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Use of 3-dimensional dynamic modeling of CO₂ injection for comparison to regional static capacity assessments of Miocene sandstone reservoirs in the Texas State Waters, Gulf of MexicoWallace, Kerstan Josef 01 November 2013 (has links)
Geologic sequestration has been suggested as a viable method for greenhouse gas emission reduction. Regional studies of CO₂ storage capacity are used to estimate available storage, yet little work has been done to tie site specific results to regional estimates. In this study, a 9,258,880 acre (37469.4 km²) area of the coastal and offshore Texas Miocene interval is evaluated for CO₂ storage capacity using a static volumetric approach, which is essentially a discounted pore volume calculation. Capacity is calculated for the Miocene interval above overpressure depth and below depths where CO₂ is not supercritical. The goal of this study is to determine the effectiveness of such a regional capacity assessment, by performing refinement techniques that include simple analytical and complex reservoir injection simulations. Initial refinement of regional estimates is performed through net sand picking which is used instead of the gross thickness assumed in the standard regional calculation. The efficiency factor is recalculated to exclude net-to-gross considerations, and a net storage capacity estimate is calculated. Initial reservoir-scale refinement is performed by simulating injection into a seismically mapped saline reservoir, near San Luis Pass. The refinement uses a simplified analytical solution that solves for pressure and fluid front evolution through time (Jain and Bryant, 2011). Porosity, permeability, and irreducible water saturation are varied to generate model runs for 6,206 samples populated using data from the Atlas of Northern Gulf of Mexico Gas and Oil Reservoirs (Seni, 2006). As a final refinement step, a 3D dynamic model mesh is generated. Nine model cases are generated for homogeneous, statistically heterogeneous, and seismic-based heterogeneous meshes to observe the effect of various geologic parameters on injection capacity. We observe downward revisions (decreases) in total capacity estimation with increasingly refined geologic data and scale. Results show that estimates of storage capacity can decrease significantly (by as much as 88%) for the single geologic setting investigated. Though this decrease depends on the criteria used for capacity comparison and varies within a given region, it serves to illustrate the potential overestimation of regional capacity assessments compared to estimates that include additional geologic complexity at the reservoir scale. / text
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Φωτοβαρυτικό περιορισμένο πρόβλημα των τριών σωμάτων : τρισδιάστατες περιοδικές κινήσεις γύρω από τα εκτός τροχιακού επιπέδου σημεία ισορροπίαςΔεσύλλας, Γιάννης 12 November 2008 (has links)
Στην συγκεκριμένη διπλωματική εργασία ασχολήθηκα με το φωτοβαρυτικό περιορισμένο πρόβλημα των τριών σωμάτων.Εστίασα στις τρισδιάστατες περιοδικές κινήσεις και περιέγραψα αναλυτικά οικογένειες τρισδιάστατων περιοδικών τροχιών. / At this master I work on the photogravitational
restricted 3-orbit problem. Espesially I focus on the 3-dimensional orbits solutions and I describe families of 3-dimensional orbits.
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Graphical Tools, Incorporating Cost and Optimizing Central Composite Designs for Split-Plot Response Surface Methodology ExperimentsLiang, Li 14 April 2005 (has links)
In many industrial experiments, completely randomized designs (CRDs) are impractical due to restrictions on randomization, or the existence of one or more hard-to-change factors. Under these situations, split-plot experiments are more realistic. The two separate randomizations in split-plot experiments lead to different error structure from in CRDs, and hence this affects not only response modeling but also the choice of design. In this dissertation, two graphical tools, three-dimensional variance dispersion graphs (3-D VDGs) and fractions of design space (FDS) plots are adapted for split-plot designs (SPDs). They are used for examining and comparing different variations of central composite designs (CCDs) with standard, V- and G-optimal factorial levels. The graphical tools are shown to be informative for evaluating and developing strategies for improving the prediction performance of SPDs. The overall cost of a SPD involves two types of experiment units, and often each individual whole plot is more expensive than individual subplot and measurement. Therefore, considering only the total number of observations is likely not the best way to reflect the cost of split-plot experiments. In this dissertation, cost formulation involving the weighted sum of the number of whole plots and the total number of observations is discussed and the three cost adjusted optimality criteria are proposed. The effects of considering different cost scenarios on the choice of design are shown in two examples. Often in practice it is difficult for the experimenter to select only one aspect to find the optimal design. A realistic strategy is to select a design with good balance for multiple estimation and prediction criteria. Variations of the CCDs with the best cost-adjusted performance for estimation and prediction are studied for the combination of D-, G- and V-optimality criteria and each individual criterion. / Ph. D.
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Estuarine Dynamics as a Function of Barrier Island Transgression and Wetland Loss: Understanding the Transport and Exchange ProcessesSchindler, Jennifer 17 December 2010 (has links)
The Northern Gulf of Mexico and coastal Louisiana are experiencing accelerated relative sea level rise rates; therefore, the region is ideal for modeling the global affects of sea level rise (SLR) on estuarine dynamics in a transgressive barrier island setting. The field methods and numerical modeling in this study show that as barrier islands are converted to inner shoals, tidal exchange increases between the estuary and coastal ocean. If marshes are unable to accrete at a pace comparable to SLR, wetlands will deteriorate and the tidal exchange and tidal prism will further increase. Secondary to hurricanes, winter storms are a primary driver in coastal morphology in this region, and this study shows that wind direction and magnitude, as well as atmospheric pressure change greatly affect estuarine exchange. Significant wetland loss and winter storm events produce changes in local and regional circulation patterns, thereby affecting the hydrodynamic exchange and resulting transport.
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Development of an innovative fabrication method for n-MOS to p-MOS tunable single metal gate/high-[kappa] insulator devices for multiple threshold voltage applicationsBurham, Cynthia Faye 10 June 2011 (has links)
Aggressive scaling required to augment device performance has caused conventional electrode materials to approach their physical scaling limits. Alternative metal gate/high dielectric constant (MG/High-[kappa]) stacks have been implemented successfully in commercial devices and hold promise for further scaling based performance advances. Existing MG/High-[kappa] technology does not achieve a single metal n-MOS to p-MOS effective work function (EWF) tuning range suitable for bulk silicon (Si) device applications. Dual metal gates (DMGs) utilizing a separate metal for n-MOS and p-MOS electrodes increases the cost and complexity of fabrication. The research presented herein introduces a method by which the cost and complexity of MG/High-[kappa] device fabrication may be reduced. Innovative fin field effect transistors (FinFETs) incorporating 3 dimensional ultra thin body silicon on oxide (3-D UTB-SOI) technology display superior electrical characteristics compared to bulk Si devices at the nanometer (nm) dimension and require only a +/-200meV n-MOS to p-MOS EWF tuning range around the Si mid-gap. Single metals capable of achieving this +/-200meV EWF tuning range have been evaluated herein and the tuning mechanisms investigated and engineered to develop a single MG/High-[kappa] FinFET the fabrication complexity of which is reduced by 40%. More specifically, the research shows that the metal thickness of titanium nitride/hafnium silicon oxide (TiN/HfSiOx) gate stack may be engineered to achieve an n-MOS (thinner TiN) to p-MOS (thicker TiN) appropriate FinFET EWF tuning range. FinFETs may be fabricated by depositing a single p-MOS appropriate TiN thickness which may be selectively etched back to achieve thinner, n-MOS appropriate films. Similar electrical behavior is exhibited by etched back and as deposited TiN electrode FinFETs. The single metal etch back fabrication method removes many of the additional steps required for DMG fabrication and preserves the integrity of the MG/High-[kappa] interface between n-MOS and p-MOS devices. These advantages result in reduced fabrication complexity and improved reliability and reproducibility. / text
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Ingénierie électrochimique pour déchiffrer les mécanismes de formation des biofilms électroactifs / Electrochemical engineering for deciphering the mechanisms of electroactive biofilm formationChong, Poehere 23 November 2018 (has links)
Les biofilms électroactifs (EA) sont des consortia de bactéries mono- ou multi-espèces qui ont la capacité de catalyser des réactions électrochimiques en échangeant des électrons avec les électrodes sur lesquelles ils se développent. Les biofilms EA ont ouvert la voie à de nombreux procédés électrochimiques innovants, l’exemple le plus connu étant la pile à combustible microbienne. Dans ce cadre, des électrodes tridimensionnelles poreuses sont couramment mises en oeuvre afin d’offrir aux biofilms EA une surface maximale pour se développer. Toutefois, à ce jour les études théoriques qui permettraient de guider l’élaboration de ces électrodes restent très peu nombreuses. Une synthèse bibliographique a mis en évidence l’importance cruciale de la taille des pores et a montré que des pores de l’ordre du millimètre conduisent aux densités de courant les plus élevées. La première partie de la thèse a donc été consacrée à caractérise l’impact de la taille des pores, entre 1 à 5 mm, sur le développement et les performances électrochimiques d’un biofilm EA multiespèces. Ces tailles permettent la colonisation microbienne sur plusieurs centimètres de profondeur et favorisent la stabilité du courant à long terme. Par contre, l’effet limitant des transferts de matière est significatif, particulièrement pour ce qui concerne les espèces tampon. Enfin, un découplage est mis en évidence entre la colonisation qui se déploie sur plusieurs semaines et l’établissement du courant qui se réalise en quelques jours seulement. Un second dispositif expérimental a mis en évidence une sélection des populations microbiennes en fonction des longueurs de pore de 5 à 24 mm. La deuxième partie de la thèse se focalise sur l’étude des premiers instants de formation du biofilm électroactif à la surface d’une électrode. Une tentative d’identification des mécanismes impliqués dans le mouvement des bactéries électroactives vers l’électrode est proposée. / Electroactive (EA) biofilms refer to single- or multi-species bacterial consortia, which have theability to catalyse electrochemical reactions by exchanging electrons with the electrodes on whichthey develop. EA biofilms have paved the way for many innovative electrochemical processes, themost well-known example is microbial fuel cell. In this context, 3-dimensional porous electrodesare commonly used to offer EA biofilms a maximum surface area for development. However, todate, very few theoretical studies have been carried out to guide the development of theseelectrodes. A bibliographic synthesis highlighted the importance of the pore size and indicated thatpore sizes of the order of a few millimetres lead to the highest current densities. The first part ofthe thesis was therefore devoted to characterizing the impact of size, between 1 and 5 mm, on thedevelopment and electrochemical performance of a multi-species EA biofilm. These sizes allowmicrobial colonization several centimetres deep and promote long-term current stability. However,limiting effect of the mass transfer is significant, particularly for the buffer species. Finally, adecoupling is highlighted between the colonisation, which takes place over several weeks, and theestablishment of the current which takes a few days only. A second experimental set up showsthat a selection occurs on the microbial populations in function of pore lengths from 5 to 24 mm.The second part of the thesis focuses on the study of the early stages of the EA biofilm formation at the electrode surface. In particular, an attempt to identify the mechanisms involved in the electroactive bacteria movement towards the electrode is proposed.
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Fundamental study on seismic behavior of hinge types of precast arch culverts in culvert longitudinal direction / ヒンジ式プレキャストアーチカルバート縦断方向の地震時挙動に関する基礎的研究Miyazaki, Yusuke 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21736号 / 工博第4553号 / 新制||工||1710(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 木村 亮, 教授 岸田 潔, 准教授 木元 小百合 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Image Processing Methods for Myocardial Scar Analysis from 3D Late-Gadolinium Enhanced Cardiac Magnetic Resonance ImagesUsta, Fatma 25 July 2018 (has links)
Myocardial scar, a non-viable tissue which occurs on the myocardium due to the insufficient blood supply to the heart muscle, is one of the leading causes of life-threatening heart disorders, including arrhythmias. Analysis of myocardial scar is important for predicting the risk of arrhythmia and locations of re-entrant circuits in patients’ hearts. For applications, such as computational modeling of cardiac electrophysiology aimed at stratifying patient risk for post-infarction arrhythmias, reconstruction of the intact geometry of scar is required.
Currently, 2D multi-slice late gadolinium-enhanced magnetic resonance imaging (LGEMRI) is widely used to detect and quantify myocardial scar regions of the heart. However, due to the anisotropic spatial dimensions in 2D LGE-MR images, creating scar geometry from these images results in substantial reconstruction errors. For applications requiring reconstructing the intact geometry of scar surfaces, 3D LGE-MR images are more suited as they are isotropic in voxel dimensions and have a higher resolution.
While many techniques have been reported for segmentation of scar using 2D LGEMR images, the equivalent studies for 3D LGE-MRI are limited. Most of these 2D and
3D techniques are basic intensity threshold-based methods. However, due to the lack of optimum threshold (Th) value, these intensity threshold-based methods are not robust in dealing with complex scar segmentation problems. In this study, we propose an algorithm for segmentation of myocardial scar from 3D LGE-MR images based on Markov random field based continuous max-flow (CMF) method. We utilize the segmented myocardium as the region of interest for our algorithm.
We evaluated our CMF method for accuracy by comparing its results to manual delineations using 3D LGE-MR images of 34 patients. We also compared the results of the CMF technique to ones by conventional full-width-at-half-maximum (FWHM) and signal-threshold-to-reference-mean (STRM) methods. The CMF method yields a Dice similarity coefficient (DSC) of 71 +- 8.7% and an absolute volume error (|VE|) of 7.56 +- 7 cm3. Overall, the CMF method outperformed the conventional methods for almost all reported metrics in scar segmentation. We present a comparison study for scar geometries obtained from 2D vs 3D LGE-MRI.
As the myocardial scar geometry greatly influences the sensitivity of risk prediction in
patients, we compare and understand the differences in reconstructed geometry of scar generated using 2D versus 3D LGE-MR images beside providing a scar segmentation study. We use a retrospectively acquired dataset of 24 patients with a myocardial scar who underwent both 2D and 3D LGE-MR imaging. We use manually segmented scar volumes from 2D and 3D LGE-MRI. We then reconstruct the 2D scar segmentation boundaries to 3D surfaces using a LogOdds-based interpolation method. We use numerous metrics to quantify and analyze the scar geometry including fractal dimensions, the number-of-connected-components, and mean volume difference. The higher 3D fractal dimension results indicate that the 3D LGE-MRI produces a more complex surface geometry by better capturing the sparse nature of the scar. Finally, 3D LGE-MRI produces a larger scar surface volume (27.49 +- 20.38 cm3) than 2D-reconstructed LGE-MRI (25.07 +- 16.54 cm3).
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Vytvoření interaktivních pomůcek z oblasti 3D počítačové grafiky / Interactive teaching aids for 3D computer graphicsBalusek, Radim January 2012 (has links)
This diploma thesis deals with the creation of interactive tools for 3D computer graphics. The introduction of the thesis focuses on general theory of curves and surfaces and its mathematical description. The topics of Geometric transformation, Perspective projection and Parametric description of 3-dimensional surface are analysed in more detail. The successive chapter deals with the subject of visualisation of spatial objects in Java platform interface. The practical part describes the implementation of individual applets. JAVA programming language, which uses the library functions JOGL, was employed for the very realization of the interactive tools. The goal of the diploma thesis is the creation of a set of interactive applets in the field of computer graphics. These applets will be placed on the website of the faculty and they will serve students of VUT in Brno to improve the quality of education.
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Développement d’un nouveau modèle de criblage tridimensionnel pour la découverte de médicaments épigénétiques contre le cancer du poumonMc Innes, Gabrielle 11 1900 (has links)
La découverte de médicaments en oncologie repose encore majoritairement sur les criblages pharmacologiques à haut débit. Cependant, les modèles traditionnels de culture cellulaire en deux dimensions (2D) ne reflètent pas les conditions physiopathologiques des tumeurs solides in situ. Au laboratoire, notre hypothèse est que le manque de représentativité des cellules en culture 2D par rapport aux tumeurs in situ lors des essais de criblage pharmacologique in vitro est responsable du faible taux de succès des petites molécules lors d’essais cliniques. Pour pallier ce problème, nous avons développé une méthode de culture à long-terme en trois dimensions (3D) avec des cellules d’adénocarcinome du poumon qui permet le maintien des cellules en sphéroïdes jusqu’à 38 jours. Les cellules s’adaptent rapidement à la culture 3D en diminuant leur taille et en ralentissant significativement leur métabolisme. Au niveau épigénétique, l’expression du complexe KAT3A/KAT3B et de BRG1 est significativement diminuée, et ce de manière temps-dépendante. À l’inverse, l’expression de HDAC6 est augmentée lors du passage en 3D. Finalement, nous avons vérifié si les changements épigénétiques induits par la culture 3D influençaient significativement la réponse aux médicaments. Ainsi, nous avons traité les cellules en 2D et après 10 ou 24 jours en 3D avec une pharmacothèque de 154 médicaments épigénétiques. 60% des médicaments ont démontré une activité anticancéreuse significative sur les cellules en 2D, contrairement à 9% sur les sphéroïdes de 10 jours. Avec les sphéroïdes de 24 jours, uniquement 1 médicament, le MS023, un inhibiteur des arginines méthyltransférases (PRMT) de type I, a été efficace. L’augmentation de la sensibilité au MS023 concorde avec une augmentation de la méthylation des arginines dans les sphéroïdes. En conclusion, mon projet démontre que la culture 3D modifie l’épigénome des cellules cancéreuses du poumon de manière temps-dépendant et que ces changements sensibilisent les cellules à une inhibition des PRMT de type I. L’étude des sphéroïdes nous permet d’améliorer notre compréhension de la biologie tumorale et des processus de découverte de médicaments ce qui pourrait pallier le faible taux de succès associé aux modèles 2D classique. / Small molecule development in oncology mainly involves high-throughput drug screenings and preclinical validation studies using cancer cells grown in two-dimension (2D). However, classical cell culture methods poorly reflect tumor biology and cell epigenome. Here, our objective is to develop a 3D model that displays key epigenetic features of solid tumors in order to identify new actionable targets. First, we determined culture conditions for long-term expansion of adenocarcinoma spheroids to allow cell adaptation and the occurrence of specific epigenetic features triggered by 3D condition. Our results demonstrate that cells cultivated in 3D spheroids exhibit significant phenotypic and epigenetic changes as compared to 2D monolayers. Notably, we observed numerous expression changes of key epigenetic regulators, all taken place at a different time-point of the 3D cell culture. We observed a decrease in the expression of the KAT3A/KAT3B complex as well as BRG1. HDAC6 expression also increased in 3D. Then, we asked whether epigenetic changes triggered by 3D culture would modify drug sensitivity. We performed a screening of 154 epigenetic drugs on cancer cells cultivated in 2D and in 3D at two different time points. 60% of epigenetic drugs showed significant anticancer activity against 2D monolayers. Interestingly, A549 cells in 3D spheroids became gradually resistant over time. Against 3D spheroids cultivated for 10 days, only 9% of epigenetic drugs in the drug library showed anticancer activity. Against 3D spheroids cultivated for 24 days, only a single epigenetic compound called MS023, a selective agent against type I PRMTs, reduced cell viability significantly. This sensitivity is correlated with an increase of arginine methylation observed within spheroids.
Taken together, we show that 3D spheroids trigger a time-dependent epigenetic context that increases lung cancer cells sensitivity to type I PRMT inhibition. 3D spheroids of well-characterized cancer cell lines will improve our understanding of tumor biology and drug discovery and can overcome the high false discovery rate associated with 2D classical models.
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