Mathematical modeling of organic liquid dissolution in heterogeneous source zones.

A simple one-dimensional heterogeneous-source model was used to simulate dissolution of organic liquid that was non-uniformly distributed in physically heterogeneous porous media. The permeability field was depicted as a pseudo-homogeneous medium. The source zone was discretized into multiple domains representing different organic-liquid configurations and hydraulic accessibilities, each with a different representative upscaled mass transfer rate coefficient that is temporally variable. This simplified approach represents a system where minimal information is available regarding system heterogeneities. All factors that influence dissolution were incorporated into the calibrated mass transfer terms. The mass transfer terms were calibrated for each zone separately. The one-dimensional, heterogeneous-source model adequately simulated the multi-stage dissolution behavior observed for column-scale systems that were packed with different natural soils, as well as for flow-cell systems wherein the source zone consisted of both a residual zone and pool. The results indicate that the model adequately simulated the presence of multiple organic-liquid zones in porous media with different configurations and hydraulic accessibilities, which accounts for the non-ideal dissolution behavior observed. The calibrated mass transfer terms for each source type were consistent with those obtained for systems that contained only one of either source type.

Brokenheartedness and accountability.

In this article, I reflect on relationship and movement building across power lines that I have experienced or witnessed in and outside of academia. I argue that the "anesthetic aesthetic" of whiteness, as illuminated by Mab Segrest, compels those like myself who are trained to be white to distance ourselves from the pain and suffering of others (as well as our own) in order to accept and assimilate into the hegemonic normative systems of power. I offer stories from my experience of feminist and queer organizing that demonstrate how this distancing looks and feels, and places of where it might be transformed. Then, I turn to healing justice as a praxis that creates communal spaces for naming, recognizing, and healing from violence, spaces to share our brokenheartedness, and to serve as a way of breaking up the gravitational pulls of white supremacist patriarchy.

The impact of transitions between two-fluid and three-fluidphases on fluid configuration and fluid-fluid interfacial areain porous media.

Multiphase-fluid distribution and flow is inherent in numerous areas of hydrology. Yet, pore-scale characterization of transitions between two and three immiscible-fluids is limited. The objective of this study was to examine the impact of such transitions on the pore-scale configuration of organic liquid in a multi-fluid system comprising natural porous media. Three-dimensional images of an organic liquid (trichloroethene) in two-phase (organic-liquid/water) and three-phase (air/organic-liquid/water) systems were obtained using X-ray microtomography before and after drainage and imbibition. Upon transition from a two-phase to a three-phase system, a significant portion of the organic liquid (intermediate wetting fluid) was observed to exist as lenses and films in contact with air (nonwetting fluid). In these cases, the air was either encased by or contiguous to the organic liquid. The presence of air resulted in an increase in the surface-area-to-volume ratios for the organic-liquid blobs. Upon imbibition, the air was displaced downgradient, and concomitantly, the morphology of the organic-liquid blobs no longer in contact with air reverted to that characteristic of a two-phase distribution (i.e., more spherical blobs and ganglia). This change in morphology resulted in a reduction in the surface-area-to-volume ratio. These results illustrate the impact of transitions between two-phase and three-phase conditions on fluid configuration, and they demonstrate the malleable nature of fluid configuration under dynamic, multiphase-flow conditions. The results have implications for characterizing and modeling pore-scale flow and mass-transfer processes.

Introducing disability studies to occupational therapy students.

This article is a work of collaborative ethnography about teaching and learning disability studies within the context of an occupational therapy graduate program. In spring 2004,14 occupational therapy students were introduced to disability studies by their cultural anthropologist (nonoccupational therapist) course instructor. During the one-credit course, they were expected to complete readings, watch films, attend guest lectures, and make a site visit. The occupational therapy students were required to write a journal to record personal reactions and new insights gained from these experiences. This article focuses on a thematic analysis of the students' journaled responses to the film "Dance Me to My Song," and a site visit to a local Independent Living Center. Students were expected to analyze these experiences from both disability studies and occupational therapy perspectives. The article addresses philosophical and practical differences between occupational therapy and disability studies and identifies opportunities for collaboration between occupational therapists and independent living specialists.