Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 72

Full-Text Articles in Physical Sciences and Mathematics

Public Perception Of Wildfire Risk And Prescribed Burning In The Wildland/Urban Interface Of The Louisiana Florida Parishes, Charlotte Ann Gerald Jan 2010

Public Perception Of Wildfire Risk And Prescribed Burning In The Wildland/Urban Interface Of The Louisiana Florida Parishes, Charlotte Ann Gerald

LSU Master's Theses

Wildfire has been suppressed in the nation’s forests for over a hundred years. The accumulation of forest fuels over time has created an urgent need to reduce fuel loads to prevent catastrophic wildfires from occurring, not only in our wildlands, but also in our Wildland/Urban Interfaces (WUI’s). The residents who live within the WUI are particularly vulnerable to extreme wildfire events. As cities become more densely populated, increasing numbers of people are moving beyond the suburbs into the WUI. A complex matrix of structures and forested land, developing communities, and impinging forests exists within the WUI. This study utilized a …


Spatial Variations Of Salinity, Temperature And Pressure On The Flank Of A Salt Dome, Offshore Louisiana: Implications For Mechanisms Of Fluid Flow, Andrew Kevin Steen Jan 2010

Spatial Variations Of Salinity, Temperature And Pressure On The Flank Of A Salt Dome, Offshore Louisiana: Implications For Mechanisms Of Fluid Flow, Andrew Kevin Steen

LSU Master's Theses

Salt dome dissolution in the Gulf of Mexico sedimentary basin is a primary cause for elevated pore water salinities in the subsurface. Temperature, pressure, salinity, lithology and fluid density are parameters often used to identify preferential conduits and driving forces for fluid migration. These parameters were calculated using 20 wireline logs covering 40 km² on the south flank of a salt dome on the continental shelf, offshore Louisiana. 3-D seismic has been utilized to determine location of faults, to aid in sand correlation, and to provide a structural overview of the dome. Vertical and lateral variations in lithology, salinity, temperature, …


Taphonomy And Sedimentology Of Two Miocene Vertebrate Fossil Sites On Fort Polk, Louisiana, Julie Lynn Hill Jan 2010

Taphonomy And Sedimentology Of Two Miocene Vertebrate Fossil Sites On Fort Polk, Louisiana, Julie Lynn Hill

LSU Master's Theses

The discovery of a terrestrial mammalian fauna in the Miocene deposits on Fort Polk, Louisiana, fills a geographic gap in the Gulf Coast paleontological framework, but the provenance of the fossils, nature of the depositional environments, and relationships between the sites is still debated. This is especially true for the TVOR site cluster. TVOR SE has a mixture of marine and terrestrial vertebrates in association with a partly dissolved, in situ bed of articulated oyster shells, which stands in contrast to the fully terrestrial and freshwater assemblage at TVOR, and the indeterminate site TVOR S. Although limited outcrop may bias …


Metamorphic Rocks In The Sawtooth Mountains, Idaho, Usa: A Window Into The Precambrian Basement Of Southwest Laurentia, Kyle Michael Metz Jan 2010

Metamorphic Rocks In The Sawtooth Mountains, Idaho, Usa: A Window Into The Precambrian Basement Of Southwest Laurentia, Kyle Michael Metz

LSU Master's Theses

The western North American craton consists of a mosaic of Precambrian basement terranes that developed through episodes of microcontinent collision and magmatic arc accretion. Defining the extent and boundaries of these terranes is critical to deciphering the Precambrian development of Laurentia. The poorly exposed Selway terrane occurs between the Archean Wyoming province and the Neoproterozoic rifted margin of Laurentia. A rare exposure of Precambrian metamorphic rocks, the Sawtooth Metamorphic Complex (SMC), crops out over 33 km2 in the Sawtooth Mountains of Idaho, USA, and potentially provides a window into the deep crust of the region. Field mapping, petrographic analyses, and …


A Characterization Of Near Outer-Planar Graphs, Tanya Allen Lueder Jan 2010

A Characterization Of Near Outer-Planar Graphs, Tanya Allen Lueder

LSU Master's Theses

This thesis focuses on graphs containing an edge whose removal results in an outer-planar graph. We present partial results towards the larger goal of describing the class of all such graphs in terms of a finite list of excluded graphs. Specifically, we give a complete description of those members of this list that are not 2-connected or do not contain a subdivision of a three-spoke wheel. We also show that no members of the list contain a five-spoke wheel.


Misconceptions On Force And Gravity Among High School Students, Jane Ragasa Pablico Jan 2010

Misconceptions On Force And Gravity Among High School Students, Jane Ragasa Pablico

LSU Master's Theses

The goal of this study is to determine prevalent or dominant misconceptions on force and gravity among high school students. A survey instrument consisting of 12 qualitative questions requiring both answers and written explanations was used to gather students’ ideas and beliefs in situations involving force and gravity. Furthermore, it examined whether the proportion of students having misconceptions per question are correlated with gender and the type of school Physics background. The results show that the respondents have misconceptions that are similar to the misconceptions found in previous research. The number of misconceptions and the proportion of students having misconceptions …


Water And Solute Transport In The Shallow Subsurface Of A Riverine Wetland Natural Levee, April Elea Newman Jan 2010

Water And Solute Transport In The Shallow Subsurface Of A Riverine Wetland Natural Levee, April Elea Newman

LSU Master's Theses

In riverine wetlands, the rate and magnitude of water exchanged between river channels and adjacent wetlands have a major influence on hydrologic function and associated aquatic habitat and water quality. River channels are generally separated from backswamps by natural levees; however, preferential flow may allow potentially substantial water and solute exchange between them. Determining the influence of preferential flow on water and solute transport in natural levees requires an innovative approach that allows measurement of transport rates at a scale large enough to capture field-scale variability. To test the hypothesis that preferential flow is important to subsurface water movement through …


Origin Of Pyrite Nodules At The Top Of The Nantuo Diamictites, Southern China, Changjie Liu Jan 2010

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 …


The Influences Of Microbial Diversity On Carbonate Geochemistry Across A Transition From Fresh To Saline Water In The Edwards Aquifer, Texas, Cassie Jo Gray Jan 2010

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 …


Rare Earth Elements As An Investigative Tool Into The Source, Age, And Ecology Of Late Miocene To Late Pleistocene Fossils From The Tunica Hills, Louisiana, Lindsey Theresa Yann Jan 2010

Rare Earth Elements As An Investigative Tool Into The Source, Age, And Ecology Of Late Miocene To Late Pleistocene Fossils From The Tunica Hills, Louisiana, Lindsey Theresa Yann

LSU Master's Theses

Rare earth elements were investigated for their potential to determine provenance and depositional environments of vertebrate fossils found as float in creeks of the Tunica Hills region of Louisiana. Elemental analyses are used to test the hypotheses that fossils span multiple time periods, from late Miocene to late Pleistocene, and that elemental profiles can distinguish terrestrial depositional settings from possible estuarine deposits. In addition, the animals present were then used to test the hypothesis that Tunica Hills had late Pleistocene environmental conditions much like the modern Great Lakes region. This study is important because it provides new insight on the …


Hepatotoxic Cyanobacterial Blooms In Louisiana's Estuaries: Analysis Of Risk To Blue Crab (Callinectes Sapidus) Following Exposure To Microcystins, Ana Cristina Garcia Jan 2010

Hepatotoxic Cyanobacterial Blooms In Louisiana's Estuaries: Analysis Of Risk To Blue Crab (Callinectes Sapidus) Following Exposure To Microcystins, Ana Cristina Garcia

LSU Master's Theses

The most common toxins detected following freshwater harmful algal blooms are microcystins, a group of hepatotoxins produced by cyanobacteria (e.g., Microcystis and Anabaena spp.). Preference for filter-feeding prey, including bivalves, makes the blue crab, Callinectes sapidus, vulnerable to microcystin contamination and makes the commercially important crab a potential vector of microcystins. I used a combination of field and laboratory studies to determine blue crab vulnerability to microcystin contamination and consequent impacts on crab physiology. Samples collected from a hyper-eutrophic freshwater lake, Lac des Allemands, Louisiana, were analyzed for cyanobacterial abundances and microcystins in surface water and blue crabs using light-microscopy …


Geothermal Resource Assessment Of The Gueydan Salt Dome And The Adjacent Southeast Gueydan Field, Vermilion Parish, Louisiana, Taylor Austin Gray Jan 2010

Geothermal Resource Assessment Of The Gueydan Salt Dome And The Adjacent Southeast Gueydan Field, Vermilion Parish, Louisiana, Taylor Austin Gray

LSU Master's Theses

The fluids heated by the high thermal conductivity and vertical geometry of salt domes in South Louisiana have the potential to be an economic source of geothermal energy. The Gueydan dome is a piercement salt diapir in Southwest Louisiana lying along the Vermilion and Acadia Parish border. Isotherms indicate a thermal anomaly at the crest of the dome with formation temperatures of 62 ˚C recorded at 1346 m, which is too cold for a geothermal prospect. The shallowest salt encountered is at a depth of 1475 m, and the surrounding strata are Cenozoic sand and clay deposits. Previous geothermal assessments …


Volcanological And Petrogenetic Characteristics Of Komatiites Of The 3.3 Ga Saw Mill Complex, Weltevreden Formation, Barberton Greenstone Belt, South Africa, Matthew Stephen Huber Jan 2010

Volcanological And Petrogenetic Characteristics Of Komatiites Of The 3.3 Ga Saw Mill Complex, Weltevreden Formation, Barberton Greenstone Belt, South Africa, Matthew Stephen Huber

LSU Master's Theses

The Saw Mill Complex (SMC) is a 1275 m thick layered komatiitic sequence in the 3.3 Ga Weltevreden Formation, uppermost stratigraphic unit of the Onverwacht Group in the northern part of the Barberton Greenstone Belt, South Africa. A series of ultramafic complexes in the Weltevreden Formation have been interpreted as layered ultramafic intrusions, consisting of thick, layered ultramafic units of peridotite, pyroxenite, dunite, and gabbro. However, recent work on the Pioneer complex of the Weltevreden Formation has demonstrated an extrusive origin of komatiites and tuffs. The Weltevreden Formation has been less studied than other Onverwacht Group units. It is likely …


Correlation Of Defaults In Complex Portfolios Using Copula Techniques, Adam Lodygowski Jan 2010

Correlation Of Defaults In Complex Portfolios Using Copula Techniques, Adam Lodygowski

LSU Master's Theses

This work, dealing with the correlation between subportfolios in more complex portfolios, begins with a brief survey of the necessary theoretical background. The basic statistical and probabilistic concepts are reviewed. The notion of copulas is introduced along with the fundamental theorem of Sklar. After this background a numerical procedure and code are developed for correlated defaults in multiple correlated portfolio. Further on, interesting results regarding the impact of changes in correlation on the portfolio performance are investigated in the simulations. The most valuable observations regarding the expected default ratios of two subportfolios considered jointly are presented and explained with particular …


Evaluation Of The Effectiveness Of Cooperative Learning Structures In Improving Students' Performance, Jonah Njenga Jan 2010

Evaluation Of The Effectiveness Of Cooperative Learning Structures In Improving Students' Performance, Jonah Njenga

LSU Master's Theses

In a desperate attempt to improve high school classroom performances, recently, schools have begun to move towards incorporating cooperative learning strategies into their classrooms. Generally, cooperative learning strategies can be described as the use of small groups to encourage learners work together and accomplish shared goals and subsequently maximize theirs and others’ potential. In an attempt to evaluate the effectiveness of this strategy on classroom learning, this study compares the gains in means of scores between a group taught using cooperative learning strategies and another group taught using non-cooperative learning strategies. Fifty-three students taking Algebra I were given a pretest …


Status Of Wintering Grassland Birds In A Post-Hurricane, Salvage-Logged Forest, Matthew Edward Brooks Jan 2010

Status Of Wintering Grassland Birds In A Post-Hurricane, Salvage-Logged Forest, Matthew Edward Brooks

LSU Master's Theses

North American grassland birds have been declining at an alarming rate. Winter habitat for grassland species in the southeastern U.S. generally occurs within forests subject to management. I studied wintering grassland bird communities in De Soto National Forest in southern Mississippi. My objectives were to: 1) Assess bird communities and vegetation structure in upland forest stands that were salvage-logged following Hurricane Katrina, in stands managed for Red-cockaded Woodpeckers (Picoides borealis, RCW), and in stands containing bogs; and 2) Determine the extent of the association between vegetation and occurrence of the common wintering grassland birds. I conducted bird and vegetation surveys …


Bioaerosols And The Risk Of Upper Respiratory Infection In Dental Hygienists, Christen Rebecca Gautreau Jan 2010

Bioaerosols And The Risk Of Upper Respiratory Infection In Dental Hygienists, Christen Rebecca Gautreau

LSU Master's Theses

Multitudes of pathogenic and infectious microbes are known to spread via contaminated aerosols. Dental personnel have an increased incidence of respiratory infections. Ultrasonic scaling procedures are reported to produce the largest amounts of contaminated aerosols of any dental procedure. The goal of the current study was to see if dental hygienists are at an increased risk of respiratory infections during the performance of their job and to see if certain dental procedures had a significant effect on this risk. This study was conducted at the Dental Hygiene Clinic of the Louisiana State University School of Dentistry in New Orleans, LA. …


Impact Of Urban Runoff On Phosphorus, Nitrogen, And Dissolved Oxygen In A Shallow Subtropical Lake, Ryan Mesmer Jan 2010

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) …


Getting Off The Ground With Ap Calculus, David Frank Woods Jan 2010

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 …


Seventh-Grade Curriculum In Probability (A Guide For Teachers), David Nganga Njenga Jan 2010

Seventh-Grade Curriculum In Probability (A Guide For Teachers), David Nganga Njenga

LSU Master's Theses

A review of the literature indicates that teachers try to make connections between experimental and theoretical probabilities while teaching their students, but these connections are often not very clear. This greatly increases misconceptions students have about probability. This thesis presents a treatment of teaching probability that is geared for seventh grade and intended to minimize the misconceptions that both teachers and students may have. We present a concise mathematical exposition of finite probability models as well as collection of examples and activities, so as to help teachers and students organize their thinking and minimize misconceptions. The various examples and activities …


Patterns Of Habitat Suitability And Abundance Trends Of Current And Candidate Coastal Fish Species Of Concern In Louisiana, Elin Rose Sandy Jan 2010

Patterns Of Habitat Suitability And Abundance Trends Of Current And Candidate Coastal Fish Species Of Concern In Louisiana, Elin Rose Sandy

LSU Master's Theses

Louisiana’s estuaries and coastal waters play an important role in providing habitat for several estuarine-dependent species and also serve as a nursery for the juveniles of several other species. The current rate of land loss in Louisiana and the decline of estuarine-dependent species force us to improve our understanding of the recruitment of these species into Louisiana’s estuaries. Habitat suitabilities were developed for several fish species of concern (SOC) and other estuarine-dependent species across three environmental gradients, abundance patterns were developed for seasons, five-year intervals, and coastal study areas (CSAs). Chi-square analyses and ANOVAs were then used to test for …


Positron Autoradiography For Intravascular Vulnerable Plaque Imaging, Peter Petrek Jan 2010

Positron Autoradiography For Intravascular Vulnerable Plaque Imaging, Peter Petrek

LSU Master's Theses

Purpose: To develop and investigate an intravascular storage phosphor detector for imaging and detection of vulnerable coronary artery plaques. Methods: The concept of the detection of vulnerable plaques (i.e., plaques with inflammation) is based on accumulation of fluorodeoxyglucose (FDG) in inflammation sites. The FDG is labeled with a radioactive isotope 18F (positron source), injected to patient, and accumulated in vulnerable plaques of coronary arteries. The radiation detector is then inserted into coronary artery, records positrons from FDG accumulated in vulnerable plaque, which allows for imaging and detection of the vulnerable plaque. A prototype detector was developed and tested. The detector …


Effects Of Habitat Structural Complexity On Nekton Assemblages: Lab And Field Observations In Southern Louisiana, Austin T. Humphries Jan 2010

Effects Of Habitat Structural Complexity On Nekton Assemblages: Lab And Field Observations In Southern Louisiana, Austin T. Humphries

LSU Master's Theses

Greater structural complexity is often associated with more diverse and abundant species assemblages. Biogenic reefs formed by the eastern oyster (Crassostrea virginica) are structurally complex in nature and have been recognized for their potential habitat value in estuarine systems along the Atlantic and Gulf of Mexico coasts. To determine how the structural complexity of newly created oyster reefs may influence the abundance and distribution of species, three objectives were established. First, to examine spatial and temporal patterns of nekton use at newly created oyster reefs, as well as the impact of wave exposure, six paired oyster reef and mud-bottom treatments …


Multi-Scale Habitat Associations Of Shorebirds During Spring Migration In Southwestern Louisiana Rice Fields, Rachel K. Villani Jan 2010

Multi-Scale Habitat Associations Of Shorebirds During Spring Migration In Southwestern Louisiana Rice Fields, Rachel K. Villani

LSU Master's Theses

Rice is the most common wetland crop in the world, and important for waterbirds and shorebirds worldwide, including the United States. In Louisiana, shorebirds use rice fields during spring migration, and are an important for foraging and refueling during migration. However, competing land uses and restoration projects may reduce the availability of rice fields, and impact the landscape that shorebirds use during migration. To determine how shorebirds use the landscape, I evaluated local and landscape factors affecting shorebird use of rice fields during spring migration in southwestern Louisiana. Using five habitat suitability zones (HSZs) based on rice density and canopy …


The Impact Of Hurricanes Katrina And Rita On The Louisiana Judicial System, Charles Simon Mccowan, Iii Jan 2010

The Impact Of Hurricanes Katrina And Rita On The Louisiana Judicial System, Charles Simon Mccowan, Iii

LSU Master's Theses

This thesis is a case study of the impact of Hurricanes Katrina and Rita on the Louisiana court system and the response of the court system to the aftermath of these two hurricanes. Although this thesis focuses on one state’s court system’s response to two natural disasters, the research, conclusions and recommendations are transferable to other states. Hurricanes Katrina and Rita struck the Gulf Coast in 2005 devastating large areas in Louisiana, Texas, Mississippi and Alabama. Millions of people, including judges and attorneys, were forced to evacuate their homes, courts and law offices. The Hurricanes caused interruptions to both federal …


Habitat Use, Movements And Spring Migration Chronology And Corridors Of Female Gadwalls That Winter Along The Louisiana Gulf Coast, Jacob M. Gray Jan 2010

Habitat Use, Movements And Spring Migration Chronology And Corridors Of Female Gadwalls That Winter Along The Louisiana Gulf Coast, Jacob M. Gray

LSU Master's Theses

The Louisiana Gulf Coast is an important wintering area for North American gadwall (Anas strepera). Conservation of winter habitat is a top priority of the Gulf Coast Joint Venture. Quantitative estimates of habitat use by wintering gadwall would help improve energetic demand models and subsequent estimates of habitat requirements. I used satellite telemetry (PTTs) to estimate winter habitat and refuge uses, spring migration chronology and corridors, as well as inter- and intra-regional winter movements of females. I used a split-plot MANOVA to evaluate the effects of individual females, female age, winter, hunt periods within winter, time of day, and all …


Effectiveness Of Forestry Best Management Practices In Minimizing Harvesting Impacts On Streamflow And Sediment Loading In Low-Gradient Headwaters Of The Gulf Coastal Plain, Kristopher Brown Jan 2010

Effectiveness Of Forestry Best Management Practices In Minimizing Harvesting Impacts On Streamflow And Sediment Loading In Low-Gradient Headwaters Of The Gulf Coastal Plain, Kristopher Brown

LSU Master's Theses

Few studies have examined the effectiveness of timber harvesting Best Management Practices (BMPs) in water quality protection of widely-spread, low-gradient, and highly intermittent headwaters on the Gulf Coastal Plain. Also, a spatial disparity exists between the plot-scale water quality benefits afforded by BMP implementation and the watershed-scale with which most watershed stewardship programs are managed. In this thesis research, paired-watershed and Before-After-Control-Impact (BACI) designs were utilized to quantify plot- and watershed-scale changes in streamflow, as well as baseflow and stormflow Total Suspended Sediment (TSS) concentration and yield for 27 months after clearcut harvesting with and without BMPs in a low-gradient, …


Understanding The Use Of Barrier Islands As Nesting Habitat For Louisiana Birds Of Concern, Cecilia Marie Leumas Jan 2010

Understanding The Use Of Barrier Islands As Nesting Habitat For Louisiana Birds Of Concern, Cecilia Marie Leumas

LSU Master's Theses

Colonial nesting seabirds are threatened by habitat loss and degradation, human disturbance, predation, and climate change. Several species of conservation concern concentrate high percentages of their total U.S. populations in Louisiana breeding colonies. We studied seabirds, including Royal Terns, Sandwich Terns, and Black Skimmers, nesting on Isles Dernieres barrier islands along the Gulf coast of Louisiana. Two of the four islands in this chain host extensive seabird colonies and two do not. We used an experimental approach to test the hypothesis that large terns and skimmers are prevented from nesting on Trinity Island, the largest of the Isles Dernieres, by …


Synthesis Of Aza-Bridged Tetraphosphine Ligands For A Dirhodium Hydroformylation Catalyst, Scott Michael Boudreaux Jan 2010

Synthesis Of Aza-Bridged Tetraphosphine Ligands For A Dirhodium Hydroformylation Catalyst, Scott Michael Boudreaux

LSU Master's Theses

A novel tetraphosphine ligand rac-et,ph-P4 (et,ph-P4 = PEt2CH2CH2(Ph)PCH2P(Ph)CH2CH2PEt2) is used for the formation of a highly active and regioselective hydroformylation catalyst. The active catalytic species, Rh2H2(ƒÝ-CO)2(et,ph-P4)]2+, is formed in situ under H2/CO pressure. This is one of the most impressive examples of homobimetallic cooperativity in homogeneous catalysis. The fragmentation of this catalyst by CO has been investigated and confirmed by in situ NMR spectroscopic studies. A new tetraphosphine ligand rac-et,ph-P4-Ph (et,ph-P4-Ph = PEt2(o-C6H4)P(Ph)CH2(Ph)P(o-C6H4)PEt2) has been synthesized to combat this fragmentation problem. However, the inability to successfully separate the meso and racemic isomers of the ligand has led to more alteration …


An Adaptable Group Communication System, Vikram Reddy Kayathi Jan 2010

An Adaptable Group Communication System, Vikram Reddy Kayathi

LSU Master's Theses

Existing group communication systems like ISIS, Spread, Jgroups etc., provide group communication in a synchronous environment. They are built on top of TCP/IP or UDP and guarantee virtual synchrony and consistency. However, wide area distributed systems are inherently asynchronous. Existing group communication systems are not suitable for wide area deployment. They do not provide persistent communication; i.e., if a node gets temporarily disconnected, all messages directed to that node during that period are lost. Hence such systems are not suitable for deployment in disadvantaged networks. While, according to Brewer’s CAP theorem, it is impossible for a distributed computer system to …