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2004

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Articles 181 - 210 of 4447

Full-Text Articles in Physical Sciences and Mathematics

Emit: An Apparatus To Test Time Reversal Invariance In Polarized Neutron Decay, H. P. Mumm, A. Garcia, L. Grout, M. Howe, L. P. Parazzoli, R. G. H. Robertson, K. M. Sundqvist, J. F. Wilkerson, S. J. Freedman, B. K. Fujikawa, L. J. Lising, M. S. Dewey, J. S. Nico, A. K. Thompson, T. E. Chupp, R. L. Cooper, K. P. Coulter, S. R. Hwang, R. C. Welsh, L. J. Broussard, C. A. Trull, F. E. Wietfeldt, Gordon L. Jones Dec 2004

Emit: An Apparatus To Test Time Reversal Invariance In Polarized Neutron Decay, H. P. Mumm, A. Garcia, L. Grout, M. Howe, L. P. Parazzoli, R. G. H. Robertson, K. M. Sundqvist, J. F. Wilkerson, S. J. Freedman, B. K. Fujikawa, L. J. Lising, M. S. Dewey, J. S. Nico, A. K. Thompson, T. E. Chupp, R. L. Cooper, K. P. Coulter, S. R. Hwang, R. C. Welsh, L. J. Broussard, C. A. Trull, F. E. Wietfeldt, Gordon L. Jones

Articles

We describe an apparatus used to measure the triple-correlation term (D (σ) over cap (n).p(e)xp(nu)) in the beta decay of polarized neutrons. The D coefficient is sensitive to possible violations of time reversal invariance. The detector has an octagonal symmetry that optimizes electron-proton coincidence rates and reduces systematic effects. A beam of longitudinally polarized cold neutrons passes through the detector chamber, where a small fraction undergo beta decay. The final-state protons are accelerated and focused onto arrays of cooled semiconductor diodes, while the coincident electrons are detected using panels of plastic scintillator. Details regarding the design and performance of the …


Measurement Of D*± Production In Deep Inelastic E±P Scattering At Desy Hera, S. Chekanov, M. Derrick, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi Dec 2004

Measurement Of D*± Production In Deep Inelastic E±P Scattering At Desy Hera, S. Chekanov, M. Derrick, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi

Faculty Publications

Inclusive production of D*± (2010) mesons in deep inelastic scattering has been measured with the ZEUS detector at DESY HERA using an integrated luminosity of 81.9 pb-1. The decay channel D*+ →D0π+ with D 0→K-π+ and corresponding antiparticle decay were used to identify D* mesons. Differential D* cross sections with 1.5


Design And Model Verification Of An Infrared Chromotomographic Imaging System, Daniel A. Lemaster Dec 2004

Design And Model Verification Of An Infrared Chromotomographic Imaging System, Daniel A. Lemaster

Theses and Dissertations

A prism chromotomographic hyperspectral imaging sensor is being developed to aid in the study of bomb phenomenology. Reliable chromotomographic reconstruction depends on accurate knowledge of the sensor specific point spread function over all wavelengths of interest. The purpose of this research is to generate the required point spread functions using wave optics techniques and a phase screen model of system aberrations. Phase screens are generated using the Richardson-Lucy algorithm for extracting point spread functions and Gerchberg-Saxton algorithm for phase retrieval. These phase screens are verified by comparing the modeled results of a blackbody source with measurements made using a chromotomographic …


On The Design Of Efficient Priority Rules For Secured Creditors: Empirical Evidence From A Change In Law, Clas Bergström, Theodore Eisenberg, Stefan Sundgren Dec 2004

On The Design Of Efficient Priority Rules For Secured Creditors: Empirical Evidence From A Change In Law, Clas Bergström, Theodore Eisenberg, Stefan Sundgren

Cornell Law Faculty Publications

This article assesses the effect of a reduction in secured creditor priority on distributions and administrative costs in liquidating bankruptcy cases by reporting the first empirical study of the effect of a priority change. Priority reform had redistributive effects in liquidating bankruptcy. As expected, average payments to general unsecured creditors were significantly higher after the reform than before the reform and payments to secured creditors decreased. Reform did not increase the size of the pie to be distributed in bankruptcy. Nor did it increase the direct costs of bankruptcy.


The Spectra Of Type Ii Cepheids. Iii. The Hα Line And Helium Emission In Long-Period Stars, Edward G. Schmidt, Dale Johnston, Kevin M. Lee, Shawn Langan, Peter R. Newman, Stephanie A. Snedden Dec 2004

The Spectra Of Type Ii Cepheids. Iii. The Hα Line And Helium Emission In Long-Period Stars, Edward G. Schmidt, Dale Johnston, Kevin M. Lee, Shawn Langan, Peter R. Newman, Stephanie A. Snedden

Department of Physics and Astronomy: Faculty Publications

We have obtained Hα profiles from 175 spectra of 37 Cepheids with periods longer than 8 days. About two-thirds of the stars are likely type II Cepheids. In contrast to the situation among short-period stars, the velocity of Hα relative to the metal-line spectrum is not a useful parameter for distinguishing type I and type II Cepheids. On the other hand, at periods longer than 11 days and shorter than 34 days strong emission is observed in many stars and appears to be a good discriminator of type. On this basis we identify one probable type I Cepheid at a …


Toward The Design Of Mr Agents For Imaging Β-Cell Function, Mark Woods, Shanrong Zhang, A. Dean Sherry Dec 2004

Toward The Design Of Mr Agents For Imaging Β-Cell Function, Mark Woods, Shanrong Zhang, A. Dean Sherry

Chemistry Faculty Publications and Presentations

The chemistry of Gd3+-based MRI agents has advanced considerably during the past decade toward agents with higher relaxivity and agents that respond to physiology and / or metabolism. This review describes various approaches that have been taken toward the development of responsive contrast agents and discusses the importance of fast water exchange for advancement of targeted Gd3+-based agents with higher sensitivity. The recent discovery of Eu3+ complexes having extraordinarily slow water exchange has opened a new avenue in contrast agent design based upon the chemical exchange saturation transfer (CEST) mechanism. These new paramagnetic complexes called PARACEST agents offer new possibilities …


Vertical Sensitivity For The Information Security Health Rating Of Enterprises, Arcot Desai Narasimhalu, Nagarajan Dayasindhu, Raghavan Subramanian Dec 2004

Vertical Sensitivity For The Information Security Health Rating Of Enterprises, Arcot Desai Narasimhalu, Nagarajan Dayasindhu, Raghavan Subramanian

Research Collection School Of Computing and Information Systems

INFOSeMM Maturity model was developed jointly by SMU and Infosys. It is recognized that different industry verticals will have different levels of recommended maturity levels. This paper articulates the need for developing the industry vertical benchmarks.


High Performance P300 Speller For Brain-Computer Interface, Cuntai Guan, Manoj Thulasidas, Jiankang Wu Dec 2004

High Performance P300 Speller For Brain-Computer Interface, Cuntai Guan, Manoj Thulasidas, Jiankang Wu

Research Collection School Of Computing and Information Systems

P300 speller is a communication tool with which one can input texts or commands to a computer by thought. The amplitude of the P300 evoked potential is inversely proportional to the probability of infrequent or task-related stimulus. In existing P300 spellers, rows and columns of a matrix are intensified successively and randomly, resulting in a stimulus frequency of 1/N (N is the number of rows or columns of the matrix). We propose a new paradigm to display each single character randomly and individually (therefore reducing the stimulus frequency to 1/(N*N)). On-line experiments showed that this new speller significantly improved the …


Design Lessons On Access Features In Paper, Yin-Leng Theng, Dion Hoe-Lian Goh, Ming Yin, Eng-Kai Suen, Ee Peng Lim Dec 2004

Design Lessons On Access Features In Paper, Yin-Leng Theng, Dion Hoe-Lian Goh, Ming Yin, Eng-Kai Suen, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Using Nielsen's Heuristic Evaluation, this paper reports a user study with six usability-trained subjects to evaluate PAPER's access features in assisting users to retrieve information efficiently, part of an on-going design partnership with stakeholders and designers/developers. PAPER (Personalised Adaptive Pathways for Exam Resources) is an improved version evolving from an earlier implementation of GeogDL built upon G-Portal, a geospatial digital library infrastructure. After two initial evaluations with student and teacher design partners, PAPER has evolved into a system containing a new bundle of personalized, interactive services with four modules: mock exam; personal coach (practice and review); trend analysis and performance …


Supporting Field Study With Personalized Project Spaces In A Geographical Digital Library, Ee Peng Lim, Aixin Sun, Zehua Liu, John Hedberg, Chew-Hung Chang, Tiong-Sa Teh, Dion Hoe-Lian Goh, Yin-Leng Theng Dec 2004

Supporting Field Study With Personalized Project Spaces In A Geographical Digital Library, Ee Peng Lim, Aixin Sun, Zehua Liu, John Hedberg, Chew-Hung Chang, Tiong-Sa Teh, Dion Hoe-Lian Goh, Yin-Leng Theng

Research Collection School Of Computing and Information Systems

Digital libraries have been rather successful in supporting learning activities by providing learners with access to information and knowledge. However, this level of support is passive to learners and interactive and collaborative learning cannot be easily achieved. In this paper, we study how digital libraries could be extended to serve a more active role in collaborative learning activities. We focus on developing new services to support a common type of learning activity, field study, in a geospatial context. We propose the concept of personal project space that allows individuals to work in their personalized environment with a mix of private …


Synthesis And Characterization Of A Recombinant Thrombin Inhibitor, Joel Lwande Dec 2004

Synthesis And Characterization Of A Recombinant Thrombin Inhibitor, Joel Lwande

Masters Theses

The final step of the blood coagulation cascade is catalyzed by thrombin, a serine protease. Like most enzyme activities, thrombin activity encounters inhibition from both direct and indirect inhibitors. A new thrombin inhibitor peptide named theromin was recently isolated from the leech Theromyzon tessulatum, and it is the most potent thrombin inhibitor isolated to date. Theromin is made up of 67 amino acid residues, out of which 16 are cysteines engaged in 8-disulfide bridges.

We synthesized the theromin gene and expressed the protein in Eschericia coli. We purified the recombinant protein and carried out thrombin inhibition assays that …


Consistency Results For The Roc Curves Of Fused Classifiers, Kristopher S. Bjerkaas Dec 2004

Consistency Results For The Roc Curves Of Fused Classifiers, Kristopher S. Bjerkaas

Theses and Dissertations

The U.S. Air Force is researching the fusion of multiple classifiers. Given a finite collection of classifiers to be fused, one seeks a new classifier with improved performance. An established performance quantifier is the Receiver Operating Characteristic (ROC) curve, which allows one to view the probability of detection versus the probability of false alarm in one graph. Previous research shows that one does not have to perform tests to determine the ROC curve of this new fused classifier. If the ROC curve for each individual classifier has been determined, then formulas for the ROC curve of the fused classifier exist …


Rayleigh-Lidar Observations Of Mesospheric Mid-Latitude Density Climatology Above Utah State University, Eric M. Lundell, Vincent B. Wickwar Dec 2004

Rayleigh-Lidar Observations Of Mesospheric Mid-Latitude Density Climatology Above Utah State University, Eric M. Lundell, Vincent B. Wickwar

Posters

Data from Rayleigh lidars have been used extensively to derive temperatures in the mesospheric region of the atmosphere. However, these data have not been used extensively in a similar way to derive neutral densities. We report on one such mid-latitude, density climatology between 45 and ~90 km, based on nearly 600 good nights of observations carried out since 1993 at the Atmospheric Lidar Observatory (ALO) at Utah State University (41.7°N 111.8°W). They produce relative density profiles that are then normalized at 45 km to an empirical model, in this case the MSISe00 model. Despite this normalization, significant differences are found …


Origin Of The Central Kalamazoo River Valley, Southwestern Michigan, Usa, Andrew Kozlowski Dec 2004

Origin Of The Central Kalamazoo River Valley, Southwestern Michigan, Usa, Andrew Kozlowski

Dissertations

Chapter I

Introduction

Southern Michigan's geomorphology is a testament to the glacial processes that buried and sculpted the landscape during the last glaciation. Many glacial landforms in southwestern Michigan, including the Kalamazoo River Valley, provide evidence that aids in understanding the chronology, ice dynamics and glacial processes that occurred in Michigan during the last ice age.

As the climate began to warm about 20,000 yr B.P. (Larson and Schaetzl, 2001) the extensive Laurentide Ice Sheet began to recede from its maximum southern position reached during the Late Wisconsinan (Figure 1). It was at this point that modem surficial drainage systems …


Hydrologic And Geochemical Cycling Within Karst Versus Non-Karst Basins Within The Interior Low Plateau Province Of South-Central Kentucky, David Ek Dec 2004

Hydrologic And Geochemical Cycling Within Karst Versus Non-Karst Basins Within The Interior Low Plateau Province Of South-Central Kentucky, David Ek

Masters Theses & Specialist Projects

This thesis summarizes my research in which I investigated differences and characteristics in hydrologic, nutrient and geochemical cycling between karst versus nonkarst basins within the Interior Low Plateau Province. Field data including stream discharge, evapotranspiration, and dissolved major ion concentrations were collected for a period of one year for two basins within Mammoth Cave National Park. Twelve percent carbonate rocks underlie one basin, while the other consists of 48 percent carbonate rocks. The carbonate rock exposures within both basins exhibit karstification. The hydrologic and geochemical differences between these basins were compared to determine to what extent that cycles are modified …


Phase Coherent Effects In The Speckle Correlation Of Light Scattered Fromvolume Disordered Media And Randomly Rough Surfaces, Bogdan Danila Dec 2004

Phase Coherent Effects In The Speckle Correlation Of Light Scattered Fromvolume Disordered Media And Randomly Rough Surfaces, Bogdan Danila

Dissertations

We present a study of the statistics of the intensity patterns produced when coherent light is scattered by random media (volume disorder) or randomly rough surfaces. Such a random, granular interference pattern is called speckle. Particular emphasis is on the statistical correlations arising between thefluctuations of the intensities corresponding to distinct scattering paths; which are quantified by the speckle correlation function. In the first part, we present results for the correlation function computed for volume-disordered media by means of numerical simulation. Our focus is on the sensitivity of the correlationfunction to statistical parameters characterizing the volume distribution of the refraction …


Interferences In Electron Emission Spectra For H+ Impact On H2, Sabbir Hossain Dec 2004

Interferences In Electron Emission Spectra For H+ Impact On H2, Sabbir Hossain

Dissertations

No abstract provided.


An Investigation Of Secondary Teachers’ Knowledge Of Rate Of Change In The Context Of Teaching A Standards-Based Curriculum, Jihwa Noh Dec 2004

An Investigation Of Secondary Teachers’ Knowledge Of Rate Of Change In The Context Of Teaching A Standards-Based Curriculum, Jihwa Noh

Dissertations

This study investigated teachers' mathematical content knowledge and pedagogical content knowledge with respect to rate of change in the context of teaching a Standards-based high school mathematics curriculum that emphasizes rate of change as a central theme, the Core-Plus Mathematics Project (CPMP) materials. A framework was designed to provide a comprehensive guide for analyzing different aspects of rate of change knowledge incorporating existing frameworks relative to rate of change, NCTM recommendations described in Curriculum and Evaluation Standards for School Mathematics andPrinciples and Standards for School Mathematics (NCTM, 2000), and research related to pedagogical understanding of rate of change.

Data …


Current And Historic Freshwater Mollusk Distributions Of The Upper Coosa River Basin, Sabrina Felicitas Novak Dec 2004

Current And Historic Freshwater Mollusk Distributions Of The Upper Coosa River Basin, Sabrina Felicitas Novak

Masters Theses and Doctoral Dissertations

This thesis contains summary data from all Tennessee Aquarium Research Institute (TNARI) survey activities of freshwater mollusks within the upper Coosa River basin (UCRB) from 1998 to 2003. Survey results of 4 different TNARI studies, a total of 515 separate collections, are presented. My component of the study examined 231 sites primarily in the Coosawattee and Etowah river basins in 2002 - 2003. In addition to the 231 sites surveyed, a large database was constructed from natural history museum records to evaluate temporal changes in species richness and distribution across the UCRB. Of 43 mussel and 33 snail species reported …


Using Linear Features For Aerial Image Sequence Mosaiking, Caixia Wang Dec 2004

Using Linear Features For Aerial Image Sequence Mosaiking, Caixia Wang

Electronic Theses and Dissertations

With recent advances in sensor technology and digital image processing techniques, automatic image mosaicking has received increased attention in a variety of geospatial applications, ranging from panorama generation and video surveillance to image based rendering. The geometric transformation used to link images in a mosaic is the subject of image orientation, a fundamental photogrammetric task that represents a major research area in digital image analysis. It involves the determination of the parameters that express the location and pose of a camera at the time it captured an image. In aerial applications the typical parameters comprise two translations (along the x …


Forensic Analysis Of Digital Image Tampering, Jonathan R. Sturak Dec 2004

Forensic Analysis Of Digital Image Tampering, Jonathan R. Sturak

Theses and Dissertations

The use of digital photography has increased over the past few years, a trend which opens the door for new and creative ways to forge images. The manipulation of images through forgery influences the perception an observer has of the depicted scene, potentially resulting in ill consequences if created with malicious intentions. This poses a need to verify the authenticity of images originating from unknown sources in absence of any prior digital watermarking or authentication technique. This research explores the holes left by existing research; specifically, the ability to detect image forgeries created using multiple image sources and specialized methods …


Agenda: Introduction To The Legal Foundation Of Federal Land Management, University Of Colorado Boulder. Natural Resources Law Center Dec 2004

Agenda: Introduction To The Legal Foundation Of Federal Land Management, University Of Colorado Boulder. Natural Resources Law Center

Introduction to the Legal Foundation of Federal Land Management (December 1-3)

Materials prepared for the course held at the National Center for Atmospheric Research in Boulder, Colorado on December 1-3, 2004

Course instructors: Charles Wilkinson; Sarah Krakoff; Kathryn Mutz; Ann Morgan; Maggie Fox

Contents:

Introduction -- Agenda -- Summaries of laws -- Case studies. Travel management; Oil and gas development; Timber/fuels reduction -- How to influence agency decision makers -- Natural resource related legal and policy resources for the non-legal professional


South East Humps Focus Catchment Report, A Hollick Dec 2004

South East Humps Focus Catchment Report, A Hollick

Resource management technical reports

This report provides a record of the activities carried out by the Lockhart Focus Support Team and the Catchment Group. It covers the results of the investigations and a summary of the group's catchment plan for the South East Humps Catchment east of Hyden in Western Australia. It covers the current best available information on soils, groundwater hydrology, surface water control, alternative crops and pastures, and revegetation options.


The Dependence Of Dijet Production On Photon Virtuality In Ep Collisions At Hera, S. Chekanov, M. Derrick, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, N. Pavel, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, L. Rinaldi Dec 2004

The Dependence Of Dijet Production On Photon Virtuality In Ep Collisions At Hera, S. Chekanov, M. Derrick, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, N. Pavel, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, L. Rinaldi

Faculty Publications

The dependence of dijet production on the virtuality of the exchanged photon, Q2, has been studied by measuring dijet cross sections in the range 0 ≲ Q2 < 2000 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. Dijet cross sections were measured for jets with transverse energy ETjet > 7.5 and 6.5 GeV and pseudorapidities in the photon-proton centre-of-mass frame in the range -3 < jet < 0. The variable xγobs, a measure of the photon momentum entering the hard process, was used to enhance the sensitivity of the measurement to the photon structure. The Q2 dependence of the ratio of low- to high-xγobs events was measured. Next-to-leading-order QCD predictions were found to generally underestimate the low-xγobs contribution relative to that at high xγobs. Monte Carlo models based on leading-logarithmic parton-showers, using a partonic structure for the photon which falls smoothly with increasing Q2, provide a qualitative description of the data. © Springer-Verlag / Società Italiana di Fisica 2004.


Dissociation Of Virtual Photons In Events With A Leading Proton At Hera, S. Chekanov, M. Derrick, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, N. Pavel, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, T. Massam, A. Montanari, R. Nania, F. Palmonari, A. Pesci Dec 2004

Dissociation Of Virtual Photons In Events With A Leading Proton At Hera, S. Chekanov, M. Derrick, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, N. Pavel, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, T. Massam, A. Montanari, R. Nania, F. Palmonari, A. Pesci

Faculty Publications

The ZEUS detector has been used to study dissociation of virtual photons in events with a leading proton, γ*p → Xp, in e+p collisions at HERA. The data cover photon virtualities in two ranges, 0.03 < Q2 < 0.60 GeV2 and 2 < Q2 < 100 GeV2, with MX > 1.5 GeV, where MX is the mass of the hadronic final state, X. Events were required to have a leading proton, detected in the ZEUS leading proton spectrometer, carrying at least 90% of the incoming proton energy. The cross section is presented as a function of t, the squared four-momentum transfer at the proton vertex, Φ, the azimuthal angle between the positron scattering plane and …


Wetland And Nest Scale Habitat Use By The Four-Toed Salamander (Hemidactylium Scutatum) In Maine, And A Comparison Of Survey Methods, Rebecca J. Chalmers Dec 2004

Wetland And Nest Scale Habitat Use By The Four-Toed Salamander (Hemidactylium Scutatum) In Maine, And A Comparison Of Survey Methods, Rebecca J. Chalmers

Electronic Theses and Dissertations

Conserving amphibian populations requires knowledge of a species and its habitat relationships. The four-toed salamander (Hemidactylium scutatum) is listed as Special Concern in Maine and 11 additional states and provinces, Threatened in Illinois, and Endangered in Indiana (Appendix A). Little is known of H. scutatum ecology despite the species' extensive range. Infrequent sightings of H. scutatum throughout its range may indicate either low numbers or that the species' behavior make detection difficult. Records for H. scutatum in Maine existed from only 32 sites before my study, and the total number of occurrences of this species in Maine is …


Evidence For Microbial Enhanced Electrical Conductivity In Hydrocarbon-Contaminated Sediments, Estella A. Atekwana, Eliot A. Atekwana, D. Dale Werkema, Jonathan P. Allen, Laura A. Smart, Joseph W. Duris, Daniel P. Cassidy, William A. Sauck, Silvia Rossbach Dec 2004

Evidence For Microbial Enhanced Electrical Conductivity In Hydrocarbon-Contaminated Sediments, Estella A. Atekwana, Eliot A. Atekwana, D. Dale Werkema, Jonathan P. Allen, Laura A. Smart, Joseph W. Duris, Daniel P. Cassidy, William A. Sauck, Silvia Rossbach

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Bulk electrical conductivity of sediments during microbial mineralization of diesel was investigated in a mesoscale laboratory experiment consisting of biotic contaminated and uncontaminated columns. Population numbers of oil degrading microorganisms increased with a clear pattern of depth zonation within the contaminated column not observed in the uncontaminated column. Microbial community structure determined from ribosomal DNA intergenic spacer analysis showed a highly specialized microbial community in the contaminated column. The contaminated column showed temporal increases in bulk conductivity, dissolved inorganic carbon, and calcium, suggesting that the high bulk conductivity is due to enhanced mineral weathering from microbial activity. The greatest change …


Field Evidence For Geophysical Detection Of Subsurface Zones Of Enhanced Microbial Activity, Eliot A. Atekwana, Estella A. Atekwana, Franklyn D. Legall, R. V. Krishnamurthy Dec 2004

Field Evidence For Geophysical Detection Of Subsurface Zones Of Enhanced Microbial Activity, Eliot A. Atekwana, Estella A. Atekwana, Franklyn D. Legall, R. V. Krishnamurthy

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Geochemical data from closely spaced vertical intervals in a hydrocarbon-impacted aquifer were used to assess the relationship between bulk conductivity and zones of enhanced microbial activity. The bulk conductivity was measured using in situ vertical resistivity probes. Microbial activity was verified using terminal electron acceptors (nitrate, sulfate, iron, and manganese), dissolved inorganic carbon (DIC), and major ion chemistry. Peaks in bulk conductivity in the aquifer overlapped with zones where nitrates and sulfates were depleted, total petroleum hydrocarbon, iron, manganese, dissolved ions, and DIC were elevated, suggesting a link between higher electrical conductivity and zones of enhanced microbial activity stimulated by …


Slope Stability Analysis Of A Lake Michigan Coastal Bluff, Gregory Carlton Young Dec 2004

Slope Stability Analysis Of A Lake Michigan Coastal Bluff, Gregory Carlton Young

Masters Theses

Bluff failure along the Lake Michigan coast can be produced primarily by increased pore pressure from perched water tables above lacustrine clay deposits. To test this theory, a site in Allegan County, Michigan with alternating layers of sand, clay and glacial till was chosen for bluff failure monitoring. Historically, the site experiences sporadic massive failures as opposed to neighboring sites that show more regular and uniform displacements. Four pole and cable monitoring lines were measured bi-weekly from December 2001 to October 2003. Lake levels were low and no erosion of material at the base of the slope occurred. Slumps above …


Hydrogeologic Model Of A Leachate Plume In An Unconfined Coastal Plain Aquifer And Chemical Transport Mechanisms Of Metals And Dense Non-Aqueous Phase Liquids, Thomas Lindblad Dec 2004

Hydrogeologic Model Of A Leachate Plume In An Unconfined Coastal Plain Aquifer And Chemical Transport Mechanisms Of Metals And Dense Non-Aqueous Phase Liquids, Thomas Lindblad

Theses and Dissertations

Groundwater contamination is of increasing environmental concern as many aquifers across the globe have experienced a decrease in water quality in recent time. The growth of the world's population over the last couple of decades has caused a dramatic increase in the rate of groundwater use. One potential source of groundwater contamination is waste material in landfills. The 1 st Division Road Sanitary landfill at Fort Benning Military Reservation was studied to evaluate the potential effect on local groundwater and a leachate plume was recognized using data from 16 groundwater monitoring wells located around the facility. The study site is …