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Full-Text Articles in Physical Sciences and Mathematics

Communication Of Recycling Through Labeling And Packaging, Serena Mistry Dec 2012

Communication Of Recycling Through Labeling And Packaging, Serena Mistry

Graphic Communication

Recycling has become a more prevalent practice in the last few decades. However, the labeling system on today’s packaging is not always clear in indicating whether something is recyclable. Recently, there has been a great deal of attention directed at a new system, known as the How2Recycle label, an innovative labeling system expected to launch in the next few years. As the population continues to grow at unprecedented levels and more strain is placed on the global environment, recycling becomes more crucial. In the United States, the lack of a standard system for recycling on labeling and packaging deters people …


Aspects Of General Relativity In 1+1 Dimensions, Richard D. Mellinger Jr Dec 2012

Aspects Of General Relativity In 1+1 Dimensions, Richard D. Mellinger Jr

Physics

What would be the properties of a universe with only one spatial dimension and one time dimension? General relativity in 1+1 dimensions is unique since the two curvature terms in the Einstein field equations cancel. This makes the Einstein field equations algebraic rather than differential equations. This special feature can make 1+1 dimensionality attractive as an instructional tool to simplify the mathematics that many beginners find opaque. We explore the implications and features of the Einstein field equations in 1+1 dimensions and find they provide a surprisingly rich and interesting model. We then study an alternate theory and its implications …


Building An Alpha Spectrometer For The Cuore Collaboration, David J. Miller Dec 2012

Building An Alpha Spectrometer For The Cuore Collaboration, David J. Miller

Physics

This paper will give the reader a brief introduction to the Standard Model, Neutrinoless Double Beta Decay (0νββ), and the CUORE experiment under construction at Gran Sasso National Lab in Assergi, Italy. The remainder of the paper will describe the process of creating a working alpha spectrometry system using silicon detectors and NIM and CAMAC electronics. Extensive details of the troubleshooting and calibration period are presented as a way for the reader to better understand the concepts involved in alpha spectroscopy and to not repeat mistakes made in this development process.


Investigation Of Optical Dipole Traps For Trapping Neutral Atoms For Quantum Computing, Danielle May Dec 2012

Investigation Of Optical Dipole Traps For Trapping Neutral Atoms For Quantum Computing, Danielle May

Physics

No abstract provided.


Determining Stellar Velocity Dispersion In Active Galaxies: Is The [Oiii] Width A Valid Surrogate?, Kelsi Flatland Dec 2012

Determining Stellar Velocity Dispersion In Active Galaxies: Is The [Oiii] Width A Valid Surrogate?, Kelsi Flatland

Physics

The tight empirical relation between the stellar velocity dispersion (sigma) of the bulge and the mass of the supermassive black hole (BH) at its center indicates a close connection between galactic evolution and BH growth. The evolution of this relation with cosmic time provides valuable clues to its origin. While the mass of the BH can be easily estimated using the Doppler broadening of the Hbeta emission line in type I active galactic nuclei (AGNs), measuring sigma simultaneously is challenging, since the nuclear emission outshines the host galaxy. Thus, it is highly desirable to find an alternative way to estimate …


Effects Of Silvicultural Management On Coast Redwood Forest Composition, Density And Structure In Santa Cruz And San Mateo Counties, Michael J. Papa Dec 2012

Effects Of Silvicultural Management On Coast Redwood Forest Composition, Density And Structure In Santa Cruz And San Mateo Counties, Michael J. Papa

Master's Theses

The multiple-objective exploratory study investigates effects of various silvicultural management regimes commonly applied to coast redwood (Sequoia sempervirens [D. Don] Endl.) forests in Santa Cruz and San Mateo Counties, California, USA. A temporary forest inventory was installed in 24 harvest origin stands and 4 natural origin stands throughout the study area (sample area = 1189 acres). Data from the systematic sample of 233 one-quarter acre nested cluster plots (sample intensity = 4.9%) rendered overall forest descriptions in terms of species composition, density, and structure. The common forestry measures of trees per acre (TPA), basal area per acre (BA), and …


Mortality Assessment Of Redwood And Mixed Conifer Forest Types In Santa Cruz County Following Wildfire, Steve R. Auten Dec 2012

Mortality Assessment Of Redwood And Mixed Conifer Forest Types In Santa Cruz County Following Wildfire, Steve R. Auten

Master's Theses

On August 12, 2009, the Lockheed Fire ignited the west slope of the Santa Cruz Mountains burning approximately 7,819 acres. Foresters and other land managers were left with challenging decisions on how to evaluate tree mortality. Big Creek Lumber Company, California Polytechnic State University, San Luis Obispo (Cal Poly)’s Swanton Pacific Ranch (SPR), and other resource professionals familiar with this region teamed up to develop a method for evaluating damage and thereby mortality for redwood, California nutmeg, live oak, tanoak, California bay, Pacific madrone, big leaf maple, Douglas-fir, Monterey pine, and knobcone pine. Quantitative damage criteria were used to design …


The Effects Of Color Concentrates On The Rheology Of Tint Bases, Doug James Herrick Dec 2012

The Effects Of Color Concentrates On The Rheology Of Tint Bases, Doug James Herrick

Master's Theses

ABSTRACT

THE EFFECTS OF COLOR CONCENTRATES ON THE RHEOLOGY OF TINT BASES

Douglas James Herrick

Waterborne coatings are formulated with a number of different ingredients; water, latex polymers, pigments, surfactants, dispersants, defoamers, biocides, coalescing aids, and rheology modifiers or thickeners. Rheology modifiers are necessary in order to improve the physical properties of the coating before, during, and after application to a substrate. There are two kinds of rheology modifiers used in waterborne coatings; associative thickeners and non-associative thickeners. Coatings formulated with associative thickeners are quite sensitive to coating variations; the slightest change in the formulation has profound effects on the …


Controlling Nanoparticle Dispersion For Nanoscopic Self-Assembly, Nathan S. Starkweather Dec 2012

Controlling Nanoparticle Dispersion For Nanoscopic Self-Assembly, Nathan S. Starkweather

Master's Theses

Nanotechnology is the manipulation of matter and devices on the nanometer scale. Below the critical dimension length of 100nm, materials begin to display vastly different properties than their macro- or micro- scale counterparts. The exotic properties of nanomaterials may trigger the start of a new technological revolution, similar to the electronics revolution of the late 20th century. Current applications of nanotechnology primarily make use of nanoparticles in bulk, often being made into composites or mixtures. While these materials have fantastic properties, organization of nano and microstructures of nanoparticles may allow the development of novel devices with many unique properties. …


Elementary Orbifold Differential Topology, Joseph E. Borzellino, Victor Brunsden Nov 2012

Elementary Orbifold Differential Topology, Joseph E. Borzellino, Victor Brunsden

Mathematics

Taking an elementary and straightforward approach, we develop the concept of a regular value for a smooth map f:OP between smooth orbifolds O and P. We show that Sardʼs theorem holds and that the inverse image of a regular value is a smooth full suborbifold of O. We also study some constraints that the existence of a smooth orbifold map imposes on local isotropy groups. As an application, we prove a Borsuk no retraction theorem for compact orbifolds with boundary and some obstructions to the existence of real-valued orbifold maps from local model orbifold …


Climate Change And The Water Crisis In Israel, Lauren Deutsch Nov 2012

Climate Change And The Water Crisis In Israel, Lauren Deutsch

Natural Resources Management and Environmental Sciences

Israel’s water crisis is controlled by the availability and location of water resources that are affected by climate change and geopolitics in southwest Asia. Conflict between Israel and the Palestinian occupied territories in the Gaza Strip and the West Bank have put strains on the allocation of water recourses. The goal of this research was to model how much a change in climate will affect the amount of available freshwater in Israel. Intensive research taken from Israel and the occupied territories was carried out to understand how the amount of precipitation, rainfall, and the rate of evaporation is affected by …


Geochemistry And Geochronology Of The Central Metasedimentary Belt Boundary Thrust Zone Thrust Sheets In Southern Ontario, Grenville Province, Kenjo Agustsson Nov 2012

Geochemistry And Geochronology Of The Central Metasedimentary Belt Boundary Thrust Zone Thrust Sheets In Southern Ontario, Grenville Province, Kenjo Agustsson

Natural Resources Management and Environmental Sciences

Studies of pre-Grenvillian (1.4–1.3 Ga) plutons offer insight into the dynamics of arc amalgamation and backarc rifting prior to continental collision in the Ottawan orogeny. The Central Metasedimentary Belt boundary thrust zone (CMBbtz) is a northeast–southwest trending thrust zone consisting of metaplutonic thrust sheets enveloped in gneissic tectonites and calcitic– dolomitic marbles. Tonalitic CMBbtz thrust sheets (Dysart and Redstone) are made up of upper amphibolite-facies, foliation-concordant metatonalites (+ amphibole ± biotite ± accessory zircon and titanite) and amphibolites (± biotite ± clinopyroxene), and are located in the southern Ontario Grenville Province. These thrust sheets are thought to have formed and …


P3ht:Pcpdtbt:Pcbm Multi- Polymer Single Layer Solar Cells, Ted Andreas Nov 2012

P3ht:Pcpdtbt:Pcbm Multi- Polymer Single Layer Solar Cells, Ted Andreas

Physics

OPV efficiencies are limited by their narrow absorption; rather than using tandem architecture to overcome this obstacle, our group combined P3HT and PCPDTBT into a single layer BHJ solar cell that achieved 2.0% PCE. This is 33% higher than the pure P3HT control from this group, proving that multi-polymer solar cells have the potential to outperform their single-polymer components.


Quantifying The Regional Water Footprint Of Biofuel Production By Incorporating Hydrologic Modeling, M. Wu, Y. Chiu, Y. Demissie Oct 2012

Quantifying The Regional Water Footprint Of Biofuel Production By Incorporating Hydrologic Modeling, M. Wu, Y. Chiu, Y. Demissie

Natural Resources Management and Environmental Sciences

A spatially explicit life cycle water analysis framework is proposed, in which a standardized water footprint methodology is coupled with hydrologic modeling to assess blue water, green water (rainfall), and agricultural grey water discharge in the production of biofuel feedstock at county-level resolution. Grey water is simulated via SWAT, a watershed model. Evapotranspiration (ET) estimates generated with the Penman-Monteith equation and crop parameters were verified by using remote sensing results, a satellite-imagery-derived data set, and other field measurements. Crop irrigation survey data are used to corroborate the estimate of irrigation ET. An application of the concept is presented in a …


Pyroprinting Sensitivity Analysis On The Gpu, Douglas Brandt, Aldrin Montana, Bob Somers, Alex Dekhtyar, Christopher Lupo, Michael Black, Anya Goodman, Christopher Kitts Oct 2012

Pyroprinting Sensitivity Analysis On The Gpu, Douglas Brandt, Aldrin Montana, Bob Somers, Alex Dekhtyar, Christopher Lupo, Michael Black, Anya Goodman, Christopher Kitts

Computer Science and Software Engineering

Microbial Source Tracking (MST) is a field in which microbial strains are identified and associated with a specific host source (e.g., human, canine, avian, etc). Identifying the hosts of microbial strains lies at the heart of many studies of bacterial contamination in the environment. Being able to determine which host species is responsible, e.g., for fecal contamination of a creek, allows the parties involved to develop specific measures for addressing the contamination. The paper presents an in-silico study to investigate the sensitivity of the pyroprinting method. Given a collection of possible DNA sequences that can be found in the sequenced …


Building Semantic Corpus From Wordnet, Lubomir Stanchev Oct 2012

Building Semantic Corpus From Wordnet, Lubomir Stanchev

Computer Science and Software Engineering

We propose a novel methodology for extracting semantic similarity knowledge from semi-structured sources, such as WordNet. Unlike existing approaches that only explore the structured information (e.g., the hypernym relationship in WordNet), we present a framework that allows us to utilize all available information, including natural language descriptions. Our approach constructs a semantic corpus. It is represented using a graph that models the relationship between phrases using numbers. The data in the semantic corpus can be used to measure the similarity between phrases, the similarity between documents, or to perform a semantic search in a set of documents that uses the …


Estimating The R-Value Of Earth's Atmosphere, David Hafemeister Oct 2012

Estimating The R-Value Of Earth's Atmosphere, David Hafemeister

Physics

No abstract provided.


Accretion Properties Of High- And Low-Excitation Young Radio Galaxies, Donghoon Son, Jong-Hak Woo, Sang Chul Kim, Hai Fu, Nozomu Kawakatu, Vardha N. Bennert, Tohru Nagao, Daeseong Park Oct 2012

Accretion Properties Of High- And Low-Excitation Young Radio Galaxies, Donghoon Son, Jong-Hak Woo, Sang Chul Kim, Hai Fu, Nozomu Kawakatu, Vardha N. Bennert, Tohru Nagao, Daeseong Park

Physics

Young radio galaxies (YRGs) provide an ideal laboratory to explore the connection between the accretion disk and radio jet thanks to their recent jet formation. We investigate the relationship between the emission-line properties, the black hole accretion rate, and the radio properties using a sample of 34 low-redshift (z < 0.4) YRGs. We classify YRGs as high-excitation galaxies (HEGs) and low-excitation galaxies (LEGs) based on the flux ratio of high-ionization to low-ionization emission lines. Using the Hα luminosities as a proxy of accretion rate, we find that HEGs in YRGs have ~1 dex higher Eddington ratios than LEGs in YRGs, suggesting that HEGs have a higher mass accretion rate or higher radiative efficiency than LEGs. In agreement with previous studies, we find that the luminosities of emission lines, in particular Hα, are correlated with radio core luminosity, suggesting that accretion and young radio activities are fundamentally connected.


Selection Of Hydrologic Modeling Approaches For Climate Change Assessment: A Comparison Of Model Scale And Structures, Christopher G. Surfleet, Desirèe Tullos, Heejun Chang, Il-Won Jung Sep 2012

Selection Of Hydrologic Modeling Approaches For Climate Change Assessment: A Comparison Of Model Scale And Structures, Christopher G. Surfleet, Desirèe Tullos, Heejun Chang, Il-Won Jung

Natural Resources Management and Environmental Sciences

A wide variety of approaches to hydrologic (rainfall–runoff) modeling of river basins confounds our ability to select, develop, and interpret models, particularly in the evaluation of prediction uncertainty associated with climate change assessment. To inform the model selection process, we characterized and compared three structurally-distinct approaches and spatial scales of parameterization to modeling catchment hydrology: a large-scale approach (using the VIC model; 671,000 km2 area), a basin-scale approach (using the PRMS model; 29,700 km2 area), and a site-specific approach (the GSFLOW model; 4700 km2 area) forced by the same future climate estimates. For each approach, we present …


Performances And Future Plans Of The Lhc Rf, P. Baudrenghien, T. Mastoridis Sep 2012

Performances And Future Plans Of The Lhc Rf, P. Baudrenghien, T. Mastoridis

Physics

The ramp-up of the LHC operation has been exceptionally fast: from the first acceleration of a single bunch at nominal intensity (1.1E11 p) to 3.5 TeV/c on May 2010, to the accumulation of 11 fb-1 integrated luminosity two years later (June 2012). On the RF side this was made possible by a few key design choices and several developments, that allow reliable LHC operation with 0.35 A DC beam at 4 TeV/c (1380 bunches at 50 ns spacing, 1.5E11 p per bunch). This paper reviews the RF design and presents its performance. Plans are also outlined that would allow operation …


Measurements Of The Lhc Longitudinal Resistive Impedance With Beam, J.F. Esteban Muller, T. Argyropoulos, T. Bohl, T. Mastoridis, N. Mounet, G. Papotti, B. Salvant, E. Shaposhnikova, D. Valuch Sep 2012

Measurements Of The Lhc Longitudinal Resistive Impedance With Beam, J.F. Esteban Muller, T. Argyropoulos, T. Bohl, T. Mastoridis, N. Mounet, G. Papotti, B. Salvant, E. Shaposhnikova, D. Valuch

Physics

The resistive part of the longitudinal impedance contributes to the heat deposition on different elements in the LHC ring including the beam screens, where it has to be absorbed by the cryogenic system and can be a practical limitation for the maximum beam intensity. In this paper, we present the first measurements of the LHC longitudinal resistive impedance with beam, done through synchronous phase shift measurements duringMachine Development sessions in 2012. Synchronous phase shift is measured for different bunch intensities and lengths using the high-precision LHC Beam Phase Module and then data are post-processed to further increase the accuracy. The …


Lhc Impedance Model: Experience With High Intensity Operation In The Lhc, B. Salvant, O. Aberle, G. Arduini, R. Assmann, V. Baglin, M.J. Barnes, P. Baudrenghien, A. Bertarelli, C. Bracco, R. Bruce, X. Buffat, F. Carra, G. Cattenoz, F. Caspers, S. Claudet, H. Day, J. Esteban Mueller, M. Garlasché, L. Gentini, B. Goddard, A. Grudiev, B. Henrist, W. Herr, S. Jakobsen, R. Jones, G. Lanza, L. Lari, T. Mastoridis, E. Métral, N. Mounet, A. Nosych, J.L Nougaret, S. Persichelli, T. Pieloni, A.M. Piguiet, S. Redaelli, F. Roncarolo, G. Rumolo, B. Salvachua, M. Sapinski, E. Shaposhnikova, L. Tavian, M. Timmins, J. Uythoven, A. Vidal, R. Wasef, D. Wollman, A. Burov, S. White Sep 2012

Lhc Impedance Model: Experience With High Intensity Operation In The Lhc, B. Salvant, O. Aberle, G. Arduini, R. Assmann, V. Baglin, M.J. Barnes, P. Baudrenghien, A. Bertarelli, C. Bracco, R. Bruce, X. Buffat, F. Carra, G. Cattenoz, F. Caspers, S. Claudet, H. Day, J. Esteban Mueller, M. Garlasché, L. Gentini, B. Goddard, A. Grudiev, B. Henrist, W. Herr, S. Jakobsen, R. Jones, G. Lanza, L. Lari, T. Mastoridis, E. Métral, N. Mounet, A. Nosych, J.L Nougaret, S. Persichelli, T. Pieloni, A.M. Piguiet, S. Redaelli, F. Roncarolo, G. Rumolo, B. Salvachua, M. Sapinski, E. Shaposhnikova, L. Tavian, M. Timmins, J. Uythoven, A. Vidal, R. Wasef, D. Wollman, A. Burov, S. White

Physics

The CERN Large Hadron Collider (LHC) is now in luminosity production mode and has been pushing its performance in the past months by increasing the proton beam brightness, the collision energy and the machine availability. As a consequence, collective effects have started to become more and more visible and have effectively slowed down the performance increase of the machine. Among these collective effects, the interaction of brighter LHC bunches with the longitudinal and transverse impedance of the machine has been observed to generate beam induced heating, as well as longitudinal and transverse instabilities since 2010. This contribution reviews the current …


Comparative Analysis Of Dispersion Parameter Estimates In Loglinear Modeling: Applied To E-Commerce Sales And Customer Data, Scott Davis Sep 2012

Comparative Analysis Of Dispersion Parameter Estimates In Loglinear Modeling: Applied To E-Commerce Sales And Customer Data, Scott Davis

Statistics

When loglinear models are applied to count data the issue of over-dispersion often arises. Moment and maximum likelihood estimation methods in accounting for over-dispersion are widely used because they allow for model checking tools such as Chi-square, F, and likelihood ratio tests. Here is a comparison between R functions that each uses one method; glm.nb uses MLE, and glm.poisson.disp uses MME. The Index of Dissimilarity and visual model selection (ECDF plots) are also incorporated. These are applied to sales data using product and customer information compiled over the last five years that was generously provided by an e-commerce company.


Analysis Of Cornell Electron-Positron Storage Ring Test Accelerator's Double Slit Visual Beam Size Monitor, Robert Campbell Sep 2012

Analysis Of Cornell Electron-Positron Storage Ring Test Accelerator's Double Slit Visual Beam Size Monitor, Robert Campbell

Physics

In the past year, a double slit interferometer was installed to measure the horizontal beam size in the Cornell Electron-Positron Storage Ring Test Accelerator (CesrTA) at Cornell University in Ithaca, NY. To better understand the systematics of this device, a replica of the CesrTA instrument was assembled at California Polytechnic State University San Luis Obispo. From the prototype, it was found that the device will produce a calculated beam size that agrees with measurements as long as it is optimized with the proper double slits for a small range of beam sizes.


Anti-Corrosion Performance Of Primer And Top Coat Formulations For Metal Substrates, Laural Elizabeth Hargrove Sep 2012

Anti-Corrosion Performance Of Primer And Top Coat Formulations For Metal Substrates, Laural Elizabeth Hargrove

Master's Theses

This project involved the improvement of several properties of the current “universal” primer coating sold by Kelly-Moore Paint Company. This formulation is an all purpose primer used both for interior and exterior applications. However, its corrosion resistance has room for improvement. The addition of sodium nitrite, an aminocarboxylate salt, and a zinc phosphate-based additive were all tested as corrosion inhibitors. In addition, during the project the coating binder was changed to improve adhesion. After a systematic experimental program, a new “universal” primer with increased corrosion resistance and adhesion was formulated.

A direct to metal top coat formulation sold by Kelly-Moore …


Using Modeling And Simulation To Analyze Complex Aircraft, Kimberlee Margosian, Jason Lechniak Aug 2012

Using Modeling And Simulation To Analyze Complex Aircraft, Kimberlee Margosian, Jason Lechniak

STAR Program Research Presentations

Modeling and Simulation (M&S) is used at the Air Force Flight Test Center (AFFTC) on Edwards Air Force Base (AFB) to better understand physical phenomena on aircraft. M&S allows for the reduction of cost and risk by providing a better understanding of required flight tests and the interactions between various forces and the aircraft (i.e. wind resistance, pressure change, and temperature change). Without this process, the lives of pilots would be at a much greater risk when testing their aircraft and there would be little to no funds to fly due to the cost to repair or modify the aircraft. …


The Implementation Of The Shear Correlation Function And The Matter Power Spectrum In R, Allison A. Scheppelmann, Deborah J. Bard Aug 2012

The Implementation Of The Shear Correlation Function And The Matter Power Spectrum In R, Allison A. Scheppelmann, Deborah J. Bard

STAR Program Research Presentations

Weak gravitational lensing is an important tool in understanding the large-scale structure of the universe. One component in understanding the effect of weak gravitational lensing is the shear correlation function and matter power spectrum. The calculation of these values is often complicated and time consuming. In order to decrease the cost of these calculations they were implemented in R using parallelization. This resulted in the calculations completing faster and the process to be easily changed in order to fit the need of each researcher using the algorithms created in R.


Electric Currents Due To Stress-Activated Positive Hole Charge Carriers In Ice, Cary T. Keller P.E., Friedemann T. Freund, Dale P. Cruikshank Aug 2012

Electric Currents Due To Stress-Activated Positive Hole Charge Carriers In Ice, Cary T. Keller P.E., Friedemann T. Freund, Dale P. Cruikshank

STAR Program Research Presentations

Jupiter’s satellite Europa, whose surface is composed of ice with a possible water ocean beneath, could conceivably serve as an abode for extraterrestrial life. This and other icy celestial bodies may contain organic macromolecular solid material that is produced when surface ices are exposed to ultraviolet radiation and/or electrical energy. Tidal and tectonic stresses or meteorite impacts in icy crusts may produce electrical discharges, which would provide the energy for in-situ synthesis of the organic solids. This electrical energy can be provided by positive hole charge carrier activation. Positive holes exhibit properties such as the ability to flow out of …


Investigation Of Spillover Effect To Enhance Hydrogen Storage, Sarah C. Corrigan, Lin Simpson, Thomas Gennett Aug 2012

Investigation Of Spillover Effect To Enhance Hydrogen Storage, Sarah C. Corrigan, Lin Simpson, Thomas Gennett

STAR Program Research Presentations

Hydrogen is an attractive energy option because of its low
environmental impact, but a critical problem is its low energy
density, which makes it difficult to store. For example, the US
Department of Energy (DOE) hydrogen plan for fuel cell powered
vehicles requires a gravimetric density of 6.5 wt%. There are several
existing hydrogen storage methods, including compressed gas,
liquefaction, metal hydrides, and physisorption, but at present, none
of these technologies comes close to achieving the targets set by the
DOE. Although chemical storage methods have been claimed to be the
most promising hydrogen storage technology, and activated carbons the …


The Abundance And Distribution Of Gelatinous Zooplankton In The San Francisco Estuary, Amalia Borson, Lindsay Sullivan, Wim Kimmerer Aug 2012

The Abundance And Distribution Of Gelatinous Zooplankton In The San Francisco Estuary, Amalia Borson, Lindsay Sullivan, Wim Kimmerer

STAR Program Research Presentations

Until recently, gelatinous zooplankton were not considered important components of the San Francisco Estuary (SFE) foodweb. However, anecdotal evidence, ongoing research, and a few published reports and papers suggest an increase in their abundance over the last 10 to 20 years. Of particular interests are three species of introduced hydromedusae (Blackfordia virginica, Maeotias marginata, and Moerisia lyonsi). All three inhabit the fresh to brackish regions of the estuary, including Suisun Bay, the channels of Suisun Marsh, and the western Sacramento-San Joaquin Delta, and are seasonally abundant throughout late summer and fall. As a result, they overlap …