Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "radiolysis" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 24
Tytuł:
Influence of alpha and gamma radiolysis on Pu retention in the solvent TBP/kerosene
Autorzy:
Gao, Y
Zheng, W.
Cao, X.
Chen, S.
Powiązania:
https://bibliotekanauki.pl/articles/148296.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
purex process
TBP solvent
alpha radiolysis
gamma radiolysis
Pu retention
Opis:
In light of the issue of radiolysis of the solvent system in PUREX process, alpha and gamma radiation stability of tributyl phosphate (TBP)/kerosene (OK) have been studied in this paper, in which 238Pu dissolved in the organic phase and 60Co are selected as alpha and gamma irradiation sources, respectively. The amount of the degradation products not easily removed after the washing process has been measured by the plutonium retention. The effects of the absorbed dose, the TBP volume fraction, the cumulative absorbed dose and the presence of UO2 2+ and Zr4+ on the radiolysis of the solvents have been investigated. The results have indicated that the Pu retention increases with the increase of the absorbed dose after alpha or gamma irradiation, and is larger for the solvent containing less TBP. There is competition between UO2 2+ and Pu4+ to complex with the degradation products, and Zr4+ accelerates the radiolysis of the system.
Źródło:
Nukleonika; 2014, 59, 4; 123-128
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The mechanism and kinetics of ozone formation in a pulse radiolysis study of the Ar-O2 system
Autorzy:
Wojciechowski, K.
Sugier, D.
Wnorowski, K.
Kowalczyk, J.
Jówko, A.
Powiązania:
https://bibliotekanauki.pl/articles/147852.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
pulse radiolysis
argon
oxygen
ozone
Opis:
The mechanism and kinetics of O3 formation after an electron pulse have been studied in the Ar-O2 systems by time resolved optical measurements at gamma = 260 nm. The second order rate constant of energy transfer from excited Ar(4s,4p) states to O2 molecules: (1) Ar*,Ar** + O2 → O2* + Ar, was found to be (8.9 ± 2.1) x 10-10 cm3 s-1. It was found also the evidence of the third order process contribution to the energy transfer: (2) Ar*,Ar** + Ar + O2 → products, with the rate constant in the range (1.5-3.7) x 10-29 cm6 s-1. The rate constant of the deactivation of excited ozone molecules by O2 was found to be (5.1 ± 0.6) ´ 10-15 cm3 s-1.
Źródło:
Nukleonika; 2005, 50,suppl.2; 29-33
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation of Br2 '-, BrSCN'- and (SCN)2'-intermediates in the ionic liquid methyltributylammonium bis[(trifluoromethyl)sulfonyl]imide. Pulse radiolysis study
Autorzy:
Grodkowski, J.
Nyga, M.
Mirkowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/147848.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
ionic liquids
pulse radiolysis
Br2
Opis:
The reactions of Br2 '- anion radicals with thiocyanate anions in the ionic liquid methyltributylammonium bis[(trifluoromethyl)sulfonyl]imide (R4NNTf2) were studied by pulse radiolysis. Reaction of solvated electrons with BrCH2CH2Br (DBE), k = (1 2)×108 L.mol 1.s 1, leads to the production of Br2'- anion radicals. The intermediate absorption spectra following pulse radiolysis of DBE/SCN-/Br-/ solutions in R4NNTf2 correspond to Br2 '-, BrSCNo- and (SCN)2'- anion radicals. The participation of these radicals in the spectra changes with progressing reactions and depends on the concentration Br- and SCN- in the solution.
Źródło:
Nukleonika; 2005, 50,suppl.2; 35-38
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EPR study of highly stable methyl radicals trapped in synthetic H-rho zeolite
Autorzy:
Danilczuk, M.
Sadło, J.
Lund, A.
Yamada, H.
Michalik, J.
Powiązania:
https://bibliotekanauki.pl/articles/147860.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
methyl radicals
zeolite rho
EPR
radiolysis
Opis:
Methyl radicals generated by ă-irradiation in the proton form of synthetic rho zeolite exposed to CH4 have been investigated by electron paramagnetic resonance (EPR) in the temperature range 110-370 K. Depending on the methane adsorption temperature two EPR spectra of oCH3 radicals were recorded. The isotropic quartet observed after CH4 adsorption at room temperature was assigned to oCH3 radicals freely rotating in the middle of octagonal prism. After adsorption at 413 K, the isotropic quartet is overlapped with the second signal characterized with anisotropy of hyperfine splitting and g-value. It is postulated that anisotropic signal represents the oCH3 radicals located in á-cages and strongly interacting with silicaalumina framework. The mechanisms of radiolytic formation of methyl radicals and the possible stabilization sites are also discussed.
Źródło:
Nukleonika; 2005, 50,suppl.2; 51-54
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism of peroxynitrite interaction with cytochrome c.
Autorzy:
Gębicka, Lidia
Didik, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/1043459.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cytochrome c
radiolysis
peroxynitrite
stopped-flow spectrophotometry
Opis:
Kinetics of the reaction of peroxynitrite with ferric cytochrome c in the absence and presence of bicarbonate was studied. It was found that the heme iron in ferric cytochrome c does not react directly with peroxynitrite. The rates of the absorbance changes in the Soret region of cytochrome c spectrum caused by peroxynitrite or peroxynitrite/bicarbonate were the same as the rate of spontaneous isomerization of peroxynitrite or as the rate of the reaction of peroxynitrite with bicarbonate, respectively. This means that intermediate products of peroxynitrite decomposition, ·OH/·NO2 or, in the presence of bicarbonate, CO3-·/·NO2, are the species responsible for the absorbance changes in the Soret band of cytochrome c. Modifications of the heme center of cytochrome c by radiolytically produced radicals, ·OH, ·NO2 or CO3-·, were also studied. The absorbance changes in the Soret band caused by radiolytically produced ·OH or CO3-· were much more significant that those observed after peroxynitrite treatment, compared under similar concentrations of radicals. ·NO2 produced radiolytically did not interact with the heme center of cytochrome c. Cytochrome c exhibited an increased peroxidase-like activity after reaction with peroxynitrite as well as with radiolytically produced ·OH, ·NO2 or CO3-· radicals. This means that modification of protein structure: oxidation of amino acids and/or tyrosine nitration, facilitates reaction of H2O2 with the heme iron of cytochrome c, followed by reaction with the second substrate.
Źródło:
Acta Biochimica Polonica; 2003, 50, 3; 815-823
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiolysis of chloroalkanes: 1,2-dichloroethane
Autorzy:
Truszkowski, S.
Chostenko, A.
Powiązania:
https://bibliotekanauki.pl/articles/148596.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
1,2-dichloroethane (DCE)
chloroalkanes
radiolysis products
Opis:
The stable products of radiolysis of 1,2-dichloroethane (12DCE) ?-irradiated in an oxygen-free atmosphere were investigated. The pure products of radiolysis were separated by preparative gas chromatography and identified by 1H, 13C NMR and mass spectroscopy as well as quantitative gas chromatography. In the gas phase we have obtained H2 and HCl; in the liquid phase: chloroethane, 1,1-dichloroethane, 1,1,2-trichloroethane, 1,2,4-trichlorobutane and 1,2,3,4-tetrachlorobutanes (dland meso-: [2R,3R] or [2S,3S] and [2R,3S]-isomers). On the basis of the results obtained a preliminary scheme for the formation of the stable products is proposed.
Źródło:
Nukleonika; 2003, 48, 1; 41-44
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation-heterogenic processes of hydrogen accumulation in water-cooled nuclear reactors
Autorzy:
Garibov, A.
Powiązania:
https://bibliotekanauki.pl/articles/147650.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
zirconium
corrosion
water-cooled nuclear reactor
hydrogen
radiolysis
Opis:
The research into the influence of radiation on the process of hydrogen accumulation and zirconium oxidation as a result of heterogeneous processes taking place in contact of zirconium and Zr + 1 per cent Nb alloy with water vapour was conducted. Due to such contact the contribution of radiation processes into radiolysis and thermo-radiolysis of water decomposition processes was revealed. It was determined that radiation-heterogenic processes in contact of zirconium materials with water invoked earlier accumulation of hydrogen originating from both the protective oxidation film on surface formation and destructive oxidation of metallic materials.
Źródło:
Nukleonika; 2011, 56, 4; 333-342
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physico chemical properties of irradiated i-SANEX diluents
Autorzy:
Mossini, E.
Macerata, E.
Giola, M.
Brambilla, L.
Castiglioni, C.
Mariani, M.
Powiązania:
https://bibliotekanauki.pl/articles/147044.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
density
i-SANEX
partitioning
radiolysis
Raman
UV-Vis
viscosity
Opis:
The development of effective processes to recover minor actinides from spent nuclear fuel cannot leave out of consideration the evaluation of the impact of ionizing radiations on safety, fluid dynamics and extraction efficiency. It is common knowledge from the literature that radiation damage mainly affects the diluents and, indirectly, the extractants [1], but a lack of knowledge remains regarding the radiolytic behavior of innovative selective actinide extraction (i-SANEX) diluents [2, 3]. As natural prosecution of the work already performed on diluted nitric acid solutions [4], 0.44 M nitric acid solutions were irradiated in contact with a mixture of kerosene + 5 vol.% 1-octanol by a Co-60 source at 2.5 kGy/h dose rate and up to 100 kGy absorbed dose, conditions of interest for the future industrial facility. Density, viscosity, acidity, nitrate anion concentration and phase transfers were systematically measured before and after γ-irradiation. This was performed because radiation-induced modifi cations of these parameters may induce alterations of both the fluid dynamics and the separation performances of the extracting system. The results suggest that the fluid-dynamics of the system should be unaltered. In fact, only slight alterations of the organic phase viscosity and of the aqueous phase acidity were measured after irradiation, suggesting the occurrence of limited phase transfers and of diluent by-products formation.
Źródło:
Nukleonika; 2015, 60, No. 4, part 2; 893-898
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GC investigation of post-irradiation oxidation phenomena on polypropylene
Autorzy:
Głuszewski, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/2055682.pdf
Data publikacji:
2021
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gas chromatography
polypropylene
post-radiation oxidation
protective effect
radiolysis
Opis:
The paper summarizes the results of research on gas products of polypropylene (PP) radiolysis. Particular attention was paid to the phenomena of post-radiation degradation of PP. The protective effect of selected aromatic compounds was investigated. The research was carried out both from the point of view of obtaining radiation-resistant PP varieties and the possibility of accelerating biodegradation phenomena, e.g., PP/cellulose composition. The phenomena of post-radiation chain oxidation of PP were investigated by gas chromatography (GC). The GC in the system used (packed column, thermal conductivity detector, argon – carrier gas) enables the determination of H2, O2, CO, and CH4 in one measurement. The samples were irradiated with electron beams (EBs) accelerated in accelerators: Elektronika 10/10 with a power of 10 kW and energy of 10 MeV and LAE 13/9 with a power of 9 kW and energy up to 13 MeV. In the tests, PP without stabilizing additives (obtained directly from the production line) and non-stabilized styrene were used. Radiolytic efficiency of hydrogen evolution allowed us to estimate the number of originally formed free radicals. The maintenance of the secondary oxidation processes was the loss of oxygen and the formation of oxidation products (CO, CH4). Attention is paid to the protective effect of aromatic compounds (polystyrene (PS), polyethylene terephthalate (PET), anthracene, fluoranthene, acenaphthene, pyrene, naphthalene) both at the stage of hydrogen atom separation and the secondary oxidation process. The examples of post-radiation oxidation of PP irradiated in cryogenic conditions (–196°C) are presented. All used aromatic compounds showed a protective effect in PP radiolysis. We suppose that this phenomenon is responsible for the charge transfer along the polymer chain from the ionization spurs to the aromatic compound. The protective ranges of PS in PP radiolysis were estimated for the variously prepared PP/PS type compositions from 6 mers to 28 mers.
Źródło:
Nukleonika; 2021, 66, 4; 187--192
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowania radiolizy polimerów w energetyce
Autorzy:
Głuszewski, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/2096869.pdf
Data publikacji:
2022
Wydawca:
Nowa Energia
Tematy:
technologie
radioliza
polimery
energetyka
technologies
radiolysis
polymers
power engineering
Opis:
Słowo radioliza (przez analogię do elektrolizy) wprowadziła do nauki Maria Skłodowska-Curie. Termin ten oznacza obecnie ogół procesów chemicznych wywołanych działaniem promieniowania jonizującego na materię. W przypadku radiolizy węglowodorowych tworzyw polimerowych głównym produktem gazowym jest wodór (H2). W miejscu oderwania atomu wodoru, który w formie cząsteczkowej bezpowrotnie opuszcza materiał powstaje wolny rodnik.
Źródło:
Nowa Energia; 2022, 1; 41-43
1899-0886
Pojawia się w:
Nowa Energia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation chemistry of radioactive waste to be stored in the salt mine repository
Autorzy:
Zagórski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/148590.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dehydrogenation
ionization spurs
radioactive waste
radiolysis of polymers
repository chemistry
Opis:
Different aspects of radiation chemistry connected with long storage of radioactive waste are discussed. More details are given on the dehydrogenation of organic, and in particular polymeric waste, contaminated with transuranium nuclides. Determinations of radiation yields of hydrogen from typical waste were made, indicating limits of safe activities tolerable. No danger of chain reactions of hydrogen release was detected.
Źródło:
Nukleonika; 2006, 51,suppl.2; 87-92
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computation of the effect of pH on spur chemistry in water radiolysis at elevated temperatures
Autorzy:
Swiatla-Wojcik, D.
Powiązania:
https://bibliotekanauki.pl/articles/147674.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
effect of pH
radiolysis of water
elevated temperatures
diffusion-kinetic calculations
Opis:
Diffusion-kinetic model has been employed to calculate the effect of pH and associated ionic strength on the primary yields in the radiolysis of water from ambient temperature to 200°C. Account has been taken of the effect of ionic strength, I, up to 0.1 molźdm-3 in both acidic and alkaline solutions resulting from the addition of H+ and OH-,assuming the counter ions have unit charge. The primary yields are essentially independent of pH for I ? 10-4. AboveI = 10-4 molźdm-3 the primary yields of e-aq and H2 in acidic solutions decrease whereas the primary yields of the H atom, hydroxyl radical and hydrogen peroxide increase. At I >10-3 molźdm-3 in alkaline solutions, the OH radical and hydrogen peroxide are partially converted into Oo- and HO-2 , respectively. Increases in the total yields GoOH + GOo- and Ge-aq + GHo and a decrease in GH2O2 + GHO-2 have been found with increasing pH. At elevated temperatures the effect of pH is diminished. The temperature effect on the primary yields in acidic and alkaline solutions is nearly the same as in neutral water.
Źródło:
Nukleonika; 2008, 53, suppl. 1; 31-37
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radioliza biodegradowalnych pianek PLA/PCL
Radiolysis of PLA /PCL biodegradable foams
Autorzy:
Głuszewski, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/214363.pdf
Data publikacji:
2019
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radioliza polimerów
pianki
PLA
PCL
biodegradacja
radiolysis of polymers
foams
biodegradation
Opis:
Degradacja polimerowych tworzyw komórkowych do nietoksycznych produktów jest warunkiem koniecznym w przypadku wielu materiałów medycznych. Duże nadzieje w wytwarzaniu np. trójwymiarowych porowatych skafoldów wiąże się z biodegradowalnymi polimerami a w szczególności polilaktydem (PLA) oraz polikaprolaktonem (PCL). Wygodnym sposobem kontroli czasu ich degradacji jest wykorzystanie indukowanych promieniowaniem jonizacyjnym zjawisk postradiacyjnego utleniania. W artykule zaproponowano wykorzystanie do badań radiolizy biodegradowalnych polimerów chromatografii gazowej i DRS.
Degradation of polymeric cellular materials to non-toxic products is a desirable phenomenon in many medical materials. High hopes for the production of e.g. three-dimensional porous spheres are associated with biodegradable polymers, in particular polylactide (PLA) and polycaprolactone (PCL). A convenient way to modify and control degradation can be postradiation oxidation induced by ionizing radiation. The article draws attention to the possibility of using for radiolysis of biodegradable polymers of gas chromatography and DRS.
Źródło:
Postępy Techniki Jądrowej; 2019, 2; 33-35
0551-6846
Pojawia się w:
Postępy Techniki Jądrowej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma radiolytic stability of CyMe4BTBP and the effect of nitric acid
Autorzy:
Schmidt, H.
Wilden, A.
Modolo, G.
Švehla, J.
Grüner, B.
Ekberg, C.
Powiązania:
https://bibliotekanauki.pl/articles/148662.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
CyMe4BTBP
gamma radiolysis
liquid-liquid extraction
nitric acid
partitioning
protective effect
Opis:
The highly selective nitrogen donor ligand CyMe4BTBP for An(III) separation by solvent extraction was irradiated in a 60Co γ-source under varying conditions. Organic solutions of 10 mmol/L ligand in 1-octanol were contacted with different concentrations of nitric acid to observe the influence of an aqueous phase during irradiation. In subsequent liquid-liquid extraction experiments, distribution ratios of 241Am and 152Eu were determined. Distribution ratios decreased with increasing absorbed dose when irradiation was performed in the absence of nitric acid. With addition of nitric acid, initial distribution ratios remained constant over the whole examined dose range up to 300 kGy. For qualitative determination of radiolysis products, HPLC-MS measurements were performed. The protective effect of nitric acid was confi rmed, since in samples irradiated with acid contact, no degradation products were observed, but only addition products of the 1-octanol molecule to the CyMe4BTBP molecule.
Źródło:
Nukleonika; 2015, 60, No. 4, part 2; 879-884
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free radicals in chemistry, biology and medicine: contribution of radiation chemistry
Autorzy:
Bobrowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/147946.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
free radicals
pulse radiolysis
oxidative stress
ionic liquids
long range electron transfer
beta-amyloid peptide
Opis:
The scope of this article is limited to the concept of free radical and its historical background and a brief introduction to time-resolved techniques (pulse radiolysis, laser flash photolysis), which allowed direct observation of free radicals on real time. The selected contributions of pulse radiolysis to better understanding the role of free radical reactions in chemistry, biology and medicine are presented and some selected future research needs and opportunities in radiation chemistry are briefly addressed.
Źródło:
Nukleonika; 2005, 50,suppl.3; 67-76
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 24

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies