Engineering Commons^™

Phase Transformation In Monolayer Molybdenum Disulphide With And Without Defects Under Tension Predicted By Atomistic Simulations, Khanh Quoc Dang

Graduate Theses and Dissertations

In addition to its use as a solid lubricant, molybdenum disulphide (MoS2) has gained recent attention as a possible substitute for silicon as it is increasingly difficult to keep shrinking down electronic devices made of silicon, the conventional electronic material. When thinned down to atomic thickness, monolayer MoS2 possesses very unique and promising electronic and electrical properties. Unlike electronic and electrical properties, knowledge of the mechanical properties and role of structural defects on these properties of monolayer MoS2 is unexplored. For this thesis, the two main objectives are (1) to gain insight about the failure mechanism of monolayer MoS2 by …

The Investigation Of Cold-Mix Asphalt Creep Stiffness Testing Using Multiple Test Apparatuses And Gradations, Alexander Jackson

Graduate Theses and Dissertations

Many current methods of designing and testing Cold In-Place Recycled (CIR) asphalt are undesirable because they require large amounts of material and significant preparation. In an effort to lessen the cost and time of materials testing, this research utilizes several different methods of small scale testing of creep stiffness. These methods include using a Discovery Hybrid Rheometer (DHR) and a three point bending test to find the creep stiffness of emulsion based CIR. The new testing methods utilized samples on the scale of up to a hundredth the size of what the traditional methods of testing require. The two smaller …

The Characterization Of Foamed Asphalt Binders Using A Rotational Viscometer, John William Ryan

Graduate Theses and Dissertations

Foamed asphalt is a popular technic of vaporizing water into asphalt binder that falls under the umbrella term of warm-mix asphalt. In order to understand how to adjust mix designs for the use foamed asphalt, methods must be developed for characterizing different foamed asphalt binders. One way to characterize the asphalt binder is through viscosity testing using a rotational viscometer. The standard method of using a viscometer to measure the viscosity of asphalt binder is insufficient when dealing with foamed asphalts, so a new method has been created along with 4 metrics to analyze the data to characterize foamed asphalt …

Redesigning The Walker: A More Durable & Dignified Device, Gianna M. Curcio

Renée Crown University Honors Thesis Projects - All

Aging and Rehabilitation Engineering is a prominent field with ample room for development of and improvement upon existing options. Surveying city sidewalks, family gatherings, hospital waiting rooms it becomes apparent that the need for mobility aids is abundant. My proposal for Capstone is to redesign the walker from both my mechanical engineering and sculptural perspectives. A walker is meant to improve the quality of life for those who are unable to walk unassisted, but should not come at the cost of the user’s dignity. The way we carry ourselves says a lot about us (i.e. character, will, and level of …

A Study Of Ciliary Beating In Chlamydomonas, Xin Li

Renée Crown University Honors Thesis Projects - All

The goal of this research is to understand how a unicellular green alga, Chlamydomonas-reinhardtii, responds to red light (670nm) and sound waves, by monitoring the beating frequency of its two cilia, which control cell motility. Ciliary beating frequency (BF) is proportional to the production of ATP, mainly generated by photosynthesis. A photosynthesis inhibitor, 3-(3-, 4-dichlorophenyl)-1, 1-dimethylurea (DCMU) decreases ATP production by photosynthesis. I used DCMU as a tool to analyze the red light effect on BF.

In the process of studying the effect of red light, I unexpectedly discovered experimental conditions for unstable ciliary beating (as shown in the video). …

Security Analysis Of Phasor Measurement Units In Smart Grid Communication Infrastructures, Mehrnaz Sharifian

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

Phasor Measurement Units (PMUs), or synchrophasors, are rapidly being deployed in the smart grid with the goal of measuring phasor quantities concurrently from wide area distribution substations. By utilizing GPS receivers, PMUs can take a wide area snapshot of power systems. Thus, the possibility of blackouts in the smart grid, the next generation power grid, will be reduced. As the main enabler of Wide Area Measurement Systems (WAMS), PMUs transmit measured values to Phasor Data Concentrators (PDCs) by the synchrophasor standard IEEE C37.118. IEC 61850 and IEC 62351 are the communication protocols for the substation automation system and the security …

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

University Scholar Projects

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …

Protecting Patient Privacy While Preserving Medical Information For Research, Gang Xiang, Jason O'Rawe, Vladik Kreinovich, Janos Hajagos, Scott Ferson

Departmental Technical Reports (CS)

Patient health records possess a great deal of information that would be useful in medical research, but access to these data is impossible or severely limited because of the private nature of most personal health records. Anonymization strategies, to be effective, must usually go much further than simply omitting explicit identifiers because even statistics computed from groups of records can often be leveraged by hackers to re-identify individuals. Methods of balancing the informativeness of data for research with the information loss required to minimize disclosure risk are needed before these private data can be widely released to researchers who can …

Ear Contour Detection And Modeling Using Statistical Shape Models, Satish Ravindran

All Theses

Ear detection is an actively growing area of research because of its applications in human head tracking and biometric recognition. In head tracking, it is used to augment face detectors and to perform pose estimation. In biometric systems, it is used both as an independent modality and in multi-modal biometric recognition. The ear shape is the preferred feature used to perform detection because of its unique structure in both 2D color images and 3D range images. Ear shape models have also been used in literature to perform ear detection, but at a cost of a loss in information about the …

An Analytical And Experimental Biosensor For Human Mig Using Algan/Gan Based Hemt Devices, Hector Trevino Ii

Theses and Dissertations - UTB/UTPA

An amperometric biosensor using AlGaN/GaN based HEMT devices is constructed experimentally and validated through analytical and numerical techniques for detection of a key protein in allograft rejection (Human MIG/CXCL9). The prototype developed provides a reliable sensing platform that will allow label-free and marker-free detection. By exploiting characteristics unique to AlGaN/GaN based HEMT devices, a floating gate configuration is employed to allow reliable sensing without the need for any reference electrode. Self-assembled monolayers (SAM) are formed at the gate surface by using a crosslinker (DSP) to allow for appropriate immobilization of target antibodies. A theoretical analytical and numerical model is developed …

Influence Of Surface Modification On Corrosion And Biocompatibility Of Titanium Alloys, Zia Ur Rahman

Theses and Dissertations - UTB/UTPA

Titanium alloys enhance the quality and longevity of human life by replacing or treating various parts of the body. However, the aggressive body fluids lead to corrosion and metal ions dissolution. These ions leach to the adjacent tissues and causes adverse reactions. Surface modifications improve corrosion resistance and biological activity. In this investigation, electropolishing, magnetoelectropolishing, titanium coating and hydroxyapatite coating were carried out on commercially pure titanium (CPTi), Ti6Al4V and Ti6Al4V-ELI (Extra Low Interstitials). These surface modifications are known to affect surface chemistry, morphology, wettability, corrosion resistance and biocompatibility of these materials. In vitro cyclic potentiodynamic polarization tests were conducted …

Identifying Target Properties For The Design Of Meta-Material Tank Track Pads, Venkata Sampath Dangeti

All Theses

On track vehicle systems, track pads are designed to provide traction and support the weight of the vehicle, they have limited service life due to common failure by blowout. According to the literature, blowout is a failure mode caused by overheating due to hysteresis in elastomeric materials during high speed operations. Elastomers are used primarily for their high compliance, which is essential to protect the suspension components and maintain structural integrity of the track pad. The objective of the work is to explore the use of linear elastic meta-materials with optimized topology to replace elastomers and reduce or eliminate the …

Design Of A Custom Software Application To Monitor And Communicate Cnc Machining Process Information To Aid In Chatter Identification, Valerie Pezzullo

All Theses

In any manufacturing environment, it is important to be able to monitor the Computer Numerical Control (CNC) machining process so that high quality parts can be produced in the least amount of time in order to be profitable. This involves acquiring the proper parameters needed from the machine's controller, which can prove to be difficult with proprietary machine tools that tend to limit access to the internal data collected by the controller. This closed approach to controller design also means that many technological advances that have recently become prevalent in society are not being adopted in the manufacturing industry, preventing …

Reliability Analysis For Shear In Lightweight Reinforced Concrete Bridges Using Shear Beam Database, Danile F. Jensen

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

The objective of this report is to analyze and calibrate the reliability indices for shear in reinforced concrete bridge girders. Existing statistical models are based on limited experimental data from only a few research tests. These existing models show that our current procedures for analysis are about 10-15% less conservative for lightweight concrete compared to an analysis for normal weight concrete. Accurate load models are used to find shear and moment envelopes of loads applied to bridges. Analysis is based on different span lengths, span number and girder dimensions. Design calculations are performed using design values and loads calculated from …

The Development And Validation Of An Isokinetic Calibration System For Multiple Aerosol Instruments, Wendy Michelle Merkley

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

A multi-port calibration xture for the cross calibration of aerosol point sensors has been developed. The system was designed for comparative calibrations of instruments using differing measurement methods such as optical particle counters, aerodynamic impactors, etc. Four isokinetic sampling ports are attached to a laminar ow plenum such that all four sampling ports sample identical aerosol concentrations under identical ow conditions. Correlation and correction factors are applied to each instrument creating a standard method. This standard method can be applied to inter-compare and calibrate aerosol sensing instrumentation and/or to characterize the microphysical properties of a test aerosol. The performance of …

Wireless Network Intrusion Detection System, Calvin Jia Liang

Computer Engineering

The Wireless Network Intrusion Detection System is a network-based intrusion detection system (IDS) that listens on a wireless network. The IDS device is a self-contained single-board-computer capable of monitoring the user’s wireless network, detecting suspicious network traffic, and reporting to the user via email. The device has two network interfaces: the wireless interface is used to monitor network traffic, and the wired interface is used to configure the system and to send out detection alerts. The system requires minimal setup, configuration, and maintenance. It is a relatively inexpensive device that tries to improve user’s situational-awareness of one’s wireless network.

Rssi And Lqi Data Clustering Techniques To Determine The Number Of Nodes In Wireless Sensor Networks, Yanwen Wang, Ivan G. Guardiola, Xiaoling Wu

Engineering Management and Systems Engineering Faculty Research & Creative Works

With the rapid proliferation of wireless sensor networks, different network topologies are likely to exist in the same geographical region, each of which is able to perform its own functions individually. However, these networks are prone to cause interference to neighbor networks, such as data duplication or interception. How to detect, determine, and locate the unknown wireless topologies in a given geographical area has become a significant issue in the wireless industry. This problem is especially acute in military use, such as spy-nodes detection and communication orientation systems. In this paper, three different clustering methods are applied to classify the …

Nanostructured Transition Metal Oxides For Energy Storage And Conversion, Qiang Li

Theses and Dissertations - UTB/UTPA

The conventional film configuration of electrochemical electrodes hardly fulfills the high energy and efficiency requirements because heavy electroactive material deposition restricts ion diffusion path, and lowers power density and fault tolerance. In this thesis, I demonstrate that novel nanoarchitectured transition metal oxides (TMOs), e.g. MnO2, V2O5, and ZnO, and their relevant nanocomposites were designed, fabricated and assembled into devices to deliver superior electrochemical performances such as high energy and power densities, and rate capacity. These improvements could be attributed to the significant enhancement of surface area, shortened ion diffusion distances and facile penetration of electrolyte solution into open structures of …

Corrosion Assessment And Enhanced Biocompatibility Analysis Of Biodegradable Magnesium-Based Alloys, Luis Enrique Pompa

Theses and Dissertations - UTB/UTPA

Magnesium alloys have raised immense interest to many researchers because of its evolution as a new third generation material. Due to their biocompatibility, density, and mechanical properties, magnesium alloys are frequently reported as prospective biodegradable implant materials. Moreover, magnesium based alloys experience a natural phenomena to biodegrade in aqueous solutions due to its corrosive activity, which is excellent for orthopedic and cardiovascular applications. However, major concerns with such alloys are fast and non-uniform corrosion degradation. Controlling the degradation rate in the physiological environment determines the success of an implant. In this investigation, three grades of magnesium alloys: AZ31B, AZ91E and …

Advancements In Alternative Energy Applications For Space Conditioning., Brian S. Robinson

Electronic Theses and Dissertations

This dissertation documents advancements made in passive, renewable energy applications for building space conditioning (heating and cooling). Since, for most climates across the US, space heating requires a much larger annual energy demand than space cooling, the majority of this dissertation is focused on the heating season. The dissertation is divided into five chapters, primarily covering computer simulations and experimental studies pertaining to specific space conditioning technologies. Chapter One discusses the significance of supplanting fossil fuel based energy production with clean, renewable sources, and provides further detail on the organization of this dissertation. Chapter Two provides background on the heat …

Development And Evaluation Of A Calibration Free Exhaustive Coulometric Detection System For Remote Sensing., Thomas James Roussel

Electronic Theses and Dissertations

Most quantitative analytical measurement techniques require calibration to correlate signal with the quantity of analyte. The purpose of this study was to employ exhaustive coulometry, an implementation of coulometric analysis in a stopped-flow, fixed-volume, thin-layer cell, to attain calibration-free measurements that would directly benefit intervention-free analysis systems designed for remote deployment. This technique capitalizes on the short diffusion lengths (< 100 µm) to dramatically reduce the time for analysis (< 30 sec). For this work, a thin-layer fluidic cell was designed in software, fabricated via CNC machining, and evaluated using Ferri/Ferrocyanide {Fe(CN)63-/4-} as a model analyte. The 2 µL fixed volume incorporated an oval, 8mm by 4 mm, thin-film gold electrode sensor with an integrated Ag|AgCl pseudo-reference electrode. The flow cell area matched the shape of the sensor, with a volume set by the thickness of a laser-cut silicone rubber gasket (~80 µm). A semi-permeable membrane isolated the working electrode and counter electrode chambers to prevent analyte diffusion. A miniaturized custom potentiostat was designed and built to measure reaction currents ranging from 10 mA to 0.1 nA. Software was developed to perform step voltammetry as well as cyclic voltammetry analysis for verifying electrode condition and optimal redox potential levels. Experimentally determined oxidation/reduction potentials of -100 mV and 400 mV, respectively, were applied to the working electrode for sample concentrations ranging from 50 µM to 10,000 µM. The current generated during the reactions was recorded and the total charge captured at each concentration was obtained by integrating the amperograms. When compared to the expected charge for a 2 µL sample, the total charge vs. concentration plots displayed a near perfect linearity over the full concentration range, and the expected charge (100 % converted) was reached within 20 seconds. The reaction currents ideally should have decayed to background levels, but exhibited constant offset values slightly larger than the background signal, a phenomenon assumed to be lingering residual flow from sample injection. After adding rigid tubing and external valves, the thin-layer cell was shown to remain within 6% of the theoretical charge after 200 seconds. Continued development of this system will offer the possibility of remote, calibration-free determinations of real-world analytes such mercury and lead.

Image Based Approach For Early Assessment Of Heart Failure., Hisham Z. Sliman

Electronic Theses and Dissertations

In diagnosing heart diseases, the estimation of cardiac performance indices requires accurate segmentation of the left ventricle (LV) wall from cine cardiac magnetic resonance (CMR) images. MR imaging is noninvasive and generates clear images; however, it is impractical to manually process the huge number of images generated to calculate the performance indices. In this dissertation, we introduce a novel, fast, robust, bi-directional coupled parametric deformable models that are capable of segmenting the LV wall borders using first- and second-order visual appearance features. These features are embedded in a new stochastic external force that preserves the topology of the LV wall …

Development Of A Light-Powered Microstructure : Enhancing Thermal Actuation With Near-Infrared Absorbent Gold Nanoparticles., Thomas Matthew Lucas

Electronic Theses and Dissertations

Development of microscale actuating technologies has considerably added to the toolset for interacting with natural components at the cellular level. Small-scale actuators and switches have potential in areas such as microscale pumping and particle manipulation. Thermal actuation has been used with asymmetric geometry to create large deflections with high force relative to electrostatically driven systems. However, many thermally based techniques require a physical connection for power and operate outside the temperature range conducive for biological studies and medical applications. The work presented here describes the design of an out-of-plane bistable switch that responds to near-infrared light with wavelength-specific response. In …

After Sales Supply Chain Risk Management., Steffen Luksch

Electronic Theses and Dissertations

Lean supply chains with cost optimized production and logistics processes in the automotive industry have become a benchmark for other industries. Short delivery times, low inventories and high availability are parameters which assume a robust supply chain. In industrial practice we see, however, that in the After Sales business particularly related to the supply of automotive spare parts, that there are always unforeseen delays in delivery. In order to avoid service level losses on the focal firm level due to missing parts it is necessary to understand the risk structure on the supplier side. For this reason, a risk model …

Pavement Deterioration Modeling And Design Of A Composite Pavement Distress Index For Kentucky Interstate Highways And Parkways., Chenglong Luo

Electronic Theses and Dissertations

Pavement deterioration is one of the most important driver for prioritizing pavement management and preservation (PMP) projects. The primary goal of this thesis is to provide reasonable predictive functions from multiple linear regression (MLR) models and artificial neural networks (ANN) that can be adopted by Kentucky Transportation Cabinet (KYTC). Furthermore, we use analytic hierarchy process (AHP) to design a composite pavement distress index in order to help Kentucky Transportation Cabinet (KYTC) prioritizing PMP projects based on 11 different distress indices. Numerical results show that the MLR models provide relatively high R square values of approximately 0.8. Both MLR and ANN …

Two-Stage Network Design In Humanitarian Logistics., Seyed Soroush Moeini

Electronic Theses and Dissertations

Natural disasters such as floods and earthquakes can cause multiple deaths, injuries, and severe damage to properties. In order to minimize the impact of such disasters, emergency response plans should be developed well in advance of such events. Moreover, because different organizations such as non-governmental organizations (NGOs), governments, and militaries are involved in emergency response, the development of a coordination scheme is necessary to efficiently organize all the activities and minimize the impact of disasters. The logistics network design component of emergency management includes determining where to store emergency relief materials, the corresponding quantities and distribution to the affected areas …

Privacy Protection In Context Aware Systems., Anala Aniruddha Pandit

Electronic Theses and Dissertations

Smartphones, loaded with users’ personal information, are a primary computing device for many. Advent of 4G networks, IPV6 and increased number of subscribers to these has triggered a host of application developers to develop softwares that are easy to install on the mobile devices. During the application download process, users accept the terms and conditions that permit revelation of private information. The free application markets are sustainable as the revenue model for most of these service providers is through profiling of users and pushing advertisements to the users. This creates a serious threat to users privacy and hence it is …

A Novel Numerical Framework For Simulation Of Multiscale Spatio-Temporally Non-Linear Systems In Additive Manufacturing Processes., Nachiket Patil

Electronic Theses and Dissertations

New computationally efficient numerical techniques have been formulated for multi-scale analysis in order to bridge mesoscopic and macroscopic scales of thermal and mechanical responses of a material. These numerical techniques will reduce computational efforts required to simulate metal based Additive Manufacturing (AM) processes. Considering the availability of physics based constitutive models for response at mesoscopic scales, these techniques will help in the evaluation of the thermal response and mechanical properties during layer-by-layer processing in AM. Two classes of numerical techniques have been explored. The first class of numerical techniques has been developed for evaluating the periodic spatiotemporal thermal response involving …

Three-Dimensional Modeling Of The Human Jaw/Teeth Using Optics And Statistics., Aly Saber Abdelrahim

Electronic Theses and Dissertations

Object modeling is a fundamental problem in engineering, involving talents from computer-aided design, computational geometry, computer vision and advanced manufacturing. The process of object modeling takes three stages: sensing, representation, and analysis. Various sensors may be used to capture information about objects; optical cameras and laser scanners are common with rigid objects, while X-ray, CT and MRI are common with biological organs. These sensors may provide a direct or an indirect inference about the object, requiring a geometric representation in the computer that is suitable for subsequent usage. Geometric representations that are compact, i.e., capture the main features of the …

Text Stylometry For Chat Bot Identification And Intelligence Estimation., Nawaf Ali

Electronic Theses and Dissertations

Authorship identification is a technique used to identify the author of an unclaimed document, by attempting to find traits that will match those of the original author. Authorship identification has a great potential for applications in forensics. It can also be used in identifying chat bots, a form of intelligent software created to mimic the human conversations, by their unique style. The online criminal community is utilizing chat bots as a new way to steal private information and commit fraud and identity theft. The need for identifying chat bots by their style is becoming essential to overcome the danger of …