Engineering Commons^™

Investigation And Development Of Exhaust Flow Rate Estimation Methodologies For Heavy-Duty Vehicles, Chakradhar Reddy Vardhireddy

Graduate Theses, Dissertations, and Problem Reports (ETD)

Exhaust gas flow rate from a vehicle tailpipe has a great influence on emission mass rate calculations, as the emission fractions of individual gases in the exhaust are calculated by using the measured exhaust flow rate. The development of high-end sensor technologies and emission pollutant measurement instruments, which can give instantaneous values of volume concentration of pollutants flowing out of the engine are gaining importance because of their ease of operation. The volume concentrations measured can then be used with the instantaneous exhaust flow rate values to obtain mass flow rates of pollutants.

With the recent promulgation of real world …

Experimental And Numerical Study Of The Stirling Engine Robust Foil Regenerator, Koji Yanaga

Graduate Theses, Dissertations, and Problem Reports (ETD)

The regenerator is located between the heat accepter and the heat rejecter of the Stirling engine. It works as a thermal energy storage component in the engine. Most of the regenerators are made of woven screen or random fiber. However, the flow going through the woven screen or random fiber is similar to the cylinders in crossflow which has flow separation. To achieve higher engine efficiency, it is required to design a regenerator which has higher convective heat transfer, lower pressure drops. Therefore, a parallel channel regenerator called a robust foil regenerator was designed and manufactured.

In this study, a …

Low Power Voltage Reference Cells For Sensing Applications, Kody Ray Tucker

Graduate Theses, Dissertations, and Problem Reports (ETD)

Two low-power voltage reference cells for a system on-chip design are presented in this report. Both cells utilize a combination of standard transistors to produce an output voltage near 1 volt. Choosing the appropriate design procedures can aid in minimizing the temperature coefficient (TC) of the output reference voltage coming out of the cell. One circuit, covered first, is currently being fabricated on a standard 0.5 µm chip complementary metal oxide semiconductor (CMOS) process, while the other is still in the designing stage. The first one has a TC of 86 ppm/◦C with a reference voltage of 1.10 V while …

Data Driven Intelligent Grid Stability Monitoring And Adaptive Emergency Response, Hasan Ul Banna

Graduate Theses, Dissertations, and Problem Reports (ETD)

Power grids are large cyber-physical systems with physical operation controlled and integrated through communications. The technological breakthroughs made by the availability of low-cost, high speed communications, larger storage spaces, greater internet bandwidths have led to increased attentions towards advantages of these systems. The use of Phasor Measurement Unit (PMU) in complex interconnected power system for monitoring and control has increased significantly. This has resulted in huge amounts of data and growing databases, thus gearing towards an era where utilities might encounter an enormous amount of data daily from their measurement units including sensitive information useful for daily operations. With increasing …

Can Fitts' Throughput Be A Predictor Of Muscle Fatigue – A Study Based On Metacarpal Gloves?, Sachin Sah

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, Fitts’ throughput was used to estimate throughput for metacarpal gloves. Fitts’ throughput combines speed and accuracy during target transfer/movement tasks into a single performance index. It was hypothesized that the throughput will be affected by the glove condition and it will exhibit a relationship with the physiological response of hand muscles and perceived exertions. Fifteen healthy participants (10 males, 5 females) were recruited for data collection. Each participant performed a series of target transfer tasks using four glove conditions: (1) a pigskin leather (glove 1); (2) a synthetic fiber glove (glove 2); (3) a goat-grain leather glove …

An Assistive Device That Aids The Visiually Imparied People To The Crosswalk, Jiayue Wang

All ETDs from UAB

The visually impaired people mostly rely on a blind cane or specially trained the dogs (Guide dogs) to help them walk or cross the road safely. However, the white canes are for only avoiding obstacles on the roadway and training the guide dogs is a long-term process. Deficiency of reliable assistive tools, traffic accidents seem to be inevitable, especially to visually impaired or blind people. In order to address this problem and decrease the accidents of this nature, technologically more advanced and intelligent tools are necessary. This proposed thesis work will help visually impaired individuals, without affecting their daily activities …

Wireless Charging And Data Communication Of An Unmanned Aerial Vehicle, Shang-Kai Wei

All ETDs from UAB

Wireless charging system in current market usually uses Class D oscillator in the transceiver side, however, this design is highly power consumption and low transfer efficiency. In this report, Class E oscillator is used to decrease the power consumption. Class E oscillator is perfectly zero voltage switching and high transfer efficiency. To increase the wireless transfer efficiency, spiral PCB inductor is also used as the wireless charging pad. Spiral PCB inductor usually uses for RF circuit with high accurately, moreover, the inductance and Q-factor is higher than current wireless charging coil with Litz or magnetic wire. In the receiver side, …

Genetic And Epigenetic Underpinnings Of End-Stage Human Heart Failure, Mark Emile Pepin

All ETDs from UAB

Heart failure (HF) is the clinical endpoint of numerous diseases that negatively impact the heart’s capacity to pump and/or fill with blood. A variety of genetic and environmental factors have been identified as critical determinants of HF susceptibility; however, these factors cannot independently explain the phenotypic diversity of human HF. Instead, a complex interplay has been theorized to exist between genetics and the environment, although the molecular underpinnings of this synergy remain poorly understood. Of the possible mechanisms, epigenetic influences are uniquely capable of explaining how acute stressors of the cardiac microenvironment trigger the stable – yet reversible – reprogramming …

Development And Validation Of A Recumbent Patient Weighing Scale, Kayla Rettig

All ETDs from UAB

Today, most medications are administered according to a standard amount or based on the patient’s weight (weight-based). For emergency departments and emergency medical services, weight-based medications are difficult to administer as medical personnel do not have a means to obtain accurate patient weights. Paramedics generally rely on visual estimation for adults and height- or age-based estimation tools for children in order to obtain weight. Over the past year, a team of biomedical engineering students, including the present author, worked to design and fabricate a weighing device for in-ambulance use. This device consists of three separate scales, wired together as one, …

Enhancing Work Zone Mobility Through Design And Control Of Lane Closures, Troyee Saha

All ETDs from UAB

Work zones hinder mobility, affecting travelers and transportation agencies that are trying to ensure efficient traffic flow through work zones. A study by Wunderlich & Hardesty, 2002 reported that nearly 20% of the National Highway System roads have scheduled construction work during the peak construction season. Additionally, approximately 24% of non-recurring delays on freeways are caused by work zones. Given the time lost by travelers due to work zone induced traffic congestion, it is critically important to efficiently plan temporary traffic control (TTC) at work zones. However, earlier research conducted by Sisiopiku & Ramadan, 2017 confirms that the majority of …

The Efficacy Of Weakly Supervised Learning For Biomedical Imaging, Solomon Lee Hatcher

All ETDs from UAB

This paper aims to investigate the use of unsupervised saliency proposals in extracting suitable prior information from computed tomography scans of the head using image-level labels. The weak supervision learning method obtains useful information about an object’s location and fuses this result with an unsupervised saliency proposal to propagate labels to all related pixels. However, it is shown that unsupervised saliency guidance fails to supply the synthetic annotations with enough coherence to produce suitable segmentation.

The Effect Of Communication And Vehicle Properties On The Search Performance Of A Swarm Of Unmanned Aerial Vehicles, Jenna E. Newcomb, Andrew Ning

Faculty Publications

An unmanned aerial vehicle (UAV) swarm allows for a more time-efficient method of searching a specified area than a single UAV or piloted plane. There are a variety of factors that affect how well an area is surveyed. We specifically analyzed the effect both vehicle properties and communication had on the swarm search performance. We used non-dimensionalization to examine the effect vehicle properties had on search performance so the results can be applied to any domain size with any number and type of vehicle. We found that even if vehicles could only sense 10% of the grid area at any …

Towards Safeguarding Users Against Phishing And Ransomware Attacks, Arsh Arora

All ETDs from UAB

Over the past decade, malicious software (malware) attacks have skyrocketed and increased at a considerably faster pace than predicted. The variety in the number of malware categories is one of the contributing factors to this rapid insurgence. According to Microsoft statistics, a range of 300,000-400,000 malware binaries is observed on average per day. With this increase, there is an unmet need for innovative approaches to detect new malware, as current nomenclature is not equipped to handle the prevention against continuous growth. Developing appropriate preventive measures to stop these malware attacks has been an ongoing struggle for security experts. The most …

A Study Of Approximation Error In Eulerian Hydrocodes, Parth Yogeshbhai Patel

All ETDs from UAB

In this study, we examine a number of approximations in the formulation of hydrocodes. These approximations were borne out of an original requirement for the code to run as fast as possible i.e. with accuracy being secondary to speed. Many of these approximations originated from the 1970’s when computers were slow and memory was at a premium. Although speed and memory are not as much of an issue today, these approximations are still used to formulate the hydrocodes. In this study, the effect of these approximations is examined systematically. The lumped mass approximation is a simplification to the consistent mass …

Framework For Validation Of Different Media Types Using A Model Based On Consensus, Adilahmed Patel

All ETDs from UAB

Increasingly people of all ages consume news and entertainment through electronic media and social media [1]. As the internet in general and social media in particular are a recent phenomenon, the laws governing them and the technologies to monitor them are still evolving. There is a general consensus on the ubiquity and power of these media, hence the worry of how to handle these media. In this context, validating the online content becomes of paramount importance. Fighting fake content is not only relevant to news and current affairs but is very useful in other areas like technical content, legal content …

Assessment Of Whole Building Energy Modeling For Use In Building Retrofit, Steven A. Wyss

All ETDs from UAB

With rising energy costs and a move towards more efficient buildings, developing methods to predict energy usage has become more important than in past years. This study delineates a method for creating and verifying a baseline energy model. This baseline energy model is then modified to test various possible retrofits to identify their potential benefits on the building’s energy usage. This baseline is of the Hoehn Engineering Building located at the University of Alabama at Birmingham (UAB). The building being over 30 years old and having little focus on energy efficient upgrades makes it an excellent candidate for energy modeling. …

Modified Cpd Model For Coal Devolatilization At Underground Coal Thermal Treatment Conditions, Ding Wang, Thomas H. Fletcher, Swomitra Mohanty, Hoaquan Hu, Eric G. Eddings

Faculty Publications

To study coal pyrolysis behavior at underground coal thermal treatment (UCTT) conditions, a modified CPD (M-CPD) model was developed and evaluated using two scales of experiments as well as two different coals, Utah Sufco and Illinois #6. Compared with the original CPD model, three major aspects were changed, including (1) rewriting the algorithm using MATLAB built-in functions; (2) developing a correlation method between coal elemental composition and the initial functional group population to calculate the effect of cross-linking on the lattice structure; and (3) using a two-activation energy approach for gas generation kinetics modeling. Results predicted by the M-CPD model …

Pyrolysis Kinetics Of Live And Dead Wildland Vegetation From The Southern United States, Elham Amini, Mohammad-Saeed Safdari, David R. Weise, Thomas H. Fletcher

Faculty Publications

The fundamental combustion behavior of live wildland vegetation is not fully understood. Since the combustion process during wildland fire starts with pyrolysis, there is a need for better understanding of pyrolysis to develop improved wildland fire models. The kinetics of pyrolysis of live and dead wildland vegetation has not been explored in detail. In this study, the pyrolysis kinetics were determined for 14 different plant species (live and dead) which are all native to the forests in the southern United States. Pyrolysis experiments were carried out in a Thermogravimetric analyzer (TGA) under inert conditions at 5 different heating rates ranged …

Characterization Of Pyrolysis Products From Slow Pyrolysis Of Live And Dead Vegetation Native To The Southern United States, Elham Amini, Mohammad-Saeed Safdari, Jonathan Deyoung, David R. Weise, Thomas H. Fletcher

Faculty Publications

Prescribed (i.e., controlled) burning is a common practice used in many vegetation types in the world to accomplish a wide range of land management objectives including wildfire risk reduction, wildlife habitat improvement, forest regeneration, and land clearing. To properly apply controlled fire and reduce unwanted fire behavior, an improved understanding of fundamental processes related to combustion of live and dead vegetation is needed. Since the combustion process starts with pyrolysis, there is a need for more data and better models of pyrolysis of live and dead fuels. In this study, slow pyrolysis experiments were carried out in a pyrolyzer apparatus …

Enhancing The Thermal Stability Of Carbon Nanomaterials With Dna, Mohammad Moein Safee, Mitchell Gravely, Adeline Lamothe, Megan Mcsweeney, Daniel E. Roxbury

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Single-walled carbon nanotubes (SWCNTs) have recently been utilized as fillers that reduce the flammability and enhance the strength and thermal conductivity of material composites. Enhancing the thermal stability of SWCNTs is crucial when these materials are applied to high temperature applications. In many instances, SWCNTs are applied to composites with surface coatings that are toxic to living organisms. Alternatively, single-stranded DNA, a naturally occurring biological polymer, has recently been utilized to form singly-dispersed hybrids with SWCNTs as well as suppress their known toxicological effects. These hybrids have shown unrivaled stabilities in both aqueous suspension or as a dried material. Furthermore, …

Biomolecular Functionalization Of A Nanomaterial To Control Stability And Retention Within Live Cells, Mitchell Gravely, Mohammad Moein Safaee, Daniel E. Roxbury

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Noncovalent hybrids of single-stranded DNA and single-walled carbon nanotubes (SWCNTs) have demonstrated applications in biomedical imaging and sensing due to their enhanced biocompatibility and photostable, environmentally responsive near-infrared (NIR) fluorescence. The fundamental properties of such DNA-SWCNTs have been studied to determine the correlative relationships between oligonucleotide sequence and length, SWCNT species, and the physical attributes of the resultant hybrids. However, intracellular environments introduce harsh conditions that can change the physical identities of the hybrid nanomaterials, thus altering their intrinsic optical properties. Here, through visible and NIR fluorescence imaging in addition to confocal Raman microscopy, we show that the oligonucleotide length …

Ultrasonic Generation Of Pulsatile And Sequential Therapeutic Delivery Profiles From Calcium-Crosslinked Alginate Hydrogels, Tania Emi, Kendra Michaud, Emma Orton, Grace Santilli, Catherine Linh, Meaghan O'Connell, Fatima Issa, Stephen Kennedy

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Control over of biological processes can potentially be therapeutically regulated through localized biomolecular deliveries. While implantable hydrogels can provide localized therapeutic deliveries, they do not traditionally provide the temporally complex therapeutic delivery profiles required to regulate complex biological processes. Ionically crosslinked alginate hydrogels have been shown to release encapsulated payloads in response to a remotely applied ultrasonic stimulus, thus potentially enabling more temporally complex therapeutic delivery profiles. However, thorough characterizations of how different types of therapeutic payloads are retained and ultrasonically released need to be performed. Additionally, the impact of potentially disruptive ultrasonic stimulations on hydrogel structure and temperature need …

An Investigation Of The Magneto-Active Slosh Control For Cylindrical Propellant Tanks Using Floating Membranes, Manikandan Vairamani, Pedro Llanos, Balaji Sivasubramanian, Somnath Nagendra, Kevin Crosby

Publications

The phenomenon of sloshing is a substantial challenge in propellant management, particularly in reduced gravity where surface tension-driven flows result in large slosh amplitudes and relatively long decay time scales. Propellant Management Devices (PMDs) such as the rigid baffles and elastomeric membranes are often employed to counteract motion of the free surface. In the present study, we investigate an active PMD that utilizes a free-floating membrane that, under an applied static magnetic field, becomes rigid and suppresses slosh. This semi-rigid structural layer can thereby replace bulky baffle structures and reduce the overall weight of the tank. In this paper, the …

Estimating The Spectrum In Computed Tomography Via Kullback–Leibler Divergence Constrained Optimization, Wooseok Ha, Emil Y. Sidky, Rina Foygel Barber, Taly Gilat Schmidt, Xiaochuan Pan

Biomedical Engineering Faculty Research and Publications

Purpose

We study the problem of spectrum estimation from transmission data of a known phantom. The goal is to reconstruct an x‐ray spectrum that can accurately model the x‐ray transmission curves and reflects a realistic shape of the typical energy spectra of the CT system.

Methods

Spectrum estimation is posed as an optimization problem with x‐ray spectrum as unknown variables, and a Kullback–Leibler (KL)‐divergence constraint is employed to incorporate prior knowledge of the spectrum and enhance numerical stability of the estimation process. The formulated constrained optimization problem is convex and can be solved efficiently by use of the exponentiated‐gradient (EG) …

Evaluation Of A Marketing Strategy Based On The Concept Of Virtual Energy Audit, Goutham Kumar Reddy Challa

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the growing world population and efforts to bring better energy access to the people, energy needs of the world are expected to grow in the coming years. Given the limited availability of non-renewable resources, there has been a mounting consensus among the users and the stakeholders to utilize the available energy in the most efficient way by implementing various methods like use of advanced technologies, source reduction, behavioral changes, etc. Energy efficiency in general is considered as a win-win scenario for all the users and/or stakeholders involved as it not only lowers the base load for power generating companies, …

Minimizing Trihalomethane Formation Through Source Water Monitoring And Optimizing Treatment Practices, Nashid Mirza

Graduate Theses, Dissertations, and Problem Reports (ETD)

Trihalomethanes, a family of halogenated disinfection byproducts, are prevalent in finished drinking water. According to USEPA’s Disinfectants and Disinfection Byproducts Rules (DBPRs), the regulatory standard of the total trihalomethanes (TTHMs) is 80 μg/L, and water treatment plant operators are required to closely monitor TTHMs in the finished water on a quarterly basis. Although total organic carbon (TOC) has been identified as a precursor for the TTHMs, knowledge gaps still exist in how specific water and treatment related factors (e.g., intake water quality, seasonal variation, contact time, and treatment train) affect TTHMs formation. Focusing on water treatment plants in southwestern Pennsylvania, …

A Tunable Electrostatic Mems Pressure Switch, Mark Pallay, Ronald N. Miles, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

We demonstrate a tunable air pressure switch. The switch detects when the ambient pressure drops below a threshold value and automatically triggers without the need for any computational overhead to read the pressure or trigger the switch. The switch exploits the significant fluid interaction of a MEMS beam undergoing a large oscillation from electrostatic levitation to detect changes in ambient pressure. If the oscillation amplitude near the resonant frequency is above a threshold level, dynamic pullin is triggered and the switch is closed. The pressure at which the switch closes can be tuned by adjusting the voltage applied to the …

State Estimation For An Agonistic‐Antagonistic Muscle System, Thang Tien Nguyen, Holly Warner, Hung La, Hanieh Mohammadi, Daniel J. Simon, Hanz Richter

Electrical and Computer Engineering Faculty Publications

Research on assistive technology, rehabilitation, and prosthetics requires the understanding of human machine interaction, in which human muscular properties play a pivotal role. This paper studies a nonlinear agonistic‐antagonistic muscle system based on the Hill muscle model. To investigate the characteristics of the muscle model, the problem of estimating the state variables and activation signals of the dual muscle system is considered. In this work, parameter uncertainty and unknown inputs are taken into account for the estimation problem. Three observers are presented: a high gain observer, a sliding mode observer, and an adaptive sliding mode observer. Theoretical analysis shows the …

High Order Volumetric Directional Pattern For Video-Based Face Recognition, Almabrok Essa, Vijayan Asari

Electrical and Computer Engineering Faculty Publications

Describing the dynamic textures has attracted growing attention in the field of computer vision and pattern recognition. In this paper, a novel approach for recognizing dynamic textures, namely, high order volumetric directional pattern (HOVDP), is proposed. It is an extension of the volumetric directional pattern (VDP) which extracts and fuses the temporal information (dynamic features) from three consecutive frames. HOVDP combines the movement and appearance features together considering the nth order volumetric directional variation patterns of all neighboring pixels from three consecutive frames. In experiments with two challenging video face databases, YouTube Celebrities and Honda/UCSD, HOVDP clearly outperformed a set …

Non-Hermitian And Space-Time Mode Management, Nicholas Nye

Electronic Theses and Dissertations

In the last few years, optics has witnessed the emergence of two fields namely metasurfaces and parity-time (PT) symmetry. Optical metasurfaces are engineered structures that provide unique responses to electromagnetic waves, absent in natural materials. On the other hand, PT symmetry has emerged from quantum mechanics, when a new class of non-Hermitian Hamiltonian quantum systems was shown to have real eigenvalues. In this work, we demonstrate how PT-symmetric diffractive structures are capable of eliminating diffraction orders in specific directions, while maintaining/enhancing the remaining orders. In the second part of this work, we emphasize on supersymmetry (SUSY) and its applications in …