The formation and growth of sigma phase in 2205 duplex stainless steel was observed and measured in real time using synchrotron radiation during 10 hr isothermal heat treatments at temperatures between 700 C and 850 C. Sigma formed in near-equilibrium quantities during the isothermal holds, starting from a microstructure which contained a balanced mixture of metastable ferrite and austenite. In situ synchrotron diffraction continuously monitored the transformation, and these results were compared to those predicted by thermodynamic calculations. Differences between the calculated and measured amounts of sigma, ferrite and austenite suggest that the thermodynamic calculations underpredict the sigma dissolution temperature by approximately 50 C. The data were further analyzed using a modified Johnson-Mehl-Avrami (JMA) approach to determine kinetic parameters for sigma formation over this temperature range. The initial JMA exponent, n, at low fractions of sigma was found to be approximately 7.0, however, towards the end of the transformation, n decreased to values of approximately 0.75. The change in the JMA exponent was attributed to a change in the transformation mechanism from discontinuous precipitation with increasing nucleation rate, to growth of the existing sigma phase after nucleation site saturation occurred. Because of this change in mechanism, it was not possible …

The experimental and theoretical status of the ''near perfect fluid'' at RHIC is discussed. While the hydrodynamic paradigm for understanding collisions at RHIC is well established, there remain many important open questions to address in order to understand its relevance and scope. It is also a crucial issue to understand how the early equilibration is achieved, requiring insight into the active degrees of freedom at early times.

We examine the utility of very high redshift Type Ia supernovae for cosmology and systematic uncertainty control. Next generation space surveys such as the Supernova/Acceleration Probe (SNAP) will obtain thousands of supernovae at z>1.7, beyond the design redshift for which the supernovae will be exquisitely characterized. We find that any z gtrsim 2 standard candles' use for cosmological parameter estimation is quite modest and subject to pitfalls; we examine gravitational lensing, redshift calibration, and contamination effects in some detail. The very high redshift supernovae - both thermonuclear and core collapse - will provide copious interesting information on star formation, environment, and evolution. However, the new observational systematics that must be faced, as well as the limited expansion of SN-parameter space afforded, does not point to high value for 1.7<z<3 SNe Ia in controlling evolutionary systematics relative to what SNAP can already achieve at z<1.7. Synergy with observations from JWST and thirty meter class telescopes afford rich opportunities for advances throughout astrophysics.

The PHENIX Experiment at the Relativistic Heavy Ion Collider has conducted a survey of fluctuations in charged hadron multiplicity in Au+Au and Cu+Cu collisions at {radical}s{sub NN} = 22, 62, and 200 GeV. A universal power law scaling for multiplicity fluctuations expressed as {sigma}{sup 2}/{mu}{sup 2} is observed as a function of N{sub part} for all species studied that is independent of the transverse momentum range of the measurement. PHENIX has also measured transverse momentum correlation amplitudes in p+p, d+Au, and Au+Au collisions. At low transverse momentum, significant differences in the correlations between the baseline p+p and d+Au data and the Au+Au data are presented.

The systematics of bulk entropy production in experimental data on Ai-A, p + y and e{sup +}e{sup -} interactions at high energies and large {mu}{sub B} is discussed. It is proposed that scenarios with very early thermalization, such as Landau's hydrodynamical model, capture several essential features of the experimental results. It is also pointed out that the dynamics of systems which reach the hydrodynamic regime give similar multiplicities and angular distributions as those calculated in weak-coupling approximations (e.g. pQCD) over a wide range of beam energies. Finally, it is shown that the dynamics of baryon stopping are relevant to the physics of total entropy production, explaining why A+A and e{sup +}e{sup -} multiplicities are different at low beam energies.

The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) is a collaboration of Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, and Princeton Plasma Physics Laboratory. These laboratories, in cooperation with researchers at other institutions, are carrying out a coordinated effort to apply intense ion beams as drivers for studies of the physics of matter at extreme conditions, and ultimately for inertial fusion energy. Progress on this endeavor depends upon coordinated application of experiments, theory, and simulations. This paper describes the state of the art, with an emphasis on the coordination of modeling and experiment; developments in the simulation tools, and in the methods that underly them, are also treated.

We describe a receiver that performs optical code division multiple access (O-CDMA) decoding followed by pulse position modulation (PPM) symbol detection that behaves like a radar quadrant receiver. Simulations determine the impact of multi-access interference on symbol detection for up to 32 users.

We report the results of first-principles calculations of the Young's modulus and other mechanical properties of hydrogen-passivated Si <001> nanowires. The nanowires are taken to have predominantly {l_brace}100{r_brace} surfaces, with small {l_brace}110{r_brace} facets according to the Wulff shape. The Young's modulus, the equilibrium length and the constrained residual stress of a series of prismatic beams of differing sizes is found to have a size dependence that scales like the surface area to volume ratio for all but the smallest beam. The results are compared with two different models (and the results of classical atomistic calculations based on an empirical potential). We discuss the physics of the hydrogen interactions on the surface and the charge density variations within the beam that may account for the discrepancies of the models and the first principles results.

Elucidating the relationship between polymorphic sequences and risk of common disease is a challenge. For example, although it is clear that variation in DNA repair genes is associated with familial cancer, aging and neurological disease, progress toward identifying polymorphisms associated with elevated risk of sporadic disease has been slow. This is partly due to the complexity of the genetic variation, the existence of large numbers of mostly low frequency variants and the contribution of many genes to variation in susceptibility. There has been limited development of methods to find associations between genotypes having many polymorphisms and pathway function or health outcome. We have explored several statistical methods for identifying polymorphisms associated with variation in DNA repair phenotypes. The model system used was 80 cell lines that had been resequenced to identify variation; 191 single nucleotide substitution polymorphisms (SNPs) are included, of which 172 are in 31 base excision repair pathway genes, 19 in 5 anti-oxidation genes, and DNA repair phenotypes based on single strand breaks measured by the alkaline Comet assay. Univariate analyses were of limited value in identifying SNPs associated with phenotype variation. Of the multivariable model selection methods tested: the easiest that provided reduced error of prediction of …

In this report we discuss the capabilities and limitations of the STAR detector to search for signatures of the QCD critical point in a low energy scan at RHIC. We find that a RHIC low energy scan will cover a broad region of interest in the nuclear matter phase diagram and that the STAR detector--a detector designed to measure the quantities that will be of interest in this search--will provide new observables and improve on previous measurements in this energy range.