All-sky Relative Opacity Mapping Using Night Time Panoramic Images

An all-sky cloud monitoring system that generates relative opacity maps over many of the world's premier astronomical observatories is described. Photometric measurements of numerous background stars are combined with simultaneous sky brightness measurements to differentiate thin clouds from sky glow sources such as air glow and zodiacal light. The system takes a continuous pipeline of all-sky images, and compares them to canonical images taken on other nights at the same sidereal time. Data interpolation then yields transmission maps covering almost the entire sky. An implementation of this system is currently operating through the Night Sky Live network of CONCAM3s located at Cerro Pachon (Chile), Mauna Kea (Hawaii), Haleakala (Hawaii), SALT (South Africa) and the Canary Islands (Northwestern Africa).Comment: Accepted for publication in PAS

Massive Black Hole Binary Systems in Hierarchical Scenario of Structure Formation

The hierarchical scenario of structure formation describes how objects like galaxies and galaxy clusters are formed by mergers of small objects. In this scenario, mergers of galaxies can lead to the formation of massive black hole (MBH) binary systems. On the other hand, the merger of two MBH could produce a gravitational wave signal detectable, in principle, by the Laser Interferometer Space Antenna (LISA). In the present work, we use the Press-Schechter formalism, and its extension, to describe the merger rate of haloes which contain massive black holes. Here, we do not study the gravitational wave emission of these systems. However, we present an initial study to determine the number of systems formed via mergers that could permit, in a future extension of this work, the calculation of the signature in gravitational waves of these systems.Comment: to match the published version in International Journal of Modern Physics

Método de substituição de seiva para preservação de mourões.

bitstream/CNPF-2009-09/35558/1/com_tec97.pd

Non-Collinear Ferromagnetic Luttinger Liquids

The presence of electron-electron interactions in one dimension profoundly changes the properties of a system. The separation of charge and spin degrees of freedom is just one example. We consider what happens when a system consisting of a ferromagnetic region of non-collinearity, i.e. a domain wall, is coupled to interacting electrons in one-dimension (more specifically a Luttinger liquid). The ferromagnetism breaks spin charge separation and the presence of the domain wall introduces a spin dependent scatterer into the problem. The absence of spin charge separation and the effects of the electron correlations results in very different behaviour for the excitations in the system and for spin-transfer-torque effects in this model.Comment: 6 pages, submitted to Journal of Physics: Conference Series for JEMS 201

OT 060420: A Seemingly Optical Transient Recorded by All-Sky Cameras

We report on a ~5th magnitude flash detected for approximately 10 minutes by two CONCAM all-sky cameras located in Cerro Pachon - Chile and La Palma - Spain. A third all-sky camera, located in Cerro Paranal - Chile did not detect the flash, and therefore the authors of this paper suggest that the flash was a series of cosmic-ray hits, meteors, or satellite glints. Another proposed hypothesis is that the flash was an astronomical transient with variable luminosity. In this paper we discuss bright optical transient detection using fish-eye all-sky monitors, analyze the apparently false-positive optical transient, and propose possible causes to false optical transient detection in all-sky cameras.Comment: 7 figures, 3 tables, accepted PAS

Lorentzian spin foam amplitudes: graphical calculus and asymptotics

The amplitude for the 4-simplex in a spin foam model for quantum gravity is defined using a graphical calculus for the unitary representations of the Lorentz group. The asymptotics of this amplitude are studied in the limit when the representation parameters are large, for various cases of boundary data. It is shown that for boundary data corresponding to a Lorentzian simplex, the asymptotic formula has two terms, with phase plus or minus the Lorentzian signature Regge action for the 4-simplex geometry, multiplied by an Immirzi parameter. Other cases of boundary data are also considered, including a surprising contribution from Euclidean signature metrics.Comment: 30 pages. v2: references now appear. v3: presentation greatly improved (particularly diagrammatic calculus). Definition of "Regge state" now the same as in previous work; signs change in final formula as a result. v4: two references adde

Influência do uso nas características físico químicas de um latossolo amarelo, textura muito argilosa, Manaus, AM.

O objetivo deste estudo foi: verificar alterações em algumas propriedades físico-químicas do solos provocadas pelo uso; a que profundidade ocorre e verificar o efeito da cobertura do solo com kudzu. As áreas em que foram feitas as amostragens se localizam no Campo Experimental da EMBRAPA-CPAA, Km 29 da AM-010, no município de Manaus, AM

The role of damped Alfven waves on magnetospheric accretion models of young stars

We examine the role of Alfven wave damping in heating the plasma in the magnetic funnels of magnetospheric accretion models of young stars. We study four different damping mechanisms of the Alfven waves: nonlinear, turbulent, viscous-resistive and collisional. Two different possible origins for the Alfven waves are discussed: 1) Alfven waves generated at the surface of the star by the shock produced by the infalling matter; and 2) Alfven waves generated locally in the funnel by the Kelvin-Helmholtz instability. We find that, in general, the damping lengths are smaller than the tube length. Since thermal conduction in the tube is not efficient, Alfven waves generated only at the star's surface cannot heat the tube to the temperatures necessary to fit the observations. Only for very low frequency Alfven waves ~10^{-5} the ion cyclotron frequency, is the viscous-resistive damping length greater than the tube length. In this case, the Alfven waves produced at the surface of the star are able to heat the whole tube. Otherwise, local production of Alfven waves is required to explain the observations. The turbulence level is calculated for different frequencies for optically thin and thick media. We find that turbulent velocities varies greatly for different damping mechanisms, reaching \~100 km s^{-1} for the collisional damping of small frequency waves.Comment: 29 pages, 12 figures, to appear in The Astrophysical Journa

COMBUSTION ANALYSIS OF D-LIMONENE AS AN ADDITIVE TO DIESEL-BIODIESEL BLENDS IN COMPRESSION IGNITION ENGINES

Vegetable oils, when subjected to transesterification process generate “vegetable oils esters”, with similar properties as density, cetane number, heating values, air-fuel ratio. However, problems resulting from the higher viscosity, leads to a worst spraying and combustion, formation of undesirable deposits on engine parts and contamination of the lubricant oil. Due to these problems, it is interesting to study an additive, also derived from biomass, to improve the characteristics of biodiesel for a suitable use in diesel engines. This paper proposes an additive (d-limonene obtained from orange peel) and preliminary results obtained from the tests in a stationary diesel engine fueled with mixtures of diesel/biodiesel/d-limonene, in different concentration to compare with a regular diesel-biodiesel blend and analyzes the influence of the additive on the combustion process. The diesel oil used was purchased from BR supply network (containing 7% biodiesel in its composition) and two blends with different concentrations of the additive (1% and 3% of d-limonene) were prepared and tested. Diesel without additive was also tested. The effects of the DS10 addititivation with d-limonene in the combustion process of a diesel engine have been analyzed, the results obtained were satisfactory showing the positive effects in the combustion process with the addition of d-limonene in diesel-biodiesel blends, decreasing the ignition delay around 2 degrees and showing an improvement in the cetane number of the fuel

Leg-focused high-weight resistance training improves ventricular stroke volume, exercise capacity and strength in young patients with a Fontan circulation

INTRODUCTION: Effective therapy to improve exercise capacity in Fontan patients is lacking. Leg-focused high-weight resistance training might augment the peripheral muscle pump and thereby improve exercise capacity.METHODS: This randomized semi-cross-over controlled trial investigated effects of a 12-week leg-focused high-weight resistance training plus high-protein diet, on (sub)maximal exercise capacity, cardiac function (assessed with cardiovascular magnetic resonance), muscle strength and quality of life in pediatric Fontan patients.RESULTS: Twenty-eight pediatric Fontan patients were included, 27 patients, (median age 12.9 [10.5-15.7]), successfully completed the program. Peak oxygen uptake (PeakVO2) at baseline was reduced (33.3 ml/kg/min [27.1-37.4],73% [62-79] of predicted). After training PeakVO2/kg and Peak workload improved significantly with +6.2 ml/kg/min [95%CI: 3.4-9.0](+18%) p&lt;0.001 and +22 Watts [95%CI: 12-32](+18%) p&lt;0.001 respectively, compared to the control period. Indexed single ventricle stroke volume increased significantly (43 ml/beat/m2 [40-49] versus 46 [41-53], p=0.014), as did inferior vena cava flow (21 ml/beat/m2 [18-24] versus 23 [20-28], p=0.015), while superior vena cava flow remained unchanged. Strength of all measured leg muscles increased significantly compared to the control period. Self-reported quality of life improved on the physical functioning and change in health domains of the child health questionnaire, parent-reported quality of life improved on the bodily pain, general health perception, and change in health domains compared to the control period.CONCLUSION:In a relatively large group of 27 older Fontan children, 12-weeks of leg-focused high-weight resistance training improved exercise capacity, stroke volume, (sub)maximal exercise capacity, muscle strength, and domains of quality of life.</p