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2010

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Articles 271 - 300 of 8620

Full-Text Articles in Physical Sciences and Mathematics

Nicholas Reactions In The Construction Of Cyclohepta[De]Naphthalenes And Cyclohepta[De]Naphthalenones. The Total Synthesis Of Microstegiol, Rafiq Taj, James R. Green Dec 2010

Nicholas Reactions In The Construction Of Cyclohepta[De]Naphthalenes And Cyclohepta[De]Naphthalenones. The Total Synthesis Of Microstegiol, Rafiq Taj, James R. Green

Chemistry and Biochemistry Publications

The application of the Nicholas reaction chemistry of 2,7-dioxygenated naphthalenes in the synthesis of cyclohepta[de]napthalenes and in the synthesis of (±)-microstegiol (1) is presented. The substitution profile of Nicholas monosubstitution (predominantly C-1) and disubstitution reactions (predominantly 1,6-) on 2,7-dioxygenated napthalenes is reported. Application of a 1,8-dicondensation product and selected C-1 monocondensation products to the construction of cyclohepta[de]naphthalenes by way of ring closing metathesis and intramolecular Friedel−Crafts reactions, respectively, is described. Deprotection of the C-7 oxygen function to the corresponding naphthol allows tautomerization to cyclohepta[de]naphthalene-1-ones upon seven-membered-ring closure in most cases, and replacement …


Intramolecular Nicholas Reactions In The Synthesis Of Dibenzocycloheptanes. Synthesis Of Allocolchicine Nsc 51046 And Analogues And The Formal Synthesis Of (−)-Allocolchicine, Sinisa Djurdjevic, Fei Yang, James R. Green Dec 2010

Intramolecular Nicholas Reactions In The Synthesis Of Dibenzocycloheptanes. Synthesis Of Allocolchicine Nsc 51046 And Analogues And The Formal Synthesis Of (−)-Allocolchicine, Sinisa Djurdjevic, Fei Yang, James R. Green

Chemistry and Biochemistry Publications

The preparation of dibenzocycloheptyne-Co2(CO)6 complexes by intramolecular Nicholas reactions of biaryl-2-propargyl alcohol-Co2(CO)6 derivatives is described. Reductive decomplexation of the dibenzocycloheptyne-Co2(CO)6 complexes affords the corresponding dibenzocycloheptenes, individual members of which have been employed in a formal total synthesis of (−)-allocolchicine, the preparation of 6,7-dihydro-3,4,9,10,11-pentamethoxy-5H-dibenzo[a,c]cyclohepten-5-one, and the enantioselective total syntheses of NSC 51046 and its 3,8,9,10-tetramethoxy regioisomer.


Ecological Impacts Of Stream Bank Stabilization In A Great Plains River, Christopher M. Pracheil Dec 2010

Ecological Impacts Of Stream Bank Stabilization In A Great Plains River, Christopher M. Pracheil

School of Natural Resources: Dissertations, Theses, and Student Research

Reduced ecological complexity, decreased water quality, and accelerated stream bank erosion are common disturbances in rivers with agriculturally dominated watersheds. Massive bank failures, increased sediment loads, and decreased riverine habitat are current problems in the agriculturally dominated Cedar River of central Nebraska. In an effort to slow erosion and prevent further ecological degradation, 20 reach scale stream bank stabilization projects were installed on the Cedar River from 2001 to 2004. The objective of this study was to determine the impact of the Cedar River stream bank stabilization projects on the ecological conditions within the Cedar River. Stream bank erosion, suspended …


Quantitative Stability And Optimality Conditions In Convex Semi-Infinite And Infinite Programming, M J. Cánovas, M A. Lopez, Boris S. Mordukhovich, J Parra Dec 2010

Quantitative Stability And Optimality Conditions In Convex Semi-Infinite And Infinite Programming, M J. Cánovas, M A. Lopez, Boris S. Mordukhovich, J Parra

Mathematics Research Reports

This paper concerns parameterized convex infinite (or semi-infinite) inequality systems whose decision variables run over general infinite-dimensional Banach (resp. finite-dimensional) spaces and that are indexed by an arbitrary fixed set T. Parameter perturbations on the right-hand side of the inequalities are measurable and bounded, and thus the natural parameter space is loo(T). Based on advanced variational analysis, we derive a precise formula for computing the exact Lipschitzian bound of the feasible solution map, which involves only the system data, and then show that this exact bound agrees with the coderivative norm of the aforementioned mapping. On one hand, in this …


Proyecto De Investigación: La Primera Agencia Espacial Mexicana: La Comisión Nacional Del Espacio Exterior (1962-1977), J. R. Joel Flores-Mariscal Dec 2010

Proyecto De Investigación: La Primera Agencia Espacial Mexicana: La Comisión Nacional Del Espacio Exterior (1962-1977), J. R. Joel Flores-Mariscal

J. R. Joel Flores-Mariscal

No abstract provided.


Proyecto De Investigación: Los Mexicanos En Las Operaciones De La Segunda Guerra Mundial, J. R. Joel Flores-Mariscal Dec 2010

Proyecto De Investigación: Los Mexicanos En Las Operaciones De La Segunda Guerra Mundial, J. R. Joel Flores-Mariscal

J. R. Joel Flores-Mariscal

No abstract provided.


Random Automata Networks: Why Playing Dice Is Not A Vice, Christof Teuscher Dec 2010

Random Automata Networks: Why Playing Dice Is Not A Vice, Christof Teuscher

Systems Science Friday Noon Seminar Series

Random automata networks consist of a set of simple compute nodes interacting with each other. In this generic model, one or multiple model parameters, such as the the node interactions and/or the compute functions, are chosen at random. Random Boolean Networks (RBNs) are a particular case of discrete dynamical automata networks where both time and states are discrete. While traditional RBNs are generally credited to Stuart Kauffman (1969), who introduced them as simplified models of gene regulation, Alan Turing proposed unorganized machines as early as 1948. In this talk I will start with Alan Turing's early work on unorganized machines, …


Measurements Of Gas‐Phase Inorganic And Organic Acids From Biomass Fires By Negative‐Ion Proton‐Transfer Chemical‐Ionization Mass Spectrometry, P. Veres, James M. Roberts, I. R. Burling, C. Warneke, Joost De Gouw, Robert J. Yokelson Dec 2010

Measurements Of Gas‐Phase Inorganic And Organic Acids From Biomass Fires By Negative‐Ion Proton‐Transfer Chemical‐Ionization Mass Spectrometry, P. Veres, James M. Roberts, I. R. Burling, C. Warneke, Joost De Gouw, Robert J. Yokelson

Chemistry and Biochemistry Faculty Publications

[1] Emissions from 34 laboratory biomass fires were investigated at the combustion facility of the U.S. Department of Agriculture Fire Sciences Laboratory in Missoula, Montana. Gas-phase organic and inorganic acids were quantified using negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), open-path Fourier transform infrared spectroscopy (OP-FTIR), and proton-transfer-reaction mass spectrometry (PTR-MS). NI-PT-CIMS is a novel technique that measures the mass-to-charge ratio (m/z) of ions generated from reactions of acetate (CH3C(O)O) ions with inorganic and organic acids. The emission ratios for various important reactive acids with respect to CO were determined. Emission ratios for isocyanic acid (HNCO), 1,2 …


Network Science: Using Information Technology To Enable Collaboration, Arden L. Bement Jr. Dec 2010

Network Science: Using Information Technology To Enable Collaboration, Arden L. Bement Jr.

PPRI Digital Library

No abstract provided.


Spatial Semantics For Better Interoperability And Analysis: Challenges And Experiences In Building Semantically Rich Applications In Web 3.0, Amit P. Sheth Dec 2010

Spatial Semantics For Better Interoperability And Analysis: Challenges And Experiences In Building Semantically Rich Applications In Web 3.0, Amit P. Sheth

Kno.e.sis Publications

No abstract provided.


Lego Rover Control, Gang-Ryung Uh Dec 2010

Lego Rover Control, Gang-Ryung Uh

Gang-Ryung Uh

Four-wheel Lego Mars Rover that can be wirelessly controlled over Bluetooth.


Lake Whatcom Bathymetry And Morphology, Robert J. Mitchell, Gerry Gabrisch, Robin A. Matthews Dec 2010

Lake Whatcom Bathymetry And Morphology, Robert J. Mitchell, Gerry Gabrisch, Robin A. Matthews

Lake Whatcom Bathymetry Report

Our objective for this study was to produce an accurate and usable bathymetric model and morphological data for Lake Whatcom to replace that produced by Lighthart et al. (1972). Herein, we summarize the techniques used to convert the 1999 the U. S. Bureau of Reclamation (BOR) hydrographic survey soundings and shoreline contours of Lake Whatcom into metric units and a Triangulated Irregular Network (TIN) bathymetry model. We also describe the procedures used to delineate the major lake basins and to calculate surface area, water volumes, and other morphometric parameters for each basin and the lake as a whole.


Solving A Generalized Heron Problem By Means Of Convex Analysis, Boris S. Mordukhovich, Nguyen Mau Nam, Juan Salinas Jr Dec 2010

Solving A Generalized Heron Problem By Means Of Convex Analysis, Boris S. Mordukhovich, Nguyen Mau Nam, Juan Salinas Jr

Mathematics Research Reports

The classical Heron problem states: on a given straight line in the plane, find a point C such that the sum of the distances from C to the given points A and B is minimal. This problem can be solved using standard geometry or differential calculus. In the light of modern convex analysis, we are able to investigate more general versions of this problem. In this paper we propose and solve the following problem: on a given nonempty closed convex subset of IR!, find a point such that the sum of the distances from that point to n given nonempty …


Opinion Formation On Adaptive Networks With Intensive Average Degree, Beate Schmittmann, Abhishek Mukhopadhyay Dec 2010

Opinion Formation On Adaptive Networks With Intensive Average Degree, Beate Schmittmann, Abhishek Mukhopadhyay

Beate Schmittmann

We study the evolution of binary opinions on a simple adaptive network of N nodes. At each time step, a randomly selected node updates its state (“opinion”) according to the majority opinion of the nodes that it is linked to; subsequently, all links are reassigned with probability p̃ (q̃ ) if they connect nodes with equal (opposite) opinions. In contrast to earlier work, we ensure that the average connectivity (“degree”) of each node is independent of the system size (“intensive”), by choosing p̃ and q̃ to be of O(1/N). Using simulations and analytic arguments, we determine the final steady states …


Positive Solutions Of Singular Complementary Lidstone Boundary Value Problems, Ravi P. Agarwal, Donal O'Regan, Svatoslav Staněk Dec 2010

Positive Solutions Of Singular Complementary Lidstone Boundary Value Problems, Ravi P. Agarwal, Donal O'Regan, Svatoslav Staněk

Mathematics and System Engineering Faculty Publications

We investigate the existence of positive solutions of singular problem (-1)mx(2m+1) = f(t, x,⋯, x(2m)), x (0) = 0, x(2i-1) (0) = x(2i-1) (T) = 0, 1 ≤ i ≤ m. Here, m ≥ 1 and the Carathéodory function f (t, x0,⋯, x2m) may be singular in all its space variables x0,⋯, x2m. The results are proved by regularization and sequential techniques. In limit processes, the Vitali convergence theorem is used.


Burkholder Integrals, Morrey's Problem And Quasiconformal Mappings, Kari Astala, Tadeusz Iwaniec, Istvan Prause, Eero Saksman Dec 2010

Burkholder Integrals, Morrey's Problem And Quasiconformal Mappings, Kari Astala, Tadeusz Iwaniec, Istvan Prause, Eero Saksman

Mathematics - All Scholarship

Inspired by Morrey's Problem (on rank-one convex functionals) and the Burkholder integrals (of his martingale theory) we find that the Burkholder functionals Bp, p > 2, are quasiconcave, when tested on deformations of identity f in Id+Coinifinty (omega) with Bp (Df(x)) > 0 pointwise, or equivalently, deformations such that abs[Df]2 < (p/(p-2))Jf. In particular, this holds in explicit neighbourhoods of the identity map. Among the many immediate consequences, this gives the strongest possible Lp-estimates for the gradient of a principal solution to the Beltrami equation fz = mu(z)fz , for any p in …


Development Of An Arcuate Fold-Thrust Belt As A Result Of Basement Configuration: An Example From The Rocky Mountain Front Range, Montana, Caroline M. Burberry, D. L. Cannon, T. Engelder, J. W. Cosgrove Dec 2010

Development Of An Arcuate Fold-Thrust Belt As A Result Of Basement Configuration: An Example From The Rocky Mountain Front Range, Montana, Caroline M. Burberry, D. L. Cannon, T. Engelder, J. W. Cosgrove

Department of Earth and Atmospheric Sciences: Faculty Publications

The Sawtooth Range forms part of the Montana Disturbed Belt in the Front Ranges of the Rocky Mountains, along strike from the Alberta Syncline in the Canadian Rockies. The belt developed in the footwall to the Lewis Thrust during the Sevier orogeny and is similar in deformation style to the Canadian Foothills, with a series of stacked thrust sheets carrying Palaeozoic carbonates. The Sawtooth Range can be divided into an inner and outer deformed belt, separated by exposed fold structures in the overlying clastic sequence. Structures in the deformed belts plunge into the culmination of the NE-trending Scapegoat-Bannatyne trend, part …


Shovelnose Sturgeon Age And Growth Characteristics And Fish Community Characteristics Of The Lower Platte River And Missouri River Near Nebraska, Tara L. Anderson Dec 2010

Shovelnose Sturgeon Age And Growth Characteristics And Fish Community Characteristics Of The Lower Platte River And Missouri River Near Nebraska, Tara L. Anderson

School of Natural Resources: Dissertations, Theses, and Student Research

There have been documented widespread losses of freshwater biodiversity over the past several decades. Many of these losses may be due to anthropogenic causes such as habitat alterations, pollution, and overharvest. Shovelnose sturgeon may also be influenced by anthropogenic causes and have experienced declines in population abundance near Nebraska. My objectives were to first to describe the age, growth and mortality of shovelnose sturgeon found in the lower Platte River (LPR). Second, I quantitatively evaluated similarities and differences between the Missouri River (MR) and the LPR fish community composition (presence-absence of species) and structure (abundance of species). We used trammel …


Propagating And Non-Propagating Intraseasonal Oscillations In The Tropical Atmosphere: Their Vertical And Horizontal Structures And Developing Mechanisms, Zhaoning Liang Dec 2010

Propagating And Non-Propagating Intraseasonal Oscillations In The Tropical Atmosphere: Their Vertical And Horizontal Structures And Developing Mechanisms, Zhaoning Liang

School of Natural Resources: Dissertations, Theses, and Student Research

A fixed beamformer is proposed and designed to identify source regions of Intra-Seasonal Oscillations (ISO) in the tropical atmosphere. After tested by simulations of single and complex sources of waves, the fixed beamformer is applied to the ECMWF interpolated data grids to detect and identify source regions of the ISO in the tropical Indian and Pacific Ocean region. Results show that the fixed beamforming technique can uniquely identify the source region of the ISO, the source regions of all major ISO in the tropical Indian and western equatorial Pacific region from 1974 to 2002 have been identified.

Examinations of ISO …


Invariant And Coinvariant Spaces For The Algebra Of Symmetric Polynomials In Non-Commuting Variables, Francois Bergeron, Aaron Lauve Dec 2010

Invariant And Coinvariant Spaces For The Algebra Of Symmetric Polynomials In Non-Commuting Variables, Francois Bergeron, Aaron Lauve

Mathematics and Statistics: Faculty Publications and Other Works

We analyze the structure of the algebra K⟨x⟩Sn of symmetric polynomials in non-commuting variables in so far as it relates to K[x]Sn, its commutative counterpart. Using the "place-action" of the symmetric group, we are able to realize the latter as the invariant polynomials inside the former. We discover a tensor product decomposition of K⟨x⟩Sn analogous to the classical theorems of Chevalley, Shephard-Todd on finite reflection groups.

Résumé. Nous analysons la structure de l'algèbre K⟨x⟩Sn des polynômes symétriques en des variables non-commutatives pour obtenir des analogues des résultats classiques concernant la structure de l'anneau K[x]Sn des polynômes symétriques en des variables …


Microvariability Of The Blazar 3c279, Hannah M. Clemmons Dec 2010

Microvariability Of The Blazar 3c279, Hannah M. Clemmons

Physics and Astronomy Theses

Active Galactic Nuclei (AGN) are some of the most extreme objects in the universe. They output copious amounts of energy spanning the entire electromagnetic spectrum. There are many different subclasses of AGN depending on your viewing angle. Blazars, viewing down the relativistic jet, are the most variable class of AGN known. They exhibit extreme variability in all wavelengths on timescales as short as minutes. In this thesis I will consider the extreme faintness of 3C279 with respect to the long-term light curve as well as recent observations of microvariability. I am able to confirm small amplitude events using simultaneous observations …


Novel Electrochemical Detections Of Biologically And Environmentally Relevant Substances, Clarissa E. Tatum Dec 2010

Novel Electrochemical Detections Of Biologically And Environmentally Relevant Substances, Clarissa E. Tatum

Doctoral Dissertations

Development and studies of new electrochemical methods for the detection of various biologically and environmentally relevant substances are the focus of this dissertation. A dual amperometric sensor, capable of the simultaneous, real-time determination of NO and O,2, has been developed and optimized. Many tests were performed in order to reduce cross-talking between the two sensors, and an electro-deposited polymer, poly-5-amino-1-naphthol, was shown to reduce the cross-talking to insignificant levels. The use of bismuth-based electrodes in the detection of various metals has been explored. A bismuth bulk electrode has been developed, optimized, and used for the individual and simultaneous determination of …


Tantalum Carbene And Imide Complexes. Synthesis, Characterization, And Pathways Of Formation, Julia Kathryn Covington Abbott Dec 2010

Tantalum Carbene And Imide Complexes. Synthesis, Characterization, And Pathways Of Formation, Julia Kathryn Covington Abbott

Doctoral Dissertations

This dissertation focuses on two different types of organometallic compounds, carbenes and imides. The first project deals with the archetypal Schrock carbene, and the second project studies complexes that contain metal-nitrogen bonds, both amides and imides.

A summary of the research in this dissertation is discussed in Chapter 1. Chapter 2 begins the studies of the archetypal Schrock carbene (ButCH2)3Ta=CHBut. The studies include the synthesis of deuterated compounds (ButCD2)3TaCl2 and ButCD2Li, observation and identification of the intermediate, Ta(CD2But …


Spin-Lattice Coupling In The Iron-Pnictide High-Temperature Superconductors, Daniel E Parshall Dec 2010

Spin-Lattice Coupling In The Iron-Pnictide High-Temperature Superconductors, Daniel E Parshall

Doctoral Dissertations

The recent discovery of the iron-pnictide superconductors has generated tremendous excitement, in part because there are many tantalizing similarities to the cuprate superconductors. As with the cuprates, it is strongly suspected that the spins contribute to superconductivity.

There seems to be a strong relationship between the lattice and magnetism in this system. Several authors have discussed the possibility of spin-phonon coupling, but direct experimental evidence has remained elusive.

This work discusses the relationship between the spins and the lattice in the $BaFe_{2}As_{2}$ family. We demonstrate the presence of negative thermal expansion in these materials, which is a strong indicator of …


A Visual Approach To Automated Text Mining And Knowledge Discovery, Andrey A. Puretskiy Dec 2010

A Visual Approach To Automated Text Mining And Knowledge Discovery, Andrey A. Puretskiy

Doctoral Dissertations

The focus of this dissertation has been on improving the non-negative tensor factorization technique of text mining. The improvements have been made in both pre-processing and post-processing stages, with the goal of making the non-negative tensor factorization algorithm accessible to the casual user. The improved implementation allows the user to construct and modify the contents of the tensor, experiment with relative term weights and trust measures, and experiment with the total number of algorithm output features. Non-negative tensor factorization output feature production is closely integrated with a visual post-processing tool, FutureLens, that allows the user to perform in depth analysis …


Human Decomposition Ecology At The University Of Tennessee Anthropology Research Facility, Franklin Edward Damann Dec 2010

Human Decomposition Ecology At The University Of Tennessee Anthropology Research Facility, Franklin Edward Damann

Doctoral Dissertations

The University of Tennessee Anthropology Research Facility (ARF) is well known for its unique history as a site of human decomposition research in a natural environment. It has been integral to our understanding of the processes of human decomposition. Over the last 30 years 1,089 bodies have decomposed at this 1.28 acre facility, producing a density of 850 corpses per acre of land. This project evaluated the abiotic and biotic characteristics of the soil exposed to various levels of human decomposition in order to determine the effect on the physicochemical properties and the indigenous bacterial communities.

Specifically, 75 soil samples …


The Importance Of Chain Connectivity In The Formation Of Non-Covalent Interactions Between Polymers And Single-Walled Carbon Nanotubes And Its Impact On Dispersion, Dias Linton Dec 2010

The Importance Of Chain Connectivity In The Formation Of Non-Covalent Interactions Between Polymers And Single-Walled Carbon Nanotubes And Its Impact On Dispersion, Dias Linton

Doctoral Dissertations

Polymer nanocomposites have garnered incredible promise in the field of material science due to the excellent mechanical strength, thermal and electrical conductivities of the nanoparticles and the extension of these properties to the processing flexibility inherent to plastics. However, practical realization of these nanoparticle-based materials has been hindered by the tendency of these nanoparticles to aggregate as a result of strong inter-particle forces. In this dissertation, we investigate the formation of non-covalent charge transfer interactions between polymers and single-walled carbon nanotubes (SWNTs) with the goal of optimizing interfacial adhesion and homogeneity of nanocomposites without modifying the SWNT native surface.

Nanocomposites …


Like Mother Like Child: An Investigation Of Mother Characteristics And Child Temperaments, Tempus Fugitt Dec 2010

Like Mother Like Child: An Investigation Of Mother Characteristics And Child Temperaments, Tempus Fugitt

Statistics

Much research has gone into what biological and social factors raise the risk of children developing cognitive, social, or behavioral problems. This project looks at what characteristics of the mother are significantly associated with different temperaments in the child which may predict problems developed in the child later in life. These characteristics include mother’s age, her education level, household income, parenting attitudes, involvement with the child, and drug and alcohol use. Data was used from the Fragile Families and Child Wellbeing Study conducted by the Office of Population Research at Princeton University. Cumulative logistic regression was used to analyze the …


Completeness Of Ordered Fields, James Forsythe Hall Dec 2010

Completeness Of Ordered Fields, James Forsythe Hall

Mathematics

The main goal of this project is to prove the equivalency of several characterizations of completeness of Archimedean ordered fields; some of which appear in most modern literature as theorems following from the Dedekind completeness of the real numbers, while a couple are not as well known and have to do with other areas of mathematics, such as nonstandard analysis. Continuing, we study the completeness of non-Archimedean fields, and provide several examples of such fields with varying degrees of properties, using nonstandard analysis to produce some relatively "nice" (in particular, they are Cantor complete) final examples. As a small detour, …


Kinematics And Vorticity In Kangmar Dome, Southern Tibet: Testing Midcrustal Channel-Flow Models For The Himalaya, Tom Wagner, Jeffrey Lee, Bradley R. Hacker, Gareth Seward Dec 2010

Kinematics And Vorticity In Kangmar Dome, Southern Tibet: Testing Midcrustal Channel-Flow Models For The Himalaya, Tom Wagner, Jeffrey Lee, Bradley R. Hacker, Gareth Seward

All Faculty Scholarship for the College of the Sciences

Kinematic, kinematic vorticity (Wm), and deformation temperature analyses were completed to test the hypothesis that midcrustal rocks exposed in the core of the Kangmar gneiss dome, southern Tibet record ductile deformation patterns of a “frozen” segment of a southward flowing midcrustal channel. Microscopic and mesoscopic kinematic indicators exhibit a downward transition from a subequal mix of top-north and top-south shear in garnet zone rocks to dominantly top-north shear in staurolite/kyanite zone and deeper rocks. Kinematic vorticity values indicate an increase in pure shear component with depth from ∼48% pure shear in chloritoid zone rocks through ∼62% in …