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Estimating canopy fuel parameters for Atlantic Coastal Plain forest types.

Description: Abstract It is necessary to quantify forest canopy characteristics to assess crown fire hazard, prioritize treatment areas, and design treatments to reduce crown fire potential. A number of fire behavior models such as FARSITE, FIRETEC, and NEXUS require as input four particular canopy fuel parameters: 1) canopy cover, 2) stand height, 3) crown base height, and 4) canopy bulk density. These canopy characteristics must be mapped across the landscape at high spatial resolution to accurately simulate crown fire. Currently no models exist to forecast these four canopy parameters for forests of the Atlantic Coastal Plain, a region that supports millions of acres of loblolly, longleaf, and slash pine forests as well as pine-broadleaf forests and mixed species broadleaf forests. Many forest cover types are recognized, too many to efficiently model. For expediency, forests of the Savannah River Site are categorized as belonging to 1 of 7 broad forest type groups, based on composition: 1) loblolly pine, 2) longleaf pine, 3) slash pine, 4) pine-hardwood, 5) hardwood-pine, 6) hardwoods, and 7) cypress-tupelo. These 7 broad forest types typify forests of the Atlantic Coastal Plain region, from Maryland to Florida.
Date: January 15, 2007
Creator: Parresol, Bernard, R.
Partner: UNT Libraries Government Documents Department

DESIGN AND PERFORMANCE OBJECTIVES OF THE SINGLE CELL TEST SYSTEM FOR SO2 DEPOLARIZED ELECTROLYZER DEVELOPMENT

Description: The single cell test system development for the SRNL sulfur dioxide-depolarized electrolyzer has been completed. Operating experience and improved operating procedures were developed during test operations in FY06 and the first quarter of FY07. Eight different cell configurations, using various MEA designs, have been tested. The single cell test electrolyzer has been modified to overcome difficulties experienced during testing, including modifications to the inlet connection to eliminate minute acid leaks that caused short circuits. The test facility was modified by adding a water bath for cell heating, thus permitting operation over a wider range of flowrates and cell temperatures. Modifications were also identified to permit continuous water flushing of the cathode to remove sulfur, thus extending operating time between required shutdowns. This is also expected to permit a means of independently measuring the rate of sulfur formation, and the corresponding SO{sub 2} flux through the membrane. This report contains a discussion of the design issues being addressed by the single cell test program, a test matrix being conducted to address these issues, and a summary of the performance objectives for the single cell test system. The current primary objective of single cell test system is to characterize and qualify electrolyzer configurations for the following 100-hour longevity tests. Although the single cell test system development is considered complete, SRNL will continue to utilize the test facility and the single cell electrolyzer to measure the operability and performance of various cell design configurations, including new MEA's produced by the component development tasks.
Date: January 15, 2007
Creator: Steimke, J
Partner: UNT Libraries Government Documents Department

Synthesis and Integration of Energy Related Tropospheric Chemistry Research

Description: This is a final report of work done in support of DOE interests in air quality assessment or managemnt and tropospheric aerosol chemistry. A central focus for the activities was support for the North American cooperative, NARSTO. Leaderrship and oversight was provided for NARSTO products including two major state-of-science assessments on airborne particles (particulate matter) and the fundamentals of pollutant emissions characterization. In addition, review sof so-called 'policy related air quality science were prepared addressing multi-scale atmospheric phenomena, snowpack chemistry and pollution, and North American aerosol baseline or background conditions. The relationship between the identification of pollution sourcees and human exposure to outdoor particles was investigated, and results critiqued. This work led to a major review of the integration of atmospheric chemistry, epedimiology and toxicology in linking airborne particles with human health effects. The last topical area of work in the project related to the carbon component of tropospheric aerosols. Work was done in support of a project to obtain samples of power plant effluents to estimate the carbon present in palnt emissions. The results suggsted only a minor amount of ambient particles were carbon from coal-fired plants. Another studied provided a conceptual plan for using isotopic carbon data to provide a vapor and condensed phase carbon balance for particles, including fossil and biogenic sources.
Date: January 15, 2007
Creator: Hidy, George M.
Partner: UNT Libraries Government Documents Department

India's Worsening Uranium Shortage

Description: As a result of NSG restrictions, India cannot import the natural uranium required to fuel its Pressurized Heavy Water Reactors (PHWRs); consequently, it is forced to rely on the expediency of domestic uranium production. However, domestic production from mines and byproduct sources has not kept pace with demand from commercial reactors. This shortage has been officially confirmed by the Indian Planning Commission’s Mid-Term Appraisal of the country’s current Five Year Plan. The report stresses that as a result of the uranium shortage, Indian PHWR load factors have been continually decreasing. The Uranium Corporation of India Ltd (UCIL) operates a number of underground mines in the Singhbhum Shear Zone of Jharkhand, and it is all processed at a single mill in Jaduguda. UCIL is attempting to aggrandize operations by establishing new mines and mills in other states, but the requisite permit-gathering and development time will defer production until at least 2009. A significant portion of India’s uranium comes from byproduct sources, but a number of these are derived from accumulated stores that are nearing exhaustion. A current maximum estimate of indigenous uranium production is 430t/yr (230t from mines and 200t from byproduct sources); whereas, the current uranium requirement for Indian PHWRs is 455t/yr (depending on plant capacity factor). This deficit is exacerbated by the additional requirements of the Indian weapons program. Present power generation capacity of Indian nuclear plants is 4350 MWe. The power generation target set by the Indian Department of Atomic Energy (DAE) is 20,000 MWe by the year 2020. It is expected that around half of this total will be provided by PHWRs using indigenously supplied uranium with the bulk of the remainder provided by breeder reactors or pressurized water reactors using imported low-enriched uranium.
Date: January 15, 2007
Creator: Curtis, Michael M.
Partner: UNT Libraries Government Documents Department

A Comprehensive Statistically-Based Method to Interpret Real-Time Flowing Measurements

Description: With the recent development of temperature measurement systems, continuous temperature profiles can be obtained with high precision. Small temperature changes can be detected by modern temperature measuring instruments such as fiber optic distributed temperature sensor (DTS) in intelligent completions and will potentially aid the diagnosis of downhole flow conditions. In vertical wells, since elevational geothermal changes make the wellbore temperature sensitive to the amount and the type of fluids produced, temperature logs can be used successfully to diagnose the downhole flow conditions. However, geothermal temperature changes along the wellbore being small for horizontal wells, interpretations of a temperature log become difficult. The primary temperature differences for each phase (oil, water, and gas) are caused by frictional effects. Therefore, in developing a thermal model for horizontal wellbore, subtle temperature changes must be accounted for. In this project, we have rigorously derived governing equations for a producing horizontal wellbore and developed a prediction model of the temperature and pressure by coupling the wellbore and reservoir equations. Also, we applied Ramey's model (1962) to the build section and used an energy balance to infer the temperature profile at the junction. The multilateral wellbore temperature model was applied to a wide range of cases at varying fluid thermal properties, absolute values of temperature and pressure, geothermal gradients, flow rates from each lateral, and the trajectories of each build section. With the prediction models developed, we present inversion studies of synthetic and field examples. These results are essential to identify water or gas entry, to guide flow control devices in intelligent completions, and to decide if reservoir stimulation is needed in particular horizontal sections. This study will complete and validate these inversion studies.
Date: January 15, 2007
Creator: Yoshioka, Keita; Dawkrajai, Pinan; Romero, Analis A.; Zhu, Ding; Hill, A. D. & Lake, Larry W.
Partner: UNT Libraries Government Documents Department