Evaluation of EC Comparison on the Determination of 226Ra, 228Ra, 234U and 238U in Mineral Waters

This report describes all details of the comparison for the determination of 226Ra, 228Ra, 234U and 238U in mineral waters among 45 European laboratories monitoring radioactivity in food and the environment. Three commercially available mineral waters were provided as comparison samples. Reference values of the four radionuclides under study in this comparison were determined in collaborative work of IRMM and the Bundesamt für Strahlenschutz (BfS), using tracer techniques and standardised radionuclide solutions. The reference values are thus traceable to the SI units. The sample preparation and measurement processes applied in the participating laboratories are described and the results of the comparison are presented and discussed in detail. Whereas, in general, the measurement results for the uranium isotopes show a relatively favourable agreement with the reference value, the results of this comparison point at severe problems of 226Ra and 228Ra determination in about one fourth and more than one third of the laboratories, respectively. For radium, 19 results corresponding to 14 % of all are even off by a factor of two or more. By comparison, for uranium, this number amounts to 6 % (9 results out of 150). Nevertheless, also for the determination of uranium, 14 % to 23 % of the laboratories report results not compliant with the En evaluation criterion. The corresponding participants are urgently requested to investigate and revise their analytical methods.JRC.D.4-Nuclear physic

Magnetic phase transitions in Ta/CoFeB/MgO multilayers

We study thin films and magnetic tunnel junction nanopillars based on Ta/Co$_{20}$Fe$_{60}$B$_{20}$/MgO multilayers by electrical transport and magnetometry measurements. These measurements suggest that an ultrathin magnetic oxide layer forms at the Co$_{20}$Fe$_{60}$B$_{20}$/MgO interface. At approximately 160 K, the oxide undergoes a phase transition from an insulating antiferromagnet at low temperatures to a conductive weak ferromagnet at high temperatures. This interfacial magnetic oxide is expected to have significant impact on the magnetic properties of CoFeB-based multilayers used in spin torque memories

Atypical work and unemployment protection in Europe

This paper evaluates the degree of income protection the tax-benefit system provides to atypical workers in the event of unemployment. Our approach relies on simulating transitions from employment to unemployment for the entire workforce in EU member states to compare household financial circumstances before and after the transition. Our results show that coverage rates of unemployment insurance are low among atypical workers, who are also more exposed to the risk of poverty, both while in work and in unemployment. Low work intensity employees are characterized by high net replacement rates. However, this is due to the major role played by market incomes of other household members. Finally, we show that in countries where self-employed workers are not eligible for unemployment insurance benefits, extending the eligibility to this group of workers would increase their replacement rates and make them less likely to fall into poverty in the event of unemployment

Enhanced biomedical heat-triggered carriers via nanomagnetism tuning in ferrite-based nanoparticles

Biomedical nanomagnetic carriers are getting a higher impact in therapy and diagnosis schemes while their constraints and prerequisites are more and more successfully confronted. Such particles should possess a well-defined size with minimum agglomeration and they should be synthesized in a facile and reproducible high-yield way together with a controllable response to an applied static or dynamic field tailored for the specific application. Here, we attempt to enhance the heating efficiency in magnetic particle hyperthermia treatment through the proper adjustment of the core–shell morphology in ferrite particles, by controlling exchange and dipolar magnetic interactions at the nanoscale. Thus, core–shell nanoparticles with mutual coupling of magnetically hard (CoFe2O4) and soft (MnFe2O4) components are synthesized with facile synthetic controls resulting in uniform size and shell thickness as evidenced by high resolution transmission electron microscopy imaging, excellent crystallinity and size monodispersity. Such a magnetic coupling enables the fine tuning of magnetic anisotropy and magnetic interactions without sparing the good structural, chemical and colloidal stability. Consequently, the magnetic heating efficiency of CoFe2O4 and MnFe2O4 core–shell nanoparticles is distinctively different from that of their counterparts, even though all these nanocrystals were synthesized under similar conditions. For better understanding of the AC magnetic hyperthermia response and its correlation with magnetic-origin features we study the effect of the volume ratio of magnetic hard and soft phases in the bimagnetic core−shell nanocrystals. Eventually, such particles may be considered as novel heating carriers that under further biomedical functionalization may become adaptable multifunctional heat-triggered nanoplatforms

Magnetic hardening of Fe30Co70nanowires

3d transition metal-based magnetic nanowires (NWs) are currently considered as potential candidates for alternative rare-earth-free alloys as novel permanent magnets. Here, we report on the magnetic hardening of FeConanowires in anodic aluminium oxide templates with diameters of 20 nm and 40 nm (length 6 μm and 7.5 μm, respectively) by means of magnetic pinning at the tips of the NWs. We observe that a 3-4 nm naturally formed ferrimagnetic FeCo oxide layer covering the tip of the FeCo NW increases the coercive field by 20%, indicating that domain wall nucleation starts at the tip of the magnetic NW. Ferromagnetic resonance (FMR) measurements were used to quantify the magnetic uniaxial anisotropy energy of the samples. Micromagnetic simulations support our experimental findings, showing that the increase of the coercive field can be achieved by controlling domain wall nucleation using magnetic materials with antiferromagnetic exchange coupling, i.e. antiferromagnets or ferrimagnets, as a capping layer at the nanowire tips.We acknowledge funding from the European Community's Seventh Framework Programme (FP7-NMP) under grant agreement no. 280670 (REFREEPERMAG)