Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. To support detection instruments, we are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. We are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Sample preparation functions are accomplished with acoustic radiation pressure, dielectrophoresis, and solid phase extraction. We are integrating these technologies into packaged systems with pumps and valves to control fluid flow and investigating small-scale detection methods.

The solution of hydrogen and hydride formation in FCC substitutional solid solution Pd0.9Rh0.1-xAlx alloys have been examined. In contrast to some other Pd ternary alloys, a linear relation does not obtain between the H capacity and x for the Pd0.9Rh0.1-xAlx alloys investigated here where the H capacity of the alloys is estimated from the H content of the steeply rising part of the isotherms in the hydride phase regions. A linear increase of the dilute phase H solubility with x for these Pd0.9Rh0.1-xAlx alloys does, however, obtain for these alloys. Although Pd-Rh binary alloys have broader plateaux than does Pd itself, small amounts of Al substituted into Pd0.85Rh0.15 or Pd0.80Rh0.20 alloys can reduce or eliminate the two phase regions, the plateaux; there is, however, not much effect on the dilute phase solubilities. For example, small amounts of Al substituted into the Pd0.85Rh0.15 or Pd0.80Rh0.20 alloys eliminate the plateaux. On the other hand, alloying Pd with Al to form binary alloys with Xal equals 0.015 or 0.030 does not eliminate the plateaux which are present in these binary alloys up to Xal equals 0.075 (298 K). Small amounts of Al substitution do not have such a dramatic effect on the plateau …

The major emphasis of Public Key Infrastructure has been to provide a cryptographically secure means of authenticating identities. While there are a number of proposed standards for authorization structures and protocols based on X.509 or other key-based identities, none have been widely adopted. As part of an effort to use X.509 identities to provide authorization in highly distributed environments, we have developed and deployed an authorization service based on X.509 identified users and access policy contained in certificates signed by X.509 identified stakeholders. The major goal of this system, called Akenti, is to produce a usable authorization system for an environment consisting of distributed resources used by geographically and administratively distributed users.

Metal matrix composites (MMCs) are promising engineering materials for a wide spectrum of applications. There are many possible matrix-reinforcement combinations including MMCs containing copper or copper alloy matrices [1-3]. The present study is concerned with copper reinforced with SiC particles. The materials studied here were processed from nano-scale matrix powders and consolidated using dynamic compaction.

This erratum corrects a computational error affecting the calculation of the intrinsic luminosities of several objects in the article "Is there a metallicity-luminosity relationship in active galactic nuclei? The case of narrow-line Seyfert 1 galaxies." This does not affect any of the main results of the article.