Physical Sciences and Mathematics Commons^™

Design And Simulation On A Novel Sliding Mode Control For Linear Induction Motor, Kaiwei Han, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: The speed-tracking problem of linear induction motors under the influence of unmatched disturbances is studied. Based on the extended disturbance observers, the novel sliding mode controllers are designed to make the motor have effective response characteristics under unmatched disturbances. The extended disturbance observersis designed for the unmatched disturbances in the linear induction motor model with edge effects. The observations of the disturbance derivatives are filtered. The novel sliding mode controllers are designed based on the observations of the disturbances and their derivatives. The simulations results show that the designed controller has effective response characteristics and robustness. In addition, it …

Declining Co2 Price Paths, Gernot Wagner

Sustainability Seminar Series

Pricing greenhouse-gas (GHG) emissions involves making trade-offs between consumption today and unknown damages in the (distant) future. While decision making under risk and uncertainty is the forte of financial economics, important insights from pricing financial assets do not typically inform standard climate–economy models. Here, we introduce EZ-Climate, a simple recursive dynamic asset pricing model that allows for a calibration of the carbon dioxide (CO2) price path based on probabilistic assumptions around climate damages. Atmospheric CO2 is the “asset” with a negative expected return. The economic model focuses on society’s willingness to substitute consumption across time and across uncertain states of …

Impact Of Interlayer Cation Composition And Strongly Bound Water On Smectite ẟ²H, As Determined By A Modified Tcea Method, Nadine J. Kanik

Electronic Thesis and Dissertation Repository

Interlayer cation composition and cation hydration enthalpy can potentially affect the excess hydrogen-yield and δ²H of smectitic clays. Complexities arise from condensed atmospheric water adsorbed on the clay, as it constitutes a potential additional source of hydrogen when attempting to measure the δ²H of structural OH groups. To approach this problem, the δ²H of different cation-saturated, dried forms of six Clay Minerals Society Source Clay smectites were measured. A modified sample drying and on-line High-Temperature-Conversion-Elemental-Analysis (TCEA) Continuous-Flow-Isotope-Ratio-Mass-Spectrometry protocol, facilitated isotopic measurements. A stronger interlayer cation hydration enthalpy (Ca²⁺>Na⁺>K⁺), …

Deep-Ultraviolet Laser Ablation For Biomolecular Analysis, Oluwaremilekun Omowunmi Lawal

LSU Doctoral Dissertations

New sampling and ionization techniques were developed using a deep-ultraviolet (DUV) laser at 193 nm wavelength for analysis of large biomolecules. A micrometer spatial resolution DUV laser ablation and capture system was constructed to sample tissue biomolecules. The spot size measurements of the focused beam showed that subcellular spots with ca. 2 μm diameter can be readily achieved with this wavelength. To demonstrate the extraction of tissue biomolecules with the DUV laser, regions of tissue sections were ablated and captured for offline proteomic and genomic analysis. The proteomic studies revealed that the tissue proteins were ejected without fragmentation and that …

Structure And Dynamics Of Phospholipid Vesicles And The Dependence On Nanoscale Interactions With Molecules Of Varying Complexity, Lakshapathy Widanelage Judith Upeka De Mel

LSU Doctoral Dissertations

In this dissertation, molecular interactions and changes imposed by nano-scale structures on phospholipid vesicles were investigated. 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) large unilamellar vesicles (LUVs) were used as the model system. Understanding changes of the bilayer structure, interfacial properties, lipid dynamics, and self-assembly, allows bridging relationships between biological cell membrane structure and dynamics to cellular functionalities. For example, membrane curvature changes are linked to membrane protein functions, although the exact mechanisms of control are not yet understood. Moreover, the knowledge gained from vesicle models allows exploring novel strategies for drug delivery applications. To achieve this, DOPC LUVs were synthesized and characterized by a …

Computational Investigations Of Battery Electrolytes, Ke Li

LSU Doctoral Dissertations

In this dissertation, the structure and dynamics of battery electrolytes were investigated using atomistic molecular dynamics (MD) simulations. Battery electrolytes play a key role in transporting ions between the cathode and anode. The chemical stability and ionic conductivity of electrolytes influence battery performance. In order to design better electrolytes, one needs an understanding of the relationship between electrolyte structure, dynamics, and bulk properties. To bridge the gap between the macroscopic phenomenon and the hidden molecular physics, in the first project we focused on probing an ether-based electrolyte, chosen for its relevance in sodium-based batteries. Through studying the impact of concentration …

Development Of Reduced Order Models Using Reservoir Simulation And Physics Informed Machine Learning Techniques, Mark V. Behl Jr

LSU Master's Theses

Reservoir simulation is the industry standard for prediction and characterization of processes in the subsurface. However, simulation is computationally expensive and time consuming. This study explores reduced order models (ROMs) as an appropriate alternative. ROMs that use neural networks effectively capture nonlinear dependencies, and only require available operational data as inputs. Neural networks are a black box and difficult to interpret, however. Physics informed neural networks (PINNs) provide a potential solution to these shortcomings, but have not yet been applied extensively in petroleum engineering.

A mature black-oil simulation model from Volve public data release was used to generate training data …

Radial Basis Densities And The Density Functional-Based Atom-In-Molecule: Designing Charge-Transfer Potentials, Godwin Amo-Kwao

Nanoscience and Microsystems ETDs

Classical potentials that are capable of describing charge transfer and charge polarization in complex systems are of central importance for classical atomistic simulation of biomolecules and materials. Current potentials—regardless of the system—do not generalize well, and, with the exception of highly-specialized empirical potentials tuned for specific systems, cannot describe chemical bond formation and breaking. The charge-transfer embedded atom method (CT-EAM), a formal, DFT-based extension to the original EAM for metals, has been developed to address these issues by modeling charge distortion and charge transfer in interacting systems using pseudoatom building blocks instead of the electron densities of isolated atoms. CT-EAM …

Covid-19_Umaine News_Umaine Students Get Immersive Experience In Engineering Education, University Of Maine Division Of Marketing And Communications

Division of Marketing & Communications

Screenshot of UMaine News press release regarding Asli Sezen-Barrie, associate professor of curriculum, assessment and instruction in the University of Maine College of Education and Human Development redesigning her class on Teaching Science in the Secondary School to provide more opportunities for preservice teachers at UMaine to learn about engineering concepts and meet with engineers.

Evaluation Of Reliability Indicators Of Mobile Communication System Bases, Dilmurod Davronbekov, Utkir Karimovich Matyokubov, Malika Ilkhamovna Abdullayeva

Bulletin of TUIT: Management and Communication Technologies

In this study, the reliability of mobile system base stations (BTS) is assessed by analyzing data obtained on faults in about 200 BTS over a six-month period. Five BTSs with the highest number of failures and duration of failure were selected in these BTSs. Based on the data obtained, reliability parameters were calculated and compared.

The study used Weibull’s dismissal process distribution method. The breakdown times of each BTS were sorted. In all five BTS, it was found that β(where the value of β is the approximate value obtained from the values of the smallest squares of the Weibull graph), …

An Analysis Of The Effectiveness Of Cuban Cyberactivism, Neta Kanny

Journal of Global Initiatives: Policy, Pedagogy, Perspective

This article applies power-law degree distribution and network theory as a conceptual framework for assessing the effectiveness of Cuban cyberactivism based on an analysis of previous scholarly work on the topic. While Cuban cyberactivism indicates the potential for a more accessible, just, and transparent media environment, the movement continues to face serious obstacles due to extensive controls put in place by the Communist Party of Cuba.

Natalia Shustova Answers Questions About 15 Years Of Research On Covalent Organic Frameworks, Natalia B. Shustova Prof. Dr.

Faculty Publications

No abstract provided.

Cft Unitarity And The Ads Cutkosky Rules, David Meltzer, Allic Sivaramakrishnan

Physics and Astronomy Faculty Publications

We derive the Cutkosky rules for conformal field theories (CFTs) at weak and strong coupling. These rules give a simple, diagrammatic method to compute the double-commutator that appears in the Lorentzian inversion formula. We first revisit weakly-coupled CFTs in flat space, where the cuts are performed on Feynman diagrams. We then generalize these rules to strongly-coupled holographic CFTs, where the cuts are performed on the Witten diagrams of the dual theory. In both cases, Cutkosky rules factorize loop diagrams into on-shell sub-diagrams and generalize the standard S-matrix cutting rules. These rules are naturally formulated and derived in Lorentzian momentum space, …

The Birds Of The Nebraska Sandhills, Paul A. Johnsgard, Josef Kren

Zea E-Books Collection

This book provides basic information on all the species of birds that have been reliably reported from the Nebraska Sandhills region as of 2020. They include 46 permanent residents, 125 summer breeders, 125 migrants, and 102 rare or accidental species, totaling 398 species. Information on status, migration, and habitats is provided for all but the very rare and accidental species. There are also descriptions of 46 refuges, preserves, and other public-access natural areas in the region and seven suggested birding routes. The text contains more than 90,000 words and over 250 literature references along with more than 20 drawings, 9 …

An Agent-Based Simulator For The Gastrointestinal Pathway Of Listeria Monocytogenes, Ashrafur Rahman, Ali Asgary, Daniel Munther, Aamir Fazil, Ben A. Smith, Jianhong Wu

Mathematics and Statistics Faculty Publications

We developed an agent-based gastric simulator for a human host to illustrate the within host survival mechanisms of Listeria monocytogenes. The simulator incorporates the gastric physiology and digestion processes that are critical for pathogen survival in the stomach. Mathematical formulations for the pH dynamics, stomach emptying time, and survival probability in the presence of gastric acid are integrated in the simulator to evaluate the portion of ingested bacteria that survives in the stomach and reaches the small intestine. The parameters are estimated using in vitro data relevant to the human stomach and L. monocytogenes. The simulator predicts that 5%–29% of …

Different Approximation Algorithms For Channel Scheduling In Wireless Networks, Qiufen Ni, Chuanhe Huang, Panos M. Pardalos, Jia Ye, Bin Fu

Computer Science Faculty Publications and Presentations

We introduce a new two-side approximation method for the channel scheduling problem, which controls the accuracy of approximation in two sides by a pair of parameters . We present a series of simple and practical-for-implementation greedy algorithms which give constant factor approximation in both sides. First, we propose four approximation algorithms for the weighted channel allocation problem: 1. a greedy algorithm for the multichannel with fixed interference radius scheduling problem is proposed and an one side -IS-approximation is obtained; 2. a greedy -approximation algorithm for single channel with fixed interference radius scheduling problem is presented; 3. we improve the existing …

Star Formation In Dwarf Galaxies, Simeon L. Bolds

FIU Electronic Theses and Dissertations

A catalog of neutral hydrogen (HI) of nearby dwarf galaxies obtained from the LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey) project along with ancillary data are used to examine the relative importance of star-induced star formation associated with the HI holes in 31 dwarf galaxies. HI shells/rings surrounding the HI holes are defined and the fractional amounts of HI and star formation in the rings relative to the global galactic amounts are calculated. These are then compared to look for correlations between the amount of star formation and neutral hydrogen in the rings. Two …

Formulating A Crowd State Prediction Problem For Application To Crowd Control, Brooks A. Butler

Theses and Dissertations

This project considers a new application of crowd control, namely, keeping the public safe during large scale demonstrations. This problem is difficult for a variety of reasons, including limited access to informative sensing and effective actuation mechanisms, as well as limited understanding of crowd psychology and dynamics. This project takes a first step towards solving this problem by formulating a crowd state prediction problem in consideration of recent work involving crowd behavior identification, crowd movement modeling, and crowd psychology modeling. We build a non-linear crowd behavior model incorporating components of personality modeling, human emotion modeling, group opinion dynamics, and group …

Probing The Magnetic Anisotropy Of Co(Ii) Complexes Featuring Redox-Active Ligands, Praveen Kumar, Daniel J. Santa Lucia, Kinga Kaniewska-Laskowska, Sergey Lindeman, Andrew Ozarowski, J. Krzystek, Mykhaylo Ozerov, Joshua Telser, John F. Berry, Adam T. Fiedler

Chemistry Faculty Research and Publications

Coordination complexes that possess large magnetic anisotropy (otherwise known as zero-field splitting, ZFS) have possible applications in the field of magnetic materials, including single molecule magnets (SMMs). Previous studies have explored the role of coordination number and geometry in controlling the magnetic anisotropy and SMM behavior of high-spin (S = 3/2) Co(II) complexes. Building upon these efforts, the present work examines the impact of ligand oxidation state and structural distortions on the spin states and ZFS parameters of pentacoordinate Co(II) complexes. The five complexes included in this study (1–5) have the general formula, [Co(Tp^{Ph2 …}

Fredholm-Regularity Of Holomorphic Discs In Plane Bundles Over Compact Surfaces, Brendan Guilfoyle, Wilhelm Klingenberg

Publications

We study the space of holomorphic discs with boundary on a surface in a real 2-dimensional vector bundle over a compact 2-manifold. We prove that, if the ambient 4-manifold admits a fibre-preserving transitive holomorphic action, then a section with a single complex point has C2,α-close sections such that any (non-multiply covered) holomorphic disc with boundary in these sections are Fredholm regular. Fredholm regularity is also established when the complex surface is neutral K¨ahler, the action is both holomorphic and symplectic, and the section is Lagrangian with a single complex point.

Effects Of Different Management On Soil Organic Carbon Dynamics In Chinese Grassland Systems, Feng Shi, Yu'e Li, Qingzhu Gao, Lin Jin

IGC Proceedings (1993-2023)

No abstract provided.

The Application Of Dynamic Evaluating Models Of The Meteorological Condition Effects On Natural Grassland Vegetation In China, Shuan Qian, L. X. Mao, M. Wang, Y. H. Zhang

IGC Proceedings (1993-2023)

No abstract provided.

Methane Yields From Grazing Livestock: An Overview, Cesar S. Pinares-Patiño, H. Clark

IGC Proceedings (1993-2023)

No abstract provided.

Initial Responses Of Carbon Cycling To Elevated Co2 And Warming In Native Semiarid Grassland, Wyoming, Usa, Elise Pendall, S. Bachman, F. A. Dijkstra, Jack A. Morgan, M. A. Wallenstein, D. G. Williams

IGC Proceedings (1993-2023)

No abstract provided.

Research On The Relationship Between Climate And Plant Community In North Grassland Of China, Xuebiao Pan, Yurong Wei, Buju Long, Zhihua Pan

IGC Proceedings (1993-2023)

No abstract provided.

The Soil Organic Carbon Spatial Distribution Of Degraded Grassland With Black Soil Type In The Source Region Of Yellow River, Duofeng Pan, Y. S. Ma, Y. X. Zhang

IGC Proceedings (1993-2023)

No abstract provided.

A Conceptual Model To Explain Increasing Woody Biomass In Arid And Semi‐Arid Regions, Anthony R. Palmer, D. Eamus

IGC Proceedings (1993-2023)

No abstract provided.

A Bayesian Network Analysis Of The Human Exposure To Escherichia Coli Bacteria In The Environment, Brandon G. De Flon

Mathematics & Statistics ETDs

Diarrhea is a leading cause of death worldwide because a lack thereof in household sanitization exposes humans to high concentrations of pathogenic Escherichia coli. In 2016, the University of New Mexico’s Nepal Study Center collected cross-sectional survey data using proportional random sampling on three communities in Western Nepal. Structural and parameter learning estimation and approximate inference of Bayesian networks studied diarrheagenic E. coli exposure while incorporating participation in sanitary behaviors, access to sanitary built-in environments, and other human characteristics. Of the reported sickness, hand washing resulted in a 20 percent decrease, water treatment 8 percent, and both 28 percent. Of …

Potential Of Hemp (Cannabis Sativa L.) For Paired Phytoremediation And Bioenergy Production, Hanah T. Rheay, Emmanuel C. Omondi, Catherine E. Brewer

Agricultural and Environmental Sciences Faculty Research

Hemp (Cannabis sativa L.) is a multi-use crop that has been investigated for its potential use in phytoremediation of heavy metals, radionuclides, and organic contaminants, and as a feedstock for bioenergy production. A review of research literature indicates that hemp is a suitable crop for phytoremediation, and a competitive option for bioenergy. Coupling phytoremediation and bioenergy production from a single hemp crop is a potential solution to overcoming the economic constraints of phytoremediation projects. The current challenge is ensuring that the extracted contaminants are not introduced into the consumer marketplace. After several decades of limited research on hemp in the …

Unraveling The Gordian Knot: Eight Testable Hypotheses On The Effects Of Nutrient Enrichment On Tidal Wetland Sustainability, Thomas J. Mozdzer, Elizabeth Burke Watson, William H. Orem, Christopher M. Swarzenski, R. Eugene Turner

Faculty Publications

The position of tidal wetlands at the land-sea interface makes them especially vulnerable to the effects of nutrient discharges and sea level rise (SLR). Experimental studies of coastal wetland nutrient additions report conflicting results among and within habitats, highlighting the importance of site-specific factors, and how spatial and temporal scaling modulates responses. This suite of influences as SIR accelerates creates a "Gordian Knot" that may compromise coastal habitat integrity. We present eight testable hypotheses here to loosen this knot by identifying critical modulators about nutrient form, soil type and porosity, physiochemical gradients, and eco-evolutionary responses that may control the impacts …