Silva C.D.,Universitario |
Lima R.C.O.,Universitario |
Figueiredo J.M.R.,Universitario |
Silva I.A.,Universitario |
And 2 more authors.
Materials Science Forum | Year: 2015
Organoclays are used as disperse agent in the composition of drilling fluids, which play important roles during the drilling of petroleum wells. This work is intended to develop several kinds of smectite from Cubati-PB for use in drilling fluids, using the ionic surfactant Praepagen WB. The following materials were used: natural Gray and Superior Green bentonite, from the town of Cubati-PB, and quaternary ammonium salts: Praepagen WB® with 45% active matter. The organoclays were characterized by laser diffraction granulometric analysis, chemical composition by X-ray fluorescence, thermogravimetric analysis, differential thermal analysis and X-ray diffraction. In general, we noticed that the clays present diffractograms and thermal behavior typical of bentonites. The results showed that the studied clay has potential for organofilization. With respect to the process variables, we observed that they do not interfere in the organofilization process. © (2015) Trans Tech Publications, Switzerland.
Lopes Neto J.P.,Universitario |
do Nascimento J.W.B.,Universitario
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013
For design involving storage of bulk solids to be safe and reliable, it is important to know a large number of variables such as flow properties, geometry of silos and flow pattern. With the objective to validate prediction using flow theories and silo design procedures, the flow properties of three bulk solids were determined and Jenike's flow theory and Enstad's hopper design equations were applied and compared with those obtained experimentally in a reduced model of silo of semicircular section. The experimental results confirm the method of Jenike and Enstad for flow pattern and hopper design, respectively. The values of discharge orifice obtained by Jenike's equation are demonstrated to be oversized, being 45% higher than needed to provide flow.
da Trindade D.F.V.,Universitario |
Coelho G.C.,University of South Santa Catarina
IForest | Year: 2012
The successional model of forest restoration is based on the facilitation process, in which the establishment of pioneer tree species favors the late successional tree species. We tested the hypothesis of facilitation through a case study, comparing tree species diversity in the understory of two Neotropical native tree species plantations, Trema micrantha (L.) Blüme (Cannabaceae) and Schinus molle L. (Anacardiaceae). Results obtained under the plantations were compared with an adjacent area under spontaneous secondary succession, analyzing the ligneous plant diversity, soil physic-chemistry and shading. Additionally, the seed rain under the two plantations was analyzed. The area of spontaneous secondary succession and the area with T. micrantha had the highest ligneous plant diversity. The understory of T. micrantha plantation had the lowest light intensity and higher late successional species abundance. In addition, T. micrantha had higher plant diversity than S. molle, which could be explained at least partially by higher diversity in the seed rain. Higher litterfall and mineral content of leaves and twigs of T. micrantha did not coincide with higher topsoil mineral content under that species. Instead, soil under S. molle had higher level of P than the soil under T. micrantha. Data suggest that a high diversity of ligneous plants could be thrived by the spontaneous succession. On the other hand, T. micrantha had promoted a higher richness and abundance of late successional species, which could be related to a more pronounced shade effect, in agreement with the facilitation conception. The lowest diversity and density of ligneous plant species under S. molle characterizes an inhibition effect. T. micrantha could be included in restoration plans assembled with other species or combined with areas without intervention, whenever the spontaneous regeneration is possible. © iForest - Biogeosciences and Forestry.
Machado S.C.,Universitario |
McManus C.M.,University of Brasilia |
Stumpf M.T.,Federal University of Rio Grande do Sul |
Fischer V.,Federal University of Rio Grande do Sul
Tropical Animal Health and Production | Year: 2014
This study aimed to evaluate the effect of concentrate-to-forage ratio (C:F) on the performance, blood profile, and milk physicochemical characteristics of mid-lactation cows fed a corn silage-based diet. Twenty four Holstein cows, with BW 575 ± 70 kg, body condition score (BCS) 3.1 ± 0.2, milk yield 18.4 ± 3.0 kg, and days in milk (DIM) 121 ± 21 were randomly allocated into three treatments with C:F ratios of 35:65, 45:55, and 55:45 on a dry matter (DM) basis. Data was submitted to analyses of variance and regression. Increasing C:F from 35 to 55 % linearly enhanced milk production (22 to 23.6 kg day-1) and serum urea nitrogen (16.8 to 19.6 mg/dL), while it linearly reduced lactose and fat in milk (4.8 to 4.6 %; 3.9 to 3.6 %, respectively). Body weight, BCS, milk acidity, ethanol stability, coagulation time, and milk and blood mineral contents did not differ among treatments. During the last period of measurements, increased C:F reduced urinary pH and milk urea nitrogen. Changes of concentrate-to-forage proportion from 35 to 55 % increased milk yield, altered chemical composition without changing BW, BCS, acidity, stability, and mineral content of milk and blood attributes. © 2014 Springer Science+Business Media Dordrecht.
Knicker H.,CSIC - Institute of Natural Resources and Agriculture Biology of Seville |
Knicker H.,TU Munich |
Nikolova R.,TU Munich |
Dick D.P.,Federal University of Rio Grande do Sul |
Geoderma | Year: 2012
The impact of ceasing biannual burning on the composition and the amount of soil organic matter (SOM) in grassland soils from Southern Brazil was studied by means of solid-state 13C and 15N NMR spectroscopy using soil duplicates of fields without 1, 2, 5 and 22years of burning. The examination of the duplicates demonstrated good reproducibility. Demineralization of the soil with hydrofluoric acid (HF) indicated that the fire frequency had no impact on the amount of HF-extractable SOM. Exclusion of fire resulted in a considerable decrease of the organic C stocks, whereas N and S stocks were only slightly affected. The content of pyrogenic organic C (PyOC) in the soils was determined via a combination of chemical oxidation with acid dichromate and solid-state 13C NMR spectroscopy of the oxidation resistant fraction. This analysis revealed that this decline was caused by the reduced input of decaying plant roots remaining in the soil after combustion of the aboveground vegetation during a fire. In spite of frequent burning for centuries, the PyOC concentrations were unexpectedly low in the top 5cm of the studied soils but increased clearly with soil depth, indicating that some charcoal constituents can be translocated with the soil solution. With respect to the stability of charcoal in the grassland soils, our study revealed that comparable to SOM, pyrogenic organic matter (PyOM) is composed of fractions with different stability against microbial degradation. Whereas the labile PyOM fraction showed C losses similar to that of O-alkyl C, the more stable PyOM was selectively preserved together with an alkyl C fraction. Based on the results of the present study, one can conclude that frequent burning of grassland can lead to an increased C-sequestration potential of a soil. Because the input of the additional C is mainly caused by a higher biomass production after the fire, the additional SOM contributes to the labile pool with short turn-over times rather than to the recalcitrant carbon fraction. After ceasing burning, the reduced litter input cannot compensate the fast consumption of this pool and a quick decrease of the C stocks is expected. © 2012 Elsevier B.V.
Azevedo E.P.D.P.,Federal Rural University of Pernambuco |
de Azevedo Filho C.A.,Universitario |
Santos B.S.,Federal University of Pernambuco |
da Silva L.T.,Federal Rural University of Pernambuco |
And 2 more authors.
Food Analytical Methods | Year: 2015
A fast and simple method for determination of six folate forms was developed through a study of standards and tested in New Zealand spinach (Tetragonia expansa) samples. A systematic evaluation of the standard solubilization conditions, pH, and molar concentration of the aqueous solvent of the mobile phase was performed and evaluated by means of chromatographic parameters: retention time (tr), capacity factor (k), alpha (α), and resolution (Rs). The optimal separation was achieved using phosphate buffer pH 2.0, 100 mmol L−1 and methanol in the ratio 85:15 isocratic mode using C18 Spherisorb ODS-2, 2.0 × 100 mm, 5 μm column, and DAD detection 200–400 nm. The following k values were obtained: 0.58, 1.17, 1.06, 1.98, 3.03, and 6.05, respectively, to tetrahydrofolate, 5-methyltetrahydrofolate, 10-formyltetrahydrofolate, 5-formyltetrahydrofolate, folic, and pteroic acid and α values of 1.81, 1.10, 1.69, 1.53, and 1.99. The elution order of the six folate forms is explained using the Lewis theory of acids and bases. This method was applied to samples of New Zealand spinach and monitored through chromatographic and spectral parameters obtained in the region of maximum absorption of λ. Moreover, the similarity and the purity of the peaks in standards and samples were investigated. For all folate forms, α and Rs values were above 1, except tetrahydrofolate. The similarity index was above 75 % and a purity above 90 % in samples, except for 10-formytetrahydrofolate, indicating that the method has good selectivity for complex matrices. © 2015 Springer Science+Business Media New York
da Silva M.M.P.,UEPB |
de Sousa J.T.,UEPB |
Ceballos B.S.O.,UEPB |
Feitosa W.B.S.,Universitario |
Revista Caatinga | Year: 2010
The goals of this work consisted of identifying the prevalence of helminth eggs in household organic wastes generated in the urban zone of cities of the semiarid of the Paraíba. The work was accomplished from June to December of 2006 in 30 homes in the urban center of Cabaceiras, 30 in Caraúbas and 50 in Queimadas. Organic solid residues were collected during in three consecutive weeks and alternate days (Monday, Wednesday and Friday) in the generating source. For quantification of the helminth eggs three composed samples were picked up by city, resultants of ten fractions of organic solid residues collected in the homes. The amount of helminth eggs varied from 12.82 to 14.39 eggs/gST, with viability of 95.42%. In prevalence order, they enrolled Ancylostoma sp., Enterobius vermiculares, Fasciola hepatica and Ascaris lumbricoides. The eggs of Ancylostoma sp. were identified in 100% of the examined samples. The terrible sanitary quality verified for the household organic waste solid in three cities, located geographically in the area of the paraiban semiarid they suggest that these residues constitute important source of contamination to the environment and the human being, requesting the appropriate management.
Floristic and phytossociology of woody component of riparian vegetation of bodocongó river in the semi-arid of paraiba state [Florística e fitossociologia do componente lenhoso da mata ciliar do riacho de bodocongó, semiárido paraibano]
Trovao D.M.B.M.,Universitario |
Freire A.M.,UNIASSELVI |
de Melo J.I.M.,Universitario
Revista Caatinga | Year: 2010
The gallery forest and other unequal vegetal areas of semiarid suffered the antropized influence but this first kind of vegetation has been less studied. The floristic composition and phytosociological study of the woody representatives in the riparian forest of the Bodocongó River, semi-arid of the Paraiba State, it was studied through of the insertion of four transects perpendicularly to the water body in and each transect were plotted three parcels with 10×20 m. It was used Mata Nativa II program to calculate phytosociological parameters. The analyzed vegetation was represented by 357 individuals belonged to 16 genera and 7 families. The species that presented the most number of individuals were: Prosopis juliflora (221), Croton sonderianus (52), Pithecellobium dulce (20) and Ziziphus joazeiro (14). Prosopis juliflora occurred in all studied areas demonstrating its aggressive characteristic and also showing the susceptibility of areas that passed by human influence to invader areas. The highest importance value of quantity of species (VI) was Prosopis juliflora (49.22%), allowed for Ziziphus joazeiro, Croton sonderianus and Pithecellobium dulce. It was demonstrated that the bordering forest of Bodocongo River hasn't contain an expressive floristic composition that it is related probably to the influence and degradation resulting from human action.
de Silva T.R.G.,Universitario |
da Cunha B.B.,Universitario |
Agrawal P.,Universitario |
Araujo E.M.,Universitario |
de Melo T.J.A.,Universitario
Materials Science Forum | Year: 2014
In this work, the effect of the PCL content and E-GMA compatibilizer on the mechanical properties and morphology of poly (lactic acid) - PLA/ poly (ε -caprolactone)-PCL blends was investigated. The results of the mechanical properties showed that there was a reduction in the elastic modulus and tensile strength when PCL was added to PLA. The decrease in the modulus was more pronounced when the PCL content was increased from 10 to 20% (wt). The PLA/PCL/EGMA blend showed the lower modulus and tensile strength. This blend also presented the higher elongation at break and impact strength. The morphology analysis by SEM showed that the PLA/PCL blends where characterized by lack of adhesion between the PLA and PCL phases. The presence of E-GMA in the PLA/PCL/E-GMA blend improved the adhesion between the PLA and PCL phases. © (2014) Trans Tech Publications, Switzerland.
PubMed | Universitario
Type: Journal Article | Journal: Thorax | Year: 2012
Fibroblast to myofibroblast transition is believed to contribute to airway remodelling in lung diseases such as asthma and chronic obstructive pulmonary disease. This study examines the role of aclidinium, a new long-acting muscarinic antagonist, on human fibroblast to myofibroblast transition.Human bronchial fibroblasts were stimulated with carbachol (10(-8) to 10(-5) M) or transforming growth factor-1 (TGF-1; 2 ng/ml) in the presence or absence of aclidinium (10(-9) to 10(-7) M) or different drug modulators for 48 h. Characterisation of myofibroblasts was performed by analysis of collagen type I and -smooth muscle actin (-SMA) mRNA and protein expression as well as -SMA microfilament immunofluorescence. ERK1/2 phosphorylation, RhoA-GTP and muscarinic receptors (M) 1, 2 and 3 protein expression were determined by western blot analysis and adenosine 3-5 cyclic monophosphate levels were determined by ELISA. Proliferation and migration of fibroblasts were also assessed.Collagen type I and -SMA mRNA and protein expression, as well as percentage -SMA microfilament-positive cells, were upregulated in a similar way by carbachol and TGF-1, and aclidinium reversed these effects. Carbachol-induced myofibroblast transition was mediated by an increase in ERK1/2 phosphorylation, RhoA-GTP activation and cyclic monophosphate downregulation as well as by the autocrine TGF-1 release, which were effectively reduced by aclidinium. TGF-1 activated the non-neuronal cholinergic system. Suppression of M1, M2 or M3 partially prevented carbachol- and TGF-1-induced myofibroblast transition. Aclidinium dose-dependently reduced fibroblast proliferation and migration.Aclidinium inhibits human lung fibroblast to myofibrobast transition.