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2008

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Articles 5851 - 5871 of 5871

Full-Text Articles in Physical Sciences and Mathematics

Syntheses, Structures And Magnetic Characterization Of Di- And Trivalent Hydridotris(3,5-Dimethylpyrazol-1-Yl)Borate Cyanomanganates, Minao Tang Jan 2008

Syntheses, Structures And Magnetic Characterization Of Di- And Trivalent Hydridotris(3,5-Dimethylpyrazol-1-Yl)Borate Cyanomanganates, Minao Tang

University of Kentucky Master's Theses

The syntheses, structures, and magnetic properties of a series of di/trivalent hydridotris(3,5-dimethylpyrazol-1-yl)borate (Tp*) cyanomanganates were investigated. Treatment of manganese(III)acetylacetonate with KTp* followed by tetra(ethyl)- ammonium cyanide affords [NEt4][(Tp*)MnII(acac)(CN)] (1). Attempts to oxidize 1 with iodine affords {(Tp*)MnII(κ2O-acac-CN)}n (7); a minor complex {[NEt4][(Tp*)MnII(κ2O-acac-3-CN)]2(µ-CN) (8) was also isolated.

The manganese(II) complex [NEt4][(Tp*)MnII(κ2O-acac-3-CN)(κ1N -3-NC-acac)] (2) was obtained via treatment of Mn(3-acacCN)3 with KTp* and [NEt4]CN. [NEt4]2[Mn …


An Evaluation Of Earthquake Ground-Motion Site Effects At Two Sites Underlain By Deep Soils In Western Kentucky, Jonathan Larry Mcintyre Jan 2008

An Evaluation Of Earthquake Ground-Motion Site Effects At Two Sites Underlain By Deep Soils In Western Kentucky, Jonathan Larry Mcintyre

University of Kentucky Master's Theses

Six earthquake acceleration time histories were used to evaluate the groundmotion response of two sites, VSAP and VSAS, near the New Madrid Seismic Zone. These earthquakes ranged in magnitude from Mw 3.6 to Mw 5.2 and were located 46 to 173 km away from the recording instruments. These two sites are underlain by thick sequences (100 and 590 m) of unlithified soil that have been shown to greatly influence earthquake ground motions.

Near-surface soil dynamic properties were characterized at the two sites using seismic SH-wave refraction, P-S suspension logging, borehole electrical logs, and geotechnical logging methods. The soil …


Subsurface Characterization And Seuqence Stratigraphy Of Late Mississippian Strata In The Black Warrior Basin, Alabama And Mississippi, Carrie A. Kidd Jan 2008

Subsurface Characterization And Seuqence Stratigraphy Of Late Mississippian Strata In The Black Warrior Basin, Alabama And Mississippi, Carrie A. Kidd

University of Kentucky Master's Theses

A depositional framework for the Mississippian (Chesterian) Pride Mountain Formation/Hartselle Sandstone clastic tongue and the lower Bangor Limestone carbonate ramp in the Black Warrior basin, Mississippi and Alabama, is constructed from approximately 250 geophysical well logs, 15 well cuttings descriptions, and outcrop data. The framework is based upon cross sections, isopach maps, and transgressive-regressive sequence stratigraphy.

The Lowndes-Pickens synsedimentary fault block controlled sediment dispersal in during Pride Mountain/Hartselle deposition. The basin filled from the southwest, which pushed the depocenter northeastward during Hartselle deposition. The Hartselle sub-basin is composed of the Hartselle barrier-island and back-barrier deposits to the southwest, including the …


Integrated Geophysical Imaging Of Subsurface Geologic Conditions Across A Contaminant Plume, Mccracken County, Kentucky, Cora A. Blits Jan 2008

Integrated Geophysical Imaging Of Subsurface Geologic Conditions Across A Contaminant Plume, Mccracken County, Kentucky, Cora A. Blits

University of Kentucky Master's Theses

Over 7.8 km of seismic reflection data and 2 km of electrical resistivity data were acquired, processed, and interpreted during this multi-method geophysical study. Objectives included the definition of geologic conditions underlying a contaminant plume in McCracken County, western Kentucky, and the determination of the potential for structural control on the rate and direction of plume migration. Both geophysical methods indicate the presence of multiple high-angle normal faults outlining a series of asymmetric grabens ranging in width from 160 m to almost 300 m and striking between N40°E and N45°E. There was agreement between the two methods on fault location …


The Development Of A Novel And Potentially Nondestructive Pretreatment For The Radiocarbon Dating Of Archaeological Artifacts, Mary Ellen Ellis Jan 2008

The Development Of A Novel And Potentially Nondestructive Pretreatment For The Radiocarbon Dating Of Archaeological Artifacts, Mary Ellen Ellis

Master's Theses and Doctoral Dissertations

Because the traditional acid-alkali-acid method for pretreating archaeological artifacts prior to radiocarbon dating is destructive to most materials, the possibility of developing an alternative pretreatment is important to preserving culturally- and historically-significant artifacts. The alkali step usually involves a 1M or higher concentration NaOH wash to remove humic acid contamination. The purpose of this work is to replace the alkali step with an equally effective, yet less harsh treatment. Charcoal soaked in a humic acid standard was used to mimic a contaminated artifact. Residues from treatments with NaOH, phosphate buffer (pH 8), and deionized water were characterized using THM-GC-MS. Preliminary …


Differential Geometry In Cartesian Closed Categories Of Smooth Spaces, Martin Laubinger Jan 2008

Differential Geometry In Cartesian Closed Categories Of Smooth Spaces, Martin Laubinger

LSU Doctoral Dissertations

The main categories of study in this thesis are the categories of diffeological and Fr\"olicher spaces. They form concrete cartesian closed categories. In Chapter 1 we provide relevant background from category theory and differentiation theory in locally convex spaces. In Chapter 2 we define a class of categories whose objects are sets with a structure determined by functions into the set. Fr\"olicher's $M$-spaces, Chen's differentiable spaces and Souriau's diffeological spaces fall into this class of categories. We prove cartesian closedness of the two main categories, and show that they have all limits and colimits. We exhibit an adjunction between the …


Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray Jan 2008

Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray

Electrical & Computer Engineering Faculty Publications

There is a need for better integration of the fault tolerant and the control designs for safety critical systems such as aircraft. The dependability of current designs is assessed primarily with measures of the interconnection of fault tolerant components: the reliability function and the mean time to failure. These measures do not directly take into account the interaction of the fault tolerant components with the dynamics of the aircraft. In this paper, a first step to better integrate these designs is made. It is based on the observation that unstable systems are intrinsically unreliable and that a necessary condition for …


Vegetation Identification Based On Satellite Imagery, Vamsi K.R. Mantena, Ramu Pedada, Srinivas Jakkula, Yuzhong Shen, Jiang Li, Hamid R. Arabnia (Ed.) Jan 2008

Vegetation Identification Based On Satellite Imagery, Vamsi K.R. Mantena, Ramu Pedada, Srinivas Jakkula, Yuzhong Shen, Jiang Li, Hamid R. Arabnia (Ed.)

Electrical & Computer Engineering Faculty Publications

Automatic vegetation identification plays an important role in many applications including remote sensing and high performance flight simulations. This paper presents a method to automatically identify vegetation based upon satellite imagery. First, we utilize the ISODATA algorithm to cluster pixels in the images where the number of clusters is determined by the algorithm. We then apply morphological operations to the clustered images to smooth the boundaries between clusters and to fill holes inside clusters. After that, we compute six features for each cluster. These six features then go through a feature selection algorithm and three of them are determined to …


Methods Development In Qualitative And Quantitative Proteomics, Ting Liu Jan 2008

Methods Development In Qualitative And Quantitative Proteomics, Ting Liu

University of Kentucky Doctoral Dissertations

Proteomics based on liquid chromatography coupled to mass spectrometry has developed rapidly in the last decade and become a powerful tool for protein mixtures analysis. LC-MS based proteomics involves four steps, sample preparation, liquid chromatography, mass spectrometry and bioinformatics. Improvements in each step have extended its applications to new biological research areas. This dissertation mainly focuses on method developments in both qualitative and quantitative proteomics.

The first part of this dissertation focuses on qualitative analysis of T. gondii Parasitophorous Vacuole Membrane (PVM) proteins, which is very important for T. gondii’s survival. The hypothesis of this study is that proteomic …


Electron Density And Temperature Measurement Of An Atmospheric Pressure Plasma By Millimeter Wave Interferometer, Xinpei Lu, Mounir Laroussi Jan 2008

Electron Density And Temperature Measurement Of An Atmospheric Pressure Plasma By Millimeter Wave Interferometer, Xinpei Lu, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

In this paper, a 105 GHz millimeter wave interferometer system is used to measure the electron density and temperature of an atmospheric pressure helium plasma driven by submicrosecond pulses. The peak electron density and electron-neutral collision frequency reach 8 X 1012 cm-3 and 2.1 X 1012 s-1, respectively. According to the electron-helium collision cross section and the measured electron-neutral collision frequency, the electron temperature of the plasma is estimated to reach a peak value of about 8.7 eV.


Reproducible Increased Mg Incorporation And Large Hole Concentration In Gan Using Metal Modulated Epitaxy, Shawn D. Burnham, Gon Namkoong, David C. Look, Bruce Clafin, W. Alan Doolittle Jan 2008

Reproducible Increased Mg Incorporation And Large Hole Concentration In Gan Using Metal Modulated Epitaxy, Shawn D. Burnham, Gon Namkoong, David C. Look, Bruce Clafin, W. Alan Doolittle

Electrical & Computer Engineering Faculty Publications

The metal modulated epitaxy (MME) growth technique is reported as a reliable approach to obtain reproducible large hole concentrations in Mg-doped GaN grown by plasma-assisted molecular-beam epitaxy on c-plane sapphire substrates. An extremely Ga-rich flux was used, and modulated with the Mg source according to the MME growth technique. The shutter modulation approach of the MME technique allows optimal Mg surface coverage to build between MME cycles and Mg to incorporate at efficient levels in GaN films. The maximum sustained concentration of Mg obtained in GaN films using the MME technique was above 7 × 1020 cm-3 …


Correction To "Stochastic Comparisons Of Parallel Systems When Components Have Proportional Hazard Rates", Subhash C. Kochar, Maochao Xu Jan 2008

Correction To "Stochastic Comparisons Of Parallel Systems When Components Have Proportional Hazard Rates", Subhash C. Kochar, Maochao Xu

Mathematics and Statistics Faculty Publications and Presentations

In the article "Stochastic comparisons of parallel systems when component have proportional hazard rates" we found a gap in the middle of the proof of Theorem 3.2. Therefore, we do not know whether Theorem 3.2 is true for the reverse hazard rate order. However, we could prove the following weaker result for the stochastic order.


Nonthermal Laser-Induced Formation Of Crystalline Ge Quantum Dots On Si(100), M. S. Hegazy, H. E. Elsayed-Ali Jan 2008

Nonthermal Laser-Induced Formation Of Crystalline Ge Quantum Dots On Si(100), M. S. Hegazy, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The effects of laser-induced electronic excitations on the self-assembly of Ge quantum dots on Si (100) - (2×1) grown by pulsed laser deposition are studied. Electronic excitations due to laser irradiation of the Si substrate and the Ge film during growth are shown to decrease the roughness of films grown at a substrate temperature of ∼120 °C. At this temperature, the grown films are nonepitaxial. Electronic excitation results in the formation of an epitaxial wetting layer and crystalline Ge quantum dots at ∼260 °C, a temperature at which no crystalline quantum dots form without excitation under the same deposition conditions. …


Activation Energy Of Surface Diffusion And Terrace Width Dynamics During The Growth Of In (4×3) On Si (100) - (2×1) By Femtosecond Pulsed Laser Deposition, M. A. Hafez, H. E. Elsayed-Ali Jan 2008

Activation Energy Of Surface Diffusion And Terrace Width Dynamics During The Growth Of In (4×3) On Si (100) - (2×1) By Femtosecond Pulsed Laser Deposition, M. A. Hafez, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The nucleation and growth of indium on a vicinal Si (100) - (2×1) surface at high temperature by femtosecond pulsed laser deposition was investigated by in situ reflection high energy electron diffraction (RHEED). RHEED intensity relaxation was observed for the first ∼2 ML during the growth of In (4×3) by step flow. From the temperature dependence of the rate of relaxation, an activation energy of 1.4±0.2 eV of surface diffusion was determined. The results indicate that indium small clusters diffused to terrace step edges with a diffusion frequency constant of (1.0±0.1) × 1011 s-1. The RHEED specular …


Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis Jan 2008

Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

To welcome yet another book on sustainable development, a reviewer must look for what is unique and what adds value to the volumes already published. In Agricultural Systems, editors Sieglinde Snapp and Barry Pound have assembled a collection of chapters that goes beyond the usual praise and criticism of the green revolution and the focus on economic development. Their book provides a first-hand story by people with lengthy experiences in the field, especially in Africa, who have developed and tested grassroots, participatory development approaches. The result is a valuable set of principles, strategies and case studies that paint a new …


Modeling The Fate Of Pharmaceuticals And Personal Care Products In Sewage Treatment Plants, Craig D. Adams Jan 2008

Modeling The Fate Of Pharmaceuticals And Personal Care Products In Sewage Treatment Plants, Craig D. Adams

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Chemical fate models can be used to estimate the transformation reactions and the partitioning behavior of pharmaceuticals and personal care products (PPCPs) in sewage treatment plants (STPs). Modeling the fate of PPCPs in a STP requires parameters such as rate constants or partition coefficients that are often unique to a specific STP, and that may exhibit significant temporal variability. Chemical fate models provide both a valuable test of our understanding of the fundamental underlying mechanisms regarding the fate of PPCPs in STPs, as well as a means of providing both qualitative and quantitative estimates for PPCP removal. This paper is …


Multigrid Convergence For Second Order Elliptic Problems With Smooth Complex Coefficients, Jay Gopalakrishnan, Joseph E. Pasciak Jan 2008

Multigrid Convergence For Second Order Elliptic Problems With Smooth Complex Coefficients, Jay Gopalakrishnan, Joseph E. Pasciak

Mathematics and Statistics Faculty Publications and Presentations

The finite element method when applied to a second order partial differential equation in divergence form can generate operators that are neither Hermitian nor definite when the coefficient function is complex valued. For such problems, under a uniqueness assumption, we prove the continuous dependence of the exact solution and its finite element approximations on data provided that the coefficients are smooth and uniformly bounded away from zero. Then we show that a multigrid algorithm converges once the coarse mesh size is smaller than some fixed number, providing an efficient solver for computing discrete approximations. Numerical experiments, while confirming the theory, …


Asymptotic And Numerical Techniques For Resonances Of Thin Photonic Structures, Jay Gopalakrishnan, Shari Moskow, Fadil Santosa Jan 2008

Asymptotic And Numerical Techniques For Resonances Of Thin Photonic Structures, Jay Gopalakrishnan, Shari Moskow, Fadil Santosa

Mathematics and Statistics Faculty Publications and Presentations

We consider the problem of calculating resonance frequencies and radiative losses of an optical resonator. The optical resonator is in the form of a thin membrane with variable dielectric properties. This work provides two very different approaches for doing such calculations. The first is an asymptotic method which exploits the small thickness and high index of the membrane. We derive a limiting resonance problem as the thickness goes to zero, and for the case of a simple resonance, find a first order correction. The limiting problem and the correction are in one less space dimension, which can make the approach …


The Indefinite Metric Of R. Mrugala And The Geometry Of The Thermodynamical Phase Space, Serge Preston, James Vargo Jan 2008

The Indefinite Metric Of R. Mrugala And The Geometry Of The Thermodynamical Phase Space, Serge Preston, James Vargo

Mathematics and Statistics Faculty Publications and Presentations

We study an indefinite metric G which was introduced by R. Mrugala and is defined on the contact phase space (P, θ) of a homogeneous thermodynamical system. We describe the curvature properties and the isometry group of the metric G. We established an isomorphism of the space (P, θ, G) with the Heisenberg Lie group Hn, endowed with the right invariant contact structure and the right invariant indefinite metric. The lift of the metric G to the symplectization of contact space (P, θ) and its properties are studied. Finally we introduce the "hyperbolic projectivization" of the space …


Uniform Materials And The Multiplicative Decomposition Of The Deformation Gradient In Finite Elasto-Plasticity, Vincenzo Ciancio, Marina Dolfin, Mauro Francaviglia, Serge Preston Jan 2008

Uniform Materials And The Multiplicative Decomposition Of The Deformation Gradient In Finite Elasto-Plasticity, Vincenzo Ciancio, Marina Dolfin, Mauro Francaviglia, Serge Preston

Mathematics and Statistics Faculty Publications and Presentations

In this work we analyze the relation between the multiplicative decomposition F = F e F p of the deformation gradient as a product of the elastic and plastic factors and the theory of uniform materials. We prove that postulating such a decomposition is equivalent to having a uniform material model with two configurations – total φ and the inelastic φ1. We introduce strain tensors characterizing different types of evolutions of the material and discuss the form of the internal energy and that of the dissipative potential. The evolution equations are obtained for the configurations (φ, φ1) and the material …


On The Spectra Of Certain Directed Paths, Carlos Martins Da Fonseca, J. J. P. Veerman Jan 2008

On The Spectra Of Certain Directed Paths, Carlos Martins Da Fonseca, J. J. P. Veerman

Mathematics and Statistics Faculty Publications and Presentations

We describe the eigenpairs of special kinds of tridiagonal matrices related to problems on traffic on a one-lane road. Some numerical examples are provided.