Mechanical Engineering Commons^™

Switched Kinematic And Force Control For Lower-Limb Motorized Exoskeletons And Functional Electrical Stimulation, Chen-Hao Chang

Dissertations - ALL

Millions of people experience movement deficits from neurological conditions (NCs) that impair their walking ability and leg function. Exercise-based rehabilitation procedures have shown the potential to facilitate neurological reorganization and functional recovery. Lower-limb powered exoskeletons and motorized ergometers have been combined with functional electrical stimulation (FES) to provide repetitive movement, partially reduce the burden of therapists, improve range of motion, and induce therapeutic benefits. FES evokes artificial muscles contractions and can improve muscle mass and strength, and bone density in people with NCs. Stationary cycling is recommended for individuals who cannot perform load-bearing activities or have increased risks of falling. …

Automatic Generation Of Near-Body Structured Grids, Yuyan Hao

Dissertations - ALL

Numerical grid generation has been a bottleneck in the computational fluid dynamics process for a long time when using the structured overset grids. Many current structured overset grid generation schemes like the hyperbolic grid generation method require significant user interaction to generate good computational grids robustly. Other grid generation schemes like the elliptic grid generation method take a significant amount of time for grid calculation, which is not desirable for computational fluid dynamics.

Herein a new grid generation method is presented that combines the hyperbolic grid generation scheme with the elliptic grid generation scheme that uses Poisson’s equation. The new …

Study Of Urethane Double-Coated Nylon Membranes For Fluid-Storage Applications, Micah Austin Howell

Masters Theses

Polymer-coated fabrics are used for many fuel and water storage applications, such as in U.S. military field operations. Urethane-double-coated nylon (UDCN) is one such material used in collapsible fluid storage tanks. Research into the mechanical properties of UDCN membranes under different environmental conditions is necessary for substantiating its current operations as well as developing new technologies. Novel modular, closed-loop and scalable pumped-storage hydropower (PSH) systems are one technology that could use UDCN membrane tanks in order to mitigate large costs, risks, environmental impacts, and time-for deployment associated with PSH system construction due to their modular, closed-loop technology. This study focuses …

Comprehensive Review Of Heat Transfer Correlations Of Supercritical Co2 In Straight Tubes Near The Critical Point: A Historical Perspective, Nicholas C. Lopes, Yang Chao, Vinusha Dasarla, Neil P. Sullivan, Mark Ricklick, Sandra Boetcher

Publications

An exhaustive review was undertaken to assemble all available correlations for supercritical CO2 in straight, round tubes of any orientation with special attention paid to how the wildly varying fluid properties near the critical point are handled. The assemblage of correlations, and subsequent discussion, is presented from a historical perspective, starting from pioneering work on the topic in the 1950s to the modern day. Despite the growing sophistication of sCO2 heat transfer correlations, modern correlations are still only generally applicable over a relatively small range of operating conditions, and there has not been a substantial increase in predictive capabilities. Recently, …

In-Person Instruction Or Remote Learning?: Understanding Students' Learning Experiences During Covid-19, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

Research attests that student success in engineering education is cultivated largely due to classroom environments, academic inclusion, and engagement in undergraduate research. It is further revealed that the social and academic fabric of the institution such as academic advising, peer tutoring, disability services, and outdoor recreational programs is essential towards fostering well-being, recruitment, retention, and student success. However, these studies were conducted in a period in which students experienced traditional face-to-face instruction. In the wake of COVID-19, most institutions responded by terminating in-person instruction, mandating to seek off-campus housing, and shifting to a fully remote context. As such, educators were …

Navigating The Virtual Landscape: Implementing A Pedagogical Framework In A Virtual Summer Engineering Course To Enhance Students' Academic Development, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this evidence-based practice paper, the recently established CIRE educational model was incorporated, and modified, to establish an alternative pedagogical framework for a virtual, fast-paced summer engineering course in a private university in Texas. Transitioning to fully online courses in the wake of COVID-19 required a rapid modification of traditional pedagogical methods to overcome challenges such as the lack of academic resources and established campus practices, while simultaneously ensuring the academic and social development of students. In this regard, a pedagogical framework known as the CIRE model – which is the acronym for Communication, Initiation, Reduction, and Extension – was …

Thermal Degradation And Organic Chlorine Removal From Mixed Plastic Wastes, Zhuo Xu, Victor Ierulli, Ezra Bar Ziv, Armando G. Mcdonald

Michigan Tech Publications, Part 1

Plastic waste accumulation has been growing due to the increase in plastic generation and the lack of infrastructure for recycling. One of the approaches is to treat the mixed plastic waste (MPW) through thermal processes to produce feedstocks for other applications. However, the presence of polyvinyl chloride (PVC) in MPW would produce HCl during processing and has negative impacts (emission, catalyst poisoning, etc.). In addition, due to the high heterogeneity of MPW, it is difficult to generate consistent experimental data. In this study, MPW was homogenized through double compounding–extrusion and then formed into a sheet to be treated at 400 …

Removal Of Selenium And Heavy Metals From Coal Combustion Residuals Wastewater Using Surface Modified Iron Based Media, Madan Tandukar, Alex Korff, Andrew Vincent, Chris Hardin

World of Coal Ash Proceedings

No abstract provided.

Collaborative Research: Harnessing Mechanics For The Design Of All-Solid-State Lithium Batteries, Haoran Wang

Funded Research Records

No abstract provided.

Myosin Ii Adjusts Motility Properties And Regulates Force Production Based On Motor Environment, Omayma Y. Al Azzam, Janie C. Watts, Justin E. Reynolds, Juliana E. Davis, Dana N. Reinemann

Faculty and Student Publications

Introduction—Myosin II has been investigated with optical trapping, but single motor-filament assay arrangements are not reflective of the complex cellular environment. To understand how myosin interactions propagate up in scale to accomplish system force generation, we devised a novel actomyosin ensemble optical trapping assay that reflects the hierarchy and compliancy of a physiological environment and is modular for interrogating force effectors.

Methods—Hierarchical actomyosin bundles were formed in vitro. Fluorescent template and cargo actin filaments (AF) were assembled in a flow cell and bundled by myosin. Beads were added in the presence of ATP to bind the cargo AF …

Three-Dimensional Printed Abdominal Imaging Windows For In Vivo Imaging Of Deep-Lying Tissues, Mitchell Kuss, Ayrianne J. Crawford, Olawale A. Alimi, Michael A. Hollingsworth, Bin Duan

Department of Mechanical and Materials Engineering: Faculty Publications

The ability to microscopically image diseased or damaged tissue throughout a longitudinal study in living mice would provide more insight into disease progression than having just a couple of time points to study. In vivo disease development and monitoring provides more insight than in vitro studies as well. In this study, we developed permanent 3D-printed, surgically implantable abdominal imaging windows (AIWs) to allow for longitudinal imaging of deep-lying tissues or organs in the abdominal cavity of living mice. They are designed to prevent organ movement while allowing the animal to behave normally throughout longitudinal studies. The AIW also acts as …

Comparative Study Of Tapered Versus Conventional Cylindrical Balloon For Stent Implantation In Stenotic Tapered Artery, Xiang Shen, Jiabao Jiang, Hongfei Zhu, Kaikai Lu, Pengfei Dong, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The natural tapering of coronary arteries often creates a dilemma for optimal balloon sizing during stenting. The influence of different balloon types, namely, a tapered balloon and a conventional cylindrical balloon, on the mechanical performance of the stent as well as arterial mechanics was investigated via the finite element method. Stent free-expansion and stent deployment in a stenotic tapered artery were investigated numerically. The biomechanical behavior of the two balloon types was compared in terms of stent foreshortening, stent deformation, stent stress distribution, and arterial wall stress distribution. Results indicate that balloon types affect the transient behavior of the stent …

Disk Engine With Circumferential Swirl Radial Combustor, Brian Bohan, Marc Polanka, Bennett Staton

AFIT Patents

A disk engine and system configured to provide high power at a reduced axial length is disclosed herein. The disk engine includes a radial compressor, a compressor discharge manifold positioned circumferentially about compressor, a combustion chamber positioned within the discharge manifold and a radial turbine positioned radially inward of the combustion chamber.

Purification Of Artepillin C (Arc) With Anticancer Activities From Supercritical Co2-Ethanol Extracts Of Brazilian Green Propolis By Using Adsorption Column Chromatography, Lin-Hsiang Chuang, Wen-Chin Chen, Wen Pei, Ming-Hsi Chuang, Todd Hsu, Po-Chao Chuang

Journal of Marine Science and Technology–Taiwan

Phenolic compounds with varying phenolic structures are present in both terrestrial and marine organisms. Artepillin C (ARC) is a prenylated phenolic compound produced specifically in Brazilian green propolis. Earlier studies have demonstrated the potential of ARC as a dietary supplement for cancer prevention due to its ability to suppress tumor growth and metastasis. Here we report the development of an effective adsorption chromatography combined with supercritical CO2 extraction for the massive purification of ARC. A mixture of supercritical CO2 and ethanol extract of Brazilian green propolis was passed through a stainless chromatographic column packed with protruding metals at 4,000 psi …

A Stochastic Sailing Speed Optimization And Vessel Deployment Problem In Liner Shipping, Dung-Ying Lin, Pak Weng Leong

Journal of Marine Science and Technology–Taiwan

In this research, we consider the stochastic sailing speed optimization and vessel deployment problem and examine the trade-off between sailing speed and the number of vessels required to provide a certain service in international liner shipping. Solving this kind of stochastic program is a challenging task. To address this issue, we construct a mathematical formulation based on Ng (1) and Ng (2) and enhance the linearization techniques from Wang and Meng (3) so that problem instances of an even larger scale can be solved. The proposed formulation has been numerically applied to solve realistic cases, and the empirical results show …

Vehicle Assignment For Chemicals Transportation, Yu-Liang Liu, Juan Huang, Ching-Wu Chu

Journal of Marine Science and Technology–Taiwan

Vehicle assignment is a significant challenge faced by chemical logistics companies. The chemical industry typically outsources the delivery of chemicals to professional logistics companies to meet customers' complex and demanding needs. In this regard, this research explores the case study of a logistics company that selects its delivery modes and formulates its vehicle assignment plans based on its personnel’s experience rather than any formal system and plans its vehicle routes on the day before the delivery. This study seeks to improve the efficiency and immediacy of logistics companies’ vehicle assignments, understand vehicle route planning, maximize space utilization, and minimize transportation …

A Hybrid Finite Difference Method For Singularly Perturbed Delay Partial Differential Equations With Discontinuous Coefficient And Source, Nitika Sharma, Aditya Kaushik

Journal of Marine Science and Technology–Taiwan

The article presents a hybrid finite difference scheme to solve a singularly perturbed parabolic functional differential equation with discontinuous coefficient and source. The simultaneous presence of deviating argument with a discontinuous source and coefficient makes the problem stiff. The solution of the problem exhibits turning point behaviour across discontinuity as tends to zero. The hybrid scheme presented is a composition of a central difference scheme and a midpoint upwind scheme on a specially generated mesh. At the same time, an implicit finite difference method is used to discretize the time variable. Consistency, stability, and convergence of the presented numerical approach …

Simulating And Predicting Offshore Oil Spills By Using Cellular Automata, Lin Liu, Wanwu Li, Yumeng Cui, Guanghui Hu, Hang Li

Journal of Marine Science and Technology–Taiwan

In recent years, offshore oil spill accidents have caused substantial damage to both marine organisms and marine ecology. Accurate simulation and prediction of oil spills could provide a scientific basis for assessing losses due to oil spills and provide support for emergency decisions regarding oil spills. We analyzed the advantages and disadvantages of existing oil spill models and constructed an offshore oil spill model based on cellular automata (CA). By considering both the flow field and wind field, we formulated new CA rules for the diffusion and drift of a pollution zone, and in our model, the cellular state in …

Design And Testing Of A Bearing Less Piezo Jet Micro Heat Sink, Rong-Tsu Wang, Jung-Chang Wang, Sih-Li Chen

Journal of Marine Science and Technology–Taiwan

The present study utilized piezoelectric ceramics (PC) as actuators to design five new piezoelectric heatsinks and preliminarily investigated the different design types and their operating conditions, such as the frequency, placement distance, thickness between piezoelectric sheets, piezoelectric sheet size, and noise produced. The results showed that when the micro heatsink bearingless piezo jet was placed too close to the heat source, the high temperature sucked back the surrounding fluids, causing the fluid chamber temperature to rise and the cooling effect to be reduced. Therefore, the heatsink should be placed between 10 and 20 mm from the heat source. With the …

Preface Of Volume 1 Issue 1 On Journal Of Materials Exploration And Findings (Jmef), Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.

The Optimization Of Failure Risk Estimation On The Uniform Corrosion Rate With A Non-Linear Function, Fernanda Hartoyo, Jaka Fajar Fatriansyah, Imam Abdillah Mas'ud, Farhan Rama Digita, Hanna Ovelia, D. Rizal Asral

Journal of Materials Exploration and Findings

Failures in the oil and gas pipeline system are conditions that must be avoided and anticipated because the losses due to the failures can occur at a very high level. Internal corrosion is one of the significant causes of the failures in pipeline systems. In addition, this type of corrosion is due to the high content of carbon dioxide and other corrosive substances in crude oil and natural gas. Therefore, an optimal inspection scheduling system is required to prevent the possibility of pipeline failures due to corrosion and to avoid any overspending on the budget due to excessive inspection scheduling. …

Material Selection Of Below-Knee Leg Prosthetics, Raihan Kenji Rizqillah

Journal of Materials Exploration and Findings

The effort to select the best pylon material, part of below-knee leg prosthetic, has been performed. It begins with function analysis to generate design requirement, which concludes that the objective is to select material that gives proper mechanical properties with lowest weigth and cost. Constraint requirements eliminate unsuitable material. Material indices, a scoring function, are derived from objective with respect to a function, and used for ranking material candidates. Ranking from material indices gives top material candidates of woods. Al alloy, Mg alloy, and ferrous alloy. Further seek of documentation is undertaken by failure analysis, value analysis, fabrication, and environmental …

The Effect Of Sample Placement In The Furnace During The Heat Treatment Process Of 7075-T6 Aluminum Alloy On Microstructure, Hardness, And Electrical Conductivity, Donanta Dhaneswara, Hardi Rindharto, Muhammad Syauqi Aqilafif

Journal of Materials Exploration and Findings

This paper reports the effects of sample placement during the heat treatment on the microstructural morphology and mechanical properties of 7075 Al alloy such as hardness value and electrical conductivity. The material was in the formed of Al alloy sheets where samples were machined into a square with dimensions of 1.5 x 1.5 inch. The 7075-T0 Al alloy as samples were given heat treatment by precipitation hardening (aging) at temperature 120°C for 24 hours, so it becomes 7075-T6 Al alloy. Samples were subjected to some mechanical tests and the morphology of the resulting microstructures were characterized by optical microscopy. The …

Contents, Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.

Modeling, Analysis, And Simulation To Reveal The Mechanisms Of Ciliary Beating, Louis Woodhams

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cilia are microscopic cellular appendages that help us breathe by clearing our airways, maintain the health of our central nervous system by circulating cerebrospinal fluid, and allow us to reproduce by transporting eggs and propelling sperm cells. Cilia even determine the asymmetry of our internal organs during embryonic development. However, the mechanisms underlying ciliary beating are not fully understood. Questions remain as to how arrays of the motor protein dynein generate the propulsive waveforms observed in cilia and how structural elements within the cilium and its connection to the cell deform during beating. In the current work, mathematical modeling, analysis, …

Droplet Dynamics And Heat Transfer During Condensation On Lubricant-Infused Surfaces, Jianxing Sun

McKelvey School of Engineering Graduate Student Theses & Dissertations

Inspired by pitcher plants, a micro/nano- structured solid surface infused with low-surface-tension lubricant constitutes a novel class of biomimetic surfaces—lubricant-infused surfaces (LISs). Unlike solid hydrophobic and superhydrophobic surfaces, a LIS is “hemi-solid and hemi-liquid”. The thin lubricating film can extraordinarily decrease adhesion and avoid contact line pinning between the working fluid and the underlying solid, displaying many desirable properties, such as excellent liquid repellency, suppression of fouling, and self-healing. Hence, LISs are ideal for applications where liquids or contaminants must be efficiently removed from surfaces in harsh environments. For example, LISs can promote stable dropwise condensation of water or low-surface-tension …

Testing Oxygenated Microbubbles Via Intraperitoneal And Intrathoracic Routes On A Large Pig Model Of Lps-Induced Acute Respiratory Distress Syndrome, Riaz Ur Rehman Mohammed, Nathaniel T. Zollinger, Andrea R. Mccain, Roser Romaguera-Matas, Seth P. Harris, Keely L. Buesing, Mark A. Borden, Benjamin S. Terry

Department of Mechanical and Materials Engineering: Faculty Publications

With a mortality rate of 46% before the onset of COVID-19, acute respiratory distress syndrome (ARDS) affected 200,000 people in the US, causing 75,000 deaths. Mortality rates in COVID-19 ARDS patients are currently at 39%. Extrapulmonary support for ARDS aims to supplement mechanical ventilation by providing life-sustaining oxygen to the patient. A new rapid-onset, human-sized pig ARDS model in a porcine intensive care unit (ICU) was developed. The pigs were nebulized intratracheally with a high dose (4 mg/kg) of the endotoxin lipopolysaccharide (LPS) over a 2 h duration to induce rapid-onset moderate-to- severe ARDS. They were then catheterized to monitor …

A Physics-Based Modeling Of A Hydraulically Amplified Electrostatic Actuator, Alexandrea Washington, Zakai Olsen, Ji Su, Kwang J. Kim

Mechanical Engineering Faculty Research

The focus of this study is to understand the physical phenomenon of the liquid-based electroactive polymer (EAP) actuator known as the Hydraulically Amplified Self-Healing Electrostatic (HASEL) actuator. Specifically, this study provides data in several areas, including the deformation of the film material, the dynamics of the dielectric liquid, and the electrical conditions within the actuator body. A two-dimensional model was developed in the finite element software, COMSOL Multiphysics, to create a generalized physics-based framework that describes the actuation mechanism. Much of the predictive data agreed well with the experimental data, such as the electrode pull-in occurring at ∼4.5 kV and …

Strain And Strain Rate In Friction Extrusion, Xiao Li, Md Reza-E- Rabby, Anthony Guzman, Glenn Grant, Suveen Mathaudhu, Michah Hinton, Anthony P. Reynolds

Faculty Publications

Friction extrusion is a metal forming process that generates large plastic strains and deformation-induced heating through friction between a rotating die and the material to be extruded. The final deformation state in friction extruded wire has been visualized in previous studies but the distribution and evolution of strain and strain rate inside the solid material have yet to be elucidated. This paper develops an approach that reveals the deformation during the process by visualizing the shape change of the pre-embedded markers in the remnant billet. For the first time, the distribution of steady-state strain and strain rate in friction extrusion …

The Effect Of Heat Treatment On Mechanical Properties Of Additively Manufactured 17-4 Ph Stainless Steel, Nicholas Aaron Hopkins

Theses and Dissertations

Additive manufacturing (AM) is used to create geometries otherwise impossible to machine. Topology optimization, microstructural texture control, and the use of lattices could be created through AM to increase performance of systems. Currently research focuses on solution aging of printed 17-4 PH, while other heat treatments are not as heavily studied. This study identifies different heat treatments applied to additively manufactured 17-4 precipitation hardened (PH) and the effects on mechanical properties. This study used quasi-static tension, quasi-static compression, and Charpy V-notch testing to analyze the effects of heat treatment as well as the effectiveness of additive manufacturing compared to traditional …