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AbstractAbstract
[en] Effects of dispersity of initial ZrO2 powder and holding time at high temperature were investigated for the process of zirconium reduction by calcium thermic method. The charge containing zirconium dioxide and metallic calcium chip was heated in argon up to 1100 deg C with holding at heat for 1.5 and 3 h. Calcium oxide obtained then was removed with the help of hydrochloric acid and distilled water. Fragmentation composition of zirconium powder after drying was determined by sedimentation technique. It was found out, that the tendency to universal distribution function with maximum at 5 μm took place indipendently of initial distribution function
Original Title
Vliyanie dispersnosti dioksida tsirkoniya na fraktsionnyj sostav poroshka tsirkoniya, poluchaemogo kal'tsietermicheskim metodom
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Ruddock, C.F.
Radiochemical Centre Ltd., Amersham (UK)1980
Radiochemical Centre Ltd., Amersham (UK)1980
AbstractAbstract
[en] Process for reducing the 'pertechnetate' ion TcO4-, whereby an aqueous solution of 'pertechnetate' is mixed with tin metal or a tin alloy as 'pertechnetate' reducing agent, and a soluble salt of a metal below tin in the electro-chemical tension scale, as activator for the reducing tin. This reduced 'pertechnetate' is used for forming usable complexes in medical diagnosis exploration
[fr]
Procede de reduction de l'ion pertechnetate TcO4-, selon lequel on melange une solution aqueuse de pertechnetate avec de l'etain metallique ou un alliage d'etain comme agent reducteur du pertechnetate, et un sel soluble d'un metal situe au-dessous de l'etain dans l'echelle des tensions electro-chimiques, comme activant pour l'etain reducteur. Ce pertechnetate reduit est utilise pour former des complexes utilisables en exploration medicale de diagnosticOriginal Title
Procede de reduction de l'anion pertechnetate; by tin or tin alloys
Source
26 Sep 1980; 19 p; FR PATENT DOCUMENT 2450234/A/; Available from Institut National de la Propriete Industrielle, Paris (France); Priority claim: 27 Feb 1979, GB.
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Patent
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AbstractAbstract
[en] Kinetics of catalytic reduction of uranyl species, U(VI) to U(IV) with hydrazine nitrate was studied over Pt/SiO2 catalyst in nitric acid medium. Experiments were carried out in a stainless-steel autoclave as a function of mixing intensity, temperature, catalyst loading and concentration of nitric acid, hydrazine and uranium. Langmuir-Hinshelwood approach was considered to derive various model equations and each of them was evaluated. Results of the present study indicated that catalytic reduction of U(VI) can be described by surface reaction between adsorbed molecules. The activation energy of the reaction was calculated to be 74.5 kJ/mol, suggesting a chemical reaction controlled process. (author)
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29 refs.
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Journal Article
Journal
Journal of Radioanalytical and Nuclear Chemistry; ISSN 0236-5731;
; CODEN JRNCDM; v. 325(2); p. 425-434

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AbstractAbstract
No abstract available
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Journal Article
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Progress Report
Journal
J. Metals; v. 22 p. 45-49
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AbstractAbstract
[en] A new material for neutralization of nitrogen oxides is presented. Two or three metals containing catalysts with a good activity and selectivity towards NOx have been obtained. Preparation of carbon catalysts by deposition of the active phase precursor on the initial carbon material prior to activation is considered as the most promising method. An active carbon-based catalyst (AC/Co) has been synthesized Apricot shells preliminary impregnated with a water-alcohol solution of Co nitrate have been used as initial carbon material. after drying they have been subjected to one-phase steam pyrolysis using a fix-bed reactor. The catalyst thus obtained has a specific surface area (BET) of 53 m2g-1, a favorable mesopore volume/total volume ratio (about 0.85) determined by nitrogen adsorption, a suitable mesopore distribution, about 70% of the mesopores being characterized by rp larger than 25 A and a high dispersion of the Co oxide phase. In addition the catalyst possesses the necessary mechanical resistance. The catalyst has exhibited a high activity with respect to NOx reduction with CO at low temperatures (at 150-250oC which are the temperatures of industrial flue gases, nO conversion up to 60-95% occurs) and a high selectivity. No presence of H2O has been established over the whole temperature range (100-300oC). An additional advantage of the catalyst is the fact that the amount of CO above 150oC is lower than the stoichiometric which indicates parallel participation in the process of both the active phase and the support (active carbon) It is also important that the presented catalyst has a low price due to the use of waste products from agriculture and the elimination of special thermal treatment of the supported Co nitrate. There are possibilities of using of other organic wastes from agriculture as well as wastes obtained during flotation of coal. (author)
Primary Subject
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1997; 4 p; Energy Forum'97; Varna (Bulgaria); 11-13 Jun 1997; Available from the Bulgarian INIS Centre, 69, Shipchenski Prokhod blvd., 1574 Sofia (BG); 6 refs., 2 figs.
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Miscellaneous
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Conference
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AbstractAbstract
[en] Purpose: Evaluation of the emphasis of themes pertaining to radiation dose and dose reduction at the Meeting of the German Radiological Society from 1998-2008 in comparison to international data. Materials and Methods: Retrospective analysis of 9440 abstracts with documentation of study presentation character, type of imaging, and examined body region. Abstracts stating radiation dose or primarily dealing with radiation dose/dose reduction were documented. Results were compared with a Pubmed query. Results: The percentage of purely scientific presentations sank in the observation period from 88 to 66%. While contributions dealing with MRI sank from 48 to 34%, those dealing with CT rose from 30 to 34%. The percentage of abstracts dealing with radiation dose rose from 7 to 10%, while that of work primarily pertaining to dose/dose reduction grew from 4 to 6% and 2 to 4%, respectively. Of all abstracts concerning CT, 15% touched on radiation dose, while 9% and 6% primarily dealt with dose and dose reduction. The respective numbers for cardiac CT, whose relative share of all CT abstracts rose from 3% in 1998 to 12% in 2008, were 10%, 7%, and 5%. An online query produced 137,791 publications on CT, and 2% of these abstracts mentioned radiation dose and 0.5% mentioned dose reduction. Conclusion: The number of presentations dealing with dose at the Meeting of the German Radiological Society has risen with time and is higher than the international number. On the other hand, >90% of all presentations and >85% of all CT abstracts do not mention radiation dose. In light of increasing public concern relating to radiation exposure, more intensive research of these themes is warranted. (orig.)
Original Title
Die Struktur des Deutschen Roentgenkongresses und die wissenschaftliche Behandlung der Themen Strahlendosis und Dosisreduktion. Eine Analyse der Jahre 1998-2008
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Secondary Subject
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Journal Article
Journal
RoeFo - Fortschritte auf dem Gebiete der Roentgenstrahlen und der bildgebenden Verfahren; ISSN 1438-9029;
; CODEN RFGNDO; v. 181(11); p. 1065-1072

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David, F.; Fourest, B.; Peretrukin, V.F.; Maslennikov, A.G.
Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire1989
Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire1989
AbstractAbstract
[en] The electrochemical reduction of some transplutonium elements (Pu - Cf) and rare earths (Eu, Tm) from aqueous complexing solutions to amalgams was studied over a wide range of cathodic potentials in order to get the best separation of californium. The reduction process in acetate media (pH 1.5 - 4.6) at potential around - 1.7, 1.9 V leads to quantitative extractions of californium into the mercury phase, while more negative potentials are required for the reduction of the lighter transuranium elements and lanthanides. Thus, the optimal conditions of the californium purification from the investigated actinides and lanthanides were determined. Separation factors α were found to be 25 - 90 excepted in the case of Cf/Eu, where poor values (α varying from 7 to 12) were observed. Applications of more negative cathodic potentials decrease the selectivity of the reduction process. A similar study with lithium citrate solutions (pH ∼ 6) shows that a good separation of californium from lighter and heavier actinides is achievable. Separation factor of 88 is obtained for Cf/Am at - 1.98 V. The anodic stripping of mixed amalgams (Pu, Am, Cm, Bk, Tm and Cf) Hg in nitric acid and acetic solutions at potentials + 0.1, - 0.7 V proceeds slowly and proved to be uneffective for californium separation from light actinides under described conditions
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1989; 11 p
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Report
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Lojou, E.; Giudici-Orticoni, M.Th.; Bianco, P.
Rennes-1 Univ., Lab. d'Electrochimie Moleculaire et Macromoleculaire, SESO - UMR CNRS 6510, 35 (France)2005
Rennes-1 Univ., Lab. d'Electrochimie Moleculaire et Macromoleculaire, SESO - UMR CNRS 6510, 35 (France)2005
AbstractAbstract
[en] With the development of bio electrochemistry, researches appeared on the enzymes immobilization at the surface of electrodes for the realization of bioreactors and bio sensors. One of the main challenges is the development of host matrix able to immobilize the protein material preserving its integrity. In this framework the authors developed graphite electrodes modified by clay films. These electrodes are examined for two enzyme reactions involving proteins of sulfate-reduction bacteria. Then in the framework of the hydrogen biological production and bioreactors for the environmental pollution de-pollution, the electrochemical behavior of the cytochrome c3 in two different clays deposed at the electrode is examined
Original Title
Activites enzymatiques impliquant des cytochromes bacteriens incorpores dans des matrices argileuses
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Source
2005; 1 p; JE'05: Electrochemistry meeting Saint Malo 2005; JE Saint Malo 2005. Journees d'Electrochimie 2005; Saint Malo (France); 5-8 Jul 2005
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AbstractAbstract
[en] The aluminothermic process for the reduction of vanadium pentoxide is considered. Its thermochemistry features are presented, as well as the heat transfer and the rate phenomena concerning such a reaction system. It is pointed out also the effect of the process parameters on the recovery of metallic vanadium. (Author)
[pt]
Analisa-se o processo aluminotermico de obtencao de vanadio metalurgico a partir de pentoxido de vanadio, compreendendo estudos termodinamicos, cineticos e transporte de calor. Comenta-se a influencia de algumas variaveis de processo sobre a recuperacao do metal. (Autor)Original Title
Aspectos fundamentais da reducao aluminotermica do pentoxido de vanadio
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1982; 22 p; 37. Annual Congress of the Brazilian Association of Metals; Rio de Janeiro (Brazil); Jul 1982
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AbstractAbstract
[en] In this paper we prove the Marsden-Misiolek-Ortega-Perlmutter-Ratiu Stages Hypothesis, which is a sufficient condition for a general reduction by stages theorem. Our Lie-algebraic approach allows us to prove this conjecture in a general case (not only for semidirect products of groups with cocycle) and to simplify the proof of a general reduction by stages theorem (with some modifications). Bibliography: 8 titles
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Source
Available from http://dx.doi.org/10.1070/SM2008v199n05ABEH003938; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
Journal
Sbornik. Mathematics; ISSN 1064-5616;
; v. 199(5); p. 663-671

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