Colorado State University Solar Heated and Cooled House (open access)

Colorado State University Solar Heated and Cooled House

None
Date: January 1, 1974
Creator: Lof, G.O.G.
Object Type: Article
System: The UNT Digital Library
Design, Construction, and Testing of a Residential Solar Heating and Cooling System. Progress Report, 1 September 1973--31 January 1974 (open access)

Design, Construction, and Testing of a Residential Solar Heating and Cooling System. Progress Report, 1 September 1973--31 January 1974

None
Date: March 1, 1974
Creator: Lof, G.O.G. & Ward, D.S.
Object Type: Report
System: The UNT Digital Library
Palladium Catalyzed Coupling Reactions: Mechanism of Reductive Elimination. Progress Report, October 1, 1979-September 30, 1980. [Ethane Elimination] (open access)

Palladium Catalyzed Coupling Reactions: Mechanism of Reductive Elimination. Progress Report, October 1, 1979-September 30, 1980. [Ethane Elimination]

The 1,1-reductive elimination of ethane from three cis-bis(phosphine)-dimethylpalladium complexes, L/sub 2/Pd(CH/sub 3/)/sub 2/ (L = PPh/sub 3/, PPh/sub 2/,CH/sub 3/ and L/sub 2/ = Ph/sub 2/PCH/sub 2/CH/sub 2/PPh/sub 2/), and three trans analogs (L = PPh/sub 3/, PPh/sub 2/CH/sub 3/ and L/sub 2/ = 2,11-bis(diphenylphosphinomethyl)benzo(c)phenanthrene (TRANSPHOS)) was carried out. The three cis complexes underwent reductive elimination in the presence of coordinating solvents (DMSO, DMF, and THF). The trans complexes which could isomerize to cis (L = PPh/sub 3/, PPh/sub 2/CH/sub 3/) did so in polar solvents and then underwent reductive elimination. TRANSPHOS dimethylpalladium would not undergo reductive elimination of ethane. The eliminations from the cis isomers were intramolecular and displayed first order kinetics. Although TRANSPHOS dimethylpalladium(II) would not undergo a 1,1-reductive elimination of ethane, the addition of CD/sub 3/I to a DMSO solution of this complex at 25/sup 0/C rapidly produced CD/sub 3/-CH/sub 3/, implicating a transient palladium(IV) intermediate. E- and Z-bromostyrylbis(diphenylmethylphosphine)palladium(0) react with methyl lithium in THF at ambient temperature to give the E- and Z- propenylbenzenes, respectively. At -78/sup 0/C, the intermediate E- and Z-styrylmethylbis(diphenylmethylphosphine)palladium(II) complexes (9a,b) can be isolated. On raising the temperature of solutions of 9a,b in THF, E- and Z-propenylbenzenes are produced. The reductive elimination …
Date: September 1, 1980
Creator: Stille, J. K.
Object Type: Report
System: The UNT Digital Library
Planetary-Wave Behavior and Arctic Air Pollution (open access)

Planetary-Wave Behavior and Arctic Air Pollution

An attempt was made to relate episodes of air pollution at Barrow, Alaska, containing vanadium, to the behavior of planetary waves in middle and high latitudes. A stationarity index for planetary waves is defined as the ratio between amplitudes computed from monthly mean maps and the mean amplitudes computed on a daily basis and averaged over the same month, irrespective of phase angle. Longitude-time sections of 500-mb height anomalies at various latitudes are related to vanadium pollution episodes at Barrow.
Date: January 1, 1979
Creator: Reiter, Elmar R.
Object Type: Report
System: The UNT Digital Library
Steady-State Thermomechanical Finite Element Analysis of Elastoviscoplastic Metal Forming Processes (open access)

Steady-State Thermomechanical Finite Element Analysis of Elastoviscoplastic Metal Forming Processes

Extrusion and rolling processes exhibiting large amounts of plastic flow are analyzed using a finite element technique that is based on a modified creeping viscous flow approximation. The technique, called the initial stress-rate method, iteratively corrects creeping viscous flow solutions to generate results that include elastic response. The momentum equations have been coupled with the energy equation to provide the capability to predict thermomechanical response during forming operations.
Date: January 1, 1977
Creator: Dawson, P.R. & Thompson, E.G.
Object Type: Article
System: The UNT Digital Library
Novel Concepts in Electrochemical Solar Cells. Third Quarterly Progress Report, November 15, 1979-January 15, 1980. [Molten Salt Electrolytes] (open access)

Novel Concepts in Electrochemical Solar Cells. Third Quarterly Progress Report, November 15, 1979-January 15, 1980. [Molten Salt Electrolytes]

Efforts have been primarily directed toward evaluation of the room temperature molten salt electrolyte in terms of its overall performance for photovoltaic cells. Mass transport processes may prove to be the rate-limiting factor for such electrolytes, unless the concentration of the photo-active redox component can be increased and the solvent viscosity reduced. Acid-base surface chemistry of n-GaAs as occurs in aqueous systems, has been found present and its consequences will be further explored. The selection and optimization of PEC electrolytes is a complex task and we believe that a systems approach would facilitate in identifying the basic electrolyte properties needed. A preliminary analysis reveals that although some of the criteria for an electrolyte are definable precisely, others do require empirical experimentation. It can be concluded that relatively few electrolytes in current use are adequate and it would appear that greater efforts to develop electrolytes would be advantageous. The various types of electrolytes that could be used for PEC's have been identified. Good quality MoSe/sub 2/ single crystals can be grown and short circuit currents greater than previously reported have been achieved in an I/sub 2//I/sup -//Pt cell. A novel technique to produce photo-active films by anodization is being investigated, initially …
Date: January 1, 1980
Creator: DuBow, J.; Job, R. & Krishnan, R.
Object Type: Report
System: The UNT Digital Library
Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes (open access)

Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes

We are making progress on our investigation of the mechanism of olefin exchange with Os{sub 2}(C{sub 2}H{sub 4})(CO){sub 8}. We are probing this system by kinetic study of the reaction of Os{sub 2}(C{sub 2}H{sub 4})(CO){sub 8} with butyl acrylate (BA) under various pressures of ethylene.
Date: May 1, 1992
Creator: Norton, J.R.
Object Type: Report
System: The UNT Digital Library
Wind Load Reduction for Heliostats (open access)

Wind Load Reduction for Heliostats

This report presents the results of wind-tunnel tests supported through the Solar Energy Research Institute (SERI) by the Office of Solar Thermal Technology of the US Department of Energy as part of the SERI research effort on innovative concentrators. As gravity loads on drive mechanisms are reduced through stretched-membrane technology, the wind-load contribution of the required drive capacity increases in percentage. Reduction of wind loads can provide economy in support structure and heliostat drive. Wind-tunnel tests have been directed at finding methods to reduce wind loads on heliostats. The tests investigated primarily the mean forces, moments, and the possibility of measuring fluctuating forces in anticipation of reducing those forces. A significant increase in ability to predict heliostat wind loads and their reduction within a heliostat field was achieved.
Date: May 1, 1986
Creator: Peterka, J. A.; Hosoya, N.; Bienkiewicz, B. & Cermak, J. E.
Object Type: Report
System: The UNT Digital Library
Influence of Geometry on Natural Convection in Buildings (open access)

Influence of Geometry on Natural Convection in Buildings

Strong free convection airflows occur within passive solar buildings resulting from elevated temperatures of surfaces irradiated by solar energy compared with the cooler surfaces not receiving radiation. The geometry of a building has a large influence on the directions and magnitudes of natural airflows, and thus heat transfer between zones. This investigation has utilized a variety of reduced-scale building configurations to study the effects of geometry on natural convection heat transfer. Similarity between the reduced-scale model and a full-scale passive solar building is achieved by having similar geometries and by replacing air with Freon-12 gas as the model's working fluid. Filling the model with Freon-12 gas results in similarity in Prandtl numbers and Rayleigh numbers based on temperature differences in the range from 10/sup 9/ to 10/sup 11/. Results from four geometries are described with an emphasis placed on the effects of heat loss on zone temperature stratification shifts.
Date: January 1, 1985
Creator: White, M. D.; Winn, C. B.; Jones, G. F. & Balcomb, J. D.
Object Type: Article
System: The UNT Digital Library
Exploratory Study of Metal Vapor Lasers Operating in the Ultra-Violet at Kilowatt Power Levels. Final Report, June 1, 1975--March 31, 1979 (open access)

Exploratory Study of Metal Vapor Lasers Operating in the Ultra-Violet at Kilowatt Power Levels. Final Report, June 1, 1975--March 31, 1979

Cw laser action has been extended down to 220 nm. Moreover, cw oscillation has been obtained on twenty additional transitions in the spectral range between 220 and 320 nm. Ultra-violet laser thresholds as low as 2 A have been observed. In comparison, rare gas ion lasers require 20 to 50 A to reach threshold. Metals of interest are sputtered into the discharge giving metal densities of 10/sup 14/ atoms cm/sup -3/ without using external ovens or discharge heating. Recent attempts to scale the output power levels to 1 W cw are presented with particular emphasis on the 780 nm transitions of Cu II and the 840 nm transitions of Ag II.
Date: March 1, 1979
Creator: Collins, G.J.
Object Type: Report
System: The UNT Digital Library
Rapid estimation of /sup 226/Ra in soil for the Grand Junction RASA/UMTRA project (open access)

Rapid estimation of /sup 226/Ra in soil for the Grand Junction RASA/UMTRA project

The Radiological Survey Activities (RASA) Group of the Health and Safety Research Division at Oak Ridge National Laboratory (ORNL) is an Inclusion Survey Contractor (ISC) for the Uranium Mill Tailings Remedial Action Program (UMTRAP). The purpose of the ISC is to survey designated sites potentially contaminated with radioactive material originating from the 24 inactive uranium mill sites and make recommendations as to whether the site should be included in or excluded from further consideration by UMTRAP. An important aspect of the program is a prompt and inexpensive estimation of Radium-226 (/sup 226/Ra) concentration in soil samples. A large sodium iodide (NaI) well crystal coupled to a multichannel analyzer is used to count soil samples. Count data are currently analyzed with an algorithm that utilizes three regions of interest (ROI). A lack of agreement was observed when samples were also analyzed with lithium-drifted germanium (GeLi) spectrometers. The average estimate of /sup 226/Ra obtained using the current algorithm was 19% greater than the GeLi determination. Some possible reasons for these differences were examined. In 8.5% of the samples, the relative concentration of Cesium-137 (/sup 137/Cs) was highly correlated to the extent of error. Using alternative analysis techniques, the error for /sup 226/Ra …
Date: January 1, 1986
Creator: Kark, J.B.; Borak, T.B.; Kearney, P.D. & Rood, A.S.
Object Type: Article
System: The UNT Digital Library
Role of Polycrystallinity in Cdte and Cuinse Sub 2 Photovoltaic Cells (open access)

Role of Polycrystallinity in Cdte and Cuinse Sub 2 Photovoltaic Cells

The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.
Date: January 1, 1991
Creator: Sites, J.R. (Colorado State Univ., Fort Collins, CO (United States))
Object Type: Report
System: The UNT Digital Library
Comparative Performance of Two Types of Evacuated Tube Solar Collectors in a Residential Heating and Cooling System - The Progress Report (open access)

Comparative Performance of Two Types of Evacuated Tube Solar Collectors in a Residential Heating and Cooling System - The Progress Report

Two types of evacuated tube solar collectors have been operated in space heating, cooling and domestic hot water heating systems in Colorado State University Solar House I. An experimental collector from Corning Glass Works supplied heat to the system from January 1977 through February 1978, and an experimental collector from Philips Research Laboratory, Aachen, which is currently in use, has been operating since August 1978. A flat absorber plate inside a single-walled glass tube is used in the Corning design, whereas heat is conducted through a single glass wall to an external heat exchanger plate in the Philips collector. In comparison with conventional flat-plate collectors, both types show reduced heat losses and improved efficiency. For space heating and hot water supply in winter, the solar delivery efficiency of the Corning collector ranged from 49% to 60% of the incident solar energy. The portion of the space heating and domestic hot water load carried by solar energy through fall and winter ranged from 50% to 74%, with a four-month contribution of 61% of the total requirements. Data on the Philips collector are currently being analyzed.
Date: January 1, 1979
Creator: Conway, T. M.; Duff, W. S.; Loef, G. O. G. & Pratt, R. G.
Object Type: Article
System: The UNT Digital Library
Mean and Peak Wind Load Reduction on Heliostats (open access)

Mean and Peak Wind Load Reduction on Heliostats

This report presents the results of wind-tunnel tests supported through the Solar Energy Research Institute (SERI) by the Office of Solar Thermal Technology of the US Department of Energy as part of the SERI research effort on innovative concentrators. As gravity loads on drive mechanisms are reduced through stretched-membrane technology, the wind-load contribution of the required drive capacity increases in percentage. Reduction of wind loads can provide economy in support structure and heliostat drive. Wind-tunnel tests have been directed at finding methods to reduce wind loads on heliostats. The tests investigated both mean and peak forces, and moments. A significant increase in ability to predict heliostat wind loads and their reduction within a heliostat field was achieved. In addition, a preliminary review of wind loads on parabolic dish collectors was conducted, resulting in a recommended research program for these type collectors. 42 refs., 38 figs., 1 tab.
Date: September 1, 1987
Creator: Peterka, J. A.; Tan, L.; Bienkiewcz, B. & Cermak, J. E.
Object Type: Report
System: The UNT Digital Library
Solar Thermal Electric Power Systems With Line-Focus Collectors. Final Report (open access)

Solar Thermal Electric Power Systems With Line-Focus Collectors. Final Report

Electric power generation by conventional Rankine cycle heat engines with heat supplied by line-focus solar collectors was investigated. The objectives of the study were: (1) determine which of four types of line-focus solar collectors coupled with turbine-generators of conventional design has the potential to produce low-cost electric power with thermal energy in 100 to 300/sup 0/C range; (2) develop performance and cost relationships for organic Rankine cycle engines for power generation capacities from 3 MW/sub e/ to 300 MW/sub e/; (3) develop conceptual storage units for organic fluid systems. Evaluation procedures and study results and conclusion are presented and discussed in detail. (WHK)
Date: December 1, 1978
Creator: Duff, W. S.; Karaki, S.; Shaner, W. W.; Wilbur, P. J.; Somers, E. V.; Grimble, R. E. et al.
Object Type: Report
System: The UNT Digital Library
Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes (open access)

Diosmacycloalkanes as models for the formation of hydrocarbons from surface methylenes

We have obtained a neutron diffraction data set for Os{sub 2}(CO){sub 8}({mu}-C{sub 2}H{sub 4}). While the structure is still being solved, it is already clear that the hybridization at both of the ethylene carbons is sp{sup 3}. Our first interpretation of our liquid crystal NMR results had suggested a very acute H-C-H angle. We have also obtained {sup 13}C liquid crystal data for Os{sub 2}(CO){sub 8}({mu}-C{sub 2}H{sub 4}). Liquid crystal NMR ({sup 13}C as well as {sup 1}H) spectra have been obtained for Os(CO){sub 4}(C{sub 2}H{sub 4}) and its solution structure determined, in order to test our methodology on a molecule with a rigid structure. The normal modes of Os(CO){sub 4}({mu}-C{sub 2}H{sub 4}) and its deuterated and {sup 13}C-labelled isotopomers have been completely assigned. A partial vibrational analysis of Os{sub 2}(CO){sub 8}({mu}-propene), Os{sub 2}(CO){sub 8}(trans-2-butene), and Os{sub 2}(CO){sub 8}(1-butene) has been completed. We have prepared Os(CO){sub 4}({mu}-CH{sub 2}CH{sub 2}CH{sub 2}) and its 3,3-dideuterio analog. In the course of this work the reaction of Na{sub 2}Os(CO){sub 4} with a number of 1,3-propanediol derivatives has been examined. 1,3-Propanediol ditosylate afforded much better yields of the osmacycle than did either the ditriflate or diiodide. 2,2-Dideutero-1,3-propanediol ditosylate was used to prepare the deuterium-labelled osmacyclobutane.
Date: January 1, 1989
Creator: Norton, J.R.
Object Type: Report
System: The UNT Digital Library
Palladium Catalyzed Coupling Reactions: Mechanism of Reductive Elimination. Progress Report, June 1, 1978-September 30, 1979 (open access)

Palladium Catalyzed Coupling Reactions: Mechanism of Reductive Elimination. Progress Report, June 1, 1978-September 30, 1979

The coupling reaction of benzyl halides and organolithium, organotin, or Grignard Reagents is catalyzed by palladium. The sequence of events in the catalytic cycle is oxidative addition of the benzyl halide to palladium(0), methathesis by the organometallic reagent to give a benzyl methyl palladium(II) complex, oxidative addition of the benzyl halide to give a palladium(IV) complex, and reductive elimination of benzyl and methyl to give ethylbenzene. The reductive elimination from palladium bearing an optically active ..cap alpha..-deuteriobenzyl group takes place with retention of configuration at carbon, and is therefore concerted or nearly concerted. Since rho is positive in the catalytic reaction with substituted aryl halides, an oxidative addition, probably during the Pd(II) to Pd(IV) reaction, is the slow step in the catalytic cycle. The intermediate diorganopalladium species can be isolated when the two groups attached to palladium are both methyl or methyl and either cis or trans-..beta..-styryl. The decomposition of these species can be followed by NMR. In the case of methylstyrylpalladium(II) complexes, the reductive elimination gives propenyl benzene with stereospecific retention of double bond geometry. Cis-dimethylbis(diphenylmethylphosphine)palladium(II) does not undergo isomerization to the more stable trans isomer in an inert solvent, and is stable toward reductive elimination up to 50/sup …
Date: September 1, 1979
Creator: Stille, J. K.
Object Type: Report
System: The UNT Digital Library
Overburden Characterization and Post-Burn Study of the Hanna Iv, Underground Coal Gasification Site, Wyoming, and Comparison to Other Wyoming Ucg Sites (open access)

Overburden Characterization and Post-Burn Study of the Hanna Iv, Underground Coal Gasification Site, Wyoming, and Comparison to Other Wyoming Ucg Sites

Analysis of 21 post-burn cores taken from the Hanna IV UCG site allows 96 m (315 ft) of overburden to be subdivided into four local stratigraphic units. The 7.6 m (25 ft) thick Hanna No. 1 coal seam is overlain by a laterally discontinuous, 3.3 m (11 ft) thick shaley mudstone (Unit A') in part of the Hanna IV site. A more widespread, 30 m (90 ft) thick well-indurated sandstone (Unit A) overlies the A' unit. Unit A is the roof rock for both of the Hanna IV cavities. Overlying Unit A is a 33 m (108 ft) thick sequence of mudstone and claystone (Unit B), and the uppermost unit at the Hanna IV site (Unit C) is a coarse-grained sandstone that ranges in thickness from 40 to 67 m (131 to 220 ft). Two elliptical cavities were formed during the two phases of the Hanna IV experiment. The larger cavity, Hanna IVa, is 45 x 15 m in plan and has a maximum height of 18 m (59 ft) from the base of the coal seam to the top of the cavity; the Hanna IVb cavity is 40 x 15 m in plan and has a maximum height of …
Date: November 1, 1984
Creator: Marcouiller, B.A.; Burns, L.K. & Ethridge, F.G.
Object Type: Report
System: The UNT Digital Library
Comparison of the Response of a Nai Scintillation Crystal With a Pressurized Ionization Chamber as a Function of Altitude, Radiation Level and RA-226 Concentration (open access)

Comparison of the Response of a Nai Scintillation Crystal With a Pressurized Ionization Chamber as a Function of Altitude, Radiation Level and RA-226 Concentration

The Grand Junction Uranium Mill Tailings Remedial Action-Radiological Survey Activities Group (UMTRA-RASA) program employs a screening method in which external exposure rates are used to determine if a property contaminated with uranium mill tailings is eligible for remedial action. Portable NaI detectors are used by survey technicians to locate contaminated areas and determine exposure rates. The exposure rate is calculated using a regression equation derived from paired measurements made with a pressurized ionization chamber (PIC) and a NaI detector. During July of 1985 extensive measurements were taken using a PIC and a NaI scintillator with both analogue and digital readout for a wide range of exposure rates and at a variety of elevations. The surface soil was sampled at most of these locations and analyzed for /sup 226/Ra. The response of the NaI detectors was shown to be highly correlated to radiation level but not to /sup 226/Ra concentration or elevation.
Date: January 1, 1986
Creator: Provencher, R.; Smith, G.; Borak, T.B. & Kearney, P.
Object Type: Article
System: The UNT Digital Library
Rehabilitation Potential and Practices of Colorado Oil Shale Lands. Progress Report, June 1, 1978--May 31, 1979 (open access)

Rehabilitation Potential and Practices of Colorado Oil Shale Lands. Progress Report, June 1, 1978--May 31, 1979

The following document is a third-year progress report for the period June 1, 1978 to May 31, 1979. The overall objective of the project is to study the effects of seeding techniques, species mixtures, fertilizer, ecotypes, improved plant materials, mycorrhizal fungi, and soil microorganisms on the initial and final stages of reclamation obtained through seeding and subsequent succession on disturbed oil shale lands. Plant growth medias that are being used in field-established test plots include retorted shale, soil over retorted shale, subsoil materials, and surface disturbed topsoils. Because of the long-term nature of successional and ecologically oriented studies the project is just beginning to generate significant publications. Several of the studies associated with the project have some phases being conducted principally in the laboratories and greenhouses at Colorado State Univerisity. The majority of the research, however, is being conducted on a 20 hectare Intensive Study Site located near the focal points of oil shale activity in the Piceance Basin. The site is at an elevation of 2,042 m, receives approximately 30 to 55 cm of precipitation annually, and encompasses the plant communities most typical of the Piceance Basin. Most of the information contained in this report originated from the monitoring …
Date: March 1, 1979
Creator: Cook, C.W.
Object Type: Report
System: The UNT Digital Library
Milk Production and Distribution in Nine Western States in the 1950s (open access)

Milk Production and Distribution in Nine Western States in the 1950s

This report provides information on milk distribution and dairy cattle feeding practices in Nevada, Utah and portions of seven other adjacent states during the 1950s. The information was gathered to support the US Department of Energy's ''Offsite Radiation Exposure Review Project (ORERP).'' This project is charged with providing radiation dose estimates for residents of Nevada, Utah, and surrounding states from nuclear weapons testing conducted at the Nevada Test Site from 1951 through 1962. The information on milk production and distribution is essential for assessment of the internal organ doses received by people as a result of ingesting radioactive fallout-contaminated foods. The information is used as input data for Colorado State University's PATHWAY computer code which estimates the ingestion of twenty radionuclides by people relative to a given level of fallout deposition.
Date: March 1, 1987
Creator: Ward, G. M. & Whicker, F. W.
Object Type: Report
System: The UNT Digital Library
Characterization of Fly Ash From Coal Combustion (open access)

Characterization of Fly Ash From Coal Combustion

Fly ash derived from coal combustion contains predominantly spherical particles which consist of an insoluble aluminosilicate glass containing several mineral impurities. An outer layer, 50 to 300 A thick, is rich in many potentially toxic trace elements in the form of simple and complex sulfates. This layer, which is soluble in water, contains essentially all of the particulate sulfur present in fly ash in the form of sulfate. The actual mechanism(s) of formation of particulate sulfate salts are ill-defined but probably involve adsorption of condensation of gaseous sulfur species onto fly ash surfaces within the power plant stack system.
Date: January 1, 1978
Creator: Natusch, D. F.S.
Object Type: Article
System: The UNT Digital Library
Ornithogalum Virens as a Plant Assay for Beta and Gamma Radiation Effects (open access)

Ornithogalum Virens as a Plant Assay for Beta and Gamma Radiation Effects

The purpose of this study was to determine if the monocotyledonous angiosperm, Ornithogalum virens (Quintanilha and Cabral, 1947), could be used in such a biological assay system. After exposing O. virens plants to acute (/sup 60/Co) and chronic (/sup 137/Cs) gamma radiation and internal beta radiation (/sup 32/P), lethality (LD/sub 50/, LD/sub 100/), growth inhibition, and chromosome aberrations were investigated. The LD/sub 50/ and LD/sub 100/ for acute gamma radiation were estimated to be between 0.91 to 1.8 krad and less than 3.6 krad, respectively. Though growth inhibition and abnormal growth were observed in the acute and chronic gamma radiation studies, the changes in the growth of the plants were so variable that these parameters were found to be unreliable measures of radiation effects. Chromosome aberrations were a more reliable measure of radiation damage because linear relationships between total aberrations and dose were found for both gamma and beta radiation.
Date: January 1, 1979
Creator: Herron, V J
Object Type: Report
System: The UNT Digital Library
Grassland/Atmosphere Response to Changing Climate: Coupling Regional and Local Scales. Final Report (open access)

Grassland/Atmosphere Response to Changing Climate: Coupling Regional and Local Scales. Final Report

The objectives of the study were: to evaluate the response of grassland ecosystems to atmospheric change at regional and site scales, and to develop multiscaled modeling systems to relate ecological and atmospheric models with different spatial and temporal resolutions. A menu-driven shell was developed to facilitate use of models at different temporal scales and to facilitate exchange information between models at different temporal scales. A detailed ecosystem model predicted that C{sub 3} temperate grasslands wig respond more strongly to elevated CO{sub 2} than temperate C{sub 4} grasslands in the short-term while a large positive N-PP response was predicted for a C{sub 4} Kenyan grassland. Long-term climate change scenarios produced either decreases or increases in Colorado plant productivity (NPP) depending on rainfall, but uniform increases in N-PP were predicted in Kenya. Elevated CO{sub 2} is likely to have little effect on ecosystem carbon storage in Colorado while it will increase carbon storage in Kenya. A synoptic climate classification processor (SCP) was developed to evaluate results of GCM climate sensitivity experiments. Roughly 80% agreement was achieved with manual classifications. Comparison of lx and 2xCO{sub 2} GCM Simulations revealed relatively small differences.
Date: October 1, 1993
Creator: Coughenour, M. B.; Kittel, T. G. F.; Pielke, R. A. & Eastman, J.
Object Type: Report
System: The UNT Digital Library