Tracer dynamics in two-layer density stratified estuarine flow

This paper considers tidal-driven particle motion in Tampa Bay, Florida, USA under fully stratified conditions with riverine inflow. The flow field is modelled by means of the two-layer shallow-water equations solved on an adaptive quadtree grid using a second-order Roe-type finite-volume scheme. Tracer dynamics are then obtained through Lagrangian particle tracking. The results show that the effect of external forcing is concentrated primarily in the upper layer, with particles in the lower layer less mixed and exhibiting relatively longer residence time in the semi-enclosed tidal bay. Particle flushing from Old Tampa Bay into the open sea is particularly hindered by the narrow inlet, whereas particles in Hillsborough Bay experience rapid transport seaward due to the large influx of river discharge. Particle patches are typically stretched in Middle Tampa Bay and may be trapped in the shallow Lower Tampa Bay region. The study reveals interesting underlying mixing features that cannot be produced by a single-layer depth-averaged shallow-water model. </jats:p

Every Inch a Queen: Reckoning with Misogyny/Reclaiming the Feminine in Shakespeare's King Lear

This paper presents a production concept for Shakespeares King Lear, to be adapted and directed by Alistair Newton as a part of the 35th Anniversary of Canadian Stages Shakespeare in High Park presentations. The production employs a conceptual framework which seeks to interrogate the misogyny inherent in the play by recasting the king as a queen, inspired by the final days of queen Elizabeth I. Shakespeares play is put into its historical context, the original source material that inspired its writing is examined, and an interrogation of Elizabethan attitudes towards gender is undertaken. This leads to the description of a directorial concept which addresses the plays problematic aspects, and employs the conceptual strategies of cross-gender casting, drag and gender play, and a queer reading of two of the central characters as a method of challenge and reinterpretation. The design for the physical production is then described in some detail.This paper presents a production concept for Shakespeares King Lear, to be adapted and directed by Alistair Newton as a part of the 35th Anniversary of Canadian Stages Shakespeare in High Park presentations. The production employs a conceptual framework which seeks to interrogate the misogyny inherent in the play by recasting the king as a queen, inspired by the final days of queen Elizabeth I. Shakespeares play is put into its historical context, the original source material that inspired its writing is examined, and an interrogation of Elizabethan attitudes towards gender is undertaken. This leads to the description of a directorial concept which addresses the plays problematic aspects, and employs the conceptual strategies of cross-gender casting, drag and gender play, and a queer reading of two of the central characters as a method of challenge and reinterpretation. The design for the physical production is then described in some detail

The structures, binding energies and vibrational frequencies of Ca3 and Ca4: An application of the CCSD(T) method

The Ca3 and Ca4 metallic clusters have been investigated using state-of-the-art ab initio quantum mechanical methods. Large atomic natural orbital basis sets have been used in conjunction with the singles and doubles coupled-cluster (CCSD) method, a coupled-cluster method that includes a perturbational estimate of connected triple excitations, denoted CCSD(T), and the multireference configuration interaction (MRCI) method. The equilibrium geometries, binding energies and harmonic vibrational frequencies have been determined with each of the methods so that the accuracy of the coupled-cluster methods may be assessed. Since the CCSD(T) method reproduces the MRCI results very well, cubic and quartic force fields of Ca3 and Ca4 have been determined using this approach and used to evaluate the fundamental vibrational frequencies. The infrared intensities of both the e' mode of Ca3 and the t2 mode of Ca4 are found to be small. The results obtained in this study are compared and contrasted with those from our earlier studies on small Be and Mg clusters

Comparison of the quadratic configuration interaction and coupled cluster approaches to electron correlation including the effect of triple excitations

The recently proposed quadratic configuration interaction (QCI) method is compared with the more rigorous coupled cluster (CC) approach for a variety of chemical systems. Some of these systems are well represented by a single-determinant reference function and others are not. The finite order singles and doubles correlation energy, the perturbational triples correlation energy, and a recently devised diagnostic for estimating the importance of multireference effects are considered. The spectroscopic constants of CuH, the equilibrium structure of cis-(NO)2 and the binding energies of Be3, Be4, Mg3, and Mg4 were calculated using both approaches. The diagnostic for estimating multireference character clearly demonstrates that the QCI method becomes less satisfactory than the CC approach as non-dynamical correlation becomes more important, in agreement with a perturbational analysis of the two methods and the numerical estimates of the triple excitation energies they yield. The results for CuH show that the differences between the two methods become more apparent as the chemical systems under investigation becomes more multireference in nature and the QCI results consequently become less reliable. Nonetheless, when the system of interest is dominated by a single reference determinant both QCI and CC give very similar results

Theoretical investigations of the structures and binding energies of Be(sub n) and Mg(sub n) (n = 3-5) clusters

Researchers determined the equilibrium geometries and binding energies of Be and Mg trimers, tetramers and pentamers using single and double excitation coupled cluster (CCSD) and complete active space self-consistent-field (CASSCF) multireference configuration interaction (MRCI) wave functions in conjunction with extended atomic basis sets. Best estimates of the cluster binding energies are 24, 83 and 110 kcal/mole for Be3, Be4 and Be5; and 9, 31 and 41 kcal/mole for Mg3, Mg4 and Mg5, respectively. A comparison of the MRCI and CCSD results shows that even the best single-reference approach (limited to single and double excitations) is not capable of quantitative accuracy in determining the binding energies of Be and Mg clusters

From tradition to modern: attitudes and applications of guanxi in Chinese entrepreneurship.

Purpose - This article aims to examine one aspect of Chinese culture, guanxi. Guanxi, "special relationships" has long been employed to facilitate business in China. The authors ask whether this is likely to continue in the rapidly changing environment. China's long history of insularity has created a culture and business environment considered to be uniquely based on Confucian values. Yet in the last couple of decades China has opened its doors to globalisation. These forces, in conjunction with what many see as Confucian dynamism of Chinese entrepreneurship, have generated economic growth levels in excess of 11 per cent per annum. This blending of the old and the new raises questions about how practices may be changing. Design/methodology/approach - The authors employed a survey of two groups; middle managers in Hong Kong and young middle class in mainland China. These groups represent the modern, Hong Kong as westernised; the old, but with new perspectives, the affluent middle classes of present day China. Open-ended questions about perceptions of understanding and use of guanxi were asked. Findings - The research finds many contrasts between the respondent groups. The Hong Kong respondents did not really understand guanxi, but still thought it important in China. The mainland group both understood and used guanxi, but similarly to the Hong Kong group, did not like it or enjoy its use. Both groups saw a diminishing application of guanxi as China's regulatory and market environment improves. Originality/value - The paper establishes that guanxi persists and may remain essential in China. However guanxi will work in conjunction with markets and regulations, rather than as a replacement

Numerical modelling of unbonded post tensioned concrete structures in fire including explicit modelling of creep in prestressing steel tendons

Due to the unbonded nature of tendons to the slab within Unbonded Post Tensioned (UPT) concrete structures, tendon stress relaxation under heating affects all regions of the slab spanned by the tendon; not just in the locality of the fire. The numerical modelling of bonded and unbonded post tensioned concrete structures in fire has been performed to some degree, notably by Bailey and Ellobody. The consideration of elevated temperature creep to the relaxation of tendon prestress however, has not been considered. This thesis attempts to incorporate a uniaxial creep strain rate function of stress and temperature into the commercial FE software package Abaqus, compatible for use within the in-built multiaxial metal plasticity constitutive framework. What follows is a validation study of the Harmathy’s uniaxial creep strain accumulation function via the modelling of stress relaxation in isolated, tensioned and heated prestressing steel tendons, against experimental data. From here, UPT concrete slab models are analysed whilst exposed to a standard fire temperature-time curve and subsequently allowed to cool. Tendon prestress relaxation and resulting UPT concrete slab deflection is compared, where tendon creep is explicitly modelled, as opposed to implicitly covered by Eurocode 2 determined temperature dependent stress-strain curves. Following this, a large scale continuous one-way spanning UPT concrete structural model is developed to consider global structural behaviour resulting from localised fire, where realistic boundary conditions such as beam rotation and deflection are permitted. The ignorance of explicit elevated temperature creep consideration, in prestressing steel tendons, is commonly justified through the implicit accountability stated within Eurocode 2 temperature dependent stress-strain curves. This however is not completely true; Eurocode 2 states implicit accountability only holds should the tendon be heating at a rate within the bounds of 2⁰C/min to 50⁰C/min. Where only heating of a UPT concrete slab is considered, evidence from this thesis suggests Eurocode 2 determined stress-strain curves can implicitly account for accumulated creep strain up to limited temperatures. Prestressing steel tendons are however embedded within a concrete slab through which thermal gradients build up during fire. This means heat transfer can continue to the tendon, increasing its temperature postfire at an ever decreasing rate until it reaches its peak. Should post-fire cooling behaviour not be considered, continued tendon heating and subsequent creep strain accumulation will be ignored. Further, during the transition from heating to cooling within the tendon, it will be exposed to elevated temperatures with a rate of change below 2⁰C/min, whereby Eurocode 2, as stated cannot implicitly account for creep. It is shown, a significant degree of subsequent relaxation of prestress, UPT concrete slab deflection and concrete damage in hogging can occur during this phase of postfire behaviour, where the tendon temperature peaks during its transition from heating to cooling. In order to justify non consideration of creep, it should be shown tendon temperature will remain suitably low throughout the entire heating-cooling regime to which the UPT concrete slab is exposed. This must be achieved through adequate specification of minimum concrete cover to tendons to limit tendon temperature exposure for a given parametric fire curve duration, including the potential continued rise post-fire. Evidence within this thesis identifies 350⁰C as a critical temperature whereby the explicit consideration of tendon creep does not significantly increase predicted prestress relaxation and subsequent UPT concrete slab deformation, compared to implicit creep consideration from Eurocode 2. The manufacturing standard to which prestressing steel tendon strands are produced has been shown experimentally by Gales to significantly influence their susceptibility to elevated temperature creep. This is reflected by Gales determining differing creep parameters as a function of stress for incorporation in Harmathy’s uniaxial creep strain function. Modelled prestress relaxation of isolated, tensioned and heated tendons within this thesis is therefore significantly reduced when tendons are manufactured to a yield stress of 1860MPa according to the BS 5896 standard, as opposed to the ASTM A416 standard. As a result Eurocode 2 determined stress-strain curves implicitly account for accumulated creep strain during heating, at 10⁰C per minute, up to approximately 400⁰C for grade 1860 ASTM A416 manufactured tendons and 500⁰C for grade 1860 BS 5896 standard tendons. The aforementioned critical temperature of 350⁰C does not in actuality apply to necessary explicit creep consideration for UPT concrete slabs modelled with grade 1860 BS 5896 standard tendons. This temperature however remains a design temperature limit, owing to the potential onset of microstructural recrystallization beyond 400⁰C and the associated degradation of mechanical properties that coincides. The reasons for such differing elevated temperature creep and stress relaxation behaviour between the two manufacturing standards of prestressing steel wires and strands has been postulated within this thesis to be due to differing chemical compositions. This relates specifically to large relative differences of phosphorus and sulphur found in wires manufactures to each standard as tested by Gales