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AbstractAbstract
[en] There has been an enormous amount of investigation of the luminescence of the uranyl (UO22+) ion and its photochemical reactions. Considerable attention has been given to a study of the photochemical reduction of UO22+ by organic compounds. It was long considered that UV irradiation of aqueous solutions of uranyl not containing organic impurities did not lead to any significant change in the chemical composition of the solution. However, the high oxidation-reduction potential of UO22+ (2.7 V) permits its reaction with water. Burrows and Kemp have proposed that some portion of UO2+ and the ·OH radicals, which do not enter a geminal reaction, leave the cage and small amounts of U(IV) and H2O2 then accumulate in the solution. And the mechanism for the photochemical reduction of uranyl by water through electron transfer has found only indirect evidence by τ-metry (relative to the quenching of the photoluminescence of UO22+ by a water molecule). For a study of the radiation chemical reduction of uranium(IV) in aqueous sulfuric acid in the absence of ·OH radical acceptors, the authors proposed a chemiluminescence (CL) method based on the possibility of detecting small amounts of uranium(IV) (down to 10-9 mole/liter) on the background of a significant excess of uranium(VI)(up to 10-1 mole/liter) using the chemiluminescence of the oxidation of tetravalent uranium compounds by xenon trioxide
Source
Cover-to-cover Translation of Doklady Akademii Nauk SSSR; Translated from Doklady Akademii Nauk; 329: No. 4, 465-468(Apr 1993).
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Journal Article
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Translation
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AbstractAbstract
[en] The infrared absorption spectrum in the 16-17 μm region of the transient UF5 molecule formed form laser photolysis of UF6 is presented. The absorption contour and the intensity measurements allow tentative assignment of the molecular structure. (Auth.)
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Journal Article
Journal
Chemical Physics Letters; ISSN 0009-2614;
; v. 63(3); p. 471-474

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AbstractAbstract
[en] Two pheomelanin model compounds were prepared and their photochemistries examined. Upon irradiation, an oxygen-mediated photopolymerization reaction was observed. The photopolymers obtained were characterized by their apparent molecular weights, UV and fluorescence spectra. The implications of these findings with respect to the structure and photobiology of pheomelanin are discussed. (author)
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Journal Article
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Photochemistry and Photobiology; ISSN 0031-8655;
; v. 36(2); p. 251-254

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Kusari, Souvik; Prabhakaran, Deivasigamani; Lamshoeft, Marc; Spiteller, Michael, E-mail: m.spiteller@infu.uni-dortmund.de2009
AbstractAbstract
[en] Fluoroquinolones like difloxacin (DIF) and sarafloxacin (SARA) are adsorbed in soil and enter the aquatic environment wherein they are subjected to photolytic degradation. To evaluate the fate of DIF and SARA, their photolysis was performed in water under stimulated natural sunlight conditions. DIF primarily degrades to SARA. On prolonged photodegradation, seven photoproducts were elucidated by HR-LC-MS/MS, three of which were entirely novel. The residual anti-bacterial activities of DIF, SARA and their photoproducts were studied against a group of pathogenic strains. DIF and SARA revealed potency against both Gram-positive and -negative bacteria. The photoproducts also exhibited varying degrees of efficacies against the tested bacteria. Even without isolating the individual photoproducts, their impact on the aquatic environment could be assessed. Therefore, the present results call for prudence in estimating the fate of these compounds in water and in avoiding emergence of resistance in bacteria caused by the photoproducts of DIF and SARA. - Assessment of the residual anti-bacterial efficacies of difloxacin, sarafloxacin and their photoproducts in water, and estimating their impact on the aquatic environment in inducing resistance to microorganisms.
Primary Subject
Source
S0269-7491(09)00240-1; Available from http://dx.doi.org/10.1016/j.envpol.2009.04.033; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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Hackett, P.A.; Willis, C.
National Research Council of Canada, Ottawa, Ontario1982
National Research Council of Canada, Ottawa, Ontario1982
AbstractAbstract
[en] A multistage process for isotopic enrichment is provided. A gaseous mixture of the primary isotope substrate and a primary transfer agent is irradiated with a laser at a first wavelength. After the primary transfer agent has been removed, a secondary transfer agent is added and the mixture is irradiated at a second wavelength. The enriched product is then separated from the secondary transfer agent and the depleted substrate. The overall separation factor is the product of the individual separation factors of each stage
Primary Subject
Source
8 Jun 1982; 8 p; CA PATENT DOCUMENT 1125230/A/; U.S. pat. appl. 064085 (6 Aug 1979).
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Patent
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AbstractAbstract
No abstract available
Original Title
Foto-oxidacao do polibutadieno : evidencias de que nao ocorre via oxigenio singlete
Source
34. Annual Meeting of the Brazilian Society for the Advancement of Science; Campinas, SP (Brazil); 6 - 14 Jul 1982; Published in summary form only.
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Journal Article
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Conference
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Cienc. Cult. (Sao Paulo) Supl; v. 34(7); p. 529
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AbstractAbstract
[en] A general description of a decay process as a half-collision is presented. Two different sets of definitions of the non-decay probabilities and the spectra of the decay products are compared. A special role is stressed of a bound state of the total Hamiltonian, which may be generated in the threshold region. An example of near-threshold photodetachment is pointed out as the case in which distinguishing between different definitions may be essential. (orig.)
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Journal Article
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Elsayed-Ali, H.E.
Illinois Univ., Urbana, IL (United States). Graduate Coll1985
Illinois Univ., Urbana, IL (United States). Graduate Coll1985
AbstractAbstract
[en] The radiation chemistry of oxygen discharges is better-studied system. The discharges were made by irradiation with high energy helium and lithium ions created by a neutron-induced reaction in boron (10). A detailed numerical model and a simplified analytical model of oxygen radiolysis have been developed to interpret the data. A summary of the data on the ozone yield from irradiation of He-O2, Ne-O2 and Ar-O2 is presented. Dose rates are also indicated. The present work appears to be the first to measure the steady state ozone concentration in noble gas-oxygen discharges and the effect of SF6 on this steady state concentration. 106 refs
Secondary Subject
Source
1985; 297 p; Available through the King Abdulaziz City Center for Science and Technology, Riyadh-11442, Saudi Arabia; Microfiche only, 4 MF.; Thesis (Ph.D.).
Record Type
Miscellaneous
Literature Type
Thesis/Dissertation
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Tung, T.Y.
Northwestern Univ., Chicago, IL (United States)1992
Northwestern Univ., Chicago, IL (United States)1992
AbstractAbstract
[en] The authors have measured the differential cross section for two-body deuteron photodisintegration at θcm = 90 degrees, 114 degrees and 143 degrees, and for photon energies between 0.8 and 1.8 GeV. At energies above ≅1.2 GeV, the data at θcm = 90 degrees, and 114 degrees appear to obey a simple scaling law predicted by constituent-counting rules assuming parton degrees of freedom for the deuteron and nucleons. The shape of the angular distribution shows an abrupt change at Eγ ≥ 1.4 GeV, in that at 1.4 and 1.6 GeV cross sections peak at θcm = 143 degrees, but this is not the case for Eγ < 1.2 GeV. Agreement with model calculations based on meson exchange and on open-quotes reduced nuclear amplitudesclose quotes is discussed
Primary Subject
Source
1992; 184 p; Northwestern Univ; Chicago, IL (United States); Available from University Microfilms, P.O. Box 1764, Ann Arbor, MI (United States). Order No. 93-09,474; Thesis (Ph.D.).
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Miscellaneous
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Thesis/Dissertation
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Lattelais, M.; Pauzat, F.; Ellinger, Y.; Ceccarelli, C., E-mail: lattelais@lct.jussieu.fr, E-mail: pauzat@lct.jussieu.fr, E-mail: ellinger@lct.jussieu.fr, E-mail: Cecilia.Ceccarelli@obs.ujf-grenoble.fr2009
AbstractAbstract
[en] The hunt for complex organic molecules (COMs) is a major concern for understanding the possible role of interstellar chemistry in the synthesis of the molecules that ultimately may be at the origin of life. A comprehensive screening of the 14 species effectively observed under 32 different isomeric forms in the interstellar medium has been done by means of high-level quantum chemical simulations. Confrontation between calculations and observations shows that when several isomers of the same generic formula are identified, it is always the most stable one that is the most abundant. Moreover, the abundance ratio of the most stable isomer to the other isomers is directly related to their energy difference. What can be seen as a minimum energy principle is verified in molecular clouds, hot cores/corinos, photodissociation regions, and asymptotic giant branch stars. The few exceptions encountered could be rationalized either by the existence of different routes of formation with no intermediate in common and/or specific depletion on the grains of one isomer with respect to the others.
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Source
Available from http://dx.doi.org/10.1088/0004-637X/696/2/L133; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
Journal
Astrophysical Journal (Online); ISSN 1538-4357;
; v. 696(2); p. L133-L136

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