The purpose of this research was to characterize the residual solids produced from hydraulic fracturing operations in the Marcellus Shale region. Four field samples were evaluated: drilling mud, treated sludge from the chemical treatment of process water, solids from the gravity settling of produced water, and sludge solidified prior to disposal in a municipal landfill. Cement kiln dust (CKD), used for solidification, was also considered in this study. All samples were subjected to a variety of laboratory techniques to determine their elemental composition and the potential for the elements to leach from the landfill. Strong acid digestion using a 3:1 combination of nitric acid to hydrochloric acid in a microwave with closed vessels was used to determine overall elemental composition. Leaching experiments were performed with de-ionized water and acetic acid (0.57%, pH 2.88) in an attempt to respectively evaluate the effects of weak and strong fluids that might be encountered by the residuals in landfill environments. Elements were analyzed by means of ICP-MS revealing the increased tendency for alkali metals, alkaline earth metals and halogens to leach. Leachablility was further increased for metals when exposed to acidic conditions. / Master of Science

This thesis provides a report on the numerical analysis of stress distributions within granular materials held in silos and hoppers. Stress distributions within granular materials stored in silos and hoppers have been the subject of research for over 100 years, work starting in this field in 1895 (Janssen). Knowledge of stress distributions within the granular materials contained is essential to allow structural design of the silo and hopper shell and attachments, and to allow estimation of likelihood and location of cohesive arch formation. National design codes for silos and hoppers (including BS EN 1993-4-1:2007 Eurocode 3 and DIN 1055-6:2005-03) are based on approximate techniques that assume vertical and horizontal directions of principal stresses, with constant horizontal stress across the silos. According to the knowledge of the author there are no industrial standards that allow calculation of loading on inserts within hoppers. The objective of the research project is to develop algorithms to predict stresses in hoppers and silos using principal stress arc geometry methods, and implementation of these methods in various silo and hopper configurations including those with inserts for the purposes of aiding flow. The research project algorithms are spreadsheet- and QB64 platform-based, and are able to produce stress distributions within silos and hoppers. This is achieved by extension of the principal stress arc method of analysis. The new algorithms allow prediction of common flow problems and provide new information on structural loading of silos and hoppers, including inserts used to promote flow. The research project models allow estimation of azimuthal stresses within three-dimensional case studies.

Master of Science / Department of Biology / Walter K. Dodds / North America has lost more than 95% of the original tallgrass prairie because of heavy land conversion, making prairie streams some of the most endangered habitats in North America. In order to effectively manage aquatic systems and improve biotic integrity of prairie streams research is needed that assesses the ecosystem characteristics of natural systems and evaluates the influence of anthropogenic alteration. We described the ecosystem characteristics of six ephemeral headwater streams draining tallgrass prairie within the Osage Plains of southwest Missouri. NO-3-N among all sites ranged from 1.56-91.36 μg L-1, NH+4-N ranged from 5.27-228.23 μg L-1, soluble reactive phosphorus ranged from below detection (1.0 μg L-1) to 41.22 μg L-1, TN ranged from 113.82-882.89 μg L-1, and TP ranged from 8.18-158.5 μg L-1during baseflow conditions. TN:TP molar ratios ranged from 22:1 to 53:1 indicating possible P was limiting relative to N in some streams. TSS during baseflow conditions ranged from 0.27-31.80 mg L-1. Autotrophic and heterotrophic comparisons of our study sites and reference sites classified our study streams as oligo-, meso-, and eu-autotrophic (N= 1, 4, and 1, respectively) and oligo-, meso-, and eu-heterotrophic (N= 4, 1, and 1, respectively). This study suggests that good water quality and moderate heterotrophic condition, with greater GPP resulting from an open canopy, are common conditions of tallgrass prairie streams. We also investigated interactions between land use/land cover, discharge rate, hydrologic alteration, and in-stream total suspended solids concentration in 23 Kansas- Missouri streams. Most streams had break points in the TSS loading rates at discharge rates exceeded <25% of days. Our estimates showed that 88% of the total annual TSS load occurred during the 11% of days with the greatest discharge rates. Buffered streams with greater percentages of grass and/or forest riparian areas had lower breakpoint values (indicating greater discharge rates were required to transport solid particles) and lower regression intercepts, which correlated to lesser TSS concentrations relative to unbuffered streams during high discharge days. In addition, grass buffered streams had smaller flood peaks and slower rise rates and forest buffered streams had less frequent floods, which lead to less total TSS transport.

Call number: LD2668 .T4 1978 T66 / Master of Science

The electronic bandstructure of solids near room temperature has been successfully explored with previous versions of modulation spectroscopy. Modulation of parameters which enter into the bandstructure produce a dielectric function variation. This changes the optical observables, such as reflectance or absorptance. Modulation resonances are observed near singularities in the joint density-of-states function. These resonances must also be detectable in the emittance, an observable which also depends on the dielectric function. Thus, this work investigates the possibility of detection of optical resonances riding on the temperature derivative of the blackbody emission from a solid at high temperature. The modulated emittance was separated from the thermal background by a detection scheme utilizing a CCD and computer. The resonances were not observed because of excessive CCD noise. The existance and magnitude of the resonances was based upon results from other modulation spectroscopies.

Finite Element Method (FEM) is a powerful numerical tool which, combined with the fast development of Computer Science in the lastdecades, had made possible to perform mechanical analysis of a widerange of bodies and boundary conditions. However, the complexity of some cases may turn the calculationprocess too slow and sometimes even unaffordable for most computers. This work aims to simplify an intricate system of layers withdifferent geometries and material properties by approximating itthrough a homogeneous material, with unique mechanical parameters.Besides the Finite Element analysis, a theoretical model is created, in order to understand the basis of the problem, and, as a firstapproach, check whether the assumptions made in the FEM model areacceptable or not. This work intends to make a small contribution to the understandingof the mechanical behaviour of the Vasa vessel, which will eventuallylead to the design of a new support structure for the ship. The preservation of the Vasa is a priority for the Swedish Property Board, as it is one of the main monuments of Sweden.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

In this thesis, we have investigated some interesting dynamical problems in microstructural continuum using Eringen's polar theory. These problems are pertaining to surface waves in a microstretch plate, Stoneley waves at an interface between two different microstretch half-spaces, surface waves in a micropolar cylindrical borehole filled with micropolar fluid, reflection and transmission of elastic waves at a liquid/solid half-space and reflection of elastic waves from a micropolar mixture porous half-space.

No description available.

This thesis focused on the mechanisms involved in negative thermal expansion of 2D/3D lattice structures. The effects of varying the constituent materials and geometry were explored. The lattices had geometries similar to those found in light-weight structures in many transport applications, including aerospace and spacecraft. One specific case was to determine how to reduce the coefficient of thermal expansivity (CTE) of such structures to near zero, by using two constituent materials with contrasting CTEs, without incurring penalties in terms of other elastic and failure properties, mass and manufacturability. The lattice geometries able to exhibit altered CTE were explored, and penalties in terms of other elastic properties were quantified. The results were scale-independent and so were generic to all such lattices. Analytical prediction and generic relationships between the geometries of the lattices and their performance were proposed. Experimental validation of the model predictions was undertaken using physical samples. The thermomechanical properties were simulated by commercial finite element method (FEM) codes (Ansys 11, Ansys, Inc.). Ansys parametric design language was adopted to generate large sets of solutions to be evaluated against chosen criteria. Results show small or, in some cases, no penalties to be paid in terms of stiffness and mass for implementing dual-material lattices with near-zero CTE. Such lattices may compete favourably with high-cost and high-density materials (e.g. Invar) and the manufacture of dual-material lattices can be by standard processes or alternative new process such as Additive Layer Manufacturing (ALM). An example of truss core sandwich application for aerospace application was modelled by FEM. Applications as cores in sandwich panels might be the first route by which the ALM manufacturing process is required to develop dual-material capability.