Physical Sciences and Mathematics Commons^™

Wavelet Sets With And Without Groups And Multiresolution Analysis, Mihaela Dobrescu

LSU Doctoral Dissertations

In this dissertation we study a special kind of wavelets, the so-called minimally supported frequency wavelets and the associated wavelet sets. Most of the examples of wavelet sets are for dilation sets which are groups. In this work we construct wavelet sets for which the dilation set, D, is of the form D=MN, where the product is direct, and so D is not necessarily group. In the second part of this dissertation we construct multiwavelets associated with MRA's and we generalize the rotations in the dilation sets to Coxeter groups.

Active Security Mechanisms For Wireless Sensor Networks And Energy Optimization For Passive Security Routing, Lydia Ray

LSU Doctoral Dissertations

Wireless sensor networks consisting of numerous tiny low power autonomous sensor nodes provide us with the remarkable ability to remotely view and interact with the previously unobservable physical world. However, incorporating computation intensive security measures in sensor networks with limited resources is a challenging research issue. The objective of our thesis is to explore different security aspects of sensor networks and provide novel solutions for significant problems. We classify security mechanisms into two categories - active category and passive category. The problem of providing a secure communication infrastructure among randomly deployed sensor nodes requires active security measurements. Key pre-distribution is …

Characterization Of A Modified Poly(Propylene Imine) Dendrimer Host System, Amy D. Morara

LSU Doctoral Dissertations

The research in this dissertation focuses on the design of a novel redox-responsive host system that has the ability to encapsulate guest molecules. The host at hand is a tri(ethylene oxide), TEO, pyrrole-terminated PPI dendrimer that possesses water-solubility as a result of the presence of the TEO chains on the pyrrole groups and redox-responsive activity from the pyrrole groups after their oligomerization. The pyrrole moieties at the periphery of the dendrimer exhibit the ability to be oligomerized by oxidation chemistry, and this is shown to aid in the retention and egress of guest molecules located within the dendrimer interior. These …

Characterization Of Aged Polymer Modified Asphalt Cements For Recycling Purposes, Codrin Daranga

LSU Doctoral Dissertations

Since polymer modified asphalt cement (PMAC) has been employed for a decade, the lifetime and wear on some of these pavements is reaching a stage where resurfacing is necessary. This research focuses on the characterization of aged polymer modified asphalt cements (PMAC) to evaluate their potential for recycling. A styrene-butadiene-styrene tri-block (SBS) polymer modified asphalt cement was selected and characterized using standard asphalt binder qualification techniques, i.e., the Superpave PG protocol. We developed a procedure to characterize the relative concentration of polymer in asphalt cements by gel permeation chromatography (GPC). Infrared spectrographic, thermogravimetric and rheological techniques were used to identify …

Radiative Transfer Modeling Of Thermal Infrared Emissivity Spectra: Applications To Martian Regolith Observations, Karly Mariah Pitman

LSU Doctoral Dissertations

Satellite and rover remote sensing of planetary regolith surfaces, in the form of thermal infrared emissivity spectra taken at nadir and off-nadir angles of emergence from the surface, requires use of theoretical models for interpretation of constituent grain physical properties. However, such models have remained in stasis in recent years, with nearly a ten-year gap in significant advances. To date, no radiative transfer model (semiempirical, exact, or hybrid solution) has been able to adequately predict the nadir emissivity behavior of simple mineral assemblages. Few measurements have been attempted in the laboratory or field regarding directional emissivity effects of planetary regoliths; …

Learning Discrete Hidden Markov Models From State Distribution Vectors, Luis G. Moscovich

LSU Doctoral Dissertations

Hidden Markov Models (HMMs) are probabilistic models that have been widely applied to a number of fields since their inception in the late 1960’s. Computational Biology, Image Processing, and Signal Processing, are but a few of the application areas of HMMs. In this dissertation, we develop several new efficient learning algorithms for learning HMM parameters. First, we propose a new polynomial-time algorithm for supervised learning of the parameters of a first order HMM from a state probability distribution (SD) oracle. The SD oracle provides the learner with the state distribution vector corresponding to a query string. We prove the correctness …

Detection Of Biologically Important Molecules, Kyukwang Kim

LSU Doctoral Dissertations

Anions play important roles in biological systems. The design of anion sensors has been of great interest. The selective detection of a specific anion is particularly challenging. In the first chapter, I describe the synthesis of a TBS-protected fluorescein dye (1.1) and its use for the selective detection of fluoride. Solutions of 1.1 either in DCM or in aqueous media at physiological pH show the excellent selectivity towards fluoride to afford color formation while solutions of other interfering anions remain colorless. The monitoring of homocysteine (Hcy) and cysteine (Cys) levels is important since they are biomarkers associated with Alzheimer’s and …

Combining High Conductivity With Complete Optical Transparency: A Band Structure Approach, Julia E. Medvedeva, Arthur J. Freeman

Physics Faculty Research & Creative Works

A comparison of the structural, optical and electronic properties of the recently discovered transparent conducting oxide (TCO), nanoporous Ca12Al14O33, with those of the conventional TCOs (such as Sc-doped CdO) indicates that this material belongs conceptually to a new class of transparent conductors. For this class of materials, we formulate criteria for the successful combination of high electrical conductivity with complete transparency in the visible range and emphasize the significant correlation between their structural characteristics and electronic and optical properties. Our analysis suggests that this set of requirements can be met for a group of novel materials called electrides which may …

Fabrication Of Inverted Opal Zno Photonic Crystals By Atomic Layer Deposition, Michael Scharrer, Xiaohua Wu, Alexey Yamilov, Hui Cao, Robert P. H. Chang

Physics Faculty Research & Creative Works

We have fabricated three-dimensional optically active ZnO photonic crystals by infiltrating polystyrene opal templates using a low-temperature atomic layer deposition process. The polystyrene is removed by firing the samples at elevated temperatures, and reactive ion etching is used to remove the top layer of ZnO and expose the (111) photonic crystal surface. The resulting structures have high filling fractions, possess photonic band gaps in the near-UV to visible spectrum, and exhibit efficient photoluminescence.

Roc Comparison Of Acquisition Parameters For Two Pet/Ct Scanners Based On Lesion Detectability In A Torso Phantom, Kenneth Bernstein

LSU Master's Theses

Positron emission tomography (PET) and computed tomography (CT) are well established and powerful tools for medical diagnostics but even integrated PET/CT scanner images still lack the necessary quality and resolution that would make medical diagnoses flawless. In this thesis experiments were performed to statistically determine the effect that image acquisition parameters have upon diagnostic accuracy. Images from different PET/CT scanners were assessed by comparing subject human diagnostic accuracy from a sample of both professional and student volunteers. The assessment results were compared to the objective NEMA-standards performance data provided by the manufacturers for each scanner. The data analysis method is …

Using Ground Penetrating Radar, Light Detection And Ranging, Geodetic Leveling, And Area Hydrogeology To Study The Baton Rouge And Scotlandville Faults, East Baton Rouge Parish, La, Angela Mooi Thomas

LSU Master's Theses

East Baton Rouge Parish, Louisiana, is situated on at least two faults, the Baton Rouge Fault and the Denham Springs-Scotlandville Fault. These faults have surface expressions in the form of escarpments and damage to man-made structures. The purpose of this thesis is to study these faults in the shallow subsurface, in climate and soils found in Louisiana, and to study their ability to block fluid flow and whether groundwater withdrawal influences the amount and rate of subsidence along these faults. Techniques used to gather field data or to research and compile previously acquired data for this thesis includes: Ground Penetrating …

Environmental Factors Influencing Incubation Constancy And Recess Frequency In Gadwall (Anas Strepera) In The Prairie Pothole Region Of North Dakota, Nicole F. Lorenz

LSU Master's Theses

I examined nest attendance patterns for 132 Gadwall (Anas strepera) females breeding in the prairie pothole region located in Towner County, North Dakota from May to July 2000 - 2001. Overall, Gadwall had a daily incubation constancy of 76.5 ± 10.8%, and daily recess frequency of 2.2 ± 1.1 with each recess lasting 179.8 ± 133.8 minutes. Unlike other waterfowl species, Gadwall increased incubation constancy and decreased recess frequency as daily high temperature increased and showed no change in constancy with precipitation. Gadwall incubation constancy did not fit the body-size hypothesis, as Gadwall have a lower incubation constancy compared to …

Energy-Rate Based Mac Protocol For Wireless Sensor Networks And Key Pre-Distribution Schemes, Ramaraju Kalidindi

LSU Master's Theses

Sensor networks are typically unattended because of their deployment in hazardous, hostile or remote environments. This makes the problem of conserving energy at individual sensor nodes challenging. S-MAC and PAMAS are two MAC protocols which periodically put nodes (selected at random) to sleep in order to achieve energy savings. Unlike these protocols, we propose an approach in which node duty cycles (i.e sleep and wake schedules) are based on their criticality. A distributed algorithm is used to find sets of winners and losers, who are then assigned appropriate slots in our TDMA based MAC protocol. We introduce the concept of …

Effect Of Estradiol-17b On The Gonadal Developemnt Of Diploid And Triploid Female Eastern Oysters, Roberto Quintana

LSU Master's Theses

Declines in annual oyster landings and problems associated with seasonal reduction of oyster meat yields have increased interest for development of techniques to produce oysters with enhanced growth characteristics. Research interest has been focused on developing improved lines by induction of polyploidy. The goal of the present study was to evaluate the enhancement of gonadal development of triploid oysters, by the use of the hormone estradiol 17-â (E2) to produce viable eggs for the development of tetraploid broodstocks. Previous studies with the Pacific oyster, Crassostrea gigas, have shown: (1) the need to use the larger eggs of triploid females to …

Experimental Method Development For Direct Dosimetry Of Permanent Interstitial Prostate Brachytherapy Implants, John Michael Jarrett

LSU Master's Theses

Purpose: To ascertain if PET image data of a positron tracer can be used for the quantitative description of dose distribution in support of direct prostate seed dosimetry. Materials and Methods: Simulated brachytherapy seeds were constructed containing trace amounts of a positron emitter, F-18, such that all annihilation events took place in the encapsulation wall. An acrylic prostate phantom containing these seeds was imaged with a GE Discovery ST PET/CT scanner in 2D and 3D acquisition modes and several image reconstruction methods. The PET scan data was used as the input for Monte Carlo calculation of dose distribution due to …

Performance Evaluation Of Two Czt Gamma Ray Imaging Systems, Laurie Kelly

LSU Master's Theses

The purpose of this research was to evaluate the performance of the imaging characteristics of two versions of a cadmium zinc telluride (CZT) gamma radiation detector system called the Laboratory Radioactive Assay Tracer (LabRAT). The performance evaluation follows the National Electrical Manufacturers Association standards for pixellated detector cameras. The LabRAT detector system hardware was developed by Mosaic Imaging Technology, Inc. LabRAT is a portable nuclear medicine imaging detector system intended for small field of view applications such as small animal imaging, portable radioisotope imaging in emergency room or intensive care units, and as an instruction tool for radiology residents and …

The Moral Dilemma Of Genetically Modified Foods (Gmos), Anamarie Beluch

Student Theses 2001-2013

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Identification Of Genetically Modified Organisms In Foodstuffs, Anamarie Beluch

Student Theses 2001-2013

In this lab we identified GMOs, through the method of PCR, in all of our food samples, in our organic samples, and in corn versus soy samples. We accepted are alternative hypothesis that there were GMOs in our food samples. We also accepted our alternative hypothesis that there were GMOs in our organic samples. We then compared GMOs in our corn versus soy samples, and rejected are null hypothesis that there were the same percentage of GMOs in corn and soy. The chi square test was performed for conventional corn and soy, and organic corn and soy. We calculated the …

Examining The Screening Limit Of Field Effect Devices Via The Metal-Insulator Transition, X. Hong, A. Posadas, C. H. Ahn

Xia Hong Publications

The electronic screening length, the distance over which an electric field is attenuated in a material, imposes a lower physical bound on the lateral size scaling of semiconductor field effect devices. Alternatives will be needed to achieve devices whose characteristic dimensions approach a nanometer. In this work, we demonstrate the atomic-scale nature of screening at high electron densities, using the polarization field of a ferroelectric oxide, Pb(Zr,Ti)O₃, to electrostatically modulate the metallicity of ultrathin manganite La_1−xSr_xMnO₃ (LSMO) films near the metal-insulator transition. Within the screening length, the transport characteristics of LSMO vary sharply …

Phase Transition In Single Crystal Cs2Nb4O11, Jianjun Liu, E. P. Kharitonova, Chun-Gang Duan, Wai-Ning Mei, R. W. Smith, John R. Hardy

John R. Hardy Papers

We studied temperature dependence of complex capacitance, impedance, and polarized Raman spectra of single crystal Cs₂Nb₄O₁₁. First, we observed a sharp λ-shaped peak at 165 °C in the complex capacitance, then found drastic changes in the Raman spectra in the same temperature range. Utilizing the pseudosymmetry search of structure space group, we attributed the observed anomalies to a structural change from the room temperature orthorhombic Pnn2 to another orthorhombic Imm2. We also measured room temperature polarized Raman spectra in different symmetries of normal vibrations and assigned high wavenumber Raman bands to the …

Julian Cecil Stanley Papers, Zach S. Henderson Library, Special Collections

Finding Aids

This collection consists of the research materials of Johns Hopkins professor of psychology, Julian C. Stanley. Materials range from 1950-2005 and include his published reprints, abstracts, reports, letters, and seminar papers. The collection also includes reviews of research materials and articles by prominent psychologists in similar fields.

Find this collection in the University Libraries' catalog.

Laser Power Meter, Akinwunmi O. Odeniyi

Honors Thesis

LASER- Light Amplification by Stimulated Emission of Radiation - can produce a very intense and powerful beam of light that is useful in many scientific and technological fields as well as in everyday life. Laser beams can be focused to a spot a few wavelengths in diameter. In this research project, a laser power meter that measures the amount of light coming from any laser was built using a thermopile.

A thermopile is alight detector which uses the effect that the absorption of light by the material causes a change in the detector material's temperature, resulting in a voltage difference …

Generalized Geologic Map For Land-Use Planning: Henry County, Kentucky, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

Diagnostics Of Disks Around Hot Stars, David H. Cohen, M. H. Hanson, R. H.D. Townsend, K. S. Bjorkman, M. Gagné

Physics & Astronomy Faculty Works

We discuss three different observational diagnostics related to disks around hot stars: absorption line determinations of rotational velocities of Be stars; polarization diagnostics of circumstellar disks; and X-ray line diagnostics of one specific magnetized hot star, theta(1) Ori C. Some common themes that emerge from these studies include (a) the benefits of having a specific physical model as a framework for interpreting diagnostic data; (b) the importance of combining several different types of observational diagnostics of the same objects; and (c) that while there is often the need to reinterpret traditional diagnostics in light of new theoretical advances, there are …

An Investigation Into Long Range Detection Of Passive Uhf Rfid Tags, Craig Valli, Andrew Woodward, Ken Wild, Reino Karvinen

Research outputs pre 2011

Radio frequency identification tags (RFID) have been in use for a number of years, in a variety of applications. They are a small computer chip like device that can range in size from a thumbnail to a credit card size device. They consist of a small silicon chip, and an antenna used to receive and transmit data. When a tag receives a signal from a valid reader it sends a response, typically a tag ID and any other requested/available data back to the reader device. The newer range of RFID chips that are coming into use now use higher frequencies …

Srt Division Algorithms As Dynamical Systems, Mark Mccann, Nicholas Pippenger

All HMC Faculty Publications and Research

Sweeney--Robertson--Tocher (SRT) division, as it was discovered in the late 1950s, represented an important improvement in the speed of division algorithms for computers at the time. A variant of SRT division is still commonly implemented in computers today. Although some bounds on the performance of the original SRT division method were obtained, a great many questions remained unanswered. In this paper, the original version of SRT division is described as a dynamical system. This enables us to bring modern dynamical systems theory, a relatively new development in mathematics, to bear on an older problem. In doing so, we are able …

The Closed Topological Vertex Via The Cremona Transform, Jim Bryan, Dagan Karp

All HMC Faculty Publications and Research

We compute the local Gromov-Witten invariants of the "closed vertex", that is, a configuration of three rational curves meeting in a single triple point in a Calabi-Yau threefold. The method is to express the local invariants of the vertex in terms of ordinary Gromov-Witten invariants of a certain blowup of CP^3 and then to compute those invariants via the geometry of the Cremona transformation.

Dielectric Properties And Maxwell-Wagner Relaxation Of Xompounds Acu3Ti4O12 (A=Ca,Bi2/3,Y2/3,La2/3), Jianjun Liu, Chun-Gang Duan, Wai-Ning Mei, R. W. Smith, John R. Hardy

John R. Hardy Papers

We have studied the frequency and temperature dependences of permittivity and impedance of the compounds ACu₃Ti₄O₁₂ (A=Ca, Bi_2/3, Y_2/3, Las2/3) in the ranges of 10⁻¹–10⁶ Hz and −150–200 °C. All compounds investigated display similar dielectric properties. Specifically, they all have a Debye-like relaxation and their dielectric constants are independent of frequency and temperature over a wide range. They all have two electrical responses in impedance formalism, indicating that there are two distinct contributions. We attribute them to grains and grain boundaries in the ceramic samples and explain the …

Investigation Of The Mechanism Of Polarization Switching In Ferroelectric Capacitors By Three-Dimensional Piezoresponse Force Microscopy, Brian J. Rodriguez, Alexei Gruverman, Angus I. Kingon, Robert J. Nemanich, J. S. Cross

Alexei Gruverman Publications

A mechanism for the switching behavior of (111)-oriented Pb(Zr, Ti)O₃-based 1 × 1.5 μm² capacitors has been investigated using three-dimensional piezoresponse force microscopy (3D-PFM). A combination of vertical and lateral piezoresponse force microscopy (VPFM and LPFM) has been used to map the out-of-plane and the in-plane components of the polarization. The three-dimensional polarization distribution was reconstructed by quantitative analysis of the PFM amplitude images of poled PZT capacitors while taking into account contrast variations in the PFM phase images. The switching behavior of the capacitors was determined by comparison of the static domain patterns in the same …

Domain Growth Kinetics In Lithium Niobate Single Crystals Studied By Piezoresponse Force Microscopy, B. J. Rodriguez, R. J. Nemanich, A. I. Kingon, Alexei Gruverman, Sergei V. Kalinin, K. Terabe, X. Y. Liu, K. Kitamura

Alexei Gruverman Publications

The kinetics of sidewise domain growth in an inhomogeneous electric field has been investigated in stoichiometric LiNbO₃ single crystals by measuring the lateral domain size as a function of the voltage pulse magnitude and duration using piezoresponse force microscopy. The domain size increases linearly with the voltage magnitude suggesting that the domain size is kinetically limited in a wide range of pulse magnitudes and durations. In spite of that, the written domains exhibit strong retention behavior. It is suggested that the switching behavior can be described by the universal scaling curve. Domain kinetics can be described as an activation …