The effect of weathering processes on the vertical turbulent dispersion characteristics of crude oil spilled on the sea

Since the Exxon Valdez accident in 1987, renewed interest has come forth to better understand and predict the fate and transport of crude oil lost to marine environments. The short-term fate of an Arabian Crude oil was simulated in laboratory experiments using artificial seawater. The time-dependent changes in the rheological and chemical properties of the oil under the influence of natural weathering processes were characterized, including dispersion behavior of the oil under simulated ocean turbulence. Methodology included monitoring the changes in the chemical composition of the oil by Gas Chromatography/Mass Spectrometry (GCMS), toxicity evaluations for the oil dispersions by Microtox analysis, and quantification of dispersed soluble aromatics by fluorescence spectrometry. Results for this oil show a sharp initial increase in viscosity, due to evaporative losses of lower molecular weight hydrocarbons, with the formation of stable water-in-oil emulsions occurring within one week. Toxicity evaluations indicate a decreased EC-50 value (higher toxicity) occurring after the oil has weathered eight hours, with maximum toxicity being observed after weathering seven days. Particle charge distributions, determined by electrophoretic techniques using a Coulter DELSA 440, reveal that an unstable oil dispersion exists within the size range of 1.5 to 2.5 um, with recombination processes being observed between sequential laser runs of a single sample.

Gulf Oil Spill Teach-In, May 15,2010

Panel discussion on the subject of the Deepwater Horizion oil spill on the Gulf Coast,held at Florida International University Biscayne Bay Campus Wolfe University Center Ballroom on May 15, 2010. Panelists included FIU Interim Provost and Executive Vice President Douglas Wartzok, School of Environment and Society director Michael Heithaus, executive director of the Applied Research Center John Proni, Biological Sciences professor James Fourqurean, Chemistry and Biology professor Piero Gardinali, Management and International Business clinical professor Edward Glab, and Geology professor Grenville Draper.

Enhanced zinc oxide and graphene nanostructures for electronics and sensing applications

Zinc oxide and graphene nanostructures are important technological materials because of their unique properties and potential applications in future generation of electronic and sensing devices. This dissertation investigates a brief account of the strategies to grow zinc oxide nanostructures (thin film and nanowire) and graphene, and their applications as enhanced field effect transistors, chemical sensors and transparent flexible electrodes. Nanostructured zinc oxide (ZnO) and low-gallium doped zinc oxide (GZO) thin films were synthesized by a magnetron sputtering process. Zinc oxide nanowires (ZNWs) were grown by a chemical vapor deposition method. Field effect transistors (FETs) of ZnO and GZO thin films and ZNWs were fabricated by standard photo and electron beam lithography processes. Electrical characteristics of these devices were investigated by nondestructive surface cleaning, ultraviolet irradiation treatment at high temperature and under vacuum. GZO thin film transistors showed a mobility of ∼5.7 cm2/V·s at low operation voltage of <5 V and a low turn-on voltage of ∼0.5 V with a sub threshold swing of ∼85 mV/decade. Bottom gated FET fabricated from ZNWs exhibit a very high on-to-off ratio (∼106) and mobility (∼28 cm2/V·s). A bottom gated FET showed large hysteresis of ∼5.0 to 8.0 V which was significantly reduced to ∼1.0 V by the surface treatment process. The results demonstrate charge transport in ZnO nanostructures strongly depends on its surface environmental conditions and can be explained by formation of depletion layer at the surface by various surface states. A nitric oxide (NO) gas sensor using single ZNW, functionalized with Cr nanoparticles was developed. The sensor exhibited average sensitivity of ∼46% and a minimum detection limit of ∼1.5 ppm for NO gas. The sensor also is selective towards NO gas as demonstrated by a cross sensitivity test with N2, CO and CO2 gases. Graphene film on copper foil was synthesized by chemical vapor deposition method. A hot press lamination process was developed for transferring graphene film to flexible polymer substrate. The graphene/polymer film exhibited a high quality, flexible transparent conductive structure with unique electrical-mechanical properties; ∼88.80% light transmittance and ∼1.1742Ω/sq k sheet resistance. The application of a graphene/polymer film as a flexible and transparent electrode for field emission displays was demonstrated.

Synthesis and electron emission properties of aligned carbon nanotube arrays

Carbon nanotubes (CNTs) have become one of the most interesting allotropes of carbon due to their intriguing mechanical, electrical, thermal and optical properties. The synthesis and electron emission properties of CNT arrays have been investigated in this work. Vertically aligned CNTs of different densities were synthesized on copper substrate with catalyst dots patterned by nanosphere lithography. The CNTs synthesized with catalyst dots patterned by spheres of 500 nm diameter exhibited the best electron emission properties with the lowest turn-on/threshold electric fields and the highest field enhancement factor. Furthermore, CNTs were treated with NH3 plasma for various durations and the optimum enhancement was obtained for a plasma treatment of 1.0 min. CNT point emitters were also synthesized on a flat-tip or a sharp-tip to understand the effect of emitter geometry on the electron emission. The experimental results show that electron emission can be enhanced by decreasing the screening effect of the electric field by neighboring CNTs. In another part of the dissertation, vertically aligned CNTs were synthesized on stainless steel (SS) substrates with and without chemical etching or catalyst deposition. The density and length of CNTs were determined by synthesis time. For a prolonged growth time, the catalyst activity terminated and the plasma started etching CNTs destructively. CNTs with uniform diameter and length were synthesized on SS substrates subjected to chemical etching for a period of 40 minutes before the growth. The direct contact of CNTs with stainless steel allowed for the better field emission performance of CNTs synthesized on pristine SS as compared to the CNTs synthesized on Ni/Cr coated SS. Finally, fabrication of large arrays of free-standing vertically aligned CNT/SnO2 core-shell structures was explored by using a simple wet-chemical route. The structure of the SnO2 nanoparticles was studied by X-ray diffraction and electron microscopy. Transmission electron microscopy reveals that a uniform layer of SnO2 is conformally coated on every tapered CNT. The strong adhesion of CNTs with SS guaranteed the formation of the core-shell structures of CNTs with SnO2 or other metal oxides, which are expected to have applications in chemical sensors and lithium ion batteries.

The effects of Chinese painting appreciation education on the artistic achievement of junior high school students in Taiwan

For the Chinese, fine art is one of the most important items in human life. The goals of fine arts education enhance the student so that s/he can make reasonable judgments about work, gain knowledge of color and understand the process of designing environmental layouts. Related technique and creativity training are offered students in accordance with individual differences and social expectations.^ Traditionally, Taiwan's junior high school fine art program teaches mainly painting technique. The Ministry of Education in Taiwan determines the curriculum of junior high school fine art education. The purpose of this study was to determine the effects of teaching Chinese painting appreciation on the artistic achievements of junior high school students in Taiwan. The subjects were seventh grade students who had never learned Chinese painting before. Two classes were randomly chosen from each target school and were designated as the experimental or control group. Instruction in all groups was delivered by the researcher himself. At the end of the study, data about subjects' related knowledge, creative technique, and feeling toward Chinese painting were systematically collected and analyzed.^ The result of the study was that students in the experimental group were more motivated to learn Chinese painting than were the students in the control group. Students in the experimental group made better progress in the development of creative skill, had better critical ability, and demonstrated better performance in Chinese painting form, set up, stroke and color of related knowledge than did students in the control group. It was therefore concluded that Chinese painting appreciation education can promote better artistic achievement and that this approach should be used in other areas of art education. ^

Fat Absorption in Commercial French Fries Depending on Oil Type and Coating

This study examines the effect of edible coatings, type of oil used, and cooking method on the fat content of commercially available French fries. In contrast to earlier studies that examined laboratory prepared French fries, this study assesses commercially available French fries and cooking oils. This study also measured the fat content in oven baked French fries, comparing the two cooking methods in addition to the comparisons of different coatings’ oil uptake. The findings of this study were that the type of oil used did have a significant impact on the final oil content of the uncoated and seasoned fries. The fries coated in modified food starch and fried in peanut and soy oils had what appeared to be significantly higher oil content than those fried in corn oil or baked, but the difference was not statistically significant. Additionally, fat content in French fries with hydrocollidial coatings that were prepared in corn oil were not significantly different than French fries with the same coating that were baked.

Effects of resource limitation on the essential oil production in Ledum palustre ssp decumbens (Ait.) Hultén

To understand the relationship between resource limitation and essential oil production of the widely-distributed boreal/arctic shrub, Ledum palustre ssp decumbens, I documented naturally occurring variation of essential oils over a growing season withfield collections along a latitudinal transect spanning boreal forest to arctic tundra. Collections from a long-term resource manipulation experiment at a single tundra site served as a means of teasing apart those factors that might be influencing the essential oil production of the species. The essential oil composition varied significantly along thetransect in the number of detectable components, but the relationships among resources and essential oil production were complex. In the manipulation experiment, essential oil components varied greatly among the treatments, with significant differences in the qualitative expression of the specific essential oil components. Both studies suggest that future climate changes have the potential for large changes in production and quality of essential oils.