251 research outputs found
The role of lawyers in strategic alliances (tape 2 of 3)
No full textSymposium presented on October 4, 2002. Symposium explores how lawyers can bargain effectively without impairing trust and devise contract terms that will enhance trust and cooperation to maximize the profitability of alliances. --program flyer. Introduction by Gerald Korngold, Dean of the School of Law; moderated by Professor George W. Dent, Jr.; Steven Fraidin and Rachelle C. Sampson, speakers; commentators Daniel F. Austin, Edward Bernstein, Jeanne M. Rickert, Hewitt B. Shaw, Jr., and Wendy C. Shiba
Contents: Strategic alliances and corporate control / Stephen Fraidin -- Alliance structure: selection and consequences / Rachelle C. Sampson -- Negotiating and drafting for strategic alliances / George W. Dent, J
Convective shutdown in a porous medium at high Rayleigh number
No full textConvection in a closed domain driven by a dense buoyancy source along the upper boundary soon starts to wane owing to the increase of the average interior density. In this paper, theoretical and numerical models are developed of the subsequent long period of shutdown of convection in a two-dimensional porous medium at high Rayleigh number Ra\mathit{Ra}. The aims of this paper are twofold. Firstly, the relationship between this slowly evolving ‘one-sided’ shutdown system and the statistically steady ‘two-sided’ Rayleigh–Bénard (RB) cell is investigated. Numerical measurements of the Nusselt number Nu\mathit{Nu} from an RB cell (Hewitt et al., Phys. Rev. Lett., vol. 108, 2012, 224503) are very well described by the simple parametrization Nu=2.75+0.0069Ra\mathit{Nu}= 2. 75+ 0. 0069\mathit{Ra}. This parametrization is used in theoretical box models of the one-sided shutdown system and found to give excellent agreement with high-resolution numerical simulations of this system. The dynamical structure of shutdown can also be accurately predicted by measurements from an RB cell. Results are presented for a general power-law equation of state. Secondly, these ideas are extended to model more complex physical systems, which comprise two fluid layers with an equation of state such that the solution that forms at the (moving) interface is more dense than either layer. The two fluids are either immiscible or miscible. Theoretical box models compare well with numerical simulations in the case of a flat interface between the fluids. Experimental results from a Hele-Shaw cell and numerical simulations both show that interfacial deformation can dramatically enhance the convective flux. The applicability of these results to the convective dissolution of geologically sequestered CO2{\mathrm{CO} }_{2} in a saline aquifer is discussed
The role of lawyers in strategic alliances (tape 1 of 3)
No full textSymposium presented on October 4, 2002. Symposium explores how lawyers can bargain effectively without impairing trust and devise contract terms that will enhance trust and cooperation to maximize the profitability of alliances. --program flyer. Introduction by Gerald Korngold, Dean of the School of Law; moderated by Professor George W. Dent, Jr.; Steven Fraidin and Rachelle C. Sampson, speakers; commentators Daniel F. Austin, Edward Bernstein, Jeanne M. Rickert, Hewitt B. Shaw, Jr., and Wendy C. Shiba
Contents: Strategic alliances and corporate control / Stephen Fraidin -- Alliance structure: selection and consequences / Rachelle C. Sampson -- Negotiating and drafting for strategic alliances / George W. Dent, J
Estudo do escoamento imiscível água/óleo mediante experimentação em célula de Hele-Shaw e simulação CFD
No full textDissertação (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
The role of lawyers in strategic alliances (tape 1 of 3)
No full textSymposium explores how lawyers can bargain effectively without impairing trust and devise contract terms that will enhance trust and cooperation to maximize the profitability of alliances. --program flyer. Introduction by Gerald Korngold, Dean of the School of Law; moderated by Professor George W. Dent, Jr.; Steven Fraidin and Rachelle C. Sampson, speakers; commentators Daniel F. Austin, Edward Bernstein, Jeanne M. Rickert, Hewitt B. Shaw, Jr., and Wendy C. Shiba Strategic alliances and corporate control / Stephen Fraidin -- Alliance structure: selection and consequences / Rachelle C. Sampson -- Negotiating and drafting for strategic alliances / George W. Dent, J
The role of lawyers in strategic alliances (tape 3 of 3)
No full textSymposium explores how lawyers can bargain effectively without impairing trust and devise contract terms that will enhance trust and cooperation to maximize the profitability of alliances. --program flyer. Introduction by Gerald Korngold, Dean of the School of Law; moderated by Professor George W. Dent, Jr.; Steven Fraidin and Rachelle C. Sampson, speakers; commentators Daniel F. Austin, Edward Bernstein, Jeanne M. Rickert, Hewitt B. Shaw, Jr., and Wendy C. Shiba Strategic alliances and corporate control / Stephen Fraidin -- Alliance structure: selection and consequences / Rachelle C. Sampson -- Negotiating and drafting for strategic alliances / George W. Dent, J
The role of lawyers in strategic alliances (tape 2 of 3)
No full textSymposium explores how lawyers can bargain effectively without impairing trust and devise contract terms that will enhance trust and cooperation to maximize the profitability of alliances. --program flyer. Introduction by Gerald Korngold, Dean of the School of Law; moderated by Professor George W. Dent, Jr.; Steven Fraidin and Rachelle C. Sampson, speakers; commentators Daniel F. Austin, Edward Bernstein, Jeanne M. Rickert, Hewitt B. Shaw, Jr., and Wendy C. Shiba Strategic alliances and corporate control / Stephen Fraidin -- Alliance structure: selection and consequences / Rachelle C. Sampson -- Negotiating and drafting for strategic alliances / George W. Dent, J
The effect of patients’ preference on outcome in the EVerT cryotherapy versus salicylic acid for the treatment of plantar warts (verruca) trial
No full textBackground
Randomised controlled trials are widely accepted as the gold standard method to evaluate medical interventions, but they are still open to bias. One such bias is the effect of patient’s preference on outcome measures. The aims of this study were to examine whether patients’ treatment preference affected clearance of plantar warts and explore whether there were any associations between patients’ treatment preference and baseline variables in the EverT trial.
Methods
Two hundred and forty patients were recruited from University podiatry schools, NHS podiatry clinics and primary care. Patients were aged 12 years and over and had at least one plantar wart which was suitable for treatment with salicylic acid and cryotherapy. Patients were asked their treatment preference prior to randomisation. The Kruskal-Wallis test was performed to test the association between preference group and continuous baseline variables. The Fisher’s exact test was performed to test the association between preference group and categorical baseline variables. A logistic regression analysis was undertaken with verruca clearance (yes or no) as the dependent variable and treatment, age, type of verruca, previous treatment, treatment preference as independent variables. Two analyses were undertaken, one using the health professional reported outcome and one using the patient’s self reported outcomes. Data on whether the patient found it necessary to stop the treatment to which they had been allocated and whether they started another treatment were summarised by treatment group.
Results
Pre-randomisation preferences were: 10% for salicylic acid; 42% for cryotherapy and 48% no treatment preference. There was no evidence of an association between treatment preference group and either patient (p=0.95) or healthcare professional (p=0.46) reported verruca clearance rates. There was no evidence of an association between preference group and any of the baseline variables except gender, with more females expressing a preference for salicylic acid (p=0.004). There was no evidence that the number of times salicylic acid was applied was different between the preference groups at one week (p=0.89) or at three weeks (p=0.24). Similarly, for the number of clinic visits for cryotherapy (p=0.71)
Conclusions
This secondary analysis showed no evidence to suggest that patients’ baseline preferences affected verruca clearance rates or adherence with the treatment
The inexorable spread of a newly arisen neo-Y chromosome
No full textThis work was financially supported by a Natural Environment Research Council grant to RAN. (NER-B-S-2003-00859) and a studentship from Queen Mary University of London to PV.A newly arisen Y-chromosome can become established in one part of a species range by genetic drift or through the effects of selection on sexually antagonistic alleles. However, it is difficult to explain why it should then spread throughout the species range after this initial episode. As it spreads into new populations, it will actually enter females. It would then be expected to perform poorly since it will have been shaped by the selective regime of the male-only environment from which it came. We address this problem using computer models of hybrid zone dynamics where a neo-XY chromosomal race meets the ancestral karyotype. Our models consider that the neo-Y was established by the fusion of an autosome with the ancestral X-chromosome (thereby creating the Y and the ‘fused X’). Our principal finding is that sexually antagonistic effects of the Y induce indirect selection in favour of the fused X-chromosomes, causing their spread. The Y-chromosome can then spread, protected behind the advancing shield of the fused X distribution. This mode of spread provides a robust explanation of how newly arisen Y-chromosomes can spread. A Y-chromosome would be expected to accumulate mutations that would cause it to be selected against when it is a rare newly arrived migrant. The Y can spread, nevertheless, because of the indirect selection induced by gene flow (which can only be observed in models comprising multiple populations). These results suggest a fundamental re-evaluation of sex-chromosome hybrid zones. The well-understood evolutionary events that initiate the Y-chromosome's degeneration will actually fuel its range expansion.Peer reviewe
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