Excising das All: Evolving Maxwell waves beyond scri

We study the numerical propagation of waves through future null infinity in a conformally compactified spacetime. We introduce an artificial cosmological constant, which allows us some control over the causal structure near null infinity. We exploit this freedom to ensure that all light cones are tilted outward in a region near null infinity, which allows us to impose excision-style boundary conditions in our finite difference code. In this preliminary study we consider electromagnetic waves propagating in a static, conformally compactified spacetime.Comment: 13 pages; incorporated material from gr-qc/051216

Some Physical and Chemical Properties of Processed Milk Products

The experiments described in the thesis were mainly concerned with the nature and the prevention of deterioration in spray-dried, whole and separated milk. Part I describes the analytical methods and techniques used, Part II deals with the work on whole-milk powder and Part III with the work on separated-milk powder. Part IV describes an investigation to determine the validity of the methods which have been proposed to measure the solubility of milk powders. (Abstract shortened by ProQuest.)

Sindbis virus proteins nsP1 and nsP2 contain homology to nonstructural proteins from several RNA plant viruses

Although the genetic organization of tobacco mosaic virus (TMV) differs considerably from that of the tripartite viruses (alfalfa mosaic virus [AlMV] and brome mosaic virus [BMV]), all of these RNA plant viruses share three domains of homology among their nonstructural proteins. One such domain, common to the AlMV and BMV 2a proteins and the readthrough portion of TMV p183, is also homologous to the readthrough protein nsP4 of Sindbis virus (Haseloff et al., Proc. Natl. Acad. Sci. U.S.A. 81:4358-4362, 1984). Two more domains are conserved among the AlMV and BMV 1a proteins and TMV p126. We show here that these domains have homology with portions of the Sindbis proteins nsP1 and nsP2, respectively. These results strengthen the view that the four viruses share mechanistic similarities in their replication strategies and may be evolutionarily related. These results also suggest that either the AlMV 1a, BMV 1a, and TMV p126 proteins are multifunctional or Sindbis proteins nsP1 and nsP2 function together as subunits in a single complex

Adaptation of Turfgrasses in Hawaii

The major turfgrasses used in Hawaii are described in terms of their tolerances to shade, salt, weeds, and drought, and they are compared in their density, establishment rate, mowing factors, and other requirements

Nature of Ag+ self-diffusion in AgF

Journal ArticleMeasurements of the nuclear magnetic resonance (NMR) dipolar relaxation times T w and T i (51°) have been made on the 1 9 F resonance in AgF powder over the temperature range 60-300 K. Also the technique of Stokes and Ailion for detecting the diffusion of weakly magnetic spins has been verified for powder samples by measuring T ,(9f) v s 'n KF: 0.1 at. % CaF2 powder. A comparison of the NMR results with conductivity measurements of Raaen, Svare, and Fjeldly allows one to rule out diffusion mechanisms in AgF which give rise to strong-collision NMR relaxation, like Ag + vacancy or Ag + interstitialcy diffusion in AgF, thereby suggesting the dominance of a weak-collision mechanism like Ag+ interstitial or possibly grainboundary diffusion

High sensitivity nuclear quadrupole resonance approach for detection of modulation wave motion in incommensurate systems

Journal ArticleIn contrast to conventional NMR techniques that use magnetic field gradients (MFCs) to detect the diffusion of moving atoms, we have developed a highly sensitive approach for detecting electric field gradient (EFG) fluctuations seen by stationary atoms. These EFG fluctuations were observed in the quadrupole perturbed NMR behavior of a stationary nucleus (9 3Nb) in the incommensurate insulator barium sodium niobate and are attributed to motion of the modulation wave. We observed effective diffusion constants of order 10~13 cm2/s, which are 4 orders of magnitude smaller than those currently detectable with MFG NMR

Towards Verification of Cyber-Physical Systems with UTP and Isabelle/HOL

In this paper, we outline our vision for building verification tools for Cyber-Physical Systems based on Hoare and He’s Unifying Theories of Programming (UTP) and interactive proof technology in Isabelle/HOL. We describe our mechanisation and explain some of the design decisions that we have taken to get a convenient and smooth implementation. In particular, we describe our use of lenses to encode state. We illustrate our work with an example UTP theory and describe the implementation of three foundational theories: designs, reactive processes, and the hybrid relational calculus. We conclude by reflecting on how tools are linked by unifying theories