Identification of the mineral phases responsible for cementation of Lurgi spent oil shale (open access)

Identification of the mineral phases responsible for cementation of Lurgi spent oil shale

The purpose of this study is to investigate the mineralogical character of the cements that are responsible for the increased strength of the spent oil shale. Several techniques to identify the nature of the cementing agents have been used in this study. X-ray diffraction was used to identify mineral dissolution and formation; scanning electron microscopy (SEM) was used to observe the cementing agents; energy dispersive X-ray analysis (EDXA) was used to provide information on the elemental composition of both the bulk material and the cementing agents; and differential thermal analyses and thermogravimetric analyses were used to document the presence of suspected minerals that may be involved in formation of the cementing material.
Date: February 1, 1991
Creator: Brown, M.; Huntington, G. & Brown, T.
Object Type: Report
System: The UNT Digital Library
Identification of the mineral phases responsible for cementation of Lurgi spent oil shale (open access)

Identification of the mineral phases responsible for cementation of Lurgi spent oil shale

The purpose of this study is to investigate the mineralogical character of the cements that are responsible for the increased strength of the spent oil shale. Several techniques to identify the nature of the cementing agents have been used in this study. X-ray diffraction was used to identify mineral dissolution and formation; scanning electron microscopy (SEM) was used to observe the cementing agents; energy dispersive X-ray analysis (EDXA) was used to provide information on the elemental composition of both the bulk material and the cementing agents; and differential thermal analyses and thermogravimetric analyses were used to document the presence of suspected minerals that may be involved in formation of the cementing material.
Date: February 1, 1991
Creator: Brown, M.; Huntington, G. & Brown, T.
Object Type: Report
System: The UNT Digital Library
Results of Phase 2 postburn drilling, coring, and logging: Rocky Mountain 1 Underground Coal Gasification Test, Hanna, Wyoming (open access)

Results of Phase 2 postburn drilling, coring, and logging: Rocky Mountain 1 Underground Coal Gasification Test, Hanna, Wyoming

The Rocky Mountain 1 (RM1) Underground Coal Gasification (UCG) site consisted of two different module configurations: the controlled retracting injection point (CRIP) and elongated linked well (ELW) configurations. The postburn coring of the RM1 UCG site was designed in two phases to fulfill seven objectives outlined in Western Research Institute's Annual Project Plan for 1989 (Western Research Institute 1989). The seven objectives were to (1) delineate the areal extent of the cavities, (2) identify the extent of roof collapse, (3) obtain samples of all major cavity rock types, (4) characterize outflow channels and cavity stratigraphy, (5) characterize the area near CRIP points and ignition points, (6) further define the structural geology of the site, and (7) identify the vertical positioning of the horizontal process wells within the coal seam. Phase 1 of the coring was completed during the summer of 1989 and served to partially accomplish all seven objectives. A detailed description of Phase 1 results was presented in a separate report (Lindblom et al. 1990). Phase 2, completed during the summer of 1990, was designed to complete the seven objectives; more specifically, to further define the areal extent and location of the cavities, to evaluate the outflow channels for …
Date: February 1, 1991
Creator: Oliver, R. L.; Lindblom, S. R. & Covell, J. R.
Object Type: Report
System: The UNT Digital Library
Evaluation of saponite and saponite/sepiolite fluids for geothermal drilling (open access)

Evaluation of saponite and saponite/sepiolite fluids for geothermal drilling

The rheology and other properties of drilling fluids containing saponite and a saponite-sepiolite mixture as the main vicosifier have been systematically evaluated in the temperature range of 300-600{degree}F under appropriate confining pressures up to 16,000 psi. Saponite represents the magnesium analog of the clay mineral montmorillonite, which is the main constituent in conventional bentonite-based fluids. The fluid with 6% saponite exhibits a prominent viscosity enhancement at temperatures above 250{degree}F. This viscosity enhancement is easily controlled by salts and hydroxides of Na and K. The addition of Na-polyacrylates (low- and high-molecular weight polymers) eliminates the viscosity anomaly of pure saponite fluids. These polymers also increase the filtration control of saponite. The anomalous viscosity enhancement of saponite is significantly reduced by the addition of sepiolite (a clay mineral with a fibrous morphology). 12 refs., 31 figs., 26 tabs.
Date: February 1, 1991
Creator: Guven, N.; Panfil, D. J. & Carney, L. L. (Texas Tech Univ., Lubbock, TX (USA). Dept. of Geosciences)
Object Type: Report
System: The UNT Digital Library
Surfactant-enhanced alkaline flooding with weak alkalis (open access)

Surfactant-enhanced alkaline flooding with weak alkalis

The objective of Project BE4B in FY90 was to develop cost-effective and efficient chemical flooding formulations using surfactant-enhanced, lower pH (weak) alkaline chemical systems. Chemical systems were studied that mitigate the deleterious effects of divalent ions. The experiments were conducted with carbonate mixtures and carbonate/phosphate mixtures of pH 10.5, where most of the phosphate ions exist as the monohydrogen phosphate species. Orthophosphate did not further reduce the deleterious effect of divalent ions on interfacial tension behavior in carbonate solutions, where the deleterious effect of the divalent ions is already very low. When added to a carbonate mixture, orthophosphate did substantially reduce the adsorption of an atomic surfactant, which was an expected result; however, there was no correlation between the amount of reduction and the divalent ion levels. For acidic oils, a variety of surfactants are available commercially that have potential for use between pH 8.3 and pH 9.5. Several of these surfactants were tested with oil from Wilmington (CA) field and found to be suitable for use in that field. Two low-acid crude oils, with acid numbers of 0.01 and 0.27 mg KOH/g of oil, were studied. It was shown that surfactant-enhanced alkaline flooding does have merit for use with …
Date: February 1, 1991
Creator: French, T. R. & Josephson, C. B.
Object Type: Report
System: The UNT Digital Library
Design and operation of a geopressurized-geothermal hybrid cycle power plant (open access)

Design and operation of a geopressurized-geothermal hybrid cycle power plant

Geopressured-geothermal resources can contribute significantly to the national electricity supply once technical and economic obstacles are overcome. Power plant performance under the harsh conditions of a geopressured resource was unproven, so a demonstration power plant was built and operated on the Pleasant Bayou geopressured resource in Texas. This one megawatt facility provided valuable data over a range of operating conditions. This power plant was a first-of-a-kind demonstration of the hybrid cycle concept. A hybrid cycle was used to take advantage of the fact that geopressured resources contain energy in more than one form -- hot water and natural gas. Studies have shown that hybrid cycles can yield thirty percent more power than stand-alone geothermal and fossil fuel power plants operating on the same resource. In the hybrid cycle at Pleasant Bayou, gas was burned in engines to generate electricity directly. Exhaust heat from the engines was then combined with heat from the brine to generate additional electricity in a binary cycle. Heat from the gas engine was available at high temperature, thus improving the efficiency of the binary portion of the hybrid cycle. Design power output was achieved, and 3445 MWh of power were sold to the local utility over …
Date: February 1, 1991
Creator: Campbell, R. G. & Hattar, M. M.
Object Type: Report
System: The UNT Digital Library
Slipstream, Volume 29, Number 2, February 1991 (open access)

Slipstream, Volume 29, Number 2, February 1991

Monthly magazine published by the Maverick Region of the Porsche Club of America containing stories related to the organization or of interest to the group's members including news, upcoming and past events, other feature articles, and classified advertisements.
Date: February 1991
Creator: Porsche Club of America. Maverick Region.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Parks & Wildlife, Volume 49, Number 2, February 1991 (open access)

Texas Parks & Wildlife, Volume 49, Number 2, February 1991

Magazine discussing natural resources, parks, hunting and fishing, and other information related to the outdoors in Texas.
Date: February 1991
Creator: Texas. Parks and Wildlife Department.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Weatherford Coyote (Weatherford, Tex.), Ed. 1 Friday, February 1, 1991 (open access)

Weatherford Coyote (Weatherford, Tex.), Ed. 1 Friday, February 1, 1991

School newspaper from Weatherford College in Weatherford, Texas that includes news of interest to students, staff, and alumni along with advertising.
Date: February 1, 1991
Creator: Weatherford College
Object Type: Newspaper
System: The Portal to Texas History

Oral History Interview with Curtis O. Greer, Jr., February 14, 1991

Access: Use of this item is restricted to the UNT Community
Interview with Curtis O. Greer, Jr., a former member of the Civilian Conservation Corps from Fort Worth, Texas, regarding his experiences and memories of participating in the CCC during the Great Depression. An appendix with an outline for the interview is included.
Date: February 14, 1991
Creator: Maschino, Ellen & Greer, Curtis O., Jr.
Object Type: Book
System: The UNT Digital Library
The Olney Enterprise (Olney, Tex.), Vol. 82, No. 8, Ed. 1 Thursday, February 21, 1991 (open access)

The Olney Enterprise (Olney, Tex.), Vol. 82, No. 8, Ed. 1 Thursday, February 21, 1991

Weekly newspaper from Olney, Texas that includes local, state, and national news along with advertising.
Date: February 21, 1991
Creator: Penn, David H.
Object Type: Newspaper
System: The Portal to Texas History
The Dublin Citizen (Dublin, Tex.), Vol. 1, No. 23, Ed. 1 Thursday, February 7, 1991 (open access)

The Dublin Citizen (Dublin, Tex.), Vol. 1, No. 23, Ed. 1 Thursday, February 7, 1991

Weekly newspaper from Dublin, Texas that includes local, state, and national news along with advertising.
Date: February 7, 1991
Creator: Wright, Karen
Object Type: Newspaper
System: The Portal to Texas History
Sulphur Springs News-Telegram (Sulphur Springs, Tex.), Vol. 113, No. 34, Ed. 1 Sunday, February 10, 1991 (open access)

Sulphur Springs News-Telegram (Sulphur Springs, Tex.), Vol. 113, No. 34, Ed. 1 Sunday, February 10, 1991

Daily newspaper from Sulphur Springs, Texas that includes local, state, and national news along with advertising.
Date: February 10, 1991
Creator: Keys, Clarke
Object Type: Newspaper
System: The Portal to Texas History
The J-TAC (Stephenville, Tex.), Ed. 1 Thursday, February 7, 1991 (open access)

The J-TAC (Stephenville, Tex.), Ed. 1 Thursday, February 7, 1991

Weekly student newspaper from Tarleton State University in Stephenville, Texas that includes local, state and campus news along with advertising.
Date: February 7, 1991
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Baytown Sun (Baytown, Tex.), Vol. 69, No. 82, Ed. 1 Monday, February 4, 1991 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 69, No. 82, Ed. 1 Monday, February 4, 1991

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: February 4, 1991
Creator: Brown, Leon
Object Type: Newspaper
System: The Portal to Texas History
The Hopkins County Echo (Sulphur Springs, Tex.), Vol. 116, No. 8, Ed. 1 Friday, February 22, 1991 (open access)

The Hopkins County Echo (Sulphur Springs, Tex.), Vol. 116, No. 8, Ed. 1 Friday, February 22, 1991

Weekly newspaper from Sulphur Springs, Texas that includes local, state, and national news along with advertising.
Date: February 22, 1991
Creator: Keys, Clarke & Davis, Mary Grant
Object Type: Newspaper
System: The Portal to Texas History
Burleson Star (Burleson, Tex.), Vol. 26, No. 56, Ed. 1 Thursday, February 21, 1991 (open access)

Burleson Star (Burleson, Tex.), Vol. 26, No. 56, Ed. 1 Thursday, February 21, 1991

Tri-weekly newspaper from Burleson, Texas that includes local, state, and national news along with advertising.
Date: February 21, 1991
Creator: Moody, James
Object Type: Newspaper
System: The Portal to Texas History
The Comanche Chief (Comanche, Tex.), Vol. 118, No. 41, Ed. 1 Thursday, February 28, 1991 (open access)

The Comanche Chief (Comanche, Tex.), Vol. 118, No. 41, Ed. 1 Thursday, February 28, 1991

Weekly newspaper from Comanche, Texas that includes local, state, and national news along with advertising.
Date: February 28, 1991
Creator: Wilkerson, James C., III
Object Type: Newspaper
System: The Portal to Texas History
Archer County News (Archer City, Tex.), No. 8, Ed. 1 Thursday, February 21, 1991 (open access)

Archer County News (Archer City, Tex.), No. 8, Ed. 1 Thursday, February 21, 1991

Weekly newspaper from Archer City, Texas that includes local, state and national news along with advertising.
Date: February 21, 1991
Creator: Lobpries, F. Mike & Lobpries, Fran
Object Type: Newspaper
System: The Portal to Texas History
The Dublin Citizen (Dublin, Tex.), Vol. 1, No. 24, Ed. 1 Thursday, February 14, 1991 (open access)

The Dublin Citizen (Dublin, Tex.), Vol. 1, No. 24, Ed. 1 Thursday, February 14, 1991

Weekly newspaper from Dublin, Texas that includes local, state, and national news along with advertising.
Date: February 14, 1991
Creator: Wright, Karen
Object Type: Newspaper
System: The Portal to Texas History
Stamford American (Stamford, Tex.), Vol. 69, No. 46, Ed. 1 Thursday, February 14, 1991 (open access)

Stamford American (Stamford, Tex.), Vol. 69, No. 46, Ed. 1 Thursday, February 14, 1991

Weekly newspaper from Stamford, Texas that includes local, state, and national news along with advertising.
Date: February 14, 1991
Creator: Mathis, Chandra
Object Type: Newspaper
System: The Portal to Texas History
Burleson Star (Burleson, Tex.), Vol. 26, No. 51, Ed. 1 Friday, February 8, 1991 (open access)

Burleson Star (Burleson, Tex.), Vol. 26, No. 51, Ed. 1 Friday, February 8, 1991

Tri-weekly newspaper from Burleson, Texas that includes local, state, and national news along with advertising.
Date: February 8, 1991
Creator: Moody, James
Object Type: Newspaper
System: The Portal to Texas History
The Paducah Post (Paducah, Tex.), Vol. 84, No. 51, Ed. 1 Wednesday, February 6, 1991 (open access)

The Paducah Post (Paducah, Tex.), Vol. 84, No. 51, Ed. 1 Wednesday, February 6, 1991

Weekly newspaper from Paducah, Texas that includes local, state, and national news along with advertising.
Date: February 6, 1991
Creator: Taylor, Jimmye C.
Object Type: Newspaper
System: The Portal to Texas History
The Paducah Post (Paducah, Tex.), Vol. 85, No. 1, Ed. 1 Wednesday, February 20, 1991 (open access)

The Paducah Post (Paducah, Tex.), Vol. 85, No. 1, Ed. 1 Wednesday, February 20, 1991

Weekly newspaper from Paducah, Texas that includes local, state, and national news along with advertising.
Date: February 20, 1991
Creator: Taylor, Jimmye C.
Object Type: Newspaper
System: The Portal to Texas History