Titan's influence on Saturnian substorm occurrence

Substorms play an important role in the energization and transport of plasmas in planetary magnetospheres, including the shedding of the mass added by moons in the case of Jupiter and Saturn. Mass shedding occurs through rapid reconnection in the near tail resulting in dipolarization on the magnetospheric side of the reconnection point and plasmoid formation down tail. Observations of these sudden reconnection events in Saturn’s near-tail region provide additional insight into this process. Saturnian substorms, at least on occasion, have a plasmoid formation phase leading to a traveling compression region. Changes in the field strength across reconnection events suggest that open flux has been removed from the tail. The timing of tail reconnection events appears to be controlled by both the orbital phase of Titan, and the variable stretching of the near-tail field as Saturn rotates.Fil: Russell, C. T.. University of California; Estados UnidosFil: Jackman, C. M.. Imperial College London; Reino UnidoFil: Wei, H. Y.. University of California; Estados UnidosFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Imperial College Of Science And Technology; Reino UnidoFil: Dougherty, M. K.. Imperial College Of Science And Technology; Reino Unid

Proton cyclotron wave generation mechanisms upstream of Venus

[1] Long-term observations of proton cyclotron waves in the upstream region of Venus raise the question of under which general solar wind conditions these waves are generated and maintained. The waves are characterized by their occurrence at the local proton cyclotron frequency and left-hand polarization, both in the spacecraft frame. Magnetometer data of the Venus Express spacecraft for two Venus years of observations are analyzed before, during, and after the occurrence of these waves. The configuration of the upstream magnetic field and the solar wind velocity is investigated, to study if the waves are generated from a ring distribution of pickup ions in velocity space or from a parallel pickup ion beam, i.e., for quasi-parallel conditions of solar wind velocity and magnetic field when the solar wind motional electric field is weak. It is found that stable and mainly quasi-parallel magnetic field conditions for up to ∼20 min prior to wave observation are present, enabling sufficient ion pickup and wave growth to obtain observable waves in the magnetometer data. Persistent waves occur mainly under quasi-parallel conditions. This is in agreement with linear theory, which predicts efficient wave growth for instabilities driven by field-aligned planetary ion beams, already for low pickup ion density. The occurrence of highly coherent waves at 4 RV upstream toward the Sun implies that planetary neutral hydrogen is initially picked up at least 5 RV toward the Sun from a sufficiently dense Venus hydrogen exosphere.Fil: Delva, M.. Austrian Academy of Sciences; AustriaFil: Mazelle, C.. Universitá Paul Sabatier; FranciaFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Volwerk, M.. Austrian Academy of Sciences; AustriaFil: Vörös, Z.. University of Innsbruck; AustriaFil: Zhang, T. L.. Austrian Academy of Sciences; Austri

Upstream proton cyclotron waves at Venus near solar maximum

Long-term magnetometer data of Venus Express are analyzed for the occurrence of waves at the proton cyclotron frequency in the spacecraft frame in the upstream region of Venus, for conditions of rising solar activity. The data of two Venus years up to the time of highest sunspot number so far (1 Mar 2011 to 31 May 2012) are studied to reveal the properties of the waves and the interplanetary magnetic field (IMF) conditions under which they are observed. In general, waves generated by newborn protons from exospheric hydrogen are observed under quasi- anti)parallel conditions of the IMF and the solar wind velocity, as is expected from theoretical models. The present study near solar maximum finds significantly more waves than a previous study for solar minimum, with an asymmetry in the wave occurrence, i.e., mainly under antiparallel conditions. The plasma data from the Analyzer of Space Plasmas and Energetic Atoms instrument aboard Venus Express enable analysis of the background solar wind conditions. The prevalence of waves for IMF in direction toward the Sun is related to the stronger southward tilt of the heliospheric current sheet for the rising phase of Solar Cycle 24, i.e., the ?bashful ballerina? is responsible for asymmetric background solar wind conditions. The increase of the number of wave occurrences may be explained by a significant increase in the relative density of planetary protons with respect to the solar wind background. An exceptionally low solar wind proton density is observed during the rising phase of Solar Cycle 24. At the same time, higher EUV increases the ionization in the Venus exosphere, resulting in higher supply of energy from a higher number of newborn protons to the wave. We conclude that in addition to quasi- (anti)parallel conditions of the IMF and the solar wind velocity direction, the higher relative density of Venus exospheric protons with respect to the background solar wind proton density is the key parameter for the higher number of observable proton cyclotron waves near solar maximum.Fil: Delva, M.. Space Research Institute; AustriaFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Volwerk, M.. Space Research Institute; AustriaFil: Lundin, R.. Swedish Institute For Space Physics; SueciaFil: Mazelle, C.. Irap UPS-CNRS; FranciaFil: Romanelli, Norberto Julio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin

Instrumentação e processamento de dados para avaliação de aumento de escala em reator do tipo air-lift.

Entrada correta: FARINAS, C. S

Proton cyclotron waves upstream from Mars: Observations from Mars Global Surveyor

We present a study on the properties of electromagnetic plasma waves in the region upstream of the Martian bow shock, detected by the magnetometer and electron reflectometer (MAG / ER) onboard the Mars Global Surveyor (MGS) spacecraft during the period known as Science Phasing Orbits (SPO). The frequency of these waves, measured in the MGS reference frame (SC), is close to the local proton cyclotron frequency. Minimum variance analysis (MVA) shows that these ‘proton cyclotron frequency’ waves (PCWs) are characterized – in the SC frame – by a left-hand, elliptical polarization and propagate almost parallel to the background magnetic field. They also have a small degree of compressibility and an amplitude that decreases with the increase of the interplanetary magnetic field (IMF) cone angle and radial distance from the planet. The latter result supports the idea that the source of these waves is Mars. In addition, we find that these waves are not associated with the foreshock and their properties (ellipticity, degree of polarization, direction of propagation) do not depend on the IMF cone angle. Empirical evidence and theoretical approaches suggest that most of these observations correspond to the ion–ion right hand (RH) mode originating from the pick-up of ionized exospheric hydrogen. The left-hand (LH) mode might be present in cases where the IMF is almost perpendicular to the Solar Wind direction. PCWs occur in 62% of the time during SPO1 subphase, whereas occurrence drops to 8% during SPO2. Also, SPO1 PCWs preserve their characteristics for longer time periods and have greater degree of polarization and coherence than those in SPO2. We discuss these results in the context of possible changes in the pick-up conditions from SPO1 to SPO2, or steady, spatial inhomogeneities in the wave distribution. The lack of influence from the Solar Wind’s convective electric field upon the location of PCWs indicates that, as suggested by recent theoretical results, there is no clear relation between the spatial distribution of PCWs and that of pick-up ions.Fil: Romanelli, Norberto Julio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Gomez, Daniel Osvaldo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mazelle, C.. Geophysique Planetaire et Plasmas Spatiaux ; FranciaFil: Delva, M.. Space Research Institute; Austri

Aproveitamento do caroço do açaí como substrato para a produção de enzimas por fermentação em estado sólido.

bitstream/CNPDIA-2010/12625/1/BPD30-2009.pd

Evaluation of operational parameters on the precipitation of endoglucanase and xylanase produced by solid state fermentation of Aspergillus niger

In order to develop cost effective processes for converting biomass into biofuels, it is essential to improve enzyme production yields, stability and specific activity. In this context, the aim of this work was to evaluate the concentration of two enzymes involved in the hydrolysis of biomass, endoglucanase and xylanase, through precipitation. Statistical experimental design was used to evaluate the influence of precipitant agent concentration (ammonium sulfate and ethanol), aging time, and temperature on enzyme activity recovery. Precipitant agent concentration and aging time showed a statistically significant effect at the 95% confidence level, on both enzyme activity recoveries. The recovery of endoglucanase with ammonium sulfate and ethanol reached values up to 65 and 61%, respectively. For xylanase, the recovery rates were lower, 27 and 25% with ammonium sulfate and ethanol, respectively. The results obtained allowed the selection of the variables relevant to improving enzyme activity recovery within operational conditions suitable for industrial applications.1726Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Earth-Satelite Monitoring System for Storaged Grains.

Abstract— Despite Brazil being the fifth country in the world in area and population, it is the largest in terms of cultivated land area, becoming a global player related to food production and exportation in the last decades. At the same time, food production increases year by year as do infrastructure problems. One of the crucial problems is related to grain storage. The availability of grain storage now is lower than the total of grain produced, leading producers to promptly sell production that could not be stored. Some companies sell to farmers solutions like silo bags, or plastic bags, as a fast way to overcome this kind of problem. Grains stored in silos are susceptible to insect infestation and fungal growth, depending on initial conditions and storage conditions, which can lead to the loss of part or even the entire stock. The statistics are unclear or do not exist, but it is estimated that technology can reduce losses from 40-50% to 1-2%. This project proposes monitoring post-harvest variables to detect or even forecast potential risks to the quality of the stored product. This solution requires data transmission in areas that lack cellular network coverage. To overcome this limitation and offer a robust solution, the team chose to use a satellite to communicate between two ground stations: one that sends the measured data and the other close to the data center to receive and process the data. This demand was embraced by the company CRIAR Space Systems which is, together with Embrapa, working on solutions such as installing silo bags, monitoring physical and chemical variables in those silos to automatically produce alert signals. These signals can indicate the presence of contamination in the silos due to local fermentation, or due to the presence of high/low bulk moisture and temperature, for instance. Another CRIAR feature is the development of communication antennas for satellite signals with the purpose of further launching a private satellite dedicated to monitoring all farms covered by this service. The scope of this work in progress is to show how this is being planned and applied