Critical behavior in reaction-diffusion systems exhibiting absorbing phase transition

Phase transitions of reaction-diffusion systems with site occupation restriction and with particle creation that requires n>1 parents and where explicit diffusion of single particles (A) exists are reviewed. Arguments based on mean-field approximation and simulations are given which support novel kind of non-equilibrium criticality. These are in contradiction with the implications of a suggested phenomenological, multiplicative noise Langevin equation approach and with some of recent numerical analysis. Simulation results for the one and two dimensional binary spreading 2A -> 4A, 4A -> 2A model display a new type of mean-field criticality characterized by alpha=1/3 and beta=1/2 critical exponents suggested in cond-mat/0210615.Comment: 6 pages, 4 figures included, submitted to a special number of the Brazilian Journal of Physic

Universality classes in nonequilibrium lattice systems

This work is designed to overview our present knowledge about universality classes occurring in nonequilibrium systems defined on regular lattices. In the first section I summarize the most important critical exponents, relations and the field theoretical formalism used in the text. In the second section I briefly address the question of scaling behavior at first order phase transitions. In section three I review dynamical extensions of basic static classes, show the effect of mixing dynamics and the percolation behavior. The main body of this work is given in section four where genuine, dynamical universality classes specific to nonequilibrium systems are introduced. In section five I continue overviewing such nonequilibrium classes but in coupled, multi-component systems. Most of the known nonequilibrium transition classes are explored in low dimensions between active and absorbing states of reaction-diffusion type of systems. However by mapping they can be related to universal behavior of interface growth models, which I overview in section six. Finally in section seven I summarize families of absorbing state system classes, mean-field classes and give an outlook for further directions of research.Comment: Updated comprehensive review, 62 pages (two column), 29 figs included. Scheduled for publication in Reviews of Modern Physics in April 200

An analysis of food-economy companies’ environmental behaviour in North-East Hungary

After outlining environmental problems regarding food-economy2 companies and clarifying the concept of environmental behaviour, I will present the results of my questionnaire survey which focussed on food-economy companies in the Northern Great Plain region (Region). Based on solid data, the survey was designed to evaluate the companies’ commitment toward environmental protection. Sometimes the observed value systems conformed with the results of other national surveys (e.g. environmental behaviour factors; environmental protection’s rank among business aims), but at times I observed that in certain areas they truly lagged behind: for example, this held true for . the number of companies with a certified environmental-management system (EMS) and also for companies which were producing environmental reports and publishing them. It can be concluded that in the Region companies with higher revenues – and thus higher capability – do not try to do better at environmental management than companies with small or medium revenues.food-economy, environmental challenges, environmental behaviour, environmental-conscious management., Agribusiness, Environmental Economics and Policy, Marketing, Research Methods/ Statistical Methods,

Nonequilibrium Kinetic Ising Models: Phase Transition and Universality Classes in One Dimension

Nonequilibrium kinetic Ising models evolving under the competing effect of spin flips at zero temperature and Kawasaki-type spin-exchange kinetics at infinite temperature T are investigated here in one dimension from the point of view of phase transition and critical behaviour. Branching annihilating random walks with an even number of offspring (on the part of the ferromagnetic domain boundaries), is a decisive process in forming the steady state of the system for a range of parameters, in the family of models considered. A wide variety of quantities characterize the critical behaviour of the system. Results of computer simulations and of a generalized mean field theory are presented and discussed.Comment: 23 pages, 10 figures include

Hand tool permits shrink sizing of assembled tubing

Portable tool sizes tubing ends without disassembling the tubing installation. The shrink sizing tool is clamped to the tubing and operated by a ratchet wrench. A gear train forces the tubing end against an appropriate die or mandrel to effect the sizing

The Impact of Olfactory Cues on Attention: The Case of Stroop Interference

This study explores the relationship between odor imagery, color associations, and visual attention through a Stroop-task based on common odor-color associations. This Stroop-task was designed using three fruits with odor-color associations: lime with green, strawberry with red, and lemon with yellow. Each possible word-color combination was lexically presented in the experimental trials. Three experiments were conducted that used the Stroop-task with different odors present. They suggest that odor imagery can affect visual attention, the inhibition of odor-color associations, and that odor imagery appears to be facilitated in the presence of a related odor