Self-Consistent Theory of Normal-to-Superconducting Transition

I study the normal-to-superconducting (NS) transition within the Ginzburg-Landau (GL) model, taking into account the fluctuations in the $m$-component complex order parameter \psi\a and the vector potential $\vec A$ in the arbitrary dimension $d$, for any $m$. I find that the transition is of second-order and that the previous conclusion of the fluctuation-driven first-order transition is an artifact of the breakdown of the \eps-expansion and the inaccuracy of the $1/m$-expansion for physical values \eps=1, $m=1$. I compute the anomalous $\eta(d,m)$ exponent at the NS transition, and find $\eta (3,1)\approx-0.38$. In the $m\to\infty$ limit, $\eta(d,m)$ becomes exact and agrees with the $1/m$-expansion. Near $d=4$ the theory is also in good agreement with the perturbative \eps-expansion results for $m>183$ and provides a sensible interpolation formula for arbitrary $d$ and $m$.Comment: 9 pages, TeX + harvmac.tex (included), 2 figures and hard copies are available from [email protected] To appear in Europhysics Letters, January, 199

Literacy as supply and demand

This paper draws on three data sources – a national survey from Germany of adult literacy and numeracy skills (leo. – Level-One Study), the OECD's Programme for the International Assessment of Adult Competences (PIAAC), and case studies of workplaces in England – to argue for a greater focus by policymakers and researchers on the literacy demand experienced by adults. We consider the heterogeneity of the population of adults deemed functionally illiterate by large-scale national and international surveys and question how such a large group of adults are indeed able to function in society. We draw on concepts of literacy practices and the literate environment to try to understand the demands on adults’ reading and writing and suggest that adults with poor literacy skills may be reluctant to engage in learning because they experience very low demand. Engagement in literate practices is an important mechanism through which literacy is improved and developed. If the demands on many adults’ literacy are so low, their skills may decline/fail to develop, leaving a large sub-class excluded from the literate environment and relying on others for interpretation and access to information. This vicious circle of underuse and consequent loss of skills should be a major concern for policy makers

Impact of poor English and maths skills on employers: literature review

This literature review synthesises evidence from qualitative and quantitative studies that shed light on the costs to employers of poor English and maths skills. It also addresses the benefits of, and the barriers to, workplace training, with a focus on employer perceptions of the need for and efficacy of workplace training in English and maths. The review also considers and summarises key theoretical and methodological issues

Mechanical Dispersion of a Semi-Solid Binder in a Wet Granulation Process

High viscosity surfactant pastes have recently gained popularity in the production of high efficiency laundry detergents due to their ability to increase surfactant loading in granules. When using high viscosity semi-solid binders a unique challenge is presented because it forces granules to be formed primarily by mechanical dispersion; a relatively poorly understood process. Developing mechanistic models of this process will enhance knowledge of mechanical dispersion processes and improve process development for granules produced using this method. Experiments to determine the effect of three process parameters; paste temperature, impeller RPM, and time were carried out in a lab-scale granulator. Binder temperature was varied between 40-60 degrees Celsius to cover paste temperatures from solidification to decomposition. Impeller RPM was varied between 600 -1200 RPM to capture the full range of potential industrial impeller velocities. Mixing time was varied from zero to ten seconds; the time scale of the industrial process. The particle size distribution for the process was determined to rely primarily on mixing time especially at impeller speeds above 900 RPM where fully developed annular flow occurs in the mixer. The Sauter mean diameter of particles was determined to be linearly related to mixing RPM, while temperature was shown to have little effect on the Sauter mean diameter. Experimental data was in relatively good agreement with values predicted by an existing breakage simulation, but could be improved upon. These conclusions will be used in developing a breakage kernel for the process based on material properties

Spectrum and polarization of laser light scattered by solids

Laser light scattering from yttrium-iron garne

Harmonic crossover exponents in O(n) models with the pseudo-epsilon expansion approach

We determine the crossover exponents associated with the traceless tensorial quadratic field, the third- and fourth-harmonic operators for O(n) vector models by re-analyzing the existing six-loop fixed dimension series with pseudo-epsilon expansion. Within this approach we obtain the most accurate theoretical estimates that are in optimum agreement with other theoretical and experimental results.Comment: 12 pages, 1 figure. Final version accepted for publicatio

Scale-up Considerations in Granulation

Scale-up of any engineering process is a great technical and economic challenge. Scale-up of granulation processes, in particular, is difficult and often problematic due to the inherently heterogenous nature of the materials used. However, recent improved understanding of the rate processes that control granulation improves our ability to do rational scale-up

Binder-treated segregation-free aluminum alloy powders

Two paraffin waxes with different melting points and mixed at a specific mass ratio were used as a binder for premixed aluminum alloy powders. Dusting, segregation, and part-to-part variability were significantly reduced and powder flow improved compared to untreated powder In addition, the green density of compacts fabricated from the binder-treated powders was higher than that of the untreated powders. Sintered mechanical properties were not significantly affected by the addition of the binder Air-drying alkyd binders and water-based wax emulsions were also tested, but the results were less satisfactory

First order isotropic - smectic-A transition in liquid crystal-aerosil gels

The short-range order which remains when the isotropic to smectic-A transition is perturbed by a gel of silica nanoparticles (aerosils) has been studied using high-resolution synchrotron x-ray diffraction. The gels have been created \textit{in situ} in decylcyanobiphenyl (10CB), which has a strongly first-order isotropic to smectic-A transition. The effects are determined by detailed analysis of the temperature and gel density dependence of the smectic structure factor. In previous studies of the continuous nematic to smectic-A transition in a variety of thermotropic liquid crystals the aerosil gel appeared to pin, at random, the phase of the smectic density modulation. For the isotropic to smectic-A transition the same gel perturbation yields different results. The smectic correlation length decreases more slowly with increasing random field variance in good quantitative agreement with the effect of a random pinning field at a transition from a uniform phase directly to a phase with one-dimensional translational order. We thus compare the influence of random fields on a \textit{freezing} transition with and without an intervening orientationally ordered phase.Comment: 8 pages, 8 figure

Pharmacovigilance in hospice/palliative care: Net effect of haloperidol for delirium

Introduction: Prescribing practice in hospice/palliative care is largely extrapolated from other areas of clinical practice, with few studies of net medication effects (benefits and harms) in hospice/palliative care to guide prescribing decisions. Hospice/palliative care patients differ in multiple ways from better studied participant groups, hence the applicability of studies in other participant groups is uncertain. Haloperidol, a butyrophenone derivative and dopamine antagonist, is commonly prescribed for nausea, vomiting, and delirium in hospice/palliative care. Its frequent use in delirium occurs despite little evidence of the effect of antipsychotics on the untreated course of delirium. The aim of this study was to examine the immediate and short-term clinical benefits and harms of haloperidol for delirium in hospice/palliative care patients. Method: A consecutive cohort of participants from 14 centers across four countries who had haloperidol commenced for delirium were recruited. Data were collected at three time points: baseline, 48 hours (clinical benefits), and day 10 (clinical harms). Investigators were also able to report clinical harms at any time up to 14 days after it was commenced. Results: Of the 119 participants included, the average dose was 2.1 mg per 24 hours; 42 of 106 (35.2%) reported benefit at 48 hours. Harm was reported in 14 of 119 (12%) at 10 days, the most frequent being somnolence (n=11) and urinary retention (n=6). Seven participants had their medication ceased due to harms (2 for somnolence and 2 for rigidity). Approximately half (55/119) were still being treated with haloperidol after 10 days. Conclusion: Overall, 1 in 3 participants gained net clinical benefit at 10 days. © Copyright 2013, Mary Ann Liebert, Inc. 2013