[en] In this letter, the authors report transport measurements with field and current parallel to the b axis (perpendicular to the conducting plane) in the organic superconductor κ-(BEDT-TTF)₂Cu[N(CN)₂]Br. The isothermal magnetoresistance R(H) displays a peak effect as a function of field. The peak resistance is substantially larger than that in large fields. The results are in sharp contrast to the conventional dissipation mechanisms in the mixed state of anisotropic superconductors, as in the case of Bi₂Sr₂CaCu₂O₈. Comparison with H_c2(T) obtained from magnetic measurements shows that the peak effect in R(H) occurs in the mixed state. Analysis of the data suggests a much larger Josephson junction resistance in the mixed state than that in the normal state, indicative of a new charge transport scattering mechanism in the presence of vortices

[en] The US Department of Energy (DOE) Deputy Assistant Secretary of Energy for Environmental Management has issued a challenge to complete DOE environmental cleanup within a decade. The response for Oak Ridge facilities is in accordance with the DOE ten-year plan which calls for completion of > 95% of environmental management work by the year 2006. This will result in a 99% risk reduction and in a significant savings in base line costs in waste management (legacy waste); remedial action (groundwater, soil, etc.); and decontamination and decommissioning (D and D). It is assumed that there will be long-term institutional control of cascade equipment, i.e., there will be no walk away from sites, and that there will be firm radioactivity release limits by 1999 for recycle metals. An integral part of these plants is the removal of uranium deposits which pose nuclear criticality safety concerns in the shut down of the Oak Ridge Gaseous Diffusion Plant. DOE has initiated the Nuclear Criticality Stabilization Program to improve nuclear criticality safety by removing the larger uranium deposits from unfavorable geometry equipment. Nondestructive assay (NDA) measurements have identified the location of these deposits. The objective of the K-25 Site Nuclear Criticality Stabilization Program is to remove and place uranium deposits into safe geometry storage containers to meet the double contingency principle. Each step of the removal process results in safer conditions where multiple controls are present. Upon completion of the Program, nuclear criticality risks will be greatly reduced

[en] ¹³⁷Cs, produced as a by-product of the atmospheric testing of thermonuclear weapons during the period extending from the 1950s to the 1970s, was distributed globally within the stratosphere and deposited as wet and/or dry fallout. The last great amount of radioactive caesium was deposited on the earth surface after Chernobyl accident. Significant variations in caesium activity levels in soils are caused by Chernobyl-derived fallout with relatively short period of contamination and great variabilities in activity and/or quantity of rainfall. However, total weapon testing-derived caesium pollution can be treated as generally uniform, i.e., numerous events over an extended period that minimise any local variation. Meanwhile, caesium, as well as the other radionuclides that behave like cations, can be moved upward by plant's uptake depending on various factors: plant species, sorption and desorption processes in soil, mineral soil composition, grain size and soil types, lateral caesium migration, etc. Certain plant species are known as caesium pollution indicators, but the uptake by an individual plant can be very different

[en] Because of the long distance between Guatemala and Chernobyl, the country did not undergo direct consequences of radioactive contamination in the short term. However, the accident repercussions were evident in the medium and long-term, mainly in two sectors, the economic-political and the environmental sectors

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[en] Influence of ionizing radiation on forest ecosystems most clearly revealed itself near the Chernobyl NPP (ChNPP), were magnitudes of absorbed doses reached 'lethal' values, as applied to conifers. Main contribution to absorbed dose was due to beta-radiation of short-living radionuclides. To largest extent the radiobiological effects appeared at injured plantations of pines and firs. Nevertheless, during the first year maximum absorbed doses influenced also on leaf-bearing trees (birch, alder, asp) which then rehabilitated themselves completely

[en] Honey bee and the products (honey, pollen, wax, propolis) are generally considered as efficient bioindicators of the environmental pollution. Honey bee activity upon a territory is well defined both in space and time and honey bee itself is easier to control than other animal bioindicators (birds, fish, wild animals). Networks of bee hives near nuclear and industrial installations are therefore often used for, environment pollution research and control. The investigations started in 1983/84. Gamma exposure and Cs-137 activity measurements provided information on ''zero status'' of the radioecological situation in the region. During the nuclear plant accident at Chernobyl in April 1986 and afterworks through the year, over two hundred samples of honey, grass and meadow flora have been examined. Investigations of the radioactivity in soils, meadow flora and honey in the region continued up to 1991 and afterwards. The vertical distribution of Cs-134 and Cs-137 in different soils provided data on the migration rate through soil and on concentration factors for different phases of the ''soil-plant-honey'' ecosystem

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