Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Mathematics (744)
- Chemistry (580)
- Analysis (564)
- Other Mathematics (556)
- Environmental Sciences (499)
-
- Earth Sciences (372)
- Oceanography and Atmospheric Sciences and Meteorology (342)
- Computer Sciences (243)
- Applied Mathematics (225)
- Physics (134)
- Oceanography (105)
- Geology (103)
- Astrophysics and Astronomy (79)
- Life Sciences (72)
- Engineering (71)
- Analytical Chemistry (34)
- Natural Resources and Conservation (33)
- Hydrology (32)
- Sedimentology (31)
- Geophysics and Seismology (29)
- Quantum Physics (28)
- Statistics and Probability (28)
- Other Physics (27)
- Physical Chemistry (26)
- Geochemistry (25)
- Geomorphology (25)
- Organic Chemistry (25)
- Ecology and Evolutionary Biology (24)
- Medicine and Health Sciences (24)
- Keyword
-
- Louisiana (58)
- Gulf of Mexico (36)
- Geology (22)
- Mississippi River (22)
- Wetlands (21)
-
- Analytical chemistry (20)
- Geochemistry (20)
- Organic chemistry (20)
- Synthesis (20)
- Machine learning (19)
- Microfluidics (17)
- Nanoparticles (17)
- Nitrogen (17)
- Antarctica (16)
- Hypoxia (16)
- Salinity (16)
- Estuary (15)
- Gravitational waves (14)
- Habitat (14)
- Hydrology (14)
- Modeling (14)
- Palynology (14)
- Stable isotopes (14)
- Climate change (13)
- Eutrophication (13)
- Mass spectrometry (13)
- Molecular dynamics (13)
- Phosphorus (13)
- Restoration (13)
- Barataria Bay (12)
- Publication Year
- Publication
- Publication Type
Articles 1501 - 1530 of 3417
Full-Text Articles in Physical Sciences and Mathematics
Sediment Patterns In Relation To Vegetative Community Shifts At Catahoula Lake, Louisiana, Karen Doerr Latuso
Sediment Patterns In Relation To Vegetative Community Shifts At Catahoula Lake, Louisiana, Karen Doerr Latuso
LSU Master's Theses
The processes that control species composition and structure in wetland ecosystems are complex and controlled by many factors including seasonality, depth and duration of flooding, and nutrient dynamics. Catahoula Lake is a floodplain lake that has existed with seasonally fluctuating water levels for at least 4,000 years. The herbaceous vegetation that attracts these waterfowl is slowly being outcompeted by woody vegetation, most notably water-elm (Planera aquatica). Our general goal is to understand the processes that cause this shift, focusing on the role of sediments. Our first objective was to use historical aerial imagery to detect historical changes in plant communities …
Legacy Phosphorus Implications In The Lake Pontchartrain Estuary Sediment Due To The 2011 Bonnet Carre Spillway Opening, Nhan Thanh Nguyen
Legacy Phosphorus Implications In The Lake Pontchartrain Estuary Sediment Due To The 2011 Bonnet Carre Spillway Opening, Nhan Thanh Nguyen
LSU Master's Theses
Phosphorus (P) is an essential nutrient for life and excess P in aquatic systems can trigger algal blooms. Nutrient-rich Mississippi River water is diverted into the Lake Pontchartrain estuary (LPE) periodically through the Bonnet Carré Spillway (BCS) to avoid downstream flooding to the city of New Orleans, Louisiana and can significantly increase the internal P load in the sediment. A sequential P fractionation procedure was performed on sediments collected before the opening and after the closing of the 2011 BCS operation to understand the role of these large river diversions on P dynamics. Before the 2011 BCS opening, 10,368 Mt …
Oxygen Isotope Composition Of Phosphate Along Vertical Weathering Profiles That Developed On Igneous Rocks: Testing Modern Analogues For Identifying Terrestrial Life In Ancient Paleosols, Dustin Warn Boyd
LSU Master's Theses
Life on Earth began in its early oceans before moving on to land. Determining the exact timing of an established biosphere on land, however, has been elusive, due largely to the lack of either fossil or chemical evidence on land deposits. Here I test a hypothesis that the activity of land biota can be recorded in the oxygen isotope composition of phosphate in weathering profiles developed on igneous parent rocks. Igneous rock contains phosphate (PO43-), which is readily utilized for biological activities during soil development. The oxygen in PO43- does not readily exchange its oxygen …
A Toolkit For Tracking And Mediating Parametric Objects Upon Commodity Mobile Devices, Shantanu Thatte
A Toolkit For Tracking And Mediating Parametric Objects Upon Commodity Mobile Devices, Shantanu Thatte
LSU Master's Theses
The large number of mobile devices introduced in the market in recent years provide numerous interaction opportunities. We used commercially available products to create an interface for interaction with diverse datasets. We extended this scenario to include multiple physical instances, realizing a real-time multi-party interaction session. Tangibles act as tools and containers, in a fashion that requires their physical location and orientation to be evaluated continuously during a session. We present a technique to detect an object using only the touchscreen of a mobile device as an input, by means of touch patterns created on the screen. This helps avoid …
Palynology Of The Upper Cretaceous Ferron-Notom Sandstone, Utah, Isil Akyuz
Palynology Of The Upper Cretaceous Ferron-Notom Sandstone, Utah, Isil Akyuz
LSU Master's Theses
ABSTRACT The Late Cretaceous Ferron-Notom Sandstone Member of the Mancos Shale Formation plays a dominant role in oil production in Utah. Although numerous sedimentological and sequence stratigraphic studies have been conducted in recent years on this sequence, palynological analyses had not yet been undertaken. Here we present palynological data from one hundred twenty eight samples collected in the Ferron-Noton Sandstone Member outcroping in south-central Utah. The purpose of this study is to refine our understanding of climatic and depositional environments and to build a biostratigraphic palynological framework. The dominance of terrestrial palynomorphs, especially the high yield in moisture-loving cryptogam spores …
Species Composition And Spatial Ecology Of Amazonian Understory Mixed-Species Flocks In A Fragmented Landscape, Karl Mokross
Species Composition And Spatial Ecology Of Amazonian Understory Mixed-Species Flocks In A Fragmented Landscape, Karl Mokross
LSU Doctoral Dissertations
With the ongoing advance of the agricultural frontier in the Amazon basin, it is inevitable that heterogeneous landscapes will play a key role in conservation. These landscapes are mostly composed of patchworks of small forest fragments, secondary forests and roads. Conservation, however must take species interactions into consideration as they play a pivotal part the maintenance of several biological processes in the tropics. One of the most conspicuous interspecific interactions are seen in mixed-species flocks of birds, which in the Amazon, represent one of the best organized systems of bird aggregations. In this research, I assess how flock spatial behavior …
Conical Representations For Direct Limits Of Riemannian Symmetric Spaces., Matthew Glenn Dawson
Conical Representations For Direct Limits Of Riemannian Symmetric Spaces., Matthew Glenn Dawson
LSU Doctoral Dissertations
We extend the definition of conical representations for Riemannian symmetric space to a certain class of infinite-dimensional Riemannian symmetric spaces. Using an infinite-dimensional version of Weyl's Unitary Trick, there is a correspondence between smooth representations of infinite-dimensional noncompact-type Riemannian symmetric spaces and smooth representations of infinite-dimensional compact-type symmetric spaces. We classify all smooth conical representations which are unitary on the compact-type side. Finally, a new class of non-smooth unitary conical representations appears on the compact-type side which has no analogue in the finite-dimensional case. We classify these representations and show how to decompose them into direct integrals of irreducible conical …
Space-Efficient Data Structures For String Searching And Retrieval, Sharma Valliyil Thankachan
Space-Efficient Data Structures For String Searching And Retrieval, Sharma Valliyil Thankachan
LSU Doctoral Dissertations
Let D = {d_1, d_2, ...} be a collection of string documents of n characters in total, which are drawn from an alphabet set Sigma =[sigma] ={1,2,3,...sigma}. The top-k document retrieval problem is to maintain D as a data structure, such that when ever a query Q=(P, k) comes, we can report (the identifiers of) those k documents that are most relevant to the pattern P (of p characters). The relevance of a document d_r with respect to a pattern P is captured by score(P, d_r), which can be any function of the set of locations where P occurs in …
Observations Of Terrestrial Gamma Flashes With Tetra And Lago, Rebecca Ringuette
Observations Of Terrestrial Gamma Flashes With Tetra And Lago, Rebecca Ringuette
LSU Doctoral Dissertations
Terrestrial Gamma ray Flashes (TGFs) -- very short, intense bursts of electrons, positrons, and energetic photons originating from terrestrial thunderstorms -- have been detected with satellite instruments. The TGF and Energetic Thunderstorm Rooftop Array (TETRA), an array of NaI(Tl) scintillators at Louisiana State University, has now been used to detect similar bursts of 50 keV to over 2 MeV gamma rays at ground level. After 3.3 years of observation, twenty-eight events with durations 0.02 - 4.2 msec have been detected associated with nearby lightning, three of them coincident events observed by detectors separated by ~1000 m. Nine of the events …
Exponentially Convergent Generalized Finite Element Method For Multi-Scale Problems, Xu Huang
Exponentially Convergent Generalized Finite Element Method For Multi-Scale Problems, Xu Huang
LSU Doctoral Dissertations
The overall approach I take in the thesis falls into the category of multiscale finite element methods(MsFEM). I work to identify a new class of local approximation spaces with good approximation properties. This is carried out for the equilibrium problem of linear elasticity. The choice of local approximation spaces is motivated by the kolmogorov n-width. Part of my thesis work develops an estimate to show that it is possible to achieve a local approximation error of ô with respect to the energy norm using at most lnd+1 &frac1ô local basis functions. The global approximation error ôis controlled by the …
Substitution And Disorder Effects In Ternary Intermetallics, Larico Juan Treadwell
Substitution And Disorder Effects In Ternary Intermetallics, Larico Juan Treadwell
LSU Doctoral Dissertations
The focal point of this dissertation is the investigation of substitution and disorder effects in ternary intermetallics. The crystal growth, crystal structure, and physical properties are reported on single crystals of Ln6W4-xAl43-yTx+y (Ln = Gd, Yb; T= Mn, Fe), LnCr2FexAl20-x (Ln = Yb, Gd), Sm1.33Pd3Ga8, and CeCo2-xMxAl8 (M = Mn, Fe, Ni; 0 ≤ x < 1). The reported compounds were grown via the flux growth method with the strategic synthetic parameters described. Correlations between the structural and physical properties in relation to substitution and disorder of Ln6W4-xAl43-yTx+y (Ln = Gd, Yb; T= Mn, Fe), LnCr2FexAl20-x (Ln = Yb, Gd), Sm1.33Pd3Ga8, and CeCo2-xMxAl8 (M = Mn, Fe, Ni; 0 ≤ x < 1) are discussed. The synthesis and characterization of Mn- and Fe- substituted Ln6W4Al43 (Ln = Gd, Yb) are reported. The compounds adopt the Ho6Mo4Al43 structure type with lattice parameters of a ~ 11 Å and c ~ 17.8 Å with structural site preferences for Mn and Fe. The magnetization of Yb6W4Al43 is sensitive to Mn and Fe doping, which is evident by an increase in the field dependent magnetization. Gd6W4Al43, Gd6W4Al42.31(11)Mn0.69(11), and Gd6W4Al41.69(12)Fe1.30(12) order antiferromagnetically in the ab- and c-direction at 15, 14, and 13 K, respectively, with positive Weiss constants, suggesting the presence of ferromagnetic exchange interactions. Anisotropic magnetization data of Gd6W4Al43-yTy (T= Mn, Fe) analogs are discussed. Crystal growth, structure determination, and magnetic properties of LnCr2Al20-xFex (Ln = La, Gd, Yb) adopting the CeCr2Al20 structure type with space group Fd3¯ m, a ~ 14.5 Å, type are reported. Single crystal X-ray diffraction and Mössbauer spectroscopy are employed to fully characterize the crystal structure of LnCr2Al20-xFex (Ln = La, Gd, Yb). LnCr2Al20-xFex (Ln = La, Gd, Yb) are the first pseudo-ternaries adopting the CeCr2Al20 structure type with a transition metal occupying the main group site. The Yb analogues are Pauli paramagnets with the Yb ion adopting an electronic configuration close to Yb2+, while the Gd analogues show paramagnetic behavior with no magnetic order down to 3 K. The synthesis and characterization of Sm1.33Pd3Ga8 is reported. Sm1.33Pd3Ga8 adopts a disordered variant of the Er4Pt9Al24-structure type with lattice parameters of a = 4.353(5) and c = 38.98(4) Å and V = 639.70(12) Å3. The structure of Sm1.33Pd3Ga8 is composed of three distinct building blocks: Pd2Ga4, PdGa2, and Sm0.67Ga. The Sm0.67Ga slab does not magnetically order, which directly affect the structure. Sm1.33Pd3Ga8 is a temperature independent paramagnet. Field dependent magnetization of Sm1.33Pd3Ga8 displays anisotropic behavior. Single crystals of CeCo2-xMxAl8 (M = Mn, Fe, Ni; 0 ≤ x < 1) were grown and crystallize in the CaCo2Al8 structure type with space group Pbam. Single crystal X-ray diffraction data suggest that the Ce 4f-state is valence fluctuating as Fe concentration increases, whereas the Ni-doped analogues do not exhibit valence fluctuating. The results suggest that hole doping leads to an admixture of Ce3+/Ce4+.
Design, Synthesis, And Exploration Of A Chimeric Antioxidant And New Crosslinkers For Molecular Imprinting, Danielle Songe Meador
Design, Synthesis, And Exploration Of A Chimeric Antioxidant And New Crosslinkers For Molecular Imprinting, Danielle Songe Meador
LSU Doctoral Dissertations
The improvement and utility of crosslinkers are important topics of molecular imprinting. Crosslinker significance is evident when molecularly imprinted polymer (MIP) composition related to performance as separation media is examined. Crosslinkers account for the bulk of MIP formulations made through traditional imprinting (80-90%) and is even greater when the One Monomer Molecularly Imprinted Polymer (OMNiMIP) approach is utilized (100%.) It is not surprising that alteration of the bulk component will result in different separation performances. Crosslinkers studied in this work were designed, synthesized, and evaluated toward improvement in OMNiMIP selectivity. In particular, functionality and number of polymerizable groups, addition of …
Problem Solving Strategies And Metacognitive Skills For Gifted Students In Middle School, Lorena Aguelo Java
Problem Solving Strategies And Metacognitive Skills For Gifted Students In Middle School, Lorena Aguelo Java
LSU Master's Theses
This study is conducted to investigate if the designed four-step method strategy (GEAR strategy adapted from Polya, 1973) in solving math problems has improved students’ performance scores and enhanced the metacognitive skills of gifted students. The respondents of this study include middle school gifted students who took math eight course in the school year 2013-2014 at Westdale Middle School in East Baton Rouge Parish School System. There are four classes of math eight gifted students who participated in the study. The classes were chosen randomly for experimental and controlled group and were equalized on the basis of the pre-test results …
Polymer Micro- And Nanofluidic Systems For In Vitro Diagnostics: Analyzing Single Cells And Molecules, Swathi Reddy Pullagurla
Polymer Micro- And Nanofluidic Systems For In Vitro Diagnostics: Analyzing Single Cells And Molecules, Swathi Reddy Pullagurla
LSU Doctoral Dissertations
Polymer micro- and nanofluidic systems, with their critical dimensions, offer a potential to outperform conventional analysis techniques and diagnostic methods by enhancing speed, accuracy, sensitivity and specificity. In this work, applications of microfluidics have been demonstrated to address the existing challenges in stroke diagnosis, by mRNA expression profiling from whole blood within <20 min. A brief overview of various biomarkers for stroke diagnosis is given in chapter 1 followed by design and testing of individual microfluidic modules (chapter 2 and 3) required for the development of POC diagnostic strategy for stroke. We have designed and evaluated the performance of polymer microfluidic devices for the isolation of leukocyte subsets, known for their differential gene expression in the event of stroke. Target cells (T-cells and neutrophils) were selected from with greater purities, from 50 µl whole human blood by using affinity based capture in COC devices within a 6.6 min processing time. In addition, we have also demonstrated the ability to isolate and purify total RNA by using UV activated polycarbonate solid phase extraction platform. Polymer-based nanofluidic devices were used to study the effects of surface charge on the electrodynamic transport dynamics of target molecules. In this work, we report the fabrication of mixed-scale micro- and nanofluidic networks in poly(methylmethacrylate), PMMA, using thermal nanoimprint lithography using a resin stamp and surface modification of polymer nanoslits and nanochannels for the assessment of the associated electrokinetic parameters – surface charge density, zeta potential and electroosmotic flow. This study provided information on possible routes that can be adopted to engineer proper wall chemistry of polymer nanochannels for the enhancement or reduction of solute/wall interactions in a variety of relevant single-molecule studies.
Performance Improvement Of Distributed Computing Framework And Scientific Big Data Analysis, Praveenkumar Kondikoppa
Performance Improvement Of Distributed Computing Framework And Scientific Big Data Analysis, Praveenkumar Kondikoppa
LSU Doctoral Dissertations
Analysis of Big data to gain better insights has been the focus of researchers in the recent past. Traditional desktop computers or database management systems may not be suitable for efficient and timely analysis, due to the requirement of massive parallel processing. Distributed computing frameworks are being explored as a viable solution. For example, Google proposed MapReduce, which is becoming a de facto computing architecture for Big data solutions. However, scheduling in MapReduce is coarse grained and remains as a challenge for improvement. Related with MapReduce scheduler when configured over distributed clusters, we identify two issues: data locality disruption and …
Search-Based Model-Driven Loop Optimizations For Tensor Contractions, Ajay Panyala
Search-Based Model-Driven Loop Optimizations For Tensor Contractions, Ajay Panyala
LSU Doctoral Dissertations
Complex tensor contraction expressions arise in accurate electronic structure models in quantum chemistry, such as the coupled cluster method. The Tensor Contraction Engine (TCE) is a high-level program synthesis system that facilitates the generation of high-performance parallel programs from tensor contraction equations. We are developing a new software infrastructure for the TCE that is designed to allow experimentation with optimization algorithms for modern computing platforms, including for heterogeneous architectures employing general-purpose graphics processing units (GPGPUs). In this dissertation, we present improvements and extensions to the loop fusion optimization algorithm, which can be used with cost models, e.g., for minimizing memory …
Gumbos- And Ionic Liquid-Coated Quartz Crystal Microbalance Sensors For Detection And Molecular Weight Determination Of Organic Vapors, Bishnu Prasad Regmi
Gumbos- And Ionic Liquid-Coated Quartz Crystal Microbalance Sensors For Detection And Molecular Weight Determination Of Organic Vapors, Bishnu Prasad Regmi
LSU Doctoral Dissertations
There has been an ever-increasing demand for the development of high-performance sensing devices for detection and discrimination of volatile organic compounds (VOCs) present in different environments. Among a number of sensing devices currently available, sorption-based sensors are particularly attractive because they are simple and inexpensive, require low power, and are appropriate for fabrication of multisensor arrays. A sorption-based sensor is comprised of a chemically active coating immobilized on the surface of a physical transducer. The chemically active film interacts with analytes, and the transducer converts the binding event into an electrical signal. This dissertation is focused on a sorption-based sensor …
Coloring Graphs Drawn With Crossings, Daniel Allen Guillot
Coloring Graphs Drawn With Crossings, Daniel Allen Guillot
LSU Doctoral Dissertations
This dissertation will examine various results for graph colorings. It begins by introducing some basic graph theory concepts, focusing on those ideas relevant to graph embeddings, and by introducing terminology to allow a formal discussion of drawings of graphs. Chapter 2 focuses on results for proper colorings of graphs with good drawings, using a previous result from Král and Stacho as inspiration. Chapter 3 expands on the ideas of Chapter 2 and focuses on cyclic colorings of embedded graphs. Chapters 5 and 6 examine results for total and list colorings, respectively, of drawings of graphs. Finally, Chapter 6 introduces generalized …
Phases Of Bosons In Optical Lattices And Coupled To Artificial Gauge Fields, Qinqin Lu
Phases Of Bosons In Optical Lattices And Coupled To Artificial Gauge Fields, Qinqin Lu
LSU Doctoral Dissertations
Ultracold atoms have emerged as an indispensable setting to study quantum many-body systems. Recent experimental and theoretical work has explored the curious phases and novel properties of Bose-Einstein Condensate with optical lattices, and Bose-Einstein Condensate with light-induced artificial spin-orbit coupling. In this thesis, we report our research on these two types of boson systems. In the first topic, in contrast with calculations of bosons in optical lattices that focus on the tight-binding regime, we note that the single-particle states of bosons in a periodic potential generally satisfy the Mathieu equation, and have developed a formalism for studying bosons in an …
Effects Of Forest Fragmentation On Central Amazonian Bird Demography, Jared Desmond Wolfe
Effects Of Forest Fragmentation On Central Amazonian Bird Demography, Jared Desmond Wolfe
LSU Doctoral Dissertations
Avian diversity in degraded fragmented Amazonian landscapes depends on the persistence of species in cleared and disturbed areas. Regenerating forest facilitates bird dispersal within degraded Amazonian landscapes and may tip the balance in favor of persistence in previously depauperate habitat patches. Despite the potential value of Amazonian second growth, we lack comparisons of demography among second growth, continuous forest, forest fragments in regenerating landscapes, and truly isolated fragments. Here, we used point-count and capture data to compare Amazonian bird communities among continuous forest plots, 100 ha forest fragments with adjacent second growth, 100 ha forested islands bounded by water, young …
Cyanobacteria Harmful Algal Blooms In South Louisiana Estuaries : A Synthesis Of Field Research, Management Implications, And Outreach, Emily Anne Smith
Cyanobacteria Harmful Algal Blooms In South Louisiana Estuaries : A Synthesis Of Field Research, Management Implications, And Outreach, Emily Anne Smith
LSU Doctoral Dissertations
Estuaries are biologically productive and important habitats for several fisheries. However, human intervention has separated many estuaries from their needed freshwater source and the commonly used solution is to use diversions to regulate the flow. This episodic increase in nutrients into estuaries has sometimes led to the formation of freshwater cyanobacteria HABs (CyanoHABs). The goal of this dissertation was to look at a field research study of phytoplankton bloom dynamics; management implications for cyanobacteria entering estuaries; and an outreach effort in relation to residents knowledge about cyanobacteria and algae. The first study compared the phytoplankton bloom dynamics, specifically CyanoHABs, in …
Phytoplankton Response To South Louisiana Crude Oil Exposure: Determining Impacts At Individual, Community, Toxin Production, Enzymatic-Activity And Gene-Expression Levels, Koray Ozhan
LSU Doctoral Dissertations
The Deepwater Horizon oil spill in the Gulf of Mexico (GoM) raised an important question. What is the ecological impact of the oil, the dispersant, and the dispersed oil to the GoM ecosystem? Significant and varying research efforts have contributed answers to this question. However, to better understand the complete ecological consequences of the spill in the GoM, the impact of the spill at the base of marine food web should be examined. This research aims to understand impact of the spilled oil, South Louisiana crude oil (LSC), the chemical dispersant, Corexit® EC9500A, and the dispersed oil on phytoplankton communities …
Efficient Indexing For Structured And Unstructured Data, Manish Madhukar Patil
Efficient Indexing For Structured And Unstructured Data, Manish Madhukar Patil
LSU Doctoral Dissertations
The collection of digital data is growing at an exponential rate. Data originates from wide range of data sources such as text feeds, biological sequencers, internet traffic over routers, through sensors and many other sources. To mine intelligent information from these sources, users have to query the data. Indexing techniques aim to reduce the query time by preprocessing the data. Diversity of data sources in real world makes it imperative to develop application specific indexing solutions based on the data to be queried. Data can be structured i.e., relational tables or unstructured i.e., free text. Moreover, increasingly many applications need …
From Micro- To Nano-Scale: Applications Of Solid-Phase Enzymatic Reactors For Biopolymer Disassembly, Nyote J. Calixte
From Micro- To Nano-Scale: Applications Of Solid-Phase Enzymatic Reactors For Biopolymer Disassembly, Nyote J. Calixte
LSU Doctoral Dissertations
The process of immobilizing enzymes onto solid supports for bioreactions has some compelling advantages compared to their solution-based counterpart including the facile separation of enzyme from products, elimination of enzyme autodigestion, and increased enzyme stability and activity. We report in this work, the immobilization of λ-exonuclease onto poly(methylmethacrylate) (PMMA) micro- and nano-pillars populated within a fluidic devices for the micro and nanoscale on-chip digestion of double-stranded DNA. Enzyme immobilization in both studies was successfully accomplished using 3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling to carboxylic acid functionalized PMMA micropillars. Our micro-scale results suggest that the reaction efficiency for the catalysis of dsDNA digestion …
Local Conjugations Of Groups And Applications To Number Fields, Bir B. Kafle
Local Conjugations Of Groups And Applications To Number Fields, Bir B. Kafle
LSU Doctoral Dissertations
This dissertation studies pairs of subgroups H, H' of a finite group G together with a bijective map Φ H −> H' that is a local conjugation, meaning that each element h in H is conjugate in G to its image Φ(h). The map Φ is not required to take products to products. The motivation for studying such pairs comes from a paper of F. Gassmann in 1926, in which he formulated an equivalent but different-sounding condition now known as Gassmann’s condition. There are now at least ten equivalent reformulations of Gassmann’s condition, of which local conjugation is perhaps the …
Surface Chemistry And Growth Of Oxide Supported Metal Nanoparticles, Ziyu Zhang
Surface Chemistry And Growth Of Oxide Supported Metal Nanoparticles, Ziyu Zhang
LSU Doctoral Dissertations
A model heterogeneous catalyst inspired by a real catalyst is synthesized for the purpose of understanding how it works. To make such model catalysts, we choose to evaporate metal atoms on metal oxide single crystals and measure them under UHV conditions. The study of model catalysts could advance the understandings of fundamental catalytic properties of real catalysts and helps to optimize or redesign industrial catalysts. In our experiments, many ultra-high vacuum (UHV) techniques have been employed to investigate the atomic and electronic structure of the surface as well as the interface of the prepared samples. In particular, the surface-sensitive tools …
Improved Synthesis, Separation, Transition Metal Coordination And Reaction Chemistry Of A New Binucleating Tetraphosphine Ligand, Ekaterina Kalachnikova
Improved Synthesis, Separation, Transition Metal Coordination And Reaction Chemistry Of A New Binucleating Tetraphosphine Ligand, Ekaterina Kalachnikova
LSU Doctoral Dissertations
The first chapter of this dissertation involves discussion of alkene hydration and oxidative cleavage reactions catalyzed by late transition metal complexes. Previously reported results are summarized here. Mechanistic aspects of alkene hydration catalyzed by late transition metal complexes are also explained. The second part of Chapter 1 focuses on motivation for using bimetallic nickel phosphine complexes as possible catalytic precursors for alkene hydration. Chapter 2 describes studies into alkene hydration in the presence of catalytic amounts of dinickel phosphine complexes based on linear tetraphosphine ligand, PEt2CH2CH2(Ph)PCH2P(Ph)CH2CH2PEt2, et,ph-P4. Under conditions tested no alcohol products were detected. However we have observed formation …
Spin-Mediated Transport In Superconducting And Spin-Polarized Systems, Joseph C. Prestigiacomo
Spin-Mediated Transport In Superconducting And Spin-Polarized Systems, Joseph C. Prestigiacomo
LSU Doctoral Dissertations
The effects of spin-imbalance on the electronic transport properties of spin-polarized and superconducting systems have been studied in detail. The transport properties of the quaternary Heusler alloys Co2MnSi1-xAlx (0≤x≤1), which have been theoretically predicted to develop a half-metallic band structure as x→0, were investigated. Resistivity versus temperature measurements as a function of Al concentration (x) revealed a systematic reduction in the residual resistivity ratio as well as a transition from weakly-localized to half-metallic conduction as x→0. From measurements of the ordinary and anomalous Hall effects, the charge carrier concentration was found to increase, while the anomalous Hall coefficient decreased by …
“Trans-Positioning” Carbons Within Strained Caged Bicyclic(S): Rom/Rcm (Ring-Opening/Ring-Closing) Metathesis And Dieckmann/Retro-Dieckmann Condensation Routes To A Cis-Decalin Infrastructure, Stefan Malone Cooper Jr
“Trans-Positioning” Carbons Within Strained Caged Bicyclic(S): Rom/Rcm (Ring-Opening/Ring-Closing) Metathesis And Dieckmann/Retro-Dieckmann Condensation Routes To A Cis-Decalin Infrastructure, Stefan Malone Cooper Jr
LSU Doctoral Dissertations
This dissertation describes methodology work involving a “Trans-Positioning” motif engaging strategically positioned carbons within a strained bi-carbocyclic core and on a tethered free-dangling hydrocarbon chain ultimately for skeletal rearrangement. Trans-alkenylation and trans-acylation processes are devised for investigation with bicyclo[2.2.2]octyl and bicyclo[2.2.1]heptyl strained cores. Recent advances in olefin metathesis led to an independent proposal of the now applicable, RRM (Ring-Rearranging Metathesis) for trans-alkenylation purposes. A resourceful Dieckmann/retro-Dieckmann sequence is devised for trans-acylation motives. Finally, this dissertation includes atypical diastereoselective reductions and additions which were serendipitously found with trigonal carbon atoms appended to our pertinent strained systems while in pursuit of our …
A Standardized Ultrasonography Classification For Channel Catfish Ovarian Development, Noel D. Novelo
A Standardized Ultrasonography Classification For Channel Catfish Ovarian Development, Noel D. Novelo
LSU Doctoral Dissertations
The goal of this dissertation was to develop application of ultrasonography as a decision-making tool in genetic improvement programs for channel catfish Ictalurus punctatus. A literature review on the use of ultrasonography in fish reproduction generated a comprehensive reference data set intended to benefit existing and potential users. It exposed the need for reporting of instrument control settings and standardization of fish handling and imaging procedures. These issues were addressed from the onset of this work by assessing more than 6,300 channel catfish ovaries by use of initial fish handling and imaging procedures developed (2004-2005) at the Louisiana State University …