Sulfur Dioxide (SO2) is a difficult air pollutant to characterize spatially since it is primarily emitted from a few point sources typically having tall stacks. A better comprehension of the behavior and advection of ambient SO2 in metro Atlanta will help in the interpretation of epidemiologic analyses as well as establish an understanding of the source contributions to ambient SO2 in Atlanta. The operation and SO2 emission characteristics of four coal-fired power plants and a coal-fired cement kiln, all of which lie in the vicinity of Atlanta, were examined. Data retrieved from three downtown Atlanta monitoring stations that record ambient SO2 concentrations were also examined. Trends from ambient SO2 data agree with emission trends from the four coal-fired power plants, suggesting that one or more of the power plants are contributing to the ambient SO2 in Atlanta. SO2 rose plots using concentration and wind direction data from downtown monitoring stations were developed to identify from which direction the elevated levels of ambient SO2 were originating. A strong peak in the northwest direction of Atlanta suggests that Plant Bowen, Plant McDonough, or Lafarge Building Materials may be contributing to high concentrations of ambient SO2 in Atlanta. Further analysis concluded that Lafarge was not a likely contributor to the northwest peak. The plumes of Plant Bowen and Plant McDonough were modeled using air parcel trajectories and the Gaussian dispersion model. The results suggest that, when the wind is blowing from the northwest direction, Plant McDonoughs plume is the primary contributor to the elevated levels of SO2 recorded by downtown Atlanta monitoring stations.

The purpose of this thesis is to describe the preliminary results from the investigation of shallow (<20m) hydrothermal vents with a total venting area of about 0.5 km2 off the eastern tip of Kueishantao Island. The chemical compositions of hot fluids, sediments and rocks as well as a continuous record of fluid temperature of a fumarole were measured in order to understand the venting process of hydrothermal fluids. The continuous temperature records show that the attainment of the maximum temperature of the hot fluids is related to the tidal cycle. The temperature variation seems to be associated with changes in the boiling point of seawater, which is affected by changes in water pressure. Such a correlation has not been reported in the literature. The hydrothermal fluids reach their highest temperature about 3.5 hours after each high tide, which is indicative of a shallow infiltration of seawater since the time it takes the boiling seawater to exit is so short. The hottest temperature recorded in our study area is 116¢J, while the lowest pH is 1.75, both a record in the world amid shallow hydrothermal systems. And, 1.75 is the lowest pH been reported on hydrothermal systems in the literature. At one point, the temperature recorder was covered with sand as a result of an encroaching typhoon. This suggests that the topography of the study area is susceptible to external forces. Based on salinity, the source of the hot fluids is taken to be ambient seawater, with no meteoric water from the islet involved. Concentrations of major ions in the hydrothermal fluids are almost the same as those in the ambient seawater. Mg is slightly enriched, however, which is unlike other hydrothermal fluids where, as reported elsewhere, Mg is generally lower because it replaces Ca in the bedrock. Low concentrations of Si in the studied fluids make for another distinct feature. Compared with other hydrothermal fluids in the world, the concentrations of Si in our study area are much lower, possibly on account of there being insufficient time for the rock to dissolve in the infiltrated seawater. Black and white smokers have widely been reported in the literature, but here are found heretofore unheard of yellow smokers as high as 6 meters. Other than one vent which emits liquid sulfur and forms a sulfur chimney, some vent sulfur from sulfur mounds. Still others are low- temperature vents which do not emit sulfur whatsoever. The most active venting activities are off the eastern tip of the islet. There are no other large reliefs associated with the hydrothermal activity, except for the chimney and a depression down to 35m deep. the chimney and a depression down to 35m deep. The composition of gravel on the seafloor is andesite, which is the same as the rock on the islet. The major composition of the sediments collected from the seafloor is sulfur, which is different from the sediments of the hydrothermal systems in the Okinawa Trough. The sulfur particles observed in this study originate from the fumaroles. Besides, sulfur balls the size of softballs and with distinct growth rings are found near some vents. The formation mechanism of these rings at this time, however, remains unclear. The bubbles from the vents are mostly made up of CO2, which is different from the composition of the shallow hot springs on the beach of Green islet. The 3He/4He of the emitted gas is high, this indicates that the gas may have originated from the mantle.

Immobilization and detoxification of chromium in the vadose zone is made possible by the existence of an effective reductant, SO2, that exists in a gaseous form at room temperature. Experimental studies were designed to characterize stoichiometry and kinetics of chromium reduction both in aqueous solutions at pH values near neutrality and in soil. First, batch experiments and elemental analyses were conducted to characterize the stoichiometry and kinetics of Cr(VI) reduction in water. The stoichiometric ratio of S(IV) removed to Cr(VI) removed ranged between 1.6 and 1.8. The overall reaction is believed to be the result of a linear combination of two reactions in which dithionate is an intermediate and sulfate is the stable oxidized product. The reaction was also rapid, with the half-time of about 45 minutes at pH 6 and about 16 hours at pH 7. A two-step kinetic model was developed to describe changes in concentrations of Cr(VI), S(IV), and S(V). Nonlinear regression was applied to obtain the kinetic parameters. The rate of reaction was assumed to be second-order with respect to [Cr(VI)] and first-order with respect to [S(IV)], and [S(V)]. The values for the rate coefficient for the first reaction (k1) were found to be 4.5 (?10%), 0.25 (?9.4%) (mM-2h-1) at pH 6 and 7, respectively. The values of the rate coefficient for the second reaction (k2) were 25 (?29%), 1.1 (? 30%) (mM-2h-1) at pH 6 and 7, respectively. The reaction rate decreased as pH increased. Experiments showed that the rate at pH 7 was lower than that at pH 6 by one order of magnitude. Second, batch experiments and elemental analyses were conducted to characterize the stoichiometry and kinetics of Cr(VI) reduction in soil. The stoichiometric ratio of S(IV) removed to Cr(VI) removed was almost 2, which is slightly higher than that for the reaction in water. This higher value may be due to S(IV) oxidation by soil-derived Fe(III). The reaction was rapid, with the half-time less than 2 minutes, which is faster than in water. The rate coefficients, k1 and k2, were 22 (?41%) and 13 (?77%) (M-2h-1), respectively.

Previous studies have indicated the level of total sulfur amino acids (TSAA) (methionine + cystine) is most limiting in practical diet formulations for hybrid striped bass (HSB), especially if animal feedstuffs are replaced with plant feedstuffs. Reduction of costly animal feedstuffs such as fish meal while maintaining adequate dietary levels of TSAA may enhance cost effectiveness of production. Therefore, this study, consisting of four separate feeding trials, investigated three different aspects of sulfur amino acid nutrition of HSB including: (1) the efficacy of crystalline methionine hydroxy analog (MHA) and liquid MHA (AlimetTM) relative to L-methionine in meeting the requirement for TSAA; (2) the cystine sparing value for methionine; and, (3) the influence of various sulfur amino acid supplements on ammonia excretion. During the feeding trials, juvenile HSB were fed various diets including a basal diet deficient in TSAA (0.33 or 0.51% of diet), and experimental diets supplemented on an equalsulfur basis with different levels of either L-methionine, AlimetTM or crystalline MHA. Diets containing TSAA at 1% of diet and different ratios of cystine to methionine (60:40, 55:45, 50:50, and 45:55) also were fed to re-evaluate sparing effects of cystine on methionine. During the ammonia excretion trial, HSB were fed diets containing either L-methionine,AlimetTM or crystalline MHA after which total ammonia nitrogen (TAN) excretion was determined 4 h postprandial. In trial 1, AlimetTM was 73% as effective in promoting growth as L-methionine at the same concentration while MHA was 83% as effective. In trial 3, fish fed AlimetTM at 1.25% of diet displayed similar growth performance as those fed TSAA at 1.0% of diet while weight gain of fish fed AlimetTM at 1% was only 58% of that displayed by fish fed TSAA at 1.0%. No significant differences in weight gain, feed utilization or survival were observed among fish fed diets containing various ratios of cystine to methionine although the diet with 60:40 cystine to methionine supported the lowest responses. Inclusion of MHA or AlimetTM did not affect TAN excretion of HSB. These findings will aid in refining diet formulations for HSB to ensure adequate sulfur amino acid nutrition.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 120-124). Also available on the Internet.

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Microbiology and Molecular Genetics." Includes bibliographical references (p. 89-98).

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 120-124). Also available on the Internet.

Thesis (Ph. D.)--Ohio state University, 1924. / Autobiography. "Reprinted from the Ohio journal of science, vol. XXVIII, no. 1, January, 1928." Bibliography: p. 38.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xviii, 218 p.; also includes graphics. Includes abstract and vita. Advisor: Jean Michael Guldmann, City and Regional Planning Graduate Program. Includes bibliographical references (p. 130-133).

Thesis--University of Florida, 1971. / Description based on print version record. Manuscript copy. Vita. Bibliography: leaves 173-190.