Physical Sciences and Mathematics Commons^™

Two Problems Of Gerhard Ringel, Adrian Pastine

Dissertations, Master's Theses and Master's Reports

Gerhard Ringel was an Austrian Mathematician, and is regarded as one of the most influential graph theorists of the twentieth century. This work deals with two problems that arose from Ringel's research: the Hamilton-Waterloo Problem, and the problem of R-Sequences.

The Hamilton-Waterloo Problem (HWP) in the case of C_m-factors and C_n-factors asks whether K_v, where v is odd (or K_v-F, where F is a 1-factor and v is even), can be decomposed into r copies of a 2-factor made entirely of m-cycles and s copies of a 2-factor made entirely of …

Modeling Spring Catchment Discharge: A Case Study Of Candela, Panama, Central America, Jordan P. Van Sickle

Dissertations, Master's Theses and Master's Reports

Where the proper geological and hydrological conditions exist, natural springs have provided a reliable source of clean water to mankind for eons. Changing climates and land development can negatively impact spring source replenishment and threaten their reliability as a source of water. In the face of prospects of diminishing supplies and increasing population demands, community leaders question whether and how to invest in development for enhancing sustainability and protecting water quality, causing water managers to dispute their reliability given decreasing flows. Springs located in the rugged jungle of western Panama serve as the primary water supply for many indigenous communities, …

Experimental Study Of The Flow Of Ferrofluid In A Porous Media Under A Magnetic Field, Muskaan Khurana

Dissertations, Master's Theses and Master's Reports

This research presents results from a laboratory-scale experimental setup that was designed to visualize the behavior of ferrofluid percolation through a porous media. Ferrofluids are colloidal suspensions made of magnetic particles of a few nanometers and stabilized in carrier liquids like water or mineral oil. Ferrofluids get magnetized and align themselves in the direction of a magnetic field when a field gradient is applied.

With the help of this experiment we investigate the viability of controlling fluid flow in porous medium by a magnetic field in vicinity. The experiments show that ferrofluids can be used as a transporting media to …

Influence Of The Weathered Layer On Retrieving Body Wave Using Passive Siesmic Interferometry, Boming Wu

Dissertations, Master's Theses and Master's Reports

Passive seismic interferometry (SI) is an increasingly popular seismic method due to its cost-efficient advantage because it does not need an active source. Techniques in using SI to retrieve surface waves are relatively well established, but using SI to retrieve body waves is still under development by many authors. These geophysicists have proved that many factors, such as average duration of the natural sources, the number of natural sources that occurred during recording time, source distribution, etc., influence the quality of body waves retrieved. In this research, I focus on how to make use of the attenuation property of weathered …

An Assessment Of The Validity Of The Kinetic Model For Liquid-Vapor Phase Change By Examining Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

Evaporation is ubiquitous in nature and occurs even in a microgravity space envi- ronment. Long term space missions require storage of cryogenic propellents and an accurate prediction of phase change rates. Kinetic theory has been used to model and predict evaporation rates for over a century but the reported values of accommodation coefficients are highly inconsistent and no accurate data is available for cryogens. The proposed study involves a combined experimental and computational approach to ex- tract the accommodation coefficients. Neutron imaging is used as the visualization technique due to the difference in attenuation between the cryogen and the metallic …

Laboratory Measurements Of Contact Nucleation By Mineral Dusts, Bacteria, And Soluble Salts, Joseph Niehaus

Dissertations, Master's Theses and Master's Reports

We present results from experiments that emulate atmospheric ice nucleation by aerosols. We have refined experimental techniques to improve measurements of ice forming nuclei in the contact mode. Our results show that atmospherically relevant dusts such as kaolinite, feldspar, rhyolitic ash, and Arizona Test Dust have efficiencies in the contact mode that are higher than the immersion mode. Experiments with bacteria show that biological material has the potential to contribute significantly to ice concentrations, but has large variability. By choosing a soluble compound as an ice nucleus, we are able to place bounds on the timescale for contact freezing and …

Improved Parameter Estimation Of The Log-Logistic Distribution With Applications, Joseph Reath

Dissertations, Master's Theses and Master's Reports

In this report, we work with parameter estimation of the log-logistic distribution. We first consider one of the most common methods encountered in the literature, the maximum likelihood (ML) method. However, it is widely known that the maximum likelihood estimators (MLEs) are usually biased with a finite sample size. This motivates a study of obtaining unbiased or nearly unbiased estimators for this distribution. Specifically, we consider a certain `corrective' approach and Efron's bootstrap resampling method, which both can reduce the biases of the MLEs to the second order of magnitude. As a comparison, we also consider the generalized moments (GM) …

Atmospheric Sensitivity To Roughness Length In A Regional Atmospheric Model Over The Ohio-Tennessee River Valley, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Intercomparison And Evaluation Of Satellite Peroxyacetyl Nitrate Observations In The Upper Troposphere-Lower Stratosphere, Richard J. Pope, Nigel A. D. Richards, Martyn P. Chipperfield, David P. Moore, Sarah A. Monks, Stephen R. Arnold, Norbert Glatthor, Michael Kiefer, Tom J. Breider, Jeremy J. Harrison, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Peroxyacetyl nitrate (PAN) is an important chemical species in the troposphere as it aids the long-range transport of NO_x and subsequent formation of O₃ in relatively clean remote regions. Over the past few decades observations from aircraft campaigns and surface sites have been used to better understand the regional distribution of PAN. However, recent measurements made by satellites allow for a global assessment of PAN in the upper troposphere-lower stratosphere (UTLS). In this study, we investigate global PAN distributions from two independent retrieval methodologies, based on measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument, on …

Studies On Hydroxyl Radical Formation And Correlated Photoflocculation Process Using Degraded Wood Leachate As A Cdom Source, Luni Sun, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

In this study, we examined hydroxyl radical (•OH) formation with respect to photoreactivity of colored dissolved organic matter (CDOM), the Fenton reaction, and photoflocculation using leachate from decaying wood. The relationship between •OH photoproduction rate and leachate optical properties (UV-visible absorption and fluorescence excitation-emission matrices (EEMS)) was studied during irradiation using a UV solar simulator. The results showed that the •OH photochemical formation rate is strongly related to humic-like fluorescence as characterized by parallel factor analysis (PARAFAC), and that these fluorescence components are more photolabile than most of the other CDOM components. Fourier transform infrared spectroscopy (FT-IR) indicated the photodegradation …

A Study On $^{7}$Li + $^{120}$Sn Quasi-Elastic Scattering, Murat Aygün, Zeynep Aygün

Turkish Journal of Physics

In the present study, we reexamine quasi-elastic scattering of $^{7}$Li by $^{120}$Sn at incident energies E$_{Lab}$ = 19.5, 20.5, and 25.0 MeV. The theoretical results are obtained by using both a phenomenological model and double-folding model (DFM) within the framework of an optical model. We also investigate the role of the surface potential, which is connected to direct reactions. The agreement between the phenomenological model and the DFM is shown in comparison to each other in connection with the experimental data. This comparison provides information about the similarities and the differences between the models used during the calculations.

Radon Concentration Measurements At A University Campus In Turkey, Melekşah Altinsöz, Emel Alğin, Celal Aşici, Haci Soğukpinar

Turkish Journal of Physics

In this study we measured radon (222Rn) concentrations in offices at the Meşelik campus of Eskişehir Osmangazi University to estimate the effective dose of 222Rn and its progeny for office occupants. The measurements were performed four times in 2011 over a period of 3 months using solid state nuclear track detectors (LR-115). A total of 381 LR-115 detectors were installed in 110 different offices, choosing three offices on each floor in the same building. 222Rn concentrations obtained in the first, second, third, and fourth measurement periods were 163 (73) Bq m-3, 77 (43) Bq m-3, and 164 (70) Bq m-3 …

Supergravity Backgrounds And Symmetry Superalgebras, Ümi̇t Ertem

Turkish Journal of Physics

We consider the bosonic sectors of supergravity theories in ten and eleven dimensions corresponding to the low energy limits of string theories and M-theory. The solutions of supergravity field equations are known as supergravity backgrounds and the number of preserved supersymmetries in those backgrounds are determined by Killing spinors. We provide some examples of supergravity backgrounds that preserve different fractions of supersymmetry. An important invariant for the characterization of supergravity backgrounds is their Killing superalgebras, which are constructed out of Killing vectors and Killing spinors of the background. After constructing Killing superalgebras of some special supergravity backgrounds, we discuss the …

Exact Solutions To The Geodesic Equations Of Linear Dilaton Black Holes, Alan Hameed Hussein Hamo, Izzet Sakalli

Turkish Journal of Physics

In this paper, we analyze the geodesics of the 4-dimensional linear dilaton black hole (LDBH) spacetime, which is an exact solution to the Einstein-Maxwell-dilaton theory. LDBHs have nonasymptotically flat geometry, and their Hawking radiation is an isothermal process. The geodesics motions of the test particles are studied via the standard Lagrangian method. After obtaining the Euler-Lagrange equations, we show that exact analytical solutions to the radial and angular geodesic equations can be obtained. In particular, it is shown that one of the possible solutions for the radial trajectories can be given in terms of the Weierstrass P-function ($\wp $-function), which …

The Observational Status Of Simple Inflationary Models: An Update, Nobuchika Okada, Vedat Nefer Şenoğuz, Qaisar Shafi

Turkish Journal of Physics

We provide an update on five relatively well-motivated inflationary models in which the inflaton is a Standard Model singlet scalar field. These include i) the textbook quadratic and quartic potential models but with additional couplings of the inflaton to fermions and bosons, which enable reheating and also modify the naive predictions for the scalar spectral index $n_s$ and $r$, ii) models with Higgs and Coleman-Weinberg potentials, and finally iii) a quartic potential model with nonminimal coupling of the inflaton to gravity. For $n_s$ values close to 0.96, as determined by the WMAP9 and Planck experiments, most of the considered models …

It Is Sufficient To Set The Cosmological Constant To Zero Or To A Small Number At An Initial Time, Recai̇ Erdem

Turkish Journal of Physics

I point out a simple but usually overlooked fact about the cosmological constant problem: to solve the cosmological constant problem it is sufficient to find a symmetry or mechanism that sets the cosmological constant to zero or to a tiny value at some time in the past, provided that general relativity is the relevant theory of gravity, and the energy-momentum tensor (excluding the part of the form of a cosmological constant) is conserved. The relevant symmetry or mechanism need not be applicable today. Any additional cosmological constant term induced by a phase transition in the energy-momentum tensor in this case …

A New Method For Grain Texture Manipulation In Post-Deposition Niobium Films, J. Musson, L. Phillips, K. Macha, H. Elsayed-Ali, W. Cao

Electrical & Computer Engineering Faculty Publications

Niobium films are frequently grown using forms of energetic condensation, with modest substrate temperatures to control grain structure. As an alternative, energetic deposition onto a cold substrate results in a dense amorphous film, with a much larger energy density than the re-crystallized state. Re-crystallization is then performed using a pulsed UV (HIPPO) laser, with minimal damage to the substrate. In addition, a graded interface between the substrate and Nb film is created during the early stages of energetic deposition. Experimental approach and apparatus are described.

Geochemistry Of Aegean Sea Sediments: Implications For Surface- And Bottom-Water Conditions During Sapropel Deposition Since Mis 5, Ekrem Bursi̇n İşler, Ali̇ Engi̇n Aksu, Richard Nicholas Hiscott

Turkish Journal of Earth Sciences

Piston cores collected from the Aegean Sea provide a record of sapropel sequence S1, S3-S5. Primary productivity calculations using the equations of Müller and Suess suggest surface paleoproductivities ranged from 180 to 995 g C m-2 year-1 for sapropels and from 40 to 180 g C m-2 year-1 for nonsapropel sediments with corresponding total organic carbon values of 9%-12% and 1%-3%, respectively. The higher paleoproductivities exceed those in the most fertile modern upwelling zones, so are probably overestimated. Instead, enhanced preservation, particularly for S4 and S5, likely resulted from poor bottom-water ventilation beneath a salinity-stratified water column. If the preservation …

Strike-Slip Neotectonic Regime And Related Structures In The Cappadocia Region: A Case Study In The Salanda Basin, Central Anatolia, Turkey, Ali̇ Koçyi̇ği̇t, Uğur Doğan

Turkish Journal of Earth Sciences

The study area is a strike-slip basin of approximately 1-9 km wide, 66 km long and N65°W trending, located between the historical Kesikköprü in the west and the Sarıhıdır settlement in the east along the northern side of the Central Anatolian Volcanic Province. It was evolved on a regional erosional surface of a pre-Quaternary volcanosedimentary sequence during Quaternary. This is evidenced by the stratigraphical, structural, and seismic data. The total amounts of throw and dextral strike-slip displacement accumulated on the basin-boundary faults during the evolutionary history of the basin are 178 m and 5 km, respectively. The average slip rate …

A Comparative Analysis Of An Interior-Point Method And A Sequential Quadratic Programming Method For The Markowitz Portfolio Management Problem, Zhifu Xiao

Honors Papers

In this paper, I give a brief introduction of the general optimization problem as well as the convex optimization problem. The portfolio selection problem, as a typical type of convex optimization problem, can be easily solved in polynomial time. However, when the number of available stocks in the portfolio becomes large, there might be a significant difference in the running time of different polynomial-time solving methods. In this paper, I perform a comparative analysis of two different solving methods and discuss the characteristics and differences.

The Map Portal Project At The Geological Survey Of Israel, Marcelo Rosensaft, Howard R. Feldman

Lander College for Women - The Anna Ruth and Mark Hasten School Publications and Research

The Geological Survey of Israel is mandated to prepare official geological maps of Israel at different scales. When, by the end of the 80’s, GIS systems became more popular and a realistic option for us, we started the development of a methodology and system that led to the completion of a new geological map of Israel at 1:200,000 in 1998. This resulted in a huge impetus for the preparation of the Geological Map of Israel at 1:50,000 in 79 separate sheets. In addition, using the above GIS system, other maps were prepared; outcomes of various projects - in hydrogeology, geological …

Diffusion And Invasion Percolation: A Coupled Model To Simulate The Fate Of Trapped And Compressed Gases In Partially-Saturated Low Permeability Media, Ross Berry

Electronic Theses and Dissertations

No abstract provided.

Complexity Theory And Its Applications In Linear Quantum Optics, Jonathan Olson

LSU Doctoral Dissertations

This thesis is intended in part to summarize and also to contribute to the newest developments in passive linear optics that have resulted, directly or indirectly, from the somewhat shocking discovery in 2010 that the BosonSampling problem is likely hard for a classical computer to simulate. In doing so, I hope to provide a historic context for the original result, as well as an outlook on the future of technology derived from these newer developments. An emphasis is made in each section to provide a broader conceptual framework for understanding the consequences of each result in light of the others. …

Prioritizing Management And Protection Of The Colorado River's Environmental Resources, Colorado River Research Group

Books, Reports, and Studies

4 pages.

Proposal For An Enhanced Colorado Water Bank, Anne J. Castle, Lawrence J. Macdonnell

Books, Reports, and Studies

4 pages.

Outlines and explains 8 characteristics of an enhanced Colorado water bank.

Watershed Planning And Management In Colorado, University Of Colorado Boulder. Getches-Wilkinson Center For Natural Resources, Energy, And The Environment

Books, Reports, and Studies

9 pages.

Introduction -- The watershed approach in Colorado -- Moving to the next level : implementation of the BIPs -- Possible next steps -- Conclusion.

Improving Irrigation Water Uses For Agricultural And Environmental Benefits, Anne Castle, Amy Beattie, Zach Smith, Drew Peternell, Ted Kowalski

Books, Reports, and Studies

37 pages : color pictures, color maps.

Introduction -- Agricultural and environmental enhancements -- An ag and environmental enhancement program for Colorado -- Appendix A: Conservation case studies in Colorado -- Appendix B: Related Colorado water law -- Appendix C: Relevant laws from other states -- Appendix D: Legislative attempts to statutorily recognize conserved water -- Appendix E: The problem of vocabulary

Particulate Inorganic Carbon Flux And Sediment Transport Dynamics In Karst: Significance To Landscape Evolution And The Carbon Cycle., Randall Lee Paylor

LSU Doctoral Dissertations

Research focused on three areas of karst hydrogeology and sediment transport that have been poorly studied in the past: the role of particulate inorganic carbon transport in calculating carbon sink rates in karst; rapid changes in surface vs. subsurface sediment mixing in karst conduits; and comparison of landscape denudation calculations using dissolved carbonate load vs. total dissolved/sediment load. Carbonate bedrock weathering is a significant component of the atmospheric carbon sink. Particulate inorganic carbon (PIC) in bed and suspended sediment load of karst waters is frequently dismissed as insignificant for calculating denudation and carbon transport/sink rates, but PIC flux has not …

Understanding Chemical Reactions In Novel Materials: From Metal Organic Frameworks To Oxyallyl Cations, Kiara Taylor-Edinbyrd

LSU Doctoral Dissertations

The work of this dissertation investigates the chemical processes of novel materials through quantum mechanical calculations and molecular dynamics simulations. The first section of this work focuses on probing copper based metal organic frameworks (MOFs) for their ability to catalytically release nitric oxide from s-nitrosothiol (RSNO) precursors in a slow, controlled and sustained manner and compares these findings to a free copper ion/ethanol solution. Through the use of electronic structure calculations and molecular dynamics simulations, studies are carried out to better understand how the barriers of RSNOs approach to the catalytic copper center changes with modifications to the R-group (of …

Quantum Radiation Pressure Noise: Exposing The Quantum Mechanics Of Optomechanical Interactions, Robinjeet Singh

LSU Doctoral Dissertations

The detection of gravitational waves has further motivated the scientists to push horizons for an improved sensitivity sphere of the advanced LIGO. Below 100 Hz, design sensitivity of the advanced LIGO is predicted to be limited by the quantum backaction or the quantum radiation pressure noise (QRPN). In this thesis, I present the experimental progress towards the measurement of the QRPN. This work is in part an effort towards establishing a tabletop test experiment to calibrate the QRPN evasion through various proposed schemes, and further bring to light new nonlinear optomechanical dynamics. The experiment consists of a high optical and …