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Full-Text Articles in Physics

Stratified Turbulence In The Nearshore Coastal Ocean: Dynamics And Evolution In The Presence Of Internal Bores, Ryan K. Walter, Michael E. Squibb, C. Brock Woodson, Jeffrey R. Koseff, Stephen G. Monismith Dec 2014

Stratified Turbulence In The Nearshore Coastal Ocean: Dynamics And Evolution In The Presence Of Internal Bores, Ryan K. Walter, Michael E. Squibb, C. Brock Woodson, Jeffrey R. Koseff, Stephen G. Monismith

Physics

High-frequency measurements of stratified turbulence throughout the water column were collected over a 2 week period in the nearshore environment of southern Monterey Bay, CA, using a cabled observatory system and an underwater turbulence flux tower. The tower contained a vertical array of acoustic Doppler velocimeters and fast-response conductivity-temperature sensors, providing a nearly continuous data set of turbulent velocity and density fluctuations and a unique look into the stratified turbulence field. The evolution of various turbulence quantities and direct measurements of the vertical turbulent diffusivity is examined in the presence of nearshore internal bores, both in the near-bed region and ...


Exploring The Neutrinoless Double Beta Decay In The Inverted Neutrino Hierarchy With Bolometric Detectors, D.R. Artusa, F.T. Avignone Iii, O. Azzolini, M. Balata, T.I. Banks, G. Bari, J. Beeman, F. Bellini, A. Bersani, M. Biassoni, C. Brofferio, C. Bucci, X.Z. Cai, A. Camacho, L. Canonica, X.G. Cao, S. Capelli, L. Carbone, L. Cardani, M. Carrettoni, N. Casali, D. Chiesa, N. Chott, M. Clemenza, C. Cosmelli, O. Cremonesi, R.J. Creswick, I. Dafinei, A. Dally, V. Datskov, A. De Biasi, M.M. Deninno, S. Di Domizio, M.L. Di Vacri, L. Ejzak, D.Q. Fang, H.A. Farach, M. Faverzani, G. Fernandes, 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, T.D. Gutierrez, E.E. Haller, K. Han, K.M. Heeger, R. Hennings-Yeomans, H.Z. Huang, R. Kadel, K. Kazkaz, G. Keppel, Yu. G. Kolomensky, 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. Nisi, C. Nones, E.B. Norman, A. Nucciotti, T. O'Donnell, F. Orio, D. Orlandi, J.L. Ouellet, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, V. Pettinacci, G. Piperno, C. Pira, S. Pirro, E. Previtali, V. Rampazzo, C. Rosenfeld, C. Rusconi, E. Sala, S. Sangiorgio, N.D. Scielzo, M. Sisti, A.R. Smith, L. Taffarello, M. Tenconi, F. Terranova, W.D. Tian, C. Tomei, S. Trentalange, G. Ventura, M. Vignati, B.S. Wang, H.W. Wang, L. Wielgus, J. Wilson, L.A. Winslow, T. Wise, A. Woodcraft, L. Zanotti, C. Zarra, B.X. Zhu, S. Zucchelli Oct 2014

Exploring The Neutrinoless Double Beta Decay In The Inverted Neutrino Hierarchy With Bolometric Detectors, D.R. Artusa, F.T. Avignone Iii, O. Azzolini, M. Balata, T.I. Banks, G. Bari, J. Beeman, F. Bellini, A. Bersani, M. Biassoni, C. Brofferio, C. Bucci, X.Z. Cai, A. Camacho, L. Canonica, X.G. Cao, S. Capelli, L. Carbone, L. Cardani, M. Carrettoni, N. Casali, D. Chiesa, N. Chott, M. Clemenza, C. Cosmelli, O. Cremonesi, R.J. Creswick, I. Dafinei, A. Dally, V. Datskov, A. De Biasi, M.M. Deninno, S. Di Domizio, M.L. Di Vacri, L. Ejzak, D.Q. Fang, H.A. Farach, M. Faverzani, G. Fernandes, 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, T.D. Gutierrez, E.E. Haller, K. Han, K.M. Heeger, R. Hennings-Yeomans, H.Z. Huang, R. Kadel, K. Kazkaz, G. Keppel, Yu. G. Kolomensky, 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. Nisi, C. Nones, E.B. Norman, A. Nucciotti, T. O'Donnell, F. Orio, D. Orlandi, J.L. Ouellet, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, V. Pettinacci, G. Piperno, C. Pira, S. Pirro, E. Previtali, V. Rampazzo, C. Rosenfeld, C. Rusconi, E. Sala, S. Sangiorgio, N.D. Scielzo, M. Sisti, A.R. Smith, L. Taffarello, M. Tenconi, F. Terranova, W.D. Tian, C. Tomei, S. Trentalange, G. Ventura, M. Vignati, B.S. Wang, H.W. Wang, L. Wielgus, J. Wilson, L.A. Winslow, T. Wise, A. Woodcraft, L. Zanotti, C. Zarra, B.X. Zhu, S. Zucchelli

Physics

Neutrinoless double beta decay (0νββ" style="position: relative;" tabindex="0" id="MathJax-Element-1-Frame">0νββ) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0νββ" style="position: relative;" tabindex="0" id="MathJax-Element-2-Frame">0νββ decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric 0νββ ...


Fluid-Induced Propulsion Of Rigid Particles In Wormlike Micellar Solutions, David A. Gagnon, Nathan C. Keim, Xiaoning Shen, Paulo E. Arratia Oct 2014

Fluid-Induced Propulsion Of Rigid Particles In Wormlike Micellar Solutions, David A. Gagnon, Nathan C. Keim, Xiaoning Shen, Paulo E. Arratia

Physics

In the absence of inertia, a reciprocal swimmer achieves no net motion in a viscous Newtonian fluid. Here, using tracking methods and birefringence imaging, we investigate the ability of a reciprocally actuated particle to translate through a complex fluid that possesses a network. A geometrically polar particle, a rod with a bead on one end, is reciprocally rotated using magnetic fields. The particle is immersed in a wormlike micellar (WLM) solution that is known to be susceptible to the formation of shear bands and other localized structures due to shear-induced remodeling of its microstructure. Results show that the nonlinearities present ...


Undulatory Swimming In Shear-Thinning Fluids: Experiments With C. Elegans, David A. Gagnon, Nathan C. Keim, Paulo E. Arratia Sep 2014

Undulatory Swimming In Shear-Thinning Fluids: Experiments With C. Elegans, David A. Gagnon, Nathan C. Keim, Paulo E. Arratia

Physics

The swimming behaviour of microorganisms can be strongly influenced by the rheology of their fluid environment. In this manuscript, we experimentally investigate the effects of shear-thinning viscosity on the swimming behaviour of an undulatory swimmer, the nematode Caenorhabditis elegans. Tracking methods are used to measure the swimmer’s kinematic data (including propulsion speed) and velocity fields. We find that shear-thinning viscosity modifies the velocity fields produced by the swimming nematode but does not modify the nematode’s speed and beating kinematics. Velocimetry data show significant enhancement in local vorticity and circulation, and an increase in fluid velocity near the nematode ...


Spatially Resolved Spectra Of The “Teacup” Active Galactic Nucleus: Tracing The History Of A Dying Quasar, J.P. Gagne, D.M. Crenshaw, S.B. Kraemer, H.R. Schmitt, W.C. Keel, S. Rafter, T.C. Fischer, K. Schawinski, V.N Bennert Sep 2014

Spatially Resolved Spectra Of The “Teacup” Active Galactic Nucleus: Tracing The History Of A Dying Quasar, J.P. Gagne, D.M. Crenshaw, S.B. Kraemer, H.R. Schmitt, W.C. Keel, S. Rafter, T.C. Fischer, K. Schawinski, V.N Bennert

Physics

The Sloan Digital Sky Survey (SDSS) Galaxy Zoo project has revealed a number of spectacular galaxies possessing extended emission-line regions (EELRs), the most famous being Hanny’s Voorwerp galaxy. We present another EELR object discovered in the SDSS endeavor: the Teacup active galactic nucleus (AGN). Nicknamed for its EELR, which has a “handle”-like structure protruding 15 kpc into the northeast quadrant of the galaxy. We analyze the physical conditions of this galaxy with long-slit, ground-based spectroscopy from the Lowell, Lick, and KPNO observatories. With the Lowell 1.8 m Perkin’s telescope we took multiple observations at different offset ...


First Cuore-0 Performance Results And Status Of Cuore Experiment, L. Canonica, D.R. Artusa, F.T. Avignone Iii, N. Chott, R.J. Crewick, H.A. Farach, S. Newman, C. Rosenfeld, J. Wilson, O. Azzolini, A. Camacho, A. De Biasi, G. Keppel, V. Palmieri, C. Pira, V. Rampazzo, T.I. Banks, S.J. Freedman, L. Kogler, Yu. G. Kolomensky, T. O'Donnell, J.L. Ouellet, T. Bloxham, B.K. Fujikawa, K. Han, Y. Mei, G. Bari, M.M. Deninno, N. Moggi, F. Rimondi, S. Zucchelli, J. Beeman, E.E. Haller, F. Bellini, L. Cardani, C. Cosmelli, R. Faccini, F. Ferroni, G. Piperno, I. Dafinei, S. Morganti, F. Orio, C. Tomei, M. Vignati, A. Bersani, S. Didomizio, G. Fernandes, M. Pallavicini, M. Biassoni, C. Brofferio, S. Capelli, M. Carrettoni, D. Chiesa, M. Clemenza, M. Faverzani, E. Ferri, E. Fiorini, A. Giachero, L. Gironi, C. Gotti, C. Miaino, M. Maino, A. Nucciotti, M. Pavan, E. Sala, M. Sisti, L. Zanotti, L. Carbone, O. Cremonesi, V. Datskov, G. Pessina, S. Pirro, E. Previtali, C. Rusconi, F. Terranova, X.Z. Cai, X. Cao, D.Q. Fang, Y.L. Li, Y.G. Ma, W.D. Tian, H.W. Wang, A. Dally, L. Ejzak, K.M. Heeger, D. Lenz, R.H. Maruyama, L. Wielgus, T. Wise, M.A. Franceschi, C. Ligi, T. Napolitano, A. Guiliani, M. Tenconi, T. D. Gutierrez, E.E. Haller, H.Z. Huang, X. Liu, S. Trentalange, B.X. Zhu, R. Kadel, Yu.G. Kolomensky, K. Kazkaz, E.B. Norman, M. Pedretti, S. Sangiorgio, N.D. Scielzo, B.S. Wang, M. Martinez, C. Nones, F. Rimondi, S. Zucchelli, A.R. Smith, L. Taffarello, G. Ventura, A. Woodcraft Sep 2014

First Cuore-0 Performance Results And Status Of Cuore Experiment, L. Canonica, D.R. Artusa, F.T. Avignone Iii, N. Chott, R.J. Crewick, H.A. Farach, S. Newman, C. Rosenfeld, J. Wilson, O. Azzolini, A. Camacho, A. De Biasi, G. Keppel, V. Palmieri, C. Pira, V. Rampazzo, T.I. Banks, S.J. Freedman, L. Kogler, Yu. G. Kolomensky, T. O'Donnell, J.L. Ouellet, T. Bloxham, B.K. Fujikawa, K. Han, Y. Mei, G. Bari, M.M. Deninno, N. Moggi, F. Rimondi, S. Zucchelli, J. Beeman, E.E. Haller, F. Bellini, L. Cardani, C. Cosmelli, R. Faccini, F. Ferroni, G. Piperno, I. Dafinei, S. Morganti, F. Orio, C. Tomei, M. Vignati, A. Bersani, S. Didomizio, G. Fernandes, M. Pallavicini, M. Biassoni, C. Brofferio, S. Capelli, M. Carrettoni, D. Chiesa, M. Clemenza, M. Faverzani, E. Ferri, E. Fiorini, A. Giachero, L. Gironi, C. Gotti, C. Miaino, M. Maino, A. Nucciotti, M. Pavan, E. Sala, M. Sisti, L. Zanotti, L. Carbone, O. Cremonesi, V. Datskov, G. Pessina, S. Pirro, E. Previtali, C. Rusconi, F. Terranova, X.Z. Cai, X. Cao, D.Q. Fang, Y.L. Li, Y.G. Ma, W.D. Tian, H.W. Wang, A. Dally, L. Ejzak, K.M. Heeger, D. Lenz, R.H. Maruyama, L. Wielgus, T. Wise, M.A. Franceschi, C. Ligi, T. Napolitano, A. Guiliani, M. Tenconi, T. D. Gutierrez, E.E. Haller, H.Z. Huang, X. Liu, S. Trentalange, B.X. Zhu, R. Kadel, Yu.G. Kolomensky, K. Kazkaz, E.B. Norman, M. Pedretti, S. Sangiorgio, N.D. Scielzo, B.S. Wang, M. Martinez, C. Nones, F. Rimondi, S. Zucchelli, A.R. Smith, L. Taffarello, G. Ventura, A. Woodcraft

Physics

The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay in 130" style="position: relative;" tabindex="0" id="MathJax-Element-1-Frame">130Te. Observation of the process would unambiguously establish that neutrinos are Majorana particles as well as provide information about the absolute neutrino mass scale and mass hierarchy.The CUORE setup will consist of an array of 988 tellurium dioxide crystals (containing 206 kg of 130" style="position: relative;" tabindex="0" id="MathJax-Element-2-Frame">130Te in total), operated as bolometers at a temperature of ∼" style="position: relative;" tabindex="0" id="MathJax-Element-3-Frame">∼10 mK. The experiment is now ...


Multiple Transient Memories In Experiments On Sheared Non-Brownian Suspensions, Joseph D. Paulsen, Nathan Keim, Sidney R. Nagel Aug 2014

Multiple Transient Memories In Experiments On Sheared Non-Brownian Suspensions, Joseph D. Paulsen, Nathan Keim, Sidney R. Nagel

Physics

A system with multiple transient memories can remember a set of inputs but subsequently forgets almost all of them, even as they are continually applied. If noise is added, the system can store all memories indefinitely. The phenomenon has recently been predicted for cyclically sheared non-Brownian suspensions. Here we present experiments on such suspensions, finding behavior consistent with multiple transient memories and showing how memories can be stabilized by noise.


Transcritical Generation Of Nonlinear Internal Waves In The Presence Of Background Shear Flow, Marek Stastna, Ryan Walter Aug 2014

Transcritical Generation Of Nonlinear Internal Waves In The Presence Of Background Shear Flow, Marek Stastna, Ryan Walter

Physics

While the occurrence of large amplitude internal waves in the Earth's natural bodies of water is widely documented, the generation of these waves remains an active area of exploration. We discuss numerical simulations of transcritical flows of a density stratified fluid with a dual focus on the role of a background shear current and transitions of the background current from super to subcritical. We demonstrate that the presence of a background shear can lead to the formation of large quasi-trapped regions of high vorticity over the downstream slope of the topography, but that this vorticity leads to only moderate ...


Initial Performance Of The Cuore-0 Experiment, D.R. Artusa, F.T. Avignone Iii, O. Azzolini, M. Balata, T.I. Banks, G. Bari, J. Beeman, F. Bellini, A. Bersani, M. Biassoni, C. Brofferio, C. Bucci, X.Z. Cai, L. Canonica, X.G. Cao, S. Capelli, L. Carbone, L. Cardani, M. Carrettoni, N. Casali, D. Chiesa, N. Chott, M. Clemenza, C. Cosmelli, O. Cremonesi, R.J. Creswick, I. Dafinei, A. Dally, V. Datskov, M.M. Deninno, S. Di Domizio, M.L. Di Vacri, L. Ejzak, D.Q. Fang, H.A. Farach, M. Facerzani, G. Fernandes, E. Ferri, F. Ferroni, E. Fiorini, S.J. Freedman, B.K. Fujikawa, A. Giachero, L. Gironi, A. Guiliani, J. Goett, P. Gorla, C. Gotti, T. D. Gutierrez, E.E. Haller, K. Han, K.M. Heeger, R. Hennings-Yeomans, H.Z. Huang, R. Kadel, K. Kazkaz, G. Keppel, Yu.G. Kolomensky, Y.L. Li, K.E. Lim, X. Liu, Y.G. Ma, C. Maiano, M. Maino, M. Martinez, R.H. Maruyama, Y. Mei, N. Moggi, S. Morganti, S. Nisi, C. Nones, E.B. Norman, A. Nucciotti, T. O'Donnell, F. Orio, D. Orlandi, J.L. Ouellet, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, V. Pettinacci, G. Piperno, S. Pirro, E. Previtali, C. Rosenfeld, E. Sala, S. Sangiorgio, N.D. Scielzo, M. Sisti, A.R. Smith, L. Taffarello, M. Tenconi, F. Terranova, W.D. Tian, C. Tomei, S. Trentalange, G. Ventura, M. Vignati, B.S. Wang, H.W. Wang, L. Wielgus, J. Wilson, L.A. Winslow, T. Wise, L. Zanotti, C. Zarra, B.X. Zhu, S. Zucchelli Aug 2014

Initial Performance Of The Cuore-0 Experiment, D.R. Artusa, F.T. Avignone Iii, O. Azzolini, M. Balata, T.I. Banks, G. Bari, J. Beeman, F. Bellini, A. Bersani, M. Biassoni, C. Brofferio, C. Bucci, X.Z. Cai, L. Canonica, X.G. Cao, S. Capelli, L. Carbone, L. Cardani, M. Carrettoni, N. Casali, D. Chiesa, N. Chott, M. Clemenza, C. Cosmelli, O. Cremonesi, R.J. Creswick, I. Dafinei, A. Dally, V. Datskov, M.M. Deninno, S. Di Domizio, M.L. Di Vacri, L. Ejzak, D.Q. Fang, H.A. Farach, M. Facerzani, G. Fernandes, E. Ferri, F. Ferroni, E. Fiorini, S.J. Freedman, B.K. Fujikawa, A. Giachero, L. Gironi, A. Guiliani, J. Goett, P. Gorla, C. Gotti, T. D. Gutierrez, E.E. Haller, K. Han, K.M. Heeger, R. Hennings-Yeomans, H.Z. Huang, R. Kadel, K. Kazkaz, G. Keppel, Yu.G. Kolomensky, Y.L. Li, K.E. Lim, X. Liu, Y.G. Ma, C. Maiano, M. Maino, M. Martinez, R.H. Maruyama, Y. Mei, N. Moggi, S. Morganti, S. Nisi, C. Nones, E.B. Norman, A. Nucciotti, T. O'Donnell, F. Orio, D. Orlandi, J.L. Ouellet, M. Pallavicini, V. Palmieri, L. Pattavina, M. Pavan, M. Pedretti, G. Pessina, V. Pettinacci, G. Piperno, S. Pirro, E. Previtali, C. Rosenfeld, E. Sala, S. Sangiorgio, N.D. Scielzo, M. Sisti, A.R. Smith, L. Taffarello, M. Tenconi, F. Terranova, W.D. Tian, C. Tomei, S. Trentalange, G. Ventura, M. Vignati, B.S. Wang, H.W. Wang, L. Wielgus, J. Wilson, L.A. Winslow, T. Wise, L. Zanotti, C. Zarra, B.X. Zhu, S. Zucchelli

Physics

CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers to search for neutrinoless double-beta decay of 130Te" style="position: relative;" tabindex="0" id="MathJax-Element-1-Frame">130Te. We present the first data analysis with 7.1kg⋅y" style="position: relative;" tabindex="0" id="MathJax-Element-2-Frame">7.1kg⋅y of total TeO2" style="position: relative;" tabindex="0" id="MathJax-Element-3-Frame">TeO2 exposure focusing on background measurements and energy resolution. The background rates in the neutrinoless double-beta decay region of interest (2.47 to 2.57MeV" style="position: relative;" tabindex="0" id="MathJax-Element-4-Frame">2.57MeV) and in the α" style="position: relative ...


Tuffoam Density Variation Through Radiography, Sergio Contreras Esquivel Aug 2014

Tuffoam Density Variation Through Radiography, Sergio Contreras Esquivel

STAR (STEM Teacher and Researcher) Presentations

TufFoam is a low density, high impact tolerant polyurethane foam with good high voltage breakdown developed at the Sandia National Laboratories. Identically shaped samples have been produced with various formulations and production conditions. Eight different variables were studied. Our aim is to compare the density variation of the material when produced and processed under distinct conditions. The density of TufFoam is determined using radiographic imaging. We extract the foam density by fitting the radiographic density of each step in a plastic step wedge with 10 steps from 0.1 to 1.0 inches and applying the resulting equation to convert ...


Particle Image Velocimetry Of Transverse Jets In Crossflow, Jesse K. Tsai, Kayla Kuzmich, David Forliti, Kriss Vanderhyde, Nils Sedano Aug 2014

Particle Image Velocimetry Of Transverse Jets In Crossflow, Jesse K. Tsai, Kayla Kuzmich, David Forliti, Kriss Vanderhyde, Nils Sedano

STAR (STEM Teacher and Researcher) Presentations

The jet in crossflow (JICF) has been an ongoing study for the past several decades with applications in the field of fluid mechanics. This particular flow field produces vortical structures tied to the entrainment and mixing of two separate fluids. Research of the JICF seeks to determine a model and trajectory scaling law for future designs. This will help future designers to optimize the mixing and homogeneity of the two fluids to decrease emissions from pollutants, make ignition easier, and improve combustion efficiency of rockets.

Our experiment will employ Particle Image Velocimetry (PIV) to determine the fluid motion of the ...


Environmental Testing Of Lasers For Jpl's Cold Atom Laboratory, Carey L. Baxter Aug 2014

Environmental Testing Of Lasers For Jpl's Cold Atom Laboratory, Carey L. Baxter

STAR (STEM Teacher and Researcher) Presentations

NASA’s Cold Atom Lab (CAL) is a multi-user facility designed to study ultra-cold quantum gases in the microgravity environment of the International Space Station (ISS). One of the main goals of CAL is to explore the unknown territory of extremely low temperatures—possibly as low as the picokelvin range!—where new and fascinating quantum phenomena can be observed. At such temperatures matter stops behaving as particles and instead becomes macroscopic matter waves. CAL will be remotely controlled to perform a multitude of experiments and is scheduled to launch in 2016. In order to anticipate problems that might occur during ...


A Prototype Microwave Cavity Control Circuit For Use In Next Generation Free Electron Laser, Josh Thompson, Peter Neal Barrina, Jiayi Jiang, Joe Frisch, Steve Smith, Daniel Van Winkle Aug 2014

A Prototype Microwave Cavity Control Circuit For Use In Next Generation Free Electron Laser, Josh Thompson, Peter Neal Barrina, Jiayi Jiang, Joe Frisch, Steve Smith, Daniel Van Winkle

STAR (STEM Teacher and Researcher) Presentations

One of the current programs at SLAC National Accelerator Laboratory is the Linac Coherent Light Source, or LCLS. Using the existing hardware of the last third of their linear accelerator (or “linac”), SLAC has created one of the most energetic X-ray free electron lasers (or “FEL”). Since 2009, LCLS has used this FEL to perform a wide range of experiments across all sciences, most notably ultrafast filming at the molecular scale. As requests for beam-time with this laser increases, SLAC is purposing a linac upgrade to better match this demand. This upgrade, named LCLS-II, will replace existing copper radio frequency ...


Laser Frequency Stabilization For Lisa, Andrew B. Parker, Andrew J. Sutton, Glenn De Vine Aug 2014

Laser Frequency Stabilization For Lisa, Andrew B. Parker, Andrew J. Sutton, Glenn De Vine

STAR (STEM Teacher and Researcher) Presentations

This research focuses on laser ranging developments for LISA (Laser Interferometer Space Antenna), a planned NASA-ESA gravitational wave detector in space. LISA will utilize precision laser interferometry to track the changes in separation between three satellites orbiting 5 million kilometers apart. Specifically, our goal is to investigate options for laser frequency stabilization. Previous research has shown that an optical cavity system can meet LISA's stability requirements, but these units are large and heavy, adding cost to the implementation. A heterodyne Mach-Zehnder interferometer could be integrated onto LISA’s existing optical bench, greatly reducing the weight, provided the interferometer meets ...


Exploring Soil Moisture Protocol Alternatives For The Classroom Setting, Garrett Smith Aug 2014

Exploring Soil Moisture Protocol Alternatives For The Classroom Setting, Garrett Smith

STAR (STEM Teacher and Researcher) Presentations

Climate change poses a direct threat to future water resources but current climate models suffer from uncertainties regarding the availability of regional water. SMAP or the Soil Moisture Active Passive mission seeks to make improvements to climate models by taking highly accurate, high resolution measurements of global soil moisture. To engage students around the world in a collection of meaningful data that may support the SMAP satellite mission, the Global Learning and Observations to Benefit the Environment program or GLOBE, has forged a partnership with NASA and JPL. GLOBE brings the power of citizen science to the SMAP mission, empowering ...


Maximizing Precision Of Variable Star Photometry With Digital Cameras In Suburban Environments, David Hergesheimer Aug 2014

Maximizing Precision Of Variable Star Photometry With Digital Cameras In Suburban Environments, David Hergesheimer

STAR (STEM Teacher and Researcher) Presentations

Photometry is the measure of the brightness of an object. When making such measurements on stars, it is done is units of magnitude, which is on a logarithmic scale with a base of ~2.512. Variable star photometry using a commercially available digital camera is not going to be as accurate and precise as equipment used by astronomers, and because of the logarithmic scale of magnitude used, determining how much of an effect different error reduction strategies have is not straightforward, and is best done experimentally.

My research is conducting photometry on variable stars (changing brightness) with a digital camera ...


Does A Plastron Improve Heat Transfer?, Madani A. Khan, Jeffrey Alston, Andrew Guenthner Aug 2014

Does A Plastron Improve Heat Transfer?, Madani A. Khan, Jeffrey Alston, Andrew Guenthner

STAR (STEM Teacher and Researcher) Presentations

Superamphiphobic surfaces strongly repel both water and oils. In this work, aluminum coupons are processed by sanding with various grit of sand paper to impart microscale roughness. Subsequent submersion of the aluminum substrate in boiling water grows nanoscale grass-like structures. The oxide layer of Al is slightly soluble in water. During a fast diffusion/equilibrium, Al2O3 nanograss grows on the surface. A low energy coating is then deposited on the surface. The micro and nanoscale features create re-entrant structures that trap air enabling contact liquid to be in a Cassie-Baxter state. Superamphiphobicity of the samples were confirmed ...


Calculating And Visualizing The Density Of States For Simple Quantum Mechanical Systems, Declan Mulhall, Matthew J. Moelter Jul 2014

Calculating And Visualizing The Density Of States For Simple Quantum Mechanical Systems, Declan Mulhall, Matthew J. Moelter

Physics

We present a graphical approach to understanding the degeneracy, density of states, and cumulative state number for some simple quantum systems. By taking advantage of basic computing operations, we define a straightforward procedure for determining the relationship between discrete quantum energy levels and the corresponding density of states and cumulative level number. The density of states for a particle in a rigid box of various shapes and dimensions is examined and graphed. It is seen that the dimension of the box, rather than its shape, is the most important feature. In addition, we look at the density of states for ...


Connecting Wind-Driven Upwelling And Offshore Stratification To Nearshore Internal Bores And Oxygen Variability, Ryan K. Walter, C. Brock Woodson, Paul R. Leary, Stephen G. Monismith Jun 2014

Connecting Wind-Driven Upwelling And Offshore Stratification To Nearshore Internal Bores And Oxygen Variability, Ryan K. Walter, C. Brock Woodson, Paul R. Leary, Stephen G. Monismith

Physics

This study utilizes field observations in southern Monterey Bay, CA, to examine how regional-scale upwelling and changing offshore (shelf) conditions influence nearshore internal bores. We show that the low-frequency wind forcing (e.g., upwelling/relaxation time scales) modifies the offshore stratification and thermocline depth. This in turn alters the strength and structure of observed internal bores in the near-shore. An internal bore strength index is defined using the high-pass filtered potential energy density anomaly in the nearshore. During weak upwelling favorable conditions and wind relaxations, the offshore thermocline deepens. In this case, both the amplitude of the offshore internal tide ...


Nonlinear Internal Waves, Internal Bores, And Turbulent Mixing In The Nearshore Coastal Environment, Ryan K. Walter Jun 2014

Nonlinear Internal Waves, Internal Bores, And Turbulent Mixing In The Nearshore Coastal Environment, Ryan K. Walter

Physics

The nearshore coastal environment is generally taken to be one of the most productive and ecologically important parts of the ocean. The nearshore is also a complex environment from a physical standpoint, due in large part to the widespread and often irregular occurrence of nonlinear internal waves (NLIWs) that frequently appear more bore-like than wave-like. Indeed, this region of the ocean can be thought of as the “swash zone” for larger-scale internal wave fields on the continental shelf. These nearshore NLIWs and bores have considerable implications for the cross-shelf exchange and transport of nutrients, sediments, contaminants, larvae, and other scalars ...


Preface: Nuclear Weapon Issues In The 21st Century, Pierce Corden, David Hafemeister, Peter Zimmerman May 2014

Preface: Nuclear Weapon Issues In The 21st Century, Pierce Corden, David Hafemeister, Peter Zimmerman

Physics

No abstract provided.


Primer On Nuclear Exchange Models, David W. Hafemeister May 2014

Primer On Nuclear Exchange Models, David W. Hafemeister

Physics

Basic physics is applied to nuclear force exchange models between two nations. Ultimately, this scenario approach can be used to try and answer the age old question of "how much is enough?" This work is based on Chapter 2 of Physics of Societal Issues: Calculations on National Security, Environment and Energy (Springer, 2007 and 2014).


Appendix A: Nuclear Arms Chronology, David Hafemeister May 2014

Appendix A: Nuclear Arms Chronology, David Hafemeister

Physics

No abstract provided.


Nuclear Proliferation And Testing: A Tale Of Two Treaties, Pierce S. Corden, David Hafemeister Apr 2014

Nuclear Proliferation And Testing: A Tale Of Two Treaties, Pierce S. Corden, David Hafemeister

Physics

Despite progress in reducing stockpiles after the end of the Cold War, the disturbing actions of some nations could spread nuclear weapon capabilities and enlarge existing arsenals.


Mechanical And Microscopic Properties Of The Reversible Plastic Regime In A 2d Jammed Material, Nathan C. Keim, Paulo E. Arratia Jan 2014

Mechanical And Microscopic Properties Of The Reversible Plastic Regime In A 2d Jammed Material, Nathan C. Keim, Paulo E. Arratia

Physics

At the microscopic level, plastic flow of a jammed, disordered material consists of a series of particle rearrangements that cannot be reversed by subsequent deformation. An infinitesimal deformation of the same material has no rearrangements. Yet between these limits, there may be a self-organized plastic regime with rearrangements, but with no net change upon reversing a deformation. We measure the oscillatory response of a jammed interfacial material, and directly observe rearrangements that couple to bulk stress and dissipate energy, but do not always give rise to global irreversibility.


An Introduction To The Inverse Quantum Bound-State Problem In One Dimension, Thomas D. Gutierrez Jan 2014

An Introduction To The Inverse Quantum Bound-State Problem In One Dimension, Thomas D. Gutierrez

Physics

A technique to reconstruct one-dimensional, reflectionless potentials and the associated quantum wave functions starting from a finite number of known energy spectra is discussed. The method is demonstrated using spectra that scale like the lowest energy states of standard problems encountered in the undergraduate curriculum, such as the infinite square well and the simple harmonic oscillator.


Evolution Of Perturbations In Flow Field Mechanics, Samantha R. Bell, David Forliti, Nils Sedano, Kriss Vanderhyde Jan 2014

Evolution Of Perturbations In Flow Field Mechanics, Samantha R. Bell, David Forliti, Nils Sedano, Kriss Vanderhyde

STAR (STEM Teacher and Researcher) Presentations

This project explores the stability analysis of a given flow field. Specifically, where the peak disturbance occurs in a flow as this is the disturbance that is most likely to occur. In rocket combustion, it is important to understand where the maximum disturbance occurs so that the mixing of fuel can be stabilized. The instabilities are the results of frequencies in the area surrounding the flow field. The linear stability governing equations are employed to better understand the disturbance. The governing equations for continuity and momentum in the x and y directions are used to form an equation for the ...


Characterization Of Polarized Synchrotron Light, Britny N. Delp, Jeff Corbett Jan 2014

Characterization Of Polarized Synchrotron Light, Britny N. Delp, Jeff Corbett

STAR (STEM Teacher and Researcher) Presentations

The Stanford Synchrotron Radiation Light accelerates electrons around a 234-meter circumference ring at relativistic speeds. The x-ray radiation produced by this process is used in many fields of science ranging from materials science to medicine.

This project seeks to measure the polarization of the 532 nanometer wavelength component in the visible light beam emitted from the SPEAR-3 synchrotron as a function of vertical position. The beam was focused through a lens, then passed through a 532 nm band pass filter and a polarizer mounted on a rotating stand. The beam power was measured as a function of vertical position and ...


Radiographic Image Quality Enhancement By The Use Of Copper Filters, Timothy T. Sakogawa, Bernice Mills Jan 2014

Radiographic Image Quality Enhancement By The Use Of Copper Filters, Timothy T. Sakogawa, Bernice Mills

STAR (STEM Teacher and Researcher) Presentations

In x-radiography, filters are often used in order to improve the overall image quality. Filters achieve this by making the x-ray beam have less energy spread, resulting in a cleaner image. Step wedges of different materials were used to compare radiographic density with and without a copper filter to identify the effect of the copper filter at different energies and exposure times. The step wedges used were CRS 1018 (cold rolled steel), Stainless Steel 304L, Al 1100, Al 6061 T6, titanium, copper, PTFE (polytetrafluoroethylene or Teflon), brass, carbon, magnesium, phenolic, tungsten, and tantalum. Out of the 14 step wedges tested ...