Physical Sciences and Mathematics Commons^™

The Effects Of Electrode Geometry On Current Pulse Caused By Electrical Discharge Over An Ultra-Fast Laser Filament, Matthew Bubelnik

Electronic Theses and Dissertations

The time-resolved electrical conductivity of a short-pulse generated plasma filament in air was studied. Close-coupled metal electrodes were used to discharge the stored energy of a high-voltage capacitor and the resulting microsecond-scale electrical discharge was measured using fast current sensors. Significant differences in the time dependence of the current were seen with the two electrode geometries used. Using sharp-tipped electrodes additional peaks in the time-resolved conductivity were seen, relative to the single peak seen with spherical electrodes. We attribute these additional features to secondary electron collisional ionization brought about by field enhancement at the tips. Additional discrepancies in the currents …

Design And Assessment Of Compact Optical Systems Towards Special Effects Imaging, Vesselin Chaoulov

Electronic Theses and Dissertations

A main challenge in the field of special effects is to create special effects in real time in a way that the user can preview the effect before taking the actual picture or movie sequence. There are many techniques currently used to create computer-simulated special effects, however current techniques in computer graphics do not provide the option for the creation of real-time texture synthesis. Thus, while computer graphics is a powerful tool in the field of special effects, it is neither portable nor does it provide work in real-time capabilities. Real-time special effects may, however, be created optically. Such approach …

Liquid Crystal Materials And Tunable Devices For Optical Communications, Fang Du

Electronic Theses and Dissertations

In this dissertation, liquid crystal materials and devices are investigated in meeting the challenges for photonics and communications applications. The first part deals with polymer-stabilized liquid crystal (PSLC) materials and devices. Three polymer-stabilized liquid crystal systems are developed for optical communications. The second part reports the experimental investigation of a novel liquid-crystal-infiltrated photonic crystal fiber (PCF) and explores its applications in fiber-optic communications. The curing temperature is found to have significant effects on the PSLC performance. The electro-optic properties of nematic polymer network liquid crystal (PNLC) at different curing temperatures are investigated experimentally. At high curing temperature, a high contrast, …

Silcrete Hardpan In The North-Eastern Wheatbelt : Hydrological Implications For Oil Mallees, D L. Bennett, Russell Speed, Adrian Goodreid, Peter Taylor

Resource management technical reports

Silcrete is a brittle, intensely indurated rock comprising primarily quartz grains cemented with siliceous allophane. It occurs at 1.5 to 7 metres deep and is often several metres thick and extremely hard, requiring excavation. This Report discusses the extent of silcrete layers in the north-eastern wheatbelt area of Western Australia, the effects of silcrete on water absorption by the soil, and the effects of this physical obstacle on the growth and expansion of oil mallee trees of the region.

Upper Yilgarn Catchment Appraisal 2005, Keith Ohlsen, Susan Murphy-White

Resource management technical reports

Soil degradation on farmland reduces agricultural production and will often lead to damage to natural resources such as remnant vegetation and waterways, as well as to infrastructure, including roads and townsites. This report provides current information on the land degradation status for the Upper Yilgarn Catchment area in Western Australia by outlining: condition of the soils, hydrology, natural vegetation, farming systems and agricultural production and risks to natural resources.

Polyethylene And Polypropylene Nanocomposites Based Upon An Oligomerically-Modified Clay, Jinguo Zhang, David D. Jiang, Charles A. Wilkie

Chemistry Faculty Research and Publications

Montmorillonite clay was modified with an oligomeric surfactant, which was then melt blended with polyethylene and polypropylene in a Brabender mixer. The morphology was characterized by X-ray diffraction and transmission electron microscopy, while thermal stability was evaluated from thermogravimetric analysis and the fire properties by cone calorimetry. The nanocomposites are best described as mixed immiscible/intercalated/delaminated systems and the reduction in peak heat release rate is about 40% at 5% inorganic clay loading.

The Effects Of Triphenylphosphate And Recorcinolbis(Diphenylphosphate) On The Thermal Degradation Of Polycarbonate In Air, Bok Nam Jang, Charles A. Wilkie

Chemistry Faculty Research and Publications

The thermal degradation of polycarbonate/triphenylphosphate (PC/TPP) and PC/resocinolbis(diphenylphosphate) (PC/RDP) in air has been studied using TGA/FTIR and GC/MS. In PC/phosphate blends, the phosphate stabilizes the carbonate group of polycarbonate from alcoholysis between the alcohol products of polycarbonate degradation and the carbonate linkage. Thus, the evolution of bisphenol A, which is mainly produced via hydrolysis/alcoholysis of the carbonate linkage, is significantly reduced, while, the evolution of various alkylphenols and diarylcarbonates increases. The bonds that are broken first in the thermal degradation of both the carbonate and isopropylidene linkages of polycarbonate are the weakest bonds in each, when a phosphate is present. …

Data Structures And Algorithms For Efficient Solution Of Simultaneous Linear Equations From 3-D Ice Sheet Models, Rodney A. Jacobs

Electronic Theses and Dissertations

Two current software packages for solving large systems of sparse simultaneous l~neare equations are evaluated in terms of their applicability to solving systems of equations generated by the University of Maine Ice Sheet Model. SuperLU, the first package, has been developed by researchers at the University of California at Berkeley and the Lawrence Berkeley National Laboratory. UMFPACK, the second package, has been developed by T. A. Davis of the University of Florida who has ties with the U. C. Berkeley researchers as well as European researchers. Both packages are direct solvers that use LU factorization with forward and backward substitution. …

Splitting Of Vector Bundles On Punctured Spectrum Of Regular Local Rings, Mahdi Majidi-Zolbanin

Dissertations, Theses, and Capstone Projects

In this dissertation we study splitting of vector bundles of small rank on punctured spectrum of regular local rings. We give a splitting criterion for vector bundles of small rank in terms of vanishing of their intermediate cohomology modules Hⁱ(U, E)_{2_i_n−3}, where n is the dimension of the regular local ring. This is the local analog of a result by N. Mohan Kumar, C. Peterson, and A. Prabhakar Rao for splitting of vector bundles of small rank on projective spaces.

As an application we give a positive answer (in a special case) to a conjecture …

A Content-Based Fuzzy Image Database Based On The Fuzzy Artmap Architecture, M. Uysal, Fatoş Tünay Yarman Vural

Turkish Journal of Electrical Engineering and Computer Sciences

A major design issue in content-based image retrieval system is the selection of the feature set. This study attacks the problem of finding a discriminative feature for each class, which is optimal in some sense. Fuzzy ARTMAP architecture is used to find this discriminative feature set. For this purpose, initially, a large variety of features are extracted from the regions of the pre-segmented images. Then, the feature set of each object class is learned using the Fuzzy Art Map Architecture, by identifying the weights of each feature for each object class. In the querying phase, trained set of feature weights …

Commutative Quartic P-Galois Extensions Over A Field Of Characteristic Not 2, Atsushi Nakajima

Turkish Journal of Mathematics

In [2], K. Kishimoto introduced the notion of P-Galois extensions and gave some fundamental properties of these extensions. P-Galois extensions relate Hopf Galois extensions, and the author treated these topics in [5]. Moreover, the cubic P-Galois extensions over a field were completely determined in [6]. Continuing [5] and [6], we classify commutative quartic P-Galois extensions over a field of characteristic not 2.

On A Class Of Para-Sakakian Manifolds, Ci̇han Özgür

Turkish Journal of Mathematics

In this study, we investigate Weyl-pseudosymmetric Para-Sasakian manifolds and Para-Sasakian manifolds satisfying the condition C \cdot S=0.

Characterizations Of Augmented Graded Rings, Mashhoor Refai, Fida A. M. Moh'd

Turkish Journal of Mathematics

In this paper, we introduce some characterizations for augmented graded rings in special cases.

On Banach Lattice Algebras, Ayşe Uyar

Turkish Journal of Mathematics

In this study, without using the assumption a^{-1} > 0, it is shown that E is lattice - and algebra - isometric isomorphic to the reals R whenever E is a Banach lattice f-algebra with unit e, e = 1, in which for every a > 0 the inverse a^{-1} exists. Subsequently, an alternative proof to a result of Huijsmans is given for Banach lattice algebras.

Anion And Cation-Yield Spectroscopy Of Core-Excited Sf6, Maria Novella Piancastelli, Wayne C. Stolte, Renaud Guillemin, A. Wolska, M. M. Sant'anna, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We report an extensive study on total and partial-ion-yield spectroscopy around both the S 2p and F 1s thresholds in SF₆. All positive and negative single-ion channels have been measured. Below the F 1s threshold we detect a large variation in relative intensity of the resonant structures according to the specific channel monitored, indicating selective fragmentation. Above threshold, at variance with previous cases described by us, we detect high-intensity structures related to shape resonances not only in the cation channels but also for the anions. We discuss the applicability and limits of a model we …

Near-Edge X-Ray Absorption Fine Structure Study Of Ion-Beam-Induced Phase Transformation In Gd2(Ti1-Yzry)2o7, Ponnusamy Nachimuthu, S. Thevuthasan, V. Shutthanandan, E. M. Adams, W. J. Weber, B. D. Begg, D. K. Shuh, Dennis W. Lindle, Eric M. Gullikson, Rupert C. Perera

Chemistry and Biochemistry Faculty Research

The structural and electronic properties of Gd₂(Ti_1−yZr_y)₂O₇ (y=0–1) pyrochlores following a 2.0-MeV Au²⁺ ion-beam irradiation (~5.0 X 10¹⁴ Au²⁺/cm²) have been investigated by Ti 2p and O 1s near-edge x-ray absorption fine structure (NEXAFS). The irradiation of Gd₂(Ti_1−yZr_y)₂O₇ leads to the phase transformation from the ordered pyrochlore structure (Fd3m) to the defect fluorite structure (Fm3m) regardless of Zr concentration. Irradiated Gd₂(Ti_{1−y …}

Marketing Locally Produced Foods: Consumer And Farmer Opinions In Washington County, Nebraska, Mindi L. Schneider, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Local food system potentials were studied in Washington County, Nebraska, United States. As a departure from most studies of locally based systems, farmers were surveyed in addition to consumers for potential participation. Data about the current food system and opinions and preferences for local production, marketing, and purchasing of food were collected using self-administered mail questionnaires. The response rate was 35% for the farmer survey and 37% for the consumer survey. Results indicated that, on the farming side of the food system, conventional corn and soybean production and marketing predominated in Washington County, and farmer interest in producing for local …

Applying Scenario-Based Design And Claim Analysis To The Design Of A Digital Library Of Geography Examination Resources, Yin-Leng Theng, Dion Hoe-Lian Goh, Ee Peng Lim, Zehua Liu, Ming Yin, Natalie Lee-San Pang, Patricia Bao-Bao Wong

Research Collection School Of Computing and Information Systems

This paper describes the application of Carroll’s scenario-based design and claims analysis as a means of refinement to the initial design of a digital library of geographical resources (GeogDL) to prepare Singapore students to take a national examination in geography. GeogDL is built on top of G-Portal, a digital library providing services over geospatial and georeferenced Web content. Beyond improving the initial design of GeogDL, a main contribution of the paper is making explicit the use of Carroll’s strong theory-based but undercapitalized scenario-based design and claims analysis that inspired recommendations for the refinement of GeogDL. The paper concludes with an …

The Twiggs Clay: Mineralogy, Origin, And Industrial Properties Of An Upper Eocene Opaline Claystone In The Coastal Plain Province Of Georgia, U.S., Lori G. Eversull

LSU Doctoral Dissertations

The Twiggs Clay is an upper Eocene claystone found as discontinuous deposits downdip of the Fall Line in the Coastal Plain Province of eastern and central Georgia. A distinctive facies of the Twiggs is found in two lenses near the town of Wrens. The nature, origin, and potential commercial application of this resource are examined. Four strata and two mineralogic assemblages are recognized in the Wrens deposit. The lower three strata are near white in color and very low in density. These strata are mineralogically similar and are composed predominantly of disordered silica and smectite. The smectite is dioctahedral, and …

Nitrate Reduction And Methane Formation As Influenced By Iron-Centered Intermediate Redox Processes In Rice Soils, Bin Huang

LSU Doctoral Dissertations

Rice fields are a major source of the greenhouse gases methane (CH₄) and nitrous oxide (N₂O) and contribute to nitrate (NO₃^-) pollution in waters. Ferric iron (Fe³⁺) and manganic manganese (Mn⁴⁺) are two intermediate alternative electron acceptors (AEAs) capable of regeneration in freshwater soils. In this investigation, the influences of iron-centered intermediate redox processes on NO₃^- reduction and CH₄ formation in rice soils were studied using soil slurries, soil columns, and potted rice. Reduction of Fe³⁺-centered intermediate AEAs was mainly mediated by obligate anaerobes …

Automatic Segmentation Of Magnetic Resonance Images Of The Brain, Kirk V. N. Spence

LSU Doctoral Dissertations

Magnetic resonance imaging (MRI) is a technique used primarily in medical settings to produce high quality images of the human body’s internal anatomy. Each image is of a thin slice through the body, with the typical distance between slices being a few millimeters. Brain segmentation is the delineation of one or more anatomical structures within images of the brain. It promotes greater understanding of spatial relationships to aid in such tasks as surgical planning and clinical diagnoses, particularly when the segmented outlines from each image slice are displayed together as a surface in three-dimensions. A review of the literature indicates …

Computation Of Association Probabilities For Single Target Tracking With The Use Of Adaptive Neuro-Fuzzy Inference System, İlke Türkmen, Keri̇m Güney

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a simple method based on the adaptive neuro-fuzzy inference system (ANFIS) is presented for computing the association probabilities. The computed association probabilities are used to track the single manoeuvring target in the cluttered environment. A hybrid learning algorithm, which combines the least square method and the backpropagation algorithm, is used to identify the parameters of ANFIS. The tracks estimated by using the method proposed in this study are in very good agreement with the true tracks. Better accuracy with respect to the well known nearest neighbour Kalman filter and probabilistic data association algorithms is obtained.

Decentralized Discrete-Time Neural Network Controller For A Class Of Nonlinear Systems With Unknown Interconnections, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel decentralized neural network (NN) controller in discrete-time is designed for a class of uncertain nonlinear discrete-time systems with unknown interconnections. Neural networks are used to approximate both the uncertain dynamics of the nonlinear systems and the unknown interconnections. Only local signals are needed for the decentralized controller design and the stability of the overall system can be guaranteed using the Lyapunov analysis. Further, controller redesign for the original subsystems is not required when additional subsystems are appended. Simulation results demonstrate the effectiveness of the proposed controller. The NN does not require an offline learning phase and the weights …

Block Phase Correlation-Based Automatic Drift Compensation For Atomic Force Microscopes, Qinmin Yang, Eric W. Bohannan, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Automatic nanomanipulation and nanofabrication with an Atomic Force Microscope (AFM) is a precursor for nanomanufacturing. In ambient conditions without stringent environmental controls, nanomanipulation tasks require extensive human intervention to compensate for the many spatial uncertainties of the AFM. Among these uncertainties, thermal drift is especially hard to solve because it tends to increase with time and cannot be compensated simultaneously by feedback. In this paper, an automatic compensation scheme is introduced to measure and estimate drift. This information can be subsequently utilized to compensate for the thermal drift so that a real-time controller for nanomanipulation can be designed as if …

On-Road Emissions In Asia Measured By Remote Sensing (Presentation), Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Vehicle Remote Sensing For Nitrogen Dioxide (Presentation), Thomas R. Dalton, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Bio-Inspired Approaches For Critical Infrastructure Protection: Application Of Clonal Selection Principle For Intrusion Detection And Facts Placement, Kasthurirangan Parthasarathy

Masters Theses

"In this research, Clonal Selection, an immune system inspired approach, is utilized along with Evolutionary Algorithms to solve complex engineering problems such as Intrusion Detection and optimization of Flexible AC Transmission System (FACTS) device placement in a power grid. The clonal selection principle increases the strength of good solutions and alters their properties to find better solutions in a problem space. A special class of evolutionary algorithms that utilizes the clonal selection principle to guide its heuristic search process is termed Clonal EA. Clonal EAs can be used to solve complex pattern recognition and function optimization problems, which involve searching …

The Effect Of Sample Size On Rapid Bioassessment Scores And Management Efficiency, Uttam Kumar Rai

Theses and Dissertations

The rapid bioassessment method for stream bio monitoring generally uses a fixed count of 200 macro invertebrates as the standard subsample size. This number has been argued to be too small to provide accurate estimates on the richness of macro invertebrate communities and is believed to give misleading information pertaining to stream health. In this study, I used data collected from multiple habitats from 29 streams located in several subecoregions of Georgia to examine how the rapid bioassessment scores perform across subsample sizes of 100, 200, and 300 organisms. Subsample sizes of 100 and 200 organisms were found to underestimate …

Interval Neutrosophic Sets And Logic; Theory And Applications In Computing, Haibin Wang, Florentin Smarandache, Yan-Qing Zhang, Rajshekhar Sunderraman

Branch Mathematics and Statistics Faculty and Staff Publications

This book presents the advancements and applications of neutrosophics. Chapter 1 first introduces the interval neutrosophic sets which is an instance of neutrosophic sets. In this chapter, the definition of interval neutrosophic sets and set-theoretic operators are given and various properties of interval neutrosophic set are proved. Chapter 2 defines the interval neutrosophic logic based on interval neutrosophic sets including the syntax and semantics of first order interval neutrosophic propositional logic and first order interval neutrosophic predicate logic. The interval neutrosophic logic can reason and model fuzzy, incomplete and inconsistent information. In this chapter, we also design an interval neutrosophic …

Quantum Quasi-Paradoxes And Quantum Sorites Paradoxes, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

There can be generated many paradoxes or quasi-paradoxes that may occur from the combination of quantum and non-quantum worlds in physics. Even the passage from the micro-cosmos to the macro-cosmos, and reciprocally, can generate unsolved questions or counter-intuitive ideas. We define a quasi-paradox as a statement which has a prima facie self-contradictory support or an explicit contradiction, but which is not completely proven as a paradox. We present herein four elementary quantum quasi-paradoxes and their corresponding quantum Sorites paradoxes, which form a class of quantum quasi-paradoxes.