AuNx stabilization with interstitial nitrogen atoms: A Density Functional Theory Study

Researchers have been studying 4d and 5d Series Transition Metal Nitrides lately as a result of the experimental production of AuN, PtN, CuN. In this paper, we used the Density Functional Theory (DFT) implementing a pseudopotential plane-wave method to study the incorporation of nitrogen atoms in the face-centered cube (fcc) lattice of gold (Au). First, we took the fcc structure of gold, and gradually located the nitrogen atoms in tetrahedral (TH) and octahedral (OH) interstitial sites. AuN stabilized in: 2OH (30%), 4OH and 4TH (50%), 4OH - 2TH (close to the wurtzite structure) and 6TH (60%). This leads us to think that AuN behaves like a Transition Metal Nitride since the nitrogen atoms look for tetrahedral sites. © Published under licence by IOP Publishing Ltd

The cluster environments of radio-loud AGN

Copyright IAURadio-loud AGN play an important role in galaxy evolution. We need to understand their properties, and the processes that affect their behaviour in order to model galaxy formation and development. We here present preliminary results of an investigation into the cluster environments of radio galaxies. We have found evidence of a strong correlation between radio luminosity and environment richness for low excitation radio galaxies, and no evidence of evolution of the environment with redshift. Conversely, for high excitation radio galaxies, we found no correlation with environment richness, and tentative evidence of evolution of the cluster environment

A compartive study of the retentive capability of the Sydney mini-screw with 6mm orthodontic anchorage miniscrews in the tibia and femur of New Zealand rabbits by removal torque test

Aim: To investigate the retentive capability of the Sydney Mini-screw with injectable bone cement by removal torque. Method: 16 New Zealand White rabbits were divided evenly into 2 groups, T1 0 week to assess primary stability and T2 8 weeks to test secondary stability. Three groups of miniscrews Sydney Mini-screw with Cement (SMSC) N=12, Sydney Miniscrew without cement (SMS) N=10 and control Aarhus (CA) 6mm screw N=10 were placed randomly and evenly between the right and left tibial and femoral sites. The SMSC and SMS required predrilling of a pilot hole and the SMSC had injectable bone cement PRODENSE. Removal torque was measured and Friedman's Test and two-sample t-test were used for statistical analysis, where appropriate. Results: Removal torque values at T1 for CA, SMS, SMSC were not significantly different (p=0.072) but were significantly different at T2 (p=0.012). Only SMS (p=0.006) showed statistically significant difference between T1 and T2. The different surgical locations at T2 did not statistically differ from each other either (p=0.948). Conclusion: Sydney Miniscrew with and without cement had significantly higher secondary stability and had a trend towards increased primary compared to a normal control miniscrew. More research is required with an increased sample size

SPECIFICATIONS FOR FUEL ASSEMBLIES FOR CORE I OF THE EXPERIMENTAL GAS- COOLED REACTOR

Specifications for the fuel assemblies Experimental Gas Cooled Reactor (EGCR) Core-I were developed for use in procuring the first core loading. A fuel assembly for the EGCR consists of a cluster of seven cylindrical fuel elements spaced and supported within a graphite sleeve. Each fuel element consists of a stainless-steel tube containing a column of hollow UO/sub 2/ pellets and having a spacer brazed at the midsection to control the spacing between fuel elements in a cluster. A master specification for the fuel assembly, a supplementary specification for each of the components, and a specification on record keeping daring manufacture are included. (auth

Criticality and Bifurcation in the Gravitational Collapse of a Self-Coupled Scalar Field

We examine the gravitational collapse of a non-linear sigma model in spherical symmetry. There exists a family of continuously self-similar solutions parameterized by the coupling constant of the theory. These solutions are calculated together with the critical exponents for black hole formation of these collapse models. We also find that the sequence of solutions exhibits a Hopf-type bifurcation as the continuously self-similar solutions become unstable to perturbations away from self-similarity.Comment: 18 pages; one figure, uuencoded postscript; figure is also available at http://www.physics.ucsb.edu/people/eric_hirschman