22,033 research outputs found
Fisiologia e tecnologia pós-colheita do pedúnculo do caju.
O extenso territorio brasileiro, caracterizado por variadas condicoes climaticas e por distintos tipos de solos, apresenta uma producao agricola extremamente diversificada, que confere ao pais o titulo de principal produtor mundial de varios produtos. A fruticultura, nao obstante representar apenas 5% das areas cultivadas no pais, e uma das atividades capazes de assegurar ao Brasil um percentual significativo do volume de producao global, colocando-se em primeiro lugar no ranking dos produtores de frutas (FAO, 1992 e Carraro & Cunha, 1994). Apesar da importancia do setor para o pais, nao existe paralelismo entre aumento da producao e avanco de tecnologias de pos-colheita capazes de minimizar as perdas.bitstream/item/34621/1/Dc-017.pd
Remote experimentation: integrating research, education, and industrial application
This paper presents a low-cost scaled model of a silo for drying and airing cereal grains. It allows the control and monitor of several parameters associated to the silo's operation, through a remote accessible infrastructure. The scaled model consists of a 2.50 m wide × 2.10 m long plant with all control and monitor capacities provided by micro-Web servers. An application running on the micro-Web servers enables storing all parameters in a data basis for later analysis. The implemented model aims to support a remote experimentation facility for technological education, research-oriented tutorials, and industrial applications. Given the low-cost requirement, this remote facility can be easily replicated in other institutions to support a network of remote labs, which encompasses the concurrent access of several users (e.g. students)
From cheating to teaching: a path for conversion of illegal gambling machines
Video poker machines, a former symbol of fraud and gambling in Brazil, are now being
converted into computer-based educational tools for Brazilian public primary schools and also
for governmental and non-governmental institutions dealing with communities of poverty and
social exclusion, in an attempt to reduce poverty risks (decrease money spent on gambling)
and promote social inclusion (increase access and motivation to education). Thousands of
illegal gambling machines are seized by federal authorities, in Brazil, every year, and usually
destroyed at the end of the criminal apprehension process.
This paper describes a project developed by the University of Southern Santa Catarina, Brazil,
responsible for the conversion process of gambling machines, and the social inclusion
opportunities derived from it. All project members worked on a volunteer basis, seeking to
promote social inclusion of Brazilian young boys and girls, namely through digital inclusion. So
far, the project has been able to convert over 200 gambling machines and install them in over
40 public primary schools, thus directly benefiting more than 12,000 schoolchildren.
The initial motivation behind this project was technology based, however the different options
arising from the conversion process of the gambling machines have also motivated a rather
innovative and unique experience in allowing schoolchildren and young people with special
(educational) needs to access to computer-based pedagogical applications. The availability of these converted machines also helps to place Information and
Communication Technologies (ICT) in the very daily educational environment of these children
and youngsters, thus serving social and cultural inclusion aspects, by establishing a dialogue
with the community and their technological expectations, and also directly contributing to their
digital literacy
Geometric scaling of purely-elastic flow instabilities
We present a combined experimental, numerical and theoretical investigation
of the geometric scaling of the onset of a purely-elastic flow instability in a
serpentine channel. Good qualitative agreement is obtained between experiments,
using dilute solutions of flexible polymers in microfluidic devices, and
two-dimensional numerical simulations using the UCM model. The results are
confirmed by a simple theoretical analysis, based on the dimensionless
criterion proposed by Pakdel-McKinley for onset of a purely-elastic
instability
The extended gaussian ensemble and metastabilities in the Blume-Capel model
The Blume-Capel model with infinite-range interactions presents analytical
solutions in both canonical and microcanonical ensembles and therefore, its
phase diagram is known in both ensembles. This model exhibits nonequivalent
solutions and the microcanonical thermodynamical features present peculiar
behaviors like nonconcave entropy, negative specific heat, and a jump in the
thermodynamical temperature. Examples of nonequivalent ensembles are in general
related to systems with long-range interactions that undergo canonical
first-order phase transitions. Recently, the extended gaussian ensemble (EGE)
solution was obtained for this model. The gaussian ensemble and its extended
version can be considered as a regularization of the microcanonical ensemble.
They are known to play the role of an interpolating ensemble between the
microcanonical and the canonical ones. Here, we explicitly show how the
microcanonical energy equilibrium states related to the metastable and unstable
canonical solutions for the Blume-Capel model are recovered from EGE, which
presents a concave "extended" entropy as a function of energy.Comment: 6 pages, 5 eps figures. Presented at the XI Latin American Workshop
on Nonlinear Phenomena, October 05-09 (2009), B\'uzios (RJ), Brazil. To
appear in JPC
Seleção de progênies experimentais de cupuaçuzeiro tolerante a vassoura de bruxa no estado do Pará.
Objetivou-se com esse trabalho selecionar progênies resistentes ao avanço da vassoura de bruxa e por consequência melhorar os índices de produção do cupuaçu. O experimento foi implantado na fazenda Santa Tereza, no período de 2005 a 2014, no município de São Francisco do Pará, no Pará. O delineamento experimental utilizado foi em blocos casualizados, com 20 progênies de irmãos germanos de cupuaçuzeiro, com cinco repetições e três plantas na parcela. As mudas foram postas em covas espaçadas em 5,0 x 5,0 m e consorciadas com Banana e Açaí que estava no espaçamento de 2,5 x 2,5 m e 10 x 10 m, respectivamente. Foram analisados, primeiramente, o desenvolvimento vegetativo (altura e diâmetro) e posteriormente iniciou-se a avaliação de produção das sete safras e o nível de infecção por Moniliophthora perniciosa. Verificou-se que na variável altura a progênie que mais se destacou foi a 37, já com o diâmetro a progênie 13, que teve a menor média do ensaio, diferiu em nível de 5% de significância das progênies 19, 24, 36, 37 e 51. Com relação à produção de frutos a média das sete safras foi de 9,44 frutos/planta, sendo a progênie 36 a mais promissora com média de 13,6 frutos/planta/safra. Os materiais mostraram-se ser suscetível ao ataque da vassoura-de-bruxa, pois 35% apresentaram sintomas da doença. As progênies 36 e 37 mostraram-se como os materiais mais promissores para a sequência do programa de melhoramento genético, sendo resistentes a M. perniciosa, assim como os mais produtivos e com melhor desenvolvimento vegetativo.VII ENAAG
Avaliação da produção de clones experimentais de cupuaçuzeiro em três ambientes do Nordeste paraense.
O objetivo desse trabalho foi avaliar, preliminarmente, clones experimentais de cupuaçuzeiro para ampliar a base genética da cultura e incorpora-la no programa de melhoramento genético da Embrapa Amazônia Oriental. Os experimentos foram conduzidos em três propriedades rurais, no período de 2005 a 2014, no município de Tomé Açu, situada na mesorregião do Nordeste Paraense. O delineamento experimental utilizado foi em blocos casualizados, com 25 clones de cupuaçuzeiro, com cinco repetições e três plantas na parcela. Foram analisados a produção das sete safras e o nível de infecção por Moniliophthora perniciosa nos três ambientes testados. Nos três ambientes os grandes destaques foram os clones 36 e 37, com média de produção, no primeiro ambiente, de 17,1 e 18,1 frutos/planta, respectivamente. No segundo ambiente as médias dos clones foram de 15,5 e 15,3 frutos/planta. E no terceiro ambiente a produção dos clones foi em média foram 13,0 e 13,2 frutos/planta. Os materiais mostraram-se ser suscetível ao ataque da vassoura-de-bruxa, pois 36% apresentaram sintomas da doença. No Ambiente 1 os clones mostraram-se mais produtivos indicando presença da interação genótipo x ambiente. Os clones 36 e 37 mostraram-se como os materiais mais promissores para a sequência do programa de melhoramento genético, sendo resistentes a M. perniciosa, assim como os mais produtivos.VII ENAAG
The Nature of the Dense Core Population in the Pipe Nebula: Thermal Cores Under Pressure
In this paper we present the results of a systematic investigation of an
entire population of starless dust cores within a single molecular cloud.
Analysis of extinction data shows the cores to be dense objects characterized
by a narrow range of density. Analysis of C18O and NH3 molecular-line
observations reveals very narrow lines. The non-thermal velocity dispersions
measured in both these tracers are found to be subsonic for the large majority
of the cores and show no correlation with core mass (or size). Thermal pressure
is thus the dominate source of internal gas pressure and support for most of
the core population. The total internal gas pressures of the cores are found to
be roughly independent of core mass over the entire range of the core mass
function (CMF) indicating that the cores are in pressure equilibrium with an
external source of pressure. This external pressure is most likely provided by
the weight of the surrounding Pipe cloud within which the cores are embedded.
Most of the cores appear to be pressure confined, gravitationally unbound
entities whose nature, structure and future evolution are determined by only a
few physical factors which include self-gravity, the fundamental processes of
thermal physics and the simple requirement of pressure equilibrium with the
surrounding environment. The observed core properties likely constitute the
initial conditions for star formation in dense gas. The entire core population
is found to be characterized by a single critical Bonnor-Ebert mass. This mass
coincides with the characteristic mass of the Pipe CMF indicating that most
cores formed in the cloud are near critical stability. This suggests that the
mass function of cores (and the IMF) has its origin in the physical process of
thermal fragmentation in a pressurized medium.Comment: To appear in the Astrophysical Journa
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