Staircase algorithm and construction of convex spline interpolants up to the continuity C3

AbstractThis paper is concerned with the convex interpolation of data sets. Based on the staircase algorithm, several methods are presented which allow the construction of convex spline interpolants up to the continuity C3

Grid simulation services for the medical community

The first part of this paper presents a selection of medical simulation applications, including image reconstruction, near real-time registration for neuro-surgery, enhanced dose distribution calculation for radio-therapy, inhaled drug delivery prediction, plastic surgery planning and cardio-vascular system simulation. The latter two topics are discussed in some detail. In the second part, we show how such services can be made available to the clinical practitioner using Grid technology. We discuss the developments and experience made during the EU project GEMSS, which provides reliable, efficient, secure and lawful medical Grid services

Thinking about the future of global water governance

Global water problems are likely to increase in severity, rendering existing governance approaches unable to cope with the resulting problems. We inquire into the relationship between global water governance structures, particularly those involving the United Nations, and look at how those structures are likely to respond to and shape projected water futures. Building on story lines of possible water futures taken from existing scenarios, we discuss the functions to be performed by global water governance. We aim to open a discussion about four global water governance options and to introduce the constraints and possibilities for each option. We argue that the nature of the water problem calls for structural changes. However unfeasible these may appear today, such transitions do occur, and, if the narrative is sufficiently sound, it can be used by social movements and networks to mobilize policy entrepreneurs and directional leaders to work for such changes

Mixtures of Charged Colloid and Neutral Polymer: Influence of Electrostatic Interactions on Demixing and Interfacial Tension

The equilibrium phase behavior of a binary mixture of charged colloids and neutral, non-adsorbing polymers is studied within free-volume theory. A model mixture of charged hard-sphere macroions and ideal, coarse-grained, effective-sphere polymers is mapped first onto a binary hard-sphere mixture with non-additive diameters and then onto an effective Asakura-Oosawa model [S. Asakura and F. Oosawa, J. Chem. Phys. 22, 1255 (1954)]. The effective model is defined by a single dimensionless parameter -- the ratio of the polymer diameter to the effective colloid diameter. For high salt-to-counterion concentration ratios, a free-volume approximation for the free energy is used to compute the fluid phase diagram, which describes demixing into colloid-rich (liquid) and colloid-poor (vapor) phases. Increasing the range of electrostatic interactions shifts the demixing binodal toward higher polymer concentration, stabilizing the mixture. The enhanced stability is attributed to a weakening of polymer depletion-induced attraction between electrostatically repelling macroions. Comparison with predictions of density-functional theory reveals a corresponding increase in the liquid-vapor interfacial tension. The predicted trends in phase stability are consistent with observed behavior of protein-polysaccharide mixtures in food colloids.Comment: 16 pages, 5 figure

Cyanide intermediates in catalytic reduction of NO by C2H4 on Rhodium(III)

Temp.-programmed reaction spectroscopy and secondary ion mass spectrometry (SIMS) have been applied to study reactions of NO and C2H4 coadsorbed on Rh(111). As expected, H2O, CO2, and N2 are the main products at low C2H4 coverages, but at higher coverages H2, HCN, CO, and NO, and even some C2N2 evolve as well. Static SIMS indicates the formation of a large supply of adsorbed cyanide species, part of which desorbs as HCN, while the remainder decomps. and is responsible for delayed formation of N2. For the highest C2H4 coverages, the majority of the nitrogen atoms in the initially adsorbed NO desorbs as HC

Westinghouse Hanford Company operational environmental monitoring annual report - calendar year 1995

This document summarizes the results of the Westinghouse Hanford Company (WHC) near-facility operational environmental monitoring for 1995 in the 100, 200/600, and 300/400 Areas of the Hanford Site, in south-central Washington State. Surveillance activities included sampling and analyses of ambient air, surface water,groundwater, soil, sediments, and biota. Also, external radiation measurements and radiological surveys were taken at waste disposal sites, radiologically controlled areas, and roads. These activities were conducted to assess and control the effects of nuclear facilities and waste sites on the local environment. In addition, diffuse sources were monitored to determine compliance with Federal, State, and/or local regulations. In general, although effects from nuclear facilities can still be observed on the Hanford Site and radiation levels are slightly elevated when compared to offsite locations, the differences are less than in previous years

Shape Preserving C2-Spline Histopolation

AbstractIn this paper, an area matching approximation of histograms is considered under constraints like convexity, monotonicity, or positivity. Using rational-lacunary C2-splines, sufficient conditions for the existence of convex, monotone, or positive histosplines as well as algorithms for constructing them effectively are given. Moreover, the existence criteria are shown to be satisfied for sufficiently large rationality or lacunarity parameters

Dynamical System Approach to Cosmological Models with a Varying Speed of Light

Methods of dynamical systems have been used to study homogeneous and isotropic cosmological models with a varying speed of light (VSL). We propose two methods of reduction of dynamics to the form of planar Hamiltonian dynamical systems for models with a time dependent equation of state. The solutions are analyzed on two-dimensional phase space in the variables $(x, \dot{x})$ where $x$ is a function of a scale factor $a$. Then we show how the horizon problem may be solved on some evolutional paths. It is shown that the models with negative curvature overcome the horizon and flatness problems. The presented method of reduction can be adopted to the analysis of dynamics of the universe with the general form of the equation of state $p=\gamma(a)\epsilon$. This is demonstrated using as an example the dynamics of VSL models filled with a non-interacting fluid. We demonstrate a new type of evolution near the initial singularity caused by a varying speed of light. The singularity-free oscillating universes are also admitted for positive cosmological constant. We consider a quantum VSL FRW closed model with radiation and show that the highest tunnelling rate occurs for a constant velocity of light if $c(a) \propto a^n$ and $-1 < n \le 0$. It is also proved that the considered class of models is structurally unstable for the case of $n < 0$.Comment: 18 pages, 5 figures, RevTeX4; final version to appear in PR

Raman spectroscopies in shock-compressed materials

Spontaneous Raman spectroscopy, stimulated Raman scattering and coherent anti-Stokes Raman scattering have been used to measure temperatures and changes in molecular vibrational frequencies for detonating and shocked materials. Inverse Raman and Raman induced Kerr effect spectroscopies have been suggested as diagnostic probes for determining and phenomenology of shock-induced chemical reactions. The practicality, advantages, and disadvantages of using Raman scattering techniques as diagnostic probes of microscopic phenomenology through and immediately behind the shock front of shock-compressed molecular systems are discussed

Fermions and world-line supersymmetry

The world-line path-integral representation of fermion propagators is discussed. Particular attention is paid to the representation of $\gamma_5$, which is connected to the realization of manifest world-line supersymmetry.Comment: Contr. Proc. Buckow Symposium (1995); latex, 12 page