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Photoinduced Charge Separation by Polymer-Bound Chromophores

Description: This project has examined the photodynamic behavior of water-soluble polymers that have covalently linked hydrophobic chromophores spaced along the chains. These polymeric systems have been examined for photoinduced charge separation with electron-accepting ions having different total charge. Focus has been on the excited singlet (S{sub 1}) state formed by laser flash absorption. The effects of pH and ionic strength -- factors that govern the conformational nature of the polymer in solution -- … more
Date: September 1, 1991
Creator: Rodgers, M. A. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

High-Sensitivity Single-Molecule Fluorescence Detection in Theory and Practice

Description: The number of emitted photons that can be obtained from a fluorophore increases with the incident light intensity and the duration of illumination. However, saturation of the absorption transition and photodestruction place natural limits on the ultimate signal-to-noise ratio that can be obtained. Equations have been derived to describe the fluorescence-to-background-noise ratio in the presence of saturating light intensities and photodestruction. The fluorescence lifetime and the photodestruct… more
Date: 1989
Creator: Mathies, R. A.; Peck, K. & Stryer, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Energy dependence of metallic-encapsulated thermoluminescent dosimeters. Annual report

Description: The gamma-ray energy responses of encapsulated /sup 7/LiF and CaF/sub 2/:Mn thermoluminescent dosimeters were measured and compred to calculated values. This study was performed in order to improve the accuracy of gamma-ray heating measurements made in polyenergetic gamma-ray fields such as Argonne National Laboratory's Zero Power Reactors. Equations used in the development of the TERC/III computer code and code input parameters are specified. A section on TLD precision is also included. Compar… more
Date: June 1980
Creator: Simons, G. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation of induced unimolecular decomposition for development of visible chemical lasers. Final report, 1 May 1976--30 April 1977

Description: This report summarizes the results of a study of azide decomposition for possible application in a visible chemical laser. Task 1 of the subject contract involved thorough review of the chemical literature pertaining to azide decomposition. Covalently bonded azides decompose directly into an electronically excited nitrene (RN) and ground-state molecular nitrogen. Ionic azides decompose to metal atoms and azide radicals. The azide radicals subsequently recombine to form electronically excited ni… more
Date: May 1, 1977
Creator: Piper, L G & Taylor, R L
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Vapor phase spectroscopy of complex lanthanide halide--aluminum halide molecular species

Description: The absorption spectrum of ErCl/sub 3/ (AlCl/sub 3/)/sub x/ vapor complex was measured and analyzed using the Judd-Ofelt theory. Structural correlations in other AlCl/sub 3/ vapor complexes and radiation emission are discussed. Fluorescence of TbCl/sub 3/ (AlCl/sub 3/)/sub x/ vapor complex and in the NdCl/sub 3/ (AlCl/sub 3/)/sub x/ system were studied. (DLC)
Date: January 1, 1977
Creator: Carnall, W T; Hessler, J P; Williams, C W & Hoekstra, H R
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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STUDIES OF THE SCINTILLATION PROCESS IN CsI(Tl)

Description: The scintillation response of CsI(Tl) crystals, having various thallium contents, was measured for excitation of the crystals by monoenergetic gamma rays, protons, and alpha particles. The investi gation was made to provide a test of some of the features of a theoretical model of the scintillation process in thallium-activated alkali iodides proposed by Murray and Meyer. In order to insure that the results obtained in this program would provide a critical test of the scintillation model, specia… more
Date: November 30, 1962
Creator: Gwin, R. & Murray, R. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Excited-state proton-transfer kinetics in 1-naphthol, 1-naphthol-sulfonates, and organometallic complexes

Description: The dissociation of 1-naphthol in aqueous solution occurs so rapidly that the fluorescence from the neutral form, ROH, has been previously described as completely extinguished or hardly noticeable. Apparently nearly all of the fluorescence originates from the naphtholate ion. This paper reports on the proton-transfer characteristics of a series of 1-naphthol compounds, and also reports preliminary data on excited-state proton transfer in an organometallic complex of ruthenium.
Date: July 1, 1980
Creator: Shapiro, S. L.; Winn, K. R. & Clark, J. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Experimental investigation of the chemistry of excited states of rare gases. First quarterly progress report, October 15, 1977--January 15, 1978

Description: The quenching of XeF(B) was studied using the steady-state photolysis of XeF/sub 2/ as the source of XeF(B). The product states from the sensitized reaction of Xe(/sup 3/P/sub 1/) with Cl/sub 2/ and COCl/sub 2/ also were studied. The new XeF(B) quenching rate constants are described. The pulsed laser induced fluorescence technique was used to measure radiative lifetimes and two-body quenching rate constant (with Ar) for the low energy Xe(6p)* states. Serious signal/noise problems for the lowest… more
Date: February 1978
Creator: Setser, D. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

NO/sub 2/ levels in diesel exhaust

Description: The safe operation of diesel-powered equipment in underground mines is predicated on there being sufficient ventilation to dilute the exhaust such that none of the toxicants in the dilute mixture exceed allowable levels. In order to determine the ventilation requirement for an engine, it is necessary to measure levels of the various toxicants in the exhaust. Measurements in the past typically either have excluded nitrogen dioxide or have not provided information on nitrogen dioxide specifically… more
Date: January 1, 1978
Creator: Marshall, W.F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Hyper filter-fluorescer spectrometer for x rays above 120 keV

Description: An apparatus utilizing filter-fluorescer combinations is provided to measure short bursts of high fluence x-rays above 120 keV energy, where there are no practical absorption edges available for conventional filter-fluorescer techniques. The absorption edge of the prefilter is chosen to be less than that of the fluorescer, i.e., E/sub PRF/ < E/sub F/, contrary to the prior art technique E/sub PRF/ > E/sub F/. In this way, the response function is virtually zero between E/sub PRF/ and E/sub F/ a… more
Date: July 7, 1981
Creator: Wang, C. L.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
open access

Silicon halide-alkali metal flames as a source of solar grade silicon. Second quarterly report, September 1--November 30, 1977

Description: The experimental effort on this program has concentrated thus far on Na/SiCl/sub 4/ and K/SiCl/sub 4/ opposed jet diffusion flames in an evacuated reaction vessel; both reactants are supplied as vapors. The flames are self-igniting, fast burning and intensely chemiluminescent. Solid reaction products have been collected, separated by simple washing, and some preliminary analyses performed which indicate that the concentrations of most impurities in the reagents are reduced during the course of … more
Date: December 1, 1977
Creator: Miller, W.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Low Temperature Thermoluminescence of Gamma Irradiated Potassium Dihydrogen Phosphate

Description: Thermoluminescence in potassium dihydrogen phosphate (KDP) induced by Co/ sup 60/ gamma irradiation at liquid nitrogen temperature (-198 deg C) was investigated. Glow curves in the temperature range --196 to 0 deg C were measured for a series of gamma exposure dosages ranging from 10/sup 4/ roentgen to 5 x 10/sup 6/ roentgen. The heating rate used for glow curve measurements was 12 deg C per minute. Twice recrystallized Mallinckrodt reagent grade potassium dihydrogen phosphate, with a grain siz… more
Date: October 19, 1962
Creator: Sims, T. M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Genes and gene expression: Localization, damage and control -- A multilevel and inter-disciplinary study

Description: All projects are working toward a goal for describing the three dimensional nuclear topography in terms of relative spatial relationships among genes (specific DNA sequence). Methods are now being perfected to detect these genes, quantitatively and spatially, to perturb these genes specifically, and to measure the perturbation in order to assure specificity. We are developing methods to assay, after perturbation of the target DNA within living cells, whether or not only the target sequence are … more
Date: September 1, 1990
Creator: Ts'o, P.O.P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Molecular biological enhancement of coal biodesulfurization. [Rhodococcus, thiobacillus]

Description: The objective of this project is to produce one or more microorganisms capable of removing the organic and inorganic sulfur in coal. The original specific technical objectives of the project were to: clone and characterize the genes encoding the enzymes of the 4S'' pathway (sulfoxide/sulfone/sulfonate/sulfate) for release of organic sulfur from coal; return multiple copies of genes to the original host to enhance the biodesulfurization activity of that organism; transfer this pathway into a fas… more
Date: June 14, 1990
Creator: Litchfield, J. H.; Fry, I.; Wyza, R. E.; Palmer, D. T.; Zupancic, T. J. & Conkle, H. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Chemiluminescence from the reaction of Ba /sup 3/D with nitric oxide

Description: The reaction of laser excited Ba*(/sup 3/D) states with nitric oxide is presented. BaO product is not detected, although the channel is thermodynamically open, and instead chemiluminescence is observed. Experiments which suggest that radiative recombination, Ba + NO ..-->.. BaNO* ..-->.. BaNO, is the observed reaction channel will also be presented.
Date: January 5, 1977
Creator: Johnson, S. A.; Solarz, R. W.; Dubrin, J. W. & Brotzmann, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Atomic and molecular science with synchrotron radiation

Description: This paper discusses the following topics: electron correlation in atoms; atomic innershell excitation and decay mechanisms; timing experiments; x-ray scattering; properties of ionized species; electronic properties of actinide atoms; total photon-interaction cross sections; and molecular physics. 66 refs. (LSP)
Date: November 7, 1989
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Experimental development of nuclear pumped laser candidate for inertial confinement fusion driver

Description: A report is given on progress made during the second year of a three year contract studying the feasibility of nuclear pumping the atomic iodine laser. Experimental results are presented showing efficiencies of 25--38% at converting neutron-induced nuclear reaction energy in the excimer XeBr into UV photons which can be used to pump the laser. Parametric studies were done utilizing the {sup 10}B(n,{alpha}){sup 7}Li reaction, with three bromine donor chemicals, over a range of pressures and mix … more
Date: June 6, 1990
Creator: Miley, George H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Activated recombinative desorption: a potential component in mechanisms of spacecraft glow

Description: The concept of activated recombination of atomic species on surfaces is capable of explaining the production of vibrationally and translationally excited desorbed molecular species. Equilibrium statistical mechanics predicts that the molecular quantum state distributions of desorbing molecules is a function of only the surface temperature when the adsorption probability is unity and independent of initial collision conditions. In most cases though the adsorption probability is dependent upon in… more
Date: January 1, 1985
Creator: Cross, J.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Quantification of surface contamination: principles and applications

Description: The applications discussed in this paper underscore the usefulness and versatility of molecular luminescence spectroscopy as an efficient surface detection technique. The technique can be used not only as a qualitative characterization method, but also as a quantitative analytical tool to detect trace contaminants on surfaces. Recent advances in instrumentation and methodology have expanded the applicability of surface luminescence into many new problem areas. Trace organics are emphasized here. more
Date: January 1, 1982
Creator: Vo-Dinh, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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General Chemistry Division quarterly report, July--September 1977

Description: Analytical research and development work is reported on multielement analysis, time-resolved spectroscopy, fluorescence analysis, ionization potential of NP, excited state chemistry, polarized x ray sources, potentiometric titration of Na, determination of TATB in DMSO, determination of nitrobenzene in TATB, analysis of explosive composites, mass spectrometer automation, mass spectra calculation, solids formation in geothermal brine, water quality laboratory automation, aerosol coagulation, and… more
Date: November 30, 1977
Creator: Harrar, J.E. (ed.)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Direct and Indirect Immunofluorescence Staining of Fecal Streptococci for Rapid Assessment of Water Quality

Description: Immunofluorescence (IF) techniques were employed in an attempt to develop a rapid test for the identification of fecal streptococci. Fresh isolates were obtained from river waters and raw sewage. Identification to species were made by the conventional physiological, biochemical, and serological tests. Both whole and disrupted cells of representative strains of each species were used for the preparation of the fecal streptococcal vaccine. Globulin fractions of individual and pooled antisera were… more
Date: January 1, 1975
Creator: Pavlova, M. T.; Beauvais, E.; Brezenski, F. T. & Litsky, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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