M. Mostafavi, M.O. Delcourt, N. Keghouche, G. Picq
{"title":"Early steps of formation of silver/polyacrylate complexed oligomer clusters. A pulse radiolysis study","authors":"M. Mostafavi, M.O. Delcourt, N. Keghouche, G. Picq","doi":"10.1016/1359-0197(92)90208-W","DOIUrl":"10.1016/1359-0197(92)90208-W","url":null,"abstract":"<div><p>Pulse radiolysis has been carried out on aqueous solutions of silver ions complexed with polycrylate (PA). Over the time scale 10<sup>−8</sup>−10 s, only a few kinetic steps have been observed which have been identified through spectroscopic and kinetic analysis. The reaction rate of e<sup>-</sup><sub>aq</sub> with Ag<sup>+</sup> is lowered in the presence of PA (3.6×10<sup>9</sup>lmol<sup>−1</sup>s<sup>−1</sup> when [PA]/[Ag<sup>+</sup>]=100). The first products (Ag<sup>0</sup> λ<sub>max</sub>≈360 nm, Ag<sup>+</sup><sub>2</sub> λ<sub>max</sub>=310 nm) are similar to those obtained in the absence of PA, except for an additional absorption band (350–450 nm) which indicates that Ag<sup>+</sup><sub>2</sub> is itself complexed. Then through dimerization (2k=3×10<sup>9</sup>lmol<sup>−1</sup>s<sup>−1</sup>) and reaction with the alcoholic radical (in the presence of 2-PrOH, 1.5×10<sup>9</sup>lmol<sup>−1</sup>s<sup>−1</sup>), Ag<sup>+</sup><sub>2</sub> leads to an “Ag<sub>2</sub>” species peaking at 300, 320 and 360 nm, noticeably different from the reported Ag<sup>2+</sup><sub>4</sub> species. Two further steps are observed which are assigned to a ligand reorganization of “Ag<sub>2</sub>” in the millisecond range (10<sup>3</sup><em>s</em><sup>−1</sup>), followed by a coalescence to “Ag<sub>4</sub>” in the range of seconds (10<sup>5</sup>lmol<sup>−1</sup>s<sup>−1</sup>). This last product is thought to be the stable Ag<sub>a</sub> cluster known to be formed by γ-radiolysis. A kinetic simulation accounts for the whole mechanism which is much lower than in the absence of PA.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 445-450"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90208-W","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85924111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Cobut , Y. Frongillo , J.-P. Jay-Gerin , J.-P. Patau
{"title":"A Monte Carlo calculation of subexcitation and vibrationally-relaxing electron spectra in irradiated liquid water","authors":"V. Cobut , Y. Frongillo , J.-P. Jay-Gerin , J.-P. Patau","doi":"10.1016/1359-0197(92)90229-9","DOIUrl":"10.1016/1359-0197(92)90229-9","url":null,"abstract":"<div><p>An energy spectrum of “subexcitation electrons” produced in liquid water by electrons with initial energies of a few keV is obtained by using a Monte Carlo transport simulation calculation. It is found that the introduction of vibrational-excitation cross sections leads to the appearance of a sharp peak in the probability density function near the electronic-excitation threshold. Electrons contributing to this peak are shown to be more naturally described if a novel energy spectrum, that we propose to name “vibrationally-relaxing electron” spectrum, is introduced. The corresponding distribution function is presented, and an empirical expression of it is given.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 589-591"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90229-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78040661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Marchioni , M. Tousch , V. Zumsteeg , F. Kuntz , C. Hasselmann
{"title":"Alterations of mitochondrial DNA: A method for the detection of irradiated beef liver","authors":"E. Marchioni , M. Tousch , V. Zumsteeg , F. Kuntz , C. Hasselmann","doi":"10.1016/1359-0197(92)90213-Y","DOIUrl":"10.1016/1359-0197(92)90213-Y","url":null,"abstract":"<div><p>The study of the radio degradation of DNA is one of a number of phenomena being investigated to develop methods for identifying irradiated foods. The specific behaviour under radiation of the mitochondrial DNA from beef liver gives the possibility of detecting if the product has been irradiated or not. An identification method could finally be developed. The appraisal of the mitochondrial supercoiled DNA fraction constitutes an unambiguous detection test for beef liver irradiation. A total of 120 different samples were irradiated at 5 different doses. The dose limit of detection is lower than 2 kGy. No effects due to storage conditions were observed.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 485-488"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90213-Y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77962873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Protection in radiolysis of n-hexadecane—2. Radiolysis of n-hexadecane in the presence of additives","authors":"Yanti S. Soebianto , Yosuke Katsumura , Kenkichi Ishigure , Junichi Kubo , Takeo Koizumi","doi":"10.1016/1359-0197(92)90209-X","DOIUrl":"10.1016/1359-0197(92)90209-X","url":null,"abstract":"<div><p>Protection effect of aromatic (naphthalene, phenanthrene) and hydroaromatic (tetralin, octahydrophenanthrene) compounds in irradiated liquid alkane has been investigated as a model experiment for the radiolysis of polymers. Liquid <em>n</em>-hexadecane has been selected as the model linear amorphous polymer and the protection effect has been studied by analyzing the radiolysis products. In the presence of additives, degradation of <em>n</em>-hexadecane, reduction of radiolysis products, including H<sub>2</sub> evolution, and selective degradation of the additive have been observed. Energy transfer (excitation and charge) to the additive reduces the solvent excitation which is the precursor of the radiolysis products. The additive reacts with the solvent molecules according to its reactivity to form adduct compounds. Mass analysis shows that these adduct compounds have a smaller number of double bonds in their aromatic rings due to hydrogenation. Aromatic compounds are more reactive than hydroaromatic compounds towards <em>n</em>-hexadecane and their adducts consume more hydrogen than those of the hydroaromatic compounds, and therefore aromatic compounds reduce gas formation more effectively than hydroaromatic compounds. From the effect of aromatic compounds, it is concluded that hexadecene is produced neither by H<sub>2</sub> elimination from the lowest excited state of <em>n</em>-hexadecane nor by disproportionation of <em>n</em>-hexadecyl radicals, but is mainly produced directly from the decomposition of the excited cations of <em>n</em>-hexadecane.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 451-459"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90209-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83988578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reactions of hydrated electron and alcohol radicals with halogenated aromatic compounds: A pulse radiolysis study","authors":"H. Mohan , M. Mudaliar , B.S.M. Rao , J.P. Mittal","doi":"10.1016/1359-0197(92)90217-4","DOIUrl":"10.1016/1359-0197(92)90217-4","url":null,"abstract":"<div><p>The bimolecular rate constants for the reaction of e<sup>-</sup><sub>aq</sub> with chlorotoluenes, chloronitrobenzenes and chloronitrotoluenes have been determined from the decay of e<sup>-</sup><sub>aq</sub>. With chlorotoluenes, e<sup>-</sup><sub>aq</sub> reacts by dissociative electron capture without any transient absorption band in 270–500 nm region. In case of chloronitrobenzenes and chloronitrotoluenes, e<sup>-</sup><sub>aq</sub> forms a transient band with λ<sub>max</sub> in 290–310 nm region without any Cl<sup>-</sup> formation. Hydroxyl alkyl radicals, derived from alcohols, do not seem to react with chlorotoluenes whereas a transient species with <em>λ</em><sub>max</sub>=305–315 nm region are formed on addition of hydroxy alkyl radical to —NO<sub>2</sub> group of chloronitrobenzenes.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 513-517"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90217-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90454121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of hydroaromatics on post-oxidation of polyolefins induced by electron irradiation","authors":"Junichi Kubo , Kazushige Otsuhata","doi":"10.1016/1359-0197(92)90212-X","DOIUrl":"10.1016/1359-0197(92)90212-X","url":null,"abstract":"<div><p>Additive effects of hydroaromatics towards radiation degradation and post-oxidation of high density polyethylene and isotactic polypropylene were investigated. At the same time, the radical scavenging effects of hydroaromatics were examined using DPPH(<em>N,N</em>-diphenyl-<em>N</em>'-picrylhydrazyl). It was found that: </p><ul><li><span>1.</span><span><p>(1) the addition of HHAP (multi-component type hydroaromatics, produced by the hydrogenation of highly aromatic heavy fraction from petroleum) was obviously effective in inhibiting both radiation (electron beam in air) degradation and post-oxidation of polyolefins,</p></span></li><li><span>2.</span><span><p>(2) hydroaromatics (tetralin, octahydrophenanthrene and HHAP) have evident radical scavenging abilities from the tests using DPPH and</p></span></li><li><span>3.</span><span><p>(3) the inhibiting effects of HHAP can be attributed to its radical scavenging ability.</p></span></li></ul></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 477-483"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90212-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79822858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Wood-plastic composite using water soluble monomer","authors":"Mubarak A. Khan, K.M.Idriss Ali","doi":"10.1016/1359-0197(92)90206-U","DOIUrl":"10.1016/1359-0197(92)90206-U","url":null,"abstract":"<div><p>Wood-plastic composite (WPC) has been prepared with simul using acrylamide (AM), a water soluble monomer, in place of styrene (ST) and butylmethacrylate (BA). The highest polymer loading (PL) is achieved with AM along with the highest tensile strengths (TS) among the three bulk monomers studied. Effect of urea, NVP and TMPTA has been investigated in these systems. Co-additive (urea) has played a significant role in presence of NVP and TMPTA with AM compared to ST and BA systems. Methanol, water and water/methanol mixtures have been used as swelling agents in order to study their effect on PL and <em>T<sub>f</sub></em> values. TS loss due to the weathering effect is minimum with the WPC, particularly if prepared with swelling agent methanol.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 433-436"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90206-U","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79371860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Role of additives on tensile strength of wood-plastic composite","authors":"Mubarak A. Khan, K.M.Idriss Ali","doi":"10.1016/1359-0197(92)90204-S","DOIUrl":"10.1016/1359-0197(92)90204-S","url":null,"abstract":"<div><p>Wood-plastic composite (WPC) formation has been studied with simul+styrene system at various compositions of styrene with methanol as the swelling solvent. Effect of additives, e.g. multifunctional monomers (MFM) and oligomers used in very low quantity (1% v/v) on the polymer loading (PL) and tensile strength (TS) of the WPC has been elaborately investigated. Enhanced PL and TS values are observed. Inorganic co-additives like Lithium (Li<sup>+</sup>), Copper (Cu<sup>2+</sup>) and acid (H<sup>+</sup>) and urea (U) used in combinations with additives (MFM or oligomers) have influenced the results of PL and TS in these systems. Li<sup>+</sup> ion has been a good replacement for H<sup>+</sup> ion; U has substantially enhanced the PL values with retention of the TS values of WPC. Co-additive Cu<sup>2+</sup> used in these system can act as a preservative and protective agent for WPC.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 421-426"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90204-S","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91383497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Radiation-induced transmethylation and transsulfuration in the system DNA-methionine","authors":"W. Köhnlein , O. Merwitz , P. Ohneseit","doi":"10.1016/1359-0197(92)90205-T","DOIUrl":"10.1016/1359-0197(92)90205-T","url":null,"abstract":"<div><p>Evidence is presented for the radiation-induced transmethylation and transsulfuration in a DNA-methionine model system. The extent of such alkylation of DNA is found to be comparable with that of alkylating agents. Therefore, both processes could be initial steps in radiation carcinogenesis.</p><p>The protective effect of methionine on DNA strand breaks, due to scavenging of OH radicals, causes the formation of methyl and thiyl radicals.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 6","pages":"Pages 427-432"},"PeriodicalIF":0.0,"publicationDate":"1992-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90205-T","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86422271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Primary processes induced in polyethylene film by electron beam irradiation at low and very low temperatures","authors":"J. Kroh , S. Wysocki","doi":"10.1016/1359-0197(92)90201-P","DOIUrl":"10.1016/1359-0197(92)90201-P","url":null,"abstract":"<div><p>The pulse radiolysis of low density polyethylene (LPDE), using optical absorption detection and emission spectroscopy, has been investigated in the temperature range 6–150 K, the experiments being complemented by a study of the photoluminescence.</p><p>It was found that excitons can be autolocalized at temperatures below 20 K, and this process is strongly dependent on the thermal history of the sample.</p></div>","PeriodicalId":14262,"journal":{"name":"International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry","volume":"40 5","pages":"Pages 395-400"},"PeriodicalIF":0.0,"publicationDate":"1992-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/1359-0197(92)90201-P","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90944059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}