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2017

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Articles 2251 - 2280 of 12521

Full-Text Articles in Physical Sciences and Mathematics

Flood-Inundation Maps For The Meramec River At Valley Park And At Fenton, Missouri, 2017, Benjamin J. Dietsch, Jacob N. Sappington Sep 2017

Flood-Inundation Maps For The Meramec River At Valley Park And At Fenton, Missouri, 2017, Benjamin J. Dietsch, Jacob N. Sappington

United States Geological Survey: Water Reports and Publications

Two sets of digital flood-inundation map libraries that spanned a combined 16.7-mile reach of the Meramec River that extends upstream from Valley Park, Missouri, to downstream from Fenton, Missouri, were created by the United States Geological Survey (USGS) in cooperation with the United States Army Corps of Engineers, St. Louis Metropolitan Sewer District, Missouri Department of Transportation, Missouri American Water, and Federal Emergency Management Agency Region 7. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science website at https://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels …


Aluminum Complexes Of N2o23‒ Formazanate Ligands Supported By Phosphine Oxide Donors, Ryan Maar, Amir Rabiee Kenaree, Ruizhong Zhang, Yichen Tao, Benjamin D. Katzman, Viktor N. Staroverov, Zhifeng Ding, Joe Gilroy Sep 2017

Aluminum Complexes Of N2o23‒ Formazanate Ligands Supported By Phosphine Oxide Donors, Ryan Maar, Amir Rabiee Kenaree, Ruizhong Zhang, Yichen Tao, Benjamin D. Katzman, Viktor N. Staroverov, Zhifeng Ding, Joe Gilroy

Chemistry Publications

The synthesis and characterization of a new family of phosphine-oxide-supported aluminum formazanate complexes (7a, 7b, 8a, 9a) are reported. X-ray diffraction studies revealed that the aluminum atoms in the complexes adopt an octahedral geometry in the solid state. The equatorial positions are occupied by an N2O23‒ formazanate ligand, and the axial positions are occupied by L-type phosphine oxide donors. UV-vis absorption spectroscopy revealed that the complexes were strongly absorbing (ε ~ 30,000 M‒1 cm‒1) between 500 and 700 nm. The absorption maxima in this region were simulated using …


Halogen Bonds Formed Between Substituted Imidazoliums And N Bases Of Varying N-Hybridization, Steve Scheiner Sep 2017

Halogen Bonds Formed Between Substituted Imidazoliums And N Bases Of Varying N-Hybridization, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Heterodimers are constructed containing imidazolium and its halogen-substituted derivatives as Lewis acid. N in its sp3, sp2 and sp hybridizations is taken as the electron-donating base. The halogen bond is strengthened in the Cl < Br < I order, with the H-bond generally similar in magnitude to the Br-bond. Methyl substitution on the N electron donor enhances the binding energy. Very little perturbation arises if the imidazolium is attached to a phenyl ring. The energetics are not sensitive to the hybridization of the N atom. More regular patterns appear in the individual phenomena. Charge transfer diminishes uniformly on going from amine to imine to nitrile, a pattern that is echoed by the elongation of the C-Z (Z=H, Cl, Br, I) bond in the Lewis acid. These trends are also evident in the Atoms in Molecules topography of the electron density. Molecular electrostatic potentials are not entirely consistent with energetics. Although I of the Lewis acid engages in a stronger bond than does H, it is the potential of the latter which is much more positive. The minimum on the potential of the base is most negative for the nitrile even though acetonitrile does not form the strongest bonds. Placing the systems in dichloromethane solvent reduces the binding energies but leaves intact most of the trends observed in vacuo; the same can be said of ∆G in solution.


The Cosm Aggregate, Georgia Southern University Sep 2017

The Cosm Aggregate, Georgia Southern University

COSM Aggregate (2017)

No abstract provided.


Stochastic Resonance In A Proton Pumping Complex I Of Mitochondria Membranes, Davneet Kaur, Ilan Filonenko, Lev Mourokh, Cornelius Fendler, Robert H. Blick Sep 2017

Stochastic Resonance In A Proton Pumping Complex I Of Mitochondria Membranes, Davneet Kaur, Ilan Filonenko, Lev Mourokh, Cornelius Fendler, Robert H. Blick

Publications and Research

We make use of the physical mechanism of proton pumping in the so-called Complex I within mitochondria membranes. Our model is based on sequential charge transfer assisted by conformational changes which facilitate the indirect electron-proton coupling. The equations of motion for the proton operators are derived and solved numerically in combination with the phenomenological Langevin equation describing the periodic conformational changes. We show that with an appropriate set of parameters, protons can be transferred against an applied voltage. In addition, we demonstrate that only the joint action of the periodic energy modulation and thermal noise leads to efficient uphill proton …


Intramolecular Glycosylation, Alexei Demchenko, Xiao Jia Sep 2017

Intramolecular Glycosylation, Alexei Demchenko, Xiao Jia

Chemistry & Biochemistry Faculty Works

Carbohydrate oligomers remain challenging targets for chemists due to the requirement for elaborate protecting and leaving group manipulations, functionalization, tedious purification, and sophisticated characterization. Achieving high stereocontrol in glycosylation reactions is arguably the major hurdle that chemists experience. This review article overviews methods for intramolecular glycosylation reactions wherein the facial stereoselectivity is achieved by tethering of the glycosyl donor and acceptor counterparts.


Controlling Water Exchange Kinetics And Improving Paracest Imaging, Jacqueline R. Slack Sep 2017

Controlling Water Exchange Kinetics And Improving Paracest Imaging, Jacqueline R. Slack

Dissertations and Theses

Generating MR image contrast from exogenous contrast media through chemical exchange saturation transfer (CEST) offers several exciting new possibilities, such as multicolored imaging, the interleaving of pre- and post-contrast images, and the potential to perform ratiometric metabolic imaging. The major limitation of the deployment of CEST imaging is the comparatively high detection limits of exogenous agents and particularly at the low B1 power levels required to meet SAR requirements. The large chemical shifts afforded by paramagnetic (paraCEST) agents permit more rapid exchange kinetics and therefore potentially more effective contrast agents. Despite comparatively large chemical shifts, many Ln3+ DOTA-tetraamide …


Proton Transfer And Esterification Reactions In Emimoac-Based Acidic Ionic Liquids, Anh T. Tran, Phuoc H. Lam, Alexandra M. Miller, Dustin J. Walczyk, Jay Tomlin, Timothy D. Vaden, Lei Yu Sep 2017

Proton Transfer And Esterification Reactions In Emimoac-Based Acidic Ionic Liquids, Anh T. Tran, Phuoc H. Lam, Alexandra M. Miller, Dustin J. Walczyk, Jay Tomlin, Timothy D. Vaden, Lei Yu

Lei Yu

Acetate-based ionic liquids (such as 1-ethyl-3-methylimidazolium acetate, EMIMOAc) have potential applications for CO2 absorption and electrochemical reduction, chemical separations and extractions, and Fischer esterification of alcohols, amines, and starch. Both strong and weak organic acids can be dissolved in EMIMOAc and yield interesting proton-rich acidic ionic liquid solutions. We have used GCMS vapor pressure measurements, spectroscopic methods, calorimetry, and viscosity/conductivity measurements to investigate the properties and reactions of various acids dissolved in EMIMOAc. Unique proton transfer and esterification reactions are observed in many of these acidic solutions with carboxylic acids or sulfonic acids as solutes. Some acids react with the …


Intramolecular Glycosylation, Alexei Demchenko, Xiao G. Jia Sep 2017

Intramolecular Glycosylation, Alexei Demchenko, Xiao G. Jia

Alexei Demchenko

Carbohydrate oligomers remain challenging targets for chemists due to the requirement for elaborate protecting and leaving group manipulations, functionalization, tedious purification, and sophisticated characterization. Achieving high stereocontrol in glycosylation reactions is arguably the major hurdle that chemists experience. This review article overviews methods for intramolecular glycosylation reactions wherein the facial stereoselectivity is achieved by tethering of the glycosyl donor and acceptor counterparts.


Determining The Reactivity And Oxidation Intermediates Of An Allylnickel (N-Heterocyclic Carbene) Chloride Complex, Scott W. E. Hendriks Sep 2017

Determining The Reactivity And Oxidation Intermediates Of An Allylnickel (N-Heterocyclic Carbene) Chloride Complex, Scott W. E. Hendriks

Electronic Thesis and Dissertation Repository

The oxidation of C-H bonds to carbonyl functional groups using molecular oxygen (O2) is a desirable process as O2 is environmentally benign and inexpensive. However, oxidations that employ O2 have lower product selectivity, making it industrially unappealing. The metal complexes NiCl(π-cinnamyl)(NHC) oxidize stoichiometrically with O2 as the oxidant to selectively form the ketone and aldehyde products.

This thesis details the attempted catalysis with the NiCl(π-allyl)(NHC) complex and the stoichiometric reactivity of NiCl(π-allyl)(NHC) and NiCl(π-cinnamyl)(NHC) complexes upon O2 exposure. An investigation of the intermediate and decomposition species of the NiCl(π-allyl)(NHC) complex was conducted. The complexes …


The Firece Green Fire: Vol. 8 Issue 4, Wofford College Environmental Studies Program Sep 2017

The Firece Green Fire: Vol. 8 Issue 4, Wofford College Environmental Studies Program

The Fierce Green Fire

No abstract provided.


The Study Of Superheavy Elements At The Intensity Frontier: Reactions And New Methods Of Synthesis, Devaraja H. M Sep 2017

The Study Of Superheavy Elements At The Intensity Frontier: Reactions And New Methods Of Synthesis, Devaraja H. M

University Departments

No abstract provided.


The Santa Clara, 2017-09-28, Santa Clara University Sep 2017

The Santa Clara, 2017-09-28, Santa Clara University

The Santa Clara

No abstract provided.


You, Me And Life In The Sea Ocg 106g, Joanna Burkhardt Sep 2017

You, Me And Life In The Sea Ocg 106g, Joanna Burkhardt

Library Impact Statements

No abstract provided.


Additive Negative Effects Of Anthropogenic Sedimentation And Warming On The Survival Of Coral Recruits, Francesca Fourney, Joana Figueiredo Sep 2017

Additive Negative Effects Of Anthropogenic Sedimentation And Warming On The Survival Of Coral Recruits, Francesca Fourney, Joana Figueiredo

Marine & Environmental Sciences Faculty Articles

Corals worldwide are facing population declines due to global climate change and local anthropogenic impacts. Global climate change effects are hard to tackle but recent studies show that some coral species can better handle climate change stress when provided with additional energy resources. The local stressor that most undermines energy acquisition is sedimentation because it impedes coral heterotrophic feeding and their ability to photosynthesize. To investigate if reducing local sedimentation will enable corals to better endure ocean warming, we quantitatively assessed the combined effects of increased temperature and sedimentation (concentration and turbidity) on the survival of coral recruits of the …


Collaborative Research: Mathematics Of Doing, Understanding, Learning And Educating For Secondary Schools, Brynja R. Kohler Sep 2017

Collaborative Research: Mathematics Of Doing, Understanding, Learning And Educating For Secondary Schools, Brynja R. Kohler

Funded Research Records

No abstract provided.


Supporting Optimal Aging Through The Innovative Use Of Virtual Reality Technology, Sally Hughes, Kathryn Warren-Norton, Pat Spadafora, Lia Tsotsos Sep 2017

Supporting Optimal Aging Through The Innovative Use Of Virtual Reality Technology, Sally Hughes, Kathryn Warren-Norton, Pat Spadafora, Lia Tsotsos

Publications and Scholarship

Although virtual reality (VR) technology has been implemented as a tool to address the health issues of older adults, its applicability to social connectedness is underrepresented in the literature, and less is known about its efficacy in this area in contributing to overall wellness and well-being in later life. Expanding the VR possibilities beyond traditional entertainment purposes holds considerable potential for the older adult market. Technological tools have been employed in the elder health care field for many years, and cutting-edge developments such as virtual and augmented reality have begun to be used to facilitate optimal wellness in aging. Such …


Role Of Viruses Within Metaorganisms: Ciona Intestinalis As A Model System, Brittany A. Leigh Sep 2017

Role Of Viruses Within Metaorganisms: Ciona Intestinalis As A Model System, Brittany A. Leigh

USF Tampa Graduate Theses and Dissertations

Marine animals live and thrive in a literal sea of microorganisms, yet are often able to maintain specific associations that are largely dictated by the environment, host immunity and microbial interactions. Animal-associated microbiomes include bacteria and viruses that vastly outnumber host cells, especially in the gut environment, and are considered to be integral parts of healthy, functioning animals that act as a metaorganism. However, the processes underlying the initial establishment of these microbial communities are not very well understood. This dissertation focuses on the establishment of a well-known developmental animal model, Ciona intestinalis (sea squirt), to study the establishment and …


Improved Scoring Models For Semantic Image Retrieval Using Scene Graphs, Erik Timothy Conser Sep 2017

Improved Scoring Models For Semantic Image Retrieval Using Scene Graphs, Erik Timothy Conser

Dissertations and Theses

Image retrieval via a structured query is explored in Johnson, et al. [7]. The query is structured as a scene graph and a graphical model is generated from the scene graph's object, attribute, and relationship structure. Inference is performed on the graphical model with candidate images and the energy results are used to rank the best matches. In [7], scene graph objects that are not in the set of recognized objects are not represented in the graphical model. This work proposes and tests two approaches for modeling the unrecognized objects in order to leverage the attribute and relationship models to …


Refining Bounding-Box Regression For Object Localization, Naomi Lynn Dickerson Sep 2017

Refining Bounding-Box Regression For Object Localization, Naomi Lynn Dickerson

Dissertations and Theses

For the last several years, convolutional neural network (CNN) based object detection systems have used a regression technique to predict improved object bounding boxes based on an initial proposal using low-level image features extracted from the CNN. In spite of its prevalence, there is little critical analysis of bounding-box regression or in-depth performance evaluation. This thesis surveys an array of techniques and parameter settings in order to further optimize bounding-box regression and provide guidance for its implementation. I refute a claim regarding training procedure, and demonstrate the effectiveness of using principal component analysis to handle unwieldy numbers of features produced …


Miniclean Dark Matter Experiment, Juijen Wang Sep 2017

Miniclean Dark Matter Experiment, Juijen Wang

Physics & Astronomy ETDs

Particle Dark Matter is a hypothesis accounting for a number of observed astrophysical phenomena such as the anomalous galactic rotation curves. From these astronomical observation, about 23% of the universe appears to consist of dark matter. Among the possible candidates for dark matter, a plausible one is a Weakly Interacting Massive Particle (WIMP). A particle with the required properties is beyond the standard model of particle physics. The MiniCLEAN experiment is single-phase liquid-argon detector instrumented with 92 photomultiplier tubes placed inside the cryogenic liquid with 4-pi coverage of a 500 kg (150 kg) target (fiducial) mass. For this experiment, PMT …


Linking Mining Wastewater Discharge To Methylmercury Production In A Sub-Arctic Peatland, Lauren E. Twible Sep 2017

Linking Mining Wastewater Discharge To Methylmercury Production In A Sub-Arctic Peatland, Lauren E. Twible

Electronic Thesis and Dissertation Repository

It is well established that the addition of sulphate (SO42-) to peatlands increases methylmercury (MeHg) concentrations in pore waters via microbial methylation. Less information exists about the effects of different concentrations and sources of SO42- loading on MeHg production in remote, non- SO42- impacted regions like Canada’s north, where increased SO42- loadings come not from the atmosphere, but often from mining waste water and rock tailings. A three year field study (two years of loading; one year of recovery) examined the effects of simulated wastewater (containing 27.2 mg/L SO42- …


Accessibility And Usability Of Government Websites In Tanzania, Joel S. Mtebe, Aron W. Kondoro Sep 2017

Accessibility And Usability Of Government Websites In Tanzania, Joel S. Mtebe, Aron W. Kondoro

The African Journal of Information Systems

The government of Tanzania has been embracing information systems specifically websites in order to widen access to government services, lower administrative costs, and to increase public participation in decision making. As a result, almost every ministry, department, and agency (MDA) has developed a website of different kind. However, the majority of existing websites were developed without sufficiently considering user needs which indicates that they do have some usability and accessibility problems. This study used SortSite tool to evaluate accessibility and usability of government websites taking a sample of 22 websites. The report from the SortSite tool was then checked against …


Systematic Analysis Of Enterprise Perception Towards Cloud Adoption In The African States: The Nigerian Perspective, George A. Oguntala, Prof. Raed A. Abd-Alhameed, Dr. Janet O. Odeyemi Sep 2017

Systematic Analysis Of Enterprise Perception Towards Cloud Adoption In The African States: The Nigerian Perspective, George A. Oguntala, Prof. Raed A. Abd-Alhameed, Dr. Janet O. Odeyemi

The African Journal of Information Systems

The desirous benefits of cloud computing such as high return on investment through efficient resource management, high application throughput and on-demand capabilities have resulted in the unprecedented global acceptance of the computing paradigm. However, research on cloud adoption indicates that fewer organisations in the African states are adopting cloud services. Thus, the purview of the paper is to examine the factors responsible for the poor adoption of cloud computing in most African enterprises using Nigeria as a case study. The study focus on the perception of IT and non-IT employees towards cloud computing. Moreover, the paper reviews the literature on …


Spatial Analysis Of High-Resolution Radar Rainfall And Citizen-Reported Flash Flood Data In Ultra-Urban New York City, Brianne Smith, Stephanie Rodriguez Sep 2017

Spatial Analysis Of High-Resolution Radar Rainfall And Citizen-Reported Flash Flood Data In Ultra-Urban New York City, Brianne Smith, Stephanie Rodriguez

Publications and Research

New York City (NYC) is an ultra-urban region, with over 50% impervious cover and buried stream channels. Traditional flood studies rely on the presence of stream gages to detect flood stage and discharge, but these methods cannot be used in ultra-urban areas. Here we create a high-resolution radar rainfall dataset for NYC and utilize citizen and expert reports of flooding throughout the city to study flash flooding in NYC. Results indicate that interactions between the urban area and land–sea boundary have an important impact on the spatial variability of both heavy rainfall and flooding, sometimes in contrast to results obtained …


Assessment Of Thermal Maturity Trends In Devonian–Mississippian Source Rocks Using Raman Spectroscopy: Limitations Of Peak-Fitting Method, Jason S. Lupoi, Luke P. Fritz, Thomas M. Parris, Paul C. Hackley, Logan Solotky, Courtland F. Eble, Steve Schlaegle Sep 2017

Assessment Of Thermal Maturity Trends In Devonian–Mississippian Source Rocks Using Raman Spectroscopy: Limitations Of Peak-Fitting Method, Jason S. Lupoi, Luke P. Fritz, Thomas M. Parris, Paul C. Hackley, Logan Solotky, Courtland F. Eble, Steve Schlaegle

Faculty, Staff, and Affiliated Publications--KGS

The thermal maturity of shale is often measured by vitrinite reflectance (VRo). VRo measurements for the Devonian–Mississippian black shale source rocks evaluated herein predicted thermal immaturity in areas where associated reservoir rocks are oil-producing. This limitation of the VRo method led to the current evaluation of Raman spectroscopy as a suitable alternative for developing correlations between thermal maturity and Raman spectra. In this study, Raman spectra of Devonian–Mississippian black shale source rocks were regressed against measured VRo or sample-depth. Attempts were made to develop quantitative correlations of thermal maturity. Using sample-depth as a proxy for thermal maturity is not without …


Enhancing The Internet Of Things Architecture With Flow Semantics, Allen Ronald Deserranno Sep 2017

Enhancing The Internet Of Things Architecture With Flow Semantics, Allen Ronald Deserranno

USF Tampa Graduate Theses and Dissertations

Internet of Things (‘IoT’) systems are complex, asynchronous solutions often comprised of various software and hardware components developed in isolation of each other. These components function with different degrees of reliability and performance over an inherently unreliable network, the Internet. Many IoT systems are developed within silos that do not provide the ability to communicate or be interoperable with other systems and platforms. Literature exists on how these systems should be designed, how they should interoperate, and how they could be improved, but practice does not always consult literature.

The work brings together a proposed reference architecture for the IoT …


Oligomers Of Cyclopentadithiophene-Vinylene In Aromatic And Quinoidal Versions And Redox Species With Intermediate Forms, Paula Mayorga Burrezo, Rocío Domínguez, José L. Zafra, Ted M. Pappenfus, Pilar De La Cruz, Lorena Welte, Daron E. Janzen, Juan T. López Navarrete, Fernando Langa, Juan Casado Sep 2017

Oligomers Of Cyclopentadithiophene-Vinylene In Aromatic And Quinoidal Versions And Redox Species With Intermediate Forms, Paula Mayorga Burrezo, Rocío Domínguez, José L. Zafra, Ted M. Pappenfus, Pilar De La Cruz, Lorena Welte, Daron E. Janzen, Juan T. López Navarrete, Fernando Langa, Juan Casado

Daron E Janzen, Ph.D.

No abstract provided.


Offshore Wind Power: Can New Jersey Find A Place At The Table?, Jeremy Firestone Sep 2017

Offshore Wind Power: Can New Jersey Find A Place At The Table?, Jeremy Firestone

Sustainability Seminar Series

NJ enacted an offshore renewable energy certificate (OREC) law in 2010. It was thought that the OREC law would usher in a new era for New Jersey, with it enjoying clean, carbon-free renewable offshore wind energy. Offshore wind development, however, has so far been stalled in New Jersey. This presentation looks beyond past and existing conflicts with elected officials and regulators that has resulted in the OREC law effectively being sidelined to consider research that sheds light on public perceptions and de-conflicting uses with an emphasis on New Jersey, but as enlightened by broader research findings and trends.


Potential For Natural Evaporation As A Reliable Renewable Energy Resource, Ahmet-Hamdi Cavusoglu, Xi Chen, Pierre Gentine, Ozgur Sahin Sep 2017

Potential For Natural Evaporation As A Reliable Renewable Energy Resource, Ahmet-Hamdi Cavusoglu, Xi Chen, Pierre Gentine, Ozgur Sahin

Advanced Science Research Center

About 50% of the solar energy absorbed at the Earth’s surface drives evaporation, fueling the water cycle that affects various renewable energy resources, such as wind and hydropower. Recent advances demonstrate our nascent ability to convert evaporation energy into work, yet there is little understanding about the potential of this resource. Here we study the energy available from natural evaporation to predict the potential of this ubiquitous resource. We find that natural evaporation from open water surfaces could provide power densities comparable to current wind and solar technologies while cutting evaporative water losses by nearly half. We estimate up to …