Slowed Relaxational Dynamics Beyond the Fluctuation-Dissipation Theorem

To describe the slow dynamics of a system out of equilibrium, but close to a dynamical arrest, we generalize the ideas of previous work to the case where time-translational invariance is broken. We introduce a model of the dynamics that is reasonably general, and show how all of the unknown parameters of this model may be related to the observables or to averages of the noise. One result is a generalisation of the Fluctuation Dissipation Theorem of type two (FDT2), and the method is thereby freed from this constraint. Significantly, a systematic means of implementing the theory to higher order is outlined. We propose the simplest possible closure of these generalized equations, following the same type of approximations that have been long known for the equilibrium case of Mode Coupling Theory (MCT). Naturally, equilibrium MCT equations are found as a limit of this generalized formalism. %We indicate that, within the same general %framework, it should be possible to make higher level approximations, %leading to more general applicability.Comment: 14 pages, Physica A (in press

Arrest of flow and emergence of activated processes at the glass transition of a suspension of particles with hard sphere-like interactions

By combining aspects of the coherent and self intermediate scattering functions, measured by dynamical light scattering on a suspension of hard sphere-like particles, we show that the arrest of particle number density fluctuations spreads from the position of the main structure factor peak. Taking the velocity auto-correlation function into account we propose that as density fluctuations are arrested the system's ability to respond to diffusing momentum currents is impaired and, accordingly, the viscosity increases. From the stretching of the coherent intermediate scattering function we read a quantitative manifestation of the undissipated thermal energy, the source of those, ergodicity restoring, processes that short-circuit the sharp transition to a perfect glass.Comment: 9 pages, 4 figure

Technology integration for educators : The why and the how

This project explores TPCK (Technological Pedagogical Content Knowledge) and its use in successful technology integration in the classroom. It also discusses the implications of technology integration if TPCK is not used. It consists of two main sections. The first section is a brief explanation of the importance of pre-service and in-service teachers to have a well-rounded knowledge including technological knowledge in order to accomplish technological integration. The second and larger section is a library of video tutorials and evaluations on technology tools for the classroom and examples of how they could be used using TPCK

Flow curves of colloidal dispersions close to the glass transition: Asymptotic scaling laws in a schematic model of mode coupling theory

The flow curves, viz. the curves of stationary stress under steady shearing, are obtained close to the glass transition in dense colloidal dispersions using asymptotic expansions in a schematic model of mode coupling theory. The shear thinning of the viscosity in fluid states and the yielding of glassy states is discussed. At the transition between fluid and shear-molten glass, simple and generalized Herschel-Bulkley laws are derived with power law exponents that can be computed for different particle interactions from the equilibrium structure factor.Comment: 14 pages, 14 figures, 4 tables, Eur. Phys. J. E (submitted

Asymptotic laws for tagged-particle motion in glassy systems

Within the mode-coupling theory for structural relaxation in simple systems the asymptotic laws and their leading-asymptotic correction formulas are derived for the motion of a tagged particle near a glass-transition singularity. These analytic results are compared with numerical ones of the equations of motion evaluated for a tagged hard sphere moving in a hard-sphere system. It is found that the long-time part of the two-step relaxation process for the mean-squared displacement can be characterized by the $\alpha$-relaxation-scaling law and von Schweidler's power-law decay while the critical-decay regime is dominated by the corrections to the leading power-law behavior. For parameters of interest for the interpretations of experimental data, the corrections to the leading asymptotic laws for the non-Gaussian parameter are found to be so large that the leading asymptotic results are altered qualitatively by the corrections. Results for the non-Gaussian parameter are shown to follow qualitatively the findings reported in the molecular-dynamics-simulations work by Kob and Andersen [Phys. Rev. E 51, 4626 (1995)]

What I\u27m Reading Blog Assignment

This assignment was designed for Megen Boyett\u27s English 102 course

Acting on what we hear: the impact of a listening methodology in a community literacy program.

Calls for better listening, especially to racially and linguistically marginalized populations, are popular and necessary in community literacy studies. However, while scholarship has clarified the need for attending to a range of voices across the life of a community program and demonstrated clear results of good listening, it has not sufficiently outlined a methodology for listening, especially as it applies to community-engaged action. Even less scholarship has focused on attending to current listening practices, so that scholars and community partners hoping to practice active listening interpret participants’ input through a soundtrack of other, unnoticed, “voices,” and have no way of working through misaligned goals and consequences. This dissertation begins by arguing that we cannot outline engaged listening practices until we understand how we currently listen, and what “voices” we attend to as we interpret participant input. I use a community program for refugee and immigrant mothers that I helped pilot as my central case study, tracing how organizers’ listening processes led to program implementation. Demonstrating a methodology I term “listening back,” I argue that the gap between our goals and consequences often stemmed from past programmatic practices and ever-circulating deficit discourses that “spoke into” planning meetings and program sessions. Using a community wealth model to interpret core participants’ literate histories, I outline a set of new narratives that organizers might use as they shift away from deficit discourse, highlighting the rich literate repetoires that women bring into community literacy contexts. Finally, because grassroots community literacy programs are often small and short-lived, but in relationship with sustainable funders and partners, I argue that organizers must look for ways to amplify our listening work. End of program documents, which are used in grant narratives and program proposals, are both a relationship-building tool and a place for gentle critique. In establishing the effectiveness of a program and detailing practices that attend to women’s cultural and literate wealth, rather than their lack, we can shift the narrative about immigrant and refugee families on a larger scale than merely in a single program

Space bitches, witches, and kick-ass princesses: Star Wars and popular feminism

In this article I illustrate some of the diverse “interpretations and aims” of feminist discourse that are created by the complex interplay between fans and the multi-authored, media-industrial franchise that is Star Wars. First I look at discourses of feminism and the representation of women in Star Wars, paying special attention to the stories outside of the films. Then I explore the way the storyworld’s non-narrative paratexts—toys, clothes, and merchandising—impact its engagement with feminist discourse. Finally, I look at some of the ways in which fans and storytellers have politicized Star Wars, and what this may tell us about the future of the franchise. These examples will also provide a brief but informative glimpse at the history of Star Wars’s engagement with feminist discourse, and the wealth of material still to be explored. One thing is certain: Star Wars is not just for boys, nor has it ever been. But the question of whether Star Wars is feminist has been controversial throughout its forty-year history