Petroleum hydrocarbon (PHC) contamination poses a serious threat to aquifer systems worldwide. Accidental releases of PHCs due to gasoline spills and leakage from underground storage tanks can often result in PHC subsurface contamination. The main compounds of concern associated with gasoline spills are benzene, toluene, ethylbenzene and xylenes (BTEX), trimethylbenzenes (TMBs) and naphthalene, due to their high mobility and potential human health risks. Sodium persulphate is one of the newest oxidants to gain widespread use for in situ chemical oxidation (ISCO), however its effectiveness in treating PHCs is not fully understood. In this study, the ability to use unactivated sodium persulphate as a remediation tool in treating dissolved and residual BTEX contamination was tested during a bench-scale laboratory study and within a pilot-scale field investigation. In both cases unactivated sodium persulphate was used at a concentration of 100 g/L. A laboratory-scale degradation potential batch test was conducted to assess the efficacy of unactivated sodium persulphate to oxidize petroleum hydrocarbon contaminated groundwater in conjunction with aquifer material from a field site. Data from the control reactions indicated that persulphate was stable for the entire 35-day experimental period and that the decrease in PHC concentrations for most of the samples followed a first-order degradation. The behaviour and ability for sodium persulphate to oxidize dissolved and residual BTEX contamination was further evaluated in a controlled pilot scale field study. 200 kg of sodium persulphate was dissolved in 2000 L of water and injected into the subsurface. Electrical conductivity (EC), pH, sodium, persulphate, sulphate and BTEX concentrations were all monitored throughout the 158-day study period. Field research showed that there was a strong correlation between EC and sodium concentrations. Hence, this relationship allowed for real-time EC measurements to be used to effectively predict the extent of the injectate. Based on the calculated aqueous density of sodium persulphate at a concentration of 100g/L, predicted simulation model results and observed tracer field results, density effects were present and played a very important role in the transport of the injectate. The heterogeneous geology of the site also greatly influenced the transport of the injectate. The majority of the injectate appeared to have flowed out of the layers with higher hydraulic conductivity that intersected the upper and lower portion of the injection well’s screen length. The extent of the injected slug in the layers with lower hydraulic conductivity located in the centre portion of the injection well’s screen length was less in comparison. In general, areas with elevated tracer, persulphate and sulphate concentrations, also showed a decrease in BTEX concentration. Four main responses were observed. Group 1 consists of sampling points where tracer levels were elevated along with a corresponding short-term decrease in dissolved BTEX. Group 2 consists of sampling points where elevated tracer levels was observed along with a long-term apparent decrease in dissolved BTEX. Group 3 consists of sampling points where the tracer was elevated however dissolved BTEX levels remained essentially at background levels. And finally, group 4 consists of sampling points where the tracer was not observed to be elevated hence no decrease in dissolved BTEX was observed. Laboratory studies showed that the oxidation of BTEX compounds by unactivated sodium persulphate could be very successful. However, field study results showed that complexities such as heterogeneity of the field site and injectate density effects play a key role in the success of the remediation system.

Visible and near infrared diffuse reflectance spectroscopy (VisNIR-DRS) is a method being investigated for quantifying soil properties and mapping soil profiles. Because a VisNIR-DRS system mounted in a soil penetrometer is now commercially available for scanning soil profiles in situ, methodologies for using scans to map soils and quantify soil properties are needed. The overall goal of this research is to investigate methodologies for collecting and analyzing VisNIR-DRS scans of intact soil profiles to identify soil series. Methodologies tested include scanning at variable versus uniform moistures, using individual versus averaged spectra, boosting an intact spectral library with local samples, and comparing quantitative and categorical classifications of soil series. Thirty-two soil cores from two fields, representing three soil series, were extracted and scanned every 2.5 cm from the soil surface to 1.5 m or to the depth of parent material at variable field moist conditions and at uniform moist condition. Laboratory analyses for clay, sand, and silt were performed on each horizon. Soil series were classified using partial least squares regression (PLS) and linear discriminant analysis (LDA). A Central Texas intact spectral library (n=70 intact cores) was used for PLS modeling, alone and boosted with the two fields. Because whole-field independent validation was used, relative percent difference (RPD) values were used to compare model performance. Wetting soils to uniform moisture prior to scanning improved prediction accuracy of total clay and RPD improved by 53 percent. Averaging side-by-side scans of the same soil profile improved prediction accuracy of RPD by 10 percent. When creating calibration models, boosting a library with local samples improved prediction accuracy of clay content by 80 and 34 percent for the two fields. Principal component plots provided insight on the spectral similarities between these datasets. Overall, using PLS alone performed the same as LDA at predicting soil series. Most importantly, results of this project reiterate the importance of fully-independent calibration and validation for assessing the true potential of VisNIR-DRS. Using VisNIR-DRS is an effective way for in situ characterization and classification of soil properties.

Two mechanisms appear to be primarily responsible for the formation of cirrus clouds in Tropical Tropopause Layer (TTL): detrainment from deep convective anvils and in situ initiation. Here we propose to identify TTL cirrus clouds by analyzing water content measurements from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and Aura Microwave Limb Sounder (MLS). Using ice water content (IWC) and water vapor (H2O) abundances we identify TTL cirrus clouds that contain too much ice to have been formed in situ — and therefore must be of convective origin. We use two methods to infer amounts of water vapor available for in situ formation. Clouds with IWC greater than this threshold are categorized as being of convective origin; clouds with IWC below the threshold are ambiguous — they could either form from in situ or still be of convective origin. Applying the thresholds from December 2008 to November 2009, we found that at least 19.2% of tropical cirrus were definitively of convective origin at the tropopause (375 K) during boreal winter. At each level, we found three maxima in the occurrence of convective cirrus: western Pacific, equatorial Africa, and South America. Averaged over the entire tropics (30oS to 30oN), we found convective cirrus occurs more frequently in boreal winter and less frequently in boreal summer, basically following the a decreasing trend from DJF, MAM, SON, to JJA. During boreal summer, we found that only 4.6% of tropical cirrus come from convection. Sensitivity tests show that the thresholds derived at 390 K have the largest uncertainty. At lower levels, especially 375 K, our thresholds are robust.

Diversion in carbonates is more difficult than in sandstones because of the ability of acid to significantly increase the permeability in carbonates as it reacts in the pore spaces and flow channels of matrix. In-situ gelled acids that are based on polymers have been used in the field for several years and were the subject of many lab studies. An extensive literature survey reveals that there are conflicting opinions about using these acids. On one hand, these acids were used in the field with mixed results. Recent lab work indicated that these acids can cause damage under certain conditions. There is no agreement on when this system can be successfully applied in the field. Therefore, this study was conducted to better understand this acid system and determine factors that impact its performance. Lab test of polymer-based in-situ gelled acids reveal that polymer and other additives separate out of the acid when these acids are prepared in high salinity water. In coreflood tests, in-situ gelled acid formed a gel inside 20” long core samples, and the acid changed its direction several times. Unexpectantly, the core's permeability was reduced at low shear rate. Wormhole length increased as the shear rate was increased; while the diameter of the wormhole increased as the acid cumulative injected volume was increased. CT scan indicated the presence of gel residue inside and around the wormhole. Gel residue increased at low shear rates. Material balance on the cross-linker indicated that a significant amount of the crosslinker was retained in the core. Based on the results obtained from this study the in-situ gelled acids should be used only at low HCl concentrations (5 wt percent HCl). Acid should be prepared in low salinity water and the acid injection rate should be determined based on the expected shear rate in the formation. A core flood experiment is recommended to confirm optimum injected rate. Well flow back is needed to minimize the residual gel inside the formation. The data obtained in this study can be used as a guideline for injection rate selection.

Iridovirus infections have led to serious economic loss in the aquaculture industry in Kaohsiung County as well as the whole Southern Taiwan region. Identified susceptible host species in this region includes hybrid grouper (Epinephelus hybrid), giant seaperch (Lates calcarifer), largemouth bass (Micropterum salmoides), king grouper (Epinephelus lanceolatus), spotted butter fish (Scatophagus argus), yellow-wax pomfrat (Trachinotus blochii), goldlined seabream (Sparus sarba), humpback grouper (Chromileptes altivelis), Mangrove red snapper (Lutjanus argentimaculatus). In this study, a diagnostic PCR primer pair CY15n-F/CY15nR, and its nested primer pair RY16-F/RY16-R, were designed and applied to amplify virus-specific products of 1339 bp and 305 bp, respectively. This primer set did not amplify products from lymphocystis disease virus, largemouth bass virus, or healthy control fish DNA. This sensitive technique can detect the presence of 50 fg plasmid with viral DNA insert in the presence of 100 ng/£gl host DNA, or 0.05 fg DNA from infected fish. Comparing sequences of CY15 fragment, ATPase gene, predicted major capsid protein and partial DNA polymerase genes among iridoviruses, it is suggested that the viruses found in this area should be classified as the Megalocytivirus of Iridoviridae. These viruses are clearly different from the Ranavirus, another fish-pathogenic iridovirus. Those iridoviruses can be classified into two genotypes: the CY630 type, which is the Taiwan grouper iridovirus; and the CY113 type, which is similar to red seabream iridovirus (RSIV). The identity in CY15 fragment sequences is about 91%. Microscopically, enlarged cells can be found in organs of infected fishes. They appear in the spleen, head kidney, and trunk kidney in infected groupers. The enlarged cells may be relocated from other organs. In giant seaperch, the enlarged cells appeared in the above mentioned organs, and also in the digestive tract and the heart. Two kinds of the enlarged cells in grouper can be distinguished by their H&E staining properties: the basophilic and the eosinophilic enlarged cells. The result from in situ hybridization and electron microscopy suggest that the viruses only appear in the basophilic enlarged cells. Both nucleus and cell volume increase in basophilic enlarged cells, while only the cell volume increases in the eosinophilic enlarged cells. The viruses appeared first in the nuclei of the basophilic enlarged cells, after the mid-phase of the infection they distributed into the whole cells. Judging from the results of phagocytosis, acid phosphatase activity and the ultrastructure of infected cells, it is suggested that this target cell is macrophage or monocyte. The viral capsid is assembled in the viromatrix, and the virogenic stroma can be either ring-shped or disc-shaped. The diameter of mature virus is 120-130 nm from side to side, or 160-170 nm from apex to apex. The electron-lucent space between the capsid and the envelope is about 20-50 nm. The virus particles can be found in (1) lysosome-like vesicles in the cytoplasm, if the host cell still has its nucleus; or (2) the viromatrix, When the host nucleus is dissolved or only has some vestige nuclear membrane left.

The sponge Cinachyrella australiensis (Demospongiae: Spirophorida) is widely distributed in Indian ocean, West Pacific ocean, and Australian waters. It also can be found in the intertidal pools of Wun-Li-Ton in southern Taiwan. The sponge can propagate asexually by budding. According to the previous studies, this sponge was suspected to be symbiotic with sulfur-oxidizing chemoautotrophic bacteria. How the generation do obtain this symbiont is still unknow. In this study, PCR was used to amplify the DNA extracted from buds and sponges to obtained the 16S rDNAs. A total of 20 clones from each bud and mature sponge samples were randomly selected and sequenced. The results indicated that the major symbiotic bacteria constitute 65¢H of the clones derived form the mature sponge and 15¢H from the buds. The dominant symbionts contain RubisCO gene and are related to the sulfur-oxidizing chemoautotrophic bacteria, associated with the tube worms of the deep sea hydrothermal vents. The location of the sulfur-oxidizing chemoautotrophic bacteria was observed by fluorescence in situ hybridization (FISH). It was found that the sulfur-oxidizing chemoautotrophic bacteria were intracellular symbiosis within the cells of cortex, archaeocytes of mesoglial, and bud. Similar results were also observed at the junction of a developing bud and mature sponge. Apparently, the symbionts are transmitted from sponge to bud vertically. Furthermore, in this study, we also found several other intracelluar symbionts besides the major symbiotic bacterium,some of them are autotrophic in nature.

Chlorinated organic compounds are widely used in various industrial processes. Due to their high density and low water solubility, they are mainly utilized as cleaning solvents in dry cleaning operations, as well as semiconductor manufacturers. Many chlorinated organic compounds spilled sites contain residuals, which present in a pure liquid phase (dense non-aqueous phase liquids, DNAPLs). Trichloroethylene (TCE) is the most typical compound as a result. In situ bioremediation has been successfully used for the removal of TCE. This process has several advantages, such as relative simplicity, low cost, and potentially remarkable efficiency in contamination removal than others. By using the in situ bioremediation to remediate TCE contaminated groundwater, it must ensure (1) biodegradability of contaminants, and the presence of a competent biodegrading population of microorganisms, (2) presence of electron acceptors, and (3) environment condition and, nutrient sources. A field study for biodegradation TCE through molasses injection was conducted at the industrial trading estate in Kaohsiung City. The study included electronic products, semiconductor, nicety optical industry and so on. Molasses, nitrate and phosphate were introduced from injection well (BW1-1 and BW2-1) into aerobic and anaerobic groundwater contaminated site. In the aerobic zone, there were four wells being monitored: BW1-1, C029, BW1-2 and BW1-3. After 213 days of biostimulation treatment, TCE concentration detection results showed TCE concentrations in all wells monitored. BW1-1 and C029, there was a sharp decrease from 0.0853 mg/L to below the detection limit and from 0.1340 mg/L to 0.0038 mg/L. BW1-2 and BW1-3 showed a slight decrease from 0.0668 mg/L to 0.0211 mg/L and from 0.0323 mg/L to 0.0161 mg/L. After treatments, TCE concentrations in all wells monitored were dropped to 0.05 mg/L. In anaerobic zone, there were four wells being monitored: BW2-1, SW-4, BW2-2 and BW2-3. After 193 days of biostimulation treatment, TCE concentration detection results showed TCE concentrations in all wells monitored. BW2-1, SW-4, BW2-2 and BW2-3 all had a slight decrease from 0.0399 mg/L to 0.0043 mg/L, from 0.14603 mg/L to 0.0687 mg/L, from 0.1030 mg/L to 0.0365 mg/L and from 0.0492 mg/L to 0.0289 mg/L. According to the results from BIOCHLOR modeling, elevated aqueous concentration of chloroethenes with a classical reduction pathway for TCE leading to an accumulation of vinyl chloride and ethane. All the results revealed that bioremediation technology is one of the more feasible approaches to clean up TCE contaminated groundwater in this field.

Reactive Sputtering is a widely used technique in processing of thin compound films. Such films can be sputtered from metal targets, which are comparatively cost efficient. Also the fact that sputtering from metal targets can ccur in the dc mode reduces the cost of the sputtering equipment. To keep the deposition process stable, its necessary to know the effects of target poisoning including its hyteresis behavior. The aim of this work was to nvestigate the evolution of reactive gas coverage on a titanium magnetron target surface, by real time, in-situ ion beam analysis during magnetron sputtering. A cylindrical 2 inch magnetron was used for reactive sputtering of TiN. It was operated in an Ar/N2 gas mixture at achamber pressure of about 3∙10-3 mbar. The argon/nitrogen flux ratio was variated between 0 and 20%. The nitrogen concentration on the target was determinated using the 14N(d, α)12C, nuclear reaction at a deuterium beam energy of 1.8 MeV. Depending on the adjusted nitrogen flow the target incorporation varies between 0 and about 1∙1016 N∙cm-2. Further the expected hysteresis behaviour ofnitrogen partial pressure, target voltage and nitrogen concentration at increasing/decreasing nitrogen gas flow is confirmed. The lateral distribution of nitrogen was measured across the diameter of target surface. In the zone of higher erosion (the \"race track\") the nitrogen concentration is 50% lower than in the middle or the edge of the target. A deposition zone in the center of the target could not be detected. By increasing the nitrogen flow into the chamber a saturation in nitrogen content in the target was found at an Ar/N2 flow ratio of about 10%. Assuming nitrogen implantation with a depth of 2.5 nm under the influence of typical target voltage during magnetron sputtering, this saturation is at a concentration value where stoichiomtric TiN is formed. Within the precision of the measurements, a mobile fraction of nitrogen could not determined. The concentration in the target remains unchanged after switching off the magnetron.

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. David Balkwill, Florida State University, School of Arts and Sciences, Dept. of Oceanography. Title and description from dissertation home page (viewed Apr. 7, 2004). Includes bibliographical references.

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 78-89).