Optimization of satellite constellations in the moon

Nowadays, we return to live a period of lunar exploration. China, Japan and India heavily invest in missions to the moon, and then try to implement manned bases on this satellite. These bases must be installed in polar regions due to the apparent existence of water. Therefore, the study of the feasibility of satellite constellations for navigation, control and communication recovers importance. The Moon's gravitational potential and resonant movements due to the proximity to Earth as the Kozai-Lidov resonance, must be considered in addition to other perturbations of lesser magnitude. The usual satellite constellations provide, as a basic feature, continuous and global coverage of the Earth. With this goal, they are designed for the smallest number of objects possible to perform a specific task and this amount is directly related to the altitude of the orbits and visual abilities of the members of the constellation. However the problem is different when the area to be covered is reduced to a given zone. The required number of space objects can be reduced. Furthermore, depending on the mission requirements it may be not necessary to provide continuous coverage. Taking into account the possibility of setting up a constellation that covers a specific region of the Moon on a non-continuous base, in this study we seek a criterion of optimization related to the time between visits. The propagation of the orbits of objects in the constellation in conjunction with the coverage constraints, provide information on the periods of time in which points of the surface are covered by a satellite, and time intervals in which they are not. So we minimize the time between visits considering several sets of possible constellations and using genetic algorithms.

Delimitação do Embasamento da Bacia de Taubat

The aim of this study is to define the basement map of the Taubaté Basin applying geostatistics to seismic, gravimetric and deep wells data. The study consisted of the interpretation of eleven seismic sections obtained in the central and northeastern portions of the basin. The altitude of the basement and the distribution of faults was determined based on these sections. New information was obtained from 79 wells located mainly in the regions of São José dos Campos and Jacareí. The method of kriging with an external drift was applied, using seismic and well data as the main variables and the gravimetric map as the secondary variable. The basement contour map obtained has a strong correlation with the main faults. It was possible to obtain a better resolution in the region of São José dos Campos and in the northeast area, where the vast majority of wells are located.

Influence of nonsphericity of planetary satellites and perturbation of the third-body on the artificial satellites motion

Some orbital characteristics of lunar artificial satellites is presented taking into account the perturbation of the third-body in elliptical orbit and the non-uniform distribution of mass of the Moon. We consider the development of the non-sphericity of the Moon in zonal spherical harmonics up to the ninth order and sectorial harmonic C 22 due to the lunar equatorial ellipticity. The motion of the artificial satellite is studied under the single-averaged analytical model. The average is applied to the mean anomaly of the satellite to analyze low-altitude orbits which are of highest importance for future lunar missions. We found families of frozen orbits with long lifetimes for the problem of an orbiter travelling around the Moon.

Paleosuperfícies e perfis bauxíticos no Planalto de Poços de Caldas, São Paulo/Minas Gerais, Brasil

This work has the objective of correlating altitude with the bauxite profiles in the Poços de Caldas Plateau in order to identify paleosurfaces. Then, bauxite profiles found in the Plateau have been classified and mapped through DEM. Three different types of bauxite profiles are highlighted in the area: (1) Rim Profiles which are well-developed and thick and are located in the areas of highest altitude in the Plateau; (2) Plateau Profiles which are not very thick and very clayey, normally appear in the lower portion of the landscape; (3) Reworked Profiles, characterized by bauxite reworked fragments composed by similar materials found in the tops of Rim and Plateau Profiles. After relating altitude to the constituting materials of the bauxite profiles, it is noticed that there are occurrences of Rim Bauxite Profiles located in altitudes of Plateau Profiles and Reworked Profiles located over Rim Profiles, above 1,400 meters of altitude. In the opposite direction, tops of the same elevation are found, where there should be Rim Profiles, there are rocky outcrops observed in field, without any evidence of laterite profiles. It is concluded, therefore, that the elevation rates by themselves, at least in this area, are not good enough references to determine the existence and distribution of paleosurfaces.

Potential hydroponics systems for seed potato production in tropical conditions

In tropical conditions such as Brazil, depending on the local altitude, potatoes can be planted and harvested in every month of the year successively, which favors pest and disease incidence, especially aphids transmission viruses. Therefore, obtaining good yield depends on constant pest and disease control and quality potato seed acquisition. One of the main strategies to increase a healthier seed potato multiplication rate and production is the use of hydroponic systems, with or without substrates, in channels, pots or boxes. In 2005 and 2008, researches investigated several hydroponic systems with and without the use of substrates. In the hydroponic systems without substrate, the aeroponic system resulted in the highest multiplication rate, with 47 tubers plant-1 compared to NFT and DFT, 35 and 37 tubers plant-1, respectively. With the use of substrates, the pot system obtained better results, reaching 12 tubers plant-1, followed by the capillary system and boxes, with 8 and 7 tubers plant-1, respectively. Potato seed production was influenced by hydroponics systems. Among hydroponic systems with substrate, the pots were shown as the best option. However, higher yields were obtained in the hydroponics systems without substrate, with the aeroponic system that provided the best results.

Spin stabilized satellite's attitude propagation with quaternions

This paper presents a study of a modeling scheme for the spin stabilized satellites attitude, entirely developed in terms of quaternion parametrization. The analysis includes numerical propagation of the rotational motion equation, considering the influence of the following torques: aerodynamic, gravity gradient, residual magnetic, eddy currents and the one due to the Lorentz force. Applications are developed considering the Brazilian Spin Stabilized Satellites SCD1 and SCD2, which are quite appropriated for verification and comparison of the theory with the real data generated and processed by the INPE's Satellite Control Center (SCC). The results show that for SCD1 and SCD2 the influence of the eddy current torque is bigger than the others ones, not only due to the orbit altitude, but also to other specific satellites characteristics. The influence of the torque due to Lorentz force is smaller than the others ones because of the dimension and the electrical charges of the SCD1 and SCD2. In all performed tests the errors remained within the dispersion range specified for the attitude determination system of INPE's SCC. The results show the feasibility of using the quaternion attitude parametrization for modeling the satellite dynamics of spin stabilized satellites.

Mume clonal rootstocks for 'Aurora-1' peach in São Paulo State, Brazil

In spite of significant results achieved with scion genetic improvement in stone fruits, the peach culture in Brazil still needs studies and new technologies regarding the use of rootstocks. A wide research project has being developed at the Faculdade de Ciências Agrárias e Veterinárias (FCAV/UNESP), Jaboticabal, Brazil, dealing with the use of mume clones (Prunus mume) as rootstocks for peach trees, which has produced promising results. In this research, two mume genotypes propagated by herbaceous cuttings were tested as rootstocks for peach cultivar Aurora-1. Three different tree spacing were used: 6 x 2 m, 6 x 3 m and 6 x 4 m. The experiment was carried out at Vista Alegre do Alto (21°10'14 S, 48°37'45 W, 700 m of altitude), São Paulo State, Brazil. Growing field conditions included Hapludalfs soil with medium sandy texture and using micro sprinkler irrigation. The region has an average chilling accumulation 17.9 hours per year. The evaluations were taken in 2005 and 2006 (2nd and 3rd year after planting, respectively). The trunk diameter was evaluated every three months, from the 24th to the 41st month after planting, totalizing seven evaluations. Plants on 'Rigitano' had higher trunk diameter on the 33rd, 39th and 41st month after planting (May/06, November/06 and February/07, respectively). No significant differences were observed in the other evaluations. The diameter at 5 cm above to the graft point was larger than below, but no incompatibility symptoms were observed between rootstocks and scion. Spacing tested did not influence trunk diameter, phenology and flower bud production in 'Aurora-1' scion. In conclusion, 'Rigitano' and 'Clone 15' are recommended for high density plantings of peach 'Aurora-1' in Brazil, and the 6 x 2 m spacing can be recommended, with productivity advantages for peach under low air relative humidity and mild winter conditions. © ISHS 2012.

Primeiro relato de atividade patogênica de Hirsutella thompsonii (Fischer) sobre o ácaro-da-erinose-da-lichia Aceria litchii (Keifer)

The litchi erineum mite, Aceria litchii (Keifer) is found in all producing regions attacking leaves and flowers of litchi plants. The mite attack young leaves and causes the erinea on leaf surface, which later become brown galls with velvety appearance. Severe attacks can cause leaf drop and destruction of branches end directly production affecting. In 2009 year it was registered a heavy infestation of the pest on litchi plants (Litchi chinensis Sonn.) in the municipality of Casa Branca, São Paulo, Brazil (2127'O; 4702'S; 679 m altitude). In June, many galls caused by mite infestation showed a mycelium of white coloration and many eriophyid dead. The fungus was identified as Hirsutella thompsonii (Fischer). The results suggest that galls may facilitate the fungus development and its permanence on the plants. Thus, the possibility of mite biological control with H. thompsonii should be investigated.

Inoculação de sementes com bactéria diazotrófica e aplicação de nitrogênio em cobertura e foliar em milho

Considering the importance of nitrogen management and its biological fixation with diazotrophic bacteria, this study was carried out aiming to evaluate the agronomic performance of maize, in response to seed inoculation with Azospirillum brasilense and nitrogen application in side-dressing and leaf. The experiment was conducted in Selvíria, Mato Grosso of Sul State, Brazil, during the growing season 2010/2011, on a clayey Rhodic Haplustox (20° 20' S and 51° 24' W, with altitude of 340 m). Sixteen treatments were established with four replications, in randomized blocks with the combination of the factors A. brasilense (with and without inoculante), nitrogen rate (0 and 90 kg ha-1, in V5 growth stage) and urea leaf application (0, 4, 8 and 12%: application in V5 and V8 growth stage). The maize hybrid used was the DKB 390 YG®, sowed in the row spacing of 0.9 m. Parameters measured were productive and morphological components of culture and crop yield. Increase in maize yield by seed inoculation with A. brasilense was observed. The application of 90 kg ha -1 of nitrogen in side-dressing provided higher chlorophyll leaf index, stalk diameter and prolificacy, however, the yield not was increased. The application of urea leaf did not agronomic efficiency and, therefore, should not be used as the unique form of supply and alternative to nitrogen addition to crop.

Seasonal effects on semen and testosterone in zebu and taurine bulls

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Coeficientes de cultura para a melancieira irrigada por gotejamento no Vale do Gurgueia - PI

The aim of this work was to determine crop coefficients (Kc) of drip irrigated watermelon in the climatic and growing conditions of the Gurgueia Vale, State of Piaui, Brazil, located at 8 ° 26' S, 43 ° 47' W and altitude of 251 m. The reference evapotranspiration (ET0) was determined by the sum of hourly values of ET0 obtained by the Penman-Monteith method parameterized by FAO with climatic data obtained from an automatic weather station. The daily crop evapotranspiration (ETc) was measured by three weighing lysimeters of load cells. Aiming high fruit yield in this region, we recommend that the following local values of Kc and Kcb be used for planning and management of irrigation, respectively: initial stage (crop establishment) - 0.34 and 0.24; intermediate stage (growth and fruit maturation) - 1.16 and 1.10; end stage (harvest) - 0.93 and 0.86. These Kc values of initial and intermediate phases are statistically higher than the values of Kc and Kcb already adjusted according to the methodology presented in the FAO Irrigation and Drainage Paper 56. The values of Kc and Kcb at the end phase are not statistically different from the FAO values.

Lodos de esgoto, escória de aciaria e lama cal na cultura da soja sob sistema plantio direto em latossolo vermelho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comportamento de milho (Zea Mays L.) e propriedades físicas do solo, no sistema plantio direto, em resposta a aplicação de fertilizante organomineral

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biogeografia histórica do gênero Brachygastra Perty, 1833 (Hymenoptera: Vespidae: Polistinae: Epiponini)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uso de habitats e ecomorfologia de girinos na Serra da Mantiqueira, SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)