An alternative methodology to predict aging effects on the mechanical properties of glass fiber reinforced cement (GRC)

The effect of three different aging methods (immersion in hot water, freeze–thaw cycles and wet–dry cycles) on the mechanical properties of GRC were studied and compared. Test results showed that immersion in hot water may be an unreliable method for modified GRC formulations, with it being in probability a very harmful procedure. A new aging method, mixing freeze–thaw cycles and wet–dry cycles, seems to be the most accurate simulation of weather conditions that produce a noticeable change in GRC mechanical properties. Future work should be carried out to find a correlation between real weather and the proposed aging method

Dynamic transition in Landau-Zener-St\"uckelberg interferometry of dissipative systems: the case of the flux qubit

We study Landau-Zener-Stuckelberg (LZS) interferometry in multilevel systems coupled to an Ohmic quantum bath. We consider the case of superconducting flux qubits driven by a dc+ac magnetic fields, but our results can apply to other similar systems. We find a dynamic transition manifested by a symmetry change in the structure of the LZS interference pattern, plotted as a function of ac amplitude and dc detuning. The dynamic transition is from a LZS pattern with nearly symmetric multiphoton resonances to antisymmetric multiphoton resonances at long times (above the relaxation time). We also show that the presence of a resonant mode in the quantum bath can impede the dynamic transition when the resonant frequency is of the order of the qubit gap. Our results are obtained by a numerical calculation of the finite time and the asymptotic stationary population of the qubit states, using the Floquet-Markov approach to solve a realistic model of the flux qubit considering up to 10 energy levels.Comment: One new figure added. Final version to be published in PR

Surcar la moral. Delirio de Laura Restrepo

Este ensayo argumenta que en la novela Delirio (2004) de la escritora colombiana Laura Restrepo (1950), quien delira es el cuerpo social mismo y no el individuo y su psiquis —en el personaje de Agustina—. Para ello despliega tres ideas: el secreto como algo visible o sentido común; la ceguera moral de sus personajes como impotencia autoimpuesta, y el encierro como técnica social de sometimiento. Usa la pragmática literaria para proponer una lectura inmanente de la novela, es decir, interpreta el delirio desde el delirio mismo. A su vez, para describir a los personajes,recupera la tipología del esclavo de Nietzsche

Nonequilibrium Phase Transitions in Directed Small-World Networks

Many social, biological, and economic systems can be approached by complex networks of interacting units. The behaviour of several models on small-world networks has recently been studied. These models are expected to capture the essential features of the complex processes taking place on real networks like disease spreading, formation of public opinion, distribution of wealth, etc. In many of these systems relations are directed, in the sense that links only act in one direction (outwards or inwards). We investigate the effect of directed links on the behaviour of a simple spin-like model evolving on a small-world network. We show that directed networks may lead to a highly nontrivial phase diagram including first and second-order phase transitions out of equilibrium.Comment: 4 pages, RevTeX format, 4 postscript figs, uses eps

Deleuze extraviado en Norteamérica

El texto evalúa una de las maneras predominantes de la recepción de Gilles Deleuze. Establece una crítica de los desencuentros y misreadings en torno a la filosofía de Deleuze. Muestra esos desencuentros como un proceso sin contexto ni densidad histórica, sin unos mínimos elementos que permitan comprender los complejos procesos de su recepción. Mucho menos su genealogía. Para ello, el texto evalúa la lectura de Deleuze que hace Jacques Ranciere, a la luz de la recepción de ambos en el contexto universitario norteamericano

O desmoronamento da verdade social na Colômbia de Camilo Torres(ou, o sujeito como exceção)

Existe algum momento em que não se sucumba à insinuação do Estado? Ou em termos mais precisos, é possível encontrar anomalias em processos tão avassaladores como o desejado advento do Estado secular? Em particular, no debate sobre a secularização e a socialização liberal do indivíduo, nos países da margem, predominam versões que postulam ditos processos como registros de tendências econômicas e avanços materiais e do movimento da consciência que conduzem à experiência “moderna”. Nossa inquietude, pelo contrário, é se é possível rastrear ali campos de experiência nos quais se abram possibilidades para a constituição subjetiva, distintas à unidade individual. Em suma, perguntamo-nos pela existência de práticas que, em países como o nosso, fazem que seja possível cumprir com o lema tão apreciado pelo indivíduo: “faz-te apreciar por teu amo o sufi ciente para que ele te liberte”