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Full-Text Articles in Engineering

Impacts Of Climate Change On Water Resources And Corresponding Adaptation Strategies Of The Nam Ngum River Basin, Laos, Dumindu Lasitha Jayasekera Dec 2013

Impacts Of Climate Change On Water Resources And Corresponding Adaptation Strategies Of The Nam Ngum River Basin, Laos, Dumindu Lasitha Jayasekera

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Nam Ngum River Basin (NNRB) in Laos has received attention of foreign investors due to high hydropower development potential and low per capita electricity consumption. The NNRB is rapidly developing due to its hydropower generation potentials while water demands will increase for agricultural and domestic purposes due to population increase and land-use changes. Water availability conditions will be affected with the increasing water demand and climate change may worsen the water availability conditions. Climate is often defined as the weather averaged over time whereas weather describes atmospheric conditions at a particular place and time in terms of air temperature, …


An Algorithm To Recognize Multi-Stable Behavior From An Ensemble Of Stochastic Simulation Runs, Eduardo Monzon Dec 2013

An Algorithm To Recognize Multi-Stable Behavior From An Ensemble Of Stochastic Simulation Runs, Eduardo Monzon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Synthetic biological designers are demanding tools to help with the design and verification process of new biological models. Some of the most common tools available aggregate multiple simulation results into one “clean” trajectory that hopefully is representative of the system’s behavior. However, for systems exhibiting multiple stable states, these techniques fail to show all the possible trajectories of the system. This work introduces a method capable of detecting the presence of more than one “typical” trajectory in a system, which can also be integrated with other available simulation tools.


Alternative Steel Reinforcement In Mechanically Stabilized Earth (Mse) Walls, Daniel T. Pond Dec 2013

Alternative Steel Reinforcement In Mechanically Stabilized Earth (Mse) Walls, Daniel T. Pond

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mechanically Stabilize Earth (MSE) is a method in which soil tensile strength and shear resistance is increased by using reinforcement. The traditional forms of reinforcement include bars, galvanized strips, welded wire mats or steel grids, and geosynthetics.
When steel is used as reinforcement in MSE walls, it gets corroded or decayed. Certain shapes of reinforcement will have less corrosion because less surface area is exposed. Pullout resistance is the ability to resist a tensile force. This can be affected by the design and shape of the steel. This study simulates different overburden depths or pressures for pullout resistance and evaluates …


Computer Self-Efficacy, Cognitive Actions, And Metacognitive Strategies Of High School Students While Engaged In Interactive Learning Modules, Harry Budi Santoso Dec 2013

Computer Self-Efficacy, Cognitive Actions, And Metacognitive Strategies Of High School Students While Engaged In Interactive Learning Modules, Harry Budi Santoso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to investigate high school students’ computer self-efficacy, cognitive actions, and metacognitive strategies in a self-regulated learning (SRL) framework while utilizing an interactive learning module. The researcher hypothesized that computer self-efficacy is correlated positively with cognitive actions and metacognitive strategies while the students are engaged with interactive learning modules. This research used a mixed-methods approach to answer the research questions. Two research questions guided this research: (1) How is students’ computer self-efficacy related to cognitive actions and metacognitive strategies while using interactive learning modules?; and (2) How do students plan monitor their cognitive actions, and …


Development Of A Coupled Fluid And Colloidall Particle Transport Model, Scott Ripplinger Dec 2013

Development Of A Coupled Fluid And Colloidall Particle Transport Model, Scott Ripplinger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A colloidal system usually refers to when very small particles are suspended within a solution. The study of these systems encompasses a variety of cases including bacteria in ground water, blood cells and platelets in blood plasma, and river silt transport. Taking a look at these kinds of systems using computer simulation can provide a great deal of insight into how they work. Most approaches to date do not look at the details of the system, however, and are specific to given system. In this study a program called OpenFOAM is used as a basis to build a computer simulation …


Conventional And Catalytic Pyrolysis Of Pinyon Juniper Biomass, Bhuvanesh Kumar Yathavan Dec 2013

Conventional And Catalytic Pyrolysis Of Pinyon Juniper Biomass, Bhuvanesh Kumar Yathavan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pinyon and juniper are invasive woody species which has occupied more than 47 million acres of land in Western United States. Pinyon juniper woodlands domination decreases the herbaceous vegetation, increase bare lands which in turn increases soil erosion and nutrition loss. Thus, The US Bureau of Land Management (BLM) has focused on harvesting these woody species to make room for herbaceous vegetation. The major application of harvested pinyon-juniper (PJ) is low value firewood. Thus, there is a need to develop new high value products from this woody biomass to reduce the cost of harvesting. In this study pyrolysis was carried …


Evapotranspiration Modeling And Forecasting For Efficient Management Of Irrigation Command Areas, Roula Bachour Dec 2013

Evapotranspiration Modeling And Forecasting For Efficient Management Of Irrigation Command Areas, Roula Bachour

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It has become very crucial to manage water resources to meet the needs of the growing population. In irrigation command areas, and in order to build a better plan to manage service delivery from canals and reservoirs, it is important to build appropriate knowledge of water needs on a field basis. There is often a lag between the order and delivery of water to the field. Knowledge of the crop water requirement at the field level helps the decision maker to make the right choices leading to more efficient handling of the available water. The purpose of this study was …


Utilizing Municipal And Industrial Wastes For The Production Of Bioproducts: From Metagenomics To Bioproducts, Joshua T. Ellis Aug 2013

Utilizing Municipal And Industrial Wastes For The Production Of Bioproducts: From Metagenomics To Bioproducts, Joshua T. Ellis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Developing renewable sources of energy is gaining interest due to limited supplies, rising costs, and environmental impacts of exploiting fossil fuels. Biosolvents such as acetone, butanol, and ethanol are attractive sources of fuel which can aid in replacing our dependence on foreign oil. Butanol is of particular interest due to its ability to directly replace gasoline, thus considered a drop-in-fuel. Biological hydrogen and methane gas are also attractive energy sources that can lower dependence on fossil energy.

This research focused on incorporating DNA sequencing technologies in parallel with fermentation methods for understanding and producing energy. The natural environment provides diverse …


Nutrient And Carbon-Dioxide Requirements For Large-Scale Microalgae Biofuel Production, Benjamin K. Shurtz Aug 2013

Nutrient And Carbon-Dioxide Requirements For Large-Scale Microalgae Biofuel Production, Benjamin K. Shurtz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ever-increasing fuel prices and a limited supply of oil worldwide are threatening our economy and way of life in both the near and distant future. In order to reduce oil
dependence, the US Department of Energy (DOE) has established a goal that by the year 2030, 30% of the US transportation fuel will be renewable. The goal equates to
approximately 60 billion gallons per year of renewable fuel.

In an effort to reach the DOE renewable fuel goal, numerous types of plants are being studied, whose oil can be harvested and refined to serve as replacement fuel.
Among the various …


Transparent Antennas For Solar Cell Integration, Tursunjan Yasin Aug 2013

Transparent Antennas For Solar Cell Integration, Tursunjan Yasin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Transparent patch antennas have a certain level of optical transparency. Highly transparent patch antennas can be integrated with the solar panels of small satellites, which are becoming increasingly important in space exploration. Traditional patch antennas, which are not transparent, are employed on small satellites and compete with solar cells for surface area. But a transparent patch antenna can be placed directly on top of the solar cells and alleviate the issue of limited surface real estate. For such an integration, a high optical transparency of the patch antenna is required from the solar cells’ point of view since the solar …


Functional Ontologies And Their Application To Hydrologic Modeling: Development Of An Integrated Semantic And Procedural Knowledge Model And Reasoning Engine, Aaron Range Byrd Aug 2013

Functional Ontologies And Their Application To Hydrologic Modeling: Development Of An Integrated Semantic And Procedural Knowledge Model And Reasoning Engine, Aaron Range Byrd

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In hydrology we straddle the domains of science and engineering. As hydrologists our goal is to predict the movement and volume of water. As scientists we seek to improve our understanding of water-related processes and how to model them. As engineers we seek to be able answer specific water-related questions to provide protection and an essential resource for the people we serve. Underlying all of our work is a body of knowledge that we have developed and continue to develop. This knowledge involves many aspects, such as the role of various hydrologic processes, how to obtain data, computational models that …


Geosynchronous Earth Orbit/Low Earth Orbit Space Object Inspection And Debris Disposal: A Preliminary Analysis Using A Carrier Satellite With Deployable Small Satellites, Derick A. Crockett Aug 2013

Geosynchronous Earth Orbit/Low Earth Orbit Space Object Inspection And Debris Disposal: A Preliminary Analysis Using A Carrier Satellite With Deployable Small Satellites, Derick A. Crockett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

From communication to weather prediction, to national security, geosynchronous satellites play an important role in our society. Geosynchronous satellites are about 35,786 km (22,236 miles) from the surface of the earth. Getting a satellite to this altitude is very expensive, making geosynchronous satellites highly valued assets. Ground-based observation of these satellites is very limited and provides little insight when failures or anomalies occur. To provide detailed images and information of these critical satellites, highly functioning smaller satellites can be employed. This study explores the potential benefits of using these smaller satellites to perform on-orbit proximity inspections of geosynchronous satellites. The …


Effects Of Communication Delay And Kinematic Variation In Vehicle Platooning, Megan R. Emmons Aug 2013

Effects Of Communication Delay And Kinematic Variation In Vehicle Platooning, Megan R. Emmons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vehicle platoons are efficient, closely-spaced groups of robotically controlled vehicles which travel at high speeds down the road, similar to carts in a train. Within this thesis, a promising control algorithm for vehicle platooning is explored. The control algorithm was previously demonstrated in a sterile setting which significantly reduced the challenges facing full-scale implementation of platoons, most notably loss of shared data and imprecision within the data.

As found within this work, transmission loss and imprecise position, velocity, and acceleration data significantly degraded the control algorithm's performance. Vehicles in the platoon became more closely spaced, changed speeds more frequently, and …


Shear And Flexural Capacity Of High Strength Prestressed Concrete Bridge Girders, Arek Tilmann Higgs Aug 2013

Shear And Flexural Capacity Of High Strength Prestressed Concrete Bridge Girders, Arek Tilmann Higgs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The section of highway over the 400 South roadway in Orem, Utah is made up of two separate three span bridges. The bridges were originally constructed in 1960 and were expanded in 2004 to accommodate for one extra lane per bridge. During the fall of 2012 both bridges were scheduled for demolition and four girders were salvaged from the southernmost span of the 2004 expansion. These girders were transported to the Structural Materials And Systems Health Lab (SMASH Lab) where a series of tests were performed to determine the prestressing losses, flexural, shear, and shear-flexure capacity of the girders. The …


Digital Microfluidics As A Reconfiguration Mechanism For Antennas, Yasin Damgaci Aug 2013

Digital Microfluidics As A Reconfiguration Mechanism For Antennas, Yasin Damgaci

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The properties of conventional antennas are fixed by the initial design and cannot be changed. A reconfigurable antenna, on the other hand, can dynamically change its properties, and it can adjust its behavior for a given propagation condition. This dissertation work concentrates on novel reconfiguration technologies, including design, microfabrication, and characterization aspects with an emphasis on their applications to multifunctional reconfigurable antennas. In the literature, reconfigurable antennas have made use of various reconfiguration techniques. The most common techniques utilized revolved around switching mechanisms. Other techniques such as the incorporation of variable capacitors, varactors, and physical structure manipulation surfaced recently to …


Effective Thermal Conductivity Of Carbon Nanotube-Based Cryogenic Nanofluids, Lucas Samuel Anderson Aug 2013

Effective Thermal Conductivity Of Carbon Nanotube-Based Cryogenic Nanofluids, Lucas Samuel Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heat removal and management is a concern for any technology that deals with high power, small size, or a lack of convenient thermal transport methods. A potential solution to this heat crisis lies in the field of nanofluids, which consist of colloidal suspensions of nanometer (one billionth of a meter) sized particles within a host fluid. Nanofluids have been of particular interest since their creation due to their exciting, unique, and often times anomalous thermal transport behavior. In many cases, a nanofluid can be custom made to fit a particular need and can act as a flexible cooling method, adapting …


The Design And Implementation Of The Dynamic Ionosphere Cubesat Experiment (Dice) Science Instruments, Steven Reed Burr Aug 2013

The Design And Implementation Of The Dynamic Ionosphere Cubesat Experiment (Dice) Science Instruments, Steven Reed Burr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dynamic Ionosphere Cubesat Experiment (DICE) is a cubesat satellite project funded by the National Science Foundation (NSF) to study the ionosphere. Cubesats are small satellites in the shape of a cube around 10cm on a side, and allow better access to space. Three main properties of the ionosphere are measured by the DICE mission, which are electric field, magnetic field, and plasma density with an instrument for each. The limitation of power, mass, and volume contributes to the difficulty of cubesat design. Mission and instrumentation requirements must be carefully planned to ensure mission success. Each instrument’s requirements and design are …


Experimental Analysis Of The Effects Of Manipulations In Weighted Voting Games, Ramoni Olaoluwa Lasisi Aug 2013

Experimental Analysis Of The Effects Of Manipulations In Weighted Voting Games, Ramoni Olaoluwa Lasisi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation investigates weighted voting games and three methods of manipulating those games, called splitting, merging, and annexation. The manipulations involve an agent or some agents misrepresenting their identities in anticipation of gaining more power over the outcomes of games. Indeed, in open anonymous environments, manipulation can be easy and cheap to achieve. We provide clear and sufficient discussion on related work and backgrounds to motivate this research topic, which certainly deserves attention. Weighted voting games are among key cooperative games, and the manipulations considered in this dissertation are natural, and have practical applications, that are likely …


Linear Covariance Analysis For Gimbaled Pointing Systems, Randall S. Christensen Aug 2013

Linear Covariance Analysis For Gimbaled Pointing Systems, Randall S. Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Linear covariance analysis has been utilized in a wide variety of applications. Historically, the theory has made significant contributions to navigation system design and analysis. More recently, the theory has been extended to capture the combined effect of navigation errors and closed-loop control on the performance of the system. These advancements have made possible rapid analysis and comprehensive trade studies of complicated systems ranging from autonomous rendezvous to vehicle ascent trajectory analysis. Comprehensive trade studies are also needed in the area of gimbaled pointing systems where the information needs are different from previous applications. It is therefore the objective of …


Optical Sensors For Mapping Temperature And Winds In The Thermosphere From A Cubesat Platform, Stephanie Whalen Sullivan May 2013

Optical Sensors For Mapping Temperature And Winds In The Thermosphere From A Cubesat Platform, Stephanie Whalen Sullivan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the same way that mariners desire to know the weather their ships are about to encounter, satellite owners would like to know the conditions along their satellites' orbits. Accurate forecasts would allow operators to secure sensitive components prior to passing through a storm to reduce the risk of damage. Large solar arrays, which can act like sails, can be re-oriented to prevent the satellite from being moved out of its desired orbit. While terrestrial weather forecasters have thousands of sensors with continuous data streams available to generate weather models, very few sensors exist for space weather. Cost of sensing …


Applications Of Bayesian Statistics In Fluvial Bed Load Transport, Mark L. Schmelter May 2013

Applications Of Bayesian Statistics In Fluvial Bed Load Transport, Mark L. Schmelter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The science of fluvial sediment transport studies the processes involved in the movement of river sediments. It is commonly understood that when rivers flood they have a great capacity to move sand, gravel, and even larger cobbles and boulders. This process is not only limited to the big floods that usually attract so much attention, but also the more common river flows play a very important role in forming a river. As engineers and scientists, we like to be able to develop equations and relationships that describe some natural phenomenon—in this case, fluvial sediment transport. While we are able to …


Enhance Variational Asymptotic Method For Unit Cell Homogenization (Vamuch) For Real Engineering Structures And Materials, Zheng Ye May 2013

Enhance Variational Asymptotic Method For Unit Cell Homogenization (Vamuch) For Real Engineering Structures And Materials, Zheng Ye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The applications of heterogeneous materials and other materials with engineered microstructures growth rapidly in all industries to achieve better performance. These materials and structures are defined such as composites and nanotube. With the increasing of computing power, though the well-established commercial finite element analysis (FEA) has the ability to analyze such material of a small portion. It is not feasible for the structure level, since the computing requirements of a finite element model can easily exceed the bearable time in analysis or the capability of the best mainstream computers. To reduce the computational efforts, an efficient way is to use …


Improvement In Computational Fluid Dynamics Through Boundary Verification And Preconditioning, David E. Folkner May 2013

Improvement In Computational Fluid Dynamics Through Boundary Verification And Preconditioning, David E. Folkner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis focuses on improvements to numerical simulation of fluid dynamic problems. A study of computation fluid dynamics is done to improve simulation accuracy and efficiency. Accurate and fast results are the desire of simulation techniques. Two main improvements to current CFD methods are implemented and tested: a new boundary condition verification procedure and a new preconditioning technique.

First, mathematical code verification methods are extended to also include boundary conditions that can often drive fluid dynamics problems. A new framework is created to implement a variety of desirable boundaries. With this framework, a robust verification procedure for these boundaries is …


Most Progress Made Algorithm: Combating Synchronization Induced Performance Loss On Salvaged Chip Multi-Processors, Jacob J. Dutson May 2013

Most Progress Made Algorithm: Combating Synchronization Induced Performance Loss On Salvaged Chip Multi-Processors, Jacob J. Dutson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Most modern personal computers come with processors which contain multiple cores. Often, one or more of these cores is damaged during manufacturing. These faults are increasing as manufacturers try to make processors run faster. Many processor designs allow a damaged core to continue working after manufacturing, but these salvaged cores run slower than a fully functional core.

In an attempt to make software run as fast as possible for its users, software designers write applications that are split into multiple parts called threads. These threads can be run on separate cores at the same time and get more work done …


Secure Localization Topology And Methodology For A Dedicated Automated Highway System, Bhaswati Deka May 2013

Secure Localization Topology And Methodology For A Dedicated Automated Highway System, Bhaswati Deka

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In today’s fast-paced world, mobility is a very important factor in improving the quality of living. The purpose of an automated transportation system (ATS) is to provide mobility to one and all, irrespective of their capabilities. An ATS requires a lot of planning to be efficient and safe for public use. One of the main aspects of safety is to determine the location of the individual vehicles within the system and ensure that their location is not posing any hazard to other vehicles in the system or any other entity outside the system. The process of determining or verifying the …


Computational Fluid Dynamics Validation Of Buoyant Turbulent Flow Heat Transfer, Jared M. Iverson May 2013

Computational Fluid Dynamics Validation Of Buoyant Turbulent Flow Heat Transfer, Jared M. Iverson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Computational fluid dynamics (CFD) is commonly used to visualize and understand complicated fluid flow and heat transfer in many industries. It is imperative to validate the CFD computer models in order to avoid costly design choices where experimentation cannot be used to ratify the predictions of computer models. Assessments of CFD computer models in the literature conclude that significant errors occur in computer model predictions of fluid flow influenced by buoyancy forces.

The Experimental Fluid Dynamics Laboratory at Utah State University constructed a wind tunnel with which to perform experiments on buoyancy induced fluid flow. The experiments measured the heat …


Variational Asymptotic Method For Unit Cell Homogenization Of Thermomechanical Behavior Of Composite Materials, Chong Teng May 2013

Variational Asymptotic Method For Unit Cell Homogenization Of Thermomechanical Behavior Of Composite Materials, Chong Teng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To seek better material behaviors, the research of material properties has been massively carried out in both industrial and academic fields throughout the twentieth century. Composite materials are known for their abilities of combining constituent materials in or- der to fulfill the desirable overall material performance. One of the advantages of composite materials is the adjustment between stiffness and lightness of materials in order to meet the needs of various engineering designs. Even though the finite element analysis is mature, composites are heterogeneous in nature and can present difficulties at the structural level with the acceptable computational time. A way …


Minimizing The Disruption Of Traffic Flow Of Automated Vehicles During Lane Changes, Divya Desiraju May 2013

Minimizing The Disruption Of Traffic Flow Of Automated Vehicles During Lane Changes, Divya Desiraju

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In intelligent transportation systems, most of the research work has focused on lane change assistant systems. No existing work considers minimizing the interruption of traffic flow by maximizing the number of lane changes while eliminating the collisions. In this thesis, we develop qualitative and quantitative approaches for minimizing the interruption of traffic flow for three lane scenarios and show that we can extend our approach to any random number of lanes. The algorithm we propose in this thesis is able to achieve the maximum number of lane changes provided that only one vehicle per group (novel concept which is described …


Cationic Starch Synthesis, Development, And Evaluation For Harvesting Microalgae For Wastewater Treatment, Renil John Anthony May 2013

Cationic Starch Synthesis, Development, And Evaluation For Harvesting Microalgae For Wastewater Treatment, Renil John Anthony

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microalgae are the preferred crop for the production of biodiesel. Microalgae are microplants that have the ability to harness sunlight more efficiently than other plants and store 20-80% lipids per g of dry algae in their cells. Microalgae have the extraordinary ability to grow in brackish water or wastewater. Microalgae can be grown in municipal wastewater to uptake phosphorus and nitrogen and remediate the wastewater of these nutrients. Microalgae thus cultivated accomplishes a dual role of wastewater treatment and provides a sustainable feedstock for biofuels and other bioproducts.

This study focused on efficiently harvesting microalgae from water using modified starch. …


The Effect Of Navigation State Selection On Fuel Dispersions For Powered Lunar Descent, Jessica Thornley Anderson May 2013

The Effect Of Navigation State Selection On Fuel Dispersions For Powered Lunar Descent, Jessica Thornley Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A Monte Carlo simulation is developed to study the performance of the closed-loop guidance, navigation, and control (GN&C) system of a lunar lander in powered descent. The simulation includes six-degrees-of-freedom dynamics, an extended Kalman filter, guidance based upon modified Apollo methods, an attitude control system, and several different types of sensors. Sensors included in the sensor suite include accelerometers, gyroscopes, a star camera, an altimeter, a velocimeter, and a radio navigation system. The simulation is used to examine the effects of sensor errors and the number of navigation states on total fuel use.