Saturation of swelling in neutron irradiated molybdenum and its dependence on irradiation temperature and starting microstructural state

Molybdenum and its alloys are of interest for potential fusion application due to their high melting point and relatively good thermal conductivities. The development of void superlattices during neutron irradiation appears to limit void swelling in pure molybdenum to values below 4% over a wide range of irradiation temperatures. The saturation value of swelling and the void superlattice parameter each appear to be somewhat dependent on temperature, but independent of the thermomechanical starting state. Formation of technetium and ruthenium by transmutation may also play some minor role in the microstructural evolution, but do not appear to be involved in the limitation of swelling

Nanosecond electric pulses penetrate the nucleus and enhance speckle formation

Nanosecond electric pulses generate nanopores in the interior membranes of cells and modulate cellular functions. Here, we used confocal microscopy and flow cytometry to observe Smith antigen antibody (Y12) binding to nuclear speckles, known as small nuclear ribonucleoprotein particles (snRNPs) or intrachromatin granule clusters (IGCs), in Jurkat cells following one or five 10 ns, 150 kV/cm pulses. Using confocal microscopy and flow cytometry, we observed changes in nuclear speckle labeling that suggested a disruption of pre-messenger RNA splicing mechanisms. Pulse exposure increased the nuclear speckled substructures by 2.5-fold above basal levels while the propidium iodide (PI) uptake in pulsed cells was unchanged. The resulting nuclear speckle changes were also cell cycle dependent. These findings suggest that 10 ns pulses directly influenced nuclear processes, such as the changes in the nuclear RNA–protein complexes

Lower Mississippian Cephalopods of Michigan. Part III. Ammonoids and Summary

113-173http://deepblue.lib.umich.edu/bitstream/2027.42/48293/2/ID133.pd

Irradiation of copper alloys in FFTF

Nine copper-base alloys in thirteen material conditions have been inserted into the MOTA-18 experiment for irradiation in FFTF at approx.450/sup 0/C. The alloy Ni-1.9Be is also included in this experiment, which includes both TEM disks and miniature tensile specimens

Radiation-induced evolution of austenite matrix in silicon-modified AISI 316 alloys

The microstructures of a series of silicon-modified AISI 316 alloys irradiated to fast neutron fluences of about 2-3 and 10 x 10/sup 22/ n/cm/sup 2/ (E > 0.1 MeV at temperatures ranging from 400/sup 0/C to 600/sup 0/C have been examined. The irradiation of AISI 316 leads to an extensive repartition of several elements, particularly nickel and silicon, between the matrix and various precipitate phases. The segregation of nickel at void and grain boundary surfaces at the expense of other faster-diffusing elements is a clear indication that one of the mechanisms driving the microchemical evolution is the Inverse Kirkendall effect. There is evidence that at one sink this mechanism is in competition with the solute drag process associated with interstitial gradients

Lower Mississippian Cephalopods of Michigan. Part I. Orthoconic Nautiloids

159-192http://deepblue.lib.umich.edu/bitstream/2027.42/48270/2/ID109.pd

DAFS contribution: the influence of dislocation density and radiation on carbon activity and phase development in AISI 316. [LMFBR]

The objective of this effort is to identify the role of each major element in the microchemical evolution of AISI 316 and the dependence of that role on preirradiation treatment and parameters such as neutron energy and flux, temperature and stress

Low-energy quenching of positronium by helium

Very low-energy scattering of orthopositronium by helium has been investigated for simultaneous study of elastic cross section and pick-off quenching rate using a model exchange potential. The present calculational scheme, while agrees with the measured cross section of Skalsey et al, reproduces successfully the parameter ^ 1Z_{\makebox{eff}}, the effective number of electrons per atom in a singlet state relative to the positron. Together with the fact that this model potential also leads to an agreement with measured medium energy cross sections of this system, this study seems to resolve the long-standing discrepancy at low energies among different theoretical calculations and experimental measurements.Comment: 4 latex pages, 3 postscript figure

Collapse of Amphibian Communities Due to an Introduced Ranavirus

This work was supported by Natural Environment Research Council grant NE/G011885/1, the Systematics and Taxonomy (SynTax) research scheme administered by the Linnean Society of London, the Fundación General CSIC, Banco Santander, and European Research Council grant 260801-BIG-IDE