Engineering Commons^™

Analysis Of The Enzymatic Decomposition Of Barley Starch To Simple Carbohydrates, Mark Mathiew Williams

Master's Theses

The decomposition of barley starch plays a fundamental role in the final quality of fermented beverages in the brewing industry. The process of mashing involves steeping milled barley in water to stimulate the enzymatic decomposition of starch into simple carbohydrates. The temperature of the water significantly impacts the activity of the enzymes and in turn the resulting concentrations of sugar products. A kinetic model accurately predicting the types and quantities of sugars formed as a function of mash temperature would serve as a tool to tailor sugar profiles and optimize mashing procedures for a desired product.

Sixty minutes mashes were …

Model Development And Application Of Molecular Simulations For The Study Of Proton Transport In Bulk Water And For The Prediction Of Dipole Moments Of Organic Compounds, Abhishek Asthana

Theses and Dissertations

The present work demonstrates the application of molecular simulations (MD) in two different areas: proton transport in bulk water and estimation of the dipole moment of polar organic compounds. In both areas, relatively few successful and robust methodologies exist. In the first part, a new polarizable water model is developed for MD simulations of the proton transport process. The model was parametrized from a combination of quantum chemical calculations and experimental water properties. The model was implemented in MD simulation studies of liquid water at room temperature, as well as with excess protons. For pure water the model gave good …

Contextual Effects In Modeling For Small Domain Estimation, Mohammad-Reza Namazi-Rad, David G. Steel

Professor David Steel

Many different Small Area Estimation (SAE) methods have been proposed to overcome the challenge of findingreliable estimates for small domains. Often, the required data for various research purposes are available at differentlevels of aggregation. Based on the available data, individual-level or aggregated-level models are used in SAE.However, parameter estimates obtained from individual and aggregated level analysis may be different, in practice.This may happen due to some substantial contextual or area-level effects in the covariates which may be misspecifiedin individual-level analysis. If small area models are going to be interpretable in practice, possible contextualeffects should be included. Ignoring these effects leads …

Advancing Cyberinfrastructure To Support High Resolution Water Resources Modeling (Invited), David G. Tarboton, F. L. Ogden, N. Jones, Jeffery S. Horsburgh

Civil and Environmental Engineering Faculty Publications

Addressing the problem of how the availability and quality of water resources at large scales are sensitive to climate variability, watershed alterations and management activities requires computational resources that combine data from multiple sources and support integrated modeling. Related cyberinfrastructure challenges include: 1) how can we best structure data and computer models to address this scientific problem through the use of high-performance and data-intensive computing, and 2) how can we do this in a way that discipline scientists without extensive computational and algorithmic knowledge and experience can take advantage of advances in cyberinfrastructure? This presentation will describe a new system …

Hydraulic Modeling: Pipe Network Analysis, Trevor T. Datwyler

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Water modeling is becoming an increasingly important part of hydraulic engineering. One application of hydraulic modeling is pipe network analysis. Using programmed algorithms to repeatedly solve continuity and energy equations, computer software can greatly reduce the amount of time required to analyze a closed conduit system. Such hydraulic models can become a valuable tool for cities to maintain their water systems and plan for future growth. The Utah Division of Drinking Water regulations require cities to maintain hydraulic models of their culinary water systems, and before additional connections can be made to the water system, a licensed professional engineer must …

Reverse Osmosis Desalination With Integrated Compressed Air Energy Storage: Conceptual Design And Modeling, Pooja Mahajan

All Theses

Growing fresh water needs have led to an interest in water desalination using reverse osmosis (RO) membranes. Energy consumption has a large share in the expenses incurred to drive a reverse osmosis desalination system. With depleting fossil fuel reserves, tapping renewable sources of energy is a promising alternative to meet the energy requirements. Wind power coupled to an RO desalination system is a potential means of delivering clean water using sustainable energy. This work investigates modeling of a conceptual wind-energy-driven RO desalination system that is made possible because of an air-pressure energy storage mechanism. Bench-scale experiments were performed on an …

Analysis Of Irrigation Decision Behavior And Forecasting Future Irrigation Decisions, Sanyogita Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Farmers play a pivotal role in food production. To be economically successful, farmers must make many decisions during the course of a growing season about the allocation of inputs to production. For farmers in arid regions, one of these decisions on any given day is whether to irrigate. This research is the first of its kind to investigate the probable reasons that lead a farmer to make irrigation decisions and use those reasons/factors to forecast future irrigation decisions. This study can help water managers and canal operators to estimate short-term irrigation demands, thereby gaining information that might be useful to …

Evaluating Participatory Modeling: Developing A Framework For Cross-Case Analysis. Socio-Economics And The Environment In Discussion (Seed), Natalie A. Jones, Pascal Perez, Thomas G. Measham, Gail J. Kelly, Patrick D'Aquino, Katherine Daniell, Anne Dray, Nils Ferrand

Professor Pascal Perez

Participatory modeling is increasingly recognised as an effective way to assist collective decision-making processes in the domain of natural resource management. This paper introduces a framework for evaluating projects that have adopted a participatory modeling approach. This framework – known as the ‘Protocol of Canberra’ – was developed through a collaboration between French and Australian researchers engaged in participatory modeling and evaluation research. The framework seeks to assess the extent to which different participatory modeling practices reinforce or divert from the theoretical assumptions they are built upon. The paper discusses the application of the framework in three case-studies, two from …

Towards A Fluid Solid Interaction Model Of A Dynamic Lung, Justin C. Jacobs

Electronic Theses and Dissertations

Because the pulmonary system is a site for both environmental particulate contamination, as well as drug delivery into the body, numerous research groups have focused on precisely understanding its inner-workings. Past research has demonstrated the need to realistically model the lung walls in order to accurately capture the complex airflow profile throughout all of the branches. Since this is paramount to properly replicating particulate transport in the lung, computational fluid dynamics simulations on their own are inadequate, as they cannot account for lung wall dilation. Only by coupling the fluid and solid domains can natural lung behavior can be effectively …

Characterization And Modeling Of Conjugated Polymer Sensors, Yang Fang, Xiaobo Tan, Andrew Temme, Gursel Alici

Gursel Alici

In this paper the behavior of conjugated polymers as mechanical sensors is experimentally characterized and modeled. A trilayer conjugated polymer sensor is considered, where two polypyrrole (PPy) layers sandwich an amorphous polyvinylidene fluoride (PVDF) layer, with the latter serving as an electrolyte tank. A theory for the sensing mechanism is proposed by postulating that, through its influence on the pore structure, mechanical deformation correlates directly to the concentration of ions at the PPy/PVDF interface. This provides a key boundary condition for the partial differential equation (PDE) governing the ion diffusion and migration dynamics. By ignoring the migration term in the …

Bending Modeling And Its Experimental Verification For Conducting Polymer Actuators Dedicated To Manipulation Applications, Christopher Cook, Gursel Alici, Brian Mui

Christopher Cook

No abstract provided.

Drilling Of Carbon Composites Using A One Shot Drill Bit. Part 2 Empirical Modeling Of Maximum Thrust Force, Marta Fernandes, Christopher Cook

Christopher Cook

In order to extend tool life and improve quality of hole drilling in carboncomposite materials, a better understanding of ‘oneshot’ hole drilling is required. This paper describes the development of an empirical model of the maximum thrust force and torque produced during drilling of carbon fiber with a ‘oneshot’ drillbit. Shaw's simplified equations are adapted in order to accommodate for tool wear and used to predict maximum thrust force and torque in the drilling of carboncomposite with a ‘oneshot’ drillbit. The mathematical model is dependent on the number of holes drilled previously, the geometry of the drillbit, the feed used …

Modeling Of Power Semiconductor Devices, Tanya Kirilova Gachovska

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

One of the requirements for choosing a proper power electronic device for a converter is that it must possess a low specific on-resistance. The specific on-resistance of a bipolar device is related to the base width and doping concentration of the lightly doped drift region. This means that the doping concentration and the width of the low-doped base region in a bipolar device must be carefully considered to achieve a desired avalanche breakdown voltage and on-resistance. In order to determine the technological parameters of a semiconductor device, a one dimensional analysis is used to calculate the minimum depletion layer width, …

Effect Of Mechanical Abrasion On Oil/Water Contact Angle In Metals, Simin Salam Tabrizi

Theses and Dissertations

In this study the oil/water angle for brass, aluminum, hastelloy and 316 stainless steel was experimentally studied as a function of surface roughness. Samples were mechanically abraded by sandpaper in the way that all the scratches were parallel. Surface roughness was measured by profilometer, Nano-Indenter, and Atomic Force Microscope (AFM). The relationship between sandpaper particle size and surface roughness for all four metals was established. The highest surface roughness obtained for steel 316 ground by 180 grit sandpaper (1.23µm) and the smoothest surfaces were achieved for brass and aluminum after grinding with alumina (0.03 µm).Then oil/water contact angles were measured …

Remanufacturing Cleaning Process Evaluation, Comparison And Planning, Ozan Yagar

Theses and Dissertations - UTB/UTPA

This thesis aims to combine previous research on remanufacturing cleaning processes and applications into a single decision-making tool, in the form of software, which a remanufacturer can use to find a cleaning system that matches their specific demands. This thesis will provide an in-depth review of each cleaning process, the chemicals used in those processes, and the contamination types for which they were developed. This research also provides evaluation and comparison that assists remanufacturers in designing their cleaning systems. Finally, there will be a description and demonstration of the software. The ultimate goal is to find correct cleaning process to …

2d Modeling Of Forcespinning™ Nanofiber Formation With Experimental Study And Validation, Simon Padron

Theses and Dissertations - UTB/UTPA

A newly developed method of producing nanofibers, called Forcespinning™, has proven to be a viable alternative to mass produce nanofibers. Forcespinning™ utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers while also providing a significant increase in yield and ease of production. To improve and enhance the Forcespinning™ production method, a 2D computational Forcespinning™ fluid dynamics model is developed. Three computer models, namely time-independent and time-dependent inviscid models and a viscous model are obtained and the influences of various parameters on Forcespinning™ fiber formation are obtained. This work also presents a detailed explanation …

Modeling Potential Hydrochemical Responses To Climate Change And Increasing Co2 At The Hubbard Brook Experimental Forest Using A Dynamic Biogeochemical Model (Pnet-Bgc), Afshin Pourmokhtaria, Charles T. Driscoll, John L. Campbell, Katharine Hayhoe

Civil and Environmental Engineering

Dynamic hydrochemical models are useful tools for understanding and predicting the interactive effects of climate change, atmospheric CO2, and atmospheric deposition on the hydrology and water quality of forested watersheds. We used the biogeochemical model, PnET-BGC, to evaluate the effects of potential future changes in temperature, precipitation, solar radiation, and atmospheric CO2 on pools, concentrations, and fluxes of major elements at the Hubbard Brook Experimental Forest in New Hampshire, United States. Future climate projections used to run PnET-BGC were generated specifically for the Hubbard Brook Experimental Forest with a statistical technique that downscales climate output (e.g., air temperature, precipitation, solar …

The Impact Of Additional Weather Inputs On Gas Load Forecasting, Bo Pang

Master's Theses (2009 -)

No abstract provided.

The Incorporation Of Electrohydrodynamics And Other Modifications Into A Dry Spinning Model To Develop A Theoretical Framework For Electrospinning, Yuki Imura

Dissertations

The objective of this research was the development of a mathematical model of the electrospinning process using dry spinning modeling principles as a basis. This model is directed at the identification of parameters which influence final fiber characteristics, e.g., solvent concentration, temperature, spin line tension, and electric field. Preliminary computer simulations were performed; however, the generated data was inconclusive and was determined to be due in part to the complexity of the modeled system and the subsequent computational difficulties encountered. Although a comprehensive computational model of the electrospinning process has not yet been demonstrated, the theoretical development that was undertaken …

Using Ground Penetrating Radar Signal Reflection To Model A Highly Transmissive Bedrock Aquifer, Daniel J. Brockmeyer Mr.

Master's Theses

The use of numerical modeling software to characterize groundwater contaminant fate and transport requires an understanding of the distribution of hydraulic properties of the aquifer. As the complexity of this distribution increases, a more sophisticated understanding is required. Modeling contaminant transport in bedrock aquifers requires that the spatial distributions of highly conductive geologic features are characterized along with the hydraulic transmissivities of those features (Shapiro, 2003). The goal of this research is to refine the numerical model of a highly transmissive crystalline aquifer by characterizing the spatial variability of the hydraulic transmissivity using the attenuation of the ground penetrating radar …

Planning And Management Modeling For Treated Wastewater Usage, Leila Ahmadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Population growth, urbanization and water scarcity in many parts of the world has resulted in transfer of agricultural water to municipal and industrial users on one hand and excessive production of wastewater on the other hand. Due to importance of agriculture in food production and in the economy of many regions around the world,
water resources management and considering new water resources (such as treated wastewater) is critical.This study focused on analyzing the effects of population and
urban growth on water demand for various users and municipal wastewater quantity changes; as well as investigating the feasibility of wastewater reuse projects. …

Simulation Study On Vehicle Dispatching Strategies For Returnable Transport Packaging, Sagar V. Kamarthi, Surendra M. Gupta, Jarupan Lerpong

Sagar Kamarthi

Returnable transport packaging plays an important role in facilitating the transfer of a large volume of products in a close-loop distribution network. To make effective use of returnable transport packaging, vehicle dispatching strategies are crucial. With an appropriate vehicle dispatching strategy, for example, a fast turnover time and a short waiting time for packaging dispatch can be achieved. However, there are some factors that directly influence vehicle dispatching strategies. These factors include the arrival demand fluctuations, the availability of serving vehicles, and the geographic proximity of the facility to the customer's locations. In this study, authors investigate the effect of …

Modeling Cardiac Muscle Mechanics, Lorenzo Sewanan

Senior Theses and Projects

The heart is a complex electro-mechanical system which is intrinsically and intimately linked to physiology and pathology. Cardiac muscle tissue underlies the dynamics of the heart; understanding cardiac muscle tissue allows insight into the working of the heart at a fundamental level. Indeed, models allow a theoretical understanding of systems which necessarily exceeds that of experiment. Here, we describe a novel mathematical model of cardiac muscle mechanics based on functional relations.

Modeling Of A New Structure Of Precision Air Conditioning System Using Secondary Condenser For Rh Regulation, Aries Subiantoro, Nasruddin Nasruddin, Feri Yusivar, Muhammad Idrus Al-Hamid, Bagio Budiardjo

Makara Journal of Technology

A dynamic mathematical model for a new structure of precision air conditioning (PAC) has been developed. The proposed PAC uses an additional secondary condenser for relative humidity regulation compared to a basic refrigeration system. The work mechanism for this system and a vapour-compression cycle process of the system are illustrated using psychrometric chart and pressure-enthalpy diagram. A non-linear system model is derived based on the conservation of mass and energy balance principles and then linearized at steady state operating point for developing a 8th-order state space model suited for multivariable controller design. The quality of linearized model is analyzed in …

Influence Of Defects And Impurities On Solar Cell Performance, Vinay Budhraja

Dissertations

Multicrystalline silicon (mc-Si) solar cells exhibit high impurity content and higher density of crystal defects such as grain boundaries, dislocations, stacking faults and impurity precipitates. Even though the effect of dislocations on mc-Si solar cell performance has been studied, a severe lack of understanding of the quantitative effects of dislocations on cell parameters still exists. Some correlation has been reported under the assumption of a uniform distribution of dislocation density and a negligible effect of front and back surface recombination velocity. This assumption can cause a significant error as the current mc-Si technology provides good surface passivation by SiN:H and …

Canopy Radiation Transmission For An Energy Balance Snowmelt Model, Vinod Mahat, David G. Tarboton

Civil and Environmental Engineering Faculty Publications

To better estimate the radiation energy within and beneath the forest canopy for energy balance snowmelt models, a two stream radiation transfer model that explicitly accounts for canopy scattering, absorption and reflection was developed. Upward and downward radiation streams represented by two differential equations using a single path assumption were solved analytically to approximate the radiation transmitted through or reflected by the canopy with multiple scattering. This approximation results in an exponential decrease of radiation intensity with canopy depth, similar to Beer's law for a deep canopy. The solution for a finite canopy is obtained by applying recursive superposition of …

Transport Phenomena Associated With Liquid Metal Flow Over Topographically Modified Surfaces, Wen Liu

Theses and Dissertations--Mechanical Engineering

Brazing and soldering, as advanced manufacturing processes, are of significant importance to industrial applications. It is widely accepted that joining by brazing or soldering is possible if a liquid metal wets the solids to be joined. Wetting, hence spreading and capillary action of liquid metal (often called filler) is of significant importance. Good wetting is required to distribute liquid metal over/between the substrate materials for a successful bonding.

Topographically altered surfaces have been used to exploit novel wetting phenomena and associated capillary actions, such as imbibitions (a penetration of a liquid front over/through a rough, patterned surface). Modification of surface …

Normalized Confinement Stiffness Approach For Modeling Frp-Confined Concrete, Veysel Yazici, Muhammad N. S Hadi

Faculty of Engineering - Papers (Archive)

Passive confinement provided by fiber-reinforced polymer (FRP) jackets increases the compressive strength and axial deformation capacity of concrete. This study explains a normalized confinement stiffness approach to quantify the strength and strain increase of FRP confined concrete using a previously proposed and most widely-used model for both active and passive confinement of concrete, and claims that these equations can still be used for FRP-confined concrete with very simple modifications. A comparison of the proposed model's accuracy to American Concrete Institute guidelines was made using experimental results reported in the literature. The proposed modified model was shown to be quite effective …

Electron Contamination Modeling And Skin Dose In 6 Mv Longitudinal Field Mrigrt: Impact Of The Mri And Mri Fringe Field, Bradley Oborn, Peter E. Metcalfe, Martin Butson, Anatoly B. Rosenfeld, P J. Keall

Faculty of Engineering - Papers (Archive)

PURPOSE: In recent times, longitudinal field MRI-linac systems have been proposed for 6 MV MRI-guided radiotherapy (MRIgRT). The magnetic field is parallel with the beam axis and so will alter the transport properties of any electron contamination particles. The purpose of this work is to provide a first investigation into the potential effects of the MR and fringe magnetic fields on the electron contamination as it is transported toward a phantom, in turn, providing an estimate of the expected patient skin dose changes in such a modality. METHODS: Geant4 Monte Carlo simulations of a water phantom exposed to a 6 …

Theory, Figures Of Merit, And Design Recipe Of The Plasmonic Structure Composed Of A Nano-Slit Aperture Surrounded By Surface Corrugations, Guangyuan Li, Feng Xiao, Kun Li, Kamal Alameh, Anshi Xu

Research outputs 2012

We theoretically investigate a widely-used plasmonic structure composed of a nano-slit aperture surrounded by surface corrugations. A systematical semi-analytical theory in form of two nested coupled-mode models is developed to provide intuitive physical pictures. Based on the theory, figures of merit (FoMs) of the structures designed for normal and for oblique incidence/beaming are defined for the first time to incorporate the interlinks among key structural parameters, making global optimization simple and efficient. Both the theory and the FoMs are quantitatively validated with exhaustive calculations and shown to be highly accurate on performance prediction and structural optimization. With the theory and …