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2011

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Articles 541 - 570 of 691

Full-Text Articles in Earth Sciences

Integrated Biostratigraphy Of Eocene Deposits In The Gubs Section (Northern Caucasus) With Special Attention To The Ypresian/Lutetian Boundary And To The Peritethyan-Tethyan Correlation, Elena Zakrevskaya, Vladimir Beniamovsky, György Less, Mária Báldi-Beke Jan 2011

Integrated Biostratigraphy Of Eocene Deposits In The Gubs Section (Northern Caucasus) With Special Attention To The Ypresian/Lutetian Boundary And To The Peritethyan-Tethyan Correlation, Elena Zakrevskaya, Vladimir Beniamovsky, György Less, Mária Báldi-Beke

Turkish Journal of Earth Sciences

The Ypresian to Priabonian Gubs river section, in the Adygean high of the northern slope of the Caucasus, is a rare locality, in whichYpresian-Lutetian representative larger benthic foraminifera coexist with planktonic Foraminifera and calcareous nannoplankton. This provides a good opportunity to apply and refine the zonal Ypresian-Lutetian scheme of the Crimean-Caucasus region, to correlate the zonal subdivision of the three most important Palaeogene groups of microfossils and to give a new insight on the position of the Ypresian/Lutetian boundary. About 50 species and subspecies of larger foraminifera, represented by orthophragmines (Discocyclina, Nemkovella, Orbitoclypeus and Asterocyclina) and nummulitids (Nummulites and Operculina) …


Subsurface Compaction A Guide For Wa Farmers And Consultants, Stephen Davies, Alison Lacey Jan 2011

Subsurface Compaction A Guide For Wa Farmers And Consultants, Stephen Davies, Alison Lacey

Bulletins 4000 -

For plants to grow in agricultural soils, roots and emerging shoots must be able to force their way through the soil. In soils of high strength, this growth is physically restricted. High strength soils may be due to natural soil characteristics and conditions or develop as a result of agricultural practices and may be in layers or throughout the soil profile.

In agriculture, high strength soils commonly occur as a result of compaction. Compaction of agricultural soils can be in the surface (often caused by stock trampling or rain drop splatter) or in the subsurface (usually in a layer at …


Laboratory Scale Seismic Analysis Of A Spatially Variable Hydrological Surface In Unconfined, Unconsolidated Sand, David E. Smolkin Jan 2011

Laboratory Scale Seismic Analysis Of A Spatially Variable Hydrological Surface In Unconfined, Unconsolidated Sand, David E. Smolkin

LSU Master's Theses

The ability to measure the depth to the water table can provide information such as reservoir characteristics, soil conditions for agriculture, and actions to be taken with contaminant flow and removal. We attempt to detect this boundary in a larger-than-lab scale experiment. We attempt to simulate a spatially variable water level and attempt to image changes in the depth of this water level. We try to reduce the normally complex natural conditions to those of a nominally homogeneous and isotropic, unconfined sand volume for modeling. These simplified conditions help isolate the effects of remaining complexities such as the variable saturation …


Provenance And Origin Of Holocene Beach Ridge And Modern Beach Sands From The Costa De Nayarit, Western Mexico, Ruben Abe Cisneros Jan 2011

Provenance And Origin Of Holocene Beach Ridge And Modern Beach Sands From The Costa De Nayarit, Western Mexico, Ruben Abe Cisneros

LSU Master's Theses

The Costa de Nayarit in western Mexico is a classic modern example of the progradation of a coastline in a wave-dominated depositional environment. Throughout the Pleistocene, sediments have been brought to the Costa De Nayarit via three major river systems, the Rio Grande de Santiago, the Rio San Pedro and the Rio Acaponeta. These river systems obtain their sediments from two distinctly different volcanic provinces within central Mexico, the Sierra Madre Occidental (SMO), a volcanic province characterized by its predominance of felsic volcanism (rhyolites) and pyroclastic flows (welded ash flow tuff and ignimbrite), and the Trans-Mexican Volcanic Belt (TMVB), which …


Glacial Deposits, Vol. 39, 2010-2011, Department Of Geography-Geology Jan 2011

Glacial Deposits, Vol. 39, 2010-2011, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology


A Palynological And Sequence Stratigraphic Study Of Santonian - Maastrichtan Strata From The Upper Magdalena Basin, Sandra Garzon Jan 2011

A Palynological And Sequence Stratigraphic Study Of Santonian - Maastrichtan Strata From The Upper Magdalena Basin, Sandra Garzon

LSU Master's Theses

This manuscript presents a biostratigraphic and sequence stratigraphic interpretation of palynological data from two outcrop sections on the NE flank of the Upper Magdalena Valley (UMV) basin comprising the Santonian to Lower Maastrichtian interval. The objectives of this study where: a) to characterize the lithologically similar Lower Lidita, Upper Lidita, and El Cobre, Buscavidas formations and b) to provide a better understanding of important correlation horizons in the northeastern part of the UMV basin and to confirm the age assignment of stratal units. A cyclic pattern of palynomorph distribution was recognized in both sections and tied to the different stages …


Soft Sediment Relay Zones: A High Resolution Seismic Survey Livingston Parish, Louisiana, Erin T. Elliott Jan 2011

Soft Sediment Relay Zones: A High Resolution Seismic Survey Livingston Parish, Louisiana, Erin T. Elliott

LSU Master's Theses

The southern coast of the United States, bordering the Gulf of Mexico, is home to several down-to-the-south, listric, normal fault systems striking parallel to the coast. One of these, the Baton Rouge–Tepetate Fault System located in southern Louisiana, consists of a series of near-surface, reactivated growth faults and relay ramps– a broad area of ductile strain, with contemporaneous sedimentation. Evidence of recent fault and relay ramp movement is seen in surficial fault line scarps and offset roads. This thesis utilizes two near-surface (<500 >m), high-resolution (10 - 300 Hz), continuous seismic reflection profiles (360 m and 480 m long, 3 …


Geomicrobiology Of Louisiana Coastal Marshes Before And After The Deepwater Horizon Oil Spill, Chang Liu Jan 2011

Geomicrobiology Of Louisiana Coastal Marshes Before And After The Deepwater Horizon Oil Spill, Chang Liu

LSU Master's Theses

The 2010 Deepwater Horizon oil spill in the Gulf of Mexico not only impacted open ocean and shoreline geochemical and ecological environments, but it served to promote research of microbial ecosystems in poorly studied habitats, such as Louisiana marshes. Sediment and water samples from four main marshes in southern Louisiana were collected in May 2010 (pre-oil), September 2010 (oiled), and June 2011 (post-oil). Sites near the Mississippi River had exceptionally low salinity in the immediate months following the oil spill due to freshwater diversion efforts; salinity increased by an order of magnitude one year later. Microbial diversity was evaluated from …


Miscible Column Studies Of Unfractured And Saturated Cores Of Topopah Spring Tuff From Yucca Mountain, Nevada Using Hydrophobic Organic Pollutants, Kody V. Kramer Jan 2011

Miscible Column Studies Of Unfractured And Saturated Cores Of Topopah Spring Tuff From Yucca Mountain, Nevada Using Hydrophobic Organic Pollutants, Kody V. Kramer

LSU Master's Theses

Miscible displacement column studies were conducted on unfractured cores of Topopah Spring Tuff to quantify transport characteristics of bromide&44; pentafluorobenzoic acid &40;PFBA&41;&44; trichloroethylene &40;TCE&41;&44; and naphthalene. Three 5 cm diameter by 2 cm long cores were flushed with pulses of simulated groundwater containing these tracers&44; followed by tracer&45;free solution. Effective porosities were gravimetrically measured as 11&37;&44; 10.6&37;&44; and 9.5&37;. The tracers achieved full breakthrough in an order correlating to their hydrophobicities. Bromide and PFBA sorbed least&44; achieving full breakthrough in fewer than 10 pore volumes. As water analogues&44; both exhibited no quantifiable sorption. Delay to full breakthrough was contributed to …


Investigation Into The Cause Of Earthen Embankment Instability Along The "V-Line" Artificial Levee In Marrero, Louisiana, Usa, Jason Hicks Jan 2011

Investigation Into The Cause Of Earthen Embankment Instability Along The "V-Line" Artificial Levee In Marrero, Louisiana, Usa, Jason Hicks

LSU Master's Theses

The “V-line” levee, located in Marrero, LA, has a crack along its crest, measuring approximately 100 meters in length, 30 centimeters in depth, and 30 centimeters in width. This crack is a sign of levee instability. Seismic shear wave, CPT, and laboratory shear strength data were collected and processed to identify the cause of the instability. A zone of low seismic shear wave velocity was interpreted approximately 3 meters deep from the berm of the levee. Because of the large spacing between laboratory shear strength test sampling and CPT sites, a similar zone of low shear strength was not found …


Early Season Depletion Of Dissolved Iron In The Ross Sea Polynya: Implications For Iron Dynamics On The Antarctic Continental Shelf, Peter N. Sedwick, C. M. Marsay, B. M. Sohst, A. M. Aguilar-Islas, M. C. Lohan, M. C. Long, K. R. Arrigo, R. B. Dunbar, M. A. Saito, W. O. Smith, G. R. Ditullio Jan 2011

Early Season Depletion Of Dissolved Iron In The Ross Sea Polynya: Implications For Iron Dynamics On The Antarctic Continental Shelf, Peter N. Sedwick, C. M. Marsay, B. M. Sohst, A. M. Aguilar-Islas, M. C. Lohan, M. C. Long, K. R. Arrigo, R. B. Dunbar, M. A. Saito, W. O. Smith, G. R. Ditullio

OES Faculty Publications

The Ross Sea polynya is among the most productive regions in the Southern Ocean and may constitute a significant oceanic CO2sink. Based on results from several field studies, this region has been considered seasonally iron limited, whereby a "winter reserve" of dissolved iron (dFe) is progressively depleted during the growing season to low concentrations (~ 0.1 nM) that limit phytoplankton growth in the austral summer (December-February). Here we report new iron data for the Ross Sea polynya during austral summer 2005-2006 (27 December-22 January) and the following austral spring 2006 (16 November-3 December). The summer 2005-2006 data show …


A Scanning Electron Microscope Technique For Identifying The Mineralogy Of Dust In Ice Cores, Rachel Obbard, Ian Baker, David Prior Jan 2011

A Scanning Electron Microscope Technique For Identifying The Mineralogy Of Dust In Ice Cores, Rachel Obbard, Ian Baker, David Prior

Dartmouth Scholarship

Dust particles in an ice core from East Rongbuk Glacier on the northern slope of Qomolangma (Mount Everest; 28deg 01' N, 58deg 00' E; 6518m a.s.l.), central Himalaya, have been identified as mica using a combination of scanning electron microscope-based techniques and energy-dispersive X-ray spectroscopy to identify the elements present, and electron backscatter diffraction to identify the crystal type. This technique for identifying individual crystalline dust particles in samples of glacial ice could be especially useful in the future for identifying water-soluble crystals in ice, for studying the strain history (glaciotectonics) of basal ice or in studies of icemica composites …


Seasonal Ice Mass-Balance Buoys: Adapting Tools To The Changing Arctic, Chris Polashenski, Don Perovich, Jackie Richter-Menge, Bruce Elder Jan 2011

Seasonal Ice Mass-Balance Buoys: Adapting Tools To The Changing Arctic, Chris Polashenski, Don Perovich, Jackie Richter-Menge, Bruce Elder

Dartmouth Scholarship

Monitoring the local mass balance of Arctic sea ice provides opportunities to attribute the observed changes in a particular floe’s mass balance to specific forcing phenomena. A shift from multi- year to seasonal ice in large portions of the Arctic presents a challenge for the existing Lagrangian array of autonomous ice mass-balance buoys, which were designed with a perennial ice cover in mind. This work identifies the anticipated challenges of operation in seasonal ice and presents a new autonomous buoy designed to monitor ice mass balance in the seasonal ice zone. The new design presented incorporates features which allow the …


Arctic Sea-Ice Melt In 2008 And The Role Of Solar Heating, Donald K. Perovich, Jacqueline A. Richter-Menge, Kathleen F. Jones, Bonnie Light Jan 2011

Arctic Sea-Ice Melt In 2008 And The Role Of Solar Heating, Donald K. Perovich, Jacqueline A. Richter-Menge, Kathleen F. Jones, Bonnie Light

Dartmouth Scholarship

There has been a marked decline in the summer extent of Arctic sea ice over the past few decades. Data from autonomous ice mass-balance buoys can enhance our understanding of this decline. These buoys monitor changes in snow deposition and ablation, ice growth, and ice surface and bottom melt. Results from the summer of 2008 showed considerable large-scale spatial variability in the amount of surface and bottom melt. Small amounts of melting were observed north of Greenland, while melting in the southern Beaufort Sea was quite large. Comparison of net solar heat input to the ice and heat required for …


Late Cretaceous Faunal Dynamics In The Western Interior Seaway: The Record From The Red Bird Section, Eastern Wyoming, Joshua Stephen Slattery Jan 2011

Late Cretaceous Faunal Dynamics In The Western Interior Seaway: The Record From The Red Bird Section, Eastern Wyoming, Joshua Stephen Slattery

USF Tampa Graduate Theses and Dissertations

Studies examining bioevents (e.g., mass extinctions, faunal turnovers, diversification events) usually only scrutinize a short interval prior to such events, however, understanding their actual paleobiological implications requires a thorough understanding of the background conditions. The objective of this study is to document the background biodiversity dynamics in a single lithofacies of the Upper Cretaceous Pierre Shale that was deposited in an offshore setting of the Western Interior Seaway (WIS) and to place these changes into an environmental context. To assess the background biodiversity dynamics, the concretionary faunas of the Baculites eliasi through B. clinolobatus biozones of the Pierre Shale in …


Modeling Direct Runoff Hydrographs With The Surge Function, Denis Voytenko Jan 2011

Modeling Direct Runoff Hydrographs With The Surge Function, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

A surge function is a mathematical function of the form f(x)=axpe-bx. We simplify the surge function by holding p constant at 1 and investigate the simplified form as a potential model to represent the full peak of a stream discharge hydrograph. The previously studied Weibull and gamma distributions are included for comparison. We develop an analysis algorithm which produces the best-fit parameters for every peak for each model function, and we process the data with a MATLAB script that uses spectral analysis to filter year-long, 15-minute, stream-discharge data sets. The filtering is necessary to locate the …


Alternative Statistical Methods For Analyzing Geological Phenomena: Bridging The Gap Between Scientific Disciplines, Joseph Frank Van Gaalen Jan 2011

Alternative Statistical Methods For Analyzing Geological Phenomena: Bridging The Gap Between Scientific Disciplines, Joseph Frank Van Gaalen

USF Tampa Graduate Theses and Dissertations

When we consider the nature of the scientific community in conjunction with a sense of typical economic circumstances we find that there are two distinct paths for development. One path involves hypothesis testing and evolution of strategies that are linked with iterations in equipment advances. A second, more complicated scenario, can involve external influences whether economic, political, or otherwise, such as the government closure of NASA's space program in 2011 which will no doubt influence research in associated fields. The following chapters are an account of examples of two statistical techniques and the importance of both on the two relatively …


Microstructural Evolution Of Fine-Grained Layers Through The Firn Column At Summit, Greenland, R. Lomonaco, M. Albert, I. Baker Jan 2011

Microstructural Evolution Of Fine-Grained Layers Through The Firn Column At Summit, Greenland, R. Lomonaco, M. Albert, I. Baker

Dartmouth Scholarship

We present a microstructural characterization of fine-grained layers from the top 90 m of firn from Summit, Greenland, performed using a combination of scanning electron microscopy techniques including secondary electron imaging, energy-dispersive spectroscopy and electron backscattered patterns, and X-ray microcomputed tomography. The impurities in the firn, both soluble impurities and dust particles, were found largely in the grain interiors. Both c- and a-axis pole figures do not show strong evidence of a preferred orientation of the grains even at the bottom of the firn column. The firn structure became increasingly anisotropic with vertical alignment in the top 3 m, probably …


Biodegradation Of Bisphenol-A And 17b-Estradiol In Soil Mesocosms Under Alternating Aerobic/Anoxic/Anaerobic Conditions, Won-Seok Kim Jan 2011

Biodegradation Of Bisphenol-A And 17b-Estradiol In Soil Mesocosms Under Alternating Aerobic/Anoxic/Anaerobic Conditions, Won-Seok Kim

USF Tampa Graduate Theses and Dissertations

Soil-aquifer treatment (SAT) has been proposed as a method for reusing treated municipal wastewater. SAT is characterized by alternating cycles of aerobic and anaerobic conditions in the subsurface, in response to alternating cycles of flooding and drainage of a surface impoundment. It is not yet known how these alternating redox conditions affect the removal of potentially harmful endocrine-disrupting compounds (EDCs) from treated effluent.

The overall objective of my doctoral research is to determine the fate of EDCs in alternating aerobic/anoxic/anaerobic conditions under simulated SAT conditions. To assess the fate of EDCs in simulated SAT conditions, I first had to develop …


High-Resolution Event Stratigraphy Of Mm-Scale Laminated Sediments From Coastal Salt Ponds: St. John, Us Virgin Islands, Rebekka Amie Larson Jan 2011

High-Resolution Event Stratigraphy Of Mm-Scale Laminated Sediments From Coastal Salt Ponds: St. John, Us Virgin Islands, Rebekka Amie Larson

USF Tampa Graduate Theses and Dissertations

A multi-proxy approach is utilized on mm- to cm-scale laminated sediment records in coastal salt ponds on St. John, U.S. Virgin Islands to characterize the sediments, identify their sources and depositional processes/events (heavy rainfall, tropical cyclones, tsunamis). Historical records are combined with high-resolution geochronology (short-lived radioisotopes, 210Pb, 137Cs, 7Be) and scanning elemental techniques (XRF and LA-ICP-MS) to link depositional events to how they are manifested in the sedimentary record. Volcanic rocks are the terrigenous sediment source and the sedimentary signature of terrigenous sediment in the geologic record consists of higher amounts of Al, Fe, Ti, Co, and …


Urbanization And Land Surface Temperature In Pinellas County, Florida, Bruce Coffyn Mitchell Jan 2011

Urbanization And Land Surface Temperature In Pinellas County, Florida, Bruce Coffyn Mitchell

USF Tampa Graduate Theses and Dissertations

Since the early 1800's, many studies have recognized increased heat in urban areas, known as the urban heat island (UHI) effect, as one of the results of human modification to the natural landscape. UHI is related to differences in land surface temperature (LST) between rural areas and urban areas where factors of the built environment such as the thermodynamic capacities of materials, structural geometry, and heat generating activities cause increased storage and re-radiation of heat to the atmosphere. This thesis examines the correlation between factors of urbanization and differences in land surface temperature (LST) in the subtropical climate of Pinellas …


Stable Isotope Studies Of Paleoenvironment And Paleoclimate From Afar, Ethiopia, Zelalem K. Bedaso Jan 2011

Stable Isotope Studies Of Paleoenvironment And Paleoclimate From Afar, Ethiopia, Zelalem K. Bedaso

USF Tampa Graduate Theses and Dissertations

The sedimentary deposits of the Hadar Formation at Dikika and the Mount Galili Formation at Galili preserve a wealth of paleoenvironmental and paleoclimatic records spanning the last 5.29 Ma. Stable carbon and oxygen isotopic compositions of herbivore tooth enamel were analyzed for more than 600 specimens of 15 different taxa from 10 stratigraphic intervals. The application of carbon and oxygen isotopes here aims principally at reconstructing shifts in the relative abundance of C4 grasses, and its implications for climate indicators including temperature, aridity, and seasonality. The full range of δ13Cenamel values throughout the Plio-Pleistocene signifies a …


Initial Ablation Of The Laurentide Ice Sheet Based On Gulf Of Mexico Sediments, Elizabeth A. Brown Jan 2011

Initial Ablation Of The Laurentide Ice Sheet Based On Gulf Of Mexico Sediments, Elizabeth A. Brown

USF Tampa Graduate Theses and Dissertations

The objective of this project is to reconstruct a picture of initial Laurentide Ice Sheet retreat at the end of the Last Glacial Maximum (LGM) using geochemical proxies in Gulf of Mexico sediments, and place the reconstruction into global perspective. The project asks two questions. (1) Can a time frame be established for initial retreat of the Laurentide Ice Sheet? (2) If so, how does the timing compare to that of other large ice sheets and mountain glaciers in both hemispheres?

Sediment core MD02-2550 from the anoxic Orca Basin offers excellent preservation and a high sediment accumulation rate. Twelve accelerator …


Geochemical Systematics Among Amphibolitic Rocks In The Central Blue Ridge Province Of Southwestern North Carolina, Nathan Collins Jan 2011

Geochemical Systematics Among Amphibolitic Rocks In The Central Blue Ridge Province Of Southwestern North Carolina, Nathan Collins

USF Tampa Graduate Theses and Dissertations

The Central Blue Ridge sub-province of the southern Appalachian Mountains preserves an unique and complex geologic history. The Cartoogechaye terrane is the westernmost terrane of the Central Blue Ridge sub-province, and is characterized by extensive olistostromal sequences, including mafic-ultramafic massifs, isolated mafic units, and block-in-matrix structures of varying scales. This study investigates the genetic and tectonic relationships, and regional chemical and metamorphic trends of the amphibolitic rocks entrained within units of the Cartoogechaye and nearby terranes, toward constraining the origins of these regional sequences, and examining the rationale for the current Blue Ridge terrane designations.

A distinct compositional variation exists …


Crustal Structure Across The Central Alaska Range: Anatomy Of A Mesozoic Collisional Zone, P.R.K. Brennan, H. Gilbert, K. D. Ridgway Jan 2011

Crustal Structure Across The Central Alaska Range: Anatomy Of A Mesozoic Collisional Zone, P.R.K. Brennan, H. Gilbert, K. D. Ridgway

Department of Earth, Atmospheric, and Planetary Sciences Faculty Publications

A first-order process in the growth of continents is the collision and accretion of terranes against continental margins. Collision leads to the formation of a suture zone between the accreted terrane and the former continental margin. New insights on the suturing process are observed from two receiver function transects across the Mesozoic Alaska Range suture zone. Three distinct crustal sections are identified from observations of crustal thickness, intracrustal discontinuities, and Vp/Vs: a northern section with ∼27 km thick crust of felsic to intermediate composition, a central section that is ∼37 km thick that exhibits intracrustal discontinuities and has felsic to …


Sequence Stratigraphy And Source Rock Characterization Of Organic-Rich Shales Within The Jurassic Smackover Formation, Conecuh Embayment, Alabama, U.S.A., Patrick W. Niemeyer Jan 2011

Sequence Stratigraphy And Source Rock Characterization Of Organic-Rich Shales Within The Jurassic Smackover Formation, Conecuh Embayment, Alabama, U.S.A., Patrick W. Niemeyer

Electronic Theses and Dissertations

The Upper Jurassic Smackover Formation is a prolific producer of hydrocarbons known throughout the U.S. Gulf Coast region, and typically consists of carbonate lime mudstones, ooid grainstones, microbial boundstones, and dolostones. Recent exploration efforts in the Conecuh Embayment of southwest Alabama revealed the presence of two black, siliciclastic shale layers containing abundant terrestrially derived organic matter within the Smackover Formation. The shale layers provide interesting insight into the sequence stratigraphy and paleoclimate of the Conecuh Embayment, and the source of the hydrocarbons accumulated there. The two shale layers reach a maximum thickness of 50 feet along the longitudinal axis of …


Volcanism And Astrobiology: Life On Earth And Beyond, Charles S. Cockell, Sherry L. Cady, Nicola Mcloughlin Jan 2011

Volcanism And Astrobiology: Life On Earth And Beyond, Charles S. Cockell, Sherry L. Cady, Nicola Mcloughlin

Geology Faculty Publications and Presentations

Editorial Introduction to the 2011 Special Issue of Astrobiology.


Two New Spline-Based Methods And Real Data Applications: High-Resolution Receiver Function Calculations From Teleseismic Broadband Waveforms And High-Accuracy Practical Potential-Field Integral Transformations, Bingzhu Wang Jan 2011

Two New Spline-Based Methods And Real Data Applications: High-Resolution Receiver Function Calculations From Teleseismic Broadband Waveforms And High-Accuracy Practical Potential-Field Integral Transformations, Bingzhu Wang

Doctoral Dissertations

"While receiver function (RF) calculation is fundamentally important and widely used, it is not well solved due to unstable deconvolution. A spline-based RF calculation method was proposed and it is demonstrated that both individual RFs and the stacked RF calculated with the spline method have sharper peaks than those with the water-level spectral division method and the iterative deconvolution method. At the common peaks on the stacked RFs, there are close similarities for all three RF calculation methods. The better calculated RFs with the spline method lead to improved H - K analysis and improved determination of the optimal Moho …


The Kozeny-Carman Equation Considered With A Percolation Threshold, Lee Brenson Porter Ii Jan 2011

The Kozeny-Carman Equation Considered With A Percolation Threshold, Lee Brenson Porter Ii

Browse all Theses and Dissertations

A procedure has been developed for calculating permeability (k) from the Kozeny-Carmen equation, a procedure that links ideas from percolation theory with the ideas of Koltermann and Gorelick (1995) and Esselburn et al. (2011). The approach focuses on the proportion of coarser pores that are occupied by finer sediments and defines a threshold proportion. For proportions below this threshold, the unoccupied coarser pores percolate. Following the ideas of Koltermann and Gorelick (1995), the effective grain-size term in the Kozeny-Carman equation is calculated using the geometric mean if below the threshold proportion, and with the harmonic mean if above. Following ideas …


Methylmercury In Mosquitoes: Impact Of A Large Coal-Fired Power Station In Central Ohio, Matthew J. Konkler Jan 2011

Methylmercury In Mosquitoes: Impact Of A Large Coal-Fired Power Station In Central Ohio, Matthew J. Konkler

Browse all Theses and Dissertations

Emissions from coal-fired utilities are the major anthropogenic source of mercury (Hg) to the atmosphere. Because emitted Hg may be deposited near the source, there are concerns on levels of toxic monomethylmercury (MeHg) in local biota. We investigated the potential impact of a large Hg-emitting (> 500 kg Hg y-1) coal-fired power station on MeHg levels in mosquitoes near the Conesville power station in central Ohio. Mosquitoes were sampled with CO2-baited traps at 23 locations within a 60 km radius of the utility and at three reference sites distant from Hg combustion sources. MeHg in mosquitoes within a 30-km radius …