Pesquisa-ação: fundamentos do planejamento e do diagnóstico em comunidades rurais.

O presente trabalho nasceu da necessidade de divulgar um aspecto operacional da metodologia da pesquisa-ação chamada de diagnóstico. O estudo tem sido realizado por uma equipe de pesquisadores, extensionistas e agricultores nos Estados da Bahia, Pernambuco e Paraíba através da Embrapa Mandioca e Fruticultura, EMATER-PB, EBDA, EMATER-PE. No Brasil, as comunidades, municípios e regiões apresentam-se de forma diferenciada, com menor ou maior complexidade. Logo, para se intervir em determinada área para promover um processo de mudanças e necessário compreender primeiro sua realidade.bitstream/item/81305/1/Pesquisa-Acao-Jose-Cerqueira-Documentos-93-2000.pd

GMOS-IFU Spectroscopy of 167-317 (LV2) Proplyd in Orion

We present high spatial resolution spectroscopic observations of the proplyd 167-317 (LV2) near the Trapezium cluster in the Orion nebula, obtained during the System Verification run of the Gemini Multi Object Spectrograph (GMOS) Integral Field Unit (IFU) at the Gemini South Observatory. We have detected 38 forbidden and permitted emission lines associated with the proplyd and its redshifted jet. We have been able to detect three velocity components in the profiles of some of these lines: a peak with a 28-33 km/s systemic velocity that is associated with the photoevaporated proplyd flow, a highly redshifted component associated with a previously reported jet (which has receding velocities of about 80-120 km/s with respect to the systemic velocity and is spatially distributed to the southeast of the proplyd) and a less obvious, approaching structure, which may possibly be associated with a faint counter-jet with systemic velocity of (-75 +/- 15) km/s. We find evidences that the redshifted jet has a variable velocity, with slow fluctuations as a function of the distance from the proplyd. We present several background subtracted, spatially distributed emission line maps and we use this information to obtain the dynamical characteristics over the observed field. Using a simple model and with the extinction corrected Halpha fluxes, we estimate the mass loss rate for both the proplyd photoevaporated flow and the redshifted microjet, obtaining (6.2 +/- 0.6) x 10^{-7} M_sun/year and (2.0 +/- 0.7) x 10^{-8} M_sun/year, respectively.Comment: 26 pages, 10 figures (6 are in colors), accepted by A

Magnetically Driven Outflows in a Starburst Environment

We here investigate the possibility that the observed collimated outflows in luminous infrared galaxies (LIGs) and some Seyfert galaxies can be produced in a starburst (SB) environment. A nuclear disk can be quickly produced by gas infall during star formation in a rotating, stellar cluster. We find that massive nuclear SBs with core disk masses M_d \sim 10^8 - 10^9 M_{\odot}, and supernova rates \nu_{SN} \simeq 5 \times 10^{-3} - 2 yr^{-1} (which are consistent with the \nu_{SN} values inferred from the observed non-thermal radio power in source candidates) may inject kinetic energies which are high enough to blow out directed flows from the accreting disk surface, within the SB lifetimes. In our models, the acceleration and collimation of the nuclear outflow are provided by magnetic fields anchored into the rotating SB-disk. The emerging outflow carries a kinetic power that is only a small fraction (a few percent) of the supernovae energy rate produced in the SB. Based on conditions determined from observed outflows and disks, we find that moderate disk magnetic fields (\gtrsim 8 \times 10^{-4} G) are able to accelerate the outflows up to the observed terminal velocities (\lesssim few 100 km s^{-1} in the case of the Seyfert galaxies, and \sim 400 - 950 km s^{-1} in the case of the LIGs). The outflow is produced within a wind zone in the disk of radius \lesssim 100 pc in the LIGs, and \lesssim 10 pc in the Seyferts, with wind mass loss to disk accretion rate ratios \dot M_w /\dot M_d \gtrsim 0.1 (where \dot M_d \sim 100 M_{\odot} yr^{-1}). The observation of rotating nuclear disks of gas within few 100 pc scales in source candidates like the LIG Arp 220, and magnetized outflows provide observational support for the picture drawn here.Comment: 31 pages, Latex file, 1 Figure, accepted for publication in the Astrophys. Journa

Edible coatings from galactomannans and their application to tropical fruits

Edible coatings play an important role in the quality and in the resistance to transportation, storage and display of a wide range of fresh and processed foods. Polysaccharide coatings with an oil-free appearance and low caloric content can be used to increase the shelf life of fresh fruits, since they allow the modification of the internal gas composition of fruits, retarding their senescence. The objective of this work was to study the ability of seed galactomannans, with different manose:galactose relation, from the Leguminosae Caesalpinea pulcherrima (2.8:1) and Adenanthera pavonina (2:1) as coatings to extend the shelf life of acerola (Malpighia emarginata), cajá (Spondias lutea), mango (Mangifera indica), pitanga (Eugenia uniflora) and sirigüela (Spondias purpurea). Fresh fruits surface properties, galactomannans relative viscosity as well as the wetting capacity of the coatings were determined. Galactomannans were obtained from seed endosperm and their toxicological safety was determined by oral administration to Wistar adult rats. No toxic effects were detected. Blends with different galactomannan:glycerol proportions were tested as coatings. The blends wettability was determined by the spreading coefficient using the sessile-drop method. The best proportions of galactomannan/glycerol were determined for coatings of C.pulcherrima and A.pavonina in the various fruits tested.Fundação para a Ciência e a Tecnologia (FCT) ; Alfa-Valnatura; CNPq; CAPES; FUNCAP.Alfa-Valnatur

Emission lines from rotating proto-stellar jets with variable velocity profiles. I. Three-dimensional numerical simulation of the non-magnetic case

Using the Yguazu-a three-dimensional hydrodynamic code, we have computed a set of numerical simulations of heavy, supersonic, radiatively cooling jets including variabilities in both the ejection direction (precession) and the jet velocity (intermittence). In order to investigate the effects of jet rotation on the shape of the line profiles, we also introduce an initial toroidal rotation velocity profile, in agreement with some recent observational evidence found in jets from T Tauri stars which seems to support the presence of a rotation velocity pattern inside the jet beam, near the jet production region. Since the Yguazu-a code includes an atomic/ionic network, we are able to compute the emission coefficients for several emission lines, and we generate line profiles for the H, [O I]6300, [S II]6716 and [N II]6548 lines. Using initial parameters that are suitable for the DG Tau microjet, we show that the computed radial velocity shift for the medium-velocity component of the line profile as a function of distance from the jet axis is strikingly similar for rotating and non-rotating jet models. These findings lead us to put forward some caveats on the interpretation of the observed radial velocity distribution from a few outflows from young stellar objects, and we claim that these data should not be directly used as a doubtless confirmation of the magnetocentrifugal wind acceleration models.Comment: 15 pages, 8 figures. Accepted to publication in Astronomy and Astrophysic

Development of beeswax oleogels and the influence of gelator concentration and oil type on their final properties

[Excerpt] Introduction: Concerns regarding food nutritional value, sensory attributes, and consumer health urge to get a valid and feasible answer. The use of food‐grade materials that guarantee gel‐like behaviour and address consumer needs is currently essential in food industry. Structuring edible oils (i.e. oleogels) can be the response for such challenge, offering a healthier alternative (e.g. replacing saturated and trans fats) with tailored functionalities (e.g. different melting behaviour). This work focused on how different types of oil phase – medium chain triglycerides (MCT) and long chain triglycerides (LCT) – influence the gelation process of beeswax and the properties of the organogels produced thereof. [...]info:eu-repo/semantics/publishedVersio