Cultivo sustentável de feijão caupi (Vigna unguiculata (L.) Walp.) em ecossistema de várzea amazônica.

Este trabalho objetivou avaliar 20 genótipos de feijão caupi em ecossistema de várzea amazônica situada à margem do Rio Solimões, nas condições edafoclimáticas de Iranduba-AM

Isolated Salter-Harris Type IV Distal Ulna Fracture: a Case Report

info:eu-repo/semantics/publishedVersio

Experimental and theoretical evidences for the ice regime in planar artificial spin ices

In this work, we explore a kind of geometrical effect in the thermodynamics of artificial spin ices (ASI). In general, such artificial materials are athermal. Here, We demonstrate that geometrically driven dynamics in ASI can open up the panorama of exploring distinct ground states and thermally magnetic monopole excitations. It is shown that a particular ASI lattice will provide a richer thermodynamics with nanomagnet spins experiencing less restriction to flip precisely in a kind of rhombic lattice. This can be observed by analysis of only three types of rectangular artificial spin ices (RASI). Denoting the horizontal and vertical lattice spacings by a and b, respectively, then, a RASI material can be described by its aspect ratio $\gamma$=a/b. The rhombic lattice emerges when $\gamma$=$\sqrt{3}$. So, by comparing the impact of thermal effects on the spin flips in these three appropriate different RASI arrays, it is possible to find a system very close to the ice regime

Cosmic homogeneity: a spectroscopic and model-independent measurement

Cosmology relies on the Cosmological Principle, i.e., the hypothesis that the Universe is homogeneous and isotropic on large scales. This implies in particular that the counts of galaxies should approach a homogeneous scaling with volume at sufficiently large scales. Testing homogeneity is crucial to obtain a correct interpretation of the physical assumptions underlying the current cosmic acceleration and structure formation of the Universe. In this Letter, we use the Baryon Oscillation Spectroscopic Survey to make the first spectroscopic and model-independent measurements of the angular homogeneity scale $\theta_{\rm h}$. Applying four statistical estimators, we show that the angular distribution of galaxies in the range 0.46 < z < 0.62 is consistent with homogeneity at large scales, and that $\theta_{\rm h}$ varies with redshift, indicating a smoother Universe in the past. These results are in agreement with the foundations of the standard cosmological paradigm.Comment: 5 pages, 2 figures, Version accepted by MNRA

Ocorrência de plantas daninhas em áreas submetidas a diferentes sistemas de manejo do solo.

Os objetivos deste trabalho foram: 1- realizar um levantamento florístico de plantas daninhas em área cultivada com milho sob diferentes manejos do solo; e 2- comparar a similaridade das populações entre estas áreas

Mineralization of olive mill wastewater over DSA

Bioenergy recovery from olive mill wastewater (OMW) has been effectively accomplished by anaerobic digestion [1]. Nevertheless, a post treatment is required to attain the discharge limit values. After the anaerobic treatment of OMW, the main issues are related to the remaining organic matter (COD), recalcitrant phenolic compounds (40-50%) and effluent dark-brown colour. The electrochemical treatment is proposed in this work as a final step to mineralise the OMW non-biodegradable fraction. The electrochemical oxidation of OMW anaerobically digested was investigated over DSAs. The performance of RuO2 and IrO2 based DSAs was studied by cyclic voltammetry and bulk electrolysis. The experiments were carried out with alkaline samples from the anaerobic reactor comprising 1 to 10 g COD/L, depending to the digester operational conditions. KNO3 was used as electrolyte, alternatively to the preferred NaCl [2], to avoid obtaining an effluent with higher toxicity than the initial one. It was found that RuO2 based anode was significantly more efficient than IrO2, mainly for the COD removal (Figure 1). With an electrolysis charge of Q=1517 C it was obtained COD removals of 9 and 52%, phenols removals of 72 and 98% and colour removal of 61 and 98%, for IrO2 and RuO2 type DSAs, respectively. The exclusion of the centrifugation/filtration step before the electrochemical treatment was considered, since the anaerobic treatment step reduces considerably the solids fraction. It is concluded that the electrochemical oxidation over DSAs is a suitable second step treatment for OMW disposal after the recovery of its energetic potential. The outcome energy from biogas production can balance or reduce the costs of the electrochemical treatment

Phase diagram of a random-anisotropy mixed-spin Ising model

We investigate the phase diagram of a mixed spin-1/2--spin-1 Ising system in the presence of quenched disordered anisotropy. We carry out a mean-field and a standard self-consistent Bethe--Peierls calculation. Depending on the amount of disorder, there appear novel transition lines and multicritical points. Also, we report some connections with a percolation problem and an exact result in one dimension.Comment: 8 pages, 4 figures, accepted for publication in Physical Review

Strong curvature singularities in quasispherical asymptotically de Sitter dust collapse

We study the occurrence, visibility, and curvature strength of singularities in dust-containing Szekeres spacetimes (which possess no Killing vectors) with a positive cosmological constant. We find that such singularities can be locally naked, Tipler strong, and develop from a non-zero-measure set of regular initial data. When examined along timelike geodesics, the singularity's curvature strength is found to be independent of the initial data.Comment: 16 pages, LaTeX, uses IOP package, 2 eps figures; accepted for publication in Class. Quantum Gra