Porous glass-ceramics from alkali activation and sinter-crystallization of mixtures of waste glass and residues from plasma processing of municipal solid waste

Alkali-activated aqueous slurries of fine glass powders, mostly deriving from the plasma processing of municipal solid waste ('Plasmastone'), were found to undergo progressive hardening at low temperature (75 degrees C) owing to the formation of C-S-H (calcium silicate hydrate) gels. Before complete setting, slurries could be easily foamed by vigorous mechanical stirring, with the help of a surfactant; finally, the resulting open-celled structure could be 'frozen' by a subsequent sintering treatment, with crystallization of Ca-Fe silicates. The densification of the struts upon firing was enhanced by mixing Plasmastone with up to 30 wt% recycled glasses and increasing the firing temperature from 800 to 1000 degrees C. A total porosity exceeding 75 vol%, comprising both well-interconnected macro- and micro-sized pores on cell walls, was accompanied by good compressive strength, well above 1 MPa. The stabilization of pollutants generally increased with increasing firing temperature and glass content, with some exceptions; no practical leaching was observed from samples deriving from Plasmastone combined with 30 wt% boro-aluminosilicate glass from the recycling of pharmaceutical vials

A Stochastic Broadcast Pi-Calculus

In this paper we propose a stochastic broadcast PI-calculus which can be used to model server-client based systems where synchronization is always governed by only one participant. Therefore, there is no need to determine the joint synchronization rates. We also take immediate transitions into account which is useful to model behaviors with no impact on the temporal properties of a system. Since immediate transitions may introduce non-determinism, we will show how these non-determinism can be resolved, and as result a valid CTMC will be obtained finally. Also some practical examples are given to show the application of this calculus.Comment: In Proceedings QAPL 2011, arXiv:1107.074

An interactive dynamic programming approach to multicriteria discrete programming

AbstractSeveral interactive schemes for solving multicriteria discrete programming problems are developed under a dynamic programming framework. It is assumed that the decision maker's preference structure satisfies the conditions of transitivity, monotonicity, and nonsatiation. Hybrid procedures are also structured by including branch and bound ideas into the recursions. Initial computational results are offered

Philosophical and methodological aspects of Operations Research: the evolution of an interdisciplinary area

Operations Research fits into the history of the great technological and scientific events of the twentieth century. Its influence on the emergence of other sciences and applications, whose developments in the post-war period contributed to the increased rationalization of modern society are evident. Given this context, this article aims to trace an analytical reconstruction on the philosophical and methodological aspects that mark the history of operations research. Such reconstruction will be developed based on a historical method using bibliography and documents. The refinement of Operations Research techniques was a determining factor for its success, and its methodological and philosophical aspects have revered thinkers such as John Dewey, Churchman, and Capra, who are references to understand modern men's thought. It turns out that World War II was determinant for science in general and more specifically for the great advance of operations research. The achievements of the OR, largely, result from the formation of multidisciplinary groups that allowed the evolution of the area in several directions, providing an interdisciplinary dialogue

Analytical approach to soliton ratchets in asymmetric potentials

We use soliton perturbation theory and collective coordinate ansatz to investigate the mechanism of soliton ratchets in a driven and damped asymmetric double sine-Gordon equation. We show that, at the second order of the perturbation scheme, the soliton internal vibrations can couple {\it effectively}, in presence of damping, to the motion of the center of mass, giving rise to transport. An analytical expression for the mean velocity of the soliton is derived. The results of our analysis confirm the internal mode mechanism of soliton ratchets proposed in [Phys. Rev. E {\bf 65} 025602(R) (2002)].Comment: 9 figures. Submitted to Phys. Rev.

Poseidon Linux 3.x - The scientific GNU/Linux option

This software review is about the newest version of Poseidon Linux (3.x). The current Poseidon Linux is a remastering from Ubuntu LTS family (Long Term Support), with extra specific software applicable to many areas of scientific research and education. It contains specialist software for GIS/Mapping, bathymetry, numerical modeling, 2D/3D/4D visualization, bioinformatics, chemistry, statistics, as well as tools for creating simple and complex graphics and programming languages. It also includes basic packages as would be expected on a normal desktop, such as a complete office suite, internet browser, e-mail client, instant messaging, chat, multimedia and many other tools. Poseidon Linux can run in two modes, as a live-DVD or installed on the hard disk. There are versions for 32 and 64 bit computers, and support for Brazilian Portuguese, English, Spanish, French, Greek, Italian and German languages. Resumo. Poseidon Linux 3.x – A opção científica GNU/Linux. Esta resenha trata da nova versão do software Poseidon Linux (3.x). A versão atual é uma remasterização a partir do sistema operacional Ubuntu, família LTS (Suporte de Longo Prazo), com pacotes extras para várias áreas da ciência e educação. Contém programas específicos para SIG/mapeamento, batimetria, modelagem numérica, visualização 2D/3D/4D, bioinformática, química, estatística, bem como ferramentas para elaboração de gráficos simples e complexos e linguagem de programação. Inclui também os programas necessários encontrados num sistema operacional desktop, tais como suporte completo para escritório, navegador de internet, programas para envio e recebimento de mensagens instantâneas, multimídia e várias outras ferramentas. O Poseidon Linux pode ser utilizado de duas formas: diretamente do DVD, sem instalá-lo, ou instalando-o no disco rígido do computador. É apresentado nas versões 32 e 64 bits e pode ser totalmente configurado em Português do Brasil, Inglês, Espanhol, Francês, Grego, Italiano e Alemão

Cosmology at the top of the α′ tower

The cosmology of the fully $\alpha'$-corrected duality-invariant action for the Neveu-Schwarz sector of string theory is revisited, with special emphasis on its coupling to matter sources. The role of the duality covariant pressure and dilatonic charge of the matter sector is explored in various contexts, from the low-curvature regime to non-perturbative solutions in $\alpha'$. We comment on how an infinite tower of $\alpha'$ corrections allows for fixed-dilaton de Sitter solutions, even in vacuum. We further investigate the necessary conditions for accelerated expansion in the Einstein frame, as well as for non-singular bounces that could resolve the big bang singularity. In particular, explicit examples are constructed, which show that the tower of $\alpha'$ corrections may support an Einstein-frame non-singular cosmological bouncing background, even when the matter sector respects the null energy condition