3,314 research outputs found

    Evaluating the Variability of Urban Land Surface Temperatures Using Drone Observations

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    Urbanization and climate change are driving increases in urban land surface temperatures that pose a threat to human and environmental health. To address this challenge, we must be able to observe land surface temperatures within spatially complex urban environments. However, many existing remote sensing studies are based upon satellite or aerial imagery that capture temperature at coarse resolutions that fail to capture the spatial complexities of urban land surfaces that can change at a sub-meter resolution. This study seeks to fill this gap by evaluating the spatial variability of land surface temperatures through drone thermal imagery captured at high-resolutions (13 cm). In this study, flights were conducted using a quadcopter drone and thermal camera at two case study locations in Milwaukee, Wisconsin and El Paso, Texas. Results indicate that land use types exhibit significant variability in their surface temperatures (3.9–15.8 °C) and that this variability is influenced by surface material properties, traffic, weather and urban geometry. Air temperature and solar radiation were statistically significant predictors of land surface temperature (R2 0.37–0.84) but the predictive power of the models was lower for land use types that were heavily impacted by pedestrian or vehicular traffic. The findings from this study ultimately elucidate factors that contribute to land surface temperature variability in the urban environment, which can be applied to develop better temperature mitigation practices to protect human and environmental health

    Interference Effects Due to Commensurate Electron Trajectories and Topological Crossovers in (TMTSF)2ClO4

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    We report angle-dependent magnetoresistance measurements on (TMTSF)2ClO4 that provide strong support for a new macroscopic quantum phenomenon, the interference commensurate (IC) effect, in quasi-one dimensional metals. In addition to observing rich magnetoresistance oscillations, and fitting them with one-electron calculations, we observe a clear demarcation of field-dependent behavior at local resistance minima and maxima (versus field angle). Anticipated by a theoretical treatment of the IC effect in terms of Bragg reflections in the extended Brillouin zone, this behavior results from 1D-2D topological crossovers of electron wave functions as a function of field orientation.Comment: 14 page

    Darkness Visible: A Consideration of Alternative Directions and Outcomes of Transformative Learning Theory, Teaching and Practice

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    Transformative learning theory has enjoyed a thirty-plus year history as a dominant adult learning theory. It has been the subject of innumerable articles and books as well as meriting its own journal, conference and graduate degrees. Yet, the fertile nature of this theory to produce such a wide swath of scholarship is deceiving and, indeed, surprisingly limited in its reach. The major goal of this symposium is to challenge current discourse of transformative learning theory, teaching and practice which seems almost wholly tethered to scholarship on outcomes that result in individual healing or attainment of more enlightened states; or collective actions with goals firmly embedded in the promulgation of social justice

    Impact of hurricane Harvey on the results of regional flood frequency analysis

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    Hurricane Harvey was an unprecedented event that resulted in immense damage to life and property. As a result, it is important to determine how this event, as well as past and future events like it, will impact engineering design equations that are based upon historical data, such as flood frequency analysis equations. This study seeks to contribute to this discussion by evaluating the extent to which Harvey influenced estimations of instantaneous peak discharges in rural ungauged basins in southeast Texas. Results indicate that Harvey significantly increased the computations of design floods using Log‐Pearson Type III analysis (e.g., 3–55% for 2‐year flood and 3–80% for the 100‐year flood). This subsequently impacted the estimation of instantaneous peak discharges through regional flood frequency analysis by up to 28%. These results highlight the influence that recent and future hurricanes can have on engineering design equations that are used for managing floodplains, assessing flood risk, and designing infrastructure such as levees, bridges, and culverts

    Interference Commensurate Oscillations in Q1D Conductors

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    We suggest an analytical theory to describe angular magnetic oscillations recently discovered in quasi-one-dimensional conductor (TMTSF)2PF6 [see Phys. Rev. B, 57, 7423 (1998)] and define the positions of the oscillation minima. The origin of these oscillations is related to interference effects resulting from an interplay of quasi-periodic and periodic ("commensurate") electron trajectories in an inclined magnetic field. We reproduce via calculations existing experimental data and predict some novel effects.Comment: 10 pages, 2 figure
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