Biomechanical Engineering Commons^™

Numerical Study Of Nutrient Mixing In Trabecular Bone In Microgravity, Disuse And Normogravity, Sagar Gharti

Doctoral Dissertations and Master's Theses

Mechanical loading is known to regulate bone remodeling by driving interstitial fluid flow which stimulates cells and drives nutrient transport within the trabecular network. In microgravity, the absence of mechanical stimulation or loading suppresses convective flow processes, causing diffusion-driven nutrient mixing and renewal, and accelerated bone loss. This thesis investigates how oscillation frequency and trabecular bone density jointly control nutrient mixing and wall shear stress within trabecular cavities.

A computational fluid dynamics (CFD) framework is developed in STAR-CCM+ using a soft-cap oscillation model that mimics cyclic compression. Three idealized trabecular morphologies are simulated across different frequencies to represent microgravity or …

Automated Plant Morphological Assessment And Microbial Community Monitoring In Simulated Lunar Regolith, Collin R. Topolski

Doctoral Dissertations and Master's Theses

Upcoming lunar bases will need to leverage in-situ resources to ensure long-term sustainability and reduce mission costs. One key challenge is food production, which could be addressed by growing crops in lunar regolith-based substrates. However, lunar regolith lacks essential nutrients, requiring organic amendments to support continuous plant cultivation. This study examined the impact of manure-amended lunar regolith simulant on Mizuna mustard growth while assessing microbial community diversity and functionality. To support this effort, a custom software pipeline utilizing an open-source library, PlantCV, was developed to automatically track plant leaf area and height via image analysis. Results indicated that amended rhizosphere …

Assessing The Impact Of Femur Morphological Variations On Pediatric Hip Joint Biomechanics Using Statistical Shape Modeling, Tamara Chambers

Doctoral Dissertations and Master's Theses

This dissertation aimed to (1) quantify morphological variations in the pediatric hip joint and (2) evaluate the sensitivity of an infant musculoskeletal model (MSM) to these variations, considering hip joint center estimation errors. A shape statistical model (SSM) of decedent infant femurs from the Ortolani collection was created using ShapeWorks, capturing key morphological features, such as variations in the femoral neck-shaft and anteversion angles. Seven synthetic femurs were generated from the SSM to create SSM-informed MSMs, which were systematically evaluated through kinematics and kinetics analyses in OpenSim. Incorporating the SSM led to slight changes in the pediatric MSMs’ kinematics but …

Finite Element Model Of The Pediatric Hip Joint During The Barlow Maneuver, Christina M. Zlock

Doctoral Dissertations and Master's Theses

Developmental Dysplasia of the Hip is the dysplasia or dislocation of an unstable femoral head in the acetabulum of the pelvis. This is a result of an abnormal or underdeveloped growth of the acetabulum and triradiate cartilages and/or an out of place and uncentered femoral head in the acetabulum. This underdevelopment, if not diagnosed and treated at an early age, may lead to abnormal and pain and osteoarthritis later in life. A common step in diagnosis is to perform a physical examination of the hip, one method is the Barlow maneuver.

The aim of the project is to use healthy …

A Meshless Approach To Computational Pharmacokinetics, Anthony Matthew Khoury

Doctoral Dissertations and Master's Theses

The meshless method is an incredibly powerful technique for solving a variety of problems with unparalleled accuracy and efficiency. The pharmacokinetic problem of transdermal drug delivery (TDDD) is one such topic and is of significant complexity. The locally collocated meshless method (LCMM) is developed in solution to this topic. First, the meshless method is formulated to model this transport phenomenon and is then validated against an analytical solution of a pharmacokinetic problem set, to demonstrate this accuracy and efficiency. The analytical solution provides a locus by which convergence behavior are evaluated, demonstrating the super convergence of the locally collocated meshless …

Validation Of A Two-Dimensional Clinostat Design To Provide Functional Weightlessness To Custom Gas Exchange Vessels, Collin R. Topolski

Doctoral Dissertations and Master's Theses

Understanding the impacts of microgravity on bacteria is vital for successful long duration space missions. In this environment, bacteria have been shown to become more virulent, more resistant to antibiotics and form more biofilms. To learn more about these phenomena, many experiments must be sent to the International Space Station, which is cost- and time prohibitive. Instead, the use of ground-based analogs is advantageous to define preliminary results that can later be verified with a space-based experiment. This research explored the development of an innovative 2D clinostat for simulating microgravity using bacteria. Computational fluid dynamics, standards established by previous literature …

Multi-Scale Fluid Flow Analysis Of The Cardiovascular System, Zaid Mahmood

Doctoral Dissertations and Master's Theses

The hypoplastic left heart syndrome (HLHS) is one of the rarest congenital heart diseases affecting infants. Out of 150 babies born, one baby suffers from congenital heart disease. Furthermore, nine percent out of those suffering from congenital heart disease specifically suffer from hypoplastic left heart syndrome (HLHS). To this end, the Fontan operation which is a procedure to generate a harmonic blood flow in single functioning ventricle patients has been executed to palliate HLHS patients. In this operation, the inferior vena cava (IVC) and the superior vena cava (SVC), carrying the low-oxygenated blood returning from the lower and upper body …

Lumped Parameter Model For A Self Powered Fontan Palliation Of The Hypoplastic Left Heart Syndrome, Jang Ho Park

Doctoral Dissertations and Master's Theses

Out of all newborn infants with congenital heart disease (CHD), 8% have a single functioning ventricle. The Fontan surgical procedure, where the superior and inferior venous returns are connected directly to the pulmonary arteries to allow the single functioning ventricle to perfuse the systemic circulation, has been around for decades, yet the patients who undergo this operation suffer from chronic illnesses and their survivability is less than 50% by adulthood [1-10]. Some suggest that the Fontan operation can be improved by implanting a synthetic pump. However, synthetic pumps also present some complications due to mechanical failure, risk of stroke, and …

Creating Standards Compliant Biodiesel Production Capability Using Waste Peanut Oil At Embry-Riddle Aeronautical University, Jintana Nina Phanthanousy

Doctoral Dissertations and Master's Theses

During the past year, Embry-Riddle Aeronautical University has been in the process of making a viable biodiesel using waste peanut oil from a Chick-Fil-A fast food restaurant on campus. Past research and biodiesel production from the previous two years on campus was taken into consideration and a catalyst change was proposed. Sample test batches were conducted to create a viable biodiesel and a consistent recipe. The biodiesel was tested for quality and also sent in for ASTM Standards testing. Biodiesel that passed quality testing would be permitted to be used as a B100 in campus facilities and university projects. It …

Facility Implementation, Production, And Use Of Biodiesel On A University Campus, Michelle Erin Rodio

Doctoral Dissertations and Master's Theses

During the last two years, Embry-Riddle Aeronautical University has been in the process of having a fully-functional biodiesel processing facility on campus. Within this time, it was shown that biodiesel was a great alternative to diesel fuel based on emissions, performance, and cost, allowing for a grant of $10,000 being awarded to fund the project. Upon properly producing biodiesel, the fuel was tested in a John Deere 2653A tractor to see what differences, if any, existed when using a biodiesel blend over diesel fuel. In doing this, carbon buildup and fuel economy were compared, and a cost analysis conducted. It …