Cumbaru no Pantanal.

bitstream/item/80014/1/ADM127.pdfFormato eletrônico. Disponível também em: pantanalecoturismo.tur.br; bonitobrazil.com.br; douradosinforma.com.br; folhadoms.com.br; agenciapantanal.com.br; douradosnews.com.br; portalbonito.com.br; agrolink.com.br; perfilnews.com.br; naviraí.news.com.br; infobibos.com; opantaneiro.com.br; clickpantanal.com.br; agorams.com.br; cassilandianews.com.br; bbcnews.com.br; boletimpecuario.com.br; capitaldopantanal.com.br; msnoticias.com.br; corumbaonline.com.br; portaldoagronegocio.com.br; campogrande.news.com.br; criareplantar.com.br; reporterms.com.br; agrosoft.org.br; aquidauananews.com; repams.org.br; ultimahoranews.com; maracaju.news.com.br; agronline.com.br, atribunanews.com.br; o estado de Mato Grosso do Sul (06/10/08)

A Landscape Analysis of Constraint Satisfaction Problems

We discuss an analysis of Constraint Satisfaction problems, such as Sphere Packing, K-SAT and Graph Coloring, in terms of an effective energy landscape. Several intriguing geometrical properties of the solution space become in this light familiar in terms of the well-studied ones of rugged (glassy) energy landscapes. A `benchmark' algorithm naturally suggested by this construction finds solutions in polynomial time up to a point beyond the `clustering' and in some cases even the `thermodynamic' transitions. This point has a simple geometric meaning and can be in principle determined with standard Statistical Mechanical methods, thus pushing the analytic bound up to which problems are guaranteed to be easy. We illustrate this for the graph three and four-coloring problem. For Packing problems the present discussion allows to better characterize the `J-point', proposed as a systematic definition of Random Close Packing, and to place it in the context of other theories of glasses.Comment: 17 pages, 69 citations, 12 figure

Effects of quark family nonuniversality in SU(3)_c X SU(4)_L X U(1)_x models

Flavour changing neutral currents arise in the $SU(3)_c\otimes SU(4)_L\otimes U(1)_X$ extension of the standard model because anomaly cancellation among the fermion families requires one generation of quarks to transform differently from the other two under the gauge group. In the weak basis the distinction between quark families is meaningless. However, in the mass eigenstates basis, the Cabibbo-Kobayashi-Maskawa mixing matrix motivates us to classify left-handed quarks in families. In this sense there are, in principle, three different assignments of quark weak eigenstates into mass eigenstates. In this work, by using measurements at the Z-pole, atomic parity violation data and experimental input from neutral meson mixing, we examine two different models without exotic electric charges based on the 3-4-1 symmetry, and address the effects of quark family nonuniversality on the bounds on the mixing angle between two of the neutral currents present in the models and on the mass scales $M_{Z_2}$ and $M_{Z_3}$ of the new neutral gauge bosons predicted by the theory. The heaviest family of quarks must transform differently in order to keep lower bounds on $M_{Z_2}$ and $M_{Z_3}$ as low as possible without violating experimental constraints.Comment: 27 pages, 10 tables, 2 figures. Equation (19) and typos corrected. Matches version to appear in Phys. Rev.

Earthquakes and robustness for timber structures

Major similarities between robustness assessment and seismic design exist, and significant information can be brought from seismic design to robustness design. As will be discussed, although some methods and limitations considered in seismic design can improve robustness, the capacity of the structure to sustain limited damage without disproportionate effects is significantly more complex. In fact, seismic design can either improve or reduce the resistance of structures to unforeseeable events, depending on structural type, triggering event, structural material, among others.European Cooperation in Science and Technology (COST

Simulation study of the effect of the chemical heterogeneity of activated carbon on water adsorption

In this paper we present results from the molecular simulation of water adsorption in slit-shaped activated carbon pores. We calculate adsorption isotherms by grand canonical Monte Carlo (GCMC) simulation, Henry's constants by Monte Carlo integration, and vapor-liquid equilibrium data by the gauge-cell Monte Carlo method, to investigate the chemical heterogeneity of activated carbon adsorbents. Several types of polar oxygen-containing sites are placed on the surface of the carbon with different densities and local distributions, in order to determine the individual effects of each of these factors on the adsorption of water. Our results confirm the role of surface sites in the enhancement of water adsorption, Furthermore, we show that the local distribution of these sites has a strong effect on low-pressure adsorption, while the overall site density affects mainly the vapor-liquid phase transition. The type of oxygen-containing group is shown not to be of critical importance, since more complex groups can effectively be represented by simpler sites. This study forms the basis for the development of a model for activated carbon that is able to represent the chemical heterogeneity of this type of material

Removing zero Lyapunov exponents in volume-preserving flows

Baraviera and Bonatti proved that it is possible to perturb, in the c^1 topology, a volume-preserving and partial hyperbolic diffeomorphism in order to obtain a non-zero sum of all the Lyapunov exponents in the central direction. In this article we obtain the analogous result for volume-preserving flows.Comment: 10 page

On the thermal and double episode emissions in GRB 970828

Following the recent theoretical interpretation of GRB 090618 and GRB 101023, we here interpret GRB 970828 in terms of a double episode emission: the first episode, observed in the first 40 s of the emission, is interpreted as the proto-black-hole emission; the second episode, observed after t$_0$+50 s, as a canonical gamma ray burst. The transition between the two episodes marks the black hole formation. The characteristics of the real GRB, in the second episode, are an energy of $E_{tot}^{e^+e^-} = 1.60 \times 10^{53}$ erg, a baryon load of $B = 7 \times 10^{-3}$ and a bulk Lorentz factor at transparency of $\Gamma = 142.5$. The clear analogy with GRB 090618 would require also in GRB 970828 the presence of a possible supernova. We also infer that the GRB exploded in an environment with a large average particle density $\, \approx 10^3$ part/cm$^3$ and dense clouds characterized by typical dimensions of $(4 - 8) \times 10^{14}$ cm and $\delta n/n \propto 10$. Such an environment is in line with the observed large column density absorption, which might have darkened both the supernova emission and the GRB optical afterglow.Comment: 7 pages, 10 figures, submitted to Ap