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Full-Text Articles in Mechanical Engineering
Optimizing Biomechanical Models: Estimation Of Muscle Tendon Parameters And Ankle Foot Orthosis Stiffness, Sepehr Ramezani
Optimizing Biomechanical Models: Estimation Of Muscle Tendon Parameters And Ankle Foot Orthosis Stiffness, Sepehr Ramezani
Electronic Theses and Dissertations, 2020-
The complexity of the human musculoskeletal system presents challenges in accurately identifying its characteristics, particularly due to the presence of redundant actuators on a single joint. Non-invasive measures are necessary to overcome these challenges. Optimization algorithms have emerged as a crucial tool to advance subject-specific musculoskeletal modeling allows a more realistic representation of biomechanical behaviors, enhancing our understanding of human movement and enabling better clinical decision-making. Furthermore, optimization algorithms play a vital role in customizing rehabilitation and assistive devices, such as orthoses and prostheses. The current ankle-foot orthosis (AFO) stiffness measurement methods require bulky, complex designs, and often permanent modification …
Investigation Of Endothelial Mechanics On Primary Cell Functions: Endothelium Permeability And Wound Healing, Sean Beverung
Investigation Of Endothelial Mechanics On Primary Cell Functions: Endothelium Permeability And Wound Healing, Sean Beverung
Electronic Theses and Dissertations, 2020-
The endothelium composes the inner lining of blood vessels, the heart, and lymphatic vessels. Within the cardiovascular system, it is an extremely important structure, aiding in the regulation of blood pressure with the vascular tone, recruiting immune response, regulating the transfer of material in and out of the bloodstream, and the creation of new blood vessels through angiogenesis. The endothelium is composed entirely of endothelial cells. These cells lay in a flat squamous formation and are in direct contact with blood and aid in the regulation and transfer of material in and out of the bloodstream via active and passive …
Non-Invasive Detection Of Elevated Intracranial Pressure Using Spontaneous Tympanic Membrane Pulsation, Rajkumar Dhar
Non-Invasive Detection Of Elevated Intracranial Pressure Using Spontaneous Tympanic Membrane Pulsation, Rajkumar Dhar
Electronic Theses and Dissertations, 2020-
Monitoring intracranial pressure (ICP) is a standard diagnostic tool for various neurological conditions such as head injury, ruptured aneurysms, intracerebral and intracranial hemorrhage, and hydrocephalus. Currently, ICP monitoring relies on invasive pressure measurements. These include intraventricular catheter, subdural screw, epidural sensor, and lumbar puncture. Invasive methods pose the risk of infection and hemorrhage, are expensive, and require special clinical skills. A noninvasive method that is reliable, simple to use, low-cost, and provides easily interpretable results can help avoid the complications associated with the invasive methods. This study proposes a novel method for noninvasive ICP monitoring using tympanic membrane pulsation (TMp). …
Influence Of Ecm Composition And Intracellular Calcium On Endothelial Biomechanics And Prediction Of Cellular Stresses Using Machine Learning, Vignesh Aravind Subramanian Balachandar
Influence Of Ecm Composition And Intracellular Calcium On Endothelial Biomechanics And Prediction Of Cellular Stresses Using Machine Learning, Vignesh Aravind Subramanian Balachandar
Electronic Theses and Dissertations, 2020-
Endothelial cells, which form the inner layer of the vasculature, constantly interact with their external microenvironment called the extracellular matrix (ECM) by exerting contractile cell-substrate stresses called tractions and cell-cell stresses called intercellular stresses. This cellular mechanosensing can become aberrant and act as a precursor for many vascular pathological and physiological processes such as cancer metastasis, atherosclerosis, cell differentiation, migration, and morphogenesis. Also, intracellular calcium signalling plays an important role in endothelial cell motility and in maintaining vascular tone. Alteration in ECM composition has been linked to several pathologies, in fact, a transition to a fibronectin-rich matrix from a type …
Mid-Infrared Laser Absorption Spectroscopy And Ignition Delay Time Measurements Of Advanced Renewable Fuels At High Pressure In A Shock Tube, Erik Ninnemann
Mid-Infrared Laser Absorption Spectroscopy And Ignition Delay Time Measurements Of Advanced Renewable Fuels At High Pressure In A Shock Tube, Erik Ninnemann
Electronic Theses and Dissertations, 2020-
The United States government has set 2050 as the target for net-zero greenhouse gas emissions due to their increasing levels and the subsequent rise in global temperatures. To meet this target, there has been renewed interest in the combustion of high-energy biofuels that could combat these issues. Thus, the Department of Energy started the Co-Optimization of Fuels and Engines program to find bioderived blendstocks that can harmonize with current and future generation engines to increase power and efficiency, all while reducing overall emissions. As part of this program, it is crucial to understand the combustion of these fuels at the …
Wind Turbine Main Bearing Fatigue Prognosis With Physics-Informed Machine Learning, Yigit Yucesan
Wind Turbine Main Bearing Fatigue Prognosis With Physics-Informed Machine Learning, Yigit Yucesan
Electronic Theses and Dissertations, 2020-
Unexpected main bearing failure on a wind turbine causes unscheduled maintenance and increased operation costs (mainly due to crane, parts, labor, and production loss). Unfortunately, historical data indicates that failure can happen far earlier than the component designed lives (due to manufacturing problems, for example). For the legacy fleet, which composes the majority of the installed basis, fatigue has become a major issue. Although bearing fatigue can be expressed with physics-informed models, they often inherent large uncertainties due to operation and unknown lubricant degradation mechanism. Apart from the unknown physics of failure, additional uncertainties associated with the grease that surrounds …
The Mechanics And Multiphysics Of Biomimetic Discrete Exoskeleton Substrates, Hessein Ali
The Mechanics And Multiphysics Of Biomimetic Discrete Exoskeleton Substrates, Hessein Ali
Electronic Theses and Dissertations, 2020-
Biological structures have inspired synthetic materials with unparalleled performances such as ultra-lightweight design, tunable elasticity, camouflaging, and antifouling. Among biological structures, exoskeletal scales that cover the exterior surfaces of fishes, fur, and many reptiles. These exoskeletal scales had appeared in the earliest stages of evolution of complex multicellular life and continued their existence in spite of millions of years of evolutionary pressures. This makes them an attractive candidate for biomimicry to produce high performance multifunctional materials with applications to soft robotics, wearables, energy efficient smart skins, antifouling surfaces and on-demand tunable materials. Canonically speaking, biomimetic samples can be fabricated by …
Mechanics Of Low Dimensional Biomimetic Scale Metamaterials, Hossein Ebrahimi
Mechanics Of Low Dimensional Biomimetic Scale Metamaterials, Hossein Ebrahimi
Electronic Theses and Dissertations, 2020-
Combination of topology and material could play an important role in giving rise to nontraditional behavior in mechanical structures and is a typical strategy in nature. Topology is concerned with the geometrical and spatial properties of the objects, which are preserved under continues mechanical deformation of the object such as stretching, bending, twisting, etc. In this work, we focus on structures based on fish scale inspired surface topology. The utilized idea for surface topology is a bioinspired design on the substrate of biological scale-covered systems. Scales are a path breaking evolutionary adaptation that accompanied vertebrate evolution for the past 500 …
Understanding Forearm Muscle Coordination In Children, Miguel Gonzalez
Understanding Forearm Muscle Coordination In Children, Miguel Gonzalez
Electronic Theses and Dissertations, 2020-
A combination of surface electromyography (EMG) and pattern recognition algorithms have led to improvements in the functionality of upper limb prosthetics. This method of control relies on user's ability to repeatedly generate consistent muscle contractions. Research in EMG based control of prosthesis has mainly utilized adult subjects who have fully developed neuromuscular control. Little is known about children's ability to generate consistent EMG signals necessary to control artificial limbs with multiple degrees of freedom. To address this gap, two experiments were designed to validate and benchmark an experimental protocol that quantifies the ability to coordinate forearm muscle contractions in able-bodied …
Corticomuscular Adaptation To Mechanical Perturbations In A Seated Locomotor Task, Seyed Yahya Shirazi
Corticomuscular Adaptation To Mechanical Perturbations In A Seated Locomotor Task, Seyed Yahya Shirazi
Electronic Theses and Dissertations, 2020-
Cortical control during walking is most pronounced when the person is perturbed. Although seated locomotor tasks such as cycling or recumbent stepping improve walking performance, the electrocortical correlates of perturbed seated tasks have not been studied in detail. The primary purpose of this research was to quantify cortical and muscular responses to mechanical perturbations during recumbent stepping. We also aimed to quantify possible differences between young and older adults' responses to perturbed stepping. A secondary aim of this research was to determine the accuracy of electroencephalography (EEG) source imaging to interpret the electrocortical findings adequately. We hypothesized that both young …
Seismocardiographic Signal Variability And Pulmonary Phase Detection In Adults, Md Khurshidul Azad
Seismocardiographic Signal Variability And Pulmonary Phase Detection In Adults, Md Khurshidul Azad
Electronic Theses and Dissertations, 2020-
Cardiovascular disease is one of the leading causes of mortality in the world. Early detection and intervention can significantly improve disease management and patient quality of life. Current methods of evaluating cardiac function often involve history and physical examination (including stethoscope auscultation), electrocardiograms (ECG), echocardiogram imaging, computed tomography, and various blood tests. Seismocardiographic signals (SCG) are the chest surface vibrations resulting from cardiomechanical activity. SCG may be recorded using accelerometers and can be used for monitoring and predicting cardiac health. SCG's potential utility may be impeded by its spatial, postural, respiratory, and longitudinal variability. In this dissertation, the SCG variability …
Seismocardiography - Genesis, And Utilization Of Machine Learning For Variability Reduction And Improved Cardiac Health Monitoring, Peshala Thibbotuwawa Gamage
Seismocardiography - Genesis, And Utilization Of Machine Learning For Variability Reduction And Improved Cardiac Health Monitoring, Peshala Thibbotuwawa Gamage
Electronic Theses and Dissertations, 2020-
Seismocardiography (SCG) is the measured chest surface vibrations resulting from cardiac activity. Although SCG can contain information that correlate with cardiac health, its utility may be limited by lack of understanding of the signal genesis and a variability that can mask subtle SCG changes. The current research utilized medical imaging reconstruction and finite element method (FEM) to simulate SCG by modeling the propagation of myocardial movements to the chest surface. FEM analysis provided a link between myocardial movements and the SCG signals measured at the chest surface and suggested that myocardial movement is a primary source of SCG. Increased understanding …