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Understanding and predicting climate changes at the urban scale have been an important yet challenging problem in environmental engineering. The lack of reliable long-term observations at the urban scale makes it difficult to even assess past climate changes. Numerical modeling plays an important role in filling the gap of observation

Understanding and predicting climate changes at the urban scale have been an important yet challenging problem in environmental engineering. The lack of reliable long-term observations at the urban scale makes it difficult to even assess past climate changes. Numerical modeling plays an important role in filling the gap of observation and predicting future changes. Numerical studies on the climatic effect of desert urbanization have focused on basic meteorological fields such as temperature and wind. For desert cities, urban expansion can lead to substantial changes in the local production of wind-blown dust, which have implications for air quality and public health. This study expands the existing framework of numerical simulation for desert urbanization to include the computation of dust generation related to urban land-use changes. This is accomplished by connecting a suite of numerical models, including a meso-scale meteorological model, a land-surface model, an urban canopy model, and a turbulence model, to produce the key parameters that control the surface fluxes of wind-blown dust. Those models generate the near-surface turbulence intensity, soil moisture, and land-surface properties, which are used to determine the dust fluxes from a set of laboratory-based empirical formulas. This framework is applied to a series of simulations for the desert city of Erbil across a period of rapid urbanization. The changes in surface dust fluxes associated with urbanization are quantified. An analysis of the model output further reveals the dependence of surface dust fluxes on local meteorological conditions. Future applications of the models to environmental prediction are discussed.
ContributorsTahir, Sherzad Tahseen (Author) / Huang, Huei-Ping (Thesis advisor) / Phelan, Patrick (Committee member) / Herrmann, Marcus (Committee member) / Chen, Kangping (Committee member) / Clarke, Amanda (Committee member) / Arizona State University (Publisher)
Created2019
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To investigate the impacts of an energy efficiency retrofit, indoor air quality and resident health were evaluated at a low‐income senior housing apartment complex in Phoenix, Arizona, before and after a green energy building renovation. Indoor and outdoor air quality sampling was carried out simultaneously with a questionnaire to characterize

To investigate the impacts of an energy efficiency retrofit, indoor air quality and resident health were evaluated at a low‐income senior housing apartment complex in Phoenix, Arizona, before and after a green energy building renovation. Indoor and outdoor air quality sampling was carried out simultaneously with a questionnaire to characterize personal habits and general health of residents. Measured indoor formaldehyde levels before the building retrofit routinely exceeded reference exposure limits, but in the long‐term follow‐up sampling, indoor formaldehyde decreased for the entire study population by a statistically significant margin. Indoor PM levels were dominated by fine particles and showed a statistically significant decrease in the long‐term follow‐up sampling within certain resident subpopulations (i.e. residents who report smoking and residents who had lived longer at the apartment complex).

ContributorsFrey, S.E. (Author) / Destaillats, H. (Author) / Cohn, S. (Author) / Ahrentzen, S. (Author) / Fraser, M.P. (Author)
Created2015
Description
Particulate matter (PM) air pollution is a known factor to exacerbate cardiopulmonary diseases. We previously demonstrated that PM mediated endothelial injury and barrier disruption via modulation of the endothelial cytoskeleton and cell-cell junctions, while the effects of PM exposure on cell-cell communication and gap junction activity are still unknown. This

Particulate matter (PM) air pollution is a known factor to exacerbate cardiopulmonary diseases. We previously demonstrated that PM mediated endothelial injury and barrier disruption via modulation of the endothelial cytoskeleton and cell-cell junctions, while the effects of PM exposure on cell-cell communication and gap junction activity are still unknown. This study is focused on the characterization of PM-mediated endothelial dysfunction via Connexin 43 (Cx43), the most abundant Gap junction protein expressed in lung endothelial cells (ECs). PM exposure induces a time-dependent elevation of Cx43 in human lung ECs, at both mRNA and protein levels. N-acetyl-cysteine (NAC), an ROS scavenger, significantly suppresses PM-induced Cx43 expression. Membrane-associated and ER/ Golgi apparatus Cx43 protein are elevated upon PM challenge. In addition, PM also activates the gap junction activity, indicated by the transportation of green fluorescence dye between two adjacent ECs. Moreover, GAP27, a selective Cx43 channel inhibitor, attenuates PM-reduced human lung EC barrier disruption, measured by trans-endothelial electrical resistance (TER) with an electric cell-substrate impedance sensing system. Moreover, knock-down the expression of Cx43 by its selective siRNA alleviates PM-induced MLC phosphorylation. These results highly suggest that Cx43 plays a key role in PM-mediated endothelial barrier disruption and signal transduction. Cx43 may deputy as a therapeutic target in PM-mediated cardiopulmonary disorders.
ContributorsKheshtchin-Kamel, Nabia (Author) / Welcome, Natalie (Thesis director) / Wang, Ting (Committee member) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12