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Sources of Ambient Sulfur Dioxide (SO₂) in the Metro Atlanta AreaLowe, Miranda Jeanne 09 April 2007 (has links)
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.
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Preliminary investigation of the hydrothermal activities off Kueishantao IslandKuo, Fu-Wen 13 September 2001 (has links)
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.
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Remediation of chromium(VI) in the vadose zone: stoichiometry and kinetics of chromium(VI) reduction by sulfur dioxideAhn, Min 15 November 2004 (has links)
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.
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Refined understanding of sulfur amino acid nutrition in hybrid striped bass, Morone chrysops (male symbol) x M. saxatilis (female symbol)Kelly, Mark Christopher 29 August 2005 (has links)
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.
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Diffusion of sulfur into natural diamond : characterization and applications in radiation detection /West, Matthew K. January 1999 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 120-124). Also available on the Internet.
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Diversity of chemosynthetic thiosulfate oxidizing bacteria from diffuse flow hydrothermal vents and their role in mercury detoxificationCrespo-Medina, Melitza. January 2009 (has links)
Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Microbiology and Molecular Genetics." Includes bibliographical references (p. 89-98).
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Diffusion of sulfur into natural diamond characterization and applications in radiation detection /West, Matthew K. January 1999 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 120-124). Also available on the Internet.
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Studies on elemental sulfur as a soil insecticideBulger, Jacob Work, January 1928 (has links)
Thesis (Ph. D.)--Ohio state University, 1924. / Autobiography. "Reprinted from the Ohio journal of science, vol. XXVIII, no. 1, January, 1928." Bibliography: p. 38.
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Dynamic analysis of sulfur dioxide monthly emissions in U.S. power plantsKim, Tae-Kyung, January 2004 (has links)
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).
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Reactions of reduced sulfur compounds with ozoneTuggle, Michael Larry, January 1971 (has links)
Thesis--University of Florida, 1971. / Description based on print version record. Manuscript copy. Vita. Bibliography: leaves 173-190.
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