5,455 research outputs found
Gamma-ray spectrometry in the field: Radioactive heat production in the Central Slovakian Volcanic Zone
We report 62 sets of measurements from central-southern Slovakia, obtained using a modern portable gamma-ray spectrometer, which reveal the radioactive heat production in intrusive and extrusive igneous rocks of the Late Cenozoic Central Slovakian Volcanic Zone. Sites in granodiorite of the Štiavnica pluton are thus shown to have heat production in the range ~ 2.2–4.9 μW m− 3, this variability being primarily a reflection of variations in content of the trace element uranium. Sites in dioritic parts of this pluton have a lower, but overlapping, range of values, ~ 2.1–4.4 μW m− 3. Sites that have been interpreted in adjoining minor dioritic intrusions of similar age have heat production in the range ~ 1.4–3.3 μW m− 3. The main Štiavnica pluton has zoned composition, with potassium and uranium content and radioactive heat production typically increasing inward from its margins, reflecting variations observed in other granodioritic plutons elsewhere. It is indeed possible that the adjoining dioritic rocks, hitherto assigned to other minor intrusions of similar age, located around the periphery of the Štiavnica pluton, in reality provide further evidence for zonation of the same pluton. The vicinity of this pluton is associated with surface heat flow ~ 40 mW m− 2 above the regional background. On the basis of our heat production measurements, we thus infer that the pluton has a substantial vertical extent, our preferred estimate for the scale depth for its downward decrease in radioactive heat production being ~ 8 km. Nonetheless, this pluton lacks any significant negative Bouguer gravity anomaly. We attribute this to the effect of the surrounding volcanic caldera, filled with relatively low-density lavas, ‘masking’ the pluton's own gravity anomaly. We envisage that emplacement occurred when the pluton was much hotter, and thus of lower density, than at present, its continued uplift, evident from the local geomorphology, being the isostatic consequence of localized erosion. The heat production in this intrusion evidently plays a significant role, hitherto unrecognized, in the regional geothermics
Stress, Anxiety, and Depression in Aerospace Students
This study investigates and compares the levels of stress, anxiety, and depression among a sample of 574 undergraduate students in the Aerospace Professional Pilot concentration, Aerospace majors in concentrations other than Professional Pilot, and Non-Aerospace students at Middle Tennessee State University. This study sought to determine if Aerospace students exhibited higher levels of depression, anxiety, and stress. The participants of this study completed the DASS-21, a survey instrument that measures three separate constructs: depression, anxiety, and stress. The scores from this survey were used to compare depression, anxiety, and stress levels between the three groups of students using ANOVA and a Tukey HSD post hoc. The results of this study found that Aerospace students did not exhibit higher levels of depression, anxiety, or stress and that non-Aerospace students scored higher in all three categories
Remote Quantification of Smokestack Total Effluent Mass Flow Rates Using Imaging Fourier-Transform Spectroscopy
A Telops Hyper-Cam midwave infrared (1.5 − 5.5μm) imaging Fourier-transform spectrometer (IFTS) was used to estimate industrial smokestack total effluent mass flow rates by combining spectrally-determined species concentrations with flow rates estimated via analysis of sequential images in the raw interferogram cube. Strong emissions from H2O, CO2, CO, SO2, and NO were observed in the spectrum. A previously established plume radiative transfer model was used to estimate gas concentrations, and a simple temporal cross-correlation analysis of sequential imagery enabled an estimation of the flow velocity. Final effluent mass flow rates for CO2 and SO2 of 13.5 ± 3.78 kg/s and 71.3 ± 19.3 g/s were in good agreement with in situ rates of 11.6 ± 0.07 kg/s and 67.8 ± 0.52 g/s. NO was estimated at 16.1 ± 4.19 g/s, which did not compare well to the total NOx (NO + NO2) reported value of 11.2 ± 0.16 g/s. Unmonitored H2O, HCl, and CO were also estimated at 7.76 ± 2.25 kg/s, 7.40 ± 2.00 g/s, and 15.0 ± 4.05 g/s respectively
The Electoral Success of Communist-Successor Parties in the Czech Republic and Romania
Communist-successor parties are impacted by six social and political factors: party reimaging, coalition building, corruption and scandal, party leadership, EU accession, and social indicators. This project explores how the descendants of the totalitarian communist parties in the Czech Republic and Romania are influenced by each factor by analyzing election result data against these indicators. Party reimaging and coalition building are the most influential in determining voter turnout, while the other four work in conjunction to influence election results. This project contributes to the literature on electoral volatility, post-communist countries, voter behavior, and seeks to offer a model that can predict party success under various conditions
Development of Imaging Fourier-Transform Spectroscopy for the Characterization of Turbulent Jet Flames
Recent advances in computational models to simulate turbulent, reactive flow fields have outpaced the ability to collect highly constraining data--throughout the entire flow field--for validating and improving such models. In particular, the ability to quantify in three dimensions both the mean scalar fields (i.e. temperature & species concentrations) and their respective fluctuation statistics via hyperspectral imaging would be a game-changing advancement in combustion diagnostics, with high impact in both validation and improvement efforts for computational combustion models. This research effort establishes imaging Fourier-transform spectrometry (IFTS) as a valuable tool (which complements laser diagnostics) for the study of turbulent combustion. Specifically, this effort (1) demonstrates that IFTS can be used to quantitatively measure spatially resolved spectra from a canonical turbulent flame; (2) establishes the utility of quantile spectra in first-ever quantitative comparisons between measured and modeled turbulent radiation interaction (TRI); (3) develops a simple onion-peeling-like spectral inversion methodology suitable for estimating radial scalar distributions in axisymmetric, optically-thick flames; (4) builds understanding of quantile spectra and demonstrates proof of concept for their use in estimating scalar fluctuation statistics
Alien Registration- Bennett, Harley L. (Paris, Oxford County)
https://digitalmaine.com/alien_docs/21168/thumbnail.jp
Historical Fire In Longleaf Pine (\u3ci\u3ePinus palustris\u3c/i\u3e) Forests of South Mississippi and Its Relation to Land Use and Climate
We characterized historical fire regimes in Pinus palustris (longleaf pine) forests of southern Mississippi with regard to global and regional coupled climate systems (e.g., El Niño–Southern Oscillation) and past human activity. The composite fire chronology spanned 1756–2013 with 132 individual scars representing 89 separate fire events. The mean fire interval was 2.9 yr, and mean intervals were significantly different between identified time periods (e.g., settlement period vs. management period). Evidence of biannual fire activity (up to three fires occurring within a 12‐ to 15‐month period) was found coeval with a peak in livestock grazing and logging from the 1850s through the 1880s. Connections were also found between historical fire and Pacific climate variability (e.g., El Niño–Southern Oscillation and Pacific Decadal Oscillation; P \u3c 0.05), yet the fire–climate linkage was likely at least partially masked by substantial human land use activities over the past several centuries. Coupled climate and human land use activity controlled the historical fire regime over the past ca. 240 yr. Although the many fire adaptions of P. palustris yield limitations in tree‐ring‐based fire history studies (e.g., thick bark), we highlight the efficacy of considering the height at which fire scars are analyzed along the bole as a way to glean a more accurate depiction of historical fire occurrence, especially in ecosystems characterized by a frequent, low‐severity fire regime. This study suggests growing‐season fire prescribed at a 2‐ to 3‐yr interval would be the first step toward simulating historical landscape conditions and fire activity, should that be the goal by land managers
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