Non-linear Poisson-Boltzmann Theory for Swollen Clays

The non-linear Poisson-Boltzmann equation for a circular, uniformly charged platelet, confined together with co- and counter-ions to a cylindrical cell, is solved semi-analytically by transforming it into an integral equation and solving the latter iteratively. This method proves efficient, robust, and can be readily generalized to other problems based on cell models, treated within non-linear Poisson-like theory. The solution to the PB equation is computed over a wide range of physical conditions, and the resulting osmotic equation of state is shown to be in fair agreement with recent experimental data for Laponite clay suspensions, in the concentrated gel phase.Comment: 13 pages, 4 postscript figure

Hibridação intrespecífica em algodoeiro visando a seleção de cultivares com novas colorações de fibra.

bitstream/CNPA/20779/1/DOC165.pd

A Search for Molecular Gas in GHz Peaked Spectrum Radio Sources

We present searches for molecular gas (CO, OH, CS, and Ammonia) in six GHz Peaked Spectrum (GPS) radio sources. We do not detect gas in any source and place upper limits on the mass of molecular gas which are generally in the range 1E9 to a few times 1E10 solar masses. These limits are consistent with the following interpretations: (1) GPS sources do not require very dense gas in their hosts, and (2) The GPS sources are unlikely to be confined by dense gas and will evolve to become larger radio sources

Gluon saturation and the Froissart bound: a simple approach

At very high energies we expect that the hadronic cross sections satisfy the Froissart bound, which is a well-established property of the strong interactions. In this energy regime we also expect the formation of the Color Glass Condensate, characterized by gluon saturation and a typical momentum scale: the saturation scale $Q_s$. In this paper we show that if a saturation window exists between the nonperturbative and perturbative regimes of Quantum Chromodynamics (QCD), the total cross sections satisfy the Froissart bound. Furthermore, we show that our approach allows us to describe the high energy experimental data on $pp/p\bar{p}$ total cross sections.Comment: 6 pages, 5 figures. Includes additional figures, discussion and reference

Dark matter from cosmic defects on galactic scales?

We discuss the possible dynamical role of extended cosmic defects on galactic scales, specifically focusing on the possibility that they may provide the dark matter suggested by the classical problem of galactic rotation curves. We emphasize that the more standard defects (such as Goto-Nambu strings) are unsuitable for this task, but show that more general models (such as transonic wiggly strings) could in principle have a better chance. In any case, we show that observational data severely restricts any such scenarios.Comment: Submitted to Phys. Rev. D (Brief Reports). v2: Reference added and some typos corrected, matches published versio

Iliopsoas Release for Internal Snapping Hip using a Minimally Open Medial Hip Approach-Case Report

Internal snapping hip is a recognized cause of hip pain caused by recurrent subluxation of the iliopsoas tendon. When conservative treatment fails, surgical release of the iliopsoas tendon may be indicated using an arthroscopic or open hip approach. Results have been better with arthroscopic release. We report a case of a 32-year-old active female with a painful internal snapping hip. The right hip extension from a flexed position produced a strong and audible snap. A tenotomy of the iliopsoas in combination with a resection of the lesser trochanter was performed, using a limited medial hip approach different than the one described by Ludloff or Ferguson. The pain and snapping phenomenon were solved; however, a slight heterotopic ossification, as well as a weakness in the flexion of the hip was noted after the procedure, with no functional limitation. The minimally invasive medial hip approach appears to be a simple, reproducible and successful operation for the treatment of an internal snapping hip caused by the iliopsoas tendon, namely in orthopaedics departments with limited experience in hip arthroscopic approach, but it is not superior to arthroscopic release.info:eu-repo/semantics/publishedVersio

Pestalotiopsis spp. associado à palmeira jarina no estado do Pará.

Anais do 36º Congresso Paulista de Fitopatologia, 2013, São Paulo

Detecting relevant tweets in very large tweet collections: the London Riots case study

In this paper we propose to approach the subject of detecting relevant tweets when in the presence of very large tweet collections containing a large number of different trending topics. We use a large database of tweets collected during the 2011 London Riots as a case study to demonstrate the application of the proposed techniques. In order to extract relevant content, we extend, formalize and apply a recent technique, called Twitter Topic Fuzzy Fingerprints, which, in the scope of social media, outperforms other well known text based classification methods, while being less computationally demanding, an essential feature when processing large volumes of streaming data. Using this technique we were able to detect 45% additional relevant tweets within the database