Mechanical Engineering Commons^™

Nonparametric Identification Of A Mems Resonator Actuated By Levitation Forces, Mohammed Abdel Razzaq, Rodrigo T. Rocha, Yu Tian, Shahrzad Towfighian, Sami F. Masri, Mohammad I. Younis

Mechanical Engineering Faculty Scholarship

This work presents nonparametric identification of a Micro-Electro-Mechanical Systems (MEMS) beam subjected to a non-classical nonlinear electrostatic (levitation) force. The approach is based on the Restoring Force Surface method and the Chebyshev polynomials. The study examines the main challenges associated with the used approach as applied to small-scale systems, such as the inability to measure the restoring force and acceleration. In this work, we use a mix of analytical techniques, experimental data, and Lagrange polynomial interpolation to estimate the restoring forces of the system and its nonlinearities. The extracted results are compared with the measurements, which show excellent agreement. Results …

Obliquely Impinging Jet Heat Transfer Fields: Effects Of Mach Number On Nozzle-To-Plate Distance, Thinnesh Ragupathy

Masters Theses

This study investigates the consistent features of heat flux patterns on surfaces impacted by jets at various Mach numbers, ranging from 0.1 to 1.0. It utilizes temperature-sensitive paint (TSP) analysis to examine how these patterns change. The research also explores the presence of self-similarity in both the fluctuation of heat flux and skin friction patterns, which are derived from temperature and heat flux data. A semi-empirical model is proposed to explain this self-similarity, suggesting that Mach number primarily affects heat flux patterns through the recovery temperature at the impact site.

Understanding the self-similarity of heat flux patterns across different Mach …

Redesign Of Robotic Walking Training Device To Involve Zero Gravity Capabilities And Daily Activities, Chad Ballard

Mechanical Engineering Theses

Many patients struggle with disabilities that hinder their ability to walk. This project aimed to create a leg assembly capable of variable gravity so that it could be combined with a Robotic Walking Training Device, and lead to better rehabilitation options for patients. This was accomplished by deriving equations of joint torque, creating circuit diagrams for Arduino systems, modeling leg assemblies in CAD, and finally combining it to create a working small-scale prototype. The result of the prototype testing showed accurate movement on each joint, especially the ankle and knee segments, to create virtual zero gravity. In addition to this, …

Removable Equipment Climate Canopy, Jessica Perez, Sabine Heid, Zil Panchal, Anali Salazar

Mechanical Engineering

The Climate Canopy Project has developed an improved solution for creating an adjustable shade mechanism tailored specifically for users of pull walkers. Through extensive research, goal setting, and a comprehensive framework our project has examined the challenges faced by individuals who rely on walkers for mobility. Our stakeholder requires a product that is lightweight, removable, and compact. This study dissected the designs of previous products on the market and aimed to build a product that aligns with our sponsor’s desires.

This report presents the main goals for the design and manufacturing process, along with key design features utilized to produce …

Convolutional Spiking Neural Networks For Intent Detection Based On Anticipatory Brain Potentials Using Electroencephalogram, Nathan Lutes, V. Sriram Siddhardh Nadendla, K. Krishnamurthy

Computer Science Faculty Research & Creative Works

Spiking neural networks (SNNs) are receiving increased attention because they mimic synaptic connections in biological systems and produce spike trains, which can be approximated by binary values for computational efficiency. Recently, the addition of convolutional layers to combine the feature extraction power of convolutional networks with the computational efficiency of SNNs has been introduced. This paper studies the feasibility of using a convolutional spiking neural network (CSNN) to detect anticipatory slow cortical potentials (SCPs) related to braking intention in human participants using an electroencephalogram (EEG). Data was collected during an experiment wherein participants operated a remote-controlled vehicle on a testbed …

Cosolvent Incorporation Modulates The Thermal And Structural Response Of Pnipam/Silyl Methacrylate Copolymers, Jason D. Linn, Fabian A. Rodriguez, Michelle A. Calabrese

Mechanical Engineering Faculty Publications

Polymers functionalized with inorganic silane groups have been used in wide-ranging applications due to the silane reactivity, which enables formation of covalently-crosslinked polymeric structures. Utilizing stimuli-responsive polymers in these hybrid systems can lead to smart and tunable behavior for sensing, drug delivery, and optical coatings. Previously, the thermoresponsive polymer poly(N-isopropyl acrylamide) (PNIPAM) functionalized with 3-(trimethoxysilyl)propyl methacrylate (TMA) has demonstrated unique aqueous self-assembly and optical responses following temperature elevation. Here, we investigate how cosolvent addition, particularly ethanol and N,N-dimethyl formamide (DMF), impacts these transition temperatures, optical clouding, and structure formation in NIPAM/TMA copolymers. Versus purely aqueous …

Lamina Cribrosa Insertions Into The Sclera Are Sparser, Narrower, And More Slanted In The Anterior Lamina, Fengting Ji, Mohammad R. Islam, Bingrui Wang, Yi Hua, Ian A. Sigal

Mechanical Engineering Faculty Publications

Purpose: The lamina cribrosa (LC) depends on the sclera for support. The support must be provided through the LC insertions. Although a continuous insertion over the whole LC periphery is often assumed, LC insertions are actually discrete locations where LC collagenous beams meet the sclera. We hypothesized that LC insertions vary in number, size, and shape by quadrant and depth.

Methods: Coronal cryosections through the full LCs from six healthy monkey eyes were imaged using instant polarized light microscopy. The images were registered into a stack, on which we manually marked LC insertion outlines, nothing their position in-depth and quadrant …

Design Of A Launchable Remote-Controlled Rover And Protective Aeroshell, Matthew Loewer, Colby Weeks, Lake Williams, Jackson Zazzaro

Senior Theses

Planetary rovers, vehicles that can traverse challenging terrain, have excelled in their exploration missions to other celestial bodies. They have been especially suitable for exploring Mars, as rovers such as Opportunity and Perseverance have collected valuable geological, atmospheric, seismic, and magnetic information from the Martian surface. Rovers will remain vital in future space exploration missions, and it is necessary to understand their design and functionality. This paper focuses on the design and prototyping of a miniature rover that can survive the rough Martian terrain while collecting and submitting environmental data for scientific analysis. The design is based off proven Martian …

Safety Evaluation Of Hawaii Dot Modified Type A-1 Flared Buried In Backslope Guardrail End Terminal, Sina Changizian

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

The Hawaii Department of Transportation (HDOT) desired to evaluate the crashworthiness of a guardrail end terminal design in which the upstream guardrail anchorage was connected to a block partially buried in a cut slope, known as a “Buried in Backslope” or BIB design. The HDOT BIB system used an upper W-beam with 8-in. deep blockouts attached to W6x9 steel posts and a lower W-beam rubrail located 3 in. below the upper rail. The system used two horizontal flares: 7.4:1 near the upstream anchor block and a 13:1 flare through the ditch.

Critical impact points (CIPs) were identified and recommended for …

Synthesis And Structure-Property Relationships Of Sustainable Nanostructured Materials Towards Energy And Environment Applications, Nizamudeen Cherupurakal

Dissertations

This doctoral research aims to advance clean energy technologies by developing specialized nanostructured materials. The study covers significant research themes, each forming separate sections in the thesis, explaining the important role of nanostructures in enhancing the efficiency and sustainability of energy devices and photocatalytic technologies.

The enduring effort toward stabilizing and improving the efficiency of Dye-Sensitized Solar Cells (DSSCs) has stirred the solar research community to follow innovative approaches. The primary objective of the research is centered on electrode materials design, which improves photoanodes' Light-Harvesting Efficiency (LHE). To improve the Photoanode of DSSCs, a Metal-Organic Framework (MOF) derived porous photoanodes …

Experimental Investigation Of Various Hydrogen Knock Limit Extension Strategies On A Hydrogen-Gasoline Dual Fuel Spark Ignition Engine, Sanad Thurakkal Puthan

Dissertations

Hydrogen is a clean and carbon free substitute with the ability to significantly cut down the harmful emissions while enhancing the energy efficiency of internal combustion engines (ICE) typically powered by conventional fossil fuels. Hydrogen is the most abundant elements which can be easily obtained from sources like water and biomass. The wide flammability range and high laminar flame velocity outstands hydrogen from other fuels. However, hydrogen fueled engines are more prone to abnormal combustion like knock and backfire due to its low ignition energy and high adiabatic flame temperature. To avoid backfire, several well developed approaches have been reported. …

Friction Stir Welding Of Tube-To-Tubesheet And Spot Joints For Virgin And Recycled Thermoplastic Materials, Syed Haris Iftikhar

Dissertations

Thermoplastic materials are becoming popular, due to their chemically inert and anti-fouling properties, for use in industrial heat exchanger applications involving heating/cooling of highly reactive fluids like acids. A novel non-conventional joining framework, based on the Friction Stir Welding (FSW) technique, is developed to create high-quality thermoplastic Tube-to-Tubesheet Joints (TTJs). The proposed technique has applications in the thermoplastic shell-and-tube heat exchanger and piping industries (as flange-to-pipe joints). The primary objective is to study the feasibility of the FSW technique for developing thermoplastic TTJs, followed by optimization of the process parameters and detailed material characterizations. This work used workpieces (tube, tubesheet) …

A Variable Shape Metastructure Based On Controlled Bistable Structural Elements, Mehmet R. Simsek

Mechanical & Aerospace Engineering Theses & Dissertations

The so-called hybrid position feedback controller is an unstable-then-stable position feedback controller, which is a second-order single-degree-of-freedom system in nature. This hybrid controller takes advantage of the resonant mode of a bistable system about one equilibrium position, destabilizes the system, and dynamically induces snap-through between the two equilibria. In this dissertation, a new multi degree of freedom metastructure concept that utilizes the hybrid position feedback controller is introduced. An arbitrary number of bistable “segments” or “structural elements” are attached to each other in a serial (or parallel) manner to generate a “distributed” bistable structure – also referred to as a …

Small Scale Wave Energy Convertor For Remote Applications, Rafael Torres Rodriguez, John Stephenson, Max Mailloux-Beauchemin, Brandon Nguyen, Ryan Chang

Mechanical Engineering Senior Theses

The following thesis showcases the yearlong culmination of a senior design project focused on the development of a small-scale wave energy generator intended to provide consistent and sustainable energy for remote marine environments. This project’s main customers include, but are not limited to, the National Oceanic and Atmospheric Administration, the Atlantic White Shark Conservancy, and scuba diving sites worldwide. Based on these identified customers and their needs, a target power output of 50 watts was determined. Beyond this power requirement, the generator is required to resist corrosion, withstand rough marine conditions, and be modular as well as requiring low maintenance. …

A Technical Survey On Using Oxyhydrogen With Biodiesel/Diesel Blend For Homogeneous Charge Compression Ignition Engine, Mai H. Aboubakr, Medhat Elkelawy, Hagar Alm-Eldin Bastawissi, Ayman R. El-Tohamy

Journal of Engineering Research

Renewable energy should be used instead of fossil fuels owing to the negative impact of fossil fuels on both humans and the environment, as well as the toxic emissions of carbon dioxide, unburned hydrocarbons, and nitrogen oxide. Studies investigated the consideration of using alternative fuel that is renewable, sustainable, and eco-friendly, especially because of the huge demand for energy, the decline, and the environmental initiatives to decrease the usage of petroleum sources. The addition of oxyhydrogen [HHO] to biodiesel and diesel blends can enhance characteristics; however, there is a concern about raising nitrogen oxide levels, which can have negative impacts …

Performance Augmentation Of Single-Slope Solar Distiller Using An Evacuated Tube Solar Collector: Theoretical Study, Eman Mohammed Abuelezz Eng., Yasser El-Samadony Prof., Khaled Khodary Esmaeil Assoc. Prof., Mohamed Elsheshtawy Zayed Dr.

Journal of Engineering Research

In this research, the performance analysis of a solar-powered desalination system incorporating a single slope-slope solar still and an evacuated tube solar collector is theoretically investigated. The system comprises a solar evacuated tube that absorbs solar radiation, transferring heat to saline water. This water then flows into a solar still, where it absorbs solar energy, boosting the evaporation rate. Two solar distillers, namely the conventional solar distiller (Still-I) and solar still integrated with evacuated tube solar collector (Still-II), are simulated and analyzed under identical outdoor conditions in Tanta, Egypt. A comprehensive theoretical model, developed using FORTAN programming, simulates the performance …

Cfd Study On Two-Phase Flow Patterns In A Pipe With 90º Elbow In Different Operating Conditions, Hagar Alm-Eldin Bastawissi, Mohammed Ahmed Khafagy, E. A. El Shenawy Prof. Dr., Ahmed M. Salem Dr

Journal of Engineering Research

Recently, CFD has offered a technological solution for modelling multi-phase flow in which we can make endless simulations with reduced expenses and effort in high accuracy results; we shall also mention that experimental studies have limitations for safety considerations when experimenting with flow in high temperature or pressure values or medium nature as in nuclear or chemical flows.In this paper, we used the ANSYS FLUENT CFD program to simulate the two-phase flow in a pipe to study the effect of attaching a 90-degree elbow fitting to the piping system, seeking to find out the change in the pattern and resulting …

Numerical Analysis Of Flow Fields For The Different Models Of The Shrouded Savonius Rotor, Alsaied Khalil Mahmoud, Mohamed Mahgoub Bassuoni, Mohamed Fawzy Obiaa, Ahmed Mostafa Khaira

Journal of Engineering Research

In this study, the effect of three different lengths (short, medium, and long) of flanged shrouded Savonius wind turbines is investigated three-dimensional (3-D) numerically by ANSYS-FLUENT. The 3-D numerical model of a simple rotor is validated by comparing the results with previous published experimental ones at the same operating conditions and geometry. The numerical and experimental results indicate a good agreement with each other when using the SST K-ω model with a time step size of 0.0025 s.The analysis of the numerical results of the three flanged shrouded models shows an enhancement of the torque coefficient at tip speed ratio …

Advanced Spatio-Temporal Froth Analysis Using Smart Soft Sensors In Mineral Processing, Ahmed Bendaouia, El Hassan Abdelwahed, Sara Qassimi, Abdelmalek Boussetta, Intissar Benzakour, Oumkeltoum Amar, Mohamed Chekroun, Oussama Hasidi, Oussama Lachihab

Manufacturing & Industrial Engineering Faculty Publications

In the transformative field of mineral processing, the need for innovative technologies to overcome inherent difficulties and a critical shortage of high-quality data is an acute challenge. This study addresses these pressing issues by leveraging advanced spatio-temporal deep learning techniques, specifically Convolutional Long Short-Term Memory (ConvLSTM). Focused on the Zinc flotation circuit at CMG Managem Group in Morocco, our comprehensive approach encompasses meticulous data collection from a real-world industrial setting, rigorous spatial and temporal analyses, practical and accurate data augmentation, and the development of a ConvLSTM model for precise prediction of mineral grades. By capturing the temporal intricacies of froth …

Casar Public Lecture: "Women & Stem Education In Egypt & The Us: Stepping Into A Man's World Of Science & Technology", The Prince Alwaleed Center For American Studies And Research Casar, Yasmeen El Ghazaly, Mark W. Deets

Performances, Events, and Presentations

In celebration of International Women's Day this Month, we held a public lecture titled: "Women & STEM Education in Egypt & the US : Stepping into a Man's World of Science & Technology " on Thursday March 28th, 2024 from 12:15 pm to 1:15 pm (assembly hour) – Conference and Visitor Center, Mary Cross Hall AUC New Cairo Despite a plethora of advances made by women in the world we live in today, they are still woefully underrepresented in the realm of STEM education and the associated career paths. At this event, we uncovered the history, reasons & challenges women …

Predicting The Rate Of Degradation Related To Oxygen Electrode Delamination In Solid Oxide-Ion Electrolyzers, Yeting Wen, Kevin Huang

Faculty Publications

Language comprehension is often affected in individuals with post-stroke aphasia. However, deficits in auditory comprehension are not fully correlated with deficits in reading comprehension and the mechanisms underlying this dissociation remain unclear. This distinction is important for understanding language mechanisms, predicting long-term impairments and future development of treatment interventions. Using comprehensive auditory and reading measures from a large cohort of individuals with aphasia, we evaluated the relationship between aphasia type and reading comprehension impairments, the relationship between auditory versus reading comprehension deficits and the crucial neuroanatomy supporting the dissociation between post-stroke reading and auditory deficits. Scores from the Western Aphasia …

Photoswitchable Optoelectronic Properties Of 2d Mose2/Diarylethene Hybrid Structures, Sewon Park, Jaehoon Ji, Connor Cunningham, Srajan Pillai, Jean Rouillon, Carlos Benitez-Martin, Mengqi Fang, Eui-Hyeok Yang, Joakim Andreasson, Jeong Ho You, Jong Hyun Choi

Purdue University Libraries Open Access Publishing Fund

The ability to modulate optical and electrical properties of two-dimensional (2D) semiconductors has sparked considerable interest in transition metal dichalcogenides (TMDs). Herein, we introduce a facile strategy for modulating optoelectronic properties of monolayer MoSe2 with external light. Photochromic diarylethene (DAE) molecules formed a 2-nm-thick uniform layer on MoSe2, switching between its closed- and open-form isomers under UV and visible irradiation, respectively. We have discovered that the closed DAE conformation under UV has its lowest unoccupied molecular orbital energy level lower than the conduction band minimum of MoSe2, which facilitates photoinduced charge separation at the hybrid interface and quenches photoluminescence (PL) …

Existence Of A Nonzero Worst-Case Ach For Short-Term Exposure In Ventilated Indoor Spaces, K. A. Krishnaprasad, ‪Nadim Zgheib, K. Choudhary, M. Y. Ha, C. Y. Choi, K. S. Bang, S. Jang, S. Balachandar

Mechanical Engineering Faculty Publications

A well-ventilated room is essential to reduce the risk of airborne transmission. As such, the scientific community sets minimum limits on ventilation with the idea that increased ventilation reduces pathogen concentration and thus reduces the risk of transmission. In contrast, the upper limit on ventilation is usually determined by human comfort and the need to reduce energy consumption. While average pathogen concentration decreases with increased ventilation, local concentration depends on multiple factors and may not follow the same trend, especially within short exposure times over large separation distances. Here, we show through experiments and high-fidelity simulations the existence of a …

Characterization Of Oscillatory Response Of Light-Weight Wind Turbine Rotors Under Controlled Gust Pulses, Fernando Ponta, Alayna Farrell, Apurva Baruah, North Yates

Michigan Tech Publications

Given the industry-wide trend of continual increases in the size of utility-scale wind turbines, a point will come where reductions will need to be made in terms of the weight of the turbine’s blades to ensure they can be as long as needed without sacrificing structural stability. One such technique that may be considered is to decrease the material used for the shell and spar cap. While this will solve the weight issue, it creates a new one entirely—less material for the shell and spar cap will in turn create blades that are more flexible than what is currently used. …

Underwater Double Vortex Generation Using 3d Printed Acoustic Lens And Field Multiplexing, Chadi Ellouzi, Ali Zabihi, Farhood Aghdasi, Aidan Kayes, Milton Rivera, Jiaxin Zhong, Amir Miri, Chen Shen

Henry M. Rowan College of Engineering Departmental Research

The generation of acoustic vortex beams has attracted an increasing amount of research attention in recent years, offering a range of functions, including acoustic communication, particle manipulation, and biomedical ultrasound. However, incorporating more vortices and broadening the capacity of these beams and associated devices in three dimensions pose challenges. Traditional methods often necessitate complex transducer arrays and are constrained by conditions such as system complexity and the medium in which they operate. In this paper, a 3D printed acoustic lens capable of generating a double vortex pattern with an optional focusing profile in water was demonstrated. The performance of the …

Effects Of The Loading Rate On Mechanical Properties Of The Human Superficial Femoral Artery, Ali Zolfaghari Sichani, Majid Jadidi

UNO Student Research and Creative Activity Fair

INTRODUCTION: Blood vessels are known for their viscoelastic mechanical behavior, including a dependency on the loading rate. Previous studies have shown mixed results regarding the effects of the loading rate on the mechanical properties of the arterial wall. In this study, our aim was to evaluate the loading rate dependency in the human Superficial Femoral Artery (SFA), the main artery of the leg....

Mechanical Properties Of A Structural Component Processed In High-Pressure Die Casting (Hpdc) With A Non-Heat-Treated Aluminum Alloy, David Servando Cantú-Fernández, Jaime Taha-Tijerina, Alejandro González, Pablo Guajardo Hernández, Brian Quinn

Informatics and Engineering Systems Faculty Publications

This industrial research focuses on the implementation and development of a productive process for an automotive structural component (Shock tower) manufactured by a high-pressure die casting (HPDC) process made of aluminum alloy AuralTM-5. This aluminum alloy has been considered in diverse automotive and aerospace components that do not require heat treatment due to its mechanical properties as cast material (F temper). On the other hand, AuralTM-5 has been designed for processing as HPDC because it is an alloy with good fluidity, making it ideal for large castings with thin-wall thicknesses, like safety structural components such as rails, supports, rocker panels, …

Under Pressure: The Soft Robotic Clap-And-Fling Of Cuvierina Atlantica, Daniel Mead

USF Tampa Graduate Theses and Dissertations

Evolution over billions of years has led to unique animals of all types. The tiny sea butterfly is one that remains mostly anonymous because of its size and low place on the food chain, but it is a swimming creature that when examined closely reveals a surprise. Shockingly, it has a swimming motion nearly identical to small insects flying at intermediate Reynolds numbers, referred to as the clap-and-fling. The centimeter long pteropod flapping briskly at 5Hz escapes attention with its size and speed. Modeling the clap-and-fling motion of the sea butterfly at a larger scale allows the benefits and uniqueness …

Comparison Of Conventional And Adaptive Acoustic Beamforming Algorithms Using A Tetrahedral Microphone Array In Noisy Environments, Megan Brittany Ewers

Dissertations and Theses

In situ acoustic measurements are often plagued by interfering sound sources that occur within the measurement environment. Both adaptive and conventional beamforming algorithms, when applied to the outputs of a microphone array arranged in a tetrahedral geometry, are able to capture sound sources in desired directions and reject sound from unwanted directions. Adaptive algorithms may be able to measure a desired sound source with greater spatial precision, but require more calculations and, therefore, computational power. A conventional frequency-domain phase-shift algorithm and a modified adaptive frequency-domain Minimum Variance Distortionless Response (MVDR) algorithm were applied to simulated and recorded signals from a …

Impact Of Welding Parameters In The Porosity Of A Dissimilar Welded Lap Joint Of Cp800-Xpf1000 Steel Weldment By Gmaw-P, Julio Cesar Garcia-Guerrero, Francisco Fernando Curiel-López, Víctor Hugo López-Morelos, Jaime Taha-Tijerina, Teresita Jesus Sánchez-Cruz, Maria Del Carmen Ramirez-Lopez, Eduardo Cortes-Carillo, Miguel Angel Quinones-Salinas

Informatics and Engineering Systems Faculty Publications

The use of the orthogonal array L4 allows a determination of the effect between the welding parameters peak current (Ip), background current (Ib) and frequency (f) on the porosities in a dissimilar welded lap joint of CP800 and XPF1000 steel weldment by the gas metal arc welding process with the transfer pulsed mode. According to the results, modifications in the welding parameters affect the heat input during welding. A heat input higher than 0.30 KJ/mm generates up to 0.32% porosity in the weld metal, while a heat input lower than 0.25 KJ/mm generates up to 28% porosity in the weld …