Physics Commons^™

Neutral Density Behavior From 45-90 Km Based On Rayleigh Lidar Observations Above Usu, David Barton

Physics Capstone Projects

There are over 900 nights of observations taken by the Rayleigh lidar above Utah State University from 1993 to 2004. The data have been reduced to give absolute temperatures and relative densities in the mesosphere, from 45-90 km (Herron, 2004, 2007). From the 11 years of relative density data an 11-year climatology of mesospheric densities above Logan, Utah has been created. From this climatology I have been able to normalize the 11 years of density data to the following models: the MSISe00 empirical model, the CPC (Climate Prediction Center) reanalysis model, the ERA Interim reanalysis model, and the NASA MERRA …

Carbon Nanotube Sensors And Field Emitters, Ben Pound

Physics Capstone Projects

Carbon nanotube (CNT) forests are arrays of free-standing CNTs, as seen in Fig. 1a. The goal of this project was to deposit 1,5-diaminonaphthalene (DAN) evenly on each CNT. The motivation is that CNTs cannot effectively participate in chemical reactions by themselves. However, DAN can bind to the CNT surface in such a way that it can participate in chemical reactions while staying on the CNT side wall¹. If DAN could be coated evenly on the CNTs throughout the forest, it could make a very sensitive biological sensor. A sensor is only as good as the number of detection …

Creating Hertzprung-Russel Diagrams Of Open Clusters, Margaret Jensen

Physics Capstone Projects

This research project is meant to set up Utah State University’s 20 inch diameter telescope and use imaging techniques to do research science with stellar clusters. Using known information taken from stellar catalogues, open clusters will be selected to image. From the im- age, absolute magnitudes or luminocities will be collected from each star in the cluster using imaging software. We will then compare these to their spectral types, or tem- peratures, to create Hertzprung-Russell diagrams of the open clusters. A Hertzprung-Russell (H-R) diagram is a scatter plot of luminocity vs spectral type for stars. The following report will explain …

Rainich Geometrization Of Real Massless Scalar Fields, Dionisios Krongos

Physics Capstone Projects

Rainich geometrization is the process of eliminating the source from Einstein's field equations and thus expressing the equations solely with geometric quantities. This report briefly covers the theory, due to Kuchar, involved in the Rainich geometrization of a real massless scalar field with no cosmological constant. The theory contains the conditions which the Ricci tensor must satisfy such that the spacetime permits the scalar field and also explains the method used to reconstruct the field. Two procedures are written which automate this process and they are used extensively through the rest of the paper to both verify existing solutions, such …

Improved Measurements In Conductivity For Highly Disorganized Resistive Materials, Phil Lundgren

Physics Capstone Projects

Determining the electrical properties of highly insulating materials can be a challenging task. These materials are designed to greatly resist the flow of electrical current. This makes them useful for various applications including terrestrial transmission lines, spacecraft charging, and capacitor-driven charge storage devices. Every year over 370 billion kWhr are lost during transportation along power lines in the US. That is roughly $36B which is thrown away each year due to inefficiency in our power transmission network (1). Due to the fact that satellites are isolated from ground, charging caused by the plasma environment found at typical orbital radii (2) …

Analyzing Solutions To The Einstein Equations Using Differential Geometry, Jordan Rozum

Physics Capstone Projects

In part one, I walk through some examples using the Minkowski metric.

In part two, I continue analyzing the Minkowski metric by looking at its isometry algebra in more detail.

In part three, I go over how to use MetricSearch to retrieve cataloged metrics and analyze a couple of example metrics.

In part four, I provide the code, with minimal introduction, that I used to automate the procedures discussed in the previous tutorials.

Gaspacs Structure: Designing To Survive, John Ellis

Physics Capstone Projects

The USU Get Away Special (GAS) Team is creating a self-­‐stabilizing CubeSat through the utilization of a deploying boom and panel combination. Commercially available CubeSat frame cannot accommodate any deployable panels and have no space to fit a packed boom. Therefore a custom frame needed to be designed from the ground up to meet the mission needs while still conforming to the designated specifications produced by Cal Poly. The frame needs to be a 10 cm cube, hold together during liftoff, and not melt the avionics boards within the satellite. Several models were designed and tested through the use of …

Computational Modeling Of Doped Helium Clusters, Ryan Carlsen

Physics Capstone Projects

Prior to starting my coursework for this class, I had little experience in this area. I had done some related coursework in physical chemistry and computer science, but I had little direct experience. Thus, over the course of the year I learned very many things that are important to the research, but I did not reach a stage at which a lot of output occurred. Thus, in general this is a report of the things that I learned that will enable me to be effective in generating research output in the future, as I plan to continue participating int his …

High Precision Rapid Convergence Of Asian Options, Mario Y. Harper

Physics Capstone Projects

We show various methods that increase the precision and convergence speed of simulated stochastic processes. We demonstrate our precision and speed by using an example from the finance world, namely that of an Asian Option. An Asian Option is a path dependent pricing mechanism that is normally priced using Monte Carlo methods, it can be thought of as a path dependent diffusion equation. We show that the precision of the simulations is increased by 70% using Control Variates (derived by approximating the true mean from an analytic closed form solution). Using sequential Monte Carlo and parallel computing across a GPU …

Constructing A Flat Field For Scientific Astronomical Imaging, Catharine Bunn

Physics Capstone Projects

There are consistent problems that occur during the process of capturing astronomical images which cause defects to be present on the raw image captured. Some of these problems include vignetting, dust on the lens or the digital sensor’s surface, and dead or less sensitive pixels. This is a problem when the images are meant to be used in photometry, where the brightness of each pixel is taken into account. One can simply clean all surfaces of dust, but it will always come back. A more solid solution is to use a calibration frame called a “flat field” to correct each …

Soft Circuits: Improving Attitudes Toward Circuits Through Crafternoons, Darren Mckinnon

Physics Capstone Projects

Historically, STEM fields (science, technology, engineering, and mathematics) have shown to be less appealing to girls and women. In an attempt to appeal directly to females learning the science of circuits, Utah State University added a new soft circuits lab involving sewing circuits using conductive thread. Building upon the work of the Georgia Tech computing camps, attitude changes due to this soft circuits lab were studied. A Utah State University physics course for elementary education majors comprised the test group. The test group was largely comprised of females, who as a whole showed a significant positive response to building circuits …

Creating An Electronic Analog Of A Stomatal Network, David Berg

Physics Capstone Projects

Stomata are microscopic variable aperture pores on the surfaces of leaves. In response to different environmental stimuli, they control the exchange rate of both water vapor and carbon dioxide between the air and the leaf interior, making their role an important determination of the status of plant life on Earth. This study is based on a recently developed stomatal model in which the aperture size is governed by vapor phase humidity. The study describes an electronic analog of the stomatal unit; in it, current models water flow, a transistor represents the variable resistance of the stomatal aperture, capacitor voltages represent …

Diffusive Electron Heat Flow And Temperature Variance Along Magnetic Field Lines, Michael Kushlan

Physics Capstone Projects

In this research we examine how electron heat moves along magnetic field lines and how this affects temperature variations in plasmas. Specifically we wrote FORTRAN code to solve the electron temperature equation numerically. We also solved the steady state electron temperature equation analytically using an integrating factor. We verified that the numerical and analytical solutions obtained the same result. Finally we calculated the standard deviation of temperature in our domain for the steady state. Gaussian legendre quadrature was used to integrate various functions. We represented our magnetic field and heat source with Fourier series. The sin and cosine coefficients for …

A Study Of Anisotropic Chemical Etching On Crystalline Silicon, Gregory D. Erickson

Physics Capstone Projects

It is known that chemical reaction rates can be different on different crystal planes. KOH is a common etchant for Si and the reaction rate on {100} planes is much faster than the {111} planes. Therefore a square etch window on a (100) Si surface can become an inverse pyramid at some point after KOH etch. However, it is not clear how a 3-­‐dimensional cubic crystal will evolve by KOH etching. In this study we use a dicing saw to create arrays of rectangular crystal pillars of different dimensions in two different orientations followed by 6M KOH etch at 50º …