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Articles 1 - 30 of 46
Full-Text Articles in Physics
Relationship Between Thermal Conductivity And Free Electrons In Metal, Yansong Liu
Relationship Between Thermal Conductivity And Free Electrons In Metal, Yansong Liu
Senior Theses
An experiment was designed and conducted to explore the relationship between thermal conductivity with free electrons in metal. In the experiment, copper, iron, aluminum, and titanium rods with close diameters were used to carry out the experiment. Each rod was heated up by a heat unit at one end while cooled on the other end with a heat sink to maintain a steady state. DC current was applied to rods in the direction along, as well as against, the heat flow. Thermal conductivities were measured in these two situations for each rod. Results showed electrons do dominate thermal flow inside …
Securing Pint Glasses On Serving Trays With Magnetic Attachments, Jayden Commendatore
Securing Pint Glasses On Serving Trays With Magnetic Attachments, Jayden Commendatore
Senior Theses
It is extremely common for servers in the restaurant industry to have pint glasses slip off their serving tray, wasting both time and money for the restaurant. I have designed a sleeve attachment that will clip on to the bottom of a pint glass. The metal sleeve attachment will be attracted to a magnet placed into the serving tray. This increases the normal force of the pint glass, resulting in an increase in the friction force between the tray and sleeve attachment, and helping secure the glass to the tray. In order to optimize the design, the value of the …
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.
Quantifying Complex Systems Via Computational Fly Swarms, Troy Taylor
Quantifying Complex Systems Via Computational Fly Swarms, Troy Taylor
Senior Theses
Complexity is prevalent both in natural and in human-made systems, yet is not well understood quantitatively. Qualitatively, complexity describes a phenomena in which a system composed of individual pieces, each having simple interactions with one another, results in interesting bulk properties that would otherwise not exist. One example of a complex biological system is the bird flock, in particular, a starling murmuration. Starlings are known to move in the direction of their neighbors and avoid collisions with fellow starlings, but as a result of these simple movement choices, the flock as a whole tends to exhibit fluid-like movements and form …
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.
A Human Powered Micro-Generator For Charging Electronic Devices, John Adam
A Human Powered Micro-Generator For Charging Electronic Devices, John Adam
Senior Theses
A hand-pulled generator has been designed and tested. A preliminary result has been obtained and discussed. This device was created to provide outlet-free charging. Electronic devices are useful when going out into the wilderness. A portable power supply is necessary to keep an electronic device alive. This project created a device that converts human energy into electricity to charge electronic devices. This thesis overviews the device’s design, build, and tests. Two different tests were run to determine that the device is capable of charging the storage battery. The device presented can provide 14 minutes of charging time with one hour …
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 …
Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck
Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck
Senior Theses
The field of thermoelectrics has many applications, and more are found in everyday systems. From its current studies, it is apparent that improving the figure of merit zT (which defines a good thermoelectric material) is important in the effectiveness of power generation. Another important part of thermoelectrics is the duality of these devices. They can both move heat and generate power, depending on their role in the system. In this thesis research, a process was made to test these thermoelectric relationships for a few Peltier devices in order to understand their efficiencies and what systems they can be applied to.
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. …
The Computational Study Of Fly Swarms & Complexity, Austin Bebee
The Computational Study Of Fly Swarms & Complexity, Austin Bebee
Senior Theses
A system is considered complex if it is composed of individual parts that abide by their own set of rules, while the system, as a whole, will produce non-deterministic properties. This prevents the behavior of such systems from being accurately predicted. The motivation for studying complexity spurs from the fact that it is a fundamental aspect of innumerable systems. Among complex systems, fly swarms are relatively simple, but even so they are still not well understood. In this research, several computational models were developed to assist with the understanding of fly swarms. These models were primarily analyzed by using the …
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 …
Thin Film Thermal Deposition At Various Pressures, James Kela Yee Keen Grace
Thin Film Thermal Deposition At Various Pressures, James Kela Yee Keen Grace
Senior Theses
This research was to verify the hypothesis that resistivity of metal's thin film deposited in a low-pressure environment is the same as its solid material. Thermal Evaporation is a thin film deposition technique in which metal inside a vacuum is evaporated, then deposited onto a surface. Higher quality metal films are deposited when the vacuum pressure is lower. At higher pressures, more air molecules are trapped within the layers of metal, thus increasing scattering sites and increasing the resistance. However, reaching a lower pressure requires more time and effort. In this research, films were deposited at various pressures and resistivities …
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.
Observing Orbital Angular Momentum Transfer From Electron Vortex Beams To Matter, Hannah Devyldere
Observing Orbital Angular Momentum Transfer From Electron Vortex Beams To Matter, Hannah Devyldere
Senior Theses
It is possible to produce electron beams with non-zero orbital angular momentum. Such beams, known as electron vortex beams, are theoretically able to transfer their orbital angular momenta to matter, causing the matter to rotate. Nanoparticles in an aqueous solution were observed with an electron vortex beam to detect the transfer of orbital angular momentum in a low-friction environment. Observing the transfer of orbital angular momentum to particles in solution is difficult due to the necessity of imaging the particles through a liquid and the random movement of particles in the solution. Thus, orbital angular momentum transfer to matter could …
Building And Validating A Model For Investigating The Dynamics Of Isolated Water Molecules, Grant Cates
Building And Validating A Model For Investigating The Dynamics Of Isolated Water Molecules, Grant Cates
Senior Theses
Understanding how water molecules behave in isolation is vital to understand many fundamental processes in nature. To that end, scientists have begun studying crystals in which single water molecules become trapped in regularly occurring cavities in the crystal structure. As part of that investigation, numerical models used to investigate the dynamics of isolated water molecules are sought to help bolster our fundamental understanding of how these systems behave. To that end, the efficacy of three computational methods—the Euler Method, the Euler-Aspel Method and the Beeman Method—is compared using a newly defined parameter, called the predictive stability coefficient ρ. This …
A Study Of Anti-Muon-Neutrino Induced Resonance Production In Nomad Three-Track Topology, Edward Dunton
A Study Of Anti-Muon-Neutrino Induced Resonance Production In Nomad Three-Track Topology, Edward Dunton
Senior Theses
In this study we are attempting to measure the sensitivity of our methods to anti-muon neutrino induced resonance interactions in the 3-track topology of the NOMAD experiment. We will use a set of Monte Carlo data meant to resemble the NOMAD outputs but with true event type known and then proceed by using a system of single-variable cuts and multivariable analysis through a multilayer perception neural network to distinguish events from these interactions and events from other neutrino or non-neutrino interactions. We will then produce a measurement of the sensitivity to these interactions and determine whether or not proceeding with …
Expanded Parameters In The Self-Organized Critical Forest Fire Model, Riley Self
Expanded Parameters In The Self-Organized Critical Forest Fire Model, Riley Self
Senior Theses
The forest fire model has been used to test the theory of Self-Organized Criticality as a model of complexity. The goal is to search for scale invariance in randomly generated forest fires using a computer simulation. In a previous model by B. Drossel and F. Schwabl,1 power-law behavior was seen when the nearest neighbors to a tree on fire catch on fire, and it has been assumed that if further trees also catch fire, then it will still exhibit self-organized criticality, showing scale invariance. Testing this assumption aids to the exploration of the applicability of self-organized criticality because the …
Nonlinear Harmonic Modes Of Steel Strings On An Electric Guitar, Joel Wenrich
Nonlinear Harmonic Modes Of Steel Strings On An Electric Guitar, Joel Wenrich
Senior Theses
Steel strings used on electric and acoustic guitars are non-ideal oscillators that can produce imperfect intonation. According to theory, this intonation should be a function of the bending stiffness of the string, which is related to the dimensions of length and thickness of the string. To test this theory, solid steel strings of three different linear densities were analyzed using an oscilloscope and a Fast Fourier Transform function. We found that strings exhibited more drastic nonlinear harmonic behavior as their effective length was shortened and as linear density increased.
Modeling The Behavior Of The Graphene To Liquid Interfaces In An Electrolytic Liquid, Caitlin Duffner
Modeling The Behavior Of The Graphene To Liquid Interfaces In An Electrolytic Liquid, Caitlin Duffner
Senior Theses
Understanding the mechanism for charge transfer between a graphene biosensor and its electrodes within an electrolyte solution is vital to better understand the sources of electrical noise in the system. By measuring the effective resistance and capacitance of the system at different frequencies, it is possible to develop a circuit model of the system's electrical behavior. This model provides a deeper understanding of the fundamental interactions that occur in a top-gated graphene device and provides opportunities to improve a signal. To reduce noise created at the liquid to graphene interface, a buffer layer of Yttrium Oxide was applied. While the …
Effect Of Electrolyte Concentration On The Capacitance And Mobility Of Graphene, Flint A. Martino
Effect Of Electrolyte Concentration On The Capacitance And Mobility Of Graphene, Flint A. Martino
Senior Theses
The use of graphene field-effect transistors as a biosensor is increasingly being used to study biological phenomena, due to the sensitivity and low reactivity of graphene. To further improve sensitivity in biological environments, we examined how different salt concentrations affect the mobility of capacitance of the graphene. Samples were also measured after an annealing process. We report on the positive correlation between sensitivity and electrolyte concentration and speculate on methods to improve future detectors. Mobility of the device was found to change from 1.07*103cm2/ (V*s) in de-ionized water to 2.78*103cm2/ (V*s) in …
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. …
Searching To Distinguish Defects And The Presence Of Negative Capacitance, Thaddeus Cox
Searching To Distinguish Defects And The Presence Of Negative Capacitance, Thaddeus Cox
Senior Theses
In the search for solar cells with lower manufacturing costs, thin film technology was developed. These thin films are only micrometers thick and are grown at relatively low temperatures, resulting in films with imperfections known as defects. Defects can cause thin film solar cells to have lower efficiencies than their single crystalline counterparts. In order to create more efficient thin film solar cells the physical mechanisms behind defects need to be investigated by sensitive techniques. Capacitance measurements of solar cells detect minute changes in charge in the material. For that reason, capacitance is used to electrically characterize the solar cell. …
Modeling A Circuit That Represents An Electrolytic Solution At Different Concentrations, Daniel C. Miller Ii
Modeling A Circuit That Represents An Electrolytic Solution At Different Concentrations, Daniel C. Miller Ii
Senior Theses
Electrodes are often placed within bio samples in order to measure the electrical changes that occur within a system. In order to understand the information provided through the microelectrodes, this paper will describe an experiment to measure the capacitance and the resistance between two micro electrodes as an electrolyte becomes more concentrated. This resulted in a capacitance and a resistance that increased and decreased exponentially, respectively, as an electrolyte concentration increased logarithmically.
Protein Folding & Self-Organized Criticality, Arun Bajracharya
Protein Folding & Self-Organized Criticality, Arun Bajracharya
Senior Theses
Proteins are known to fold into tertiary structures that determine their functionality in living organisms. However, the complex dynamics of protein folding and the way they consistently fold into the same structures is unknown. Experimental studies of the folding process are difficult as proteins are made of more than one subunit and possess a high degree of conformational flexibility. Theoretically, self-organized criticality (SOC) has provided a framework for understanding complex systems in various scientific disciplines through scale invariance and the associated "fractal" power law behavior. Evidence of this criticality phenomena has been found in neural systems, cell cultures, and anesthetized …