Digital Commons Network^™

Spatiotemporal Distribution Of Marine Magnetotactic Bacteria In A Seasonally Stratified Coastal Salt Pond, S. L. Simmons, S. M. Sievert, Richard B. Frankel, Dennis A. Bazylinski, K. J. Edwards

Physics

The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. The distributions of these groups displayed sharp changes in abundance over small length scales within the water column as well as strong seasonal fluctuations in population abundance. We identified a novel, greigite-producing rod in the sulfidic hypolimnion …

Nitrogen Isotope Dynamics Of The Cariaco Basin, Venezuela, Robert C. Thunell, Daniel M. Sigman, Frank E. Muller-Karger, Yrene Astor, Ramon Varela

Marine Science Faculty Publications

We report ¹⁵N/¹⁴N measurements of water column nitrate and ammonium, sinking particles, and sediments from the Cariaco Basin, an anoxic marine basin off the coast of Venezuela. Water column denitrification occurring in the basin has only a very small isotopic imprint on nitrate in the basin because nitrate consumption is nearly complete in the actively denitrifying water near the oxic/anoxic interface (∼275 m). Being free of a large denitrification signal, the δ¹⁵N of shallow thermocline nitrate is ∼3.5‰, significantly lower than the mean deep ocean nitrate δ¹⁵N of 5‰. This may be due …

Tracing The Source Of The Elephant And Hippopotamus Ivory From The 14th Century B.C. Uluburun Shipwreck: The Archaeological, Historical, And Isotopic Evidence, Kathryn Anne Lafrenz

USF Tampa Graduate Theses and Dissertations

The aim of this study is to establish the provenance of the elephant and hippopotamus ivory recovered from the 14th century B.C. Uluburun shipwreck in order to reconstruct the trade mechanisms and associated social relationships (e.g. diplomacy) operating in the eastern Mediterranean during the Late Bronze Age (LBA). Elephant ivory came either from Northeastern Libya, Southeastern Sudan via Egypt or northwestern Syria during this period. Hippopotamus ivory likewise was obtained from Syria, Palestine, or Egypt.

The Uluburun's cargo is reconstructed by the excavator, George Bass, as "royal," and primarily originates from Cyprus and Syro-Palestine. Indeed, LBA trade is largely understood …

Efforts Toward The First Enantioselective Total Synthesis Of Praziquantel And Synthetic Model Studies On Ecteinascidin 743 By Novel Aromatic C-H Insertion Methodology, Chiliu Chen

USF Tampa Graduate Theses and Dissertations

The thesis is composed of three chapters. The aim of this thesis is to apply the novel dirhodium perfluorobutyrate-catalyzed intramolecular aromatic C-H insertion methodology to the enantioselective total synthesis of praziquantel and synthetic model studies on ecteinascidin 743, which belongs to the important tetrahydroisoquinoline family.

The first introductory chapter deals with the biological significance and previous synthetic methodologies. Our novel methodology is based on dirhodium perfluorobutyrate-catalyzed intromolecular aromatic C-H insertion reaction, which is crucial in the pivotal carbon-carbon bond formation when constructing isoquinolone moiety, which is ubiquitous in numerous natural products of significant biological and pharmacological activities.

The second chapter …

Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 2. First Intercomparison Of Open-Path Ftir, Ptr-Ms, And Gc-Ms/Fid/Ecd, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wein Min Hao, T. Shirai, Donald R. Blake

Chemistry and Biochemistry Faculty Publications

No abstract provided.

Synthesis Of The Novel Crown Ether 1 ,9-Dioxa-4,6-Dithiacycloundecane, Cassie Booth

Capstone Research Projects

Attempts to produce novel crowns, incorporating a thioacetal fragment, were made via two synthetic pathways. Despite the well-established reactions found in path A (see figure 3), this method failed to produce the desired crown. Path B, a one-pot reaction originally designed to close rings via the addition of a thioacetal fragment, yielded an oily product that was purified with a silica gel column (48.3% yield). Initial analysis by 1H NMR showed a structure consistent with that of the desired crown (figure 2). Mass spectroscopy was used to verify product identity, confirming the creation of our target molecule 1 ,9-dioxa-4,6-dithiacycloundecane.

Merredin Townsite Groundwater Pumping And Desalination Pilot Project, Rosemary Nott, Mark Pridham, Juana Roe, Jeff Ibbott, Alan Leeson, A Leeson

Resource management technical reports

Townsite salinity affects more than 40 towns in the WA wheatbelt. Waterlogging and salinity are responsible for damamge to townsite infrastructure. Through groundwater pumping and desalination, the State Salinity Council (now the Natural Resource Management Council) granted Merredin the the chance to prevent further damage to the townsite by funding this project.

Uri Undergraduate And Graduate Course Catalog 2004-2005, University Of Rhode Island

URI Course Catalogs Archive

No abstract provided.

Determination Of Site Use As Inferred From The Lithics Data Of The Post Adandonment Occupation Of Housepit 7 At The Keatley Creek Site: Comparing Winter Village And Short-Term Camp Models, Andreì B. Jendresen

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.

Redox Reactions Of The Pyranopterin System Of The Molybdenum Cofactor, Sharon J. Nieter Burgmayer, Dori L. Pearsall, Shannon M. Blaney, Eva M. Moore, Calies Sauk-Schubert

Chemistry Faculty Research and Scholarship

This work provides the first extensive study of the redox reactivity of the pyranopterin system that is a component of the catalytic site of all molybdenum and tungsten enzymes possessing molybdopterin. The pyranopterin system possesses certain characteristics typical of tetrahydropterins, such as a reduced pyrazine ring; however, it behaves as a dihydropterin in redox reactions with oxidants. Titrations using ferricyanide and dichloroindophenol (DCIP) prove a 2e(-)/2H(+) stoichiometry for pyranopterin oxidations. Oxidations of pyranopterin by Fe(CN)(6)(3-) or DCIP are slower than tetrahydropterin oxidation under a variety of conditions, but are considerably faster than observed for oxidations of dihydropterin. The rate of …

Slurry Chemistry Effects On Copper Chemical Mechanical Planarization, Ying Luo

Electronic Theses and Dissertations

Chemical-mechanical Planarization (CMP) has emerged as one of the fastest-growing processes in the semiconductor manufacturing industry, and it is expected to show equally explosive growth in the future (Braun, 2001). The development of CMP has been fueled by the introduction of copper interconnects in microelectronic devices. Other novel applications of CMP include the fabrications of microelectromechanical systems (MEMS), advanced displays, three dimensional systems, and so on (Evans, 2002). CMP is expected to play a key role in the next-generation micro- and nanofabrication technologies (Singh, et al., 2002). Despite the rapid increase in CMP applications, the fundamental understanding of the CMP …

Electronic Structural Investigations Of Bi- And Polymetallic Complexes Using Quantum Mechanical Methods, Zakiya Sheni Wilson

LSU Doctoral Dissertations

Understanding the dynamics influencing chemical reactivity is essential for properly exploiting matter into more useful purposes. In that manner, computational chemistry is a tool frequently used to study chemical properties at the most intimate level, i.e. the single molecule.

With this work, we probe the chemistry governing a variety of multi-faceted bi- and polymetallic compounds. To date our research consists of four major projects: bimetallic rhodium-catalyzed hydroformylation and aldehyde-water shift hydrocarboxylation catalysis; a novel linear M-H-M interaction in a bridged bis(dialkylphosphino)methane complex of nickel; and CeBe₁₃, a heavy fermion conductor. Computational investigations on these systems allow us to …

Interaction Effects Of Slurry Chemistry On Chemical Mechanical Planarization Of Electroplated Copper, Peter A. Miranda, Jerome A. Imonigie, Amy J. Moll

Electrical and Computer Engineering Faculty Publications and Presentations

Recent studies have been conducted investigating the effects of slurry chemistry on the copper CMP process. Slurry pH and hydrogen peroxide concentration are two important variables that must be carefully formulated in order to achieve desired removal rates and uniformity. In applications such as throughwafer vertical interconnects, slurry chemistry effects must be thoroughly understood when copper plating thicknesses can measure up to 20 microns thick. The species of copper present on the surface of the wafer can be controlled through formulation of the slurry chemistry resulting in minimizing non-uniformity while aggressively removing copper. Using a design of experiments (DOE) approach, …

Boron Doped Nanostructured Diamond Films., Qi Liang

All ETDs from UAB

No abstract provided.

Development Of The Formal Reasoning Abilities Of College Students In A General Chemistry Guided-Inquiry Laboratory, Kereen Monteyne

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.

Analysis Of The Atmospheric Distribution, Sources, And Sinks Of Oxygenated Volatile Organic Chemicals Based On Measurements Over The Pacific During Trace‐P, H. B. Singh, L. J. Salas, R. B. Chatfield, E. Czech, A. Fried, J. Walega, M. J. Evans, B. S. Field, D. J. Jacob, D. Blake, Brian G. Heikes, R. Talbot, G. Sachse, J. H. Crawford, M. A. Avery, S. Sandholm, H. Fuelberg

Graduate School of Oceanography Faculty Publications

Airborne measurements of a large number of oxygenated volatile organic chemicals (OVOC) were carried out in the Pacific troposphere (0.1–12 km) in winter/spring of 2001 (24 February to 10 April). Specifically, these measurements included acetone (CH₃COCH₃), methylethyl ketone (CH₃COC₂H₅, MEK), methanol (CH₃OH), ethanol (C₂H₅OH), acetaldehyde (CH₃CHO), propionaldehyde (C₂H₅CHO), peroxyacylnitrates (PANs) (C_nH_2n+1COO₂NO₂), and organic nitrates (C_nH_2n+1ONO₂). Complementary measurements of formaldehyde (HCHO), …

Stormwater Diversion As A Potential Coastal Wetland Restoration Method, Jennifer Howard Woods

LSU Master's Theses

The Barataria-Terrebonne estuary has been eroding at a rate of up to 103.6 km2 yr-1 for several decades. If the current rate of loss is not reduced, an additional 2,550 km2 of coastal wetlands will be lost by the year 2050. Currently, stormwater in Terrebonne Parish is pumped into canals, ultimately discharging into the Gulf of Mexico. An opportunity exists to use this stormwater for wetland restoration; however, the ecological impacts of stormwater diversions on wetlands are unknown. The objectives of this project were to 1) to investigate the seed banks of a degraded marsh to determine if a viable …