Sulfur segregation to the surface poses a perplexing problem in basic research on low surface area nickel materials. In addition sulfur effectively poisons catalytic reactions involving CO adsorption on nickel as well as other transition metal catalysts in technically important processes such as methanation and Fischer-Tropsch synthesis. It is not surprising then that considerable attention has...

The confrontation between General Relativity and experimental results, notably binary pulsar data, is summarized and its significance discussed. The agreement between experiment and theory is numerically very impressive. However, some recent theoretical findings (existence of non-perturbative strong-field effects, natural cosmological attraction toward zero scalar couplings) suggest that the pr...

Ab initio molecular dynamics calculations of deuterium desorbing from Si(100) have been performed in order to monitor the energy redistribution among the hydrogen and silicon degrees of freedom during the desorption process. The calculations show that part of the potential energy at the transition state to desorption is transferred to the silicon lattice. The deuterium molecules leave the surfa...

Q: How long w i l l i t be before this rou nd o f dow nsiz ing is completed? A: What you arc seeing now is the be g inn ing 'o f the second wave o f downsizing, w h ich really was formalized by the revo lt in Iran. We already had started on the downsiz­ ing. The j cars had already been en­ gineered. We increased the capacity o f those cars — we changed all the plans at that point. W e'll start ...

The chemical and mechanical properties of extracellular matrices (ECMs) modulate diverse aspects of cellular fates; however, how regional heterogeneity in ECM composition regulates developmental programs is not well understood. We discovered that fibronectin 1 (Fn1) is expressed in strikingly non-uniform patterns during mouse development, suggesting that regionalized synthesis of the ECM plays ...

Family Planning Perspectives riculum of its kind. It is brief and takes up little class time and, given its focus on postponing sex, has broad appeal to parents and schools. Moreover, an Atlanta-based evaluation of the PSI program implemented in combination with a five-session human sexuality course suggested that the curriculum delayed the initiation of first intercourse.2 However, serious que...

Here I indulge in wide-ranging speculations on the shape of physics, and technology closely related to physics, over the next one hundred years. Themes include the many faces of unification, the re-imagining of quantum theory, and new forms of engineering on small, intermediate, and large scales. When Leon Cooper, on behalf of Brown University, asked me to contribute to their 250th anniversary ...

Recently, Van Noorden, Maher, and Nuzzo (2014) published a list of papers which are among the 100 most highly cited papers of all time. This letter argues that such a list should not be produced on the base of bare citation counts, but normalized bibliometric indicators – the standard in bibliometrics.

95 THE CANADIAN HIGHWAY NETwork consists mainly of two-lane highways where passing slower cars requires traveling in the lane assigned to the opposite traffic. Therefore, studying the mechanism of the passing maneuver is important for maintaining traffic safety, as well enhancing the highway’s level of service. Models for passing maneuvers are available in the design guides1,2 while different v...