The dynamics of A + B → C reaction fronts is studied under modulated gravitational acceleration by means of a combination of parabolic flight experiments and numerical simulations. During modulated gravity the front position undergoes periodic modulation with an accelerated front propagation under hyper-gravity together with a slowing down under low gravity. The underlying reason for this is an amplification and a decay, respectively, of the buoyancy-driven double vortex associated with the front propagation under standard gravitational acceleration, as explained by reaction–diffusion–convection simulations of convection around an A + B → C front. Deeper insights into the correlation between grey-value changes in the experimental shadowgraph images and characteristic changes in the concentration profiles are obtained by a numerical simulation of the imaging process. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

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Three historic communities with varying levels of social, economic and historic preservation issues are studied in the following chapters to determine motivations for negotiating community benefits agreements (CBAs), and to determine motivations for the specific benefits outlined within each community’s respective CBA. The case study research examines the historic preservation language within each CBA as well as how the development itself and the other benefits prescribed in the CBAs will positively or negatively impact each community. The case study communities demonstrate that CBAs can be used as historic preservation planning and implementation tools. By including thoughtful and transparent community benefits language, a community will be able to use the tools – i.e. financing, technical assistance, advice and guidance, etc. – provided to them within the CBA to successfully carry out the benefits promised within the CBA. / Department of Architecture

In 1918, Archbishop Shaw invited the Texas Catholic religious order, Missionary Oblates of Mary Immaculate, to New Orleans to manage the St. Louis Cathedral and its filial parish for Southern Italians, St. Mary’s Church. This thesis will look at the personalities and preferentialism that affected this early 20th century transfer of religious power from secular priests to a religious order. Comparing the language used by Archbishop Shaw in correspondence with Oblate Fathers with the language he used with his secular priests will determine that Shaw displayed favoritism in his decision to invite the Oblates. This decision was affected by four primary factors: Shaw’s prior relationship with the Oblates as Bishop of San Antonio, his concerns with archdiocesan finances, his perceived threat of encroaching Protestantism, and politics of discontent amongst his secular clergy. Shaw’s distinct idealistic pragmatism shows the dynamic nature of the institution of the Catholic Church in Louisiana.

Integrated theoretical and experimental analysis is carried out in this work to investigate the fundamental failure mechanisms and flow patterns involved in the process of fluid injection into dense granular media. The experimental work is conducted with aqueous glycerin solutions, utilizing a novel setup based on a Hele-Shaw cell filled with dense dry sand. The two dimensional nature of the setup allows direct visualization and imaging analysis of the real-time fluid and grain kinematics. The experimental results reveal that the fluid flow patterns show a transition from simple radial flow to a ramified morphology while the granular media behaviors change from that of rigid porous media to localized failure that lead to development of fluid channels. Based on the failure/flow patterns, four distinct failure/flow regimes can be identified, namely, (i) a simple radial flow regime, (ii) an infiltration-dominated regime, (iii) a grain displacement-dominated regime, and (iv) a viscous fingering-dominated regime. These distinct failure/flow regimes emerge as a result of competition among various energy dissipation mechanisms, namely, viscous dissipation through infiltration, dissipation due to grain displacements, and viscous dissipation through flow in thin channels and can be classified based on the characteristic times associated with fluid injection, hydromechanical coupling and viscoelastoplasticity. The injection process is also analyzed numerically using the discrete element method (DEM) coupled with two fluid flow scheme, a fixed coarse grid scheme based on computational fluid dynamics (CFD) and a pore network modeling scheme. The numerical results from the two complementary methods reproduce phenomena consistent with the experimental observations and justify the concept of associating the displacement regimes with the partition among energy dissipation mechanisms. The research in this work, though fundamental in nature, will have direct impacts on many engineering problems in civil, environmental and petroleum engineering such as ground improvement, environmental remediation and reservoir stimulation.

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This paper explores how changing conceptions of religion, race, and gender at the beginning of the twentieth century promoted transnational anti-systemic movements and increased cooperation between progressive intellectuals and political activists. Using the cases of Bertrand Russell, George Bernard Shaw, W.E.B. Du Bois, Marcus Garvey, Jane Addams, and Sylvia Pankhurst, this paper chronicles and analyzes protest to the First World War and objection to the organization of the world-system.

Submitted by Daniella Sodre (daniella.sodre@ufpe.br) on 2015-04-08T12:57:46Z No. of bitstreams: 2 TESE Eduardo Olímpio Dias.pdf: 4555696 bytes, checksum: a1e7972a45dbba945f075adf6ee33606 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-04-08T12:57:46Z (GMT). No. of bitstreams: 2 TESE Eduardo Olímpio Dias.pdf: 4555696 bytes, checksum: a1e7972a45dbba945f075adf6ee33606 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2014-02-28 / CNPq / A formação de padrões na natureza tem sido uma fonte de grande interesse acadêmico e tecnológico. Nesta tese, estudamos a dinâmica de interfaces instáveis de três sistemas fundamentais: a instabilidade hidrodinâmica de Sa man-Taylor (os chamados dedos viscosos ), a instabilidade de Mullins-Sekerka (refere-se ao crescimento de cristais) e a propaga ção de ondas de ionização através de descargas elétricas. Dentre estes sistemas, o problema Sa man-Taylor é o mais abordado. Esta instabilidade surge na interface que separa dois uidos viscosos con nados entre duas placas paralela, num dispositivo conhecido como célula de Hele-Shaw, ou imersos em um meio poroso. Ao longo da tese, estudamos meios de selecionar o número de onda dominante dos padrões na interface uido- uido, os efeitos da inércia do uido na instabilidade e, principalmente, métodos de controle e minimização das perturbações na interface. Um dos meios de controle das instabilidade é através de uma suave modi cação geométrica no aparato no qual o uido está con nado. Nesse contexto, fomos capazes tanto de favorecer quanto de inibir e, eventualmente, suprimir os dedos viscosos. Um outro protocolo de estabilização, que consiste no principal método de controle desta tese, é através do cálculo variacional. O objetivo desse procedimento é encontrar uma forma funcional para a taxa de injeção de uido que minimize as instabilidades. Comprovamos experimentalmente e por simulações numéricas a e cácia desse processo. Tal método também é utilizado para minimizar instabilidades em crescimento de cristais e em processos de descarga elétrica. Além da investigação de interfaces instáveis, nós estudamos a força e a energia de adesão de uidos complexos con nados entre placas paralelas. Neste caso, nosso método variacional visa obter a equação de levantamento ideal da placa superior a m de minimizar a energia de adesão. Finalmente, efeitos de inércia na força de levantamento são estudados.

The objectives of this research were to 1) measure the extent to which water vapor movement results in water accumulation in freezing base materials; 2) evaluate the effect of soil stabilization on water vapor movement in freezing base materials; 3) determine if the corresponding changes in water content are sufficient to cause frost heave during winter; 4) determine if the corresponding changes in water content are sufficient to cause reductions in stiffness during spring; 5) evaluate relationships between selected material properties, freezing conditions, and the occurrence and impact of water vapor movement; and 6) numerically simulate heat and water movement in selected pavement design scenarios. The research involved extensive laboratory and field testing, statistical analyses, and numerical modeling. The results of the laboratory testing, which included gradations, Atterberg limits, soil classifications, specific gravity and absorption values, electrical conductivity values, moisture-density relationships, soil-water characteristic curves, moisture-stiffness curves, hydraulic conductivity values, and frost susceptibility assessments, were used to characterize each material and enable subsequent statistical analyses. Testing of both treated and untreated materials enabled investigation of a wide variety of material properties. The results of the field testing, which included temperature, moisture content, water potential, elevation, and stiffness data over time, provided the basis for comparing pavement sections with and without capillary barriers and established the framework for numerical modeling. In a pavement section with a capillary barrier underlying the base layer, water vapor movement from the subgrade through the capillary barrier may be expected to increase the water content of the base layer by 1 to 3 percent during a typical winter season in northern Utah for base materials similar to those studied in this research. During winter, cold temperatures create an ideal environment for water vapor to travel upward from the warm subgrade soil below the frost line, through the capillary barrier, and into the base material. Soil stabilization can lead to increased or decreased amounts of water vapor movement in freezing base materials depending on the properties of the stabilized soil, which may be affected by gradation, mineralogy, and stabilizer type and concentration. Accumulation of water from long-term water vapor movement into frost-susceptible base materials underlain by a capillary barrier can lead to frost heave of the base layer as it approaches saturation, as water available in the layer can be redistributed upwards to create ice lenses upon freezing. However, the incremental increase in total water content that may occur exclusively from water vapor movement during a single winter season in northern Utah would not be expected to cause measurable increases in thaw weakening of the base layer during spring. Because water in a base layer overlying a capillary barrier cannot drain until nearly reaching positive pore pressures, the base layer will remain indefinitely saturated or nearly saturated as demonstrated in this research. For materials similar to those studied in this research, potentially important material properties related to the occurrence of water vapor movement during freezing include dry density, percent of material finer than the No. 200 sieve, percent of material finer than 0.02 mm, apparent specific gravity, absorption, initial water content, porosity, degree of saturation, hydraulic conductivity, and electrical conductivity. The rate at which water vapor movement occurs is also dependent on the thermal gradient within the given material, where higher thermal gradients are associated with higher amounts of water vapor movement. The numerical modeling supported the field observations that the capillary barrier effectively trapped moisture in the overlying base material, causing it to remain saturated or nearly saturated throughout the monitoring period. Only non-frost-susceptible aggregate base materials should be specified for use in cold climates in conjunction with capillary barriers, and the base material in this case should be assumed to remain in a saturated or nearly saturated condition during the entire service life of the pavement. Further study is recommended on water vapor movement in freezing aggregate base materials.

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