Engineering Commons^™

An Overview Of Current Applications, Challenges, And Future Trends In Distributed Process-Based Models In Hydrology, Simone Fatichi, Enrique R. Vivoni, Fred L. Ogden, Valeriy Y. Ivanov, Benjamin Mirus, David Gochis, Charles W. Downer, Matteo Camporese, Jason H. Davison, Brian Ebel, Norm Jones, Jongho Kim, Giuseppe Mascaro, Richard Niswonger, Pedro Restrepo, Riccardo Rigon, Chaopeng Shen, Mauro Sulis, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

Process-based hydrological models have a long history dating back to the 1960s. Criticized by some as over-parameterized, overly complex, and difficult to use, a more nuanced view is that these tools are necessary in many situations and, in a certain class of problems, they are the most appropriate type of hydrological model. This is especially the case in situations where knowledge of flow paths or distributed state variables and/or preservation of physical constraints is important. Examples of this include: spatiotemporal variability of soil moisture, groundwater flow and runoff generation, sediment and contaminant transport, or when feedbacks among various Earth’s system …

An Overview Of Current Applications, Challenges, And Future Trends In Distributed Process-Based Models In Hydrology, Simone Fatichi, Enrique R. Vivoni, Fred L. Ogden, Valeriy Y. Ivanov, Benjamin Mirus, David Gochis, Charles W. Downer, Matteo Camporese, Jason H. Davidson, Brian Ebel, Norm Jones, Jongho Kim, Giuseppe Mascaro, Richard Niswonger, Pedro Restrepo, Riccardo Rigon, Chaopeng Shen, Mauro Sulis, David Tarboton

Faculty Publications

Process-based hydrological models have a long history dating back to the 1960s. Criticized by some as over-parameterized, overly complex, and difficult to use, a more nuanced view is that these tools are necessary in many situations and, in a certain class of problems, they are the most appropriate type of hydrological model. This is especially the case in situations where knowledge of flow paths or distributed state variables and/or preservation of physical constraints is important. Examples of this include: spatiotemporal variability of soil moisture, groundwater flow and runoff generation, sediment and contaminant transport, or when feedbacks among various Earth’s system …

Enhancement Of Supercapacitor Energy Storage By Leakage Reduction And Electrode Modification, Tete Tevi

USF Tampa Graduate Theses and Dissertations

Supercapacitors have emerged in recent years as a promising energy storage technology. The main mechanism of energy storage is based on electrostatic separation of charges in a region at the electrode-electrolyte interface called double layer. Various electrode materials including carbon and conducting polymers have been used in supercapacitors. Also, supercapacitors offer high life cycle and high power density among electrochemical energy storage devices. Despite their interesting features, supercapacitors present some disadvantages that limit their competitivity with other storage devices in some applications. One of those drawbacks is high self-discharge or leakage. The leakage occurs when electrons cross the double layer …

Simple Models For Estimating The Rotational Stiffness Of Steel Column-To-Footing Connections, Joshua Edwin Tryon

Theses and Dissertations

Despite the crucial role they play in transferring loads from the superstructure to the foundation, steel column-to-footing connections have received little attention in research. Though shallow embedded connections are typically characterized as pinned, studies have shown that they exhibit significant rotational stiffness. The objective of this thesis is to quantify the rotational stiffness of such connections. A method named the continuum model is developed by which the rotational stiffness of embedded connections may be calculated. Outputs from this model are compared with experimental data on steel connections embedded in concrete. The continuum model is shown to be capable of reasonably …

Estimation Of Annual Average Daily Traffic On Local Roads In Kentucky, William Nicholas Staats

Theses and Dissertations--Civil Engineering

Annual average daily traffic (AADT) is used to estimate intersection performance across Kentucky. The Kentucky Transportation Cabinet (KYTC) currently collects AADTs for state maintained roads, but lacks this information on local roads. A method is needed to estimate local road AADTs in a cost-effective and reasonable manner. A literature review was conducted on AADT models and found no models suitable to Kentucky. Therefore an AADT model using non-linear regression was developed for local roads in Kentucky

This model divided the state into three regions utilizing Kentucky’s highway districts. This partitioning accounted for geographic and socioeconomic variability across the state. Each …

Modeling And Control Of Fuel Cell-Battery Hybrid Energy Sources, Nima Lotfi

Doctoral Dissertations

"Environmental, political, and availability concerns regarding fossil fuels in recent decades have garnered substantial research and development in the area of alternative energy systems. Among various alternative energy systems, fuel cells and batteries have attracted significant attention both in academia and industry considering their superior performances and numerous advantages. In this dissertation, the modeling and control of these two electrochemical sources as the main constituents of fuel cell-battery hybrid energy sources are studied with ultimate goals of improving their performance, reducing their development and operational costs and consequently, easing their widespread commercialization. More specifically, Paper I provides a comprehensive background …

Nres/Metr/Bsen 479/879: Hydroclimatology—A Peer Review Of Teaching Project Benchmark Portfolio, Francisco Munoz-Arriola

UNL Faculty Course Portfolios

Rising temperatures and extreme hydrometeorological and climate events are evidences of a changing climate. An increasing population together with their demands for food, energy and water make changes in climate evidence the need to train a new generation of multidisciplinary professionals with a clear understanding of the effects of a changing climate in their activities. Historically, climate sciences were used for scientific and weather operational contexts and engineers applied stationary assumptions for multi-term planning. My goal is to identify elements built from classroom experiences about (a) the suitability of a hydroclimatology course for engineers and scientists; (b) the multidisciplinary skills; …

Computation Aided Design Of Multicomponent Refractory Alloys With A Focus On Mechanical Properties, Paul Daniel Clark

Electronic Theses and Dissertations

Quantum mechanical calculations paired with exponential growth in computer processing speed has created a paradigm shift in materials discovery. Simulations can be carried out to accurately predict structure-composition-property relationships of novel systems. This work focuses on calculating elastic properties of high entropy alloys, a new class of alloys that are built from 4+ elements in equi-atomic proportion. These alloys often exhibit simple microstructures and each constituent element contributes its properties to the overall bulk properties of the amalgamated material. This "cocktail" effect has led to the discovery of many alloys which could drive technical advances in the future. Elastic properties …

Hydrodynamic Simulations Of The Prototype Mississippi River And Expanded Small-Scale Physical Model To Investigate Impact Of Sea Level Rise, Linsey Brooke Olivier

LSU Master's Theses

The Expanded Small-Scale Physical Model (ESSPM) is a distorted-scale, moveable bed model that will complement numerical and field studies studying management strategies in the lower ~140 miles of the Mississippi River and their effect on flooding, navigation and coastal restoration. It is recognized that relative sea level rise (RSLR), the combination of eustatic sea level rise (ESLR) and subsidence, will have an impact on the hydraulics and sediment transport in the lower River. However, it is physically impossible to replicate subsidence in the ESSPM; thus, future RSLR conditions will be experimentally simulated by raising Gulf of Mexico (GoM) levels commensurate …

Modeling Churn And Annular Flow Regimes In Vertical And Near-Vertical Pipes With Small And Large Diameters, Erika Viana Pagan

LSU Master's Theses

This thesis presents an improved model for gas-liquid two-phase flow in churn and annular flow regimes for small- and large-diameter in vertical and near-vertical pipes. This new model assumes that a net liquid film moves upward along the pipe wall and gas phase moves upward, occupying the majority of the central part of the pipes, and forming a gas core, in both flow regimes. The model is validated using field and laboratory experimental data from several different studies from the literature, in terms of pressure along the wellbore or bottomhole pressure for field conditions (for high-pressure flows in long pipes, …

Automated Image Analysis And Spatial Computational Modeling Of Nf-Kb In Cerebrovascular Endothelial Cells, Kasey Catalfomo

Theses and Dissertations

Cerebrovascular endothelial cells play a key part in the inflammatory response of the blood-brain barrier in pathological conditions such as Alzheimer’s disease. Specifically, the NF-κB signaling pathway plays a central role. Better understanding of the factors in inflammatory disease progression can lead to more effective treatments for such devastating illnesses like Alzheimer’s, asthma, arthritis, cancer, diabetes and many more inflammatory diseases. The proposed approach analyzes spatial NF-κB distribution contained in multispectral stacked micrograph images of cerebrovascular endothelial cells indexed based on dose of the activating protein and the length of activation. Image analysis code identifies the location of nuclear boundaries …

Development And Testing Of A Fracture Energy-Based Model Of Explosive Asteroid Deflection, James A. Veerkamp

Masters Theses

"While asteroid deflection has been studied for the past half century, efforts have generally been directed towards methods that attempt to minimize disruption of the rock body. In order to widen the base of research, a fracture energy-based model of asteroid fragmentation was developed and applied to both asteroid scale and lab testable scale cases. Modeling of the orbital case suggests the capability to deflect a 100 meter diameter asteroid on a 10 year timescale. The model's predicted energy transfer is then compared to laboratory testing using a ballistic pendulum. The results of this testing suggest that the model as …

An Experimental Investigation Of The Effect Of Temperature And Space Velocity On The Performance Of A Cu-Zeolite Flow-Through Scr And A Scr Catalyst On A Dpf With And Without Pm Loading, Vaibhav Kadam

Dissertations, Master's Theses and Master's Reports

Abstract The heavy-duty diesel (HDD) engines use the diesel oxidation catalyst (DOC), catalyzed particulate filter (CPF) and urea injection based selective catalytic reduction (SCR) systems in sequential combination, to meet the US EPA 2010 PM and NOₓ emission standards. The SCR along with a NH₃ slip control catalyst (AMOX) offer NOₓ reduction >90 % with NH₃ slipHowever, there is a strong desire to further improve the NOₓ reduction performance of such systems, to meet the California Optional Low NOₓ Standard implemented since 2015. Integrating SCR functionality into a diesel particulate filter (DPF), by coating the SCR catalyst on the DPF, …

Panic That Spreads Sociobehavioral Contagion In Pedestrian Evacuations, Terra Elzie, Erika Frydenlund, Andrew J. Collins, R. Michael Robinson

VMASC Publications

Crowds are a part of everyday public life, from stadiums and arenas to school hallways. Occasionally, pushing within the crowd spontaneously escalates to crushing behavior, resulting in injuries and even death. The rarity and unpredictability of these incidents provides few options to collect data for research on the prediction and prevention of hazardous emergent behaviors in crowds. This study takes a close look at the way states of agitation, such as panic, can spread through crowds. Group composition—mainly family groups composed of members with differing mobility levels—plays an important role in the spread of agitation through the crowd, ultimately affecting …

Modeling Embankment Breach Due To Overtopping, Ali Asghari Tabrizi

Theses and Dissertations

Despite numerous embankment failures around the world, in-depth assessments as well as reliable, comprehensive sets of data of such failures are limited. Detailed understanding of the earthen embankment failure process and the dominant parameters affecting the failure are needed to predict and model the breach process precisely. Therefore, a series of laboratory experiments on embankment (i.e., dam and levee) overtopping as well as erodibility measurements using the Submerged Jet test are conducted. Also, to study the influence of different model parameters (e.g., turbulence model, bedload formula), one of the dam embankment experiments is simulated. The main goal of this research …

Expedient Airfield Runway Repair Using Folded Fiberglass Mat, Christopher Y. Tuan, Willaim C. Dass

Department of Civil and Environmental Engineering: Faculty Publications

For expedient airfield runway repair, the US Air Force has developed a folded fiberglass mat to cover craters repaired with a well-compacted granular base material. The objective of this study was to evaluate the adequacy of using polymer plugs to anchor the mat to a repaired asphalt pavement for heavy aircraft operations. The effort consisted of materials testing, field experiments and analytical modeling. An 89,800-kg (198,000-pound) load cart having the footprint of a single C-5 main gear was pulled on a mat with wheels locked to simulate full braking forces. Anchor bushings were instrumented to measure anchor loads. A simplified …

Multiscale Musculoskeletal Modeling Of The Lower Limb To Perform Personalized Simulations Of Movement, Alessandro Navacchia

Electronic Theses and Dissertations

Computational modeling has been used for many decades to inform design and decision-making in several fields of engineering, such as aerospace, automotive, petroleum, and others. However, it still struggles to have a similar impact in fields of medicine, such as orthopaedics. Three of the challenges that have limited the use of computational modeling in the clinical practice and in product development are model validation, personalization, and realism. Validation is a challenge because several internal parameters of the human body, such as muscle forces, are not safely measurable in vivo and, consequently, a thorough comparison between model outputs …

Modeling, Simulation And Control Of Hybrid Electric Vehicle Drive While Minimizing Energy Input Requirements Using Optimized Gear Ratios, Sanjai Massey

Dissertations, Master's Theses and Master's Reports

This project was conducted to analyze (model and simulate) and optimize an electric motor based drive system to propel a typical passenger vehicle in an urban driving environment. Although there are many HEV and EV type systems on the market today, this paper chose the Toyota Prius HEV system as a baseline using a brushless AC motor.

Although a vehicle can be driven many ways, a more standardized Urban Dynamometer Driving Schedule, UDDS, was chosen to simulate real driving conditions. This schedule is determined by the US Environmental Protection Agency, EPA, and is intended to represent the city driving conditions …

Stability Assessment Of Isolated Six-Phase Induction Generator Feeding Static Loads, Kiran Singh, Girish Kumar Singh

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the stability analysis of a six-phase self-excited induction generator (SP-SEIG) based on the eigenvalue stability criteria for its linearized model. This demonstrates the small signal stability behavior during steady-state operating conditions. The eigenvalue approach also establishes an opportunity to correlate eigenvalues with machine parameters. The investigation in this paper reveals that the eigenvalues are dependent upon the machine parameters, and the most critical parameter is the variation in magnetizing inductance (L$_{m})$. The eigenvalues are varied in accordance with the machine variables and give focus to the stabilization of the SP-SEIG. A particular voltage build-up phenomenon is also …

Design And Implementation Of A New Manet Simulator Model For Aodv Simulation, Si̇nan Tüncel, Hüseyi̇n Eki̇z, Ahmet Zengi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Modeling And Rotor Field-Oriented Control Of A Faulty Three-Phase Induction Motor Based On Gsa For Tuning Of Pi Controllers, Ali Monadi, Mohammad Jannati, Nik Rumizi Nik Idris, Ahmad Athif Mohd Faudzi, Frede Blaabjerg

Turkish Journal of Electrical Engineering and Computer Sciences

modeling and a rotor field-oriented control (RFOC) system for controlling a faulty three-phase induction motor (three-phase IM when one of the phases is disconnected). In the adapted scheme for controlling the faulty IM, it is necessary for the PI controller coefficients to change. For this purpose, the gravitational search algorithm (GSA) is used for tuning of PI controllers. The results show the strength and ability of the technique to improve the performance of the faulty IM control.

Intercode Advanced Fuels And Cladding Comparison Using Bison, Frapcon, And Femaxi Fuel Performance Codes, Aaren Rice

Theses and Dissertations

The high density uranium-based fuels are regaining popularity as the current fleet of LWR’s are showing interest in uprating plants to increase accident tolerance and performance. Fuels such as U3Si2, UN, and UC all contain a higher uranium loading and thermal conductivity than that of UO2 making them attractive in combination with an advanced cladding type such as the ceramic SiC cladding. In addition to adding more mass uranium to the core without surpassing current enrichment limits, these advanced fuels and claddings are designed with increased accident tolerance performance in a LOCA type scenario in mind. One of the possible …

Modeling And Simulation Of Micro Electrical Discharge Machining Process, Bai Shao

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Micro parts and systems are playing crucial roles in the area of semiconductor, biomedical device, micro fluid devices, automotive, aerospace and so forth. Micro manufacturing is one of the most important technologies in realizing miniaturization. Compared to other micro manufacturing methods, micro-EDM is drawing lots of attention due to its ability to machine complex 3D parts regardless of the hardness of the workpiece material.

Micro-EDM is the cumulative result of numerous single discharges; therefore, it is crucial to understand the single discharge material removal process in micro-EDM. However, due to the stochastic nature and complex process mechanism, micro-EDM, including its …

Oxidation Process Of H 2 O /Uv For Cod Reduction Of Wastewater From Soybean Tofu Production, Komala Pontas, Abrar Muslim

Makara Journal of Technology

Chemical Oxygen Demand (COD) reduction of wastewater from soybean tofu production was studied by conducting advanced oxidation process (AOP) using hydrogen peroxide with UV radiation catalysts in a closed cylindrical glass reactor. The hydroxyl radical (*OH) concentration from H2O2 decomposition was modeled, and exponential trends were found for the *OH concentration over radiation time and operation temperature. As a result, it was found that the maximal *OH concentration was 0.209 mol L-1 at 240 minutes and 50 °C. The *OH concentration exponentially increased following rise in operation temperature. The H2O2/UV AOP application reduced COD concentration to approximately 42.41% from 10,545 …

Estimating The Water Quality Condition Of River And Lake Water In The Midwestern United States From Its Spectral Characteristics, Jing Tan

Open Access Dissertations

This study focuses on developing/calibrating remote sensing algorithms for water quality retrieval in Midwestern rivers and lakes. In the first part of this study, the spectral measurements collected using a hand-held spectrometer as well as water quality observations for the Wabash River and its tributary the Tippecanoe River in Indiana were used to develop empirical models for the retrieval of chlorophyll (chl) and total suspended solids (TSS). A method for removing sky and sun glint from field spectra for turbid inland waters was developed and tested. Empirical models were then developed using a subset of the field measurements with the …

Numerical Simulation And Modeling Of Combustion In Scramjets, Ryan James Clark

Dissertations

In the last fifteen years the development of a viable scramjet has quickly approached the following long term goals: responsive sub-orbital space access; long-range, prompt global strike; and high-speed transportation. Nonetheless, there are significant challenges that need to be resolved. These challenges include high skin friction drag and high heat transfer rates, inherent to vehicles in sustained, hypersonic flight. Another challenge is sustaining combustion. Numerical simulation and modeling was performed to provide insight into reducing skin friction drag and sustaining combustion.

Numerical simulation was used to investigate boundary layer combustion, which has been shown to reduce skin friction drag. The …

Thermodynamics Of Migration In Polymers: Can Contamination From Materials In Contact Be Predicted, Controlled And Possibly Avoided?, Olivier Vitrac, Phuong Nguyen

Single-Use Technologies: Bridging Polymer Science to Biotechnology Applications

The contamination from materials is coined as “migration” and refers to a combination of various mass transfer mechanisms under thermodynamic control: molecular or mutual diffusion, sorption and desorption phenomena linear with concentration or not. The contamination pathways are particularly complicated when they involve several components or steps and strong interactions between materials and the medium in contact. They have been studied and mathematically described with two possible purposes: i) simplified approaches with a goal of overestimating the real contamination and ii) more sophisticated approaches to optimize the design of polymer materials, packaging materials or to redesign plastic additives with lower …

Thermophotovoltaic System Simulation With Realistic Experimental Considerations, Evan L. Schlenker, Zhiguang Zhou, Peter Bermel

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermophotovoltaic (TPV) systems are a promising type of energy generation method that convert heat into electricity via thermal radiation. TPV has potential to benefit the economy, the energy sector, and the environment by converting waste heat from other power generation methods into electricity. Simulations of these systems can play a key role in designing TPV systems and validating their experimental performance. Current simulation tools can model important aspects of TPV systems fairly accurately, but generally make certain simplifying assumptions that are challenging to reproduce in experiments. Developing a simulation tool that accurately captures thermal emission and reflection in complex, realistic …

In Need Of A Domain-Specific Language Modeling Notation For Smartphone Applications With Portable Capability, Hamza Ghandorh, Luiz Fernando Capretz Dr., Ali Bou Nassif Dr.

Electrical and Computer Engineering Publications

The rapid growth of the smartphone market and its increasing revenue has motivated developers to target multiple platforms. Market leaders, such as Apple, Google, and Microsoft, develop their smartphone applications complying with their platform specifications. The specification of each platform makes a platform-dedicated application incompatible with other platforms due to the diversity of operating systems, programming languages, and design patterns. Conventional development methodologies are applied to smartphone applications, yet they perform less well. Smartphone applications have unique hardware and software requirements. All previous factors push smartphone developers to build less sophisticated and low-quality products when targeting multiple smartphone platforms. Model-driven …

Interdisciplinary Modeling For Water-Related Issues Graduate Course, Laurel Saito, Alexander Fernald, Timothy Link

All ECSTATIC Materials

The science and management of aquatic ecosystems is inherently interdisciplinary, with issues associated with hydrology, atmospheric science, water quality, geochemistry, sociology, economics, environmental science, and ecology. Addressing water resources issues in any one discipline invariably involves effects that concern other disciplines, and attempts to address one issue often have consequences that exacerbate existing issues or concerns, or create new ones (Jørgensen et al. 1992; Lackey et al. 1975; Straskraba 1994) due to the strongly interactive nature of key processes (Christensen et al. 1996). Thus, research and management of aquatic ecosystems must be interdisciplinary to be most effective, but such truly …