4,262 research outputs found
Principal components in the study of soil and plant properties in precision coffee farming
ArticleIn this work, a principal component analysis was performed to evaluate the possibility
of discarding obsolete soil and plant variables in a coffee field to eliminate redundant and
difficult-to-measure information in precision coffee farming. This work was conducted at Brejão
Farm in Três Pontas, Minas Gerais, Brazil, in a coffee field planted with 22 ha of Topázio cultivar.
The evaluated variables were the yield, plant height, crown diameter, fruit maturation index,
degree of fruit maturation, leafing, soil pH, available phosphorus (P), remaining phosphorus
(Prem), available potassium (K), exchangeable calcium (Ca2+), exchangeable magnesium
(Mg2+), exchangeable acidity (Al3+), potential acidity (H + Al), aluminium saturation (N(Al)),
potential CEC (CECp), actual CEC (CECa), sum of bases (SB), base saturation (BS) and organic
matter (OM). The data were evaluated by a principal component analysis, which generated 20
components. Of these, 7 representing 88.98% of the data variation were chosen. The variables
were discarded based on the preservation of the variables with the greatest coefficients in absolute
values corresponding to the first component, followed by the variable with the second highest
absolute value corresponding to the second principal component. Based on the results, the
variables V, OM, fruit maturity index, plant height, yield, leafing and P were selected. The other
variables were discarded
Resonating Valence Bond Theory of Superconductivity for Dopant Carriers: Application to the Cobaltates
Within the -- model Hamiltonian we present a RVB mean field theory
directly in terms of dopant particles. We apply this theory to
and show that the
resulting phase diagram versus doping is in qualitative agreement with
the experimental results
Spatial variability of litter temperature, relative air humidity and skin temperature of chicks in a commercial broiler house
ArticleThe thermal environment inside a broiler house has a great influence on animal welfare
and productivity during the production phase. Among the importance of the chicken litter is the
function of absorbing moisture, provide thermal insulation and provide a soft surface for broilers.
The skin temperature is an important physiological parameter to quantify the thermal comfort of
animals, its variations may occur as a function of thermal variables. So, the aim of this work was
to analyse the magnitude and spatial variability of chicken litter temperature and relative humidity
of the air and to correlate them with the spatial distribution of chicks’ skin surface temperature
throughout the broiler house during the 7th, 14th and 21st days of the chicks’ life, using
geostatistical techniques. The experiment was performed in a commercial broiler house located
in the western mesoregion of Minas Gerais, Brazil, where 28,000 male Cobb chicks were housed.
The heating system consisted of an industrial indirect-fired biomass furnace. The heated air was
inflated by an AC motor, 2,206 W of power, 1,725 RPM. Geostatistical techniques were used
through semivariogram analysis and isochore maps were generated through data interpolation by
kriging. The semivariogram was fitted by the restricted maximum likelihood method. The used
mathematical model was the spherical one. After fitting the semivariograms, the data were
interpolated by ordinary kriging. The semivariograms along with the isochore maps allowed
identifying the non-uniformity of spatial distribution of the broiler litter temperature throughout
the broiler house for 3 days of chicks’ life. It was observed that skin surface presented a positive
correlation with the litter temperature and a negative correlation with the air humidity. The
semivariograms along with the isochore maps allowed identifying the non-uniformity of spatial
distribution of the litter temperature, air humidity and skin temperature of chicks throughout the
broiler aviary for the three days. In addition, the use of geostatistics and distribution maps made
possible to identify different environmental conditions in regions inside the broiler house that
may harm the development of chicks
Sistema de produção de banana para a Zona da Mata de Pernambuco.
bitstream/item/27822/1/sp-3.pd
Capybara (Hydrochoerus hydrochaeris) distribution in agroecosystems: a cross-scale habitat analysis.
RGB vegetation indices applied to grass monitoring: a qualitative analysis
ArticleIn developing countries such as Brazil, research on low-cost remote sensing and
computational techniques become essential for the development of precision agriculture (PA),
and improving the quality of the agricultural products. Faced with the scenario of increasing
production of emerald grass (Zoysia Japônica) in Brazil, and the value added the quality of this
agricultural product. The objective of this work was to evaluate the performance of RGB (IV)
vegetation indices in the identification of exposed soil and vegetation. The study was developed
in an irrigated area of 58 ha cultivated with emerald grass at Bom Sucesso, Minas Gerais, Brazil.
The images were obtained by a RGB digital camera coupled to an remotely piloted aircraft. The
flight plan was setup to take overlapping images of 70% and the aircraft speed was 10 m s
-1
. Six
RGB Vegetation index (MGVRI, GLI, RGBVI, MPRI, VEG, ExG) were evaluated in a mosaic
resulting from the images of the study area. All of the VIs evaluated were affected by the
variability of lighting conditions in the area but MPRI and MGVRI were the ones that presented
the best results in a qualitative evaluation regarding the discrimination of vegetation and soil
Applications of Bioceramics in the Management of Orbital Floor Fractures and Anophthalmic Cavity: A Review
Biocompatible ceramics, commonly known as “bioceramics”, are an extremely versatile class of materials with a wide range of applications in modern medicine. Given the inorganic nature and physico-mechanical properties of most bioceramics, which are relatively close to the mineral phase of bone, orthopedics and dentistry are the preferred areas of usage for such biomaterials. Another clinical field where bioceramics play an important role is oculo-orbital surgery, a highly cross-and interdisciplinary medical specialty addressing to the management of injured eye orbit, with particular focus on the repair of orbital bone fractures and/or the placement of orbital implants following removal of a diseased eye. In the latter case, orbital implants are not intended for bone repair but, being placed inside the ocular cavity, have to be biointegrated in soft ocular tissues. This article reviews the state of the art of currently-used bioceramics in orbital surgery, highlighting the current limitations and the promises for the future in this field
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
Chirikov Diffusion in the Asteroidal Three-Body Resonance (5,-2,-2)
The theory of diffusion in many-dimensional Hamiltonian system is applied to
asteroidal dynamics. The general formulations developed by Chirikov is applied
to the Nesvorn\'{y}-Morbidelli analytic model of three-body (three-orbit)
mean-motion resonances (Jupiter-Saturn-asteroid system). In particular, we
investigate the diffusion \emph{along} and \emph{across} the separatrices of
the (5,-2,-2) resonance of the (490) Veritas asteroidal family and their
relationship to diffusion in semi-major axis and eccentricity. The estimations
of diffusion were obtained using the Melnikov integral, a Hadjidemetriou-type
sympletic map and numerical integrations for times up to years.Comment: 27 pages, 6 figure
Antecedente de vida rural ou de vida urbana e doença de Parkinson
Although the precise etiology of Parkinson's disease (PD) is as yet unknown, it appears that certain environmental factors are involved. Prior living in a rural area has been implicated as a possible risk factor for PD, particularly in the early onset type. We evaluated the role of previous living conditions in the clinical correlates and outcome characteristics of 118 PD patients. All of them were seen from January 1987 to October 1992. The Rural Group (RG) comprised 71 patients (60.2%) who had lived in the rural area for at least 10 years (mainly in early phase of life) and the Urban Group (UG) consisted of 47 patients (39.8%) who had lived their entire life in an urban environment. The average age at the beginning of the symptoms was 58.8 in the RG and 54.1 in the UG. The mixed form of the disease (tremor, rigidity and akinesia) was the most frequent in both groups. A minimum 6-month follow-up period was undertaken with 63 patients (average 20 months) and no difference in response to treatment or in progression of the illness was detected between the two groups. Our data show that the previous living environment does not appear to be a determining factor in either the clinical or outcome characteristics of PD.A etiologia da doença de Parkinson (DP) é ainda desconhecida mas parece que fatores ambientais podem estar envolvidos. A incidência da DP, particularmente a de início precoce, parece ser maior em indivíduos com antecedente de moradia na zona rural. Avaliamos as características clínicas e a progressão da DP em 118 pacientes segundo os antecedentes de área de moradia pregressa. Havia 71 pacientes (60,2%) com antecedente de no mínimo 10 anos na zona rural (especialmente nas fases iniciais da vida), o chamado Grupo Rural (GR), e 47 pacientes (39,8%) que tiveram antecedente de vida exclusivamente urbana, o chamado Grupo Urbano (GU). A média de idade de início dos sintomas foi 58,8 anos no GR e de 54,1 anos no GU. A forma mista da DP (com tremor, bradicinesia e rigidez) foi a mais frequente em ambos os grupos. Um período de acompanhamento de no mínimo 6 meses foi obtido em 63 pacientes (média de 20 meses de acompanhamento) e a progressão da sintomatologia foi semelhante nos dois grupos (GR e GU). Nossos dados indicam que o antecedente de moradia não parece ser determinante para o padrão de manifestação clínica e de evolução da DP.Universidade Federal de São Paulo (UNIFESP) Department of Neurology and Neurosurgery Movement Disorders UnitUniversidade de São Paulo Faculdade de Medicina Department of Neurology, Psychiatry and Medical PsychologyUNIFESP, Department of Neurology and Neurosurgery Movement Disorders UnitSciEL
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