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The Application of Tracer Techniques to the Determination of Uranium Extraction Coefficients

Description: Abstract: This report deals with the development of a method using tracer technique for determining uranium extraction coefficients on solutions of low uranium concentration. It was found that extraction coefficients could be determined on systems containing as low as one part per million uranium using 1900 level uranium as the tracer. Results of several extraction series are presented in which aluminum nitrate is used as the salting agent and dibutyl carbitol the organic extractant.
Date: January 23, 1947
Creator: Lee, D. A.; Woodard, R. W. & Clewett, G. H.
Partner: UNT Libraries Government Documents Department

Ion Tracer Technique for Airspeed Measurement at Low Densities

Description: Note presenting a study of the aerodynamic and production-detection problems associated with ion tracer velocity measurement techniques, with particular emphasis on those aspects unique to low-density gas dynamics. A critical survey was made of the various techniques which have been employed and specific suggestions are offered relative to the successful use of ion tracer velocity measuring methods at low densities.
Date: March 1954
Creator: Kunkel, W. B. & Talbot, L.
Partner: UNT Libraries Government Documents Department

Utilization of the noble gases in studies of underground nuclear detonations

Description: From symposium on noble gases; Las Vegas, Nevada, USA (24 Sep 1973). The Livermore Gas Diagnostics Program employs a number of rare gas isotopes, both stable and radioactive, in its investigations of the phenomenology of underground nuclear detonations. Radioactive gases in a sample are radiochemically purified by elution chromatography, and the separated gases are radioassayed by gamma-ray spectrometry and by internal or thin-window beta proportional counting. Concentrations of the stable gases are determined by mass-spectrometry, following chemical removal of the reactive gases in the sample. The most general application of the noble gases is as device fraction indicators to provide a basis for estimating totals of chimney-gas components. All of the stable rare gases except argon have been used as tracers, as have /sup 127/Xe and /sup 85/Kr. /sup 37/Ar and /sup 85/Kr have proven to be of particular value in the absence of a good tracer material as reference species for studies of chimney-gas chemistry. The rate of mixing of chimney gases and the degree to which the sampled gas truly represents the underground gas mixture can be studied with the aid of the fission- product gases. /sup 222/Ra and He are released to the cavity from the surrounding rock and are therefore useful in studies of the interaction of the detonation with the surrounding medium. (auth)
Date: September 17, 1973
Creator: Smith, C.F.
Partner: UNT Libraries Government Documents Department

Test plan for determining breathing rates in single shell tanksusing tracer gases. Revision 2

Description: This test plan specifies the requirements and conditions for the injection of tracer gases into eight tanks. Eight single shell tanks shall be injected with inert tracer gas, Helium (He), and then samples taken periodically to measure breathing rates. The eight tanks to be tested are; A-101, AX-102, AX-103, BY-105, C-107, U-103 (tested once in the winter and will be tested once in the summer), and U-105. The headspace of these tanks shall be sampled and analyzed periodically to obtain breathing rate information.
Date: June 26, 1997
Creator: Andersen, J.A.
Partner: UNT Libraries Government Documents Department

Tracer Tests in a Fractured Dolomite: 4. Double Porosity, Multiple-Rate Mass Transfer Processes in Two-Well Convergent Flow Tests

Description: Two-well convergent-flow tracer tests conducted in the Culebra dolomite (Rustler Formation, New Mexico, USA) are analyzed with both single-and multiple-rate, double-porosity models. Parameter estimation is used to determine the mean and standard deviation of a Iog- normal distribution of diffision rate coefficients as well as the advective porosity and longitudinal dispersivity. At two different test sites, both mukirate and single-rate models are capable of accurately modeling the observed data. Estimated model parameters are tested against breakthrough curves obtained along the same transport pathway at a different pumping rate. Implications of the rnultirate mass-transfer model at time and length scales greater than those of the tracer tests include the instantaneous saturation of a fraction of the matrix ~d the possibility of a fraction of the matrix remaining unsaturated at long times.
Date: March 4, 1999
Creator: Haggerty, R.; McKenna, S.A. & Meigs, L.C.
Partner: UNT Libraries Government Documents Department

Characterization of Mixed Wettability at Different Scales and Its Impact on Oil Recovery Efficiency

Description: The objectives of the this research project were to: (1) Quantify the pore scale mechanisms that determine the wettability state of a reservoir; (2) Study the effect of crude oil, brine and mineral compositions in the establishment of mixed wet states; (3) Clarify the effect of mixed-wettability on oil displacement efficiency in waterfloods; and (4) Develop a new tracer technique to measure wettability, fluid distributions, residual saturations and relative permeabilities.
Date: September 1, 2003
Creator: Sharma, Mukul M. & Hirasaki, George J.
Partner: UNT Libraries Government Documents Department

Characterization of Mixed Wettablility at Different Scales and Its Impact on Oil Recovery Efficiency

Description: The objectives of the this research project were to: (1) Quantify the pore scale mechanisms that determine the wettability state of a reservoir; (2) Study the effect of crude oil, brine and mineral compositions in the establishment of mixed wet states; (3) Clarify the effect of mixed-wettability on oil displacement efficiency in waterfloods; and (4) Develop a new tracer technique to measure wettability, fluid distributions, residual saturations and relative permeabilities.
Date: August 31, 2003
Creator: Sharma, Mukul M. & Hirasaki, George J.
Partner: UNT Libraries Government Documents Department

Contributions and future of radioisotopes in medical, industrial and space applications

Description: There are 333 isotopes that have a half-life between 1 day and 100,000 years that have a wide variety of applications including public health, medicine,industrial technology, food technology and packaging, agriculture, energy supply, and national security. This paper provides an overview of some of the most extensive applications of radioisotopes including some observations of future uses. Examples are discussed that indicate that the use of radioisotopes is almost unlimited and will continue to grow. There is a growing need for future applications development and production. 12 refs., 1 tab. (BM)
Date: November 1, 1990
Creator: Tingey, G.L.; Dix, G.P. & Wahlquist, E.J.
Partner: UNT Libraries Government Documents Department

Metabolism of $sup 90$Sr and of other elements in man, July 1, 1974--June 30, 1975

Description: Trace element studies have been carried out under strictly controlled dietary conditions in adult males during different calcium intakes. Complete metabolic balances of cadmium, copper, zinc, lead, manganese, and nickel were determined in each 6-day metabolic period by analyzing the constant diet and the urinary and fecal excretions of these naturally occurring elements. In addition to the trace element studies, $sup 85$Sr studies were carried out in man in order to complete previously initiated investigations. (auth)
Date: December 31, 1975
Partner: UNT Libraries Government Documents Department

Water flux in animals: analysis of potential errors in the tritiated water method

Description: Laboratory studies indicate that tritiated water measurements of water flux are accurate to within -7 to +4% in mammals, but errors are larger in some reptiles. However, under conditions that can occur in field studies, errors may be much greater. Influx of environmental water vapor via lungs and skin can cause errors exceeding +-50% in some circumstances. If water flux rates in an animal vary through time, errors approach +-15% in extreme situations, but are near +-3% in more typical circumstances. Errors due to fractional evaporation of tritiated water may approach -9%. This error probably varies between species. Use of an inappropriate equation for calculating water flux from isotope data can cause errors exceeding +-100%. The following sources of error are either negligible or avoidable: use of isotope dilution space as a measure of body water volume, loss of nonaqueous tritium bound to excreta, binding of tritium with nonaqueous substances in the body, radiation toxicity effects, and small analytical errors in isotope measurements. Water flux rates measured with tritiated water should be within +-10% of actual flux rates in most situations.
Date: March 1, 1979
Creator: Nagy, K.A. & Costa, D.
Partner: UNT Libraries Government Documents Department

Measurement of the Bovine pancreatic trypsin inhibitors by radioimmunoassay

Description: Bovine pancreas contains two polypeptide trypsin inhibitors that are not homologous and differ in their inhibitory activity towards chymotrypsin, kallikrein, elastase, and other serine proteinases. The Kunitz inhibitor and the Kazal inhibitor are present in approximately equimolar concentrations in bovine pancreatic tissue, yet only the Kazal inhibitor is detectable in the pancreatic juice. The Kazal inhibitor has been named the pancreatic secretory trypsin inhibitor, PSTI because its concentration in the pancreatic juice parallels that of the exocrine secretory proteins. The Kunitz inhibitor is considered the intracellular inhibitor, however, no direct information is available concerning the intracellular localization of these inhibitors in the pancreas. The preparation of /sup 125/I-labeled derivatives of Kazal and Kunitz inhibitors by the lactoperoxidase method and a radioimmunoassay for each inhibitor are described. (auth)
Date: January 1, 1973
Creator: Fink, E. & Greene, L.J.
Partner: UNT Libraries Government Documents Department

Users' guides for radioactivity standards

Description: A short guide to chemical and counting problems for standards that are in common use or are expected to be available is presented. The Users' Guides are prepared separately for every element, so that the user need only consult a few paragraphs. The discussions are far too brief to provide adequate information on the chemical and nuclear decay properties of the substance; the ochemistry Subcommittee, NASNRC, and Nuclear Data Sheets should be consulted for this purpose. (DHM)
Date: February 1, 1974
Partner: UNT Libraries Government Documents Department

Membrane vesicles: A simplified system for studying auxin transport. Final technical report

Description: Indoleacetic acid (IAA), the auxin responsible for regulation of growth, is transported polarly in plants. Several different models have been suggested to account for IAA transport by cells and its accumulation by membrane vesicles. One model sees diffusion of IAA driven by a pH gradient. The anion of a lipophilic weak acid like IAA or butyrate accumulates in an alkaline compartment in accord with the size of the pH gradient The accumulation of IAA may be diminished by the permeability of its lipophilic anion. This anion leak may be blocked by NPA. With anion efflux blocked, a gradient of two pH units would support an IAA accumulation of less than 50-fold at equilibrium (2) Another model sees diffusion of IAA in parallel with a saturable symport (IAA{sup {minus}} + nH{sup +}), driven by both the pH gradient and membrane voltage. Such a symport should be highly accumulative, however, with a lipophilic weak acid such as IAA, net diffusive efflux of IAAH whenever IAAHI{sub i} > IAAH{sub o} would constitute a leak. (3) A third model sees a pH change driven IAA uptake and saturable symport enhanced by internal binding sites. Following pH gradient-driven accumulation of IAA, the anion may bind to an intravesicular site, permitting further uptake of IAA. NPA, by blocking anion efflux, enhances this binding. We have reported that membrane vesicles isolated from actively growing plant tissues are a good system for studying the mechanisms involved in the transport and accumulation of auxin.
Date: December 31, 1989
Creator: Goldsmith, M. H. M.
Partner: UNT Libraries Government Documents Department

SBH and the integration of complementary approaches in the mapping, sequencing, and understanding of complex genomes

Description: A variant of sequencing by hybridization (SBH) is being developed with a potential to inexpensively determine up to 100 million base pairs per year. The method comprises (1) arraying short clones in 864-well plates; (2) growth of the M13 clones or PCR of the inserts; (3) automated spotting of DNAs by corresponding pin-arrays; (4) hybridization of dotted samples with 200-3000 {sup 32}P- or {sup 33}P-labeled 6- to 8-mer probes; and (5) scoring hybridization signals using storage phosphor plates. Some 200 7- to 8-mers can provide an inventory of the genes if CDNA clones are hybridized, or can define the order of 2-kb genomic clones, creating physical and structural maps with 100-bp resolution; the distribution of G+C, LINEs, SINEs, and gene families would be revealed. cDNAs that represent new genes and genomic clones in regions of interest selected by SBH can be sequenced by a gel method. Uniformly distributed clones from the previous step will be hybridized with 2000--3000 6- to 8-mers. As a result, approximately 50--60% of the genomic regions containing members of large repetitive and gene families and those families represented in GenBank would be completely sequenced. In the less redundant regions, every base pair is expected to be read with 3-4 probes, but the complete sequence can not be reconstructed. Such partial sequences allow the inference of similarity and the recognition of coding, regulatory, and repetitive sequences, as well as study of the evolutionary processes all the way up to the species delineation.
Date: December 1, 1992
Creator: Drmanac, R.; Drmanac, S.; Labat, I.; Vicentic, A.; Gemmell, A.; Stavropoulos, N. et al.
Partner: UNT Libraries Government Documents Department

Regulated expression of the MRP8 and MRP14 genes in human promyelocytic leukemic HL-60 cell treated with the differentiation-inducing agents mycophenolic acid and 1{alpha},25-Dihydroxyvitamin D{sub 3}

Description: The calcium-binding proteins MRP8 and MEP14 are present in mature monomyelocytic cells and are induced during differentiation. Previous studies have demonstrated that the proteins may mediate the growth arrest in differentiating HL-60 cells. We determined the levels of a protein complex (PC) containing MRP8 and MRP14 and investigated the mechanism by which the genes encoding these proteins are regulated in HL-60 cells treated with the differentiation-inducing agent mycophenorc acid (MPA)While the PC was barely detectable in untreated cells, MPA treatment resulted in elevated levels of the PC which were maximal at 3-4 d, and were found to directly parallel gains in the steady-state levels of MRP8 and MRP14 MRNA. Transcription studies with the use of nuclear run-on experiments revealed increased transcription initiation at the MRP8 and MRP14 promoters after MPA treatment. 1{alpha},25-Dihydroxyvitamin D{sub 3}, which induces HL-60 cell differentiation by another mechanism, was also found to increase transcription initiation at the MRP8 and MRP14 promoters. Our results suggest that this initiation is the major control of maturation agent-mediated increases in MRP8 and MRPl4 gene expression, and support a role for the PC in terminal differentiation of human monomyelocytic cells.
Date: December 31, 1992
Creator: Warner-Bartnicki, A. L.; Murao, S.; Collart, F. R. & Huberman, E.
Partner: UNT Libraries Government Documents Department

KINETICS OF PARTICLE GROWTH IN A FLUIDIZED CALCINER

Description: Fluidized calcination involves the injection of an atomized feed solution containing dissolved solids into a bed of fluidized partioles at elevated temperatures suitable for drying and calcining. The study was conducted in a threeinch diameter fluidized column using aluminum oxide as bed material and aqueous aluminum nitrate solution as feed. Products were removed at regular intervals to maintain a constant bed weight. Particle growth was traced by adding radioactive aluminum oxide seeds of a given size to the starting bed and following their progress as they grew into successively larger sieve fractions. The effects on the growth rate of operating variables and physical properties of the feed were studied, including fluidizing air velocity, atomizing air rate, column temperature, feed concentration, feed rate, and viscosity and surface tension of the feed. For each product using screen analysis and gammacounting data a volume-surface mean diameter of the seedcontaining particles was calculated. Upon statistical analysis a linear relationship between the mean diameter of seed-containing particles and time exhibited very strong correlation, substantiating the hypothesis that particle growth was proportional to its surface area. From this linear relationship the over-all growth constant, equal to the slope, was obtained. Attrition effect of the atomizing air was found statistically to be non-significant. Normal growth far outweighed attrition and for steady-state operation other methods to produce seeds, such as jet or target attrition must be employed to balance normal growth. (auth)
Date: June 1, 1960
Creator: Lee, B. S.
Partner: UNT Libraries Government Documents Department