Mechanical Engineering Commons^™

Nuclear Envelope Mechanobiology: Linking The Nuclear Structure And Function, Matthew Goelzer, Julianna Goelzer, Matthew L. Ferguson, Corey P. Neu, Gunes Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The nucleus, central to cellular activity, relies on both direct mechanical input as well as its molecular transducers to sense external stimuli and respond by regulating intra-nuclear chromatin organization that determines cell function and fate. In mesenchymal stem cells of musculoskeletal tissues, changes in nuclear structures are emerging as a key modulator of their differentiation and proliferation programs. In this review we will first introduce the structural elements of the nucleoskeleton and discuss the current literature on how nuclear structure and signaling are altered in relation to environmental and tissue level mechanical cues. We will focus on state-of-the-art techniques to …

Using Dynamic In Vivo Kinematics For Subject-Specific Calibration Of Knee Ligament Parameters, Stephen Nelson

Boise State University Theses and Dissertations

In vivo clinical studies are the optimal way to investigate the biomechanical outcomes of new prosthetic devices. This particular style of testing can be difficult and, in certain cases, unethical to perform. The testing of unproven devices, surgical techniques, and materials put patients at risk from unanticipated outcomes in how these devices respond to the in vivo environment and patient-specific loading conditions. Biomechanical computational models were developed to provide validation to new devices prior to clinical testing. Computational models for use in optimizing knee prosthetics frequently include ligament representations, but these representations have inherent uncertainty due to wide intersubject variation …

How To Recognize And Control Interfacial Phenomena That Hinder The Advancement Of Clean Energy Technologies, Corey Michael Efaw

Boise State University Theses and Dissertations

Nuclear energy and electrochemical energy storage, such as batteries, are key parts to the clean energy transition of critical infrastructure. This work aims to define, monitor, and modify interfacial layers that would improve the utility of materials in harsh environments seen in nuclear and energy storage applications. First, the studying of zirconium alloys, which is used as nuclear cladding, was done to better understand the degradation mechanisms within an extreme environment. High-resolution characterization techniques were used to correlate corrosion mechanisms to equivalent circuit models from novel in-pile electrochemical impedance spectroscopy sensors. Advancement in this sensor technology could provide further insight …

Integration Of Neural Architecture Within A Finite Element Framework For Improved Neuromusculoskeletal Modeling, Victoria L. Volk, Landon D. Hamilton, Donald R. Hume, Kevin B. Shelburne, Clare K. Fitzpatrick

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Neuromusculoskeletal (NMS) models can aid in studying the impacts of the nervous and musculoskeletal systems on one another. These computational models facilitate studies investigating mechanisms and treatment of musculoskeletal and neurodegenerative conditions. In this study, we present a predictive NMS model that uses an embedded neural architecture within a finite element (FE) framework to simulate muscle activation. A previously developed neuromuscular model of a motor neuron was embedded into a simple FE musculoskeletal model. Input stimulation profiles from literature were simulated in the FE NMS model to verify effective integration of the software platforms. Motor unit recruitment and rate coding …

Three-Dimensional Phase Field Modeling Of Fracture In Shape Memory Ceramics, Ehsan Moshkelgosha, Mahmood Mamivand

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Despite the vast applications of transformable ceramics, such as zirconia-based ceramics, in different areas from biomedical to aerospace, the fundamental knowledge about their mechanical degradation procedure is limited. The interaction of the phase transformation and crack growth is crucial as the essential underlying mechanism in fracture of these transformable ceramics, also known as shape memory ceramics. This study develops a three-dimensional (3D) multiphysics model that couples the variational formulation of brittle crack growth to the Ginzburg-Landau equations of martensitic transformation. We parameterized the model for the 3D single crystal zirconia, which experienced stress- and thermal-induced tetragonal to monoclinic transformation. The …

Musculoskeletal Adaptation Of Young And Older Adults In Response To Environmental, Physical, And Cognitive Conditions, Amy E. Holcomb

Boise State University Theses and Dissertations

Accidental falls present a large functional and financial burden among people aged 65 years and older. Falls, injuries associated with falls, and the fear of falling decrease quality of life, physical function, and independence for older adults. To prevent falls, improve stability, and protect joints from damage or injury, the typical response to "challenging" conditions include cautious gait, increase muscle co-contraction, and decreased range of motion. These compensatory strategies are more pronounced in the older adult population with apprehensive "cautious" gait at slower speeds, decreased knee flexion, and increased muscle activation around the knee and ankle. The underlying mechanisms and …

Phase Change Temperature Sensor For High Radiation Environment: Material, Additive Technology And Structure Development, Al Amin Ahmed Simon

Boise State University Theses and Dissertations

Performance of any sensor in a nuclear reactor involves reliable operation under a harsh environment (i.e., high temperature, neutron irradiation, and a high dose of ionizing radiation). In this environment, accurate and continuous monitoring of temperature is critical for the reactor's stability and proper functionality. Furthermore, during the development and testing stages of new materials and structural components for these systems, it is imperative to collect in-situ measurement data about the exact test conditions for real-time analysis of their performance. To meet the compelling need of such sensing devices, we propose radiation-hard temperature sensors based on the phase change phenomenon …

Effect Of Temperature On Abrasion Erosion In Particle Based Concentrating Solar Powerplants, Nipun Goel, Tessa Mei-Lin Fong, John P. Shingledecker, Andrew Russell, Michael W. Keller, Siamack A. Shirazi, Todd Otanicar

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The use of solid particles as a heat transfer medium is being explored for concentrated solar power plants (CSP) to increase their efficiency by achieving operating temperature >700 °C. During operation, these hot particles are expected to move along the various components within the collector system, resulting in material degradation from a combination of high-temperature oxidation and erosion. In the present study, the performance of candidate materials was evaluated through a series of abrasion erosion experiments at room temperature as well as at 800 °C. Wear in metallic and refractory type materials was investigated using CarboBead® HSP 40/70 particles inside …

Evaluating Stem Course Re-Design Strategies In Light Of Covid-19, Ulises Juan Trujillo Garcia, Krishna Pakala, Samantha Schauer, Diana Bairaktarova, Bhaskar Chittoori

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The COVID-19 pandemic brought on unprecedented challenges to the teaching and learning communities that required faculty to make purposeful changes in their teaching approaches. Many faculty members had to shift rapidly from in-person to online mode of instruction. This study documents perceptions of STEM faculty who made the change to online teaching. It reports on what strategies faculty used to transition to remote/online teaching and how this change impacted student learning. The study results indicated that almost two-thirds of the faculty changed how they evaluated their students. Results also showed that the sudden change to remote learning negatively impacted student …

Centralized And Decentralized Optimal Control Of Variable Speed Heat Pumps, Ryan S. Montrose, John F. Gardner, Aykut C. Satici

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Utility service providers are often challenged with the synchronization of thermostatically controlled loads. Load synchronization, as a result of naturally occurring and demand-response events, has the potential to damage power distribution equipment. Because thermostatically controlled loads constitute most of the power consumed by the grid at any given time, the proper control of such devices can lead to significant energy savings and improved grid stability. The contribution of this paper is the development of an optimal control algorithm for commonly used variable speed heat pumps. By means of selective peer-to-peer communication, our control architecture allows for the regulation of home …

Lamin A/C Is Dispensable To Mechanical Repression Of Adipogenesis, Matthew Goelzer, Gunes Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Mesenchymal stem cells (MSCs) maintain the musculoskeletal system by differentiating into multiple lineages, including osteoblasts and adipocytes. Mechanical signals, including strain and low-intensity vibration (LIV), are important regulators of MSC differentiation via control exerted through the cell structure. Lamin A/C is a protein vital to the nuclear architecture that supports chromatin organization and differentiation and contributes to the mechanical integrity of the nucleus. We investigated whether lamin A/C and mechanoresponsiveness are functionally coupled during adipogenesis in MSCs. siRNA depletion of lamin A/C increased the nuclear area, height, and volume and decreased the circularity and stiffness. Lamin A/C depletion significantly decreased …

Binary Particle Mixtures As A Heat Transfer Media In Shell-And-Plate Moving Packed Bed Heat Exchangers, Chase Ellsworth Christen

Boise State University Theses and Dissertations

Solid particles are being considered in several high temperature thermal energy storage systems and as heat transfer media in concentrated solar power (CSP) plants. The downside of such an approach is the low overall heat transfer coefficients in shell-and-plate moving packed bed heat exchangers caused by the inherently low packed bed thermal conductivity values of the low-cost solid media. Choosing the right particle size distribution of currently available solid media can make a substantial difference in packed bed thermal conductivity, and thus, a substantial difference in the overall heat transfer coefficient of shell-and-plate moving packed bed heat exchangers. Current research …

First-Principles Studies Of Nucleation Of Atomic-Layered Molybdenum Disulfide By Atomic Layer Deposition, Matthew Lawson

Boise State University Theses and Dissertations

This dissertation implements first-principles calculations to understand the nucleation mechanisms for atomic layer deposition (ALD) of molybdenum disulfide (MoS₂) using MoF₆ and H₂S precursors. ALD is a self-limiting process that can deposit a range of materials at the nanoscale, while maintaining chemical stoichiometry, atomic scale thickness control, and can conform to high-aspect ratio substrate designs. ALD is extremely sensitive to surface chemistry and morphology; therefore, it is critical to understand how these factors control deposition.

Density functional theory (DFT) was used to understand what factors can control the nucleation for ALD of MoS₂ using …

Kinematic And Kinetic Changes After Total Hip Arthroplasty During Sit-To-Stand Transfers: Systematic Review, Junsig Wang, Safeer F. Siddicky, Michael P. Dohm, C. Lowry Barnes, Erin M. Mannen

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Background: Total hip arthroplasty (THA) is a common and effective surgical procedure that allows patients with hip osteoarthritis to restore functional ability and relieve pain. Sit-to-stand transfers are common demanding tasks during activities of daily living and are performed more than 50 times per day. The purpose of this systematic review is to obtain a comprehensive understanding of biomechanical changes during sit-to-stand transfers after THA.

Methods: Relevant articles were selected through MEDLINE, Scopus, Embase, and Web of Science. Articles were included if they met the following inclusion criteria: 1) participants underwent total hip arthroplasty without restriction on the arthroplasty design, …

Data-Driven Design Of Energy-Shaping Controllers For Swing-Up Control Of Underactuated Robots, Wankun Sirichotiyakul, Aykut C. Satici

Mechanical and Biomedical Engineering Faculty Publications and Presentations

We propose a novel data-driven procedure to train a neural network for the swing-up control of underactuated robotic systems. Our approach is inspired by several recent developments ranging from nonlinear control theory to machine learning. We embed a neural network indirectly into the equations of motion of the robotic manipulator as its control input. Using familiar results from passivity-based and energy-shaping control literature, this control function is determined by the appropriate gradients of a neural network, acting as an energy-like (Lyapunov) function. We encode the task of swinging-up robotic systems through the use of transverse coordinates and goal sets; which …