Bacterially induced precipitation of CaCO sub 3 : An example from studies of cyanobacterial mats (open access)

Bacterially induced precipitation of CaCO sub 3 : An example from studies of cyanobacterial mats

Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, induced the precipitation of calcium carbonate under controlled conditions. Crusts, the largest features formed, are composed of 5--200{mu}m diameter bundles which are, in turn, composed of numerous individual crystals. The smallest observed features are 0.1--0.4{mu}m spheres and rods which comprise some individual crystals and crystal bundles. Crystal bundles resembling rhombohedra, tetragonal disphenoids, tetragonal dipyramids, and calcite dumbbells appear to be uniquely bacterial in origin, and they have all been observed in recent sediments. Swollen rods, discs, curved dumbbells, and 50--200{mu}m optically continuous crystals resembling brushes may be uniquely bacterial in origin, however, they have not been reported by other laboratories nor observed in natural settings. Presence of any of these forms in recent sediments should be taken as strong evidence for bacterial influence. Spheres and aragonite dumbbells have also been …
Date: April 30, 1990
Creator: Chafetz, H. S.
Object Type: Report
System: The UNT Digital Library
Energy-conserving perennial agriculture for marginal land in southern Appalachia. Final technical report (open access)

Energy-conserving perennial agriculture for marginal land in southern Appalachia. Final technical report

USDA economists predict the end of surplus farm production in the US within this decade. More and more marginal land will be cropped to provide feed for the growing world population and to produce energy. Much of this potential cropland in Southern Appalachia is poorly suited to annual crops, such as corn. Perennial crops are much better suited to steep, rocky, and wet sites. Research was undertaken on the theoretical potentials of perennial species with high predicted yields of protein, carbohydrates, or oils. Several candidate staple perennial crops for marginal land in Southern Appalachia were identified, and estimates were made of their yields, energy input requirements, and general suitabilities. Cropping systems incorporating honeylocust, persimmon, mulberry, jujube, and beech were compared with corn cropping systems. It appears that these candidate staple perennials show distinct advantages for energy conservation and environmental preservation. Detailed economic analyses must await actual demonstration trials, but preliminary indications for ethanol conversion systems with honeylocust are encouraging. It is suggested that short-term loans to farmers undertaking this new type of agriculture would be appropriate to solve cash-flow problems.
Date: January 30, 1982
Creator: Williams, G.
Object Type: Report
System: The UNT Digital Library
THE DEVELOPMENT OF COAL-BASED TECHNOLOGIES FOR DEPARTMENT OF DEFENSE FACILITIES (open access)

THE DEVELOPMENT OF COAL-BASED TECHNOLOGIES FOR DEPARTMENT OF DEFENSE FACILITIES

The third phase of a three-phase project investigating the development of coal-based technologies for US Department of Defense (DOD) facilities was completed. The objectives of the project were to: decrease DOD's dependence on foreign oil and increase its use of coal; promote public and private sector deployment of technologies for utilizing coal-based fuels in oil-designed combustion equipment; and provide a continuing environment for research and development of coal-based fuel technologies for small-scale applications at a time when market conditions in the US are not favorable for the introduction of coal-fired equipment in the commercial and industrial capacity ranges. The Phase III activities were focused on evaluating deeply-cleaned coals as fuels for industrial boilers and investigating emissions control strategies for providing ultra-low emissions when firing coal-based fuels. This was addressed by performing coal beneficiation and preparation studies, and bench- to demonstration-scale emissions reduction studies. In addition, economic studies were conducted focused on determining cost and market penetration, selection of incentives, and regional economic impacts of coal-based technologies.
Date: January 30, 2004
Creator: Miller, Bruce G.; Miller, Sharon Falcone; Pisupati, Sarma V.; Song, Chunshan; Wasco, Ronald S.; Wincek, Ronald T. et al.
Object Type: Report
System: The UNT Digital Library
Bacterially induced precipitation of CaCO{sub 3}: An example from studies of cyanobacterial mats. Final report (open access)

Bacterially induced precipitation of CaCO{sub 3}: An example from studies of cyanobacterial mats. Final report

Bacteria induce the precipitation of calcium carbonate in the laboratory and in nature by altering their chemical environment. Geologists are recognizing the possibility that bacterially induced precipitates may form significant mineral deposits, unfortunately, there are currently no sound criteria by which they can be recognized in recent sediments, or in the rock record. Cultures of aerobic and facultative bacteria from cyanobacterial mats on Andros Island, Bahamas, and Baffin Bay, Texas, induced the precipitation of calcium carbonate under controlled conditions. Crusts, the largest features formed, are composed of 5--200{mu}m diameter bundles which are, in turn, composed of numerous individual crystals. The smallest observed features are 0.1--0.4{mu}m spheres and rods which comprise some individual crystals and crystal bundles. Crystal bundles resembling rhombohedra, tetragonal disphenoids, tetragonal dipyramids, and calcite dumbbells appear to be uniquely bacterial in origin, and they have all been observed in recent sediments. Swollen rods, discs, curved dumbbells, and 50--200{mu}m optically continuous crystals resembling brushes may be uniquely bacterial in origin, however, they have not been reported by other laboratories nor observed in natural settings. Presence of any of these forms in recent sediments should be taken as strong evidence for bacterial influence. Spheres and aragonite dumbbells have also been …
Date: April 30, 1990
Creator: Chafetz, H. S.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Establishment of an Industry-Driven Consortium Focused on Improving the Production Performance of Domestic Stripper Wells (open access)

Establishment of an Industry-Driven Consortium Focused on Improving the Production Performance of Domestic Stripper Wells

None
Date: June 30, 2005
Creator: Morrison, Joel L.
Object Type: Report
System: The UNT Digital Library
Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico (open access)

Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

None
Date: April 30, 2008
Creator: Mancini, Ernest
Object Type: Report
System: The UNT Digital Library
An Assessment of Geological Carbon Sequestration Options in the Illinois Basin (open access)

An Assessment of Geological Carbon Sequestration Options in the Illinois Basin

The Midwest Geological Sequestration Consortium (MGSC) has investigated the options for geological carbon dioxide (CO{sub 2}) sequestration in the 155,400-km{sup 2} (60,000-mi{sup 2}) Illinois Basin. Within the Basin, underlying most of Illinois, western Indiana, and western Kentucky, are relatively deeper and/or thinner coal resources, numerous mature oil fields, and deep salt-water-bearing reservoirs that are potentially capable of storing CO{sub 2}. The objective of this Assessment was to determine the technical and economic feasibility of using these geological sinks for long-term storage to avoid atmospheric release of CO{sub 2} from fossil fuel combustion and thereby avoid the potential for adverse climate change. The MGSC is a consortium of the geological surveys of Illinois, Indiana, and Kentucky joined by six private corporations, five professional business associations, one interstate compact, two university researchers, two Illinois state agencies, and two consultants. The purpose of the Consortium is to assess carbon capture, transportation, and storage processes and their costs and viability in the three-state Illinois Basin region. The Illinois State Geological Survey serves as Lead Technical Contractor for the Consortium. The Illinois Basin region has annual emissions from stationary anthropogenic sources exceeding 276 million metric tonnes (304 million tons) of CO{sub 2} (>70 million tonnes …
Date: September 30, 2005
Creator: Finley, Robert
Object Type: Report
System: The UNT Digital Library
The development of coal-based technologies for Department of Defense facilities. Semiannual technical progress report, September 28, 1993--March 27, 1994 (open access)

The development of coal-based technologies for Department of Defense facilities. Semiannual technical progress report, September 28, 1993--March 27, 1994

The U.S. Department of Defense (DOD), through an Interagency Agreement with the U.S. Department of Energy (DOE), has initiated a three-phase program with the Consortium for Coal-Water Slurry Fuel Technology, with the aim of decreasing DOD`s reliance on imported oil by increasing its use of coal. The program is being conducted as a cooperative agreement between the Consortium and DOE and the first two phases of the program are underway. To achieve the objectives of the program, a team of researchers was assembled. Phase I activities are focused on developing clean, coal-based combustion technologies for the utilization of both micronized coal-water slurry fuels (MCWSFS) and dry, micronized coal (DMC) in fuel oil-designed industrial boilers. Phase II research and development activities will continue to focus on industrial boiler retrofit technologies by addressing emissions control and precombustion (i.e., slagging combustion and/or gasification) strategies for the utilization of high ash, high sulfur coals. Phase III activities will examine coal-based fuel combustion systems that cofire wastes. Each phase includes an engineering cost analysis and technology assessment. The activities and status of Phases I and II are described below. The objective in Phase I is to deliver fully engineered retrofit options for a fuel oil-designed …
Date: November 30, 1994
Creator: Miller, B. G.; Morrison, J. L.; Sharifi, R.; Shepard, J. F.; Scaroni, A. W.; Hogg, R. et al.
Object Type: Report
System: The UNT Digital Library
Assessing the impacts of climate change on natural resource systems (open access)

Assessing the impacts of climate change on natural resource systems

This volume is a collection of papers addressing the theme of potential impacts of climatic change. Papers are entitled Integrated Assessments of the Impacts of Climatic Change on Natural Resources: An Introductory Editorial; Framework for Integrated Assessments of Global Warming Impacts; Modeling Land Use and Cover as Part of Global Environmental Change; Assessing Impacts of Climatic Change on Forests: The State of Biological Modeling; Integrating Climatic Change and Forests: Economic and Ecological Assessments; Environmental Change in Grasslands: Assessment using Models; Assessing the Socio-economic Impacts of Climatic Change on Grazinglands; Modeling the Effects of Climatic Change on Water Resources- A Review; Assessing the Socioeconomic Consequences of Climate Change on Water Resources; and Conclusions, Remaining Issues, and Next Steps.
Date: November 30, 1994
Creator: Frederick, Kenneth D. & Rosenberg, Norman J.
Object Type: Report
System: The UNT Digital Library
Assessment of plant-derived hydrocarbons. Final report (open access)

Assessment of plant-derived hydrocarbons. Final report

A number of hydrocarbon producing plants are evaluated as possible sources of rubber, liquid fuels, and industrial lubricants. The plants considered are Euphorbia lathyris or gopher plant, milkweeds, guayule, rabbit brush, jojoba, and meadow foam. (ACR)
Date: September 30, 1981
Creator: McFadden, Kathleen & Nelson, Samuel H.
Object Type: Report
System: The UNT Digital Library
Slurry pipelines: economic and political issues. A review (open access)

Slurry pipelines: economic and political issues. A review

In the controversy surrounding the proposal to grant Federal eminent domain to coal-slurry pipelines, the fundamental issue is whether, on balance, such a grant is in the national interest. The principal subissues (peripheral issues) of economics, water supply and disposal, energy consumption and conservation, employment, safety, and environmental impact are analyzed. It is found that, as compared with unit trains, which are the only immediate alternative for movement of large quantities of Western coal, the pipelines are not against the national interest, except in the case of employment. It is concluded that, on balance, the pipelines are in the national interest and should be granted the power of Federal eminent domain.
Date: November 30, 1977
Creator: Banks, W. F.
Object Type: Report
System: The UNT Digital Library