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California Polytechnic State University, San Luis Obispo

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Full-Text Articles in Physics

Detrital Zircon Geochronology And Evolution Of The Nacimiento Block Late Mesozoic Forearc Basin, Central California Coast, Scott Johnston, Andrew R.C. Kylander-Clark, Alan D. Chapman Dec 2018

Detrital Zircon Geochronology And Evolution Of The Nacimiento Block Late Mesozoic Forearc Basin, Central California Coast, Scott Johnston, Andrew R.C. Kylander-Clark, Alan D. Chapman

Physics

Forearc basins are first-order products of convergent-margin tectonics, and their sedimentary deposits offer unique perspectives on coeval evolution of adjacent arcs and subduction complexes. New detrital zircon U-Pb geochronologic data from 23 sandstones and 11 individual conglomerate clasts sampled from forearc basin strata of the Nacimiento block, an enigmatic stretch of the Cordilleran forearc exposed along the central California coast, place constraints on models for forearc deformation during evolution of the archetypical Cordilleran Mesozoic margin. Deposition and provenance of the Nacimiento forearc developed in three stages: (1) Late Jurassic– Valanginian deposition of lower Nacimiento forearc strata with zircon derived from ...


Geologic Map And Structural Development Of The Noerthernmost Sur-Nacimiento Fault Zone, Central California Coast, Scott M. Johnston, John S. Singleton, Alan D. Chapman, Gabriella Murray Dec 2018

Geologic Map And Structural Development Of The Noerthernmost Sur-Nacimiento Fault Zone, Central California Coast, Scott M. Johnston, John S. Singleton, Alan D. Chapman, Gabriella Murray

Physics

The Sur-Nacimiento fault exposed along the central California coast (United States) juxtaposes the Salinian block arc against the Nacimiento block accretionary complex, cuts out the majority of the forearc basin and western arc, and requires a minimum of 150 km of orogen-normal crustal excision within the Mesozoic California convergent margin. Despite this significant strain, the kinematic evolution of the Sur-Nacimiento fault remains poorly understood, with diverse hypotheses suggesting sinistral, dextral, thrust, or normal displacement along the fault. This Late Cretaceous–Paleogene strain history is complicated by the location of the fault within a belt of subparallel faults that have accommodated ...


Reversible Motion In A Contact Line, Audrey Profeta, Esmeralda Orozco, Juan A. Ortiz Salazar, Dani Medina, Nathan C. Keim Sep 2018

Reversible Motion In A Contact Line, Audrey Profeta, Esmeralda Orozco, Juan A. Ortiz Salazar, Dani Medina, Nathan C. Keim

STAR (STEM Teacher and Researcher) Presentations

When a body of liquid sits on a surface, an irregular border between the wet and dry regions of the surface exists, called the contact line. Driving this contact line back and forth repeatedly can change its shape.We use a syringe pump to cyclically infuse and withdraw a predetermined volume of water, and take photos of the contact line after each cycle. Comparing these images to each other determines if the contact line is returning to the same shape. We find that below a critical value of infused volume, after many cycles the contact line reaches a steady state ...


Anisotropic Conductive Adhesives For Interdigitated Back Contact (Ibc) Silicon Solar Cells, Katherine M. Lohmuste, Manuel Schnabel, Maikel F.A.M. Van Hest Aug 2018

Anisotropic Conductive Adhesives For Interdigitated Back Contact (Ibc) Silicon Solar Cells, Katherine M. Lohmuste, Manuel Schnabel, Maikel F.A.M. Van Hest

STAR (STEM Teacher and Researcher) Presentations

The current manufacturing process for solar panels using interdigitated back contact (IBC) silicon solar cells involves a multi-step metallization and interconnection process in which a substantial amount of silver is used. This work focuses on a new process using conductive adhesives (CA) which would increase efficiency and lower cost through a one-step metallization and interconnection process that combines with encapsulation using little silver and only requiring metal patterning on the back sheet or back glass. It would also not require direct metallization of the silicon, which would result in fewer defects, while increasing voltage and therefore efficiency. Silver-coated Poly(Methyl ...


X-Ray Spectroscopy Of Nio And Nanodiamond At Ssrl, Jackson Earl Jan 2018

X-Ray Spectroscopy Of Nio And Nanodiamond At Ssrl, Jackson Earl

STAR (STEM Teacher and Researcher) Presentations

The first aspect of this research project focuses on investigating the surface chemistry of high pressure high temperature (HPHT) nanodiamond by using X-ray spectroscopy techniques at the Stanford Synchrotron Radiation Lightsource (SSRL). HPHT nanodiamond is being examined as a biosensing tool for electric field detection based on the fluorescent nitrogen vacancy center hosted within diamond. With use of the transition edge spectrometer (TES), a state-of-the-art X-ray fluorescence detector, we are able to probe the surface and bulk properties of diamond. Preliminary work using density functional theory (DFT) has been done, offering insight into ground state energies and electronic structure. DFT ...


Resistance Temperature Detectors In A Cryostat Refrigeration System, Kirsten Marie Manahan, Alice Callen Jan 2018

Resistance Temperature Detectors In A Cryostat Refrigeration System, Kirsten Marie Manahan, Alice Callen

STAR (STEM Teacher and Researcher) Presentations

The Large Synoptic Survey Telescope (LSST) is a ground-based telescope that will survey the Southern sky every few nights. Located in the telescope will be a 3.2 gigapixel digital camera. To ensure proper instrumentation of the camera, there must be a monitored stable temperature. As part of my research, I assembled resistance temperature detectors and tested them to verify their reliability in measuring temperature in the camera’s cryostat refrigeration cooling system. Resistance temperature detectors function by the principle of thermal resistivity, in which their electrical resistances vary as temperature varies. Through testing, I was able to determine whether ...


Development, Implementation, And Validation Of A California Coastal Ocean Modeling, Data Assimilation, And Forecasting System, Yi Chao, John D. Farrara, Hongchun Zhang, Kevin Armenta, Luca Centurioni, Francisco Chavez, James B. Girton, Dan Rudnick, Ryan K. Walter Apr 2017

Development, Implementation, And Validation Of A California Coastal Ocean Modeling, Data Assimilation, And Forecasting System, Yi Chao, John D. Farrara, Hongchun Zhang, Kevin Armenta, Luca Centurioni, Francisco Chavez, James B. Girton, Dan Rudnick, Ryan K. Walter

Physics

A three-dimensional, near real-time data-assimilative modeling system for the California coastal ocean is presented. The system consists of a Regional Ocean Modeling System (ROMS) forced by the North American Mesoscale Forecast System (NAM). The ocean model has a horizontal resolution of approximately three kilometers and utilizes a multi-scale three-dimensional variational (3DVAR) data assimilation methodology. The system is run in near real-time to produce a nowcast every six hours and a 72-hour forecast every day. The performance of this nowcast system is presented using results from a six-year period of 2009–2015.

The ROMS results are first compared with the assimilated ...


Extending The Calibration Of C Iv-Based Single-Epoch Black Hole Mass Estimators For Active Galactic Nuclei, Daeseong Park, Aaron J. Barth, Jong-Hak Woo, Matthew A. Malkan, Tommaso Treu, Vardha Nicola Bennert, Roberto J. Assef, Anna Pancoast Apr 2017

Extending The Calibration Of C Iv-Based Single-Epoch Black Hole Mass Estimators For Active Galactic Nuclei, Daeseong Park, Aaron J. Barth, Jong-Hak Woo, Matthew A. Malkan, Tommaso Treu, Vardha Nicola Bennert, Roberto J. Assef, Anna Pancoast

Physics

We provide an updated calibration of C iv broad emission line–based single-epoch (SE) black hole (BH) mass estimators for active galactic nuclei (AGNs) using new data for six reverberation-mapped AGNs at redshift with BH masses (bolometric luminosities) in the range ( erg s−1). New rest-frame UV-to-optical spectra covering 1150–5700 Å for the six AGNs were obtained with the Hubble Space Telescope (HST). Multicomponent spectral decompositions of the HST spectra were used to measure SE emission-line widths for the C iv, Mg ii, and Hβ lines, as well as continuum luminosities in the spectral region around each line ...


Fading Agn Candidates: Agn Histories And Outflow Signatures, William C. Keel, Chris J. Lintott, W. Peter Maksym, Vardha N. Bennert, S. Drew Chojnowski, Alexei Moiseev, Aleksandrina Smirnova, Kevin Schawinski, Lia F. Sartori, C. Megan Urry, Anna Pancoast, Mischa Schirmer, Bryan Scott, Charles Grant Showley, Kelsi Flatland Feb 2017

Fading Agn Candidates: Agn Histories And Outflow Signatures, William C. Keel, Chris J. Lintott, W. Peter Maksym, Vardha N. Bennert, S. Drew Chojnowski, Alexei Moiseev, Aleksandrina Smirnova, Kevin Schawinski, Lia F. Sartori, C. Megan Urry, Anna Pancoast, Mischa Schirmer, Bryan Scott, Charles Grant Showley, Kelsi Flatland

Physics

We consider the energy budgets and radiative history of eight fading active galactic nuclei (AGNs), identified from an energy shortfall between the requirements to ionize very extended (radius > 10 kpc) ionized clouds and the luminosity of the nucleus as we view it directly. All show evidence of significant fading on timescales of ≈50,000 yr. We explore the use of minimum ionizing luminosity Qion derived from photoionization balance in the brightest pixels in Hα at each projected radius. Tests using presumably constant Palomar–Green QSOs, and one of our targets with detailed photoionization modeling, suggest that we can ...


Local Diurnal Wind‐Driven Variability And Upwelling In A Small Coastal Embayment, Ryan K. Walter, Emma C. Reid, Kristen A. Davis, Kevin Armenta, Kevin Merhoff, Nicholas J. Nidzieko Jan 2017

Local Diurnal Wind‐Driven Variability And Upwelling In A Small Coastal Embayment, Ryan K. Walter, Emma C. Reid, Kristen A. Davis, Kevin Armenta, Kevin Merhoff, Nicholas J. Nidzieko

Physics

The oceanic response to high‐frequency local diurnal wind forcing is examined in a small coastal embayment located along an understudied stretch of the central California coast. We show that local diurnal wind forcing is the dominant control on nearshore temperature variability and circulation patterns. A complex empirical orthogonal function (CEOF) analysis of velocities in San Luis Obispo Bay reveals that the first‐mode CEOF amplitude time series, which accounts for 47.9% of the variance, is significantly coherent with the local wind signal at the diurnal frequency and aligns with periods of weak and strong wind forcing. The diurnal ...


Large-Scale Outflows In Luminous Qsos Revisited: The Impact Of Beam Smearing On Agn Feedback Efficiencies, Bernd Husemann, Julia Scharwächter, Vardha N. Bennert, V. Manieri, Jong-Hak Woo, Darshan Kakkad Oct 2016

Large-Scale Outflows In Luminous Qsos Revisited: The Impact Of Beam Smearing On Agn Feedback Efficiencies, Bernd Husemann, Julia Scharwächter, Vardha N. Bennert, V. Manieri, Jong-Hak Woo, Darshan Kakkad

Physics

Context. Feedback from active galactic nuclei (AGN) is thought to play an important role in quenching star formation in galaxies. However, the efficiency with which AGN dissipate their radiative energy into the ambient medium remains strongly debated.

Aims. Enormous observational efforts have been made to constrain the energetics of AGN feedback by mapping the kinematics of the ionized gas on kpc scale. We study how the observed kinematics and inferred energetics are affected by beam smearing of a bright unresolved narrow-line region (NLR) due to seeing.

Methods. We re-analyse optical integral-field spectroscopy of a sample of twelve luminous unobscured quasi-stellar ...


Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka Oct 2016

Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka

STAR (STEM Teacher and Researcher) Presentations

Dark matter is an unknown type of matter that composes roughly 27% of the observable universe and, as cosmological structure models suggest, the earth should be passing through a “dark halo” of this unknown matter present in the Milky Way galaxy. As we pass through this halo, the Super Cryogenic Dark Matter Search (SuperCDMS) experiment aims to directly detect dark -matter particles. Though many dark matter particle candidates exist, SuperCDMS focuses on the detection of particles called WIMPS (weakly interacting massive particles) as predicted by super-symmetric theories beyond the standard model. Due to the high-sensitivity of the germanium detectors employed ...


Exploring Mathematical Strategies For Finding Hidden Features In Multi-Dimensional Big Datasets, Tri Duong, Fang Ren, Apurva Mehta Oct 2016

Exploring Mathematical Strategies For Finding Hidden Features In Multi-Dimensional Big Datasets, Tri Duong, Fang Ren, Apurva Mehta

STAR (STEM Teacher and Researcher) Presentations

With advances in technology in brighter sources and larger and faster detectors, the amount of data generated at national user facilities such as SLAC is increasing exponentially. Humans have a superb ability to recognize patterns in complex and noisy data and therefore, data is still curated and analyzed by humans. However, a human brain is unable to keep up with the accelerated pace of data generation, and as a consequence, the rate of new discoveries hasn't kept pace with the rate of data creation. Therefore, new procedures to quickly assess and analyze the data are needed. Machine learning approaches ...


Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney Oct 2016

Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney

STAR (STEM Teacher and Researcher) Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) conducts research on a modified Boeing 747sp aircraft. By using a variety of infrared science instruments mounted on a 2.7 meter telescope, researchers can make discoveries about the galactic center, star formation, and various topics associated with a deeper understanding of our universe. To efficiently collect data through the SOFIA instruments, the instruments must be tested and prepared prior to being placed on the aircraft. Therefore, with the use of the Telescope Assembly Alignment Simulator (TAAS), researchers can design and construct improvements needed for these instruments to efficiently perform while in flight ...


Community Outreach With Play-Doh® Electronics, Thomas J. Bensky, William Bensky Oct 2016

Community Outreach With Play-Doh® Electronics, Thomas J. Bensky, William Bensky

Physics

It never fails: you’re in your office and the phone rings. Your department head says, “Hi! Fifty kids are coming to campus in 30 minutes. Can you meet with them and give them a one-hour hands-on activity that will make them excited about physics?” Likely you’ll run to your demonstration room and grab anything that’ll generate a bright light or cause something to explode or levitate, right? In recent years, we’ve taken a more systematic approach to hosting visitors by developing a ready-to-go hands-on activity that provides opportunities for learning about DC electric circuits.


An Analysis Of The Microseismic Peak At Ligo Hanford Observatory, Nathan Sweem Oct 2016

An Analysis Of The Microseismic Peak At Ligo Hanford Observatory, Nathan Sweem

STAR (STEM Teacher and Researcher) Presentations

The Laser Interferometer Gravitational-Wave Observatory (LIGO) consists of two facilities, LIGO Hanford Observatory (LHO) and LIGO Livingston Observatory (LLO). Gravitational-wave astronomy began when LIGO observed gravitational-waves for the first time in 2015 during the inaugural observation run (01) of the advanced detector era. Isolation of LIGO detectors from seismic noise is necessary to achieve a desired level of performance. Analysis of seismic noise is essential to make improvements in seismic isolation, and to validate gravitational-wave candidates with a high degree of certainty. Hourly trends of seismic noise in the 0.1 – 0.3 Hz frequency band from Guralp CMG-40T three-axis ...


Optimization And Coding Of A Lcls Control Program, Tanner M. Worden Sep 2016

Optimization And Coding Of A Lcls Control Program, Tanner M. Worden

STAR (STEM Teacher and Researcher) Presentations

SLAS’s, Linac Coherent Light Source (LCLS) also known as X-ray free-electron laser (XFEL) is the first X-ray laser of its kind. It gave Scientist from around the world the unique ability to observe the world at a subatomic level. Allowing for major advancements in the field of biological chemistry, drug science, material science and many more. Since the LCLS is a fairly unique scientific instrument, the demand for its use by the scientific community has always been high since it turned on back in 2009. This means that any and all time that the laser is not being used ...


About Agn Ionization Echoes, Thermal Echoes, And Ionization Deficits In Low Redshift Lyman-Alpha Blobs, Mischa Schirmer, Sangeeta Malhotra, Nancy A. Levenson, Hai Fu, Rebecca L. Davies, William Keel, Paul Torrey, Vardha Nicola Bennert, Anna Pancoast, James E. H. Turner Jul 2016

About Agn Ionization Echoes, Thermal Echoes, And Ionization Deficits In Low Redshift Lyman-Alpha Blobs, Mischa Schirmer, Sangeeta Malhotra, Nancy A. Levenson, Hai Fu, Rebecca L. Davies, William Keel, Paul Torrey, Vardha Nicola Bennert, Anna Pancoast, James E. H. Turner

Physics

We report the discovery of 14 Lyα blobs (LABs) at z ∼ 0.3, existing at least 4–7 billion years later in the Universe than all other LABs known. Their optical diameters are 20–70 kpc, and GALEX data imply Lyα luminosities of (0.4–6.3) × 1043 erg s−1. Contrary to high-z LABs, they live in low-density areas. They are ionized by AGN, suggesting that cold accretion streams as a power source must deplete between z = 2 and 0.3. We also show that transient AGN naturally explain the ionization deficits observed in many LABs. Their ...


Broad HΒ Emission-Line Variability In A Sample Of 102 Local Active Galaxies, Jordan Runco, Maren Cosens, Vardha Nicola Bennert, Bryan Scott, S. Komossa, Matthew A. Malkan, Mariana S. Lazarova, Matthew W. Auger, Tommaso Treu, Daeseong Park Apr 2016

Broad HΒ Emission-Line Variability In A Sample Of 102 Local Active Galaxies, Jordan Runco, Maren Cosens, Vardha Nicola Bennert, Bryan Scott, S. Komossa, Matthew A. Malkan, Mariana S. Lazarova, Matthew W. Auger, Tommaso Treu, Daeseong Park

Physics

A sample of 102 local (0.02 ≤ z ≤ 0.1) Seyfert galaxies with black hole masses MBH > 107M was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between MBH and host galaxy properties. We study profile changes of the broad Hβ emission line within the three to nine year time frame between the two sets of spectra. The variability of the broad Hβ emission line is of particular interest, not only because it is used to estimate MBH, but also ...


Observations Of Nonlinear Internal Waves At A Persistent Coastal Upwelling Front, Ryan K. Walter, Marek Stastna, C. Brock Woodson, Stephen G. Monismith Apr 2016

Observations Of Nonlinear Internal Waves At A Persistent Coastal Upwelling Front, Ryan K. Walter, Marek Stastna, C. Brock Woodson, Stephen G. Monismith

Physics

We collected high-resolution observations of nonlinear internal waves (NLIWs) at a persistent upwelling front in the shallow coastal environment (~20 m) of northern Monterey Bay, CA. The coastal upwelling front forms between recently upwelled waters and warmer stratified waters that are trapped in the bay (upwelling shadow). The front propagates up and down the coast in the along-shore direction as a buoyant plume front due to modulation by strong diurnal wind forcing. The evolution of the coastal upwelling front, and the subsequent modulation of background environmental conditions, is examined using both individual events and composite day averages. We demonstrate that ...


Internal Bore Seasonality And Tidal Pumping Of Subthermocline Waters At The Head Of The Monterey Submarine Canyon, Ryan K. Walter, P. Joe Phelan Mar 2016

Internal Bore Seasonality And Tidal Pumping Of Subthermocline Waters At The Head Of The Monterey Submarine Canyon, Ryan K. Walter, P. Joe Phelan

Physics

This study utilizes more than a year of observations made in shallow waters (~30 m) at the head of the Monterey Submarine Canyon to assess variability in the physical environment and internal bore field. The interaction of the internal tide with the canyon rim results in a semidiurnal tidal period pumping of cold–water masses (subthermocline waters) onto the adjacent shelf (i.e., internal bores). These internal bores are shown to be significantly coherent with the local sea surface height with minimal spatial variability when comparing two sites near the canyon head region. During the summer months, and periods of ...


Understanding Molecular Bonding In Vitamin B12 Using X-Ray Spectroscopy, Jamie N. Lehnen Jan 2016

Understanding Molecular Bonding In Vitamin B12 Using X-Ray Spectroscopy, Jamie N. Lehnen

STAR (STEM Teacher and Researcher) Presentations

It is often difficult to accurately describe the electronic configuration of large molecules like cobalamin (Vitamin B12). By defining the electronic and geometric structure of a molecule using X-ray spectroscopy, we can better understand how that molecule behaves. Cobalamin is a molecule of interest because it typically displays dehalogenating properties in the body. By understanding more of how cobalamin analogues operate, it becomes possible to know their chemical properties and reactions.


Drag Reduction Using Graphene In Viscous Laminar Flow With Water And Isopropanol, Jessica M. Patalano, Akm Newaz Dr. Jan 2016

Drag Reduction Using Graphene In Viscous Laminar Flow With Water And Isopropanol, Jessica M. Patalano, Akm Newaz Dr.

STAR (STEM Teacher and Researcher) Presentations

America has over 2.6 million miles of pipeline for the transportation of energy products, such as liquid petroleum and natural gas. Friction is one of the main sources for energy dissipation at liquid/solid interfaces that limits the transport of a fluid through a cylindrical pipe or tube. In order to make these pipelines more efficient and enhance the flow of these materials, it is necessary to find a coating material that reduces the frictional drag. The ideal material would reduce the drag between the fluid and solid interface while being easily synthesizable on the surface. The goal of ...


Migmatite Gneiss Of The Jættedal Complex, Liverpool Land, East Greenland: Protracted High-T Metamorphism In The Overriding Plate Of The Caledonian Orogen, S. M. Johnston, A. Kylander-Clark, H. K. Brueckner Dec 2015

Migmatite Gneiss Of The Jættedal Complex, Liverpool Land, East Greenland: Protracted High-T Metamorphism In The Overriding Plate Of The Caledonian Orogen, S. M. Johnston, A. Kylander-Clark, H. K. Brueckner

Physics

The Greenland Caledonides (GC) formed in the overriding Laurentian plate during the closure of the Iapetus Ocean and the subduction of Baltica, and offer a unique opportunity to study metamorphic patterns, regional structures and the kinematic evolution of the overriding plate of a continental collision. We present new metamorphic petrology and coupled zircon geochronology and geochemistry data from the Jættedal complex in southern Liverpool Land to document the thermal evolution of the orogenic core of the southern GC. Pelitic migmatite gneisses from the Jættedal complex document metamorphic conditions of 850–730 °C at pressures of 11–9.5 kbar. Zircon ...


The Muse View Of Qso Pg 1307+085: An Elliptical Galaxy On The MBh–Σ* Relation Interacting With Its Group Environment, Bernd Husemann, Vardha Nicola Bennert, Julia Scharwächter, J.-H. Woo, O. S. Choundhury Nov 2015

The Muse View Of Qso Pg 1307+085: An Elliptical Galaxy On The MBh–Σ* Relation Interacting With Its Group Environment, Bernd Husemann, Vardha Nicola Bennert, Julia Scharwächter, J.-H. Woo, O. S. Choundhury

Physics

We report deep optical integral-field spectroscopy with the Multi-Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope of the luminous radio-quiet quasi-stellar object (QSO) PG 1307+085 obtained during commissioning. Given the high sensitivity and spatial resolution delivered by MUSE, we are able to resolve the compact (re ∼ 1.3 arcsec) elliptical host galaxy. After spectroscopic deblending of the QSO and host galaxy emission, we infer a stellar velocity dispersion of σ* = 155 ± 19 km s−1. This places PG 1307+085 on the local MBH–σ* relation within its intrinsic scatter but offset towards a higher black ...


A Local Baseline Of The Black Hole Mass Scaling Relations For Active Galaxies. Iii. The Mbh-Σ Relation, Vardha Nicola Bennert, Tommaso Treu, Matthew W. Auger, Maren Cosens, Daeseong Park, Rebecca Rosen, Chelsea E. Harris, Matthew A. Malkan, Jong-Hak Woo Aug 2015

A Local Baseline Of The Black Hole Mass Scaling Relations For Active Galaxies. Iii. The Mbh-Σ Relation, Vardha Nicola Bennert, Tommaso Treu, Matthew W. Auger, Maren Cosens, Daeseong Park, Rebecca Rosen, Chelsea E. Harris, Matthew A. Malkan, Jong-Hak Woo

Physics

We create a baseline of the black hole (BH) mass ()—stellar-velocity dispersion (σ) relation for active galaxies, using a sample of 66 local () Seyfert-1 galaxies, selected from the Sloan Digital Sky Survey (SDSS). Analysis of SDSS images yields AGN luminosities free of host-galaxy contamination, and morphological classification. 51/66 galaxies have spiral morphology. Out of these, 28 bulges have Sérsic index and are considered candidate pseudo-bulges, with eight being definite pseudo-bulges based on multiple classification criteria met. Only 4/66 galaxies show signs of interaction/merging. High signal-to-noise ratio Keck spectra provide the width of the broad Hβ emission ...


Calculating The Energy Barriers Required To Join Metal-Organic Framework Synthesis Intermediates With Non-Equilibrium Molecular Simulation, Marcus A. Tubbs, David Cantu, Roger Rousseau, Vassiliki-Alexandra Glezakou Aug 2015

Calculating The Energy Barriers Required To Join Metal-Organic Framework Synthesis Intermediates With Non-Equilibrium Molecular Simulation, Marcus A. Tubbs, David Cantu, Roger Rousseau, Vassiliki-Alexandra Glezakou

STAR (STEM Teacher and Researcher) Presentations

Metal organic frameworks (MOFs) are synthetic materials made of a cage-like lattice of metal nodes connected by organic linkers. The pores between the nodes define the characteristics of the material. A MOF, MIL-101, has shown great capacity in the adsorption of carbon dioxide and methane, as well as in hydrogenation catalysis with palladium. While there has been success in synthesizing MIL-101 and other MOFs, the mechanistic details behind their assembly remain unknown. Understanding the synthesis mechanism is necessary to understand the kinetics involved and be able to produce this useful material on an industrial scale. Using MIL-101 as a prototypical ...


Design And Fabrication Of Liquid Scintillator Counter, Andrea Calderon Saucedo, John L. Orrell Aug 2015

Design And Fabrication Of Liquid Scintillator Counter, Andrea Calderon Saucedo, John L. Orrell

STAR (STEM Teacher and Researcher) Presentations

Pacific Northwest National Laboratory (PNNL) is currently developing an ultra-low background liquid scintillator counter (ULB LSC) in the shallow underground laboratory. At a depth of 35-meters water-equivalent, the underground laboratory has a multi-layered shielding to keep out cosmic-ray induced background. The ULB LSC, which is located in a clean room facility, is a multi-layered design made up of various materials, including plastic scintillator veto panels, borated polyethylene, lead and copper. These layers help lower the contributions of the terrestrial background and intrinsic background, resulting from the impurities present in the materials, to the overall background count rate observed by the ...


Mapping Open Water Bodeis With Optical Remote Sensing, Mary Ellen O'Donnell, Erika Podest Aug 2015

Mapping Open Water Bodeis With Optical Remote Sensing, Mary Ellen O'Donnell, Erika Podest

STAR (STEM Teacher and Researcher) Presentations

There is interest in mapping open water bodies using remote sensing data. Coverage and persistence of open water is currently a poorly measured variable due to its spatial and temporal variability across landscapes, especially in remote areas. The presence and persistence of open water is one of the primary indicators of conditions suitable for mosquito breeding habitats. Predicting the risk of mosquito caused disease outbreaks is a required step towards their control and eradication. Satellite observations can provide needed data to support agency decisions for deployment of preventative measures and control resources. This study, which will try to map open ...


Yielding And Microstructure In A 2d Jammed Material Under Shear Deformation, Nathan C, Keim, Paulo E. Arratia Jul 2015

Yielding And Microstructure In A 2d Jammed Material Under Shear Deformation, Nathan C, Keim, Paulo E. Arratia

Physics

The question of how a disordered material's microstructure translates into macroscopic mechanical response is central to understanding and designing materials like pastes, foams and metallic glasses. Here, we examine a 2D soft jammed material under cyclic shear, imaging the structure of ∼5 × 104 particles. Below a certain strain amplitude, the structure becomes conserved at long times, while above, it continually rearranges. We identify the boundary between these regimes as a yield strain, defined without rheological measurement. Its value is consistent with a simultaneous but independent measurement of yielding by stress-controlled bulk rheometry. While there are virtually no irreversible ...