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1
Hacquart, Romain. "Sites de surface des fumées d'oxyde de magnésium". Paris 6, 2006. http://www.theses.fr/2006PA066568.
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Chu, Sterling B. (Sterling Ben). "Steric and kinetic measurements at well-defined surface sites". Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118215.
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Thesis: Ph. D. in Inorganic Chemistry, Massachusetts Institute of Technology, Department of Chemistry, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references.
Extended sp² carbon materials display a wide variety of oxidic moieties on edge sites that can be selectively targeted for functionalization. Monarch 1300 (Cabot Corporation) is a carbon black consisting of 10 nm graphitic particles terminated by oxidic sites. This thesis aims to explore new avenues of research enabled by the covalent nature of linkages to graphitic nanocarbons. Covalent linkages to this surface allow for the decoupling of individual ligand properties from surface-solution ligand dynamics, a phenomenon on semiconductor and metal nanoparticles that inhibits the rational study of ligand effects on those materials. The covalent linkage to carbon is exploited in two different ways. When the ligand of interest is directly bound to carbon, its length and steric profile can be modulated without affecting the surface packing density. This enables isolation of ligand steric profile as a single contributing factor in the overall steric inhibition of the nanocatalyst. When the ligand of interest is bound to a conjugated organometallic complex, the complex is anchored, but the ligand is free to exchange. This allows for study of ligand exchange kinetics without the convoluting factors of surface migration or co-dissociation of surface metal atoms. The appendix contains two chapters with applications of carbon functionalization and a chapter on protection of 1,2-diamines. The first chapter demonstrates passivation of inner-sphere ET processes on glassy carbon via deposition of a fluorinated aryl film onto the electrode. At sufficiently thin deposition layers, outer-sphere ET rates are preserved. The second chapter describes condensation of crown ethers onto the electrode surface to serve as ionophores for aqueous metal ion detection. Binding of metal ions into the crown ether shifts the redox potential of the pyrazine linkage to the carbon electrode, and the concentration of metal ion can be quantified electrochemically. The third chapter explores various protection and deprotection strategies for 1,2-diamines, a moiety crucial for precursors to pyrazine-linked GCC materials.
by Sterling B. Chu.
Ph. D. in Inorganic Chemistry
3
Mo, Young Keun. "Surfactant proteins in extra pulmonary sites /". [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19083.pdf.
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Berruyer, Pierrick. "Three-Dimensional Structure Determination of Surface Sites with Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEN042/document.
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La capacité à déterminer les structures moléculaires en trois dimensions à partir de monocristaux par des méthodes de diffraction a transformé la chimie des matériaux. Le problème de la détermination de structure est en grande partie non résolu, en particulier si le système étudié est situé à une surface et n'a pas de périodicité, comme dans la plupart des matériaux fonctionnels actuels. La Résonance Magnétique Nucléaire (RMN) à l’état solide serait une méthode de choix pour caractériser les surfaces mais la limite de détection de la RMN est beaucoup trop faible pour permettre à la RMN de caractériser les surfaces. L’introduction récente d’une nouvelle approche utilisant la Polarisation Dynamique Nucléaire (DNP) pour améliorer la sensibilité de la RMN des surfaces (DNP SENS) permet à présent de réaliser des expériences qui étaient totalement impossible il y a quelques années encore. Plus particulièrement, grâce à la méthode DNP SENS, les présents travaux de thèse aboutissent à la première structure tridimensionnelle d’un complexe organométallique supporté sur silice, avec une précision de 0,7 Å. De nombreux aspects de l’expérience DNP SENS ont été exploré. Le transport de de l’hyperpolarisation par diffusion de spin est primordial et un modèle numérique dans les matériaux mésoporeux a été développé. De plus, une nouvelle matrice aqueuse se basant sur des gels polyacrylamides a été mise au point et utilisée pour la caractérisation par RMN de nanoparticules permettant ainsi d’étendre les domaines d’application de DNP SENS. Enfin les premières expériences RMN DNP combinant hauts champs magnétiques et haute fréquence de rotation d’échantillon sont présentéesThe ability to understand the properties of chemical systems relies on their detailed description at the molecular level. Over the last century, several methods based on X-ray diffraction have allowed a structure-based understanding of many materials. However, several key questions often remain unanswered. In particular when the system under investigation is located on a surface. Although an extensive range of surface-sensitive methods are available for surface science and give valuable information, they only lead to a partial understanding of surfaces at the molecular level. Moreover, these methods are not compatible with all kinds of materials and usually require the use of a model and pristine surface. Solid-State NMR would be a method of choice to characterize surfaces. However, the approach suffers from its intrinsically low sensitivity and this is strongly emphasize in the case of surfaces where the atoms of interest are diluted in the matrix. Dynamic Nuclear Polarization (DNP) applied to surfaces (SENS) recently emerged as a very promising method to characterize surface sites. It offers a dramatic enhancement of NMR sensitivity and DNP applied to materials has led to many examples in the last ten years. In the present thesis, I have shown that DNP SENS, in combination with EXAFS, allowed the detailed 3D structure determination of the silica-supported organometallic complex determined with a precision of 0.7 angstroms. In parallel, some experimental aspect of DNP SENS have been explored. A spin diffusion has been developed to understand diffusion of hyperpolarization in porous media. A new aqueous DNP matrix, coined DNP Jelly, has been developed to characterize nanoparticles and thus expanding experimental range of DNP SENS. Finally, the first experiment of DNP NMR at fast magic angle spinning (up to 40 kHz) and high field are reported
5
Sheader, Karen. "The architecture and control of variant surface glycoprotein gene expression sites". Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403985.
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CRAWFORD, AARON. "sites for sight: Another projection for the surface of contemporary architecture". University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1053376672.
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Fahringer, Peter E. "Geophysical investigations of near-surface mine sites in northern West Virginia". Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=1087.
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Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains ix, 130 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 128-130).
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Crawford, Aaron. "Sites for sight another projection for the surface of contemporary architecture /". Cincinnati, Ohio : University of Cincinnati, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1053376672.
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Foster, C. L. "Thermodynamics of adsorption at the kaolinite/solution interface". Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376483.
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Mestre, Manuel. "Détermination d'intervalles de confiance par prédiction et optimisation de la position des sites de mesure en métrologie dimensionnelle des surfaces fabriquées". Cachan, Ecole normale supérieure, 1993. http://www.theses.fr/1993DENS0012.
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La métrologie dimensionnelle des surfaces fabriquées calcule le défaut de forme a partir d'échantillons de points mesures, ignorant le comportement de la surface en tous les autres points. Pour remédier à cela, cette thèse applique aux surfaces les méthodes classiques de prédiction linéaire d'un signal aléatoire à incréments gaussiens, stationnaires, ergodiques. Lorsque la surface se conforme à ces hypothèses, la prédiction est très satisfaisante. Dans le cas contraire, la prédiction présente diverses pathologies qu'il est possible de traiter par des méthodes corrigées. Toutes les surfaces peuvent alors être prédites de façon satisfaisante. Cette thèse étudie expérimentalement les propriétés statistiques et spectrales des surfaces fabriquées industrielles, en vue de la prédiction. D'autre part, les critères classiques d'optimisation de la position des sites de mesure, maximisant l'information apportée par un échantillon, donnent de bons résultats
11
Ziemann, Astrid, Klaus Arnold i Armin Raabe. "Acoustic tomography as a method to characterize measuring sites". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-216514.
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The method of acoustic tomography, based on external sonic energy, is applied inside the atmospheric surface layer to observe near-surface temperature fields. Important advantages of this technique as compared to other measurement methods are their remote-sensing capacity and the possibility to directly derivate area-averaged meteorological quantities. The needed input data for the tomographically inverse algorithm are provided by the interaction of sound waves with the scanned atmospheric layer. The resulting horizontal slices lead to statements on the inhomogeneity of the underlying surface which may result in noticeable difficulties during the analysis of measuring campaigns with conventional methodsDie auf der Aussendung von Schallenergie basierende Methode der akustischen Tomographie wird in der atmosphärischen Bodenschicht angewendet, um bodennahe Temperaturfelder zu beobachten. Bedeutende Vorteile dieses Verfahrens im Vergleich zu anderen Meßmethoden sind die Fernerkundungskapazität und die Möglichkeit, flächengemittelte Werte meteorologischer Größen direkt abzuleiten. Die für den tomographischen Invertierungsalgorithmus benötigten Eingangsdaten werden durch die Wechselwirkung von Schallwellen mit der durchstrahlten Luftschicht bereitgestellt. Die resultierenden horizontalen Schnittbilder führen zu Darstellungen der Inhomogenität der Oberfläche. Letztere können beachtliche Schwierigkeiten während der Analyse von Messkampagnen mit konventionellen Methoden hervorrufen
12
Debold, Ryan J. "Catalyzing the urban surface : strategizing sites along the historic Smoky Hill River corridor". Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4087.
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Finlay, Dewar Darren. "Data driven selection of optimal electrocardiographic recording sites from body surface potential maps". Thesis, University of Ulster, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428809.
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Petitjean, Hugo. "De MgO à CaO : modélisation expérimentale et théorique des sites basiques de surface". Paris 6, 2009. http://www.theses.fr/2009PA066097.
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MgO et CaO, isostructuraux, sont choisis comme solides modèles pour élucider le fonctionnement des sites basiques de surface, en déprotonation (adsorption de méthanol) et en catalyse (conversion du2-méthylbut-3-yn-2-ol [MBOH]). La modélisation dans le cadre de la DFT montre que l’adsorption d’oxoacides à la surface de MgO est gouvernée par la topologie des sites (concave ou convexe) et la coordinence des ions impliquées. Expérimentalement, seule une combinaison de techniques (microcalorimétrie et FTIR) permet de décrire complètement la déprotonation. Catalytiquement, l’importance des espèces adsorbées (OH et carbonates) est pointée. Quantitativement, CaO est plus déprotonant et plus réactif que MgO mais dans les deux cas, les sites hydroxylés sont plus actifs que les déshydroxylés, pourtant plus déprotonants. Cette exaltation particulière de réactivité par hydroxylation est discutée en termes de stabilisation du MBOH déprotoné et de flexibilité des hydroxyles de surface.
15
Tsutsumi, Kazuo. "Energie de surface et distribution en énergie des sites superficiels de solides minéraux". Mulhouse, 1985. http://www.theses.fr/1985MULH0007.
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COUSTET, VALERIE. "Sites de surface de l'oxyde de magnesium, de l'alumine et de la silice". Paris 6, 1994. http://www.theses.fr/1994PA066535.
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Les sites de surface d'echantillons massifs d'oxyde de magnesium, d'alumine et de silice vitreuse ont ete caracterises par adsorption de molecules sondes (eau, methanol, acides formique et acetique). Les adsorbats ont ete analyses par spectroscopies de pertes d'energie d'electrons a haute resolution (hreels) et de photoelectrons (xps). Sur les surfaces alpha-al#2o#3(0001) et mgo(100), nous avons montre que des couches hydroxylees stables sont formees par adsorption dissociative de l'eau. Dans les deux cas, le deplacement chimique du niveau o 1s associe aux groupements hydroxyles formes a ete determine, ainsi que la frequence de la vibration d'elongation de la liaison o-h correspondante. Une diffusion hreels resonante de cette vibration d'elongation, propriete intrinseque des groupements oh, a ete mise en evidence pour les faibles energies d'impact. C'est grace a elle que les pics de pertes d'energie associes aux vibrations d'elongation des liaisons o-h ont pu etre distingues de ceux, tres intenses, dus aux phonons optiques. Sur mgo(100), un deplacement en frequence de ces vibrations d'elongation en fonction du recouvrement a ete observe. Ce phenomene est attribue, au moins pour une part, aux variations du champ de madelung interne a la couche hydroxylee. L'etude systematique de la reactivite chimique des trois surfaces deshydroxylees mgo(100), al#2o#3(0001) et sio#2 amorphe vis-a-vis de molecules sondes a permis de mettre en evidence le caractere basique de la surface d'oxyde de magnesium, compare au caractere plus acide des surfaces d'alumine et de silice. En conclusion, l'hydroxylation controlee de surfaces de cristaux d'oxydes a permis d'isoler des molecules de surface oh-substrat bien definies et de caracteriser separement les sites de bronsted et de lewis
17
GUENEAU, LETHICIA. "Sites de surface, greffage et photodegradation d'organosilanes, sur sio#2 et tio#2". Paris 11, 1998. http://www.theses.fr/1998PA112424.
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Nous avons compare la photodegradation de couches auto-assemblees d'organosilanes sur des couches minces de silice et d'oxyde de titane. Les couches d'oxydes ont ete deposees par pulverisation cathodique sur substrats plans de germanium. Par ailleurs, nous avons suivi et controle le depot des couches auto-assemblees de silane et nous avons caracterise les sites presents sur les deux surfaces d'oxyde. Les sites de surface des couches ont ete etudies par adsorption de molecules sondes suivies par spectroscopie infrarouge en multireflexion interne (ftir-atr). Les molecules sondes choisies sont l'acetone, la pyridine et l'eau lourde. En appliquant le modele de langmuir aux isothermes d'adsorption, le nombre maximal de molecules adsorbees, suppose egal au nombre de sites d'adsorption, a ete calcule. De facon a mettre en evidence le role de l'eau presente dans les solutions et a la surface des oxydes sur les adsorptions, celles-ci ont ete realisees apres chauffage de la surface ou mise des solutions sur tamis moleculaire. Le greffage sur ces deux surfaces de deux silanes, l'un monochlore, le diethylchlorosilane (decs) et l'autre trichlore, l'octadecyltrichlorosilane (ots), a ete suivi in situ par spectroscopie ftir-atr. Dans les memes conditions, le decs ne reagit pas a la surface du tio#2 tandis que la quantite greffee sur sio#2 est estimee a 1,9 molecules. Nm##2. Le greffage de l'ots mene a une couche auto-assemblee a la surface des deux oxydes, avec un organisation quasi-cristalline des chaines alkyles. L'effet sur le greffage de la temperature et de la quantite d'eau presente ont ete etudies. Une cellule atr a ete specialement concue pour suivre in situ la photodegradation sous irradiation uv des couches d'ots greffees sur les deux surfaces d'oxydes. Nous mettons en evidence la photodegradation de la couche d'ots sur la surface de tio#2, impliquant des reactions de photocatalyse. En revanche, la couche de silane greffee a la surface de la silice est photochimiquement stable.
18
Flack, Paul E. 1960. "A method for establishing base-line soil loss rates on surface mine sites". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276985.
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Surface mining operations require a comparison of post-mining erosion rates with pre-mining soil loss to ascertain if remedial measures are needed. In this study the Universal Soil-Loss Equation (USLE) was modified to reflect conditions of western rangelands to develop a procedure for estimating pre-mining soil loss rates. The modification used back-calculation for the C-Factor and an adjusted R-Factor based on storm size. Soil loss simulation based on stochastic precipitation patterns is appropriate to the site--the La Plata mine area in northern New Mexico--and increases the flexibility of the USLE as a soil loss predictor for western rangelands.
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Guillaume, Denis. "Modification et caractérisation des sites responsables du craquage acide sur des supports à base d'alumine". Paris 6, 1997. http://www.theses.fr/1997PA066368.
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L'objectif de ce travail reside dans la caracterisation du spectre d'acidite de l'alumine, en terme de nature, de nombre de force et d'environnement des sites acides. Les techniques utilisees sont : le suivi par rmn ram du #3#1p de la thermodesorption de la trimethylphosphine, la spectroscopie ir directe, le craquage du n-heptane, la modification de l'alumine par l'addition de chlore, de silicium, de cations alcalins (k#+, na#+), alcalino-terreux (mg#2#+, ca#2#+) et lanthane (la#3#+). Cette approche multimethode a permis d'identifier les proprietes acides de surface de l'alumine, impliquees dans les reactions de transformation du n-heptane dans les conditions de reformage. L'acidite de lewis est a l'origine des reactions de craquage menant a la formation des couples de produits c#1-c#6 et c#2-c#5 tandis que le craquage du n-heptane en c#3-c#4 implique des sites acides de bronsted. Les reactions de cyclisation et d'isomerisation font intervenir egalement des sites acides de bronsted mais de plus faible force acide. Les mecanismes impliques dans la formation des produits de ces reactions ont pu etre precises. Malgre la complexite de l'acidite de surface de l'alumine , cette etude a permis de preciser l'environnement des sites acides actifs en catalyse, en considerant en particulier la presence de lacunes cationiques superficielles.
20
Larsson, Paulina. "A comparison of the temperature climate at twourban sites in Uppsala". Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-302887.
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Meteorological data from two observation sites in Uppsala, the Observatory Park (Op) andthe Geocentre (Gc), during the period January 1998 to September 2000, have been used tocheck the differences in the temperature climate at the two places. Since Op is situatedcloser to the city centre than Gc the site is thought to be more affected by the so calledurban heat island effect. Dependence on different meteorological parameters, time of theday and time of the year, has been investigated and different methods to correct thetemperature for the inhomogeneity that was introduced when the observation site wasmoved from the Observatory Park to the Geocentre. From the different methods investigated it is shown that to correct the temperaturesmeasured at the Geocentre to make them represent the conditions at the Observatory Parka division according to wind speed, wind direction, cloudiness and time of the year wasshown to be the most reliable method. But if it had been possible to divide the material alsointo hours of the day, this would probably have increased the reliability of the correction.For practical purposes a correction simply based on the monthly mean differences betweenthe two sites is probably accurate enough, as the most important factor is the annual cycle inthe temperature difference between the two urban sites.Väderdata från två observationsplatser i Uppsala, Observatorieparken (Op) och Geocentrum(Gc), under perioden januari 1998 till september 2000, har använts för att undersökaskillnader i temperaturklimatet vid de två platserna. Eftersom Op ligger närmare stadenscentrum än Gc, anses platsen vara mer påverkad av den så kallade värmeöeffekten. Beroendeav olika meteorologiska parametrar, tid på dygnet och tid på året, har undersökts, samt olikametoder att korrigera för inhomogeniteten i temperaturen som introducerades dåobservationsplatsen flyttades från Observatorieparken till Geocentrum. Bland de olika metoder som undersökts för att korrigera de vid Geocentrum uppmättatemperaturerna så att de ska representera förhållandena vid Observatorieparken, visas enuppdelning med avseende på vindhastighet, vindriktning, molnighet och tid på året vara denmest pålitliga metoden, men hade det varit möjligt att dela in materialet även i tid på dygnet,skulle detta troligtvis ha ökat pålitligheten av korrektionen. För praktisk användning är enkorrektion baserad endast på de månatliga medelskillnaderna mellan de två platsernaantagligen tillräcklig, eftersom den viktigaste faktorn är den årliga cykeln itemperaturskillnaden mellan de två platserna.
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Sobocinski, Raymond Louis 1962. "LASER-INDUCED THERMAL DECAY OF PYRIDINE AND CHLORIDE SURFACE-ENHANCED RAMAN SCATTERING AS A PROBE OF SILVER SURFACE-ACTIVE SITES". Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276553.
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The activation parameters for the temperature dependent irreversible loss of surface-enhanced Raman scattered (SERS) intensity from pyridine and chloride adsorbed at silver surfaces in an electrochemical environment have been determined. Laser-induced heating is introduced as a probe of the chemical nature of SERS-active sites. Surface temperatures are calculated from spectroscopic data. The activation energies associated with the destruction of SERS-active sites at a surface roughened by an illuminated oxidation-reduction cycle (ORC) are 12.8 ± 3.2 kcal/mole and 27.7 ± 3.1 kcal/mole for pyridine at two different types of sites on the Ag surface. Similarly, values for coadsorbed chloride are found to be 11.1 ± 2.4 kcal/mole and 24.5 ± 3.8 kcal/mole. An activation energy of 27.4 ± 1.9 kcal/mole is obtained for pyridine on a silver surface roughened by a nonilluminated ORC. Evidence for the desorption of pyridine and chloride is presented.
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Bertel, Jeffrey D. "Analytical study of the spectral-analysis-of-surface-waves method at complex geotechnical sites". Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4625.
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Thesis (M.S.) University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 21, 2007) Includes bibliographical references.
23
Ramos, Reynaldo Perez. "Infrastructure siting development for land surface disposal of toxic and hazardous wastes in the Philippines /". [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19147.pdf.
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Chakradhar, Ashish. "Identification of Active Sites in Heterogeneous Catalysis and Surface Chemistry Study of Alkanes Adsorption". Diss., North Dakota State University, 2014. https://hdl.handle.net/10365/27339.
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Heterogeneous catalysis is considered the basis of the chemical industry. Surface science investigations on model catalysts have made significant contributions in gaining molecular level understanding of heterogeneously catalyzed reactions. Surface science studies involving the interactions of coal combustion gases such as CO and CO2 on electron beam lithography (EBL)-fabricated CuOx/SiO2 nanoclusters to identify active sites and kinetics data characterizing the alkane adsorption on surfaces of alkaline earth metal oxides, metalloids, and metals are investigated in this dissertation. Diverse surface phenomena such as surface-adsorbate interactions, adsorbate-adsorbate interactions, chemical rearrangements of adsorbed reaction intermediates, identification of active sites, and formation of products have been studied utilizing surface science techniques. Thermal desorption spectroscopy (TDS) and molecular beam scattering (MBS) were utilized to study the adsorption kinetics and dynamics, respectively, of probe molecules on catalyst surfaces. The catalyst surfaces were characterized by various surface science techniques such as Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), low energy electron diffraction (LEED), and scanning electron microscopy (SEM). Active sites on the catalyst surface of EBL-fabricated Cu/CuOx nanoclusters (methanol synthesis model catalyst) were identified for CO and CO2 adsorption. Experimentally, it was proven that CO2 adsorbs preferentially along the clusters' rim site and CO on both the rim and terrace sites. Identifying the active sites on a catalyst surface forms the basis of systematic catalyst design strategies. Bond activation in alkanes is a crucial step in the catalytic processing of alkanes in application such as the catalytic combustion of natural gas, exhaust gas remediation, and the selective oxidation of alkanes to high demand products. Adsorption of small chain alkanes such as n-butane, n-pentane, and n-hexane on CaO(100) surface resulted in bond activation to form mostly methane and ethylene via hydrogen abstraction. This production of hydrogen gas has significant economic and environmental benefits. Whereas, the adsorption of n-butane on Sb(111) and silica-supported Mo clusters was found to be molecular and non-activated. However, a strong hydrophobic property of Sb(111) surface was characterized by studying co-adsorption of n-butane and water. In addition, the adsorption sites for n-butane on Sb(111) and Mo nanoclusters were characterized.
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Ziemann, Astrid, Klaus Arnold i Armin Raabe. "Acoustic tomography as a method to characterize measuring sites". Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 22 = Meteorologische Arbeiten aus Leipzig ; 6 (2001), S. 50-59, 2001. https://ul.qucosa.de/id/qucosa%3A15199.
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The method of acoustic tomography, based on external sonic energy, is applied inside the atmospheric surface layer to observe near-surface temperature fields. Important advantages of this technique as compared to other measurement methods are their remote-sensing capacity and the possibility to directly derivate area-averaged meteorological quantities. The needed input data for the tomographically inverse algorithm are provided by the interaction of sound waves with the scanned atmospheric layer. The resulting horizontal slices lead to statements on the inhomogeneity of the underlying surface which may result in noticeable difficulties during the analysis of measuring campaigns with conventional methods.Die auf der Aussendung von Schallenergie basierende Methode der akustischen Tomographie wird in der atmosphärischen Bodenschicht angewendet, um bodennahe Temperaturfelder zu beobachten. Bedeutende Vorteile dieses Verfahrens im Vergleich zu anderen Meßmethoden sind die Fernerkundungskapazität und die Möglichkeit, flächengemittelte Werte meteorologischer Größen direkt abzuleiten. Die für den tomographischen Invertierungsalgorithmus benötigten Eingangsdaten werden durch die Wechselwirkung von Schallwellen mit der durchstrahlten Luftschicht bereitgestellt. Die resultierenden horizontalen Schnittbilder führen zu Darstellungen der Inhomogenität der Oberfläche. Letztere können beachtliche Schwierigkeiten während der Analyse von Messkampagnen mit konventionellen Methoden hervorrufen.
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Fu, L. J., H. P. Zhang, Y. P. Wu, H. Q. Wu i R. Holze. "Surface Active Sites: An Important Factor Affecting the Sensitivity of Carbon Anode Material towards Humidity". Universitätsbibliothek Chemnitz, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200900606.
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In this paper, we report that various kinds of active sites on graphite surface including active hydrophilic sites markedly affect the electrochemical performance of graphite anodes for lithium ion batteries under different humidity conditions. After depositing metals such as Ag and Cu by immersing and heat-treating, these active sites on the graphite surface were removed or covered and its electrochemical performance under the high humidity conditions was markedly improved. This suggests that lithium ion batteries can be assembled under less strict conditions and that it provides a valuable direction to lower the manufacturing cost for lithium ion batteries.
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Inoo, Akane. "Electrochemical Analysis on Reaction Sites of Graphite Electrodes with Surface Film in Lithium-ion Batteries". Kyoto University, 2020. http://hdl.handle.net/2433/253292.
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Baron, Kim L. "Enzymatic and chemical modifications of erythrocyte surface antigens to identify Plasmodium falciparum merozoite binding sites". Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/46043.
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Malaria is a disease caused by the protozoan parasite Plasmodium where the species that causes the most severe form of malaria in humans is known as Plasmodium falciparum. At least 40% of the global population is at risk of contracting malaria with 627 000 people dying as a result of this disease in 2012. Approximately 90% of all malaria deaths occur in sub-Saharan Africa, where approximately every 30 seconds a young child dies, making malaria the leading cause of death in children under the age of five years old.
The malaria parasite has a complex life cycle utilising both invertebrate and vertebrate hosts across sexual and asexual stages. The erythrocyte invasion stage of the life cycle in the human whereby the invasive merozoite form of the parasite enters the erythrocyte is a central and essential step, and it is during this stage that the clinical symptoms of malaria manifest themselves. Merozoites invade erythrocytes utilising multiple, highly specific receptor-ligand interactions in a series of co-ordinated events. The aim of this study was to better understand the interactions occurring between the merozoite and erythrocyte during invasion by using modern, cutting-edge proteomic techniques. This was done in the hope of laying the foundation for the discovery of new key therapeutic targets for antimalarial drug and vaccine-based strategies, as there is currently no commercially available antimalarial vaccine and no drug to which the parasite has not at least started showing resistance.
In this study healthy human erythrocytes were treated separately with different protein-altering enzymes and chemicals being trypsin, the potent oxidant sodium periodate (NaIO4), the amine cross-linker tris(2-chloroethyl)amine hydrochloride (TCEA) and the thiol cross-linker 1,11-bis(maleimido)triethylene glycol (BM(PEG)3). The resulting erythrocyte protein alterations were visualised as protein band differences on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE), where treated and untreated control erythrocyte ghost protein fingerprints were visually compared to one another. The protein bands showing differences between treated and control samples were in-gel digested using trypsin then sequenced by liquid chromatography tandem mass spectrometry (LC-MS/MS) and identified using proteomics-based software. In this way, the erythrocyte proteins altered by each enzyme/chemical treatment were identified.
Malaria invasion assays were performed where each treatment group of erythrocytes as well as the control erythrocytes were incubated separately with schizont stage malaria parasites for the duration of one complete life cycle. Using fluorescent staining and flow cytometry, the invasion inhibition efficiency for each treatment group was evaluated. By utilising these methods, the identification and the relative importance of the erythrocyte proteins involved in the invasion process were determined. Protein fingerprints of control and treated erythrocyte ghosts were visualised and optimised on SDS PAGE where induced protein band differences were successfully identified by LC-MS/MS. It was found that each treatment altered erythrocyte proteins with changes found in Band 3, actin, phosphoglycerate kinase 1, spectrin alpha, spectrin beta, ankyrin, haemoglobin, Bands 4.1 and 4.2, glycophorin A and stomatin. The invasion assays revealed that TCEA inhibited invasion to the greatest extent as compared to the other treatments, followed by BM(PEG)3 and trypsin. Sodium periodate-treated erythrocytes could not be assessed using the invasion assay due to auto-haemolysis. Band 3, glycophorin A, Band 4.1 and stomatin appear to be of higher relative importance in the invasion process as compared to the other altered erythrocyte proteins. These results confirmed the known roles of spectrin alpha, spectrin beta, glycophorin A, Band 3 and Band 4.1 in invasion, and suggested that ankyrin, Band 4.2 and stomatin may also be involved.
This study highlighted the potential that modern, cutting-edge proteomic techniques provide when applied to previous comparative studies found in older literature, as previously unidentified proteins that can be involved in invasion were revealed.
These results can be used as a foundation in future studies in order to identify new key targets for the development of new antimalarial drug- and vaccine-based strategies, with the hope of preventing the suffering of the millions of malaria-inflicted people worldwide, and ultimately eradicating this deadly disease.Dissertation (MSc)--University of Pretoria, 2014.
tm2015
Pharmacology
MSc
Unrestricted
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Wang, Jisheng. "The role of active surface sites in CO₂ gasification of polymer char and coal chars". Thesis, University of Bath, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328540.
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Pusset, Nadia. "Porosité et propriétés de surface de carbones actives par le gaz carbonique". Mulhouse, 1991. http://www.theses.fr/1991MULH0192.
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De nombreuses recherches portent actuellement sur le développement de la porosité des matériaux carbonés. L'objectif de cette étude est de suivre simultanément l'évolution de la porosité et de développement de l'air des sites actifs au cours de la gazéification de carbones par le gaz carbonique à 900°C. Deux types de précurseurs ont été étudiés : un précurseur carbone particulaire la mésophase et des précurseurs filamentaires (fibres phénolique, ex-polyacrylonitrile, ex-brai). Le volume microporeux a été déterminé de deux manières différentes, à partir des isothermes d'adsorption d'azote à 196°C par la méthode a s, et de dioxyde de carbone à 0°C selon la méthode Dubinin-Radushkevich. L'aire des sites actifs (ASA) est mesurée par chimisorption d'oxygène à 300°C puis thermodésorption programmée des espèces CO et CO2. L'étude du développement de la texture poreuse montre qu'il y a élargissement des micropores après 30-40% d'usure suivant la nature du carbone. Le rapport (ASA/surface totale) montre que les parois des micropores sont essentiellement constituées par des plans de base. En combinant les résultats d'adsorption physique et de chimisorption, il a été possible d'établir un mécanisme d'activation dont la première étape est fonction de la nature microporeuse du carbone de départ. Pour les taux d'usure élevés, le mécanisme de gazéification semble être le même pour tous les carbones avec formation de supermicropores
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Govindan, Rajesh. "Development of an unsupervised remote sensing methodology of detect surface leakage from terrestrial CO2 storage sites". Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/11543.
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El, Samrout Ola. "Molecules at surfaces : formation, reactivity, assembly of (bio)molecules on external and internal surfaces of nanosized/nanostructured materials". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS085.
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Cette thèse vise à étudier en profondeur la polymérisation des monomères Gly sur de la silice amorphe afin de mieux comprendre son mécanisme réactionnel, sa cinétique et les paramètres liés à la nature du produit de condensation obtenu dans différentes conditions environnementales. Dans la première partie, le comportement des différents groupes silanol de la silice a été étudié en profondeur par spectroscopie IR pour avoir un aperçu de la réactivité des groupes fonctionnels de la silice. Par la suite, la réaction de formation de liaison peptidique a été largement étudiée sous atmosphère contrôlée avec des mesures de spectroscopie IR in situ pour étudier le comportement des monomères Gly et ceux des groupes fonctionnels de la silice lors de l'adsorption sur la surface ainsi que pendant les étapes intermédiaires de polymérisation. . Un mécanisme d'adsorption/activation des monomères sur la silice suivi de la polymérisation en chaînes linéaires plus longues de poly-Gly a été suggéré. En utilisant la technique MS avec TGA, il a été possible d'évaluer le nombre de mers qui constituent les longs peptides linéaires obtenus sur la surface. De plus, le comportement du poly-Gly au contact de l'eau a également été étudié où les peptides se déplacent pour former des structures auto-assemblées. Dans la seconde partie, la réaction de polymérisation du Gly sur silice amorphe a été étudiée dans des environnements fluctuants : un système soumis uniquement à des fluctuations de température par rapport à un autre soumis à la fois à des fluctuations de température et d'humidité. Les données recueillies par IR in situ ont montré qu'un système soumis à des fluctuations de température et d'humidité représentait le système le plus favorable pour une polymérisation, Par la suite, un mécanisme d'allongement des chaînes linéaires dans des structures ordonnées et auto-assemblées avec des indications de une polymérisation matricielle a été suggérée. La dynamique structurelle des peptides linéaires ainsi que les différentes structures secondaires ont été évaluées au cours de la réaction. De plus, la résistance et la croissance des structures auto-assemblées sur la surface ont été étudiées pendant une durée prolongée de la réaction de polymérisation. Dans la troisième partie, une étude des paramètres qui déterminent la formation de peptides linéaires et de dimères cycliques (DKP) sur la surface de la silice lors du dépôt de Gly à partir des phases gazeuse et liquide a été réalisée. Concernant le dépôt de Gly en phase gazeuse, les monomères ont été déposés par dépôt chimique en phase vapeur sous flux d'argon sur des surfaces de silice de différentes surfaces spécifiques, sous forme vierge ou traitées thermiquement à différentes températures. Les résultats de la spectroscopie IR combinés à ceux de la TGA, de la spectroscopie Raman, de l'ATR, de la XRD et de l'analyse BET ont montré que la présence de types spécifiques de groupes silanol ainsi qu'un cadre renforcé avec de grands anneaux de siloxane favorisent la formation de peptides linéaires sur la silice. surface sur les cycliques. Concernant le dépôt à partir de la phase liquide, différentes charges de Gly ont été déposées sur de la silice de différentes surfaces spécifiques (SSA) en utilisant la méthode d'imprégnation par humidité naissante suivie d'une simple activation thermique. Le SSA de la surface de la silice montre un impact direct sur le type de produit de condensation obtenu et sur la croissance des cristallins en surface. Le rôle bénéfique des molécules d'eau dans la formation de peptides linéaires sur une silice à SSA relativement élevé a également été mis en évidence. Le DKP considéré jusqu'alors comme un produit cyclique sans intérêt a également été étudié sur des surfaces de silice amorphe. Les résultats ont montré que le DKP au lieu d'être un produit sans issue, il représente un dimère utile pour la prolongation rapide des peptides linéairesThis PhD thesis aims to deeply study the polymerization of Gly monomers on amorphous silica to better understand its reaction mechanism, kinetics, and parameters related to the nature of the condensation product obtained under different environmental conditions. In the first part, the behavior of the different silanol groups of silica were deeply studied by IR spectroscopy to have some insights on the reactivity of the silica functional groups. Subsequently, the peptide bond formation reaction was heavily studied under controlled atmosphere with in-situ IR spectroscopy measurements to investigate the behavior of the Gly monomers and the ones of the functional groups of silica upon adsorption on the surface as well during the intermediate steps of polymerization. A mechanism of adsorption/activation of monomers on silica followed by the polymerization into longer linear chains of poly-Gly was suggested. Using MS technique along with TGA, it was possible to evaluate the number of mers that constitute the long linear peptides obtained on the surface. Furthermore, the behavior of the poly-Gly upon contact with water was also studied where peptides move to form self-assembled structures. In the second part, the polymerization reaction of Gly on amorphous silica was studied under fluctuating environments: a system subjected only to temperature fluctuations in comparison with another one subjected to both temperature and humidity fluctuations. The data collected by in-situ IR showed that a system subjected to fluctuations of both temperature and humidity represented the most favor system for a polymerization, Subsequently, a mechanism about the elongation of the linear chains in ordered and self-assembled structures with indications of a templated polymerization was suggested. The structural dynamics of the linear peptides along with the different secondary structures were evaluated during the reaction. Moreover, the resistance and growth of the self-assembled structures on the surface were investigated for an extended duration of the polymerization reaction. In the third part, a study of the parameters that determine the formation of linear peptides and cyclic dimers (DKP) on silica surface upon Gly deposition from gas and liquid phases was carried out. Regarding the Gly deposition from gas phase, the monomers were deposited using chemical vapor deposition under argon flow on silica surfaces of different specific surface areas, in pristine form or thermal treated at different temperatures. The results of IR spectroscopy combined with the ones of TGA, Raman spectroscopy, ATR, XRD, and BET analysis, showed that the presence of specific types of silanol groups along with a framework enhanced with large siloxane rings favor the formation of linear peptides on silica surface over cyclic ones. Concerning the deposition from liquid phase, various Gly loading were deposited on silica of different specific surface areas (SSA) using incipient wetness impregnation method followed by a simple thermal activation. The SSA of silica surface shows a direct impact on the type of the condensation product obtained and on the growth of crystalline on the surface. The beneficial role of water molecules in the formation of linear peptides on a silica with a relatively high SSA was also highlighted. The DKP considered so far as an uninteresting cyclic product was also studied on amorphous silica surfaces. The results showed that DKP instead of being a dead-end product, it represents a useful dimer for the fast prolongation of linear peptides
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Konkel, Michael Edward. "In vitro analysis of the invasive properties of Campylobacter jejuni". Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185029.
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A HEp-2 cell culture model was used to investigate the invasive properties of Campylobacter species. Two of twenty-five Campylobacter isolates did not invade HEp-2 cells, and one of these isolates did not adhere to the epithelial cells. Penetration of HEp-2 epithelial cells by C. jejuni was significantly (P < 0.05) inhibited with C. jejuni lysates and a MAb (1B4) in competitive inhibition studies. Immunogold electron microscopic studies revealed that the 1B4 MAb bound to the flagella and cell surface of low passage (invasive) C. jejuni M 96, whereas only the flagella of high passage (non-invasive) C. jejuni were labelled. Western blot analysis revealed that the 1B4 MAb identified an epitope on antigens ranging in size from 66 to 44 kDa in invasive and non-invasive organisms. Antigens were also recognized in lysates prepared only from invasive strains from 42 to 38 kDa. Sodium meta-periodate chemical treatment of C. jejuni lysates significantly (P < 0.05) affected its inhibitory capacity. Additionally, proteinase K and sodium meta-periodate treatment of lysates changed the mobility of antigens recognized by the 1B4 MAb. This suggests that the antigens required for epithelial cell penetration by C. jejuni may be glycoprotein in nature and that the functional binding site is dependent upon an intact carbohydrate moiety. Co-infection of HEp-2 epithelial cells with coxsackievirus B3, echovirus 7, polio virus (LSc type 1), porcine enterovirus and Campylobacter isolates was performed to determine if a synergistic effect could be obtained. The invasiveness of C. jejuni was significantly increased for HEp-2 cells pre-infected with echovirus 7, coxsackievirus B3, and UV-inactivated (non-infectious) coxsackievirus B3 particles. Polio and porcine enterovirus had no effect on C. jejuni adherence and invasiveness. C. hyointestinalis and C. mucosalis, two non-invasive isolates, did not invade virus-infected HEp-2 cells. The increase of invasiveness of C. jejuni appears to be the result of specific interactions between the virus and the HEp-2 cell membrane. The data suggest that the invasiveness of Campylobacter is dependent upon the inherent properties of the organism. Virus-induced cell alterations can potentiate the invasiveness of virulent Campylobacter but are not sufficient to allow internalization by non-invasive bacteria.
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Dennis, Kim Jason. "Use of isomerizable N-alkylmerocyanine dyes to robe molecular interactions within micellar solubilization sites". Scholarly Commons, 1986. https://scholarlycommons.pacific.edu/uop_etds/2116.
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Effects of aqueous surfactant solutions upon cis/trans isomerization reactions of various N-alkyl-merocyanine dyes (II) were studied. Dramatic rate enhancements were found for all dyes in CTAB and SDS solutions above the CMC. CTAB solutions showed the greatest effect with some dye isomerizations catalyzed in excess of 1000-fold. Increases in either CTAB concentration or dye isomerization rates. N-methyl through N-pentyl dye isomerization rates were measured as a function of CTAB concentration and the data treated according to the pseudophase model for micellar catalysis. KS values ranged from 198 to 2000 M-1 for N-methyl to N-pentyl dyes, respectively. Micellar rate constants also increased as dye hydrophobicity was increased. Thermodynamic activation parameters were determined for N-methyl through N-hexylmerocyanine dyes in CTAB solutions. Rate enhancements in CTAB (above the CMC) relative to those in purely aqueous solutions were shown to be due to a substantial lowering of ΔH‡, for the various dyes. Increased CTAB concentrations of N-methyl dye solutions gave reaction rate increases resulting from a lowering of ΔS‡. In 0.054 M CTAB, increases in reaction rates with increased N-alkyl chain length were due to large increases ΔS‡ (from ca. 0 eu for N-methyl to 13 eu for N-hexyl). The data were discussed in terms of molecular interactions which can occur within the micellar solubilization sites.
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Sun, Ruixue. "Near Surface High Resolution Seismic Imaging of Glacial Deposits in Sweden at the Heby and Marsta Sites". Licentiate thesis, Uppsala universitet, Institutionen för geovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-417104.
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Near surface seismic methods have the potential for mapping theoverburden and bedrock in the Nordic environment. They can provideeffective information about shallow glacial deposits and groundwaterresources in Sweden. We analysed seismic data from the Heby andMarsta sites with the aim of improving the imaging resolution andunderstanding the substructures better, developing systematicstrategies to deal with the detection of aquifers and the delineation ofsome significant boundaries. The general scheme for every case studyis composed of processing, inversion and forward modelling.Processing strategies for the Heby and Marsta have different keypoints, because of the different acquisition equipment and systems.The Heby data were acquired by dynamite and collected withconventional geophones, while the Marsta data were acquired by asledge hammer source and a 3C data landstreamer with MEMSsensors. Inversion can be used for enhancing image quality,particularly in velocity model building. Strongly undulatedsubstructures in the Heby profile cause ambiguities and conflictingdips in the stacked section. By employing the tomographic inversionresult as a starting point to implement prestack depth migration(PSDM) the final image shows better continuity at the top of bedrockand shallow layers are resolved clearer. At Marsta, vertical and radialcomponent data were used to obtain PP and PS information,respectively, to delineate the bedrock surface. Common conversionPoint (CCP) binning of the radial component identifies the surface inbetter resolution, even a 2m variation in the depth of the bedrock canbe seen. PSDM radial component data supports and complements theresult from the CCP binning. In both the Heby and Marsta cases,forward modelling was applied for testing processing workflows forthe field data using models that mimick the real substructures.Acoustic modelling was used for understanding the P-wave responsein the Heby single component data, while elastic wave modelling wasperformed to simulate the multicomponent data at Marsta. The resultsdemonstrate that a comprehensive application of seismic methods inthe near surface (shallower than 100m) can provide adequateresolution. Noteworthy is that an accurate velocity estimation plays asignificant role in the whole scheme for seismic imaging. Thestrategies for building the velocity are also meaningful in thisresearch.
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Garutti, Claudio. "Prediction of Protein-Ligand and Protein-Protein Interactions based on Local Surface Similarity". Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426155.
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The three-dimensional structure of a protein determines its function. This thesis describes a suite of methods for the problem of protein binding site recognition, based on a spin-images representation of the molecular surface. A procedure for cavity detection is coupled with a procedure for the recog- nition of similar regions in two proteins, and applied to the comparison of two protein's cavities, the all-to-all pairwise comparison of a set of cavities, and the recognition of multiple binding sites in one cavity. All the presented methods can be used to screen large collections of proteins.La struttura tridimensionale di una proteina determina la sua funzione. Questa tesi descrive una suite di metodi per il problema del riconoscimento di siti di legame di proteine, basati su una rappresentazione a spin-images della supercie molecolare. Una procedura per l'identicazione di cavita' integrata con una procedura per il riconoscimento di regioni simili in due proteine, e applicata al confronto delle cavita' di due proteine, il confronto all-to-all pairwise di un insieme di cavita', e il riconoscimento di siti di legame multipli in una cavita'. I metodi presentato possono essere usati per analizzare vaste collezioni di proteine.
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Gilland, Keith E. "Early Successional Processes of Experimentally-Reclaimed Mine Sites in Eastern Ohio and the Restoration of American Chestnut". Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1364912232.
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Loftus, Emma. "Sea surface temperatures from oxygen isotopes in marine molluscs in Middle and Later Stone Age sites, South Africa". Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:b9219c2d-ec92-4baf-b316-cfe1d46b8836.
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The southernmost coast of South Africa has been proposed to have been a uniquely important region in later human evolution, in part due to the abundance of nutritious and dense coastal resources. Yet, strong contrasts in the Middle Stone Age (MSA) and subsequent Later Stone Age (LSA) archaeological records cast uncertainty on the significance of shellfish utilisation for processes of human evolution. Further, climatic shifts are frequently advanced as drivers of widespread technological change but few climate proxy records correspond adequately to the archaeological evidence at a temporal or spatial level to be unambiguously linked to human cultural activity. This thesis presents a temporally and spatially distributed record of near-shore seasonal sea surface temperatures (SSTs) from serial δ18O shell measurements of archaeological Turbo sarmaticus opercula. In addition, the annual timing of shellfish harvesting captured in the temperature signal of the shells' final few growth increments is indicative of the scheduling of foraging behaviours and social organisation. A non-destructive method for evaluating the preservation of the original aragonitic shell carbonate using Fourier transform infrared spectrometry with an attenuated reflectance attachment is presented, allowing for robust SST reconstructions. Near-shore SST reconstructions are presented from the LSA levels of Nelson Bay Cave and Byneskranskop 1, with new radiocarbon chronologies spanning the terminal Pleistocene and the Holocene, and the MSA deposits at Pinnacle Point 5-6 and Klasies River Main site, dated to periods in Marine Isotope Stage (MIS) 5 and across the MIS5/4 transition. These reconstructions confirm the utility of near-shore SST records for terrestrial climate reconstructions, indicating summer rainfall shifts during the Holocene and across MIS5/4. The annual timing of shellfish foraging is shown to be markedly different between the MSA and LSA, and more nuanced assessments of foraging behaviours within the MSA and LSA emerge.
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de, la Torre Guzman Jorge. "The development of a performance assessment methodology for CO2 storage sites using dynamic pressure and surface deformation data". Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/56924.
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A basic requirement for safe geological storage of CO2 is the ability and integrity of the storage complex to contain the CO2. However, the storage formation and the caprock may contain fractures and/or faults that could provide a permeable conduit for CO2 migration out of the prime storage formation. Furthermore, CO2 injection may induce or reactivate fracture networks and faults providing a pathway for CO2 leakage. Recent experience from large scale industrial CO2 storage projects have shown that the geomechanical response of structural features to CO2 injection is a critical parameter controlling the injection performance. The monitoring of the geomechanical response using InSAR surface deformation, injection pressure data and seismic data have provided valuable insight into CO2 injection and storage performance. There is, however, a need for greater integration between monitored data and numerical modelling techniques used to assess performance in order to establish the conformity of the actual behaviour of the injected CO2 with the modelled behaviour. Research presented in this thesis developed an integrated performance assessment methodology for CO2 storage sites, which incorporates satellite (InSAR) monitoring data, time-lapse seismic monitoring data, bottom hole pressure (BHP) data, inverse modelling, and coupled flow-geomechanical simulations using the ensemble Kalman filter (EnKF). The developed methodology has been applied to the In Salah CO2 storage field dataset in order to demonstrate its application and usefulness for the performance assessment of CO2 storage sites. First, an inversion scheme using Weiner filters based on a numerical geomechanical model was developed and used to invert InSAR surface deformation for reservoir pressure change. A forward coupled flow-geomechanical modelling study in conjunction with an InSAR and time-lapse seismic analysis was then performed. This lead to an improved understanding of the flow and pressure behaviour at one of the injection wells. Finally, an integrated approach combining inverse and forward modelling using the EnKF was developed and applied. The EnKF tool developed provides a framework for the updating of flow and geomechanical model parameters through the joint assimilation of bottom hole pressure and InSAR data.
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Joffre, Jacques. "Modélisation de réactions d'hydrotraitement sur des sites catalytiques modélisés à la surface de MoS adsorption, désulfuration et désazotation". Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375985231.
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Treps, Laureline. "Définition à l'échelle atomique de la surface externe de la zéolithe ZSM-5 et de son interface avec le liant". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN040.
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La mise en forme des zéolithes dans le domaine industriel est une chimie qui a été mise au point de manière empirique. De récentes études sur l’impact physico-chimique des liants sur les propriétés des zéolithes montrent qu’une étude rigoureuse et détaillée des processus se produisant lors de la mise en forme manque, et permettrait de mieux maîtriser sa mise en œuvre. A ce jour aucune étude ab initio n’a été menée sur ce sujet.Dans le travail proposé, la ZSM-5 (MFI) et l’effet du liant sur ses propriétés sont étudiés via l’utilisation de modèles quantiques (VASP DFT périodique) et de modèles de champs de force réactifs (ReaxFF). Un ensemble de modèles de la surface externe de la ZSM-5 a été construit, étudié (nature de la surface, hydratation, sites acides, …) et comparé à des données expérimentales (RMN du proton, FT-IR, adsorption de molécules sondes) de manière à pouvoir simuler ensuite mis au contact de liant et/ou composant du liant. Deux types de sites d’alumination de surface ont été mis en évidence, les hydroxyles pontant Al-OH-Si et de l’eau non dissociée sur la surface Al-(H2O)(OH)n. Grâce à la modélisation de l’adsorption de pyridine ou de diterbutylpyridine, l’acidité du premier type de sites a été montrée comme étant la plus forte et plus particulièrement aux localisations permettant un fort confinement. Le second type de sites a été montré comme étant le plus stable en surface et a fait le sujet d’études d’hydratation et de déshydratation. Les simulations des interactions avec les liants montrent que l’alumine a une forte interaction avec les zone riches en aluminium de la zéolithe et que le sodium issu de la silice empoisonne les sites acides des zéolithes. L’optimisation des paramètres du champ de force réactif et les simulations ont permis la modélisation à l’échelle adaptée de la mise en contact de surface de zéolithes avec des surfaces de liants. Les caractéristiques de la surface et les interactions avec le liant ont été mises en lien avec les expériences conduite à IFPEN, ce qui apporte un éclairage nouveau sur les phénomènes physico-chimiques se produisant lors de la mise en formeZeolites are nanoporous aluminosilicates crystals of prominent fundamental and industrial importance. Among these, ZSM-5 is one of the most investigated solid, with paramount industrial use, that can be obtained in various forms. Some of these (hierarchical forms, nanoslabs, nanosheets and nanocrystals) exhibit a very high surface over volume ratio which make them useful for multiple industrial processes. The shaping is used to adapt ZSM-5 (and zeolites in general) to the needs of the industrial reactors. Empirically, preparing a technical zeolite is a strong industrial know-how, but with limited physic-chemical understanding of the zeolite-binder interface. Periodic Density Functional Theory (DFT, VASP, PAW, PBE dDsC) calculations of the relative stability of relevant surface orientations for silicalite and ZSM-5 crystals ((100), (010) and (101)) were performed at different hydration levels thanks to ab initio thermodynamics. Their relative acidities (pyridine and di-tertbutylpyridine adsorption) and spectral features (vibration modes, NMR chemical shifts) are determined. The interaction of the most relevant ones with binders (alumina, silica) is simulated ab initio, and an empirical reactive force field (ReaxFF) is built on purpose to model larger scales. Several kinds of surface sites have been identified. Bridging Al-OH-Si are present at the pore mouth, of similar or higher stability with respect to bulk sites. These are not stable at the outermost surface, where the following groups prevail: Si-OH, Al-OH and most importantly water adsorbed on aluminum Al-(H2O)(OH)n. Models of pyridine and 2,6-ditertbutylpyridine adsorption show that the acidity of the bridging groups is stronger than the other, and more particularly with a strong confinement. Al-(H2O)(OH)n surface site are shown to be the most stable at the external surface of ZSM-5 and are studied upon the hydration and dehydration of the ZSM-5 external surfaces. The results issue from these DFT simulations are compared to FT-IR, 1H NMR, and pyridine/2,6-ditertbutylpyridine adsorption experiments conducted at IFPEN. The interaction between zeolite and binders (silica, alumina) is first modeled by the interaction of the zeolite with small components like Si(OH)4, Na+ - present in some silica sources - and Al(OH)3(H2O). The results show that alumina components are more strongly attracted by the aluminum of the zeolitic network than silicic species. Na+ binds more strongly with the zeolite rather than silica and these results are once more compared to experimental data. The reactive force field parameters optimization is allowing to model larger external zeolite surfaces that are in contact with more realistic binder surfaces. All these results provide a rational understanding of a large set of experimental observations from the literature, that remained so far poorly understood. These findings are likely not limited to the case of the MFI framework (some of them already appeared to be valid for zeolite Beta), as our conclusions are mainly dictated by local topology aspects. The zeolite we investigate and the reactive sites we reveal are of both fundamental and industrial importance
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Poulson, Christopher. "Arriving at the surface : an analysis of the organisation of the surface of paintings and the space around them as sites to generate specific practices of thought". Thesis, Middlesex University, 2009. http://eprints.mdx.ac.uk/9118/.
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This research project presents a number of approaches towards the surfaces produced within my own practice. In this sense it is a reversed critique, a meditation upon the practice of considering artworks shaped by the structures of the works themselves, rather than an attempt to align the works with other existing external structures of explanation. The surface of the picture plane presents the researcher with grave difficulties. It is silent and fixed, and necessarily complete unto itself. It has a defined border that divides it from the flux of the world around it. Meditation upon such a site would seem to produce only a stream of interpretive reflection. Without the precise definitions of language, images might only appear to offer the opportunity for highly subjective responses, becoming material for textual metaphor. This approach overlooks the possibility that the site of the painting does not just represent ideas, but actually can be an apparatus to generate and contain thought. The ‘surface’ becomes not the hard unyielding face of the image, but a shifting border that must account for the movements of time and the mechanisms of perception. The surface is an object, and a series of events collapsed into this object. To explore this possible ‘event’ in my own practice I undertook the exploration a number of different forms of organising and presenting works, combined with simultaneous investigations into other artist’s work and methods. This mimics the way in which I construct my own work; allowing a group of image/ideas to coalesce around a projected ‘surface’, which here would be a defined space of production (a canvas, a exhibition space, a live performance). The danger of this approach is that the clumps of thought/image will remain singular and disconnected, and the surface will not exist as anything more than a collection of things. For the works to succeed as sites to generate specific thought they must also reveal some kind of method of investigation to the viewer. This project examines some particular instances where such methodologies can be seen in operation.
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Renaudin, Alan. "Réalisation d'une plate-forme à ondes acoustiques de surface pour une microfluidique digitale dédiée à la biologie". Lille 1, 2006. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2006/50376_2006_190.pdf.
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Ce travail porte sur la microfluidique digitale dans les Lab-on-Chips dédiés aux applications biologiques. Nous présentons les résultats concernant le déplacement et la manipulation de gouttes de liquides à partir d'ondes acoustiques de surface (SAW) utilisées comme mode d'actuation. Ces ondes sont propagées dans le substrat piézoélectrique à partir de transducteurs à peignes interdigités travaillant à 20MHz. Les gouttes peuvent être pincées entre ce substrat et un couvercle de fermeture qui limite l'évaporation. Des traitements de surface et des conditions d'excitation SAW optimisés permettent de déplacer, de fusionner et de mélanger des gouttes de liquides sur une plate-forme dédiée. Nous exposons ensuite une méthode innovante de pulse-écho que nous avons développée pour localiser la goutte avec une précision submillimétrique. Le logiciel développé au laboratoire permet la gestion en aveugle du déplacement des gouttes et leurs entrées-sorties sur des zones bioactives. Nous précisons aussi les conditions pour maîtriser la température d'une goutte immobile. Dans ce contexte, une goutte de volume calibré allant du nanolitre au microlitre et contenant des analytes (protéines. . ) devient un microlaboratoire mobile dont le contenu peut interagir par contact avec les zones fonctionnalisées du couvercle. L'architecture originale et les solutions microfluidiques que nous proposons permettent d'envisager la réalisation d'un premier prototype de microsystème fluidique SAW pour l'analyse de protéines par spectrométrie de masse de type MALDI.
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Simon, Georg Hermann [Verfasser], i Mario [Akademischer Betreuer] Dähne. "Dynamic Force Microscopy on Ultrathin Alumina - Surface Oxygen Lattice, Domain Boundaries, Adsorption Sites / Georg Hermann Simon. Betreuer: Mario Dähne". Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2011. http://d-nb.info/101489140X/34.
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Zhao, Weitao. "Hydrogen Production : supported Mo-based catalysts for water gas shift reaction". Electronic Thesis or Diss., Normandie, 2022. http://www.theses.fr/2022NORMC213.
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Ce travail vise à mieux comprendre les performances catalytiques de sites spécifiques (sites M-edge, S-edge ou CoMoS) des catalyseurs sulfures et à élucider leurs mécanismes réactionnels pour la réaction de Water Gas Shift (WGS). La caractérisation des sites actifs par adsorption de CO à basse température suivie par la spectroscopie IR (CO/IR) met en évidence que la réactivité de H2O et de CO dépend de la structure des différents sites actifs. Pour les catalyseurs de Mo non promus, les sites des bords M sont sensibles à l'eau et forment des sites Mo(SxOy)zc via une réaction d'échange S-O, tandis que les sites des bords S sont sensibles au CO pour former des lacunes et libérer du COS. Il est ausssi mis en evidence que les sites Mo(SxOy)zc formés in situ ne sont pas réactifs vis-à-vis d’un traitement ultérieur en CO, ce qui démontre que le mécanisme redox conventionnel dans lequel la surface du catalyseur est alternativement oxydée par l'eau/échangée par l’oxygène et réduite par le CO, ne s’applique pas aux catalyseurs sulfures. En outre, les expériences IR operando qui montrent la formation d’especes intermédiaires formiate et sulfure de carbonyle pendant la réaction de WGS, sont en accord avec une voie formiate et un nouveau mécanisme redox via COS. L'extension de l'étude au rôle de l'additif potassium et du promoteur cobalt dans la réaction de WGS montre que les atomes de soufre terminaux sont activés par K et Co, ce qui les fait réagir plus facilement avec CO pour former COS à basse température. Plus important encore, le cobalt, qui facilite la transformation réversible de la phase oxysulfure en sulfure par H2S, peut contribuer à limiter la désactivation du catalyseur pendant la réaction de WGSThis work aimed to gain insights into the catalytic performance of specific sites (M-edge, S-edge or CoMoS sites) and elucidate the Water Gas Shift (WGS) reaction mechanism over sulfide catalysts. In this study, the novel findings concerning the H2O and CO reactivity at the various active sites were revealed by monitoring active sites after in situ post-treatment using low temperature CO adsorption followed by IR spectroscopy (CO/IR). It was shown that on unpromoted Mo catalysts, M-edge site is sensitive to water to form the oxygen-substituted Mo(SxOy)zc site via S-O exchange reaction, while the S-edge site is sensitive to CO to form vacancies and release COS. Furthermore, stepwise surface reaction experiments show that Mo(SxOy)zc sites formed in situ are not reactive towards subsequent CO feed in contradiction with the conventional redox mechanism in which the catalyst surface is alternately oxidized/or oxygen-exchanged by water and reduced by CO. In addition, operando experiments demonstrate that formate and carbonyl sulfur intermediates are directly observed during WGS reaction, in accordance with a formate pathway and a novel redox mechanism via COS route. The extension of the study on the role of potassium additive and cobalt promoter in WGS reaction shows that the terminal sulfur atoms are activated by K and Co, making them reacting more easily with CO to form COS at low temperature. More importantly, cobalt, which facilitates the reversible transformation of the oxysulfide phase to sulfide by H2S, can help limiting catalyst deactivation during WGS reaction
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Williams, John G. "Extraction of surface texture data from low quality photographs to aid the construction of virtual reality models of archaeological sites". Master's thesis, University of Cape Town, 2001. http://hdl.handle.net/11427/8776.
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Bibliography: leaves 100-104.A tool has been designed and implemented to use information extracted from photographs captured using uncalibrated cameras (so-called casual photographs) to fill the occlusions which occur in three-dimensional models of photogrammetrically captured sites. Capturing the geometry of archaeological sites by photogrammetric means is relatively expensive and, because of the layouts typical of such sites, usually results in a degree of occlusion. Occlusions are filled by extracting texture and calculating hidden geometry from casual photographs with the support of three-dimensional geometric data gleaned from the photogrammetric survey. The essential philosophy underlying the tool is to segment each occlusion into surfaces which may be approximated using curves and then use known geometry in the region of the occlusion to calculate the most probable locations of the junctions of such surface segments. The tool is primarily a combination of existing techniques for pre-filtering and calibrating the casual photograph, boundary detection and ultimately texture adjustment. The technique implemented for calculating the locations of occluded comers using minimisation of least square errors is new. The tool has been applied to occlusions of the various configurations that are expected to be typical of archaeological sites and has been found to deal well with such features and to provide accurate patches from typical data sets. It is also shown that the three-dimensional geometric model is clearly improved by the filling-in of the occlusion.
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Petit, Patrice. "Mitochondries, membranes mitochondriales et interactions subcellulaires aspects métaboliques, sites récepteurs, potentiel de membrane, propriétés de surface et homogénéité des populations /". Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37617439d.
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Poulton, Mary Moens 1962. "EXTRACTION OF SURFACE AND SUBSURFACE GEOLOGIC INFORMATION FROM DIGITAL IMAGES OF THE PROPOSED ARIZONA SUPERCONDUCTING SUPER COLLIDER SITES (REMOTE SENSING)". Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276424.
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Carriger, John Fletcher. "An aquatic ecological risk assessment on pesticides in surface waters of the C-111 canal system and related estuarine discharge sites". FIU Digital Commons, 2004. http://digitalcommons.fiu.edu/etd/2056.
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A screening level ecological risk assessment (SERA) was completed to evaluate the potential risks of pesticides found in water in the lower Canal 111 (C-111) Basin and adjacent tidal zones in South Florida. This risk assessment was conducted under general U.S. EPA guidelines and focuses on effects of water exposure to the herbicides atrazine and metolachlor and to the insecticides chlorpyrifos, endosulfan, and malathion. Results found that the highest potential risk was associated with the acute effects of endosulfan to freshwater arthropods at sites near water control structure S-178 and Canal 111e, a branch of C-111. The highest potential risk of acute effects of endosulfan for saltwater organisms was in Joe Bay, which receives discharges from C-111. Results from evaluations of risk of chronic effects from pesticide exposure show that the highest potential risk is associated with endosulfan in freshwater.
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PETIT, PATRICE-XAVIER. "Mitochondries, membranes mitochondriales et interactions sub-cellulaires : aspects metaboliques, sites recepteurs, potentiel de membrane, proprietes de surface et homogeneite des populations". Paris 6, 1988. http://www.theses.fr/1988PA06A008.
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