Digital Commons Network^™

Effect And Interactions Of Commercial Additives And Chloride Ion In Copper Electrowinning, Wenyuan Cui

Masters Theses

"This thesis is to understand and compare the effects and interactions of modified polysaccharide (HydroStar), polyacrylamide (Cyquest N-900) and chloride ion on copper electrowinning. A study of the nucleation and growth was conducted in a synthetic electrolyte (40 g/L Cu, 160 g/L H₂SO₄, 20 mg/L Cl-) with the addition of HydroStar or Cyquest N-900 using potential step measurements. The current responses generated were compared to theoretical models of nucleation and growth mechanisms. The nucleation and growth mechanism changed as function of potential and the presence of organic additives. The nucleation and growth mechanisms were confirmed using scanning electron microscopy (SEM). …

Methamphetamine Absorption By Skin Oils: Accumulated Mass, Partition Coefficients And The Influence Of Fatty Acids, Kristia Parker

Masters Theses

"Occupants of former methamphetamine laboratories, often residences, may experience increased exposure through the accumulation of the methamphetamine in skin oil. The objectives of this study were to determine equilibrium partition coefficients of vapor-phase methamphetamine with artificial skin oil (ASO), artificial skin oil without fatty acids and real skin oil. A 10 L flow through stainless-steel chamber and in-line filter holders were used to expose skin-oil coated filters to vapor-phase methamphetamine at concentrations ranging from 12 ppb to 159 ppb and samples were analyzed for exposure time periods from 2 hours to 60 days. For a low vapor-phase methamphetamine concentration range …

Performance Analysis Of Zero Forcing And Minimum Mean Square Error Equalizers On Multiple Input Multiple Output System On A Spinning Vehicle, Aditya Kulkarni

Masters Theses

"Channel equalizers based on minimum mean square error (MMSE) and zero forcing (ZF) criteria have been formulated for a general scalable multiple input multiple output (MIMO) system and implemented for a 2x2 MIMO system with spatial multiplexing (SM) for Rayleigh channel associated with additive white Gaussian noise. A model to emulate transmitters and receivers on a spinning vehicle has been developed. A transceiver based on the BLAST architecture is developed in this work. A mathematical framework to explain the behavior of the ZF and MMSE equalizers is formulated. The performance of the equalizers has been validated for a case with …

Modeling Of Multi-Terminal Vsc-Based Hvdc Systems, Mohammed Mabrook Alharbi

Masters Theses

"Improving the efficiency and operation of power transmission is important due to the continual increase in demand for electric power. In addition, many remote areas throughout the world lack sufficient access to electricity. Unfortunately, utilities cannot satisfy the high demand of power by building new power stations because of economic and environmental reasons. However, utilities can increase generation and transmission line efficiencies by controlling the power flow through their systems. One new attractive technology that enables the control of power flow in the system is Voltage-Source-Converter High Voltage Direct Current (VSC-HVDC) transmission.

Multi-terminal-HVDC (M-HVDC) can be built using VSC technology. …

Crime Pattern Detection Using Online Social Media, Raja Ashok Bolla

Masters Theses

"In this research, we show online social networks can be used to study crime detection problems. Crime is defined as an act harmful not only to the individual involved, but also to the community as a whole. It is also a forbidden act that is punishable by law. Crimes are social nuisances that place heavy financial burdens on society. Here we look at use of data mining followed by sentiment analysis on online social networks, to help detect the crime patterns. Twitter is an online social networking and microblogging service that enables users to post brief text updates, also referred …

Energy Efficient Scheduling And Allocation Of Tasks In Sensor Cloud, Rashmi Dalvi

Masters Theses

"Wireless Sensor Network (WSN) is a class of ad hoc networks that has capability of self-organizing, in-network data processing, and unattended environment monitoring. Sensor-cloud is a cloud of heterogeneous WSNs. It is attractive as it can change the computation paradigm of wireless sensor networks. In Sensor-Cloud, to gain profit from underutilized WSNs, multiple WSN owners collaborate to provide a cloud service. Sensor Cloud users can simply rent the sensing services which eliminates the cost of ownership, enabling the usage of large scale sensor networks become affordable. The nature of Sensor-Cloud enables resource sharing and allows virtual sensors to be scaled …

Development And Characterization Of Spiral Additions In A Ceramic Matrix, Andrea Lynn Els

Masters Theses

"A novel spiral architecture was formed using titanium diboride and silicon carbide ceramics as either the spiral or matrix phase. Particulate composites with the same compositions were fabricated to compare to the materials in this study. Spiral additions were formed using powder loaded polymers followed by a single and/or multi-filament co-extrusion. For 25 vol% SiC spiral additions to TiB₂, boron nitride was added to the SiC spiral to alter the bonding at the interface and reduce thermal residual stresses. All samples were hot-pressed to near full density at 1980 ⁰C. Hot pressed multi-filament co-extrusion of 2.4 mm / …

Effects Of Grain Properties And Compaction On Single-Tool Normal Indentation Of Granular Materials, Dennis Chieze Duru

Masters Theses

"The behavior of three granular materials; filter sand, crushed garnet, and shale cutting, were investigated in an effort to evaluate the effect of grain size and shape, and material compaction under single tool load-indentation test. Force-penetration data was collected continuously through the end of each test and specific energy and specific penetration was calculated from the data.

Grain size and compaction affected the force penetration behavior. The higher the grain size, the more the fluctuation in the force of penetration. In addition, compaction reduces the force fluctuation in the fine aggregate grains, but increases the magnitude of the force fluctuations …

Influence Of Erosional Unloading On The State Of Stress For Low Amplitude Single-Layer Buckle Folds - Implications For Tensile Fracture Occurrence, Mengke Li

Masters Theses

"The existence of fractures associated to buckle folds is related to the strain distribution of the fold. The erosional unloading process can amplify the remnant strain in the folded layer. Two-dimensional plane strain Finite Element Analysis (FEA) is used to investigate the influence of the erosional unloading step on both the evolution of the state of stress and the associated failure patterns in low amplitude buckle folds. Sensitivity analyses on different input parameters, including viscosity, shortening ratio, and overburden pressure, are performed. Based on the simulation results, tensile stress can be initiated both in the crest and in the limb …

Polyurethane Foam Infill For Fiber Reinforced Polymer (Frp) Bridge Deck Panels: An Evaluation Of Core Alternatives Using Small Scale Experimental Testing, Matthew Scott Hopkins

Masters Theses

"Fiber reinforced polymer (FRP) decking is a concept that has been explored in recent decades as one solution to the performance issues of conventional concrete bridge decking. Many sandwich panel designs made of glass reinforced polyester or vinyl ester resin have been well developed, and manufactured using filament winding, hand lay-up, and extrusion methods. The major benefits of these panels was their light weight, corrosion resistance, fatigue performance, and potential for rapid field assembly. However, high initial costs coupled with small state budgets have kept them from main stream adoption. A viable alternative, is a foam/reinforced foam core sandwich panel …

Quantifying Economic Benefits For Rail Infrastructure Projects, Akhilesh Ojha

Masters Theses

"Investment in rail infrastructure is necessary to maintain existing service and to cater for future growth in freight and passenger services. Many communities have realized the importance of investment in rail infrastructure projects and set up goals and visions to achieve economic development through investing in such projects. Due to limited funds available, communities have to select a single or very few projects from a variety of projects. It is very critical that right projects must be selected at the right time for a community to realize economic development. The limited methods for quantifying the economic benefits to the stakeholders …

Evaluation Of Prosper For Modeling Long Lateral Gas Well Productivity In Toe Up, Toe Down, Horizontal Well Geometry, Abdussalam Mahmoud Mohamed

Masters Theses

"Most horizontal wells are not truly horizontal and may be drilled 'toe-up' or 'toe-down' to follow geological formations or in an attempt to keep the well from loading up. Challenges in directional drilling may also lead to horizontal gas wells with undulating wellbore profiles. This wellbore profile creates natural traps for heavy fluids in the lows and light fluid in the highs, which may result in chocked production. Hence, there is an interest in determining the best wellbore trajectory - toe-up, horizontal, or toe-down - for well unloading.

This study evaluates the capability of the well productivity software PROSPER to …

Computer Vision Libraries For Trailer Truck Testbed Using Open Source Computer Vision Libraries, Krishnan Raghavan

Masters Theses

"Computer Vision is a field that aims at understanding and analyzing images from the real world to produce numerical and symbolical data. It is a first step at duplicating the capabilities of human vision by electronically understanding the image and perceiving its features. This work aims at providing some of the features of a human eye to a trailer truck. These features include getting a 3D wireframe from continuous images and prediction of the next position of the objects in view, while the truck is moving.

The thesis has been divided into 3 sections. First section is acquiring images in …

Shear-Wave Splitting And Mantle Deformation Beneath The Western Tibetan Plateau, Melissa Ann Ray

Masters Theses

"The Tibetan Plateau has been an enigma to the scientific community since scientists first began to focus their attention on the area. Numerous studies over the decades were conducted to address how the plateau formed, mostly in the central and eastern portions of the Tibetan Plateau. Many questions still remain regarding the western Tibetan Plateau, and this study will add constraints to the mechanisms which regulated the formation of the plateau.

Data was acquired from over 13,000 measurements from 172 stations covering the western region of the plateau encompassing the Qiangtang Terrane, the Lhasa Terrane, and the Himalayan Orogenic Zone. …

An Iterative Algorithm For Variational Data Assimilation Problems, Xin Shen

Masters Theses

"Data assimilation is a very powerful and efficient tool to use collected raw data for improving model prediction in numerical weather forecasting, hydrology, and many other areas of geosciences. In this thesis, an iterative algorithm [23] of variational data assimilation with finite element method is utilized to study different models. One motivation for this fundamental mathematical study is to provide a potential tool for simulation of CO₂ sequestration by extending it to more realistic and sophisticated models in the future. The basic idea of variational data assimilation is to utilize the framework of optimal control problems. We apply the …

Hedge Fund Replication Using A Strategy Specific Modeling Approach, Sujit Subhash

Masters Theses

"Institutional investors and wealthy individuals have in the past allocated a significant portion of their portfolios to hedge funds with the expectation of unconditional and uncorrelated returns to the market. However, the financial crisis of 2008 has heightened investor sensitivity to the high fees, illiquidity, and lockup periods typically associated with hedge funds. Hedge fund indexes showing excellent returns and low volatility contain funds that are closed to new investments, while the performance of investable funds have been shown to be inferior to their non-investable counterparts. The lack of transparency and extreme variation in the performance of hedge funds make …

"Green" On-Chip Inductors In Three-Dimensional Integrated Circuits, Umamaheswara Rao Tida

Masters Theses

"This thesis focuses on the technique for the improvement of quality factor and inductance of the TSV inductors and then on the utilization of TSV inductors in various on-chip applications such as DC-DC converter and resonant clocking. Through-silicon-vias (TSVs) are the enabling technique for three-dimensional integrated circuits (3D ICs). However, their large area significantly reduces the benefits that can be obtained by 3D ICs. On the other hand, a major limiting factor for the implementation of many on-chip circuits such as DC-DC converters and resonant clocking is the large area overhead induced by spiral inductors. Several works have been proposed …

Computation Of Cross-Talk Alignment By Mixed Integer Linear Programming, Qifeng Chen

Masters Theses

"Noise analysis has been an important and difficult part of design flow of very large-scale integrated (VLSI) systems in many years. In this thesis, the problem of signal alignment resulting in possible maximum peak interconnect coupling noise and propose a variation aware technique for computing combined noise pulse taking into account timing constraints on signal transitions has been discussed. This work shows that the worst noise alignment algorithm can be formulated as mixed integer programming (MLIP) problem both in deterministic window cases and variational window cases. For deterministic window cases, it is assumed that timing windows are given for each …

Fabrication Of Out-Of-Autoclave Bismaleimide Based Composite Laminates With Embedded Fiber Optic Sensors, Sudharshan Anandan

Masters Theses

"Composites are becoming the material of choice in applications where weight savings are critical, like aerospace structures. The common composites used are- Carbon/Epoxy and Carbon/Bismaleimide (BMI). BMI based systems are preferred in applications which involve operating temperatures higher than conventional epoxies. Carbon/BMI laminates are traditionally fabricated in an autoclave, which is associated with high operating costs. In this work, a low cost out of autoclave (OOA) process is evaluated. It is desirable to have BMI OOA prepreg systems cure at reasonably low temperatures with sufficient degree of cure and green strength to maintain rigidity for subsequent freestanding post cure Carbon/BMI …

Performance Analysis Of Cutting Graphite-Epoxy Composite Using A 90,000 Psi Abrasive Waterjet, Aiswarya Choppali

Masters Theses

"Graphite-epoxy composites are being widely used in many aerospace and structural applications because of their properties: which include lighter weight, higher strength to weight ratio and a greater flexibility in design. However, the inherent anisotropy of these composites makes it difficult to machine them using conventional methods. To overcome the major issues that develop with conventional machining such as fiber pull out, delamination, heat generation and high tooling costs, an effort is herein made to study abrasive waterjet machining of composites. An abrasive waterjet is used to cut 1" thick graphite epoxy composites based on baseline data obtained from the …

A Driving Simulator Study To Evaluate The Impact Of Portable Changeable Message Signs (Pcms) On Driver Speed Characteristics, Bharath Kolar Venkat

Masters Theses

"This research project examined the effects of sequential Portable Changeable Message Signs (PCMS) on driver behavior in work zones. PCMS are temporary traffic control (TTC) devices, part of Intelligent Transportation Systems, which supplement static signs to provide advance warning and real-time information to drivers. Text and number based messages are displayed on the PCMS for which detailed evaluation has not been carried out before. This research fills this gap using a driving simulator (DS) supplemented by objective and subjective surveys. A work zone on I-44 in rural Missouri was replicated in the DS using video recordings and GIS (Geographical Information …

Cable Discharge Events (Cde) -- A Modeling And Simulation Perspective, Viswa Pilla

Masters Theses

"Cable discharge events (CDE) typically occur when a charged cable is connected to an electronic device. Several CDE damages in Ethernet LAN and USB communication interface equipment are reported by the IC manufacturers. CDE differs from other types of ESD such as human body model (HBM), charged device model (CDM) and IEC 61000-4-2 mainly due to faster rise times, longer pulse widths and higher peak currents. Various factors such as cable geometries, charging and discharging mechanisms, and load conditions influence CDE. Several researchers have developed some measurement techniques to understand CDE waveforms. However, there is little information regarding its modeling …

Design And Implementation Of Two Non-Isolated High Gain Dc-Dc Converters, Huawei Yang

Masters Theses

"In most solar energy systems, the output voltage of a photovoltaic panel is usually between 20 to 40 Vdc. In order to interface the panels to a 400 Vdc bus, a high voltage gain dc-dc converter is required.

This thesis starts with analyzing and simulating several topologies that have been already introduced for this application. The voltage gain and efficiency are investigated analytically. A hardware prototype of one of the existing topologies, the interleaved boost converter with voltage multiplier cell, has been developed. Finally, a new topology with a higher voltage transfer ratio is proposed and its experimental results are …

Economic And Environmental Comparison Of Different Ordering Policies For An Integrated Inventory Control And Supplier Selection Problem, Sepideh Almasi Monfared

Masters Theses

"This study analyzes an integrated inventory control and supplier selection problem in stochastic demand environment under carbon emissions regulations. In particular, a continuous review inventory model with multiple suppliers is investigated under carbon taxing and carbon trading regulations. We analyze and compare the optimal supplier selection and order splitting decisions with single sourcing and two alternative delivery structures for multi-sourcing, namely, sequential ordering and sequential delivery. For each of the three ordering policies, a solution method is proposed and these policies are compared in terms of their economic as well as environmental performances. A numerical study is conducted to demonstrate …

Uterine Cervical Cancer Histology Image Feature Extraction And Classification, Koyel Banerjee

Masters Theses

"The current study presents the investigation and development of image processing, computational intelligence, fuzzy logic, and statistical techniques for different types of data fusion for a varied range of applications. Raw data, decision level and feature level fusion techniques are explored for detection of pre Cervical cancer (CIN) grades from digital histology images of the cervical epithelium tissues.

In previous research, an automated, localized, fusion-based approach was investigated for classifying squamous epithelium into Normal, CIN1, CIN2, and CIN3 grades of cervical intraepithelial neoplasia (CIN) based on image analysis. The approach included medial axis determination, vertical segment partitioning as medial axis …

Quench The Thirst: A Content Analysis Of The Persuasive Techniques Of Unicef's Tap Project, Rachel Chadalavada

Masters Theses

This study analyzes the persuasive techniques utilized by UNICEF's Tap Project. This water related campaign began in 2007 and since then has created four themes. These themes are: Dine out, Celebrity Tap, Facebook Push and Cellphone Challenge. The study finds that the videos employed by the Tap Project portray all six Facets of Effects. However, their usage was based on the message that was being delivered. That said, not all videos utilized all of the facets. This implies that an advertisement need not necessarily use all six Facets of Effects to be successful. The facet of association however, stood out …

Folkloric Musicians Among The Bugakhwe, Robert Veith

Masters Theses

Increased access to global media by traditional culture in remote parts of Africa has, in many cases, seen indigenous music marginalized in favor of imported forms. In some places, a folkloric tradition thrives, though this music may face extinction if those who practice it do not document their art in a way which can be passed down to future generations. For this project, I recorded seven musician/composers of the Bugakhwe, a Khoisan people group living in the Okavango Delta region of Botswana. Two were given enough studio time to create a complete CD-length set, so as to show off the …

Outcomes Assessment Of An Outdoor Orientation Program Through Means-End Theory, Kristofer James Cortez

Masters Theses

There is a lack of research investigating the effectiveness of outdoor orientation programs. Specifically, there is an absence of research examining what program elements contribute to student development and how those elements support that growth. Programs have relied on anecdotal evidence of outcome achievement but these indicators do not sufficiently identify the processes that specifically influence participant development. This study uses means-end theory to assess an outdoor orientation program at a large public university. Participant interviews identified meaningful features of their program experience and explained what outcomes were achieved as a result of those specific features. Laddering and means-end analysis …

Milton‘S Feminized Satan: A Study Of Gender Imbalance In Paradise Lost, Kari Anne Wiest

Masters Theses

Critics have observed how Satan‘s personality changes dramatically over the course of Milton‘s Paradise Lost, but what they have missed is that this transformation in his character is due to an identity crisis that spirals into a gender shift. There are no studies of Satan as feminine. Drawing upon feminist theory, I contend that it is important for readers to see Satan as a female voice in Paradise Lost and not as a positive one at that. In Milton‘s attempt to ―justify the ways of God to men‖ he, by necessity, must explain the character and purpose of Satan …

"God Made Me Thisaway": Mary Wilkins Freeman, Flannery O'Connor, And Religiosity As Challenge To Heteronormativity, Anna M. Worm

Masters Theses

The fiction of Mary Wilkins Freeman and Flannery O'Connor, especially Freeman's “A New England Nun” and “The Balsam Fir” and O'Connor's “A Temple of the Holy Ghost” and “Good Country People,” expose and challenge heteronormativity. Consideration of heteronormativity and compulsory heterosexuality, as well as religious themes demonstrates the way their works offer an avenue of challenge for characters struggling with societal forces that push them towards an unwanted or unfulfilling heterosexuality. Although Freeman's works suggest that a satisfactory life outside heterosexual norms is unrealistic, with community alienation the price for resistance, she envisions religion a valuable tool in such resistances. …