4,399 research outputs found
Gravitational Waves from Wobbling Pulsars
The prospects for detection of gravitational waves from precessing pulsars
have been considered by constructing fully relativistic rotating neutron star
models and evaluating the expected wave amplitude from a galactic source.
For a "typical" neutron matter equation of state and observed rotation rates,
it is shown that moderate wobble angles may render an observable signal from a
nearby source once the present generation of interferometric antennas becomes
operative.Comment: PlainTex, 7 pp. , no figures, IAG/USP Rep. 6
La influencia de huertos agroforestales en la sostenibilidad ambiental, en la soberanía alimentaria y en el empoderamiento de las mujeres de una comunidad de Manaus, Amazonas, Brasil.
Este trabajo evalúo el impacto de la adopción de huertos agroforestales en el empoderamiento de las mujeres y en la sostenibilidad ambiental de una comunidad periurbana de Manaus, Amazonas, Brasil
Temperature oscillations of magnetization observed in nanofluid ferromagnetic graphite
We report on unusual magnetic properties observed in the nanofluid
room-temperature ferromagnetic graphite (with an average particle size of
l=10nm). More precisely, the measured magnetization exhibits a low-temperature
anomaly (attributed to manifestation of finite size effects below the quantum
temperature) as well as pronounced temperature oscillations above T=50K
(attributed to manifestation of the hard-sphere type pair correlations between
ferromagnetic particles in the nanofluid)
Watersheds are Schramm-Loewner Evolution curves
We show that in the continuum limit watersheds dividing drainage basins are
Schramm-Loewner Evolution (SLE) curves, being described by one single parameter
. Several numerical evaluations are applied to ascertain this. All
calculations are consistent with SLE, with ,
being the only known physical example of an SLE with . This lies
outside the well-known duality conjecture, bringing up new questions regarding
the existence and reversibility of dual models. Furthermore it constitutes a
strong indication for conformal invariance in random landscapes and suggests
that watersheds likely correspond to a logarithmic Conformal Field Theory (CFT)
with central charge .Comment: 5 pages and 4 figure
The Highly Miniaturised Radiation Monitor
We present the design and preliminary calibration results of a novel highly
miniaturised particle radiation monitor (HMRM) for spacecraft use. The HMRM
device comprises a telescopic configuration of active pixel sensors enclosed in
a titanium shield, with an estimated total mass of 52 g and volume of 15
cm. The monitor is intended to provide real-time dosimetry and
identification of energetic charged particles in fluxes of up to 10
cm s (omnidirectional). Achieving this capability with such a
small instrument could open new prospects for radiation detection in space.Comment: 17 pages, 15 figure
Anomalous Hall effect in superconductors with spin-orbit interaction
We calculate the anomalous Hall conductance of superconductors with
spin-orbit interaction and with either uniform or local magnetization. In the
first case we consider a uniform ferromagnetic ordering in a spin triplet
superconductor, while in the second case we consider a conventional s-wave spin
singlet superconductor with a magnetic impurity (or a diluted set of magnetic
impurities). In the latter case we show that the anomalous Hall conductance can
be used to track the quantum phase transition, that occurs when the spin
coupling between the impurity and electronic spin density exceeds a certain
critical value. In both cases we find that for large spin-orbit coupling the
superconductivity is destroyed and the Hall conductance oscillates strongly.Comment: 10 pages, 6 figure
Simultaneous Papillary Carcinoma in Thyroglossal Duct Cyst and Thyroid
Thyroglossal duct cyst (TDC) is a cystic expansion of a remnant of the thyroglossal duct tract. Carcinomas in the TDC are extremely rare and are usually an incidental finding after the Sistrunk procedure. In this report, an unusual case of a 36-year-old woman with concurrent papillary thyroid carcinoma arising in the TDC and on the thyroid gland is presented, followed by a discussion of the controversies surrounding the possible origins of a papillary carcinoma in the TDC, as well as the current management options
Caracterização da matéria orgânica e mineralógica dos solos das bacias dos rios Acre e Iaco, estado do Acre.
Na região Amazônica, o uso da terra tem levado, no decorrer dos anos, a um mosaico de agroecossistemas que caracterizam e registram a resposta do ambiente às suas alterações. Os conhecimentos pedoambientais e a ação antrópica nestes ambientes são de importância fundamental para o melhor uso dos ecossistemas. O objetivo do presente trabalho foi estudar duas bacias contíguas com componentes pedológicos distintos utilizando como base de estratificação a matéria orgânica e a mineralogia de forma a subsidiar o manejo dos solos nesta região. Nos perfis descritos e coletados nas duas bacias de estudo, bacia do rio Acre e Iaco, foram realizados: extração e fracionamento de substâncias húmicas, fracionamento físico da matéria orgânica para obtenção da fração leve e análises de difratometria por raios X, para análises mineralógicas. Os resultados revelaram o domínio de frações húmicas em superfície, sempre reduzindo em profundidade e diferenças mineralógicas nas bacias estudadas, onde a bacia do rio Acre apresentou minerais mais evoluídos como caulinita e gibbsita e na bacia do rio Iaco, mineralogia do tipo 2:1 como vermiculita e esmectita, que revela o caráter jovens de seus solos e uma maior vulnerabilidade a ação antrópica
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