Mechanical Engineering Commons^™

Radiomic Features To Predict Overall Survival Time For Patients With Glioblastoma Brain Tumors Based On Machine Learning And Deep Learning Methods, Lina Chato

UNLV Theses, Dissertations, Professional Papers, and Capstones

Machine Learning (ML) methods including Deep Learning (DL) Methods have been employed in the medical field to improve diagnosis process and patient’s prognosis outcomes. Glioblastoma multiforme is an extremely aggressive Glioma brain tumor that has a poor survival rate. Understanding the behavior of the Glioblastoma brain tumor is still uncertain and some factors are still unrecognized. In fact, the tumor behavior is important to decide a proper treatment plan and to improve a patient’s health. The aim of this dissertation is to develop a Computer-Aided-Diagnosis system (CADiag) based on ML/DL methods to automatically estimate the Overall Survival Time (OST) for …

Fuel Injector Design Of A Hypersonic Jet Engine Using Computational Fluid Dynamics, Melissa Rose Mercado

UNLV Theses, Dissertations, Professional Papers, and Capstones

The development of hypersonic airbreathing engines, such as a supersonic combustion ramjet, or scramjet, are implemented for flight Mach numbers over 5 where combustion must occur in supersonic conditions. The advancement of scramjet propulsion has led to favored usage over rocket propulsion systems for in atmosphere applications due to their lighter weight, higher specific impulse, and greater maneuverability [1]. The combustor section of a scramjet engine houses the fuel injectors. Fuel is injected into the supersonic flow with the main objective of achieving rapid and thorough fuel-air mixing because the residence time in the combustion chamber has a timescale of …

New Mathematical Models For Acoustic Insertion Loss Of Fiberglass Lining In Hvac Duct, Michael Anthony Schwob

UNLV Theses, Dissertations, Professional Papers, and Capstones

The design objectives for HVAC air distribution systems are thermal comfort, good indoor air quality, energy efficiency, low construction cost, and appropriate indoor noise levels. The last objective requires that the designer can predict the attenuation of sound transmitted through an air duct. One form of attenuation commonly introduced to an air distribution system to achieve interior noise criteria is fiberglass liner. Past research has been conducted to obtain reliable and accurate insertion loss (IL) data for duct with fiberglass liner. Empirical efforts have relied on limited data sets. Computational efforts have produced numerical models that are not practical for …

Predicting The Progression Of Diabetes Mellitus Using Dynamic Plantar Pressure Parameters, Mathew Sunil Varre

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Diabetic peripheral neuropathy is one of the common complications of type-2 diabetes mellitus (DM). Changes in the intrinsic plantar tissue coupled with repetitive mechanical loads and loss of sensation may lead to foot related complications (skin break down, ulcerations, and amputations) in persons with neuropathy if left untreated. The purpose of this dissertation was to stratify individuals with pre-diabetes, diabetes with and without neuropathy using dynamic plantar pressure parameters during walking, using machine learning algorithms.Methods: Plantar pressure data was collected from one hundred participants during walking with pressure measuring insoles fixed between the feet and thin socks. Simultaneously high-definition …

Design Of Path Correction For Improved Gait Rehabilitation, Zvonimir Pusnik

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

Following a serious neurological injury or disease, such as a spinal cord injury or multiple sclerosis, many patients develop impaired gait (the ability to walk). There are many different pieces of equipment to help rehabilitate people with impaired gait, ranging from over ground walking with exoskeletons to treadmills with partial bodyweight support. Since the 1990s and 2000s, elliptical trainers have entered the rehabilitative field as a machine with low impact forces and gait-like motion. This led researchers at Madonna Rehabilitation Hospitals to collaborate with the University of Nebraska-Lincoln to create the Intelligently Controlled Assistive Rehabilitation Elliptical (ICARE).

While the ICARE …

Thermodynamic Analysis Of A Novel Cycle For Nuclear Smr And Heat Transfer Performance Validation Of The Related Supercritical Working Fluids, Benjamin M. Pepper

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Currently, all operating nuclear power facilities in the U.S. follow the same general design and process: light-water reactors boil water into steam using bundles of nuclear fuel rods as a heat source, pumping that steam through a turbine which powers a generator to produce clean year-round electricity. Water is an effective coolant, but other facilities around the world have demonstrated the ability to use non-water-based coolants in nuclear reactor designs, which consequently have their own trade-offs. Some positive consequences of using different reactor designs include enhanced safety, better economics, and cheaper clean consumer energy. The work described in this paper …

Calibration Procedure For Dic Strain Measurements During Vibration-Based Fatigue Testing, Benjamin D. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vibration-based fatigue testing is fast and effective method for determining failure characteristics of a material. Often, a small electrical device called a strain gage is bonded to a rectangular plate specimen to measure the deformation of the plate during a test. However, these strain gages break before the plate does, so an alternative method would improve the results obtained from the test. As an alternative to strain gages, Digital Image Correlation (DIC) is a non-contacting, camera-based technique that measures the deformation of an object by comparing digital images taken before and after the object is deformed. During a vibration-based fatigue …

Release Of Large Water Droplets, Jeffrey N. Fonnesbeck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water is familiar to all human beings and water droplets are an integral part of our daily lives. From irrigation sprinklers to waterfalls we can observe the formation of water droplets. For most, the droplets are so common and mundane that no thought is given to how the droplets form. Scientists have spent many decades detailing the processes that lead to droplet formation. Current theories and experiments agree quite well for specific cases such as pendant drop formation and jet breakup, but in regards to large volumes of free falling liquid there is very little experimental work to confirm the …

Quantifying The Dynamics Of An Idealized Oil-Plume In Stratified Environment Using Direct Numerical Simulations, Jasmin Ahmed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Deep-water oil spills such as the incident in the northern Gulf of Mexico 2010, produce turbulent oil plumes. Multiphase turbulent plumes under stratification are simulated to understand the dynamics of oil plume in oceanic environment. The evolution of the plume is strongly affected by the level of turbulent mixing during the rise of oil through the stratified water. The relative velocity due to the difference in density between oil and water causes slip of oil in water. The plume has been modeled as a two fluid mixture-model, which allows the use of one continuity and momentum equation for the oil-water …

Large Eddy Simulation Of The Wakes Of Three Urban Air Mobility Vehicles, Denis-Gabriel Caprace, Andrew Ning

Faculty Publications

Recent advances in urban air mobility have driven the development of many new VTOL concepts. These vehicles often feature original designs and futuristic shapes. Due to their novelty, the wake characteristics of such aircraft are unknown. However, large wake-induced velocities, should they exist, may be dangerous for any other vehicle evolving in their close proximity. Therefore, improved knowledge about the wakes of VTOL vehicles is needed to guarantee the safety of urban air mobility operations. In this work, we study the wake of three VTOL aircraft in cruise by means of large eddy simulation. We present a two-stage numerical procedure …

The Grate Solution: Simplifying Viking Oven Packaging Processes, Megan Jansen

Honors Theses

The following report details work completed to improve the Viking Oven Corporation’s gas oven assembly line. The current state of the line hosts an unreliable system for packaging oven grates. Viking manufactures two types of gas ovens on the same line: open burner and closed burner. These different types require different prepackaged grates to be included in the final assembly area. Viking estimates that the wrong grates are sent to the customer ten percent of the time. The following report presents research, brainstorming, problem-solving techniques, and proposed solutions to the problem. The proposed solution would solve the problem at little …

A Study Of Asymmetric Supersonic Wind Tunnel Nozzle Design, Brittany A. Davis

Mechanical & Aerospace Engineering Theses & Dissertations

Achieving higher Mach numbers for private and commercial flight is a growing interest in the aerospace community. To qualify vehicles prior to flight, tests must be run in wind tunnels. Asymmetric wind tunnel nozzles are of continuing interest to the aerospace community due to their ability to change throat geometry, allowing for a range of Mach numbers to be achieved that encompasses all of the supersonic regime. The sliding block wind tunnel at Old Dominion University (ODU) is designed for a range of Mach numbers from about 1.8 to 3.5 but is limited to an upper limit of 2.8 by …

Development Of Modeling And Simulation Platform For Path-Planning And Control Of Autonomous Underwater Vehicles In Three-Dimensional Spaces, Sai Krishna Abhiram Kondapalli

Mechanical & Aerospace Engineering Theses & Dissertations

Autonomous underwater vehicles (AUVs) operating in deep sea and littoral environments have diverse applications including marine biology exploration, ocean environment monitoring, search for plane crash sites, inspection of ship-hulls and pipelines, underwater oil rig maintenance, border patrol, etc. Achieving autonomy in underwater vehicles relies on a tight integration between modules of sensing, navigation, decision-making, path-planning, trajectory tracking, and low-level control. This system integration task benefits from testing the related algorithms and techniques in a simulated environment before implementation in a physical test bed. This thesis reports on the development of a modeling and simulation platform that supports the design and …

Enhancement Of Biogas Production Through Solid-State Anaerobic Co-Digestion Of Food Waste And Corn Cobs, Lukhi Mulia Shitophyta, Anisa Salsabila, Firanita Angraini Putri, Siti Jamilatun

Makara Journal of Technology

Although biogas has been primarily produced through liquid anaerobic digestion, this method leads to the floating and stratification of fibers and non-homogeneous mixing, which can reduce the biogas yield. Alternatively, biogas can be produced by the solid-state anaerobic digestion (SS-AD) of organic material with a high solid content, such as corn cobs. We investigated the co-digestion of food waste and corn cobs as a biomass feedstock for SS-AD in biogas production. We measured the effects of the total solid (TS) content, percentage of food waste, and reduction in volatile solids (VS), from which we determined its appropriate kinetic model. We …

Control Strategy For Solar Energy-Saving Lamps For Optimized Energy Utilization And Sustainability Of Operation Durability: Indonesia Case, Burhanuddin Halimi, Agus Purwadi, Nana Heryana

Makara Journal of Technology

To solve the electrification ratio issue, the Indonesian government has promoted the use of solar energy-saving lamps. This study proposes a control strategy that adopts current reference time-based profiling for solar energy-saving lamps. For optimal energy consumption, the current reference profile is determined according to users’ daily energy requirements. From the aspect of user comfort, a gradual step reference profile is also introduced to provide a subtle change in lighting intensity level. The proposed control strategy can minimize energy consumption and optimize the operation durability of the system. The concept is verified by simulating four scenarios, the results of which …

Prediction Of Residual Stresses In L-Pbf Ti-6al-4v Fatigue Specimens Using A Thermo-Mechanical Finite Element Model, Haley Petersen, Brad J. Sampson

ME 4233/6233 Fundamentals of FEA

Laser Powder Bed Fusion (L-PBF) is an additive manufacturing process that is becoming widely adopted in the automotive, aerospace, and biomedical industries. It uses a laser to melt metal in the form of powder to build parts in a layer-by-layer fashion based on an imported CAD geometry. The constant remelting of previous layers can produce unwanted thermally induced residual stresses in the part due to large thermal gradients, which can drastically reduce the fatigue life of the material. Predicting these residual stresses within the as-built part would be advantageous because one could better understand how the part will perform in …

Trust Nonlinear Dynamic, Sami Zeggar, Adib El Mrabet Tarmach

ME 4233/6233 Fundamentals of FEA

The TRUST project's goal is to promote the efficient and responsive development of experimental, modeling, and simulation capabilities for future systems by constructing realistic testbeds that can be exercised more readily and efficiently. The testbeds will be used to conduct experiments in present and future engineering environments using complimentary modeling and simulation. TRUST required several tools in preproduction states and helped identify key features for future development. The required tools include: 1. Automated simulation management from the engineering common model framework (ECMF) 2. Version controlled model repositories for engineering analysis baseline models (EABM) 3. Experimental results databases (TIMS) 4. Communication …

Autonomous Navigator Mobile Robot Upgrade, David Sansoucy

Thinking Matters Symposium

The mobile robot platform has been developed over the course of 10 years at USM. In Spring 2020, Belle-Isle and Werner updated the previous framework by rewriting the software to use the ROS framework running on an on-board Raspberry Pi 3. They also implemented navigation using an A* motion planning algorithm and image processing. In Summer 2021, Ames incorporated Lidar and Kinect sensors onto the robot to improve its real-time navigation capabilities. He also made improvements to the power distribution systems. This project aimed to build on the ROS frameworks developed by the previous 2 teams with the main goal …

Ads-B Aircraft Photography, Gabriel Michael Adamson, Wesley Crouch, Jacob Elmore

Honors Capstone Projects and Theses

No abstract provided.

A Computational Approach For The Estimation Of Elastic Behavior Of Metal Matrix Composites, Emmanuel Michalakis

ME 4233/6233 Fundamentals of FEA

Composite materials are being widely used in many industries for their properties and efficiency. The current work presents a computational approach that can estimate the elastic behavior of metal composites and porous materials using finite element models of representative volume elements (RVEs) which have been used to test and design particulate composite materials. The required size of the RVE for the determination of elastic properties, the effects of the elastic modulus fraction Einc/Emat on the homogenized elasticity and the convergence of the homogenized properties E11, E22 and E33 with the size of the RVE is explored.

Methodology To Compare Performance Of Residential Hvac Systems Operating In Cooling Mode, Manoj Bhandari

Mechanical Engineering Theses

Residential HVAC systems are selected and installed based on the goals of the customer. For spec homes, the most common types of systems are traditionally ducted with standard efficiency. However, for custom homes, the recent trend has included high-efficiency HVAC systems that are often accompanied by air-tight home envelopes with highly thermally resistant foam insulation in the walls. Several high-efficiency systems are available in the market with the performance of these systems varying between the different manufacturers and the types of systems. The systems available in the market can be compared and ranked based on their thermal performance and energy …

Understanding Processing And Mechanics Of Extrusion-Based Additive Manufacturing For Multi-Material Parts, Jafar N/A Ghorbani

Mechanical Engineering ETDs

Despite the design freedom that additive manufacturing (AM) processes provide, there are still challenges in using some AM processes for end-use products. Fused filament fabrication (FFF), also known as material extrusion, is one of the AM technologies that has been used mainly for prototyping due to the low cost of machines, raw material, and ease of operation. Another advantage of FFF is its ease of integration with other additive or subtractive technologies. However, some disadvantages such as relatively poor and anisotropic mechanical properties have hindered FFF for end-use engineering components. The first chapter of this dissertation is a brief review …

Audio-Based Wildfire Detection On Embedded Systems, Hung-Tien Huang, Austin Downey, Jason D. Bakos

Faculty Publications

The occurrence of wildfires often results in significant fatalities. As wildfires are notorious for their high speed of spread, the ability to identify wildfire at its early stage is essential in quickly obtaining control of the fire and in reducing property loss and preventing loss of life. This work presents a machine learning wildfire detecting data pipeline that can be deployed on embedded systems in remote locations. The proposed data pipeline consists of three main steps: audio preprocessing, feature engineering, and classification. Experiments show that the proposed data pipeline is capable of detecting wildfire effectively with high precision and is …

Inertially Stabilized Gimbal, Miranda Grace Bilbrey

Honors Capstone Projects and Theses

No abstract provided.

Zintl Phase Compounds Mg3Sb2-XBiX (X=0, 1, And 2) Monolayers: Electronic, Phonon And Thermoelectric Properties From Ab Initio Calculations, Zheng Chang, Jing Ma, Kunpeng Yuan, Jiongzhi Zheng, Bin Wei, Mohammed Al-Fahdi, Yufei Gao, Xiaoliang Zhang, Hezhu Shao, Ming Hu, Dawei Tang

Faculty Publications

The Mg₃Sb_2−xBi_x family has emerged as the potential candidates for thermoelectric applications due to their ultra-low lattice thermal conductivity (K_L) at room temperature (RT) and structural complexity. Here, using ab initio calculations of the electron-phonon averaged (EPA) approximation coupled with Boltzmann transport equation (BTE), we have studied electronic, phonon and thermoelectric properties of Mg₃Sb_2−xBi_x (x = 0, 1, and 2) monolayers. In violation of common mass-trend expectations, increasing Bi element content with heavier Zintl phase compounds yields an abnormal change in K_L in two-dimensional Mg₃Sb …

A Molecular Dynamics Study Of The Laser Sintering Process And Subsequent Mechanical Properties Of Γ-Tial Nanoparticles, Eleanor Dickens

Honors Theses

Using molecular dynamics (MD) simulations, the laser sintering additive manufacturing process is investigated through the observation of γ-TiAl nanoparticles. This process is conducted using both uni-directional chain and stacking configurations. By mimicking the heating process and varying laser sintering parameters such as heating rater, sintering temperature, and particle orientation, the fusion behavior and resulting products are analyzed for both chain and stacking NP patterns. In of single chain cases, it is noticed that slower heating rates and higher melting temperatures yield larger neck growth between each individual particle and thus produce a more stable product. This leads to stronger mechanical …

A Novel Imaging Methodology To Estimate Advective Losses From A Concentrating Solar Power Particle Receiver, Jesus Daniel Ortega

Mechanical Engineering ETDs

Falling particle receivers (FPRs) such as the one at Sandia National Labs, represent the state-of-the-art Concentrating Solar Power (CSP) technology for energy harvesting. The FPR operates by creating a gravity-driven particle curtain in a receiver that is irradiated by concentrated sunlight from a field of concentrators. The particles are used directly as the heat transfer and storage media for the concentrated energy absorbed. However, during operation, particles can egress through the open aperture of the receiver cavity, resulting in particle-inventory and heat losses from the system. The particle plumes egressing from the cavity present a unique challenge to metrology due …

Viability And Accessibility Of Urban Heat Island And Lake Microclimate Data Over Current Tmy Weather Data For Accurate Energy Demand Predictions., Irena A. Weclawiak

ETD Archive

Building Energy Simulations (BES) are necessary for designing energy-efficient systems. Open-source simulation software developed by the Department of Energy (DOE), EnergyPlus (EP) provides Typical Meteorological Year (TMY) weather data that consists of a 15-year average. Two major concerns about this data are the inability to detect extreme conditions and limited data locations. There is a greater number of Microclimate (MC) stations that can be used for simulations, but it involves time-consuming data preparation to match the EP format. This study investigated the effects of Urban Heat Island (UHI) and the MC of Lake Erie. A comparison of the MC data …

An Evaluation And Economic Analysis Of A Water Main Geothermal System In A Residential Space, Brian L. Kohut

ETD Archive

Iron-based magnetic alloys possess very good magnetic and mechanical properties. Among these alloys Fe-Si-B-based alloys show outstanding saturation magnetization and coercivity which makes them great candidates for many industrial applications. Addition of certain elements to the Fe-Si-B base is proven to improve the homogeneity and fineness of microstructure as well as enhance the magnetic behavior of these alloys. In this research work, we have studied the effect of adding copper and niobium to the Fe-Si-B base alloy. Previous studies have shown that magnetic alloys show better magnetic properties when their microstructure consists of nanocrystals embedded in an amorphous matrix. In …

Dc Microgrid Fault Detection Using Multiresolution Analysis Of Traveling Waves, Rudy Montoya

Mechanical Engineering ETDs

Fast detection and isolation of faults in a DC microgrid is of particular importance. Fast tripping protection (i) increases the lifetime of power electronics (PE) switches by avoiding high fault current magnitudes and (ii) enhances the controllability of PE converters. This thesis proposes a traveling wave (TW) based scheme for fast tripping protection of DC microgrids. The proposed scheme utilizes a discrete wavelet transform (DWT) to calculate the high-frequency components of DC fault currents. Multiresolution analysis (MRA) using DWT is utilized to detect TW components for different frequency ranges. The Parseval energy calculated from the MRA coefficients are then used …