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FY97 Status Report on the HSV and Titanium Tritide Samples

Description: The HSV in storage in MTF has been monitored, and the gas sampled and analyzed. The net conclusion is that no significant He evolution has occurred to date, and thus the HSV is performing as expected. The annual resorption isotherms have been recorded on a titanium tritide sample with 582 total days tritium exposure, and no significant effects have been noted. A gas sample was also taken from the test cell and analyzed.
Date: February 3, 1999
Creator: Shanahan, K.L.
Partner: UNT Libraries Government Documents Department

Lateral interaction energy derived from Frumkin isotherm for c(2 x 2) Br/Ag(100)

Description: The structure of the bromide adlayer on Ag(100) and the adsorption isotherm have been determined by using in situ surface x-ray scattering techniques and chronocoulometry. Bromide adsorbed on Ag(100) forms a fourfold-hollow-site lattice gas and the adsorption saturates at 1/2 monolayer in a c(2 x 2) structure. The Frumkin isotherm has been employed to fit the experimentally obtained isotherm. Using the experimentally determined electrosorption valency, the lateral interaction energy of 220 meV/atom at full coverage is obtained.
Date: October 1997
Creator: Wang, J. X.; Ocko, B. M. & Wandlowski, T.
Partner: UNT Libraries Government Documents Department

Pressure-composition-isotherms of palladium alloys

Description: About one year ago a summary report was submitted covering the previous three years of the contract. This earlier report should be consulted as a useful survey and evaluation of the research carried out by the authors. Because of difficulties during the current contract period arising from the anomalous nature of the melt-spun alloys received from LANL, it is not possible to contribute much beyond that given in last year's summary with regard to the overall picture of the behavior of Pd-rich alloys towards hydrogen and its isotopes. In this contract year deuterium was employed instead of hydrogen and instead of using cycled alloys, the alloys employed for each isotherm measurement were in their virgin condition. Because of the anomalous behavior of the melt-spun alloys, it was not feasible or worthwhile in some cases, e.g., when the alloy behaved anomalously, to carry out all of the originally proposed work. Nonetheless considering these obstacles, some useful data were obtained. For example, the obtaining of deuterium isotherms for the Pd-Rh alloys down to {minus}40 C using internally oxidized melt-spun alloys may prove to be useful.
Date: November 1, 1996
Creator: Flanagan, T.B.
Partner: UNT Libraries Government Documents Department

Equilibrium binding studies of mono, di and triisocyanide ligands on Au powder surfaces

Description: The author`s group has previously shown that isocyanides are readily adsorbed from solutions to Au powder and bind to the Au surface in an end-on fashion through the terminal carbon. Later work demonstrated that the equilibrium constants for the reversible adsorption of electronically inequivalent isocyanides could be obtained using the Langmuir isotherm technique. This dissertation describes two projects completed which complement the initial findings of this group. Initially, several alkylisocyanides were synthesized to examine the effect of tail length on Au powder adsorption. It was observed that the length of the alkyl chain affected not only the Au surface binding affinity, but also the rate of surface saturation and saturation coverage values. Direct competition studies were also studied using a {sup 13}C-labeled isocyanide. These studies demonstrated the stabilization afforded by substrate-substrate packing forces in SAM`s formed by the longer chain isocyanides. In a second study, di and triisocyanides were synthesized to determine the effect that the length of the connecting link and the number of isocyanide groups (as points of attachment) have on Au adsorption stability. The work in this area describes the binding modes, relative binding affinities and surface coverage values for a series of flexible alkyl and xylyldiisocyanides on Au powder surfaces. This report contains only the introductory material, and general summary. Two chapters have been processed separately. 56 refs.
Date: October 8, 1997
Creator: Ontko, A.
Partner: UNT Libraries Government Documents Department

Tritium Aging Effects in Palladium on Kieselguhr

Description: 50 weight % Pd on kieselguhr (Pd/k) is used in hydrogen isotope separation processes at the Savannah River Site. Long term aging studies on this material were undertaken in June, 1992. P-c-T data showing the aging effect of tritium loading for long periods will be presented and discussed covering from June, 1992 to March, 1997. Lowering of plateau pressures and increasing indications of in homogeneities have been observed in both tritium and deuterium absorption isotherms at 0 C, and desorption isotherms at 80 and 120 C.
Date: October 1, 1998
Creator: Shanahan, K.L.; Holder, J.S. & Wermer, J.R.
Partner: UNT Libraries Government Documents Department

Technical Report - Final report

Description: This project was a collaborative effort between Dr Teresa Burns and Dr John Larese to study the physisorption of polar molecules on ionic substrates. The work will be completed at both Coastal Carolina University and Brookhaven National Laboratory. The goals of the research are: 1) to provide detailed thermodynamic information about dipolar molecules adsorbed on ionic substrates, critical to accurately modeling the systems of interest using a spin-1 Ising model; 2) to study the structure of the adsorbed layer from the gas phase, experimentally verifying the application of the model to these systems; 3) to extend the modeling studies and structural measurements to systems adsorbed from the liquid phase. The systems will be studied using thermodynamic techniques, e.g., adsorption isotherm both from the gas and liquid phase, and x-ray structural measurements. This project will strengthen the physical science research efforts at CCU, and hence in South Carolina.
Date: October 30, 2008
Creator: Burns, Teresa
Partner: UNT Libraries Government Documents Department

Diagnosis and correction of soil nutrient limitations in intensively managed Southern pine forests. Quarterly report for the period January-March 2000

Description: This report is a summary of project status and activities performed during the quarter: (1) Initial error runs were finished and coding was adjusted to account for errors. A documentation manual and users manual have been written and gone through the first editing. The model was presented to the forest industry during a review meeting and adjustments were made to the model based on their input. The model has been sent to interested parties in Canada and Australia to test it and report back on any errors or modifications they feel would be necessary. (2) Based on the laboratory studies, one paper was written and submitted to the Soil and Water Science for internal review. It is currently under internal review. This paper describes a method for measuring resorption isotherms. A second paper that uses this method to investigate desorption isotherms for different soils is in progress. (3) All soil samples have been dried and sieved. All tissue samples have been ground and the ashing of the tissue samples has just begun. (4) A literature search continued focusing on root to shoot relationships of fast growing pine in order to assist the development of the nutrient demand section of the model. This is about 40% done.
Date: March 1, 2000
Creator: Comerford, N.B.
Partner: UNT Libraries Government Documents Department

Oxidation of coal and coal pyrite mechanisms and influence on surface characteristics. Technical progress report

Description: The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical cleaning processes. Work during the nineteenth quarter has concluded studies of the surface functional groups produced on coal by severe thermal and chemical oxidation, and on investigating the partition of metal ions between such strongly oxidized coal samples and aqueous solutions. This partitioning behavior was being followed to obtain further information on the chemistry of the coal surfaces after different oxidation treatments. Adsorption isotherms for the uptake of Cd{sup 2+} on coal oxidized by different methods were obtained, and these and the Cu{sup 2+} adsorption isotherms reported in the last report have been scrutinized, and interpreted more exhaustively. The apparent discrepancies noted in the last report for the analysis of surface functional groups have been investigated further. The adsorption behavior has been related to the surface chemistry of Upper Freeport coal oxidized by different methods.
Date: May 31, 1995
Creator: Doyle, F.M.
Partner: UNT Libraries Government Documents Department

Fractal analysis of granular activated carbons using isotherm data

Description: Utilization of adsorption on solid surfaces was exercised for the first time in 1785. Practical application of unactivated carbon filters, and powdered carbon were first demonstrated in the American water treatment plant, and a municipal treatment plant in New Jersey, in 1883 and 1930, respectively. The use of activated carbon became widespread in the next few decades. At present, adsorption on carbons has a wide spread application in water treatment and removal of taste, odor, removal of synthetic organic chemicals, color-forming organics, and desinfection by-products and their naturally occurring precursors. This paper presents an analysis of the surface fractal dimension and adsorption capacity of a group of carbons.
Date: August 1, 1997
Creator: Khalili, N.R.; Pan, M. & Sandi, G.
Partner: UNT Libraries Government Documents Department

Control of the accumulation of non-process elements and organic compounds in pulp mills with bleach filtrate reuse. Milestones and progress, Quarter 8 (April 1--June 30, 1998)

Description: Overall, this project is on schedule and proceeding as planned. Two approach changes are recommended. One is to rely on commercially developed software, in particular that developed by OLI Systems, Inc., and now being expanded in a collaborative effort between OLI Systems, Inc. and IPST to provide a simulation package for the pulp and paper industry and to integrate it with existing process simulation tools used by that industry. The second is the development of a detailed brownstock/bleached fiber washer model as a tool to evaluate the data and methods developed in this study, and to demonstrate its utility to industry. Both of these are discussed in more detail in the Approach Changes section of this report. Two tasks are behind schedule. They are Task A-2.3, Measurement of stability constants for wood organics with metal ions (scheduled completion date: 6/98), and Task C-1.2, Estimation of unavailable thermodynamic parameters (scheduled completion date: 12/97). The reasons and expected completion dates for these tasks are discussed in the Performance Variances and Open Items section of this report. All other tasks are either completed, or on or ahead of schedule.
Date: August 1, 1998
Creator: Frederick, W.J.; Laver, M.L.; Rorrer, G.L.; Rudie, A.W. & Schmidl, W.
Partner: UNT Libraries Government Documents Department


Description: High resolution adsorption isotherms, temperature programmed desorption (TPD), x-ray diffraction (XRD) and x-ray absorption near edge spectroscopy (XANES) methods were used to investigate the interaction of SO{sub 2} with high quality MgO powders. The results of these investigations indicate that when SO{sub 2} is deposited on MgO in monolayer quantities at temperatures near 100K both SO{sub 2} and SO{sub 4} species form that are not removed by simply pumping on the pre-dosed samples at room temperature. TPD and XANES studies indicate that heating of pre-dosed MgO samples to temperatures above 350 C is required for full removal of the SO{sub 3}/SO{sub 4} species. XANES measurements made as a function of film thickness indicate for coverages near monolayer completion that the SO{sub 4} species form first.
Date: November 29, 1999
Creator: FREITAG,A.
Partner: UNT Libraries Government Documents Department

Field verification of CO{sub 2} Foam. Final report

Description: The East Vacuum Grayburg/San Andres Unit (EVGSAU), operated by Phillips Petroleum Company, was the site selected for a comprehensive evaluation of the use of foam for improving the effectiveness of a CO{sub 2} flood. This project, entitled {open_quotes}Field Verification of CO{sub 2-}Foam,{close_quotes} was jointly funded by the EVGSAU working interest owners, the U.S. Department of Energy (DOE), and the State of New Mexico. The DOE provided $2 million or approximately 34% of the total project costs, the EVGSAU provided $2.46 million, the State of New Mexico contributed approximately $1.2 million, and about $103,000 of other industrial funds were used. The Petroleum Recovery Research Center (PRRC), a division of the New Mexico Institute of Mining and Technology, provided laboratory and research support for the project. A joint project advisory team composed of technical representatives from several major oil companies provided input, review, and guidance for the project. The project, which began in 1989, had a scheduled duration of four years, but the DOE granted a no-cost extension to the end of March 1995 for the purpose of continued project evaluation. A field test of the CO{sub 2}-foam has been successfully conducted, and preliminary results are promising. Response in the foam injection well has been as anticipated, and an offset producing well experienced a positive oil response as a result of the foam test. Based on the favorable results observed in the foam injection test, a second foam test was conducted. The monitoring program included analysis of injectivity data, pressure falloff tests, observation well logs, interwell tracer response, production logs, history of production rates, and changes in gas-oil ratio. This report presents an overview of the project and provides results of the laboratory work, simulation studies, and field tests.
Date: February 1, 1996
Creator: Martin, F.D.; Heller, J.P. & Weiss, W.W.
Partner: UNT Libraries Government Documents Department

Oxygen Transport Ceramic Membranes

Description: A non-agglomerated and nanocrystalline-sized powder was successfully produced using ethylene glycol nitrate methods. The LSFT powder prepared using this method exhibits well dispersed and nano-sized particles about 100-200 nm. The density of LSFT sintered at 1300 C was about 90% of the theoretical density at which is 100 C less than that of the previous LSFT which was sintered at 1400 C. The sample sintered at 1400 C exhibited the evidence of a liquid phase at the grain boundaries and 2nd phase formation which probably caused low mechanical stability. The electrical conductivity and Seebeck coefficient were measured as a function of temperature. The LSFT-CGO specimens were cut from the as sintered bars and used for the evaluation of Mechanical Properties after polishing. The effect of strain rate on the flexural strength of the LSFT-CGO test specimens was studied. Three strain rates 6, 60 and 600 {micro}m/ min were chosen for this study. It is observed from the results that with increasing cross head speed the membrane takes higher loads to fail. A reduction in the strength of the membrane was observed at 1000 C in N{sub 2}. Two different routes were investigated to synthesis GDC using either formate or carbonate precursors. The precursor and CGO particle morphologies were examined by scanning electron microscopy. The thermal decomposition behaviors of Ce(Gd)(HCOO){sub 3} and Ce(Gd)(CO{sub 3})(OH) were determined by thermogravimetric analysis (TGA) at a rate of 3 C/min in air. The X-ray powder diffraction patterns of the precursor and CGO were collected and nitrogen adsorption isotherms were measured. Conductivity measurements were made by AC impedance spectroscopy on sintered disks in air using platinum electrodes.
Date: June 30, 2006
Creator: Bandopadhyay, S. & Nithyanantham, T.
Partner: UNT Libraries Government Documents Department

Permeability changes in coal resulting from gas desorption. Tenth quarterly report, January 1, 1992--March 31, 1992

Description: Research continued on the study of coal permeability and gas desorption. This quarter, most of the effort involved identifying problems with the microbalance and then getting it repaired. Measurement of the amount of gas adsorbed with the microbalance involved corrections for the buoyancy change with pressure and several experiments with helium were made to determine this correction.
Date: December 31, 1992
Creator: Levine, J. R. & Johnson, P. M.
Partner: UNT Libraries Government Documents Department

Design and Evaluation of Ionic Liquids as Novel CO2 Absorbents

Description: Progress from the third quarter 2006 activity on the project ''Design and Evaluation of Ionic Liquids as Novel CO{sub 2} Absorbents'' is provided. Major activities in two areas are reported: property measurement and molecular modeling. We have measured CO{sub 2} solubility in an ammonium lactate ionic liquid. Previous work has shown that the lactate anion enables chemical complexation to occur. We hypothesized that the lactate anion would not be as effective in complexing when paired with an ammonium cation as compared to when it is paired with an imidazolium cation. The results confirm this. We also measured CO{sub 2} solubility in a functionalized ionic liquid containing an amine group. These so-called task specific ionic liquids (TSILs) are expected to have dramatically higher CO{sub 2} solubility than physical absorbents. We report isotherms as well as entropies and enthalpies of absorption for CO{sub 2} in one TSIL. CO{sub 2} solubilities are higher in this compound than in any previous IL we have observed. Finally, we also developed a new simulation method that will enable us to compute full isotherms of gases in ionic liquids. So far, we have tested the method against model systems and found it to be highly effective.
Date: September 30, 2006
Creator: Maginn, Edward J.
Partner: UNT Libraries Government Documents Department

One-dimensional steam flow in porous media under desorption

Description: Performance forecasting for a hypothetical field with Geysers greywacke rock is performed to demonstrate the importance of desorption effect, the actual adsorption isotherm was found to be well approximated by the Langmuir equation. Results obtained suggest that adsorption is the dominant mechanism for steam in geothermal reservoirs.
Date: January 1, 1991
Creator: Nghiem, Cuong Phu & Ramey, Henry J., Jr.
Partner: UNT Libraries Government Documents Department

Configurational diffusion of asphaltenes in fresh and aged catalyst extrudates. Quarterly progress report, June 20, 1993--September 20, 1993

Description: This quarter, we measured the surface areas and effective diffusivities for fresh, spent and regenerated unimodal Criterion 324 and bimodal EXP-AO-60 catalysts. The results showed that the surface areas for spent catalysts decreased greatly due to coke formation and metal deposition during coal liquefaction process. After regeneration, the catalyst surface areas were partially or completely restored. Adsorption equilibrium experiments showed that the adsorption isotherms for quinoline in cyclohexane with these six sample of catalysts could be well represented by Freundlich isotherms. The effective diffusivities with these catalysts were obtained by fitting experimental data with the diffusional model. The results indicated that the effective diffusivity for fresh bimodal catalyst with larger pore size was greater than that for fresh unimodal catalyst with a smaller pore size. After the catalysts were used in a coal liquefaction process, the effective diffusivities decreased to less than 1% of those for fresh catalysts. When the spent catalysts were regenerated in air, the effective diffusivites were recovered to 35--50% of those for fresh catalysts.
Date: December 1, 1993
Creator: Guin, J. A. & Tarrer, A. R.
Partner: UNT Libraries Government Documents Department


Description: The thermodynamic data for LaNi{sub 4.25}Al{sub 0.75} tritide, reported by Wang et al. (W.-d. Wang et al., J. Alloys Compd. (2006) doi:10.1016/j.jallcom.206.09.122), are in variance with our published data. The plateau pressures for the P-C-T isotherms at all temperatures are significantly lower than published data. As a result, the derived thermodynamic parameters, {Delta}H{sup o} and {Delta}S{sup o}, are questionable. Using the thermodynamic parameters derived from the data reported by Wang et al. will result in under estimating the expected pressures, and therefore not provide the desired performance for storing and processing tritium.
Date: April 10, 2007
Creator: Walters, T
Partner: UNT Libraries Government Documents Department

Kinetics and Equilibrium Sorption Models: Fitting Plutonium, Strontium, Uranium and Neptunium Loading on Monosodium Titanate (MST)

Description: The Dubinin-Astashov (DA) isotherm parameters for U, Pu, Sr and Np have been updated to include additional data obtained since the original derivation. The DA isotherms were modified to include a kinetic function derived by Rahn to describe sorbate loading from the beginning of sorption up to steady state. The final functions describe both kinetic and thermodynamic sorption.
Date: March 8, 2006
Creator: Fondeur, F
Partner: UNT Libraries Government Documents Department

Novel Anionic Clay Adsorbents for Boiler-Blow Down Waters Reclaim and Reuse

Description: Our goal in this study is to utilize novel anionic clay sorbents for treating and reclaiming/reusing power-plant effluents, in particular, boiler blow-down waters containing heavy metals, such as As and Se. Developing and using novel materials for such application is dictated by the challenge posed by reclaiming and recycling these too-clean-to-clean effluent streams, generated during electricity production, whose contaminant levels are in the ppm/ppb (or even less) trace levels. During the study model blow-down streams have been treated in batch experiments. Adsorption isotherms as a function of pH/temperature have been established for both As and Se. Adsorption rates have also measured as a function of concentration, temperature, pH, and space time. For both the equilibrium and rate measurements, we have studied the As/Se interaction, and competition from background anions. A homogeneous surface diffusion model is used to describe the experimental kinetic data. The estimated diffusivity values are shown to depend on the particle size. On the other hand, a model taking into account the polycrystalline nature of these adsorbent particles, and the presence of an intercrystallite porous region predicts correctly that the surface diffusivity is particle size independent. A mathematical model to describe flow experiments in packed-beds has also been developed during phase I of this project. The goal is to validate this model with flow experiments in packed-beds during the phase II of this project, to determine the adsorption capacity under flow conditions, and to compare it with the capacity estimated from the adsorption isotherms determined from the batch studies.
Date: December 1, 2005
Creator: Sahimi, Muhammad & Tsotsis, Theodore T.
Partner: UNT Libraries Government Documents Department

Hydride compositions

Description: Disclosed are a composition for use in storing hydrogen and a method for making the composition. The composition comprises a mixture of two or more hydrides, each hydride having a different series of hydrogen sorption isotherms that contribute to the overall isotherms of the mixture. The hydrides are chosen so that the isotherms of the mixture have regions wherein the H equilibrium pressure increases with increasing hydrogen, preferably linearly. The isotherms of the mixture can be adjusted by selecting hydrides with different isotherms and by varying the amounts of the individual hydrides, or both. Preferably, the mixture is made up of hydrides that have isotherms with substantially flat plateaus and in nearly equimolar amounts. The composition is activated by degassing, exposing to H, and then heating below the softening temperature of any of the constituents. When the composition is used to store hydrogen, its hydrogen content can be found simply by measuring P{sub H}{sub 2} and determining H/M from the isothermic function of the composition.
Date: February 7, 1994
Creator: Lee, Myung W.
Partner: UNT Libraries Government Documents Department

Hindered diffusion of asphaltenes at elevated temperature and pressure. [Semi-annual report], September 20, 1995--March 20, 1996

Description: In this study equilibrium adsorption isotherms were determined for two petroleum asphaltenes, AAD-1 and AAK-1, and one coal asphaltene, called No. 97500. Isotherms were determined for three different temperatures, namely 20, 35 and 50{degrees}C. The experimental data for the petroleum asphaltenes were fitted with a Freundlich isotherm. For the coal asphaltene a Freundlich isotherm was used to fit the experimental data for lower concentrations; however, for higher concentrations a linear isotherm fitted the experimental data better. The coal asphaltene showed a tendency to form multilayers on the catalyst surface. Upon comparison of the adsorption isotherms for the three different temperatures, an interesting effect was observed. Although a decrease of the asphaltenes adsorption for higher temperatures was expected, the adsorption as a function of the temperature in fact showed a maximum for the petroleum asphaltenes and a minimum for the coal asphaltenes. This interesting and unexpected behavior was speculated to be due to the formation of micelles in the coal asphaltene solution and the different dependence of micelle formation and adsorption on temperature. Comparing the adsorption isotherms for the three different asphaltenes revealed that the adsorption of the coal asphaltenes was initially lower than the adsorption of the petroleum asphaltenes, but increased more rapidly, finally becoming near and even greater than the adsorption of the petroleum asphaltenes. This was suggested to be due to the tendency of coal asphaltenes for multilayer adsorption on the solid surface.
Date: April 12, 1996
Creator: Guin, J.A.
Partner: UNT Libraries Government Documents Department

Control of the accumulation of non-process elements and organic compounds in pulp mills with bleach filtrate reuse. Milestones and progress, Quarter 9 (July 1--September 30, 1998)

Description: The two approach changes that were discussed and recommended in the Quarter 8 (April 1--June 30, 1998) progress report have been implemented in the current project plan. The OLI software has been used to develop a preliminary process model for predicting the distribution of NPE`s in a two stage brownstock washer, and the OLI database has been upgraded to include improved chemical equilibrium data for metal-organic interactions. This exercise served as a tool to evaluate the data and methods developed in this study, and to demonstrate its utility to industry. The Weyerhaeuser-NAELS software has also been applied to predicting inorganic solubility behavior. Task C-1.2, Estimation of unavailable thermodynamic parameters (scheduled completion date: 12/97), has been combined with Task D-2.1, Evaluation of the estimation procedure (scheduled completion date: 3/99) with a new scheduled completion date of 8/99. A model for the adsorption of metal ions on wood pulp fibers will include transport effects as well as adsorption equilibrium, and will be combined with a brownstock washer model to evaluate its predictive capability in comparison with mill data, and to demonstrate the applicability of the results obtained in this project. Three tasks are behind schedule: Task A-2.3, Measurement of stability constants for wood organics with metal ions (scheduled completion date: 6/98), Task B-2.1, Measure metal adsorption isotherms on wood pulp (scheduled completion date: 9/97), and Task B-2.3, Measure metal ion adsorption kinetics for strongly adsorbing metal species (scheduled completion date: 3/98). The reasons and expected completion dates are discussed in the Performance Variances and Open Items section. All other tasks are either completed, on, or ahead of schedule.
Date: December 31, 1998
Creator: Frederick, W.J.; Laver, M.L.; Rorrer, G.L.; Rudie, A.W. & Schmidl, W.
Partner: UNT Libraries Government Documents Department