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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

The distribution and morphology of Fucus distichus in an estuarine environment and the effect of selected ions on the uptake of inorganic carbon and nitrate

Robinson, Dale Howard 01 January 1983 (has links)
The morphology, distribution, and habitat of dwarf and normal forms of Fucus distichus in Nehalem Bay were examined. The dwarf form lacked the holdfast and sexual structures of the normal form and was more highly branched. Examples of the dwarf form were found growing as outgrowths of fragmented normal forms indicating that both forms are the same species. The normal form occurred attached to rocks near the mouth of the bay in waters of oceanic salinity. The dwarf form occurred as a free-living form in the salt marshes and in waters of lower salinity. These observations suggested that the occurrence of the dwarf form is related to salinity. Nutrient uptake studies with nitrate and carbon demonstrated that both forms have similar responses to changes in salinity. The dwarf form however, was better adaptated to the lower salinities than the normal form. Both forms showed a drop in carbon uptake and a slight rise in nitrate uptake as salinity was decreased, but the dwarf form maintained near maximal carbon uptake rates to a much lower salinity. It was shown that carbon uptake is sensitive to sodium and potassium ions, and nitrate uptake is sensitive to potassium ions. Reducing the sodium ion concentration by changing the medium composition decreased the carbon uptake rate. This rate was reduced further by the addition of potassium ion. The addition of sodium and potassium specific ionophores to the medium also depressed the uptake rate of carbon. Nitrate uptake was relatively unaffected by decreased sodium concentrations, but was drastically reduced by elevated potassium levels. The potassium specific ionophore valinomycin also produced a significant drop in the nitrate uptake rate. These data suggested that chemical potentials for sodium and potassium drive the uptake of carbon and that potassium is involved in the uptake of nitrate in F. distichus.
352

Experimental Studies of Barite Growth Using Hydrothermal Atomic Force Microscopy in Alkali Metal Salt Solutions at 108 C

Ahmed, Sohan 04 September 2019 (has links)
No description available.
353

Spectrophotometric Study of the Copper (II) Complexes of Alpha-Omega Diamino Adipic acid and Alpha-Omega diamino Pimelic acid

Hastings, Julius Caesar 01 January 1965 (has links) (PDF)
The chenistry of diamino dicarboxylic acids together with that of monoamino dicarboxylie and monocarboxylic acids in of great importance to the chemist because of the rolation- ship of these compounds to the biochemistry of cancer. Diamino dicarboxylic acids in general, contain two asymmetric carbon atoms and may exist in one optically inactive and two optically active forma. Alpha-omoga diamino pinolic acid is the only member of the alpha-omoga diamino dicarboxylic acids thus far known to occur naturally.
354

Subirrigation with brackish water.

Patel, Ramanbhai Motibhai. January 1997 (has links)
No description available.
355

Assessment of LEACHM-C model for semi-arid saline irrigation

Hagi-Bishow, Mohamed. January 1998 (has links)
No description available.
356

Use of time domain reflectometry to monitor water content and electrical conductivity of saline soil

Entus, Jonathan January 2000 (has links)
No description available.
357

Molecular Dynamics Simulation of transport and structural properties of molten reactor salts

Renganathan, Ananthi 04 October 2021 (has links)
No description available.
358

SYNTHESIS AND BIOLOGICAL EVALUATION OF IMIDAZOLIUM SALTS AS ANTI-CANCER AGENTS

Southerland, Marie R. 23 May 2018 (has links)
No description available.
359

Preparation and Characterization of Battery Salts and COF Electrodes for K-based Batteries

Schkeryantz, Luke 27 September 2022 (has links)
No description available.
360

Comparison of Cation-Anion Oxidizer Pairings in Electrically Controllable Solid Propellants

Sellards, Emily Rose 13 February 2024 (has links)
Electrically controllable solid propellants are an area of interest as a viable solution to the lack of throttle-ability in solid propellant rocket motors. Existing studies have focused on propellants compositions using hydroxyl-ammonium nitrate, ammonium nitrate, or lithium perchlorate as oxidizers. Additionally, the thermochemical and electrochemical reaction mechanisms have not yet been fully defined. The research in this thesis explores the nitrate and perchlorate oxidizer families to compare their cation-anion relationships. Using these oxidizers, pseudo electrically controllable solid propellant compositions were created with the addition of multi-wall carbon nanotubes to enhance ohmic heating capabilities. These additives were selected based on theory that with a non-complexing polymer, an oxidizer melt layer is required for ions to dissociate and electrically controlled ignition to occur. Using an applied voltage, ignition delay and current draw experiments were performed to expand on prior findings that ignition delay follows oxidizer melt temperature while mobility is associated with the size of the ionic radii. Additionally, neat oxidizer pellets were electrically decomposed to determine their linear regression rate. These results help to characterize the mechanism of reaction. This advances the knowledge of oxidizers in electrically controllable applications. / Master of Science / Solid propellant rocket motors have been extensively studied and used in both space and military applications because they do not use air as the source of oxygen. Their main limitation is the lack of throttle-ability, or inability to control propellant burning. This is because solid propellants, which are generally composed of an ionic oxidizer salt, a polymer fuel, and additives, are pre-combined and stored within the rocket motor. An emerging viable solution to this limitation is electrically controllable solid propellants. With an applied voltage, the oxidizer is heated and melts, allowing ions to dissociate and current to flow between electrodes. This reaction can then be controlled by turning the power supply on and off. Cations, or ions which have a net positive charge, move to the negatively charged cathode while anions, which have a net negative charge, move to the negatively charged anode. The research in this thesis explores different cation-anion oxidizer pairings using both a propellant composition and as a pure oxidizer under an applied voltage. The results help to characterize the mechanism of reaction of each oxidizer in an electrically controllable context and determine their effectiveness in these propellant applications.

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