Nickel clusters embedded in carbon nanotubes as high performance magnets

Ensembles of fcc nickel nanowires have been synthesized with defined mean sizes in the interior of single wall carbon nanotubes. The method allows the intrinsic nature of single domain magnets to emerge with large coercivity as their size becomes as small as the exchange length of nickel. By means of X ray magnetic circular dichroism we probe electronic interactions at nickel carbon interfaces where nickel exhibit no hysteresis and size dependent spin magnetic moment. A manifestation of the interacting two subsystems on a bulk scale is traced in the nanotube s magnetoresistance as explained within the framework of weak localizatio

Cs content and concentration factors in benthic organisms in the dump sites for solid radioactive waste in the Kara Sea

Radioactive contamination was studied in macrobenthic invertebrates and algae of the Abrosimov, Stepovoy and Tsivolky Bays of the Novaya Zemlya Archipelago and the adjacent regions of the Kara Sea during the cruises 73d and 81st on board R/V Professor Shtokman in the years 2005–2006. Maximum concentration 137Cs in sediment in studied area has been detected in the layer 10–12 cm in the Abrosimov Bay (150 Bq/kg) and in the layer 4–6 cm in the Stepovoy Bay (100 Bq/kg). Concentration of 137Cs in benthos was up to 3.19 Bq/kg of wet weight. The highest concentration has been found in benthos of the Abrosimov and Stepovoy Bays: the holothurian Myriotrochus rinkii, the isopod Saduria sabini, ophiuroids Ophiocten sericeum and Stegophiura nodosa. Myriotrochus rinkii, Saduria sabini and the brown alga Laminaria saccharina were characterized by the highest 137Cs concentration factor – 994, 599 and 425 respectively. Caesium-137 contamination occurs locally in the studied area closed to the radioactive waste disposal and does not affect on qualitative structure of the macrobenthic communities

(Table 1) Cesium-137 concentrations and salinity in surface waters from the Atlantic and Pacific Oceans in January-May 1978

Cesium-137 concentrations of surface waters were measured during Cruise 20 of R/V Dmitry Mendeleev across the Atlantic and Pacific Oceans. The measurements were combined with simultaneous salinity measurements. The radioactivity field of surface waters is governed by presence of closed circulation systems and their component currents. Crossing the oceans from west to east decrease in cesium-137 concentrations was noted. In surface waters in the northeastern periphery of the southern anticyclonic gyre in the Pacific Ocean Cs-137 concentrations increased (up to 21.5 Bq/m**3) due to a series of nuclear tests on the Muroroa Atoll

(Table 1) Concentrations of phosphorus- and nitrogen forms in the near-bottom layer of the Baltic Sea

Nitrogen and phosphorus compounds in the near-bottom layer and interstitial waters in sediments of the Baltic Sea were studied. Statistical analysis of data revealed that variability of hydrochemical conditions in regions of fluid fluxes is higher than in regions without such fluxes. Hydrochemical conditions (concentrations of mineral phosphorus and ammonia in the near-bottom layer) in locations of fluid fluxes appeared to depend on intensity of these fluid fluxes. Influence of the fluid fluxes on formation of the hydrochemical structure and specific conditions is discussed