Manejo comunitário de microbacias hidrográficas em áreas de assentamento do Sudeste Paraense.

bitstream/item/28760/1/Doc237.pdf2ª impressão: 2009

Características morfológicas e produção de matéria seca da palma forrageira cv. gigante adensada submetida à adubação nitrogenada.

Resumo: Sistemas intensivos de cultivo da palma forrageira no Rio Grande do Norte, com plantio adensado e irrigação, permitem cortes com idades inferiores ao manejo tradicional com dois anos. Dessa forma, objetivou-se avaliar as características morfológicas e a produção de matéria seca da palma forrageira cv. gigante adensada submetida à adubação nitrogenada, seis meses após o plantio. O delineamento experimental adotado foi em blocos ao acaso com quatro tratamentos (0, 38, 76 e 152 kg/N/ha) e seis blocos. Foi avaliado número de cladódios por planta, comprimento, largura, espessura, perímetro, área de cladódio (AC), índice de área de cladódio (IAC) e produção de material seca (PMS). Não houve diferença significativa (P>0,05) entre os tratamentos, apresentando valores médios de 5,5 cladódios/planta; 25 cm; 12 cm; 58 cm; 12,5 mm; 302 cm2; 0,15 e 2,6 t/ha, respectivamente para número de cladódios/planta, comprimento, largura, perímetro, espessura, AC, IAC e produção de matéria seca da palma forrageira gigante aos seis meses de idade. A aplicação da adubação nitrogenada não influenciou no crescimento e na produção de matéria seca da palma forrageira cv. gigante. [Morphological characteristics and dry matter yield of cactus pear cv. gigante dense planted with nitrogen fertilization]. Abstract: Cultivated intensive systems of cactus pear at Rio Grande do Norte State, dense sowed and with irrigation, allow cuts before the traditional management with two years of age. The aim of the study was to evaluate the morphological characteristics and dry matter yield of cactus pear cv. gigante dense planted subjected to nitrogen fertilization at six months after planting. The experimental design was randomized blocks with four treatments (0, 38, 76 and 152 kg N / ha) and six blocks. The evaluated parameters were: number of cladodes per plant, length, width, thickness, perimeter, area of cladodes (AC), cladodes area index (CAI) and dry matter yield (DMY). There was no significant difference (P> 0.05) among treatments, showing average values of 5.5 cladodes per plant, 25 cm, 12 cm, 58 cm, 12.5 mm, 302 cm2, 0.15 and 2.6 t / ha, respectively for number of cladodes per plant, length, width, perimeter, thickness, AC, IAC and dry matter yield of cactus pear cv. gigante at six months old. The nitrogen fertilization had no effect on growth and dry matter yield of cactus pear cv. gigante

Density profiles and density oscillations of an interacting three-component normal Fermi gas

We use a semiclassical approximation to investigate density variations and dipole oscillations of an interacting three-component normal Fermi gas in a harmonic trap. We consider both attractive and repulsive interactions between different pairs of fermions and study the effect of population imbalance on densities. We find that the density profiles significantly deviate from those of non-interacting profiles and extremely sensitive to interactions and population imbalance. Unlike for a two-component Fermi system, we find density imbalance even for balanced populations. For some range of parameters, one component completely repels from the trap center giving rise a donut shape density profile. Further, we find that the in-phase dipole oscillation frequency is consistent with Kohn's theorem and other two dipole mode frequencies are strongly effected by the interactions and the number of atoms in the harmonic trap.Comment: Total seven pages with five figures. Published versio

Positive tension 3-branes in an AdS5AdS_{5} bulk

In this work, we review and extend the so-called consistency conditions for the existence of a braneworld scenario in arbitrary dimensions in the Brans-Dicke (BD) gravitational theory. After that, we consider the particular case of a five-dimensional scenario which seems to have phenomenological interesting implications. We show that, in the BD framework, it is possible to achieve necessary conditions pointing to the possibility of accommodating branes with positive tensions in an AdS bulk by the presence of the additional BD scalar field, avoiding in this way the necessity of including unstable objects in the compactification scheme. Furthermore, in the context of time variable brane tension, it is shown that the brane tension may change its sign, following the bulk cosmological constant sign.Comment: 15 pages, new version to appear in JHE

Accretion of Chaplygin gas upon black holes: Formation of faster outflowing winds

We study the accretion of modified Chaplygin gas upon different types of black hole. Modified Chaplygin gas is one of the best candidates for a combined model of dark matter and dark energy. In addition, from a field theoretical point of view the modified Chaplygin gas model is equivalent to that of a scalar field having a self-interacting potential. We formulate the equations related to both spherical accretion and disc accretion, and respective winds. The corresponding numerical solutions of the flow, particularly of velocity, are presented and are analyzed. We show that the accretion-wind system of modified Chaplygin gas dramatically alters the wind solutions, producing faster winds, upon changes in physical parameters, while accretion solutions qualitatively remain unaffected. This implies that modified Chaplygin gas is more prone to produce outflow which is the natural consequence of the dark energy into the system.Comment: 21 pages including 7 figures; published in Classical and Quantum Gravit

Elodie metallicity-biased search for transiting Hot Jupiters IV. Intermediate period planets orbiting the stars HD43691 and HD132406

We report here the discovery of two planet candidates as a result of our planet-search programme biased in favour of high-metallicity stars, using the ELODIE spectrograph at the Observatoire de Haute Provence. One of them has a minimum mass m_2\sin{i} = 2.5 M_Jup and is orbiting the metal-rich star HD43691 with period P = 40 days and eccentricity e = 0.14. The other planet has a minimum mass m_2\sin{i} = 5.6 M_Jup and orbits the slightly metal-rich star HD132406 with period P = 974 days and eccentricity e = 0.34. Both stars were followed up with additional observations using the new SOPHIE spectrograph that replaces the ELODIE instrument, allowing an improved orbital solution for the systems.Comment: 6 pages, 4 figures, to be published in A&

Rendimento de biomassa da palma Miúda irrigada sob doses de adubação orgânica e intensidades de corte.

Resumo: No semiárido nordestino existe um severo déficit na oferta de forragem e a palma forrageira apresenta-se como uma alternativa para melhorar o desempenho dos rebanhos. No entanto, em vários municípios do Rio Grande do Norte ocorrem murchas severas da palma. Assim, a utilização da irrigação com quantidade mínima de água tem sido uma opção para sua produção nessas regiões. A pesquisa objetivou avaliar o efeito da adubação orgânica e de diferentes intensidades de corte sobre a produção de matéria verde (PMV) e seca (PMS) da palma forrageira cv. Miúda (Nopalea cochenillifera) sob condições de irrigação com 12 meses de rebrota. Foi utilizado o delineamento inteiramente casualizado em parcelas subdivididas, onde as doses da adubação orgânica (20, 40 e 60 Mg ha-1 ano-1) constituíram às parcelas e as intensidades de corte (deixando somente o cladódio mãe, todos os primários e todos os secundários) as subparcelas, com seis repetições. O plantio foi feito no espaçamento 2,0 x 0,10 m (50.000 plantas ha-1). A água utilizada na irrigação foi classificada como C4S1T3. A lâmina aplicada foi de cinco litros (2,5 mm) por metro a cada sete dias ou 10 mm por mês. O sistema de irrigação foi o de gotejamento em fileiras simples. As intensidades de corte e adubação orgânica influenciaram a PMV e a PMS. A maior PMS (30,47 Mg ha-1ano-1) foi obtida quando todos os cladódios secundários foram preservados e com aplicação de 37,5 Mg ha-1ano-1de esterco bovino. [Biomass yield of irrigated Miúda spineless forage cactus under organic fertilization doses and different cutting intensities]. Abstract: In the Brazilian Northeast semi-arid region there is a severe deficit in the supply of fodder and forage and cactus pear is an important alternative to improve the performance of the herds. However, in several municipalities of Rio Grande do Norte State occur severe withered of these cacti. Thus, the use of irrigation with a minimum amount of water has been an option for production in these regions. The research aimed to evaluate the effect of organic fertilizer (bovine manure) and different cutting intensities on the production of fresh (PFM) and dry matter (PDM)) of spineless cactus pear cv. Miúda (Nopalea cochenillifera) under irrigation with 12 months of regrowth. A completely randomized design with a split plot was applied, where organic fertilizers doses (20, 40 and 60 Mg ha-1 yr-1) were the main plots and cutting intensities (leaving only the mother cladode, all primary and all secondary cladodes), the subplots, with six replicates. The planting was done in 2.0 x 0.10 m spacing (50,000 plants ha-1). The water used for irrigation was classified as C4S1T3. The lamina applied was 2.5 mm every seven days or 10 mm month-1. The irrigation system was dripping in single rows. The cutting intensities and organic fertilization influenced the PFM and PDM. The highest PDM (30.47 Mg ha-1 yr-1) was obtained when all secondary cladodes were preserved with an application of 37.5 Mg ha-1 yr-1 of bovine manure

Refined parameters and spectroscopic transit of the super-massive planet HD147506b

In this paper, we report a refined determination of the orbital parameters and the detection of the Rossiter-McLaughlin effect of the recently discovered transiting exoplanet HD147506b (HAT-P-2b). The large orbital eccentricity at the short orbital period of this exoplanet is unexpected and is distinguishing from other known transiting exoplanets. We performed high-precision radial velocity spectroscopic observations of HD147506 (HAT-P-2) with the new spectrograph SOPHIE, mounted on the 1.93 m telescope at the Haute-Provence observatory (OHP). We obtained 63 new measurements, including 35 on May 14 and 20 on June 11, when the planet was transiting its parent star. The radial velocity (RV) anomaly observed illustrates that HAT-P-2b orbital motion is set in the same direction as its parent star spin. The sky-projected angle between the normal of the orbital plane and the stellar spin axis, \lambda = 0.2 +12.2 -12.5 deg, is consistent with zero. The planetary and stellar radii were re-determined, yielding R_p = 0.951 +0.039 -0.053 R_Jup, R_s = 1.416 +0.040 -0.062 R_Sun. The mass M_p = 8.62 +0.39 -0.55 M_Jup and radius of HAT-P-2b indicate a density of 12.5 +2.6 -3.6 g cm^{-3}, suggesting an object in between the known close-in planets with typical density of the order of 1 g cm^{-3}, and the very low-mass stars, with density greater than 50 g cm^{-3}.Comment: Submitted to A&A; V2: Replaced by accepted versio