4,764 research outputs found
U-Pn geochronology of deformed metagranites in central Sutherland, Scotland: evidence for widespread late Silurian metamorphism and ductile deformation of the Moine Supergroup during the Caledonian orogeny
No full textWithin the Caledonides of central Sutherland, Scotland, the Neoproterozoic metasedimentary rocks of the Moine Supergroup record NW-directed D2 ductile thrusting and nappe assembly, accompanied by widespread tight-to-isoclinal folding and amphibolite-facies metamorphism. A series of metagranite sheets which were emplaced and penetratively deformed during D2 have been dated using SHRIMP UâPb geochronology. Zircon ages of 424 8 Ma (Vagastie Bridge granite), 420 6 Ma (Klibreck granite) and 429 11 Ma (Strathnaver granite) are interpreted to date emplacement, and hence regional D2 deformation, during
mid- to late Silurian time. Titanite ages of 413 3 Ma (Vagastie Bridge granite) and 416 3 Ma (Klibreck granite) are thought to date post-metamorphic cooling through a blocking temperature of c. 550â 500 8C. A mid- to late Silurian age for D2 deformation supports published models that have viewed the internal ductile thrusts of this part of the orogen as part of the same kinematically linked system of forelandpropagating thrusts as the marginal Moine Thrust Zone. The new data contrast with previous interpretations that have viewed the dominant structures and metamorphic assemblages within the Moine Supergroup as having formed during the early to mid-Ordovician Grampian arcâcontinent orogeny. The mid-to late Silurian D2 nappe stacking event in Sutherland is probably a result of the collision of Baltica with the Scottish segment of Laurentia
Advanced modelling and visualisation of liquid-liquid separations of complex sample components, with variable phase distribution and mode of operation
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This research is about liquid-liquid chromatography modelling. While the main focus was on liquid-liquid chromatography, where the stationary and mobile phases are both liquid, theory of different types of chromatography, including the currently most used techniques, were considered as well. The main goal of this research was to develop a versatile liquid-liquid separation model, able to model all potential operating scenarios and modes of operation. A second goal was to create effective and usable interfaces to such a model, implying primarily information visualisation, and secondarily educative visualisation. The first model developed was a model based on Counter-Current Distribution. Next a new more elemental model was developed, the probabilistic model, which better models continuous liquid-liquid chromatography
techniques. Finally, a more traditional model was developed using transport theory. These models were used and compared to experimental data taken from literature. The models were demonstrated to model all main liquid-liquid chromatography techniques, incorporated the different modes of operation, and were able to accurately model many sample components and complex sample injections. A model interface was developed, permitting functional and effective model configuration, exploration and analysis using visualisation and interactivity. Different versions of the interface were then evaluated using questionnaires, group interviews and Insight Evaluation. The visualisation and interactivity enhancements have proven to contribute understanding and insight of the underlying chromatography process. This also proved the value of the Insight Evaluation method, providing valuable qualitative evaluation results desired for this model interface evaluation. A prototype of a new graphical user interface developed, and showed great potential for combining model parameter input and exploring the liquid-liquid chromatography processes. Additionally, a new visualisation method was developed that can accurately visualise different modes of operation. This was used to create animations, which were also evaluated. The results of this evaluation show the new visualisation helps understanding of the liquid-liquid chromatography process amongst CCC novices. The model software will be a valuable tool for industry for predicting, evaluating and validating experimental
separations and production processes. While effective models already existed, the use of
interactive visualisation permits users to explore the relationship between parameters and performances in a simpler yet more powerful way. It will also be a valuable tool for academia for teaching & training, both staff and students, on how to use the technology. Prior to this work no such tool existed or existing tools were limited in their accessibility and educational value.This study was supported by Brunel University and the Royal Academy of Engineering
On using Directional Information for Parameter Space Decomposition in Ellipse Detection
No full textIn this paper we use the parametric polar representation to extend the application of edge directional information from circle to ellipse extraction. As a result we obtain a mapping which decomposes the parameter space required for ellipse extraction into two independent sub-spaces and one final histogram accumulator. The mapping includes the tangent of the angle of the first and second directional derivatives. These tangents are computed by considering edge direction at two border points. We show that the use of gradient information for parameter space decomposition avoids the intensive point labelling imposed by geometric constraints used by other approaches
Large-scale patterns in turbulent Rayleigh-Bénard convection in very large aspect ratio cells
No full textLarge-scale patterns, which are well-known from the spiral defect chaos regime of thermal convection at Rayleigh numbers Ra 105. They are uncovered when the turbulent fields are averaged in time and turbulent fluctuations are thus removed. We apply the Boussinesq closure to calculate turbulent viscosities and diffusivities, respectively. The resulting turbulent Rayleigh number Ra_, that describes the convection of the mean patterns, is indeed in the spiral defect chaos range. Interestingly, the turbulent Prandtl numbers are smaller than one with 0:2 _ Pr_ _ 0:4 for Prandtl numbers 0:7 _ Pr _ 10. Finally, we demonstrate that these mean flow patterns are robust to an additional finite-amplitude side wall-forcing when the level of turbulent fluctuations in the flow is sufficiently high
Reynolds number effect on 3D turbulent offset jet reattaching to a free surface
No full textExperimental study was carried out to investigate the effect of Reynolds number on 3D offset jet reattaching to above free surface. Sharp edged square nozzle was used to produce the jets, and the measurements were performed at the following six different Reynolds numbers: 2300, 3700, 5100, 7900, 10300 and 11900. Detailed velocity measurements were made in the symmetry plane. From the PIV data, the mean velocity and turbulence statistics were obtained to study the effects of Reynolds number on the salient features of the jet flow. Preliminary results on streamwise mean velocity decay along the nozzle centerline, contours of streamwise mean velocity and Reynolds shear stress are presented herein
The Benefits of Being Economics Professor A (and not Z)
No full textAlphabetic name ordering on multi-authored academic papers, which is the convention in the economics discipline and various other disciplines, is to the advantage of people whose last name initials are placed early in the alphabet. As it turns out, Professor A, who has been a first author more often than Professor Z, will have published more articles and experienced afaster growth rate over the course of her career as a result of reputation and visibility. Moreover, authors know that name ordering matters and indeed take ordering seriously: Several characteristics of an author group composition determine the decision to deviate from the default alphabetic name order to a significant extent.performance measurement, incentives, economists, name ordering
<i>Entrenchment, wealth, power, and the constitution of democratic societies</i> by Paul Starr
No full textEntrenchment, Wealth, Power, and the Constitution of Democratic Societies, by Paul Starr, New Haven, CT: Yale University Press. 2019. 280 pages, hardcover.Why should we, as Management scholars and educators, care about a book on political diagnosis? The answer is twofold. First, the calibre of the author (Paul Starr), an awardee of both Bancroft and Pulitzer Prizes, a former policy advisor to the Clinton administration, and the author of The Transformation of American Medicine (1982), a book with a profound impact on American policy circles. Second, the core concept (entrenchment) of the book, and its potential to advance the process of institutional development, and the ways in which we can reform and change our institutions to better meet the current and pressing needs of the many, rather than preserve the unequal privileges of a few. In light of the geopolitical, social, and environmental pressures we see currently rising across the world (George, Howard-Grenville, Joshi & Tihanyi, 2016; Howard-Grenville, Buckle, Hoskins & George, 2014) there is no better time to examine whether and how we can address some of these grand challenges by reforming and improving our institutions
M.S. Kutorga and V.M. Vedrov: Conflict of Teacher and Student
No full textВ статье рассматривается конфликт между М.С. Куторгой и его учеником В.М. Ведровым. Исследуются причины конфликта, а также то влияние, которое он оказал на дальнейшую научную карьеру ученика. This article discusses the conflict between M.S. Kutorga and his student V.M. Vedrov. The author investigates the causes of the conflict and its impact on academic career V.M. Vedrov
Ultra-fast escape of a deformable jet-propelled body
No full textIn this work a cephalopod-like deformable body that fills an internal cavity with fluid and expels it to propel an escape manoeuvre, while undergoing a drastic external shape change through shrinking, is shown to employ viscous as well as mainly inviscid hydrodynamic mechanisms to power an impressively fast start. First, we show that recovery of added-mass energy enables a shrinking rocket in a dense inviscid flow to achieve greater escape speed than an identical rocket in a vacuum. Next, we extend the shrinking body results of Weymouth & Triantafyllou (J. Fluid Mech., vol. 702, 2012, pp. 470–487) to three-dimensional bodies and show that three hydrodynamic mechanisms must be combined to achieve rapid escape performance in a viscous fluid: added-mass energy recovery; flow separation elimination; and an optimized energy storage and recovery. In particular, we show that the mechanism of separation elimination achieved through rapid body shrinking, coordinated with the mechanism of recovering the initially imparted added-mass energy, is critical to achieving a high escape speed. Hence a flexible, collapsing body can be vastly superior to a rigid-shell jet-propelled body
March 30, 1912 Page four Fire narrowly averted Irondale spelling bee Fine eating place Ordered to quarantine
No full textSmith, William; Sutherland, Marie; Davis, Marion; Crompton, Edward; Mussier, Robert; Roth, Gussie; Grey, Helen; Butler, Thomas; Winton, Ethel; Scott, M.S.
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