Magnetic levitation fluid dynamics

This work is concerned with the accurate computation of flow in a rapidly deforming liquid metal droplet, suspended in an AC magnetic field. Intense flow motion due to the induced electromagnetic force distorts dynamically the droplet envelope, which is initially spherical. The relative positional change between the liquid metal surface and the surrounding coil means that fluid flow and magnetic field computations need to be closely coupled. A spectral technique is used to solve this problem, which is assumed axisymmetric. The computed results are compared against a physical experiment and "ideal sphere" analytic solutions. A comparison between the "magnetic pressure" approximation and the full electromagnetic force solutions, shows fundamental differences; the full electromagnetic force solution is necessary for accurate results in most practical applications of this technique. The physical reason for the fundamental discrepancy is the difference in the electromagnetic force representation: only the gradient part of the full force is accounted for in the "magnetic pressure" approximation. Figs 9, Refs 13.

Liquid metal induction heating modelling for cold crucible applications

The time dependent numerical model of cold crucible melting is based on the coupled electromagnetic, temperature and turbulent velocity field calculation accounting for the magnetically confined liquid metal shape continuous change. The model is applied to investigate the process energy efficiency dependence on the critical choice of AC power supply frequency and an optional addition of a DC magnetic field. Test cases of the metal load up to 50 kg are considered. The behaviour of the numerical model at high AC frequencies is instructively validated by the use of the electromagnetic analytical solution for a sphere and temperature measurements in a commercial size cold crucible furnace

L'histoire assassinee: Manfredo Tafuri and the present

Italian historian Manfredo Tafuri develops his ‘historical project’ in architecture during the 1960’s and 1970’s in three seminal books, which reach the English speaking specialist audience with a certain delay. Histories and Theories of Architecture (1968), which prepares the ground for the redefinition of a critical and independent history of architecture is first translated in English in 1979. Architecture and Utopia (Progetto e utopia, 1973) is translated in 1976, and becomes a point of reference for architectural histories and for the definition of architectural theories, mainly in the United States. The Sphere and the Labyrinth (1980), translated in 1987, is the text which formally defines and presents the ‘historical project’. Tafuri’s dense and highly politicized prose is often subjected in the English versions to numerous simplifications and reductive interpretations. Yet, the time lag and the space between languages that these translations occupy are inhabited by polemical and fertile reactions to the texts from the world of architectural design. Symptomatic of all, Aldo Rossi’s L’architecture assassinée, a rebuke in drawing to some of Tafuri’s remarks in Architecture and Utopia that seemed to suggest -but the interpretation is arguable– the ‘death’ of architecture as project (progetto). Tafuri’s texts instigate a dialogue between architectural history and practice, particularly relevant at a time in the development of the discipline when history was being redefined in its critical role as a ‘project’ –thus appropriating the active and propositional role traditionally assigned to architectural design–, while architectural design –still coping with the legacy of Modernism and with changed production systems- often found itself relegated to the paper of exhibitions, competitions and theoretical projects. This paper explores the relationship between architectural history and design in Tafuri’s work, focusing on recent reconsideration and interpretations of his work. It argues that, beyond instrumental simplifications, Tafuri’s ‘project’ remains active and essential in architecture’s critical culture today.

The comparative advantage of the public sector in the development of urban water supply

This paper addresses the potential of public water operations in achieving developmental goals such as the Millennium Development Goals, and argues that the public sector has a comparative advantage in developing water services. The global importance of the public sector in urban water supply is examined through a review of current practice in the world's largest cities, including operational presence and distribution and ongoing trends. Empirical evidence shows that, in transition and developing countries, public operators are capable of undergoing successful reform. One explanatory factor is proposed to be the creation through the public sphere of highly interconnected networks among stakeholders. Such accountability networks act as vehicles for the generation and distribution of public knowledge among stakeholders, which in turn inform rational decision making on the reform and management of operations.

Social Work and theatre: considering intersections

Theatre is a cultural and artistic form that involves a process of communication between creators and is received in a space and time located in the public sphere, which has meant that, over the centuries, it has acted as a space for expression, exchange and debate regarding all manner of ideas, causes and struggles. Implicit within this process are processes of expression, creation and reception, by way of which people demonstrate, analyse and question ways of seeing and understanding life, and ways of being and existing in the world. This gives rise to educational, cultural, social and political potential, which has been endorsed in numerous studies and investigations. In this work, in which theoretical orientation is established through a review of the relevant literature, we consider different intersections that occur between theatre and social work in order to also show that dramatic and theatrical expression offers substantive methodologies for achieving some objectives of social work, particularly in areas such as critical literacy, reflexivity and recognition, awareness raising, social participation, personal and/or community development, ownership of cultural capital and access to personal and social wellbeing.

'Not Forsworn with Pink Ribbons': Hannah More, Thomas De Quincey, and the Literature of Power

De Quincey's conception of the literature of "power" as opposed to that of "knowledge," has proved to be one of the most influential of romantic theories of literature, playing no small part in the canonization of Wordsworth. De Quincey's early acquaintance with the Lyrical Ballads was made through the Evangelical circles of his mother, who was a follower of Hannah More and a member of the Clapham sect. In later years, however, De Quincey repudiated his early Evangelical upbringing and wrote quite scathingly of the literary pretensions of Hannah More. This paper attempts to uncover the revisionary nature of De Quincey's later reminiscences of More and to indicate thereby the covert influence of Evangelical thinking on his literary theorizing. Far from absolving literature of politics, however, colonialist and nationalist imperatives typical of Evangelical thinking may be seen to operate within the spiritualized and aesthetic sphere to which literary power is arrogated by De Quincey.

Melancholy and the Early Modern University

Critics have observed that in early Stuart England, the broad, socially significant concept of melancholy was recoded as a specifically medical phenomenon—a disease rather than a fashion. This recoding made melancholy seem less a social attitude than a private ailment. However, I argue that at the Stuart universities, this recoded melancholy became a covert expression of the disillusionment, disappointment, and frustration produced by pressures there—the overcrowding and competition which left many men “disappointed” in preferment, alongside James I’s unprecedented royal involvement in the universities. My argument has implications for Jürgen Habermas’s account of the emergence of the public sphere, which he claims did not occur until the eighteenth-century. I argue that although the university was increasingly subordinated to the crown’s authority, a lingering sense of autonomy persisted there, a residue of the medieval university’s relative autonomy from the crown; politicized by the encroaching Stuart presence, an alienated community at the university formed a kind of public in private from authority within that authority’s midst. The audience for the printed book, a sphere apart from court or university, represented a forum in which the publicity at the universities could be consolidated, especially in seemingly “private” literary forms such as the treatise on melancholy. I argue that Robert Burton’s exaggerated performance of melancholy in The Anatomy of Melancholy, which gains him license to say almost anything, resembles the performed melancholy that the student-prince Hamlet uses to frustrate his uncle’s attempts to surveil him. After tracing melancholy’s evolving literary function through Hamlet, I go on to discuss James’s interventions into the universities. I conclude by considering two printed (and widely circulated) books by university men: the aforementioned The Anatomy of Melancholy by Burton, an Oxford cleric, and The Temple by George Herbert, who left a career as Cambridge’s public orator to become a country parson. I examine how each of these books uses the affective pattern of courtly-scholarly disappointment—transumed by Burton as melancholy, and by Herbert as holy affliction—to develop an empathic form of publicity among its readership which is in tacit opposition to the Stuart court.

Microscopic models for dielectric relaxation in disordered systems

It is shown how the Debye rotational diffusion model of dielectric relaxation of polar molecules (which may be described in microscopic fashion as the diffusion limit of a discrete time random walk on the surface of the unit sphere) may be extended to yield the empirical Havriliak-Negami (HN) equation of anomalous dielectric relaxation from a microscopic model based on a kinetic equation just as in the Debye model. This kinetic equation is obtained by means of a generalization of the noninertial Fokker-Planck equation of conventional Brownian motion (generally known as the Smoluchowski equation) to fractional kinetics governed by the HN relaxation mechanism. For the simple case of noninteracting dipoles it may be solved by Fourier transform techniques to yield the Green function and the complex dielectric susceptibility corresponding to the HN anomalous relaxation mechanism.

Synthesis of Piano Stool Complexes Employing the Pentafluorophenyl Substituted Diphosphine (C6F5)2PCH2P(C6F5)2 and the Effect of Phosphine Modifiers on Hydrogen Transfer Catalysis.

Ruthenium, rhodium, and iridium piano stool complexes of the pentafluorophenyl-substituted diphosphine (C6F5)2PCH2P(C6F5)2 (2) have been prepared and structurally characterized by single-crystal X-ray diffraction. The Cp-P tethered complex [{(C5Me4CH2C6F4(C6F5)CH2P(C6F5)2}RhCl2] (9), in which only one phosphorus is coordinated to the rhodium, was prepared by thermolysis of a slurry of [Cp*RhCl(-Cl)]2 and 2 and was structurally characterized by single-crystal X-ray diffraction. The tethering occurs by intramolecular dehydrofluorinative coupling of the pentamethylcyclopentadienyl ligand and P,P-coordinated 2. The geometric changes that occur on tethering force dissociation of one of the phosphorus atoms. The effects of introducing phosphine ligands to the coordination sphere of piano stool hydrogen transfer catalysts have been studied. The complexes of fluorinated phosphine complexes are found to transfer hydrogen at rates that compare favorably with leading catalysts, particularly when the phosphine and cyclopentadienyl functionalities are tethered. The highly chelating Cp-PP complex [(C5Me4CH2-2-C5F3N-4-PPhCH2CH2PPh2)RhCl]BF4 (1) was found to outperform all other complexes tested. The mechanism of hydrogen transfer catalyzed by piano stool phosphine complexes is discussed with reference to the trends in activity observed.

Isolation of retinal progenitor and stem cells from the porcine eye

Purpose: Retinal progenitor cells (RPCs) and retinal stem cells (RSCs) from rodents and humans have been isolated and characterized in vitro. Transplantation experiments have confirmed their potential as tools for cell replacement in retinal degenerative diseases. The pig represents an ideal pre-clinical animal model to study the impact of transplantation because of the similarity of its eye to the human eye. However, little is known about porcine RPCs and RSCs. We aimed to identify and characterize in vitro RPCs and RSCs from porcine ocular tissues. Methods: Cells from different subregions of embryonic, postnatal and adult porcine eyes were grown in suspension sphere culture in serum-free medium containing basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Growth curves and BrdU incorporation assays were performed to establish the proliferative capacity of isolated porcine retina-derived RPCs and ciliary epithelium (CE)-derived RSCs. Self-renewal potential was investigated by subsphere formation assays. Changes in gene expression were assayed by reverse transcription polymerase chain reaction (RT-PCR) at different passages in culture. Finally, differentiation was induced by addition of serum to the cultures and expression of markers for retinal cell types was detected by immunohistochemical staining with specific antibodies. Results: Dissociated cells from embryonic retina and CE at different postnatal ages generated primary nestin- and Pax6-immunoreactive neurosphere colonies in vitro in numbers that decreased with age. Embryonic and postnatal retina-derived RPCs and young CE-derived RSCs displayed self-renewal capacity, generating secondary neurosphere colonies. However, their self-renewal and proliferation capacity gradually decreased and they became more committed to differentiated states with subsequent passages. The expansion capacity of RPCs and RSCs was higher when they were maintained in monolayer culture. Porcine RPCs and RSCs could be induced to differentiate in vitro to express markers of retinal neurons and glia. Conclusions: Porcine retina and CE contain RPCs and RSCs which are undifferentiated, self-renewing and multipotent and which show characteristics similar to their human counterparts. Therefore, the pig could be a useful source of cells to further investigate the cell biology of RPCs and RSCs and it could be used as a non-primate large animal model for pre-clinical studies on stem cell-based approaches to regenerative medicine in the retina.

A Blueprint for Democratic Policing Anywhere in the World? Police Reform, Political Transition and Conflict Resolution in Northern Ireland

This article provides an overview of the police reform process undertaken in Northern Ireland since 1999 as part of a broader program of conflict resolution. It considers the recommendations of the Independent Commission on Policing (ICP), which proposed a number of changes to policing structures and arrangements in Northern Ireland, and it assesses the degree to which these have been operationalized in the 8 years since the ICP published its report. It suggests that although the police reform process in Northern Ireland has been moderately successful and provides a number of international best practice lessons, the overall pace of change has been hindered by difficulties of implementation and, more fundamentally, by developments in the political sphere and civil society.

Monitoring treatment fidelity in a randomised controlled trial of a complex intervention.

Aim. This paper is a report of a study to describe how treatment fidelity is being enhanced and monitored, using a model from the National Institutes of Health Behavior Change Consortium. Background. The objective of treatment fidelity is to minimize errors in interpreting research trial outcomes, and to ascribe those outcomes directly to the intervention at hand. Treatment fidelity procedures are included in trials of complex interventions to account for inferences made from study outcomes. Monitoring treatment fidelity can help improve study design, maximize reliability of results, increase statistical power, determine whether theory-based interventions are responsible for observed changes, and inform the research dissemination process. Methods. Treatment fidelity recommendations from the Behavior Change Consortium were applied to the SPHERE study (Secondary Prevention of Heart DiseasE in GeneRal PracticE), a randomized controlled trial of a complex intervention. Procedures to enhance and monitor intervention implementation included standardizing training sessions, observing intervention consultations, structuring patient recall systems, and using written practice and patient care plans. The research nurse plays an important role in monitoring intervention implementation. Findings. Several methods of applying treatment fidelity procedures to monitoring interventions are possible. The procedure used may be determined by availability of appropriate personnel, fiscal constraints, or time limits. Complex interventions are not straightforward and necessitate a monitoring process at trial stage. Conclusion. The Behavior Change Consortium’s model of treatment fidelity is useful for structuring a system to monitor the implementation of a complex intervention, and helps to increase the reliability and validity of evaluation findings.

Geometry in preduals of spaces of 2-homogeneous polynomials on Hilbert spaces

Let H be a (real or complex) Hilbert space. Using spectral theory and properties of the Schatten–Von Neumann operators, we prove that every symmetric tensor of unit norm in HoH is an infinite absolute convex combination of points of the form xox with x in the unit sphere of the Hilbert space. We use this to obtain explicit characterizations of the smooth points of the unit ball of HoH .

Behavior of the heterogeneous electron-transfer rate constants of arenes and substituted anthracenes in room-temperature ionic liquids

We report the anodic oxidation of several arenes and anthracenes within room-temperature ionic liquids (RTILs). In particular, the heterogeneous electron-transfer rates (k(0)) for substituted anthracenes and arenes are also investigated in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C(2)mim][NTf2]) and found not to obey the outer-sphere Marcus-type behavior of these compounds in contrast to the behavior in traditional organic solvents,in particular the predictions for k(0) with molecular size and solvent static dielectric constant. To obtain the electron-transfer rate for 9-phenylanthracene, the dimerization and heterogeneous electron-transfer kinetics of its electrogenerated radical cations is studied in [C(2)mim][NTf2] and eight other RTILs and are both found to be largely independent of the solution viscosity.

Species distribution and coordination of uranyl chloro complexes in acetonitrile

The complex formation of the uranyl ion, UO22+, with chloride ions in acetonitrile has been investigated by factor analysis of UV-vis absorption and U L-3 edge EXAFS (extended X-ray absorption fine structure) spectra. As a function of increasing [Cl-]/[UO22+] ratio, the five monomeric species [UO2(H2O)(5)](2+), [UO2Cl(H2O)(2)(MeCN)(2)](+), [UO2Cl2(H2O)(MeCN)(2)], [UO2Cl3(MeCN)(2)](-), and [UO2Cl4](2-) have been observed. The distances determined in the first coordination sphere are: U-O-ax = 1.77 angstrom, U-O-H2O = 2.43 angstrom, U-N-MeCN = 2.53 angstrom, and U-Cl = 2.68 angstrom. A crystalline material has been obtained from the intermediate solution with the [Cl-]/[UO22+] ratio of similar to 2, where [UO2Cl2(H2O)(MeCN)(2)] is the dominating species. The crystal structure analysis of this material revealed a tetrameric complex, [(UO2)(4)(mu(2)-Cl)(4)(mu(3)-O)(2)(H2O)(2)(CH3CN)(4)]center dot(CH3CN). The crystal data are: monoclinic, space group P2(1)/n, a 10.6388(5) angstrom, b = 14.8441(5) angstrom, c = 10.8521(5) angstrom, beta = 109.164(5)degrees, and Z = 2. The U(VI) coordination of the solution species [UO2Cl2(H2O)(MeCN)(2)] changes during the crystallization by replacing one MeCN molecule with a bridging mu(3)-O atom in the tetramer.