Temporal Modulation of Traveling Waves in the Flow Between Rotating Cylinders With Broken Azimuthal Symmetry

The effect of temporal modulation on traveling waves in the flows in two distinct systems of rotating cylinders, both with broken azimuthal symmetry, has been investigated. It is shown that by modulating the control parameter at twice the critical frequency one can excite phase-locked standing waves and standing-wave-like states which are not allowed when the system is rotationally symmetric. We also show how previous theoretical results can be extended to handle patterns such as these, that are periodic in two spatial direction.Comment: 17 pages in LaTeX, 22 figures available as postscript files from http://www.esam.nwu.edu/riecke/lit/lit.htm

Random-mass Dirac fermions in an imaginary vector potential: Delocalization transition and localization length

One dimensional system of Dirac fermions with a random-varying mass is studied by the transfer-matrix methods which we developed recently. We investigate the effects of nonlocal correlation of the spatial-varying Dirac mass on the delocalization transition. Especially we numerically calculate both the "typical" and "mean" localization lengths as a function of energy and the correlation length of the random mass. To this end we introduce an imaginary vector potential as suggested by Hatano and Nelson and solve the eigenvalue problem. Numerical calculations are in good agreement with the results of the analytical calculations.Comment: 4 page

Smectic ordering in liquid crystal - aerosil dispersions II. Scaling analysis

Liquid crystals offer many unique opportunities to study various phase transitions with continuous symmetry in the presence of quenched random disorder (QRD). The QRD arises from the presence of porous solids in the form of a random gel network. Experimental and theoretical work support the view that for fixed (static) inclusions, quasi-long-range smectic order is destroyed for arbitrarily small volume fractions of the solid. However, the presence of porous solids indicates that finite-size effects could play some role in limiting long-range order. In an earlier work, the nematic - smectic-A transition region of octylcyanobiphenyl (8CB) and silica aerosils was investigated calorimetrically. A detailed x-ray study of this system is presented in the preceding Paper I, which indicates that pseudo-critical scaling behavior is observed. In the present paper, the role of finite-size scaling and two-scale universality aspects of the 8CB+aerosil system are presented and the dependence of the QRD strength on the aerosil density is discussed.Comment: 14 pages, 10 figures, 1 table. Companion paper to "Smectic ordering in liquid crystal - aerosil dispersions I. X-ray scattering" by R.L. Leheny, S. Park, R.J. Birgeneau, J.-L. Gallani, C.W. Garland, and G.S. Iannacchion

Influence of Shear-Thinning Rheology on the Mixing Dynamics in Taylor-Couette Flow

Non‐Newtonian rheology can have a significant effect on mixing efficiency, which remains poorly understood. The effect of shear‐thinning rheology in a Taylor‐Couette reactor is studied using a combination of particle image velocimetry and flow visualization. Shear‐thinning is found to alter the critical Reynolds numbers for the formation of Taylor vortices and the higher‐order wavy instability, and is associated with an increase in the axial wavelength. Strong shear‐thinning and weak viscoelasticity can also lead to sudden transitions in wavelength as the Reynolds number is varied. Finally, it is shown that shear‐thinning causes an increase in the mixing time within vortices, due to a reduction in their circulation, but enhances the axial dispersion of fluid in the reactor

Local Authority planning provision for Event Management in Ireland: A Socio-Cultural Perspective

The increasing popularity of the event sector in Ireland has resulted in many community events being developed and marketed to international and domestic tourists alike. This growth has had an effect on host communities in a positive and negative manner. This paper assesses the current levels of Local Authority socio-cultural planning provision and guidelines for event management in Ireland. To achieve this, a content analysis approach was used to illustrate which Local Authorities in the Republic of Ireland employed socio-cultural tools and indicators for event management. Accordingly, analysis revealed a lack of Local Authority socio-cultural planning guidelines or policies for event management. However, this offers and opportunity to be improved by implementing and applying best practice indicators in socio-cultural policies and guidelines for event management in Ireland

‘What’s the plan?’ ‘What plan?’ Changing aspirations among Gypsy youngsters, and implications for future cultural identities and group membership

PublishedMartin Levinson University of Exeter Graduate School of Education Heavitree Road Exeter EX1 2LU United KingdomArticleThis is an Accepted Manuscript of an article published by Taylor & Francis in British Journal of Sociology of Education on 28 March 2014, available online: http://wwww.tandfonline.com/10.1080/01425692.2014.897217Copyright © 2014 Taylor & FrancisConsidering data from a research project with two Gypsy communities (2010–2012) in South West England, this article explores issues of education and identity. The two communities have contrasting experiences within the education system. Informed by inter-disciplinary perspectives on identity and assimilation theories, the article explores these experiences within the wider context of the researcher’s work with Romani communities over the past two decades, exploring the impact of schooling on cultural identity and group membership. Questions are raised about theories concerning hybrid and multiple identities. Finally, the author emphasizes the need to acknowledge the heterogeneity of minority groups in formulating policy