Digital Commons Network^™

A Meta-Architecture Analysis For A Coevolved System-Of-Systems, George Anthony Muller Iv

Masters Theses

"Modern engineered systems are becoming increasingly complex. This is driven in part by an increase in the use of systems-of-systems and network-centric concepts to improve system performance. The growth of systems-of-systems allows stakeholders to achieve improved performance, but also presents new challenges due to increased complexity. These challenges include managing the integration of asynchronously developed systems and assessing SoS performance in uncertain environments.

Many modern systems-of-systems must adapt to operating environment changes to maintain or improve performance. Coevolution is the result of the system and the environment adapting to changes in each other to obtain a performance advantage. The complexity …

Assessing Downstream Stormwater Impacts For Urban Watershed Planning, Johanna Meyer Pavlowsky

Masters Theses

"The urbanization of watersheds has caused debilitating effects to downstream aquatic ecosystems in catchments and streams. The implementation of green infrastructure (GI), such as permeable pavements and bioretention facilities, has been shown to alleviate these effects by both reducing runoff and mitigating pollutants; however, the implements are often not designed with a specific goal of water improvement. This study targets understanding a small, impaired urban watershed, and the benefits green infrastructure may have to provide environmental, social, and economic improvement to the watershed.

Portions of Rolla including much of the S&T campus drain into the impaired urban waterbody Frisco Lake, …

Material Properties Affecting The Penetration Of Metal Targets By Copper Linear Shaped Charges, Kevin Lee Phelps

Masters Theses

"A linear shaped charge (LSC) is an explosive device used in demolition, aerospace, and in other applications that require the cutting of metal. Users of LSC's typically know the size of shaped charge needed to cut their target but commonly encounter previously untested materials. The motivation for this thesis is to provide an understanding as to what target material properties are good indicators of cutting performance so the selection of LSC can be more efficient. The author found that penetration theories for other types shaped charges were insufficient for the LSC, possibly because of the relatively slow projectile created by …

Application Of Embedded Frequency Selective Surfaces For Structural Health Monitoring, Dustin Franklin Pieper

Masters Theses

"This thesis proposes the use of Frequency Selective Surfaces (FSSs) as an embedded structural health monitoring (SHM) sensor. FSSs are periodic arrays of conductive elements that filter certain frequencies of incident electromagnetic radiation. The behavior of this filter is heavily dependent on the geometry of the FSS and local environment. Therefore, by monitoring how this filtering response changes when the geometric or environmental changes take place, information about those changes may be determined. In previous works, FSS-based sensing has shown promise for sensing normal strain (a stretching or compressing geometrical deformation). This concept is extended in this thesis by investigating …

Numerical Analysis Of Flexural Slip During Viscoelastic Buckle Folding, Davi Rodrigues Damasceno

Masters Theses

"Flexural slip is considered to be an important folding mechanism contributing in the development of different folds such as chevron, and kink-band buckle folds. Various filed studies have provided a general conceptual and qualitative understanding of flexural slip. However, quantitative evidence of the importance of the flexural slip mechanism during fold evolution is sparse, as the actual amount of surface parallel displacement, and timing, is difficult to measure accurately, due to the lack of suitable strain markers.

In this study 2D finite element analysis is used to overcome these disadvantages and to simulate flexural slip during viscoelastic buckle folding. Variations …

A Cost Benefit Analysis Of Sst Based Volt-Var Control, Guruprasad Ramani

Masters Theses

"The overall objective of this thesis work is to improve system power quality with the help of solid state transformers (SSTs). Two methods to improve the system power quality are explored: a) achieving a unity power factor at all the load buses, and b) improving the system voltage profile to meet a desired voltage regulation requirement of 0.95

A Feasibility Study Of A Nuclear Power Plant With No Moving Parts, Jonathan Mark Schattke

Masters Theses

"In a nuclear reactor design, every moving part in a system is considered a failure point. In this study, a proposal is made for designing a nuclear reactor that has no moving parts by coupling an accelerator driven core (removing control system moving parts) to a magnetohydrodynamic generator (removing power generation moving parts) using mercury coolant (removing pumping system moving parts). Further safety is realized by using a subcritical core, where the core is never able to sustain a chain reaction on its own, obviating many safety systems. The design is verified with a Monte Carlo simulation "--Abstract, page iii.

Thermal Characterization Of Phase Change Materials For Thermal Energy Storage, Rami Mohammad Reda Saeed

Masters Theses

"The study provides a valuable and useful database for Phase Change Materials (PCMs) for Thermal Energy Storage (TES) applications. Only a few existing studies have provided an overall investigation of thermophysical properties of PCMs in this detailed manner. Several organic PCMs, namely Myristic acid, Capric Acid, Lauryl Alcohol, Palmitic acid and Lauric acid, have been characterized after being carefully selected to cover wide range of TES applications. Insights and information gained from this work will be applied toward the design and modelling of many low temperature thermal energy storage applications. The study experimentally investigated uncertainty of thermal characterization of PCMs …

Evaluation Of Ultra-High Performance Concrete (Uhpc) In Joints Of Bridge Girders, Saipavan Rallabhandhi

Masters Theses

"Joints are often considered as the weak link in a structure and often deterioration of the structure initiates from the joints. Joints transfer the stresses from super-structure to sub-structure and in this process are subjected to large transfer stresses. Not much attention is given to the design of joints as they are positioned in low moment regions and typically a 4 to 6 ksi (28 to 41 MPa) concrete is used to fill the joints. One of the solution to this problem is Ultra-high performance concrete (UHPC). In the recent past significant research has been done to use UHPC in …

Data Analysis Of Surfactant-Induced Wettability Alteration In Carbonate Reservoirs, Hao Sun

Masters Theses

"Most carbonate formations prove to be oil-wet due to oil aging effect. Therefore it is essential to employ wettability alteration methods for a more effective enhanced oil recovery process. It is confirmed by researchers that surfactant treatment has positive effects on wettability alteration of carbonate rock, from strong oil-wet to intermediate wet or to even weak water-wet. A number of experiments have the same conclusion and yet, a systematic screening guide development with the support of sufficient data analysis is lacking.

This study involves screening guide development for surfactant-induced wettability alteration method. 199 experiments collected from published literatures are analyzed …

Automated Channel Emulator Based On Mems Switch And Improvement Of Signal Transition, Jingdong Sun

Masters Theses

"Channel Emulator, which is widely used in communication system development, is an instrument that emulates the real-world signal propagation environment between transmitter and. [sic] To overcome the disadvantages of traditional channel emulator, we propose a novel structure of the automated channel emulator in Section 1, which can be controlled by software and integrated into auto-testing system. MEMS switch, with good RF performance, is used to connect and isolate multiple channels.

In Section 2, we divide the whole channel emulator system into Channel, Support, and Controller Board, and provide detailed design procedures with critical parameters of each board. The well-designed high …

Effect Of Reservoirs Heterogeneity On Injection Pressure And Placement Of Preformed Particle Gel For Conformance Control, Ze Wang

Masters Theses

"Preformed particle gels (PPG) have been successfully applied as a plugging agent for plugging fractures and then divert displacing fluid into poorly swept zones. However, PPG propagation and plugging mechanisms through open fractures have not been studied thoroughly.

This work investigated the influence of some factors (particle size, brine concentration, heterogeneity, and brine salinity) on gel injectivity, plugging performance for water flow through open fractures. Five-foot tubes were used to mimic open fractures. Three models were designed to conduct the work, including (1) single fracture with uniform fracture width, (2) single fracture with different widths, and (3) two parallel fractures …

Variable Stress Orientations In The Offshore Nile Delta: The Role Of Salt As A Mechanical Detachment Horizon, Weicheng Zhang

Masters Theses

"The offshore Nile Delta is characterized by variations of the maximum horizontal stress orientation in subsalt and supra-salt sequences. Margin-parallel SH, typical for tertiary deltas, is observed for regions that are below or do not contain evaporites. In sequences underlain by evaporates pre-dominantly margin-normal SH is observed. This observation yielded the first conclusive in situ evidence that salt acts as a mechanical detachment layer. In this study, 3D finite element analysis (FEA) is used to simulate the total stress distribution in the offshore Nile Delta featuring evaporate sequences. Several parameters such as different salt sequence geometries, friction coefficient on faults, …

3d Seismic Structural And Stratigraphic Interpretation Of The Tui-3d Field, Taranaki Basin, New Zealand, Gorkem Yagci

Masters Theses

"Identifying seismic structures and stratigraphy are important for exploration of hydrocarbons. The purpose of this study is to discover seismic structural and stratigraphic features and to utilize the results for interpreting depositional environments. A 3D seismic dataset from the Tui-3D Field, the Taranaki Basin, New Zealand with well data were used to visualize structures, to detect stratigraphic features, to identify main lithology, to understand depositional environment, and to describe seismic facies and reflection patterns of the target horizons. The major formations are in the Kapuni Group.

Seismic structural interpretation indicates thirty-two minor faults, which may play an important role in …

A Control Algorithm For The Solar Village Microgrid System, Hamad Ahmed Alharkan

Masters Theses

"In this thesis, the concept of microgrid system is introduced. Also, the major components of a microgrid will be discussed thoroughly. Both grid-connected and autonomous modes are explained. In addition, the control of a microgrid is defined for the following types: local, centralized and decentralized control.

As one of the nation's premiere research universities, the Missouri University of Science and Technology has built four inspirational solar houses (solar villages) for a competition in the US Department of Energy Solar Decathlon to allow students to research and improve different aspects of the microgrid system. Consequently, this thesis develops a computer model …

Study On The Applicability Of Relative Permeability Modifiers For Water Shutoff Using Numerical Simulation, Dheiaa Khafief Khashan Alfarge

Masters Theses

"Water production is a challenging problem to be controlled during hydrocarbon-reservoirs production life. Disproportionate Permeability Reduction (DPR) is often used as water shutoff treatment in production wells when other conventional solutions like mechanical isolations are difficult to perform. This study applied numerical simulation methods to diagnose the factors impacting DPR treatment success on macroscopic level and to see when, where and at which conditions DPR treatment can give best results.

This work indicated that the following points should be considered before DPR treatment is executed in any reservoir to get a successful treatment. Firstly, this research explored that DPR performance …

Nathaniel Gist Gee Papers - Accession 395, Nathaniel Gist Gee

Manuscript Collection

The Nathaniel Gist Gee Papers consist of various papers concerning Gee’s years in China including correspondence, reports, newspaper and magazine clippings, Chinese poetry, statistics, manifestos, statements, his professional papers concerned primarily with freshwater sponges, and professional papers and publications he collected that chronicle China’s growth. Many of the records are concerned with China’s political and social changes including China’s Nationalist and Student Movements during Gee’s stay in China.

Nathaniel Gist Gee (1876-1937), born in Union, SC, was a professor of Natural Science at Soochow University and Yenching University in China from 1901-1932.

A Statistical Analysis Of A 4.5 Mw Solar Energy Center, Archit Patnaik

Masters Theses

"This project helps a regional utility evaluate the performance of their 4.5 MW photovoltaic plant. The performance evaluation consists of characterizing the peak and average power and energy output of the plant over varying time periods. A characterization of the output power drops, or dips, is done by performing a statistical analysis of the photovoltaic plant output data. Dips are characterized by dip frequency, depth of dip, energy loss by dip, and dip duration. The results of this study will help the utility to select appropriate voltage regulating equipment on the basis of dip characteristics, and thus, optimize the performance …

Conceptual Parameters Necessary For Modeling Wettability Alteration In An Enhanced Smart Brine-Chalk System, Ahmed Abdulkareem Hussein Albahrani

Masters Theses

"Achieving higher recovery of oil from proven carbonate reserves around the world is not an easy task. One promising new method, especially for carbonate reservoirs, is the use of "Smart Water" technology, which is an injection water with carefully determined, optimal ionic composition and salinity. Recent experiments have shown good recovery results, but the mechanism of wettability alteration by this fluid are still not well understood. The goal of this study is to review the high and optimal salinity and ionic composition literature plus perform dimensional analysis of key variables in order to shed light on the physical and chemical …

Design And Analysis Of An Axisymmetric Aerospike Supersonic Micro-Nozzle For A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, Abdalla Ali Bani

Masters Theses

"The cold-gas propulsion system being developed by M-SAT requires improvements to its original nozzle design. This study documents the research, design, and analysis of a supersonic plug nozzle concept that could be integrated to the refrigerant-based cold-gas propulsion system to possibly improve its performance. As documented in this thesis, CFD analysis showed that the outlined nozzle design method resulted in a feasible nozzle concept that has the ability to out-perform a conventional nozzle of the same area ratio. The flow-fields and thrust of the aerospike nozzle, for the full and truncated nozzles, were investigated. The purpose of this study is …

Voltage Control In A Distribution System Using Active Power Loads, Mounika Chava

Masters Theses

"High penetration of renewable energy resources such as rooftop solar photovoltaic (PV) systems is exacerbating violations of the voltage limits in power distribution networks. Existing solutions to these over-/under-voltage issues include tap-changing transformers and shunt capacitors. However, tap changers only allow voltage changes in discrete steps and shunt capacitors cannot handle over-voltage situations. To overcome these problems, this thesis proposes voltage control in a distribution system by adjusting active power loads. The proposed solution can be used for both under- and over-voltage cases at any levels of voltage adjustment. First, the active power that needs to be adjusted at selected …

Artificial Neural Network Approach To Predict Blast-Induced Ground Vibration, Airblast And Rock Fragmentation, Raymond Ninnang Tiile

Masters Theses

"Blasting has been widely used as an economical and cheap way of rock breakage in mining and civil engineering applications. An optimal blast yields the best fragmentation in a safe, economic and environmentally friendly manner. The degree of fragmentation is vital as it determines to a large extent the utilization of equipment, productivity and mill throughput. Explosive energy, besides rock fragmentation, creates health and safety issues such as ground vibration, air blast, fly rock, and back breaks among others. As a result, the explosive energy impacts structures and buildings located in the vicinity of the blasting operation, and causes human …

Fluid Flow Through Deformation Band, Huining Zhang

Masters Theses

"Cataclastic deformation bands, which are common in porous sandstone, have the potential to restrict fluid flow. Geological studies have shown that permeability of deformation band shear zones can be one to five orders of magnitude less than for the sandstone host rock. However, recent studies based on simplified analytical estimates have shown that fluid flow in jointed deformation bands may not be retarded since joints play an important role in conducting fluids. In this study, 2 dimensional finite element analysis (FEA) is used to simulate the total discharge flow rate through jointed deformations. Variations of single planar and conjugate jointed …

De-Embedding Method For Electrical Response Extraction Of Through-Silicon Via (Tsv) In Silicon Interposer Technology And Signal Integrity Performance Comparison With Embedded Multi-Die Interconnect Bridge (Emib) Technology, Qian Wang

Masters Theses

"Traditional two-dimensional system-in-package (2D SiP) can no longer support the scaling of size, power, bandwidth, and cost at the same rate required by Moore's Law. Three-dimensional integrated circuits (3D-ICs), 2.5D silicon interposer technology in which through silicon vias are widely used, are implemented to meet these challenges. Embedded multi-die interconnect bridge (EMIB) technology are proposed as well.

In Section 1, a novel de-embedding method is proposed for TSV characterization by using a set of simple yet efficient test patterns. Full wave models and corresponding equivalent circuits are provided to explain the electrical performance of the test patterns clearly. Furthermore, broadband …

Study Jitter Amplification Of A Passive Channel And Investigation Of S₂₁ Magnitude Extraction Methodologies Using A Pattern Generator And Oscilloscope, Xinyun Guo

Masters Theses

"Recently the clock channel jitter amplification has been observed in several publications. Currently in many high-speed I/O systems, to avoid the cost and the complex clock recovery circuit design, people use traces forwarding clock signal from transmitting IC to receiving IC. When these clock traces are long enough, the amount of attenuation will induce not only inter-symbol-interference (ISI) but also modulate with the input jitter. Eventually it will lead some type of jitter been amplified after the channel. Similarly, the high speed communication channel (data channel) will also face this issue. Since there are no studies on the jitter amplification …

Developing An Idealistic Model To Characterize And Optimize A Photovoltaic Battery Systems, Pavani Reddy Nalladimmu

Masters Theses

"Solar energy is one of the most abundant and clean energy sources of renewable energy. Due to its unsteady nature, most photovoltaic systems require a solar storage system. Ultracapacitors have proven to be an effective solar energy storage component due to their wide range of input voltages and high power density. This research focuses on characterizing the performance of a PV/UCAP hybrid storage system to meet required household loads at various locations throughout the US as a backup energy source. A calibrated empirical model was developed to characterize system performance. A load profile was designed based on a typical 2 …

Evaluating Completion Performance For Gas Wells In The Upper And The Lower Montney Formation, Canada, Omar Qasim Mohammed

Masters Theses

"Identifying the key drivers for success of multiple fractured horizontal wells is not straightforward, especially in unconventional reservoirs like the Montney. Al-Alwani et al. (2015) provided a statistical analysis of Montney completions based on publicly available data. They showed that for the entire well population, cumulative gas recovery per stage, declines as the number of completed stages increase. However, their statistical analysis did not differentiate between completions in the Upper/Middle/Lower Montney, and did not include perforation cluster data.

This work documents the statistical analysis of 296 cased-hole horizontal gas well completions reported in the Upper and the Lower Montney. The …

Deterministic Simulation Of Thermal Neutron Radiography And Tomography, Rajarshi Pal Chowdhury

Masters Theses

"In recent years, thermal neutron radiography and tomography have gained much attention as one of the nondestructive testing methods. However, the application of thermal neutron radiography and tomography hindered by their technical complexity, radiation shielding, and time-consuming data collection processes. Monte Carlo simulations have been developed in the past to improve the neutron imaging facility's ability. In this present work, a new deterministic simulation approach has been proposed and demonstrated to simulate neutron radiographs numerically using a ray tracing algorithm. This approach has made the simulation of neutron radiographs much faster than by previously used stochastic methods (i.e Monte Carlo …

Radiation Noise Source Modeling And Near-Field Coupling Estimation In Rf Interference, Liang Li

Masters Theses

"With increasing complexities and shrinking size of modern electronic devices, the near-field RF interference issues are becoming challenging for RF-digital mixed circuit design. Predicting the coupling from digital module to RF antennas and mitigating RF interference is important to the system performance. The ultimate goal of this study is to address the desensitization issues existing in modern electronic devices that have mixed high speed digital-RF circuits, such as cellphone and wearable devices.

In order to estimate the near-field noise coupling from digital module to RF antennas, the noise source is anticipated to be replaced by its equivalent radiation model which …

Characterization Of Fracture Initiation In Non-Cylindrical Buckle Folds Using 3d Finite Element Analysis, Eli Jacob Steinbeck

Masters Theses

"The spatial distribution of fracture sets associated with buckle folds has been well documented in field studies. There are difficulties, however, in placing accurate constraints on the timing of the initiation of individual fracture sets during the deformation history of the fold under in-situ conditions. This study investigates specific conditions that give rise to the initiation of various fracture sets in the hinge and limb of a pericline, based on an analysis of the effective stress evolution during the processes of buckling and erosional unloading. A 3D finite element modeling approach is used to simulate the effective stress evolution in …