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Posouzení biologické čistitelnosti odpadních vod z výroby DPG (diphenylguanidinu). / Biological treatment expertise of sewage water rising from production od DPG (diphenylguanidine).VEPŘEKOVÁ, Tereza January 2010 (has links)
The main goal of this thesis is to expertise biological treatment of sewage water rising from production of DPG (diphenylguanidine). The theoretical part is focused on the water and means of sewage disposal. There is shortly described mechanism of physical, chemical, biological and combinated methods of sewage disposal. In practical part of this thesis, focused on expertising degradation of DPG and aniline was chosen high performance liquid chromatography (HPLC) technique, which made it possible to determined their biodegradation abilities. The next component of this thesis are sideline products determination, phenylurea especially. This thesis is focused on monitoring of biofilm´s character and the activity of Rhodococcus erythropolis bacterial culture, used in biodegradation of DPG in chemical-biological wastewater treatment plant, LZD a.s.
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Topics in Least-Squares and Discontinuous Petrov-Galerkin Finite Element AnalysisStorn, Johannes 01 August 2019 (has links)
Aufgrund der fundamentalen Bedeutung partieller Differentialgleichungen zur Beschreibung von Phänomenen in angewandten Wissenschaften ist deren Analyse ein Kerngebiet der Mathematik. Durch Computer lassen sich die Lösungen für eine Vielzahl dieser Gleichungen näherungsweise bestimmen. Die dabei verwendeten numerischen Verfahren sollen auf möglichst exakte Approximationen führen und deren Genauigkeit verifizieren. Die Least-Squares Finite-Elemente-Methode (LSFEM) und die unstetige Petrov-Galerkin (DPG) Methode sind solche Verfahren. Sie werden in dieser Dissertation untersucht.
Der erste Teil der Arbeit untersucht die Genauigkeit der mittels LSFEM berechneten Näherungen. Dazu werden Eigenschaften der zugrundeliegenden Differentialgleichungen mit den Eigenschaften der LSFEM kombiniert. Dies zeigt, dass die Abweichung der berechneten Näherung von der exakten Lösung einem berechenbaren Residuum asymptotisch entspricht. Ferner wird ein Verfahren zu Berechnung einer garantierten oberen Fehlerschranke eingeführt. Während etablierte Fehlerschätzer den Fehler signifikant überschätzt, zeigen numerische Experimente eine äußerst geringe Überschätzung des Fehlers mittels der neuen Fehlerschranke.
Die Analyse der Fehlerschranken für das Stokes-Problem offenbart ein Beziehung der LSFEM und der LBB Konstanten. Diese Konstante ist entscheidend für die Existenz und Stabilität von Lösungen in der Strömungslehre. Der zweite Teil der Arbeit nutzt diese Beziehung und entwickelt ein auf der LSFEM basierendes Verfahren zur numerischen Berechnung der LBB Konstanten.
Der dritte Teil der Arbeit untersucht die DPG Methode. Dabei werden existierende Anwendungen der DPG Methode zusammengefasst und analysiert. Diese Analyse zeigt, dass sich die DPG Methode als eine leicht gestörte LSFEM interpretieren lässt. Diese Interpretation erlaubt die Anwendung der Resultate aus dem ersten Teil der Arbeit und ermöglicht dadurch eine genauere Untersuchung existierender und die Entwicklung neuer DPG Methoden. / The analysis of partial differential equations is a core area in mathematics due to the fundamental role of partial differential equations in the description of phenomena in applied sciences. Computers can approximate the solutions to these equations for many problems. They use numerical schemes which should provide good approximations and verify the accuracy. The least-squares finite element method (LSFEM) and the discontinuous Petrov-Galerkin (DPG) method satisfy these requirements. This thesis investigates these two schemes.
The first part of this thesis explores the accuracy of solutions to the LSFEM. It combines properties of the underlying partial differential equation with properties of the LSFEM and so proves the asymptotic equality of the error and a computable residual. Moreover, this thesis introduces an novel scheme for the computation of guaranteed upper error bounds. While the established error estimator leads to a significant overestimation of the error, numerical experiments indicate a tiny overestimation with the novel bound.
The investigation of error bounds for the Stokes problem visualizes a relation of the LSFEM and the Ladyzhenskaya-Babuška-Brezzi (LBB) constant. This constant is a key in the existence and stability of solution to problems in fluid dynamics. The second part of this thesis utilizes this relation to design a competitive numerical scheme for the computation of the LBB constant.
The third part of this thesis investigates the DPG method. It analyses an abstract framework which compiles existing applications of the DPG method. The analysis relates the DPG method with a slightly perturbed LSFEM. Hence, the results from the first part of this thesis extend to the DPG method. This enables a precise investigation of existing and the design of novel DPG schemes.
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MOBILE OPERATIONS FACILITY IN SUPPORT OF THE X-33 EXTENDED TEST RANGE ALLIANCEPalmer, Robert, Wolf, Glen 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / NASA and the Air Force are increasing the number of hypersonic and access-to-space
programs creating a growing requirement for flight test ranges over large regional areas.
A principal challenge facing these extended test ranges is the ability to provide
continuous vehicle communications by filling the gaps in coverage between fixed ground
stations. Consequently, there is a need for mobile range systems that provide a multitude
of communication services under varying circumstances. This paper discusses the
functional design and systems capabilities, as well as the mission support criteria,
concerning NASA’s Mobile Operations Facility (MOF). The MOF will be deployed to
Dugway Proving Grounds (DPG), Utah, in support of the X-33 single-stage-to-orbit
(SSTO) demonstrator.
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A discontinuous Petrov-Galerkin methodology for incompressible flow problemsRoberts, Nathan Vanderkooy 12 September 2013 (has links)
Incompressible flows -- flows in which variations in the density of a fluid are negligible -- arise in a wide variety of applications, from hydraulics to aerodynamics. The incompressible Navier-Stokes equations which govern such flows are also of fundamental physical and mathematical interest. They are believed to hold the key to understanding turbulent phenomena; precise conditions for the existence and uniqueness of solutions remain unknown -- and establishing such conditions is the subject of one of the Clay Mathematics Institute's Millennium Prize Problems. Typical solutions of incompressible flow problems involve both fine- and large-scale phenomena, so that a uniform finite element mesh of sufficient granularity will at best be wasteful of computational resources, and at worst be infeasible because of resource limitations. Thus adaptive mesh refinements are required. In industry, the adaptivity schemes used are ad hoc, requiring a domain expert to predict features of the solution. A badly chosen mesh may cause the code to take considerably longer to converge, or fail to converge altogether. Typically, the Navier-Stokes solve will be just one component in an optimization loop, which means that any failure requiring human intervention is costly. Therefore, I pursue technological foundations for a solver of the incompressible Navier-Stokes equations that provides robust adaptivity starting with a coarse mesh. By robust, I mean both that the solver always converges to a solution in predictable time, and that the adaptive scheme is independent of the problem -- no special expertise is required for adaptivity. The cornerstone of my approach is the discontinuous Petrov-Galerkin (DPG) finite element methodology developed by Leszek Demkowicz and Jay Gopalakrishnan. For a large class of problems, DPG can be shown to converge at optimal rates. DPG also provides an accurate mechanism for measuring the error, and this can be used to drive adaptive mesh refinements. Several approximations to Navier-Stokes are of interest, and I study each of these in turn, culminating in the study of the steady 2D incompressible Navier-Stokes equations. The Stokes equations can be obtained by neglecting the convective term; these are accurate for "creeping" viscous flows. The Oseen equations replace the convective term, which is nonlinear, with a linear approximation. The steady-state incompressible Navier-Stokes equations approximate the transient equations by neglecting time variations. Crucial to this work is Camellia, a toolbox I developed for solving DPG problems which uses the Trilinos numerical libraries. Camellia supports 2D meshes of triangles and quads of variable polynomial order, allows simple specification of variational forms, supports h- and p-refinements, and distributes the computation of the stiffness matrix, among other features. The central contribution of this dissertation is design and development of mathematical techniques and software, based on the DPG method, for solving the 2D incompressible Navier-Stokes equations in the laminar regime (Reynolds numbers up to about 1000). Along the way, I investigate approximations to these equations -- the Stokes equations and the Oseen equations -- followed by the steady-state Navier-Stokes equations. / text
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Contribution au développement de méthodes numériques destinées à résoudre des problèmes couplés raides rencontrés en mécanique des matériaux / Contribution to Development of Numerical Methods for Solving Stiff Coupled Problems in the Framework of Mechanics of MaterielasRamazzotti, Andrea 11 July 2016 (has links)
Ce travail de recherche est une contribution au développement de la méthode Décomposition Propre Généralisée (PGD) à la résolution de problèmes de diffusion-réaction raides dédiés à la mécanique des matériaux. Ce type d’équations est notamment rencontré lors de l’oxydation des matériaux polymères et il est donc nécessaire de mettre en place un outil pour simuler ce phénomène afin de prédire numériquement le vieillissement de certains matériaux composites à matrice organique utilisés dans l’aéronautique. La méthode PGD a été choisie dans cette thèse car elle permet un gain en temps de calcul notable par rapport à la méthode des éléments finis. Néanmoins cette famille d’équations n’a jamais été traitée avec cette méthode. Cette dernière se résume à la recherche de solutions d’Équations aux Dérivées Partielles sous forme séparée. Dans le cas d’un problème 1D transitoire, cela revient à chercher la solution sous la forme d’une représentation séparée espace-temps. Dans le cadre de cette thèse, un outil numérique a été mis en place permettant une flexibilité telle que différents algorithmes peuvent être testés. La diffusion Fickienne 1D est tout d’abord évaluée avec en particulier une discussion sur l’utilisation d’un schéma de type Euler ou Runge-Kutta à pas adaptatif pour la détermination des fonctions temporelles. Le schéma de Runge-Kutta permet de réduire notablement le temps de calcul des simulations.Ensuite, la mise en place de l’outil pour les systèmes d’équation de type diffusion-réaction nécessite des algorithmes de résolution de systèmes non linéaires, couplés et raides. Pour cela, différents algorithmes ont été implémentés et discutés.Dans le cas d’un système non linéaire, l’utilisation de la méthode de Newton-Raphson dans les itérations pour la recherche du nouveau mode permet de réduire le temps de calcul en limitant le nombre de modes à considérer pour une erreur donnée. En ce qui concerne les couplages, deux stratégies de résolution ont été évaluées. Le couplage fort mène aux mêmes conclusions que dans le cas non linéaire. Les systèmes raides mais linéaires ont ensuite été traités en implémentant l’algorithme de Rosenbrock pour la détermination des fonctions temporelles. Cet algorithme permet contrairement à Euler et à Runge-Kutta de construire une solution avec un temps de calcul raisonnable liée à l’adaptation du maillage temporel sous-jacent à l’utilisation de cette méthode. La résolution d’un système d’équations de diffusion-réaction raides non linéaires utilisée pour la prédiction de l’oxydation d’un composite issu de la littérature a été testée en utilisant les différents algorithmes mis en place. Néanmoins, les non linéarités et la raideur du système génèrent des équations différentielles intermédiaires à coefficients variables pour lesquelles la méthode de Rosenbrock montre ses limites. Il sera donc nécessaire de tester ou développer d’autres algorithmes pour lever ce verrou.Mots / This work presents the development of the Proper Generalized Decomposition (PGD) method for solving stiff reaction-diffusion equations in the framework of mechanics of materials. These equations are particularly encountered in the oxidation of polymers and it is therefore necessary to develop a tool to simulate this phenomenon for example for the ageing of organic matrix composites in aircraft application. The PGD method has been chosen in this work since it allows a large time saving compared to the finite element method. However this family of equations has never been dealt with this method. The PGD method consists in approximating a solution of a Partial Differential Equation with a separated representation. The solution is sought under a space-time separated representation for a 1D transient equation.In this work, a numerical tool has been developed allowing a flexibility to test different algorithms. The 1D Fickian diffusion is first evaluated and two numerical schemes, Euler and Runge-Kutta adaptive methods, are discussed for the determination of the time modes. The Runge-Kutta method allows a large time saving. The implementation of the numerical tool for reaction-diffusion equations requires the use of specific algorithms dedicated to nonlinearity, couplingand stiffness. For this reason, different algorithms have been implemented and discussed. For nonlinear systems, the use of the Newton-Raphson algorithm at the level of the iterations to compute the new mode allows time saving by decreasing the number of modes required for a given precision. Concerning the couplings, two strategies have been evaluated. The strong coupling leads to the same conclusions as the nonlinear case. The linear stiff systems are then studied by considering a dedicated method, the Rosenbrock method, for the determination of the time modes. This algorithm allows time saving compared to the Runge-Kutta method. The solution of a realistic nonlinear stiff reaction-diffusionsystem used for the prediction of the oxidation of a composite obtained from the literature has been tested by using the various implemented algorithms. However, the nonlinearities and the stiffness of the system generate differential equations with variable coefficients for which the Rosenbrock method is limited. It will be necessary to test or develop other algorithms to overcome this barrier.
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A Cooling, Heating, And Power For Buildings (Chp-B) Instructional ModuleHardy, John David 10 May 2003 (has links)
An emerging category of energy systems, consisting of power generation equipment coupled with thermally-activated components, has evolved as Cooling, Heating, and Power (CHP). The application of CHP systems to buildings has developed into a new paradigm ? Cooling, Heating, and Power for Buildings (CHP-B). This instructional module has been developed to introduce undergraduate engineering students to CHP-B. In the typical ME curriculum, a number of courses could contain topics related to CHP. Thermodynamics, heat transfer, thermal systems design, heat and power, alternate energy systems, and HVAC courses are appropriate for CHP topics. However, the types of material needed for this mix of courses vary. In thermodynamics, basic problems involving a CHP flavor are needed, but in an alternate energy systems course much more CHP detail and content would be required. This series of lectures on CHP-B contains both a stand-alone CHP treatment and a compilation of problems/exercises.
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Temporal Variations in the Compliance of Gas Hydrate FormationsRoach, Lisa Aretha Nyala 20 March 2014 (has links)
Seafloor compliance is a non-intrusive geophysical method sensitive to the shear modulus of the sediments below the seafloor. A compliance analysis requires the computation of the frequency dependent transfer function between the vertical stress, produced at the seafloor by the ultra low frequency passive source-infra-gravity waves, and the resulting displacement, related to velocity through the frequency. The displacement of the ocean floor is dependent on the elastic structure of the sediments and the compliance function is tuned to different depths, i.e., a change in the elastic parameters at a given depth is sensed by the compliance function at a particular frequency. In a gas hydrate system, the magnitude of the stiffness is a measure of the quantity of gas hydrates present. Gas hydrates contain immense stores of greenhouse gases making them relevant to climate change science, and represent an important potential alternative source of energy. Bullseye Vent is a gas hydrate system located in an area that has been intensively studied for over 2 decades and research results suggest that this system is evolving over time.
A partnership with NEPTUNE Canada allowed for the investigation of this possible evolution. This thesis describes a compliance experiment configured for NEPTUNE Canada’s seafloor observatory and its failure. It also describes the use of 203 days of simultaneously logged pressure and velocity time-series data, measured by a Scripps differential pressure gauge, and a Güralp CMG-1T broadband seismometer on NEPTUNE Canada’s seismic station, respectively, to evaluate variations in sediment stiffness near Bullseye. The evaluation resulted in a (- 4.49 x10-3± 3.52 x 10-3) % change of the transfer function of 3rd October, 2010 and represents a 2.88% decrease in the stiffness of the sediments over the period. This thesis also outlines a new algorithm for calculating the static compliance of isotropic layered sediments.
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Temporal Variations in the Compliance of Gas Hydrate FormationsRoach, Lisa Aretha Nyala 20 March 2014 (has links)
Seafloor compliance is a non-intrusive geophysical method sensitive to the shear modulus of the sediments below the seafloor. A compliance analysis requires the computation of the frequency dependent transfer function between the vertical stress, produced at the seafloor by the ultra low frequency passive source-infra-gravity waves, and the resulting displacement, related to velocity through the frequency. The displacement of the ocean floor is dependent on the elastic structure of the sediments and the compliance function is tuned to different depths, i.e., a change in the elastic parameters at a given depth is sensed by the compliance function at a particular frequency. In a gas hydrate system, the magnitude of the stiffness is a measure of the quantity of gas hydrates present. Gas hydrates contain immense stores of greenhouse gases making them relevant to climate change science, and represent an important potential alternative source of energy. Bullseye Vent is a gas hydrate system located in an area that has been intensively studied for over 2 decades and research results suggest that this system is evolving over time.
A partnership with NEPTUNE Canada allowed for the investigation of this possible evolution. This thesis describes a compliance experiment configured for NEPTUNE Canada’s seafloor observatory and its failure. It also describes the use of 203 days of simultaneously logged pressure and velocity time-series data, measured by a Scripps differential pressure gauge, and a Güralp CMG-1T broadband seismometer on NEPTUNE Canada’s seismic station, respectively, to evaluate variations in sediment stiffness near Bullseye. The evaluation resulted in a (- 4.49 x10-3± 3.52 x 10-3) % change of the transfer function of 3rd October, 2010 and represents a 2.88% decrease in the stiffness of the sediments over the period. This thesis also outlines a new algorithm for calculating the static compliance of isotropic layered sediments.
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