2,367 research outputs found
Astrometry of mutual approximations between natural satellites. Application to the Galilean moons
Typically we can deliver astrometric positions of natural satellites with
errors in the 50-150 mas range. Apparent distances from mutual phenomena, have
much smaller errors, less than 10 mas. However, this method can only be applied
during the equinox of the planets. We developed a method that can provide
accurate astrometric data for natural satellites -- the mutual approximations.
The method can be applied when any two satellites pass close by each other in
the apparent sky plane. The fundamental parameter is the central instant
of the passage when the distances reach a minimum.
We applied the method for the Galilean moons. All observations were made with
a 0.6 m telescope with a narrow-band filter centred at 889 nm with width of 15
nm which attenuated Jupiter's scattered light. We obtained central instants for
14 mutual approximations observed in 2014-2015. We determined with an
average precision of 3.42 mas (10.43 km). For comparison, we also applied the
method for 5 occultations in the 2009 mutual phenomena campaign and for 22
occultations in the 2014-2015 campaign. The comparisons of determined by
our method with the results from mutual phenomena show an agreement by less
than 1-sigma error in , typically less than 10 mas. This new method is
particularly suitable for observations by small telescopes.Comment: 13 pages, 11 figures and 8 tables. Based on observations made at the
Laborat\'orio Nacional de Astrof\'isica (LNA), Itajub\'a-MG, Brazi
Interlinking two institutional KOS about agroecology: using LOD Agrovoc to circumvent the language barrier in identifying terminological intersections.
This work describes the methodological approach proposed to resolve the matter of indicating equivalent terms in both languages to the same concept recorded in Agrovoc related to the discipline of Agroecology
Manejo populacional de Cryptoblabes gnidiella utilizando a técnica de confusão sexual na cultura da videira.
Growth and dry matter production in sugarcane varieties grown under full irrigation
A análise de crescimento é considerada o método padrão para medir a produtividade biológica em espécies vegetais. Neste contexto objetivou-se avaliar, em onze variedades de cana-de-açúcar (SP79-1011, RB813804, RB863129, RB872552, RB943365, RB72454, RB763710, SP78-4764, SP81-3250, RB867515, RB92579) cultivadas sob irrigação plena, o crescimento e a produção de matéria seca no ciclo de cana planta. O experimento foi instalado em condições de campo no município de Carpina, PE. Utilizou-se o delineamento estatístico de blocos ao acaso, com quatro repetições. A análise de crescimento correspondeu à quantificação dos números de perfilhos e à, na mensuração da altura e diâmetro dos colmos, avaliados mensalmente em onze períodos de cultivo, os quais se estenderam dos 60 aos 360 dias após o plantio (DAP). A produção de matéria seca foi quantificada a partir dos 120 DAP, com intervalos de amostragem a cada dois meses. Observou-se que as variedades RB92579 e SP81-3250 apresentaram o maior perfilhamento e produção de matéria seca e as variedades RB813804 e RB72454 às maiores médias de altura, enquanto as variedades RB867515 e RB72454 obtiveram os maiores diâmetros do colmo.Growth analysis is considered as a standard method for measuring the biological productivity of plant species. The objective of this research was to evaluate the growth and dry matter production of eleven sugarcane varieties (SP79-1011, RB813804, RB863129, RB872552, RB943365, RB72454, RB763710, SP78-4764, SP81-3250, RB867515, RB92579), grown under full irrigation, in the planted cane cycle. The experiment was conducted in field conditions in the municipality of Carpina, PE. A randomized block design with four replications was used. The varieties' growth analysis was represented by the quantification of the tillers numbers, stalk height and diameter, measured monthly, in eleven periods of cultivation that extended from 60 to 360 days after planting (DAP). The dry matter production was measured from 120 DAP, with sampling intervals of every two months. It was observed that, at 360 DAP, the RB92579 and SP81-3250 varieties showed the highest tillering and dry matter production. The RB813804 and RB72454 varieties had the highest average for height, while the RB72454 and RB867515 varieties presented the largest stalk diameters
Photocatalytic asphalt mixtures: Mechanical performance and impacts of traffic and weathering abrasion on photocatalytic efficiency
The photocatalytic asphalt mixture provides safer roads and mitigates the air quality problems, trapping and degrading organic compounds and also harmful gases. In this research, an asphalt mixture was functionalized with nano-TiO2 by bulk incorporation, using the contents 3 and 6%, and by spraying coating using an aqueous solution over its surface at different temperatures and rates. For bulk incorporation, the mechanical performance was assessed. The factors ? application procedure, influence of temperature, spraying rate, incorporation percentage and TiO2 immobilization (from traffic and rain removal) ? were evaluated based on Rhodamine B (RhB) degradation. For bulk incorporation, the best content nano-TiO2 was 3%. The temperature of the substrate has no influence on the photocatalytic results. The most effective spraying rates were 8 and 16?mL/cm2. Before simulating the traffic effect, the spraying coating technique was more effective than the bulk incorporation one. After this process, the opposite behavior was detected. The rain simulation did not cause removal of the nanoparticles. Additionally, the exposed aggregates affected the photocatalytic efficiency, being important their contribution combined to the effect of nano-TiO2. To have the maximum benefit of the techniques studied, the ideal solution would be the combination of both, with negligible impact on mechanical performance.This work was partially financed by FCT—Fundação para a Ciência e a Tecnologia—under the project PTDC/FIS/120412/2010: “Nanobased concepts for Innovative & Eco-sustainable constructive material’s surfaces’’ and project PEst-OE/ECI/UI4047/2014
Parasites in gills of Cichla monoculus (Cichlidae) from the Jari River, a tributary of the Amazon River northern Brazil.
Astrometry of the main satellites of Uranus: 18 years of observations
We determine accurate positions of the main satellites of Uranus: Miranda,
Ariel, Umbriel, Titania, and Oberon. Positions of Uranus, as derived from those
of these satellites, are also determined. The observational period spans from
1992 to 2011. All runs were made at the Pico dos Dias Observatory, Brazil.
We used the software called Platform for Reduction of Astronomical Images
Automatically (PRAIA) to minimise (digital coronography) the influence of the
scattered light of Uranus on the astrometric measurements and to determine
accurate positions of the main satellites. The positions of Uranus were then
indirectly determined by computing the mean differences between the observed
and ephemeris positions of these satellites. A series of numerical filters was
applied to filter out spurious data. These filters are mostly based on the
comparison between the positions of Oberon with those of the other satellites
and on the offsets as given by the differences between the observed and
ephemeris positions of all satellites.
We have, for the overall offsets of the five satellites, -29 (+/-63) mas in
right ascension and -27 (+/-46) mas in declination. For the overall difference
between the offsets of Oberon and those of the other satellites, we have +3
(+/-30) mas in right ascension and -2 (+/-28) mas in declination. Ephemeris
positions for the satellites were determined from DE432+ura111. Comparisons
using other modern ephemerides for the solar system -INPOP13c- and for the
motion of the satellites -NOE-7-2013- were also made. They confirm that the
largest contribution to the offsets we find comes from the motion of the
barycenter of the Uranus system around the barycenter of the solar system, as
given by the planetary ephemerides. Catalogues with the observed positions are
provided.Comment: 13 pages, 21 figure
Flutuação populacional de Cryptobables gnidiella em videira no sistema de produção integrada.
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