The results of two experiments designed to synthesize element 115 isotopes in the 243 Am + 48 Ca reaction are presented. Two new elements with atomic numbers 113 and 115 were observed for the first time. With 248-MeV 48 Ca projectiles, we observed three similar decay chains consisting of five consecutive α decays, all detected in a total time interval of 30 s. Each chain was terminated by a spontaneous fission (SF) with a high-energy release and a lifetime of about a day. With 253-MeV 48 Ca projectiles, we registered a different decay chain of consecutive α decays detected in a time interval of 0.5 s, also terminated by spontaneous fission, but after 1.8 h. The decay properties of the eleven new αand SF-decaying nuclei are consistent with expectations for consecutive α decays originating from the parent isotopes 288 115 and 287 115, produced in the 3n-and 4n-evaporation channels, respectively. Support for the assignment of the atomic numbers of all of the nuclei in the 288 115 decay chain was obtained in an independent experiment in which a long-lived spontaneous fission activity, 268 Db (15 events), was found to be chemically consistent with the fifth group of the periodic table. The odd-odd isotope 288 115 was observed with largest cross section of about 4 pb. In the SF decay of 268 Db, a total kinetic energy of 230 MeV and a neutron multiplicity per fission of 4.2 were measured. The decay properties of the 11 new isotopes with Z = 105-115 and the production cross sections are in agreement with modern concepts of the role of nuclear shells in the stability of superheavy nuclei. The experiments were carried out at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research.

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Application of ultrasound and ball milling produces micrometer‐sized crystallites of tris‐(o‐phenylenedioxy)‐cyclotriphosphazene (TPP) that show zeolite‐like reversible sorption of I2 and CH3I (methyl iodide). The thermal stability of open‐pore TPP is improved by partial loading with pyrazine. The sorption properties of open‐pore TPP are investigated by the 131I radioactive tracer method. Comparison with activated charcoal (ACC) shows that TPP has a higher sorption efficiency for I2 dissolved in water than ACC. In the case of a humid gaseous source of CH3I also, TPP exhibits better sorption properties than ACC. Partial loading of open‐pore TPP by pyrazine increases its thermal stability by 50 °C and the binding properties for retaining CH3I are also improved. Force‐field calculations show a difference of ΔE ≈ 20 kJ mol–1, making the open‐pore system less stable than the apohost.

The distribution coefficients of Zr, Hf, Nb, Ta, Mo, W, and Pa on cation and anion exchange resins from mixed HCl/HF solutions were determined in batch experiments by radiometric measurements. From solutions of 0.05 to 0.1 M HCl with 1.0 X10"' M HF a Separation of subgroup V and VI from subgroup IV Clements is possible on DOWEX 50X8. This system is proposed for the fast on-line Separation of the Clements 105 and 106. In column experiments with cation exchangers W can be separated from Mo. This opens the possibility to determine the chemical behaviour of element 106 in comparison to the lighter homologs. Differenccs in the Sorption behaviour of Ta, Nb and Pa on cation exchange resins from 0.1 M HCl/2.0 X10"" M HF Solution should allow a Statement as to which of these Clements, element 105 has the highest similarity.

Iodine is a biologically important trace element. Its behaviour in the environment and in human metabolism is determined by the type of iodine species which takes part in chemical reactions. Knowledge of their concentrations is necessary to understand and describe the iodine reaction paths. A separation procedure is proposed for quick determination of common forms of iodine-iodide, iodate ions, molecular iodine and organoiodine (in the form of CH(3)I). The procedure consists of sequential sorption by passing the sample solution first through a solid-phase extraction cartridge to separate I(2) and CH(3)I from IO(3)(-) and I(-) then through an anion-exchange resin in a cartridge to retain the latter two species. Each loaded cartridge is eluted to separate the sorbed pair of species. Concentration determination of the resulting four solutions can be performed by standard methods, e.g. by spectrophotometry, tracer counting or with ion-selective electrodes.