948 resultados para anaerobic biodigestion


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Aiming to study the biogas produced by 5 substrates from both quality and quantity point of view, this research was conducted at the Rural Engineering Department of FCAV/UNESP - Brazil, State of São Paulo. The substractes that were used in the anaerobic digestion were characterized as: 1 - Slaughter fowls' manure with napier grass bed (MFNG); 2 - Slaughter fowls' manure with triturate napier grass bed (MFNGT); 3 - Suine manure (SM); 4 - Bovine manure (BM) and 5 - Bovine manure mixed with 50% of sugarcane bagasse (BM50S). From the data collected it was concluded that: the substract (MFNG) and the substract containing SM produced higher and lower volumes of biogas respectively, when compared to the others; the mixture of sugarcane bagasse in the substract containing Bovine manure damages the accumulated biogas production and its quality; 57 days after filling the biodigestors, all substrates produced biogas with a methane level higher than 48% except for the substrates containing Suine manure; the triturate substrates (MFNGT) did not present such distinct characteristics from the non-triturate substrates (MFNG); the quality of biogas at the maximum production stage was similar, for all the studied substrates; the biogas which presented higher quantity of methane in its composition was the one produced with BM, overcoming the value up to 17.7% over the MFNGT production.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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In this research it was studied a system composed by the anaerobic filter combined with a sand filter for the wastewater treatment. For this, three anaerobic filters were operated with hydraulic detention time of nine hours which had the effluent disposed over four sand filters in different frequencies of application. on the first sand filter, 50 L.m(-2) were applied once a day. on the second, the third and the fourth filters, the same load was disposed in twice, three and four times a day, distributed between 9 a. m. and 4 p. m. The system presented a final effluent suitable for the COD and BOD legislation maximum limit to be discharged into water body (Decreto Paulista no 8,468/1976), showing the viability of dispose a higher quantity of effluent then the one suggested by NBR 13969/1997, which guides the constructive aspects for this kind of treatment.

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The purpose of this study was to evaluate the effect of using different mathematical models to describe the relationship between treadmill running speed and time to exhaustion. All models generated a value for an aerobic parameter (critical speed; S(critical)). 35 university students performed 5-7 constant-speed 0%-slope treadmill tests at speeds that elicited exhaustion in similar to 3 min to similar to 10 min. Speed and time data were fitted using 3 models: (1) a 2-parameter hyperbolic model; (2) a 3-parameter hyperbolic model; and (3) a hybrid 3-parameter hyperbolic + exponential model. The 2-parameter model generated values for S(critical) (mean (+/- SD): 186 +/- 33 m.min(-1)) and anaerobic distance capacity (ADC; 251 +/- 122 m) with a high level of statistical certainty (i.e., with small SEEs). The 3-parameter models generated parameter estimates that were unrealistic in magnitude and/or associated with large SEEs and little statistical certainty. Therefore, it was concluded that, for the range of exercise durations used in the present study, the 2-parameter model is preferred because it provides a parsimonious description of the relationship between velocity and time to fatigue, and it produces parameters of known physiological significance, with excellent confidence.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Thyroid hormone is known to affect myocardial glycogen stores and thereby possibly limit anaerobic performance of mammalian cardiac muscle. Thyroid hormone administration (3,5,T-triiodo-L-thyroxine, 300 mu g/kg/day, sc) for 10 days decreased left ventricle (LV) glycogen concentration relative to euthyroid animals (2.78 +/- 0.46 vs. 4.28 +/- 0.29 mg/g of LV (mean +/- SEM)) while increasing the percent of V(1) myosin isozyi-ne, contractile activity and cardiac mass. In contrast, thyroidectomy increased myocardial glycogen stores (8.50 +/- 0.56 mg/g of LV) and shifted the myosin isozyme toward V(3), prolonged contractile activity and decreased LV mass. Thyroxine administration for 3, 7 and 10 days to thyroidectomized animals progressively decreased contractile duration and increased LV mass. Thyroxine administration for 3 or 7 days to thyroidectomized rats did not reduce glycogen stores (7.75 +/- 1.02 and 9.62 +/- 1.16 mg/g of LV, respectively), whereas myocardial glycogen declined to 3.30 +/- 0.58 mg/g of LV after 10 days of treatment. During hypoxia, cardiac muscle from thyroidectomized rats maintained greater active force and developed less contracture relative to euthyroid and, to a greater extent, than hyperthyroid rats. Removal of glucose from the bath decreased anaerobic performance and impaired recovery; however, myocardium from thyroidectomized rats remained more tolerant to hypoxia than the euthyroid group. Overall, the intrinsic LV glycogen content was positively correlated to anaerobic performance. These data demonstrate that the thyroid state profoundly affects myocardial growth, contractility and anaerobic performance of rat myocardium. Although energy demand may affect function during hypoxia, anaerobic substrate reserve (cardiac glycogen concentration) appears to be the primary factor determining tolerance to hypoxic stress. J. Exp. Zool. 311A:399-407, 2009. (C) 2009 Wiley-Liss, Inc.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A selection of commercially available disinfectants, sanitizers and water sanitizers based on iodophor, quaternary ammonium compounds (QACs) and phenolic compounds were tested for their activity against a phage type 4 strain of Salmonella serotype Enteritidis in the presence of a variety of organic materials. In general the phenolic preparations were the most effective followed by the QACs and the iodophors. They were all inactivated to different degrees by chick fluff, chicken faeces, feed and wood shavings. The inactivation was greatest when Salmonella organisms were pre-dried in feed. Under these conditions formaldehyde and glutaraldehyde were still active. There was some evidence that induced resistance to stress conditions including culture at 42°C and anaerobic culture increased resistance to one of the water sanitizers.

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The biofertilizer was produced through anaerobic fermentation of cow manure adding milk, sugar, salts, cow liver parts and bone powder. After 73 days of fermentation it was evaluated the effect on micelial growth of Pythium aphanidermatum, Alternaria solani, Stemphylium solani, Septoria licopersici, Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum f. sp. phaseoli and spores germination of B. cinerea, A. solani, Hemileia vastatrix and Coleosporium plumierae. In relation to micelial growth inhibition, the growth rate was calculated and it was found that, in general, concentrations over 10% caused a total inhibition of growth for the majority of fungi assayed. In case of spores germination, biofertilizer concentration over 20% has inhibited completely the germination of B. cinerea, over 10% inhibited A. solani, 5 and 1% of C. plumierae and H. vastatrix, respectively. Three different biofertilizers were also tested and one of them was less effective, which was the one produced with manure from confined cows opposed to the others produced with grazing cows.

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Atrophic gastritis patients have intestinal bacterial overgrowth which could produce menaquinones. The aim of this study was to evaluate the interaction between a diet low in phylloquinone and minidoses of warfarin in subjects with and without bacterial overgrowth. Subjects with atrophic gastritis (indicated by serum pepsinogen ratio) and healthy volunteers were studied while fed a restrictive phylloquinone diet and while receiving a minidose of warfarin. Coagulation times, serum osteocalcin, serum undercarboxylated osteocalcin, plasma phylloquinone, plasma K-epoxide, plasma undercarboxylated prothrombin (PIVKA)-II and urinary gamma-carboxyglutamic acid (Gla) were measured. At baseline, there were no differences between groups for any variable measured. Comparisons between baseline and post intervention in both groups, showed significant increases in circulating levels of K-epoxide, PIVKA II and undercarboxylated osteocalcin. However, no differences were observed when comparisons were made between groups. Our data do not support the hypothesis that bacterial synthesis of menaquinones in patients with bacterial overgrowth due to atrophic gastritis confers considerable resistance to the effect of warfarin.

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The aim of the present study was to evaluate the in vivo antimicrobial activity of 2% chlorhexidine gluconate (FCFRP-USP) used as a root canal irrigating solution in teeth with pulp necrosis and radiographically visible chronic periapical reactions. Culture techniques and measurement of the inhibition zone were used. Twenty-two root canals of incisors and molars of 12 patients were used. After accessing the canal, the first root canal sample was collected with two sterile paper points that were transferred to a tube containing reduced transport fluid. The root canal was instrumented using chlorhexidine solution. A small sterile cotton pellet was placed at the root canal entrance, and the cavity was sealed with zinc oxide-eugenol cement. The canals were maintained empty for 48 h. Three sterile paper points were then introduced to absorb the root canal fluid (second sample). One paper point was placed on an agar plate inoculated with Micrococcus luteus ATCC 9341 and incubated for 24 h at 37°C, and the other two were submitted to microbiological evaluation. Present in 10 cases at baseline, mutans streptococci was reduced by 100% at the second assessment. Treatment showed an efficiency of 77.78% for anaerobic microorganisms at the second assessment. These data suggest that chlorhexidine prevents microbial activity in vivo with residual effects in the root canal system up to 48 h. Copyright © 1999 by The American Association of Endodontists.

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The isolation of Clostridium botulinum from honey samples is described. Botulism is characterized as an intoxication provoked by ingestion of contaminated foods with this toxin. Infant botulism happens by the ingestion of spores of C. botulinum together with food that in special conditions of the intestinal tract, such as those present in babies of less than 1 year old, will allow the germination and colonization of the intestine with production and absorption of botulinic toxin. The samples were subjected to dilution and to a thermal shock and cultivated in modified CMM (Difco). Cultures were subjected to Gram smears and toxicity tests in mice. The toxic cultures were purified in RFCA (Oxoid) plates and incubated in anaerobic jars. Positive samples were typed using the mouse assay neutralization test. From the 85 honey samples analyzed, six were positive for C. botulinum (7.06%), and identified as producers of type A, B, and D toxins.

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The objectives of this study were to verify the effects of wet suits (WS) on the performance during 1500m swimming (V1500), on the velocity corresponding to the anaerobic threshold (VAT) and on the drag force (AD) as well as its coefficient (Cx). 19 swimmers randomly completed the following protocols on different days (with and without WS): 1) maximal performance of 1500m swimming; 2) VAT in field test, with fixed concentration of blood lactate (4 mM) and 3) determination of hydrodynamic indices (AD and Cx). The results demonstrated significant differences (p < 0.05) in the VAT (1.27±0.09; 1.21±0.06 m.s-1), and in the V1500 (1.21±0.08; 1.17±0.08 m.s-1), with and without WS, respectively. However the AD, and its Cx did not present significant differences (p>0.05) for the respective maximal speeds of swimming. In summary, we can conclude that WS allows swimmers to reach greater speeds in both, long- and short-course swims. This improvement can be related to the decrease of the AD, since with higher speeds (with WS) the subjects presented the same resistance, as they did when compared to speeds without a WS. Moreover, these data suggest that the methodology used in this study to determine the Cx is unable to detect the improvement caused by WS.

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β-Adrenoreceptor blockade is reported to impair endurance, power output and work capacity in healthy subjects and patients with hypertension. The purpose of this study was to investigate the effect in eighth athletic males of an acute β-adrenergic blockade with propranolol on their individual power output corresponding to a defined lactate minimum (LM). Eight fit males (cyclist or triathlete) performed a protocol to determine the power output corresponding to their individual LM (defined from an incremental exercise test after a rapidly induced exercise lactic acidosis). This protocol was performed twice in a double-blind randomized order by each athlete first ingesting propranolol (80mg) and in a second trial a placebo, 120 minutes respectively prior to the test sequence. The blood lactate concentration obtained 7 minutes after anaerobic exercise (a Wingate test) was significantly lower after acute β-adrenergic blockade (8.6 ± 1.6mM) than under the placebo condition (11.7 ± 1.6mM). The work rate at the LM was lowered from 215.0 ± 18.6 to 184.0 ± 18.6 watts and heart rate at the LM was reduced from 165 ± 1.5 to 132 ± 2.2 beats/minute as a result of the blockade. There was a non-significant correlation (r = 0.29) between the power output at the LM with and without acute β-adrenergic blockade. In conclusion, since the intensity corresponding to the LM is related to aerobic performance, the results of the present study, are able to explain in part, the reduction in aerobic power output produced during β-adrenergic blockade.