Physical/chemical closed-loop water-recycling

Water needs, water sources, and means for recycling water are examined in terms appropriate to the water quality requirements of a small crew and spacecraft intended for long duration exploration missions. Inorganic, organic, and biological hazards are estimated for waste water sources. Sensitivities to these hazards for human uses are estimated. The water recycling processes considered are humidity condensation, carbon dioxide reduction, waste oxidation, distillation, reverse osmosis, pervaporation, electrodialysis, ion exchange, carbon sorption, and electrochemical oxidation. Limitations and applications of these processes are evaluated in terms of water quality objectives. Computerized simulation of some of these chemical processes is examined. Recommendations are made for development of new water recycling technology and improvement of existing technology for near term application to life support systems for humans in space. The technological developments are equally applicable to water needs on Earth, in regions where extensive water recycling is needed or where advanced water treatment is essential to meet EPA health standards

A fast algorithm for backbones

A matching algorithm for the identification of backbones in percolation problems is introduced. Using this procedure, percolation backbones are studied in two- to five-dimensional systems containing 1.7x10^7 sites, two orders of magnitude larger than was previously possible using burning algorithms.Comment: 8 pages, 6 .eps figures. Uses epsfig and ijmpc.sty (included). To appear in Int. J. Mod. Phys.

On Nonconservative Stability Problems of Elastic Systems with Slight Damping

Equilibrium stability of linear two degree of freedom system with slight viscous damping subjected to nonconservative loadin

Statistical Laws and Mechanics of Voronoi Random Lattices

We investigate random lattices where the connectivities are determined by the Voronoi construction, while the location of the points are the dynamic degrees of freedom. The Voronoi random lattices with an associated energy are immersed in a heat bath and investigated using a Monte Carlo simulation algorithm. In thermodynamic equilibrium we measure coordination number distributions and test the Aboav-Weaire and Lewis laws.Comment: 14 pages (figures not included), LaTeX, HLRZ-26/9

Identification of an interchromosomal compartment by polymerization of nuclear-targeted vimentin

A number of structural and functional subnuclear compartments have been described, including regions exclusive of chromosomes previously hypothesized to form a reactive nuclear space. We have now explored this accessible nuclear space and interchromosomal nucleoplasmic domains experimentally using Xenopus vimentin engineered to contain a nuclear localization signal (NLS-vimentin). In stably transfected human cells incubated at 37°C, the NLS-vimentin formed a restricted number of intranuclear speckles. At 28°C, the optimal temperature for assembly of the amphibian protein, NLSvimentin progressively extended with time out from the speckles into strictly orientated intranuclear filamentous arrays. This enabled us to observe the development of a system of interconnecting channel-like areas. Quantitative analysis based on 3-D imaging microscopy revealed that these arrays were localized almost exclusively outside of chromosome territories. During mitosis the filaments disassembled and dispersed throughout the cytoplasm, while in anaphase-telophase the vimentin was recruited back into the nucleus and reassembled into filaments at the chromosome surfaces, in distributions virtually identical to those observed in the previous interphase. The filaments also colocalized with specific nuclear RNAs, coiled bodies and PML bodies, all situated outside of chromosome territories, thereby interlinking these structures. This strongly implies that these nuclear entities coexist in the same interconnected nuclear compartment. The assembling NLS-vimentin is restricted to and can be used to delineate, at least in part, the formerly proposed reticular interchromosomal domain compartment (ICD). The properties of NLS-vimentin make it an excellent tool for performing structural and functional studies on this compartment

Framework for the Integration of Service and Technology Strategies

Organised by: Cranfield UniversityAfter sales service is a highly profitable business for manufacturers of technology-driven products. Due to this fact competitors want to share in high profit margins. At the same time after sales business has to deal with an increasing range of variants of products and technologies, shorter life cycles and changing customer demands. In spite of these manifold challenges, often neither after sales departments are involved in the early product development stage nor are customer demands and technical parameters considered in the service development processes entirely. Therefore an integration of service and technology strategies is necessary. This paper presents a framework for this integration that visualises the complex interdependencies and interfaces between service as well as product and motor vehicle workshop technologies.Mori Seiki – The Machine Tool Compan

Stochastic resonance for nonequilibrium systems

Stochastic resonance (SR) is a prominent phenomenon in many natural and engineered noisy systems, whereby the response to a periodic forcing is greatly amplified when the intensity of the noise is tuned to within a specific range of values. We propose here a general mathematical framework based on large deviation theory and, specifically, on the theory of quasipotentials, for describing SR in noisy N -dimensional nonequilibrium systems possessing two metastable states and undergoing a periodically modulated forcing. The drift and the volatility fields of the equations of motion can be fairly general, and the competing attractors of the deterministic dynamics and the edge state living on the basin boundary can, in principle, feature chaotic dynamics. Similarly, the perturbation field of the forcing can be fairly general. Our approach is able to recover as special cases the classical results previously presented in the literature for systems obeying detailed balance and allows for expressing the parameters describing SR and the statistics of residence times in the two-state approximation in terms of the unperturbed drift field, the volatility field, and the perturbation field. We clarify which specific properties of the forcing are relevant for amplifying or suppressing SR in a system and classify forcings according to classes of equivalence. Our results indicate a route for a detailed understanding of SR in rather general systems