345 research outputs found
Efeito residual do herbicida Kifix® nas culturas de arroz, feijão e sorgo.
As culturas produzidas nos dias atuais necessitam cada vez mais de herbicidas eficazes para o manejo e controle de plantas daninhas nos mais diversos sistemas produtivos integrados. Portanto, torna-se necessário soluções inovadoras que possibilitam o aumento da produtividade com pouco impacto ao agroecossistema. Nesse sentido, este trabalho objetivou determinar o efeito residual do herbicida Kifix® (Imazapir 525 g.kg-1 + Imazapique 175 g.kg-1) em solos de um sistema de integração lavoura pecuária.Apresentação oral - graduação
Efeitos da substituíção da gordura do leite por gordura de soja no crescimento de bezerros.
A gordura hidrogenada de soja possibilitou um desenvolvimento corporal dos bezerros semelhantes ao conseguido atraves da gordura do leite
Tribo-rheology and sensory analysis of a dairy semi-solid
Tribology science is devoted on explaining the friction behavior of interacting surfaces in relative motion. Several tribological systems have been used to measure coefficient of friction (CoF) vs sliding speed of entrained food layer between two rubbing surfaces. These results can be correlated with fat-related attributes perceived during oral processing. This study aims to investigate the effect of starch, carrageenan and fat on the friction profile; flow behavior and particle size distribution. Friction curves were obtained for custards using a tribo-rheometer with a rotating metallic geometry rubbing the surface of 3 M tape with roughness similar to that depicted by human tongue. Confocal Laser Scanning Microscopy (CLSM) images of custard collected during friction experiment helped to explain the characteristics of tribological regimes. As expected, fat-containing samples depicted remarkably lower CoF than skim compositions (fat: 0.2 < CoF < 0.08 and skim: 0.6 < Co
Identfication and quantfication of giant bioaerosol particles over the Amazon rainforest
Eukarya dominate the coarse primary biological aerosol (PBA) above the Amazon rainforest canopy, but their vertical profile and seasonality is currently unknown. In this study, the stratification of coarse and giant PBA >5 µm were analyzed from the canopy to 300 m height at the Amazon Tall Tower Observatory in Brazil during the wet and dry seasons. We show that >2/3 of the coarse PBA were canopy debris, fungal spores commonly found on decaying matter were second most abundant (ranging from 15 to 41%), followed by pollens (up to 5%). The atmospheric roughness layer right above the canopy had the greatest giant PBA abundance. Measurements over 5 years showed an increased abundance of PBA during a low-rainfall period. Giant particles, such as pollen, are reduced at 300 m, suggesting their limited dispersal. These results give insights into the giant PBA emissions of this tropical rainforest, and present a major step in understanding the type of emitted particles and their vertical distribution
Adequação ambiental de uma propriedade rural do circuito das frutas.
A propriedade rural de agricultura familiar estudada (0,75 módulo fiscal) localiza-se no município de Atibaia (SP), que faz parte do Circuito das Frutas. O objetivo neste trabalho foi verificar o passivo ambiental relativo às áreas de preservação permanente (APPs) do município e verificar a adequação ambiental de uma típica propriedade rural segundo a legislação ambiental (Leis nº 12.651/2012 e 12.727/2012) quanto a APPs e reservas legais (RLs). Para elaborar o estudo do passivo ambiental relativo às áreas de APP para o município de Atibaia, foram utilizados o mapeamento de uso e cobertura das terras, os dados do Sicar?SP e mapas e dados da Prefeitura da Estância de Atibaia. A propriedade avaliada tem plantações de pêssego, banana, morango, laranja, carambola e goiaba, além de áreas de APP, e não apresentou inadequação ambiental em relação à legislação. Foi contabilizada no município de Atibaia uma área de 982,18 ha de APPs a passar por recuperação, recomposição, regeneração ou compensação, sendo 42,6% da área localizada em zona urbana e 57,4% em zona rural. As medidas de adequação ambiental no estado de São Paulo, em municípios ou propriedades rurais individuais deveriam ser planejadas no âmbito do território de forma integrada com a gestão pública, as instituições interessadas e a comunidade rural e urbana, para integrar os fragmentos de vegetação nativa para formar sólidos corredores ecológicos, regularizar o fluxo hídrico com redução do assoreamento dos rios sem riscos de inundações e assegurar a sustentabilidade dos ecossistemas
Single-particle characterization of aerosols collected at a remote site in the Amazonian rainforest and an urban site in Manaus, Brazil
In this study, aerosol samples collected at a remote site in the Amazonian
rainforest and an urban site in Manaus, Brazil, were investigated on a
single-particle basis using a quantitative energy-dispersive electron probe X-ray
microanalysis (ED-EPMA). A total of 23 aerosol samples were collected in four
size ranges (0.25–0.5, 0.5–1.0, 1.0–2.0, and 2.0–4.0 µm) during
the wet season in 2012 at two Amazon basin sites: 10 samples in Manaus, an
urban area; and 13 samples at an 80 m high tower, located at the Amazon Tall
Tower Observatory (ATTO) site in the middle of the rainforest, 150 km
northeast of Manaus. The aerosol particles were classified into nine particle
types based on the morphology on the secondary electron images (SEIs)
together with the elemental concentrations of 3162 individual particles:
(i) secondary organic aerosols (SOA); (ii) ammonium sulfate (AS); (iii) SOA
and AS mixtures; (iv) aged mineral dust; (v) reacted sea salts; (vi) primary
biological aerosol (PBA); (vii) carbon-rich or elemental carbon (EC)
particles, such as soot, tarball, and char; (viii) fly ash; and (ix) heavy
metal (HM, such as Fe, Zn, Ni, and Ti)-containing particles. In submicron
aerosols collected at the ATTO site, SOA and AS mixture particles were
predominant (50 %–94 % in relative abundance) with SOA and ammonium
sulfate comprising 73 %–100 %. In supermicron aerosols at the ATTO site,
aged mineral dust and sea salts (37 %–70 %) as well as SOA and ammonium
sulfate (28 %–58 %) were abundant. PBAs were observed abundantly in the
PM2−4 fraction (46 %), and EC and fly ash particles were absent in
all size fractions. The analysis of a bulk PM0.25−0.5 aerosol sample
from the ATTO site using Raman microspectrometry and attenuated total
reflection Fourier-transform infrared spectroscopy (ATR-FTIR) showed that ammonium
sulfate, organics, and minerals are the major chemical species, which is
consistent with the ED-EPMA results. In the submicron aerosols collected in
Manaus, either SOA and ammonium sulfate (17 %–80 %) or EC particles
(6 %–78 %) were dominant depending on the samples. In contrast, aged
mineral dust, reacted sea salt, PBA, SOA, ammonium sulfate, and EC particles
comprised most of the supermicron aerosols collected in Manaus. The SOA,
ammonium sulfate, and PBAs were mostly of a biogenic origin from the
rainforest, whereas the EC and HM-containing particles were of an
anthropogenic origin. Based on the different contents of SOA, ammonium
sulfate, and EC particles among the samples collected in Manaus, a
considerable influence of the rainforest over the city was observed. Aged
mineral dust and reacted sea-salt particles, including mineral dust mixed
with sea salts probably during long-range transatlantic transport, were
abundant in the supermicron fractions at both sites. Among the aged mineral
dust and reacted sea-salt particles, sulfate-containing ones outnumbered
those containing nitrates and sulfate + nitrate in the ATTO samples. In
contrast, particles containing sulfate + nitrate were comparable in
number to particles containing sulfate only in the Manaus samples, indicating
the different sources and formation mechanisms of secondary aerosols, i.e.,
the predominant presence of sulfate at the ATTO site from mostly biogenic
emissions and the elevated influences of nitrates from anthropogenic
activities at the Manaus site.</p
As experiências de Educação em Agroecologia no Brasil: diálogos a partir do II Seminário Nacional de Educação em Agroecologia (II SNEA).
Edição dos Anais do VI Congresso Latino-americano de Agroecologia; X Congresso Brasileiro de Agroecologia; V Seminário de Agroecologia do Distrito Federal e Entorno, Brasília, DF, set. 2017
Desenvolvimento, gestão e cooperação internacional: um estudo do projeto de desenvolvimento comunitário da bacia do Rio Gavião no sudoeste da Bahia
Techonolgy of Qualea grandiflora Mart. (Vochysiaceae) seeds
Qualea grandiflora Mart. (Vochysiaceae), commonly known as "pau-terra", is an arborous species native to the Brazilian savannah which possess commercial interests, as it can be used either as an ornamental or as a medicinal plant. "Pau-terra" can also be used in the heterogeneous reforestation of areas which are destined for restoration of permanent preservation degraded areas. Propagation studies with this species are scarce, being necessary then further clarification regarding the factors that influences the germination process. In this context, the objective of this work was to evaluate the influence of different temperatures, substrates and light conditions on seed germination. We selected light brown seeds which were subjected to different interactions between temperatures (15-25, 20-30, 25 and 30°C), substrate (paper, sand and vermiculite) and light (light and dark). All seeds were later dry-incubated at 32°C for 3, 6 and 12 hours. After treatments, seeds were kept in BOD at 58% RH and the following parameters were calculated: germination (%G) and germination speed index (GSI); the formation of normal and abnormal seedlings and the number dead seeds. Interaction was observed for all variables. In the optimum temperature range, the seeds behaved as photoblastic neutral or indifferent. Under alternating temperatures, darkness enhanced the germination, especially when combined with the lower temperatures. We noted that the sowing in sand, at 25°C, allowed the maintenance of suitable combinations of germination and seedling development. With respect to desiccation tolerance, "pau-terra" seeds presented an orthodox behavior, with a linear increase of the vigor as function of drying
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