Analytical attitude propagation with non-singular variables and gravity gradient torque for spin stabilized satellite

An analytical approach for the spin stabilized satellite attitude propagation is presented using the non-singular canonical variables to describe the rotational motion. Two sets of variables were introduced for Fukushima in 1994 by a canonical transformation and they are useful when the angle between z-satellite axis of a coordinate system fixed in artificial satellite and the rotational angular momentum vector is zero or when the angle between Z-equatorial axis and rotation angular momentum vector is zero. Analytical solutions for rotational motion equations and torque-free motion are discussed in terms of the elliptic functions and by the application of some simplification to get an approximated solution. These solutions are compared with a numerical solution and the results show a good agreement for many rotation periods. When the mean Hamiltonian associated with the gravity gradient torque is included, an analytical solution is obtained by the application of the successive approximations' method for the satellite in an elliptical orbit. These solutions show that the magnitude of the rotation angular moment is not affected by the gravity gradient torque but this torque causes linear and periodic variations in the angular variables, long and short periodic variations in Z-equatorial component of the rotation angular moment and short periodic variations in x-satellite component of the rotation angular moment. The goal of this analysis is to emphasize the geometrical and physical meaning of the non-singular variables and to validate the approximated analytical solution for the rotational motion without elliptic functions for a non-symmetrical satellite. The analysis can be applied for spin stabilized satellite and in this case the general solution and the approximated solution are coincidence. Then the results can be used in analysis of the space mission of the Brazilian Satellites. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

Periodic waves and solitons of two-photon propagation

We study the two-photon propagation (TPP) modelling equations. The one-phase periodic solutions are obtained in an effective form. Their modulation is investigated by means of the Whitham method. The theory developed is applied to the problem of creation of TPP solitons on the sharp front of a long pulse.

Understorey fire propagation and tree mortality on adjacent areas to an Amazonian deforestation fire

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

The effect of gene tubC on the vegetative growth of benomyl-resistant strains of Aspergillus nidulans

Two benomyl-resistant mutants, benD3 tubC41 and benD4 tubC42, of Aspergillus nidulans were isolated after UV treatment. The tubC mutations permitted good conidiation of these strains in culture media containing benomyl and were responsible for increasing their benomyl resistance levels. This implies that β3-tubulin, a product of the tubC gene, in addition to being involved in fungal conidiation, participates in the vegetative growth of the fungus. The tubC gene was located in linkage group I.

Study of some brazilian myrtaceae in jaboticabal-sp

The family Myrtaceae is one of the most important related to fruit species. In Brazil it encloses more than 100 species of native fruit from North to South of the country (Giacometti, 1992; Donadio, 1992; Mattos, 1992). The genus Eugenia, Campomanesia, Psidium and Myrciaria are the most important, grouping most of the species of some importance. The germplasm bank of the Universidade Estadual Paulista includes some of the major species. Some characteristics are typical for most of the Myrtaceae fruit species. The most relevant are the long juvenile period presented by the trees, taking long time to produce, when propagated by seed; the slow growing tree behavior; difficult to propagated by vegetative means; large variability in trees obtained by seed propagation. The cited characteristics are commented for some species as well as the fruit quality, from data obtained in trees at the same ecological conditions. The species evaluated are: 1) Eugenia stipitata Me Vaugh; 2) Eugenia tomentosa Cambes; 3) Eugenia brasiliensis Lam.; 4) Eugenia uniflora L.; 5) Eugenia luchsnathiana Berg.; 6) Eugenia uvalha Cambess; 7) Camponesia spp; 8) Plinia edulis (Veil. Sobral); 9) Eugenia involucrata D.C.; 10) Psidium acutangulum Mart.; 11) Myrciaria dubia Me Vaugh; 12) Eugenia guabiju Berg. The main conclusions based on the data analysed are: The fruits of some species present good general characteristics, mainly for fresh consumption, as high Vitamin C, sugars, pulp and other characteristics; 'Araca-boi' presents some good fruit characteristics, but is more adapted for processing, by its high acidity; Some species present low % of edible portion and need to be improved to gain commercial acceptance, mainly the 'cabeludinha' and 'cambuca'.

Systematic vegetative anatomy and ensiform leaf development in Xyris (Xyridaceae)

Ensiform leaf development in monocotyledons follows a broadly similar sequence in a wide range of relatively unrelated taxa, indicating a plastic developmental pattern, possibly associated with stressed environmental conditions, since Xyris species tend to grow in relatively damp but nutrient-poor environments. The bifacial leaf sheath surrounds the apex and the subadjacent primordium. A conical unifacial leaf tip 'Vorlauferspitze' is established at an early stage, followed by extension growth in the region behind it, generating a unifacial ensiform blade. Root and rhizome structure are also described in a systematic context, particularly in comparison with related taxa in Xyridaceae and other commelinoid monocotyledons, although information on these structure is relatively sparse.

Nonlinear short-wave propagation in ferrites

In this paper we discuss the propagation of nonlinear electromagnetic short waves in ferromagnetic insulators. We show that such propagation is perpendicular to an externally applied field. In the nonlinear regime we determine various possible propagation patterns: an isolated pulse, a modulated sinusoidal wave, and an asymptotic two-peak wave. The mathematical structure underlying the existence of these solutions is that of the integrable sine-Gordon equation.

A tobacco cDNA reveals two different transcription patterns in vegetative and reproductive organs

In order to identify genes expressed in the pistil that may have a role in the reproduction process, we have established an expressed sequence tags project to randomly sequence clones from a Nicotiana tabacum stigma/style cDNA library. A cDNA clone (MTL-8) showing high sequence similarity to genes encoding glycine-rich RNA-binding proteins was chosen for further characterization. Based on the extensive identity of MTL-8 to the RGP-1a sequence of N. sylvestris, a primer was defined to extend the 5′ sequence of MTL-8 by RT-PCR from stigma/style RNAs. The amplification product was sequenced and it was confirmed that MTL-8 corresponds to an mRNA encoding a glycine-rich RNA-binding protein. Two transcripts of different sizes and expression patterns were identified when the MTL-8 cDNA insert was used as a probe in RNA blots. The largest is 1,100 nucleotides (nt) long and markedly predominant in ovaries. The smaller transcript, with 600 nt, is ubiquitous to the vegetative and reproductive organs analyzed (roots, stems, leaves, sepals, petals, stamens, stigmas/styles and ovaries). Plants submitted to stress (wounding, virus infection and ethylene treatment) presented an increased level of the 600-nt transcript in leaves, especially after tobacco necrosis virus infection. In contrast, the level of the 1,100-nt transcript seems to be unaffected by the stress conditions tested. Results of Southern blot experiments have suggested that MTL-8 is present in one or two copies in the tobacco genome. Our results suggest that the shorter transcript is related to stress while the larger one is a flower predominant and nonstress-inducible messenger.

Soliton propagation in a medium with Kerr nonlinearity and resonant impurities: A variational approach

The soliton propagation in a medium with Kerr nonlinearity and resonant impurities was studied by a variational approach. The existence of a solitary wave was shown within the framework of a combined nonintegrable system composed of one nonlinear Schrödinger and a pair of Bloch equations. The analytical solution which was obtained, was tested through numerical simulations confirming its solitary wave nature.

Cultivation systems and planting seasons effects on the vegetative growing of net melon cultivars

Growth effects of cultivation on soil, sand and commercial substrate, on summer and winter time, of 'Bonus #2', 'Don Carlo's and 'Hy Mark' were assessed. The experiments were conducted in a greenhouse of FCAV-UNESP, in Jaboticabal- SP, Brazil, 21° 15' 22 S, 48° 18'58 W, and an altitude of 595 m, comprising the period from November '99 to April 2000 (Summer), and from July to November 2000 (Winter). On soil cultivation, chemical nutrients were used, and the plants received drip irrigation. On sand, fertigation with recirculation of the nutrient solution were used, and slabs and fertigation with non circulating nutrient solution was used with commercial substrate. 'Bonus #2', grown on sand and in the summer season had improved plant height, internodes length, stem diameter, leaf area and dry matter of shoots and roots. 'Hy Mark', when cultivated on commercial substrate had lower growth. During winter season, the growth was slower.

Effect of benzylaminopurine (BAP) on clonal propagation rate of Curcuma longa L.

Curcuma longa L. is used in many countries for its flavor, and medicinal and cosmetic attributes, as well as for its peculiar starch characteristics. These factors have driven an interest in the in vitro propagation of this species, looking for germplasm bank maintenance, production of disease free plants, genetic variability induction from callus, and as a tool for starch research. However, there are few reports concerning the micropropagation of Curcuma longa. The in vitro propagation rate of this species, cultured under two benzylaminopurine (BAP) concentrations, was the aim of this research.

In vitro propagation of Maytenus ilicifolia (Celastraceae) as potential source for antitumoral and antioxidant quinomethide triterpenes production. A rapid quantitative method for their analysis by reverse-phase high-performance liquid chromatography

Cell culture of Maytenus ilicifolia were established in order to produce and to quantify the antitumoral and antioxidant quinonemethide triterpenes. In vitro calli were induced from leaf explants of native plants and cultured in semi-solid medium under controlled conditions of humidity, temperature and photoperiod. The quinonemethide triterpenes showed maximum accumulation in the logarithmic phase growth of the cell culture. A rapid, sensitive and reliable reverse-phase HPLC method was used for quantitative determination of the antitumoral and antioxidant quinonemethide triterpenes, 22β-hydroxymaytenin and maytenin in callus of Maytenus ilicifolia. Well resolved peaks with good detection response and linearity in the range 1.0 - 100 μg/mL were obtained. This quantitative work was performed by an external standard method.

Propagation of ship waves on a sloping bottom

The numerical model FUNWAVE was adapted in order to simulate the generation and propagation of ship waves to shore, including phenomena such as refraction, diffraction, currents and breaking of waves. Results are shown for Froude numbers equal to 0.8, 1.0 and 1.1, in order to verify the refraction of the wave pattern, identify breaking conditions and to investigate the wave generation scheme as a moving pressure at the free surface. © 2009 World Scientific Publishing Co. Pte. Ltd.