6,074 research outputs found

    The Programmers\u27 Playground: I/O Abstraction for Heterogeneous Distributed Systems

    Get PDF
    I/O abstraction is offered as a new high-level approach to interprocess communication. Functional components of a concurrent system are written as encapsulated modules that act upon local data structures, some of which may be published for external use. Relationships among modules are specified by logical connections among their published data structures. Whenever a module updates published data, I/O takes place implicitly according to the configuration of logical connections. The Programmer\u27s Playground, a software library and run-time system supporting I/O abstraction, is described. Design goals include high-level communication among programs written in multiple programming languages and the uniform treatment of discrete and continuous data types. Support for the development of distributed multimedia applications is the motivation for the work

    Parameter scaling in the decoherent quantum-classical transition for chaotic systems

    Full text link
    The quantum to classical transition has been shown to depend on a number of parameters. Key among these are a scale length for the action, \hbar, a measure of the coupling between a system and its environment, DD, and, for chaotic systems, the classical Lyapunov exponent, λ\lambda. We propose computing a measure, reflecting the proximity of quantum and classical evolutions, as a multivariate function of (,λ,D)(\hbar,\lambda,D) and searching for transformations that collapse this hyper-surface into a function of a composite parameter ζ=αλβDγ\zeta = \hbar^{\alpha}\lambda^{\beta}D^{\gamma}. We report results for the quantum Cat Map, showing extremely accurate scaling behavior over a wide range of parameters and suggest that, in general, the technique may be effective in constructing universality classes in this transition.Comment: Submitte

    Self-assured Collective Data Transferring in Vehicular Ad Hoc Networks

    Get PDF
    Vehicular adhoc networks (VANETs) is the present innovation utilizing as a part of vehicles like cars and vans. Vehicles are considered as portable hubs in a MANET to make a versatile system likewise the most imperative applications for VANET is the dispersion of dynamic security messages to enhance wellbeing. In these system the Vehicle-to-vehicle (V2V) correspondences needs more secure transmission of information to the vehicles. The chart hypothesis used to devise the issue of agreeable correspondences planning and decrease the intricacy in the systems. The planning plan to allocate both vehicle-to-framework (V2I) and V2V joins for both single-bounce and double jump interchanges. Vanets are the aftereffect of the imagined Smart Transportation Systems. It permits different vehicles to speak with one another and structure system. Vanet is one application in which specially appointed systems are utilized at their maximum capacity. In vanets vehicles can get to store and course information to each other

    Isolation and characterisation of microorganisms contaminating herbal infusion sold in Minna, Nigeria

    Get PDF
    The microbiological assessment of ten herbal infusion samples from ten different locations in Minna, Niger State was investigated. The assessment of the microbial contamination on the herbal products was carried out, using standard methods. Pour plate method was used to cultivate serially diluted portions of the medicinal plant infusion samples. The results revealed that all the herbal preparations had the presence of microbial contaminants. The total heterotrophic counts of the different herbal samples ranged from 0 cfu/mL to 25.0 × 108cfu/mL while the total fungal counts ranged from 3.0×106cfu/mL to 3.5×108cfu/mL. The total viable bacteria counts showed that the highest counts of 25.0 × 108cfu/mL was recorded in the sample from Bosso and the least counts of 0 cfu/mL from Kasuwan-Gwari while the total fungal counts showed that the highest count of 3.5×108cfu/mL was found in the sample obtained from FUT campus and the least counts of 3.0×106cfu/mL in the sample from Mai-Kunkele. One way analysis of variance (ANOVA) showed that there was significant difference (p<0.05) in the microbial load of the herbal infusions from each location. The microbial isolates identified were E. coli, Staphylococcus aureus, Shigella sp, Klebsiella sp, Pseudomonas sp, Micrococcus sp, Salmonella sp, Aspergillus sp, Penicillium sp and Saccharomyces cerevisaie. Members of the genus Aspergillus were found to be predominant. This suggests that the herbal infusion harbors microorganisms that could be hazardous to human health and hence producers should maintain the highest possible level of hygiene during the processing and packaging of the products in order to ensure safety of the products

    Microbial-aided phytoremediation of heavy metals contaminated soil: a review

    Get PDF
    Anthropogenic exercises as well as industrial enterprise and agricultural practices contribute considerably to the degradation and contamination of environment that considerably affects the soil. The normal physical and chemical know-how soil washing used for soil remediation render the land useless as a medium for plant growth, as they take away all biological activities. Others are labor-intensive and have high maintenance value phytoremediation, a cheaper and sustainable in situ remediation technique was so thought of. This data can enable proposing solutions to issues of contamination and eventually convalescent sites and soils. However, plants don't have the aptitude to degrade several soil waste matters particularly the organic pollutant. It's so imperative to require advantage of the degrading ability of soil microorganisms. This review so focuses on phytoremediation techniques improved by microbial colonies. DOI: http://dx.doi.org/10.5281/zenodo.324417

    Quasiparticle photoemission intensity in doped two-dimensional quantum antiferromagnets

    Full text link
    Using the self-consistent Born approximation, and the corresponding wave function of the magnetic polaron, we calculate the quasiparticle weight corresponding to destruction of a real electron (in contrast to creation of a spinless holon), as a funtion of wave vector for one hole in a generalized tJt-J model and the strong coupling limit of a generalized Hubbard model. The results are in excellent agreement with those obtained by exact diagonalization of a sufficiently large cluster. Only the Hubbard weigth compares very well with photoemission measurements in Sr_2CuO_2Cl_2.Comment: 11 pages, latex, 3 figure

    Generic theory of colloidal transport

    Full text link
    We discuss the motion of colloidal particles relative to a two component fluid consisting of solvent and solute. Particle motion can result from (i) net body forces on the particle due to external fields such as gravity; (ii) slip velocities on the particle surface due to surface dissipative phenomena. The perturbations of the hydrodynamic flow field exhibits characteristic differences in cases (i) and (ii) which reflect different patterns of momentum flux corresponding to the existence of net forces, force dipoles or force quadrupoles. In the absence of external fields, gradients of concentration or pressure do not generate net forces on a colloidal particle. Such gradients can nevertheless induce relative motion between particle and fluid. We present a generic description of surface dissipative phenomena based on the linear response of surface fluxes driven by conjugate surface forces. In this framework we discuss different transport scenarios including self-propulsion via surface slip that is induced by active processes on the particle surface. We clarify the nature of force balances in such situations.Comment: 22 pages, 1 figur

    Organic Matter and Heavy Metals Leachate Effect on Soils of Selected Dumpsites in Selected North Central States of Nigeria

    Get PDF
    This research was conducted to assess the presence &nbsp;of some heavy metals Chromium (Cr), Iron (Fe), Copper (Cu), Manganese (Mn), Lead (Pb), Zinc (Zn) and Aluminum (Al) in municipal solid waste dumps. Heavy metals in the soils were determined at varying depths of 0-5cm, 5-15cm and 15-30cm to assess the extent of pollution and the effects of pH and organic matter in the soil. Heavy metals concentrations were analysed using Atomic Absorption Spectrophotometer. The results revealed a significant difference (p &lt; 0.05) in the concentrations of heavy metals across varying depth at the dumpsites when compared with control points in the same location. Mn had the highest mean 131.22 ± 25.98 mgkg-1&nbsp;followed by Fe, which is 69 ± 11.02 mgkg-1&nbsp;at the dumpsites. Mean concentration of all the Heavy metals investigated at the various dumpsites studied were significantly higher than at the control point and below the maximum standard levels set by FAO and WHO for agricultural soils. Result of particle distribution indicated higher sand content (&gt; 80.0%) and lower clay and silt contents in both dumpsite and control site which implies the ease of movement of dissolved metals in the soil environment. Organic Matter (OM) content at dumpsites was observed to be slightly higher than at the control sites. The data also signifies that as pH decreases and %OM decreases the concentration of these heavy metals decreases down the soil profile. It is, therefore, concluded that accumulation of heavy metals in depth was highly correlated with pH and organic matter content

    Public goods and decay in networks

    Get PDF
    We propose a simple behavioral model to analyze situations where (1) a group of agents repeatedly plays a public goods game within a network structure and (2) each agent only observes the past behavior of her neighbors, but is affected by the decisions of the whole group. The model assumes that agents are imperfect conditional cooperators, that they infer unobserved contributions assuming imperfect conditional cooperation by others, and that they have some degree of bounded rationality. We show that our model approximates quite accurately regularities derived from public goods game experiments
    corecore