Digital Commons Network^™

A Coplanar Vivaldi Antenna With Integrated Filter For Ka-Band, Kansheng Yang, Abraham Loutridis, Xiulong Bao, Patrick Mcevoy, Max Ammann

Conference Papers

A new design approach of a dual-stub coplanar Vivaldi antenna with integrated filter is presented. The dual-stub excites coupling between a parasitic elliptical element and tapered slots. The dimensions of the parasitic element are studied and optimized for wide beamwidth. The band pass filter is used for sub harmonic suppression and pattern shaping.

Lightweight And Cost Efficient Spaceborn Patch Antenna, Korbinian Schraml, Ralf Wilke, Dirk Heberling, Adam Narbudowicz

Conference Papers

In order to achieve lightweight yet low cost antennas for use in a geostationary space environment, the GeReLEO-SMART project develops a substrate-based, multilayer antenna structure which can replace traditional horn antennas as feeds for reflector antennas. To verify a design, an example mission is developed, consisting of a 2×2 patch antenna array with an integrated stripline bandpass filter. The operation frequency is 25.935 GHz. This multilayer antenna will be tested on board of the German technology demonstration mission “Heinrich-Hertz” (H2SAT). The design passed all tests for space qualification without decrease in performance.

Reconfigurable Axial Ratio In Compact Gnss Antennas, Adam Narbudowicz

Articles

A new adaptive technique for steering the direction of minimum axial ratio (AR) (

Global Mortality Impact Of The 1957–1959 Influenza Pandemic, Cecile Viboud, Lone Simonsen, Rodrigo Fuentes, Jose Flores, Mark A. Miller, Gerardo Chowell

Global Health Faculty Publications

Background. Quantitative estimates of the global burden of the 1957 influenza pandemic are lacking. Here we fill this gap by modeling historical mortality statistics.

Methods. We used annual rates of age- and cause-specific deaths to estimate pandemic-related mortality in excess of background levels in 39 countries in Europe, the Asia-Pacific region, and the Americas. We modeled the relationship between excess mortality and development indicators to extrapolate the global burden of the pandemic.

Results. The pandemic-associated excess respiratory mortality rate was 1.9/10 000 population (95% confidence interval [CI], 1.2–2.6 cases/10 000 population) on average during 1957–1959. Excess mortality rates varied 70-fold …

Exploring Geographic Distributions Of High-Risk Water, Sanitation, And Hygiene Practices And Their Association With Child Diarrhea In Uganda, Mitsuaki Hirai, Amira A. Roess, Cheng Huang, Jay P. Graham

Global Health Faculty Publications

Background: High-risk water, sanitation, and hygiene (WASH) practices are still prevalent in most low-income countries. Because of limited access to WASH, children may be put at an increased risk of diarrheal diseases.

Objectives: This study aims to 1) develop a new measure of WASH-induced burden, the WASH Resource Index (WRI), and estimate its correlation with child diarrhea and an additive index of high-risk WASH practices; 2) explore the geographic distribution of high-risk WASH practices, child diarrhea, and summary indices at the cluster level; and 3) examine the association between the WRI and child diarrhea at the individual level. …

The Equipoise Effect, Bert Huang

Faculty Scholarship

This Essay explores an overlooked way to use the remedy of disgorgement in torts, contracts, and regulation. It begins with a reminder that disgorging net gains does not force the liable actor to take a loss; by definition, it allows him to break even. As a matter of incentives, it places him in a sort of equipoise. This equipoise effect has a logical upshot that might seem counterintuitive: Substituting disgorgement for any other remedy, part of the time, can emulate the incentive effect of using that other remedy all of the time.

In theory, then, courts or regulators can sometimes …

The Early Years Of First Amendment Lochnerism, Jeremy K. Kessler

Faculty Scholarship

From Citizens United to Hobby Lobby, civil libertarian challenges to the regulation of economic activity are increasingly prevalent. Critics of this trend invoke the specter of Lochner v. New York. They suggest that the First Amendment, the Religious Freedom Restoration Act, and other legislative "conscience clauses" are being used to resurrect the economically libertarian substantive due process jurisprudence of the early twentieth century. Yet the worry that aggressive judicial enforcement of the First Amendment might erode democratic regulation of the economy and enhance the economic power of private actors has a long history. As this Article demonstrates, anxieties …

Hybrid Inorganic Core- Conjugated Polymer Shell Nanoparticles Prepared By Surface-Initiated Polymerization, Sourav Chatterjee

LSU Doctoral Dissertations

Hybrid core-shell nanoparticles have attracted attention due to their unique characteristics which combine properties of the inorganic core and organic shell in a way that generates new properties which do not exist for the two individual parts. This makes them promising candidates for the design of stimuli-responsive materials, chemo- and biosensors, and various biomedical applications. In this dissertation research, we designed and prepared a series of hybrid environmentally responsive nanoparticles where fluorescent block copolymers, including various combinations of polythiophene (PT), poly(p-phenylene) (PPP), poly(3-hexylthiophene) (P3HT) and polyallene (PA), were grafted on the surface of inorganic nanoparticles using surface-confined Kumada catalyst-transfer polymerization. …

An Augmented Gravity Model: Factors That Affect The U.S. Sugar Imports From Western Hemisphere Countries, Katherine Ramirez Hernandez

LSU Master's Theses

This study analyzes the main factors that affect sugar imports to the United States from western hemisphere producing countries. Important variables such as Free Trade Agreements, production capacity levels and the quota imposed by the United States to the imported sugar will be analyzed under the scope of the gravity model. The estimation of the model is carried out using an OLS analysis. The variables used to create a reliable single-commodity gravity model are: sugar production indicators, distances between the involved countries, population, import quotas, and a set of dummy variables such as FTA (Free Trade Agreements) and border, that …

Influence Of Motivation On Phonics Effectiveness, Rachel L. Bradley

LSU Master's Theses

Reading is a basic life skill, and is paramount to students’ success in school. In fact, skilled readers tend to succeed in subject areas including mathematics, social studies, and science (Valleley & Shriver, 2003). Phonics is one of the cornerstones of learning to read. Without mastering phonics, students are more likely to experience persistent difficulties in reading (Elbro, 1996; Bus and Marinus H. van IJzendoorn, 1999; Rose, 2006). However, student motivation to read can impact the effectiveness of reading programs (Melekoglu, 2011). The current study examines the influence of motivation on the effectiveness of a phonics program with six first-graders …

An Empirical Estimate Of Post-Lgm Grounding-Event Duration In Eastern Ross Sea: Implications From A Comparison With Constraints From New Radiocarbon Dates, Benjamin Krogmeier

LSU Master's Theses

The West Antarctic Ice Sheet (WAIS) advanced to the outer shelf during the Last Glacial Maximum (LGM) before beginning a rapid retreat to the inner shelf. In the Whales Deep paleo-ice-stream trough, subsurface and geomorphologic evidence shows that grounding-line retreat was interrupted by at least five pauses in the area between the shelf edge and the middle shelf. During the pauses, an overlapping cluster of backstepped grounding zone wedges (GZWs) was deposited. Each GZW represents a grounding event, i.e., a time interval during which the grounding-line position was relatively stable. Seismic correlation and isopach mapping show that the cluster has …

Geologic Extremes Of The Nw Himalaya: Investigations Of The Himalayan Ultra-High Pressure And Low Temperature Deformation Histories, Dennis Girard Donaldson

LSU Doctoral Dissertations

This dissertation focuses on two extremes of orogenic development in the Himalaya: the timing of early ultra-high pressure related tectonics and the subsequent emplacement of the high grade Greater Himalayan Crystallines. The Himalayan orogeny is one of if not the best example of ongoing collisional systems, marked by the ongoing convergence of the Indian and Asian continents. The presence of coesite in the Tso Morari complex respresents subduction of the Indian continental crust to ultrahigh-pressure (UHP) conditions. However, the timing of UHP metamorphism is debated, creating an uncertainty in the calculation of subduction and exhumation rates. Petrologic and geochronologic analyses …

The Darkest Nation: American Melancholia In Modernist Narratives Of The First World War, Michael Von Cannon

LSU Doctoral Dissertations

My dissertation, entitled The Darkest Nation: American Melancholia in Modernist Narratives of the First World War, re-conceptualizes U.S. modernism by attending to how the historical event of WWI inaugurated melancholia, or sustained grief, as the cornerstone of a new form of nationalism. Scholars have focused either on how consolatory mourning bolstered patriotism or how melancholia led to the demise of such an imagined community and to the growth of cosmopolitanism. I consider, however, an American modernist commitment to the nation of loss expressed, surprisingly enough, in narratives about noncombatants. For a country that entered the military conflict near its end, …

A Direct Study Of 20ne(Alpha,P)23na With The Helical Orbit Spectrometer (Helios), Jianping Lai

LSU Doctoral Dissertations

Type Ia Supernovae are thermonuclear explosions that occur on CO white dwarfs in binary systems, completely disrupting the system. While the exact progenitor of these events is unclear, there have been several studies exploring the nucleosynthesis that drives these stellar explosions. These studies have shown that a handful of reactions have a significant effect on Type Ia Supernova nucleosynthesis, specifically 12C(alpha, gamma), 12C+12C, 20Ne(alpha, p), 20Ne(alpha, gamma), and 30Si(p, gamma). While the 20Ne(alpha,p)23Na reaction has been shown to be one of the five most influential reactions, it has not been directly been measured at astrophysically relevant energies. We performed direct …

Amblyomma Maculatum Immunomodulation In Mammalian Models Of Rickettsia Parkeri Rickettsiosis, Kaikhushroo Hormazd Banajee

LSU Doctoral Dissertations

Rickettsia parkeri is an emerging human pathogen and spotted fever group Rickettsia that is transmitted via Amblyomma maculatum (the Gulf Coast tick) in the United States. Since these ticks must feed for several days in order to molt to the next life cycle, they must be able to counteract the host immune response. Despite this fact, there have been few studies that evaluate the immunomodulatory effect of this vector and the resultant influence on rickettsial disease. The hypothesis of this research is that, if A. maculatum feeding modifies the host immune response, this immunomodulation will enhance disease caused by R. …

Modelling Hydraulic Fracturing Propagation In Heterogeneous Reservoirs Using Cohesive Zone Methods, Miguel Alejandro Gonzalez-Chavez

LSU Doctoral Dissertations

The recent success in exploiting low permeability shale reservoirs has heavily relied on hydraulic fracturing to produce hydrocarbons economically in disadvantaged reservoir conditions. Although horizontal drilling significantly increases the contact area between the wellbore and the reservoir, the objective of hydraulic fracturing is set on creating further expanded conductive flow paths into the reservoir. This research uses cohesive zone method to numerically simulate hydraulic fracture propagation in the presence of natural fractures in two- and three-dimensional model. The Cohesive element approach limits fracture propagation to some predefined paths. However, in highly fractured formations since hydraulic fractures are growing through a …

Hamiltonian Formulation For Wave-Current Interactions In Stratified Rotational Flows, Adrian Constantin, Rossen Ivanov, Calin-Iulian Martin

Articles

We show that the Hamiltonian framework permits an elegant formulation of the nonlinear governing equations for the coupling between internal and surface waves in stratified water flows with piecewise constant vorticity.

Interactions Among Hydrology, Sediment And Vegetation In Accreting Wax Lake Delta: Physical And Biogeochemical Implications For Coastal Louisiana Restoration, Courtney Erin Elliton

LSU Master's Theses

River discharge pulses, wind, waves, tides, and the presence of dense vegetation are factors that interact and regulate the transport and retention of sediment in coastal regions. In particular, vegetation structural and physiognomic traits promote fine sediment trapping during tidal and river flow, maintaining the balance between soil elevation and relative sea level rise on coastline stability and land building. Mike Island, located within Wax Lake Delta, Louisiana, USA, is part of a deltaic system created by a man-made freshwater diversion (1941) and one of few coastal areas where land is expanding in coastal Louisiana as result of pulsing river …

On The N-Wave Equations With Pt-Symmetry, Vladimir Gerdjikov, Georgi Grahovski, Rossen Ivanov

Articles

We study extensions of N-wave systems with PT-symmetry. The types of (nonlocal) reductions leading to integrable equations invariant with respect to P- (spatial reflection) and T- (time reversal) symmetries is described. The corresponding constraints on the fundamental analytic solutions and the scattering data are derived. Based on examples of 3-wave (related to the algebra sl(3,C)) and 4-wave (related to the algebra so(5,C)) systems, the properties of different types of 1- and 2-soliton solutions are discussed. It is shown that the PT symmetric 3-wave equations may have regular multi-soliton solutions for some specific choices of their parameters.

The Dynamics Of Flat Surface Internal Geophysical Waves With Currents, Alan Compelli, Rossen Ivanov

Articles

A two-dimensional water wave system is examined consisting of two discrete incompressible fluid domains separated by a free common interface. In a geophysical context this is a model of an internal wave, formed at a pycnocline or thermocline in the ocean. The system is considered as being bounded at the bottom and top by a flatbed and wave-free surface respectively. A current profile with depth-dependent currents in each domain is considered. The Hamiltonian of the system is determined and expressed in terms of canonical wave-related variables. Limiting behavior is examined and compared to that of other known models. The linearised …

Unique Characterization Of Materials With Memory, John Murrough Golden

Articles

In general, materials with linear memory constitutive relations are characterized by a relaxation function. This leads to a situation where the free energy for most materials with memory is not unique. There is a convex set of free energy functionals with a minimum and a maximum element. An alternative procedure is proposed which characterizes a material by the kernel of the rate of dissipation functional. Using some recent results, we find that a unique free energy and relaxation function may then be deduced. An example is given for discrete spectrum materials. Also, the new results are used to show that …

An Investigation Of The Generalizability Of Buoyancy From Academics To Athletics, Jackie Rae Victoriano

LSU Master's Theses

Buoyancy, the ability of an individual to handle everyday setbacks, has been applied successfully to academics, and has implications for performance and well-being. The purpose of this investigation was to determine if the concept of buoyancy can be successfully applied to the domain of sports (i.e., athletic buoyancy). This study sought to examine the relationship between academic and athletic buoyancy, as well as the efficacy of five sport-oriented predictors (5Cs), confidence, coordination (planning), commitment, composure (anxiety), and control, on both athletic and academic buoyancy. Sport club athletes (N = 285) aged 18 to 31 years completed a one-time survey assessing …

Testing The Asset-Based Theory Of American Social Welfare: Does A Future-Orientation Mediate The Relationship Between Asset-Ownership And Financial Responsibility?, Louie Fletcher Bickham Iii

LSU Doctoral Dissertations

The ownership of financial assets protects American households from experiencing the struggles of income poverty. The asset-based theory of American social welfare, which was conceptualized by Professor Michael Sherraden in 1991 and amended in 2001 by other scholars, posited that social welfare programs diminish the prevalence of poverty by enabling households to save funds to purchase assets. This theory has been scantly tested—especially among American households—despite a great amount of funds being invested into programs designed to help low-income American households to build assets. The only previous study that examined the intermediary role of future-orientations on the effect of asset-ownership …

Comparison Of Advanced Radiotherapy Techniques For Post-Mastectomy Breast Cancer Patients, David Elward Heins

LSU Master's Theses

Purpose: To determine if bolus electron conformal therapy (BECT) combined with volumetric modulated arc therapy (VMAT) and flattening filter free volumetric modulated arc therapy (FFFVMAT (6x and 10x)) can maintain equal or better dose coverage than standard volumetric modulated arc therapy (VMAT) while reducing doses to organs at risk (OARs). Methods: BECT+VMAT, FFFVMAT (6x and 10x), and VMAT treatment plans were produced for ten post-mastectomy radiotherapy (PMRT) patients previously treated at our clinic. The treatment plans were created on a commercially available treatment planning system (TPS) and all completed treatment plans were reviewed and approved by a radiation oncologist. The …

Effect Of Timing Of Shade On Growth, Development, Physiology, And Fruiting Of A Primocane Fruiting Blackberry In A Controlled Environment, Olivia C. Caillouet, Curt C. Rom, Jason Mcafee, Luke Freeman, Heather Friedrich

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Primocane blackberry production in the upper south is limited by high temperatures during the bloom and early fruiting period, resulting in poor fruit set and poor fruit quality. Shade may have the potential to delay bloom and flowering to a more favorable season. A greenhouse study was established to evaluate the effects of shade on primocane blackberry growth, physiology, and fruiting. Single rooted plants of ‘Prime-Ark® 45’ were planted in 12-liter pots and grown in a greenhouse at the University of Arkansas System Division of Agriculture, Agriculture Research and Extension Center, Fayetteville, Arkansas. At approximately 0.25 m in height, one …

The Effects Of Shade On Primocane Fruiting Blackberries In The Field, Olivia C. Caillouet, Curt C. Rom, Jason Mcafee, Luke Freeman, Heather Friedrich

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Primocane fruiting blackberry production in Arkansas is limited by heat during the flowering and early fruiting season. Shade could be used to delay flowering and fruiting to more favorable growth period. This study was designed to test three levels of shade (0% [control], 30% and 50% shading) applied at three times during the growing season that examined the growth, development, physiology of flowering, and fruiting of ‘Prime-Ark® 45’ blackberries. The seven treatments were as follows: 1) an untreated control (CK), 2) early shade 30% (ES30), mid shade 30% (MS30), 4) late shade 30% (LS30), 5) early shade 50% (ES50), 6) …

Optimal Configuration Of Inspection And Rework Stations In A Multistage Flexible Flowline, Md. Shahriar Jahan Hossain

LSU Master's Theses

Inspection and rework are two important issues of quality control. In this research, an N-stage flowline is considered to make decisions on these two issues. When defective items are detected at the inspection station the items are either scrapped or reworked. A reworkable item may be repaired at the regular defect-creating workstation or at a dedicated off-line rework station. Two problems (end-of-line and multistage inspections) are considered here to deal with this situation. The end-of-line inspection (ELI) problem considers an inspection station located at the end of the line while the multistage inspection (MSI) problem deals with multiple in-line inspection …

A Study Of Fpga Resource Utilization For Pipelined Windowed Image Computations, Aswin Vijaya Varma

LSU Master's Theses

In image processing operations, each pixel is often treated independently and operated upon by using values of other pixels in the neighborhood. These operations are often called windowed image computations (or neighborhood operations). In this thesis, we examine the implementation of a windowed computation pipeline in an FPGA-based environment. Typically, the image is generated outside the FPGA environment (such as through a camera) and the result of the windowed computation is consumed outside the FPGA environment (for example, in a screen for display or an engine for higher level analysis). The image is typically large (over a million pixels 1000×1000 …

The Effects Of Carbon Nanotubes On Cells In A Synthetic Oxygen Carrier Enriched Alginate Scaffold, Joshua Paul Tate

LSU Master's Theses

Abstract Huge progress has been made in the development of three dimensionally printed tissue structures. With the use of cells, three dimensional printers, and CAD drawing software, donor identical structures can be fabricated. However, cell scaffolds currently lack significant mechanical integrity which can result in reduced cellular survival, attachment, and nutrient delivery. For this reason, multiple strategies have been developed to increase and improve mechanical stability within engineered constructs without having to sacrifice cell viability. The hypothesis of this paper was that incorporating Perfluorotributylamine (PFTBA), a greenhouse gas, with single walled carbon nanotubes (SWCNT), a allotrope of carbon with a …

Twisted Reflection Positivity, Mostafa Ahmad Hayajneh

LSU Doctoral Dissertations

Reflection positivity has several applications in both mathematics and physics. For example, reflection positivity induces a duality between group representations. In this thesis, we coin a new definition for a new kind of reflection positivity, namely, twisted reflection positive representation on a vector space. We show that all of the non-compactly causal symmetric spaces give rise to twisted reflection positive representations. We discover examples of twisted reflection positive representations on the sphere and on the Grassmannian manifold which are not unitary, namely, the generalized principle series with the Cosine transform as an intertwining operator. We give a direct proof for …