Barreiros, Brazil
Barreiros, Brazil

Time filter

Source Type

Lira L.F.B.,Federal University of Pernambuco | Lira L.F.B.,Instituto Federal Of Educaao | Dos Santos D.C.M.B.,Federal University of Bahia | Guida M.A.B.,Federal University of Bahia | And 4 more authors.
Fuel | Year: 2011

In this work, a method for the determination of phosphorus in biodiesel (B100) using flow injection analysis with spectrophotometric detection (FIA-SD) is described. Samples were digested using an acid mixture in a heating block. The phosphorus concentrations obtained by the (FIA-SD) method were similar to those obtained by the official method. Recovery tests show results between 98.6% and 101.0% for biodiesel produced from sunflower and between 102.1% and 113.5% for biodiesel produced from castor and soybeans. The limits of detection (LOD) and quantification (LOQ) obtained using the FIA system were 0.14 mg L -1 and 0.46 mg L-1, respectively. © 2011 Elsevier Ltd. All rights reserved.


Morte E.S.D.B.,Federal University of Bahia | Morte E.S.D.B.,Instituto Federal Of Educaao | Barbosa I.D.S.,Federal University of Bahia | Santos E.C.,Federal University of Bahia | And 2 more authors.
Food Chemistry | Year: 2012

In this study it was evaluated the variation of tin concentration in function of storage time in canned food samples by using an axial view inductively coupled plasma optical emission spectrometry (AX ICP OES). The effect of various parameters of the ICP OES, such as analytical lines, sample introduction systems and interferences were investigated. Eight emission lines for tin were tested, but only 283.998 nm line was found to be robust enough with respect to interferences and sensitivity, presenting a limit of quantification of 0.094 mg kg-1. A concentric nebuliser combined with a cyclonic chamber has shown better sensitivity than a V-groove nebuliser. Tin was determined in canned tomato sauce stored at room temperature (20.0 ± 1.8 °C) for 0, 30, 60, 90, 120 and 150 days. After 150 days, tin contents increased in the 43-91% range. Despite an increase of almost 100% for one sample, tin contents are well below the maximum level allowed by Agência Nacional de Vigilância Sanitária (ANVISA) regulation of 250 mg kg-1. © 2011 Elsevier Ltd. All rights reserved.


Chaves E.M.F.,Instituto Federal Of Educaao | Chaves E.M.F.,Federal University of Piauí | Silva J.N.,Tecnico Do Laboratorio Of Analise Of Alimentos Do Ifpi | Lima A.,Nucleo Of Hospitalidade | And 2 more authors.
Espacios | Year: 2015

Wild food plants are important for policies concerned with food security. Aimed to establish the nutritional content and in vitro anti-oxidant activity of species food of northeast Brazil. Were carried 93 semi-structured interviews. Bromelia laciniosa Mart. ex Schult., Hymenaea martiana Hayne, Pouteria macrophylla (Eyma) Aubl. and Swartzia flaemingii var. psilonema (Harms) Cor. are rich in carbohydrates. H. martiana, P. macrophylla and Randia armata (Sw.) DC. are notable for their bioactive compounds and their in vitro anti-oxidant activity. These species could form part of regional programs aimed at food and nutritional security.


Martins D.F.,Campus Universitario | Mazzardo-Martins L.,Campus Universitario | Gadotti V.M.,Campus Universitario | Nascimento F.P.,Campus Universitario | And 9 more authors.
Pain | Year: 2011

An important issue in physical rehabilitation is how to protect from or to reduce the effects of peripheral nerve injury. In the present study, we examined whether ankle joint mobilization (AJM) would reduce neuropathic pain and enhance motor functional recovery after nerve injury. In the axonotmesis model, AJM during 15 sessions every other day was conducted in rats. Mechanical and thermal hyperalgesia and motor performance deficit were measured for 5 weeks. After 5 weeks, we performed morphological analysis and quantified the immunoreactivity for CD11b/c and glial fibrillary acidic protein (GFAP), markers of glial activation, in the lumbar spinal cord. Mechanical and thermal hyperalgesia and motor performance deficit were found in the Crush + Anesthesia (Anes) group (P < 0.001), which was significantly decreased after AJM (P < 0.001). In the morphological analysis, the Crush + Anes group presented reduced myelin sheath thickness (P < 0.05), but the AJM group presented enhanced myelin sheath thickness (P < 0.05). Peripheral nerve injury increased the immunoreactivity for CD11b/c and GFAP in the spinal cord (P < 0.05), and AJM markedly reduced CD11b/c and GFAP immunoreactivity (P < 0.01). These results show that AJM in rats produces an antihyperalgesic effect and peripheral nerve regeneration through the inhibition of glial activation in the dorsal horn of the spinal cord. These findings suggest new approaches for physical rehabilitation to protect from or reduce the effects of nerve injury. © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.


Martins M.A.P.,Federal University of Santa Maria | Rossatto M.,Instituto Federal Of Educaao | Prola L.D.T.,Federal University of Santa Maria | Pizzuti L.,Federal University of Grande Dourados | And 5 more authors.
Ultrasonics Sonochemistry | Year: 2012

The synthesis of 14 novel N-propargylic β-enaminones from the reaction of β-alkoxy vinyltrihalomethyl[carboxyethyl] ketones [R 3C(O)CHC(R1)OMe, where R3 = CF3, CCl3, CO2Et and R1 = Me, Et, Pr, Bu, i-Pent, CH2CH2CO2Me] with propargyl amines [R 2NHCH2CCH, where R2 = Pr, PhCH2] is reported. Yields, solvents and reaction times needed for reaction completion, by microwave irradiation (MW), conventional thermal heating (TH) and under ultrasound irradiation (US) are compared. The best results were obtained under US irradiation in good to excellent yields (70-93%). © 2011 Elsevier B.V. All rights reserved.


De Lima J.C.,Federal University of Ceará | Duarte Arraes F.D.,Instituto Federal Of Educaao | De Oliveira J.B.,Instituto Federal Of Educaao | Do Nascimento F.A.L.,University Federal do Reconcavo Baiano | De Macedo K.G.,Instituto Federal Of Educaao
Revista Ciencia Agronomica | Year: 2016

The Hargreaves-Samani model is used in estimating reference evapotranspiration, and is very useful for irrigation management; it is considered to be of practical use as it uses meteorological elements, which are easily obtained, such as temperature. However, the equation is in need of regional calibration in order to accurately estimate evapotranspiration. The aim of this work was to calibrate the Hargreaves-Samani model for the State of Ceará, using meteorological data from 12 cities. The empirical parameters α (0.0023) and β (0.5) were calibrated considering two processes: firstly, the simultaneous calibration of the two parameters, and then only the α coefficient. The simultaneous calibration returned a variation in the extreme values for three cities; α ranged from 0.0004 (Campos Sales and Crateús) to 0.0019 (Guaramiranga), and exponent β varied between 0.51 (Guaramiranga) to 1.1977 (Campos Sales). The correlation between the Hargreaves-Samani model calibrated with the Penman-Monteith equation, had a maximum value for the city of Jaguaruana, 0.934 when calibrated with the two parameters, and 0.942 when calibrated with the α coefficient only, demonstrating that calibration of the Hargreaves-Samani equation is viable, and is necessary for improving estimates of evapotranspiration.


Melo D.S.,Federal University of Minas Gerais | Melo D.S.,Instituto Federal Of Educaao | Pereira-Junior S.S.,Federal University of Minas Gerais | Dos Santos E.N.,Federal University of Minas Gerais
Applied Catalysis A: General | Year: 2012

The hydroaminomethylation (hydroformylation/reductive amination) of the naturally occurring monoterpenes, i.e., limonene, camphene, and β-pinene, was studied having as condensation counterparts the amines di-n-butylamine, morpholine or n-butylamine. Moderate to good yields (75-94%) were obtained employing [Rh(cod)(μ-OMe)]2 as pre-catalyst in the presence or not of triphenylphosphine or tribenzylphosphine as ancillaries in toluene, at 100 °C and 60 bar of an equimolar mixture of carbon monoxide and hydrogen. Some of the hydroaminomethylation products derived from limonene have biological activity and the products derived from camphene and β-pinene are new. © 2011 Elsevier B.V. All rights reserved.


Carvalho-Santos V.L.,Federal University of Minas Gerais | Carvalho-Santos V.L.,Instituto Federal Of Educaao | Moura-Melo W.A.,Federal University of Minas Gerais | Pereira A.R.,Federal University of Minas Gerais | Pereira A.R.,Max Planck Institute for the Physics of Complex Systems
Journal of Applied Physics | Year: 2010

The energetics associated to the ferromagnetic, vortex, and onionlike magnetization configurations are explicitly computed in the toroidal geometry. The analysis reveals that the vortex appears to be the most prominent of such states, minimizing total energy in every torus with internal radius r≳10 nm, or even in smaller ones provided that R/ℓex≳ 1.5 (R is the torus external radius and ex is the exchange length). This possibility of having very small nanomagnets comprising a vortex-type state, might have importance in higher density binary logic and/or storage and in novel mechanisms for cancer therapy applications. © 2010 American Institute of Physics.


Da Silva C.K.F.,Federal University of Paraiba | De Oliveira A.S.S.,Instituto Federal Of Educaao | Kurozawa L.E.,University of Campinas | Murr F.E.X.,University of Campinas | Da Silva Z.E.,Federal University of Paraiba
Journal of Food Engineering | Year: 2010

A study and modeling of the mass transfer phenomenon in the drying process of agricultural products, using Fick's second law of diffusion adapted to infinite flat plate geometry, are described. An analytical solution methodology, the classical integral transform technique (CITT), is employed. Predicted results are compared with experimental data on the drying of sliced mushrooms in different operating conditions. A phenomenological analysis is made using graphics and tables. The data obtained by CITT and experimentally show negligible differences. The mass diffusion coefficient during hot air drying of mushrooms is estimated. Experimental drying kinetics are applied to the product at different air temperatures and air flow rates aiming to find a solution for the mass transfer equation, using an inverse problem with the Levenberg-Marquardt optimization technique in successive trials. Experimental data are also modified by a normal distribution of random errors. Statistical analyses show good agreement between experimental and predicted curves. © 2010 Elsevier Ltd. All rights reserved.


Matos F.B.,Instituto Federal Of Educaao | Camacho J.R.,Federal University of Uberlandia | Rodrigues P.,Federal University of Uberlandia | Guimaraes Jr. S.C.,Federal University of Uberlandia
Renewable and Sustainable Energy Reviews | Year: 2011

The Amazon is a large area of forest that shelters the largest biodiversity in the planet. Although a region of richness in energy resources, around 40% of local residents do not have access to an electrical network, and the other 60% are connected to the largest islanded system in the world, supplied mainly by thermoelectricity running on diesel engines, spread for hundreds of communities, distributed along river banks, and inside thickest rain forest in the world. This situation does not allow the implantation of enterprises and industry, and mainly the development of resident communities inside the forest what relegates the population to a situation of low social and economical development, giving space to a predatory exploitation of natural resources, risking the environment where they are inserted. The use of alternative energy sources to substitute diesel oil or for its complementation start from the knowledge of available resources for the use of solar energy in the region, allied to the natural resources available with the use of biomass and natural gas and hydraulic resources that are abundant in the region. © 2011 Elsevier Ltd. All rights reserved.

Loading Instituto Federal Of Educaao collaborators
Loading Instituto Federal Of Educaao collaborators