Physical Sciences and Mathematics Commons^™

Growth Of A Deep-Water, Predatory Fish Is Influenced By The Productivity Of A Boundary Current System, Hoang Minh Nguyen, Adam N. Rountrey, Jessica J. Meeuwig, Peter G. Coulson, Ming Feng, Stephen J. Newman, Anya M. Waite, Corey B. Wakefield, Mark G. Meekan

Fisheries Research Articles

The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the …

Arsenic Mobilization In An Alluvial Aquifer Of The Terai Region, Nepal, Jasmine Diwakar, Scott Johnston, Edward Burton, Suresh Das Shrestha

Associate Professor Edward D Burton

Study Region

A shallow (<50 m) alluvial aquifer in the Terai region of Nepal.

Study Focus

We examine the hydrogeochemical characteristics of a shallow alluvial aquifer system in the Terai region (Nawalparasi district) to identify possible mechanisms and controls on geogenic As mobilization in groundwater. Groundwater and river water samples from a topo-gradient flow-path and floodplain of a minor river draining the Siwalik forehills were analyzed for physico-chemical parameters.

New Hydrological Insights for the Region

The aquifer is characterized by Ca-HCO₃ type water and is multi-contaminated, with the WHO guideline values exceeded for As, Mn and F in 80%, 70% and 40% of cases respectively. The middle portion …

The Relationship Between Carbon Dioxide Concentration And Visitor Numbers In The Homothermic Zone Of The Balcarka Cave (Moravian Karst) During A Period Of Limited Ventilation, Marek Lang, Jiří Faimon, Camille Ek

International Journal of Speleology

The evolution of CO₂ levels with and without human presence was studied in a selected site (Gallery Chamber) of the homothermic zone of the Balcarka Cave (Moravian Karst, Czech Republic) during the fall, a period of limited ventilation. There were recognized various factors controlling the cave CO₂ levels under different conditions in the exterior and interior. When visitors were absent, CO₂ levels were controlled by the advective CO₂ fluxes linked to cave airflows and reaching up to ~1.5x10^-3 mol s^-1. These fluxes exceed by orders of magnitude the exchanged diffusive fluxes (up to …

A Web-Based Job Management System For Three-Dimensional Printing And Scanning At The University Of North Dakota, Dalyn Limesand, Stephanie Hollman, Jeremy Straub, Scott Kerlin

Jeremy Straub

Three-dimensional (3D) printers have gained popularity for use for many different projects. The work presented herein aims to make this process simpler. This paper discusses a system that will allow individuals from across campus to submit object files for printing by a 3D printer, without having to schedule appointment and manually operate it.

Logistical requirements dictate some level of human involvement, despite a goal of creating a fully automated system. Involvement areas include converting /preparing submitted files, sending the job to the printer, print tray preparation, and completed object removal. From a user’s perspective, however a seamless experience is anticipated. …

The Creation Of A Communication Systems For A Small Satellite At The University Of North Dakota, Michael Hlas, Jeremy Straub, Ronald Marsh

Jeremy Straub

Software defined radios (SDRs) are poised to significantly enhance the future of small spacecraft communications. They allow signal processing to be performed on a computer by software rather than requiring dedicated hardware. The SDR takes data from the flight computer and converts it into an analog signal that is transmitted via the spacecraft antenna. Because the signal processing is done in software, the radio can be easily reconfigured.

Data is prepared for transmission by TCP stack software onboard the OpenOrbiter Spacecraft and placed in a queue while the spacecraft is listening for a signal from a ground station. When a …

Update On The Development Of A 1-U Cubesat At The University Of North Dakota, Jeremy Straub, Ronald Marsh

Jeremy Straub

An overview of the progress on the development of the OpenOrbiter CubeSat is presented. This covers, at a high level, the work that has been performed during the past year and foundational work that occurred prior to this. This poster also discusses future plans for the Open Prototype for Educational NanoSats (OPEN) framework and the OpenOrbiter Small Spacecraft Development Initiative. Particular focus is given to the ongoing work to prepare for an orbital launch, which the program has been down-selected for through the NASA ELaNa CubeSat Launch Initiative program.

In addition to this discussion of the program’s origins, goals and …

Scheduling Algorithm Development For An Open Source Software Spacecraft, Calvin Bina, Jeremy Straub, Ronald Marsh

Jeremy Straub

The OpenOrbiter project at the University of North Dakota is working to develop a set of designs for a CubeSat class spacecraft as well as a working, modular collection of open source code that can be used by other CubeSat projects as a starting point for development. The availability of these designs and this codebase should foster accelerated development for other CubeSat projects, allowing those projects to focus their effort on their own application area, instead of reinventing the proverbial wheel. One aspect of this is to implement a task scheduler which will run on a Raspberry Pi flight computer …

Stellar Masses From The Candels Survey: The Goods-South And Uds Fields, P. Santini, H. C. Ferguson, A. Fontana, B. Mobasher, G. Barro, M. Castellano, S. L. Finkelstein, A. Grazian, L. T. Hsu, B. Lee, S.-K. Lee, J. Pforr, M. Salvato, T. Wiklind, S. Wuyts, O. Almaini, M. C. Cooper, A. Galametz, B. Weiner, R. Amorin, K. Boutsia, C. J. Conselice, T. Dahlen, M. E. Dickinson, M. Giavalisco, N. A. Grogin, Y. Guo, N. P. Hathi, Dale D. Kocevski, A. M. Koekemoer, P. Kurczynski, E. Merlin, A. Mortlock, J. A. Newman, D. Paris, L. Pentericci, R. Simons, S. P. Willner

Physics and Astronomy Faculty Publications

We present the public release of the stellar mass catalogs for the GOODS-S and UDS fields obtained using some of the deepest near-IR images available, achieved as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey project. We combine the effort from 10 different teams, who computed the stellar masses using the same photometry and the same redshifts. Each team adopted their preferred fitting code, assumptions, priors, and parameter grid. The combination of results using the same underlying stellar isochrones reduces the systematics associated with the fitting code and other choices. Thanks to the availability of different estimates, we …

Assessment Of The Consistency Among Global Microwave Land Surface Emissivity Products, Hamidreza Norouzi, M. Temimi, C. Prigent, J. Turk, Reza Khanbilvardi, Y. Tian, F. A. Furuzawa, H. Masunaga

Publications and Research

The goal of this work is to intercompare four global land surface emissivity products over various landcover conditions to assess their consistency. The intercompared land emissivity products were generated over a 5year period (2003–2007) using observations from the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E), the Special Sensor Microwave Imager (SSM/I), the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), and WindSat. First, all products were reprocessed in the same projection and spatial resolution as they were generated from sensors with various configurations. Then, the mean value and standard deviations of monthly emissivity values were calculated for each …

Investigating Seed Dispersal Distances And Long Distance Dispersal Mechanisms Of The Invasive Plant, Alliaria Petiolata, Christopher Loebach

Theses and Dissertations

Alliaria petiolata, an herbaceous plant, has aggressively invaded North American woodlands. It has been extensively studied to understand why it is a successful invader, but certain aspects of its biology have been understudied such as seed dispersal distances and long distance dispersal mechanisms (LDDM). My thesis experimentally measured A. petiolata seed dispersal distances and determined if epizoochory (external animal transport) is a LDDM. To measure dispersal distances, seed traps were placed around three A. petiolata seed point sources to capture dispersed seeds at increasing distances away from the point sources. Eight mathematical functions that describe dispersal distances were fitted to …

Winter Weather Services And Forecasting Options For Local Agencies, Michael Baldwin

Purdue Road School

Students majoring in atmospheric science at Purdue's Department of Earth, Atmospheric, and Planetary Sciences have organized a "forecasting club" to provide weather forecasting services to a wide range of customers. During the winter months, these students provide a detailed forecast of conditions across the state of Indiana that are expected to impact road maintenance operations. These forecasts are available via a web page as well as direct email. Other information regarding winter weather observations and predictions is rapidly increasing in availability. This presentation will discuss these freely available sources of winter weather information that can be used by local agencies …

Odu Hosts Fema Listening Session On New Flood Protection Standards, Public Affairs & News Bureau, Old Dominion University

News Items

No abstract provided.

Switching Quantum Dynamics For Fast Stabilization, Pierre Scaramuzza, Francesco Ticozzi

Dartmouth Scholarship

Control strategies for dissipative preparation of target quantum states, both pure and mixed, and subspaces are obtained by switching between a set of available semigroup generators. We show that the class of problems of interest can be recast, from a control-theoretic perspective, into a switched-stabilization problem for linear dynamics. This is attained by a suitable affine transformation of the coherence-vector representation. In particular, we propose and compare stabilizing time-based and state-based switching rules for entangled state preparation, showing that the latter not only ensure faster convergence with respect to nonswitching methods, but can be designed so that they retain robustness …

Intersections Of Critical Systems Thinking And Community Based Participatory Research In Developing A Web Site For Autistic Adults, Dora Madeline Raymaker

Dissertations and Theses

People with disabilities, including those on the autism spectrum, comprise the world's largest minority and experience significant inequities in Internet use. Existing standards for accessible web sites are necessary but not sufficient without the direct engagement of end users in identifying access needs. Yet little is known about methods for effective engagement, and there are no systematically derived Web accessibility guidelines for autistic end users. Here I explore a hybrid approach to direct engagement using critical systems thinking (CST) and community based participatory research (CBPR) during the co-development of a healthcare-focused web site by the Academic Autism Spectrum Partnership in …

A Novel Approach To Flow And Sediment Transport Estimation In Estuaries And Bays, Hamed Moftakhari Rostamkhani

Dissertations and Theses

Reliable estimates of river discharge and sediment transport to the ocean from large tidal rivers are vital for water resources management, efficient river and harbor management, navigational purposes, and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, hydrological and sedimentological records are typically too short to adequately characterize long-term (decadal) trends. Also, uncertainties associated with observation and calibration of hydrological models suggest a need for more accurate methods based on longer records of hydrodynamic parameters (e.g. tides). Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave …

A Revised Method For Determining Existing Acidity In Re-Flooded Acid Sulfate Soils, Scott Johnston, Edward Burton, Roslyn Hagan, Thor Aaso, Gerard Tuckerman

Associate Professor Edward D Burton

Titratable actual acidity (TAA) is a technique commonly used to estimate the existing pool of exchangeable H⁺ in acid sulfate soils (ASS). A widely adopted version of the TAA method involves titrating a 1M KCl suspension of oven-dry soil (1:40) with NaOH to a known pH endpoint. However, when ASS are subject to long term re-flooding during wetland remediation, former sulfuric horizons can develop substantial quantities of porewater Fe²⁺, non-sulfidic solid-phase Fe(II) and a variety of reduced inorganic sulfur (RIS) species (e.g. pyrite, mackinawite, greigite and elemental sulfur). For these sediments, an oven-drying approach may induce oxidation …

Enrichment And Heterogeneity Of Trace Elements At The Redox-Interface Of Fe-Rich Intertidal Sediments, Annabelle Keene, Scott Johnston, Richard Bush, Edward Burton, Leigh Sullivan, Matthew Dundoon, Angus Mcelnea, C Smith, Col Ahern, Bernard Powell

Associate Professor Edward D Burton

Redox-interfacial sediments can undergo radical geochemical changes with oscillating tides. In this study, we examine trace element enrichment and availability, at both landscape and pedon-scales, in the surface sediments of a remediating acidic tidal wetland. Fe-rich sediments at the surface-water interface (0–10 mm in depth) were collected across an elevation gradient spanning the supratidal to subtidal range. These sediments were analysed for solid phase Fe fractions and trace elements (As, Pb, Cr, Cu, Mn, Ni, Zn, V, B, Co, Mo, Ba and U) via dilute HCl-extractions and total digests. Their concentrations were compared with those of underlying (0.05–0.65 m in …

Landslide-Induced Iron Mobilisation Shapes Benthic Accumulation Of Nutrients, Trace Metals And Ree Fractionation In An Oligotrophic Alpine Stream, Scott Johnston, Andrew Rose, Edward Burton, Jenny Webster-Brown

Associate Professor Edward D Burton

Large alpine landslides that entrain substantial organic material below the water table and create suspended floodplains may have long-term consequences for the mobilisation of redox sensitive elements, such as Fe, into streamwaters. In turn, the cycling of iron in aquatic systems can influence the fate of nutrients, alter primary productivity, enhance accumulation of trace metals and induce fractionation of rare earth elements (REE). In this study we examine a reach of a pristine oligotrophic alpine stream bracketing a 30 year-old landslide and explore the consequences of landslide-induced Fe mobilisation for aqueous geochemistry and the composition of benthic stream cobble biofilm. …

Late Pleistocene Glacial History And Magnetic Chronostratigraphy, Western Adirondack Borderland, New York, Donald Pair

Donald L. Pair

New lines of evidence from the western Adirondack borderland have been employed to assess the style of deglaciation and reconstruct the nature and timing of associated proglacial lacustrine and marine (Champlain Sea) events. Contrasting styles of deglaciation, controlled primarily by water depth, resulted in landfast ice withdrawing gradually on the northern slope of the Adirondacks while actively calving ice, retreating rapidly in the deep water of Lake Iroquois, quickly evacuated the western St. Lawrence Lowland of ice. The extent of ice retreat from the western St. Lawrence Lowland during the life of Lake Iroquois has been estimated on the basis …

U.S. Drought Monitor, March 10, 2015, Matthew Rosencrans

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for March 10, 2015 (3/10/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

An Approach For Verifying Biogenic Greenhouse Gas Emissions Inventories With Atmospheric Co₂ Concentration Data, Stephen M. Ogle, Kenneth Davis, Thomas Lauvaux, Andrew Schuh, Dan Cooley, Tristram O. West, Linda S. Heath, Natasha L. Miles, Scott Richardson, F. Jay Breidt, James E. Smith, Jessica L. Mccarty, Kevin R. Gurney, Pieter Tans, A. Scott Denning

Michigan Tech Research Institute Publications

Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported emissions data to the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of a country's contribution to GHG concentrations in the atmosphere. Furthermore, verifying biogenic fluxes provides a check on estimated emissions associated with managing lands for carbon sequestration and other activities, which often have large uncertainties. We report here on the challenges and results associated with a case study using atmospheric measurements of CO₂ concentrations and inverse modeling to verify nationally-reported biogenic CO₂ emissions. The biogenic CO₂ emissions inventory was …

Signatures Of Chaos In The Dynamics Of Quantum Discord, Vaibhav Madhok, Vibhu Gupta, Denis-Alexandre Trottier, Shohini Ghose

Physics and Computer Science Faculty Publications

We identify signatures of chaos in the dynamics of discord in a multiqubit system collectively modelled as a quantum kicked top. The evolution of discord between any two qubits is quasiperiodic in regular regions, while in chaotic regions the quasiperiodicity is lost. As the initial wave function is varied from the regular regions to the chaotic sea, a contour plot of the time-averaged discord remarkably reproduces the structures of the classical stroboscopic map. We also find surprisingly opposite behavior of two-qubit discord versus entanglement of the two qubits as measured by the concurrence. Our results provide evidence of signatures of …

Negative-Quench-Induced Excitation Dynamics For Ultracold Bosons In One-Dimensional Lattices, Simeon I. Mistakidis, L. Cao, P. Schmelcher

Physics Faculty Research & Creative Works

The Nonequilibrium Dynamics Following A Quench Of Strongly Repulsive Bosonic Ensembles In One-Dimensional Finite Lattices Is Investigated By Employing Interaction Quenches And/or A Ramp Of The Lattice Potential. Both Sudden And Time-Dependent Quenches Are Analyzed In Detail. For The Case Of Interaction Quenches We Address The Transition From The Strong Repulsive To The Weakly Interacting Regime, Suppressing In This Manner The Heating Of The System. The Excitation Modes Such As The Cradle Process And The Local Breathing Mode Are Examined Via Local Density Observables. In Particular, The Cradle Mode Is Inherently Related To The Initial Delocalization And, Following A Negative …

Spitzer Space Telescope Measurements Of Dust Reverberation Lags In The Seyfert 1 Galaxy Ngc 6418, Billy Vazquez, Dan Batcheldor

Aerospace, Physics, and Space Science Faculty Publications

We present results from a 15 month campaign of high-cadence (∼3 days) mid-infrared Spitzer and optical (B and V) monitoring of the Seyfert 1 galaxy NGC 6418, with the objective of determining the characteristic size of the dusty torus in this active galactic nucleus (AGN). We find that the 3.6 and 4.5 μm flux variations lag behind those of the optical continuum by 37.2 ^+2.4 _-2.2 days and -47.1 ^+3.1 _-3.1 days, respectively. We report a cross-correlation time lag between the 4.5 and 3.6 μm flux of 13.9 ^+0.5 _-0.1 days. The lags indicate that the dust emitting at 3.6 …

Search For Stealth Supersymmetry In Events With Jets, Either Photons Or Leptons, And Low Missing Transverse Momentum In Pp Collisions At 8tev, Cms Collaboration, Cern, Switzerland, Samantha Hewamanage, Stephan Linn, Pete E. Markowitz, German Martinez, Jorge Luis Rodriguez

Department of Physics

The results of a search for new physics in final states with jets, either photons or leptons, and low missing transverse momentum are reported. The study is based on a sample of proton–proton collisions collected at a center-of-mass energy √s=8TeVwith the CMS detector in 2012. The integrated luminosity of the sample is 19.7fb−1. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in which SUSY is approximately conserved. The data …

Sensitive And Ultra-Fast Species Detection Using Pulsed Cavity Ringdown Spectroscopy, Et-Touhami Es-Sebbar

Dr. Et-touhami Es-sebbar

Pulsed cavity ringdown spectroscopy (CRDS) is used to develop a novel, ultra-fast, high-sensitivity diagnostic for measuring species concentrations in shock tube experiments. The diagnostic is demonstrated by monitoring trace concentrations of ethylene in the mid-IR region near 949.47 cm−1. Each ringdown measurement is completed in less than 1 μs and the time period between successive pulses is 10 μs. The high sensitivity diagnostic has a noise-equivalent detection limit of 1.08 x 10−5 cm−1 which enables detection of 15 ppm ethylene at fuel pyrolysis conditions (1845 K and 2 bar) and 294 ppb ethylene under ambient conditions (297 K and 1 …

Poster Session, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

1. Quantification of Common Agricultural Herbicide Dispersal and Land Use in Selected Areas of the Kentucky River Watershed, Andrew Nagel and others, Northern Kentucky University, Highland Heights, KY
2. Exploring the Effects of Herbicides on Willow Seedlings, Sarah Stryffeler and others, Dept. of Biological Sciences, Northern Kentucky University, Highland Heights, KY
3. LiDAR Mapping Sinkholes in Cane Run Watershed, Fidele Tibouo and others, Dept. Earth and Environmental Sciences, University of Kentucky, Lexington, KY
4. Surface Enhanced Raman Spectroscopy to Study Photocatalytic Degradation of Organic Pollutants, Frankie Wallace and Matthew Nee, Dept. of Chemistry, Western Kentucky University, Bowling Green, KY
5. Test …

High Electron Mobility In Free-Standing Gan Substrates, A. Saxler, David Look, Said Elhamri, J. Sizelove, D. Cull, William Mitchel, Michael Callahan, David Bliss, Lionel Bouthillette, Sheng-Qi Wang, C. Sung, Seong-Ju Park, K. Lee

Said Elhamri

High peak electron mobilities were observed in free-standing c-plane GaN substrates. Two layers, a low mobility degenerate layer and a high mobility bulk layer, were present in these samples. The carrier concentrations and mobilities for the layers were extracted using two methods: 1) magnetic field dependent Hall effect analysis and 2) a simple two carrier model with the assumption that one of the layers is degenerate. In addition, measurements were performed after etching away the degenerate layer. The mobility of the bulk layer is found to peak at nearly 8000 cm2/Vs at 60K using the magnetic field dependent Hall effect …

Growth Of Graphene Architectures On Sic, John J. Boeckl, Weijie Lu, William C. Mitchel, Kurt G. Eyink, Howard Smith, Larry Grazulis, Gerry Landis, Said Elhamri

Said Elhamri

No abstract provided.

Deep Centers In Semi-Insulating Current Topics In Solid State Physics Fe-Doped Native Gan Substrates Grown By Hydride Vapour Phase Epitaxy, Z-Q. Fang, Bruce Claflin, David Look, Said Elhamri, H. Smith, William Mitchel, D. Hanser, E. Preble, K. Evans

Said Elhamri

Electrical properties, Fe concentration, and deep centers in semi-insulating Fe-doped GaN substrates grown by hydride vapor phase epitaxy (HVPE) were characterized by temperature-dependent Hall-effect measurements, secondary ion mass spectroscopy, and thermally stimulated current (TSC) spectroscopy, Five adjacent samples from a low-[Fe] wafer displayed very high resistivity, dominated by a center at 0,94 eV. At least six traps were observed in the samples by TSC, with trap (0.56-0.60 eV) being dominant. A metastable trap A, at similar to 0.82 eV appeared after white-light illumination at 300 K-A sample from a high-[Fe] wafer displayed a lower resistivity, dominated by a center at …