Mechanical Engineering Commons^™

Carbon Black Mediated Conductive Polymer Composite, Mohamed Hussein Faris Ali

Theses

The central goal of this thesis is to produce electrically conductive nanocomposites made out of carbon black obtained from waste tires as filler into a polymeric matrix. Waste tires are discarded in substantial numbers on a daily basis, posing a significant environmental concern. By weight, about 25-35% of a tire is carbon black. Pyrolysis is a convenient and environmental friendly process to produce carbon black from tires. Due to carbon black’s low density, high electrical conductivity and economic feasibility, this thesis investigates the electrical conductivity of nanocomposites that utilizes carbon black particles as fillers. As a result of its modified …

Investigating The Relationship Between High Temperature Flow Stress And Friction Stir Weldability In Hsla Steels, David Jordan Walser

Theses and Dissertations

The feed rate at which a defect free friction stir weld can be run (friction stir weldability) on an HSLA steel plate can vary widely between heats that meet the same specified physical properties. Consequently, every time a new heat of HSLA steel is obtained, exploratory welds must be run to determine the proper feed rate for that plate. Previous research suggests that the varying levels of alloying elements related to high temperature physical properties between the different heats causes the observed change in friction stir weldability. Because of this, it was hypothesized that the high temperature physical properties of …

Low Speed Water Tunnel Testing, John J. Taylor

Theses and Dissertations - UTB/UTPA

Water tunnels are ideal for studying flow patterns for hydrodynamic effects. The functionality of the University of Texas-Pan American water tunnel was limited by not being able to measure forces and moments corresponding to flow patterns. This report delivers an experimental set-up for calibrating the velocity of the water and development of a load measuring system to relate simultaneous visual investigation. An in-depth parts breakdown of the SST-model pump and the dye injection system for flow visualization will be reviewed. Few balances have been made for water tunnels due to small and difficult to measure flow-induced forces. The motive is …

Effects Of Vapor Grown Carbon Nanofibers On Electrical And Mechanical Properties Of A Thermoplastic Elastomer, Daniel Thomas Basaldua

Theses and Dissertations - UTB/UTPA

Carbon nanofiber (CNF) reinforced composites are exceptional materials that exhibit superior properties compared to conventional composites. This paper presents the development of a vapor grown carbon nanofiber (VGCNF) thermoplastic polyurethane (TPU) composite by a melt mixing process. Dispersion and distribution of CNFs inside the TPU matrix were examined through scanning electron microscopy to determine homogeneity. The composite material underwent durometer, thermal gravimetric analysis, differential scanning calorimetry, heat transfer, hysteresis, dynamic modulus, creep, tensile, abrasion, and electrical conductivity testing to characterize its properties and predict behavior. The motivation for this research is to develop an elastomer pad that is an electrically …

Analysis And Optimization Of The Scheffler Solar Concentrator, Simone Alberti

Master's Theses

The Scheffler reflector is a new solar concentrator design which maintains a fixed focus while only having a single axis tracking mechanism. This design makes the construction and operation of high temperature solar concentrators accessible to developing nations. In this project, I wrote computer simulation codes to better understand the dynamics and the effect of deformation or deviations from ideal conditions in order to define necessary manufacturing and operational tolerances. These tools and knowledge drove the prototyping of new reflector concepts by myself and other students on my team. A fiberglass prototype was able to drive the cost of a …

Light Field Imaging Applied To Reacting And Microscopic Flows, Jonathon Remy Pendlebury

Theses and Dissertations

Light field imaging, specifically synthetic aperture (SA) refocusing is a method used to combine images from an array of cameras to generate a single image with a narrow depth of field that can be positioned arbitrarily throughout the volume under investigation. Creating a stack of narrow depth of field images at varying locations generates a focal stack that can be used to find the location of objects in three dimensions. SA refocusing is particularly useful when reconstructing particle fields that are then used to determine the movement of the fluid they are entrained in, and it can also be used …

Design, Analysis And Implementation Of An Experimental System To Harvest Energy From Atmospheric Temperature Variations Using Ethyl Chloride Filled Bellows, Gibran Ali

All Theses

The increase in global warming and the dwindling supplies of fossil fuels have shifted the focus from traditional to alternate sources of energy. This has resulted in a concerted effort towards finding new energy sources as well as better understanding traditional renewable energy sources such as wind and solar power. In addition to the shift in focus towards alternate energy, the last two decades have offered a dramatic rise in the use of digital technologies such as wireless sensor networks that require small but isolated power supplies. Energy harvesting, a method to gather energy from ambient sources including sunlight, vibrations, …

Direct Synthesis Of Methane From Co2-H2O Co-Electrolysis In Tubular Solid Oxide Electrolysis Cells, Long Chen, Fanglin Chen, Changrong Xia

Faculty Publications

Directly converting CO₂ to hydrocarbons offers a potential route for carbon-neutral energy technologies. Here we report a novel design, integrating the high-temperature CO₂–H₂O co-electrolysis and low-temperature Fischer–Tropsch synthesis in a single tubular unit, for the direct synthesis of methane from CO₂ with a substantial yield of 11.84%.

Transient Heat Transfer Between A Magnetocaloric Packed Particle Bed And Stagnant Interstitial Fluid., Michael G. Schroeder 1988-

Electronic Theses and Dissertations

In the field of magnetocaloric heat pumps, many system models have been made. What most of these models lack is heat transfer occurring while there is no fluid motion. It is the objective of this paper to analytically determine and experimentally verify heat transfer with no bulk fluid motion. The addition of a pure dwell period to the typical magnetocaloric cycle was shown to have a positive performance impact in specific conditions. These conditions correspond to regenerators that are heat transfer rate limited in operation. The heat transfer mechanism for this particular case was shown to be pure conduction via …

Investigation Of Transmission Loss Through Double Wall Structures With Varying Small Air Gaps Using Modal Analysis., Richard Michael Phillips 1988-

Electronic Theses and Dissertations

Noise reduction testing is completed for two single steel plate constructions with different thicknesses and for two double wall constructions with different air gap thicknesses that include the same two plates used in the single plate constructions. Results compare favorably with known theory and experimental results from previous literature. These favorable comparisons include the direct relationship between mass per unit area and transmission loss for single plate constructions, the presence of a noise reduction valley near the mass-air-mass frequency, the dependency of the mass-air-mass frequency on the air gap thickness, and the existence of a bridge frequency. Despite the similarities …

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as …

Aeroponic/Hydroponic Growth Module, Sean Marrs, Joshua Moreno

Mechanical Engineering

No abstract provided.

Multi-Axis Tripod Locking Mechanism, Glenn Carros, Hannah Gause, Matthew Theiss

Mechanical Engineering

No abstract provided.

Cal Poly India Project, Derek Babine, Austen Hibler, Alex Hernandez

Mechanical Engineering

This report documents the research, ideation, and development of a solution, implemented by the Cal Poly India Sanitation Team per the request of Mr. Harish Bhutani, to solve the problem of hazardous human waste management in poor villages in India. The sponsor envisioned a universal design that would give each household in those villages access to a private toilet system because the current solution is open defecation in water sources and farming fields. The initial constraints required the project be low cost, not use of electricity or water, have the ability to cater to an 8-10 person household, and be …

Temperature Controlled Packaging Container For Biologics And Pharmaceuticals, Melinda Phan, Yufay Chow-Yee, Abraham Ho

Mechanical Engineering

Clinical Supplies Management, Inc. (CSM) provides clinical trial services to biotechnology and pharmaceutical companies by shipping pharmaceuticals to clinics and other patients. In winter 2014, CSM presented a temperature control packaging project to the Cal Poly Senior Project class. As a result, three Cal Poly Mechanical Engineering Students were tasked to design, manufacture, and qualify a shipping container that would maintain ten 10 mL vials between 2-8°C for 96 hours. The final product would have to cost less to ship than the Credo Cube, CSM’s current temperature control packaging product. After considerable research and analysis on possible temperature control technologies, …

Electric Porsche Drivetrain Re-Design, Taylor Carlson, Quinton Petty, Spencer Treffry

Mechanical Engineering

The objective of this project was to redesign the drivetrain of the electric 1977 Porsche 911 Targa S with the goal of optimizing the drivetrain for motor efficiency and performance. The focus was to redesign the interface between the electric motor and rear wheels to maximize the efficiency of power transmission from the motor to the ground.

Two systems were proposed, a fixed gear reduction and two motors with an electronic differential. The fixed gear reduction was chosen to be designed and built by replacing the stock Porsche transmission with a differential featuring a favorable gear ratio for the electric …

Mega: An Energy Aware Algorithm For Self-Powered Wireless Sensor Networks In Sustainable Smart Infrastructure, Dong Qi, Yu Chen, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Smart infrastructure is attractive for possessing many desirable features, such as uninterrupted monitoring of health conditions, timely response to damages, and human-infrastructure interactions. Embedded sensors that collectinformation are critical for decision making. However, the lifetime of electronic sensors is a constraint to infrastructure lifetime if sensors are physically embedded in the infrastructure at construction time. In this paper, we studied a self-powered wireless sensor network that harvests energy from mechan-ical vibration in the environment. A dynamic, hierarchical algorithm called MEGA is proposed that constructs clusters and elects the cluster head based on residue energy and energy harvest rate. Taking a …

Mitigation Of Moving Shocks In An Expanding Duct, Veraun Chipman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Inviscid flow theory governs the bulk motion of a gas at some distance away from the walls (i.e. outside the boundary layer). That is to say, there are no viscous forces in the bulk flow, which is modeled using the Euler equations. The Euler equations are simply the Navier-Stokes equations with zero viscosity terms. An ideal inviscid fluid, when brought into contact with a surface or wall, would naturally slip right past it since the fluid has no viscosity. In real life, however, a thin boundary layer forms between the wall or surface and the bulk flow. Shock wave boundary …

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The objective …

Numerical Simulation Of The Heat Leakage At The Gasket Region Of Domestic Refrigerators, Feng Gao

All Theses

Computational Fluid Dynamics (CFD) simulations are performed to investigate the heat loss at the gasket of a standard over/under domestic refrigerator. The study numerically simulates a unique experimental test cell with only the gasket region exposed to the ambient environment and other parts protected by insulation (see picture below). The test cell is cubic with an interior cavity having dimensions 2' x 2' x 2' within which a heating element is placed to create a specified temperature difference. A matching set of door and side panels exposes a 2' width of the gasket region to heat transfer with the surroundings. …

Thermo-Physical Property Models And Effect On Heat Pipe Modelling, Devakar Dhingra

All Theses

Heat transfer devices find applications in various aspects of life. Be it residential, commercial or industrial application, efficient heat transfer is a challenge to all. Other than geometric design considerations and wick selection, the optimization of heat transfer in the heat pipe also depends on fluid selection. Heat pipe technology has proven to work efficiently with properly selected thermal fluid, from cryogenic temperatures to very high temperatures. Higher heat transfer ability through small temperature differences makes the heat pipe an efficient technology. Hence, it can be stated that selecting a proper working fluid enhances the heat transfer performance of a …

A Model Of The Diurnal Variation In Lake Surface Temperature, Jonathan L. Hodges

All Theses

Satellite measurements of water surface temperature can benefit several environmental ap-plications such as predictions of lake evaporation, meteorological forecasts, and predictions of lake overturning events, among others. However, limitations on the temporal resolution of satellite mea-surements restrict these improvements. A model of the diurnal variation in lake surface temperature could potentially increase the effective temporal resolution of satellite measurements of surface tem-perature, thereby enhancing the utility of these measurements in the above applications. Herein, a one-dimensional transient thermal model of a lake is used in combination with surface tempera-ture measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the …

Investigation Of Subgrid-Scale Mixing In Turbulent Plane Jets And Turbulent Jet Flames, Shuaishuai Liu

All Dissertations

The subgrid-scale (SGS) mixing of mixture fraction, temperature, and species mass fraction in turbulent partially premixed (Sandia) flames is studied. We focus on the effects of the SGS mixing regimes and the spatial relationships among the scalars on the SGS mixing of the species mass fractions. High resolution lines images are used to obtain the scalar filtered mass density function and the conditionally filtered diffusion. The results show that for small SGS variance the scalar fields have a relatively simple structure. For large SGS variance the structure is more complex. The spatial relationships among the scalars result in different SGS …

Autonomous Control And Automotive Simulator Based Driver Training Methodologies For Vehicle Run-Off-Road And Recovery Events, Paul Freeman

All Dissertations

Traffic fatalities and injuries continue to demand the attention of researchers and governments across the world as they remain significant factors in public health and safety. Enhanced legislature along with vehicle and roadway technology has helped to reduce the impact of traffic crashes in many scenarios. However, one specifically troublesome area of traffic safety, which persists, is run-off-road (ROR) where a vehicle's wheels leave the paved portion of the roadway and begin traveling on the shoulder or side of the road. Large percentages of fatal and injury traffic crashes are attributable to ROR. One of the most critical reasons why …

Particle Scavenging By Water Drops In An Ultrasonic Standing Wave Field, Weiyu Ran

All Dissertations

Currently the backbone of the world's energy supply is composed of fossil fuels. However, the combustion of fossil fuels results in the production of enormous quantities of particulate pollutants. The smog resulting from these particulate pollutants causes significant health problem for city dwellers. Wet scrubbers, which use a water spray to scavenge airborne particles, is one of the most widely used devices to control particulate pollutants. Typical wet scrubbers can scavenge particles with diameters bigger than 10 um, but it is inefficient in scavenging particles with diameters on the order of 1 um. Unfortunately these fine particles are more dangerous …

Thermo-Mechanical Characterization Of Glass And Its Effect On Predictions Of Stress State, Birefringence And Fracture In Precision Glass Molded Lenses, Dhananjay Joshi

All Dissertations

The Precision Glass Molding (PGM) process was established as an economical and sustainable option for the production of aspherical glass optics to satisfy the increased industrial demand. Applications of precision molded aspherical lenses range from consumer electronics products such as cell phone cameras to defense and medical systems. An aspherical lens can eliminate the spherical and optical aberrations as compared to a spherical lens thus making the lens system more compact and lighter. In spite of being a clean and environmentally friendly process, the lens molding operation suffers from a few drawbacks such as lens profile deviation, stress birefringence/refractive index …

Me-Em Enewsbrief, December 2014, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Wear Resistant Polydopamine/Ptfe Nanoparticle Composite Coating For Dry Lubrication Applications, Samuel George Beckford

Graduate Theses and Dissertations

This dissertation presents an investigation into the effect of nanoparticle fillers and a polydopamine adhesive primer on the tribological performance of thin PTFE films. The principal objective of this investigation was to reduce wear in PTFE films, an issue which precludes the use of PTFE films in tribological applications requiring high durability. The friction and wear of the composite films were evaluated using a ball-on-flat configuration in linear reciprocating motion. It was found that the use of a polydopamine adhesive primer reduces the wear of PTFE films more than 600 times. X-ray photoelectron spectroscopy (XPS) results show that a tenacious …

Highly Transparent, Self-Cleaning, And Antireflective Nanoparticle Coatings, Corey Seth Thompson

Graduate Theses and Dissertations

Current solar panel technologies require a sheet of glass to serve as both mechanical support and to protect the cells from the environment. The reflection from the glass sheet can reflect up to 8% of the incident light, reducing the power output of the panel. Antireflective coatings can be used to allow more light to enter the panel to be converted into usable electricity. However, no solid thin film materials exhibit a low enough index of refraction to serve as antireflective coatings for common solar glass. The main goal of this research was to investigate the self-cleaning, antifogging, and antireflective …

A Preventive Maintenance Framework In Dairy Production Operations, Maria F. Vargas

Theses and Dissertations - UTB/UTPA

Dairy operations suffer frequent stops. Product shrinkage is a consequence of downtime, which includes losses of packaging material, scraped finish product and capacity. This work proposes a troubleshooting methodology to identify causes of downtime, estimation of waste cost, and minimization of operation disruptions by applying a combination of a cost function to assess waste, and performance measurements. The drinkable yogurt process is evaluated to find the principal areas for wasted bottles and yogurt. In order to make a decision about which of those sources to address, a General Cost Function is used to estimate waste cost which include measurements that …