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Full-Text Articles in Life Sciences

The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White Oct 1990

The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White

OES Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and benzo[a]pyrene (B[a]P) are common in the water column and sediments of estuarine and coastal areas. The mud crab Rhithropanopeus harrisii was exposed to varying concentrations of Nap or B[a]P to determine the effects on reproductive success, embryological development, larval physiology and mortality. Nap and B[a]P decreased hatching success and prolonged embryological development. Both pollutants produced high abnormality frequencies for egg exposed larvae. Molt frequency and respiratory rates of larvae from non-exposed eggs were more chronically affected by these pollutants than were egg exposed larvae. The EC50 concentrations were determined for …


Naphthalenes Associated With Treated Wastewater Effluents In An Urban National Wildlife Refuge, John T. Tanacredi Ph.D. Feb 1990

Naphthalenes Associated With Treated Wastewater Effluents In An Urban National Wildlife Refuge, John T. Tanacredi Ph.D.

Faculty Works: CERCOM

Our coastal enviornments have become the invariable recipient of petroleum and petroleum wastes. Demands for petroleum products coupled with a lack of economic incentive to recycle waste oil, will increase the probability of greater concentrations of petroleum derived hyrdrocarbons entering our estuaries (CEQ Report, 1983).


Electron Stimulated Surface Chemistry, Miles J. Dresser Jan 1990

Electron Stimulated Surface Chemistry, Miles J. Dresser

Scanning Microscopy

When an electron beam of less than 1000 eV interacts with a surface layer a variety of phenomena may occur. In this paper I will discuss those interactions that lead to either chemical changes on the surface and/or desorption of species or fragments from the surface. Theoretical models of electron stimulated desorption, (ESD) will be presented, specifically the Menzel, Gomer, and Redhead model, the Knotek, Feibelman model and the Ramaker, White and Murday model. Experiments that display the angular distribution of the desorbing ionic or metastable fragments, (referred to as ESDIAD for Electron Stimulated Desorption: Ion Angular Distributions) are the …


Extracting Chemical Information From Auger Line Shapes, David E. Ramaker Jan 1990

Extracting Chemical Information From Auger Line Shapes, David E. Ramaker

Scanning Microscopy

We have developed a generally applicable, semi-empirical approach for quantitatively interpreting Auger line shapes. Detailed information on hybridization, electron delocalization and correlation, screening effects, bonding, and covalency can be obtained from the line shape. Methods for extracting the Auger line shape from the experimental data are briefly described. We summarize our recent results from the C KVV Auger line shapes of five different gas phase hydrocarbons (methane, ethane, cyclo-hexane, benzene, and ethylene), three solids (polyethylene, diamond, and graphite), and a molecularly chemisorbed system (ethylene/ Ni). The normal kvv component accounts for only about half of the total experimental KVV intensity …