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Full-Text Articles in Physical Sciences and Mathematics

Understanding The Behavior Of Sulfidic Colloids In The Presence Of Metals, Daniel Zamudio, Alex Quyenvo, Vincent Noël, John Bargar Sep 2019

Understanding The Behavior Of Sulfidic Colloids In The Presence Of Metals, Daniel Zamudio, Alex Quyenvo, Vincent Noël, John Bargar

STAR Program Research Presentations

Riverton, Wyoming was host to a former uranium and vanadium ore processing plant, which operated from 1958 to 1963. The milling operations at the site contaminated the surface and shallow groundwater. The area became a Department of Energy (DOE) legacy site, where the U.S. Nuclear Regulatory Commission approved the DOE’s natural flushing compliance strategy. Up until the flooding in 2010, the natural flushing compliance strategy was going underway as expected. Sampling after the flood revealed a significant increase in contaminant concentration.

New updated models need to be developed to help understand the situation at Riverton, for which this laboratory experiment …


Visualization Of Geospatial Data As An Analytical And Educational Tool, Richard A. Vu Aug 2018

Visualization Of Geospatial Data As An Analytical And Educational Tool, Richard A. Vu

STAR Program Research Presentations

World Wind is an open-source API developed for Java, Android, and browsers that is designed to visualize and interact with geospatial data. The Web World Wind client is composed of four major components: the HTML template, the globe, geospatial features, and application features. The template was implemented using Bootstrap and hosts the globe provided by World Wind. This globe draws its data from multiple imagery sources, including the Open Geospatial Consortium (OGC) Web Map Service and Web Map Tile Service. This enables the application to perform and visualize complex calculations with multiple types of data such as weather and terrain. …


Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen Jan 2017

Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen

STAR Program Research Presentations

Ranching began on Santa Rosa Island in the 1840’s, consequently introducing nonnative megafauna that put novel selective grazing pressures on endemic plant species. Their movement patterns also altered substrate integrity as the land became denuded of any stabilizing vegetation. Dense groves of island oak (Q. tomentella) are known to aid in sediment deposition and retention. The groves also function to collect water during periods of intense fog common to the island. This experiment sought to determine whether sediment is being lost or deposited on a ridge in the middle of the island containing a grove of Q. tomentella …


Development And Curation Of The Sample Data Library For The Astrobiogeochemistry Laboratory, Meika R. Nwaomah, Lorenia Jimenez, Michael Tuite Aug 2016

Development And Curation Of The Sample Data Library For The Astrobiogeochemistry Laboratory, Meika R. Nwaomah, Lorenia Jimenez, Michael Tuite

STAR Program Research Presentations

In 2011, the National Science Foundation (NSF) initiated EarthCube, an integrated cyber infrastructure initiative, to tackle challenges within geoscience research. EarthCube’s goal is to improve public access and collaboration within the geoscience community. During the summer of 2015, the Astrobiogeochemistry Laboratory (abcLab) joined the collective efforts of EarthCube by developing the Sample Data Library (SDL) for the Jet Propulsion Laboratory (JPL). The main focus of the SDL concentrates on effectively curating the samples collected by researchers within the Planetary Chemistry and Astrobiology section at JPL. The goal of this summer internship was to assimilate field notes, images, and from data …


Using Data Visualization Software To Aid In The Analysis Of Geographical Data, Matthew R. Evers, Inzamam Rahaman Aug 2015

Using Data Visualization Software To Aid In The Analysis Of Geographical Data, Matthew R. Evers, Inzamam Rahaman

STAR Program Research Presentations

NASA Web World Wind (Web WW) is designed to visualize and manage geographical data. As a first implementation of visualization and analysis, we designed an application to map earthquake data onto the globe. Portions of this code were merged with application monitoring magnetic field anomalies possibly associated with earthquake precursor activity. Web WW enabled the visualization of the directional vectors from this data to point to the source location of the earthquake. We also developed a prototype urban management application which utilizes OpenStreetMaps to provide simple features such as route navigation, geographical and services information in an area of interest. …


Identifying Glacial Movement Through Fluvial Sediment Analysis, Alexis D. Freeman Aug 2015

Identifying Glacial Movement Through Fluvial Sediment Analysis, Alexis D. Freeman

STAR Program Research Presentations

The primary purpose of this study is to better understand how climate affects river dynamics. It is also important to understand the relationship between glaciers and the transportation of sediments, as this allows us to study changes in transport through time. The studied sediments were gathered from outcrops located in Fresno Ca, off of Friant road. The origin of these sediments are the Sierra Nevada Mountains. Mesozoic metasedimentary and metavolcanic sediments are derived from the foothills, while the granitic sediments are derived from higher up in the mountains. The sediments are characterized by both their degree of rounding, and their …


Remote Exploration: Understanding Martian Surface Processes, Sarah M. Bass, Virginia C. Gulick, Natalie Glines, Patrick Freeman Aug 2014

Remote Exploration: Understanding Martian Surface Processes, Sarah M. Bass, Virginia C. Gulick, Natalie Glines, Patrick Freeman

STAR Program Research Presentations

Earth and Mars share many similar physical features, including canyons, valleys, craters, volcanoes, ice, and gullies. My research focuses on two distinct projects. The first concentrates on the formation of gullies, which are channel networks generally formed on mid-latitude crater walls on Mars. Debated gully-forming processes include the melting of snowpacks, sublimation of accumulated carbon dioxide frost, melting of snow-rich dusty mantle material, and groundwater flows. Using High Resolution Imaging Science Experiment (HiRISE) images of gullies and working with Digital Elevation Models (DEMs) in ENVI, we are able to perform detailed studies of gully morphology, including volume calculations using slope, …


Geochemical Analysis Of Ice Age River Deposits From Turlock Lake Formation, Cemex Quarry Fresno, Ca, Ray J. Bargas Aug 2014

Geochemical Analysis Of Ice Age River Deposits From Turlock Lake Formation, Cemex Quarry Fresno, Ca, Ray J. Bargas

STAR Program Research Presentations

Nineteen bags of Pleistocene Age river deposited samples were taken from the Cemex Quarry in Fresno, CA. There are three formations in the area, deposited from rivers derived from glaciers, consisting of the Modesto, Riverbank, and Turlock Lake; youngest deposited to oldest respectively.

Phi sizes refer to each of the individual grains diameter, larger sized grains are in the negative spectrum while smaller grains are positive. Each sample has phi size bags that range in sizes from -5 to 4+, excluding phi size -2. For the phi sizes of -3 to -5, each individual rock was measured on its three …


Assessment Of Salmon Habitat On The Feather River, Nathan Sweem Aug 2014

Assessment Of Salmon Habitat On The Feather River, Nathan Sweem

STAR Program Research Presentations

Human activity in central valley streams has had a significantly negative impact on salmon habitat (Williams 2006). The presence of dams impedes sediment transport which is critical to salmon spawning (Williams 2006; Kondolf 1997). As part of an effort to enhance salmon spawning, the California Department of Water Resources added 7000 ft3 of gravel to Cottonwood Hatchery, Upper Auditorium, and Auditorium riffles on the Lower Feather River below the Thermalito Dam Complex in July of 2014. Stream conditions at Cottonwood Hatchery riffle were assessed by conducting analysis of sediment grain size, water depth and velocity, gravel permeability, and dissolved …


Kenyan Climate Variation Assessment Through Rainfall Anomalies And Sea Surface Temperature (Sst) Correlations, Kimberly E. Lykens Jan 2014

Kenyan Climate Variation Assessment Through Rainfall Anomalies And Sea Surface Temperature (Sst) Correlations, Kimberly E. Lykens

STAR Program Research Presentations

The diverse and varied climate of Eastern Africa’s Kenya is home to an agriculturally dependent populace, in which farmers and other related economic sectors make up the majority of livelihoods and gross domestic product. Recurring droughts and severe flooding are major concerns for local farmers and governmental entities. The purpose of this study is to identify and categorize differences in rainfall trends over Kenya and to examine relationships between seasonal rainfall anomalies of sea surface temperature (SST), with an ultimate goal to improve predictions of wet season rainfall amounts. The analysis began with data from 27 national and cooperative weather …


The Influence Of Soil Organic Matter Stabilization Mechanisms On Carbon Mean Residence Time Within Various Ecosystems In The United States, Vicky Lynn Giese, Kate Heckman Phd Aug 2013

The Influence Of Soil Organic Matter Stabilization Mechanisms On Carbon Mean Residence Time Within Various Ecosystems In The United States, Vicky Lynn Giese, Kate Heckman Phd

STAR Program Research Presentations

Some terrestrial ecosystems and soils serve as carbon sinks, partially offsetting rising atmospheric CO2 levels. Physiochemical mechanisms of soil organic matter (SOM) stabilization affect how carbon stocks respond to global warming. In order to clarify the variance in SOM stabilization mechanisms across different soil types, SOM abundance, distribution and mean residence time (MRT) were compared for thirty-two soil samples from six ecosystems across the United States. Soils were previously described, collected and archived by the United States Geological Survey. Samples were processed by LLNL at the Center for Accelerator Mass Spectrometry (CAMS) using density fractionation to separate particulate organics …


Lithic Analysis Of Coyote Canyon Mammoth Site Sediments, Kaitlin M. Hill, George V. Last Aug 2013

Lithic Analysis Of Coyote Canyon Mammoth Site Sediments, Kaitlin M. Hill, George V. Last

STAR Program Research Presentations

The landforms and geologic layers of Southeastern Washington record fascinating, unique geologic events, including repeated catastrophic flooding that occurred during the last Ice Age. These floods left behind many distinctive features, and a variety of fossils. After discovery of mammoth-sized bones in 1999, and confirmation that more bones were still in place in 2008, the Coyote Canyon Mammoth Site near Kennewick, Washington was secured for research, and formal excavation began in 2010.

Previous research suggests that the remains are buried in Ice Age flood deposits, which are overlain by eolian sediments, and those in turn overlain by slope wash. We …


Raman Mapping Of Mars Relevant Minerals Using Multiple Excitation Wavelenghts, Victoria Campbell, William Abbey Aug 2012

Raman Mapping Of Mars Relevant Minerals Using Multiple Excitation Wavelenghts, Victoria Campbell, William Abbey

STAR Program Research Presentations

The purpose of this project is to map Mars relevant minerals using the Raman instrument Horiba LabRam Raman. The Raman spectrometer is a non-invasive sampling technique used to identify mineral composition of various compositions by measuring the “Raman Shift” of each mineral. This was accomplished by using a green (532nm) laser which acted as a monochromatic light source. This source was absorbed by the sample and reemitted. The frequency of the reemitted photons are then shifted up or down in comparison with original frequency, which is referred to as the ‘Raman Effect’. The samples with shorter wavelengths produced a stronger …


Rock Porosity Analysis Using High Resolution X-Ray Tomography, Leo Groner, Dula Parkinson, Katya Bazilevskaya Aug 2011

Rock Porosity Analysis Using High Resolution X-Ray Tomography, Leo Groner, Dula Parkinson, Katya Bazilevskaya

STAR Program Research Presentations

Understanding rock porosity, the fraction of rock volume that is in pores, is a key to modeling weathering and flow of water, petroleum and CO2 through geological structures. Weathering of rocks affects the CO2 cycle, nutrient cycle and soil formation. Rock porosity affects water flow rates and, in turn, affects weathering. Avizo software was used to explore, visualize and measure the reconstructed high-resolution X-ray micro-tomography data collected from scanned rocks. Many Avizo approaches were tried before arriving at an acceptable process to determine their porosity characteristics. Porosity dynamics are affected by weathering and lithification. At micron resolution, the image is …