7,235 research outputs found
Review of Geographies of Australian Heritages: Loving a Sunburnt Country?, ed. Roy Jones and Brian Shaw. Aldershot, Ashgate, 2007
Review of Geographies of Australian Heritages: Loving a Sunburnt Country?, ed. Roy Jones and Brian Shaw. Aldershot, Ashgate, 2007
Hele-Shaw Flow Near Cusp Singularities
This thesis discusses the radial version of the Hele-Shaw problem. Different from the channel version, traveling-wave solutions do not exist in this version. Under algebraic potentials, in the case that the droplets expand, in finite time, cusps will appear on the boundary and classical solutions may not exist afterwards. Physicists have suggested that for (2p+1,2)-cusps, that near cusp singularities of Hele-Shaw flow, after scaling X, Y by some powers of time t respectively, the main part of Y(X, t) is a one-parameter family and does not depend on time t. They have also suggested that the solutions of the Hele-Shaw problem are connected with dispersionless KdV (dKdV) hierarchy. In this study, we rigorously proved that this is the case for (3,2)-cusps when the droplets are simply connected and the external potentials are algebraic. We gave exact solutions and showed that the main parts of the exact solutions are some special solutions of the dispersionless string equation. More over, borrowed from the physical paper\cite{Teo} with a little more details, we showed the arguments of how these special solutions are related to dKdV hierarchy
Jesse Roy Shaw and Detective Howard Gurley
Image shows Jesse Roy Shaw, 40, left, tell Detective Howard Gurley how he shot and critically wounded a man on a downtown Fort Worth street. The man was charged with molesting Shaw\u27s 5 year old daughter. Detective Gurley is shown holding the weapon used.https://mavmatrix.uta.edu/specialcollections_startelegram1950s/5141/thumbnail.jp
United They Fall: Why the International Community Should Not Promote Military Integration after Civil War
The single strongest predictor of civil war is a nation having had one in the past, and preventing the recurrence of civil war has thus become the critical problem for both scholarship and policy. The conventional wisdom urges the creation of capable, legitimate, and inclusive postwar states to reduce the risk of relapse into civil war, and international peacebuilders have often encouraged the formation of a new national army including members of the war’s opposing sides. However, military integration has received little theoretical or empirical attention. Filling that gap, we argue that both the theoretical logics and the empirical record identifying military integration as a significant contributor to durable post-civil war peace are weak. Our analysis of eleven cases finds little evidence that military integration played a substantial causal role in preventing the return to civil war and little support for the likely causal mechanisms. Military integration does not usually send a costly signal of the parties’ commitment to peace, provide communal security, employ many possible spoilers, or act as a powerful symbol of a unified nation. We conclude that it is both unwise and unethical for the international community to press military integration on reluctant local forces.Based in part on a larger collective project: Roy Licklider (Ed.). (2014). New Armies from Old: Merging Competing Military Forces after Civil Wars. Washington, D.C.: Georgetown University Press; see http://press.georgetown.edu/book/georgetown/new-armies-old
Ekla Chalo Re: a tribute to Ms. Mary Roy
This is a tribute to activist Mary Roy, who passed away in 2022. The author traces the life of Mary Roy, highlighting the ways in which she challenged gendered norms and expectations. She was the applicant in a landmark case which brought equal property rights for Syrian Christian women in India. The author reminds readers that women's rights are human rights and change begins with us. 
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Yunnan (China), men with the cow caravan
A cow caravan.Image is part of research conducted by Roy Chapman Andrews for the article: Traveling in China's Southland
Author(s): Roy Chapman Andrews
Source: Geographical Review, Vol. 6, No. 2 (Aug., 1918), pp. 133-146
Published by: American Geographical Society
Stable URL: http://www.jstor.org/stable/207476http://www.jstor.org/stable/207476Grayscal
Yunnan (China), cow loaded with grass and carrying a bell
A cow loaded with grass and carrying a bell.Image is part of research conducted by Roy Chapman Andrews for the article: Traveling in China's Southland
Author(s): Roy Chapman Andrews
Source: Geographical Review, Vol. 6, No. 2 (Aug., 1918), pp. 133-146
Published by: American Geographical Society
Stable URL: http://www.jstor.org/stable/207476http://www.jstor.org/stable/207476Grayscal
Yunnan (China), women carrying salt from one of the large wells
Women carrying salt from one of the large wells.Image is part of research conducted by Roy Chapman Andrews for the article: Zoological Explorations in Yunnan Province, China
Author(s): Roy Chapman Andrews
Source: Geographical Review, Vol. 6, No. 1 (Jul., 1918), pp. 1-18
Published by: American Geographical Society
Stable URL: http://www.jstor.org/stable/207446http://www.jstor.org/stable/207446Grayscal
Estudo do escoamento imiscível água/óleo mediante experimentação em célula de Hele-Shaw e simulação CFD
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia QuímicaO estudo de sistemas água-óleo é de fundamental importância para diversos processos industriais. Procedimentos como a recuperação secundária de petróleo e o bombeamento de óleos de viscosidade elevada, mediante a injeção conjunta de água, exemplificam situações na indústria petrolífera em que o comportamento da interface água-óleo traz importantes conseqüências para a eficiência da produção. Também nos casos de vazamentos a partir de dutos submersos, e na contaminação de águas subterrâneas pela proximidade de uma fase óleo, os aspectos fenomenológicos desse sistema imiscível devem ser conhecidos a fim de que medidas adequadas de remediação e quantificação dos danos ambientais possam ser postos em prática. O fato de o petróleo ser, de um modo geral, mais viscoso e menos denso que a água faz com que, no escoamento simultâneo desses dois fluidos, a água apresente a tendência de se deslocar com maior velocidade em relação ao óleo. Como conseqüência, dependendo das diferenças de viscosidades e densidades entre os dois fluidos, além das forças de tensão interfacial, pode vir a ocorrer o fenômeno de digitação viscosa. Assim, no deslocamento de óleo por injeção de água, fingers gerados a partir da fase água podem penetrar na fase óleo, ocasionando um retardamento no deslocamento do óleo com saída antecipada da água, o que representa um prejuízo para a operação. Uma ferramenta de simulação fluidodinâmica, apta a descrever corretamente os fenômenos e padrões de escoamento de um sistema águaóleo, sob diferentes condições operacionais, pode se constituir em notável instrumento para aprofundar conhecimentos da fenomenologia envolvida e, também, gerar elementos de inovação tecnológica para as diferentes aplicações Neste trabalho, explora-se o comportamento de um sistema água-óleo através de um modelo tridimensional de uma célula de Hele-Shaw. Esse modelo reproduz uma célula real carregada com água e óleo com dimensões de 100 cm de comprimento por 30 cm de largura, com espaçamento típico entre as placas de 0,10 cm. Uma série de ensaios computacionais foram realizados para validar o modelo, além dos critérios usuais de estabilidade numérica e fechamento de balanços. O modelo computacional da célula de Hele-Shaw, possibilitou a observação do comportamento da interface. As propriedades dos fluídos (densidade, viscosidade e tensão superficial) e fenômenos físicos (temperatura, capilaridade, força gravitacional e velocidade de injeção do fluído) influenciaram diretamente na resposta do sistema. Através de simulações computacionais foi possível estudar individualmente a importância e efeito que cada fator exerce sobre o sistema, desde as propriedades dos fluidos até as condições de contorno aplicadas, foi possível também, identificar o grau de atuação das forças interfaciais, gravitacional e do arraste viscoso, levando ao surgimento do fenômeno de digitação viscosa. Comprovou-se que o aumento das forças capilares costuma levar a um aumento da instabilidade, com conseqüente aumento no número de fingers desenvolvidos, aumentando a área de óleo em atraso e reduzindo a eficiência do processo. The study of systems water-oil is of fundamental importance for several industrial processes. Procedures as the secondary recovery of petroleum and the pum situations in the industry of petroleum where the behavior of the interface wateroil brings important consequences for the efficiency of the production. Also in the cases where happen leaks starting from ducts submerged, and in cases of contamination of underground waters for the proximity of a phase oil, the aspects of phenomena of that system immiscible should be known so that appropriate measures of recovery and quantification of the environmental damages can be put into practice. The fact of the petroleum to be, in general, more viscous and less dense than the water does with that, in the simultaneous drainage of those two fluids, the water presents the tendency of moving with larger speed in relation to the oil. As consequence, depending on the differences of viscosities and densities among the two fluids, besides the forces of interface tension, it can come to happen the phenomenon of viscous fingering. Like this, in the oil displacement with injection of water, fingers generated starting from the phase water can penetrate in the phase oil, causing retardation in the displacement of the oil with premature exit of the water, what represents damage for the operation. A tool CFD # Computational Fluid Dynamics, capable to describe the phenomena and patterns of drainage of a system water-oil correctly, under different operational conditions, it can be constituted in notable instrument to deepen knowledge of the involved phenomenology and, also, to generate elements of technological innovation for the different applications. In this work, the behavior of a system water-oil is explored through a 3D model of a cell of Hele-Shaw. That model reproduces a real cell loaded with water and oil with dimensions of 100 cm of length for 30 cm of width, with typical spacing among the plates of 0,10 cm. A series of rehearsals computation was accomplished to validate the model, besides the usual criteria of numeric stability and closing of swingings. The computational model of the cell of Hele-Shaw, made possible the observation of the behavior of the interface. The properties of those flowed (density, viscosity and tension surface) and physical (temperature, capillarity, forces gravitational and speed of injection of the flowed) phenomena influenced directly in the answer of the system. Through computational simulations it was possible to study the importance and effect that each factor exercises on the system individually, from the properties of the fluids to the outline conditions applied, it was possible also, to identify the degree of performance of the interface forces, gravitational and of the it drags viscous, taking to the appearance of the phenomenon of viscous fingering. To prove that the increase of the capillary forces take the an increase of the instability, with consequent increase in the number of developed fingers, increasing the oil area in delay and reducing the efficiency of the process
Immobile History: An Interview with Emmanuel Le Roy Ladurie
The author spoke with renowned French historian Emmanuel Le Roy Ladurie about Computers, Geography and History. Le Roy Ladurie was the "standard bearer" of the third generation of the French Annales school, a group of French intellectuals that combined different disciplines such as history, geography, anthropology, and more to delve into social history
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