1. A variety of abiotic, biotic, human and historic variables related to environmental suitability and propagule pressure determine the distribution of invasive plants in a landscape. Understanding the role of these variables for invasive species is challenging because environmental variables are often correlated, many invaders have broad ecological niches, and invasive distributions are often ...

Granular sludge is a novel alternative for the treatment of wastewater and offers numerous operational and economic advantages over conventional floccular-sludge systems. The majority of research on granular sludge has focused on optimization of engineering aspects relating to reactor operation with little emphasis on the fundamental microbiology. In this study, we hypothesize two novel mechani...

Samples of porous Ti metal were subjected to different acid and heat treatments. Ectopic bone formation on specimens embedded in dog muscle was compared with the surface characteristics of the specimen. Treatment of the specimens by H2SO4/HCl and heating at 600 °C produced micrometer-scale roughness with surface layers composed of rutile phase of titanium dioxide. The acid- and heat-treated spe...

Cell formation problem mainly address how machines should be grouped and parts be processed in cells. In dynamic environments, product mix and demand change in each period of the planning horizon. Incorporating such assumption in the model increases flexibility of the system to meet customer’s requirements. In this model, to ensure the reliability of the system in presence of unreliable machine...

Gaussian Scale-space describes the local structure of images. This paper shows a stochastic analysis of the diffusion equation as put forward by Koenderink (1984) for regular images. Important classes of the stochastic process which are structurally described by the diffusion analysis include Brownian fractals, Markovian textures, and fragmentation processes. The analysis shows the diffusion co...

Abstract The study of network formation is pervasive in economics, sociology, and many other fields. In this article, we model as a ‘choice’ that made by nodes to connect nodes. We these ‘choices’ using discrete-choice models, which agents choose between two or more discrete alternatives. employ the ‘repeated-choice’ (RC) formation. argue RC overcomes important limitations multinomial logit (MN...

In this paper we report on an initial attempt at studying evolution as a multilevel process, in which interactions of different space/time scales mutually determine the evolutionary potential. Side effects of processes on one scale may form a substrate for evolution at another scale. We study the generation and maintenance of diversity in a multilevel replicator system and focus on the role of ...

? Abstract. Image formation is described by means of modern geometry in terms of curvatures. These curvatures are a quantisation of the set of rules for constructing the image. A simpliication of this set of rules is proposed by applying dynamic scale-space theory.

the nanoparticles of ni–si mixed oxides were prepared by co-precipitation method using nickel nitrate; ni(no3)2 6h2o and tetraethylorthosilicate (teos). the products were characterized by x-ray diffraction (xrd), transmission electron microscopy (tem), and hydrogen temperature program reduction (h2-tpr). the results revealed that ni–si mixed oxides particles were obtained with average particle ...