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1

Lam, Ka Wing. "Pharmaceutical salt formation guided by phase diagrams /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CBME%202009%20LAM.

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2

Cropper, Paul Edward. "A kinetic template effect in arylphosphonium salt formation." Thesis, Sheffield Hallam University, 1988. http://shura.shu.ac.uk/19513/.

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This thesis describes studies of a "kinetic template effect" which assists the formation of arylphosphonium salts from aryl halides and tertiary phosphines in the presence of a transition metal halide catalyst in refluxing ethanol. The "kinetic template effect" arises from the presence in the aryl halide of a limited range of orthosubstituents capable of intramolecular coordination with the metal at a critical stage of the reaction. In Chapter One, the "kinetic template effect" is compared with the better known "thermodynamic template effect". Earlier work on related "kinetic template effects" in the formation of aryl-phosphorus bonds is reviewed. The evidence for the possible involvement of aryl-metal intermediates in such reactions is also discussed. Chapter Two is concerned with the design and synthesis of potential template molecules. A model is proposed for the features necessary in the template substituent in terms of the nature and position of the donor atom or group essential for the replacement of the ortho-halogen under mild conditions. Chapter Three describes a kinetic study of the nickel (II) catalysed reactions of ortho-haloaryl Schiff's base and ortho-haloarylazo-dyestuff templates with tertiary phosphines. A rate law is deduced which indicates a first order dependence in each reactant, i.e. rate a [template] [phosphine] [catalyst], an overall third order expression. Rate studies also indicate that the nature of the orthohalogen is important, the order of replacement being I > Br > Cl. The effects of substituents remote from the ortho-haloaryl template are also considered. A mechanistic scheme consistent with the rate data is proposed. The X-ray crystal structures of two arylphosphonium salts derived from template aryl halides are discussed in Chapter Four, providing unequivocal proof that the position of replacement of halogen in substrates bearing more than one replaceable halogen, in different positions, is ortho with respect to the template donor group.
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3

Konishi, Hirokazu. "Formation of Dy Alloy Films by Molten Salt Electrochemical Process." Kyoto University, 2003. http://hdl.handle.net/2433/149313.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(エネルギー科学)
甲第9870号
エネ博第58号
新制||エネ||18(附属図書館)
UT51-2003-C638
京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻
(主査)教授 伊藤 靖彦, 教授 八尾 健, 教授 尾形 幸生
学位規則第4条第1項該当
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4

Ren, Lirong. "Inorganic salt nanofibers as templates for the formation of oxide nanotubes." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974105651.

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5

Chou, Tai-Li. "Kinetics of salt formation using terephthalic acid and N-methyl-2-pyrrolidinone." Thesis, Montana State University, 2004. http://etd.lib.montana.edu/etd/2004/chou/ChouT04.pdf.

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Terephthalic acid (TA) is used as a raw material for producing polyesters. As the global demand for polyesters increases at a rate of 7% per year on average for the last few years and next 10-year forecast, the demand of TA also increases. The global production exceeded 27 million tons for the year 2003, and will be in excess of 30 million tons for the year 2004. Therefore improving the production or purification process for terephthalic acid becomes more and more important. A new purification method using N-methyl-2-pyrrolidinone (NMP) as solvent was recently developed. In this process, the salt complex consisting of TA and NMP was formed to exclude the impurities. The research topic of this thesis was to characterize the salt formation rate and develop possible explanations for salt formation kinetics. Gas Chromatography was used to determine the percentage of salt in the salt formation samples as prepared by varying mixing times, temperatures and loadings. The TA-salt transition (salt formation) was found to behave as first-order solid-solid phase transition with a temperature range where both phases coexist. The salt formation rate was explained using the combination of reaction rate and salt formation possibility.
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6

Elder, David. "Physicochemical and crystallographic investigations into the salt formation of two heterocyclic drugs." Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/8721.

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Salt formation provides a means of altering the physicochemical and resultant biological characteristics of a drug entity without modifying its molecular structure. Many published reviews have indicated the importance of the selection of the most appropriate salt form. This work is an investigation into the salt formation of two heterocyclic drugs. This is done by the physicochemical and the crystallographic studies of 19 high resolution single crystal diffraction studies. The particular targets of the work are the selection of the most appropriate salt forms, investigations into the tautomerism and polymorphism (or pseudopolymorphism) and an understanding of the interactions most likely between these heterocyclic drugs and their specific receptor sites. Section 1 describes the effect of protonation on the absorption of drugs, the rationale for using various salt forms and the resultant effect this has on a number of physicochemical properties of the parent compound. Section 2 is a description of the experimental techniques used in the physicochemical investigations and in crystal structure determination. In Sections 3 and 7, the preparation and characterisation of the salts and modifications of the two heterocyclic drugs, GU and IM is described. In Sections 4 and 8, the physicochemical investigations into the hygroscopicity and solid-state stabilities of the salts of GU and IM is described. Van't Hoff solubility studies are used to determine the enthalpies of solution and where appropriate the relative thermodynamic stabilities of the various phases produced. The structures of 19 of the salts or modifications of GU and IM, together with their packing and hydrogen bonding interactions is described in Sections 5 and 9. Sections 6 and 10 describe the ionisation properties of these molecules. Both the guanidine and imidazole moieties of GU and IM, respectively, are tautomeric, the particular form(s) found in these investigations and the effect of protonation is discussed. The conformations of these structures are discussed and the effect of protonation, especially on the puckering of the piperazine ring, is described.
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7

Iida, Takahisa. "Formation of Sm and Yb Alloy Films by Molten Salt Electrochemical Process." Kyoto University, 2003. http://hdl.handle.net/2433/148653.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(エネルギー科学)
甲第10335号
エネ博第71号
新制||エネ||21(附属図書館)
UT51-2003-H756
京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻
(主査)教授 伊藤 靖彦, 教授 八尾 健, 教授 吉田 起國
学位規則第4条第1項該当
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8

Rödner, Sandra. "Interfacial colloidal particle films and their structure formation." Licentiate thesis, KTH, Chemistry, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1505.

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Abstract to“Interfacial colloidal particle films andtheir structure formation”; a licentiate thesis, whichwill be presented by Sandra Rödner in Q2, 29 November 2002at 13.00.

Colloidal particles can be made to organise themselves intoordered arrays. These colloidal structures acquire interestingand useful properties, not only from their constituentmaterials but also from the spontaneous emergence of mesoscopicorder that characterises their internal structure. Orderedarrays of colloidal particles, with lattice constants rangingfrom a few nanometers to a few microns, have potentialapplications as optical computing elements and chemicalsensors, and also has an important influence on the mechanicalproperties and optical appearance of paint films and papercoatings.

The control of colloidal structure formation starts with theparticle interactions (attractive or repulsive) and colloidaldynamics, which is the topic of this thesis. To enable adetailed understanding of the different factors that controlthe formation of dense 2D colloidal films, a method forstructural characterisation was developed. The degree of orderin the hexagonal close-packed structure, displayed by thecolloidal films, was characterised by the size of ordereddomains and by the distribution of pore sizes. The size ofordered domains was obtained from the pair distributionfunction, and the distribution of pores from a Delaunaytriangulation procedure. These methods are based on theparticle positions in the film, which were determined by lightmicroscopy and processed digital images.

The two methods were used to study the effect of particleinteractions on the structure of colloidal monoparticulatefilms, formed at the air-liquid interface. The size of theordered domains decreased exponentially with increasing bondstrength, while the pore density increased. The transfer andsubsequent drying of the formed film on a solid substrateinduced structural changes; the capillary forces transformedsmall pores into triangular order while some of the largervoids and cracks increased in size.

The structural features of colloidal monolayers, formed bydrying a dilute silica suspension on a substrate, wereinvestigated. Addition of small amounts of salt resulted indrastic changes of the particle film structure. The size of theordered domains decreased exponentially with increasing amountsof added salt (0-2.9% NaCl/Silica ratio), with a simultaneousincrease of the concentration of large defects. This suggeststhat loss of colloidal stability and onset of particle adhesionto the substrate inhibit rearrangement and ordering. Theevaporation rate was controlled by varying the relativehumidity during drying. Colloidal monolayers with the largestordered domains and the lowest concentration of stacking faultswere formed at an intermediate humidity (55% RH).

The rearrangement process during drying of dilute silicasuspensions was followed in detail by studying the changes inthe structural features during growth of colloidal monolayers.Low crystal growth rate promoted the transition of squarelattice domains to a hexagonal close-packed structure. Additionof salt to the electrostatically stabilised dispersionincreased the formation of square structured regions at thecrystal-suspension interface, due to increasing adhesion to thesubstrate. The loss of colloidal stability inhibited therearrangement process, resulting in higher concentrations ofsquare lattice domains at large distances from the crystal edgecompared to systems without added salt.

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9

Ziga, Jeffrey Michael. "The Moroni formation in Salt Creek Canyon Central, Utah: implications for paleogene topography." Connect to resource, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1149600004.

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10

Robbins, Michael. "Sedimentology and sedimentary tectonics of the Salt Wash Member, Morrison Formation, Western Colorado." Thesis, Boston College, 2009. http://hdl.handle.net/2345/658.

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Thesis advisor: Kenneth G. Galli
Thesis advisor: Noah P. Snyder
The Brushy Basin Member of the Morrison Formation records a time of increased volcanic activity in the North American Cordillera during the Late Jurassic. Sedimentological and petrographic observations in the Brushy Basin, in conjunction with findings of widespread plutonic intrusion in the source areas, point to a volcanic pulse within the Cordilleran magmatic arc. This study investigated the subjacent Salt Wash Member, for the purpose of better constraining the timing of the volcanic pulse. Petrographic and statistical analyses of the Salt Wash sandstone identified statistically significant upsection trends in volcanic rock fragment and plagioclase feldspar at one of the four study areas. The remaining three study areas showed no upsection trends in sandstone composition that would reflect a pulse in volcanism during Salt Wash Member time. It is more likely that the Salt Wash was deposited during a time of volcanic quiescence leading up to the post-Nevadan Orogeny volcanic reactivation. Sedimentology and cementation patterns of the Salt Wash Member were also studied. Cathodoluminescence indicates that the member was well-flushed with shallow formation waters, thus preventing any calcite optical zoning. Luminescence intensity suggests that the Salt Wash Member sediments were cemented at varying depths and within differing Eh-pH regimes. Field-based sedimentological observations support a model of braided stream channel deposition across a semi-arid landscape with streamflow entering the basin from both the south and west
Thesis (MS) — Boston College, 2009
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Geology and Geophysics
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11

Raad, Fadl. "Balearic Promontory architecture and history during the formation of the Mediterranean Salt Giant." Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONG018.

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Entre 5.97 et 5.33Ma, à la fin du Miocène, un événement géologique exceptionnel aux conséquences majeures a affecté le bassin méditerranéen : la Crise de Salinité Messinienne (CSM). Cet épisode, dont le scénario exact reste encore énigmatique, est responsable du dépôt d’un volume considérable d’évaporites connu sous le nom de Géant Salifère de Méditerranée (GSM). Aujourd'hui, plus de 90 % des dépôts évaporitiques du MSG sont situés dans les bassins profonds de la Méditerranée et sont enfouis sous une épaisse couche de sédiments Plio- Quaternaire. Ces évaporites ont donc été étudiées principalement par imagerie sismique. Dans ce mémoire, nous nous intéressons aux dépôts de la crise enregistrés sur Promontoire des Baléares (BP), un haut topographique situé dans bassin de la Méditerranée occidentale. Du fait qu’il contient une succession de bassins en position intermédiaire stratégique, étagés entre les bassins marginaux du pourtour Méditerranéen et les bassins profonds, le BP se révèle un lieu unique avec des dépôts évaporitiques variés, ubiquistes et peu déformés tectoniquement, permettant d’accéder à une vision complète de l’enregistrement de la crise et pouvant mener à un scénario global cohérent.Cette thèse de doctorat a été réalisée dans le cadre d’un projet transdisciplinaire : « European Training Network (ETN) SaltGiant », dont l'objectif est de comprendre le GSM. Une approche pluridisciplinaire a été appliquée sur la zone d’étude choisie pour apporter des contraintes afin de répondre à certaines des nombreuses questions encore sans réponses sur la crise de salinité messinienne. Le travail de base a consisté en l'interprétation d'un large ensemble de données de sismique réflexion en Méditerranée occidentale, particulièrement concentré sur les dépôts messiniens du BP. Ceci a permis de préciser la cartographie des unités messiniennes de cette région et de définir leurs inter-relations géométriques. Une comparaison détaillée de ces unités évaporitiques avec celles du bassin messinien sicilien de Caltanissetta a été menée afin de reconstituer l'histoire de leur dépôt pour la confronter au modèle chrono-stratigraphique « consensuel » à trois phases. Pour reconstituer la paléo-bathymétrie de la dépression centrale de Majorque (CMD), le bassin le moins déformé situé dans sa partie centrale du BP, une interprétation structurale a permis d’identifier les principaux mouvements tectoniques post-MSC, modérés et localisés dans des corridors de décrochement. L'analyse par backstripping 2D et pseudo-3D, en collaboration avec d’autres collègues du projet SaltGiant, a alors permis de restaurer la paléo-bathymétrie de la CMD. Enfin, ces résultats ont été utilisés comme contraintes bathyétriques et de volumes pour modéliser le dépôt des évaporites observées, par des modèles physiques basés sur la théorie du contrôle hydraulique des détroits. Les résultats montrent que les unités messiniennes de la CMD pourraient constituer un analogue non déformé de celles qui affleurent à terre dans le bassin sicilien de Caltanissetta. Ils démontrent aussi qu'une baisse générale du niveau marin de grande amplitude (>850m) est nécessaire pour précipiter le volume de halite observé dans la CMD. Ces résultats, très bien contraints par ces études précises, remettent en cause certaines idées parfois encore largement acceptées. Ces doutes concernent en particulier l'apparition synchrone du sel à l'échelle du bassin méditerranéen, la profondeur maximale de dépôt du gypse inférieur primaire (PLG) et le moment de la formation du gypse inférieur resédimenté (RLG). En conclusion, ce mémoire montre la nécessité de réviser le scénario consensus actuel de la CSM, et l’importance de réaliser des forages en mer dans la région clef du BP, ce qui permettrait de révéler de nombreux mystères encore enfouis sous le géant salifère de Méditerranée
The Messinian Salinity Crisis (MSC; 5.97– 5.33 Ma) is one of the most controversial geological events that influenced the evolution of the Mediterranean Basin in the late Miocene, leaving behind an immense volume of evaporites known as the Mediterranean Salt Giant (MSG). Today, more than 90% of the MSG evaporitic deposits are located offshore, buried below thick sediments that are Pliocene to Quaternary in age, and have thus been studied mainly by marine seismic reflection imaging. The Balearic Promontory (BP), a prominent topographic high in the Western Mediterranean basin, contains a unique and tectonically poorly deformed MSC record that resembles the evaporitic record of other peri-Mediterranean marginal and intermediate basins.This PhD thesis was performed in the framework of the SaltGiant European Training Network (ETN), a cross-disciplinary project whose objective is to understand the formation of the MSG. The work of the thesis is focused on the MSC deposits of the BP. Multi-disciplinary approach was applied to answer some of the still open questions concerning the MSC event. As a first step, seismic interpretation of a wide seismic reflection dataset in the Western Mediterranean in general and in the BP in particular was performed, with the aim of refining the mapping of the Messinian units covering the area. To restitute the depositional history of the MSC evaporites of the BP, a detailed comparison with the Messinian evaporitic units of the Sicilian Caltanissetta Basin was carried out, in which a discussion on how this history matches the existing 3-stages chrono-stratigraphic ‘consensus model’ is illustrated. The next step consisted in the restoration of the paleo-bathymetry of the BP at the beginning of the MSC, focusing on the relatively less-deformed basin located in the central part of the BP and called the Central Mallorca Depression (CMD). To achieve this restoration, structural interpretation in the CMD area was done where the main post-MSC tectonic-related vertical movements that altered the MSC paleo-bathymetry were identified. Then 2D and pseudo-3D backstripping analysis were applied in collaboration with other colleagues from the SaltGiant project, to restore the paleo-bathymetry. In the final step, the paleo-bathymetry was used to model the deposition of the MSC evaporite volumes observed in the CMD using physics-based models built on strait hydraulic-control theory. The results show that the MSC units of the CMD could constitute an undeformed analog of those outcropping on-land in the Sicilian Caltanissetta Basin. Moderate post-MSC deformation acted along MSC strike-slip corridors in the CMD following the MSC evaporites deposition, thus altering only locally the paleo-bathymetry. A high amplitude drawdown (>850m) is required during the halite stage of the MSC. The results rise a series of doubts about the current consensus model, still widely accepted. Doubts concern the synchronous onset of salt at the basin scale, the maximum depth of deposition of the Primary Lower Gypsum (PLG) and the timing of formation of the Resedimented Lower Gypsum (RLG). All the results and discussions hint to the need of revision of the current MSC consensus model, as well as the importance of initiating drillings offshore over the BP area, which would help revealing many of the mysteries still buried with the MSG
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12

Hall, Anne Marie. "The clay mineralogy of the lower San Andres formation, Palo Duro Basin, Texas." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/25880.

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13

Fang, Qing. "Biostratigraphic and sequence stratigraphic analysis of the Yegua Formation, Houston salt embayment, northern Gulf of Mexico /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.

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14

Smith, Kristine A. "Stratigraphy, Geochronology, and Tectonics of the Salt Lake Formation (Tertiary) of Southern Cache Valley, Utah." DigitalCommons@USU, 1997. https://digitalcommons.usu.edu/etd/6546.

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This study synthesizes the deposition and tectonic evolution of the Tertiary deposits in southern Cache Valley, a narrow, north-trending valley in the northeastern Basin-and- Range Province. The surrounding mountains consist of Proterozoic and Paleozoic sedimentary rocks. Southern Cache Valley is an east-tilted half-graben. The oldest Tertiary sediments are on the west side of the basin, and the overall dip is to the east. The Late Miocene to Early Pliocene Salt Lake Formation (Tsl) accumulated above the thin (to absent) Early to Middle Eocene Wasatch Formation (Tw) and the newly identified Fowkes and Norwood Tuff equivalents (Tfn; late Middle Eocene to Middle Oligocene). The two post-Wasatch units consist of felsic tuff, tuffaceous sandstone, pebble to boulder conglomerate, limestone, and sandstone. Pebble counts, generalized measured sections, and detailed mapping permitted subdivision of the Tertiary deposits into mappable subunits. Numerous faults and N-trending folds are present in Tertiary deposits in the SW part of the area. The Cenozoic-Paleozoic contact is offset by normal faults. The faults with ENE trends offset both the Paleozoic and Tertiary rocks, and thus are younger than 5 .1 Ma. Thick gravels, rich in Paleozoic carbonates, dominate exposures in the east, near the East Cache fault zone. Few cobbles are present within the Tfn except near the base, whereas conglomerates rich in clasts of Paleozoic carbonates are intertongued with tuffaceous sediments throughout the Tsl, especially eastward. Up to 8,000 feet (3439 m) of the Tsl accumulated as the narrow Cache Valley basin formed during the Neogene by rapid eastward downfaulting.
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15

Prochnow, Shane J. Nordt Lee C. "Paleosols as an indicator of ancient landscapes, climates and stratal response during the Triassic the Salt Anticline Region of Utah /." Waco, Tex. : Baylor University, 2005. http://hdl.handle.net/2104/3017.

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16

Roma, Nuñez Maria. "Formation and subsequent inversion of extensional salt-detached ramp-syncline basins developed above ramp-flatramp faults." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/672461.

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The widespread extensional deformation that took place during Jurassic to Cretaceous times in Western Europe and the North Atlantic margin resulted in the formation of several rift systems. Some of the resulting basins associated with these rifts show broad synclines detached on pre- or synkinematic Permian or Triassic salts and filled by thick sedimentary successions. They are rarely fault bounded, instead they are bounded by salt structures that are generally parallel to the major subsalt structures. As such, the formation of these extensional systems requires the presence of i) a subsalt extensional fault with significant dip changes and ii) an evaporitic unit above the extensional fault, which partially or completely decouples the suprasalt basin from the subsalt extensional fault. Moreover, the complexity of these scenarios further increases when some of these basins, during latest Cretaceous and Cenozoic times, were partially inverted or incorporated into fold-and-thrust belt.Synclinal basins have a significant exploration potential when their extensional geometry is preserved and when they have undergone positive tectonic inversion. However, in some cases, their subsalt geometry may not be fully recognizable, especially when the imaging of the subsalt seismic data is poor. The shape and kinematics of such faults have usually been established using the architecture of synkinematic units and by assuming complete coupling of the hangingwall rocks. Therefore, there are fault interpretations that do not consider the role of deep salt layers, which clearly act as an effective detachment, decoupling sub- and suprasalt deformations.This thesis provides a review of the formation and evolution extensional synclinal basins and an overview of the widespread-recognized salt-detached ramp-syncline basins. To obtain a deeper understanding of the geometry and kinematic evolution of these salt- detached ramp-syncline basins, the principal aim of this thesis is to decipher the factors that are involved in the development of these basins during both extension and inversion.To achieve this goal we carried out a deep investigation about the state of the art of extensional analog models, then we performed two experimental programs consisting in different sandbox models. The experimental results, together with the new used analytic tools, reveal that the kinematic evolution of the salt-detached ramp-syncline basins during extension and inversion depends on the interaction of different factors that may function simultaneously. Our results show that the main structure formed at the end of the extension is a salt-detached ramp-syncline. Its formation and evolution not only depends on the subsalt fault type and geometry, but also on the subsalt fault displacement, salt migration, salt thickness and degree of decoupling. In addition, the inversion of these salt-detached ramp- syncline basins is also controlled by syninversion sedimentation, erosion and the kinematics of the inherited extensional and salt structures (or its equivalent welding). The inversion of these basins resulted in a major thick-skinned fault-bend anticline with thin-skinned contractional structures.Our results are used to improve the interpretation of the Mesozoic Columbrets Basin (Western Mediterranean) and serve a guide for seismic sections of inverted Mesozoic salt- detached ramp-syncline basins on the Atlantic margins, where subsalt faults are not well- imaged, and thus the suprasalt geometries must be used to infer the subsalt structure.
L’extensió Juràssica – Cretàcica Inferior que va tenir lloc a l’Europa Occidental i al marge Nord Atlàntic va resultar en la formació de nombrosos sistemes de rift. Les conques associades a aquests rifts es mostres com a sinclinals amples, reomplerts per grans successions sedimentaries i desenganxats a un nivell salí (Pèrmic o Triàsic Superior). Aquestes conques rarament estan directament associades a falles, en canvi es troben limitades per estructures salines que generalment son paral∙leles a les estructures del basament. Per tant, la formació d’aquests sistemes extensionals requereix la presencia de i) una falla de basament extensiva amb diferents cabussaments i ii) una unitat evaporítica a sobre d’aquesta falla, la qual genera un desacoblament parcial o total respecte la conca i la falla extensiva. A més a més, la complexitat d’aquests contextos geològics augmenta quan algunes d’aquestes conques es troben parcialment invertides o fins i tot incorporades en cinturons de plecs i encavalcament durant el Cretaci Superior i Cenozoic.Les dades sísmiques i de camp permeten precisar la geometria d’aquestes conques sinclinals, però no la de les falles extensionals que las van originar. La geometria i la cinemàtica de las falles extensives associades ha aquestes conques, normalment s’ha establert utilitzant la geometria dels materials més superficials i assumint un acoblament total entre el basament i la cobertora. Aquestes interpretacions no consideren el paper que pot juga un nivell salí profund que clarament desacobla la deformació entre el basament i la cobertora.L’objectiu principal d’aquesta tesi es investigar els principals factors que controlen la formació i evolució de les conques sinclinals, utilitzant com a eina principal la modelització analògica. Per assolir aquest objectiu s’ha realitzat una revisió sobre conques sinclinals i una revisió de models analògics extensius realitzats fins ara. A partir d’aquests antecedents s’han realitzat dos programes experimentals. Els resultats d’aquests mostren com la formació i evolució de les conques sinclinals depenen de diversos factors que actuen simultàniament durant l’extensió i la posterior inversió.Aquesta tesi es pot utilitzar com a guia per reduir les incertes durant la interpretació de la geometria del basament associat a conques sinclinals desenvolupades en contextos salins, sobretot en els casos on les dades sísmiques disponibles no tenen bona resolució i cal utilitzar la geometria de la cobertora per reconèixer l’estructura del basament.
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Lasser, Jana Verfasser], Lucas [Akademischer Betreuer] Goehring, Andreas [Gutachter] Tilgner, and Eberhard [Gutachter] [Bodenschatz. "Geophysical Pattern Formation of Salt Playa / Jana Lasser ; Gutachter: Andreas Tilgner, Eberhard Bodenschatz ; Betreuer: Lucas Goehring." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/118142741X/34.

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18

Swan, Alistair Michael. "Quantification of a distributive fluvial system : an example from the Salt Wash unit of the Morrison Formation, Utah." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=239012.

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Fluvial systems and their associated deposits host globally important mineral deposits, water reserves and hydrocarbons. Crucial to the extraction of these resources is an understanding of heterogeneity distribution within deposits of fluvial systems. To constrain and predict heterogeneity distribution within fluvial deposits, outcrop data together with lidar and drone derived virtual outcrop models have been collected from the Salt Wash Distributive Fluvial System (DFS) in Utah and Colorado. The study records an analysis of sedimentary architecture, facies distribution and intra-channel heterogeneity of five study sites within the proximal, medial and distal reaches of the Salt Wash DFS. Specifically the fluvial style, lateral variability of fluvial architecture, intrachannel and overbank ratio, grainsize, channel body and storey width:thickness ratios and intrachannel heterolthics at outcrops considered representative of the proximal, medial and distal portions of a DFS have been documented. Data from the study sites have been used to generate 3D reservoir models. The models have been subject to flow simulation to better understand the significance of hetergenity variability within fluvial reservoirs at an 'inter-well' scale (approximatley 0.1 km2). An indepth workflow and methodology for measuring and describing DFS channel bodies and for the construction of a reservior flow simulation model from outcrop derived data are presented here. Data collection has involved mapping and measuring; palaeocurrents, barscale accretion surfaces, storey dimensions, channel body dimensions, facies and intrachannel heterolithics. Results show clear trends within channel channel bodies and associated deposits such as, intra channel heterogenity channel body percentage, channel body grain size, storey/channel body width thickness; which can be predicted within a distributive fluvial system context, ultimately leading to better subsurface interpretation with smaller datasets. This field based study of the Salt Wash DFS, coupled with virtual outcrop models has provided a quantitive analys's of channel body architectures and facies distributions. Additionally, field work conducted on point bar deposits now illustrates the limitations of 2D outcrops when attempting to describe meandering or braided fluvial deposits and why this may have resulted in gross underestimation of meanderbelt deposits in the fluvial rock record.
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Evans, Melissa Cheryl Foster. "Characterization and Formation of Particulate Nitrate in a Coastal Area." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000142.

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20

Li, Zhaoyang, and 李朝陽. "Novel strontium fortified calcium salt for enhancing bone formation: an in vitro and in vivo large animal modelstudy." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39557108.

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21

Rudolph, Wolfram W., and Gert Irmer. "Hydration and ion pair formation in common aqueous La(III) salt solutions: a Raman scattering and DFT study." Royal Society of Chemistry, 2015. https://tud.qucosa.de/id/qucosa%3A36118.

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Raman spectra of aqueous lanthanum perchlorate, triflate (trifluorosulfonate), chloride and nitrate solutions were measured over a broad concentration (0.121–3.050 mol Lˉ¹) range at room temperature (23 °C). A very weak mode at 343 cmˉ¹ with a full width at half height at 49 cmˉ¹ in the isotropic spectrum suggests that the nona-aqua La(III) ion is thermodynamically stable in dilute perchlorate solutions (∼0.2 mol Lˉ¹) while in concentrated perchlorate solutions outer-sphere ion pairs and contact ion pairs are formed. The La³⁺ nona-hydrate was also detected in a 1.2 mol Lˉ¹ La(CF₃SO₃)₃(aq). In lanthanum chloride solutions chloro-complex formation was detected over the measured concentration range from 0.5–3.050 mol Lˉ¹. The chloro-complexes in LaCl₃(aq) are fairly weak and disappear with dilution. At a concentration <0.1 mol Lˉ¹ almost all complexes disappeared. In LaCl₃ solutions, with additional HCl, a series of chloro-complexes of the type [La(OH₂)₉₋nCln]⁺³⁻ⁿ (n = 1–3) were formed. The La(NO₃)₃(aq) spectra were compared with a spectrum of a 0.409 mol Lˉ¹ NaNO₃(aq) and it was concluded that in La(NO₃)₃(aq) over the concentration range from 0.121–1.844 mol Lˉ¹, nitrato-complexes, [La(OH₂)₉₋n-(NO₃)n]⁺³⁻ⁿ (n = 1, 2) were formed. These nitrato-complexes are quite weak and disappear with dilution <0.01 mol Lˉ¹. DFT geometry optimizations and frequency calculations are reported for a lanthanumnona-hydrate with a polarizable dielectric continuum in order to take the solvent into account. The bond distances and angles for the cluster geometry of [La(OH₂)₉]³⁺ with the polarizable dielectric continuum are in good agreement with data from recent structural experimental measurements and high quality simulations. The DFT frequency of the La–O stretching mode at 328.2 cmˉ¹, is only slightly smaller than the experimental one.
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22

Cook, Ethan L. "Near-Salt Stratal Geometries and Implications for the Evolution of the Onion Creek Diapir Moab, UT." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6327.

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The Onion Creek Diapir is one of many salt domes proximal to the Uncompahgre thrust front of the ancestral rockies in the Paradox Basin. It is comprised of Paradox Formation evaporites and large blocks of Honaker Trail Formation carbonates that were deformed by loading of Permian Cutler Formation progradational alluvial to fluvial fans. The history of salt movement in the Onion Creek Diapir is recorded in the near-salt strata. Large salt bodies and their adjacent mini-basins evolve conforming to a complex relationship between salt withdrawal, creating localized accommodation, and sediment deposition. Migrating mini-basin depo-centers, thinned and folded strata, and spatial facies trends reveal the relative rates of diapirism and sedimentation. The study area outcrop, north of the diapir, is divided by significant stratigraphic horizons that help define depositional periods. Six measured sections in the study area reveal higher preservation rates of fine grained floodplain deposits, typically destroyed in alluvial environments, than at locations correlating to stratigraphic levels high in the outcrop suggesting a low accommodation environment evolving into higher accommodation where stacked channel complexes are preserved. Preserved slump folding at the base of the outcrop reveals that although some salt emergence occurred in the earliest depositional period it was not significant enough to preclude sediment deposition or to divert the Cutler fluvial network and destroy floodplain facies. A 3-D digital outcrop, modeled from photogrammetric data, illustrates the development of localized accommodation, attracting fluvial channel in a near-salt, tight axial syncline during the later depositional period. These evidences suggest a greater emergence of the diapir and likely diversion of the Cutler channel complexes.
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23

Jochems, Andrew P. "Formation, Deformation, and Incision of Colorado River Terraces Upstream of Moab, Utah." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1754.

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Fluvial terraces contain information about incision, deformation, and climate change. In this study, a chronostratigraphic record of Colorado River terraces is constructed from optically stimulated luminescence (OSL) dating of Pleistocene alluvium and real-time kinematic (RTK) GPS surveys of terrace form. This record is analyzed to relate terrace formation to late Pleistocene climate fluctuations, and terrain analyses and longitudinal profile patterns reveal recent salt-related activity in the northern Paradox Basin as well as patterns in Colorado Plateau incision. A well-preserved, correlative suite of mainstem (M) fluvial deposits exists along the Colorado River upstream of Moab, Utah. Absolute dates indicate sedimentation >70 ka (M7, M6/M5), 70-50 ka (M4), 50-40 ka (M3), and 35-25 ka (M2). The M4 and M2 formed during the crescendo to glacial maxima, but the M7, M6/M5, and M3 were deposited during variable climate of marine isotope stages (MIS) 5 and 3. Deposits include thin (<7 m) strath terraces and thick (10-20 m) fill terraces. Our results suggest that terrace sedimentation is linked to enhanced sediment flux during glaciations in Rocky Mountain headwaters (M4 and M2), but major deposits also formed during dryland tributary sediment loading with markedly different timing (M6/M5 and M3). Conversely, incision may be driven by higher deglacial flows. Clast provenance data demonstrate greater percentages of locally-sourced sediment in M6/M5 and M3 deposits. Valley-bottom geometry and neotectonics control terrace form, with strath terraces found in bedrock-restricted reaches and fill terraces in wider valleys. Previously speculated salt deformation in this area is confirmed by localized collapse preserved in M4 stratigraphy in the Cache Valley graben and ~15 m of broader subsidence upstream. Concavity and knickzone distributions in tributary profiles are discordant and represent subtle expressions of salt-tectonic activity. Finally, a surprisingly rapid incision rate of ~900 m/Ma over the past ~70 ka suggests that the Colorado River may be responding to flexural rebound in the central plateau, but is faster than that predicted by the debated bull's-eye pattern of regional incision. This locally high rate may also reflect a transient wave of incision, as suggested by increased Pleistocene rates interpreted by studies in Glen and Grand canyons.
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24

Huang, Yan. "Micro- and Nanogel Formation through the Ionic Crosslinking of Polyelectrolytes." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1417781855.

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25

Li, Zhaoyang. "Novel strontium fortified calcium salt for enhancing bone formation an in vitro and in vivo large animal model study /." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39557108.

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26

David, Sarah. "Improving the solubility and dissolution of poorly soluble drugs by salt formation and the consequent effect on mechanical properties." Thesis, Aston University, 2005. http://publications.aston.ac.uk/11026/.

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The bioavailability of BCS II compounds may be improved by an enhanced solubility and dissolution rate. Four carboxylic acid drugs were selected, which were flurbiprofen, etodolac, ibuprofen and gemfibrozil. The drugs were chosen because they are weak acids with poor aqueous solubility and should readily form salts. The counterions used for salt formation were: butylamine, pentylamine, hexylamine, octylamine, benzylamine, cyclohexylamine, tert-butylamine, 2-amino-2-methylpropan­2-ol, 2-amino-2-methyl propan-1,3-ol and tromethamine. Solubility was partially controlled by the saturated solution pH with the butylamine counterion increasing the solution pH and solubility and dissolution to the greatest extent. As the chain length increased, solubility was reduced due to the increasing lipophilic nature of the counterion. The benzylamine and cyclohexylamine counterions produced crystalline, stable salts but did not improve solubility and dissolution significantly compared to the parent compound. The substitution of hydroxyl groups to tert-butylamine counterions produced an increase in solubility and dissolution. AMP2 resulted in the most enhanced solubility and dissolution compared to the parent drug but using the tris salt did not further improve solubility due to a very stable crystal lattice structure. The parent drugs were very difficult to compress due to orientation effects and lamination. Compacts were prepared of each parent drug and salt and their modulus of elasticity values were measured using a three-point bend (Young’s modulus, E0) were extrapolated to zero porosity and compared. Compressibility and E0 were improved with the butylamine, tert-butylamine, cyclohexylamine and AMP2 counterions. The most significant improvement in compression and E0 was with the AMP2 salts. Mechanical properties were related to the hydrogen bonding within the crystal lattice structure for the gemfibrozil salt series.
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27

Brassieur, David Aaron. "An Investigation Into the Origin, Composition, and Commercial Significance of a Sedimentary Subsalt Formation: Keathley Canyon, Gulf of Mexico." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2245.

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Sub-salt oil and gas formations in deep-water northern Gulf of Mexico are high priority targets. Advances in seismic processing allow for high-resolution, below-salt imaging. Understanding the modes of salt emplacement provide insight into sub-salt traps and potential drilling hazards. A sub-salt sedimentary unit lies in the Keathley Canyon protraction. Autosutures created the transport-parallel lineaments of the upper surface of the unit. In addition, highly variable sediment aggradation rates created ramps, flats, and basal cutoffs along the base of the allochthon as salt and sediment competed for space. Seismic models identify modes of salt emplacement, salt/sediment interactions, and mechanisms responsible for the morphology. Petrophysical assessments highlight an abnormally pressured, dirty salt environment transitioning into a gouge zone. Dirty salt adds an element of difficulty to managing borehole pressures requiring a unique mud-weight plan designed to resist formation pressures without fracturing lithology.
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28

Prochaska, Lesley C. "Geochemical Evidence for Vertical Migration of Deep Formation Fluids through the Baton Rouge -Denham Springs Fault System." ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1561.

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Accumulations of brackish groundwater exist across south Louisiana within the shallow, south-dipping Pleistocene to Upper Miocene Baton Rouge Aquifer System (BRAS). This research investigates the source of brackish groundwater through geochemical analysis of representative groundwater samples by comparing the following geochemical ratios along with other trace elements. Low Bromide (Br)/Chloride (Cl) and Potassium (K) /Cl ratios, high Sodium (Na) /Cl ratios, trace Magnesium (Mg) concentrations, and low Strontium (Sr) 87/Sr86 in brackish waters from the BRAS are inconsistent with in situ saline water from marine formation fluids of similar age. The ratios are consistent with in situ saline-water sources from Lower Miocene or Paleogene formation fluids from dissolved recrystallized halite. Deep formation fluids have interacted with Louann Salt diapirs underlying the BRAS area, dissolving halite, and are shown to have moved up fault planes and entered shallow aquifers to mix with the in situ groundwaters.
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ZHANG, HUAN. "EFFECTS OF SOLUTION COMPOSITION (SALTS, PH, DIELECTRIC CONSTANT) ON POLYELECTROLYTE COMPLEX (PEC) FORMATION AND THEIR PROPERTIES." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1543848436422118.

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30

Saedtler, Marco [Verfasser], Lorenz [Gutachter] Meinel, and Ulrike [Gutachter] Holzgrabe. "Pharmaceutical formulation strategies for novel antibiotic substances utilizing salt formation and two- and three-dimensional printing techniques / Marco Saedtler ; Gutachter: Lorenz Meinel, Ulrike Holzgrabe." Würzburg : Universität Würzburg, 2021. http://d-nb.info/1225296013/34.

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31

Lohse, Samuel E. 1981. "Direct Synthesis of Thiolate-Protected Gold Nanoparticles Using Bunte Salts as Ligand Precursors: Investigations of Ligand Shell Formation and Core Growth." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11531.

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xx, 242 p. : ill. (some col.)
Applications of ligand-protected nanoparticles have increased markedly in recent years, yet their controlled synthesis remains an under-developed field. Nanoparticle syntheses are highly specialized in their execution and often possess significant limitations. For example, the synthesis of thiol-stabilized gold nanoparticles (AuNPs) with core diameters greater than 5.0 nm is difficult to achieve using existing methods. This dissertation describes the development of a synthetic strategy for thiolate-stabilized AuNPs over a wide range of core sizes using alkyl thiosulfates (Bunte salts) as ligand precursors. The use of Bunte salts permits the synthesis of larger AuNPs than can be achieved using thiols by allowing the AuNP cores to grow to larger diameters before the formation of the thiolate ligand shell. Chapter II details the development of a direct synthesis strategy using Bunte salts as ligand precursors that produces AuNPs with diameters up to 20 nm. Chapter III describes an investigation of the ligand shell formation that occurs during these syntheses. The ligand shell formation involves the adsorption of the Bunte salt to the AuNP surface, where it is converted to the thiolate. This conversion requires an excess of sodium borohydride in the synthesis of >5 nm AuNPs, but not for the synthesis of smaller AuNPs. This synthetic strategy was adapted for use in flow reactors to attain simultaneous AuNP synthesis and characterization. Chapter IV demonstrates that thiol-stabilized AuNPs can be synthesized in a microfluidic device with product monitoring provided by UV-vis absorbance spectroscopy. The development of a capillary flow reactor that permits the incorporation of new monitoring techniques is presented in Chapter V. The incorporation of Small-Angle X-ray Scattering (SAXS) analysis provides quantitative in situ determinations of AuNP diameter. The combination of synthetic control and monitoring makes capillary flow reactors powerful tools for optimization of NP syntheses and monitoring NP growth. In Chapter VI, the capillary flow reactor is used in an investigation of AuNP core growth. We also review AuNP growth mechanisms and show how to differentiate these using SAXS and UV-vis analysis. In these studies, AuNP growth is unexpectedly shown to involve a coalescence mechanism. This dissertation includes previously published and co-authored material.
Committee in charge: Victoria De Rose Chairperson; James E. Hutchison, Advisor; Catherine Page, Member; Darren W. Johnson, Member; Miriam Deutsch, Outside Member
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32

Brand, John Richard. "Structural and stratigraphic evolution of the central Mississippi Canyon Area: interaction of salt tectonics and slope processes in the formation of engineering and geologic hazards." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3327.

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Approximately 720 square miles of digital 3-dimensional seismic data covering the eastern Mississippi Canyon area, Gulf of Mexico, continental shelf was used to examine the structural and stratigraphic evolution of the geology in the study area. The analysis focused on salt tectonics and sequence stratigraphy to develop a geologic model for the study area and its potential impact on engineering and geologic hazards. Salt in the study area was found to be established structural end-members derived from shallow-emplaced salt sheets. The transition from regional to local salt tectonics was identified through structural deformation of the stratigraphic section on the seismic data and occurred no later than ~450,000 years ago. From ~450,000 years to present, slope depositional processes have become the dominant geologic process in the study area. Six stratigraphic sequences (I-VI) were identified in the study area and found to correlate with sequences previously defined for the Eastern Mississippi Fan. Condensed sections were the key to the correlation. The sequence stratigraphy for the Eastern Mississippi Fan can be extended ~28 miles west, adding another ~720 square miles to the interpreted Fan. A previously defined channel within the Eastern Fan was identified in the study area and extended the channel ~28 miles west. Previous work on the Eastern Fan identified the source of the Fan to be the Mobile River; however, extending the channel west suggests the sediment source to be from the Mississippi River, not the Mobile River. Further evidence for this was found in ponded turbidites whose source has been previously established as the Mississippi River. Ages of the stratigraphic sequences were compared to changes in eustatic sea level. The formation stratigraphic sequences appear decoupled from sea level change with ?pseudo-highstands? forming condensed sections during pronounced Pleistocene sea level lowstands. Miocene and Pleistocene depositional analogues suggest the location of the shifting Mississippi River Pleistocene depocenter is a more dominant influence on sequence formation. Thus, the application of traditional sequence interpretation with respect to sea level change should be reconsidered to also account for the shifting depocenter for both the study area as well as the broader Eastern Mississippi Fan.
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33

Olivito, João Paulo Roncolatto. "Modelo deposicional dos reservatórios carbonáticos lacustres neocretácicos da Formação Coqueiros no norte da Bacia de Campos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/182027.

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As recentes descobertas de acumulações gigantes de hidrocarboneto nas coquinas e outras rochas carbonáticas lacustres das supersequência Rifte e Pós-Rifte (pré-sal) das Bacias de Campos e Santos tem fomentado uma série de pesquisas focadas em entender a gênese destes reservatórios singulares. Esta pesquisa se concentra em entender o modelo deposicional e evolução das rochas bioclásticas retrabalhadas e demais rochas associadas pertencentes a Formação Coqueiros, depositadas em alto externo no norte da Bacia de Campos, durante a transição entre as fases final de rifte e sag, a partir da integração de dados petrográficos de amostras laterais e testemunho, dados sísmicos e de perfis de poços. Sete fácies carbonáticas, duas magnesianas, uma siliciclástica e três híbridas foram definidas a partir de análise combinando informações de amostras laterais e estruturas sedimentares interpretadas em perfis de imagem. Rudstones e grainstones bioclásticos com moderado a alto retrabalhamento das conchas representam 65% das amostras descritas. Diversas evidências apontam para um ambiente deposicional lacustre predominantemente raso, dominado por correntes de tempestades, sendo as principais: (i) presença de rudstones com estratificações cruzadas de alto ângulo (>14°) e paleo-correntes de longshore; (ii) ocorrência pontual de sedimentos lamosos intercalados a espessos pacotes de rudstones bioclásticos amalgamados, indicando ambiente sujeito a correntes de maior energia, acima da zona de ação de ondas de tempo bom; (iii) predomínio de depósitos de rudstones desprovidos de matriz sobre o alto estrutural, com grande continuidade lateral, coerentes com processos de tempestades atuantes sobre amplas áreas de lago raso; (iv) depósitos de rudstones maciços, com conchas desorganizadas, semelhantes aos depósitos bioclásticos costeiros modernos da Califórnia e de Shark Bay. Três conjuntos de associação de fácies são propostos : (i) conjunto de alta energia, representado por rudstones e grainstones bioclásticos desprovidos de matriz, depositados entre as regiões de shoreface e berma, acima do nível de ação de onda de tempo bom (FWB); (ii) conjunto de baixa energia, formado pelas fácies hibridas com matriz lamosa ou peloidal e demais fácies de granulometria inferior à areia média, depositados abaixo do FWB ou em ambientes rasos protegidos (backshore); (iii) conjunto formado principalmente por facies de oóides argilo-magnesianos, cujo controle é dado pela composição mais alcalina da água do lago. Blocos diagramas dos modelos deposicionais de cada uma das cinco unidades sismo-estratigráfica estabelecidas para a Formação Coqueiros na área de estudo permitiram inferir a evolução das associações de fácies ao longo do tempo, evidenciando uma tendência geral de raseamento do lago, culminando com a discordância Pré-Neo-Alagoas (DPA). O padrão de paleo-correntes sugere atuação de mais de uma direção de vento sobre o alto externo, um mais forte vindo de noroeste e outro mais brando vindo de sudeste, resultando em fácies bioclásticas limpas de matriz e com bom potencial como reservatório em ambos os flancos do alto estrutural. Estas direções de ventos propostas para o Eobarremiano e Neoaptiano no norte da Bacia de Campos são de extrema importância para prever a localização das melhores fácies deposicionais da Fm. Coqueiros em outras áreas alvo de exploração de hidrocarboneto.
Recent discoveries of giant hydrocarbon accumulations in coquinas and other lacustrine carbonate rocks of Rift and Post-Rift (pre-salt) supersequences of Campos and Santos Basins have stimulated a series of studies focused on understanding the genesis of these unique reservoirs. An integrated petrologic-sedimentologic-stratigraphic-seismic study of Coqueiros Formation allowed characterizing the depositional model and evolution of reworked bioclastic rocks and other associated rocks deposited on the external high in the north of Campos Basin during the transition between late rift and sag stages. Seven carbonatic facies were defined from analysis combining information from sidewall core and sedimentary structures interpreted in image logs, in addition to one siliciclastic, two magnesian, and three hybrids facies. Bioclastic rudstones and grainstones with moderate to high reworking of the shells represent 65% of the samples described. Several pieces of evidences point to a predominantly shallow lacustrine depositional environment, dominated by storm currents: (i) presence of rudstones with high-angle cross-bedding (>14°) and longshore paleocurrents; (ii) limited occurrence of muddy sediments interbedded with thick packages of amalgamated bioclastic rudstones, indicating environment subject to high energy currents, above the fairweather wave base (FWB); (iii) predominance of rudstones deposits devoid of matrix on the structural high, with great lateral continuity, consistent with processes of storms acting on large areas of shallow lake; (iv) deposits of massive rudstones, with disorganized shells, similar to the modern coastal bioclastic deposits of California and Shark Bay. Three sets of facies association are proposed: (i) high energy set, represented by bioclastic rudstones and grainstones devoid of matrix, deposited between the shoreface and berm regions, above the FWB; (ii) low energy set, formed by hybrid facies with muddy or peloidal matrix and other facies of grain-size finer than medium sand, deposited below the FWB or in protected shallow environments (backshore); (iii) and an alkaline set, formed mainly by magnesian clay ooids, whose control is given by the more alkaline composition of lake water. Block diagrams of each of the five seismic-stratigraphic units, established for the Coqueiros Formation in the study area allowed to infer the evolution of the facies associations over time, demonstrate the general falling of relative lake level culminating in the pre-Neo-Alagoas unconformity (DPA). Paleocurrents suggests the activity of more than one wind direction over the external high, the stronger coming from northwest and a milder one coming from southeast, resulting in clean matrix bioclastic facies with good reservoir potential on both flanks of the structural high. These proposed wind directions for the Eobarremian and Neoaptian in the north of Campos Basin is extremely important to predict the location of the best depositional facies of the Coqueiros Formation in other target areas for hydrocarbon exploration.
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34

Allred, Isaac John. "Spatial Trends and Facies Distribution of the High-Energy Alluvial Cutler Formation, Southeastern Utah." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6253.

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The Cutler Formation is composed of thick, arkosic, alluvial conglomerate, sandstone, and mudstone shed southwestward from the Uncompahgre Uplift into the Paradox Basin. More basin-ward the Cutler is recognized as a group consisting of differentiable formations. Discrete formations historically have not been distinguished near the uplift, but this study identified several separate successions in the Richardson Amphitheater. Research at the Richardson Amphitheater, ~12 km southwest of the uplift and ~30 km northeast of Moab, Utah, led to a systematic subdivision of the Permian Cutler Formation proximal to the uplift. Likely driven by channel cutting and migration across the alluvial fan, six 10-20 m thick successions are partially exposed. The dominant observed facies are basal conglomerate and channel-fill trough cross-stratified sandstone overlain by finer-grained distal sheetflood and frequently pedogenically altered sandstone. Down-warping of identified successions and the presence of additional sands within the area of flexure suggest that localized salt withdrawal created a sediment depocenter in the Richardson Amphitheater, ~6 km northwest of the Onion Creek salt diapir. The identified salt withdrawal feature is more proximal to the Uncompahgre Uplift than any of the major documented salt structures in the area and was not previously documented. Six measured stratigraphic sections and hundreds of high-precision differential GPS data points outlining major lateral erosional surfaces form the basis for interpretation. Five mapped erosional surfaces (bounding surfaces based upon differential GPS point interpolation) are laterally extensive within the approximately one square kilometer study area, and as such, represent stratigraphically significant surfaces. Within the generated structural geocellular model, stratigraphic data from measured sections informed facies modeling between major surfaces. This outcrop model may serve as an analogue for subsurface systems deposited in similar settings.
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35

Johnson, Graham Richard. "The Formation and Growth of Marine Aerosols and the Development of New Techniques for their In-situ Analysis." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16117/1/Graham_Johnson_Thesis.pdf.

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Marine aerosols have attracted increasing attention over the past 15 years because of their potential significance for global climate modelling. The size distribution of these aerosols extends from super-micrometer sea salt mode particles down through 150 nm accumulation mode particles, 40 nm Aitken mode particles and nucleation mode particles which extend from 25 nm right down to clusters of a few molecules. The process by which the submicrometer modes form and grow and their composition have remained topics of debate throughout this time in large part because of the difficulties associated with determining their composition and relating it to proposed models of the formation process. The work compared the modality of marine aerosol influencing the South-east-Queensland region with that of other environmental aerosols in the region. The aerosol was found to be consistent with marine aerosols observed elsewhere with concentrations below 1000 cm-3 and frequently exhibiting the distinct bimodal structure associated with cloud processing, consisting of an Aitken mode at approximately 40 nm, an accumulation mode in the range 100-200 nm and a coarse mode attributed to sea salt between 600 and 1200 nm. This work included the development of two new techniques for aerosol research. The first technique measures aerosol density using a combination of aerosol size distribution and gravimetric mass concentration measurements. This technique was used to measure the density of a number of submicrometer aerosols including laboratory generated NaCl aerosol and ambient aerosol. The densities for the laboratory generated aerosols were found to be similar to those for the bulk materials used to produce them. The technique, extended to super-micrometer particle size range may find application in ambient aerosol research where it could be used to discriminate between periods when the aerosol is dominated by NaCl and periods when the density is more representative of crustal material or sulfates. The technique may also prove useful in laboratory or industrial settings for investigating particle density or in case where the composition is known, morphology and porosity. The second technique developed, integrates the existing physicochemical techniques of volatilisation and hygroscopic growth analysis to investigate particle composition in terms of both the volatilisation temperatures of the chemical constituents and their contribution to particle hygroscopic behaviour. The resulting volatilisation and humidification tandem differential mobility analyser or VH-TDMA, has proven to be a valuable research tool which is being used in ongoing research. Findings of investigations relating the composition of the submicrometer marine aerosol modes to candidate models for their formation are presented. Sea salt was not found in the numerically dominant particle type in coastal nucleation mode or marine Aitken and accumulation modes examined on the Southeast Queensland coast during periods where back trajectories indicated marine origin. The work suggests that all three submicrometer modes contain the same four volatile chemical species and an insoluble non-volatile residue. The volatility and hygroscopic behaviours of the particles are consistent with a composition consisting of a core composed of sulfuric acid, ammonium sulfate and an iodine oxide coated with a volatile organic compound. The volume fraction of the sulfuric acid like species in the particles shows a strong dependence on particle size.
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36

Johnson, Graham Richard. "The Formation and Growth of Marine Aerosols and the Development of New Techniques for their In-situ Analysis." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16117/.

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Marine aerosols have attracted increasing attention over the past 15 years because of their potential significance for global climate modelling. The size distribution of these aerosols extends from super-micrometer sea salt mode particles down through 150 nm accumulation mode particles, 40 nm Aitken mode particles and nucleation mode particles which extend from 25 nm right down to clusters of a few molecules. The process by which the submicrometer modes form and grow and their composition have remained topics of debate throughout this time in large part because of the difficulties associated with determining their composition and relating it to proposed models of the formation process. The work compared the modality of marine aerosol influencing the South-east-Queensland region with that of other environmental aerosols in the region. The aerosol was found to be consistent with marine aerosols observed elsewhere with concentrations below 1000 cm-3 and frequently exhibiting the distinct bimodal structure associated with cloud processing, consisting of an Aitken mode at approximately 40 nm, an accumulation mode in the range 100-200 nm and a coarse mode attributed to sea salt between 600 and 1200 nm. This work included the development of two new techniques for aerosol research. The first technique measures aerosol density using a combination of aerosol size distribution and gravimetric mass concentration measurements. This technique was used to measure the density of a number of submicrometer aerosols including laboratory generated NaCl aerosol and ambient aerosol. The densities for the laboratory generated aerosols were found to be similar to those for the bulk materials used to produce them. The technique, extended to super-micrometer particle size range may find application in ambient aerosol research where it could be used to discriminate between periods when the aerosol is dominated by NaCl and periods when the density is more representative of crustal material or sulfates. The technique may also prove useful in laboratory or industrial settings for investigating particle density or in case where the composition is known, morphology and porosity. The second technique developed, integrates the existing physicochemical techniques of volatilisation and hygroscopic growth analysis to investigate particle composition in terms of both the volatilisation temperatures of the chemical constituents and their contribution to particle hygroscopic behaviour. The resulting volatilisation and humidification tandem differential mobility analyser or VH-TDMA, has proven to be a valuable research tool which is being used in ongoing research. Findings of investigations relating the composition of the submicrometer marine aerosol modes to candidate models for their formation are presented. Sea salt was not found in the numerically dominant particle type in coastal nucleation mode or marine Aitken and accumulation modes examined on the Southeast Queensland coast during periods where back trajectories indicated marine origin. The work suggests that all three submicrometer modes contain the same four volatile chemical species and an insoluble non-volatile residue. The volatility and hygroscopic behaviours of the particles are consistent with a composition consisting of a core composed of sulfuric acid, ammonium sulfate and an iodine oxide coated with a volatile organic compound. The volume fraction of the sulfuric acid like species in the particles shows a strong dependence on particle size.
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37

Shah, Manoj Kumar. "Characterizing the Impact of Stress Exposure on Survival of Foodborne Pathogens." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/29389.

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Bacterial pathogens transmitted by the fecal-oral route endure several stresses during survival/growth in host and non-host environments. For foodborne pathogens, understanding the range of phenotypic responses to stressors and the environmental factors that impact survival can provide insights for the development of control measures. For example, the gastrointestinal system presents acidic, osmotic, and cell-envelope stresses and low oxygen levels, but Listeria monocytogenes can withstand these stresses, causing illnesses in humans. Survival/growth characteristics may differ among L. monocytogenes strains under these stressors due to their genetic diversities. Our knowledge of such phenotypic characteristics under bile and salt stresses are inadequate. In this dissertation, variation in growth characteristics was observed among L. monocytogenes strains under bile and osmotic stresses with no evidence of cross-protection, but rather an antagonistic effect was observed with the formation of filaments when pre-exposed to 1% bile and treated with 6% NaCl. This shows that variation in stress adaptability exists among L. monocytogenes strains with the ability to form filaments under these conditions. Similarly, Salmonella survival in soil is dependent on several factors, such as soil, amendment types, moisture, irrigation, and desiccation stress. In this study, the use of HTPP (heat-treated poultry pellets) was investigated as a soil amendment in the survival/growth of Salmonella in soil extracts mimicking runoff events, and in soil cultivated with spinach plants to assess its safety for use for an organic fertilizer. The presence of HTPP in soil increased S. Newport survival with a greater likelihood of its transfer to and survival on spinach plants. Increased microbial loads and rpoS mutant showed decreased growth/survival in soil extracts, however, rpoS was not important for survival in soil under the tested conditions showing possible lack of desiccation stress. These results show that HTPP provided nutrients to the Salmonella for increased growth and survival in soil extracts and soil, respectively, which show that the use of treated BSAAO to soils may still require appropriate mitigation to minimize Salmonella Newport contamination of leafy greens in the pre-harvest environment. Overall, the results in this study increased our understanding of L. monocytogenes and Salmonella phenotypic adaptation to stressful environments.
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38

Kergaravat, Charlie. "Dynamique de formation et de déformation de minibassins en contexte compressif : exemple du bassin de Sivas, Turquie Approche terrain et implications structurales multiéchelles." Thesis, Pau, 2016. http://www.theses.fr/2016PAUU3005/document.

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Cette thèse porte sur les interactions entre les déformations halocinétiques locales au sein des mini-bassins salifères et les déformations régionales compressives. L’étude s’appuie sur une analyse structurale multi-échelle détaillée d’une province à mini-bassins se développant dans le bassin d’avant pays de Sivas (Turquie). Une analyse de terrain approfondie, associée à une étude de données de subsurface, permet de proposer une révision des cartes géologiques ainsi qu’une évolution tectonosédimentaire identifiant les déformations liées à la tectonique salifère et celles liées à la propagation de la ceinture de plis et de chevauchements dans l’avant-pays. A partir de l’Eocène supérieur, le fluage del’évaporite autochtone, initié et entretenu par le chargement sédimentaire différentiel ainsi que par la déformation compressive, permet la formation d’une première génération de mini-bassins. Ces minibassins, constitués par une formation continentale Oligocène, vont être recouverts par une nappe d’évaporite allochtone accueillant une seconde génération de mini-bassins constitués de formations continentales et marines Oligo-Miocène. L’initiation du domaine de mini-bassins secondaires est caractérisée par une distribution polygonale du réseau de diapirs et de murs d’évaporites. Ces mini-bassins enregistrent localement les effets de la tectonique salifère par le développement d’une grande variété de structures halocinétiques à différentes échelles telles que les séquences halocinétiques unitaires (crochet et éventail), séquences composites (tabulaire ou fuseau) et megaflaps. Une série de modélisation analogique préliminaire amontré que ces structures peuvent se développer avec ou sans l’application d’une compression aux limites. De plus, les analogies géométriques entre les mini-bassins de Sivas et les provinces salifères connues suggèrent que la dynamique de formation de ces mini-bassins est au premier ordre contrôlée par le chargement sédimentaire différentiel, découplé partiellement de la compression régionale. Néanmoins, l’analyse du réseau de fractures et de l’endommagement matriciel souligne l’enregistrement précoce de la déformation compressive régionale lors de l’initiation des mini-bassins.L’influence du raccourcissement sur la structuration de la province à mini-bassins s’exprime de manière croissante par l’écrasement des corps salifères permettant : (i) le développement de dépocentres linéaires préférentiellement perpendiculaire à la direction de raccourcissement, (ii) l’émergence de corps allochtones d’évaporites en surface, ainsi que (iii) la rotation et translation des mini-bassins. Cette province à mini-bassins génère une discontinuité dans la propagation et l’accommodation de la déformation compressive : la déformation compressive est accommodée auniveau du réseau polygonal de murs d’évaporites formant des structures multidirectionnelles. De plus, cette concentration de la déformation par écrasement des structures salifères entraine la remobilisation des évaporites vers l’avant-pays générant alors un nouveau système salifère
This doctoral work studies the interaction between withdrawal of minibasins and regional shortening during evolution of a foreland fold-and-thrust belt. This is achieved by a multiscale structural analysis of the Sivas Basin (Turkey). Extensive field work and regional seismic lines interpretations helped to build a new and detailed geologic map of the central Sivas Basin and to provide a new tectonosedimentary framework highlighting the influence of salt tectonics and the regional shortening, starting in the Late Eocene by the autochthonous evaporite deposition. This level is remobilized by the northward migrating sedimentary load, shortening and tilting of the basin southern margin during propagation of the foreland fold-and-thrust belt. Evaporite flow is recorded by the withdrawal of a primary generation of continental Oligocene minibasins which are then covered by an evaporite canopy. The canopy extending northward allows the development of second generation of continental to shallow marine mini-basins from Oligocene to Middle Miocene. Secondary minibasins initiation in the central part of the Basin, is characterized by sub-circular minibasins surrounded by polygonal diapirs and walls. Flanking these minibasins, a large variety of halokinetic structures is described: halokinetic sequences (hooks and wedges), composite halokinetic sequences and megaflaps. Preliminary sand-box modeling study suggests the development of thesehalokinetic structures both with and without shortening. Furthermore, minibasins geometries are closely similar to those imaged or mapped in other salt provinces suggesting that mini-basin withdrew is first control by sedimentary load, probably due to decoupling by the salt. However, the fractures and anisotropy of magnetic susceptibility analyses suggests the record of shortening since the minibasins initiation. The increase influence of regional shortening on the minibasins domain is expressed by salt walls and diapirs squeezing inducing: (i) the development of linear mini-basins perpendicular to the shortening direction, (ii) salt sheet emplacement and (iii) the translation/rotation of minibasins. The minibasins province produces a discontinuity for the fold-and-thrust belt propagation. Indeed, the minibasins province accommodates the shortening deformation along the polygonal network of salt walls and diapirs forming multidirectional structures. Furthermore, the regional shortening accommodation by salt structures squeezing produce an evaporitic remobilization and migration of a salt canopy toward the foreland basin
Bu doktora tezi/çalışması, bir önülke kıvrım ve bindirme kuşağının evrimi sırasında minihavzaların çekilmesi ve bölgesel kısalma arasındaki etkileşimi konu edinir. Çoklu ölçekteki bu yapısal analiz Sivas Havzası (Türkiye) ölçeğinde gerçekleştirilmiştir. Kapsamlı saha çalışması ve bölgesel olarak sismik kesitlerden ortaya çıkarılan yorumlamalar, Sivas Havzası’nın orta kesiminde detaylı bir jeolojik haritalama yapımına yardımcı olmuş ve otokton evaporit depolanmasının başladığı Geç Eosen’den başlayarak havza için tuz tektoniği ve bölgesel kısalmanın etkisindeki yeni bir tektono-sedimanter çatının ortaya çıkarılmasına neden olmuştur. Söz konusu seviye, önülke kıvrım ve bindirme kuşağının ilerlemesisüresince kuzeye doğru sedimanter dolgunun göçüyle birlikte havzanın güney kenarında kısalıma uğrayarak ve eğim kazanarak remobilize olmuştur. Evaporit akışı, kıtasal Oligosen minihavzalarının ilksel olarak oluşumundan sonra çekilmesine bağlı olarak gözlenmiş ve sonrasında evaporit yaygılarıyla örtülmüştür. Kuzeye kadar uzanan bu yaygı, Oligosen-Orta Miyosen arasında kıtasaldan sonra sığ denizel tipteki ikincil minihavzaların gelişimine de neden olmuştur.Havzanın orta kesimindeki ikincil minihavza başlangıcı, poligonal diyapir ve duvarlar tarafından çevrelenen dairesel minihavzalarla karakterize olur. Bu minihavzaların kanatlarında halokinetik yapılar tanımlanmıştır. Kanca (hook) ve kama (wedge) tiplerde olmak üzere halokinetik seriler, kompozit halokinetik seriler ve megaflaplar bu yapılar arasında sayılabilir. Çalışmanın başlangıcında yapılan kum kutusu model deneyi, bu halokinetik yapıların kısalmayla veya kısalma olmaksızın geliştiğini göstermiştir. Buna ek olarak minihavzaların geometrisi, muhtemelen tuzun ayrışmasından dolayı tortul yükün ilkkontrolünden dolayı çekilen diğer tuz bölgelerinde önerilen haritalanmış minihavzalara benzerdir. Bununla birlikte kırık ve manyetik suseptibilite analizleri, minihavzaların başlangıcından itibaren kısalmanın kayıt edilebilmesi hakkında fikir vermektedir. Minihavza bölgelerindeki bölgesel kısalımın artışı, tuz duvarları ve diyapirlerin sıkışmasıyla birlikte(i) kısalma yönüne dik durumdaki çizgisel minihavzaların gelişimi, (ii) tuz örtülerinin yerleşimi ve (iii) minihavzaların yer değiştirmesi veya dönmesiyle açıklanır. Minihavzalar bölgesi, kıvrım ve bindirme kuşağının gelişimi için bir süreksizlik üretir. Aslında, minihavzalar birçok yönde yapılar oluşturarak tuz duvarları ve diyapirlerin polygonal şekildeki yerleşimi boyunca kısalma deformasyonuna eşlik eder. Üstelik, tuz yapılarının eşlik ettiği bölgesel kısalma önülke havzalarına doğru evaporitik bir göçe de neden olmaktadır
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39

Holzammer, Christine [Verfasser], Andreas [Akademischer Betreuer] Bräuer, Andreas [Gutachter] Bräuer, and Markus [Gutachter] Richter. "Raman spectroscopic study of the effect of aqueous salt solutions on the formation and dissociation behavior of CO2 gas hydrates / Christine Holzammer ; Gutachter: Andreas Bräuer, Markus Richter ; Betreuer: Andreas Bräuer." Freiberg : Technische Universität Bergakademie Freiberg, 2020. http://d-nb.info/1220636916/34.

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40

Pei, Hongxia. "Bead Modeling of Transport Properties of Macromolecules in Free Solution and in a Gel." Digital Archive @ GSU, 2010. http://digitalarchive.gsu.edu/chemistry_diss/49.

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On the bead modeling methodology, or BMM, a macromolecule is modeled as a rigid, non-overlapping bead array with arbitrary radii. The BMM approach was pioneered by Kirkwood and coworkers (Kirkwood, J.G., Macromolecules, E.P. Auer (Ed.), Gordon and Breach, New York, 1967; Kirkwood, J.G., Riseman, J., J. Chem. Phys., 1948, 16, 565) and applied to such transport properties as diffusion, sedimentation, and viscosity. With the availability of computers, a number of investigators extended the work to account for the detailed shape of biomolecules in the 1970s. A principle objective of my research has been to apply the BMM approach to more complex transport phenomena such as transport in a gel, electrophoresis (free solution and in a gel), and also transport in more complex media (such as the viscosity of alkanes and benzene). Variables considered by the BMM include the number of beads (N), the radii of the beads, net charge and charge distribution, conformations, salt type, and salt concentration. The BMM has been extended to: (1) account for the existence of a gel; (2) characterize the charge and secondary structure of macromolecules; (3) account more accurately for hydrodynamic interaction (remove the orientationnal preaveraging approximation of hydrodynamic interaction); (4) study the effect of ion relaxation for particles in arbitrary size, shape, and charge; (5) consider the salt dependence of electrokinetic properties; (6) account for the formation of possible complex between guest ions and BGE ions. We also did diffusion constant measurement by NMR for amino acids and short peptides in 10%D2O-90% H2O at room temperature and applied to our modeling study by BMM.
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41

Valenza, Jeffery Michael. "Redbeds of the Upper Entrada Sandstone, Central Utah: Facies Analysis and Regional Implications of Interfingered Sabkha and Fluvial Terminal Splay Sediments." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6112.

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First distinguished from other sedimentary successions in 1928, the Entrada Sandstone has been the subject of numerous studies. The western extent of the formation was initially described as laterally continuous "earthy" red beds, and categorized as sub- to supratidal marine-influenced sediments. Recent workers have reexamined the sedimentary facies hosted by the Entrada Sandstone, and findings suggest purely terrestrial depositional environments. Several outcrops of the upper Entrada hosted peculiar sedimentary features, including undulatory and convex-upward, parallel-laminated bedforms, reminiscent of hummocky cross-stratification- unexpected features in a terrestrial environment. The purpose of this study was to collect detailed outcrop measurements of these and other facies present in the upper Entrada Sandstone and to place them in context within a regional sedimentary system. Measured section data was analyzed and divided into sixteen primary facies based on textures, features, bedforms, grain size, and other characteristics. Surfaces were also noted and described. Each facies and surface was recognized to have developed under specific depositional or flow conditions, including eolian, paleosol, and fluvial subcritical, critical, supercritical, and waning flow. Primary facies were grouped into observed and interpreted facies associations. A depositional environment was then assigned to each facies association. These environments included sabkha, overbank splay/paleosol, distal terminal splay, and hyper-distal terminal splay. Ancient analogs were found in the Blomidon, Skagerrak, and Ormskirk Formations, which have been described as dryland fluvial systems that terminated onto saline mudflats (sabkhas). Modern analogs were found in the central Australian continent, in the form of fluvial terminal splays in ephemeral Lakes Eyre and Frome. The sedimentary system of the upper Entrada Sandstone of the San Rafael Swell is interpreted as an interfingering fluvial terminal splay and inland sabkha system. These are marked by a wide array of sedimentary structures representing stark extremes, from hyperarid to flash flooding conditions. During arid conditions, the only source of water was evaporative pumping of a high water table. During the rare occasions when surface water flowed through the system, flash flooding events produced the highest stage of supercritical flow described in geological literature. The succession of these facies reveals allogenic and autogenic processes active at the time of deposition, including episodes of tectonic uplift and fluvial avulsions.
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42

Dippenaar, Alwyn Bernard. "Hydrate formation in pharmaceutically relevant salts." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95979.

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Thesis (MSc)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: A theoretical and experimental study was performed in order to identify factors that influence the propensity of compounds containing anionic functional groups that are commonly found on pharmaceutical drug compounds to form hydrates. A Cambridge Structural Database (CSD) survey was initially undertaken to determine the propensity of different pharmaceutically acceptable anions to form hydrates. The results showed that hydrate formation will take place more regularly when the polarity of the functional group increases. Furthermore, if the charge distribution is very concentrated over the polar groups, hydrate formation will occur more readily. This observation was further investigated by performing a series of potential energy surface (PES) scans for the hydrogen bond (H-bond) in the structure of N-(aminoiminomethyl)-N-methylglycine monohydrate (creatine monohydrate) with various Density Functional Theory (DFT) and Wave Functional Theory (WFT) methods. WFT is often also referred to as ab initio, which refers to the construction of the wave function from first principles when this theory is applied. The scans revealed that several strong and directional H-bonds with different geometrical parameters between the carboxylate group and the water molecule are possible, which suggests that the H-bond plays an important role in driving the formation of pharmaceutical hydrates. A total of 44 hydrate structures were identified that have pharmaceutically acceptable functional groups. Optimisations in the gas phase and in an implicit solvent polarisable continuum solvent model with a variety of solvents showed that there is a significant dependence of the H-bond interaction energy on the anionic group as well as the steric density of surrounding substituents. It was found that the M06-2X method utilising the 6-311++G(d,p) basis set outperformed the other methods that were tested when compared to optimisations performed with the benchmark MP2/aug-cc-pVTZ level of theory. Furthermore, the strength of the H-bond was measured in the 44 experimentally determined structures by using a total of five generalized gradient approximation (GGA) methods, of which two methods contained the DFT-D3 correction. The results of these DFT methods were subsequently compared to results obtained at the benchmark MP2/aug-cc-pVTZ level of theory. The M06-2X method was identified as the most economical method to calculate H-bond energies. It was also found that the H-bond interaction energy shows a substantial dependence on the electrostatic environment. This was observed by a significant decrease in H-bond strength as the relative permittivity of the solvent increases. The effect of steric density on the H-bond interaction energy was investigated by performing hydrogen bond propensity calculations. These values were then compared to the interaction energies of each structure and the results showed that the presence of large bulky substituents can lead to an increase in bond energy by forcing the anionic functional group closer to the water molecule. Contrastingly, the bulky group can also push the anionic group away from the water molecule and result in a decrease in bond energy. Approximate values for the amount of stabilisation offered to the H-bonding system by the surrounding crystalline environment were calculated by optimising the H-bond geometrical parameters of selected compounds with a combination of the M06-2X and MP2 methods utilising the 6-311++G(d,p) basis set. The H-bond interaction energies were then calculated at the M06-2X/6-311++G(d,p) level of theory and compared to the H-bond interaction energies in geometries that have been fully optimised. After these energies were compared and the crystal packing of each structure was investigated, it was found that the packing of some structures within the crystalline environment limits the number of H-bonds that can be formed between the water and the compound of interest. Full optimisation calculations result in structures with cooperative stabilisation, such that more than one H-bond is found between the two fragments. The effect of substituents on H-bond interaction energy was investigated by the addition of six electron-donating and electron-withdrawing groups on four aromatic compounds with different anionic functional groups, namely carboxylate, nitrogen dioxide, sulfonate and phosphonate. It should also be mentioned that the nitrogen dioxide is not an anionic functional group, but it was included as it is a neutral radical that often forms hydrogen bonds. A total of 80 structures were optimised with a combination of the M06-2X and MP2 methods utilising the 6-311++G(d,p) basis set. This was followed by counterpoise corrected single point calculations at the M06-2X/6-311++G(d,p) level of theory. The results showed that the H-bond interaction energy bears no relationship to the inductive strength or the inductive ability of the substituents, but rather the ability of these substituents to rotate the anionic functional group and allow cooperative stabilisation of the H-bond. Furthermore, AIM analysis was performed for the substituted H-bonded aromatic structure. The results showed that electron-donating groups that are placed at the para position yield stronger H-bonds, which is once again accompanied by cooperative stabilisation. Electron-withdrawing groups with sufficient inductive effects can result in a weaker H-bond when placed at the meta position. The effect of water activity (aw) on the hydrate crystal formation was investigated experimentally by performing a series of crystallisations in various solvent mixtures. These mixtures consisted of water mixed with acetone, ethanol and ethyl acetate. A total of three organic acids were used in crystal formation, namely pyridine-4-carboxylic acid (isonicotinic acid), N-amino-iminomethyl-N-methylglycine (creatine) and benzene-1,3,5-tricarboxylic acid. It was found that water activity affects the formation of the hydrate as well as the anhydrous product. Additionally, nucleation and super saturation plays a large role in crystal formation and can serve as an effective technique when the formation of crystals of an appropriate shape and size is required for further analysis.
AFRIKAANSE OPSOMMING: 'n Teoretiese en eksperimentele studie was uitgevoer om faktore te identifiseer wat die geneigdheid van verbindings met anioniese funksionele groepe wat algemeen gevind word op farmaseutiese dwelm verbindings om die hidraat produk te vorm, affekteer. 'n Opname van strukture in die Cambridge Strukturele Databasis (CSD) is onderneem om die geneigdheid van verskillende farmaseutiese aanvaarbare anione om hidrate te vorm te bepaal. Die resultate het getoon dat hidraatvorming meer gereeld plaasvind indien die polariteit van die funksionele groepe toeneem. Verder is daar ook opgemerk dat 'n gekonsentreerde ladingsverspreiding op die polêre groepe ook tot 'n toename in hidraat vorming sal lei. Hierdie waarneming is verder ondersoek deur 'n reeks potensiële energie oppervlak (PES) skanderings van die waterstof binding (H-binding) vir die struktuur van N-amino-iminometiel-N-metielglisien monohidraat (kreatien monohidraat) met verskeie Digtheids-Funksionele Teorie (DFT) en Golffunksie Teorie (WFT) metodes uit te voer. Die skanderings het getoon dat verskeie sterk, gerigte H-bindings met verskillende geometriese parameters tussen die karboksilaatgroep en die watermolekule kan vorm. Hierdie bevindinge lê klem op die belangrike rol wat H-bindings in die vorming van farmaseutiese koolhidrate speel. 'n Totaal van 44 hidraat strukture met farmaseutiese aanvaarbare funksionele groepe was geïdentifiseer. Optimaliserings is in die gas fase asook in 'n implisiete kontinuum polariseerbare oplosmiddel model met 'n verskeidenheid oplosmiddels uitgevoer. Die resultate het 'n beduidende afhanklikheid van die H-binding interaksie-energie op die anioniese groep asook die steriese afkskerming van omringende groepe getoon. Daar is bepaal dat die M06-2X metode wat saam met die 6-311++G(d,p) basisstel die mees akkuraatste resultate gelewer het in vergelyking met die ander DFT metodes asook die MP2/aug-cc-pVTZ maatstaf. Die H-binding se sterkte is vir hierdie strukture bereken deur vyf GGA metodes te gebruik, waarvan twee metodes van die DFT-D3 korreksie gebruik maak. Die resultate van die berekeninge met hierdie DFT metodes is daarna vergelyk met resultate verkry met die MP2/aug-cc-pVTZ maatstaf. Daar is gevolglik bepaal dat die M06-2X metode die mees ekonomiese metode is om H-binding energië te bereken. Die H-binding interaksie energie toon 'n aansienlike afhanklikheid op die diëlektriese konstante van die oplosmiddel aan. Hierdie waarneming is op grond van 'n beduidende afname in die H-binding interaksie-energie indien die relatiewe permittiwiteit van die oplosmiddel verhoog word gemaak. Die effek van steriese digtheid is ondersoek deur waterstofbindinggeneigdheid waardes te bereken. Hierdie waardes is met die interaksie-energië van elke struktuur vergelyk. Die resultate dui daarop dat steries digte groepe tot 'n toename in interaksie energie kan lei wanneer die anioniese funksionele groep nader aan die water molekule gestoot word. Verder is dit ook moontlik vir hierdie steries digte groepe om die anioniese groep weg van die water molekule te stoot en gevolglik 'n afname in interaksie energie te veroorsaak. Benaderde waardes vir die hoeveelheid stabilisering wat die omringende kristallyne omgewing aan die H-binding bied is bereken deur die H-binding geometriese parameters van geselekteerde verbindings met die M06-2X en MP2 metodes en die 6-311++G (d,p) basisstel te optimaliseer. Die H-binding interaksie-energië is gevolglik by die M06-2X/6-311++G(d,p) vlak van teorie bereken en met die H-binding energië in strukture wat volledige optimaliseer is vergelyk. Nadat hierdie waardes vergelyk is, is daar gevind dat die pakking van strukture in the kristallyne omgewing verhoed dat sekere H-bindings tussen die water molekule en die verbinding van belang kan vorm. Strukture wat volledig optimaliseer is, lei tot strukture wat in staat is om koöperatiewe stabilisering te ondergaan. Koöperatiewe stabilisering word gekenmerk deur die vorming van meer as een H-binding tussen twee fragmente. Die effek van substituente op die H-binding interaksie energie is ondersoek deur die bevoeging van ses elektrondonor- en elektronontrekkendegroepe op vier aromatiese verbindings, naamlike die karboksilaatgroep , stikstofdioksied , sulfonaat en fosfonaat. Dit moet ook genoem word dat stikstofdioksied nie 'n anioniese funksionele groep is nie, maar dit was wel ingesluit omdat dit ‘n neutrale radikaal groep is wat dikwels waterstofbindings vorm. 'n Totaal van 80 strukture optimiserings was uitgevoer met 'n kombinasie van die M06-2X en MP2 metodes wat gebruik maak van die 6-311++G(d,p) basisstel. Dit is gevolg deur interaksie-energie berekeninge op die M06-2X/6-311++G(d,p) vlak van teorie. Die resultate het getoon dat daar geen verband tussen die induktiewe vermoë van die substituente en die sterkte van die H-binding is nie, dit is eerder die vermoë van hierdie substituente om die anioniese funksionele groep te laat roteer wat toelaat dat koöperatiewe stabilisering van die H-binding kan geskied. Die AIM analise is op 'n gesubstitueerde H-binding struktuur toegepas. Die resultate het getoon dat elektrondonorgroepe wat by die para posisie geplaas word tot sterker H-bindings sal lei, wat weereens met koöperatiewe stabilisering vergesel word. Elektrononttrekkendegroepe met sterk induktiewe effekte kan tot 'n swakker H-binding lei indien hulle by die meta posisie geplaas word. Die effek van water aktiwiteit (𝑎w) op hidraatkristalvorming is deur die uitvoering van 'n reeks kristallisasies in verskeie oplosmiddelmengsels ondersoek. Hierdie oplosmiddel mengsels bestaan uit water met asetoon, etanol of etielasetaat gemeng. Kristallisasies is vir drie organiese sure, naamlik piridien-4-karboksielsuur, N-amino-iminometiel-N-metielglisien monohidraat en 1,3,5-benseen tri-karboksielsuur uitgevoer. Daar is gevind dat water aktiwiteit 'n invloed op die vorming van die hidraat en watervrye produkte kan hê. Daarbenewens, speel water aktiwiteit 'n belangrike rol in die nukleasie fase van kristalvorming en kan as 'n effektiewe tegniek dien om kristalle van 'n toepaslike vorm en grootte vir verdere analise te verkry.
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43

Håpnes, Mats. "Drilling in Salt Formations and Rate of Penetration Modelling." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25584.

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As the industrialization of the world is growing, both energy consumption anddemand are steadily increasing. Hydrocarbons have been an important energyprovider for several decades, but the production from mature oil and gas producersis now declining. In order to meet this rise in energy demand, new hydrocarbondeposits must be found and produced. Because large oil and gas reservoirs areassociated with salt formations, this may be an important energy source for thefuture. Salt’s low permeability and ability to deform under stress and temperature,makes it an ideal hydrocarbon-trap.The initial objective of this thesis was to establish which challenges are related todrilling for pre-salt hydrocarbons, and propose solutions for how to overcome thesechallenges. When drilling towards these oil and gas reservoirs, the first problemsmay occur already in the formations above the salt structures. The density of saltdoes not increase with burial depth. When its density becomes lower than of thesurrounding formations, salt will start to migrate and push through the overlyingrocks. Due to the combined effect of compaction disequilibrium and salt tectonics,complex stress patterns can be created in the formations surrounding the saltstructures. This may lead to many hazardous scenarios, created by rubble zonesand recumbent beds. When drilling inside salt formations, it is salt’s ability tocreep and flow that may cause problems. Salt flow may cause borehole deformation that impedes with the drilling and casing operations. When a wellbore has beendrilled, salt can creep into the removed rock volume. This may cause situationssuch as stuck-pipe, hole instability, and high levels of shock and vibration whendrilling. Salt flow is a positive function of time, so minimizing the time factorwill decrease the possibility of salt flow related problems. One of the measures tominimize exposure time is to perform drilling operations quickly. Hence, a highrate of penetration (ROP) is beneficial when drilling in salt.As part of proposing solutions to the drilling challenges in salt, two new drillbittechnologies have been evaluated. These bits may be beneficial in order to overcomemany of the problems related to salt drilling. Based on the results obtainedin previous studies, these bits are capable of reducing the shock and vibrationlevels while drilling. This is because these bits are able to drill smoother thanconventional PDC bits. Further, the reduced shock and vibration levels will allowan increase in WOB and rotary speed. Based on previous studies, these arethe two of the most important parameters to ROP. Thus, these two new drillbittechnologies might be able to increase ROP when drilling in salt.Another goal for this thesis was to establish which parameters have the most effecton ROP when drilling in salt formations. Knowing this could help minimize thechallenges faced due to salt creep and flow. Therefore, a modelling attempt wasperformed using Bourgoyne and Young’s ROP model. This model uses multiplelinear regressions to calculate a straight line that best fits the data used in themodel. In this attempt, data acquired from a well drilled in salt formation wasused. Due to lack of variation in the drilling data, several parameters had tobe discarded from the model in order to obtain physically meaningful results.This led to only three variables being used in the model. This was weight on bit(WOB), rotary speed of the drillstring, and jet impact force. It was found thatthe parameter that had most effect on ROP in salt was WOB, followed by rotaryspeed, and last, jet impact force.
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ALMEIDA, LUIZ FELIPPE MEDEIROS DE. "THERMOMECHANICAL MODELING OF ANNULAR PRESSURE BUILD UP IN SALT FORMATIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=30456@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
Este trabalho apresenta uma modelagem numérica termo-mecânica para investigação da influência da presença da rocha salina no acréscimo de pressão em anulares confinados (APB). O fenômeno de APB é resultado da expansão térmica do fluido de perfuração trapeado nos anulares do poço, induzida pelo aquecimento gerado pela produção de hidrocarbonetos em temperatura superior ao restante do poço. Os evaporitos são formações que possuem um comportamento mecânico viscoelástico, apresentando deformação contínua a partir de uma tensão constante, processo conhecido como fluência. Este comportamento do sal não é atualmente considerado pelos simuladores utilizados pela indústria do petróleo durante o projeto de poços, no que tange dimensionamento para esta carga de pressão proveniente do APB. O objetivo deste trabalho é alcançado pelo desenvolvimento uma metodologia de cálculo do fenômeno de APB frente a formações salinas, através de um modelo numérico construído no software ABAQUS, utilizando o método dos elementos finitos. Diversas simulações foram realizadas com configurações distintas de litologia, temperatura e fluidos de perfuração, para analisar a influência do comportamento viscoelástico da rocha salina no crescimento de pressão em anulares confinados. Após análise de resultados obtidos, se concluiu que a rocha salina pode agir como aliviador da pressão gerada pela expansão térmica do fluido de perfuração confinado nos anulares do poço. As tensões geradas pelo APB levam a deformações de fluência que aumentam o diâmetro do poço e consequentemente o volume anular, acomodando parte do acréscimo de pressão gerado.
This dissertation presents a thermo-mechanical numerical modeling to investigate the influence of the presence of salt rock on annular pressure build-up (APB). The APB phenomenon is a result of thermal expansion of confined drilling fluid in the well annulus, induced by heat generated by the production of hydrocarbons at temperatures above the remainder of the well. The evaporite formations have a viscoelastic mechanical behavior, with continuous deformation at constant stress, known as creep. This salt behavior is not currently considered by simulators used by the oil industry for the design of wells, with respect to this pressure load from APB. The objective is achieved by developing a methodology for calculating the APB effect for wells with saline formations, using a numerical model built in ABAQUS software, using the finite element method. Several simulations were performed with different configurations of lithology, temperature and drilling fluids, to analyze the influence of the viscoelastic behavior of the salt rock on pressure growth in confined annuli. After analyzing the results, it was concluded that the rock salt may act as a relief for the pressure generated by thermal expansion of the confined drilling fluid in the well annulus. The stresses generated by the APB lead to creep strains that increase the well diameter and consequently the annular volume, accommodating part of the generated pressure increase.
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45

Li, Bo. "Tidal channel meandering and salt marsh development in a marine transgressed incised valley system the Great Marsh at Lewes, Delaware /." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 710 p, 2006. http://proquest.umi.com/pqdweb?did=1208133431&sid=9&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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46

Morales, Daniel. "Importancia de las Salinas de San Blas durante el Periodo Formativo en la sierra central del Perú." Pontificia Universidad Católica del Perú, 2012. http://repositorio.pucp.edu.pe/index/handle/123456789/113588.

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The Salinas de San Blas Site’s Importance during the Formative Period in the Central Highlands of PerúBased on excavations at San Blas in 1974 the author presents a sequence from Late Archaic to Early Intermediate Period, completed by a short description of the latest San Blas style (late Early Intermediate Period to Late Horizon). Using analogies of ethnohistoric sources discusses the importance of salt production and connections with other areas like Kotosh, Huanuco, and the eastern flank of the Andes (Palcamayo, Tarma, Chanchamayo) showing that Chinchaycocha was not an isolated area but connected closely to wider systems.
Basado en excavaciones en el sitio de San Blas en 1974, el autor presenta una secuencia desde el Periodo Arcaico Tardío al Periodo Intermedio Temprano, complementada con una breve descripción del tardío estilo San Blas (tardío Periodo Intermedio Temprano al Horizonte Tardío) usando analogías de fuentes etnohistóricas. Discute la importancia de la producción de sal y la conexión con otras áreas como Kotosh, Huánuco, y el flanco oriental de los Andes (Palcamayo, Tarma, Chanchamayo) mostrando que la zona de Chinchaycocha no estaba aislada sino más bien conectada de forma estrecha a sistemas más amplios.
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Yee, James Gee Ken. "Carbon-carbon bond formation : reactions of alkenyltrimethylstannanes mediated by copper(I) salts." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0020/NQ56649.pdf.

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48

Blomqvist, Torbjörn. "Karolinsk Stridstaktik : artilleriets och pikens roll 1700-1712 samt bataljonens stridsformering." Thesis, Högskolan på Gotland, Institutionen för humaniora och samhällsvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-208514.

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From a new perspective, this paper will examine the artillery and the pike role in the period 1700-1712 and the battalion´s battle formation in the Caroline combat tactics. Carolinian battle tactics were practiced during the period 1700-1721. The results from my study will be compared to existing research opinion regarding the selected subject areas, if the result confirms the thesis or question the existing research opinion. The source material used consists of eyewitness accounts from the period consisting of diaries, memoir, biography, general muster rolls and historical literature covering the subject. The analysis shows that the Caroline artillery took part in 12 battles during the period of 1700-1712. The analysis also shows that there was a close working between the infantry and artillery in attacks. This result contradicts the existing facility research mixture view that artillery was subordinate other weaponry because it prevented the Caroline attack tempo. In the analysis of the pike role in Caroline combat tactics, reveals nothing that confirms existing research opinion that the pike was an offensive melee weapon. Instead it seems that the pikes role was a support weapon with a defensive focus. The analysis of the battalion`s battle formation shows that the Caroline battalion battle formation did not follow the regulations of the battle formation. According to the existing research the battalion´s battle formation was as required by regulations. But according to the general muster rolls, there are differences between the battalions when it comes to the relationship of forces. So the Caroline battalion battle formation could not have been strictly required by regulations.
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Carvalho, Elvio de. "A sala de aula de filosofia como espaço de vivências transformadoras: interculturalidade e amorosidade na formação docente." Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/12049.

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He theme of this research is focused on the training of professor of philosophy based on the same aspects of intercultural and loveliness. For the teacher can develop an emancipatory pedagogical practice teacher / pupil in exchange for meaningful experiences. Investigative space is determined as the classroom context of a Public School in the city of Rosário do Sul - RS. In this sense, we noted the need to reflect on the action of Philosophy teacher making it necessary to an understanding about the knowledge and practices that the academy is providing this professional education. Given these considerations point out as significant element the limitations of a pedagogical practice that ignores the culture and life experiences of the student, since for the construction of knowledge the desire for learning is required. Thus, affective relationship is a prerequisite for a personal and social emancipation of the subject. The affection in this research context is perceived as a broader meaning, referring to the experiences of individuals and forms of more complex and essentially human expression. .In Addition, we understand that the teacher needs to develop a critical approach to help build a school from the real, the significant and love. For this, we point out that emancipation is grounded in the knowledge and the teacher do in the relations of affection, respect and recognition as possibilities to rebuild and reinvent the history and knowledge as a fundamental part of freedom.
O tema desta investigação está centrado na formação do professor de Filosofia tendo como base da mesma aspectos da interculturalidade e da amorosidade como vivências significativas no processo de formação docente. Tal perspectiva aponta para o desenvolvimento de uma prática pedagógica emancipadora entre professor/aluno. O espaço investigativo é determinado como sendo o contexto da sala de aula de uma Escola Pública Estadual da cidade de Rosário do Sul - RS. Nesse sentido, evidenciamos a necessidade de se refletir sobre a ação do professor de Filosofia, fazendo-se necessário um entendimento acerca dos saberes e fazeres que a academia está proporcionando a esse profissional da educação. Diante de tais considerações, apontamos como elemento significativo as limitações de uma prática pedagógica que desconsidera a cultura e as vivências de vida do aluno, visto que, para a construção do conhecimento, o desejo pelo aprendizado é necessário. Dessa forma, o reconhecimento e a relação afetiva é condição básica para uma emancipação pessoal e social do sujeito. A afetividade nesse contexto de investigação é percebida como uma significação mais ampla, referindo-se às vivências dos indivíduos e às formas de expressão mais complexas e essencialmente humanas. Além disso, compreendemos que o professor precisa desenvolver uma visão crítica para auxiliar na construção de um educar a partir do real, da cultura, do cognitivo e do afetivo. Entendemos que a emancipação está calcada no saber e no fazer docente, nas relações de afeto, respeito e reconhecimento como possibilidades de reconstruir e reinventar a história e o conhecimento como parte fundamental à liberdade.
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Hasa, Dritan. "Innovative systems for drug delivery: pharmacokinetic and technological aspects." Doctoral thesis, Università degli studi di Trieste, 1985. http://hdl.handle.net/10077/9503.

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2011/2012
Nowadays, the main objective of pharmaceutical companies is to develop innovative oral dosage forms for both prolonged and immediate drug releases. In fact, oral delivery has the peculiar advantage of being highly versatile dosage-wise. However, actives suffering from low oral bioavailability may not always be administered by using traditional dosage forms or common controlled release devices, due to the bioavailability’s strict dependence on both drug solubility in gastrointestinal fluids and on drug permeability through the cellular membranes. Recently, both conventional and modified release oral dosage forms have been developed by applying innovative technologies such as a) melt extrusion, and b) solid-state mechanochemistry. a) Melt extrusion Melt extrusion is a viable technology since it allows the production of a final dosage form having the desired shape and dimension. This is achieved by means of suitable thermoplastic polymeric carriers or by using non-polymeric carriers capable of softening or melting during the process. The loaded drug can be dissolved or dispersed in both crystalline and amorphous forms. Despite the efforts of the scientific community, this process still requires an adequate technology transfer, due to the high number of physical, chemical, physicochemical, mechanical and pharmacokinetics variables influencing the melt extruded product. In this context, the first part of the thesis (Chapter 2) presents an innovative contribution, i.e., the production of unconventional melt helical shaped extrudates with a ram extruder. These extrudates, based on mixtures of microcrystalline wax and theophylline, were characterized in terms of morphology (by Scanning Electron Microscopy (SEM)), of in vitro dissolution, of solid- state (by means of Differential Scanning Calorimetry (DSC) and X-Ray Powder Diffraction (XRPD)) and by checking the presence of the drug on the surface (by Photoelectron Spectroscopy (XPS)). Finally, an ad hoc in vitro-vivo modeling, suitably describing, and predicting the drug release and absorption from such kind of systems, was designed. b) Mechanochemistry Mechanochemical activation has been successfully employed to ameliorate the oral performance of drugs having scarce solubility, and therefore, low bioavailability. Through this solvent-free solid-state process, drug-carrier composites containing the drug in a highly available form are obtained thanks to the modification of its physicochemical properties (e.g. in an amorphous or nanocrystalline drug). This is the objective of the first part of Chapter 3, where mechanochemical process has been applied to improve dissolution performance, and therefore, absorption, of two scarcely soluble highly crystalline actives, namely, vinpocetine and vincamine. The drugs were subjected to mechochemical treatment in a lab scale planetary mill, using crosslinked polyvinylpyrrolidone as a carrier for vinpocetine, and sodium crosscarmellose or crosslinked polyvinylpyrrolidone as carriers for vincamine. These studies demonstrated the suitability of these materials to the mechanochemical process, the influence of these carriers on the disruption of the crystalline lattice, and the positive influence of the carriers on the dissolution performances and in vivo absorption. The drug-carrier coground composites were then characterized by means of transmission electron microscopy (TEM), solid-state nuclear magnetic resonance (SSNMR), DSC, PXRD, and Raman spectroscopy/imaging. A second possibility of application of the mechanochemical process is the mechanochemical synthesis: this is the focus of the second part of Chapter 3, where the mechanochemical synthesis is employed, under suitable experimental conditions, to promote the solid-state salification of both vinpocetine and vincamine. Citric acid was selected as a reagent, while crosslinked polyvinylpyrrolidone and sodium cross carmellose were chosen as fillers and process adjuvants in the case of vinpocetine and vincamine, respectively. In both cases, several cogrounds (differing from one another in terms of grinding time, active–to-citric acid molar ratio, presence, or absence of the filler) were prepared. This way, by means of a proper experimental design, the influence of the above mentioned formulation and process variables were studied. XPS and high-resolution TEM were used to obtain qualitative and quantitative information about the produced salt forms and to get some insight into the salification mechanism.
Oggi, l’obiettivo principale dell’industria farmaceutica consiste nel progettare forme farmaceutiche innovative convenzionali a rilascio immediato e/o protratto, adatte per uso orale, poiché i vantaggi di questo tipo di somministrazione consistono nella versatilità del dosaggio. Tuttavia, questa strategia fallisce quando si trattano principi attivi con una bassa biodisponibilità e che quindi non possono essere somministrati in forma classica, o con i normali metodi di rilascio controllato; dove la stessa biodisponibilità è legata a parametri chiave, tra cui la solubilità del farmaco nei fluidi gastrointestinali e la sua permeabilità attraverso le membrane cellulari. Con lo scopo di migliorare sia la biodisponibilità dei principi attivi poco solubili, che di ottenere forme a rilascio controllato, recentemente, l’applicazione di tecnologie innovative, quali l’estrusione per fusione e l’attivazione meccanochimica allo stato solido, hanno permesso la realizzazione di diverse forme farmaceutiche orali convenzionali e quelle non convenzionali. L’estrusione per fusione è un processo vantaggioso perché, utilizzando opportuni leganti basso-fondenti, consente la realizzazione di prodotti farmaceutici dotati di forma e dimensioni omogenee; tutto ciò è possibile poiché con l’estrusione si sfruttano sia la termoplasticità dei polimeri sia il rammollimento o la fusione dei carrier non polimerici, per dare origine a matrici all’interno delle quali il farmaco può esser disciolto, intrappolato o disperso sotto forma cristallina. Purtroppo, benché grandi sforzi siano stati intrapresi dalla comunità scientifica per il trasferimento tecnologico del suddetto processo, rimane ancora un compito parzialmente irrisolto a causa del numero elevato di variabili fisiche, chimiche, farmacocinetiche e meccaniche correlate al processo stesso. In correlazione a questo, la prima parte di tesi (Capitolo 2) ha valuto portare un contributo innovativo, dove la preparazione di forme farmaceutiche solide per uso orale ad azione protratta, consiste nella progettazione, formulazione e caratterizzazione di estrusi con una forma non convenzionale, cioè elicoidale, in un estrusore a pistone, composti da teofillina e cera microcristallina come agente matriciale. Gli estrusi ottenuti, sono stati in seguito caratterizzati in vitro, effettuando studi morfologici mediante microscopia elettronica a scansione (SEM), test di dissoluzione, studio dello stato solido utilizzando la calorimetria a scansione differenziale (DSC), la difrattometria a raggi X per polveri (XRPD), analisi del farmaco in superficie mediante spettroscopia di fotoemissione (XPS) e una modellizzazione in vitro-vivo, che si è dimostrata adeguata alla descrizione e alla previsione del meccanismo di rilascio e di assorbimento. Per ciò che concerne l’attivazione meccano-chimica allo stato solido, quest’ultima si basa su processi che consentono di migliorare le “performance” dei principi attivi, caratterizzati da una scarsa solubilità e quindi bassa biodisponibilità. Tale tecnologia consente, infatti, di realizzare la miglior combinazione tra un principio attivo e un materiale “trasportatore”, che permette la realizzazione di materiali compositi, così da aumentarne la biodisponibilità e quindi l’efficacia del prodotto. Nel processo non si utilizzano solventi (processo allo stato solido), ma vengono migliorate le proprietà chimico-fisiche, dove un principio attivo cristallino viene trasformato in amorfo e/o nanocristallo. Una prima applicazione della suddetta tecnologia è stata trattata nella prima parte del Capitolo 3, dove allo scopo di migliorare le performance dissolutive e conseguente assorbimento, due principi attivi cristallini poco solubili quali la vinpocetina e la vincamina sono stati sottoposti ad un processo di comacinazione, in un mulino planetario, in presenza del polivinilpirrolidone reticolato per la vinpocetina, mentre sia del polivinilpirrolidone reticolato che della sodiocarbossimetilcellulosa reticolata per la vincamina. Tale strategia ha permesso di riscontrare l’attitudine di tali materiali al processo di attivazione meccanochimica, l’influenza dei carrier sulla destrutturazione del reticolo cristallino nonché la positiva influenza dei due polimeri sulle proprietà dissolutive e sull’assorbimento per via orale. I compositi ottenuti sono stati caratterizzati mediante microscopia e trasmissione elettronica (TEM), spettroscopia di risonanza magnetica nucleare allo stato solido (SSNMR), DSC, XRPD, Raman spectroscopy/imaging. Una seconda possibile applicazione del processo meccanochimico, a cui viene introdotto il lettore nella seconda parte del Capitolo 3, è la sintesi meccano-chimica allo stato solido. In questo caso tale processo è stato impiegato al fine di promuovere mediante comacinazione in un molino planetario, in opportune condizioni sperimentali, la salificazione della vinpocetina e della vincamina usando quale reagente l’acido citrico. Veniva inoltre valutata la presenza in qualità di diluente adiuvante il polivinilpirrolidone reticolato nel caso della vinpocetina, e della sodio carbossimetilcellulosa per la vincamina. E’ stata preparata un’ampia serie di comacinati, in diverse condizioni sperimentali (differente durata della comacinazione, rapporto molare principio attivo/acido citrico, presenza assenza del diluente) e l’influenza di quest’ultime variabili sul processo di salificazione è stata stimata mediante opportuni design sperimentali, dove la spettroscopia di fotoemissione (XPS) e la microscopia a trasmissione elettronica ad alta risoluzione (HRTEM) hanno permesso di fornire non solo informazioni qualitative e quantitative sul prodotto salificato, ma anche quelle sul meccanismo della reazione di salificazione stessa.
XXV Ciclo
1985
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