3,924 research outputs found
Design and construction of a low-cost remotely piloted aircraft for precision agriculture applications
ArticleThis study aimed to construct a low cost RPA capable of recording georeferenced
images. For the construction of the prototype of a quadcopter type RPA, only essential materials
were used to allow stable flight. A maximum total weight of 2 kg was stipulated, including frame
weight, electronic components, motors and cameras. The aircraft was programmed using a
low-cost microcontroller widely used in prototyping and automation research. An electronic
circuit board is designed to facilitate the connection of the microcontroller with the other
components of the design. Specific software was used for flight control. The prototype was built
successfully, being able to lift stable and controllable flight. However, we still need to acquire
equipment and programming components capable of enabling autonomous images and flights.
The final cost of the RPA was on average 772.81 to $ 1,288.00
Geostatistics applied to evaluation of thermal conditions and noise in compost dairy barns with different ventilation systems
ArticleThe objective of this work was to evaluate the spatial distribution of thermal
conditions and bed variables in compost dairy barns with different ventilation systems, through
the technique of geostatistics. The experiment was conducted in April 2017, in farms located in
Madre de Deus, Minas Gerais, Brazil. Three facilities were evaluated with different ventilation
systems: natural (NV); mechanical of low volume and high speed (LVHS); and mechanical of
high volume and low speed (HVLS). The interior of the premises was divided into 40 meshes
equidistant points, in which air temperature, relative humidity and air speed were manually
collected. Geostatistics technique was used to assess the spatial dependence of the variables.
The results showed the occurrence of dependence and spatial variability of the variables
evaluated. Based on thermal comfort indexes, it was concluded that dairy cows were under
stress conditions during the hottest hours of the day in the three animal facilities evaluated. The
results obtained allow us to understand that the thermal environment is more influenced by the
ventilation system adopted
Colonização de fragmentos de árvores para produção de inóculo de Armillaria sp.
Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso
NIRS potential use for the determination of natural resources quality from dehesa (acorn and grass) in Montanera system for Iberian pigs.
NIRS technology has been used as an alternative to conventional methods to determinate the content of nutrients of acorns and grass from dehesa ecosystem. Dry matter (DM), crude fat (CF), crude protein (CP), starch, total phenolic compounds (TP), α-tocopherol, γ-tocopherol, fatty acids, neutral detergent fiber (NDF), total antioxidant activity (TAA) and total energy (TE) were determined by conventional methods for later development of NIRS predictive equations. The NIR spectrum of each sample was collected and for all studied parameters, a predictive model was obtained and external validated. Good prediction equations were obtained for moisture, crude fat, crude protein, total energy and γ-tocopherol in acorns samples, with high coefficients of correlation (1-VR) and low standard error of prediction (SEP) (1-VR=0.81, SEP=2.62; 1-VR=0.92, SEP=0.54; 1-VR=0.86, SEP=0.47; 1-VR=0.84, SEP=0.2; 1-VR=0.88, SEP=5.4, respectively) and crude protein, NDF, α-tocopherol and linolenic acid content in grass samples (1-VR=0.9, SEP=1.99; 1-VR=0.87, SEP=4.13; 1-VR=0.76, SEP=10.9; 1-VR=0.82, SEP=0.6, respectively). Therefore, these prediction models could be used to determinate the nutritional composition of Montanera natural resources
Produção de inóculo de Trichoderma viride para o controle da armilariose em Pinus spp.
Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso
Avaliação de impacto ambiental: o caso do Projeto "Aeroporto Internacional do Rio de Janeiro - Tom Jobim": uma aplicação do método Ambitec - Agro.
Utiliza-se neste trabalho a metodologia "Sistema de Avaliação de Impacto Ambiental da Inovação Tecnológica Agropecuária" (Sistema Ambitec), segmento agropecuária (Ambitec Agro). Por se tratar de uma metodologia dirigida exclusivamente para avaliação de impactos ecológicos, os estudos devem ser complementados por avaliações específicas para as outras dimensões relevantes da avaliação de impactos. As estimativas obtidas validam a metodologia notadamente em suas características de praticidade, simplicidade, baixo custo e sua natureza integrativa de resultados. Os coeficientes e índices de impacto ambiental estimados permitem sugerir medidas de melhoria tecnológica mitigando resultados negativos e potencializando resultados positivos.bitstream/CNPS-2010/14924/1/bpd93-2006-impacto-aeroporto.pd
Orbital structure of the GJ876 extrasolar planetary system, based on the latest Keck and HARPS radial velocity data
We use full available array of radial velocity data, including recently
published HARPS and Keck observatory sets, to characterize the orbital
configuration of the planetary system orbiting GJ876. First, we propose and
describe in detail a fast method to fit perturbed orbital configuration, based
on the integration of the sensitivity equations inferred by the equations of
the original -body problem. Further, we find that it is unsatisfactory to
treat the available radial velocity data for GJ876 in the traditional white
noise model, because the actual noise appears autocorrelated (and demonstrates
non-white frequency spectrum). The time scale of this correlation is about a
few days, and the contribution of the correlated noise is about 2 m/s (i.e.,
similar to the level of internal errors in the Keck data). We propose a
variation of the maximum-likelihood algorithm to estimate the orbital
configuration of the system, taking into account the red noise effects. We
show, in particular, that the non-zero orbital eccentricity of the innermost
planet \emph{d}, obtained in previous studies, is likely a result of
misinterpreted red noise in the data. In addition to offsets in some orbital
parameters, the red noise also makes the fit uncertainties systematically
underestimated (while they are treated in the traditional white noise model).
Also, we show that the orbital eccentricity of the outermost planet is actually
ill-determined, although bounded by . Finally, we investigate
possible orbital non-coplanarity of the system, and limit the mutual
inclination between the planets \emph{b} and \emph{c} orbits by
, depending on the angular position of the mutual orbital
nodes.Comment: 36 pages, 11 figures, 3 tables; Accepted to Celestial Mechanics and
Dynamical Astronom
Spectrometric method to detect exoplanets as another test to verify the invariance of the velocity of light
Hypothetical influences of variability of light velocity due to the
parameters of the source of radiation, for the results of spectral measurements
of stars to search for exoplanets are considered. Accounting accelerations of
stars relative to the barycenter of the star - a planet (the planets) was
carried out. The dependence of the velocity of light from the barycentric
radial velocity and barycentric radial acceleration component of the star
should lead to a substantial increase (up to degree of magnitude) semi-major
axes of orbits detected candidate to extrasolar planets. Consequently, the
correct comparison of the results of spectral method with results of other
well-known modern methods of detecting extrasolar planets can regard the
results obtained in this paper as a reliable test for testing the invariance of
the velocity of light.Comment: 11 pages, 5 figure
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