Mechanical Engineering Commons^™

Combustion Characteristics Of Methane, Ethane, Propane, And Butane Blends Under Conditions Relevant Of A Dual-Fuel Diesel And Natural Gas Engine, Christopher Joseph Ulishney

Graduate Theses, Dissertations, and Problem Reports (ETD)

As natural gas production infrastructure is already in place in most of the world and will continue expanding for the foreseeable future, natural gas is an alternative to traditional liquid petroleum fuels in heavy-duty engines. Dedicated natural gas or dual-fuel diesel-natural gas heavy-duty engines are alternatives to diesel-only power generation equipment. One challenge is the large variation in the natural gas composition available for such applications, which is known to significantly affect engine’s combustion characteristics and the emissions composition. As the literature on dual-fuel combustion under low load engine operating conditions that use more realistic natural gas mixtures (i.e., mixtures …

Finite Element Modeling And Analysis Of Breech Face Impressions, James A. Hamilton

Graduate Theses, Dissertations, and Problem Reports (ETD)

Finite element analysis (FEA) is a technique which has not been widely used in Forensic Science in general and firearms examination in particular. The general utility of FEA was assessed by the simulation of scenarios commonly encountered during the investigation of firearm related crimes. As a test, simulations included the perforation of a windshield and sheet metal with a 9 mm projectile, the development of pseudo subclass characteristics during the manufacturing of a breech face, and the impact of a projectile with another projectile in air and with a solid body. Results from the simulations were compared to projectiles and …

Imitation Learning For Swarm Control Using Variational Inference, Hafeez Olafisayo Jimoh

Graduate Theses, Dissertations, and Problem Reports (ETD)

Swarms are groups of robots that can coordinate, cooperate, and communicate to achieve tasks that may be impossible for a single robot. These systems exhibit complex dynamical behavior, similar to those observed in physics, neuroscience, finance, biology, social and communication networks, etc. For instance, in Biology, schools of fish, swarm of bacteria, colony of termites exhibit flocking behavior to achieve simple and complex tasks. Modeling the dynamics of flocking in animals is challenging as we usually do not have full knowledge of the dynamics of the system and how individual agent interact. The environment of swarms is also very noisy …

Stability Of Ruddlesden-Popper Phase Lanthanum Nickelate As Air Electrode For Reversible Solid Oxide Cells, Daniel De Lorenzo Moreira

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis studied the long-term stability of Ruddlesden-Popper phase Lanthanum Nickelate under operating conditions as the air electrode for Reversible Solid Oxide Cells (R-SOC). Renewable energies have gone through increase in popularity throughout the last decades, mainly due to the consequences of the rapid population growth in the world. These new energies have been pointed as the rightful successor of fossil fuel energies in order to decrease the environmental impact of our day-to-day life. Solid Oxide Fuel Cells as well as Solid Oxide Electrolysis Cells are believed to be the key to stabilizing the energy supply when environmental conditions are …

Development Of A Quasi-Dimension Gci Combustion Model Aided By Cfd, Jinsu Kim

Graduate Theses, Dissertations, and Problem Reports (ETD)

Advanced combustion strategies have been proposed to improve fuel efficiency while minimizing exhaust emissions. Gasoline compression ignition (GCI) combustion featuring partially premixed compression ignition (PPCI) and diffusion combustion has been recognized as an attractive, viable combustion strategy for its potential and advantages over conventional diesel and gasoline engines. The optimization of the GCI engine system requires the development of a quasi-dimensional GCI combustion model capable of simulating GCI combustion while requesting less computational burden than CFD simulation, which is very critical in engine system simulation. This study developed a quasi-dimension, phenomenological combustion model for PPCI and diffusion combustion to facilitate …

Material Characterization Of Thermoplastic Polyurethane (Tpu) And Thermoplastic Elastomers (Tpe) For Development Of 3d-Printed Surrogate Organs For Medical Training, Anastasia Elizabeth Lucci

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cadaveric specimens are a necessary, albeit limited, resource for training medical students on basic surgical skills. The availability of surrogate 3D-printed organs would readily allow access to resources that could reduce or potentially eliminate the need for cadaveric specimens or, at a minimum, provide students the opportunity to practice with 3D-printed surrogates before transitioning to those specimens. This research focuses on determining which thermoplastic material most closely mimics mechanical properties such as hardness and stiffness of human organs and allows 3D printing surrogate organs to be used as safe, educational tools. Relatively “soft” materials such as thermoplastic polyurethanes (TPU) and …

Biologically – Plausible Load Feedback From Dynamically Scaled Robotic Model Insect Legs, William Zyhowski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Researchers have been studying the mechanisms underlying animal motor control for many years using computational models and biomimetic robots. Since testing some theories in animals can be challenging, this approach can enable unique contributions to the field. An example of a system that benefits from this modeling and robotics approach is the campaniform sensillum (CS), a kind of sensory organ used to detect the loads exerted on an insect's legs. The CS on the leg are found in groups on high-stress areas of the exoskeleton and have a major influence on the adaptation of walking behavior. The challenge for studying …

Design And Manufacture Of An Aerodynamic Body That Meets Scaling Law Requirements And Survives Severe G-Load Environment For Free-Flight Testing, Anthony R. Gonzalez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Design and Manufacture of an Aerodynamic Body that Meets Scaling Law Requirements and Survives Severe G-load Environment for Free-Flight Testing

Anthony Gonzalez

Developing scale models to test functionality and ascertain aerodynamic properties is critical before manufacturing full-size products. Through dimensional analysis and similitude, engineers create scale models to test any parameter of interest. This research aims to design a scale model of an aerodynamic body for repeated free-flight testing. The Froude number is the dominant scale model law used to determine the geometric, mass, and inertia scaling laws. A critical requirement for this research is that the model should be …

Development Of Automated Egg Incubator With Backup Power Supply, Allen N. Maroma, Dolly P. Maroma, Bernardo A. Pangilinan

ASEAN Journal of Community Engagement

This study addresses the development of an automated egg incubator with backup power supply that could benefit farmer communities through the developmental research approach. A prototype is developed to respond to the needs for uninterrupted incubation which is affected by the frequent power outages that reduce its efficiency in egg handling. In this project, the automated egg incubator with a backup power supply is designed to hatch a capacity of 150 eggs (75 setters and 75 hatchers) every 21 days, ensuring continuous operation even in the absence of a consistent power supply. An inverter, connected to a battery, ensures a …

An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez

College of Graduate Studies: Theses & Dissertations

Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …

Synthesis And Processing Of Pcl And Irdye Nanoparticles For Application In Drug Release Mechanism, Michael Adeniyi

College of Graduate Studies: Theses & Dissertations

The objective of this study is to produce core-shell nanoparticles utilizing PCL and IRDye and investigate the nanoparticle release mechanism. Biodegradable polymer, Polycaprolactone (PCL), was electrosprayed separately with two types of IRDye, NHS and Dextran Texas red. The solution of PCL was formed by mixing PCL in a solution of 9.47ml Acetic Acid, 9.47ml Formic Acid, and 1.05ml Trifluoroethanol, following a ratio of 9:9:1. The two solutions of IRDye were prepared by mixing 2mg of the IRdye with 20ml of DMF at a rate of 0.1mg/ml.

The NHS IRDye was electrosprayed coaxially with PCL and the Dextran Texas red dye …

Enhancing Traffic Safety In Unpredicted Environments With Integration Of Adas Features With Sensor Fusion In Intelligent Electric Vehicle Platform With Implementation Of Environmental Mapping Technology, David S. Obando Ortegon

College of Graduate Studies: Theses & Dissertations

A major objective on society is to reduce the number of accidents and fatalities on the road for drivers, and pedestrians. Therefore, the automotive engineering field is working on this problem through the development and integration of safety technologies such as advanced driving assistance systems. For this reason, this work was intended to develop and evaluate the performance of different ADAS features and IV technologies under unexpected scenarios. This by the development of safety algorithms applied to the intelligent electric vehicle designed and built in this work, through the use of ADAS sensors based on sensor fusion. Evaluation of AEB, …

Aerosol Synthesis Of Tungsten Bronze Particles For Nir Shielding, Hao Tu

Theses and Dissertations

This dissertation emphasizes the need for efficient energy use in buildings and transportation due to global warming and the energy crisis. It suggests that improving energy efficiency can help reduce energy consumption and emissions and support sustainability. The dissertation introduces various transparent materials that can block near-infrared (NIR) radiation from solar radiation to save energy and money, and it highlights the growing market value of such products. The dissertation compares tungsten bronze with other NIR shielding materials and shows its advantages. The dissertation introduces a cheap and environmentally friendly method for continuously producing tungsten bronze particles via aerosol synthesis. Particle …

Material Extrusion-Based Additive Manufacturing: G-Code And Firmware Attacks And Defense Frameworks, Haris Rais

Theses and Dissertations

Additive Manufacturing (AM) refers to a group of manufacturing processes that create physical objects by sequentially depositing thin layers. AM enables highly customized production with minimal material wastage, rapid and inexpensive prototyping, and the production of complex assemblies as single parts in smaller production facilities. These features make AM an essential component of Industry 4.0 or Smart Manufacturing. It is now used to print functional components for aircraft, rocket engines, automobiles, medical implants, and more. However, the increased popularity of AM also raises concerns about cybersecurity. Researchers have demonstrated strength degradation attacks on printed objects by injecting cavities in the …

Advanced Modeling And Innovative Transcranial Magnetic Stimulation Coil Designs For The Treatment Of Neurological Disorders, Mohannad Tashli

Theses and Dissertations

Transcranial magnetic stimulation (TMS) is a safe, effective and non-invasive treatment for several mental and psychiatric disorders. TMS is an FDA approved treatment and is commonly applied to patients who do not respond to medications for the treatment of clinical depression, smoking cessation, obsessive-compulsive disorder and migraine. Recently, there has been an increase in the development of electromagnetic neuromodulation techniques targeted at enhancing the effectiveness of TMS devices for the treatment of mental diseases. In TMS stimulation, focality is an important factor which determines the specificity of the pulses induced in different brain tissues. The electromagnetic pulses must be confined …

อิทธิพลของระยะวิ่งต่อการชาร์จและอัตราการชาร์จของยานยนต์ไฟฟ้าต่อการให้บริการ Ride Sharing ในพื้นที่จุฬา-สามย่าน, ภูมิรพี ขัดศรี

Chulalongkorn University Theses and Dissertations (Chula ETD)

หนึ่งในรูปแบบการเดินทางสมัยใหม่คือ ride sharing ซึ่งเป็นองค์ประกอบสำคัญร่วมกับระบบขนส่งสาธารณะที่จะนำไปสู่รูปแบบ Mobility as a Service ที่จะยกระดับคุณภาพและความสะดวกสบายในการเดินทางในเมืองได้มาก งานวิจัยนี้ศึกษาการใช้งานบริการ ride sharing ในพื้นที่จุฬา-สามย่าน ที่จะตอบสนองพฤติกรรมการเดินทางในพื้นที่มหาวิทยาลัย โดยมีการนำข้อมูลจากบริการจริงมาใช้ในการศึกษาผลกระทบของระยะวิ่งต่อการชาร์จและอัตราการชาร์จของยานยนต์ไฟฟ้าในการให้บริการ ride sharing ผ่านการจำลอง การจำลองบริการใน ride sharing ในพื้นที่จุฬามีขนาด 6.88 ตารางกิโลเมตร ในส่วนของ range มี 3 ขนาดได้แก่ long range, medium range, short range ตามลำดับ อัตราการชาร์จแบ่งออกเป็น 3 ขนาดได้แก่ fast charge, medium charge, slow charge ดังนั้น การจำลองจึงมี 9 สถานการณ์จำลองด้วยกันและใช้ยานพาหนะ 20 คัน ตัวชี้วัดสำหรับการจำลองการให้บริการ ได้แก่ Vehicle Kilometer Traveled (VKT) , service distance, %served และรายได้จากการให้บริการ ผลลัพธ์จากการวิเคราะห์พฤติกรรมและรูปแบบการเดินทางในพื้นที่ด้วย ride sharing ภายในจุฬาลงกรณ์มหาวิทยาลัยพบว่ามีช่วงการใช้งานสูงสุดอยู่ในช่วง 11:30-12:30 น. โดยมีจำนวนการเรียก 1 คนราว 70% และราว 92% คือการเรียกรถแบบไม่เกิน 3 คน ระยะเดินทางด้วย ride sharing ขั้นต่ำอยู่ที่ระยะทาง 400 เมตร สำหรับผลลัพธ์จากการจำลองทั้ง 9 สถานการณ์จำลองนั้น พบว่าผลกระทบจากการปรับอัตราการชาร์จนั้นส่งผลต่อการให้บริการมากกว่า range อย่างเห็นได้ชัดในทุกกรณี ซึ่งจากการสอบทวนผลลัพธ์กับผู้ประกอบการ ผลลัพธ์สอดคล้องกับการให้บริการจริง นอกจากนั้นจากผลลัพธ์พบว่าการเพิ่ม Range นั้นไม่ได้ให้ผลลัพธ์การบริการที่ดีขึ้นเสมอไป โดยกรณี short range:medium charge มี %served …

Use Of Bioheat Modeling To Characterize And Optimize Implantable Medical Devices And Neuromodulation Technologies, Adantchede Louis Zannou

Dissertations and Theses

Medical device development includes prototyping, benchtop characterization, preclinical studies, and clinical trials. Understanding the limitations and potential adverse effects of medical devices prior to their administration in humans is a crucial first step. Optimizing medical devices is essential to employing technology and improving patients care. Computational modeling is widely adopted as a powerful tool to predict stimulation/recording parameter optimization, rapid electrode/device prototyping, investigating novel mechanism of action, and testing working principles of any medical devices. Many implantable neuromodulation technologies including Spinal Cord Stimulation (SCS), which provide substantial therapeutic benefit for patient population with lower back pain, produces heat via the …

An Experimental Study Of The Impinging And Freezing Dynamics Of A Colloidal Droplet On Solid Surfaces, Andro Fayek Abdelmalek

Dissertations and Theses

In modern manufacturing, the production of complex components with intricate geometries and varying material compositions has become essential. To meet these demands, additive manufacturing (AM) has gained prominence. Various 3D printing technologies, such as stereolithography (SLA), selective laser sintering (SLS), and plastic extrusion, have been developed to produce finished components. However, each technology has its limitations, including restricted printing resolution or limited material selection. A novel idea in additive manufacturing involves the utilization of inkjet printing nozzles with colloidal fluid and implementing the freeze-dry method. This innovative technique entails depositing colloidal droplets onto a freezing substrate using an inkjet head. …

Microfluidic Dual-Gel Cell Culture Model For Studying Cell Migration Under Controlled Interstitial Flow, Alimohamamd Anbari

Dissertations and Theses

Abstract

Interstitial flow, the slow flux of fluid occurring in the interstitial space of the extracellular matrix (ECM), affects the migration of many cell types through individual and synergistic contributions of several biophysical and biochemical phenomena. Notably, interstitial flow is linked to ECM permeability and provides direct mechanical cues via shear and normal stress. Additionally, the flow also couples with biomolecular diffusion to provide chemotactic signals to the cells. Recent in vitro studies have indicated that tumor cell migration is affected by interstitial fluid velocity and ECM permeability through the mechanisms of (1) autologous chemotaxis and (2) integrin-mediated focal adhesion …

Pms And Gas Pollutants Removal By Electret Filter Media And Metal-Organic Frameworks (Mofs), Yu Zhang

Theses and Dissertations

Indoor air quality (IAQ) has been becoming a major concern worldwide because statistical data showed that the indoor concentrations of gas pollutants, e.g., volatile organic compounds (VOCs) and particulate matters (PMs) are often 2–5 times higher than that of outdoors. Especially, people spend 87% of their time indoors and increasing to more than 90% during COVID-19 pandemic. The high concentration of these indoor air pollutants is mainly due to the reduced air exchange rate for the design of energy-efficient building construction and the increased usage of furnishings, glues, paints, furnaces, etc., leading to VOC outgassing and particle emission. Evidence has …

Thermal Performance And Fluid Flow Studies Of Twisted Tape Inserts Using Scaled Surrogate Fluids For Molten Salt Energy Applications, Arturo Cabral

Theses and Dissertations

Global energy consumption is expected to increase with population growth and innovative clean sources of energy are sought out that can help meet the needs of a continuously power-hungry world. Some of these innovative sources of energy use molten salts as their operating and cooling fluid, such as fission reactors, fusion reactors, and solar power with energy storage. Molten salts are considered due to their efficient heat transfer properties, thermal energy storage capabilities, and high operating temperatures. To expedite their deployment, a further understanding of the heat transfer systems is required to accurately design and develop the heat transfer components …

High Signal-To-Noise Ratio Event-Driven Mems Motion Sensing, Mohammad Mousavi, Mohammad Alzgool, Benyamin Davaji, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Two solutions for improving MEMS triboelectric vibration sensors performance in contact-separation mode are reported experimen- tally and analytically. Triboelectric sensors have mostly been studied in the mesoscale. The gap variation between the electrodes induces a potential difference that represents the external vibration. Miniaturizing the device limits the sensor output because of the limited gap. This work offers a warped MEMS diaphragm constrained on its edges. The dome-shaped structure provides one order of magnitude larger displacement after contact-separation than standard designs resulting in one order of magnitude greater volt- age and signal-to-noise-ratio. Secondly, micro triboelectric sensors do not operate unless the …

Solid-State Electrolytes For Long Duration Molten Sodium Batteries, Ryan C. Hill

Theses and Dissertations--Chemical and Materials Engineering

Rechargeable batteries have become a staple of modern society, driving the development and expansion of portable electronics and electric vehicles. The long lifetime and high energy density provided by batteries have made them excellent candidates for use in the emerging field of long duration, grid-scale energy storage. However, traditional battery chemistries, such as Li-ion, are not an ideal solution for grid-scale storage, due to high-cost raw materials that are often sourced from volatile markets. Sodium-based batteries are a promising alternative for long duration storage, owing to the domestic abundance of raw materials and energy densities that nearly rival that of …

Optimal Spacecraft Guidance, Matthew W. Harris, M. Benjamin Rose

Mechanical and Aerospace Engineering Faculty Publications

This book is designed for a one-semester course at Utah State University titled MAE 6570 Optimal Spacecraft Guidance. The class meets for 75 minutes, twice per week, for 14 weeks. There are no prerequisites other than graduate standing in engineering. Proficiency in calculus, differential equations, linear algebra, and computer programming is required. Students find that previous experience in space dynamics, linear multivariable control, or optimal control is helpful.

The goal of the book and course is for students to develop fundamental skills needed to do professional work in the area of spacecraft guidance. After working through the book, students should …

Area Average Surface Transfer Coefficient In Unit Cell Geometries, Benjamin Gabriel Mackey

Masters Theses

"Honeycombs, metal foams, and lattice structures all provide a way to increase heat transfer due to better fluid mixing and larger surface area. Specifically, lattice structures can be a great way to provide heat transfer enhancement due to the ability to customize and optimize the unit cell geometry. In this research, a novel yet simple unit cell geometry is chosen for study. Four different configurations are tested in a lower Reynolds number range, 300–1800: single unit cell, two-unit cells in series, three-unit cells in series, and a 3x3 unit cell array. The Sherwood number of each configuration is found by …

Surface Modified Titanium And Doxycycline Loaded Pcl/Plga Nanofibers For Improved Cellular Interaction And Biocompatability, Dexter D. Kling

Graduate Research Theses & Dissertations

Biomaterials play an important role in modern medicine through their complexfunctionalities, as implants, grafts, and drug delivery systems. The addition of dopants and biomolecules in biomaterials offers unique solutions to common issues and provides new methods of improving overall health. In our work, we examined osteoblast cell interactions with titanium (Ti) after alkali treatment and deposition of magnesium (Mg) and iron (Fe). We also studied the antibacterial properties of doxycycline loaded polymeric nanofibers produced via electrospinning. To study the biological properties of surface-modified Ti, we first prepared commercially pure titanium samples by grinding and polishing, then performed alkali treatment in …

Part Design Geometry-Driven Toolpath Optimization For Additive Manufacturing Energy Sustainability Improvement, David Kolawole Somade

Graduate Research Theses & Dissertations

One of the most promising new manufacturing technologies in the past three decades isadditive manufacturing (AM), also commonly known as three-dimensional (3D) printing or rapid prototyping. The energy consumption problem in AM can be significant when it is adopted at the industrial scale or used under resource-restricted conditions. The energy consumption of an AM process is influenced by several factors including bed heating, filament extrusion, material infill, component cooling, etc. All these factors are further determined by the equipment and the toolpath for a specific printing task. Build orientation and tool-path direction are frequently used to optimize part and process …

Mechanical Behavior Of Metallic Core-Shell Nanoparticles Under Compressive Loading, Phillip Tomich

Graduate Research Theses & Dissertations

Core/shell metallic nanoparticles have been shown to be a promising material type for additive manufacturing in the aerospace and automotive fields. Within additive manufacturing they will be used to accurately make an array of nanoparticles within the grains of metal matrix composites. This in turn will help to strengthen the material while remaining ductility and light weight. In this study, copper/aluminum core/shell nanoparticles are compressed under [100], [110], [111], and [112] directions to showcase their anisotropic material properties. Models of their individual counterparts were also investigated. There are no previous works showing the deformation mechanisms of copper/aluminum core/shell nanoparticles. Molecular …

Artificial Intelligence And Multi-Physics Approach For Electrocoagulation Parameter Selection, Adam Cotton

Graduate Research Theses & Dissertations

Proper treatment of wastewater is crucial to maintain the health of the public and avoid pollution of the environment. Methods like filtering and chemical coagulation have been utilized to treat wastewater, but they have significant limitations such as inefficient treatment of micro-size pollutants, generation of secondary contaminants, and high operation and maintenance costs. The electro-coagulation system which generates coagulants from low-cost aluminum electrodes under the application of a current has received strong attention as a promising water treatment system. However, the EC system has not been fully utilized yet due to lack of understanding and operation guidelines.

In this study, …

Analysis Of The Effect Of Surface Roughness In Additive Manufacturing On Thermo-Hydraulic Performance By Ml Models Supported By Physics-Based Modeling, Kaylen A. Platt

Graduate Research Theses & Dissertations

Heat exchangers (HX) are crucial components of thermal control systems which facilitate proper transfer of heat in systems such as nuclear reactors. This research focuses on the heat transfer-enhancing effect associated with turbulence in fluid flowing conduits. Turbulence can be induced at low flow rates when surface roughness is present on channel walls. Rough surfaces are typically regarded as a flawed product of the Additive Manufacturing (AM) process during the construction of Heat Exchangers. Machining surface finishes onto AM parts is a typical post-processing method used to remove the roughness. Thorough investigations have not yet been published on the effects …