Darbe analizuojami ES-Baltarusijos ir ES-Kaliningrado santykiai, vadovaujantis Fabrizio Tassinari suformuluota „kintamųjų geometrijų“ koncepcija. „Kintamųjų geometrijų“ sąvoka, asocijuojama su ES vidaus politika, pritaikoma ES santykių su kaimyninėmis valstybėmis analizei. Naujas kontekstas bei dalinis teorinės koncepcijos modifikavimas leidžia tirti ES gravitacinės bei normatyvinės galios poveikį bei vertinti jos kaip užsienio politikos veikėjos sėkmes bei nesėkmes. Tyrimui pasirinkti du atvejai - Lietuvos kaimynystėje esančių Baltarusijos valstybės bei Rusijos Federacijos Kaliningrado srities santykiai su ES. Taikant teorinės analizės bei aprašomąjį metodą siekiama ne tik išnagrinėti ES-Baltarusijos ir ES-Kaliningrado santykius, bet ir įvertinti, kokia reikšmė jiems suteikiama platesniame Europos kontekste. „Kintamųjų geometrijų“ koncepcija skaldoma į tris sudedamąsias dalis – „idėjų“, „institucijų“ bei „ galios“ dimensijas. Ši segmentacija nulemia uždavinių formuluotę, darbo struktūrą bei esmines išvadas. „Idėjų“ matmuo skirtas ES, Baltarusijos ir Kaliningrado politinio ir geopolitinio identitetų bei jų sąveikos tyrimui, „institucijų“ dimensija pasitelkiama, kritiškai nagrinėjant skirtingus bendradarbiavimo formatus bei jų trūkumus. Pats svarbiausias - „galios“ matmuo leidžia nubrėžti teorinės koncepcijos praktinio taikymo ribas, analizuojant ES galios vaidmenį ir nurodant alternatyvius galios šaltinius. Tyrimo rezultatai leidžia nustatyti pasirinktos teorijos taikymo... [toliau žr. visą tekstą] / The paper deals with the analysis of the EU-Belarus and the EU-Kaliningrad relations applying the concept of “variable geometries“ introduced by Fabrizio Tassinari. In the conventional interpretation this concept is associated with the domestic policy of the EU. This study places it in the field of the Union‘s relations with its neighbours. New context and partial modification of the theory make it possible to examine the impact of the EU gravitational and normative power and evaluate successes and failures of the Union‘s external policy. Two topical cases have been chosen for the investigation – Lithuania‘s neighbouring Belarus and the Russian Federation Kaliningrad region relations with the EU. Selected methodology – the combination of theoretical analysis and descriptive methods – gives the possiblity to simultaneously examine the EU-Belarus and the EU-Kaliningrad relations and evaluate their role in the wider European space. Three dimensions of „variable geometries“ are distinguished: „ideas“, „institutions“ and „power“. This segmentation determines the formulation of the study tasks, structure and the main conclusions. The dimension related to „ideas“ focuses on the EU, Belarus and Kaliningrad political and geopolitical identities and on the way in which the EU as a polity affects, and is affected by, deeper relations with its neighbors. The institutional dimension deals with different formats of cooperation and their shortcomings. The main dimension, related to “power”... [to full text]

The thesis deals with definability of certain Zariski geometries, introduced by Zilber, in the theory of algebraically closed fields. I axiomatise a class of structures, called 'abstract linear spaces', which are a common reduct of these Zariski geometries. I then describe what an interpretation of an abstract linear space in an algebraically closed field looks like. I give a new proof that the structure "quantum harmonic oscillator", introduced by Zilber and Solanki, is not interpretable in an algebraically closed field. I prove that a similar structure from an unpublished note of Solanki is not definable in an algebraically closed field and explain the non-definability of both structures in terms of geometric interpretation of the group law on a Galois cohomology group H¹(k(x), μ_n). I further consider quantum Zariski geometries introduced by Zilber and give necessary and sufficient conditions that a quantum Zariski geometry be definable in an algebraically closed field. Finally, I take an attempt at extending the results described above to complex-analytic setting. I define what it means for quantum Zariski geometry to have a complex analytic model, an give a necessary and sufficient conditions for a smooth quantum Zariski geometry to have one. I then prove a theorem giving a partial description of an interpretation of an abstract linear space in the structure of compact complex spaces and discuss the difficulties that present themselves when one tries to understand interpretations of abstract linear spaces and quantum Zariski geometries in the compact complex spaces structure.

In the thesis we study particular sequences of invariant differ- ential operators of first and second order which live on homogeneous spaces of a particular type of parabolic geometries. We show that they form a reso- lution of the kernel of the first operator and that they descend to resolutions of overdetermined, constant coefficient, first order systems of PDE's called the k-Dirac operators. This gives uniform description of resolutions of the k-Dirac operator studied in Clifford analysis. We give formula for second order operators which appear in the resolutions. 1

No contexto da teoria da relatividade geral de Einstein, se estudam espaço-tempos dinâmicos do tipo buraco negro em um ambiente cosmológico, em particular, uma generalização de massa variável do espaço-tempo de McVittie. São apresentados alguns espaço-tempos resultantes de limites da solução de McVittie generalizada. Se discutem as definições padrão de buraco negro e horizonte de eventos assim como as dificuldades de aplicá-las em situações dinâmicas, outras definições para horizontes são exploradas. É usado o conceito de horizonte aparente para localizar buracos negros e horizontes cosmológicos. Soluções para a busca dos horizontes aparentes são encontradas nas geometrias de Schwarzschild-de Sitter, McVittie e McVittie generalizado. / Black hole-like spacetimes in a cosmological background are studied within the Einsteins general relativity theory framework, in particular a mass varying generalization of the McVitties spacetime. We exhibit some of the resulting spacetimes as limit cases of the generalized McVittie solution. We discuss the standard definition of black hole and event horizon, and we address the difficulties in aplying it in dynamical situations, another definitions for horizons are explored. The apparent horizon concept is used to locate black holes and cosmological horizons. Solutions for apparent horizons in Schwarzschild-de Sitter, McVittie, and generalized McVittie geometries are shown.

A utilização de ferramentas computacionais para modelagem de componentes (sistemas CAD) faz parte da realidade da maioria dos setores de desenvolvimento de produtos das empresas. Os sistemas CAD 3D auxiliam na visualização, simulação e análise do comportamento do protótipo digital sob condições reais, antes mesmo da construção do produto ou da peça, permitindo que os fabricantes lancem produtos com maior rapidez e menor quantidade de protótipos físicos. Uma das vantagens na utilização de sistemas CAD 3D é a parametrização dimensional, o que possibilita ganho de tempo durante as modificações do projeto e a validação de novos produtos. Este trabalho apresenta as formas de aplicação de geometrias paramétricas na otimização estrutural e como meio de redução do tempo de desenvolvimento de um projeto. A validação do projeto foi feita através da Análise por Elementos Finitos (AEF), na qual foi possível estabelecer um coeficiente de segurança aceitável para o mesmo com uma redução do seu peso final, de acordo com as necessidades estabelecidas nas diretrizes do projeto. / The use of computational tools for modeling of components (systems CAD) is part of the reality of the majority of the sectors of development of products of the companies. Systems CAD 3D before assist in the visualization, simulation and analysis of the behavior of the digital prototype under real conditions, exactly of the construction of the product or the part, allowing that the manufacturers launch products with bigger rapidity and minor amount of physical archetypes. One of the advantages in the use of systems CAD 3D is the dimensional parameterization, what it makes possible time profit during the modifications of the project and the validation of new products. This work presents the forms of application of parametric geometries in the structural optimization and as half of reduction of the time of development of a project. The validation of the project was made through Finite Elements Analysis (FEA), in which it was possible to establish a coefficient of acceptable security for the same with a reduction of its final weight, in accordance with the established necessities as lines of direction of the project.

O escopo deste mestrado é de se familiarizar com a chamada {\\it correspondência AdS/CFT}, que tem sido um dos mais importantes desenvolvimentos na física teórica nas últimas décadas. De acordo com essa correspondência, deformações das geometrias do lado da gravidade (ou lado \"AdS\") devem ser mapeadas para operadores das teorias de calibre duais (ou lado \"CFT\"). Em particular, nos temos estado interessados em explorar uma entrada particular no dicionário AdS/CFT, a relação entre os operadores 1/2 BPS em ${\\cal N}=4$ super Yang-Mills, e as chamadas {\\it geometrias bubbling} no lado da gravidade. A fim de fazer isso, apresentamos primeiramente as noções de ${\\cal N}=4$ SYM e soluções de Supergravidade. Portanto, podemos expor mais claramente o sentido da correspondência AdS /CFT, e depois mostrar a derivação das geometrias 1/2 BPS duais a estados 1/2 BPS em ${\\cal N}=4$ SYM como um exemplo. / The scope of this Master program was to get acquainted with the so-called {\\it AdS/CFT correspondence}, which has been one of the most important developments in theoretical physics in the last decades. According to this correspondence, deformations of the geometries in the gravity side (or \"AdS\" side) must be mapped to states of the dual gauge theories (or \"CFT\" side). In particular, we have been interested in exploring a particular entry in the AdS/CFT dictionary, namely, the relation between 1/2 BPS operators in ${\\cal N}=4$ super Yang-Mills, and the so-called {\\it bubbling geometries} on the gravity side. In order to do that, we first present the notions of N=4 SYM and Supergravity solutions. In this way, we can expose the statement of the AdS/CFT correspondence, and later show the derivation of 1/2 BPS geometries dual to 1/2 BPS states in N=4 SYM as an example of this one.

No description available.

Ammonoids were collected from the Chainman Formation (Mississippian) of southeastern Nevada and southwestern Utah, the Phosphoria Formation (Permian) of southeastern Idaho and westernmost Wyoming, and the Thaynes Formation (Triassic) of northeastern Nevada and southeastern Idaho. The collections are interpreted to represent unwinnowed, untransported death assemblages of ammonoids which were subject to chemical conditions of the nekto-benthic environment. Associated lithologies were sampled and geochemically analyzed for content of phosphate and organic matter. Ammonoid fossil collections, combined with ammonoids ilustrated in the literature, were subjected to the graphical W and D analysis of Raup (1967). The basic parameteres involved in the description of shell-coiling geometry are whorl expansion rate, W, and the distance of the generating curve from the axis of coiling of the shell, D. Values of W determined range from 1.32 to 3.96, which correspond to slight and rapid increases in whorl height during coiling. Values of D determined range from 0.02 to 0.55, which correspond to extremes of involute and evolute coiling· geometries, respectively. Body chamber length corresponds with shell coiling geometry. Values determined in this study range from 10° to 540°. Corresponding W values are 3.96 and 1.50, whereas corresponding D values are 0.02 and 0.40, respectively. Average body chamber length in analyzed ammonoids is observed to decrease from 297° to 209° from Mississippian to Triassic time. Increase in apertural area accompanied this trend, and a possible consequence was that a greater range of prey sizes was afforded ammonoids with shorter body chambers. Life-orientation, described as the angle between the apertural plane and the gravitational vector, is calculated entirely on shell form and other geometrical considerations. Recent observations concerning Nautilus, combined with fossil evidence of epizoan encrustation suggest that ammonoids had an ability to control orientation, which is not observed from preservable morphology. From Mississippian to Triassic time, no trends in reconstructed life-orientation can be substantiated, based solely on Wand D values. Rotational stability during directed locomotion is important for conservation of the energy budget of this nektonic carnivorous organ­ ism. This property is calculated by the distance between the center of buoyancy and the center of gravity of the ammonoid. Values deter­ mined range from .04 (very unstable) to .16 (very stable). Corres­ ponding W values are 1.50 and 4.00 where corresponding D values are 0.20 and 0.02, respectively. A trend toward increasing average rota­tional stability (.07 to .10) is noted for amrnonoids from Mississippian to Triassic time. Efficiency in the utilization of calcium carbonate is the ratio of internal volume of the shell to volume of shell material. Values determined range from 5.80 to 7.25. Corresponding W values are 4.00 and 1.50, corresponding D values are 0.02 and 0.54, respectively. Abundant ammonoids found in black, phosphatic limestones rich in organic matter have an average efficiency value of 6.2. Abundant ammonoids from corresponding light-colored crystalline carbonates have an average efficiency value of 6.02, and indicate no correlation between effi­ciency and abundance. Size-frequency distributions are utilized in recognition of oppor­tunistic species of ammonoids. High numerical abundance, high mortality rate of juveniles, small size and conservation of calcium carbonate typifies the paleo-opportunistic species Cravenoceras, Psuedogastrio­ceras and Ophiceras. Biovolume-relative abundance distributions are useful in discerning the carrying capacity of the habitat both in number of individuals and species diversity. A large area under the biovolume-relative abun­dance profile indicates diversification under optimum environmental conditions; a small area under the profile indicates colonization of a stressful habitat. The Chainman, Phosphoria and Thaynes (Columbites Zone) Formations have ammonoid assemblages which show small areas under the biovolume-relative abundance profile, characteristic of anoxic environmental stress. The Permian stratigraphic units correlative with the Phosphoria Formation have ammonoid assemblages which show large areas under the profile and the associated lithologies, i.e., light­ gray,crystalline carbonates, suggest environments which could support a diversified ammonoid fauna, including large-sized species. Ontogenetic variation produces changes in the body chamber length, life orientation, rotational stability, and utilization of calcium carbonate of the analyzed genera of ammonoids. These ontogenetic variations usually resulted in the development of more involute shell-coiling geometries. Corresponding size-frequency distributions suggest increased mortality rates during ontogeny for some genera (Paracravenoceras, Medlicottia) which show decreasing efficiency in the utilization of calcium carbonate. (182 pages)

Contraction flow of viscoelastic fluids has been a benchmark problem in non-Newtonian fluid mechanics because it mimics flows occurring in a number of industrial applications. It is also of considerable interest to academia to gain fundamental understanding of factors that affect the evolution of vortices and a complete understanding of the dynamics for a simple polymeric fluid has not been achieved. In this two part study we investigate the effect of pre deformation of a Boger fluid in a contraction geometry and the flow of surfactants in a parallel contraction geometry. Entry flow of a polymeric fluid results in the formation of upstream vortices,the presence of recirculation zones may lead to a nonuniform residence time and hence inferior quality products. In this work we study the effect of pre-stretching dilute flexible chain polymers by placing a cylinder in front of a contraction in a microfluidic device.This deformation applied to the polymer is remembered before it completely relaxes, this memory effect changes the rheological properties during the fading period of the deformation history. Applying pre-deformation gives rise to new type of vortex evolution that is different from the standard contraction case. Semi-dilute surfactant solutions that exhibit shear thickening nature can be potentially used in enhanced oil recovery to increase the sweep efficiency. Two parallel microfluidic contractions of different cross sectional area are used to investigate the rheological effect on the mass flux of the two channels. Shear thickening micellar solutions were found to increase the mass flux through the small channel compared to a newtonian fluid. This effect was observed only for a small range of flow rates. As flow rates increased inlet instabilities were observed that evolved into a chaotic behavior upon further increase in the net flow rate.

[pt] O deslocamento de um líquido por outro em espaços anulares é comumente encontrado na indústria do petróleo, e a maioria deles envolve materiais não newtonianos. O espaço anular muitas vezes apresenta irregularidades causadas pela erosão, onde quantidades consideráveis de fluido de perfuração podem ser deixadas para trás durante o processo de deslocamento, comprometendo a qualidade da operação de cimentação. Motivados por esse processo industrial, testes de deslocamento entre líquidos a vazão constante foram realizados em espaços anulares cuja parede externa possui, em uma determinada posição axial, um aumento repentino de diâmetro seguido de uma diminuição repentina de diâmetro mais a jusante. O objetivo dos experimentos era determinar a eficiência do deslocamento em função da vazão, reologia dos fluidos e geometria da cavidade. Os resultados revelaram forte influência desses parâmetros na eficiência de deslocamento. Ao mesmo tempo, um estudo numérico foi desenvolvido. Simulações numéricas das equações de Navier-Stokes em geometria axissimétrica para fluidos incompressíveis foram acopladas ao método Level-Set para captura da interface. Fluidos com viscosidade constante e o modelo newtoniano generalizado com função viscosidade de Carreau-Yasuda foram utilizados. Isso permitiu simular deslocamentos entre dois fluidos newtonianos e entre um fluido newtoniano e outro não-newtoniano. Este foi utilizado tanto como fluido deslocador quanto como deslocado. Foram realizadas simulações para várias razões de diâmetros, viscosidades, tempos de relaxação, e números de capilaridade e de Reynolds. Identificamos quando a aproximação do espaço anular por duas placas paralelas pode ser aplicada e calculamos como a forma da interface depende dos parâmetros investigados. / [en] The displacement of a fluid caused by another one, inside annular spaces, is commonly found in the oil industry and most of these rearrangements involve non-Newtonian materials. The annular space often shows irregularities caused by erosion, in which considerable amounts of drilling fluid can be left behind during the displacement process, compromising the cementing operation efficiency. Motivated by that industrial process, fluid-fluid displacement tests at constant flow rate were performed in annular spaces in which their exterior walls displayed - in a determined axial position - an abrupt expansion followed by an abrupt contraction. The purpose of the tests were to determine the displacement efficiency as a function of flow rate, rheological properties and geometric cavity. The results revealed a strong influence of these parameters on the displacement efficiency. At the same time, a numerical research was developed. Numerical simulations of the Navier-Stokes equations in axisymmetric geometry for incompressible fluids were coupled to the Level-Set method to capture the interface. Fluids with constant viscosity and the generalized Newtonian model with viscosity function of Carreau-Yasuda were used. That allowed to simulate displacements between two Newtonian fluids and a Newtonian and a non-Newtonian fluid. This was used both as a displacer and as a displaced fluid. Simulations were performed for several diameters and viscosities ratios, relaxatation time, capilar and Reynolds numbers. We identified when the approximation of the annular space by two parallel plates can be applied and calculated how the shape of the interface depends on the investigated parameters.