Physical Sciences and Mathematics Commons^™

Viscosity Dependence Of Faraday Wave Formation Thresholds, Lisa Michelle Slaughter

Physics

This experiment uses an electromagnetic shaker to produce standing wave patterns on the surface of a vertically oscillating sample of silicon liquid. These surface waves, known as Faraday waves, form shapes such as squares, lines, and hexagons. They are known to be dependent upon the frequency and amplitude of the forcing as well as on the viscosity and depth of the liquid in the dish. At a depth of 4mm and for various silicon liquids having kinematic viscosities of 10, 20, and 38 cSt, we determined the acceleration at which patterns form for frequencies between 10 and 60 Hz. For …

Time Variation Of The Broad Hβ And Hα Emission Lines In Active Galactic Nuclei, Bryan R. Scott

Physics

High-quality Keck/LRIS long-slit spectra for a sample of 97 active galaxies selected from the Sloan Digital Sky Survey (redshift between 0.02 & 0.1; Black Hole Mass approximately 10⁷ Solar Masses) were obtained between January 2009 and March 2010 in order to study the black hole (BH) mass scaling relation in the local universe. Typically, the width of the broad Hβ emission line is used to measure the mass of the black hole (MBH). However, signs of variability in the emission line profile are seen for eight objects: While broad Hβ emission lines had previously been observed in spectra from …

A Sub-Kpc-Scale Binary Active Galactic Nucleus With Double Narrow-Line Regions, Jong-Hak Woo, Hojin Cho, Bernd Husemann, S. Komossa, Daeseong Park, Vardha N. Bennert

Physics

We present the kinematic properties of a type-2 Quasi stellar object (QSO), SDSS J132323.33−015941.9 at z ∼ 0.35, based on the analysis of Very Large Telescope integral field spectroscopy and Hubble Space Telescope (HST) imaging, which suggest that the target is a binary active galactic nucleus (AGN) with double narrow-line regions. The QSO features double-peaked emission lines ([O iii] and Hβ) which can be decomposed into two kinematic components. The flux-weighted centroids of the blue and red components are separated by ∼0.2 arcsec (0.8 kpc in projection) and coincide with the location of the two stellar cores detected …

Investigating Fault Structure Using Electrical Resistivity Tomography, Sara Michelle Monahan

Physics

The resolving power of two-dimensional Direct Current (DC) Electrical Resistivity Tomography (ERT) is investigated in the context of shallow faults. Subsurface electrical resistivity data was collected perpendicular to a secondary fault scarp of the Los Osos Fault Zone with a Syscal KID Switch 24 resistivity meter and processed with Prosys II and Res2DInv software to produce two-dimensional cross sections of resistivity values via a smoothness-constrained least-squares optimization method. Comparison of ERT inversion results to a trench wall map of the same fault scarp suggest the location and dip direction of faults is resolvable, while detailed fault structure, such as dip …

Characterization Of Planar Wave Guides By Angle-Dependent Excitation Of Guided Modes, Edward D. Lunde

Physics

In this project a high resolution rotation stage was used to measure the angle of coupling of light into planar waveguide modes. Control of the stage and acquisition of light intensity data was done using the commercially available programming environment, MATLAB. Reliable, repeatable excitation of modes was done using prism coupling. We also investigated coupling using a surface grating on the waveguide.

Longitudinal Emittance Blowup In The Large Hadron Collider, P. Baudrenghien, T. Mastoridis

Physics

The Large Hadron Collider (LHC) relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blowup provides the required emittance growth. The method was implemented through the summer of 2010. Band-limited RF phase-noise is injected in the main accelerating cavities during the whole ramp of about 11 min. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are …

Bayesian Approach For Uncertainty Analysis Of An Urban Storm Water Model And Its Applications To A Heavily Urbanized Watershed, Misgana K. Muleta, Jonathan Mcmillan, Geremew G. Amenu, Steven J. Burian

Physics

The significance of uncertainty analysis (UA) to quantify reliability of model simulations is being recognized. Consequently, literature on parameter and predictive uncertainty assessment of water resources models has been rising. Applications dealing with urban drainage systems are, however, very limited. This study applies formal Bayesian approach for uncertainty analysis of a widely used storm water management model and illustrates the methodology using a highly urbanized watershed in the Los Angeles Basin, California. A flexible likelihood function that accommodates heteroscedasticity, non-normality, and temporal correlation of model residuals has been used for the study along with a Markov-chain Monte Carlo-based sampling scheme. …

Discovery Of An Eo-Meso-Neoarchean Terrane In The East Greenland Caledonides, Scott M. Johnston, Andrew R.C. Kylander-Clark

Physics

tThis study investigates basement gneisses from the Niggli Spids thrust sheet of the East Greenland Caledonides in an attempt to place them into the broader context of the Archean–Paleoproterozoicarchitecture of the Greenland shield. Our combined whole-rock geochemical and U–Pb zircon geochronol-ogy results from Gåseland reveal an Archean terrane defined by TTG magmatic events at 3607 Ma and3070–2980 Ma followed by metamorphism and high-K granite intrusion at 2790–2677 Ma. These results identify a relatively pristine Archean terrane with previously unknown Eoarchean rocks that holds poten-tial for future investigations into the early evolution of continental crust, and adds to a growing body …

Field Control Of The Surface Electroclinic Effect In Liquid Crystal Displays, Dana Hipolite

Physics

Liquid crystals (LCs) are a fascinating class of materials exhibiting a range of phases intermediate between liquid and crystalline. Smectic LCs consist of elongated molecules arranged in a periodic stack (along z) of liquid like layers. In the smectic-A (Sm-A) phase, the average molecular long axis (director) points along z. In the smectic-C (Sm-C) phase, it is tilted relative to z, thus picking out a special direction within the layers. Typically, the Sm-A* to Sm- C* transition will occur as temperature is decreased. In chiral smectics (Sm-*A or Sm-C*) it is possible to induce director titling (i.e. the Sm-C* phase) …

Contributions To The Cuore Collaboration, Samuel Joseph Meijer

Physics

This paper describes work done between 2010 and 2013 to contribute to the CUORE collaboration, a physics collaboration searching for neutrinoless double-beta decay in tellurium. Measurement of this decay would indicate fundamental information about the nature of the neutrino. The implementation of a parylene-coated detector frame is described. Also, a temperature stabilization system for an automated gluing system was constructed. An image recognition algorithm is described for locating spots of glue and evaluating their acceptability.

Counting Photons To Calibrate A Photometer For Stellar Intensity Interferometry, Jason Chew

Physics

We use a telescope and photometer to observe stellar photons and measure the rate of observed photons. Based on intensity spectra from the Spectrophotometric Catalogue of Stars, we also predict expected values for the photon rates, which we compare to our measurements. From this comparison, we measure the local optical depth to be τ = 0.60±0.25, a reasonable value. We find that our predictions are directly proportional to our measurements by a factor of 0.98 (+0.02, -0.27) . The similarity between our measurements and expectations shows that we are able to both predict and measure photon rates with accuracy.

The Lick Agn Monitoring Project 2011: Fe Ii Reverberation From The Outer Broad-Line Region, Aaron J. Barth, Anna Pancoast, Vardha N. Bennert, Brendon J. Brewer, Gabriela Canalizo, Alexei V. Filippenko, Elinor L. Gates, Jenny E. Greene, Weidong Li, Matthew A. Malkan, David J. Sand, Daniel Stern, Tommaso Treu, Jong-Hak Woo, Roberto J. Assef, Hyun-Jin Bae, Tabitha Buehler, S. Bradley Cenko, Kelsey I. Clubb, Michael C. Cooper, Aleksander M. Diamond-Stanic, Sebastian F. Hönig, Michael D. Joner, C. David Laney, Mariana S. Lazarova, A. M. Nierenberg, Jeffrey M. Silverman, Erik J. Tollerud, Jonelle L. Walsh

Physics

The prominent broad Fe ii emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe ii lines have met with only limited success. Here we report the detection of Fe ii reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including Hβ and Fe ii were measured by applying a fitting routine to decompose the spectra into …

Dynamics Of The Fitzhugh-Nagumo Neuron Model, Zechariah Thurman

Physics

In this paper, the dynamical behavior of the Fitzhugh-Nagumo model is examined. The relationship between neuron input current and the firing frequency of the neuron is characterized. Various coupling schemes are also examined, and their effects on the dynamics of the system is discussed. The phenomenon of stochastic resonance is studied for a single uncoupled Fitzhugh-Nagumo neuron.

Nbconvert Refactor, Jonathan Frederic

Physics

IPython is an interactive Python computing environment. It provides an enhanced interactive Python shell. The IPython Notebook is a browser based interface distributed with IPython. It enables the creation of richly formatted notebooks that contain embedded IPython code. With nbconvert, notebooks can be exported to various formats including, but not limited to, LaTeX, reveal.js, RST, and HTML. This is important for users that want to be able to share their work outside of IPython. This senior project is the addition of a Sphinx LaTeX output format and the refactor of nbconvert.

Tilt Angle And Birefringence Of Smectic Liquid Crystal Materials, Taylor Van Winkle

Physics

No abstract provided.

Organic Polymer Solar Cells: The Effects Of Device Packaging On Cell Lifetime, Spencer Herrick

Physics

As the earth runs out of nonrenewable energy sources and climate change starts to have drastic effects on the environment, the world is becoming increasingly desperate for cost efficient, renewable energy sources. Organic polymer based solar technology is a cutting edge approach to meeting the world’s energy demands. We fabricate single-layer, organic photovoltaics devices that utilize the electrical characteristics of semi-conductive polymers. These solution processable materials are beneficial due to their low material cost, lightweight, and simple fabrication requirements. Our devices utilize multiple photoactive polymers, P3HT and PCPDTBT, to absorb photons over a wide spectral range. We optimized various device …

Measuring The Refractive Index Of Infrared Materials By Dual-Wavelength Fabry-Perot Interferometry, Griffin Taylor

Physics

No abstract provided.

Analysis Of An Unusual Liquid Crystal Phase Transition, Loni Ann Fuller

Physics

Liquid crystals are a unique phase of matter that resemble a state between a solid and liquid. Within these properties, liquid crystal molecules have the ability to align and create layers. From this phenomenon, many electro-optical effects can be investigated, such as measuring the tilt angle between molecules at different temperatures and applied electric fields and also measuring the birefringence, which is a unique property of liquid crystals in which the index of refraction of the sample behaves differently along different axes. In order to better understand these electro- optical effects, we designed a more precise protocol of measuring this …

Determining The Location Of The Coronal Line Region Within Local Active Galactic Nuclei Using [Fe Vii] Emission Line Properties, Charles Grant Showley

Physics

Given a sample of 99 local AGNs, we study the characteristics of the forbidden [Fe VII] coronal line for the purpose of determining the location of the coronal line region (CLR) within the AGN. We calculate the velocity of the clouds emitting [Fe VII] using the width of the [Fe VII] emission lines compared to [O II] emission lines to establish whether the clouds are inflowing or outflowing. We plot the [Fe VII] and [O II] flux ratios against the AGNs' known black hole masses and stellar velocity dispersions in order to see if there are any correlations between them. …

Selecting Island Pixels With A Likelihood Ratio, Jordan Tweddale

Physics

A new method, called the Log Likelihood Ratio (LLR), was employed in place of a Signal-to-Noise Ratio (SNR) to pick out signal pixels on the VERITAS (Very Energetic Radiation Imaging Telescope Array System ) telescopes. The LLR test was performed on both photoelectrons and timing for VERITAS to select island pixels in Stage 2 cleaning, which is where the camera image is processed to determine which pixels on the camera are signal, and which are background. The two LLRs were combined to form a final LLR, which has a numerical cut, LLR = 11.5, between signal and background pixels. The …

An Inexpensive Scheffler Reflector For Developing Nations, Mike Kim

Physics

Scheffler reflectors are an appropriate solar technology used to provide heat for cooking surfaces and has been adopted in many developing nations. The first Scheffler was built in North America in 2010 by Jason Rapp et al., taking a group of four students approximately $2000 and 3 months. Thus, our task was to minimize certain aspects of the Scheffler construction process, so that it would be more appropriate for developing countries and industrial applications alike. Additionally, this senior project aims to incorporate the thermal storage unit and tracking system, with the current Scheffler system, to render a workable cooking technology. …

Update On Beam Induced Rf Heating In The Lhc, B. Salvant, O. Aberle, G. Arduini, R. Assmann, B. Baglin, M.J. Barnes, W. Bartmann, P. Baudrenghien, O. Berrig, C. Bracco, E. Bravin, G. Bregliozzi, R. Bruce, A. Bertarelli, F. Carra, G. Cattenoz, F. Caspers, S. Claudet, H. Day, M. Garlasche, L. Gentini, B. Goddard, A. Grudiev, B. Henrist, R. Jones, O. Kononenko, G. Lanza, L. Lari, T. Mastoridis, V. Mertens, E. Métral, N. Mounet, J.E. Muller, A.A. Nosych, J.L. Nougaret, S. Persichelli, A.M. Piguiet, S. Redaelli, F. Roncarolo, G. Rumolo, B. Salvachua, M. Sapinski, R. Schmidt, E. Shaposhnikova, L. Tavian, M. Timmins, J. Uythoven, A. Vidal, J. Wenninger, D. Wollmann, M. Zerlauth, P. Fassnacht, S. Jakobsen, M. Deile

Physics

Since June 2011 the rapid increase of the luminosity performance of the LHC has come at the expense of both increased temperature and pressure of specific, near-beam, LHC equipment. In some cases, this beam induced heating has caused delays while equipment cool-down, beam dumps and even degradation of some devices. This contribution gathers the observations of beam induced heating, attributed to longitudinal beam coupling impedance, their current level of understanding and possible actions planned to be implemented during the 1st LHC Long Shutdown (LS1) in 2013-2014.

Investigations Of The Lhc Emittance Blow-Up During The 2012 Proton Run, M. Kuhn, G. Arduini, P. Baudrenghien, J. Emery, A. Guerrero, W. Hofle, V. Kain, M. Lamont, T. Mastoridis, F. Roncarolo, M. Sapinski, M. Schaumann, R. Steinhagen, G. Trad, D. Valuch

Physics

About 30 % of the potential luminosity performance is lost through the different phases of the LHC cycle, mainly due to transverse emittance blow-up. Measuring the emittance growth is a difficult task with high intensity beams and changing energies. Improvements of the LHC transverse profile instrumentation helped to study various effects. A breakdown of the growth through the different phases of the LHC cycle is given as well as a comparison with the data from the LHC experiments for transverse beam size. In 2012 a number of possible sources and remedies have been studied. Among these are intra beam scattering, …

Search For 14.4 Kev Solar Axions From M1 Transition Of 57fe With Cuore Crystals, F. Alessandria, R Ardito, D. R. Artusa, F.T. Avignone Iii, O. Azzolini, M Balata, T.I. Banks, G. Bari, J. Beeman, F Bellini, A. Bersani, M. Biassoni, T. Bloxham, C Brofferio, C Bucci, X.Z. Cai, L. Canonica, S Capelli, L. Carbone, L. Cardani, M. Carrettoni, N. Casali, N. Chott, M Clemenza, C Cosmelli, O Cremonesi, R.J. Creswick, I Dafinei, A. Dally, V. Datskov, A. De Biasi, M.P. Decowski, M. M. Deninno, S Di Domizio, M.L. Di Vacri, L. Ejzak, R. Faccini, D.Q. Fang, H.A. Farach, E. Ferri, F Ferroni, E Fiorini, M.A. Franceschi, S.J. Freedman, B.K. Fujikawa, A Giachero, L. Gironi, A Giuliani, J. Goett, P Gorla, C. Gotti, E Guardincerri, T. D. Gutierrez, E.E. Haller, K. Han, K.M. Heeger, H.Z. Huang, R. Kadel, G. Keppel, L. Kogler, Yu. G. Kolomensky, D. Lenz, Y.L. Li, C. Ligi, X. Liu, Y.G. Ma, C. Maiano, M. Maino, M. Martinez, R.H. Maruyama, N. Moggi, S Morganti, T. Napolitano, S. Newman, S Nisi, C Nones, E.B. Norman, A Nucciotti, F. Orio, D. Orlandi, J.L. Ouellet, M Pallavicini, E. Palmieri, L. Pattavina, M Pavan, M Pedretti, G Pessina, S Pirro, E Previtali, V. Rampazzo, F. Rimondi, C Rosenfeld, C. Rusconi, S Sangiorgio, N.D. Scielzo, M Sisti, A.R. Smith, L. Taffarello, M. Tenconi, W.D. Tian, C. Tomei, S. Trentalange, G Ventura, M Vignati, B.S. Wang, H.W. Wang, C. A. Whitten Jr., T. Wise, A. Woodcraft, L Zanotti, C. Zarra, B.X. Zhu, S. Zucchelli

Physics

We report the results of a search for axions from the 14.4 keV M1 transition from ⁵⁷Fe in the core of the sun using the axio-electric effect in TeO₂bolometers. The detectors are 5

× 5 × 5 cm³ crystals operated at about 10 mK in a facility used to test bolometers for the CUORE experiment at the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 43.65 kg⋅d of data was made using a newly developed low energy trigger which was optimized to reduce the energy threshold of the detector. An upper limit of 0.58 …

Rapid Diffusion Of Electrons In Gamnas, Christopher P. Weber, Eric A. Kittlaus, Kassandra B. Mattia, Christopher J. Waight, J. Hagmann, X. Liu, M. Dobrowolska, J. K. Furdyna

Physics

We report ultrafast transient‐grating measurements, above and below the Curie temperature, of the dilute ferromagnetic semiconductor (Ga,Mn)As containing 6% Mn. At 80 K (15 K), we observe that photoexcited electrons in the conduction band have a lifetime of 8 ps (5 ps) and diffuse at about 70 cm²/s (60 cm²/s). Such rapid diffusion requires either an electronic mobility exceeding 7700 cm²/V s or a conduction‐band effective mass less than half the GaAs value. Our data suggest that neither the scattering rate nor the effective mass of the (Ga,Mn)As conduction band differs significantly from that …

Validation Of Techniques To Mitigate Copper Surface Contamination In Cuore, F. Alessandria, R. Ardito, D.R. Artusa, F.T. Avignone Iii, O. Azzolini, M. Balata, T.I. Banks, G. Bari, J. Beeman, F. Bellini, A. Bersani, M. Biassoni, T. Bloxham, C. Brofferio, C. Bucci, X.Z. Cai, L. Canonica, S. Capelli, L. Carbone, L. Cardani, M. Carrettoni, N. Casali, N. Chott, M. Clemenza, C. Cosmelli, O. Cremonesi, R.J. Creswich, I. Dafinei, A. Dally, V. Datskov, A. De Biasi, M.M. Deninno, S. Di Domizio, M.L. Di Vacri, L. Ejzak, R. Faccini, D.Q. Fang, H.A. Farach, E. Ferri, F. Ferroni, E. Fiorini, M.A. Franceschi, S.J. Freedman, B.K. Fujikawa, A. Giachero, L. Gironi, A. Giuliani, J. Goett, A. Goodsell, P. Gorla, C. Gotti, E. Guardincerri, T.D. Gutierrez, E.E. Haller, K. Han, K.M. Heeger, H.Z. Huang, R. Kadel, K. Kazkaz, G. Keppel, L. Kogler, Yu. G. Kolomensky, D. Lenz, Y.L. Li, C. Ligi, X. Liu, Y.G. Ma, C. Maiano, M. Maino, M. Martinez, R.H. Maruyama, Y. Mei, N. Moggi, S. Morganti, T. Napolitano, S. Newman, S. Nisi, C. Nones, E.B. Norman, A. Nucciotti, F. Orio, D. Orlandi, J.L. Ouellet, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, S. Pirro, E. Previtali, V. Rampazzo, R. Reil, F. Rimondi, C. Rosenfeld, C. Rusconi, S. Sangiorgio, N.D. Scielzo, M. Sisti, A.R. Smith, L. Sparks, F. Stivanello, L. Taffarello, M. Tenconi, W.D. Tian, C. Tomei, S. Trentalange, G. Ventura, M. Vignati, B.S. Wang, H.W. Wang, C.A. Whitten Jr, T. Wise, A. Woodcraft, L. Zanotti, C. Zarra, B.X. Zhu, S. Zucchelli

Physics

In this article we describe the background challenges for the CUORE experiment posed by surface contamination of inert detector materials such as copper, and present three techniques explored to mitigate these backgrounds. Using data from a dedicated test apparatus constructed to validate and compare these techniques we demonstrate that copper surface contamination levels better than 10⁻⁷- 10⁻⁸ Bq/cm² are achieved for ²³⁸U and ²³²Th. If these levels are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit on the number of background counts in the region of interest is 0.02–0.03 counts/keV/kg/y …

Modeling The Spectral Energy Distribution Of Mrk 421, Randall L. Oglesby

Physics

Blazars are astronomical objects thought to be powered by the release of gravitational energy by accretion of material into a supermassive black hole located in the central region of the host galaxy. Some AGN present strong relativistic outflows in the form of jets, with blazars being the particular subset whose jets are aligned with our line of sight. Even though blazars account for only a small fraction of all AGN, they are the dominant class source in the high-energy sky. In this thesis we study the spectral energy distribution of Mrk 421, a prototypical blazar. Using publicly available numerical code …

Michael's Awesome Italian Adventure (With A Bit Of Science, Too), Michael W. Haskin

Physics

This senior project will provide the reader with a brief background about neutrinos, neutrinoless double beta decay, and the CUORE experiment being constructed in the Gran Sasso National Laboratory in Assergi, Italy. The remainder of the paper will follow my experience working as an undergraduate researcher at the laboratory during the summer of 2012. It will discuss the process of performing a cool down with the CUORE-0 cryostat as well as quality assurance testing of Teflon spacers to be used in the CUORE towers.

Experimenting With Polymer Blend Solar Cells And Active Layer Thickness, Ryan Blumenthal

Physics

Bulk heterojunction organic photovoltaics utilize the electrical characteristics of semi-conductive polymers. These solution processable materials are beneficial because of their low material cost, light weight, and simple fabrication requirements. Our devices employ multiple photoactive polymers, P3HT and PCPDTBT, to absorb photons over a wide spectral range. We optimized various device characteristics including thickness and thermal anneal usage to reach a power conversion efficiency of 3.0% in AM1.5 sunlight. Device performance degrades over time due to atmospheric water and oxygen, prompting us to investigate device packaging to extend cell lifetime for additional testing.

The Extended Narrow-Line Region Of Two Type-I Quasi-Stellar Objects, Semyeong Oh, Jong-Hak Woo, Vardha N. Bennert, Bruno Jungwiert, Martin Haas, Christian Leipski, Marcus Albrecht

Physics

We investigate the narrow-line region (NLR) of two radio-quiet QSOs, PG1012+008 and PG1307+085, using high signal-to-noise spatially resolved long-slit spectra obtained with FORS1 at the Very Large Telescope. Although the emission is dominated by the point-spread function of the nuclear source, we are able to detect extended NLR emission out to several kiloparsec scales in both QSOs by subtracting the scaled central spectrum from outer spectra. In contrast to the nuclear spectrum, which shows a prominent blue wing and a broad line profile of the [Oiii] line, the extended emission reveals no clear signs of large-scale outflows. Exploiting the wide …