant de 12475 à 75752 ppm et une bioproductivité primaire plus importante en profondeur qu’en surface. Les éléments traces U, V et Mo ont permis d’identifier un milieu euxinique à interface eau-sédiment en subsurface du substratum (0- 32 m) tandis qu’en fin de forage (78-80 m), on distingue un milieu suboxique à anoxique. Ces différents résultats ont permis de caractériser le substratum de la baie du Banco.
The geochemical study was carried out on cuttings from the Banco Bay bedrock in the southeastern part of the Côte d'Ivoire coastal sedimentary basin. The study aimed to characterize the Banco Bay bedrock based on chemical elements and to determine the paleo conditions of the depositional environments. X-ray fluorescence spectrometry (XRF) was used to determine the major and trace elements present in the blackish lutites of the bay bedrock. The major elements identified were, in descending order, Silicon (45.33%), Iron (35.56%), Aluminium (9.24%), Potassium (2.31%), Calcium (2.22%), Titanium (2.15%), Chlorine (2.04%) and Phosphorus (1.12%). Geostatistical analysis revealed strong correlations between organic matter and reduced iron (Fe 2+), tin (Sn), arsenic (As), and sulfur (S). The Banco Bay bedrock is characterized by high sulfur concentrations ranging from 12475 to 75752 ppm, and higher primary bioproductivity at depth than at the surface. Trace elements U, V, and Mo identified an euxinic environment at the water-sediment interface in the subsurface of the bedrock (0-32 m), while at the end of the borehole (78-80 m), a suboxic to anoxic environment was distinguished. These results have enabled us to characterize the bedrock of the Banco Bay
Development of Tomato Septoria Leaf Spot and Tomato Mosaic Diseases Detection Device Using Raspberry Pi and Deep Convolutional Neural Networks
Machine learning techniques are revolutionizing multiple industries, various
researches have been put forward as regards mitigating pest and disease effect on food
production. The ability to identify plant disease on time can help reduce the level of destruction
caused by the diseases. This paper proposes the use of Deep Convolutional Neural Network
(DCNN) as classification technique using keras and tensorflow python machine learning
libraries to build a model deployed on a hand-held raspberry pi device for on-site plant disease
classification. Convolutional Neural Networks (CNN) can automatically recognize interesting
areas in images which reduces the need for image processing, training images were gotten from
plantvillage.org and split into training, testing and validation sets, the training images were
augmented and fed into a DCNN model for training the model was then tested on the test set to
check against overfitting before finally used to detect disease on the validation set which
showed very positive results. Results from this research shows that DCNN and the framework
in this paper can be used to develop highly efficient plant disease detection models
Engineering and Deploying a Cheap Recognition Security System on a Raspberry Pi Platform for a rural Settlement
Security is one of the most fundamental challenges of
mankind, providing affordable devices for apprehending
criminals. Using smart technology is on the rise and the ability to have full surveillance records of both authorised and unauthorized entrance to designated facility or important resource in a timely manner is highly desirable in modern society of today. This paper proposes the use of Histogram of Oriented Gradients (HOG) to train a model capable of recognising authorised personnel on a raspberry pi device for the purpose of security and ease of access to vital infrastructure. HOG was the preferred choice because it is not computationally intensive as compared to Convolutional
Neural Networks (CNN) and most other relatively
comparable computational algorithms. The HOG network
detect faces and sends a report to Firebase Database and an image is also sent to Google Cloud Storage (GCS) a package on the Google Cloud Platform (GCP). Both data from Firebase and GCS are sent to a companion android application where the user can view who entered specific locations, at specific time with accompanying pictorial evidence. The recognition system was deployed on a raspberry pi device that’s feeds in visual data via an inexpensive camera. Collectively, the proposed system is a relatively cheap smart technology security system with inherent ability to accomplish real-time surveillance tasks using widely penetrated android phone technology while maintaining low computational overheads
Ce(III) corrosion inhibitor release from silica and boehmite nanocontainers
Electrochemical impedance spectroscopy clearly appeared as a suitable technique to investigate the releasing properties of cerium (III) loaded on silica and boehmite nanocontainers. In this way the electrochemical behavior of the AA2024-T3 was evaluated by electrochemical impedance spectroscopy in a 0.045 mol L−1 NaCl solution with nanocontainers containing the inhibitor. Results show that the inhibitor release is influenced by both the chemical nature and the morphology of the nanocontainers. The lower loading and release phenomena were observed for the mesoporous silica nanocontainers, whereas the inhibitor is liberated until 168 h from dense silica nanocontainers. Boehmite nanocontainers combine a good loading ratio with a longer release until the second week of immersion
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