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Articles 80821 - 80850 of 196620

Full-Text Articles in Engineering

An Integrated Method For Understanding The Fluid Flow Behavior And Forecasting Well Deliverability In Gas Condensate Reservoirs With Water Aquifer Drive, Abdulaziz Mustafa Em. Ellafi Jan 2018

An Integrated Method For Understanding The Fluid Flow Behavior And Forecasting Well Deliverability In Gas Condensate Reservoirs With Water Aquifer Drive, Abdulaziz Mustafa Em. Ellafi

Masters Theses

"Gas condensate reservoirs constitute a significant portion of global hydrocarbon reserves. In these reservoirs, as bottomhole pressure falls below the dew point, liquid develops in the pore space. This results in the formation of a liquid bank near the wellbore region that decreases gas mobility, which then reduces gas inflow. Some gas condensate reservoirs have bottom aquifer drive, which also negatively impacts gas production. This research used a field case study to demonstrate an integrated workflow for forecasting well deliverability in a gas condensate field in Libya. The workflow began with the interpretation of open-hole log data to identify the …


Computational Intelligence Methods For Predicting Fetal Outcomes From Heart Rate Patterns, Vinayaka Nagendra Harikishan Gude Divya Sampath Jan 2018

Computational Intelligence Methods For Predicting Fetal Outcomes From Heart Rate Patterns, Vinayaka Nagendra Harikishan Gude Divya Sampath

Masters Theses

"In this thesis, methods for evaluating the fetal state are compared to make predictions based on Cardiotocography (CTG) data. The first part of this research is the development of an algorithm to extract features from the CTG data. A feature extraction algorithm is presented that is capable of extracting most of the features in the SISPORTO software package as well as late and variable decelerations. The resulting features are used for classification based on both U.S. National Institutes of Health (NIH) categories and umbilical cord pH data. The first experiment uses the features to classify the results into three different …


Effect Of Variation Of Parameters On Biogas Production Using Aspen Plus & Dynamic Simulation Using Mimic, Shruti Shrikant Karambelkar Jan 2018

Effect Of Variation Of Parameters On Biogas Production Using Aspen Plus & Dynamic Simulation Using Mimic, Shruti Shrikant Karambelkar

Masters Theses

"Design and management for Biogas production have gained significance in growing dependency on Renewable energy resources. This would need a detailed information on steady state and dynamic behavior of systems. In order to make this process environmentally ecofriendly, its needs a lot of improvisation on process simulation. Anaerobic digestion helps treat this inefficient water to be converted into water fit for effluent purposes.

Byproducts contain consists of organic, inorganic and wastes which lead to a high COD content and thus, cannot be discarded into the outlets. The anaerobic digestion process. A study of these effects with simulation need to be …


Characterization Of Ionic Liquid Monopropellants For A Multi-Mode Propulsion System, Alex J. Mundahl Jan 2018

Characterization Of Ionic Liquid Monopropellants For A Multi-Mode Propulsion System, Alex J. Mundahl

Masters Theses

"Multi-mode micropropulsion is a potential game-changing technology enabling rapidly composable small satellites with unprecedented mission flexibility. Maximum mission flexibility requires one shared propellant between the chemical and electric systems. A deep eutectic 1:2 molar ratio mixture of choline-nitrate and glycerol ([Cho][NO3] - glycerol) is investigated as a fuel component in a binary mixture propellant for such a multi-mode micropropulsion. Specifically, binary mixtures of the novel ionic liquid fuel with hydroxyl-ammonium nitrate (HAN) and ammonium nitrate (AN) are considered and compared against the previously investigated propellant [Emim][EtSO4]-HAN. Chemical rocket performance simulations predict this new propellant to have …


Cellulose And Sulfate Degradation In A Biochemical Reactor During Treatment Of Mine Drainage, Sweta Ojha Jan 2018

Cellulose And Sulfate Degradation In A Biochemical Reactor During Treatment Of Mine Drainage, Sweta Ojha

Masters Theses

"Seventy-two biochemical reactors were set up, and operated using a mixture of chip-bark, horse manure, and gravel as the biochemical treatment substrate. The simulated mine water containing sulfate (1000 mg/l) was pumped into each reactor at a flow rate of 0.5 ml/minute (approximate), giving an empty bed contact time of 8 days. The main idea is that the microorganisms present in horse manure would convert the cellulose in chip-bark into volatile fatty acids. The produced volatile fatty acid would enhance the metabolism of sulfate-reducing bacteria (SRB) initially present in horse manure, which would degrade (and eventually remove) the sulfate from …


Controlling Phase Fractions Of 304l-Ss In Selective Laser Melting Using Cooling Rate, Eberechukwu Anthony Okoro Jan 2018

Controlling Phase Fractions Of 304l-Ss In Selective Laser Melting Using Cooling Rate, Eberechukwu Anthony Okoro

Masters Theses

"This study examines the thermal profile and the ferrite-austenite phase fractions upon heating and cooling of 304- stainless steel powder via Selective Laser Melting (SLM). Experiments were performed to validate the ABAQUS finite element model, while the phase transformation simulation was performed using MatCalc and ThermoCalc. A correlation between the thermo-mechanical changes in ABAQUS and the microstructural changes from MatCalc was obtained by matching their cooling rates. The result indicates that cooling rate has a significant effect on the phase fractions of FCC and BCC formed in 304L stainless steel via the SLM process. The results also indicate that for …


Generalized Adaptive Variable Bit Truncation Model For Approximate Stochastic Computing, Keerthana Pamidimukkala Jan 2018

Generalized Adaptive Variable Bit Truncation Model For Approximate Stochastic Computing, Keerthana Pamidimukkala

Masters Theses

"Stochastic computing as a computing paradigm is currently undergoing revival as the advancements in technology make it applicable especially in the wake of the need for higher computing power for emerging applications. Recent research in stochastic computing exploits the benefits of approximate computing, called Approximate Stochastic Computing (ASC), which further reduces the operational overhead in implementing stochastic circuits. A mathematical model is proposed to analyze the efficiency and error involved in ASC. Using this mathematical model, a new generalized adaptive method improving on ASC is proposed in the current thesis. The proposed method has been discussed with two possible implementation …


Fuel Burnup Simulation And Analysis Of The Missouri S&T Reactor, Joshua Hinkle Rhodes Jan 2018

Fuel Burnup Simulation And Analysis Of The Missouri S&T Reactor, Joshua Hinkle Rhodes

Masters Theses

"The purpose of this work is to simulate the fuel burnup of the Missouri S&T Reactor. This work was accomplished using the Monte Carlo software MCNP. The primary core configurations of MSTR were modeled and the power history was used to determine the input parameters for the burnup simulation. These simulations were run to determine the burnup for each fuel element used in the core of MSTR.

With these simulations, the new predicted isotopic compositions were added into the model. New core configurations were determined, and the burnup corrected model was used to predict the excess reactivity and control rod …


Investigation Of The Information Provided By Light Touch For Balance Improvement In Humans, Anirudh Saini Jan 2018

Investigation Of The Information Provided By Light Touch For Balance Improvement In Humans, Anirudh Saini

Masters Theses

"This study investigates the information provided by Light Touch (LT) in improving human postural stability without mechanical assistance. Light Touch, an interaction force with a magnitude about 1 N, is known to improve postural stability in humans during quiet standing. However, the nature of the information from LT that helped improve balance is yet unknown. In this work, we hypothesized that LT provides information about one's body kinematics. We used a haptic robot to provide modulated, measurable light interaction force on the high back haptic location of humans to provide body kinematics-dependent information through LT. Standing balance experiments were performed …


Numerical Simulation Study Of Factors Affecting Production Well Gel Treatment Using Linear Models With Crossflow, Kewei Shi Jan 2018

Numerical Simulation Study Of Factors Affecting Production Well Gel Treatment Using Linear Models With Crossflow, Kewei Shi

Masters Theses

"Conformance control is an inevitable topic related to water-flooding. Polymer gel has been proved to enhance oil recovery by blocking the existing water-breakthrough channels. Water that is injected subsequently will be directed to the unswept portion of the reservoir, replacing part of the remaining oil and increasing the oil-recovery factor. Prior to pilot tests of polymer gel treatment, laboratory experiments and numerical simulations are used to design the tests. Understanding physical meanings of key parameters that affect polymer gel treatment and relating the parameters from lab data and the simulator benefit field operation design.

This thesis study tries to evaluate …


Cellular Hitchhiking Via Injectable Microparticles, Daniel Smith Jan 2018

Cellular Hitchhiking Via Injectable Microparticles, Daniel Smith

Masters Theses

"Tissue engineering is a process of developing new tissues in a host. Tissue engineering draws upon revitalizing damaged tissues that otherwise would not heal completely from the body's natural response. To augment the body's natural response to impairment, cells can be transplanted to the afflicted area to boost the healing response. Implementing these cells onto scaffolds and transplanting them into the body improves the healing response dramatically. Tissue regeneration improves when a biodegradable scaffold is used in conjunction with cells to augment the body's healing response. Microparticles provide a surface that can mimic the environment cells perceive in vivo, …


Proppant Transport With Varying Injection Points And Its Impact On Proppant Development Inside A Fracture, Shail Janakbhai Soni Jan 2018

Proppant Transport With Varying Injection Points And Its Impact On Proppant Development Inside A Fracture, Shail Janakbhai Soni

Masters Theses

"This study presents experimental work which examines the effect of perforation placement and density on proppant placement within a hydraulic fracture. The study also investigates the effect of proppant angularity.

Experiments were conducted with ceramic proppant injected in a fracture slot model consisting of three injection points at the bottom, middle and top of the fracture slot, and two outlets, at the bottom and top of the fracture model. The effect of single point injection height was investigated by injecting solely at the bottom, middle or top of the apparatus, for both bottom and top outlet conditions. Multiple injection points …


Lyapunov Stability Analysis Of Switched Microgrid Systems, Bokang Zhou Jan 2018

Lyapunov Stability Analysis Of Switched Microgrid Systems, Bokang Zhou

Masters Theses

"In this thesis, a Lyapunov-based method for analyzing the stability of a switched microgrid system is proposed. First, a small second-order system is explored as example to demonstrate the effectiveness of switching patterns on the stability of a system switching among different respectively stable operating points. Lyapunov function is employed in order to determine the proper state-based switching conditions under which global stability is guaranteed, or under which the system is driven unstable. Then, a linearized statespace model of a looped seven-node microgrid is established. Solid-state transformers (SSTs), distributed energy storage devices and synchronous generators are introduced and modeled in …


Embedded Fiber Optic Sensors For Temperature Monitoring Of Continuous Casting Mold, Yiyang Zhuang Jan 2018

Embedded Fiber Optic Sensors For Temperature Monitoring Of Continuous Casting Mold, Yiyang Zhuang

Masters Theses

"The continuous casting process has been widely used for most of the steel production in the world instead of conventional ingot casting/rolling. Traditionally, thermocouples are being widely used to monitor the mold temperature in the continuous casting which has the following drawbacks: large size, low spatial resolution, and single detection point. On the contrary, fiber optic sensors can be a promising solution to the continuous casting temperature monitoring owing to its advantage of compact size, high resolution, high-temperature survivability, etc.

In this thesis, we successfully developed extrinsic Fabry-Perot interferometer (EFPI) sensor for point temperature sensing, and optical frequency domain reflectometry …


Numerical Modeling Of Capillary-Driven Flow In Open Microchannels: An Implication Of Optimized Wicking Fabric Design, Mehrad Gholizadeh Ansari Jan 2018

Numerical Modeling Of Capillary-Driven Flow In Open Microchannels: An Implication Of Optimized Wicking Fabric Design, Mehrad Gholizadeh Ansari

Masters Theses

"The use of microfluidics to transfer fluids without applying any exterior energy source is a promising technology in different fields of science and engineering due to their compactness, simplicity and cost-effective design. In geotechnical engineering, to increase the soil's strength, hydrophilic wicking fibers as type of microfluidics have been employed to transport and drain water out of soil spontaneously by taking advantage of natural capillary force without using any pumps or other auxiliary devices. The objective of this study is to understand the scientific mechanisms of the capability for wicking fiber to drain both gravity and capillary water out of …


Evaluating Microgrid Effectiveness In Transitioning Energy Portfolios, Jacob Marshal Hale Jan 2018

Evaluating Microgrid Effectiveness In Transitioning Energy Portfolios, Jacob Marshal Hale

Masters Theses

"Microgrid energy systems have emerged as a potential solution to rising greenhouse gas emissions from dependence on fossil fuels. This research provides a framework for evaluating the utility of microgrids. Three key findings are presented: use of a state-of-the-art matrix (SAM) analysis to identify gaps in key research areas that inhibit wide-spread microgrid adoption, development of a system dynamics (SD) model, and a cost benefit analysis case study to evaluate microgrid feasibility in partially meeting the energy demand of a building. Governments play a central role in developing clean energy strategies. A SAM was developed to determine if key microgrid …


A Hybrid Cavity And Parallel-Plate Peec Method For Analysis Of Complex Power Net Area Fills, And A Tool Development For Peak Distortion Analysis, Chenxi Huang Jan 2018

A Hybrid Cavity And Parallel-Plate Peec Method For Analysis Of Complex Power Net Area Fills, And A Tool Development For Peak Distortion Analysis, Chenxi Huang

Masters Theses

"Modern ASICs and FPGAs are becoming more and more dense, which is causing an increasing demand of the current draw from the power distribution network (PDN). And one of the main design objectives of a power distribution network is to reduce the voltage noise ripple below a specified allowable limit. Although the target impedance is a commonly used criterion in most PDN designs, it may not be efficient because it's usually rather pessimistic. Herein a time domain voltage ripple decomposition approach is proposed to avoid overdesign as well as provide design guidance to PI engineers. Based on a physics-based circuit …


Computational Investigation Of Polymer Electrolyte Membrane Fuel Cell With Nature-Inspired Fibonacci Spiral Flow Field, Suleyman Kose Jan 2018

Computational Investigation Of Polymer Electrolyte Membrane Fuel Cell With Nature-Inspired Fibonacci Spiral Flow Field, Suleyman Kose

Masters Theses

"Polymer electrolyte membrane fuel cells (PEMFC) are promising clean energy devices. The flow field design has crucial role in PEMFC performance for effective distribution of reactants and removal of products. Several nature-inspired flow field designs have recently been proposed in the literature. Common characteristics of these designs were sudden changes in the flow direction through sharp bends and flow field geometries restrained to areas having corners. In this thesis, Fibonacci spiral configuration, which is found in the nature from hurricanes to seashells, was considered for flow field pattern of a PEMFC. Contrary to the bio-inspired designs proposed in previous studies, …


Designed Extrudate For Ceramic Additive Manufacturing, Devin Mcmillen Jan 2018

Designed Extrudate For Ceramic Additive Manufacturing, Devin Mcmillen

Masters Theses

"The objective of this thesis work was to design ceramic paste systems that assist in achieving a high theoretical density ( > 95%) after deposition by a novel additive manufacturing process, i.e. Ceramic On-Demand Extrusion (CODE). The work is encompassed in five main sections: Sections 1 and 2 provide an introduction and literature review of relevant topics for the following sections of experimentation. Section 3 provides an analysis of a reaction chemistry to identify three discrete materials that could be combined via CODE and result in zirconium diboride (ZrB2) post-sintering. Section 4 describes the development of a high solids …


Quantifying On-Orbit Performance Of Cubesat Micropropulsion Systems By Observing Orbital Element Variations, Bradyn William Morton Jan 2018

Quantifying On-Orbit Performance Of Cubesat Micropropulsion Systems By Observing Orbital Element Variations, Bradyn William Morton

Masters Theses

"The Advanced Propulsion Experiment mission in development by the Missouri University of Science and Technology's satellite research team (M-SAT) is a technology demonstration mission of a multi-mode propulsion system. The true test of any satellite propulsion system is the on-orbit performance. The purpose of this research is to develop methods for quantifying the on-orbit performance of the multi-mode propulsion system. This performance can be determined by observing the small variations in the orbital element parameters and using a differential corrector with the Gauss Variation of Parameter equations. Furthermore, this research could be used to determine and quantify a propulsion system's …


Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin Jan 2018

Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin

Masters Theses

The purpose of this study was to investigate durable solar cell cover glass joins produced by diffusion bonding with deep eutectic solvents (DES) and to develop a novel process of joining optically transparent materials at low temperatures. A joined PV cell-glass specimen was characterized using Raman, μ-FTIR, SEM-EDS, and thin-film XRD. DESs were created with malonic acid (MAL) and choline chloride (ChCl) of varying composition factors (CF; CF=MAL/ChCl). Joining borosilicate glass coupons was attempted using DESs with CF = 0.65 and 1 at temperatures between 100-150 °C for 20 hours. Joining the glass coupons failed at all temperatures and oxygen …


Customized Multi-Group Cross Section Generation With Njoy For Discrete Ordinates Computed Tomography And Radiography Simulation, Steven Michael Wagstaff Jan 2018

Customized Multi-Group Cross Section Generation With Njoy For Discrete Ordinates Computed Tomography And Radiography Simulation, Steven Michael Wagstaff

Masters Theses

"The purpose of this work was to explore the creation of photoatomic multi-group cross section libraries to be used with a software package DOCTORS (Discrete Ordinates Computed TOmography and Radiography Simulator). This software solves the linear Boltzmann equation using the discrete ordinates method [1]. To create these libraries, NJOY2016 was used, creating both fine and broad energy multi-group cross section files. The cross section's accuracy was tested against an equivalent Monte Carlo simulation using MCNP6.

Two simulation geometries were used. The first, a cylindrical water phantom with a single source projection placed in front, simulating an X-ray radiography. The second …


Effect Of Microstructural Features On Steel Machinability, Mark C. Emmendorfer Jan 2018

Effect Of Microstructural Features On Steel Machinability, Mark C. Emmendorfer

Masters Theses

Non-metallic inclusions can have a tremendous impact on the machinability of steel. Some oxide inclusions such as alumina, spinel, and other refractory abrasive oxide inclusions can have a detrimental effect on machinability. Modification of oxide inclusions by calcium treatment can promote the formation of low melting point oxides such as anorthite and gehlenite inclusions that can assist in chip formation and form a lubricating layer on the rake surface of the machine tool. MnS is known to be beneficial to improving the machinability of steel. They assist in chip formation by being heavily deformed in the primary shear zone. Sulfide …


The Development Of A New Formulation Of Fly Ash Class C Based Geopolymer And Assessing Its Performance In Presence Of Drilling Fluid Contamination, Mohamed Saad Ahdaya Jan 2018

The Development Of A New Formulation Of Fly Ash Class C Based Geopolymer And Assessing Its Performance In Presence Of Drilling Fluid Contamination, Mohamed Saad Ahdaya

Masters Theses

"Cementing is one of the most critical steps in the drilling and completion of oil wells. Traditionally, Portland cement is used for oil cementing operations; however, geopolymer materials have recently attracted much attention because they are more cost-effective and have less environmental impacts.

An intensive laboratory work was conducted to obtain a new formulation of fly ash class C based geopolymer cement to be used as a potential alternative cementing material to Portland cement in oil and gas cementing. Twenty-four variations of fly ash class C based geopolymers were prepared, and by comparing several of their properties using API standard …


Field Implementation Of Cement-Based Composite Strengthening Technologies, Michael Andrew Janke Jan 2018

Field Implementation Of Cement-Based Composite Strengthening Technologies, Michael Andrew Janke

Masters Theses

"With infrastructure continuing to age, technologies are being developed to strengthen structures as a more sustainable option than replacement. The use of fiber-reinforced cementitious matrix (FRCM) strengthening systems is a promising new technology for adding flexural and shear capacity to existing reinforced concrete members. While cement based systems with carbon, PBO, and steel have all been implemented in a lab setting, there is not research data available for installation in the field. FRCM composites have advantages over more widely used fiber reinforced polymer (FRP) composites such as heat resistance and compatibility with concrete substrate. FRP systems have previously been field …


An Investigation Into The Effects Of Ion Tracks On Α-Quartz, Bryant Alan Kanies Jan 2018

An Investigation Into The Effects Of Ion Tracks On Α-Quartz, Bryant Alan Kanies

Masters Theses

"The passage of a swift heavy ion through a material can cause columnar, amorphous nano-structures known as ion tracks. Swift heavy ions are present in a number of applications ranging from nuclear reactors to nuclear waste storage and onboard spacecraft. The study of ion tracks has been ongoing since the late 1950s and has led to several technological advancements. In fact, ion beams have been used to enhance material properties and aid in the production of electrical components. Ion beams, and their resultant ion tracks, can therefore be seen as a method to purposefully alter material properties such as thermal …


Characterization And Tailoring Of Powder Used In Additive Manufacturing And Plasma Spheroidization, Caitlin S. Kriewall Jan 2018

Characterization And Tailoring Of Powder Used In Additive Manufacturing And Plasma Spheroidization, Caitlin S. Kriewall

Masters Theses

"There are many processes that use metal powder as the starting material for the production of parts. With the growth of these manufacturing techniques, more critical part applications are being considered. In order to fully understand the process and create consistent parts, powder properties need to be well understood. Selective laser melting (SLM) is a powder bed-based additive manufacturing process. During processing, heat-affected powders are generated and can deposit within the build area. The current work investigated the characterization of heat-affected 304L stainless steel powder using techniques such as scanning electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy to detect …


Analysis And Mitigation Of Parallel-Plate Noise For High-Isolation Applications, Zachary Joel Legenzoff Jan 2018

Analysis And Mitigation Of Parallel-Plate Noise For High-Isolation Applications, Zachary Joel Legenzoff

Masters Theses

"Achieving highs levels of isolation between different functionalities in a PCB can be challenging. One of the major issues is that vertically adjacent planes or area fills in a PCB can form a parallel-plate waveguide with no cutoff frequency and serve as an efficient coupling mechanism between interconnects. Due to the finite size of the conductors, reflections off the edges of these parallel-plate cavities can result in the formation of standing-wave patterns with very high field strengths, resulting in high coupling at certain frequencies. This noise coupling mechanism can be suppressed by connecting the parallel plates together with an adequate …


Imaging The Subsurface In Eastern Part Of Lake Chesterfield Using A Combination Of Geophysical Tools, Jiawei Li Jan 2018

Imaging The Subsurface In Eastern Part Of Lake Chesterfield Using A Combination Of Geophysical Tools, Jiawei Li

Masters Theses

"The Lake Chesterfield North Dam in Wildwood city, Missouri has been leaking, more or less continuously since the dam was constructed in 1986 despite mitigation efforts in 1988, 1994, 1995, 2004, and 2005. Neither the grouting efforts in 1988, 1994, 1995, 2004 or 2005, nor the placement and rehabilitation of an impervious clay liner in 2005 has solved the problem. Indeed, in June of 2017, the water level in Lake Chesterfield dropped at an alarmingly rapid rate.

Prior to authorizing additional mitigation work, the Lake Chesterfield Home Owners Association (LCHOA) decided to acquire geophysical data across the dry lake bed. …


Microstructural Development And Its Effect On Aqueous Corrosion Of A Borosilicate Glass Ceramic For Waste Vitrification, Nicholas Stephen Roberts Jan 2018

Microstructural Development And Its Effect On Aqueous Corrosion Of A Borosilicate Glass Ceramic For Waste Vitrification, Nicholas Stephen Roberts

Masters Theses

"Waste loadings of reprocessed spent nuclear fuel vitrified into borosilicate glass can be increased by precipitating environmentally stable phases concentrated with waste components in a chemically stable glass matrix. The principal objective of this thesis was to characterize the development of crystalline powellite (CaMoO4 and related phases) and oxyapatite (Ca2LN8Si6O26) in borosilicate glass-ceramics and to determine how the formation of those phases affected its chemical durability.

Borosilicate glasses provided by PNNL were re-melted and quenched at rates from over 300⁰C/s to ~0.05⁰C/s. Isothermal heat treatment experiments were conducted by quenching melts …