[en] Some cosmic ray events with very large multiplicities and very high transverse momenta have recently been reported in balloon-borne emulsion chamber experiments. The explanation for these events by the standard approaches has become a bit problematical. An attempt has been made in this paper to understand and interpret them in the light of a dynamical model of multihadron production phenomena with power-law nature of average multiplicity and automatic scale-breaking derived in the model

[en] Under the likely scenario in which public support for nuclear energy remains low and fossil fuels continue to be abundant and cheap, government supported nuclear research centers must adapt their missions to ensure that they tackle problems of current significance. It will be critical to be multidisciplinary, to generate economic value, and to apply nuclear competencies to current problems. Addressing problems in nuclear safety, D and D, nuclear waste management, nonproliferation, isotope production are a few examples of current needs in the nuclear arena. Argonne's original mission, to develop nuclear reactor technology, was a critical need for the U.S. in 1946. It would be wise to recognize that this mission was a special instance of a more general one--to apply unique human and physical capital to long term, high risk technology development in response to society's needs. International collaboration will enhance the collective chances for success as the world moves into the 21st century

No abstract available

[en] Some crucial differences have been pinpointed between the observations made at the CERN pp-bar collider at Ssup(1/2) 540 GeV and pp reactions in the ISR range of energies and we have tried to analyse them in the light of a version of the sequential chain model (SCM). The conclusion is that all these differences are not simply the result of the difference of one order of magnitude in the CM energy between the two sets of experiments but, more importantly, due to other reasons connected with the constituent picture of hadrons and the consequent multiparticle dynamics as a whole. (author)

[en] The rising ratio of cosmic-ray positrons at ultra-high energies of interactions seems to have puzzled the theorists to a great extent. Here it has been made a somewhat successful attempt to interpret the behaviour of this ratio, R = e⁺/(e⁺ + e^-), by putting into use the main physical ideas from our two previous works. The importance and the implications of this observation have also been highlighted and emphasized in the proper background

[en] The aging of research reactors worldwide has resulted in a heightened awareness in the international technical decommissioning community of the timeliness to review and address the needs of these research institutes in planning for and eventually performing the decommissioning of these facilities. By using the reactors already undergoing decommissioning as test beds for evaluating enhanced or new/innovative technologies for decommissioning, it is possible that new techniques could be made available for those future research reactor decommissioning projects. Potentially, the new technologies will result in: reduced radiation doses to the work force, larger safety margins in performing decommissioning and cost and schedule savings to the research institutes in performing the decommissioning of these facilities. Testing of these enhanced technologies for decontamination, dismantling, characterization, remote operations and worker protection are critical to furthering advancements in the technical specialty of decommissioning. Furthermore, regulatory acceptance and routine utilization for future research reactor decommissioning will be assured by testing and developing these technologies in realistically contaminated environments prior to use in the research reactors. The decommissioning of the CP-5 Research Reactor is currently in the final phase of dismantlement. In this paper the authors present results of work performed at Argonne National Laboratory (ANL) in the development, testing and deployment of innovative and/or enhanced technologies for the decommissioning of research reactors

[en] Differential cross-sections for excitation of helium from ground state to 2S excited singlet state by electron impact at 29.6, 40.1, 44, 81.63 and 200eV have been calculated using quantum electrodynamics. The results are found to agree fairly well with the experimental observations. (author)

[en] Toxicity of oil and diesel fuel to freshwater biota may be increased by use of oil spill cleaning agents. - Toxicity and temporal changes in toxicity of freshwater-marsh-microcosms containing South Louisiana Crude (SLC) or diesel fuel and treated with a cleaner or dispersant, were investigated using Chironomus tentans, Daphnia pulex, and Oryzias latipes. Bioassays used microcosm water (for D. pulex and O. latipes) or soil slurry (for C. tentans) taken 1,7, 31, and 186 days after treatment. SLC was less toxic than diesel, chemical additives enhanced oil toxicity, the dispersant was more toxic than the cleaner, and toxicities were greatly reduced by day 186. Toxicities were higher in the bioassay with the benthic species than in those with the two water-column species. A separate experiment showed that C. tentans' sensitivity was intermediate to that of Tubifex tubifex and Hyallela azteca. Freshwater organisms, especially benthic invertebrates, thus appear seriously effected by oil under the worst-case-scenario of our microcosms. Moreover, the cleaner and dispersant tested were poor response options under those conditions

[en] In recent times have been widespread speculations and claims among the cosmic-ray as well as high-energy physicists about the detection of some 'signatures' for the formation of what one calls the quark-gluon plasma states in the ultrahigh-energy cosmic-ray collisions involving heavy nuclei. Furthermore, there are reportedly some hints to the detection of such states in laboratory experiments as well. What are, in general, believed to be the diagnostics for such quark-gluon plasma states are collected here and alternative explanations for all the relevant observations at laboratory energies and cosmic-ray energies are also provided. Thus the obvious conclusion is: the evidences claimed so far are neither unique and decisive nor are very substantial, tenable and conclusive, as one can understand them almost completely from an altogether different theoretical framework

[en] Relaxor thin films of Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT) with different microstructures have been grown on platinum-coated silicon substrate using pulsed excimer laser ablation technique. The microstructure of the thin films was found to be strongly influenced by the substrate temperature and the substrate microstructure. An intermediate layer of La_0.5Sr_0.5CoO₃ (LSCO) was deposited on the platinum-coated silicon substrate prior to the deposition of the (PMN-PT) thin films. We found that the both the microstructure and perovskite phase in the PMN-PT thin films could be controlled by monitoring the substrate temperature along with the microstructure of the template layer. The dielectric properties of the films with different microstructure were studied as a function frequency over a wide range of temperatures. A direct impact of the microstructure on relaxor properties has been observed in the present case