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Articles 1 - 16 of 16
Full-Text Articles in Engineering Physics
Design Of Smart Trashcan, Haoran Song
Design Of Smart Trashcan, Haoran Song
Senior Theses
A smart trashcan has been designed which can bring convenience to people for throwing their garbage away during the COVID-19 pandemic. A prototype is made from cardboard to demonstrate its function. This trashcan can sense people who are coming and leaving, and it can open and close automatically. The trashcan is powered by solar energy. A solar panel is mounted on top of the trashcan supporter. This design is specifically for use in China.
Exploring The Electrical Properties Of Twisted Bilayer Graphene, William Shannon
Exploring The Electrical Properties Of Twisted Bilayer Graphene, William Shannon
Senior Theses
Two-dimensional materials exhibit properties unlike anything else seen in conventional substances. Electrons in these materials are confined to move only in the plane. In order to explore the effects of these materials, we have built apparatus and refined procedures with which to create two-dimensional structures. Two-dimensional devices have been made using exfoliated graphene and placed on gold contacts. Their topography has been observed using Atomic Force Microscopy (AFM) confirming samples with monolayer, bilayer, and twisted bilayer structure. Relative work functions of each have been measured using Kelvin Probe Force Microscopy (KPFM) showing that twisted bilayer graphene has a surface potential …
Transferring Power Through A Magnetic Couple, Nickolas Cruz Villalobos Jr.
Transferring Power Through A Magnetic Couple, Nickolas Cruz Villalobos Jr.
Senior Theses
Properties of several working magnetic coupled rotors have been measured and their performance compared to theoretical models. Axial magnetic couplers allow rotors to work within harsh environments, without the need for seals, proper alignment, or overload protection on a motor. The influence of geometrical parameters, such as distance from the center of the rotors, polarity arrangement, and the number of dipole pairs were experimentally tested. These results can be used to improve rotor designs, to increase strength and efficiency.
Manufacturing And Testing The Permanent Magnet Linear Motor, Renjie Kang
Manufacturing And Testing The Permanent Magnet Linear Motor, Renjie Kang
Senior Theses
Controlled mechanical motion is vital in many useful applications in technology. Among them, linear motors have advantages over traditional rotating motors. In this work, we built a permanent magnet linear motor to test and measure its energy efficiency. A maximum 29% total energy efficiency, and 67% energy transfer rate, were detected. In addition, a C-shape support structure was added to the moving part in order to increase the moving accuracy. The tests show that, with the support structure, the fluctuation in the vertical direction decreases significantly, but the friction of the system slightly increases.
Increasing The Longevity Of Tungsten Filaments In A Zone Refiner, Byron D. Greenlee
Increasing The Longevity Of Tungsten Filaments In A Zone Refiner, Byron D. Greenlee
Senior Theses
Zone refining is used for its ability to purify material and grow single crystals. To produce these single crystals, a suspended molten zone, generated by electron bombardment, passes along the polycrystalline stock. During a zone refining run, the filaments that produce the electron bombardment can fail. In this project, the longevity of tungsten filaments in a zone refiner was investigated. A new bombardment geometry was constructed to attempt to increase the longevity of the filaments. The new geometry had a shield machined into it to prevent line-of-sight impurities originating in the molten zone from striking the filaments. It was found …
Effects Of Tension On Resonant Frequencies Of Strings, Blake Burnett
Effects Of Tension On Resonant Frequencies Of Strings, Blake Burnett
Senior Theses
This project tests and explores resonance of strings. Since all materials and mechanisms are affected by vibrations, it is important to know the frequencies at which resonance occurs. To explore this subject, strings were used as a model material to test the effect tension has on resonance. The fundamental frequencies and the corresponding modes of resonance were used to analyze the data. The results of this experiment show that increasing tension on a string increases its resonance frequency. Understanding the physics behind resonance frequency allows systems to be designed to take advantage of resonance properties, or to avoid resonance where …
The Effects Of Surface Pace In Baseball, Jason Farlow
The Effects Of Surface Pace In Baseball, Jason Farlow
Senior Theses
A baseball travels across different surfaces at different paces. The goal of this experiment is to find a percentage difference in speeds the ball will reflect off a given surface. The energy lost on the turf surface was far more significant than on dirt surface as the turf lost an average of 26% of its energy as compared to just 16% of the energy on dirt. In the Northwest conference, teams play on four turf-based infields and five dirt-based infields. The results of this study suggest that kinetic friction forces are more significant in reducing ball rebound speed than in …
Measuring The Double Layer Capacitance Of Electrolytes With Varied Concentrations, Geoffrey Rath
Measuring The Double Layer Capacitance Of Electrolytes With Varied Concentrations, Geoffrey Rath
Senior Theses
When electric potentials are applied from an electrolytic fluid to a metal, a double layer capacitor, Cdl, develops at the interface. The layer directly at the interface is called the Stern layer and has a thickness equal to roughly the size of the ions in the fluid. The next layer, the diffuse layer, arises from the gathering of like charges in the Stern layer. This layer is the distance needed for ionic charges to return to equilibrium. This distance, called the Debye length, λ, depends on the square root of the electrolyte concentration. To study the properties of …
Measuring The Double Layer Capacitance Of Electrolyte Solutions Using A Graphene Field Effect Transistor, Agatha Ulibarri
Measuring The Double Layer Capacitance Of Electrolyte Solutions Using A Graphene Field Effect Transistor, Agatha Ulibarri
Senior Theses
When operating graphene field effect transistors (GFETs) in fluid, a double layer capacitance (Cdl) is formed at the surface. In the literature, the Cdl is estimated using values obtained using metal electrode experiments. Due to the distinctive electronic and surface properties of graphene, there is reason to believe these estimates are inadequate. This work seeks to directly characterize the double layer capacitance of a GFET. A unique method for determining the Cdl has been implemented, and data has been obtained for three electrolytes and one ionic fluid. The results yield dramatically lower Cdl values than …
The Drag Coefficient Of Varying Dimple Patterns, James M. Seeley, Michael S. Crosser
The Drag Coefficient Of Varying Dimple Patterns, James M. Seeley, Michael S. Crosser
Senior Theses
There are many golf balls on the market today with varying dimple sizes, shapes, and distribution. These proprietary differences are all designed to reduce drag on the balls during flight, allowing golfers to hit the ball farther distances. There are limited published studies comparing how varying the dimples affects the reduction of drag. An experiment was developed in which golf balls were pulled through a water tank to measure the drag force acting on each ball. The water was chosen to allow for testing at slower velocities than the typical necessary speeds to cause turbulence for balls traveling in air. …
Operating Temperature Of A Solar Thermal Stirling Engine, Spencer Beck
Operating Temperature Of A Solar Thermal Stirling Engine, Spencer Beck
Senior Theses
This paper explores the relationship between the operating temperature and electricity production of a simple heat engine. A Stirling engine was designed and constructed which runs on solar thermal energy collected by a Fresnel lens. The surface area of the solar collector was varied. This manipulated the operating temperature of the Stirling engine in order to measure power output. The mechanical energy from the engine was converted to electricity using a DC motor running in reverse, acting like a generator, in conjunction with an Arduino for data collection. Although adjustments must be made in order to improve the efficiency of …
Are Solar Panels A Viable Power Source For A Green Energy Vehicle?, Mason C. Adams
Are Solar Panels A Viable Power Source For A Green Energy Vehicle?, Mason C. Adams
Senior Theses
A solar cell powered go-kart has been built and tested. The result shows using solar energy alone cannot meet the requirement of running a regular passenger car. This is due to the limited surface area of the passenger car. This thesis also discusses the operating principles of solar panels, the physics of P type and N type semiconductors, and the formation of the PN junction, as well as the solar current. Modifications of an existing go-kart are described in detail in this thesis. Suggestions for making green vehicles are discussed as well.
Reflective Efficiencies Of Materials For Applications Of Bifacial Solar Cells, Michael Metter
Reflective Efficiencies Of Materials For Applications Of Bifacial Solar Cells, Michael Metter
Senior Theses
The bifacial solar cell is superior to its monofacial predecessor due to its ability to convert both incident light on top and reflected light from below into energy. The scattering of the reflected light is affected by the property of the material on which it is interacting. To date, little work has been contributed to studying the properties of these materials to determine optimal quantities for bifacial solar cells. In the first experiment, reflective efficiencies compared to the angle of reflection were explored for different grit of sandpaper in order to develop an understanding of how surface texture impacts reflectivity. …
Power Maximization Of A Three-Phase Hydrokinetic Turbine, Matthew Carleson
Power Maximization Of A Three-Phase Hydrokinetic Turbine, Matthew Carleson
Senior Theses
As Earth`s expendable resources dwindle, the need for alternative, renewable energy sources grows. Out of this need, an old favorite source is rising in popularity: small water turbines. Water-driven turbines first began as a means for turning mills and eventually evolved into massive dams that can power whole regions. This project focused on the construction of, and testing the properties of, a small pico-hydro power turbine. By using compressed air to drive the turbine, a representation of the peak power output was measured, serving as a basis for determining the value of pico-power systems in regards to the world`s current …
Effect Of Seam-Height On Curveballs, Joseph S. Carroll
Effect Of Seam-Height On Curveballs, Joseph S. Carroll
Senior Theses
The difference in seam-height between raised and flat-seam baseballs causes them to react differently when thrown by a pitcher. Altering the seam-height on the ball changes the amount of drag force on it as it travels through the air. The goal of this experiment is to measure the difference in vertical deflection between the two types of balls when pitched with curveball topspin. It was discovered that the baseball with raised-seams experiences more vertical deflection than the flat-seam ball.
Measuring Strain In Trusses, Spencer Metzsch
Measuring Strain In Trusses, Spencer Metzsch
Senior Theses
Strain is an important quantity in engineering design and materials science that relates the deformation of a material to its original length, through a percentage. Different materials exhibit particular qualities under loading, for example the amount of strain due to a certain magnitude of force, or the amount of strain that can be borne before failure. This experiment aims to compare the relative strengths of three common truss configurations by measuring the strain in their members under loading. The Queen’s post truss was found to be the best at minimizing strain under similar loading conditions.