Digital Commons Network^™

Radar Signal Delay In The Dvali-Gabadadze-Porrati Gravity In The Vicinity Of The Sun, Ioannis Haranas, Omiros Ragos, Ioannis Gkigkitzis

Physics and Computer Science Faculty Publications

In this paper we examine the recently introduced Dvali-Gabadadze-Porrati (DGP) gravity model. We use the space time metric in which the local gravitation source dominates the metric over the contributions from the cosmological flow. Anticipating ideal possible solar system effects we derive expressions for the signal time delays in the vicinity of the sun, and for various angles of the signal approach. We use the corresponding numerical value for the parameter r₀ to be equal to 5 Mpc, and from that we calculate that the time contribution due to DGP correction to the metric is proportional to b^{3/2 …}

Laboratory Methods For The Advancement Of Wastewater Treatment Modeling, Holly E. Gray

Theses and Dissertations (Comprehensive)

To achieve the low levels of total phosphorus required in wastewater treatment plant effluent all chemical forms of phosphorus should be removed. The most refractory phosphorus in terms of removal is so-called “organic phosphorus”. This thesis explores potential relationships between dissolved organic matter and organic phosphorus and methods of removing organic phosphorus from waste water. Fluorescence spectroscopy will be used to characterize dissolved organic matter (DOM) in wastewater. The fluorescent DOM will then be monitored throughout the various wastewater treatment plants to investigate any changes throughout the treatment train. Correlations between fluorophore concentrations (concentrations determined for the different classifications of …

Density Functional Theory Calculations On Hydrated Dimethylarsinic Acid And Iron Oxide Clusters, Adrian Adamescu

Theses and Dissertations (Comprehensive)

Dimethylarsinic Acid (DMA) or (CH₃)₂AsO₂H is an important organoarsenical compound detected in arsenic speciation studies of environmental samples and synthesized during pyrolysis of oil shale. DMA was used historically as a herbicide on large agricultural fields and can be detected in the leachates of landfills rich in waste containing arsenic such as glass, alloys, and semiconductors, as well as biologically pre-treated municipal solid waste. Under certain soil conditions DMA can become bio-available and has the potential to be recycled to more toxic inorganic forms of arsenic. Bioavailability of DMA is largely controlled by the …

Characterizing Dissolved Organic Matter And Cu2+, Zn2+, Ni2+, And Pb2+ Binding In Salt Water And Implications For Toxicity, Rachael L. Diamond

Theses and Dissertations (Comprehensive)

The binding of metal to dissolved organic matter in aquatic environments is important in controlling the bioavailability and potential toxicity of metals such as Zn²⁺, Pb²⁺, Ni²⁺ and Cu²⁺. The purpose of this research is to: (i) quantify binding capacity to different sources of marine organic matter at environmentally relevant concentrations; (ii) test fluorescence quenching and voltammetric method for use in seawater conditions and; (iii) compare predicted speciation parameters with toxicological observations in the same samples.

Information regarding the solubility of copper and copper compounds is important for risk assessment and can be …

Synthesis And Investigation Of The Liquid Crystalline Properties Of Polycyclic Aromatic Hydrocarbons, Joseph A. Paquette

Theses and Dissertations (Comprehensive)

In this thesis, the synthesis and liquid crystalline properties of a series of novel substituted dibenz[a,c]anthracenes is reported. Specifically, a series of hexaalkoxydibenz[a,c]anthracenes were prepared and found not to exhibit a mesophase. In contrast, when substituents are introduced on the aromatic core, columnar mesophases are observed over broad temperature ranges. A series substituted derivatives was prepared and their mesomorphic properties compared. In general, electron-withdrawing substituents promote broad mesophase temperature ranges, as do larger substituents. The liquid crystalline phase is a result of the electronic effects, size and shape of the substituents in the 10 and 13 positions.

We also synthesized …

Atr-Ftir Studies On The Kinetics Of Dimethylarsinic Acid (Dma) Surface Complexation With Iron(Oxyhydr)Oxides, Julia Tofan-Lazar Miss

Theses and Dissertations (Comprehensive)

Dimethylarsinic acid (DMA) is an organoarsenical compound that, along with monomethylarsonic acid, poses a health and an environmental risk, and a challenge to the energy industry. Little is known about the surface chemistry of DMA at the molecular level with materials relevant to geochemical environments and industrial sectors. The surface chemistry of phosphorus and arsenic compounds in their organic and inorganic forms is of great interest due to its role in controlling their transport, bioaccessibility and speciation. This thesis reports the first in-situ and surface-sensitive rapid kinetic studies on the adsorption and desorption of DMA to and from Fe-(oxyhydr)oxide films …

Shoreline Changes In Point Pelee, Canada: An Airphoto-Based Analysis, Abdullah Bamasoud

Theses and Dissertations (Comprehensive)

Shoreline retreat has significant consequences for Point Pelee National Park’s (PPNP) ecological and economic systems. In this study, the shoreline changes of PPNP are examined in terms of their rates, their relationship to natural and anthropogenic influences, and methods for predicting shoreline positions.

The rates of shoreline change are analyzed for the period 1959-2004 using ortho-airphotos. The eastern shoreline of the Park exhibited varying recession in both rising and falling Lake Erie water level, especially in the Northeast Beach, where it averaged -3.14 m˖y-1. The western shoreline of the Park generally exhibited accretion and had an inverse relationship with Lake …