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Watershed morphometric analysis of Wadi Baish Dam catchment area using integrated GIS-based approach
The integration of Remote Sensing (RS) and Geographic Information Systems (GIS) constitutes a powerful tool for the evaluation of watershed morphometric parameters. The benefits of this integration include saving time and effort as well as improving the accuracy of the analysis. Moreover, this technique is appropriate for describing the watershed and its streams. In this study, a detailed morphometric analysis of the Wadi Baish catchment area has been performed using the Shuttle Radar Topography Mission (SRTM). The performed morphometric analysis includes linear, areal, and relief aspects. The results of the morphometric analysis reveal that the catchment can be described as of eighth stream order and consists of an area of 4741.07 km2. Additionally, the basin is characterized by a relatively high mean value of bifurcation (4.012), indicative of the scarcity of permeable rocks with high slope in the area. This value of bifurcation ratio is consistent with the high drainage density value of 2.064 km/km2 and confirms the impermeability of the subsurface material and mountainous relief. The hypsometric integral of the catchment is 47.4%, and the erosion integral of the catchment is 52.6%, both were indications of a mature catchment area. 相似文献
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Corey A Cohn Christopher E Pedigo Shavonne N Hylton Sanford R Simon Martin AA Schoonen 《Geochemical transactions》2009,10(1):8-9
Background
Given the importance of highly reactive oxygen species (hROS) as reactants in a wide range of biological, photochemical, and environmental systems there is an interest in detection and quantification of these species. The extreme reactivity of the hROS, which includes hydroxyl radicals, presents an analytical challenge. 3'-(p-Aminophenyl) fluorescein (APF) is a relatively new probe used for measuring hROS. Here, we further evaluate the use of APF as a method for the detection of hydroxyl radicals in particle suspensions. 相似文献4.
Alexander Smirnov Douglas Hausner Richard Laffers Daniel R Strongin Martin AA Schoonen 《Geochemical transactions》2008,9(1):1-20
Experiments with dinitrogen-, nitrite-, nitrate-containing solutions were conducted without headspace in Ti reactors (200°C), borosilicate septum bottles (70°C) and HDPE tubes (22°C) in the presence of Fe and Ni metal, awaruite (Ni80Fe20) and tetrataenite (Ni50Fe50). In general, metals used in this investigation were more reactive than alloys toward all investigated nitrogen species. Nitrite and nitrate were converted to ammonium more rapidly than dinitrogen, and the reduction process had a strong temperature dependence. We concluded from our experimental observations that Hadean submarine hydrothermal systems could have supplied significant quantities of ammonium for reactions that are generally associated with prebiotic synthesis, especially in localized environments. Several natural meteorites (octahedrites) were found to contain up to 22 ppm Ntot. While the oxidation state of N in the octahedrites was not determined, XPS analysis of metals and alloys used in the study shows that N is likely present as nitride (N3-). This observation may have implications toward the Hadean environment, since, terrestrial (e.g., oceanic) ammonium production may have been supplemented by reduced nitrogen delivered by metal-rich meteorites. This notion is based on the fact that nitrogen dissolves into metallic melts. 相似文献
5.
Corey A Cohn Shawn C Fisher Bruce J Brownawell Martin AA Schoonen 《Geochemical transactions》2010,11(1):2
Cellular exposure to particulate matter with concomitant formation of reactive oxygen species (ROS) and oxidization of biomolecules
may lead to negative health outcomes. Evaluating the particle-induced formation of ROS and the oxidation products from reaction
of ROS with biomolecules is useful for gaining a mechanistic understanding of particle-induced oxidative stress. Aqueous suspensions
of pyrite particles have been shown to form hydroxyl radicals and degrade nucleic acids. Reactions between pyrite-induced
hydroxyl radicals and nucleic acid bases, however, remain to be determined. Here, we compared the oxidation of adenine by
Fenton-generated (i.e., ferrous iron and hydrogen peroxide) hydroxyl radicals to adenine oxidation by hydroxyl radicals generated
in pyrite aqueous suspensions. Results show that adenine oxidizes in the presence of pyrite (without the addition of hydrogen
peroxide) and that the rate of oxidation is dependent on the pyrite loading. Adenine oxidation was prevented by addition of
either catalase or ethanol to the pyrite/adenine suspensions, which implies that hydrogen peroxide and hydroxyl radicals are
causing the adenine oxidation. The adenine oxidation products, 8-oxoadenine and 2-hydroxyadenine, were the same whether hydroxyl
radicals were generated by Fenton or pyrite-initiated reactions. Although nucleic acid bases are unlikely to be directly exposed
to pyrite particles, the formation of ROS in the vicinity of cells may lead to oxidative stress. 相似文献
6.
This article addresses the issue of whether airline deregulation has changed patterns of interurban accessibility. Changes in air passenger travel times between 1978 and 1990 were analyzed for flights between seven Ohio cities and the 100 largest United States air passenger destinations. The results indicate that although regional patterns in travel time changes were evident, in general deregulation has not reduced interurban accessibility. 相似文献
7.
Xiang?Zhang Michael?J?Borda Martin?AA?Schoonen Daniel?R?StronginEmail author 《Geochemical transactions》2003,4(1):8
The effect of a diacetylene-containing phospholipid on the oxidation of pyrite, FeS2, was investigated. Earlier work reported by our research group showed that the adsorption of l,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine on pyrite suppressed the extent of its oxidation by about 75% over a specific time period. Results
presented here show that the pre-exposure to UV radiation of this lipid after sorption onto pyrite results in a 90% suppression.
Attenuated total reflection (ATR) Fourier transform infra-red spectroscopy (FTIR) suggests that the UV irradiation of the
lipid does not result in degradation of the adsorbed layer. It is believed that the UV exposure results in the cross-linking
and polymerization of the adsorbed phospholipid into a relatively impermeable barrier that separates the pyrite from the aqueous
phase. The results of this study might have implications for the protection of pyrite from oxidation in the environment. 相似文献
8.
Greg?K?Druschel Martin?AA?SchoonenEmail author D?Kirk?Nordstrom James?W?Ball Yong?Xu Corey?A?Cohn 《Geochemical transactions》2003,4(1):12
A sampling protocol for the retention, extraction, and analysis of sulfoxyanions in hydrothermal waters has been developed
in the laboratory and tested at Yellowstone National Park and Green Lake, NY. Initial laboratory testing of the anion-exchange
resin Bio-Rad™ AG1-X8 indicated that the resin was well suited for the sampling, preservation, and extraction of sulfate and
thiosulfate. Synthetic solutions containing sulfate and thiosulfate were passed through AG1-X8 resin columns and eluted with
1 and 3 M KCl, respectively. Recovery ranged from 89 to 100%. Comparison of results for water samples collected from five
pools in Yellowstone National Park between on-site IC analysis (U.S. Geological Survey mobile lab) and IC analysis of resin-stored
sample at SUNY-Stony Brook indicates 96 to 100% agreement for three pools (Cinder, Cistern, and an unnamed pool near Cistern)
and 76 and 63% agreement for two pools (Sulfur Dust and Frying Pan). Attempts to extract polythionates from the AG1-X8 resin
were made using HCl solutions, but were unsuccessful. Bio-Rad™ AG2-X8, an anion-exchange resin with weaker binding sites than
the AG1-X8 resin, is better suited for polythionate extraction. Sulfate and thiosulfate extraction with this resin has been
accomplished with KCl solutions of 0.1 and 0.5 M, respectively. Trithionate and tetrathionate can be extracted with 4 M KCl.
Higher polythionates can be extracted with 9 M hydrochloric acid. Polythionate concentrations can then be determined directly
using ion chromatographic methods, and laboratory results indicate recovery of up to 90% for synthetic polythionate solutions
using AG2-X8 resin columns. 相似文献
9.
Jun Hao Curtis Cleveland Eelin Lim Daniel R Strongin Martin AA Schoonen 《Geochemical transactions》2006,7(1):8-9
The chemolithoautotrophic bacterium, Acidithiobacillus ferrooxidans, commonly occurs in acid mine drainage (AMD) environments where it is responsible for catalyzing the oxidation of pyrite
and concomitant development of acidic conditions. This investigation reports on the growth of this bacterial species on the
pyrite surface and in the aqueous phase at a pH close to 2 as well as the role of adsorbed lipid in preventing pyrite dissolution.
Both acid washed pyrite and acid-washed pyrite coated with lipids were used as substrates in the studies. The choice of lipid,
1,2-bis(10,12-tricosadiynoyl)-sn-Glycero-3-Phosphocholine lipid (23:2 Diyne PC), a phosphocholine lipid, was based on earlier work that showed that this lipid
inhibits the abiotic oxidation rate of pyrite. Atomic force microscopy showed that under the experimental conditions used
in this study, the lipid formed ~4–20 nm layers on the mineral surface. Surface-bound lipid greatly suppresses the oxidation
process catalyzed by A. ferrooxidans. This suppression continued for the duration of the experiments (25 days maximum). Analysis of the bacterial population on
the pyrite surface and in solution over the course of the experiments suggested that the pyrite oxidation was dependent in
large part on the fraction of bacteria bound to the pyrite surface. 相似文献
10.
Pyrite surface interaction with selected organic aqueous species under anoxic conditions 总被引:1,自引:0,他引:1
The interaction between low-molecular weight organic compounds and pyrite under anoxic conditions has been studied using a combination of electrophoresis and batch sorption experiments. The results suggest that acetate, carbamide, ethylamine, formamide, purine, D-ribose, and adenine, as well as the amino acids alanine, cysteine and glycine, interact within the electrophoretic shearplane of the pyrite surface. The observed surface interaction between the negatively charged surface of pyrite and the organic aqueous species takes place regardless of the formal charge of the aqueous species of interest. This indicates that the interaction of organic molecules with pyrite surfaces under anoxic conditions is dictated by interactions with specific surface sites (thiol or iron surface sites) rather than electrostatic forces. Dissolved metals typically enhance the interaction of the organics species. This enhancement is either due to an alteration in the distribution of thiol and iron groups on the pyrite surface or by the formation of ternary surface complexes. 相似文献