Characterization of different fruit wines made from cacao, cupuassu, gabiroba, jaboticaba and umbu

The main aim of this work was to produce fruit wines from pulp of gabiroba, cacao, umbu, cupuassu and jaboticaba and characterize them using gas chromatography-mass spectrometry for determination of minor compounds and gas chromatography-flame ionization detection for major compounds. Ninety-nine compounds (C(6) compounds, alcohols, monoterpenic alcohols, monoterpenic oxides, ethyl esters, acetates, volatile phenols, acids, carbonyl compounds, sulfur compounds and sugars) were identified in fruit wines. The typical composition for each fruit wine was evidenced by principal component analysis and Tukey test. The yeast UFLA CA 1162 was efficient in the fermentation of the fruit pulp used in this work. The identification and quantification of the compounds allowed a good characterization of the fruit wines. With our results, we conclude that the use of tropical fruits in the production of fruit wines is a viable alternative that allows the use of harvest surpluses and other underused fruits, resulting in the introduction of new products into the market. (C) 2010 Elsevier Ltd. All rights reserved.

Evaluation of the catalytic properties of Burkholderia cepacia lipase immobilized on non-commercial matrices to be used in biodiesel synthesis from different feedstocks

The objective of this work was to produce an immobilized form of lipase from Burkholderia cepacia (lipase PS) with advantageous catalytic properties and stability to be used in the ethanolysis of different feedstocks, mainly babassu oil and tallow beef. For this purpose lipase PS was immobilized on two different non-commercial matrices, such as inorganic matrix (niobium oxide, Nb(2)O(5)) and a hybrid matrix (polysiloxane-polyvinyl alcohol, SiO(2)-PVA) by covalent binding. The properties of free and immobilized enzymes were searched and compared. The best performance regarding all the analyzed parameters (biochemical properties, kinetic constants and thermal stability) were obtained when the lipase was immobilized on SiO(2)-PVA. The superiority of this immobilized system was also confirmed in the transe-sterification of both feedstocks, attained higher yields and productivities. (C) 2010 Elsevier Ltd. All rights reserved.

High-yield kraft pulping of Eucalyptus grandis Hill ex Maiden biotreated by Ceriporiopsis subvermispora under two different culture conditions

In the present study, it was evaluated how two different culture conditions for the biotreatment of Eucalyptus grandis by Ceriporiopsis subvermispora affect a subsequent high-yield kraft pulping process. Under the varied culture conditions investigated, different extracellular enzyme activities were observed. Manganese-peroxidase (MnP) secretion was 3.7 times higher in cultures supplemented with glucose plus corn-steep liquor (glucose/CSL) as compared to non-supplemented (NS) cultures. The biotreated samples underwent diverse levels of wood component degradation as losses of weight and lignin were increased in glucose/CSL cultures. Mass balances for lignin removal during kraft pulping showed that delignification was facilitated when both biotreated wood samples were cooked. Delignification efficiency did not correlate positively with MnP levels in the cultures. On the other hand, biopulps from NS and glucose/CSL cultures saved 27% and 38% beating time to achieve 288 Schopper-Riegler freeness during refining, respectively. Biopulps disposed of decreased tensile and tear resistances, thus easier refining of the biokraft pulps seems to be a consequence of less resistant fiber walls. Improved beatability of biopulps was tentatively related to short fibers and fines formation during refining. We suggest that to some extent polysaccharide depolymerization occurred during the biotreatment, which also resulted in diminished pulp yields in the case of glucose/CSL cultures.

Combined solution for fault location in three-terminal lines based on wavelet transforms

This work presents the study and development of a combined fault location scheme for three-terminal transmission lines using wavelet transforms (WTs). The methodology is based on the low- and high-frequency components of the transient signals originated from fault situations registered in the terminals of a system. By processing these signals and using the WT, it is possible to determine the time of travelling waves of voltages and/or currents from the fault point to the terminals, as well as estimate the fundamental frequency components. A new approach presents a reliable and accurate fault location scheme combining some different solutions. The main idea is to have a decision routine in order to select which method should be used in each situation presented to the algorithm. The combined algorithm was tested for different fault conditions by simulations using the ATP (Alternative Transients Program) software. The results obtained are promising and demonstrate a highly satisfactory degree of accuracy and reliability of the proposed method.

Limiting factors for phytoplankton growth in subtropical reservoirs: the effect of light and nutrient availability in different longitudinal compartments

Limited information is available on the interactions between environmental factors and algal growth in tropical and subtropical aquatic systems. We investigated the relationships between algal biomass (measured as chlorophyll, Chl-a) and light, total phosphorus (TP) and total nitrogen (TN) in longitudinal zones of subtropical reservoirs. We studied the seasonal variation of water variables in Itupararanga Reservoir (Brazil) and compared the results with 16 other subtropical lakes and reservoirs. The longitudinal zones in Itupararanga Reservoir were considered statistically different (p 0.05, MANOVA). From the riverine zone to the dam region of the reservoir, Spearman Correlation Test suggested that light limitation and TP limitation tended to decrease and increase, respectively. Although nitrate concentrations were high (400 g/L), the Spearman coefficients between Chl-a and TN and the TN:TP ratios (11:1 TN:TP 35:1) indicated that nitrogen may be co-limiting algal growth in the studied water body. Putting Itupararanga in a regional context allowed assessment of potential influences of land use on trophic state. Within the subtropical dataset, TP explained a greater percentage of variance in Chl-a (R2 = 0.70) than TN (R2 = 0.17). The main land use type within the reservoirs drainage area significantly influenced the concentrations of TP, TN, and Chl-a (p 0.05, MANOVA), with different relationships between nutrients and chlorophyll in forested (R2 = 0.12-0.33), agricultural (R2 = 0.50-0.68) and urban (R2 = 0.09-0.64) watersheds. Comparisons with literature values and those from reservoirs with less altered watersheds indicated that Itupararanga Reservoir is reaching the mesotrophic-eutrophic boundary, and further nutrient enrichment could cause water quality degradation.

Anaerobic degradation of linear alkylbenzene sulfonate (LAS) in fluidized bed reactor by microbial consortia in different support materials

Four anaerobic fluidized bed reactors filled with activated carbon (R1), expanded clay (R2), glass beads (R3) and sand (R4) were tested for anaerobic degradation of LAS. All reactors were inoculated with sludge from a UASB reactor treating swine wastewater and were fed with a synthetic substrate supplemented with approximately 20 mg l(-1) of LAS, on average. To 560 mg l(-1) COD influent, the maximum COD and LAS removal efficiencies were mean values of 97 +/- 2% and 99 +/- 2%, respectively, to all reactors demonstrating the potential applicability of this reactor configuration for treating LAS. The reactors were kept at 30 degrees C and operated with a hydraulic retention time (HRT) of 18 h. The use of glass beads and sand appear attractive because they favor the development of biofilms capable of supporting LAS degradation. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of samples from reactors R3 and R4 revealed that these reactors gave rise to broad microbial diversity, with microorganisms belonging to the phyla Bacteroidetes, Firmicutes, Actinobacteria and Proteobacteria, indicating the role of microbial consortia in degrading the surfactant LAS. (C) 2010 Elsevier Ltd. All rights reserved.

Effect of specific feed volume on the performance of an anaerobic sequencing batch biofilm reactor (AnSBBR) with circulation treating different wastewaters under different organic loads

The objective of this research was to study the behavior of two anaerobic sequencing batch reactors, containing immobilized biomass (AnSBBR), as a function of the ratio of the volume of treated medium in each cycle to the total volume of reaction medium. The reactors, in which mixing was accomplished by recirculation of the liquid phase, were maintained at 30 +/- 1 degrees C and treated different wastewaters in 8-h cycles. The operational conditions imposed had the objective to investigate whether maintenance of a residual volume in the reactor would affect, at the end of each cycle, process efficiency and stability, as well as to verify the intensity of the effect for different types of wastewaters and organic loading rates. The first reactor, with work volume of 2.5 L, treated reconstituted cheese whey at an organic loading rate of 12 g COD.L(-1).d(-1) and presented similar effluent quality for the four conditions under which it was operated: renewal of 100, 70, 50 and 25 % of its work volume at each cycle. Despite the fact that reduction in the renewed volume did not significantly affect effluent quality, in quantitative terms, this reduction resulted in an increase in the amount of organic matter removed by the first reactor. The second reactor, with work volume of 1.8 L, treated synthetic wastewater at organic loading rates of 3 and 5 g COD.L(-1).d(-1) and operated under two conditions for each loading: renewal of 100 and 50 % of its work volume. At the organic loading rate of 3 g COD.L(-1).d(-1), the results showed that both effluent quality and amount of organic matter removed by the second reactor were independent of the treated volume per cycle. At the organic loading rate of 5 g COD.L(-1).d(-1), although the reduction in the renewed volume did not affect the amount of organic matter removed by the reactor, effluent quality improved during reactor operation with total discharge of its volume. In general, results showed process stability under all conditions, evidencing reactor flexibility and the potential to apply this technology in the treatment of different types of wastewater.

Effects of temperature at different organic loading levels on the performance of a fluidized-bed anaerobic sequencing batch bioreactor

An investigation was performed on the effect of temperature and organic load on the stability and efficiency of a 1.8-L fluidized-bed anaerobic sequencing batch reactor (ASBR), containing granulated biomass. Assays were carried out employing superficial up How velocity of 7 m/h, total cycle length of 6 h and synthetic wastewater volume of 1.3 L per cycle. The fluidized-bed ASH was operated at 15, 20, 25 and 30 degrees C with influent organic matter concentrations of 500 and 1000 mgCOD/L The system showed stability under all conditions and presented filtered samples removal efficiency ranging from 79 to 86%. A first-order kinetic model could be fitted to the experimental values of the organic matter concentration profiles. The specific kinetic parameter values of this model ranged from 0.0435 to 0.2360 L/(gTVS h) at the implemented operation conditions. in addition, from the slope of an Arrhenius plot, the activation energy values were calculated to be 16,729 and 12,673 cal/mol for operation with 500 and 1000 mgCOD/L, respectively. These results show that treatment of synthetic wastewater. with concentration of 500 mgCOD/L, was more sensitive to temperature variations than treatment of the same residue with concentration of 1000 mgCOD/L. Comparing the activation energy value for operation at 500 mgCOD/L with the value obtained by Agibert et al. (S.A. Agibert, M.B. Moreira, S.M. Ratusznei, J.A.D. Rodrigues, M. Zaiat, E. Foresti. Influence of temperature on performance of an ASBBR with circulation applied to treatment of low-strength wastewater. journal of Applied Biochemistry and Biotechnology, 136 (2007) 193-206) in an ASBBR treating the same wastewater at the same concentration, the value obtained in the fluidized-bed ASBR showed to be superior, indicating that treatment of synthetic wastewater in a reactor containing granulated biomass was more sensitive to temperature variations than the treatment using immobilized biomass. (c) 2008 Elsevier B.V. All rights reserved.

Influence of organic shock loads in an ASBBR treating synthetic wastewater with different concentration levels

Safe application of the anaerobic sequencing biofilm batch reactor (ASBBR) still depends on deeper insight into its behavior when faced with common operational problems in wastewater treatments such as tolerance to abrupt variations in influent concentration, so called shock loads. To this end the current work shows the effect of organic shock loads on the performance of an ASBBR, with a useful volume of 5 L, containing 0.5-cm polyurethane cubes and operating at 30 degrees C with mechanical stirring of 500 rpm. In the assays 2 L of two types of synthetic wastewater were treated in 8-h cycles. Synthetic wastewater I was based on sucrose-amide-cellulose with concentration of 500 mg COD/L and synthetic wastewater II was based on volatile acids with concentration ranging from 500 to 2000 mg COD/L. Organic shock loads of 2-4 times the operation concentration were applied during one and two cycles. System efficiency was monitored before and after application of the perturbation. When operating with concentrations from 500 to 1000 mg COD/L and shock loads of 2-4 times the influent concentration during one or two cycles the system was able to regain stability after one cycle and the values of organic matter, total and intermediate volatile acids, bicarbonate alkalinity and pH were similar to those prior to the perturbations. At a concentration of 2000 mg COD/L the reactor appeared to be robust, regaining removal efficiencies similar to those prior to perturbation at shock loads twice the operation concentration lasting one cycle and stability was recovered after two cycles. However, for shock loads twice the operation concentration during two cycles and shock loads four times the operation concentration during one or two cycles filtered sample removal efficiency decreased to levels different from those prior to perturbation, on an average of 90-80%, approximately, yet the system managed to attain stability within two cycles after shock application. Therefore, this investigation envisions the potential of full scale application of this type of bioreactor which showed robustness to organic shock loads, despite discontinuous operation and the short times available for treating total wastewater volume. (c) 2007 Elsevier Ltd. All rights reserved.

Modeling and Analysis of Piezoelectric Energy Harvesting From Aeroelastic Vibrations Using the Doublet-Lattice Method

Multifunctional structures are pointed out as an important technology for the design of aircraft with volume, mass, and energy source limitations such as unmanned air vehicles (UAVs) and micro air vehicles (MAVs). In addition to its primary function of bearing aerodynamic loads, the wing/spar structure of an UAV or a MAV with embedded piezoceramics can provide an extra electrical energy source based on the concept of vibration energy harvesting to power small and wireless electronic components. Aeroelastic vibrations of a lifting surface can be converted into electricity using piezoelectric transduction. In this paper, frequency-domain piezoaeroelastic modeling and analysis of a canti-levered platelike wing with embedded piezoceramics is presented for energy harvesting. The electromechanical finite-element plate model is based on the thin-plate (Kirchhoff) assumptions while the unsteady aerodynamic model uses the doublet-lattice method. The electromechanical and aerodynamic models are combined to obtain the piezoaeroelastic equations, which are solved using a p-k scheme that accounts for the electromechanical coupling. The evolution of the aerodynamic damping and the frequency of each mode are obtained with changing airflow speed for a given electrical circuit. Expressions for piezoaeroelastically coupled frequency response functions (voltage, current, and electrical power as well the vibratory motion) are also defined by combining flow excitation with harmonic base excitation. Hence, piezoaeroelastic evolution can be investigated in frequency domain for different airflow speeds and electrical boundary conditions. [DOI:10.1115/1.4002785]

Application of molecular techniques to evaluate the methanogenic archaea and anaerobic bacteria in the presence of oxygen with different COD : sulfate ratios in a UASB reactor

In this paper, the microbial characteristics of the granular sludge in the presence of oxygen (3.0 +/- 0.7 mg O-2 1(-1)) were analyzed using molecular biology techniques. The granules were provided by an upflow anaerobic sludge blanket (UASB) operated over 469 days and fed with synthetic substrate. Ethanol and sulfate were added to obtain different COD/SO42- ratios (3.0, 2.0, and 1.6). The results of fluorescent in situ hybridization (FISH) analyses showed that archaeal cells, detected by the ARC915 probe, accounted for 77%, 84%, and 75% in the COD/SO42- ratios (3.0, 2.0, and 1.6, respectively). Methanosaeta sp. was the predominant acetoclastic archaea observed by optical microscopy and FISH analyses, and confirmed by sequencing of the excised bands of the DGGE gel with a similarity of 96%. The sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris (similarity of 99%) was verified by sequencing of the DGGE band. Others identified microorganism were similar to Shewanella sp. and Desulfitobacterium hafniense, with similarities of 95% and 99%, respectively. These results confirmed that the presence of oxygen did not severely affect the metabolism of microorganisms that are commonly considered strictly anaerobic. We obtained mean efficiencies of organic matter conversion and sulfate reducing higher than 74%. (C) 2008 Elsevier Ltd. All rights reserved.

Rheological behavior of mortars under different squeezing rates

In the present work the squeeze flow technique was used to evaluate the rheological behavior of cement-based mortars containing macroscopic aggregates up to 1.2 mm. Compositions with different water and air contents were tested at three squeezing rates (0.01, 0.1 and 1 mm/s) 15 and 60 min after mixing. The mortars prepared with low (13 wt.%) and usual water content (15 wt.%) presented opposite behaviors as a function of elapsed time and squeezing speed. The first lost its cohesion with time and required higher loads when squeezed faster, while the latter became stiffer with time and was more difficult to be squeezed slowly as a result of phase segregation. Due to the increase of air content, the effects of this compressible phase became more significant and a more complex behavior was observed. Rheological properties such as elongational viscosity and yield stress were also determined. (C) 2009 Elsevier Ltd. All rights reserved.

Particle size effect on abrasion resistance of mottled cast iron with different retained austenite contents

Effects of particle abrasive sizes on wear resistance of mottled cast iron with different retained austenite contents were studied. Abrasive wear tests using a pin test on alumina paper were carried out, using abrasive sizes between 16 mu m and 192 mu m. Retained austenite content of the matrix was determined by X-ray diffraction. The wear surface of samples and the alumina paper were examined by scanning electron microscopy for identifying the wear micromechanism. The results show that at lower abrasive sizes the mass loss was similar for the iron with different austenite contents. However, at higher abrasive sizes the samples with higher retained austenite content presented higher abrasion resistance. For lower abrasive sizes tested, samples with higher and lower retained austenite content both presented microcutting. On the other hand, the main wear micromechanism for the samples with higher retained austenite content and higher abrasive sizes was microploughing. The samples with lower retained austenite content presented microcutting and wedge formation at higher abrasive sizes. Higher abrasive size induced more microcutting in samples with lower retained austenite. The iron with lower retained austenite content presented wider grooves for the different abrasive sizes measured. SEM on the abrasive paper used on samples with higher retained austenite showed continuous and discontinuous microchips and the samples with lower retained austenite showed discontinuous microchips at 66 and 141 mu m. This research demonstrates the relation between abrasive size, wear resistance, groove width and wear micromechanism for mottled cast iron with different retained austenite contents. (C) 2009 Elsevier B.V. All rights reserved.

Abrasive wear study of white cast iron with different solidification rates

The abrasive wear resistance of white cast iron was studied. The iron was solidified using two solidification rates of 1.5 and 15 degrees C/s. Mass loss was evaluated with tests of the type pin on abrasive disc using alumina of different sizes. Two matrices were tested: one predominantly austenitic and the other predominantly martensitic, containing M(3)C carbides. Samples with cooling rate of 15 degrees C/s showed higher hardness and more refined microstructure compared with those solidified at 1.5 degrees C/s. During the test, the movement of successive abrasives gave rise to the strain hardening of the austenite phase, leading to the attainment of similar levels of surface hardness, which explains why the wear rate showed no difference compared to the austenite samples with different solidification rates. For the austenitic matrix the wear rate seems to depend on the hardness of the worn surface and not on the hardness of the material without deformation. The austenitic samples showed cracking and fracture of M(3)C carbides. For the predominantly martensitic matrix, the wear rate was higher at the solidification rate of 1.5 degrees C/s, for grain size of 66 and 93 mu m. Higher abrasive sizes were found to produce greater penetration and strain hardening of austenitic matrices. However, martensitic iron produces more microcutting, increasing the wear rate of the material. The analysis of the worn surface by scanning electron microscopy indicated abrasive wear mechanisms such as: microcutting, microfatigue and microploughing. Yet, for the iron of austenitic matrix, the microploughing mechanism was more severe. (C) 2009 Elsevier B.V. All rights reserved.

Determination of particle concentration in the breathing zone for four different types of office ventilation systems

Many factors affect the airflow patterns, thermal comfort, contaminant removal efficiency and indoor air quality at individual workstations in office buildings. In this study, four ventilation systems were used in a test chamber designed to represent an area of a typical office building floor and reproduce the real characteristics of a modern office space. Measurements of particle concentration and thermal parameters (temperature and velocity) were carried out for each of the following types of ventilation systems: (a) conventional air distribution system with ceiling supply and return; (b) conventional air distribution system with ceiling supply and return near the floor; (c) underfloor air distribution system; and (d) split system. The measurements aimed to analyse the particle removal efficiency in the breathing zone and the impact of particle concentration on an individual at the workstation. The efficiency of the ventilation system was analysed by measuring particle size and concentration, ventilation effectiveness and the indoor/outdoor ratio. Each ventilation system showed different airflow patterns and the efficiency of each ventilation system in the removal of the particles in the breathing zone showed no correlation with particle size and the various methods of analyses used. (C) 2008 Elsevier Ltd. All rights reserved.