6,706 research outputs found

    The Concept of a Research Reactor of Small Power for Isotope Processing

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    The concept of a low-power research reactor for the production of radioisotopes is proposed, the results of calculations of the neutron-physical parameters of the core are presented, which can be used to substantiate the claimed reactor characteristics. In this article, the characteristics of the core of a research reactor of low power is substantiated, the main purpose of which is the production of radioisotope products for medical purposes. Nuclear medicine is one of the most advanced and demanded in the world of modern high-tech medicine, based on the using of atomic nucleus properties. As a rule, atoms with unstable nuclei are radionuclides. The reactor method of radionuclide production allows obtaining large quantities of radioisotope products at a relatively low price, but the reactor base is currently rather limited.     Keywords: radioisotope products, research reactors, neutron-physical characteristic

    Fenntartható fluoros kémia = Sustainable fluorous chemistry

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    (1) A „zöldebb” fluoros kémia kialakítása érdekében számos trifluormetil-csoportban gazdag reagens hatékony szintézisét dolgoztuk ki, melyek könnyen hozzáférhető szerves fluorvegyületek hasznosítására és várhatóan nagyobb környezeti lebomlási készségére hívják fel a figyelmet. (2) Eljárásokat dolgoztunk ki 3-perfluoralkil-propanol és 3-perfluoralkil-propén típusú intermedierek előállítására, illetve a köztitermékként megjelenő ún. jódhidrinek sokoldalú preparatív átalakítására. (3) Új típusú fluoros ionos folyadékokat, imidazólium-sókat és más intermediereket állítottunk elő. (4) Orosz fejlesztésű kompozit anyagokat (FUKM, FUKM-M és FUKM-MT) kémiai reagensként, illetve átmenetifém katalizátor (Pd/FUKM) hordozóként alkalmaztunk. (5) Tanulmányoztuk a Hiyama- és a Heck-kapcsolási reakciók mechanizmusát és szintetikus alkalmazhatóságát. (6) CF3I reagnest S-alkilezőszerként alkalmaztuk (7) Prof. Bühlmann al együttműködve fluoros ionofórokat és elektrokémiai szenzorokat készítettünk. (8) Azonosítottuk egy új potenciális fluorátvivő reagens molekulaszerkezeti feltételeit, melynek segítségével lehetőségünk nyílik a fluoros kémiából (fluortartalmú modulok) a fluorkémiába (szén-fluor kötesek kialakítása) átlépnünk. Ez lehetőséget ad a gyógyszerkémia számára fontos egy, kettő, vagy három fluoratomot tartalmazó vegyületek hatékony előállításához. Több közlemény csak a kövtekező évben fog megjelenni, kérem az értékelésnél ezt vegyék figyelembe. | (1) For Greener Fluorous Chemistry we developed the synthesis of several reagents from easily accessible precursor, reach in CF3-goups, which expected to have less impact and shorter environmental half-lives. (2) Novel methods for the synthesis of 3-perfluoroalkyl-propanols and –propenes were disclosed along with the uses of their synthetic intermediates. (3) New types of fluorous ionic liquids were synthesised based on imidazolium-salts. (4) Carbon-fluorinated carbon composite materials of Russian origin were applied as chemical reagents and transition metal catalyst support material (e.g. Pd/FUKM) . (5) Hiyama- and Heck-reactions with fluorous substrates were studied for a synthetic and mechanistic point of view. (6) Trifluoroiodomethane was used for improved S-alkylating processes. (7) Fluorous ionophores and electrochemical sensors were designed for the first time in co-operation with Prof. Bühlmann. (8) The structural requirements for a potential new fluorine-transfer reagent were identified and a Patentable process designed. This will allow the introduction of one, two or three fluorine atoms into target pharmaceutical molecules, and allow a shift from the fluorous to the fluorine chemistry (i.e. from F-building blocks to create C-F bonds). Please consider that some more publications are expected to appear only in the next year

    New data on geology of the Osborn Plateau, Indian Ocean

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    The Osborn Plateau is a large intraplate rise in the eastern part of the Indian Ocean, which has been poorly studied by the geological and geophysical methods. In cruise SO258/1 on the R/V Sonne, new data were collected using Parasound seismic profiling and a multibeam echo-sounder survey. Faults in the sedimentary cover, which extend to the bottom surface, indicate high neotectonic activity in the Osborn Plateau area. It may continue up to the present, as well as in the adjacent segment of the Ninetyeast Ridge, where strong earthquakes have been recorded. Two reflectors in the upper part of the sedimentary cover mark the global lowering of the World Ocean level at the Miocene/Pliocene and Pliocene/Pleistocene boundaries. The reflector in the sediments at the Lower/Upper Pliocene boundary is associated with a change in the regional hydrodynamic regime that occurred at that time in the eastern Indian Ocean. The rocks dredged on Osborn Plateau are identical to some volcanic rocks of the Ninetyeast Ridge, confirming their assumed genetic link, but they are more similar to the basalts of the Kerguelen Plateau. Extremely altered vitroclastic tuffs appear to have been formed as a result of explosive volcanic eruptions of alkali basalts or foidites under subaeral or relatively shallow water conditions and represent the most recent eruptions in the region

    A new limit of T-violating transverse muon polarization in the K+π0μ+νK^{+}\to\pi^{0}\mu^{+} \nu decay

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    A search for T-violating transverse muon polarization (PTP_T) in the K+π0μ+νK^{+}\to \pi^{0}\mu^{+}\nu decay was performed using kaon decays at rest. A new improved value, PT=0.0017±0.0023(stat)±0.0011(syst)P_T= -0.0017\pm 0.0023 (stat)\pm 0.0011 (syst), was obtained giving an upper limit, PT<0.0050| P_T | < 0.0050. The T-violation parameter was determined to be Imξ=0.0053±0.0071(stat)±0.0036(syst)\xi = -0.0053 \pm 0.0071(stat)\pm 0.0036(syst) giving an upper limit, |Imξ<0.016\xi| <0.016.Comment: 5 pages, 4 figure
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