Mechanical Engineering Commons^™

Robust Predictive Analytics For Determining Acclimation Parameter Of It Equipment, Premsanth Sadasivam

Mechanical and Aerospace Engineering Theses - Archive

Acclimation is the process in which an IT equipment adjusts to a change in its environment such as a change in temperature and humidity, allowing it to maintain performance across a range of environmental conditions. In commissioning of a new cold shipped IT equipment in data centers, environmental acclimation is an important step. Proper acclimation also minimizes the risk of powering on a machine that may still be wet due to moisture condensation. An experimental study is carried out to find how the acclimation occurs and the factors influencing it. These experiments are designed with various temperature ranges and using …

Understanding The Evolution Of Surface Texture Under Boundary Lubrication, Salil T. Bapat

Graduate Theses and Dissertations

The objective of this research was to understand the evolution of surface texture under boundary/mixed lubrication (BL). Significant material/energy losses occur during BL because of direct contact between the two surfaces. Traditionally, tribofilms have been studied extensively for BL while textures have been used as a static engineering design parameter to enhance lubricant film properties. However, texture is dynamic at the tribological mating interface, where both physical and chemical interactions are continuously modulated. The evolution and the interplay between the tribofilm and texture is least studied in the literature, which is the focus of this research.

MoS2-based lubricants, known for …

Energy Sustainability Analysis Of A Baja Test Facility, Seth Bishop

Honors Theses

The objective of this paper is to study the viability of building a Baja SAE competition site so that UTC could host events in the future. Part of this includes defining a building size in square feet and estimating the construction cost. Once that is accomplished it is necessary to determine what equipment may be used at the site, how much power each piece of equipment would use, and how many hours each would be used for within the year. With this information it is then possible to estimate the annual power consumption for a competition year and a regular …

Design Of A Pneumatic Conveying Test Loop For Laboratory Testing, Natalie Burdine

Honors Theses

Pneumatic conveying is the transportation of material through a closed conveying line in a gas medium via a pressure differential. In industry, pneumatic conveying is used extensively to handle materials: specifically, bulk solids and powders. 80% of all transported materials are bulk solids and pneumatic conveying is currently experiencing industry growth at a rate of 6.4% annually. Industrial pneumatic conveyor suppliers use specialized testing systems to make design decisions regarding specific applications, taking into account the conveyed material, the structure of the plant in which the system will be installed, and desired system characteristics such as necessary filtering or safety …

Ultrasonic Nondestructive Evaluation Of Metal Additive Manufacturing., Venkata Karthik Nadimpalli

Electronic Theses and Dissertations

Metal Additive Manufacturing (AM) is increasingly being used to make functional components. One of the barriers for AM components to become mainstream is the difficulty to certify them. AM components can have widely different properties based on process parameters. Improving an AM processes requires an understanding of process-structure-property correlations, which can be gathered in-situ and post-process through nondestructive and destructive methods. In this study, two metal AM processes were studied, the first is Ultrasonic Additive Manufacturing (UAM) and the second is Laser Powder Bed Fusion (L-PBF). The typical problems with UAM components are inter-layer and inter-track defects. To improve the …

Development Of A Model To Predict The Likelihood Of Complaints Due To Assorted Tone-In-Noise Combinations, Joonhee Lee, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper develops a model to predict if listeners would be likely to complain due to annoyance when exposed to a certain noise signal with a prominent tone, such as those commonly produced by heating, ventilation, and air-conditioning systems. Twenty participants completed digit span tasks while exposed in a controlled lab to noise signals with differing levels of tones, ranging from 125 to 1000 Hz, and overall loudness. After completing the digit span tasks under each noise signal, from which task accuracy and speed of completion were captured, subjects were asked to rate level of annoyance and indicate the likelihood …

Development And Validation Of A Numerical Model Of The Co2 Dry-Ice Blasting Process For Aircraft Engine Cleaning Applications, Arthur Rudek

Doctoral

On-wing cleaning of engine compressors for commercial aircraft is a required maintenance task which results in greater operating efficiency and lower emission rates. It is typically carried out by injection of water and detergents into the intake of an engine while the engine is being cranked by the starter. Two drawbacks of this process are the risk of icing in cold weather and the collection and treatment of the water effluent. The dry-ice blasting process, a cleaning system which uses pressurized air and CO2 dry-ice particles as cleaning agent, has been proposed as an alternative method which does not suffer …

A Study Of 3d Printed Silver-Polymer Composite Structures, Cynthiya Shrestha

Senior Honors Theses

This research project primarily focuses on three major aspects: synthesis and inclusion of silver microparticles and nanowires within a polymer matrix, extrusion of composite filaments and, three-dimensional (3D) printing of multifunctional polymer composites. Since very few studies have explored the inclusion of silver nanoparticles in 3D printing materials, the findings from this study can be significant for additive manufacturing technology. Over the past few decades, the applications of additive manufacturing has been expanding considerably in several industries like automobile, biomechanics, aerospace, hardware engineering, to name a few. We are particularly interested in silver particles and nanowires because of their enhanced …

Active Permanent Magnet Attitude Control For Cubesats Using Mu-Metal Shielding, Maxwell Martin

Mechanical Engineering Undergraduate Honors Theses

Cube-Satellites (CubeSats) are nanosatellites composed of cube shaped units, each nominally 10cm to a side and around 1kg in mass. Due to their inherent size and weight limitations, it is often impractical to use conventional attitude, or rotational, control methods such as thrusters on these small satellites. Several methods, including magnetorquer rods and small reaction wheels, are often used instead of traditional methods to work around the size and weight limitations. As a new alternative to these methods, a permanent magnet mounted on a rotatable shaft could be used to achieve attitude control. In much the same way that a …

Non-Covalent Functionalization Of Graphene Films For Uniform Nanoparticle Deposition Via Atoic Layer Deposition, Ty Seiwert

Mechanical Engineering Undergraduate Honors Theses

Graphene functionalized with platinum (Pt) and palladium (Pd) has proven to be highly effective as a hydrogen sensor. Deposition methods such as Atomic layer deposition (ALD) can be further enhanced by pretreating the graphene with a non-covalent surfactant prior to nanoparticle deposition. In this study, graphene-based sensing devices will be fabricated by ALD deposition. The graphene will be non-covalently functionalized using sodium dodecyl sulfate (SDS) anionic surfactant prior to ALD deposition. The aim of this study is to test the deposition pattern achieved by varying the amount of time that graphene is treated with the SDS surfactant. Initially, ALD deposition …

Phase Field Model Of Thermally Induced Phase Separation (Tips) For The Formation Of Porous Polymer Membranes, Ashley Green, Aria Green

Mechanical Engineering Undergraduate Honors Theses

Most membrane research and development has been done through experimental work, which can be costly and time consuming. An accurate computational model would greatly reduce the need for these experiments. The focus of the research presented in this paper is to create an accurate computational model for membrane formation using thermally induced phase separation (TIPS). A phase field model is employed to create this model including the Cahn Hilliard Equation and Flory Huggins Theory. This model produced computational results that correspond well with theoretical and experimental results. The model was then adapted to correspond to the PVDF/DPC polymer-solvent system by …

Baseline Data From Servo Motors In A Robotic Arm For Autonomous Machine Fault Diagnosis, Jacob Brown

Mechanical Engineering Undergraduate Honors Theses

Fault diagnosis can prolong the life of machines if potential sources of failure are discovered and corrected before they occur. Supervised machine learning, or the use of training data to enable machines to discover these faults on their own, makes failure prevention much easier. The focus of this thesis is to investigate the feasibility of creating datasets of various faults at both the component and system level for a servomotor and a compatible robotic arm, such that this data can be used in machine learning algorithms for fault diagnosis. The faults induced at the component level in different servomotors include: …

Effects Of Hydration And Mineralization On The Mechanical Behavior Of Collagen Fibrils, Marco Fielder

Graduate Theses and Dissertations

Bone is a composite biomaterial with a structural load-bearing function. Understanding the biomechanics of bone is important for characterizing factors such as age, trauma, or disease, and in the development of scaffolds for tissue engineering and bioinspired materials. At the nanoscale, bone is primarily composed of collagen protein, apatite crystals, and water. Though several studies have characterized nanoscale bone mechanics as the mineral content changes, the effect of water, mineral, and carbon nanotube (CNT) content and distribution in fibril gap and overlap regions is unexplored. This study used molecular dynamics to investigate the change in collagen fibril deformation mechanisms as …

An Underwater Vehicle Navigation System Using Acoustic And Inertial Sensors, Khalid M. Alzahrani

Doctoral Dissertations and Master's Theses

Unmanned Underwater Vehicles (UUVs) have become an essential tool for different underwater tasks. Compared with other unmanned systems, the navigation and localization for UUVs are particularly challenging due to the unavailability of Global Positioning System (GPS) signals underwater and the complexity of the unstable environment. Alternative methods such as acoustic positioning systems, Inertial Navigation Systems (INS), and the geophysical navigation approach are used for UUV navigation. Acoustic positioning systems utilize the characteristics of acoustic signals that have a lower absorption rate and a more extended propagation distance than electromagnetic signals underwater. The significant disadvantage of the INS is the “drift,” …

Arm Position Measurement, Silvia Smith

Undergraduate Honors Capstone Projects

This capstone project addresses the design and implementation of a device that measures arm position and speed. The device is intended for use in conducting further research on the motion of limbs affected by cerebral palsy, and in the prototypic development of a device that could help control such motion, thereby allowing a user to accomplish daily tasks. This project includes the design of an appropriate experiment and testing apparatus to explore possible solution prototypes, along with suggested methods to perform analysis of the experiment results. This is considered to be the fundamental research necessary to better understand the scope …

Rickshaw For Common Ground, Marcus Dallin Cronin

Undergraduate Honors Capstone Projects

For this project my team and I were asked to design and manufacture a rickshaw, a device which will enable disabled individuals to experience outdoor hiking trails, for a non-profit organization based in Logan, Utah called Common Ground. Common Ground specializes in helping people with disabilities experience the outdoors in ways that would otherwise be impossible. The rickshaw will help Common Ground achieve its goals by providing them with a way to transport people with disabilities on moderately difficult hiking trails (i.e. Wind Caves Trail in Logan Canyon). In the past, Common Ground had use of a rickshaw that had …

Superharmonic Resonance Of Second Order For Electrostatically Actuated Mems Cantilevers, Martin Amador Botello

Theses and Dissertations

The nonlinear dynamics of electrostatically actuated micro-electro-mechanical system (MEMS) cantilever resonators are investigated. The applied Alternating Current (AC) voltage is in the realm of superharmonic resonance of the second order (near one-fourth of the natural frequency of the resonator) and hard excitations. Method of Multiple Scales (MMS) and Reduced Order Models (ROMs) are used to solve the dimensionless partial differential equation (PDE) of motion along with boundary and initial conditions. MMS transforms the PDE of motion into zero-order and first-order problems. ROMs uses mode shapes of vibration for undamped cantilever resonator as a basis of functions. ROM is …

Multifunctional Carbon Systems (Interlaminated Carbon Nanofiber Mats/ Carbon Nanotubes Polymer Composites), Homero Gonzalez Guardiola

Theses and Dissertations

Carbon nanomaterials have been an attractive topic within diverse industrial sectors given their outstanding properties for decades. One of the properties that has been calling attention is it’s shielding effectiveness (SE) for electromagnetic interference (EMI), because of the constant race of improving portable electronic and wireless communication devices among other applications. The present study, analyzes the properties of interlaminated Carbon Nanofiber (CNF) mats/Carbon Nanotubes (CNT) polymer composites, emphasizing in its capability to shield EMI. The CNF mats were developed with Polyvinyl alcohol (PVA) as a precursor and by means of the Forcespinning® technology which uses centrifugal force to create fibers …

Lead Doped Carbon Nanofibers In Li-Ion Batteries, Omar Torres

Theses and Dissertations

Lead acid batteries have been a very reliable rechargeable battery since its inception in the mid-1800s. Lithium-Ion batteries have been sought out for their light-weight and capacity of holding large amounts of energy in a small amount of space. Few studies have been conducted in the use of lead in lithium-ion batteries.

In this thesis, lead-doped carbon nanofibers were produced by using the Forcespinning® method and used as an anode on a lithium-ion battery. The morphology, material characterization and thermal properties of the anode material were analyzed using the Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), Thermogravimetric Analysis …

Fibers For Skin Regeneration, Astrid Michelle Rodriguez Negron

Theses and Dissertations

This thesis presents the successful development of biocompatible Polyvinyl Butyral (PVB), PVB/Polylysine and PVB/Tannic Acid (TA)/Polylysine fibers from an ethanol solution, Polyhydroxybutyrate (PHB), PHB/Polylysine, PHB/TA/Polylysine fibers from a chloroform solution and Chitosan (CH)/Pullulan (PL)/TA and CH/PL/TA/Polylysine fibers from an aqueous solution. The fibers were mass produced utilizing the Forcespinning® (FS) technology. The morphology of the fibers was characterized using a scanning electron microscope (SEM) and the fibers average diameter was calculated. The thermal properties of the fibers were characterized using a thermogravimetric analyzer (TGA) and a differential scanning calorimeter (DSC). The antibacterial activity of the fibers was assessed using against …

The Effect Of Heat Generation In The Railroad Bearing Thermoplastic Elastomer Suspension Element On The Thermal Behavior Of Railroad Bearing Assembly, Oscar Osvaldo Rodriguez

Theses and Dissertations

Understanding the internal heat generation of the railroad bearing elastomer suspension element during operation is essential to predict its dynamic response and structural integrity, as well as to predict the thermal behavior of the complete railroad bearing assembly including the bearing adapter. The latter is essential for sensor selection and placement within the adapter (e.g., typical temperature sensors have operating ranges of up to 125°C or 257°F). The internal heat generation is a function of the loss modulus, strain, and frequency. Based on experimental studies, estimations of internally generated heat within the thermoplastic elastomer pad were obtained. The calculations show …

The Use Of Mixed Organic/Ionic Liquid Electrolytes With Forcespun Metal Oxides/Carbon Microfiber Electrodes In Lithium Ion Batteries, Jahaziel Villarreal

Theses and Dissertations

Conventional Lithium-Ion Battery (LIB) electrolytes have serious safety concerns because of highly flammability. In order to mitigate this drawback, alternative electrolytes with low volatility and non-flammable need to be synthesis. Ionic liquids (ILs) and mixed organic ionic liquid electrolytes (MOILEs) are the most suitable replacement for the highly flammable commercial organic electrolytes. In this academic investigation, a new perspective on the electrochemical performance of the ionic liquid EMI-TFSI as an alternate non-flammable electrolyte. In parallel, the use of Forcespun nanofibers as binder-free anodes will be analyzed to further improve overall electrochemical performance.

Concomitant Crystallization In Propylene/Ethylene Random Copolymer With Strong Flow At Elevated Temperatures, Lirong Zheng, Lucia Fernandez-Ballester, Gerrit W. M. Peters, Zhe Ma

Department of Mechanical and Materials Engineering: Faculty Publications

Flow-induced crystallization of α- and γ-phases was studied for a propylene/ethylene random copolymer with 3.4 mol % ethylene at two high temperatures of 132 and 142 °C by combining a pressure-driven slit flow device with real-time synchrotron wide-angle X-ray diffraction. At 132 °C, it was found that both α- and γ-phases were generated at shear stresses ranging from 0.091 to 0.110 MPa and that the γ-phase always appeared later than the α-phase. However, for 142 °C and the same stresses, only the α-phase formed. Only upon cooling the partially crystallized copolymer did the γ-phase emerge. The lack of γ-crystals obtained …

Influence Of Impact Conditions On Feedstock Deposition Behavior Of Cold-Sprayed Fe-Based Metallic Glass, Constance Ziemian, Wendelin Wright, David E. Cipoletti

Faculty Journal Articles

Cold spray is a promising method by which to deposit dense Fe-based metallic glass coatings on conventional metal substrates. Relatively low process temperatures offer the potential to prevent the crystallization of amorphous feedstock powders while still providing adequate particle softening for bonding and coating formation. In this study, Fe48 Mo14 Cr15 Y2 C15 B6 powder was sprayed onto a mild steel substrate, using a variety of process conditions, to investigate the feasibility of forming well-bonded amorphous Fe-based coatings. Particle splat adhesion was examined relative to impact conditions, and the limiting values of temperature and velocity associated with successful softening and …

Reduced Order Modeling For Virtual Building Commissioning, Sean Rosin

Boise State University Theses and Dissertations

Model order reduction can help reduce the time and monetary constraints associated with building commissioning and significantly decrease overall building energy consumption through virtual commissioning. This research aimed to determine the effectiveness of using reduced order models to simulate the overall building energy consumption, and to estimate the energy savings from control-based commissioning recommendations.

A case study building was modeled using a ‘Lumped RC’ thermal model with three thermal resistances and capacitances (3R3C) for the building interior and a 2R1C model describing the building foundation. Due to energy consumption being dependent on building systems, this model was coupled with a …

Design And Optimization Of A Passive Magnetic Thrust Bearing, Thomas Matthew Lasko

Theses and Dissertations

High-speed turbomachines present a number of unique challenges and problems. Large centrifugal forces create high stresses in rotating components, friction leads to elevated temperatures and component failure, and rotordynamic instability makes control difficult. The weak link in these high-speed systems is often the bearings because they provide the interface between the rotating and stationary components. Traditional bearings often fail in these conditions, especially when relatively large force capacities are required. In miniature gas turbines for unmanned aerial vehicle (UAV) applications, traditional bearings exhibit a typical lifetime of only 25 hours due to excessive axial loading. This research presents a passive …

Construction Techniques And Statistical Analysis Of Dielectric Elastomer Actuators, Adam Morrone

Senior Honors Theses

In this study, a series of experiments were conducted to investigate and improve upon existing construction methods of dielectric elastomer actuators (DEAs). First, a proof of concept was built, which utilized a DEA as an active diaphragm to reproduce sound. Next, two electrode sizes and construction methods were compared via statistical analysis of electrode strain. In an attempt to develop an easier and more efficacious electrode construction method, the substance used for electrodes was then dissolved in six solvents. A commercially available graphite spray was compared against the solutions and determined to be the most promising on the basis of …

Software Defined Radio System For Cubesat Communication, Tyler Gardner

Undergraduate Honors Capstone Projects

Cube satellites, or CubeSats, are small satellites designed around a base unit cube of 10 cm by 10 cm by 10 cm which is commonly referred to as a one unit, or 1 U, CubeSat. The modular architecture of CubeSats allows multiple 1 U frames to be stacked together to form a larger (1.5U, 2U, usually up to 6U) frame as needed. Because CubeSats are cheaper to develop and deploy in orbit than larger satellites, they have become increasingly common for academic, amateur, commercial, and scientific applications over the past five to ten years. There is potential that CubeSats will …

Development Of Microdialysis Probes In Series Approach Toward Eliminating Microdialysis Sampling Calibration: Miniaturization Into A Pdms Microfluidic Device, Randy Espinal Cabrera

Graduate Theses and Dissertations

A new microdialysis sampling method and microfluidic device were developed in vitro. The method consisted of using up to four microdialysis sampling probes connected in series to evaluate the relative recovery (RR) of different model solutes methyl orange, fluorescein isothiocyanate (FITC)-dextran average mol. wt. 4,000 (FITC-4), FITC-10, FITC-20, and FITC-40. Different flow rates (0.8, 1.0, and 1.5 µL/min) were used to compare experimentally observed relative recoveries with theoretical estimations. With increasing the number of probes in series, the relative recovery increases and ~100% (99.7% ± 0.9%) relative recovery for methyl orange was obtained. For larger molecules such as fluorescein isothiocyanate …

Phase Transitions In Monochalcogenide Monolayers, Mehrshad Mehboudi

Graduate Theses and Dissertations

Since discovery of graphene in 2004 as a truly one-atom-thick material with extraordinary mechanical and electronic properties, researchers successfully predicted and synthesized many other two-dimensional materials such as transition metal dichalcogenides (TMDCs) and monochalcogenide monolayers (MMs). Graphene has a non-degenerate structural ground state that is key to its stability at room temperature. However, group IV monochalcogenides such as monolayers of SnSe, and GeSe have a fourfold degenerate ground state. This degeneracy in ground state can lead to structural instability, disorder, and phase transition in finite temperature. The energy that is required to overcome from one degenerate ground state to another …