Digital Commons Network^™

Hydrodynamics Of Trickle Bed Reactors (Tbrs) Packed With Industrial Catalyst Using Advanced Measurement Techniques, Mohammed Jaber Al-Ani

Doctoral Dissertations

"The impacts of the packing characteristics on the hydrodynamics od a trickle bed reactor (TBR) have been investigated using advanced measurements techniques of Gamma-ray densitometry (GRD) and Optical fiber probe and conventional measurement techniques of high-frequency differential pressure transducer and load cell. Two different reactor sizes of bench and pilot plant scale were used. Bench-scale TBR carried out the experiments to assess phase distribution and catalyst utilization with 1.18 cm inside diameter and 72 cm length at ambient pressure and temperature. The mixture of catalyst and fine particles displayed considerable improvements in the phase distribution, liquid holdup profile, and catalyst …

Reactor Configurations To Support Advanced Material Research, Thaqal Mazyad Alhuzaymi

Doctoral Dissertations

"The research goal is to configure a research reactor with multi-spectral capability for advance material research. This required the consideration of high and low-power levels alongside advanced fuel with high physical density and low enriched ²³⁵U. Selected fuel was U-10Mo with 19.75% ²³⁵U enrichment. The fuel and control rods system geometries were adopted from Missouri S&T Reactor (MSTR).

A high-power configuration (HPC) at 2 megawatts and low-power configuration (LPC) at 200 kilowatts were considered. Neutronic performances of the configurations were modeled using Monte Carlo N-particle (MCNP) transport code, version 6. Thermal-hydraulic analysis was performed with ANSYS Fluent. The …

Novel Insights Into Low Salinity Water Flooding Enhanced Oil Recovery In Sandstone Reservoirs, Hasan N. Al-Saedi

Doctoral Dissertations

"Ever growing global energy demand and the natural decline in oil production from mature oil fields have been the main incentives to search for methods to increase recovery efficiency for several decades. Water flooding is extensively applied worldwide to improve oil recovery. The recent drop in oil prices has turned the oil industry to the cheapest improved oil recovery (IOR) techniques, such as low salinity (LS) waterflooding. Also, the reduction in reservoir energy and the friendly environmental aspects of low salinity water flooding (LSWF) provide additional incentives for its use. That LS water requires decreasing only the active divalent cations …

Development Of Stage-I Tempered High Strength Cast Steel For Ground Engaging Tools, Viraj Ashok Athavale

Doctoral Dissertations

"Ground Engaging Tools (GET) are the expendable replacement parts used in heavy machinery used with mining or construction equipment. GET’s protect the expensive machine components from the wear and tear found common in high-impact or high-abrasion environments. The goal of this project is to develop advanced next-generation alloy choices that outperforms the existing GET materials. A method of predicting tempered hardness of mixed microstructures was formulated. Using this model, two alloy series viz. Cr-Ni-Mo and Mn-Si-Mo-V were proposed and experimented with the goal of obtaining a high strength and impact resistant cast steel. Cast iterations of Cr-Ni-Mo alloy series were …

Investigating The Performance Of High Viscosity Friction Reducers Used For Proppant Transport During Hydraulic Fracturing, Mohammed Salem Ba Geri

Doctoral Dissertations

"Over the last few recent years, high viscosity friction reducers (HVFRs) have been successfully used in the oil and gas industry across all premier shale plays in North America including Permian, Bakken, and Eagle Ford. However, selecting the most suitable fracture fluid system plays an essential role in proppant transport and minimizing or eliminating formation damage.

This study investigates the influence of the use of produced water on the rheological behavior of HVFRs compared to a traditional linear guar gel. Experimental rheological characterization was studied to investigate the viscoelastic property of HVFRs on proppant transport. In addition, the successful implication …

Experimental Study On Enhanced Oil Recovery (Eor) Mechanisms Of Nanogel Combining With Low Salinity Water For Carbonate Reservoirs, Pu Han

Doctoral Dissertations

"Nanomaterials have been widely studied and applied in the oil and gas industry. Among the developed nanomaterials, nano-sized crosslinked polymeric gel particle (nanogel) has shown great potential in recovering residual oil and improving oil recovery. This dissertation carried out their potential EOR mechanisms and the synergetic effect between nanogel and low salinity water. Nanogel used in this study was synthesized through the suspension polymerization process in our lab. The morphology, size distribution, and zeta potential were studied for nanogel dispersed in brine with variable ionic strength. The injectivity of nanogel was elucidated at first to ensure their in-depth penetration ability. …

Neuroengineering Of Clustering Algorithms, Leonardo Enzo Brito Da Silva

Doctoral Dissertations

"Cluster analysis can be broadly divided into multivariate data visualization, clustering algorithms, and cluster validation. This dissertation contributes neural network-based techniques to perform all three unsupervised learning tasks. Particularly, the first paper provides a comprehensive review on adaptive resonance theory (ART) models for engineering applications and provides context for the four subsequent papers. These papers are devoted to enhancements of ART-based clustering algorithms from (a) a practical perspective by exploiting the visual assessment of cluster tendency (VAT) sorting algorithm as a preprocessor for ART offline training, thus mitigating ordering effects; and (b) an engineering perspective by designing a family of …

The Mechanics Of Precision Presplitting, Anthony Joseph Konya

Doctoral Dissertations

"Precision Presplitting is a widely used method of presplit blasting for the mining and construction industries. In recent years considerable effort has gone into the development of empirical equations based on field data to be able to better design the Precision Presplit for various rock types and structural environments. However, the most widely discussed theory about the mechanics of the presplit formation, that of shockwave collisions, does not appear to be applicable for this method of presplitting.

This research has disproven this theory based on insufficient magnitude of the shockwave from modeling with basic wave mechanics. Other authors have suggested …

Biofuel Supply Chain Restructuring -- An Economic Viability And Environmental Sustainability Investigation For Enhancing Second Generation Biofuel Adoption, Rajkamal Kesharwani

Doctoral Dissertations

"Biofuel is a promising clean alternative to fossil fuels. Currently, first generation biofuels are commercially produced by using corn grain as biomass feedstock. However, the use of edible matter of crops, may lead to a competition between food and fuel. Therefore, there is a significant push in both industry and academia to commercialize second generation biofuel manufacturing technology, which uses non-edible matter from crops. Most research focuses on individual manufacturing processes for producing second generation biofuel, but the economic and environmental impacts of a large-scale adoption of second generation biofuel manufacturing have been less widely reported.

This work investigates the …

Application Of Computational Intelligence To Explore And Analyze System Architecture And Design Alternatives, Gene Lesinski

Doctoral Dissertations

"Systems Engineering involves the development or improvement of a system or process from effective need to a final value-added solution. Rapid advances in technology have led to development of sophisticated and complex sensor-enabled, remote, and highly networked cyber-technical systems. These complex modern systems present several challenges for systems engineers including: increased complexity associated with integration and emergent behavior, multiple and competing design metrics, and an expansive design parameter solution space. This research extends the existing knowledge base on multi-objective system design through the creation of a framework to explore and analyze system design alternatives employing computational intelligence. The first research …

Multi-Body Dynamic And Finite Element Modeling Of Ultra-Large Dump Truck - Haul Road Interactions For Machine Health And Haul Road Structural Integrity, Bruno Ayaga Kansake

Doctoral Dissertations

"Haul truck capacities have increased due to their economies of scale in large-scale surface mine production systems. Ultra-large trucks impose high dynamic loads on haul roads. The dynamic loads are exacerbated by road surface roughness and truck over-loading. The dynamic forces also subject trucks to high torsional stresses, which affect truck health. Current haul road response models are 2D and use static truckloads for low capacity trucks. Existing 3D models consider the road as a two-layer system. No models capture the truck dynamic effects on haul roads and predict strut pressures during haulage.

Lagrangian mechanics was used to formulate the …

Characterization And Modeling Of Esd Events And Near-Field Scanning Calibration Structures, Shubhankar Kashinath Marathe

Doctoral Dissertations

"This research is divided into three papers that cover, two major topics. The first topic, system-level electrostatic discharge (ESD), is discussed over the course of two papers. The second topic, a calibration structure for near-field scanning probe calibration application, is discussed in the last paper. In the first paper, software-assisted detection methods are proposed for secondary ESD discharges. The measured waveforms are analyzed with respect to waveform parameters, such as the vertical threshold of the rising edge, the derivative of the current waveform, and total charge delivered. These parameters enable automatic detection of secondary ESD while monitoring the discharge waveform …

Decoupling Methods For The Time-Dependent Navier-Stokes-Darcy Interface Model, Changxin Qiu

Doctoral Dissertations

"In this research, several decoupling methods are developed and analyzed for approximating the solution of time-dependent Navier-Stokes-Darcy (NS-Darcy) interface problems. This research on decoupling methods is motivated to efficiently solve the complex Stokes-Darcy or NS-Darcy type models, which arise from many interesting real world problems involved with or even dominated by the coupled porous media flow and free flow. We first discuss a semi-implicit, multi-step non-iterative domain decomposition (NIDDM) to solve a coupled unsteady NS-Darcy system with Beavers-Joseph-Saffman-Jones (BJSJ) interface condition and obtain optimal error estimates. Second, a parallel NIDDM is developed to solve unsteady NS-Darcy model with Beavers-Joseph (BJ) …

The Effects Of Fatigue And Weathering On The Failure Behavior Of Commercial Soda-Lime-Silicate Glass, Erica Ann Ronchetto

Doctoral Dissertations

"The principle objective of this research is to advance our understanding of the effects of humid conditions on the strength and susceptibility to fatigue of soda-lime silicate (SLS) glass. The two-point bend method was used to evaluate the fatigue characteristics and the degradation of failure strain of fibers drawn from melts of commercial soda-lime silicate glass and exposed to various environmental conditions. Soda lime silicate glasses from two commercial products but with similar nominal compositions were examined. One glass had pristine failure strains about 10% greater than the other, but both had similar fatigue parameters. The fatigue parameter increased from …

Thermomechanical Analysis Of Rock Asperity In Fractures Of Enhanced Geothermal Systems, Chao Zeng

Doctoral Dissertations

"Enhanced Geothermal Systems (EGS) offer great potential for dramatically expanding the use of geothermal energy and become a promising supplement for fossil energy. The EGS is to extract heat by creating a subsurface system to which cold water can be added through injection wells. Injected water is heated by contact with rock and returns to the surface through production well. Fracture provides the primary conduit for fluid flow and heat transfer in natural rock. Fracture is propped by fracture roughness with varying heights which is called asperity. The stability of asperity determines fracture aperture and hence imposes substantial effect on …

The Behavior Of Suas Under Explosive Loading Conditions And Implications For Safe Operating Procedures, Ashok Em Sudhakar

Doctoral Dissertations

"Drones are increasingly being used for tasks previously unimagined and the beneficial uses are evolving. The United States Congress has envisioned the possible uses of drones for both combating and conveying explosive threats and other harmful and destructive activities. Congress' intent is reflected in new laws (2018) and policies (2019).

All civilian available Small Unmanned Aerial Systems sUASs (Drones), weighing less than 55 pounds, in the current market are not designed for operations in explosive environments. This first of a kind research focuses on further understanding of sUASs response to explosive loading and the public policy implications. This research measured …

Paleoenvironment And Paleoclimate Of Ne Pangea In Early Permian-Linking Chemo- And Cyclo-Stratigraphy, Bogda Mountains, Nw China, Xin Zhan

Doctoral Dissertations

"The overall objective of this study is to understand physical and chemical responses of Earth Systems to environmental and climatic perturbations of diverse magnitudes and time scales in Bogda Mountains, NE Pangea. Field investigations, petrographic observations, and geochemical analyses have been used to interpret paleoenvironment and paleoclimate in cm-m-scale high-order cycles (HCs: 0.1-100 kyrs), low-order cycles (LCs: 1-10 Myr), and critical events of late Paleozoic ice age (LPIA: 320-260 Myr ago). Four organo-facies are one-to-one correlated with the four lithofacies in the meter-scale HCs, suggesting litho- and organo-facies are genetically linked and fundamentally controlled by environmental changes associated with lake …

Effects Of Think-Aloud Protocol On The Mathematical Problem-Solving Skills Of Seventh- And Eighth- Grade Students With Learning Disabilities, Nasa Lesley Cole

Doctoral Dissertations

The purpose of this study was to examine the effect of a cognitive- and metacognitive-strategy instruction on the mathematical problem-solving performance and metacognitive experience of 22 seventh- and eighth-grade students with learning disabilities. When solving mathematical word problems, students with learning disabilities typically lack self-regulation processes (Larson & Gerber, 2002) tend to respond impulsively, to use trial and error, and fail to evaluate or verify their solutions (Bryant, Bryant, & Hammermill, 2000). This study used the Metacognitive Experience Survey (MES), two sets of three mathematical-word-problem probes of varying complexity levels, and think-aloud protocols to measure intervention effect. The first research …

Epitaxial Growth Of Semiconductors And Chiral Metal Surfaces Using Spin Coating And Electrodeposition, Meagan V. Kelso

Doctoral Dissertations

"The current primary methods for epitaxial growth are energy intensive, requiring high temperature or high vacuum to obtain quality thin films. This dissertation explores the solution process methods of electrodeposition and spin coating for growth of epitaxial thin films. First, a method is developed to directly electrodeposit epitaxial CH₃NH₃PbI₃ perovskite for solar cells on single crystal Au by electrochemically reducing I₂ in organic solution. Perovskite is a newly explored material for solar cells, and its efficiency may be further improved by increasing the crystalline order. Second, a study on epitaxially electrodeposited chiral metal surfaces …

Oxide Inclusion Evolution And Factors That Influence Their Size And Morphology, Obinna M. Adaba

Doctoral Dissertations

"The evolution of oxide inclusion size distribution and the shape of the distribution during steelmaking and casting and the process variables that influence the inclusion characteristics at different stages were investigated and documented. A statistical method for transforming the 2D size distribution to their actual 3D distributions and the application of a kinetic model to determine nucleation and growth mechanisms were tested. Finally, laboratory experiments were performed to study the effects of preexisting inclusions, steel active oxygen content, and supersaturation on the size and morphology of Al₂O₃ inclusions.

The inclusion size, composition, and morphology following steel deoxidation …

Remanufacturing Of Precision Metal Components Using Additive Manufacturing Technology, Xinchang Zhang

Doctoral Dissertations

"Critical metallic components such as jet engine turbine blades and casting die/mold may be damaged after servicing for a period at harsh working environments such as elevated temperature and pressure, impact with foreign objects, wear, corrosion, and fatigue. Additive manufacturing has a promising application for the refurbishment of such high-costly parts by depositing materials at the damaged zone to restore the nominal geometry. However, several issues such as pre-processing of worn parts to assure the repairability, reconstructing the repair volume to generate a repair tool path for material deposition, and inspection of repaired parts are challenging. The current research aims …

Deep Neural Network Learning-Based Classifier Design For Big-Data Analytics, Krishnan Raghavan

Doctoral Dissertations

"In this digital age, big-data sets are commonly found in the field of healthcare, manufacturing and others where sustainable analysis is necessary to create useful information. Big-data sets are often characterized by high-dimensionality and massive sample size. High dimensionality refers to the presence of unwanted dimensions in the data where challenges such as noise, spurious correlation and incidental endogeneity are observed. Massive sample size, on the other hand, introduces the problem of heterogeneity because complex and unstructured data types must analyzed. To mitigate the impact of these challenges while considering the application of classification, a two step analysis approach is …

A Fully Userspace Remote Storage Access Stack, Patrick Ian Macarthur

Doctoral Dissertations

As computer networking has evolved and the available throughput has increased, the efficiency of the network software stack has become increasingly important. This is because the latency introduced by software has gone from insignificant, compared to historically poor network performance, to the largest component of latency for a modern local-area network. Currently, the vast majority of code that accesses the hardware is part of the kernel, because the kernel is responsible for ensuring that user applications do not interfere with each other when accessing the hardware. Remote Direct Memory Access~(RDMA) provides a solution for applications to perform direct data transfers …

Generalized Quasilinear Simulation Of Turbulent Channel Flow, Colleen B. Kellam

Doctoral Dissertations

Direct numerical simulation (DNS) of wall-bounded turbulent flows in physically relevant parameter regimes remains infeasible in many cases of practical interest. Accordingly, this work further establishes the generalized quasilinear (GQL) approximation, introduced by Marston et al. (Phys. Rev. Lett., 116, 2016), as a robust, accurate, and efficient alternative to existing simulation and modeling schemes by investigating its effectiveness as a tool for simulating turbulent channel flow. The GQL reduction is achieved by separating the flow variables into low and high modes via a spectral filter rather than by decomposition into a strict mean and fluctuations, as for the quasilinear (QL) …

No Lack Of Beds: Sanitationism, Gender, And Hospital Spaces In The Victorian Novel, Elizabeth Sheckler

Doctoral Dissertations

ABSTRACT

NO LACK OF BEDS:

SANITATIONISM, GENDER, AND HOSPITAL SPACES IN THE VICTORIAN NOVEL

by Elizabeth Sheckler

University of New Hampshire

May 2019

The Victorians wrote extensively about the changes in medical practice between 1800

and 1910, both in public discourse and through their fiction. As a result, Victorian scholarship

often includes medicine. While approaches are varied, they are typically either concerned with

diseases, character models (like doctors), or medical interventions alongside other public

institutions (public health).

Scholars in interdisciplinary fields as well as in Victorian literature have written on medicine in the nineteenth century, including both historiographies on topics …

I. The Binding Of Cu(Ii) And Zn(Ii) To Poly-N-Isopropylacrylamide And Its Effects On The Phase Transition And Ii. The Synthesis And Characterization Of Nickelalactones Chelated By P-N-P Pincer Ligands, Luke Aaron Fulton

Doctoral Dissertations

The responsive material poly-N-isopropylacrylamide phase-transitions from hydrophilic to hydrophobic conformations above 32 °C in aqueous media. Researchers have successfully tied that responsive behavior to other dissolved species such as pH, metal concentrations, and even glucose concentration. From our interests in developing sensor technologies we ascertained that direct interactions between metal ion and polymer had received little to no attention. Our investigations into this literature gap discovered that dissolved metal ion only slightly shifts the lower critical solution temperature. However, metal ion greatly increases the size of polymer aggregates, and is found to bind directly to the polymer. We present a …

Microchannel Plates In Mass Spectrometer Instruments For Spacecraft, Nicholas Kenneth Lubinsky

Doctoral Dissertations

Earth's magnetosphere contains plasma originating both from the solar wind and from

the ionosphere. While H+ is the dominant ion from both sources, the solar wind contains

high charge state ions such as He++, and O6+, while the ionosphere contributes singly ionized

heavy ions including He+, N+ and O+. Measuring the composition gives information on

the source and mass dependent entry, heating and acceleration mechanisms. However, most

ion composition instruments are not able to clearly distinguish between some of the heavy

ions involved in these processes, particularly N+ and O+. This thesis aims to test a new

design of a …

Evaluation Of New England Salt Marsh Support Of The American Eel, Anguilla Rostrata, And The Impacts Of Hydrologic Restriction, Alyson L. Eberhardt

Doctoral Dissertations

American eels are frequently captured in saltmarsh habitats yet little is known about eel use of these systems. Coastal systems such as salt marshes are vulnerable to habitat impacts due to high rates of coastal development, including impacts from undersized culverts that result in tidally restricted systems upstream. Given the decline in the American eel population, a need exists for a clearer understanding of the functional difference of hydrologically restricted and unrestricted salt marshes in the support of eels. To address data gaps and inform saltmarsh management to support eels, laboratory and field experiments were employed that assessed the value …

Coastal Conflicts And Cross-Sectoral Engagement: Learning From Disputes Over Science In Coastal And Ocean Systems, Lindsey C. Williams

Doctoral Dissertations

It is widely accepted that public policy decisions that account for scientific and technical advice are likely to improve outcomes for all. With more data and information available though, it is becoming increasingly difficult to even agree on the baseline facts. This research explores the question: How do cross-sectoral engagement opportunities influence science intensive disputes over the management of coastal and ocean resources? To address this question, I studied two cases in New England: 1) marine fisheries management (Northeast Multispecies Complex aka groundfish) and 2) estuarine water quality management (Great Bay, New Hampshire). Informed by participant observation and semi-structured interviews …

The Purpose And Value Of Agricultural Experiment Stations Today: A Perception Study Of The Directors Of State Agricultural Experiment Stations, Lori Wright

Doctoral Dissertations

This study investigates the dynamic relationship of the purpose and value of state agricultural experiment stations today as perceived by a sample of the directors of state agricultural experiment station in the United States funded by the Hatch Act of 1887. State agricultural experiment stations are a fundamental component of the land-grant university system; they are the original model and the first centers for applied research at most flagship state land-grant research universities in the United States (Kerr, 1987; Knoblauch, 1962). The purpose of state agricultural experiment stations has evolved since their inception as new agricultural issues have arisen, new …