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The Paths of Quintessence

Description: The structure of the dark energy equation of state phase plane holds important information on the nature of the physics. We explain the bounds of the freezing and thawing models of scalar field dark energy in terms of the tension between the steepness of the potential vs. the Hubble drag. Additionally, we extend the phase plane structure to modified gravity theories, examine trajectories of models with certain properties, and categorize regions in terms of scalar field hierarchical parameters, showing that dark energy is generically not a slow roll phenomenon.
Date: March 13, 2006
Creator: Linder, Eric V.
Partner: UNT Libraries Government Documents Department

Field Flows of Dark Energy

Description: Scalar field dark energy evolving from a long radiation- or matter-dominated epoch has characteristic dynamics. While slow-roll approximations are invalid, a well defined field expansion captures the key aspects of the dark energy evolution during much of the matter-dominated epoch. Since this behavior is determined, it is not faithfully represented if priors for dynamical quantities are chosen at random. We demonstrate these features for both thawing and freezing fields, and for some modified gravity models, and unify several special cases in the literature.
Date: July 8, 2008
Creator: Cahn, Robert N.; de Putter, Roland & Linder, Eric V.
Partner: UNT Libraries Government Documents Department

Bacteria in Permafrost

Description: Significant numbers of viable ancient microorganisms are known to be present within the permafrost. They have been isolated in both polar regions from the cores up to 400 m deep and ground temperatures of -27 C. The age of the cells corresponds to the longevity of the permanently frozen state of the soils, with the oldest cells dating back to {approx}3 million years in the Arctic, and {approx}5 million years in the Antarctic. They are the only life forms known to have retained viability over geological time. Thawing of the permafrost renews their physiological activity and exposes ancient life to modern ecosystems. Thus, the permafrost represents a stable and unique physicochemical complex, which maintains life incomparably longer than any other known habitats. If we take into account the depth of the permafrost layers, it is easy to conclude that they contain a total microbial biomass many times higher than that of the soil cover. This great mass of viable matter is peculiar to permafrost only.
Date: January 1, 2008
Creator: Gilichinsky, David A.; Vishnivetskaya, Tatiana A.; Petrova, Maya A.; Spirina, Elena V.; Mamikin, Vladimir & Rivkina, Elizaveta
Partner: UNT Libraries Government Documents Department

Evaluation of the freeze-thaw/evaporation process for the treatment of produced waters. Quarterly technical progress report, January 1, 1996--March 31, 1996

Description: The use of freeze-crystallization is being increasingly acknowledged as a crystallization is being increasingly acknowledged as a low-cost, energy-efficient method for purifying contaminated water. The natural freezing process can be coupled with natural evaporative processes to treat oil and gas produced waters year-round in regions where sub-freezing temperatures seasonally occur. The objectives of this research are related to development of a commercially-economic natural freezethaw/evaporation (FTE) process for the treatment and purification of water produced in conjunction with oil and gas Research efforts this quarter were: to complete the draft of the ``Task 1 and Task 2 Report``; to complete sampling and analysis of the FTE demonstration process streams; to begin data evaluation of the demonstration based on the results of process stream analyses; and to begin work on the final project report.
Date: April 1, 1996
Creator: Boysen, J.
Partner: UNT Libraries Government Documents Department

Task 21 - Evaluation of Artificial Freeze Crystallization and Natural Freeze-Thaw Processes for the Treatment of Contaminated Groundwater at the Strachan Gas Plant in Alberta, Canada - Sour Gas Remediation Technology R{ampersand}D

Description: During the period from 1993 to 1996, a long-term program was initiated to conduct remediation research at the Strachan Gas Plant in Alberta, Canada. As part of this research program, optimization of the existing pump-and-treat (P{ampersand}T) facility was of interest. The cost-effective treatment of contaminated groundwater produced from the P{ampersand}T system was complicated by several factors, including: (1) increased cost and reduced effectiveness of most water treatment processes because of the cold temperatures and severe winter conditions prevalent in Alberta, (2) interference caused by the mixture of inorganic and organic contaminants found in the groundwater that can reduce the effectiveness of many water treatment processes, and (3) pretreatment to prevent scaling in existing treatment process unit operations caused by the iron, manganese, and hardness of the contaminated groundwater.
Date: March 1997
Partner: UNT Libraries Government Documents Department

Biophysical and biological factors determining the ability to achieve long-term cryobiological preservation

Description: The BESTCapsule will maintain appropriate biological specimens for decades or centuries at cryogenic temperatures in the living state. Maintenance at temperatures below {approximately} {minus}140 C is not a problem. No ordinary chemical reactions in aqueous solutions can occur. The only source of damage will be the slow accumulation of physical damage to DNA from background ionizing radiation. But this source of damage should not become serious in less than a millennium. Rather, the main problem in cryopreservation is to devise procedures for cooling the biological specimens to {minus}196 C and returning them to normal temperatures without inflicting lethal injury. Regardless of the cell type, there are certain encompassing biophysical factors and constraints that determine whether they will survive or die during freezing and thawing. Superimposed on these may be special biological factors that apply to specific cell types. This paper will emphasize the former and give illustrative examples of the latter.
Date: December 1, 1997
Creator: Mazur, P.
Partner: UNT Libraries Government Documents Department

The durability of stabilized flue gas desulfurization sludge

Description: The effects of freeze-thaw cycling on the strength and durability of samples of compacted, stabilized, wet flue gas desulfurization (FGD) by-products are reported. The results of laboratory tests show a clear relationship between higher water contents and increasing vulnerability to freeze-thaw effects. In the samples tested, water contents at or above 40% were characteristic of all the freeze-thaw specimens exhibiting low strengths. Lime content and curing time were also shown to have a marked influence on the durability of the FGD material. It was shown that samples can maintain good strength under freeze-thaw conditions provided 5% lime was added before compaction and the time from compaction to first freeze was at least 60 days.
Date: December 31, 1995
Creator: Chen, X.; Wolfe, W.E. & Hargraves, M.D.
Partner: UNT Libraries Government Documents Department


Description: TASK 45 FIELD DEPLOYMENT EVALUATION OF THE FREEZE-THAW/ EVAPORATION (FTE ) PROCESS TO TREAT OIL AND GAS PRODUCED WATERS coupling evaporation with freezing. This offers operators a year- round method for treating produced water. Treating water with the FTE process reduces the volume of water to be disposed of as well as purifying the water to a level acceptable for watering livestock and agricultural lands. This process is currently used at two evaporation facilities, one in the San Juan Basin in New Mexico and one in the Green River Basin in Wyoming. the freezing point below that of pure water. When such a solution is cooled below 32EF, relatively pure ice crystals form, along with an unfrozen brine solution that contains elevated concentrations of salts. Because of the brine's high concentration of these constituents, its density is greater than that of the ice, and the purified ice and brine are easily separated. Coupling the natural processes of freezing and evaporation makes the FTE process a more cost- effective and efficient method for the treatment and disposal of produced water and allows for year-round operation of an FTE facility. drops below 32 F, produced water is automatically pumped from a holding pond and sprayed onto a freezing pad. The freezing pad consists of an elevated framework of piping with regularly placed, upright, extendable spray heads similar to those used to irrigate lawns. As the spray freezes, an ice pile forms over the elevated framework of pipes, and the brine, with an elevated constituent concentration, drains from the ice pile. The high-salinity brine, identified by its high electrical conductivity, is separated using automatic valves and pumped to a pond where it can subsequently be disposed of by conventional methods. As the ice pile increases in height, the sprayers are extended. When the ...
Date: May 1, 1999
Creator: Grisanti, Ames A. & Sorensen, James A.
Partner: UNT Libraries Government Documents Department


Description: Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. The work scope drilled and cored a well The Hot Ice No. 1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report. The Hot Ice No. 1 well was drilled from the surface to a measured depth of 2300 ft. There was almost 100% core recovery from the bottom of surface casing at 107 ft to total depth. Based on the best estimate of the bottom of the methane hydrate stability zone (which used new data obtained from Hot Ice No. 1 and new analysis of data from adjacent wells), core was recovered over its complete range. Approximately 580 ft of porous, mostly frozen, sandstone and 155 of conglomerate were recovered in the Ugnu ...
Date: February 1, 2005
Creator: Sigal, Richard; Newsham, Kent; Williams, Thomas; Freifeld, Barry; Kneafsey, Timothy; Sondergeld, Carl et al.
Partner: UNT Libraries Government Documents Department

Evaluation of the freeze-thaw/evaporation process for the treatment of produced waters. Quarterly technical progress report, July 1--September 30, 1993

Description: The objectives of this research are related to development of a commercially-economic natural freeze-thaw/evaporation (FTE) process for the treatment and purification of water produced in conjunction with oil and gas. During the reporting period of July 1, 1993 to September 30, 1993, project research concentrated on Subtasks 2.0 (Task 2 Project Reporting) and 2.1 (Laboratory-scale FTE Simulations). The objectives of Task 2 are to conduct laboratory- and bench-scale simulations for optimizing the design of the FTE process. Task 2 requires completion of six subtasks: Subtask 2.0 -- Task 2 Project Reporting (initiated March 1, 1993), Subtask 2.1 -- Laboratory-scale FTE Simulations, Subtask 2.2 -- Re-evaluation of Process Economics Based on Laboratory-scale Process Simulation Results, Subtask 2.3 -- Bench-scale FTE Simulations, Subtask 2.4 -- Economic Assessment of Bench-scale Simulations, and Subtask 2.5 -- Technical Report of Task 2. The construction and operation of the laboratory-scale process simulations planned for this quarter (Subtask 2.1) have been delayed until the contract modification to obtain co-funding from the Gas Research Institute (GRI) through their subcontractor Remediation Technologies, Inc. (RETEC) is in place.
Date: October 1, 1993
Creator: Boysen, J. & Morotti, J.
Partner: UNT Libraries Government Documents Department

D0 Collider Detector LINDE, East Chicago (LAr Contractor) Trip Report

Description: East Chicago is capable of processing air at a 6-7E6 SCFH rate. They can produce as much as 1.2E6 SCFH 02 and 4.5 SCFH N2 (not coincidently) with a peak product efficiency of 85-86% (product to total Intake). The general area demand has been as high as 10E6, as low as 4.5E6, and is currently 8E6 SCFH totaI product. The plant is really four plants in one. At anyone time one or more plants can be down for maintenance and the others online and delivering to the pipe line that distributes their product to nearby steel plants, and to the liquid reservoirs (perlite insulated tanks) of 160, 160 and 200 E6 SCF. At the time of our visit two plants were down and two were on line. The following describes the characteristics of one of the four plants. The cycle requires a base compressor (Brown Boveri, 22,600 hp) that pumps to 90-100 psig, and a booster compressor (Clark, 14,000 hp) that pumps to 300 psig. Filter houses (ca. 20-ft x 20-ft) feed the suctions and the discharge is scrubbed by dual, molecular sieve, beds 0 300 psi (6-8 hour cycle time). The beds are provided with dust blow down and down stream filter provisions. The scrubbers remove CO2, the heavy HC, and water. The effectiveness of the scrubbers is measured by the record 6 years one of the plants ran w/o the need for thawing. The thaw operation takes about 4 days. It was interesting to learn that a plant can be brought on line in two and one half hours from a warm start. Major swings from N2 rich to O2 rich production take about an hour. Argon is a small constituent in air (0.61) and thus not a major product. It comes off the main column at 761 ...
Date: February 8, 1991
Creator: Dixon, K.; Krempetz, K.; Mulholland, G.T.; Urbin, J. & /Fermilab
Partner: UNT Libraries Government Documents Department

Use of Residual Solids from Pulp and Paper Mills for Enhancing Strength and Durability of Ready-Mixed Concrete

Description: This research was conducted to establish mixture proportioning and production technologies for ready-mixed concrete containing pulp and paper mill residual solids and to study technical, economical, and performance benefits of using the residual solids in the concrete. Fibrous residuals generated from pulp and paper mills were used, and concrete mixture proportions and productions technologies were first optimized under controlled laboratory conditions. Based on the mixture proportions established in the laboratory, prototype field concrete mixtures were manufactured at a ready-mixed concrete plant. Afterward, a field construction demonstration was held to demonstrate the production and placement of structural-grade cold-weather-resistant concrete containing residual solids.
Date: September 18, 2003
Creator: Naik, Tarun R.; Chun, Yoon-moon & Kraus, Rudolph N.
Partner: UNT Libraries Government Documents Department

Evaluation of the freeze-thaw/evaporation process for the treatment of produced waters. Final report, August 1992--August 1996

Description: The use of freeze-crystallization is becoming increasingly acknowledged as a low-cost, energy-efficient method for purifying contaminated water. The natural freezing process can be coupled with natural evaporative processes to treat oil and gas produced waters year round in regions where subfreezing temperatures seasonally occur. The climates typical of Colorado`s San Juan Basin and eastern slope, as well as the oil and gas producing regions of Wyoming, are well suited for application of these processes in combination. Specifically, the objectives of this research are related to the development of a commercially-economic FTE (freeze-thaw/evaporation) process for the treatment and purification of water produced in conjunction with oil and natural gas. The research required for development of this process consists of three tasks: (1) a literature survey and process modeling and economic analysis; (2) laboratory-scale process evaluation; and (3) field demonstration of the process. Results of research conducted for the completion of these three tasks indicate that produced water treatment and disposal costs for commercial application of the process, would be in the range of $0.20 to $0.30/bbl in the Rocky Mountain region. FTE field demonstration results from northwestern New Mexico during the winter of 1995--96 indicate significant and simultaneous removal of salts, metals, and organics from produced water. Despite the unusually warm winter, process yields demonstrate disposal volume reductions on the order of 80% and confirm the potential for economic production of water suitable for various beneficial uses. The total dissolved solids concentrations of the FTE demonstration streams were 11,600 mg/L (feed), 56,900 mg/L (brine), and 940 mg/L (ice melt).
Date: June 1996
Creator: Boysen, J. E.; Walker, K. L.; Mefford, J. L.; Kirsch, J. R. & Harju, J. A.
Partner: UNT Libraries Government Documents Department

Approaches to the preservation of human granulocytes by freezing

Description: Because of its simplicity, the FDA assay can be used effectively as a screening test to eliminate procedures and treatments that are damaging to cells. In this context, a number of conclusions can be drawn from the data presented: (1) Exposure to 1 and 2 M glycerol at room temperature damages human granulocytes in a few minutes. Reducing the exposure temperature to 0/sup 0/C reduces the amount of injury substantially. (2) Human granulocytes respond to freezing and thawing in a manner typical of many mammalian cells in that they exhibit a maximum in survival at an optimum cooling rate slightly above 1/sup 0/C/min when combined with rapid warming. The use of rapid warming and a high (2 M) concentration of glycerol reduces the dependence of survival on cooling rate by broadening the range of rates over which survival is relatively high. (3) Human granulocytes show some sensitivity to dilution stresses since survival depends somewhat on the concentration of glycerol used and the severity of the dilution procedure. The reasons for the sharp decrease in cell viability following incubation of frozen-thawed granulocytes at 37/sup 0/C are not known. One possibility is that the phosphate buffered saline suspending medium used is not suitable for incubation at 37/sup 0/C. A second possibility is that some cell injury is not expressed at 0/sup 0/C and remains undetected by the FDA assay until the cells are incubated at 37/sup 0/C. There is also the possibility that lysosomal enzymes released by a few damaged cells in a sample will cause additional damage in other cells at 37/sup 0/C.
Date: January 1, 1979
Creator: Frim, J & Mazur, P
Partner: UNT Libraries Government Documents Department

Evaluation of oil shale bitumen as a pavement asphalt additive to reduce moisture damage susceptibility

Description: An unrefined shale bitumen was evaluated as an agent to reduce moisture damage susceptibility of asphalt aggregate mixtures. Some activity was observed but less than might have been expected based on the molecular weight and nitrogen content of the bitumen. The counter effects of free carboxylic acids, which are known to be variable in asphalt and which are also present in the unrefined bitumen, appear to diminish the activity of the bitumen to inhibit moisture damage. 5 refs., 1 tab.
Date: January 1, 1991
Creator: Robertson, R.E.; Harnsberger, P.M. & Wolf, J.M.
Partner: UNT Libraries Government Documents Department

Intermediate photovoltaic system application experiment operational performance report. Volume 7, for Newman Power Station, El Paso, TX

Description: Performance data are given for the month of December, 1981 for a photovoltaic power supply at a Texas power station. Data include: monthly and daily electric energy produced; monthly and daily solar energy received; monthly and daily array efficiency; plots of energy produced as a function of power level, voltage, cell temperature, and hour of the day; monthly and daily electrical energy supplied by the photovoltaic system to the load; daily system availability; monthly and hourly insolation; monthly and hourly ambient temperature; monthly and hourly wind speed; wind direction distribution; heating and cooling degree days; number of freeze/thaw cycles; hourly cell temperature; and a plot of daily data acquisition mode and recording interval. Also included are brief summaries of three site events. (LEW)
Date: January 1, 1982
Partner: UNT Libraries Government Documents Department

Models for estimation of service life of concrete barriers in low-level radioactive waste disposal

Description: Concrete barriers will be used as intimate parts of systems for isolation of low level radioactive wastes subsequent to disposal. This work reviews mathematical models for estimating the degradation rate of concrete in typical service environments. The models considered cover sulfate attack, reinforcement corrosion, calcium hydroxide leaching, carbonation, freeze/thaw, and cracking. Additionally, fluid flow, mass transport, and geochemical properties of concrete are briefly reviewed. Example calculations included illustrate the types of predictions expected of the models. 79 refs., 24 figs., 6 tabs.
Date: September 1, 1990
Creator: Walton, J.C.; Plansky, L.E. & Smith, R.W. (EG and G Idaho, Inc., Idaho Falls, ID (USA))
Partner: UNT Libraries Government Documents Department