Association of N2-fixing cyanobacteria and plants: towards novel symbioses of agricultural importance (open access)

Association of N2-fixing cyanobacteria and plants: towards novel symbioses of agricultural importance

Some nitrogen-fixing cyanobacteria are able to form symbioses with a wide variety of plants. Nostoc 2S9B is unusual in its ability to infect the roots of wheat, raising the prospect of a productive association with an important crop plant. The goal of the project was to lay the groundwork for the use of novel associations between Nostoc and crops of agronomic importance, thereby reducing our reliance on nitrogenous fertilizer. Nostoc 2S9B was found to enter roots through mechanical damage of roots and reside primarily in intercellular spaces. The strain could also be incorporated into wheat calli grown in tissue culture. In both cases, the rate of nitrogen fixation by the cyanobacterium was higher than that of the same strain grown with no plant present. Artificial nodules induced by the action of hormone 2,4D were readily infected by Nostoc 2S9B, and the cyanobacteria within such nodules fixed nitrogen under fully aerobic conditions. The nitrogen fixed was shown to be incorporated into the growing wheat seedlings. Nostoc thus differs from other bacteria in its ability to fix nitrogen in para-nodules without need for artificially microaerobic conditions. It would be useful to introduce foreign DNA into Nostoc 2S9B in order to make defined …
Date: June 25, 2001
Creator: Elhai, Jeff
Object Type: Report
System: The UNT Digital Library
Demand responsive programs - an emerging resource for competitive electricity markets? (open access)

Demand responsive programs - an emerging resource for competitive electricity markets?

The restructuring of regional electricity markets in the U.S. has been accompanied by numerous problems, including generation capacity shortages, transmission congestion, wholesale price volatility, and reduced system reliability. These problems have created significant new opportunities for technologies and business approaches that allow load serving entities and other aggregators, to control and manage the load patterns of their wholesale or retail end-users. These technologies and business approaches for manipulating end-user load shapes are known as Load Management or, more recently, Demand Responsive programs. Lawrence Berkeley National Laboratory (LBNL) is conducting case studies on innovative demand responsive programs and presents preliminary results for five case studies in this paper. These case studies illustrate the diversity of market participants and range of technologies and business approaches and focus on key program elements such as target markets, market segmentation and participation results; pricing scheme; dispatch and coordination; measurement, verification, and settlement; and operational results where available.
Date: June 25, 2001
Creator: Heffner, Grayson C. Dr. & Goldman, Charles A.
Object Type: Article
System: The UNT Digital Library
Explosion in the Granite Field: Hardening and Softening Behavior in Rocks (open access)

Explosion in the Granite Field: Hardening and Softening Behavior in Rocks

Properties of rock materials under quasistatic conditions are well characterized in laboratory experiments. Unfortunately, quasistatic data alone are not sufficient to calibrate models for use to describe inelastic wave propagation associated with conventional and nuclear explosions, or with impact. First, rock properties are size-dependent. properties measured using laboratory samples on the order of a few centimeters in size need to be modified to adequately describe wave propagation in a problem on the order of a few hundred meters in size. Second, there is lack of data about the damage (softening) behavior of rock because most laboratory tests focus on the pre-peak hardening region with very little emphasis on the post-peak softening region. This paper presents a model for granite that accounts for both the hardening and softening of geologic materials, and also provides a simple description of rubblized rock. The model is shown to reproduce results of quasistatic triaxial experiments as well as peak velocity and peak displacement attenuation from a compendium of dynamic wave propagation experiments that includes US and French nuclear tests in granite.
Date: June 25, 2001
Creator: Lomov, I N; Antoun, T H & Glenn, L A
Object Type: Article
System: The UNT Digital Library
Measured energy savings and demand reduction from a reflective roof membrane on a large retail store in Austin (open access)

Measured energy savings and demand reduction from a reflective roof membrane on a large retail store in Austin

In this study, we measured and documented summertime air-conditioning (a/c) daily energy savings and demand reduction from a reflective roof membrane retrofit on a large retail store in Austin, Texas. The original black rubber membrane was replaced with white thermoplastic resulting in a decrease in the average maximum roof surface temperature from 168 degrees F (76 degrees C) to 126 degrees F (52 degrees C). This building, with 100,000ft2 (9300m2) of roof area, yielded 3.6Wh/ft2 (39Wh/m2) in a/c average daily energy savings and 0.35W/ft2 (3.8W/m2) in average reduced demand. Total a/c annual abated energy and demand expenditures were estimated to be $7200 or $0.072/ft2 ($0.77/m2). Based on cost data provided by the building manager, the payback is instantaneous with negligible incremental combined labor and material costs. The estimated present value of future abated expenditures ranged from $62,000 to $71,000 over the baseline 13-year service life of the roof membrane.
Date: June 25, 2001
Creator: Konopacki, Steven J. & Akbari, Hashem
Object Type: Report
System: The UNT Digital Library
Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging (open access)

Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

The myriad of human activities including strategic and energy development at various DOE installations have resulted in the contamination of soils and waterways that can seriously threaten human and ecosystem health. Development of efficacious and economical remediation technologies is needed to ameliorate these immensely costly problems. Bioremediation (both plant and microbe-based) has promising potential to meet this demand but still requires advances in fundamental knowledge. For bioremediation of heavy metals, the three-way interaction of plant root, microbial community, and soil organic matter (SOM)1 in the rhizosphere is critically important for long-term sustainability but often underconsidered. Particularly urgent is the need to understand processes that lead to metal ion stabilization in soils, which is crucial to all of the goals of bioremediation: removal, stabilization, and transformation. This project will build on the knowledge that we have generated on the role of root exudation and metabolism for metal mobilization and accumulation, to address the following objectives: (1) Identify molecular markers and characterize the chemical nature of recalcitrant SOM pools that are involved in below ground metal ion interactions, which are likely to be markers for sustainable sequestration; (2) Utilize (1) to determine plant and microbial factors that contribute to sustainable metal sequestration …
Date: June 25, 2001
Creator: Fan, Teresa W. M.; Higashi, Richard M. & Crowley
Object Type: Report
System: The UNT Digital Library
Minatom of Russia Situation and Crisis Center and the Automated Federal Information System for Nuclear Material Control and Accounting (open access)

Minatom of Russia Situation and Crisis Center and the Automated Federal Information System for Nuclear Material Control and Accounting

Under the Situation and Crisis Center (SCC) management, the Information Analytical Center (IAC) of the Ministry of Atomic Energy (Minatom) of Russia was created to oversee the operation of the Federal Nuclear Material Control and Accounting Information System (FIS). During 2000, the FIS achieved an important milestone in its development: the basic functions of the information system were implemented. This includes placing into operation the collecting and processing of nuclear material control and accounting (MC&A) information from the enterprises reporting to the FIS. The FIS began working with 14 Russian enterprises to develop and implement full-function reporting (i.e., reporting inventory and inventory changes including closeout and reconciliation between the FIS and enterprises). In 2001, the system will expand to include enterprise-level inventory information for all enterprises using nuclear materials in Russia. For this reason, at the end of 2000 through the beginning of 2001, five separate training sessions were held for over 100 enterprise personnel responsible for preparation and transfer of the reports to the FIS. Through the assistance of the Nuclear Material Protection, Control and Accounting (MPC&A) program, information systems for the accounting of nuclear materials are being installed at Russia enterprises. In creating the program for modernization of …
Date: June 25, 2001
Creator: Berchik, V. P.; Kasumova, L. A.; Babcock, R. A.; Heinberg, C. L. & Tynan, D. M.
Object Type: Article
System: The UNT Digital Library
MINIMIZING NET CARBON DIOXIDE EMISSIONS BY OXIDATIVE CO-PYROLYSIS OF COAL/BIOMASS BLENDS (open access)

MINIMIZING NET CARBON DIOXIDE EMISSIONS BY OXIDATIVE CO-PYROLYSIS OF COAL/BIOMASS BLENDS

Solid fuels vary significantly with respect to the amount of CO{sub 2} directly produced per unit heating value. Elemental carbon is notably worse than other solid fuels in this regard, and since carbon (char) is an intermediate product of the combustion of almost all solid fuels, there is an opportunity to reduce specific CO{sub 2} emissions by reconfiguring processes to avoid char combustion wholly or in part. The primary goal of this one-year Innovative Concepts project is to make a fundamental thermodynamic assessment of three modes of solid fuel use: (1) combustion, (2) carbonization, and (3) oxidative pyrolysis, for a wide range of coal and alternative solid fuels. This period a large set of thermodynamic calculations were carried out to assess the potential of the three processes. The results show that the net carbon dioxide emissions and the relative ranking of the different processes depends greatly on the particular baseline fossil fuel being displaced by the new technology. As an example, in a baseline natural gas environment, it is thermodynamically more advantageous to carbonize biomass than to combust it, and even more advantageous to oxidatively pyrolyze the biomass.
Date: June 25, 2001
Creator: Hurt, Robert & Lang, Todd
Object Type: Report
System: The UNT Digital Library
Monitoring the consistency of multiphase waste forms. (open access)

Monitoring the consistency of multiphase waste forms.

Methods are being developed for demonstrating that nonstandard high-level radioactive waste (HLW) forms meet the intent of the product consistency requirement in the Waste Acceptance System Requirements document (WASRD). That requirement was established for borosilicate HLW glasses ''to ensure a consistent glass product by controlling the vitrification process, consistency is necessary to reflect consideration for the waste package designs.'' [1] The test method specified in the WASRD for HLW glasses is the 7-day product consistency test (PCT). To meet the WASRD requirement, the response of an HLW glass in the PCT must be less than that of the environmental assessment (EA) glass. The EA glass is used as a benchmark ''so that conservative but realistic assessments of the engineered barrier system performance can be made.'' [1] The PCT and the WASRD requirement were developed to bound the behaviors of the wide range of borosilicate HLW glasses that will be produced at DOE facilities for the purpose of repository design. However, the need to demonstrate that the physical, chemical, and radiological properties of HLW forms have been constrained within acceptable (i.e., as-qualified) ranges will probably apply to all HLW waste forms. The PCT may not be the appropriate method for nonstandard …
Date: June 25, 2001
Creator: Ebert, W. L.; Lewis, M. A. & Johnson, S. G.
Object Type: Article
System: The UNT Digital Library
Nuclear Material Management in Russia and New Federal Nuclear Material Control and Accounting Regulations (open access)

Nuclear Material Management in Russia and New Federal Nuclear Material Control and Accounting Regulations

The Russian Federation Ministry of Atomic Energy (Minatom) is the federal authority empowered with the management of state-owned nuclear materials, with the exception of military applications. The Russian Federal Nuclear Materials Control and Accounting Information System (FIS) is a key component in establishing an effective nuclear materials management system in the Russian Federation. In December 2000, the Russian government issued the decree to enter into force the regulation on the accounting and control of nuclear materials and directed the State System of Accounting and Control (SSAC) of nuclear materials should begin October 2001. This regulation establishes the basic accounting documents and the requirement to report them to the FIS to launch the State Nuclear Material Registry of nuclear materials. The Nuclear Material Registry contains information on agencies and operating organizations that use nuclear material, along with the kinds, quantity and other characteristics of nuclear material. Minatom will use the Registry and the supporting database and functionality that reside in the FIS for carrying out the functions of nuclear materials management. At the same time, the FIS provides for reporting from material balance areas (MBA). With American support, 14 Russian enterprises are reporting material balance area level information to the FIS …
Date: June 25, 2001
Creator: Martyanov, A. A.; Pitel, V. A.; Babcock, R. A.; Heinberg, C. L. & Tynan, D. M.
Object Type: Article
System: The UNT Digital Library
PRODUCTION CONSIDERATIONS FOR THE CLASSICAL PET NUCLIDES. (open access)

PRODUCTION CONSIDERATIONS FOR THE CLASSICAL PET NUCLIDES.

Nuclear Medicine is the specialty of medical imaging, which utilizes a variety of radionuclides incorporated into specific compounds for diagnostic imaging and therapeutic applications. During recent years, research efforts associated with this discipline have concentrated on the decay characteristics of particular radionuclides and the design of unique radiolabeled tracers necessary to achieve time-dependent molecular images. The specialty is expanding with specific Positron emission tomography (PET) and SPECT radiopharmaceuticals allowing for an extension from functional process imaging in tissue to pathologic processes and nuclide directed treatments. PET is an example of a technique that has been shown to yield the physiologic information necessary for clinical oncology diagnoses based upon altered tissue metabolism. Most PET drugs are currently produced using a cyclotron at locations that are in close proximity to the hospital or academic center at which the radiopharmaceutical will be administered. In November 1997, a law was enacted called the Food and Drug Administration Modernization Act of 1997 which directed the Food and Drug Administration (FDA) to establish appropriate procedures for the approval of PET drugs in accordance with section 505 of the Federal Food, Drug, and Cosmetic Act and to establish current good manufacturing practice requirements for such drugs. At …
Date: June 25, 2001
Creator: Finn, R. & Schlyer, D.
Object Type: Book
System: The UNT Digital Library
Re-Engineering Casting Production Systems - Final Report - 03/02/1998 - 03/01/2001 (open access)

Re-Engineering Casting Production Systems - Final Report - 03/02/1998 - 03/01/2001

The goal of this three-year project was to improve the production systems in use by steel foundries in the United States. Improvements in the production systems result in less rework, less scrap, and less material handling, all of which would significantly reduce the energy demands of the process. Furthermore, these improvements would allow the companies to be more competitive, more responsive to customers' needs, deliver products with less lead time and require less capital. The ultimate result is a stronger domestic steel casting industry, which uses less energy. A major portion of this research involved the deployment of student researchers at steel foundries, to study their production systems and collect data.
Date: June 25, 2001
Creator: Peters, Frank & Van Voorhis, Timothy
Object Type: Report
System: The UNT Digital Library
Renewable Liquid Optics with Magneto-electrostatic Control (open access)

Renewable Liquid Optics with Magneto-electrostatic Control

We suggest a new class of high-flux renewable optics, in particular, for the use at the X-ray free electron laser, LCLS, which is under discussion now. The size of optical elements we have in mind is from a fraction of a square centimeter to a few square centimeters. We suggest that working fluid be pressed through a porous substrate (made, e.g., of fused capillaries) to form a film, a few tens to a hundred microns thick. After the passage of an intense laser pulse, the liquid film is sucked back through the substrate by a reversed motion of the piston, and formed anew before the next pulse. The working surface of the film is made flat by capillary forces. We discuss the role of viscous, gravitational, and capillary forces in the dynamics of the film and show that the properly made film can be arbitrarily oriented with respect to the gravitational force. This makes the proposed optics very flexible. We discuss effects of vibrations of the supporting structures on the quality of optical elements. Limitations on the radiation intensity are formulated. We show how the shape of the film surface can be controlled by electrostatic and magnetic forces, allowing one …
Date: June 25, 2001
Creator: Ryutov, D & Toor, A
Object Type: Article
System: The UNT Digital Library
SEPARATION OF HYDROGEN AND CARBON DIOXIDE USING A NOVEL MEMBRANE REACTOR IN ADVANCED FOSSIL ENERGY CONVERSION PROCESS (open access)

SEPARATION OF HYDROGEN AND CARBON DIOXIDE USING A NOVEL MEMBRANE REACTOR IN ADVANCED FOSSIL ENERGY CONVERSION PROCESS

Inorganic membrane reactors offer the possibility of combining reaction and separation in a single operation at high temperatures to overcome the equilibrium limitations experienced in conventional reactor configurations. Such attractive features can be advantageously utilized in a number of potential commercial opportunities, which include dehydrogenation, hydrogenation, oxidative dehydrogenation, oxidation and catalytic decomposition reactions. However, to be cost effective, significant technological advances and improvements will be required to solve several key issues which include: (a) permselective thin solid film, (b) thermal, chemical and mechanical stability of the film at high temperatures, and (c) reactor engineering and module development in relation to the development of effective seals at high temperature and high pressure. In this project, we are working on the development and application of palladium and palladium-silver alloy thin-film composite membranes in membrane reactor-separator configuration for simultaneous production and separation of hydrogen and carbon dioxide at high temperature. From our research on Pd-composite membrane, we have demonstrated that the new membrane has significantly higher hydrogen flux with very high perm-selectivity than any of the membranes commercially available. The steam reforming of methane by equilibrium shift in Pd-composite membrane reactor is being studied to demonstrate the potential application this new development. To …
Date: June 25, 2001
Creator: Ilias, Shamsuddin
Object Type: Report
System: The UNT Digital Library
Slow-Growing Subdivisions in any Dimension: Towards Removing the Curse of Dimensionality (open access)

Slow-Growing Subdivisions in any Dimension: Towards Removing the Curse of Dimensionality

The efficient representation of volumetric meshes is a central problem in scientific visualization. The difference in performance between most visualization algorithm for rectilinear grids and for unstructured mesh is mostly due to fundamental difference in efficiency of their representations. In Computer Graphics the gap in performance between 2D rectilinear grids and unstructured mesh has been overcome with the development of representation schemes based on the concept of subdivision surfaces. This gap has not been bridged in the volumetric cases which is fundamental interest for Scientific Visualization. In this paper we introduce a slow-growing volumetric subdivision scheme for meshes of any topology, any intrinsic dimension d and composed of a general type of polyhedral cells (topological balls). The main feature of this approach is the ability to split in different stages cells of different dimensions. This allows to increase the resolution of the mesh slowly using small stencils for the smoothing rules. ''Sharp features'' of dimension lower than d are embedded naturally in the subdivision procedure. Automatic adaptation is provided for variable resolution. In the uniform case the slow subdivision doubles the number of vertices in the mesh at each refinement independent of its dimension d. The bisection of all the …
Date: June 25, 2001
Creator: Pascucci,V
Object Type: Report
System: The UNT Digital Library
Super-LOTIS/LOTIS/LITE: Prompt GRB Followup Experiments (open access)

Super-LOTIS/LOTIS/LITE: Prompt GRB Followup Experiments

LOTIS (Livermore Optical Transient Imaging System) and Super-LOTIS are automatic telescope systems that measure very prompt optical emission occurring within seconds of the gamma-ray energy release during a Gamma Ray Burst (GRB). Unlike hour-to-days delayed afterglow measurements, very early measurements will contain information about the GRB progenitor. To accomplish this, we developed and have been operating automated telescopes that rapidly image GRB coordinate error boxes in response to triggers distributed by the GRB Coordinate Distribution Network (GCN). LOTIS, located in California, consists of 4 cameras each with a different astronomical filter (B, V, R, open) that can respond to GRB triggers within 5 s. Super-LOTIS can point to any part of the sky within 30 s upon receipt of a GCN trigger and its sensitivity is as deep as V = 17-19 depending on the integration times. Since the shutdown of the CGRO, there has been no real-time GRE3 triggers that enable the LOTIS systems to measure real-time GRE3 counterpart fluxes as of May 2001. This paper describes performance of these systems. We also present our plan to replace the current optical CCD camera on the Super-LOTIS to a near infrared camera to be able to probe dusty GRB environment.
Date: June 25, 2001
Creator: Park, H. S.; Ables, E.; Barthelmy, S.; Bradshaw, M.; Cline, T.; Gehrels, N. et al.
Object Type: Article
System: The UNT Digital Library
Thermodynamic Critical Field and Superconducting Fluctuation of Vortices for High Temperature Cuprate Superconductor: La-214 (open access)

Thermodynamic Critical Field and Superconducting Fluctuation of Vortices for High Temperature Cuprate Superconductor: La-214

Thermodynamics has been studied systematically for the high temperature cuprate superconductor La{sub 2-x}Sr{sub x}CuO{sub 4-{delta}}, La-214, in the entire superconductive region from strongly underdoped to strongly overdoped regimes. Magnetization studies with H {parallel} c have been made in order to investigate the changes in free energy of the system as the number of carriers is reduced. Above the superconducting transition temperature, the normal-state magnetization exhibits a two-dimensional Heisenberg antiferromagnetic behavior. Below T{sub c}, magnetization data are thermodynamically reversible over large portions of the H-T plane, so the free energy is well defined in these regions. As the Sr concentration is varied over the wide range from 0.060 (strongly underdoped) to 0.234 (strongly overdoped), the free energy change goes through a maximum at the optimum doped in a manner similar to the T{sub c0} vs. x curve. The density of states, N(0), remains nearly constant in the overdoped and optimum doped regimes, taking a broad maximum around x = 0.188, and then drops abruptly towards zero in the underdoped regime. The La{sub 2-x}Sr{sub x}CuO{sub 4} (La-214) system displays the fluctuating vortex behavior with the characteristic of either 2D or 3D fluctuations as indicated by clearly identifiable crossing points T* close to …
Date: June 25, 2001
Creator: Finnemore, Douglas K.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
VNIIEF-ORNL Joint Plutonium Measurements with NMIS and Results of Plutonium Attributes Preliminary Evaluations (open access)

VNIIEF-ORNL Joint Plutonium Measurements with NMIS and Results of Plutonium Attributes Preliminary Evaluations

Within the frameworks of TO No.007 between ORNL and VNIIEF on Nuclear Materials Identification System (NMIS) mastering at VNIIEF in July 2000 there had been finalized joint measurements, in which NMIS-technique equipment was used that had been placed at VNIIEF's disposal by ORNL, as well as VNIIEF-produced unclassified samples of fissile materials. In the report there are presented results of experimental data preliminary processing to obtain absolute values of some attributes used in plutonium shells measurements: values of their mass and thickness. Possibility of fissile materials parameters absolute values obtaining from measurement data essentially widens NMIS applicability to the tasks relevant to these materials inspections.
Date: June 25, 2001
Creator: Gurov, V. V.; Kuvshinov, M. I.; Popov, V. A.; Dubinin, V. P. & J. K. Mattingly, J. T. Mihalczo
Object Type: Article
System: The UNT Digital Library
The VRFurnace: A Virtual Reality Application for Energy System Data Analysis (open access)

The VRFurnace: A Virtual Reality Application for Energy System Data Analysis

The VRFurnace is a unique VR application designed to analyze a complete coal-combustion CFD model of a power plant furnace. Although other applications have been created that analyze furnace performance, no other has included the added complications of particle tracking and the reactions associated with coal combustion. Currently the VRFurnace is a versatile analysis tool. Data translators have been written to allow data from most of the major commercial CFD software packages as well as standard data formats of hand-written code to be uploaded into the VR application. Because of this almost any type of CFD model of any power plant component can be analyzed immediately. The ease of use of the VRFurnace is another of its qualities. The menu system created for the application not only guides first time users through the various button combinations but it also helps the experienced user keep track of which tool is being used. Because the VRFurnace was designed for use in the C6 device at Iowa State University's Virtual Reality Applications Center it is naturally a collaborative project. The projection-based system allows many people to be involved in the analysis process. This type of environment opens the design process to not only …
Date: June 25, 2001
Creator: Johnson, Peter Eric
Object Type: Thesis or Dissertation
System: The UNT Digital Library
An XML-based protocol for distributed event services (open access)

An XML-based protocol for distributed event services

A recent trend in distributed computing is the construction of high-performance distributed systems called computational grids. One difficulty we have encountered is that there is no standard format for the representation of performance information and no standard protocol for transmitting this information. This limits the types of performance analysis that can be undertaken in complex distributed systems. To address this problem, we present an XML-based protocol for transmitting performance events in distributed systems and evaluate the performance of this protocol.
Date: June 25, 2001
Creator: Gunter, Dan K.; Smith, Warren & Quesnel, Darcy
Object Type: Article
System: The UNT Digital Library