Engineering Commons^™

Visibility-Based Pursuit-Evasion In The Plane, Nicholas Michael Stiffler

Theses and Dissertations

As technological advances further increase the amount of memory and computing power available to mobile robots, we are seeing an unprecedented explosion in the utilization of deployable robots for various tasks. The speed at which robots begin to enter various domains is largely dependent on the availability of robust and efficient algorithms that are capable of solving the complex planning problems inherent to the given domain. One such domain which is experiencing unprecedented growth in recent years requires a robot to detect and/or track a mobile agent or group of agents.

In these scenarios, there are typically two players with …

Modeling Human-Structure Interaction Using A Controller System, Albert Ricardo Ortiz Lasprilla

Theses and Dissertations

The effects of human loads on structures are difficult to predict because they depend on the type of activity people are performing. However, models for typical activities such as standing, sitting and jumping have been proposed in the literature. Traditional models represent the human body as a system of lumped masses, dampers and springs arranged in a system with multiple degrees of freedom. Arguably, these models might not fully represent the human body because lumped masses, dampers and springs cannot add energy to the overall system. Furthermore, people could react differently to different levels of excitation and other environmental conditions. …

An Improved Ship Design Tool For Comparing Performance Of Multiple Ship Designs Across User-Defined Missions, Helder Jose De Almeida Pais

Theses and Dissertations

In the early stages of ship design, engineers from many different disciplines need to have confidence that a design being produced converges across the electrical, mechanical, and thermal domains, and that the design meets the needs of the stakeholders, and, that a particular design performs better or more optimally than other designs produced to accomplish a mission. The tools currently available do not permit the engineering teams to gain this insight in a reasonable amount of time. In this thesis, we discuss the improvements that we have made to our existing ship design tools in the S3D environment, allowing for …

An Advanced Tabu Search Approach To The Dynamic Airlift Loading Problem, August G. Roesener, J. Wesley Barnes

Faculty Publications

This research effort presents a tabu search algorithm to solve the dynamic airlift loading problem. Given a set of palletized cargo items which require transportation from an aerial port of embarkation to an aerial port of debarkation within a pre-specified time frame, the dynamic airlift loading problem seeks to partition the pallets into aircraft loads, select an efficient and effective subset of aircraft from available aircraft, and assign the pallets to allowable positions on those aircraft. The dynamic airlift loading problem differs from many partitioning and packing problems described in the literature because, in addition to spatial constraints, factors such …

Finite Control Set Model Predictive Control Of Direct Matrix Converter And Dual-Output Power Converters, Ozan Gulbudak

Theses and Dissertations

Model Predictive Control (MPC) with a finite control set has been successfully applied to several power converter topologies as reported in the scientific literature and research activity on predictive control techniques has increased over the last few years. MPC uses a discrete-time model of the system to predict future values of control variables for all possible control actions and computes a cost function related to control objectives to find the optimal control action. The control action which minimizes the cost function is selected and applied to the system for the next time interval. Different control objectives can be introduced in …

Modeling And Loss Analysis Of Wide Bandgap Power Semiconductor Devices, Kang Peng

Theses and Dissertations

In recent times, the development of high power density and high efficiency power converters has become critical in power electronics applications like electric vehicles, aircrafts, electric ships and so on. High-switching-frequency and high-temperature operation are required to achieve this target. However, these requirements are exceeding the theoretical material-related limits of silicon (Si) based devices. The emerging wide bandgap power semiconductor technology is a promising solution to meet these requirements. Silicon Carbide (SiC) and Gallium Nitride (GaN) are the most promising among all wide bandgap semiconductor materials. SiC and GaN have almost a three times larger bandgap (about 3eV), compared with …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Project Lead the Way (PLTW) Hosted by Mechanical Engineering

3 E’S Enterprise Architecture Framework (That Encompasses Business Process, Information Systems, And Information Technology), Nicholas C. Bucciarelli Mr.

Articles

No abstract provided.

Adsorption Reversibility Of So2, No2, And No On 13x And 5a Zeolites, Peter Fairchild

Theses and Dissertations

The adsorption reversibility of gasses that are typically found in flue gas for coal based power plants, such as SO2, NO2, and NO, onto 13X and 5A zeolites was presently investigated. The four individual gas mixtures containing these species consisted of 74 ppm NO (balance He), 74 ppm NO2 (balance He), 42 ppm SO2 (balance He), and 500 ppm SO2 (balance N2), which were also consistent with the values that are found in flue gas. Another gas, 15.03 mol% CO2 (balance N2), was also used in this work to evaluate the role of exposing SO2 to the zeolite on their …

Multiscale Modeling Of Water Transport And The Influence Of Water Quality Parameters On Membrane Processes, Linkel Kwabena Boateng

Theses and Dissertations

Membrane-based desalination processes have become a viable means of producing potable water to meet water resource needs in both industrialized and developing nations. Extensive experimental investigation, in conjunction with computational modeling is critical in the development of sustainable and cost-effective desalination technologies. The overall goal of this dissertation is to develop a multiscale modeling framework to elucidate water and salt transport mechanisms and the influence of water quality parameters on membrane processes. The key tasks involved in this study are: establish a criterion for estimating water flux using Bayesian inference; develop a multiscale framework to connect molecular dynamics (MD) simulations …

Characterization, Synthesis And Stabilization Of Au Based Bimetallic Catalysis For The Hydrochlorination Of Acetylene, Kerry Charles O'Connell

Theses and Dissertations

Polyvinyl chloride (PVC) is the third most-produced plastic polymer world-wide by volume after polypropylene and polyethylene. Vinyl chloride monomer, which is polymerized into PVC, is produced via mercuric chloride catalysts that deactivate as mercury sublimes into the atmosphere from the catalyst surface, resulting in substantial environmental concerns.

In an effort to rationally synthesize non-mercuric catalysts, strong electrostatic adsorption (SEA) was used to prepare highly dispersed and active gold nanoparticles over low point of zero charge (PZC) carbon to increase the active metal surface area. The use of <1.5nm gold clusters did not lead to large increases in activity as there was an increased degree of particle coalescence during reaction for activated carbon supported samples. A pronounced support effect was observed in which oxide supports completely prevented Au sintering, but was virtually inactive. This suggests that the active site for the hydrochlorination reaction involves the carbon surface.

The stabilization of carbon supported gold nanoparticles in the HCl-rich reaction environment was …

Time-Domain Measurement Of Ultrafast Magnetization Dynamics In Magnetic Nanoparticles, Brian Egenriether

Theses and Dissertations

Ultrafast time-domain measurements are made on collections of Fe3O4 magnetic nanoparticles using an inductive measurement technique. The 10nm particles are placed directly on a coplanar waveguide (CPW) situated in an adjustable external magnetic bias field. A fast-rising step current in the CPW quickly changes the orientation of the local magnetic field causing the magnetization to align in the new field configuration. This rapidly changing magnetization induces a voltage in the CPW that is detected by a sampling oscilloscope. Magnetization dynamics predicted by the Landau-Lifshitz (LL) equation including magnetic precession and phenomenological damping are observed. The time-domain data are fitted to …

Development Of Highly Active And Stable Compressive Pt Cathode Catalysts For Polymer Electrolyte Membrane Fuel Cells, Taekeun Kim

Theses and Dissertations

With the limited fossil fuel reserve and increased power demand, polymer electrolyte membrane fuel cells (PEMFC) have been considered to be a promising alternative to the current energy consumption mode due to its high energy conversion, high efficiency, and zero emissions. However, high cost, poor stability, and sluggish kinetic for oxygen reduction reaction (ORR) of Pt/C cathode catalysts are obstacles for the commercialization of PEMFC for automotive application. The observed poor stability is attributed to a corrosion of carbon supports due to low pH, high temperature, and high anodic potentials (1.0-1.5 V) at the cathode interface during start-up/shutdown conditions. Electrochemical …

Ultrathin Microporous Metal Oxide Coatings: Preparation By Molecular Layer Deposition, Characterization And Application, Zhuonan Song

Theses and Dissertations

Molecular layer deposition (MLD), a gas phase deposition technique, was applied to deposit conformal organic-inorganic hybrid coatings by conducting a series of sequential, self-limiting surface reactions on substrates with exquisite thickness control at the sub-nanometer level. Obtained organic-inorganic hybrid coatings can subsequently be converted into porous coatings by removing the organic compound. Potential of functional coatings and membranes prepared by MLD was explored for applications from adsorptive separation, water purification, to gas storage.

We demonstrated a new concept, pore misalignment, to continuously fine tune the molecular-sieving “gate” of 5A zeolite by adjusting the external porous Al2O3 MLD coating thickness. For …

Pvdf Membranes With Stable, Ultrathin Graphene Oxide (Go) Functional Coatings For Antifouling Oil/Water Separation Under Cross-Flow Condition, Lei Wang

Theses and Dissertations

Oil/water separation plays an important role in industrial wastewater treatment and environment protection. For the treatment of oily wastewater, especially for removing oil droplets with sizes in the micrometer range, ultrafiltration (UF) membrane technology is considered the most efficient method due to its high separation efficiency and relatively simple operational process. However, caused by the deposition of the oil droplets onto the membrane surface and into the membrane pores, the fouling of UF membranes shortens their service time and degrades their separation performance in practical applications.

In this work, graphene oxide (GO) was utilized as a novel coating material to …

Repair Of Failing Spirit Lake Outlet Tunnel At Mount St. Helens, J. P. Britton, S. K. Askelson, C. M. Budai, D. H. Scofield

International Symposium on Hydraulic Structures

The 18 May 1980 eruption of Mount St. Helens resulted in one of the largest debris avalanches recorded in history. The debris avalanche blocked the natural outlet of Spirit Lake. To prevent an uncontrolled and catastrophic lake break-out, the U.S. Army Corps of Engineers (USACE) constructed the Spirit Lake Outlet Tunnel from 1984 to 1985. Because Spirit Lake is located in the Mount St. Helens National Volcanic Monument, the project was transferred to the U.S. Forest Service (USFS) for ownership and management. During original tunnel construction, the most difficulty occurred within the 90-m-wide Julie and Kathy L. shear zone complex. …

Optimization Of Air Entrained Grout Enriched Roller Compacted Concrete For Improving Freeze-Thaw Resistance Of Hydraulic Structures, E. S. Musselman, R. J. Flynn, G. J. Zimmer, J. R. Young Pe

International Symposium on Hydraulic Structures

Roller compacted concrete (RCC) is frequently used to construct gravity dams, stepped spillways, and to armor earthen embankments for passing extreme floods. Early experience on RCC dam applications in the 1980s showed a tendency for seepage to develop along the lift lines. Therefore, RCC dam designers started including an upstream facing system as a watertight barrier. An alternative facing material that has been used extensively overseas and is starting to gain more widespread acceptance in the United States is Grout Enriched RCC (GERCC). The grout enriched method of face construction has been shown to be less expensive than other facing …

South Channel Dam Rehabilitation Project - Successfully Addressing Dam Rehabilitation Challenges, M. D. Graeser, M. C. Jensen

International Symposium on Hydraulic Structures

The Post Falls South Channel Dam is located on the Spokane River in Post Falls, Idaho. The concrete gravity dam was constructed in 1906 and was recently rehabilitated. The rehabilitation project included several design elements; the primary objectives were the replacement of the six spillway gates and hoists and significant rehabilitation of the concrete. The South Channel Dam rehabilitation encountered several challenges due to the age and condition of the existing structure, the large scale of the rehabilitation, and the location of the project. The concrete rehabilitation addressed several challenges which are presented in detail. The existing concrete consisted of …

Optimizing A New Flow Diversion Structure For The Planned Expanding Of The Spillway For The Malter Dam In Germany Using A Physical Hydraulic Model, J. Schmidt, J. Wieland, J. Jensen

International Symposium on Hydraulic Structures

The State Reservoir Administration of Saxony is planning to expand the spillway discharge capacity of the 102-year-old Malter Dam. After a catastrophic flood in 2002, updated hydrologic modeling indicated that the design discharges for the dam had increased significantly. As a result, the original spillway discharge capacity was insufficient to pass the revised design flows. A design concept was developed to add a second spillway and stilling basin to the dam, and to pass flow into this spillway using a novel vertical flow separator. The design and performance of this system was evaluated using a 1:25-scale physical model. The modeling …

St. Mary Diversion Dam – Case Study Of A 100 Year Old Diversion, B. J. Heiner, J. Wagner

International Symposium on Hydraulic Structures

After 100 years of service, the St. Mary Diversion Dam is being replaced with a new design that will provide more effective fish passage and protection. The diversion is located in northern Montana, adjacent to the east side of Glacier National Park. It diverts water from the St. Mary River 1.21 km (0.75 mile) downstream of Lower St. Mary Lake. The existing 60.35-meter-long and 1.83-meter-high (198-foot-long and 6-foot-high) concrete weir diverts up to 24 cubic meters per second (850 cubic feet per second) design flow from the St. Mary River into the North Fork of the Milk River through a …

Evaluation Of Flexible Barrier And Sabo Dam To Control Effects Of Debris Flow In Santo Domingo Ravine, J. W. Cabrera Cabrera, L. F. Castillo Navarro

International Symposium on Hydraulic Structures

Coast of Peru is characterized for the presence of ephemeral creeks which drain water only on wet season. The extremely dry soil and pebble combined with precipitation produce debris flow in a seasonal geodynamic. This is the case of Santo Domingo ravine which is located at eastern Lima, and drains their water to Rimac River. In this article the vulnerability of villages near to Santo Domingo ravine by debris flow and use of flexible barrier and sabo dams are analyzed. In a first stage, the liquid hydrograph to a 100 years return period was built and a solid hydrograph, a …

Fish Passage Behavior Behavior Through Baffled And Nonbaffled Culvert, M. A. Khodier, Blake P. Tullis

International Symposium on Hydraulic Structures

Culverts can have a negative impact on fish passage. Installing baffles inside culverts can potentially improve culvert fish passage by decreasing the flow velocity and increasing the flow depth. Fish passage behaviors of wild brown trout through a small prototype-scale (0.6 m diameter), 18.3 m in length, baffled, and non-baffled culverts were observed in the laboratory for a variety of discharges and pipe slopes (up to 6%). The baffle height and spacing was 0.15 and 0.9 times the culvert diameter, respectively. The correlation between successful fish passage, sample fish population, and the fish length was evaluated. The influence of baffles …

The Role Of Physical And Numerical Modeling In Design Development Of The Priest Rapids Fish Bypass, T. C. Lyons, M. Politano, C. Dotson, L. J. Weber, D. Hay

International Symposium on Hydraulic Structures

This paper describes a number of years of physical and numerical modelling that were instrumental in the development of the final fish bypass design at Priest Rapids Dam. Three physical models and multiple numerical models were used to guide the design of the fish bypass including its location on the dam, impact on forebay and tailrace flow patterns, intake configuration, design flow rates, flow control scheme, tailrace egress, potential for scour near the dam, potential impacts on total dissolved gas (TDG), impacts on spillway and powerhouse operation, and overall fish friendliness of the bypass.

Throughout those years of design work, …

Study On The Proceeding Of Hydraulic Problem Of Simulating Natural Fish Passage, Zhijuan Wang, Qingyuan Yang, Minghai Huang, Yong He

International Symposium on Hydraulic Structures

Fish passage in water conservancy projects is an important means of improving river connectivity, and reducing the impact on the ecological environment. Simulating natural fish passage, which aims at the purpose of the river ecological corridor by the means of ecological optimization on the structure and section type based on the traditional fish passage, is promoted and applied in recent years gradually. At the same time, the hydraulic research related to the simulating natural fish passage has made great progress. In this paper, we firstly collected and summarized the research experience of the domestic and foreign typical fish passage, analyzed …

Application Of The Optical Flow Method To Velocity Determination In Hydraulic Structure Models, D. B. Bung, Daniel Valero

International Symposium on Hydraulic Structures

Optical flow estimation is used in Computer Vision for detection of moving obstacles in a sequence of images. The optical flow (OF) is defined as the displacement of brightness patterns between two sequent images. In this paper,this method is applied to high-speed images taken in hydraulic structure models for determination of velocity fields.Water is seeded with tracer particles in two cases and is self-aerated in a third case. It will be shown that the OF method gives valuable results which compare well to other velocity measurements, e.g. by Particle ImageVelocimetry. The OF method is generally more time-consuming compared to PIV, …

Technical Developments In Fish Exclusion, Guidance, And Collection Materials, A. L. Peters

International Symposium on Hydraulic Structures

Construction of mills, dams and other structures in rivers and streams, and the withdrawal of water for irrigation or cooling industrial facilities vital to social and economic progress, have impacted the survival of marine life. Barriers and guidance or collection nets can protect fish and aquatic species while allowing water to flow unimpeded for commercial and industrial use. However, nets can attract aquatic growth, fill with debris, degrade with environmental stress, and be expensive to operate and maintain.

A closer look at the technical developments of materials and net designs in diverse settings can offer guidance that will be of …

Evaluation Of Spillway Stilling Basin Performance And Reservoir Sediment Flushing In A Physical Model Case Study: Due Hydroelectric Project In Ecuador, Ali Habibzadeh, Brian Hughes, Hernan Barahona

International Symposium on Hydraulic Structures

The Due Hydroelectric Project is a proposed 50 MW run-of-river hydroelectric project being developed by Hidroalto SA. The project will be located on the Rio Due in Ecuador. The civil works of the intake facility will be comprised of a 133.45 m wide diversion weir, with two overflow spillways and six gated sluice channels; a four bay intake structure with sediment excluder; and, a fish bypass facility. Northwest Hydraulic Consultants (NHC) evaluated the initial design of the Due intake and spillway facilities using a 1:35 Froude-scaled physical model for river discharges ranging from the intake design discharge of 57.2 m3 …

Impacts Of Tailwater On The Design Of Several Stilling Basins In The Usa, L. E. Shearin-Feimster

International Symposium on Hydraulic Structures

The dissipation of excess energy from flows exiting a spillway is often needed to prevent or reduce to acceptable levels conceivable negative impacts to the downstream channel, spillway, and dam (e.g., erosion, undermining). The optimization of a hydraulic jump type stilling basin using general purpose published design methodologies (i.e., USBR, SAF, etc.) for a project can be challenging, as these methodologies may not account for all site specific conditions and structure formulations by designers. Also, it is not often clear to a designer as to which flow rates (and corresponding flood events) will have the greatest influence on the basin …

A Risk Based Framework For Evaluating Gated Spillway Operations, Greg Paxson, Marty Mccann Jr, Mark Landis

International Symposium on Hydraulic Structures

Gated spillways are often necessary to provide both operational flexibility and discharge capacity to pass large flood events. However, gated spillways present operational challenges to dam owners and operators, often necessitating development of a flood operations plan (FOP) that is used in tandem with the dam’s emergency action plan (EAP). Even a well-intentioned and robust FOP/EAP can require personnel to predict flooding, use judgment particular to the requirements of the plan, and react quickly. In addition, all of the equipment required to operate the gates need to function as designed and be operated in accordance with the FOP.

This paper …

A Remotely Controlled Siphon System For Dynamic Water Storage Management, Arturo Leon, Ali Alnahit

International Symposium on Hydraulic Structures

Previous research has concluded that upland wetlands could be effective to control small floods, yet for large floods their value may be greatly reduced as their storage capacity may be exceeded. A potential solution could be to release water from wetlands ahead of (e.g., few days before) a heavy rainfall event that is forecasted to produce flooding. In this case, the wetlands would be partially empty when this rainfall occurs. This work is part of a long term project which aims at developing a decision support system (DSS) that will determine optimal flooding scenarios with dynamic management of wetlands using …