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Morgan, J. D. "Codimension-two free boundary problems." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359484.
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Gillow, Keith A. "Codimension-two free boundary problems." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298393.
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Over the past 30 years the study of free boundary problems has stimulated much work. However, there exists a widely occurring, but little studied subclass of free boundary problems in which the free boundary has dimension two fewer than that of the underlying space rather than the more commonly studied case of one less. These problems are called `codimension-two' free boundary problems. In Chapter 1 the typical geometries required for such problems, the main mathematical techniques and the methodology used are discussed. Then, in Chapter 2, the techniques required to solve them are demonstrated using the particular example of the water entry problem. Further results for the water entry problem are then derived including an analysis of the relatively poorly understood water exit problem. In Chapter 3 a review is given of some classical contact and crack problems in solid mechanics. The inclusion of a cohesive zone in a dynamic type-III crack problem is considered. The Muskhelishvili potential method is presented and used to solve both a contact and crack problem. This enables the solution of a type-I crack problem relating to an ink delivery system to be found. In Chapter 4 a problem posed by car windscreen forming is addressed. A local solution near a corner is analysed to explain when and how point forces occur at the corners of the frame on which the simply supported windscreen rests. Then the full problem is solved numerically for different types of boundary condition. Chapters 5 and 6 deal with several sintering problems in viscous flow highlighting the value of the methodology introduced in Chapter 1. It will be shown how the Muskhelishvili potential method also carries over to Stokes flow problems. The difficulties of matching to an inner as opposed to an outer region are investigated. Last two interface problems between immiscible liquids are considered which show how the solution procedure is adapted when the field equation in the thin region is non-trivial. In the final chapter results are summarised, open problems listed and conclusions drawn.
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CAPRON, BARBARA ANNE. "TWO-PHOTON MULTIWAVE MIXING (DOPPLER-FREE SPECTROSCOPY)." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183854.
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This dissertation examines aspects of the interaction of multiple coherent light fields for the two-photon two-level model. In this model the interacting energy levels are not connected by an atomic dipole and a two-photon transition between them is necessary. We employ the density matrix formalism allowing easy comparison between the one- and two-photon two-level models. Significant differences are found due to dynamic Stark shifts and conjugate scattering off the pump-induced two-photon coherence. Averages over Doppler broadening are performed and the new upper-level relaxation mechanisms of decay to an intermediate nonresonant level and ionization from the upper state are included. The new relaxation mechanisms, introduced to the theory to better model experiments, are similar except that ionization is intensity dependent. They cause the resulting probe absorption spectra to become more complex and in general asymmetric. Doppler broadening is also important in experiments using gases. We analytically average over a Lorentzian velocity distribution for both co- and counterpropagating pump and probe beams. For copropagating fields the results are similar to those for the one-photon case averaged over inhomogeneous broadening, whereas counterpropagating pump and probe fields yield the so-called Doppler-free configuration that is normally only modelled to third order in the pump amplitude. We consider the pump field amplitude to all orders and find that as long as the width of the Doppler velocity distribution is significantly larger than the two-photon Rabi frequency the results are Doppler-free. The final part of the dissertation treats the question of two-photon squeezed states. This requires quantized sidemodes. Squeezed states are minimum uncertainty states with unequal variances in the two quadratures of the electromagnetic field amplitude. One way to generate these states is via multiwave mixing and we present here the first calculation for nondegenerate two-photon multiwave mixing as it applies to squeezed states. We find that in general two-photon squeezed states require lower intensities and detuning than those predicted by the one-photon model.
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Qiu, Shi. "Early exercise options with two free boundaries." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/early-exercise-options-with-two-free-boundaries(e19e1a9b-df0c-46e1-97f0-15cb1578689b).html.
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The main purpose of this thesis is to derive basic properties and present closed form solutions to the pricing problem of exotic options with two free boundaries. These include American strangle, American chooser, British strangle and American eagle options. These options are designed for an underlying asset with high volatility. Pricing an option with the early exercise feature is equivalent to find an optimal stopping time which will maximise the expected options payoff. Due to the Markovian nature of the underlying process, the optimal stopping problem is linked in a one-to-one way with the free-boundary problem consisting of a parabolic partial differential equation (PDE) satisfying suitable boundary conditions. By the local time-space formula on curves,the closed form solution to the options value can be derived from the free-boundary problem and we characterize two optimal stopping boundaries (free boundaries) as the unique solution pair to the system of two nonlinear integral equations. In Chapter 2 and 3, we study the American strangle option and the American chooser option respectively. The payoff of strangle options is the maximum between the payoff of American call options and the payoff of American put options. The payoff of chooser options is the maximum between the value of American call options and the value of American put options. The major undertaking in this context is to split the optimal stopping region into two disjoint closed sets and to analyse basic properties of the value function and the free boundaries. After performing the required financial analysis, we find that the returns of American strangle options outperform the returns of 'traditional' American strangle options. The returns of American chooser options underperform the returns of American strangle options if exercised before the maturity. In Chapter 4, we design the British strangle option which enjoys the early exercise feature. To inherit higher returns from the British-type option, we insert two contract drifts into the payoff function. The 'tolerance contract drift' minimises the loss and the 'preference contract drift' maximises the gain. We prove the existence of a function of time in the continuation region that implies the two free boundaries never intersect. In Chapter 5, we provide another example of an option with two free boundaries named the American eagle option. Compared with the American strangle option, the eagle option avoids the unlimited loss for the option seller and reduces the option premium for the option buyer. We show that the smooth fit is not satisfied when the free boundaries are equal to the constant caps so that the early exercise premium representation of American eagle options contains the local time term. Using basic properties of standard Brownian motion, we transfer the expectation of the local time term into a computational form. By classifying eagle options into eagle options with balanced wings and eagle options with unbalanced wings, we analyse the properties of the value function and the free boundaries, respectively. Chapter 6 gives a brief analysis of other options with two free boundaries. By changing the underlying measure and 'method of scaling strike', we reduce the high dimensional optimal stopping problem into a lower dimension. Examples of this include Asian strangle options and American lookback strangle options. Combining the payoff of vanilla options, we create American condor and American calendar options.
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Lindgren, Erik. "Regularity properties of two-phase free boundary problems." Doctoral thesis, KTH, Matematik (Inst.), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10336.
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This thesis consists of four papers which are all related to the regularity properties of free boundary problems. The problems considered have in common that they have some sort of two-phase behaviour.In papers I-III we study the interior regularity of different two-phase free boundary problems. Paper I is mainly concerned with the regularity properties of the free boundary, while in papers II and III we devote our study to the regularity of the function, but as a by-product we obtain some partial regularity of the free boundary.The problem considered in paper IV has a somewhat different nature. Here we are interested in certain approximations of the obstacle problem. Two major differences are that we study regularity properties close to the fixed boundary and that the problem converges to a one-phase free boundary problem.QC 20100728
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Kiel, David H. "Two nonlinear models of the Free Electron Laser." Thesis, Monterey, California. Naval Postgraduate School, 1990. http://hdl.handle.net/10945/30622.
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Approved for public release, distribution unlimitedThe dynamics of the Free Electron Laser are governed by Maxwell's equations which causes many highly nonlinear regimes to exist in Free Electron Laser Physics. This thesis will examine two such areas and develop simple models to describe the highly dynamic and rich behavior two of these regimes. In the strong-field, high current regime, the Free Electron Laser driving current can be modeled by a single macroparticle representing the trapped electrons. When the trapped electrons act collectively as a macroparticle representing the trapped electrons. When the trapped electrons act collectively as a macroparticle, solutions which include synchrotron oscillations can be found for the self-consistent pendulum and wave equations. In an FEL oscillator with low single-pass gain, the evolution of the optical wave can lead to sideband development. This phenomenon is studied by applying Maxwell's equations to an oscillator with two optical modes and deriving a two-mode wave and pendulum equation. The two-mode wave and pendulum equations are implemented numerically on computers so that the onset of the sideband can be explored.
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Konoplev, Ivan Vasilyevich. "Free-electron maser with two dimensional distributed feedback." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366827.
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Smith, Gregory J. "TOWARD A TWO-STAGE MODEL OF FREE CATEGORIZATION." CSUSB ScholarWorks, 2015. https://scholarworks.lib.csusb.edu/etd/234.
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This research examines how comparison of objects underlies free categorization, an essential component of human cognition. Previous results using our binomial labeling task have shown that classification probabilities are affected in a graded manner as a function of similarity, i.e., the number of features shared by two objects. In a similarity rating task, people also rated objects sharing more features as more similar. However, the effect of matching features was approximately linear in the similarity task, but superadditive (exponential) in the labeling task. We hypothesize that this difference is due to the fact that people must select specific objects to compare prior to deciding whether to put them in the same category in the labeling task, while they were given specific pairs to compare in the rating task. Thus, the number of features shared by two objects could affect both stages (selection and comparison) in the labeling task, which might explain their super-additive effect, whereas it affected only the latter comparison stage in the similarity rating task. In this experiment, participants saw visual displays consisting of 16 objects from three novel superordinate artificial categories, and were asked to generate binomial (letter-number) labels for each object to indicate their super-and-subordinate category membership. Only one object could be viewed at a time, and these objects could be viewed in any order. This made it possible to record what objects people examine when labeling a given object, which in turn permits separate assessment of stage 1 (selection) versus stage 2 (comparison/decision). Our primary objective in this experiment was to determine whether the increase in category labeling probabilities as a function of level of match (similarity) can be explained by increased sampling alone (stage 1 model), an increased perception of similarity following sampling (stage 2 model), or some combination (mixed model). The results were consistent with earlier studies in showing that the number of matching discrete features shred by two objects affected the probability of same-category label assignment. However, there was no effect of the level of match on the probability of visiting the first matching object while labeling the second. This suggests that the labeling effect is not due to differences in the likelihood of comparing matching objects (stage 1) as a function of the level of match. Thus, the present data provides support for a stage 2 only model, in which the evaluation of similarity is the primary component underlying the level of match effect on free categorization.
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Kotík, David. "Implementace jednoduchého web serveru do mikrokontroléru ColdFire MCF 52233." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217778.
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The goal this semestral work is: Simple web server implementation into microcontroller ColdFire MCF 52233. We'll meet with microcontroller family ColdFire MFC 5223X, protocol HTTP 1.1 and Free ColdFire TCP/IP by Interniche. Like last part is suggestion of implementation web server into microcontroller.
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Austvold, Stephen P. "Leading the Two Harbors Evangelical Free Church through the adjustment stage of the conflict cycle." Theological Research Exchange Network (TREN), 1991. http://www.tren.com.
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Alothman, Ahmad. "Model-Free Variable Selection For Two Groups of Variables." Diss., Temple University Libraries, 2018. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/515925.
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StatisticsPh.D.
In this dissertation we introduce two variable selection procedures for multivariate responses. Our procedures are based on sufficient dimension reduction concepts and are model-free. In the first procedure we consider the dual marginal coordinate hypotheses, where the role of the predictor and the response is not important. Motivated by canonical correlation analysis (CCA), we propose a CCA-based test for the dual marginal coordinate hypotheses, and devise a joint backward selection algorithm for dual model-free variable selection. The second procedure is based on ordinary least squares (OLS). We derive and study the asymptotic properties of the OLS-based test under the normality assumption of the predictors as well as an asymmetry assumption. When these assumptions are violated, the asymptotic test with elliptical trimming and clustering is still valid with desirable numerical performances. A backward selection algorithm for the predictor is also provided for the OLS-based test. The performances of the proposed tests and the variable selection procedures are evaluated through synthetic examples and a real data analysis.
Temple University--Theses
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Barros, Ricardo. "Gravity waves in two-layer flows with free surface." Aix-Marseille 3, 2007. http://www.theses.fr/2007AIX30080.
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Nous étudions dans cette thèse la propagation des ondes dans un écoulement à deux couches et à surface libre. Deux classes de modèles sont considérées. Nous nous consacrons d'abord à la version à deux-couches du modèle de Saint-Venant. Ce modèle est strictement hyperbolique pour des faibles vitesses relatives. Il serait naturel de considérer ce système d'équations pour la description des sauts hydrauliques. Il s'avère que, comme pour la plupart des modèles décrivant des systèmes multi-vitesses, les équations ne sont pas présentées sous forme conservative. C'est pourquoi on a réalisé une étude sur le nombre de lois de conservation pour le système qui semble indiquer que celui-ci est en fait non-conservatif. Comme conséquence, on a l'impossibilité de présenter un ensemble complet de conditions de Rankine-Hugoniot permettant ainsi la caractérisation des solutions faibles dans le sens classique. Nous obtenons ensuite un modèle dispersif adapté à la description de la propagation des ondes de grande amplitude pour le même système physique. Ce modèle est une généralisation naturelle du modèle de Green-Naghdi et sa dérivation est basée sur le principe d'Hamilton. L'idée conduisant au résultat consiste en l'obtention d'un Lagrangien pour le modèle approché en introduisant directement les approximations dans le Lagrangien du modèle complet. Par conséquent, la structure variationnelle ainsi que les propriétés de symétrie correspondantes sont préservées. De plus, aucune restriction du type ondes de faible amplitude ou écoulement potentiel n'est ici considéré. Comme dans le cas des équations d'Euler complètes, ce modèle reproduit la résonance entre les ondes courtes et les ondes longues. Dans ce cadre on montre, par des calculs numériques, l'existence de trajectoires homoclines qui correspondent aux vraies ondes solitaires ayant les mêmes vitesses à l'infini dans chaque couche. L'étude de ces ondes se réduit à l'étude d'un système Hamiltonien à deux degrés de liberté. Les ondes progressives dépendent de trois paramètres: le rapport de densité des fluides, le rapport des épaisseurs de chaque couche et le nombre de Froude. Deux régimes caractérisés par l'élévation ou la dépression de l'interface entre deux couches sont présentés. Le rapport critique des épaisseurs des couches sépare ces deux régimes et il sera montré comment le relier aux changements de la structure pour le potentiel du système Hamiltonien. L'analyse du nombre et la nature des points d'équilibre se sont montrés décisives pour établir le résultat. On a constaté que leur nombre ne peut être que de quatre ou de deux, selon la vitesse de ces ondes (pour un rapport de densité des fluides et un rapport des épaisseurs fixés). Pour les paramètres qui correspondent aux conditions océaniques, on a observé l'existence des ondes solitaires et leur élargissement ("broadening") lorsque la vitesse de ces ondes tend vers une certaine valeur limite. Enfin nous considérons différents paramètres pour lesquelles des solutions avec plusieurs bosses ( "multi-humped shaped profile") existent, illustrant la richesse et la complexité du système considéréIn this work we study the wave propagation in two-layer flows with free surface. Two distinct classes of models are contemplated. First, we consider the "two-layer" version of the shallow water equations (also known by Saint-Venant's equations). This model is strictly hyperbolic for small relative velocities. It would be natural to consider this model as suitable for the description of hydraulic jumps. However, like most of models describing multi-velocity flows, the system is not presented in conservative form. We present a survey on the number of conservation laws available for the multi-dimensional case that seems to imply that the system is truly nonconservative. Therefore, the impossibility of presenting a complete set of Rankine-Hugoniot conditions enabling the characterization of weak solutions in the classical way. Then, we obtain a dispersive model suited to the description of large amplitude waves propagating in the same physical system. The model is a "two-layer" generalization of the Green-Naghdi model and can be derived by applying Hamilton's principle to a Lagrangian that results from the insertion of approximations directly into the Lagrangian for the full waterwave problem. As a consequence, the variational structure of the original problem and the corresponding symmetry properties are preserved. In addition, it is a fully nonlinear model and deals with rotational flows. As in the case of the full problem, the present model captures the resonance between short waves and long waves. In this framework it is shown, by using numerical computations, the existence of homoclinic trajectories embedded into the continuous spectrum. These correspond to true solitary waves having the same velocities at infinity in each layer. Their study reduces to the analysis of a Hamiltonian system with two degrees of freedom. The traveling-wave solutions depend on three parameters : the density ratio, the depth ratio and the Froude number based on the bottom layer. Two wave regimes, characterized by the elevation or depression of the interface between the layers are presented. A critical depth ratio separates these two regimes and it will be shown how it relates to a change of the structure of the potential for the Hamiltonian system. The analysis of the number and nature of critical points turned out to be decisive in this work. It was found that the number of critical points can be four or two, depending on the value of the Froude number (for fixed density and depth ratios). For sets of parameters corresponding to oceanic conditions we have perceived the existence of true solitary waves and their broadening whenever the wave speed increases towards a limit value. Finally, other sets of parameters are considered for which multi-humped solitons exist, highlighting the richness and complexity of the system considered
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Botcherby, Edward J. "Aberration free extended depth of field microscopy." Thesis, University of Oxford, 2007. http://ora.ox.ac.uk/objects/uuid:7ad8bc83-6740-459f-8c48-76b048c89978.
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In recent years, the confocal and two photon microscopes have become ubiquitous tools in life science laboratories. The reason for this is that both these systems can acquire three dimensional image data from biological specimens. Specifically, this is done by acquiring a series of two-dimensional images from a set of equally spaced planes within the specimen. The resulting image stack can be manipulated and displayed on a computer to reveal a wealth of information. These systems can also be used in time lapse studies to monitor the dynamical behaviour of specimens by recording a number of image stacks at a sequence of time points. The time resolution in this situation is, however, limited by the maximum speed at which each constituent image stack can be acquired. Various techniques have emerged to speed up image acquisition and in most practical implementations a single, in-focus, image can be acquired very quickly. However, the real bottleneck in three dimensional imaging is the process of refocusing the system to image different planes. This is commonly done by physically changing the distance between the specimen and imaging lens, which is a relatively slow process. It is clear with the ever-increasing need to image biologically relevant specimens quickly that the speed limitation imposed by the refocusing process must be overcome. This thesis concerns the acquisition of data from a range of specimen depths without requiring the specimen to be moved. A new technique is demonstrated for two photon microscopy that enables data from a whole range of specimen depths to be acquired simultaneously so that a single two dimensional scan records extended depth of field image data directly. This circumvents the need to acquire a full three dimensional image stack and hence leads to a significant improvement in the temporal resolution for acquiring such data by more than an order of magnitude. In the remainder of this thesis, a new microscope architecture is presented that enables scanning to be carried out in three dimensions at high speed without moving the objective lens or specimen. Aberrations introduced by the objective lens are compensated by the introduction of an equal and opposite aberration with a second lens within the system enabling diffraction limited performance over a large range of specimen depths. Focusing is achieved by moving a very small mirror, allowing axial scan rates of several kHz; an improvement of some two orders of magnitude. This approach is extremely general and can be applied to any form of optical microscope with the very great advantage that the specimen is not disturbed. This technique is developed theoretically and experimental results are shown that demonstrate its potential application to a broad range of sectioning methods in microscopy.
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Nandkumar, Subhash. "Two-stroke linear engine." Morgantown, W. Va. : [West Virginia University Libraries], 1998. http://etd.wvu.edu/templates/showETD.cfm?recnum=153.
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Thesis (M.S.)--West Virginia University, 1998.Title from document title page. Document formatted into pages; contains x, 82 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 69-70).
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Kinjo, Tomoaki. "FRET-assisted photoactivation of flavoproteins for in vivo two-photon optogenetics." Kyoto University, 2020. http://hdl.handle.net/2433/253137.
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Morgan, Edward Dylan. "Three Essays on Environmental Economics: Subsidies, Free Riding, and Public Shaming." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31710.
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Chapter 1: When Environmental Subsidies Backfire: The Case of Black Liquor and the Alternative Fuel Mixture Tax Credit: In 2005, the US government introduced the Alternative Fuel Mixture Tax Credit (AFMTC), which paid fifty cents/gallon for alternative fuel that was mixed and burned with traditional fuel. The American chemical pulp industry, which has traditionally burned ‘Black Liquor’, a residue of the pulping process, was able to make large claims on this subsidy in 2009 by mixing diesel fuel into a process where it was not required. This scenario exhibits two main downfalls of environmental subsidies: (i) the majority of the subsidy is paid to free-riders, and (ii) there are strong incentives towards overproduction and increased pollution. In this paper, the value of the AFMTC per tonne of chemical pulp is computed and used in a simulation using the Global Forest Products Model (Buongiorno, 2001) to calculate the effects of the AFMTC on the American and Canadian chemical pulp industries. The simulation suggests that the total amount paid to the American chemical pulp industry was US$7.63 billion, that American chemical pulp production rose by 2.5 million tonnes from the baseline, and Canadian production and exports to the US fell by 285,000 and 255,000 tonnes respectively, costing Canadian chemical pulp producers US$132 million in lost production. Using Canadian chemical pulp production and pollutant release data, production/release averages were developed. These averages suggest that the increase in American chemical pulp production led to significant increase in releases of greenhouse gases, hydrogen sulfide, sulfur oxides, nitrogen oxides and particulate matter. Chapter 2: The Alternative Fuel Mixture Tax Credit and the Pulp and Paper Green Transformation Program: A Policy Comparison: In 2009, chemical pulp mills in the US and Canada were able to take advantage of two subsidy programs that paid mills fifty cents for every gallon of ‘Black Liquor’ burned during the pulping process. Black Liquor is a residue product from the production of chemical pulp, and is traditionally used as a fuel in further pulp production. These subsidies were the Alternative Fuel Mixture Tax Credit (AFMTC) in the US and the Pulp and Paper Green Transformation Program (PPGTP) in Canada. Even though the AFMTC was a subsidy that applied to many industries, and the PPGTP was only available to chemical pulp mills, in the context of the chemical pulp industry only, the subsidies were almost identical: Both paid mills the same amount for undertaking the same activity, and mills were able to claim the subsidies for roughly the same amount of time. The key difference between the two programs was stipulations on how the money was to be spent. In the US, the AFMTC was a refundable tax credit, and simply another source of revenue for a recipient mill. In Canada, a recipient of PPGTP funds was required to spend the money on some form of capital investment that would increase energy efficiency or lower pollution emissions from the mill.
In this paper, we develop a theoretical model with a representative chemical pulp mill in order to compare the effects that these two subsidies would have on the mill’s production of pulp (and in turn its production and use of black liquor), and its decision in whether to invest in a one-time capital improvement that would increase energy efficiency at the mill. The results from this model show that the PPGTP was a more effective policy than the AFMTC, in that it encouraged increased investment in energy efficiency, whereas the AFMTC did not. However, the PPGTP provides incentives to increase production, similar to the AFMTC, in two out of three possible outcomes. Even though the PPGTP is shown to be more effective than the AFMTC, it still exhibits several properties inherent in a second-best policy - because the subsidy is tied to production, it encouraged increased production, and may not have allocated funding in an efficient manner. Chapter 3: Naming, Shaming, and Abatement: Do Published ‘Top Emitter’ Lists Provide Incentive for Increasing Pollution Prevention Activities? Several works have measured the effects that publically disclosed pollutant release information has on the firms and facilities reporting the information. Most of these studies quantify the negative response that the information garners with the media, through some measure of media coverage, and measure the negative impact that this attention has on the firm; for example, by showing a negative effect on the respective company’s publically traded stock performance. Subsequent studies have then shown how these negative impacts from publicity cause firms to report lower emissions levels in following years. What is currently missing from this body of literature, however, is an examination of the step in between the firm receiving negative press and reporting lower emissions, namely, increased pollution abatement efforts on behalf of the publically labeled facility.
In this paper, we attempt to gain a better understanding of this relationship by examining Canadian self-reported facility level data on pollution prevention activities from the National Pollutant Release Inventory. Two consistent samples of data are used to empirically test the effects that ‘Top Ten’ emitter lists, published by Environment Canada in the late 1990’s, had on the number of pollution prevention activities undertaken by facilities in the following year. The results from this work were inconclusive: Between these two samples, there was a noticeable decrease in the amount of pollution prevention activities reported in years after the cessation of the Top Ten publications. Under certain model specifications, a facility that was labeled as a Top Ten emitter is estimated to have 20% more pollution prevention activities undertaken compared to a facility that was not so labeled. It was also shown that a firm that reported new pollution abatement activities also had a significant reduction in releases. This finding, along with the decreasing trend in reported activities, raises a significant policy issue, as measures that clearly reduce reported emissions are being reported with less frequency in Canada.
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Chung, Derrick Kin Hank 1980. "Equations of one and two variables over a free group." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81273.
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In this thesis we study the theory of equations over a free group. We consider basic notions in combinatorial group theory including free groups and free constructions. Using these tools and recent results involving fully residually free groups, we classify solutions to one-variable systems of equations over a free group. We examine some more sophisticated results involving splittings, and obtain a new theorem that describes solutions to two-variable systems of equations over a free group.
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Mao, Wenqun. "Numerical simulation of transient viscoelastic flows with two free surfaces." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68212.
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In this thesis, we examine the numerical simulation of transient viscoelastic flows with two moving free surfaces. A modified Galerkin finite element method is implemented to the two-dimensional non-steady motion of a viscoelastic fluid. The fluid is initially placed between two parallel plates and bounded by two straight free boundaries. In this Lagrangian finite element method, the spatial mesh deforms in time along with the moving free boundaries. The unknown shape of free surfaces is determined with the flow field u, v, $ tau$, p by the deformable finite element method, combined with a predictor-corrector scheme in an uncoupled fashion. In this study, the moving free surfaces and fluid motion of both Newtonian and non-Newtonian flows are investigated. The results include the influence of the time increment and the finite element mesh size, the effects of surface tension, fluid inertia and elasticity.
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Munther, Daniel S. "Ideal Free Dispersal: Dynamics of Two and Three Competing Species." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1312904354.
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Heitzman, Michael Thomas Chicone Carmen Charles. "A free boundary gas dynamic model as a two-body field theory problem." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/7017.
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Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 26, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Professor Carmen Chicone. Vita. Includes bibliographical references.
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Ayliffe, Michael H. "Alignment and packaging techniques for two-dimensional free-space optical interconnects." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37866.
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Two-dimensional free-space optical interconnects (2D-FSOIs) promise to deliver tremendous gains in bandwidth and architectural freedom for applications such as telecommunication switches and massively parallel computing systems. One major obstacle preventing the commercial deployment of 2D-FSOI systems is the problem of optical alignment, which is further exacerbated by the requirements that these systems be field-serviceable and able to sustain the harsh conditions of industrial environments.This thesis proposes a broad range of solutions to alleviate this alignment problem. One important aspect of this work concerns the development of a generic packaging strategy, which consists of partitioning an optical system into separate modules in such a way that the loose tolerances are between the modules while the tight tolerances are between the components inside the modules. To accomplish this, novel alignment techniques are designed and demonstrated, including the use of integrated diffractive features, CMOS position detectors, ultrathick photoresist micro-structures, and semi-kinematic fixtures using dowel pins. In all cases, emphasis is placed on approaches that are amenable to low-cost manufacturing and high-volume production.
These techniques were developed in the context of a photonic backplane prototype experiment that demonstrated 1024 free-space interconnections between four optoelectronic-VLSI (OE-VLSI) chips. The design and implementation of a module integrating an OE-VLSI chip, a mini-lens array, a thermoelectric cooler and a heatsink is presented. Optomechanical, electrical and thermal characterization results are reported.
The other aspect of this work aims at identifying the types of optical designs that provide more generous misalignment tolerances. This is done by investigating various optical configurations for the design of the chip module. The central objective is to understand the underlying reasons that make one configuration more misalignment-tolerant than another. A significant outcome of this work is to show that the inherent misalignment tolerances of 2D-FSOI systems translates into an aspect-ratio limitation similar to the one found in electrical interconnects.
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King, Andrew. "Claw-free graphs and two conjectures on omega, Delta, and chi." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66861.
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This thesis concerns the relationship between four graph invariants: omega, chi_f, chi, and Delta. These are the clique number, the fractional chromatic number, the chromatic number, and the maximum degree, respectively. Trivially omega <= chi_f <= chi <= Delta + 1. We seek to improve the upper bound on chi. We are motivated by a conjecture of Reed, which essentially states that chi is at most the average of its trivial upper and lower bounds: Conjecture. For any graph, chi <= (Delta + 2 + omega)/2. We call this the Main Conjecture, and propose a Local Strengthening based on the closed neighbourhood of a single vertex: Conjecture. For any graph G, chi <= max{v in V(G)} (d(v) + 2 + omega(G[N(v)]) + 1) / 2. We begin by showing that much of the early evidence supporting the Main Conjecture also supports the Local Strengthening. In particular, the variant of the Local Strengthening obtained by replacing chi by chi_f holds, as does the Local Strengthening when the stability number is two. Guided by the first of these results we look towards line graphs, for which chi_f and chi agree asymptotically. We prove the Main Conjecture for line graphs, then we seek to generalize this result. To do this we use recent results of Chudnovsky and Seymour, who characterized the structure of all claw-free graphs. We refine their results by introducing a graph reduction on certain types of homogeneous pairs of cliques that preserves the chromatic number. Thus we need only consider the problem of colouring _skeletal_ claw-free graphs, which cannot be reduced. The structure of skeletal claw-free graphs is simpler than that of general claw-free graphs. We generalize two results from line graphs to the class of quasi-line graphs. Namely, that the Main Conjecture holds, and that chi_f and chi agree asymptotically. We then consider all claw-free graphs. We prove the Main Conjecture for all claw-free graphs and we prove the LocalCette thèse a pour sujet la relation entre quatre invariants de graphes : omega, chi_f, chi, et Delta.Il s'agit respectivement du nombre de clique, du nombre chromatique fractionnaire,du nombre chromatique, et du degré maximum. Ces paramètres vérifient trivialementl'encadrement suivant : omega <= chi_f <= chi <= Delta+1, dans lequel on cherche ça améliorerla borne supérieure sur chi. Une des principales motivations pour ce travail est uneconjecture de Reed, qui dit essentiellement que chi est au plus la moyenne de ses bornesinférieures et supérieures triviales.Conjecture. Pour tout graph, chi <= (Delta + 2 + omega)/2.On appelle cet énoncé la Conjecture Principale, et on propose un RenforcementLocal basé sur le voisinage de chaque sommet.Conjecture. Pour tout graphe G, chi <= max{v dans V(G)} (d(v) + 2 + omega(G[N(v)]) + 1) / 2.On commence par montrer que la plupart des arguments en faveur de la ConjecturePrincipale incitent également à croire que le Renforcement Local est vrai. Enparticulier, la borne donnée par le Renforcement Local vaut pour chi_f et le RenforcementLocal peut être montré lorsque le nombre de stabilité vaut deux.Guidé par ces premiers pas, on s'intéresse aux graphes adjoints, pour lesquels chi_fet chi sont asymptotiquement équivalents. On montre la Conjecture Principale dansle cas des graphes adjoints et on cherche ensuite à généraliser ce résultat.Pour cela on utilise des résultats récents de Chudnovsky et Seymour, qui ontcaractérisé la structure les graphes sans griffes. On affine ces résultats en introduisantla notion de graphes squelettes. Dans les problèmes auxquels on s'intéresse,on peut facilement se ramener au cas des graphes squelettes, et la structure desgraphes squelettes sans griffes est plus simple que celle des graphes sans griffes engénéral.On étend deux résultats des graphes adjoints aux graphes quasi-adjoints : onmontre que la Conj
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Châteauneuf, Marc. "Design and alignment methodologies for two-dimensional free-space optical interconnects." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19655.
Full textAbstract:
Free-space optical interconnects (FSOIs) represent an attractive alternative technology for the implementation of short distance high bandwidth interconnections for applications such as massively parallel computing systems. However, FSOIs have still not been accepted commercially as an interconnect technology. Examples of obstacles preventing the commercial deployment of FSOI systems are the problem of optical alignment and the absence of optical system design tools. This thesis addresses these concerns and proposes a series of tools for the design and alignment of free-space optical links. The need for these tools was emphasised in the context of the optical design and implementation of a dense vertical-cavity surfaceemitting laser (VCSEL) based FSOI demonstrator. The link interconnected two boards separated by 83 mm through 512 optical channels giving a record channel density of 28.4 channels/mm2.
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Lee, Wing Kuen. "Interpreting tables in text using probabilistic two-dimensional context-free grammars /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?COMP%202005%20LEEW.
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Cord, Gregory A. "Free electron laser short pulse simulation and two-mode sideband analysis." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28234.
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May, Andrew J. "A Comparison of the Effectiveness of Two Free Throw Shooting Methods." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2918.
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The purpose of this study was to compare the effectiveness of two free throw shooting methods, the Ed Palubinskas Method (PM) and the Free Shoot Method (FSM), and their ability to improve free throw shooting accuracy. The experimental group, using the PM, and the control group, using the FSM, shot the same amount of free throws over a 13 week period. Subjects were 33 male intermediate basketball students at Brigham Young University. Subjects in both groups shot 26 free throws twice a week. Subjects were tested once every other week by shooting and recording the amount made out of nine attempts. There was no significant improvement for trials for both groups over the 13 weeks (F=1.583, p=.154). There was also no significant difference between groups (F=.445, p=.510) nor any interaction between groups (F=.642, p=.696). There was no significant difference in free throw shooting accuracy between the PM and FSM for the selected groups.
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Hull, Jesse F. "Recognition of mathematics using a two-dimensional trainable context-free grammar." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10587.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (leaves [100]-101).
by Jesse F. Hull.
M.Eng.
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Nord, Iza. "Reducing Greenhouse Gas Emissions Through the Use of Free Shops : A Case Study of Two Free Shops in Gothenburg." Thesis, Mittuniversitetet, Avdelningen för ekoteknik och hållbart byggande, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-33920.
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Products, throughout their life cycle from production to waste management, create emissions of greenhouse gases (GHG). This leads to environmental impacts on the climate (Swedish Environmental Protection Agency, 2016). The consumed products from households are increasing (World Wildlife Fund, 2008) and so is the waste generated from them (Avfall Sverige, n.d.). A more sustainable development generating from circular economy should be focused on to increases the reuse of products and by so reduce the amount of waste generated (Göteborgs Stad, n.d.a.) This study have examined if the use of Free Shops can help the city of Gothenburg to reach higher up the waste management hierarchy towards reuse and prevention, and if carbon dioxide equivalents (CO2e) can be avoided by using Free Shops. Two Free Shops with the purpose to increase reuse in Gothenburg have been studied and their effect on GHG emissions, presented as CO2e, have been analysed. A Life Cycle Inventory Study (LCI) has been conducted on all, but two, different materials entering the Free Shops for four weeks, including the production, waste management, transportation and storage. The result of the study shows that a mean of 10 ton CO2e per Free Shop per year can be avoided when reusing at a Free Shop instead of buying new products. This equals leaving a low energy lamp on for approximately 590 years (World Wildlife Fund, 2009) based on a low energy lamp using 0,007 kWh (Eon, 2007). To examine if the Free Shops can reduce the amount of waste disposed of by households in Gothenburg the material entering the Free Shops was weight and analysed to estimate how it corresponded to the amount of waste disposed of. The result shows that the material entering a Free Shop only corresponds to 0.0025 percent of the household waste disposed of in the city. This indicates that Free Shops by themselves will not solve the problem with increasing amounts of waste and emissions from increasing production. However, they can help in a small scale.20180625
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Kaganovskii, Yuri, Lyudmila N. Paritskaya, and Valeriy V. Bogdanov. "Lateral diffusion spreading of two competitive intermetallic phases along free surface (system Cu-Sn): Lateral diffusion spreading of two competitive intermetallicphases along free surface (system Cu-Sn)." Diffusion fundamentals 6 (2007) 43, S. 1-2, 2007. https://ul.qucosa.de/id/qucosa%3A14219.
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Viana, MartÃnio Ponte. "ToxicoproteÃmica aplicada à anÃlise de risco da proteÃna recombinante cry1ac de Bacillus thuringiensis." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17262.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorCoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Dentre os vÃrios microrganismos entomopatogÃnicos utilizados no controle biolÃgico, o Bacillus thuringiensis (Bt) vem sendo considerado uma das alternativas mais viÃveis, devido à presenÃa de proteÃnas inseticidas em seus esporos, como as δ-endotoxinas Cry. As toxinas Cry apresentam atividade contra diferentes ordens de insetos, como Coleoptera, Diptera, Hymenoptera, Hemiptera e Lepidoptera. Tais proteÃnas sÃo altamente especÃficas, ou seja, sÃo inÃcuas para a maioria dos organismos nÃo-alvo, fato que favorece sua utilizaÃÃo na agricultura. Hoje existem mais de 114 milhÃes de hectares de lavouras geneticamente modificadas e 37% expressam traÃos de proteÃnas inseticidas de Bt. Como os organismos geneticamente modificados (OGMs) estÃo se tornando cada vez mais predominantes, vÃrias organizaÃÃes internacionais tÃm dado orientaÃÃes no sentido de investigar a seguranÃa de alimentos provenientes de OGMs. Este trabalho teve como objetivo utilizar uma abordagem toxicoproteÃmica para anÃlise de risco da proteÃna recombinante Cry1Ac de Bt a fim de contribuir para uma maior compreensÃo de seus efeitos em modelo de mamÃferos. O ensaio de toxicidade foi conduzido de acordo com o protocolo 425 da âOrganizaÃÃo para a CooperaÃÃo e Desenvolvimento EconÃmicoâ - OECD e nÃo foram verificadas mortes ou sinais de toxicidade. As anÃlises proteÃmicas baseadas em gel mostraram 4 proteÃnas diferencialmente expressas Serpina α-1, Serpina A3K, CininogÃnio e Complemento C3. Essas proteÃnas tiveram uma reduÃÃo em sua expressÃo no grupo tratado com a toxina Cry1Ac. Na abordagem âgel-freeâ foram identificadas 7 proteÃnas diferencialmente expressas. Dentre elas, fator I, inibidor de tripsina H3, plasminogÃnio, serpina A6, albumina e proteÃna resistente à oxidaÃÃo apresentaram uma expressÃo maior em animais tratados com Cry1Ac, enquanto que a protrombina teve sua expressÃo reduzida em animais tratados com a mesma proteÃna. Tais molÃculas sÃo importantes para hemostasia e sistema imune, podendo interferir no processo inflamatÃrio, na ativaÃÃo da via do complemento e da cascata de coagulaÃÃo. No entanto, a abordagem toxicoproteÃmica adotada mostra-se Ãtil para a identificaÃÃo de efeitos adversos, atà mesmo de uma jà amplamente conhecida por sua baixa toxicidade. Isso encoraja a utilizaÃÃo da referida abordagem para a avaliaÃÃo de risco de proteÃnas recombinantes. Apesar das alteraÃÃes fisiolÃgicas causadas, a proteÃna Cry1Ac ainda à considerada segura jà que tais alteraÃÃes ocorreram na dose mais alta recomenda pela OECD (2000mg/Kg) e sem causar morte dos animais.
Among the various pathogenic bacteria used in biological control, Bacillus thuringiensis has been considered one of the most viable alternatives, due to the presence of insecticidal proteins in their spores, such as the δ-endotoxin, Cry. The Cry toxins exhibit activity against different insect orders, such as Coleoptera, Diptera, Hymenoptera, Hemiptera and Lepidoptera. Such proteins are highly specific, which means, they are harmless to most organisms. This fact justifies their use in agriculture. Nowadays, there are over 114 million hectares of GM crops and 37% express traits of insecticidal proteins of B. thuringiensis. Since genetically modified organisms (GMOs) are becoming increasingly prevalent, several international organizations have given guidelines to investigate the safety of food derived from GMOs. This work aimed to evaluate the acute toxicity of the entomotoxin Cry1Ac in rats through classical in vivo analyzes associated with proteomic study by two-dimensional electrophoresis and shotgum proteomic technique (gel-free). Toxicity tests were conducted according to the protocol of 425 "Organization of Economic Cooperation and Development" - OECD and no deaths or signs of toxicity were observed. The gel-based proteomic analysis showed four differentially expressed proteins: Serpin α-1, Serpin A3K, Kininogen and Complement C3. These proteins expressions were reduced for the group treated with the Cry1Ac toxin. In gel-free approach, seven differentially expressed proteins were identified. Among them, factor I, H3 trypsin inhibitor, plasminogen, serpin A6, albumin, and protein resistant to oxidation showed a higher expression in animals treated with Cry1Ac, while the prothrombin expression was reduced in animals treated with the same protein. Such molecules are important for hemostasis and immune system, and may interfere with the inflammatory process, activation of the complement pathway and the coagulation cascade. Despite the physiological changes caused by Cry1Ac, this protein is still considered safe since these changes occurred at the highest dose recommended by OECD (2000 mg / kg) and without causing death of the animals.
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Ponraj, Sathishkumar. "Stimulus-free RT level power model using belief propagation." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000531.
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Houdyschell, David. "A diesel two-stroke linear engine." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1312.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains ix, 64 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 42-43).
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Frey, Tanja [Verfasser], and Mathias [Akademischer Betreuer] Ritzmann. "Wirksamkeit einer two-shot Vakzine nach experimenteller Infektion von Endmastschweinen mit Mycoplasma hyopneumoniae / Tanja Frey. Betreuer: Mathias Ritzmann." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1053618476/34.
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Yilmaz, Burak. "Development And Validation Of Two-dimensional Depth-averaged Free Surface Flow Solver." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1089523/index.pdf.
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A numerical solution algorithm based on finite volume method is developed for
unsteady, two-dimensional, depth-averaged shallow water flow equations. The model
is verified using test cases from the literature and free surface data obtained from
measurements in a laboratory flume. Experiments are carried out in a horizontal,
rectangular channel with vertical solid boxes attached on the sidewalls to obtain freesurface
data set in flows where three-dimensionality is significant. Experimental data
contain both subcritical and supercritical states. The shallow water equations are
solved on a structured, rectangular grid system. Godunov type solution procedure
evaluates the interface fluxes using an upwind method with an exact Riemann solver.
The numerical solution reproduces analytical solutions for the test cases successfully.
Comparison of the numerical results with the experimental two-dimensional free
surface data is used to illustrate the limitations of the shallow water equations and
improvements necessary for better simulation of such cases.
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Ghamry, Haitham Kamal. "Two-dimensional vertically averaged and moment equations for shallow free-surface flows." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0026/NQ39531.pdf.
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Liu, Bo Yan. "Two-dimensional free vibration analysis of cracked FGM beams by Ritz method." Thesis, University of Macau, 2015. http://umaclib3.umac.mo/record=b3335682.
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Persaud, Michael Alan. "Doppler-free two-photon spectroscopy of one electron atoms using pulsed lasers." Thesis, University of Southampton, 1991. https://eprints.soton.ac.uk/361600/.
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In two independent experiments, frequency doubled pulse amplified dye laser light has been used in performing Doppler-free two-photon spectroscopy of the 1S½−2S½ transition in atomic hydrogen and muonium. Absolute values gained for the 1S½−2S½ transition frequencies were 2466 061 416(9) MHz and 2455 528 964(72) MHz for hydrogen and muonium respectively. Values for the ground state Lamb shifts were inferred to be 8171(9) MHz for hydrogen and 8079(73) MHz for muonium. All results were found to be in agreement with current quantum electrodynamic (QED) theory. Assuming QED theory to be accurate, then the hydrogen experiment yielded a new value for the Rydberg constant of 109 737 31.58(4) m−1, which is in agreement with other independent measurements. A separate experiment demonstrated a novel and general technique for efficiently frequency doubling mode-locked laser light, based on second harmonic generation inside an actively stabilised external ring enhancement cavity. When applied to a synchronously pumped mode-locked dye laser, over 100mW average power of tunable light around 243nm was available from the system corresponding to crystal conversion efficiencies in excess of 55%. A simple theoretical model successfully described the performance of this system. FM sideband frequency stabilisation of mode-locked lasers is treated both theoretically and experimentally. For the mode-locked dye laser, a frequency stability to within 500kHz relative to a reference interferometer was routinely possible. The frequency stabilised tunable uv light is ideal for performing Doppler-free coherent multiple pulse spectroscopy and may find application in the synchronous pumping of optical parametric oscillators or in selectively breaking chemical bonds.
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Meyers, David Morton. "Freak beer (Part two - Do not resuscitate)." Thesis, University of Iowa, 2019. https://ir.uiowa.edu/etd/6805.
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Akinbohun, Olugbenga John. "To ascertain why some women delay in seeking termination of pregnancy (TOP) for unwanted pregnancies in Lejweleputswa District (DC18), Free State." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&.
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Women of child-bearing age sometimes fail to plan for pregnancies. Often they discover that they are pregnant and are not prepared or cannot afford to raise the child. Before 1996 there was no choice for women as regards pregnancies, all pregnancies must be carried to term and delivered except on health grounds and with stringent conditions. However after the TOP act was enacted in 1996, women were allowed a choice of TOP up to and including 20 weeks of pregnancy.Regardless of the availability of choice of TOP, some pregnant women still present late (after 12 weeks) for TOP when the risks of complications and costs are higher. Women who present late for TOP usually have to be admitted to a district or regional hospital and managed. The costs at such institutions are high. TOPs before 12 weeks (early TOP) are done in a primary health care (PHC) facility (TOP center) and no admission is required hence less cost. Complications of early TOP are also very mild and rare. In Lejweleputswa district there is only one TOP Center (Kopano TOP Clinic) and this serves both Lejweleputswa and the Northern Free State districts. Early TOPs (less than 12 weeks) are done and completed at this center. Late TOPs (above 12 weeks but not more than 20 weeks) are initiated at this TOP center and referred to district or regional hospitals nearest to the patient&rsquo
s home, in both districts for completion.
Problems - An increasing number of women are seeking TOP service at late stages of pregnancies and the incidence of severe complications like severe bleeding, retained placenta, infection, amniotic fluid embolism, death etc, are increasing. The hospital&rsquo
s bed space and budget are stretched to the limit due to the influx of late term TOP to the hospitals. Lack of manpower, especially doctors, in these hospitals also create some problems, as the few doctors available have to attend to other ill patients as well. Sometimes bleeding TOP patients are transfused with blood and placed on a waiting list for theatre and this often increases the risk of complications. The emotional effect of late TOP on hospital staff (doctors and nurses) are enormous as the expelled fetus are much more developed than in early TOP where no fetus is seen at evacuation with simple Manual Vacuum Aspiration (MVA).
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Yamamoto, Shinya. "Spatiotemporal ATP Dynamics during AKI Predict Renal Prognosis." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263351.
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Vahlroos, Riikka. "I began to be free : A study on two trans-active Finnish men." Thesis, Linköping University, Department of Culture and Communication, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-16686.
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This study focuses on Finnish transmen and their life stories. It goes through the practical reality of the gender re-assignment process, but focuses on the personal experiences of two individual men. The study is based on in-depth interviews with informants, material which has been analyzed with the help of Judith Butler’s theory on gender.
Den här uppsatsen handlar om två finska transmän och deras livshistorier. Studien går igenom den praktiska realiteten av könskorrigeringsprocessen, men fokuserar på de personliga erfarenheterna av dessa två individuella män. Den är baserad på djupintervjuer med informanter, material som har analyserats med hjälp av Judith Butlers teori om genus.
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Elborai, Shihab M. (Shihab Mahmoud) 1977. "Operation and control of a two-stroke, free-piston-engine-driven linear alternator." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86476.
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Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (p. 126).
by Shihab M. Elborai.
S.B.and M.Eng.
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Zanet, Phillip. "Characterization of two novel cysteine proteases in the free-living organism «Macrostomum ligano »." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119584.
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The objective of this study was to explore Macrostomum lignano, a free-living organism, as a model organism for parasitic trematodes, such as Fasciola and Schistosoma, in order to better understand the role of their cysteine proteases (cathepsins). Using a bioinformatics approach, two novel cysteine proteases genes (mlcl1 and mlcb2) were identified and phylogenetically characterized. These genes were synthesized, cloned into the yeast secretory system Pichia pastoris (Invitrogen), and functionally-active recombinant proteins were expressed and purified. These recombinant peptidases were then characterized biochemically in terms of activity and stability in various conditions including temperature, salinity and pH. Antibodies specific for the recombinant proteins were generated through a peptide or whole-protein immunization, and tested against both the recombinant proteins and the worm extract proving that the proteins exist in the worm. These studies lay the foundation for further investigations on the biological function of the cysteine peptidases using RNAi and confocal microscopy. In conclusion, M. lignano is a tractable model organism for its parasitic counterparts.L'objectif de cette recherche était d'explorer l'organisme, vivant en liberté dans la nature, Macrostomum lignano en tant qu'organisme modèle pour ses cousins parasites, Fasciola et Schistosoma, et de mieux comprendre le rôle de leurs protéases cystéines (cathepsins). En utilisant une approche bioinformatique, deux nouveaux gènes de protéases cystéines (mlcl1 et mlcb2) ont été découverts et caractérisés phylogénétiquement. Ces gènes ont été synthétisés, clonés dans un système de sécrétion employant la levure Pichia pastoris (Invitrogen) et exprimés en tant que protéases recombinantes et actives. Ces protéases recombinantes ont alors été caractérisées biochimiquement en termes d'activité et de stabilité dans diverses conditions telles que la température, la salinité et le pH. Des anticorps spécifiques aux protéines recombinantes ont été générés en immunisant des mammifères avec des séquences de peptides ou la protéine recombinante entière, et ont été testés avec l'extrait du vers prouvant ainsi que les protéines sont bel et bien exprimées. Ces études jettent la base pour l'investigation sur la fonction biologique des protéases cystéines par l'emploi du RNAi et de la microscopie confocale. En conclusion, M. lignano est un organisme modèle tractable pour ses cousins parasites.
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Alexis, naza. "Corrosion behavior of lead-free and dezincification resistant brass alloys in tap water." Thesis, KTH, Kemi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299738.
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Avzinkningshärdiga och blyfria mässingslegeringar används i stor utsträckning för att ersätta blyinnehållande mässingslegeringar som används för dricksvattensapplikationer. På grund av det begränsade antalet korrosionsstudier av dessa legeringar är syftet med denna studie att belysa hur vattensammansättning, temperatur och exponeringstid kan påverka legeringarnas korrosionsegenskaper. Tre avzinkningshärdiga mässingslegeringar studerades i kranvatten; två blyfria mässingslegeringar (CW511L och CW724R) och en blyinnehållande mässingslegering (CW602N) som betraktades som ett referensmaterial. En kombination av elektrokemiska, mikroskopiska och ytanalystekniker användes för att utforska korrosionstyp, mekanismer samt korrosionshastighet. Även om samtliga legeringar visade godkända egenskaper i avzinkningstestet enligt ISO 6509-1:2014 var målet att bedöma deras korrosionsbeteende i kranvatten. Vattenkemin justerades för att undersöka effekten av pH, kloridkoncentration och alkalinitet hos de tre mässingslegeringarna under kortvarig exponeringstid (24 timmar). Vattnets korrosivitet varierade beroende på mässingslegeringens sammansättning. Det visade sig att CW511L var känsligare för höga kloridkoncentrationer (44.7 mg/L) och hög alkalinitet (310 mg/L) än för lågt pH (6.9). Det motsatta observerades dock för både CW724R och CW602N. Testvattnets aggressivitet påverkades också av temperaturen när den ökades från 22 °C till 50 °C under exponering i 24 timmar. Medan ingen tydlig avzinkning upptäcktes observerades en kombination av både allmän och lokal korrosion i varierande utsträckning mellan de olika legeringarna. Initieringen av det lokala korrosionsangreppet varierade både med testvattnets kemi och med legeringssammansättningen. Medan CW724R och CW602N bägge uppvisade hög känslighet för lokal korrosion i vattnet med högst pH (8.2), var CW511L mer känslig i det vatten med lågt pH (6.9) vid 50 °C. Effekten av exponeringstid undersöktes i vattnet med högst pH (8.2) för de tre mässingslegeringarna upp till 72 dagar. Korrosionshastigheten baserad på viktminskning visade en förväntad hög korrosionshastighet som minskade med kontinuerlig exponeringstid, vilket ledde till en låg korrosionshastighet för alla tre mässingslegeringarna efter 72 dagar. De blyfria mässingslegeringar uppvisade ur detta perspektiv goda korrosionsegenskaper som är konkurrenskraftiga med mässing som innehåller bly.Dezincification resistant (DZR) and lead-free brass alloys continue to be widely applied replacing lead containing brasses in the drinking water sector. Due to the limited number of corrosion studies of these alloys in tap water, the present thesis was initiated with the aim to understand how the water type, its temperature and exposure duration can affect the corrosion behavior. Three DZR brass alloys were studied in order to evaluate their corrosion behavior in tap water of varying characteristics. The alloys included were two lead-free brasses (CW511L and CW724R) and a leaded brass alloy (CW602N) considered as a reference material. A combination of electrochemical, microscopic and surface analytical techniques were adopted to explore the corrosion form, mechanisms and corrosion rate. While these alloys passed the dezincification test as per ISO 6509-1:2014, the aim was to assess their corrosion performance in tap water. The influence of water chemistry parameters including pH, chloride concentration and alkalinity on the corrosion resistance of the three DZR alloys was investigated in short-term exposures (24 h). Depending on the brass alloy, the corrosivity of the test waters varied. The results show grade CW511L to be more sensitive in tap water of higher chloride concentration (44.7 mg/L) and alkalinity (310 mg/L) compared with low pH (6.9). However, opposite results were obtained for both CW724R and CW602N. The corrosivity of the test water was also affected by the temperature when increased from 22°C to 50°C during 24 h of immersion. While no dezincification features were observed on the surfaces, a combination of general and localized corrosion was observed to a largely variable extent between the alloys. The extent of initiation of localized corrosion varied with test water and alloy composition. While CW724R and CW602N showed similar high susceptibility to localized corrosion in the alkaline (pH 8.2) tap water, CW511L was more prone to pitting corrosion in tap water of low pH (6.9). The effect of exposure duration was explored in the alkaline test water for the three brasses up to 72 days. Corrosion rates based on weight loss showed an expected initial high corrosion rate which declined with continuous immersion, leading to low and similar corrosion rates for all three brass alloys after 72 days. Thus, at given test conditions, the lead-free brasses showed good corrosion behavior being competitive to the performance of lead containing brass. Therefore, lead-free brass alloys are good candidates to substitute lead-containing brasses in tap water applications.
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Rasadurai, Rajavaheinthan. "Forced water entry and exit of two-dimensional bodies through a free surface." Thesis, Brunel University, 2014. http://bura.brunel.ac.uk/handle/2438/8327.
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The forced water entry and exit of two-dimensional bodies through a free surface is computed for various 2D bodies (symmetric wedges, asymmetric wedges, truncated wedges and boxes). These bodies enter or exit water with constant velocity or constant acceleration. The calculations are based on the fully non-linear timestepping complex-variable method of Vinje and Brevig. The model was formulated as an initial boundary-value problem with boundary conditions specified on the boundaries (dynamic and kinematic free-surface boundary conditions) and initial conditions at time zero (initial velocity and position of the body and free-surface particles). The formulated problem was solved by means of a boundary-element method using collocation points on the boundary of the domain and solutions at each time were calculated using time stepping (Runge-Kutta and Hamming predictor corrector) methods. Numerical results for the deformed free-surface profile, the speed of the point at the intersection of the body and free surface, the pressure along the wetted region of the bodies and force experienced by the bodies, are given for the entry and exit. To verify the results, various tests such as convergence checks, self-similarity for entry (gravity-free solutions) and Froude number effect for constant velocity entry and exit (half-wedge angles 5 up to 55 degrees) are investigated. The numerical results are compared with Mackie's analytical theory for water entry and exit with constant velocities, and the analytical added mass force computed for water entry and exit of symmetric wedges and boxes with constant acceleration and velocity using conformal mapping. Finally, numerical results showing the effect of finite depth are investigated for entry and exit.
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Pagden, Louise. "Free school Policy Enactment in two case-study schools : motivation, vision and reality." Thesis, University of Reading, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701639.
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In 2010 the DfE introduced 'The Academies Bill which established 'Free Schools' and invited parents, teachers and trusts to apply to set up new state-funded (but relatively independent) schools. There are now over 300 open in England. However there is little empirical evidence on the set-up process and the problems and opportunities encountered by the governing bodies. This study aims to address this gap .. This thesis examines the extent to which Free schools' visions are reflected in reality. The thesis focuses on two case-study schools: one championed by a consortium of churches and a fourth-sector organisation; the other spear-headed by parents. The study is longitudinal in nature and the data have been collected over two years: the first set of data was collected in the year prior to the schools opening and the second set at the, end of the first year of operation. The data were gathered through 13 semi-structured interviews (with members of the two steering groups) and analysed using a variety of methods. School documentation, including policies and web-literature has also been analysed. The data have been mapped onto an adapted version of Bronfenbrenner's ecosystem model. This focuses on the connections and influences between different groups and organisations .The thesis compares and contrasts the views of governing body personnel in the set-up period with their experiences once the school is open. The results highlight the pressures that act upon free schools which either facilitate or prevent their vision from becoming a reality. Key actors' influences are examined, including the government (local and national), parents, community and the staff within the school. The study reveals that, despite relative freedom, both schools' visions remain relatively traditional. However, the elements of their visions which were intended to set the schools apart from their mainstream counterparts have been more difficult to achieve in reality.
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Jonsson, Karl. "Two Problems in non-linear PDE’s with Phase Transitions." Licentiate thesis, KTH, Matematik (Avd.), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-223562.
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This thesis is in the field of non-linear partial differential equations (PDE), focusing on problems which show some type of phase-transition. A single phase Hele-Shaw flow models a Newtoninan fluid which is being injected in the space between two narrowly separated parallel planes. The time evolution of the space that the fluid occupies can be modelled by a semi-linear PDE. This is a problem within the field of free boundary problems. In the multi-phase problem we consider the time-evolution of a system of phases which interact according to the principle that the joint boundary which emerges when two phases meet is fixed for all future times. The problem is handled by introducing a parameterized equation which is regularized and penalized. The penalization is non-local in time and tracks the history of the system, penalizing the joint support of two different phases in space-time. The main result in the first paper is the existence theory of a weak solution to the parameterized equations in a Bochner space using the implicit function theorem. The family of solutions to the parameterized problem is uniformly bounded allowing us to extract a weakly convergent subsequence for the case when the penalization tends to infinity. The second problem deals with a parameterized highly oscillatory quasi-linear elliptic equation in divergence form. As the regularization parameter tends to zero the equation gets a jump in the conductivity which occur at the level set of a locally periodic function, the obstacle. As the oscillations in the problem data increases the solution to the equation experiences high frequency jumps in the conductivity, resulting in the corresponding solutions showing an effective global behaviour. The global behavior is related to the so called homogenized solution. We show that the parameterized equation has a weak solution in a Sobolev space and derive bounds on the solutions used in the analysis for the case when the regularization is lost. Surprisingly, the limiting problem in this case includes an extra term describing the interaction between the solution and the obstacle, not appearing in the case when obstacle is the zero level-set. The oscillatory nature of the problem makes standard numerical algorithms computationally expensive, since the global domain needs to be resolved on the micro scale. We develop a multi scale method for this problem based on the heterogeneous multiscale method (HMM) framework and using a finite element (FE) approach to capture the macroscopic variations of the solutions at a significantly lower cost. We numerically investigate the effect of the obstacle on the homogenized solution, finding empirical proof that certain choices of obstacles make the limiting problem have a form structurally different from that of the parameterized problem.QC 20180222
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Olsson, Elin. "Mass Conserving Simulations of Two Phase Flow." Licentiate thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3851.
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Olszak, Peter D. "Nonlinear absorption and free carrier recombination in direct gap semiconductors." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4620.
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Nonlinear absorption of Indium Antimonide (InSb) has been studied for many years, yet due to the complexity of absorption mechanisms and experimental difficulties in the infrared, this is still a subject of research. Although measurements have been made in the past, a consistent model that worked for both picosecond and nanosecond pulse widths had not been demonstrated. In this project, temperature dependent two-photon (2PA) and free carrier absorption (FCA) spectra of InSb are measured using femtosecond, picosecond, and nanosecond IR sources. The 2PA spectrum is measured at room temperature with femtosecond pulses, and the temperature dependence of 2PA and FCA is measured at 10.6[micro]meters using a nanosecond CO[sub]2 laser giving results consistent with the temperature dependent measurements at several wavelengths made with a tunable picosecond system. Measurements over this substantial range of pulse widths give results for FCA and 2PA consistent with a recent theoretical model for FCA. While the FCA cross section has been generally accepted in the past to be a constant for the temperatures and wavelengths used in this study, this model predicts that it varies significantly with temperature as well as wavelength. Additionally, the results for 2PA are consistent with the band gap scaling (Eg[super]-3) predicted by a simple two parabolic band model. Using nanosecond pulses from a CO?éé laser enables the recombination rates to be determined through nonlinear transmittance measurements. Three-photon absorption is also observed in InSb for photon energies below the 2PA band edge. Prior to this work, data on three-photon absorption (3PA) in semiconductors was scarce and most experiments were performed over narrow spectral ranges, making comparison to the available theoretical models difficult. There was also disagreement between the theoretical results generated by different models, primarily in the spectral behavior.; Therefore, we studied the band gap scaling and spectra of 3PA in several semiconductors by the Z-scan technique. The 3PA coefficient is found to vary as (Eg[super]-7), as predicted by the scaling rules of simple two parabolic band models. The spectral behavior, which is considerably more complex than for 2PA, is found to agree well with a recently published theory based on a four-band model.ID: 029050684; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2010.; Includes bibliographical references.
Ph.D.
Doctorate
Optics and Photonics
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Coppola, Owen Herbert. "A Finite Element Model for Free Surface and Two Fluid Flows on Fixed Meshes." Doctoral thesis, Universitat Politècnica de Catalunya, 2009. http://hdl.handle.net/10803/5913.
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Los flujos con interfaces móviles (problemas de superficie libres y de dos fluidos) aparecen en numerosas aplicaciones de ingeniería. Los métodos presentados en esta tesis están orientados principalmente a la simulación del proceso de llenado de molde. Sin embargo la metodología es suficientemente general para ser aplicada a la mayoría de los flujos de superficie libres y de dos fluidos. El modelado numérico proporciona un modo eficiente de analizar los fenómenos físicos que ocurren durante procesos de inyección y fundición. Permite comprender detalles del flujo que de otra forma serían muy difíciles de observar.Se usa un método de elementos finitos de malla fija, donde la posición de interfaz es capturada por la función de Level Set. Los flujos a bajo número de Froude son particularmente desafiantes para los métodos de malla fija. Una representación precisa es necesaria en los elementos cortados por el frente. Se proponen dos alternativas.
La primera alternativa usa el modelo de flujo de dos fases típico, enriqueciendo las funciones de forma de presión, para permitir una mejor aproximación de la discontinuidad en el gradiente de presión en la interfaz. La mejora de la representación del gradiente de presión es el ingrediente clave para el correcto modelado de tales flujos.
La influencia del segundo fluido puede ser ignorada en una amplia variedad de aplicaciones para terminar con un modelo de superficie libre que es más simple que el modelo de flujo de dos fases. La discontinuidad en el gradiente de presión desaparece porque sólo se simula un fluido. La particularidad de este segundo método es que se usa una malla fija. Las condiciones de contorno son aplicadas exactamente usando integración mejorada e integrándose sólo en la parte llena de los elementos cortados por el frente. Se desarrolla un método ALE de malla fija para tener en cuenta correctamente que el dominio se mueve a pesar de que se usa una malla fija. Los métodos de segregación de presión son explorados como una alternativa a la discretización monolítica de las ecuaciones de Navier Stokes. Ellos desacoplan las incógnitas de velocidad y presión, conduciendo a subproblemas más pequeños y mejor condicionados. Los métodos de corrección de presión y corrección de velocidad son presentados y comparados numéricamente. Usando un Laplaciano discreto se obtiene un método de corrección de velocidad de tercer orden numéricamente estable.
Los métodos son aplicados a problemas de llenado de moldes tridimensionales tomados directamente de la fundición con resultados muy satisfactorios. El modelo monolítico con superficial libre resulta ser la opción más robusta y eficiente. La comparación con un código comercial muestra la exactitud y la eficacia del método que proponemos.
Flows with moving interfaces (free surface and two-fluid interface problems) appear in numerous engineering applications. The methods presented in this thesis are oriented mainly to the simulation of mould filling process. Nevertheless the methodology is sufficiently general as to be applied to most free surface and two-fluid interface flows. Numerical modeling provides an efficient way of analyzing the physical phenomena that occur during casting and injection processes. It gives insight into details of the flow that would otherwise be difficult to observe.
A fixed mesh finite element method, where the interface position is captured by the Level Set function, is used. Low Froude number flows are particularly challenging for fixed grid methods. An accurate representation is needed in the elements cut by the interface for such flows. Two alternatives are proposed.
The first alternative is to use the typical two-phase flow model enriching the pressure shape functions so that the discontinuity in the pressure gradient at the interface can be better approximated. The improvement in the representation of the pressure gradient is shown to be the key to ingredient for the successful modeling of such flows.
The influence of the second fluid can be neglected on a wide range of applications to end up with a free surface model that is simpler than the twophase flow model. The discontinuity in the pressure gradient disappears because only one fluid is simulated. The particularity of this second approach is that a fixed mesh is used. Boundary conditions are applied accurately using enhanced integration and integrating only in the filled part of cut elements.
A fixed mesh ALE approach is developed to correctly take into account that the domain is moving despite a fixed mesh is used.
Pressure segregation methods are explored as an alternative to the monolithic discretization of the Navier Stokes equations. They uncouple the velocity and pressure unknowns, leading to smaller and better conditioned subproblems.
Pressure correction and velocity correction methods are presented and compared numerically. Using a discrete Laplacian a numerically stable third order velocity correction method is obtained.
The methods are applied to three dimensional mould filling problems borrowed directly from the foundry with very satisfactory results. The free surface monolithic model turns out to be the most robust and efficient option. The comparison with a commercial code shows the accuracy and efficiency of the method we propose.