Conferences, Lectures, & Seminars
Events for November
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Environmental Engineering Seminar
Fri, Nov 05, 2004 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Mario Blanco, Director, Materials and Process Simulation Center
California Institute of Technology
Pasadena, CATitle: Computational Chemistry Solutions to Problems of Environmental Interest.Abstract:The environmental sciences are beginning to take advantage of recent progress in two areas of computational science: the arrival of affordable supercomputing and the availability of user-friendly numerical codes for accurate solutions of Newton's equations of motion and the quantum mechanical Schrödinger equation. In combination with experiments these computational methods can help build new hypotheses that expand the nature and depth of the questions being asked in the environmental sciences. How is it that forests seem to "control" rain precipitation? Can multiphase (liquid/vapor) equilibrium in atmospheric aerosol be predicted solely from knowledge of the chemical composition of a complex mixture? Can the concentrations of vapor bound organic compounds be detected by an E-nose? On more global issues related to environmentally friendly energy production new questions can be addressed by means of computational chemistry. What are the molecular characteristics of oil migration distance indicators? What materials are needed in order to produce affordable fuel cells? What are the mechanisms of proton transfer responsible for their high efficiency? We will illustrate some of these recent applications of computational chemistry in the environmental sciences and entertain questions.Location: Seeley G. Mudd Bldg., Room 101
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Tales of two UnTrim Applications:
Fri, Nov 12, 2004 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Title: Tales of two UnTrim Applications: A 3D River Plume over the Continental Shelf and Wind Driven Circulation in Upper Klamath Lake, OregonSpeaker: Dr. Ralph T. Cheng, U.S. Geological Survey, Menol Park, CAAbstract:Two recent applications of the UnTRIM model are presented. (A) River derived fresh water discharging into the adjacent continental shelf forms a trapped river plume that propagates in a narrow region along the coast. The physics associated with the formation of river plumes spans a wide range of vertical and horizontal length scales. A proper description of the dynamics of river plume cannot be achieved without a realistic representation of the flow and salinity structure near the river mouth that controls the initial formation and propagation of the plume in the coastal ocean. The tidal dynamics near the river mouth shows that the ebb flow regime can be represented by a jet-like flow and a sink-like flow during flood. Strong exiting momentum in the jet-like flow being forced by Coriolis acceleration creates the initial formation of the river plume. During flooding cycle, the momentum is more evenly distributed; there is not a dominant preferred direction of freshwater. The complete river/estuary and coastal ocean system is simulated using the unstructured grid UnTRIM model. The simulations are carried out in tidal dynamics time-scales extending the simulations to cover processes in residual time-scales. The uniquely important role of Coriolis acceleration is shown. The results of this investigation show properties of the river plume and the tidal and residual characteristics of flow and salinity within the estuary; they are completely consistent with the physics of estuary and coastal ocean. (B) Wind-driven circulation in Upper Klamath Lake plays an important role determining the water quality and the health of the lake ecosystem. Time-series of water velocity measured by two ADCPs were collected in the summer of 2003. Strong correlations between the wind and circulation show clockwise circulation under prevailing wind (NW) and counterclockwise circulation as the wind shifted to SE. The UnTRIM model reproduced wind-driven circulation at a deep water station while the model results did not match observations at the shallow water station. The results of correlation analysis suggests that the ADCP time-series data at the shallow water station are suspect, which leads to the conclusion that field data must be analyzed to show consistency with the physics. When the data do not match the expected physics, there might be hidden messages in these data.
Location: Seeley G. Mudd Bldg., Room 101
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Thermochemical Sulfate Reduction Prediction:
Fri, Nov 19, 2004 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Title : THERMOCHEMICAL SULFATE REDUCTION PREDICTION:
Mitigation of Hydrogen Sulfide Risk in Petroleum ProductionSPEAKER: DR. GEOFFREY S. ELLIS,
Power, Environmental, and Energy Research Center, Division of Chemistry and Chemical Engineering, California Institute of TechnologyAbstract:Thermochemical sulfate reduction (TSR) is of increasing importance in both hydrocarbon exploration and production. On the exploration side, TSR can significantly affect the extent of oxidation of valuable resources, the maximum depth for oil potential, and the gas to oil ratio (GOR). From a production perspective, the toxicity and corrosivity of hydrogen sulfide require that costly H2S removal facilities be installed. As fossil fuel exploration progressively moves into marginal areas (e.g., deepwater offshore), the risk of encountering TSR will increase worldwide. Consequently, development of a tool for predicting the TSR risk of a given prospect is of great interest to the petroleum industry. We are combining experimental simulation with theoretical modeling in order to increase our predictive capability of TSR risk. Our experimental results suggest that while the temperature of the reaction is the most critical control on TSR reaction rates, the solubility of sulfate minerals, the ionic strength and redox conditions of the aqueous solution, the type of hydrocarbon oxidized, and the presence of reduced sulfur species and/or catalysts also significantly affect sulfate reduction. Several potential reaction mechanisms have been identified and the derivation of the kinetics of these reactions is part of our ongoing research. Additionally, diagnostic geochemical signatures such as the Ô34S composition of H2S and the pattern of hydrocarbon cracking have been identified, and can be used to constrain model predictions.Location: Seeley G. Mudd Bldg., Room 101Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Thermochemical Sulfate Reduction Prediction:
Fri, Nov 19, 2004 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Title : THERMOCHEMICAL SULFATE REDUCTION PREDICTION:
Mitigation of Hydrogen Sulfide Risk in Petroleum ProductionSPEAKER: DR. GEOFFREY S. ELLIS
Power, Environmental, and Energy Research Center, Division of Chemistry and Chemical Engineering, California Institute of TechnologyAbstract:Thermochemical sulfate reduction (TSR) is of increasing importance in both hydrocarbon exploration and production. On the exploration side, TSR can significantly affect the extent of oxidation of valuable resources, the maximum depth for oil potential, and the gas to oil ratio (GOR). From a production perspective, the toxicity and corrosivity of hydrogen sulfide require that costly H2S removal facilities be installed. As fossil fuel exploration progressively moves into marginal areas (e.g., deepwater offshore), the risk of encountering TSR will increase worldwide. Consequently, development of a tool for predicting the TSR risk of a given prospect is of great interest to the petroleum industry. We are combining experimental simulation with theoretical modeling in order to increase our predictive capability of TSR risk. Our experimental results suggest that while the temperature of the reaction is the most critical control on TSR reaction rates, the solubility of sulfate minerals, the ionic strength and redox conditions of the aqueous solution, the type of hydrocarbon oxidized, and the presence of reduced sulfur species and/or catalysts also significantly affect sulfate reduction. Several potential reaction mechanisms have been identified and the derivation of the kinetics of these reactions is part of our ongoing research. Additionally, diagnostic geochemical signatures such as the Ô34S composition of H2S and the pattern of hydrocarbon cracking have been identified, and can be used to constrain model predictions.Location: Seeley G. Mudd Bldg., Room 101Audiences: Everyone Is Invited
Contact: Evangeline Reyes