... Title : ABSOLUTE CHEMILUMINESCENT REACTION RATES FOR EMISSION OF THE O2 HERZBERG BANDS IN OXYGEN AND OXYGEN-INERT ...
DTIC Science & Technology
... of the reaction rate (defined as the absolute difference between the two reaction rates divided by the rate of photocatalysis alone) imparted by the ...
The absolute rate constants for the reaction between the NH2 free radical and acetylene and ethylene
NASA Technical Reports Server (NTRS)
... absolute rate coefficients for energy transfer reactions of O ... Descriptors : (*UPPER ATMOSPHERE, REACTION KINETICS), OXYGEN, NITROGEN ...
The reaction of tert-butoxy radicals with diphenylmethanol and with cumene was examined using nanosecond laser flash photolysis techniques in order to determine the absolute values of the rates of reaction of the radicals. The absolute rate measured for both substrates ...
Energy Citations Database
... Accession Number : AD0751310. Title : The Absolute Measurement of Rate Constants for Some Kay Reactions Involving Free Radicals. ...
A method for the production of t-butoxy radicals by the photolysis of t-butyl hypochlorite was employed to determine the absolute rate of combination of t-butoxy radicals at room temperature and to determine the absolute rate of hydrogen atom abstraction ...
National Technical Information Service (NTIS)
Rate constants for the reaction of atomic chlorine with hydrogen are measured from 200 - 500 K using
The pressure dependence of absolute rate constants for the reaction of OH + C2H2 yields products has
Absolute rate constants were measured for the reactions of cumylperoxy radicals with a number of hydrocarbons. The cumylperoxy radicals were produced from cumene hydroperoxide. Sufficient hydroperoxide was present to ensure that only cumylperoxy radicals ...
Discussed are the topics of random walk, reaction kinetics, significant structure theory of liquids, absolute rate theory, optical rotation, and circular dichroism. (Author)
The absolute rate constant for the reaction of ground state oxygen atoms with methyl radicals is reported. The methyl radicals were generated by the reaction of oxygen atoms with ethylene in a fast flow reactor, and were detected by a photoionization mass...
The absolute values of the second-order rate constants for the reactions of ozone with chloroethylenes and allyl chloride were determined in carbon tetrachloride solution at room temperature. The rate of ozone attack decreases strongly as the number of ch...
The absolute rate constants for the cycloaddition reactions of three arylhalocarbenes to two alkenes have been measured as a function of pressure in the range 0.1 to 203 MPz. In all cases the observed rate constants were found to increase with increasing ...
Rate constants for the reaction of atomic chlorine with hydrogen peroxide were measured from 265-400
... a boost by the adaptation of the Low Altitude Plume Predictor ... Absolute Rate Constant for the Reaction 0 + NaO * Na + 02 by ... 1 HQ DA DAMA-ART ...
In this report a solid propellant failure criterion is formulated. The failure criterion is a generalized form of the Tobolsky - Eyring equation which is based on the theory of absolute reaction rates. The generalized equation is applied to two propellant...
Counting efficiencies of a (gamma)-ray spectroscopy system are necessary for foil activation measurement of absolute (sup 235)U fission rate, absolute (sup 238)U capture rate and ratio of these reactions in JAERI fast critical assembly (FCA). Comparison o...
The authors report absolute removal rate constants for silylene by reaction with alkanes, olefins, 1,3-butadiene, and acetylene at ambient temperature and 5-Torr total pressure. Rate constants were determined by laser resonance absorption flash kinetic spectroscopy. The results show that silylene is unreactive with ...
... Title : ABSOLUTE RATE CONSTANTS FOR HYDROCARBON OXIDATION. XII. RATE CONSTANTS FOR SECONDARY PEROXY RADICALS,. ...
Absolute rate constants for the reaction of atomic hydrogen with ozone were obtained over the temperature range 219-360 K by the flash photolysis-resonance fluorescence technique. The results can be expressed in Arrhenius form by K = (1.33 plus or minus 0...
Using the theory of absolute reaction rates, the influence of electromagnetic fields on biological systems has been investigated. In this paper, the effect of changing the frequency of the electromagnetic field on chemical reactions is studied. The extension to biological effects is discussed.
The absolute rate constant was measured by the technique of flash photolysis-laser induced fluorescence (FP-LIF). NH2 radicals were produced by the flash photolysis of ammonia and the fluorescent NH2 photons were measured by multiscaling techniques. At ea...
The equilibrium constants for the formation of some t-alkyl tetroxides and the rate constants for irreversible decay of the tetroxides have been measured by electron spin resonance spectroscopy at low temperatures. The equilibrium constant appears to be v...
A method for determining the absolute reaction rate of nuclear events giving rise to neutron emission, according to their neutron multiplicity, is proposed. A typical application is the measurement of the ( alpha , n) and spontaneous fission rates in a fi...
In this study, both relative rate and absolute kinetic measurements were made at 298 K for the reaction of chlorine atoms with the Cl-C4 alkanes. The relative rate studies were carried out using two different reaction chambers and GC to follow the loss of the organics upon ...
Rate constants and temperature dependencies for the reactions of OH with CF3OCH3 (HFOC-143a), CF2HOCF2H (HFOC-134), and CF30CF2H (HFOC-125) were studied using a relative rate technique in the temperature range 298-393 K. The following absolute rate consta...
Dichlorocarbene is the cornerstone of singlet carbene reactivity. Moss has thoroughly characterized carbenic selectivity in cyclopropanation reactions. The reactivity of any singlet carbene (:CXY) may be standardized by comparison of its reactivity toward a standard set of alkenes with that of chlorocarbene (:CCl{sub 2}). Amazingly, however, the absolute ...
In this talk I review the main features of the coherent/diffractive pion production by neutrinos on nuclei. The method is based on PCAC and relates the reaction boson+nucleus{yields}pion+nucleus to elastic pion-nucleus scattering. Estimates for the expected rates and distributions in neutrino reactions are presented with the help of ...
Rate constants for the reaction of atomic chlorine with hydrogen peroxide were measured from 265-400 K using the flash photolysis-resonance fluorescence technique. Analytical techniques were developed to measure H2O2 under reaction conditions. Due to ambi...
The results of experiments performed at Argonne to determine absolute differential and total cross sections for outgoing protons, ..cap alpha.. particles and neutrons in deuteron-induced reactions on /sup 6/Li at energies between approximately 0.1 and 1.0 MeV are summarized. Discussion of the observed angular and energy distributions in connection with ...
Progress has been made in several areas of experimental and theoretical importance to the understanding of rate parameters in reactions important to combustion. We combined simple physical models with experiments devised to test these models with the objective of increasing our ability to estimate rate constants with an accuracy useful ...
Absolute reaction rate theory is applied to explain the increased time between successive synchronous mitotic division of the slime mold Physarum polycephalum when exposed to extremely low frequency electromagnetic fields. By ignoring the transition perio...
The rate constants for the reactions of atomic bromine with dimethyl ether and diethyl ether were measured from approximately 300 to 350 K using the relative rate method. Both isooctane and isobutane were used as the reference reactants, and the rate constants for the reactions of these ...
PubMed
The fast, epithermal, and thermal neutron flux distributions through the core of LlDO have bcen measured using absolutely calibrated thin foils. By comparing thc reaction rates of sodium manganese, indium, and gold, absolute values have been inferred for the epithermal and thermal fluxes, and some revised ...
The rate constant for the reaction Br + O3 yields BrO + O2 was measured from 200 to 360 K by the technique of flash photolysis coupled to time resolved detection of bromine atoms by resonance fluorescence (FP-RF). Br atoms were produced by the flash photo...
The rate parameters for the reaction of O(3P) with carbonyl sulfide, O(3P) + OCS yields CO + SO have been determined directly by monitoring O(3P) using the flash photolysis-resonance fluorescence technique. The value for k sub 1 was measured over a temper...
The recent concepts of absolute electronegativity, {chi}, and absolute hardness, {eta}, are briefly reviewed. Experimental values for a large number of molecules and radicals are presented. The values are shown to be in good agreement with the known chemical behavior, both as to nucleophilic-electrophilic properties and as to rates of ...
The interpretation of quantitative relationships between chemical properties and biological effects requires great caution if erroneous conclusions are to be avoided. A knowledge of intracellular concentrations is especially desirable. Since many chemical properties are themselves interrelated, reliable identification of critical reactions may be difficult. Free radicals often ...
PubMed Central
The absolute rates of reaction of tert-butoxy radicals with a variety of organic substrates in solution have been determined using laser flash photolysis techniques. The relative rates agree well with values obtained from studies of hydrocarbon halogenation by tert-butyl hypochlorite or by ESR in the case of ethers ...
The absolute rate constant for the reaction H + C4H2 has been measured over the temperature (T) interval 210-423 K, using the technique of flash photolysis-resonance fluorescence. At each of the five temperatures employed, the results were independent of variations in C4H2 concentration, total pressure of Ar or N2, and flash intensity ...
NASA Astrophysics Data System (ADS)
The reactions of alkoxy radicals determine to a large extent the products formed during the atmospheric degradations of emitted organic compounds. Experimental data concerning the decompositions, 1,5-H shift isomerizations and reactions with O2 of several classes of alkoxy radicals are inconsistent with literature estimations of their ...
The rate coefficients for the reactions of atomic bromine with toluene, tetrahydrofuran, and tetrahydropyran were measured from approximately 295 to 362 K using the relative rate method. Iso-octane was used as the reference compound for the reaction with toluene, and iso-octane and toluene were used as the ...
The rates of the various elementary reactions of the type H + H/sub 2/ yields H/sub 2/ + H, involving ortho-para conversions or isotope exchanges, have been calculated by the absolute reaction rate theory, using new fundamental energy surface, but estimating the activation energy to fit ...
The absolute rate coefficients and product yields for reactions of O(1D) with HCl(1) and HBr(2) at 287 K are presently determined by means of the time-resolved resonance fluorescence detection of O(3P) and H(2S) in conjunction with pulsed laser photolysis of O3/HX/He mixtures. Total rate coefficients for O(1D) ...
Laser flash photolysis studies of the reaction of benzylbromocarbene with pyridine enables the determination of the absolute rate constant for the 1,2-hydrogen migration in benzylbromocarbene. Thus, k = 5.6 {times} 10{sup 7}/s{sup {minus}1} at 25{degree}C. Relative reactivities of benzylbromocarbene toward electron-poor and ...
Rate constants and their temperature dependencies were measured for the chemiluminescent reaction of ozone with the flame and furnace effluents of two commercially available sulfur detectors, the Sulfur Chemiluminescence detector (registered trademark of Sievers Instruments, Inc.) and the Chemiluminescent Sulfur Detector (registered trademark of Antek ...
For two reactions of formic-C/sup 13/ acid in which the rate steps involve extraction of hydrogen by halogen atoms, the rate isotope effects, k/sub 12//k/syb 13/, have been carefully evaluated by methods involving mass spectrometric analysis of carbon-13 dioxide. The difference between the measured values of k/sub 12//k/sub ...
A Coulomb-corrected, charge independent R-matrix calculation of the four-nucleon reactions accounts for the surprisingly large branching ratio, as well as for the absolute fusion rate measured for the muon- catalyzed d{plus}d reactions. Reaction constants are given for both S-wave and P-wave ...
DOE Information Bridge
We report total cross sections for the 19F(?,n)22Na and 22Ne(p,n)22Na reactions from threshold to 3.1 and 5.4 MeV, respectively. The absolute efficiency of the 4? neutron detector was determined by Monte Carlo calculations and validated using two standard sources and two nuclear reactions. Cross sections for the inverse ...
The rate coefficients for the reaction of 1,4-dioxane with atomic chlorine were measured from T = 292-360 K using the relative rate method. The reference reactant was isobutane and the experiments were made in argon with atomic chlorine produced by photolysis of small concentrations of Cl2. The rate coefficients ...
The absolute rate constant for the reaction Cl + H2CO yields HCl + HCO was determined by the flash-photolysis resonance fluorescence method to be 7.5 plus or minus 0.9 (2 sigma) times 10 to the minus 11th power cu cm/molecule sec at 298 K and to have a ne...
Measurements of fast flux, by means of the S/sup 32/(n,p)P/sup 32/ reaction, were made along air filled ducts in the water of the LIDO Panel C facility. Using results obtained by the method of moments, a technique was devised for predicting the absolute sulfur reaction rate to better than a factor of 2 for ...
Comparisons of reaction-rate calculations with absolute dosimetry measurements in the EBR-II blanket are made for /sup 235/U/sub f/, /sup 239/Pu/sub f/, /sup 238/U/sub f/, and /sup 238/U/sub c/ reactions.
The studies use pulse radiolysis to provide absolute rate constants for reactions of many inorganic radicals and organic peroxyl radicals, key intermediates in many chemical processes, and to study electron transfer reactions of metalloporphyrins for sola...
Absolute rate constants were measured for the gas-phase reactions of the hydroxyl radical with a series of hydrochlorofluorocarbons and hydrofluorocarbons by the flash photolysis-resonance fluorescence technique. These kinetic data, when combined with data obtained independently in other laboratories, lead to the recommended ...
The rate constant is measured over the temperature interval 218-456 K using the technique of flash photolysis-laser-induced fluorescence. NH2 radicals are produced by the flash photolysis of ammonia highly diluted in argon, and the decay of fluorescent NH...
The relationships between differential and integral cross sections are considered together with their application to the calculation of reaction rates in reactor spectra. A brief review of the measurement of these quantities is given in order to show the importance of chemical analysis in all methods. Particular attention is devoted to the ...
Formulae permitting to determine the rates of parent nuclei production reactions in activation conditions in nonstationary flux, based on activation of daughter nuclei, are derived. An expression for decay correction while measuring the daughter nuclei ac...
Nuclear capture reactions play an important role in our understanding of astrophysical phenomena. For example, precise knowledge of the ^7Be(p,?)^8B reaction at solar energies is necessary for calculating the neutrino flux from the sun and for placing constraints on possible `new physics' scenarios such as neutrino flavor oscillations. Direct measurements ...
A molecular beam of Cl{sub 2} is reactively scattered from a single crystal GaAs (100) surface. Analysis of the mass spectra and of the angular and velocity distributions for the volatile reaction products over the surface temperature range 330-950 K shows that the major volatile reaction products are AsCl{sub 3}, As{sub 4}, As{sub 2}, GaCl{sub 3}, and ...
The rates of thermal and photochemical reactions of butyral-dehyde with nitrogen dioxide were measured. A least squares treatment of the data yielded a thermal rate constant of 10 to the 7.4 times base e to the minus 12,400/ (molar gas constant times absolute temperature), where the rate ...
The rate coefficients for the F + H2 and F + D2 reactions were determined to be (1.8 plus or minus X 10 to the 13th power and (9.5 plus or minus 1.7) X 10 to the 12th power cm3/mol-sec, respectively. The absolute values and the resultant ratio of H-atom to D-atom abstraction of 1.92 + or minus 0.23 are in agreement with earlier ...
The effect of intensity on the radioinduced oxidation of deaerated ferrous sulfate solutions was studied using a 1.5-Mev electron beam produced by a Van de Graaff accelerator. The decrease in the yield of Fe(III) with increasing intensity is primarily due to a competition between the combination of hydrogen atoms to produce hydrogen and the oxidation of ferrous ion by hydrogen atoms. ...
Recent progress is described on the study of the reactions, energy transfer, and dynamics of free radicals produced by ultraviolet laser photolysis. These measurements on free radical chain reactions, absolute rate coefficients, and photofragmentation dynamics are carred out by the method of time-resolved infrared ...
High resolution measurements using the ({sup 3}He,n) reaction are used to determine excitation energies of astrophysically important states. Further, spins can be assigned to these states by comparing the measured differential cross sections to Hauser-Feshbach cross sections. The astrophysical reaction rates are then calculated using ...
Absolute rate constants for the reaction of NADH with thiyl free radicals derived from various sulphur-containing compounds of biological significance were measured by using the technique of pulse radiolysis. These and related reactions with phenoxyl free radicals are believed to occur through one-electron-transfer ...
Absolute rate constants determined by using the flash photolysis-resonance fluorescence technique are reported for the reactions of hydroxyl radicals with isoprene, ..cap alpha.., and ..beta..-pinene, methyl vinyl ketone, and methacrolein in the temperature range 297-424 K, and with methylglyoxal at 297 K. These results contribute to a ...
Laser photolysis-resonance fluorescence at 298 K is used to obtain absolute rate constants for the gas-phase reactions of OH radicals with three trichloroacetaldehydes and acetaldehyde. The rate constants for all but trichloroacetaldehyde are in good agreement with previous literature with the discrepant one being ...
... the photon yields in the ... Descriptors : *CHEMICAL REACTIONS, *PHOTONS, *CHEMILUMINESCENCE ... LASERS, FLUORINE, YIELD, NITROGEN ...
... DIOXIDE, *INFRARED SPECTRA, GASES, ABSORPTION, HEAT OF REACTION, DETERMINATION, CHEMICAL EQUILIBRIUM, LIQUIDS ...
The reactions, energy transfer, and dynamics of free radicals produced by ultraviolet laser photolysis were studied. The measurements on free radical chain reactions, absolute rate coefficients, and photofragmentation dynamics were carried out by time-resolved infrared emission spectroscopy. The dynamics of hot ...
Stock solutions of (233)Th were produced by the (232)Th(n,gamma) reaction and multiple purifications were used to obtain relative intensities of weak transitions. Liquid scintillation counting (absolute disintegration rates) and gamma-ray spectroscopy with HPGe detectors yielded absolute photon intensities. ...
The absolute densities of N2(A3?u+), N(4So), and N(2Do) in an inductively coupled nitrogen plasma source were measured by cavity-ringdown and vacuum-ultraviolet absorption spectroscopies. It was found that the densities of the above three active species were on the same order of 1017 m-3. We observed the decrease in N2(A3?u+) density with increasing discharge pressure, while ...
The absolute measurement of neutron emission rate from the whole plasma is a very important diagnostics as a fusion power monitor in fusion experimental devices with D-T or D-T operations. Here measurement techniques of time-resolved and time-integrated absolute neutron emission on the present tokamaks and ITER are reviewed. In the ...
... FOR AMBIENT AND HEATED AIR ... REACTION KINETICS), (*REACTION KINETICS, IONIZATION ... DENSITY, RECOMBINATION REACTIONS, GASES ...
Absolute rate constants for reaction of .SO/sub 4//sup -/ with substituted benzenes and benzoates have been determined by pulse radiolysis. The values are found to range from about 5 x 10/sup 9/ M/sup -1/ s/sup -1/ for anisole to less than 10/sup 6/ M/sup -1/ s/sup -1/ for nitrobenzene. A correlation of the rate ...
Critical experiments are being conducted in the Battelle Pacific Northwest Lab.'s Critical Mass Lab. for the Consolidated Fuel Reprocessing Program using a variety of fast test reactor (FTR) fuel pin configurations and fissile solution concentrations. These experiments are being performed as part of a joint agreement between the US Dept. of Energy and the Power Reactor and Nuclear Fuel ...
The discharge-flow resonance fluorescence technique has been used to obtain absolute rate data for the OH + HCl reaction at total pressures from 2 to 100 torr of helium and 2 to 25 torr of 80% nitrogen plus 20% helium. At 295 K the rate constant is (7.9 +/- 0.4) x 10/sup -13/ cm/sup 3/ molecule/sup -1/s/sup -1/. ...
The reactions of vinyl butyl ether and vinyl butyrate with atomic hydrogen and deuterium lead to addition at the terminal position of the olefins. This observation is consistent with the reactions carried out earlier with other olefins. Both of the absolute rates of addition to vinylbutyl ether and vinyl butyrate, ...
The effect of the addition of gold to polycrystalline platinum and iridium foil samples on the initial reaction rates for the hydrogenolysis of propane, isobutane and n-heptane, the isomerization of isobutane, and the dehydrocyclization of n-heptane to toluene has been studied. Mass spectroscopy was used to monitor the reactions in a ...
Absolute rate constants and degradation efficiencies for hydroxyl radical and hydrated electron reactions with four different sulfa drugs in water have been evaluated using a combination of electron pulse radiolysis/absorption spectroscopy and steady-state radiolysis/high-performance liquid chromatography measurements. For ...
A coarse-grained mean-field model is proposed where the damage enhanced creep of heterogeneous materials is described by the theory of absolute reaction rates. The dynamics of the proposed model, below a critical load, is characterized by an intensive precursor activity in the form of avalanches of microscopic breaking events that ...
The 21Ne(?, n)24Mg reaction has been studied over the energy range Ec.m. = 1.4-2.57MeV, by neutron time-of-flight spectroscopy and by the detection of the subsequent ?-ray transitions in 24Mg. The astrophysical cross-section factor S(0) was determined and reaction rates were calculated for temperatures up to 5�109�K. In favorable ...
A theory of Langmuir exactly predicts the rates of many vaporization reactions as functions of temperature. For these reactions his theory is shown to be superior to absolute reaction rate theory, which can be made to yield the same rate equation, in ...
We describe an efficient procedure for calculating the rates of bimolecular chemical reactions in the gas phase within the ring polymer molecular dynamics approximation. A key feature of the procedure is that it does not require that one calculate the absolute quantum mechanical partition function of the reactants or the transition ...
... Comparison of the Absolute Quantum Yields of the ... from the O/NO gas phase reaction ... and the luminol chemiluminescence quantum yield lead to ...
The students making a good progress in studying the principles of actor's profession can learn rather easily to control at will the vegetative skin-galvanic reaction by means of mentally conceiving emotionally coloured situations and by means of visual feedback. This group of subjects is characterised by an emotiogenous increase of the heart rate of ...
parts, after trial assembly runs and sterilization tests, to verify the efficacy of .... which will be done upon a terminally sterilized ready-to-fly vehicle. ..... The chamber is sealed and pressurized to produce controlled leakage in the ...... more recent Theory of Absolute Reaction Rates are used empirically. ...
NASA Website
The strengths of resonances in exp 25 Mg(p, gamma ) exp 26 Al in the energy range 317-591 keV have been obtained. Resonance strengths at 317, 387, 433, 591 keV have been measured absolutely. The strengths of resonances at 591, 433 keV were also deduced by...
A careful determination of the absolute reaction rate constants for the vapor phase thermal decomposition of 1-(4'-methoxyphenyl)ethyl acetate and its 3'methyl and 3',5'-dimethyl derivatives provides convincing evidence that P1-orbital overlap of the meth...
... yielded the following absolute second-order OH rate coefficient expressions; k(I) = (2.17 plus or minus 0.39) x 10(exp -11) e(160 plus or minus 30)/T ...
O-labeled hydrogen peroxide and O2 have been used determine absolute rates and pathways of peroxide formation and decay processes in surface waters of a coastal marine site. Reactions were followed by incubating seawater samples with O2 or H2O2 and follow...
Rate constants for the reaction H + H + M - H2 + M, with M = H2, He, and Ar were measured over the temperature range 77 to 298 K. Hydrogen atoms were produced by thermal dissociation and absolute atom concentrations were measured through use of self-balan...
Discrete ordinate calculations are made and the results compared with measurements performed in the Poolside Facility for the purpose of validating various procedures adopted for the analysis of this facility. In addition, these calculations can be specifically used to verify the interpretation of measurements made to infer the perturbation effect of a Westinghouse surveillance capsule in a ...
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
EPA Science Inventory
... Descriptors : *EXCHANGE REACTIONS, *HYDROGEN, *CHLORINE, REACTION KINETICS, RATES, ENERGY TRANSFER, POTENTIAL ENERGY ...
Photothermal temperature control of an enzyme-catalyzed reaction in a microchip using a diode laser was demonstrated. A laser beam with energy of 10 mW was used to irradiate an absorbing target placed on top of the microchip cover plate. Theoretical calculations have shown that temperature in the microchannel can be locally increased by 5-7 degrees C during short time ...
Absolute cross sections were determined for several (d, alpha ) reactions. Thin targets were bombarded by a beam of 7.8-Mev deuterons which were collected iii a Faraday cup and measured by a current integrator. Product nuclei were separated chemically from extrancous activities. Absolute disintegration ...
The kinetics of chemical reactions of cobalt clusters Co{sub n} with deuterium are described. Absolute rate constants have been measured in the cluster range n = 7--68 at 293 K. The rate constants are found to be a strong function of cluster size, varying by up to three orders of magnitude. This size , dependence ...
A method is described for obtaining excitation functions using the stacked foil technique with an internal cyclotron beam. The method, which utilizes multiple Coulomb scattering for deflection and 180� focusing for energy separation, has the advantages of good energy resolution, high intensity, and low background. Equations are presented for the particle orbits from which are derived the energy ...
