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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

Thermobaromètrie des phylloscilicates dans les séries naturelles : conditions de la diagénèse et du métamorphisme de bas degré

Bourdelle, Franck 22 June 2011 (has links) (PDF)
Les illites et les chlorites sont des minéraux ubiquistes dans la plupart des roches diagénétiques. Leurs compositions chimiques dépendent des conditions physiques subies (pression, P ; température, T) et de la composition de l'encaissant (e.g. Vidal et al., 1999 ; Parra et al., 2002a, 2002b). Ces minéraux peuvent donc potentiellement être de très bons marqueurs de l'histoire de l'enfouissement, et sont à la base de nombreuses méthodes empiriques ou thermodynamiques d'estimation des conditions P-T.Une compilation de données naturelles et la comparaison des thermobaromètres existants ont permis d'établir leurs limitations respectives. Pour s'en affranchir, un nouveau modèle ordonné de solution solide pour les chlorites a été développé, qui rend compte des forts contenus en silicium observés dans les chlorites naturelles de basses températures. La calibration de ce nouveau thermobaromètre sur des domaines géologiques variés de BT-BP a été testée sur des analyses de chlorites naturelles de la Gulf Coast (Texas) au pic de température (où les données P-T ont été mesurées in situ) et montre d'excellents résultats. Concernant les illites, le modèle thermodynamique le plus abouti (Dubacq et al., 2010) a également été testé de manière à estimer sa précision. L'étude a été complétée par la quantification de l'influence du fer ferrique. Les analyses chimiques utilisées ont été obtenues grâce à un protocole analytique à haute résolution spatiale. Alliant FIB et MET-EDS, ce protocole a permis une étude microtexturale et chimique fine des chlorites et des illites. Il en ressort que ces minéraux possèdent une diversité intracristalline dans leurs compositions et que la zonation chimique résultante apparaît comme une potentielle source d'erreurs dans la calibration des thermobaromètres, tout en permettant d'envisager la notion d'équilibre à l'échelle locale.Cette approche a été utilisée pour quantifier les trajets P-T d'unités géologiques des Alpes de Glarus. Ces résultats, comparés à ceux obtenus avec des méthodes thermobarométriques conventionnelles, donnent une bonne image des processus d'enfouissement et d'exhumation des roches de basse température. Ainsi, il apparaît que chaque composition enregistre une portion du chemin P-T rétrograde. D'une manière générale, chaque zone d'un même cristal renvoie à une partie de l'histoire de la roche.
22

High-temperature x-ray diffraction

Clanton, Uel S., 1931- 26 August 2011 (has links)
A high-temperature x-ray diffraction furnace for use with the General Electric Model XRD-3 x-ray diffraction unit has been developed. The furnace, which was designed and constructed by the author, has an angular range of 0-165° 20. A constant temperature or continuously increasing temperature may be programmed through the temperature range of 20°C to 1000°C. Data on the high-temperature modifications of illite obtained with the high-temperature x-ray diffraction furnace indicate a contraction of the (110) spacing at 300°C and expansions at 725°C and 880°C which were not identifiable using the quench method. The existence of interlayer water in the illite structure to temperatures over 800°C is indicated, based upon the continuous decrease of the (002) basal periodicity with increasing temperature. A skeleton illite structure or a high-temperature illite phase with a d-spacing of 9.87A survives the third endothermic reaction observed by differential thermal analysis and forms a phase which is stable at 900°C. / text
23

The Timing and Causes of Illite Formation in the Cretaceous Marias River Shale, Disturbed Belt, Montana

Osborn, Stephen Gerard 09 June 2006 (has links)
The clay mineralogy data and K-Ar ages of I/S measured in this study agree with previous work conducted within the Disturbed Belt (Hoffman, 1976) and show that diagenetic I/S formed quickly at several different places in response to thrust sheet burial during the Laramide orogeny. The averages of concordant age values for clay sub-fractions separated from three bentonites of Cretaceous and Jurassic depositional age increase from southeast (53.6 Ma) to northwest (56.7 Ma) along the trend of the Disturbed Belt. This northwestward increase of mean ages of I/S is consistent with a thrust sheet emplacement model for the Disturbed Belt (Mudge and Earhart, 1980). The rate of the eastward advancement of the Lewis Thrust Sheet derived from the concordant K-Ar dates of I/S was about 1 cm/year in the Marias River area. The absence of the 2M1 illite polytype in most bentonitic shales does not permit the derivation of the age of diagenetic I/S by Illite Age Analysis and yet constrains the estimate of maximum burial temperature to 250°C.
24

Adsorption of selected organic solvents on clay & sand by inverse gas chromatography

El-Thaher, Nayef Unknown Date
No description available.
25

Adsorption of selected organic solvents on clay & sand by inverse gas chromatography

El-Thaher, Nayef 06 1900 (has links)
The technique of Inverse Gas Chromatography (IGC) was employed for the study of the interactions between various organic solvents with various types of the major inorganic materials (clay minerals and sand) found in Albertas oil sands. Heat of adsorption (-H) was measured for each solvent with respect to each of the four studied inorganic materials. The calculation we used was based on the Infinite Dilution Thermodynamics approach used by Katsanos et. al. [Journal of Chromatography A. 795, 133-184 (1998)]. Retention time data is converted into Retention Volume; H is then obtained by a plot vs. 1/T. The solvents studied were straight chain, branched and cyclic alkanes, alkenes, aromatics, and ketones. The inorganic materials studied were kaolinite, illite, illite-smectite mixed layer, and sand. Our results show that solvents had significantly less affinity for sand when compared to the three types of clay studied. Additionally, solvent affinity to illite had appreciable difference when compared to kaolinite and the mixed layer of illite-smectite. Furthermore, increase in carbon number leads to increased adsorption to the clay. Branched or cyclic alkanes have slightly lower adsorption to clay when compared to straight chain alkane of the same carbon number. Double bonds significantly increase solvent affinity to clay, but have no effect on sand. Lastly, alcohols and ketones have very high affinity to clay that no elution occurred when either solvent was injected into the GC and only ketone eluted when sand was the stationary phase in the GC column. / Chemical Engineering
26

Phenomenes de fixation desorption du mercure sur les argiles dans les eaux à salinité variable. Application a l'estuaire de la Loire /

Frenet, Maryvonne. January 1979 (has links)
Thesis (Ph. D.)--Université de Nantes, L'U.E.R. des Sciences de la Nature, 1979. / Accompanying map: "Carte des points de prélèvements éffectués dans l'estuaire de la Loire." Includes bibliographical references (p. 213-227).
27

Stratigraphic evolution and geochemistry of the Neogene Surma Group, Surma Basin, Sylhet, Bangladesh

Mannan, A. (Abdul) 15 July 2002 (has links)
Abstract The Surma basin is a part of the Bengal Basin situated in northeastern Bangladesh. The presence of eight gas fields and one oil field makes this an area that is interesting both economically and geologically. In spite of detailed geological and geophysical investigations, information available on palynostratigraphy and geochemistry for the area is scanty. The aim of the present work was to investigate the palynological assemblages, mineralogy and geochemistry of the Surma Group (SG) sequences in Surma Basin, Bangladesh. Core samples (n = 188) were gathered from the wells following: Patharia well-5, Rashidpur well-1, Atgram well-IX, Habiganj well-1, Kailastila well-1 and Fenchuganj well-2. They were provided by BAPEX (Bangladesh Petroleum Exploration Company). X-ray Fluorescence (XRF), Atomic Absorption Spectrometry (AAS), Loss of Ignition (LOI), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used for geochemical and mineralogical study of shale samples. In the palynological study, the distributions of pollens and spores were determined. For data analysis, SPSS computer programme was used. Palynological assemblages of the Surma Group of sedimentary sequence of Bangladesh include taxa range in age from the lower Miocene to the Upper Miocene which can be potentially used in dating and correlation. The Lower Miocene interval is correlated with the Simsang Palynological Zone IV of Meghalaya, India and the Bengal Palynological Zone (BPZ) V. The Upper Miocene is correlated with the Simsang Palynological Zone IV of Meghalaya, India and the BPZ Zone V of Bengal. They were deposited in two types of paleoenvironments ranging from the brackish type to shallow marine to brackish. The sequence contains reworked palynomorphs of BPZ IV and III namely Meyeripollies naharkotensis, Polypodiesporites Oligocenecus, Palmepollenities Eocencus and ornamented Tricolpate pollen of the Eocene-Oligocene age which are mainly encountered in the lower Miocene sediments indicative of increased tectonic activity in the area. Geochemical ratios (SiO2/ Al2O3, Cu/Zn, Maturity = K2O+ Al2O3/Na2O+MgO, Rb/K2O, K2O/Na2O, Cr/Rb, Zr/Rb, V/Rb, Th/U etc.) were useful for determining grain size, maturity, tectonics and environment of deposition. High Ba enrichment was detected in the Patharia well-5 and showed high surface water productivity and diagenetic mobilisation. Tectonic descrimination was achieved using SiO2 and K2O/Na2O ratio. XRD analysis revealed the minerals kaolinite, illite, chlorite, illite/smectite (I/S) and kaolinite/smectite (K/S) mixed layers. Kaolinite/Smectite here reported for the first time in Bangladesh. Clay mineral analyses provided evidence for diagenesis. Smectite diagenesis and dehydration have contributed to the generation of overpressure in the Bhuban Formation in the Patharia well -5. Geochemical ratios of the present study from the Surma Basin is undoubtedly a powerful technique and can be applied to any sedimentary basin analysis to infer the palaeoenvironment, palaeoclimate and palaeotectonics.
28

Termofyzikálne a elektrické vlastnosti keramík na báze illitu / Thermophysical and electrical properties of illite-based ceramics

Csáki, Štefan January 2018 (has links)
CSÁKI, Štefan: Thermophysical and electrical properties of illite-based ceramics. [Doctoral thesis]. Constantine the Philosopher University in Nitra. Faculty of Natural Sciences. Charles University. Faculty of Mathematics and Physics. Supervisor: prof. RNDr. Libor Vozár, CSc. (Constantine the Philosopher University in Nitra), doc. Ing. Patrik Dobroň, PhD. (Charles University). Nitra & Prague, 2018. 107 p. Illitic clays are of special importance in the ceramic industry. Therefore, a deep knowledge of the thermophysical processes, as well as the electric properties, is of special importance. The illitic clay originated in Northeastern Hungary was used in this thesis. The reactions, occurring during firing, were studied using thermal analyses (Differential thermal analysis, Thermogravimetry, Thermodilatometry) and special attention was paid to the measurement of the electrical conductivity (both DC and AC). Up to 250 řC, where the removal of the physically bond water (PBW) takes place, the dominant charge carriers were the H+ and OH- ions. After the PBW was removed, Na+ and K+ ions became the dominant charge carriers. During dehydroxylation (450 - 750 řC) H+ and OH- ions were freed from the illite structure, which supported the electrical conduction in the samples. At ~ 970 řC glassy phase appeared...
29

Разработка технологии получения кордиеритовой керамики : магистерская диссертация / Development of technology for obtaining cordierite ceramics

Гиренко, Г. С., Girenko, G. S. January 2021 (has links)
В результате проведенных исследований подобраны и исследованы отечественные сырьевые материалы, рассчитан и разработан состав массы прекурсора и синтезирован композитный материал для производства кордиеритовой керамики. Разработаны составы масс для производства кордиеритовой керамики различными способами формования: шликерным литьем, пластическим и полусухим формованием. Проведенные исследования показывают возможность получения кордиеритовой керамики на основе сырья отечественных месторождений с высоким содержанием α-кордиерита. / As a result of the conducted research, domestic raw materials were selected and studied, the composition of the precursor mass was calculated and developed, and a composite material for the production of cordierite ceramics was synthesized. Mass compositions for the production of cordierite ceramics by various molding methods have been developed: by slip casting, plastic and semi-dry molding. The results of investigation show the possibility of obtaining cordierite ceramics based on the raw materials of domestic deposits with a high content of α-cordierite.
30

Разработка технологии получения кордиеритовой керамики на основе сырья РФ : магистерская диссертация / Development of technology for obtaining cordierite ceramics based on domestic raw

Муфтеева, Л. Ф., Mufteeva, L. F. January 2022 (has links)
Разработаны составы масс для производства керамических кордиеритовых субстратов различными способами формования: полусухим и пластическим формованием. Проведенные исследования показывают возможность получения кордиеритовой керамики на основе сырья отечественных месторождений с высоким содержанием кордиерита. / Mass compositions to produce ceramic cordierite substrates by various molding methods have been developed: semi-dry and plastic molding. The conducted studies show the possibility of obtaining cordierite ceramics based on raw materials from domestic deposits with a high content of cordierite.

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