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2011

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Full-Text Articles in Engineering

Water Quality Models For Stormwater Runoff In Two Lincoln, Nebraska Urban Watersheds, Jake Fisher Dec 2011

Water Quality Models For Stormwater Runoff In Two Lincoln, Nebraska Urban Watersheds, Jake Fisher

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Water quality monitoring was conducted in two urban watersheds (Colonial Hills and Taylor Park) located in southeast Lincoln, NE over a three year period spanning from October 2008 through September 2011. In-line probes continuously measured for turbidity, conductivity, dissolved oxygen, and water temperature while other water quality constituents were analyzed for discrete water samples collected using grab and automatic sampling techniques. The water quality data was used to calculate event mean concentrations (EMCs) for sixteen storm events sampled over the duration of the project period. Three types of stormwater quality multiple linear regression models were developed for the estimation of …

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Combined Fluorescence And Reflectance Spectroscopy For In Vivo Quantification Of Cancer Biomarkers In Low- And High-Grade Glioma Surgery, Pablo A. ValdéS, Anthony Kim, Keith D. Paulsen, Frederic Leblond, Olga M. Conde, Brent T. Harris, David W. Roberts Nov 2011

Combined Fluorescence And Reflectance Spectroscopy For In Vivo Quantification Of Cancer Biomarkers In Low- And High-Grade Glioma Surgery, Pablo A. ValdéS, Anthony Kim, Keith D. Paulsen, Frederic Leblond, Olga M. Conde, Brent T. Harris, David W. Roberts

Dartmouth Scholarship

Biomarkers are indicators of biological processes and hold promise for the diagnosis and treatment of disease. Gliomas represent a heterogeneous group of brain tumors with marked intra- and inter-tumor variability. The extent of surgical resection is a significant factor influencing post-surgical recurrence and prognosis. Here, we used fluorescence and reflectance spectral signatures for in vivo quantification of multiple biomarkers during glioma surgery, with fluorescence contrast provided by exogenously-induced protoporphyrin IX (PpIX) following administration of 5-aminolevulinic acid. We performed light-transport modeling to quantify multiple biomarkers indicative of tumor biological processes, including the local concentration of PpIX and associated photoproducts, total hemoglobin …

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Attenuation In Extended Structures Coated With Thin Magneto-Dielectric Absorber Layer, Marina Koledintseva, Alexander G. Razmadze, Aleksandr Yakubovich Gafarov, Victor Khilkevich, James L. Drewniak, Takanori Tsutaoka Jul 2011

Attenuation In Extended Structures Coated With Thin Magneto-Dielectric Absorber Layer, Marina Koledintseva, Alexander G. Razmadze, Aleksandr Yakubovich Gafarov, Victor Khilkevich, James L. Drewniak, Takanori Tsutaoka

Electrical and Computer Engineering Faculty Research & Creative Works

Thin absorbing layers containing magnetic alloy or ferrite inclusions can be effectively used for attenuating common-mode currents on extended structures, such as power cords, cables, or edge-coupled microstrip lines. An analytical model to evaluate attenuation on the coaxial line with the central conductor coated with a magneto-dielectric layer is proposed and validated by the experiments and numerical modeling. The analytical model is validated using available magneto-dielectric samples of different thicknesses. This model can serve for comparing and predicting the absorptive properties of different samples of magneto-dielectric materials, whose compositions may be unknown, but dielectric and magnetic properties can be determined …

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Modeling Of Crossbred Cattle Growth, Comparison Between Cubic And Piecewise Random Regression Models, H R. Mirzaei, Wayne S. Pitchford, Arunas P. Verbyla Jan 2011

Modeling Of Crossbred Cattle Growth, Comparison Between Cubic And Piecewise Random Regression Models, H R. Mirzaei, Wayne S. Pitchford, Arunas P. Verbyla

Faculty of Engineering and Information Sciences - Papers: Part A

Two analyses, cubic and piecewise random regression, were conducted to model growth of crossbred cattle from birth to about two years of age, investigating the ability of a piecewise procedure to fit growth traits without the complications of the cubic model. During a four-year period (1994-1997) of the Australian "Southern Crossbreeding Project", mature Hereford cows (N = 581) were mated to 97 sires of Angus, Belgian Blue, Hereford, Jersey, Limousin, South Devon, and Wagyu breeds, resulting in 1141 steers and heifers born over four years. Data included 13 (for steers) and eight (for heifers) live body weight measurements, made approximately …

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Development Of Sediment-Infilled Rock Joint Models And Implications On Rockmass Stability, Buddhima Indraratna, Wuditha N. Premadasa, David Oliveira, H S. Welideniya Jan 2011

Development Of Sediment-Infilled Rock Joint Models And Implications On Rockmass Stability, Buddhima Indraratna, Wuditha N. Premadasa, David Oliveira, H S. Welideniya

Faculty of Engineering - Papers (Archive)

Soil-infi lled discontinuities adversely infl uence the stability of rockmass, because, the infi ll materials especially when saturated, drastically reduce the shear strength. The angle of shearing resistance of a discontinuity decreases signifi cantly for increasing infi ll thickness. Once it reaches a critical thickness, the shear strength of the discontinuity will be governed only by the infi ll material and the rock-walls effect becomes negligible. Owing to the lack of research on the shear behavior of infi lled rock joints, it has been common practice to assume that the shear strength of the joint is that of the infi …

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Selection Of Source And Use Of Traffic Information In Emergency Situations, R. Michael Robinson, Asad Khattak Jan 2011

Selection Of Source And Use Of Traffic Information In Emergency Situations, R. Michael Robinson, Asad Khattak

VMASC Publications

The access and the use of advanced traveler information systems (ATISs) by drivers during normal commuting have been extensively assessed and analyzed. Emergency managers and transportation officials have extended the results of studies of ATIS use under routine conditions to emergency scenarios under the assumption that drivers' responses to information under emergency conditions mimic those seen under normal driving conditions. A recent survey of potential hurricane evacuees suggests the need to revisit this assumption. Results indicate that although commercial radio reports and variable message signs continue to be the sources of traffic information cited the most frequently, other information sources …

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Analytic And Finite Element Solutions For Temperature Profiles In Welding Using Varied Heat Source Models, Djarot Darmadi, John Norrish, Anh Kiet Tieu Jan 2011

Analytic And Finite Element Solutions For Temperature Profiles In Welding Using Varied Heat Source Models, Djarot Darmadi, John Norrish, Anh Kiet Tieu

Faculty of Engineering - Papers (Archive)

Solutions for the temperature profile around a moving heat source are obtained using both analytic and finite element (FEM) methods. Analytic and FEM solutions are applied to study the temperature profile in welding. A moving heat source is represented using both point heat source and uniform distributed disc heat source models. Analytic solutions are obtained by solving the partial differential equation for energy conservation in a solid, and FEM results are provided by simulating welding using the ANSYS software. Comparison is made for quasi steady state conditions. The results provided by the analytic solutions are in good agreement with results …

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Analysis Of Bloated Droplet Theory Using Steelmaking Process Models, N Dogan, G A. Brooks, M A. Rhamdhani Jan 2011

Analysis Of Bloated Droplet Theory Using Steelmaking Process Models, N Dogan, G A. Brooks, M A. Rhamdhani

Faculty of Engineering - Papers (Archive)

There is significant evidence that droplets generated in steelmaking "bloat" due to the inability of gas generated from the decarburisation reaction to escape from the surface of liquid metal droplets. A model to describe this behavior was developed by Brooks, Subagyo, Coley and Pan based on their own experimental work and calculations and previous studies by Fruehan and co-workers. This approach has been successfully incorporated into an overall process model of oxygen steelmaking. A unique feature of this model is an evaluation of the decarburization kinetics of individual metal droplets in the emulsion and comparing this to the overall kinetics …

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Adjusting For Network Size And Composition Effects In Exponential Family Random Graph Models, Pavel N. Krivitsky, M Handcock, Martina Morris Jan 2011

Adjusting For Network Size And Composition Effects In Exponential Family Random Graph Models, Pavel N. Krivitsky, M Handcock, Martina Morris

Faculty of Engineering and Information Sciences - Papers: Part A

Exponential-family random graph models (ERGMs) provide a principled way to model and simulate features common in human social networks, such as propensities for homophily and friend-ofa- friend triad closure. We show that, without adjustment, ERGMs preserve density as network size increases. Density invariance is often not appropriate for social networks. We suggest a simple modification based on an offset which instead preserves the mean degree and accommodates changes in network composition asymptotically. We demonstrate that this approach allows ERGMs to be applied to the important situation of egocentrically sampled data. We analyze data from the National Health and Social Life …

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