2,555 research outputs found

    Definition of Throw-Away Detectors (TADs) and VLF antenna for the AMPS laboratory

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    A Throw Away Detector (TAD)/subsatellite to be used as an experiment platform for the test flights to map the EMI from the shuttle and during the AMPS science flights is defined. A range of instrument platforms of varying capabilities is examined with emphasis on the EMI test vehicle. The operational support requirements of TAD/subsatellites are determined. The throw away detector is envisioned as a simple instrument package for supporting specific experiments

    African-American Parents’ Cultural Understandings of the Concept of Autism and Implications for Parental Communication and Health Management

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    In 2023 the Centers of Disease Control reported that around 1 in 36 children are diagnosed with Autism in America and that the prevalence has increased by 178% since 2000 (CDC, 2023). Despite increases in awareness and diagnosis past research finds that the discussions of ASD in African American communities is minimal (Fombonne, 2003; Yeargin Allsopp et al., 2003). This disparity is important considering that African American children receive an ASD diagnosis years later than their white counterparts and are much more likely to be misdiagnosed (Mandell et al., 2009, 2002). Given the history of a lack of representation of African Americans in the ASD literature and disparities in its diagnosis, treatment, and management, this thesis reports an exploratory, qualitative communication study of African American parents’ understandings of ASD and their associated experiences. A purposive sample of 10 African American parents of ASD children were interviewed and analyzed using analytical induction and NVivo-12. Overall, the primary findings this thesis discovered is that many African American parents of children with ASD reported meanings associated with ASD as being neurologically “different,” but not neurologically “disordered” (as understood in the medical community). Also similar to other parents ASD is seen as something that is a “danger” to their child requiring parental protections. However, to the extent institutionalized racist patterns are perceived to exist in a given context, unique among African American parents is the perception that ASD also means a heightened need to protect the child from “yet one more way to experience discrimination” by exercising heighted caution when interacting with white medical providers. African American parents shared their difficult experiences communicating with white service providers that led to the development of a “fighting” spirit within them to advocate for their children and protect them even more. Finally, the parents expressed their difficulties of raising a child with ASD highlighting family members reactions, lack of support, cultural conflicts, and the need for more education about ASD in the African American community

    Science Mission Definition Studies for TROPIX

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    This document summarizes the results of mission definition studies for solar electric propulsion missions that have been carried out over the last approximately three years. The major output from the studies has been two proposals which were submitted to NASA in response to Announcements of Opportunity for missions and an ongoing Global Magnetospheric Dynamics mission study. The bulk of this report consists of copies of the proposals and preliminary materials from the GMD study that will be completed in the coming months

    Interplay of local hydrogen-bonding and long-ranged dipolar forces in simulations of confined water

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    Spherical truncations of Coulomb interactions in standard models for water permit efficient molecular simulations and can give remarkably accurate results for the structure of the uniform liquid. However truncations are known to produce significant errors in nonuniform systems, particularly for electrostatic properties. Local molecular field (LMF) theory corrects such truncations by use of an effective or restructured electrostatic potential that accounts for effects of the remaining long-ranged interactions through a density-weighted mean field average and satisfies a modified Poisson's equation defined with a Gaussian-smoothed charge density. We apply LMF theory to three simple molecular systems that exhibit different aspects of the failure of a naive application of spherical truncations -- water confined between hydrophobic walls, water confined between atomically-corrugated hydrophilic walls, and water confined between hydrophobic walls with an applied electric field. Spherical truncations of 1/r fail spectacularly for the final system in particular, and LMF theory corrects the failings for all three. Further, LMF theory provides a more intuitive way to understand the balance between local hydrogen bonding and longer-ranged electrostatics in molecular simulations involving water.Comment: Submitted to PNA

    A shrinking core model for steam hydration of CaO-based sorbents cycled for CO2 capture

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    Calcium looping is a developing CO2 capture technology. It is based on the reversible carbonation of CaO sorbent, which becomes less reactive upon cycling. One method of increasing the reactivity of unreactive sorbent is by hydration in the calcined (CaO) form. Here, sorbent has been subjected to repeated cycles of carbonation and calcination within a small fluidised bed reactor. Cycle numbers of 0 (i.e., one calcination), 2, 6 and 13 have been studied to generate sorbents that have been deactivated to different extents. Subsequently, the sorbent generated was subjected to steam hydration tests within a thermogravimetric analyser, using hydration temperatures of 473, 573 and 673 K. Sorbents that had been cycled less prior to hydration hydrated rapidly. However, the more cycled sorbents exhibited behaviour where the hydration conversion tended towards an asymptotic value, which is likely to be associated with pore blockage. This asymptotic value tended to be lower at higher hydration temperatures; however, the maximum rate of hydration was found to increase with increasing hydration temperature. A shrinking core model has been developed and applied to the data. It fits data from experiments that did not exhibit extensive pore blockage well, but fits data from experiments that exhibited pore blockage less well

    Representations of people in Urban Building Energy Models

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    Occupant behaviour is commonly acknowledged as a key driver for variation in building energy performance (Gaetani et al., 2016). ASHRAE (2009) notes it as an important factor in the significant discrepancy between proposed building performance and actual energy consumption. A large body of literature exists dedicated to exploring energy behaviours and the need for more holistic considerations of energy behaviours, but this has not been connected to occupant modelling in Urban Building Energy Models (UBEMs). This paper develops a framework to identify and classify representations of people in UBEMs by reviewing and connecting the behaviour change and UBEM literatures. Combined with the classification of the approaches of people’s representation, we show that schedule-based models perform better although it cannot provide a full explanation of energy practices. While agent-based approaches offer the potential to incorporate the more holistic approaches called for by Kierstead (2006) the computational burdens which result may be excessive at the urban scale. The main framework developed can provide simulation practitioners with insights into energy behaviours

    Grounding urban energy tools in the lived experiences of the urban poor - a case for incorporating participatory methods in urban building energy models

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