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Simulation Of Wave Propagation In Granular Particles Using A Discrete Element Model, Syed Tahmid Hussan

Electronic Theses and Dissertations

The understanding of Bender Element mechanism and utilization of Particle Flow Code (PFC) to simulate the seismic wave behavior is important to test the dynamic behavior of soil particles. Both discrete and finite element methods can be used to simulate wave behavior. However, Discrete Element Method (DEM) is mostly suitable, as the micro scaled soil particle cannot be fully considered as continuous specimen like a piece of rod or aluminum. Recently DEM has been widely used to study mechanical properties of soils at particle level considering the particles as balls. This study represents a comparative analysis of Voigt and Best …

Investigating The Relationship Between Inherited Geologic Framework And Saltwater Intrusion On St. Catherines Island, Georgia, Juliet Talaber, Jacque Kelly, Robert Vance

Honors College Theses

Since the late 1800s, the oldest cities on the Georgia coast have been withdrawing water from the confined Floridan Aquifer System. As the population has grown, a cone of depression has formed extending from Savannah, GA to St. Catherines Island, GA, a barrier island 50 km southeast of Savannah. On St. Catherines Island, the cone of depression has reversed the lateral and horizontal groundwater flow gradients causing saltwater intrusion into the Upper Floridan Aquifer from the Lower Floridan Aquifer through joints, faults, or solution collapse features. Previous studies from the southern and central areas of the island have found evidence …

Exploring The Consistency Of Flow Regimes Within And Among Ecoregions Of The Southeastern United States, Frank Paul Braun Iv

Electronic Theses and Dissertations

Human manipulation of river systems has long been a known contributor to the loss of freshwater biodiversity. By accounting for environmental causes of hydrologic variation among rivers, we can better understand how ecoregion mediates flow regimes and forecast species that may be at risk. Presumably, natural variation associated with ecoregion boundaries exerts strong influence on flow regimes, and may mediate relationships between other features (e.g., land use, dam operations) and hydrology. However, such between-ecoregion variation is poorly investigated, particularly at fine spatial and temporal scales. I characterized 10 hydrologic metrics, representing the five key dimensions of the flow regime (magnitude, …

Petrological And Geochemical Evaluation Of Rare-Earth Element Potential In The Sparta Granite Complex, Max J. Eshbaugh

Honors College Theses

Rare earth elements (REEs) are important resources with applications in the electronics, renewable energy, and automotive industries. REEs may be concentrated in the residual weathered portion of igneous parent rocks, typically granites. These residual deposits are mined in southeast Asia, but analogous climatic and geologic conditions suggest the existence of economically viable REE residual deposits in the southeastern United States (U.S.). The Sparta Granite Complex in east-central Georgia is a granitoid complex emplaced at the end of the Alleghanian orogeny, forming a suture between the Savannah River and Milledgeville terranes. Petrologic and geochemical assessments of the Sparta Granite and overlying …

Middle Savannah River: An A/R/Tographic Ecopedagogical Ethnography Experimenting With Rhizomatic Perspectives, Lisa Augustine-Chizmar

Electronic Theses and Dissertations

This research is an experiment in perspective. Using the four commonplaces (Schwab, 1978), I practiced letting the Savannah River teach me what there is to know about the water, the land, the people, and the other entities that depend on ki through artistic, ethnographic, and ecopedagogical lenses. The ethnographic findings describe the social actors that depend on ki and give a voice to the River. The a/r/tographic findings display the River on a canvas map through two hundred years using paint, clay, photography, video, abstract acrylics, and fabric. Together, these methods contribute to a unique ecopedagogical journey. This word cloud …

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Homecoming Alumni Breakfast 2021

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Sea Level Rise Symposium – Chatham County

The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson

Electronic Theses and Dissertations

Ocean acidification (OA) caused by CO₂ emissions is projected to decrease seawater pH to 7.6 by 2100. Scleractinian corals are at risk because excess H⁺ in seawater binds to carbonate (CO₃^2-), reducing its availability for CaCO₃ skeletons. The energy demand for skeletal growth increases as pH decreases because corals must actively purge excess H⁺ from their seawater sourced calcifying fluid to maintain high calcification rates. In scleractinian corals it is hypothesized that photosynthesis by symbiotic algae is critical to meet this increased energy demand. To test this hypothesis, I conducted laboratory and field …

Rainfall Interception And Redistribution By A Common North American Understory And Pasture Forb, Eupatorium Capillifolium (Lam. Dogfennel), D. Alex Gordon, Miriam Coenders-Gerrits, Brent A. Sellers, S. M. Moein Sadeghi, John T. Van Stan Ii

School of Earth, Environment, and Sustainability Faculty Publications

In vegetated landscapes, rain must pass through plant canopies and litter to enter soils. As a result, some rainwater is returned to the atmosphere (i.e., interception, I) and the remainder is partitioned into a canopy (and gap) drip flux (i.e., throughfall) or drained down the stem (i.e., stemflow). Current theoretical and numerical modeling frameworks for this process are almost exclusively based on data from woody overstory plants. However, herbaceous plants often populate the understory and are the primary cover for important ecosystems (e.g., grasslands and croplands). This study investigates how overstory throughfall (P_T,o) is partitioned into …

Wrack & Ruin: A Tale Of Tortured Trees, John T. Van Stan Ii, Albertus Tyasseta, Siloy, Graphic Artist

School of Earth, Environment, and Sustainability Faculty Bookshelf

Here, we visit a community of trees living along the Georgia coast, just above the high tide line, on a little lump of sand called a "hammock." This hammock plant community is battered by a hurricane. The plants that survive soon realize that they have fallen prey to a hydrological torture wrack - one composed of the salty corpses of their neighboring marsh plants (Spartina alterniflora). This sci comic is based on the publication, "Wrack and ruin: Legacy hydrologic effects of hurricane-deposited wrack..." (https://doi.org/10.1088/2515-7620/ab9527).

Wrack And Ruin: Legacy Hydrologic Effects Of Hurricane-Deposited Wrack On Hardwood-Hammock Coastal Islands, John T. Van Stan Ii, Scott T. Allen, Travis Swanson

School of Earth, Environment, and Sustainability Faculty Publications

Hurricanes can cause immediate catastrophic destruction of marsh vegetation and erosion of soils; however, they also have long-lasting ecological impacts. Those impacts include the deposition of tremendous amounts of saltmarsh litter ('wrack') onto upland ecosystems, the hydrologic effects of which have not previously been investigated. When Hurricane Irma battered the southeastern US coastline, widespread wrack deposition was reported (often exceeding 0.5 m depth), especially in vulnerable coastal hammock ecosystems: locally-elevated forests within the saltmarshes that rely on freshwater inputs from rain. We report the impacts of this deposited wrack, which has persisted for 2 years, on effective precipitation inputs to …

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Geography Research Presented
• GIS Day Savannah
• Sea Turtle Program Highlighted in Georgia Southern Magazine

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Sea Turtle Program Highlighted in Fall 2019 Georgia Southern Magazine

Computer Vision-Based Traffic Sign Detection And Extraction: A Hybrid Approach Using Gis And Machine Learning, Zihao Wu

Electronic Theses and Dissertations

Traffic sign detection and positioning have drawn considerable attention because of the recent development of autonomous driving and intelligent transportation systems. In order to detect and pinpoint traffic signs accurately, this research proposes two methods. In the first method, geo-tagged Google Street View images and road networks were utilized to locate traffic signs. In the second method, both traffic signs categories and locations were identified and extracted from the location-based GoPro video. TensorFlow is the machine learning framework used to implement these two methods. To that end, 363 stop signs were detected and mapped accurately using the first method (Google …

A Geophysical Investigation Of Stratigraphy And Structure On St. Catherines Island, Georgia, Anne M. Delua

Honors College Theses

Geophysical tools were used to investigate potential structural and stratigraphic pathways of the salt water intrusion that is affecting the surficial aquifer on St. Catherines Island, Georgia. Ground penetrating radar (GPR) is a geophysical tool that uses electromagnetic waves to view the subsurface. GPR is used for a variety of applications stratigraphically, biologically, and anthropogenically. GPR electromagnetic waves react to changes in density and composition and type and percentage of pore fluids in sediment and rock. GPR waves also react to interfaces including fractures and faults. GPR waves exhibit attenuation and decreased return signal in materials such as clay. Fresh …

Locomotion And Skeletal Morphology Of Late Cretaceous Mosasaur, Tylosaurus Proriger, Jesse A. Carpenter

Honors College Theses

Mosasaurs (Reptilia: Squamata) are apex marine predators from the Late Cretaceous (Turonian to Maastrichtian) epicontinental seas of North America, Africa, Europe, and Asia. From previous studies, it has been suggested that this group trends towards increased rib compactness, lengthening and increased posterior inclination of neural spines of intermediate and terminal caudal vertebrae to support a caudal fluke, and a transition from anguilliform to carangiform locomotion, closer to thunniform in pelagic adapted species. This study examined multiple Tylosaurus specimens using centrum length/width (CL/CW) and width/height (CW/CH) ratios along with neural spine height and angle of posterior inclination to (1) describe the …

Molecular And Optical Properties Of Tree-Derived Dissolved Organic Matter In Throughfall And Stemflow From Live Oaks And Eastern Red Cedar, Aron Stubbins, Leticia M. Silva, Thorsten Dittmar, John T. Van Stan

School of Earth, Environment, and Sustainability Faculty Publications

Studies of dissolved organic matter (DOM) transport through terrestrial aquatic systems usually start at the stream. However, the interception of rainwater by vegetation marks the beginning of the terrestrial hydrological cycle making trees the headwaters of aquatic carbon cycling. Rainwater interacts with trees picking up tree-DOM, which is then exported from the tree in stemflow and throughfall. Stemflow denotes water flowing down the tree trunk, while throughfall is the water that drips through the leaves of the canopy. We report the concentrations, optical properties (light absorbance) and molecular signatures (ultrahigh resolution mass spectrometry) of tree-DOM in throughfall and stemflow from …

Assessing Shoreline Change And Vegetation Cover Adjacent To Back-Barrier Shoreline Stabilization Structures In Georgia Estuaries, Katherine R. Wakefield

Electronic Theses and Dissertations

Anthropogenic stabilization of erosional shorelines by hard-armoring structures is used for protection of property, especially if buildings, historical monuments, cultural resources, or other infrastructure are present. The post-installation effects of shoreline stabilization structures on adjacent shorelines in the back-barrier marshes of coastal Georgia are a concern, and interest in living shorelines as erosion control devices has increased because of their use of natural materials and vegetation. AMBUR shoreline analysis software was used to calculate pre-and post-installation shoreline change rates of shorelines adjacent to riprap and bulkhead structures. There was no significant difference between the post-installation shoreline change rates of the …

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Researchers Rescue Sea Turtle

A Multilevel Analysis Of Neighborhood Socioeconomic Effect On Preterm Births In Georgia, Usa, Wei Tu, Jun Tu, Stuart H. Tedders

School of Earth, Environment, and Sustainability Faculty Publications

This study estimates the neighborhood socioeconomic status (SES) effect on the risk of preterm birth (PTB) using multilevel regression (MLR) models. Birth data retrieved from year 2000 and 2010 Georgia Vital Records were linked to their respective census tracts. Principle component analysis (PCA) was performed on nine selected census variables and the first two principal components (Fac1 and Fac2) were used to represent the neighborhood-level SES in the MLR models. Two-level random intercept MLR models were specified using 122,744 and 112,578 live and singleton births at the individual level and 1613 and 1952 census tracts at the neighborhood level, for …

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Georgia Southern Faculty Research Receives National Attention

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Geology & Geography graduates go to sea

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Georgia Southern University Signs MOU with Mindo Cloudforest Foundation of Milpe, Ecuador
• Hanson and Good Scholarships Applications Now Available

Throughfall Nutrients In A Degraded Indigenous Fagus Orientalis Forest And A Picea Abies Plantation In The Of North Of Iran, Parisa Abbasian, Pedram Attarod, Seyed Mohammad Moein Sadeghi, John T. Van Stan, Seyed M. Hojjati

School of Earth, Environment, and Sustainability Faculty Publications

Aim of study: The objective of this study was to compare the quantity and quality of TF (throughfall) in an indigenous, but degraded, stand of Fagus orientalis and Picea abies plantation.

Area of study: Forests of Kelar-Dasht region located in Mazandaran province, northern Iran.

Material and Methods: TF measured by twenty collectors that were distributed randomly underneath each stand. For 21 storms sampled in 2012 (August-December) and 2013 (April-June), we analyzed pH, EC, Ca2+, Mg2+, K+, NO3-, and P of gross rainfall (GR) and TF.

Main results: Cumulative interception (I) for F. orientalis and P. abies were 114.2 mm and …

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• C.J. Jackson’s work featured in Coastal Currents

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Study Abroad Opportunity to be offered Summer 2015

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Georgia Southern Professor studies debris flow in the Dolomite Alps

Evolution Of High Tooth Replacement Rates In Sauropod Dinosaurs, Michael D. D'Emic, John A. Whitlock, Kathlyn M. Smith, Daniel C. Fisher, Jeffrey A. Wilson

School of Earth, Environment, and Sustainability Faculty Publications

Background: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates.

Methodology/Principal Findings: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined …

Inquiry-Based Introductory Earth Science Laboratory Using Survey Equipment, Tamie J. Jovanelly

Georgia Educational Researcher

A laboratory assignment entitled was developed to give high-school students an opportunity to collect, analyze, and interpret data after they have been introduced to topographic maps and associated terminology. Survey equipment (automatic level, graduated staff, and tripod) is used to collect data with the goal of creating a topographic profile along a linear transect on campus. This assignment sets itself apart from traditional introductory earth science labs because the students are using instrumentation to collect data, rather than having a data set provided for them. The benefits of this assignment include: 1) further understanding of topographic maps, 2) practice with …

John Russell Bozeman Papers, Zach S. Henderson Library Special Collections

Finding Aids

This collection consists of research materials belonging to Georgia Southern College instructor, John Russell Bozeman. Materials span 1948-1994 and include research files on beach erosion, the ecology of the Georgia barrier islands, and general information on Southeastern ecology and topography.

Find this collection in the University Libraries' catalog.