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Planaltina, Brazil

Delgado M.N.,University of Brasilia | Delgado M.N.,Instituto Federal Of Brasilia | Bao S.N.,University of Brasilia | Amaral L.I.V.,University of Brasilia | And 2 more authors.
Revista Brasileira de Botanica | Year: 2014

This study aimed to elucidate the anatomy and morphology of extrafloral nectaries (EFNs) in Maprounea brasiliensis and whether environmental factors influence their traits of production and morphology. For this reason, we sampled leaves from individuals subjected to distinct fire and water regimes, and the anatomy and ultrastructures of EFNs as well as the chemical constitution of nectar were analyzed. EFN nectar production was associated with immature and recently expanded leaves. EFNs originate from the epidermis. At the end of ontogeny, secretory cells are surrounded by three or more layers of cells with secondary and lignified walls, isolating the EFN of vascular tissue. The ultrastructural analysis revealed mature EFNs with secretory activity. The experiments showed that EFN production was not influenced by the presence of frequent fires. However, during the rainy season, new produced leaves had nectaries in greater quantity and diameter than leaves produced during the dry season. The anatomical and ultrastructural changes demonstrated that nectar production is strongly influenced by the age of the nectaries which influence ant attendance to EFN since no ants were observed on leaves that did not secrete nectar. The seasonality experiment confirmed that EFNs of M. brasiliensis are resource dependent and evolutionary programed to appear in elevated number during the rainy season. © 2014, Botanical Society of Sao Paulo. Source

Correa P.C.,Federal University of Vicosa | Resende O.,IF Goiano | Garin S.A.,Public University of Navarra | Jaren C.,Public University of Navarra | De Oliveira G.H.H.,Instituto Federal Of Brasilia
Engenharia Agricola | Year: 2011

The present study aimed to determine the volumetric shrinkage rate of bean (Phaseolus vulgaris L.) seeds during air-drying under different conditions of air, temperature and relative humidity, and to adjust several mathematical models to the empiric values observed, and select the one that best represents the phenomenon. Six mathematical models were adjusted to the experimental values to represent the phenomenon. It was determined the degree of adjustment of each model from the value of the coefficient of determination, the behavior of the distribution of the residuals, and the magnitude of the average relative and estimated errors. The rate of volumetric shrinkage that occurred in bean seeds during drying is between 25 and 37%. It basically depends on the final moisture content, regardless of the air conditions during drying. The Modified Bala & Woods' model best represented the process. Source

Oliveira G.H.H.,Instituto Federal Of Brasilia | Correa P.C.,Federal University of Vicosa | Finger F.L.,Federal University of Vicosa | Freitas R.L.,Federal University of Vicosa | Vasconcellos D.S.L.,Federal University of Vicosa
Acta Horticulturae | Year: 2012

Means of transportation, packaging, harvesting procedures, maturation at harvest, climatic conditions, and many others variables affect the quality and postharvest life of agricultural products. In Brazil, tomatoes are still packaged in the wooden box type "k", first used to transport fuel in World War II. In this type of package, the fruits are placed randomly and the boxes are stacked during harvest, transport and distribution to the consumer. This handling leads to quantitative and qualitative losses. Better handling is needed to decrease mechanical damage and maintain the quality and price of tomatoes. The present work aimed to evaluate some quality characteristics of tomato fruits ('Pizzadoro') submitted to an induced compression, simulating the wooden boxes stacked up during transportation. A specific weight per unit area of the original wooden box "k" was determined (12.5 g cm-2), and used to obtain the weight needed (5 kg) to compress fifteen fruits inside small wooden boxes of 23×20×20 cm during 48 hours. After this treatment, these fruits and control fruits (without treatment) were stored at 15 or 25°C. The following variables were measured during eighteen days of storage: color, lycopene, total soluble solids and pH. It was concluded that the compression treatment significantly altered all variables studied, except for pH and total soluble solids of fruits stored at 15°C. Source

da Mata R.A.,Federal University of Goais | Roque F.,Instituto Federal Of Brasilia | Tidon R.,University of Brasilia
Natureza e Conservacao | Year: 2015

The relevant scales over which specific communities vary must be identified to address fundamental ecological questions and to advance the conservation of biological diversity. In this study, the variation among drosophilid assemblages associated with forests was quantified at a large temporal-spatial scale. Our results are based on data collected in four conservation units (CUs) in the Brazilian savanna across four seasons and two years. The primary component of variation occurred at the temporal scale: it was three times greater than that of the spatial scale. Significant variability was also found in the interaction between seasons and CUs. Measuring the temporal and spatial variability of drosophilid diversity in forests contributed to the improvement of the methodological framework supporting such assemblages as bioindicators and provided important insights into the mechanisms behind the dynamic patterns in time and space that ultimately can improve our understanding of Cerrado biodiversity. © 2015 Associação Brasileira de Ciência Ecológica e Conservação. Source

de Medeiros E.N.M.,Instituto Federal Of Brasilia | Sposto R.M.,University of Brasilia | de Araujo Neves G.,Federal University of Campina Grande | Menezes R.R.,Federal University of Campina Grande
Revista Escola de Minas | Year: 2014

This paper presents a technical feasibility analysis of the incorporation of Rice Husk Ash (RHA), Sludge from Water Treatment Station (SWTS) and Wood Ash (WA) in clay for the mass used in ceramic coating. The methodology involved analyzing the technological properties of various compositions. Samples were prepared for pressing, with compositions from 0 to 50% waste and 50 to 100% clay. The sintering was carried out in a muffle furnace. The properties studied were: solubility and leaching (environmental characterization), water absorption and rupture strength modulus. It was concluded that the best condition was the use of up to 25% of the residuals at temperatures of 1000 °C, 1100 °C and 1150 °C. © 2014, Escola de Minas. All right reserved. Source

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