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2008

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Articles 211 - 240 of 4190

Full-Text Articles in Engineering

Rank-Data Distribution Method (R-D Method) For Daily Time-Series Bayesian Networks And Total Maximum Daily Load Estimation, Joon-Hee Lee Dec 2008

Rank-Data Distribution Method (R-D Method) For Daily Time-Series Bayesian Networks And Total Maximum Daily Load Estimation, Joon-Hee Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Daily time series-based models are required to estimate the higher frequency fluctuations of nutrient loads and concentrations. Some mechanistic mathematical models can provide daily time series outputs of nutrient concentrations but it is difficult to incorporate non-numerical data, such as management scenarios, to mechanistic mathematical models. Bayesian networks (BNs) were designed to accept and process inputs of varied types of both numerical and non-numerical inputs.

A Rank-Data distribution method (R-D method) was developed to provide large time series of daily predicted flows and Total Phosphorus (TP) loads to BNs driving daily time series estimates of T-P concentrations into Hyrum and …


Measuring And Modeling Of Plant Root Uptake Of Organic Chemicals, Erik Dettenmaier Dec 2008

Measuring And Modeling Of Plant Root Uptake Of Organic Chemicals, Erik Dettenmaier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Determining the root uptake of xenobiotic organic chemicals into plants is critical for assessing the human and ecological health risks associated with the consumption of plants growing in contaminated environments. Root uptake of xenobiotic organics occurs passively in conjunction with transpiration and the transport from root to shoot is ultimately controlled by passage through one or more lipid root membranes. The transpiration stream concentration factor (TSCF), the ratio between the concentration of a chemical in the xylem to that in the solution used by the roots, is used to describe the relative ability of an organic chemical to be passively …


Angles-Only Navigation For Autonomous Orbital Rendezvous, David Charles Woffinden Dec 2008

Angles-Only Navigation For Autonomous Orbital Rendezvous, David Charles Woffinden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The proposed thesis of this dissertation has both a practical element and theoretical component which aim to answer key questions related to the use of angles-only navigation for autonomous orbital rendezvous. The first and fundamental principle to this work argues that an angles-only navigation filter can determine the relative position and orientation (pose) between two spacecraft to perform the necessary maneuvers and close proximity operations for autonomous orbital rendezvous. Second, the implementation of angles-only navigation for on-orbit applications is looked upon with skeptical eyes because of its perceived limitation of determining the relative range between two vehicles. This assumed, yet …


Generalized Event Tree Algorithm And Software For Dam Safety Risk Analysis, Anurag Srivastava Dec 2008

Generalized Event Tree Algorithm And Software For Dam Safety Risk Analysis, Anurag Srivastava

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Event tree analysis is a most commonly used method in dam safety risk analysis modeling. Available software tools for performing event tree analyses lack the flexibility to efficiently address many important factors in dam safety risk analysis. As a result of these practical limitations, spreadsheets have been used, sometimes including Visual Basic macros, to perform these analyses. However, this approach lacks generality and can require significant effort to apply to a specific dam or to modify the event tree structure. In response to these limitations, here a generalized event tree analysis tool, DAMRAE (DAM safety Risk Analysis Engine), has been …


Particle Characterization And Concentration Using Aerodynamic Vectoring, Zac Humes Dec 2008

Particle Characterization And Concentration Using Aerodynamic Vectoring, Zac Humes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An experimental demonstration of a new, non-contact particle characterization technique called Aerodynamic Vectoring Particle Sorting (AVPS) is presented. AVPS uses secondary blowing and suction control flows-flows that are a fraction of the jet flow rate-to sharply change the direction of a planar, particle-laden jet. As the jet is vectored, particles present in the flow experience a resultant drag force, dependent upon their size, that balances inertia. Since this balance determines the particle's trajectory, vectoring the flow leads to a separation of particles downstream. This simple, low-pressure-drop sorting technique classifies particles with less risk of damage or contamination than currently available …


Uptake And Release Kinetics Of Sulfolane By Cattail Plants, Tiffany Leo Dec 2008

Uptake And Release Kinetics Of Sulfolane By Cattail Plants, Tiffany Leo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sulfolane (tetrahydrothiophene 1,1-dioxide, C4H8O2S) is a highly water-soluble, non-ionizable, organic compound used along with diisopropanolamine in the Sulfinol™️ process to remove hydrogen sulfide from natural gas. Sulfolane has been identified in wetland vegetation near a sour gas processing facility in Alberta, Canada, and extensive uptake of sulfolane by cattails has also been demonstrated in a laboratory environment. Consequently, it has been suggested that plants could play an important role in the natural attenuation of sulfolane in contaminated wetlands. This assumes that the sulfolane is metabolized and/or sequestered in the plant and not released back …


Integrating Surface And Sub Surface Flow Models Of Different Spatial And Temporal Scales Using Potential Coupling Interfaces, Alphonce Chenjerayi Guzha Dec 2008

Integrating Surface And Sub Surface Flow Models Of Different Spatial And Temporal Scales Using Potential Coupling Interfaces, Alphonce Chenjerayi Guzha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of this research was to develop and utilize a coupled surface water groundwater model to simulate hydrological responses of watersheds. This was achieved by coupling the U.S. Geological Survey (USGS) groundwater flow model, MODFLOW, and the rainfall runoff model, TOPMODEL, in one case study and coupling MODFLOW with a networked version of TOPMODEL called TOPNET in another case study. The model coupling was achieved using the InCouple approach, which utilizes Potential Coupling Interfaces (PCIs) that are abstractions from model flow diagrams that expose only those aspects of a model relevant to coupling. Coupling the rainfall-runoff models to …


Dynamic Analysis Of Less-Than-Truckload Shipments And Test Method To Simulate This Environment, Sher Paul Singh, E. Joneson, Jay Singh, G. Grewal Dec 2008

Dynamic Analysis Of Less-Than-Truckload Shipments And Test Method To Simulate This Environment, Sher Paul Singh, E. Joneson, Jay Singh, G. Grewal

Industrial Technology and Packaging

This paper provides results from a comprehensive data measurement study that analyzed the vibration dynamics produced inside the trailers used for less-than truckload (LTL) shipments. The trailers used for this segment of the package transportation environment are very different in size and suspension than those used for full truckload shipments. This study measured the vertical, lateral and longitudinal vibration inside a trailer as a function of road surface. In addition, the study developed a video showing freight movement inside the trailer to determine physical displacement and shifting of the loads. A set of recommendations was developed to safely load and …


Biogeography-Based Optimization, Daniel J. Simon Dec 2008

Biogeography-Based Optimization, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

Biogeography is the study of the geographical distribution of biological organisms. Mathematical equations that govern the distribution of organisms were first discovered and developed during the 1960s. The mindset of the engineer is that we can learn from nature. This motivates the application of biogeography to optimization problems. Just as the mathematics of biological genetics inspired the development of genetic algorithms (GAs), and the mathematics of biological neurons inspired the development of artificial neural networks, this paper considers the mathematics of biogeography as the basis for the development of a new field: biogeography-based optimization (BBO). We discuss natural biogeography and …


Optimal Maintenance Crew Composition And Enhancement Of Crew Productivity, Robert Schober Dec 2008

Optimal Maintenance Crew Composition And Enhancement Of Crew Productivity, Robert Schober

All Theses

The South Carolina Department of Transportation (SCDOT) dedicates a large portion of its budget and other resources to the maintenance of the State's transportation infrastructure. In order to maximize the efficiency and productivity of the State's highway maintenance workforce, the SCDOT partnered with Clemson University to research the performance of these maintenance crews. The goal of this research is to identify optimal crew compositions, if possible, and to suggest potential crew productivity enhancement methods.
Data was collected from the SCDOT Highway Maintenance Management System (HMMS) and crew rankings were developed based on several pre-determined performance criteria. These rankings were then …


Analysis Of In-Flight Vibration For A Turbo Propeller Aircraft, Kyle Dunno Dec 2008

Analysis Of In-Flight Vibration For A Turbo Propeller Aircraft, Kyle Dunno

All Theses

A data recorder was utilized to record in-flight vibration of a turbo propeller aircraft. The data recorded produced power spectral density (PSD) profiles which are currently used in laboratory settings to drive vibration tables in order to simulate a particular vehicle type. Overall Grms values from the averaged data were then statistically compared to published standards and other studies to determine if there were differences in overall Grms values.
The data recorder was rigidly mounted to the cargo area of the turbo propeller aircraft. Thirty flights were recorded which varied in flight time from less than one hour to greater …


Circuit Modules For Six-Port Reflectometer On Chip, Chaojiang Li Dec 2008

Circuit Modules For Six-Port Reflectometer On Chip, Chaojiang Li

All Theses

Broadband signal generator is an indispensable module for broadband Six-Port Reflectometer (SPR). To integrate a whole SPR system on a chip, the source must be compact. In this thesis, a three-stage voltage-controlled oscillator (VCO), using two parallel weak invertor-chain oscillators and sense amplifiers, is proposed and designed in a 0.13 µm CMOS process. These two parallel weak inverter-chain oscillators extend the low frequency operating range and the sense amplifiers expand the high frequency operation. The measurement results show that the oscillator can be tuned from 430 MHz to 12 GHz, which satisfies the targeted SPR operating frequency range.
In order …


Optimal And Heuristic Resource Allocation Policies In Serial Production Systems, Ramesh Arumugam Dec 2008

Optimal And Heuristic Resource Allocation Policies In Serial Production Systems, Ramesh Arumugam

All Theses

We have studied the optimal server allocation policies for a tandem queueing system under different system settings. Motivated by an industry project, we have studied a two stage tandem queueing system with arrival to the system and having two flexible servers capable of working at either of the stations. In our research, we studied the system under two different circumstances: modeling the system to maximize throughput without cost considerations, modeling the system to include switching and holding costs along with revenue for finished goods. In the maximizing throughput scenario, we considered two different types of server allocations: collaborative and non-collaborative. …


The Effect Of Montmorillonite Nanoclay On Mechanical And Barrier Properties Of Mung Bean Starch Films, Bianca Stiller Dec 2008

The Effect Of Montmorillonite Nanoclay On Mechanical And Barrier Properties Of Mung Bean Starch Films, Bianca Stiller

All Theses

Starch is an interesting biodegradable polymer due to its excellent film forming properties, availability, and low cost. On the other hand, starch films are often limited by their poor mechanical properties, and water resistance. The addition of montmorillonite clays have improved these properties in both petroleum and biodegradable films.
The objective of the research was to determine the effect of montmorillonite clay on the mechanical and barrier properties on mung bean starch films.
The addition of 5% clay yielded the optimum balance between mechanical and barrier properties of these composite films with improved tensile strength (TS) of 20.8763± 0.789 MPa, …


Computational Analysis Of Input-Shaping Control Of Microelectromechanical Mirrors, Thomas Starling Dec 2008

Computational Analysis Of Input-Shaping Control Of Microelectromechanical Mirrors, Thomas Starling

All Theses

Advances in micromachining technology have enabled the design and development of high performance microelectromechanical systems (MEMS). There is a pressing need for control techniques that can be used to improve the dynamic behavior of MEMS such as the response speed and precision. In MEMS applications, open-loop control is attractive as it computes a priori the required system input to achieve desired dynamic behavior without using feedback, thus eliminating the problems associated with closed-loop MEMS control. While the input-shaping control is attractive due to its simplicity, the effectiveness of this control approach depends on the accuracy of the model that is …


P-M Characteristics Of Reinforced Concrete Sections, Paul Johnson Dec 2008

P-M Characteristics Of Reinforced Concrete Sections, Paul Johnson

All Theses

This manuscript presents two parametric studies which were performed to evaluate a provision which originated in the 1994 Uniform Building Code (UBC). This provision states that if gravity-induced axial loads carried by a reinforced concrete member are greater than 35% of the pure axial load-carrying capacity (Po) of that member, then the member cannot be used as part of the lateral force resisting system (LRFS). Along with the UBC provision, the Structural Engineers Association of California's (SEAOC) Blue Book states that the value of 0.35Po corresponds to the level of axial load representing a balanced state of strain, i.e., the …


Finite Element Analysis Of Carbon Fiber Composite Ripping Using Abaqus, Joy Pederson Dec 2008

Finite Element Analysis Of Carbon Fiber Composite Ripping Using Abaqus, Joy Pederson

All Theses

An energy dissipation system is proposed for use on consumer passenger automotive vehicles and auto racing stock cars. This system will be utilized to protect the occupants from frontal impacts with stationary or near stationary objects. The system will be affixed to the front of the car's primary structure. It is proposed to replace the traditional steel bumper currently in use. This system will not increase the weight of the car, nor will it adversely affect the aerodynamics of the body. The system will improve the crashworthiness of the vehicle. Advanced composites will be the primary sacrificial element in the …


An Integrated Routing And Distributed Scheduling Approach For Hybrid Ieee 802.16e Mesh Networks For Vehicular Broadband Communications, Rahul Amin Dec 2008

An Integrated Routing And Distributed Scheduling Approach For Hybrid Ieee 802.16e Mesh Networks For Vehicular Broadband Communications, Rahul Amin

All Theses

An integrated routing and distributed scheduling approach for fast deployable IEEE 802.16e networks is presented where distributed base stations with dual radios form a mesh backhaul and subscriber stations communicate through these base stations. The mesh backhaul is formed via an IEEE 802.16e mesh mode radio on each base station, while the subscriber stations communicate with base stations via PMP mode radios. The proposed routing scheme divides the deployed network into several routing zones. Each routing zone contains several base stations that form the mesh backhaul with one base station equipped with either a fiber, satellite or any other point-to-point …


Transmission Error Analysis And Avoidance For Ieee 802.15.4 Wireless Sensors On Rotating Structures, Jobin Jacob Dec 2008

Transmission Error Analysis And Avoidance For Ieee 802.15.4 Wireless Sensors On Rotating Structures, Jobin Jacob

All Theses

Wireless sensors are increasingly adopted in manufacturing and vehicular systems for monitoring critical components under continuous operation. Many such components move rapidly and frequently in metallic containments with challenging radio propagation characteristics.
For wireless sensors mounted on rotating structures, previous studies identified an eminent increase in packet transmission errors at higher rotation speeds. Such errors were found to occur at specific locations around the rotating spindle's periphery and such locations depended sensitively on sensor location and surrounding geometry. This thesis presents a systematic study of the expected packet error rates due to such errors, and analytically derives the first transmission …


Development Of A Quadrotor Testbed For Control And Sensor Development, Abhishek Bhargava Dec 2008

Development Of A Quadrotor Testbed For Control And Sensor Development, Abhishek Bhargava

All Theses

A quadrotor is an under actuated unmanned aerial vehicle (UAV) which uses thrust from four rotors to provide six degrees of freedom. This thesis outlines the development of a general purpose test bed that can be used for sensor and control algorithm development. The system includes the means to simulate a proposed controller and then a hardware in the loop implementation using the same software. The test bed was assembled and verified with a linear controller for both attitude and position control using feedback from an IMU (Inertial measurement Unit) and a Global Position System (GPS) sensor.
The linear controller …


Synchrophasor's Application In State Estimation, Linwood Ross Dec 2008

Synchrophasor's Application In State Estimation, Linwood Ross

All Theses

This thesis presents an investigation into the effect of synchrophasor measurements on the accuracy of a state estimator. Two state estimation algorithms have been developed in Matlab and tested on several systems. The first state estimator is the traditional non-linear estimator that is currently being used by most utilities. The second estimator is a hybrid linear state estimator. A bad data detection algorithm has been developed as well to determine the effect of synchrophasor measurements in bad data detection. A total of seven different systems are used for testing the proposed algorithms. Six systems are used in testing the bad …


Analysis Of Speed-Related Crashes Using Event Data Recorder Data, Swathi Korpu Dec 2008

Analysis Of Speed-Related Crashes Using Event Data Recorder Data, Swathi Korpu

All Theses

Safety in general is defined as 'the absence of unintended harm to living creatures or inanimate objects' (Evans, 2004). Traffic safety is measured in terms of motor vehicle crashes. A crash is an unplanned event which results in either fatality, or injury or property damage. Of all the factors that contribute to a crash, speed is a major issue, as more than 31 percent of all fatal crashes involve speeding (NHTSA, 2007). The speed-safety relationship can be determined by knowing the effect of speed on the frequency and severity of crashes. The relationship between speed and frequency of crashes is …


'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma Dec 2008

'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma

All Dissertations

This research focuses on fabricating blends and composites from natural polymers especially from proteins and natural epoxy, and describing the properties of plastics made from them. Specifically, plastic samples from partially denatured feathermeal and bloodmeal proteins, derived from the animal co-products (rendering) industry, were successfully produced through a compression molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. Therefore, this study explored blending methods for …


Real-Time Automatic Linear Feature Detection In Images, Guang Zeng Dec 2008

Real-Time Automatic Linear Feature Detection In Images, Guang Zeng

All Dissertations

Linear feature detection in digital images is an important low-level operation in
computer vision that has many applications. In remote sensing tasks, it can be used
to extract roads, railroads, and rivers from satellite or low-resolution aerial images,
which can be used for the capture or update of data for geographic information and
navigation systems. In addition, it is useful in medical imaging for the extraction of
blood vessels from an X-ray angiography or the bones in the skull from a CT or MR
image. It also can be applied in horticulture for underground plant root detection in
minirhizotron images. …


Characterization Of Vascular Smooth Muscle Cell Mechanical And Frictional Properties Using Atomic Force Microscopy, Jason Hemmer Dec 2008

Characterization Of Vascular Smooth Muscle Cell Mechanical And Frictional Properties Using Atomic Force Microscopy, Jason Hemmer

All Dissertations

A working hypothesis within the Laboratory of Vascular Research is that mechanical loading on vascular smooth muscle cells (VSMCs), especially due to solid contact from endovascular devices, contributes to the development of restenosis. In order to better understand the role of mechanical loading on VSMCs in vascular disease development, it is imperative to understand the mechanical properties of VSMCs themselves. To measure the viscoelastic and frictional properties of living VSMCs in an in vitro setting, an atomic force microscope (AFM) was utilized, thereby allowing for mechanical testing of living cells in a fluid environment. In the first phase of research, …


Effect Of Clinically Relevant Mechanical Forces On Smooth Muscle Cell Response In Model Of Balloon Angioplasty, Kara Acampora Dec 2008

Effect Of Clinically Relevant Mechanical Forces On Smooth Muscle Cell Response In Model Of Balloon Angioplasty, Kara Acampora

All Dissertations

Restenosis remains a common problem affecting the patency of endovascular intervention such as balloon angioplasty and stent placement as treatments for atherosclerosis. Denudation of the endothelial layer and the increased injury from balloon deployment can cause phenotypic changes in surrounding vascular smooth muscle cells (SMCs) in vivo. The presented work modeled this mechanical environment in vitro to investigate the role of the altered mechanical environment on the phenotypic response of SMCs. Through the system design and CFD channel characterization, a six-independent-channel system providing low oscillating wall shear stress (WSS) was manufactured to apply concurrent shear and tensile forces with uniform …


Aperture Coupling And Penetration In Various Configurations, Jason Keen Dec 2008

Aperture Coupling And Penetration In Various Configurations, Jason Keen

All Dissertations

The problem of a slot in a perfectly conducting surface is addressed for a variety of configurations using both integral equation and transmission line techniques. The use of Bethe hole theory to model short slots is discussed and utilized where appropriate. Primary problems of discussion are a slot array, wires coupling through slots in a ground plane, and wires coupling through slots in a bent ground plane. Additionally, the use of the extended BLT formulation for incorporation of slot effects in a transmission line problem is addressed. In this manuscript, the work of Bethe is extended to include cross-aperture coupling …


Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash Dec 2008

Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash

All Dissertations

Piezoelectrically-driven (piezoactive) systems such as nanopositioning platforms, scanning probe microscopes, and nanomechanical cantilever probes are advantageous devices enabling molecular-level imaging, manipulation, and characterization in disciplines ranging from materials science to physics and biology. Such emerging applications require precise modeling, control and manipulation of objects, components and subsystems ranging in sizes from few nanometers to micrometers. This dissertation presents a comprehensive modeling and control framework for piezoactive micro and nano systems utilized in various applications.
The development of a precise memory-based hysteresis model for feedforward tracking as well as a Lyapunov-based robust-adaptive controller for feedback tracking control of nanopositioning stages are …


Development And Characterization Of Moisture- And Heat- Activated Oxygen Scavenging Nanoparticle, Youngjae Byun Dec 2008

Development And Characterization Of Moisture- And Heat- Activated Oxygen Scavenging Nanoparticle, Youngjae Byun

All Dissertations

Alpha-tocopherol and a transition metal, iron, mixture was evaluated as a possible oxygen scavenger. The effects of moisture, amount of transition metal, and thermal processing on oxygen scavenging capability were also investigated. Results showed that alpha-tocopherol and transition metal had 6.72 cc oxygen per gram of oxygen scavenging capacity and 0.11 cc oxygen per gram per day of oxygen scavenging rate.
Nanoencapsulation technology was adopted for the possible oxygen scavenging activation system. Alpha-tocopherol-loaded poly caprolactone (PCL) nanoparticles were prepared by oil in water (O/W) emulsion solvent evaporation with ultrasonification. The effects of PCL concentration, solvent in oil phase, and ultrasonification …


Experimental And Modeling Studies For Optimizing Flocculant-Aided Sediment Retention Ponds, Byung Joon Lee Dec 2008

Experimental And Modeling Studies For Optimizing Flocculant-Aided Sediment Retention Ponds, Byung Joon Lee

All Dissertations

Attempts to control sediment-containing runoff and associated water quality problems have involved the establishment of many small to medium sediment retention ponds and the injection of nonionic and anionic polyacrylamide (PAM) flocculants to enhance colloid removal. However, to date use has been driven more by practicing engineers and trial-and-error approaches than by logical and consistent design approaches. Therefore, the purpose of this research was to optimize colloidal clay removal in PAM-aided sediment retention ponds by applying experimental and theoretical methodologies.
Initially, simple measurement techniques for the molecular weight (MW) and charge density (CD) of various PAMs were tested and their …