Digital Commons Network^™

The Micropivot : An Integrated Particle Image Velocimeter And Optical Tweezers Instrument For Microscale Investigations, Nathalie Neve De Mevergnies

Dissertations and Theses

This dissertation describes the development of a device capable of suspending a microscale object in a controlled flow. The uPIVOT is a system integrating two laser-based techniques: micron particle image velocimetry (uPIV) and optical tweezers (OT). The OT allows the suspension and manipulation of micron-sized objects such as microspheres or biological cells. uPIV provides imaging of the suspended object and velocity measurements from which fluid induced stresses can be determined. Using this device, we measured fluid velocities around an optically suspended polystyrene microsphere (an experimental first) and studied the interaction between two particles suspended in a uniform flow. The results …

Investigating Freeway Speed-Flow Relationships For Traffic Assignment Applications, Meead Saberi Kalaee

Dissertations and Theses

Developments in high resolution traffic sensors over the past decades are providing a wealth of empirical speed-flow data. Travel demand models use speed-flow relationships to assign traffic flows to network links. However, speed-flow relationships have not been revalidated against new detailed traffic sensor data. Therefore, it is necessary to revisit speed-flow relationships based on actual measured conditions on network links rather than assuming constant speed-flow relationships over entire highway network systems. Speed-flow relationships have been particularly difficult to calibrate and estimate when traffic volumes approach capacity, i.e. when the v/c ratio approaches one. This thesis empirically evaluates the speed-flow relationships …

Northeast Asia And The Avoidance Of A Nuclear Arms Race, Samuel Fogleman

Dissertations and Theses

Since the end of the Sino-Vietnamese War in 1979, Northeast Asia and its comprising countries have avoided international conflict as well as any regional set has done over the past few decades. The absence of nuclear weapons among Japan, South Korea, and Taiwan, in particular, is striking, given their technological and scientific capabilities. Though each of those countries has come close at times to developing their own nuclear weapons, one factor or another contributed to the failure of those upstart programs. The United States has played a significant role in all of them. Still, other factors remain. The purpose of …

Law In The Shadow Of Bargaining: The Feedback Effect Of Civil Settlements, Ben Depoorter

Faculty Scholarship

No abstract provided.

Hydrologic Data Assimilation: State Estimation And Model Calibration, Caleb Matthew Dechant

Dissertations and Theses

This thesis is a combination of two separate studies which examine hydrologic data assimilation techniques: 1) to determine the applicability of assimilation of remotely sensed data in operational models and 2) to compare the effectiveness of assimilation and other calibration techniques. The first study examines the ability of Data Assimilation of remotely sensed microwave radiance data to improve snow water equivalent prediction, and ultimately operational streamflow forecasts. Operational streamflow forecasts in the National Weather Service River Forecast Center are produced with a coupled SNOW17 (snow model) and SACramento Soil Moisture Accounting (SAC-SMA) model. A comparison of two assimilation techniques, the …

Designing Exhibits For Gender Equity, Toni Nicole Dancu

Dissertations and Theses

Gender equity has been a national and global aim for over half a century (Ceci & Williams, 2007; National Center for Education Statistics, 2003; National Science Board, 2008). While gains have been made, one area where inequity remains is spatial reasoning ability, where a large gender gap in favor of males has persisted over the years (Else-Quest, Linn, & Shibley Hyde, 2010; National Science Board, 2008; Ruble, Martin, & Berenbaum, 2006). This gender gap in spatial reasoning has had substantial societal impact on the career interests of females in areas of Science, Technology, Engineering, and Math (STEM), contributing to the …

Practical Type Inference For The Gadt Type System, Chuan-Kai Lin

Dissertations and Theses

Generalized algebraic data types (GADTs) are a type system extension to algebraic data types that allows the type of an algebraic data value to vary with its shape. The GADT type system allows programmers to express detailed program properties as types (for example, that a function should return a list of the same length as its input), and a general-purpose type checker will automatically check those properties at compile time. Type inference for the GADT type system and the properties of the type system are both currently areas of active research. In this dissertation, I attack both problems simultaneously by …

The Design Of A Novel Tip Enhanced Near-Field Scanning Probe Microscope For Ultra-High Resolution Optical Imaging, Derek Brant Nowak

Dissertations and Theses

Traditional light microscopy suffers from the diffraction limit, which limits the spatial resolution to λ/2. The current trend in optical microscopy is the development of techniques to bypass the diffraction limit. Resolutions below 40 nm will make it possible to probe biological systems by imaging the interactions between single molecules and cell membranes. These resolutions will allow for the development of improved drug delivery mechanisms by increasing our understanding of how chemical communication within a cell occurs. The materials sciences would also benefit from these high resolutions. Nanomaterials can be analyzed with Raman spectroscopy for molecular and atomic bond information, …

Modeling Terahertz Diffuse Scattering From Granular Media Using Radiative Transfer Theory, Kyung Moon Nam

Dissertations and Theses

Terahertz (THz) spectroscopy can potentially be used to probe and characterize inhomogeneous materials, however spectroscopic identification of such materials from spectral features of diffuse returns is a relatively underdeveloped area of study. In this thesis, diffuse THz scattering from granular media is modeled by applying radiative transfer (RT) theory for the first time in THz sensing. Both classical RT theory and dense media radiative transfer (DMRT) theory based on the quasi-crystalline approximation (QCA) are used to calculate diffuse scattered intensity. The numerical solutions of the vector radiative transfer equations (VRTE) were coded and calculated in MATLAB. The diffuse scattered field …

Exploratory Eddy Covariance Measurements Of Surface Heat And Co2 Fluxes In The Roughness Sublayer Of An Urban Environment, Benjamin F. Burnett

Dissertations and Theses

In this study eddy covariance was used to measure sensible heat, latent heat, and carbon dioxide fluxes for the months of August, September, and October of 2009 within the roughness sublayer (RSL) of the urban center of Portland, OR. Vehicle traffic and solar radiation were also measured for the month of October. Flux measurements were compared with measurements from other urban areas as a test of reasonableness. CO₂ fluxes were nearly always positive and were strongly correlated with the weekday diurnal traffic cycle. CO₂ fluxes averaged 6.6 μmol/m^²s, which is less than other published measurements in urban areas. Sensible and …

Radiative Transfer Theory Applied To Ocean Bottom Modeling, Jorge Quijano

Dissertations and Theses

Research on the propagation of acoustic waves in ocean bottom sediment is of interest for active sonar applications such as target detection and remote sensing. Currently, all seabed scattering models available in the literature are based on the full solution of the wave equation, which sometimes leads to mathematically intractable problems. In the electromagnetics community, an alternative formulation that overcomes some of this complexity is radiative transfer theory, which has established itself as an important technique for remote sensing. In this work, radiative transfer (RT) theory is proposed for the first time as a tool for the study of seabed …

Modeling The Role Of Operational Characteristics In Safety Performance Of Publictransportation Systems: The Case Of Trimet Bus Collision And Non-Collision Incidents., Paul Herman Wachana

Dissertations and Theses

The incidence of bus crashes in the US have been trending upwards, with accident, injury and fatality rates increasing 171%, 37.8%, and 5.1% respectively, between 2003 and 2007. Reversing the upward trend is an important objective of both transit providers and the society in general. This study introduces an operator-based safety methodology that utilizes data recovered from transit Intelligent Transportation Systems (ITS) technologies and related systems to identify and assess factors contributing to bus operations safety incidents at TriMet, the transit provider for the Portland, Oregon metropolitan region. The analysis specifically focuses on collision, non-collision and total incidents, as well …

The Sound Of Silence: The Continuing Legal Debate Over Class Action Rescission Under Tila, Jo Carrillo, Paul Kofoed

Faculty Scholarship

No abstract provided.

Design And Development Of Chiral And Achiral Molecularly Imprinted Stationary Phases, Jason Paul Lejeune

LSU Doctoral Dissertations

Although the cross-linker can comprise over 80% of the polymer composition, improving the nature of the cross-linker in molecularly imprinted polymers has not been studied extensively. The goal of this research is to develop novel cross-linking monomers to either use in the One MoNomer Molecularly Imprinted Polymer system (OMNiMIP) or use in conjunction with other commercially available cross-linkers and functional monomers. Chapter 2 contains research into the understanding of the performance of a new cross-linking monomer (N, O - bismethacryloyl ethanolamine, NOBE) discovered in the Spivak Research Group. The ability of this monomer to outperform traditional two monomer systems in …

Origin Of Pyrite Nodules At The Top Of The Nantuo Diamictites, Southern China, Changjie Liu

LSU Master's Theses

Pyrite nodules up to 20 cm in diameter are found at the top of the Marinoan (~635 Ma) Nantuo glacial diamictite as well as in the cap dolostones and shale/siltstones in the lower Doushantuo Formation in eastern Guizhou, southern China. Earlier studies on the occurrence and stable sulfur and triple oxygen isotope composition of barite in the cap dolostones concluded that seawater sulfate concentrations in shallow oceans in the South China Block were low during the deposition of the cap dolostones. Therefore, the occurrence of pyrite nodules suggests two scenarios: 1) Formation before the precipitation of the cap dolostone, when …

Formative Assessment In Algebra Ii, Angie Ann Byrd

LSU Master's Theses

This work reviews the assessment design process in depth, as relevant to classroom practice. The “assessment triangle’’ model of assessment and other design components are described. We discuss the content standards and the assigned classroom curriculum of the unit of the East Baton Rouge Algebra II course, which deals with quadratics. We offer an assessment that meets standards of the models that were reviewed.

Physical And Microbial Responses Of Dredged Sediment To Two-Soil-Stabilizing Amendments, Xanthan Gum And Guar Gum, For Use In Coastal Wetland Restoration, Lauren Land

LSU Master's Theses

In wetland sediments, organic matter provides a substrate for microbial activity. During metabolism, microbes release extracellular polymeric substances, which accumulate to bind soil particles. A similar concept can be implemented on a large scale to reduce wetland loss in Louisiana. Hypothetically, hydraulically dredged sediment can be amended with polymer and deposited on subsiding marshes as a restoration method where the polymer increases sediment stabilization until plants become established. This lab study focused on investigating the influence of natural polymer additions on particle aggregation to increase sediment stability and the effects on microbial activity. Sediments from three sites (i.e. freshwater, intermediate, …

Caged Morpholino Oligonucleotide For Control Of Gene Expression In Zebrafish, Chad Michael Jarreau

LSU Master's Theses

To control gene expression in vivo with spatial and temporal precision remains a significant hurdle in laboratory studies of development as well as clinical genetic therapies. Here we demonstrate such control over gene expression by use of photochemistry to reversibly inactivate the hybridization of a nucleic acid analog used for specific protein knockdown. A morpholino oligonucleotide, commonly used for knockdown of protein expression in developmental studies, was “caged” using carbodiimide conjugate chemistry which yielded photocleavable adducts that can be removed with light exposure. Photochemical inactivation approaches to produce caged molecules have been used to control the spatiotemporal activity of biomolecules …

Impact Of Urban Runoff On Phosphorus, Nitrogen, And Dissolved Oxygen In A Shallow Subtropical Lake, Ryan Mesmer

LSU Master's Theses

This research assessed the current conditions of water quality in a shallow subtropical lake, influenced by a highly developed urban environment. Specifically, the research focused on the dynamics of phosphorus, nitrogen, and dissolved oxygen, as well as the effects of stormwater runoff on lake water quality. Furthermore, the research quantified gross primary production, net primary production, and respiration in order to discern seasonal variation in lake metabolism. A water quality monitoring platform with multi-parameter probes was deployed in the center of University Lake on the Louisiana State University campus. A series of lake water quality parameters including dissolved oxygen (DO) …

Geothermal Energy Potential Of South Bossier Parish, Louisiana, John Adam D'Aquin

LSU Master's Theses

Northwestern Louisiana sits atop a geothermal anomaly that stretches across Eastern Texas and into Southern Arkansas. Geothermal gradients are observed in this area that are greater than the Gulf Coast average of 22-26oC/km. South Bossier Parish, in particular, could be an ideal location for economic production of electricity by conventional geothermal or enhanced geothermal projects due to ideal geothermal production temperatures of 120-180oC at a relatively shallow depth of approximately 3-5 km. A localized geothermal of 35oC/km gradient was determined using bottom-hole temperatures (BHTs) from 147 wells. At approximately 3.2 km depth, temperatures of approximately 130oC within the geopressured sands …

Getting Off The Ground With Ap Calculus, David Frank Woods

LSU Master's Theses

“The study of mathematics, like the Nile, begins in minuteness but ends in magnificence.” – Charles Caleb Colton Caught in a downward spiral, American mathematical students continue to be outperformed by their international peers as reported by the TIMSS. This has left educators scrambling to find an instructional strategy that will slow this decline in mathematical literacy. This thesis reports on the framework that a new teacher could use to develop and establish a successful AP Calculus program, while increasing mathematical literacy, equity in the classroom, and student achievement through the integration of educational technology into current instructional trends. This …

Copula And Default Correlation, Dongxiang Yan

LSU Master's Theses

This work presents a study of copulas, with special focus on the Gaussian copula model and its behavior under a certain conditioning process. Simulations are carried out to examine the behavior of the moments on conditional copula model, as measured by the behavior of Wick identities which hold for multivariate Gaussians.

The Influences Of Microbial Diversity On Carbonate Geochemistry Across A Transition From Fresh To Saline Water In The Edwards Aquifer, Texas, Cassie Jo Gray

LSU Master's Theses

Microbially-mediated karstification through the production of metabolic byproducts has been well-documented in cave environments, but less is known about deep karstic settings. This research aimed to distinguish between microbial and geochemical influences on carbonate dissolution in the Edwards Aquifer, a prolific karst aquifer in central Texas, specifically from a transect of six wells across a transition from fresh to saline water in New Braunfels. For the first time, a portion of the aquifer’s bacterial diversity was examined from molecular 16S rRNA gene sequence analyses, which revealed that Alphaproteobacteria, Gammaproteobacteria, and Betaproteobacteria dominated the aquifer, with rare Bacteroidetes, Nitrospirae, and Firmicutes …

Solving Continuous Linear Least-Squares Problems By Iterated Projection, Ralf Juengling

Computer Science Faculty Publications and Presentations

I present a new divide-and-conquer algorithm for solving continuous linear least-squares problems. The method is applicable when the column space of the linear system relating data to model parameters is “translation invariant”. The central operation is a matrix- vector product, which makes the method very easy to implement. Secondly, the structure of the computation suggests a straightforward parallel implementation.

A complexity analysis for sequential implementation shows that the method has the same asymptotic complexity as well-known algorithms for discrete linear least-squares. For illustration we work out the details for the problem of fitting quadratic bivariate polyno- mials to a piecewise …

Pvw: Designing Virtual World Server Infrastructure, Francis Chang, C. Mic Bowman, Wu-Chi Feng

Computer Science Faculty Publications and Presentations

This paper presents a high level overview of PVW (Partitioned Virtual Worlds), a distributed system architecture for the management of virtual worlds. PVW is designed to support arbitrarily large and complex virtual worlds while accommodating dynamic and highly variable user population and content distribution density. The PVW approach enables the task of simulating and managing the virtual world to be distributed over many servers by spatially partitioning the environment into a hierarchical structure. This structure is useful both for balancing the simulation load across many nodes, as well as features such as geometric simplification and distribution of dynamic content.

A Dynamic Physical Model For Soil Temperature And Water In Taylor Valley, Antarctica, H. W. Hunt, Andrew G. Fountain, Peter T. Doran, Hassan J. Basagic

Geography Faculty Publications and Presentations

We developed a simulation model for terrestrial sites including sensible heat exchange between the atmosphere and ground surface, inter- and intra-layer heat conduction by rock and soil, and shortwave and longwave radiation. Water fluxes included snowmelt, freezing/thawing of soil water, soil capillary flow, and vapour flows among atmosphere, soil, and snow. The model accounted for 96-99% of variation in soil temperature data. No long-term temporal trends in soil temperature were apparent. Soil water vapour concentration in thawed surface soil in summer often was higher than in frozen deeper soils, leading to downward vapour fluxes. Katabatic winds caused a reversal of …

Guest Editorial: On Method, Technorealism And Aesthetic Capitalism, Patricia Ticineto Clough

Publications and Research

The guest editorial excerpts the keynote address Professor Clough held at the First Annual Graduate Student Conference hosted by the Graduate Center's Sociology Students Association.

Women In Glaciology, An Historical Perspective, Christina L. Hulbe, Weili Wang, Simon Ommanney

Geology Faculty Publications and Presentations

Women's history in glaciology extends as far back in time as the discipline itself, although their contributions to the scientific discourse have for all of that history been constrained by the sociopolitical contexts of the times. The first Journal of Glaciology paper authored by a woman appeared in 1948, within a year of the founding of the Journal, but it was not until the 1980s that women produced more than a few percent of Journal and Annals of Glaciology papers. Here international perspectives on women's participation in the sciences are presented in order to establish an economic and sociopolitical context …

Propagation Of Long Fractures In The Ronne Ice Shelf Investigated Using A Numerical Model Of Fracture Propagation, Christina L. Hulbe, Christine Marie Ledoux, Kenneth M. Cruikshank

Geology Faculty Publications and Presentations

Long rifts near the front of the Ronne Ice Shelf, Antarctica, are observed to begin as fractures along the lateral boundaries of outlet streams feeding the shelf. These flaws eventually become the planes along which tabular icebergs calve. The fractures propagate laterally as they advect through the shelf, with orientations that can be explained by the glaciological stress field. Fracture length remains constrained over much of the advective path, and locations of crack tip arrest are observed to coincide with structural boundaries, such as suture zones between ice from adjacent outlet glaciers. Geomechanical principles and numerical models demonstrate that in …

Paleotsunami Inundation Of A Beach Ridge Plain: Cobble Ridge Overtopping And Interridge Valley Flooding In Seaside, Oregon, Usa, Curt D. Peterson, Harry M. Jol, Thomas Horning, Kenneth M. Cruikshank

Geology Faculty Publications and Presentations

The Seaside beach ridge plain was inundated by six paleotsunamis during the last ∼2500 years. Large runups (adjusted >10m in height) overtopped seawardmost cobble beach ridges (7m elevation) at ∼1.3 and ∼2.6 ka before present. Smaller paleotsunami (6−8m in height) likely entered the beach plain interior (4-5m elevation) through the paleo-Necanicum bay mouth. The AD 1700 Cascadia paleotsunami had a modest runup (6-7mheight), yet it locally inundated to 1.5 km landward distance. Bed shear stresses (100−3,300 dyne cm−2) are estimated for paleotsunami surges (0.5−2m depths) that flowed down slopes (0.002−0.017 gradient) on the landward side of the cobble beach ridges. …