Physical Sciences and Mathematics Commons^™

Integrated Approach For The Assessment And Development Of Groundwater Resources In Arid Lands: Applications In The Quetta Valley, Pakistan, Zhanay Sagintayev

Dissertations

The lack of adequate field measurements (e.g., precipitation and stream flow) and difficulty in obtaining them often hampers the construction and calibration of rainfall-runoff models over many of the world's watersheds, leaving key· elements of the hydrologic cycle unconstrained. I adopted methodologies that rely heavily on readily available remote sensing datasets as viable alternatives and useful tools for assessing, managing, and modeling the water resources of such remote and inadequately gauged regions.

The Soil and Water Assessment Tool was selected for continuous (1998-2005) rainfall-runoff modeling of the northeast part of the Pishin Lora basin (NEPL), a politically unstable area that …

Proton Capture Reactions And Network Calculations On 46Ti, 64Zn, 114Sn And 116Sn Relevant To The Rp-Process, Ravin S. T. Kodikara

Dissertations

The rp-process makes an important contribution to the stellar nucleosynthesis by producing many of the light proton rich nuclei. Successive proton captures on seed nuclei followed by occasional β-decays and electron captures are the key features of this mechanism. For a detailed rp-process analysis, proton capture cross sections and reaction rates are essential. However, the lack of experimental data forces the researcher to largely depend on statistical model predictions.

This dissertation research is an attempt to investigate the proton captures of four particular nuclides; ⁴⁶Ti, ⁶⁴Zn, ¹¹⁴Sn and ¹¹⁶Sn. At Western Michigan University Van de Graaff …

Dielectronic Recombination For Aluminum-Like Ions And Photoabsorption Cross Sections For Magnesium Ions At The K-Edge, Shahin Ahmed Abdel-Azim Abdel Naby

Dissertations

Accurate and reliable recombination data are needed for modeling the ions in the finitedensity plasmas that may take place in solar flares and in divertors of magnetically confined fusion devices such as the International Thermonuclear Experimental Reactor (ITER). Dielectronic recombination (DR) is the dominant recombination mechanism in photoionized and collisionally-ionized plasmas. DR rate coefficients for M-shell argon ions have been calculated using a configuration-average approach. DR rate coefficients for the aluminumlike isoelectronic sequence are instead calculated using the state-of-the-art multiconfiguration Breit-Pauli (MCBP) atomic structure and collision code AUTOSTRUCTURE. Good agreement is obtained with the measurements from the Heidelberg heavy-ion Test …

The K-Cores Of A Graph, Allan Bickle

Dissertations

Full abstract attached as supplemental file.

Inner-Shell Photodetachment Of Transition Metal Negative Ions, Ileana Dumitriu

Dissertations

This thesis focuses on the study of inner-shell photodetachment of transition metal negative ions, specifically Fe¯ and Ru¯. Experimental investigations have been performed with the aim of gaining new insights into the physics of negative atomic ions and providing valuable absolute cross section data for astrophysics. The experiments were performed using the X-ray radiation from the Advanced Light Source, Lawrence Berkeley National Laboratory, and the merged-beam technique for photoion spectroscopy.

Negative ions are a special class of atomic systems very different from neutral atoms and positive ions. The fundamental physics of the interaction of transition metal negative ions with photons …

Robust Interval Estimation Of A Treatment Effect In Observational Studies Using Propensity Score Matching, Scott F. Kosten

Dissertations

Estimating the treatment effect between a treatment group and a control group in an observational study is a challenging problem in statistics. Without random assignment of subjects, there are likely to be differences between the treatment group and control group on a set of baseline covariates. If one of these baseline covariates is correlated to the response variable, then the difference in sample means between the groups is likely to be a biased estimate of the true treatment effect.

Propensity score matching has become an increasingly popular strategy for reducing bias in estimates of the treatment effect. This reduction in …

Active Bundles For Protecting Confidentiality Of Sensitive Data Throughout Their Lifecycle, Lotfi Ben Othmane

Dissertations

Protecting confidentiality of shared sensitive data requires satisfying conflicting needs for disseminating data and preventing unauthorized data disclosures. We propose a solution named the active bundles scheme for protecting sensitive data from their disclosures to unauthorized parties during their dissemination. The scheme protects data throughout their entire lifecycle, from data creation through their dissemination to their evaporation or apoptosis (a partial or complete self-destruction, respectively).

An active bundle packages together sensitive data, metadata, and a virtual machine (VM) specific to the bundle. Metadata contain information related to the use of data, including data access control and dissemination policies. A VM …

Confidence Intervals And Tests On The Difference Of Means Of Two Delta Distributions, Karen Grace Villarente Rosales

Dissertations

Various research fields produce data that are lognormally distributed and inflated with zero values. This type of data follows a delta distribution. In this study, we want to extensively investigate different interval and hypothesis testing methods for comparing the means of two delta populations to see which methods are optimal under different conditions of the populations.

For confidence intervals, existing MVUE methods are extended to two sample cases and compared to classical and two proposed robust methods. We investigated the performance of the classical Student's t, Welch t, and Wilcoxon-based interval to see if these methods really perform badly on …

Biochemical Characterization Of Theromin, A Novel Leech Inhibitor, And The Interaction Between The Fourth Metalbinding Domain Of Wilson Disease Protein And Its Copper(I) Chaperone Hah1, Brian A. Zeider

Dissertations

Theromin, a novel thrombin inhibitor from the leech Theromyzon tessulatum, has been shown to be the strongest inhibitor to date. There has been a lot of attention on direct thrombin inhibitors as a much more efficient drug for anticoagulation therapy. One main reason for the need of strong direct thrombin inhibitors is that the current therapy, heparin, causes alternative clotting events in some patients where antibodies are made to the heparin/thrombin complex and causes clots to occur by different methods. Recently there has been a strong inhibitor from a leech used, hirudin, that can inhibit with a K_{i …}

Synthesis And Characterization Of Monolayer Protected Gold Nanoparticles And A Gold-Titanium Dioxide Nanocomposite Intended For Photocatalytic Degradation Of Environmental Pollutants, Piyadarsha Amaratunga

Dissertations

Semiconductor and metal clusters in the nanometer size regime display interesting optical, electronic and chemical properties that are size dependant. Highly monodisperse gold nanoparticles of different sizes have been synthesized and isolated by newly developed methodologies, using tiopronin as the capping ligand. Titanium dioxide nanoparticles (Ti0₂) have been used as the photocatalytic center and gold nanoparticles have been attached on Ti0₂ to make a nanocomposite. According to the findings, gold nanoparticles play a vital role in enhancing the photocatalytic activity of Ti0₂, by facilitating the charge separation. Further, the photocatalytic activity also can be tuned …

Isotropic And Anisotropic Metallic And Bimetallic Nanoparticles And Their Potential Applications In Biology, Minghong Liu

Dissertations

The development of synthetic procedures that produce nanoscale materials with controlled morphology is a significant area of investigation in nanotechnology. We have developed new synthetic procedures for fabrication of isotropic and/or anisotropic nanomaterials composed of palladium, ruthenium, nickel and alloys of palladium-ruthenium. The nanomaterials were fully characterized and were found to display unique size dependent properties. The electrochemical properties of isotropic palladium, ruthenium and palladium-ruthenium nanoparticles were investigated and the results showed that the particles were capable of charge storage and charge transfer on demand. Anisotropic palladium, ruthenium and palladium ruthenium nanoparticles were also fabricated and fully characterized. The nanoparticles …

Gold Nanoparticle - Modified Zinc Oxide Nanoparticles As Novel Photocatalytic Materials, Nayane Udawatte

Dissertations

The current study entails the construction of a novel nano-composite catalyst based on ZnO and Au nanoparticles and demonstrates its distinctive photocatalytic characteristics. Monodisperse gold nanoparticles (GNPs) passivated with monolayers of tiopronin or glutathione were synthesized via facile methods, and they were assembled on ZnO nanoparticles to form the nanocatalyst.

Steady state and time resolved photoluminescent studies on the nanocomposite revealed interesting charge transfer characteristics within the nanocomposite. Enhanced photooxidation of rhodamine 6G was observed for the nano-composite over bare ZnO, and modulation of photoactivity with the extent of GNP loading was illustrated. Photoreduction of thionine over the nanocomposite was …

Glaciotectonic Deformation Along The Valparaiso Upland In Southwest Michigan, Usa, Brian C. Bird

Dissertations

Glaciotectonic deformation has been observed and analyzed across parts of the Valparaiso, Kendall, and Inner Kalamazoo Moraines in southwest Michigan, USA. Deformation structures such as folds and faults have been analyzed using techniques typically used by structural geologist along with the fabric of elongated clasts in the surficial diamicton. The structures are consistent with simple shear, horizontal compressional stresses, and pure shear. A series of drumlin fields exist along the western boundary of the study area. Direct investigation of the deformed sediments was conducted at a gravel pit in one of these drumlins. Lacustrine derived sediments interbedded with coarse sand …

Option Pricing And Stable Trading Strategies In The Presence Of Information Asymmetry, Anirban Dutta

Dissertations

Pricing derivatives is one of the central issues in mathematical finance. The seminal work of Black, Scholes and Merton has been the cornerstone of option pricing since their introduction in 1973. Their work influenced the pricing theory of other derivatives as well.

This derivative pricing theory has two primary shortcomings. Firstly, the theoretical pricing in such theories are not accompanied by a stable trading strategy. Secondly, they often assume that the market agents use a uniform model for the underlying instrument and that the market prices of the derivatives reveal all the information about the underlying instrument.

Theoreticians like Grossman …

On Robustification Of Some Procedures Used In Analysis Of Covariance, Kuanwong Watcharotone

Dissertations

This study discusses robust procedures for the analysis of covariance (ANCOVA) models. These methods are based on rank-based (R) fitting procedures, which are quite analogous to the traditional ANCOVA methods based on least squares fits. Our initial empirical results show that the validity of R procedures is similar to the least squares procedures. In terms of power, there is a small loss in efficiency to least squares methods when the random errors have a normal distribution but the rank-based procedures are much more powerful for the heavy-tailed error distributions in our study.

Rank-based analogs are also developed for pick-a-point, adjusted …

Characterization Of The N-Terminal Domains And Disease-Causing Mutations Of The Human Wilson Protein, Joshua Mutambuki Muia

Dissertations

The Wilson protein (ATP7B) is a copper transporting ATPase that is involved in copper trafficking and homeostasis. Unlike the other known P-type ATPases, it possesses six homologous metal binding domains at the N-terminal end. Several mutations in the gene coding for this protein lead to Wilson disease, a hepatic disorder characterized by impaired excretion of copper in the bile, and accumulation of copper in body organs such as the liver, brain, kidney, and eye cornea. Characterization of various regions of expressed and purified ATP7B has been hampered by its low stability, aggregation and degradation.

In this research, novel methods were …

The Lipid Acyl-Chain Dynamics In Giant Liposomes And Characterization Of Domain 4 Of The Wilson Disease Protein, Wilson Okumu

Dissertations

Steady-state and nanosecond time-resolved fluorescence of the nitro-2, 1, 3- benzoxadiazol-4-yl (NBD) probe and line tension force were determined in phospholipids acyl-chain dynamics in giant liposomes made from a homologous series of phosphatidylcholines (PC). The fluorescence spectroscopy of a NBD probe attached to the headgroup (NBD PE) or the tail (NBD PC) of the phospholipid were used to determine the rate of dithionite quenching in a homologous series of phospholipids. Similar experiments were performed in the gel and the fluid phases of the l,2-dimyristoyl-s«-glycero-3-phosphocholine (DMPC ). Nanosecond time scale lifetimes and anisotropy measurements were obtained by a 470 nm LED …

Designing Molecular And Nanoscale Materials For Environmental Chemistry Processes, Wen Guo

Dissertations

This dissertation focuses on fundamental studies to identify materials that detect and degrade common organic environmental pollutants. Chapter 1 represents the overview of two widespread ground water contaminants: organohalides and organophosphorous compounds. Due to continuous usage of these compounds as well as their toxicity, reliable and sensitive methods for their detection and degradation are urgently needed. In Chapter 2 a description of molecular sensors designed with high sensitivity and selectivity to detect and distinguish between three organophosphorus (OP) pesticides are described. These sensors provide dual optical and electrochemical signals for detection, which minimizes false-positives. The signal transduction occurs in real …

The In-Situ Removal Of Menthofuran From Peppermint Oil And Subsequent Reactions Of The Solid-Supported Adduct, Robert Joseph Justice Ii

Dissertations

Menthofuran is an aromatic heterocyclic compound found naturally in the essential oil of Mentha piperita L. or peppermint. Natural peppermint oil may contain between approximately 2 to 8% menthofuran.

Peppermint oil is a complex mixture of over 350 identified chemical compounds; market demands dictate the extent of processing the oil undergoes prior to being introduced into consumer goods. Menthofuran has long been known to readily autoxidize, either alone or within the peppermint oil matrix, leading to a discolored oil with negative organoleptic consequences that adversely affects its commercial viability. Therefore, a facile method for selective removal of menthofuran was developed …