UNT Libraries Government Documents Department - 642 Matching Results

Search Results

Annual Hanford Seismic Report for Fiscal Year 2009

Description: The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The HSAP is responsible for locating and identifying sources of seismic activity and monitoring changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the HSAP works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. During FY 2009, the Hanford Seismic Network recorded nearly 3000 triggers on the seismometer system, which included over 1700 seismic events in the southeast Washington area and an additional 370 regional and teleseismic events. There were 1648 events determined to be local earthquakes relevant to the Hanford Site. Nearly all of these earthquakes were detected in the vicinity of Wooded Island, located about eight miles north of Richland just west of the Columbia River. Recording of the Wooded Island events began in January with over 250 events per month through June 2009. The frequency of events decreased starting in July 2009 to approximately 10-15 events per month through September 2009. Most of the events were considered minor (coda-length magnitude [Mc] less than 1.0) with 47 events in the 2.0-3.0 range. The estimated depths of the Wooded Island events are shallow (averaging less than 1.0 km deep) with a maximum depth estimated at 2.3 km. This places the Wooded Island events within the Columbia River ...
Date: December 31, 2009
Creator: Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.; Clayton, Ray E. & Devary, Joseph L.

Connecting Colorado's Renewable Resources to the Markets in a Cabon-Constrained Electricity Sector

Description: The benchmark goal that drives the report is to achieve a 20 percent reduction in carbon dioxide (CO{sub 2}) emissions in Colorado's electricity sector below 2005 levels by 2020. We refer to this as the '20 x 20 goal.' In discussing how to meet this goal, the report concentrates particularly on the role of utility-scale renewable energy and high-voltage transmission. An underlying recognition is that any proposed actions must not interfere with electric system reliability and should minimize financial impacts on customers and utilities. The report also describes the goals of Colorado's New Energy Economy5 - identified here, in summary, as the integration of energy, environment, and economic policies that leads to an increased quality of life in Colorado. We recognize that a wide array of options are under constant consideration by professionals in the electric industry, and the regulatory community. Many options are under discussion on this topic, and the costs and benefits of the options are inherently difficult to quantify. Accordingly, this report should not be viewed as a blueprint with specific recommendations for the timing, siting, and sizing of generating plants and high-voltage transmission lines. We convened the project with the goal of supplying information inputs for consideration by the state's electric utilities, legislators, regulators, and others as we work creatively to shape our electricity sector in a carbon-constrained world. The report addresses various issues that were raised in the Connecting Colorado's Renewable Resources to the Markets report, also known as the SB07-91 Report. That report was produced by the Senate Bill 2007-91 Renewable Resource Generation Development Areas Task Force and presented to the Colorado General Assembly in 2007. The SB07-91 Report provided the Governor, the General Assembly, and the people of Colorado with an assessment of the capability of Colorado's utility-scale renewable resources to contribute electric ...
Date: December 31, 2009

Corner rounding in EUV photoresist: tuning through molecular weight, PAG size, and development time

Description: In this paper, the corner rounding bias of a commercially available extreme ultraviolet photoresist is monitored as molecular weight, photoacid generator (PAG) size, and development time are varied. These experiments show that PAG size influences corner biasing while molecular weight and development time do not. Large PAGs are shown to exhibit less corner biasing, and in some cases, lower corner rounding, than small PAGs. In addition, heavier resist polymers are shown to exhibit less corner rounding than lighter ones.
Date: December 31, 2009
Creator: Anderson, Christopher; Daggett, Joe & Naulleau, Patrick

Daylight metrics and energy savings

Description: The drive towards sustainable, low-energy buildings has increased the need for simple, yet accurate methods to evaluate whether a daylit building meets minimum standards for energy and human comfort performance. Current metrics do not account for the temporal and spatial aspects of daylight, nor of occupants comfort or interventions. This paper reviews the historical basis of current compliance methods for achieving daylit buildings, proposes a technical basis for development of better metrics, and provides two case study examples to stimulate dialogue on how metrics can be applied in a practical, real-world context.
Date: December 31, 2009
Creator: Mardaljevic, John; Heschong, Lisa & Lee, Eleanor

Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia

Description: This project demonstrated that developing environmental credits on private land—including abandoned mined lands—is dependent on a number of factors, some of them beyond the control of the project team. In this project, acid mine drainage (AMD) was successfully remediated through the construction of a passive AMD treatment system. Extensive water quality sampling both before and after the installation of the passive AMD treatment system showed that the system achieved removal efficiencies and pollutant loading reductions for acidity, iron, aluminum and manganese that were consistent with systems of similar size and design. The success of the passive AMD treatment system should have resulted in water credits if the project had not been terminated. Developing carbon sequestration credits, however, was much more complex and was not achieved in this project. The primary challenge that the project team encountered in meeting the full project objectives was the unsuccessful attempt to have the landowner sign a conservation easement for his property. This would have allowed the project team to clear and reforest the site, monitor the progress of the newly planted trees, and eventually realize carbon sequestration credits once the forest was mature. The delays caused by the lack of a conservation easement, as well as other factors, eventually resulted in the reforestation portion of the project being cancelled. The information in this report will help the public make more informed decisions regarding the potential of using water and carbon, and other credits to support the remediation of minded lands through out the United States. The hope is that by using credits that more mined lands with be remediated.
Date: December 31, 2009
Creator: Goodrich-Mahoney, John & Donnelly, Ellen


Description: The Cementitious Barriers Partnership (CBP) Project is a multi-disciplinary, multi-institutional collaboration supported by the United States Department of Energy (US DOE) Office of Waste Processing. The objective of the CBP project is to develop a set of tools to improve understanding and prediction of the long-term structural, hydraulic, and chemical performance of cementitious barriers used in nuclear applications. A multi-disciplinary partnership of federal, academic, private sector, and international expertise has been formed to accomplish the project objective. In addition to the US DOE, the CBP partners are the Savannah River National Laboratory (SRNL), Vanderbilt University (VU)/Consortium for Risk Evaluation with Stakeholder Participation (CRESP), Energy Research Center of the Netherlands (ECN), and SIMCO Technologies, Inc. The Nuclear Regulatory Commission (NRC) is providing support under a Memorandum of Understanding. The National Institute of Standards and Technology (NIST) is providing research under an Interagency Agreement. Neither the NRC nor NIST are signatories to the CRADA. The periods of cementitious performance being evaluated are >100 years for operating facilities and > 1000 years for waste management. The set of simulation tools and data developed under this project will be used to evaluate and predict the behavior of cementitious barriers used in near surface engineered waste disposal systems, e.g., waste forms, containment structures, entombments, and environmental remediation, including decontamination and decommissioning analysis of structural concrete components of nuclear facilities (spent-fuel pools, dry spent-fuel storage units, and recycling facilities such as fuel fabrication, separations processes). Simulation parameters will be obtained from prior literature and will be experimentally measured under this project, as necessary, to demonstrate application of the simulation tools for three prototype applications (waste form in concrete vault, high-level waste tank grouting, and spent-fuel pool). Test methods and data needs to support use of the simulation tools for future applications will be defined. The CBP ...
Date: December 31, 2009
Creator: Flach, G.

Design and Implementation of Energized Fracture Treatment in Tight Gas Sands

Description: Hydraulic fracturing is essential for producing gas and oil at an economic rate from low permeability sands. Most fracturing treatments use water and polymers with a gelling agent as a fracturing fluid. The water is held in the small pore spaces by capillary pressure and is not recovered when drawdown pressures are low. The un-recovered water leaves a water saturated zone around the fracture face that stops the flow of gas into the fracture. This is a particularly acute problem in low permeability formations where capillary pressures are high. Depletion (lower reservoir pressures) causes a limitation on the drawdown pressure that can be applied. A hydraulic fracturing process can be energized by the addition of a compressible, sometimes soluble, gas phase into the treatment fluid. When the well is produced, the energized fluid expands and gas comes out of solution. Energizing the fluid creates high gas saturation in the invaded zone, thereby facilitating gas flowback. A new compositional hydraulic fracturing model has been created (EFRAC). This is the first model to include changes in composition, temperature, and phase behavior of the fluid inside the fracture. An equation of state is used to evaluate the phase behavior of the fluid. These compositional effects are coupled with the fluid rheology, proppant transport, and mechanics of fracture growth to create a general model for fracture creation when energized fluids are used. In addition to the fracture propagation model, we have also introduced another new model for hydraulically fractured well productivity. This is the first and only model that takes into account both finite fracture conductivity and damage in the invaded zone in a simple analytical way. EFRAC was successfully used to simulate several fracture treatments in a gas field in South Texas. Based on production estimates, energized fluids may be required when drawdown ...
Date: December 31, 2009
Creator: Sharma, Mukul & Friehauf, Kyle


Description: This NETL sponsored effort seeks to develop continuous technologies for the production of carbon products, which may be thought of as the heavier products currently produced from refining of crude petroleum and coal tars obtained from metallurgical grade coke ovens. This effort took binder grade pitch, produced from liquefaction of West Virginia bituminous grade coal, all the way to commercial demonstration in a state of the art arc furnace. Other products, such as crude oil, anode grade coke and metallurgical grade coke were demonstrated successfully at the bench scale. The technology developed herein diverged from the previous state of the art in direct liquefaction (also referred to as the Bergius process), in two major respects. First, direct liquefaction was accomplished with less than a percent of hydrogen per unit mass of product, or about 3 pound per barrel or less. By contrast, other variants of the Bergius process require the use of 15 pounds or more of hydrogen per barrel, resulting in an inherent materials cost. Second, the conventional Bergius process requires high pressure, in the range of 1500 psig to 3000 psig. The WVU process variant has been carried out at pressures below 400 psig, a significant difference. Thanks mainly to DOE sponsorship, the WVU process has been licensed to a Canadian Company, Quantex Energy Inc, with a commercial demonstration unit plant scheduled to be erected in 2011.
Date: December 31, 2009
Creator: Kennel, Elliot; Chen, Chong; Dadyburjor, Dady; Heavner, Mark; Katakdaunde, Manoj; Magean, Liviu et al.

Energy Conservation Projects to Benefit the Railroad Industry

Description: The Energy Conservation Projects to benefit the railroad industry using the Norfolk Southern Company as a model for the railroad industry has five unique tasks which are in areas of importance within the rail industry, and specifically in the area of energy conservation. The NIU Engineering and Technology research team looked at five significant areas in which research and development work can provide unique solutions to the railroad industry in energy the conservation. (1) Alternate Fuels - An examination of various blends of bio-based diesel fuels for the railroad industry, using Norfolk Southern as a model for the industry. The team determined that bio-diesel fuel is a suitable alternative to using straight diesel fuel, however, the cost and availability across the country varies to a great extent. (2) Utilization of fuel cells for locomotive power systems - While the application of the fuel cell has been successfully demonstrated in the passenger car, this is a very advanced topic for the railroad industry. There are many safety and power issues that the research team examined. (3) Thermal and emission reduction for current large scale diesel engines - The current locomotive system generates large amount of heat through engine cooling and heat dissipation when the traction motors are used to decelerate the train. The research team evaluated thermal management systems to efficiently deal with large thermal loads developed by the operating engines. (4) Use of Composite and Exotic Replacement Materials - Research team redesigned various components using new materials, coatings, and processes to provide the needed protection. Through design, analysis, and testing, new parts that can withstand the hostile environments were developed. (5) Tribology Applications - Identification of tribology issues in the Railroad industry which play a significant role in the improvement of energy usage. Research team analyzed and developed solutions which ...
Date: December 31, 2009
Creator: Mirman, Clifford & Vohra, Promod

Epitaxial Growth of GaN-based LEDs on Simple Sacrificial Substrates

Description: The objective of this project is to produce alternative substrate technologies for GaN-based LEDs by developing an ALD interlayer of Al{sub 2}O{sub 3} on sacrificial substrates such as ZnO and Si. A sacrificial substrate is used for device growth that can easily be removed using a wet chemical etchant leaving only the thin GaN epi-layer. After substrate removal, the GaN LED chip can then be mounted in several different ways to a metal heat sink/reflector and light extraction techniques can then be applied to the chip and compared for performance. Success in this work will lead to high efficiency LED devices with a simple low cost fabrication method and high product yield as stated by DOE goals for its solid state lighting portfolio.
Date: December 31, 2009
Creator: Ferguson, Ian & Summers, Chris


Description: The purpose of this calculation is to evaluate a temporary ten cover truss system. This system will be used to provide weather protection to the workers during replacement of the filter for the Primary Ventilation System in AP Tank Farm. The truss system has been fabricated utilizing tubes and couplers, which are normally used for scaffoldings.
Date: December 31, 2009
Creator: MA, HAQ

The Federal Budget: Current and Upcoming Issues

Description: This report examines changes to the Federal Budget for Fiscal Years 2008-2010. The report considers the factors that have an effect on various budgetary functions and decisions. The report specifically focuses on the effect of the 2007-2008 financial recession on the budget, but also considers more long-term fiscal issues such as health care for retiring Baby-Boomers.
Date: December 31, 2009
Creator: Austin, D. Andrew & Levit, Mindy R.

Geochemical Analyses of Surface and Shallow Gas Flux and Composition Over a Proposed Carbon Sequestration Site in Eastern Kentucky

Description: Using soil gas chemistry to detect leakage from underground reservoirs (i.e. microseepage) requires that the natural range of soil gas flux and chemistry be fully characterized. To meet this need, soil gas flux (CO{sub 2}, CH{sub 4}) and the bulk (CO{sub 2}, CH{sub 4}) and isotopic chemistry ({delta}{sup 13}C-CO2) of shallow soil gases (<1 m, 3.3 ft) were measured at 25 locations distributed among two active oil and gas fields, an active strip mine, and a relatively undisturbed research forest in eastern Kentucky. The measurements apportion the biologic, atmospheric, and geologic influences on soil gas composition under varying degrees of human surface disturbance. The measurements also highlight potential challenges in using soil gas chemistry as a monitoring tool where the surface cover consists of reclaimed mine land or is underlain by shallow coals. For example, enrichment of ({delta}{sup 13}C-CO2) and high CH{sub 4} concentrations in soils have been historically used as indicators of microseepage, but in the reclaimed mine lands similar soil chemistry characteristics likely result from dissolution of carbonate cement in siliciclastic clasts having {delta}{sup 13}C values close to 0{per_thousand} and degassing of coal fragments. The gases accumulate in the reclaimed mine land soils because intense compaction reduces soil permeability, thereby impeding equilibration with the atmosphere. Consequently, the reclaimed mine lands provide a false microseepage anomaly. Further potential challenges arise from low permeability zones associated with compacted soils in reclaimed mine lands and shallow coals in undisturbed areas that might impede upward gas migration. To investigate the effect of these materials on gas migration and composition, four 10 m (33 ft) deep monitoring wells were drilled in reclaimed mine material and in undisturbed soils with and without coals. The wells, configured with sampling zones at discrete intervals, show the persistence of some of the aforementioned anomalies at depth. Moreover, ...
Date: December 31, 2009
Creator: Parris, Thomas; Solis, Michael & Takacs, Kathryn

Heavy-Duty Stoichiometric Compression Ignition Engine with Improved Fuel Economy over Alternative Technologies for Meeting 2010 On-Highway Emission

Description: The objectives of the reported work were: to apply the stoichiometric compression ignition (SCI) concept to a 9.0 liter diesel engine; to obtain engine-out NO{sub x} and PM exhaust emissions so that the engine can meet 2010 on-highway emission standards by applying a three-way catalyst for NO{sub x} control and a particulate filter for PM control; and to simulate an optimize the engine and air system to approach 50% thermal efficiency using variable valve actuation and electric turbo compounding. The work demonstrated that an advanced diesel engine can be operated at stoichiometric conditions with reasonable particulate and NOx emissions at full power and peak torque conditions; calculated that the SCI engine will operate at 42% brake thermal efficiency without advanced hardware, turbocompounding, or waste heat recovery; and determined that EGR is not necessary for this advanced concept engine, and this greatly simplifies the concept.
Date: December 31, 2009
Creator: Baumgard, Kirby J. & Winsor, Richard E.

High Performance Building Facade Solutions PIER Final Project Report

Description: Building facades directly influence heating and cooling loads and indirectly influence lighting loads when daylighting is considered, and are therefore a major determinant of annual energy use and peak electric demand. Facades also significantly influence occupant comfort and satisfaction, making the design optimization challenge more complex than many other building systems.This work focused on addressing significant near-term opportunities to reduce energy use in California commercial building stock by a) targeting voluntary, design-based opportunities derived from the use of better design guidelines and tools, and b) developing and deploying more efficient glazings, shading systems, daylighting systems, facade systems and integrated controls. This two-year project, supported by the California Energy Commission PIER program and the US Department of Energy, initiated a collaborative effort between The Lawrence Berkeley National Laboratory (LBNL) and major stakeholders in the facades industry to develop, evaluate, and accelerate market deployment of emerging, high-performance, integrated facade solutions. The LBNL Windows Testbed Facility acted as the primary catalyst and mediator on both sides of the building industry supply-user business transaction by a) aiding component suppliers to create and optimize cost effective, integrated systems that work, and b) demonstrating and verifying to the owner, designer, and specifier community that these integrated systems reliably deliver required energy performance. An industry consortium was initiated amongst approximately seventy disparate stakeholders, who unlike the HVAC or lighting industry, has no single representative, multi-disciplinary body or organized means of communicating and collaborating. The consortium provided guidance on the project and more importantly, began to mutually work out and agree on the goals, criteria, and pathways needed to attain the ambitious net zero energy goals defined by California and the US.A collaborative test, monitoring, and reporting protocol was also formulated via the Windows Testbed Facility in collaboration with industry partners, transitioning industry to focus on the importance ...
Date: December 31, 2009
Creator: Lee, Eleanor & Selkowitz, Stephen

High Temperature Battery for Drilling Applications

Description: In this project rechargeable cells based on the high temperature electrochemical system Na/beta''-alumina/S(IV) in AlCl3/NaCl were developed for application as an autonomous power source in oil/gas deep drilling wells. The cells operate in the temperature range from 150 C to 250 C. A prototype DD size cell was designed and built based on the results of finite element analysis and vibration testing. The cell consisted of stainless steel case serving as anode compartment with cathode compartment installed in it and a seal closing the cell. Critical element in cell design and fabrication was hermetically sealing the cell. The seal had to be leak tight, thermally and vibration stable and compatible with electrode materials. Cathode compartment was built of beta''-alumina tube which served as an electrolyte, separator and cathode compartment.
Date: December 31, 2009
Creator: Caja, Josip

Mercury Control for Plants Firing Texas Lignite and Equipped with ESP-wet FGD

Description: This report presents the results of a multi-year test program conducted as part of Cooperative Agreement DE-FC26-06NT42779, 'Mercury Control for Plants Firing Texas Lignite and Equipped with ESP-wet FGD.' The objective of this program was to determine the level of mercury removal achievable using sorbent injection for a plant firing Texas lignite fuel and equipped with an ESP and wet FGD. The project was primarily funded by the U.S. DOE National Energy Technology Laboratory. EPRI, NRG Texas, Luminant (formerly TXU), and AEP were project co-funders. URS Group was the prime contractor, and Apogee Scientific and ADA-ES were subcontractors. The host site for this program was NRG Texas Limestone Electric Generating Station (LMS) Units 1 and 2, located in Jewett, Texas. The plant fires a blend of Texas lignite and Powder River Basin (PRB) coal. Full-scale tests were conducted to evaluate the mercury removal performance of powdered sorbents injected into the flue gas upstream of the ESP (traditional configuration), upstream of the air preheater, and/or between electric fields within the ESP (Toxecon{trademark} II configuration). Phases I through III of the test program, conducted on Unit 1 in 2006-2007, consisted of three short-term parametric test phases followed by a 60-day continuous operation test. Selected mercury sorbents were injected to treat one quarter of the flue gas (e.g., approximately 225 MW equivalence) produced by Limestone Unit 1. Six sorbents and three injection configurations were evaluated and results were used to select the best combination of sorbent (Norit Americas DARCO Hg-LH at 2 lb/Macf) and injection location (upstream of the ESP) for a two-month performance evaluation. A mercury removal rate of 50-70% was targeted for the long-term test. During this continuous-injection test, mercury removal performance and variability were evaluated as the plant operated under normal conditions. Additional evaluations were made to determine any balance-of-plant ...
Date: December 31, 2009
Creator: Dombrowski, Katherine

Novel High Temperature Materials for In-Situ Sensing Devices

Description: The overriding goal of this project was to develop gas sensor materials and systems compatible with operation at temperatures from 500 to 700 C. Gas sensors operating at these temperatures would be compatible with placement in fossil-energy exhaust streams close to the combustion chamber, and therefore have advantages for process regulation, and feedback for emissions controls. The three thrusts of our work included investigating thin film gas sensor materials based on metal oxide materials and electroceramic materials, and also development of microhotplate devices to support the gas sensing films. The metal oxide materials NiO, In{sub 2}O{sub 3}, and Ga{sub 2}O{sub 3} were investigated for their sensitivity to H{sub 2}, NO{sub x}, and CO{sub 2}, respectively, at high temperatures (T > 500 C), where the sensing properties of these materials have received little attention. New ground was broken in achieving excellent gas sensor responses (>10) for temperatures up to 600 C for NiO and In{sub 2}O{sub 3} materials. The gas sensitivity of these materials was decreasing as temperatures increased above 500 C, which indicates that achieving strong sensitivities with these materials at very high temperatures (T {ge} 650 C) will be a further challenge. The sensitivity, selectivity, stability, and reliability of these materials were investigated across a wide range of deposition conditions, temperatures, film thickness, as using surface active promoter materials. We also proposed to study the electroceramic materials BaZr{sub (1-x)}Y{sub x}O{sub (3-x/2)} and BaCe{sub (2-x)}Ca{sub x}S{sub (4-x/2)} for their ability to detect H{sub 2}O and H{sub 2}S, respectively. This report focuses on the properties and gas sensing characteristics of BaZr{sub (1-x)}Y{sub x}O{sub (3-x/2)} (Y-doped BaZrO{sub 3}), as significant difficulties were encounter in generating BaCe{sub (2-x)}Ca{sub x}S{sub (4-x/2)} sensors. Significant new results were achieved for Y-doped BaZrO{sub 3}, including sensitivities of more than 60 atm{sup -1} for H{sub 2}O vapor at ...
Date: December 31, 2009
Creator: Solzbacher, Florian; Virkar, Anil; Rieth, Loren; Kannan, Srinivasan; Chen, Xiaoxin & Steinebach, Hannwelm

A Novel Low-Temperature Fiffusion Aluminide Coating for Ultrasupercritical Coal-Fried Boiler Applications

Description: An ultrasupercritical (USC) boiler with higher steam temperature and pressure is expected to increase the efficiency of the coal-fired power plant and also decrease emissions of air pollutants. Ferritic/martensitic alloys have been developed with good creep strength for the key components in coal-fired USC plants. However, they typically suffer excessive steam-side oxidation, which contributes to one of main degradation mechanisms along with the fire-side corrosion in coal-fired boilers. As the steam temperature further increases in USC boilers, oxidation of the tube internals becomes an increasing concern, and protective coatings such as aluminide-based diffusion coatings need to be considered. However, conventional aluminizing processes via pack cementation or chemical vapor deposition are typically carried out at elevated temperatures (1000-1150 C). Thermochemical treatment of ferritic/martensitic alloys at such high temperatures could severely degrade their mechanical properties, particularly the alloy's creep resistance. The research focus of this project was to develop an aluminide coating with good oxidation resistance at temperatures {le} 700 C so that the coating processing would not detrimentally alter the creep performance of the ferritic/martensitic alloys. Nevertheless, when the aluminizing temperature is lowered, brittle Al-rich intermetallic phases, such as Fe{sub 2}Al{sub 5} and FeAl{sub 3}, tend to form in the coating, which may reduce the resistance to fatigue cracking. Al-containing binary masteralloys were selected based on thermodynamic calculations to reduce the Al activity in the pack cementation process and thus to prevent the formation of brittle Al-rich intermetallic phases. Thermodynamic computations were carried out using commercial software HSC 5.0 for a series of packs containing various Cr-Al binary masteralloys. The calculation results indicate that the equilibrium partial pressures of Al halides at 700 C were a function of Al content in the Cr-Al alloys. Cr-25Al and Cr-15Al were chosen as the masteralloys in the pack cementation process. In contrast to pure ...
Date: December 31, 2009
Creator: Zhang, Ying

Security Classification Policy and Procedure: E.O. 12958, as Amended

Description: This report describes security classification policy and procedure, largely prescribed in a series of successive presidential executive orders issued over the past 50 years. This policy provides the rationale and arrangements for designating information officially secret for reasons of national security, and for its declassification as well.
Date: December 31, 2009
Creator: Kosar, Kevin R.

Simulating Potential Switchgrass Production in the United States

Description: Using results from field trials of switchgrass (Panicum virgatum L.) in the United States, the EPIC (Environmental Policy Integrated Climate) process-level agroecosystem model was calibrated, validated, and applied to simulate potential productivity of switchgrass for use as a biofuel feedstock. The model was calibrated with a regional study of 10-yr switchgrass field trials and subsequently tested against a separate compiled dataset of field trials from across the eastern half of the country. An application of the model in a national database using 8-digit watersheds as the primary modeling unit produces 30-yr average switchgrass yield estimates that can be aggregated to 18 major watersheds. The model projects average annual switchgrass productivity of greater than 7 Mg ha-1 in the Upper Mississippi, Lower Mississippi, and Ohio watersheds. The major factors limiting simulated production vary by region; low precipitation is the primary limiting factor across the western half of the country, while moderately acidic soils limit yields on lands east of the Mississippi River. Average projected switchgrass production on all crop land in the continental US is 5.6 Mg ha-1. At this level of productivity, 28.6 million hectares of crop land would be required to produce the 16 billion gallons of cellulosic ethanol called for by 2022 in the 2007 Energy Independence and Security Act. The model described here can be applied as a tool to inform the land-use and environmental consequences of switchgrass production.
Date: December 31, 2009
Creator: Thomson, Allison M.; Izaurralde, Roberto C.; West, T. O.; Parrish, David J.; Tyler, Donald D. & Williams, Jimmy R.