955 resultados para ontology substances
Resumo:
An assessment is made of the atmospheric emissions from the life cycle of fuel ethanol coupled with the cogeneration of electricity from sugarcane in Brazil. The total exergy loss from the most quantitative relevant atmospheric emission substances produced by the life cycle of fuel ethanol is 3.26E+05 kJ/t of C(2)H(5)OH, Compared with the chemical exergy of 1 t of ethanol (calculated as 34.56E + 06 kJ). the exergy loss from the life cycle`s atmospheric emission represents 1.11% of the product`s exergy. The activity that most contributes to atmospheric emission chemical exergy losses is the harvesting of sugarcane through the methane emitted in burning. Suggestions for improved environmental quality and greater efficiency of the life cycle of fuel ethanol with cogenerated energy are: harvesting the sugarcane without burning, renewable fuels should be used in tractors, trucks and buses instead of fossil fuel and the transportation of products and input should be logistically optimized. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
This paper presents the lifecycle assessment (LCA) of fuel ethanol, as 100% of the vehicle fuel, from sugarcane in Brazil. The functional unit is 10,000 km run in an urban area by a car with a 1,600-cm(3) engine running on fuel hydrated ethanol, and the resulting reference flow is 1,000 kg of ethanol. The product system includes agricultural and industrial activities, distribution, cogeneration of electricity and steam, ethanol use during car driving, and industrial by-products recycling to irrigate sugarcane fields. The use of sugarcane by the ethanol agribusiness is one of the foremost financial resources for the economy of the Brazilian rural area, which occupies extensive areas and provides far-reaching potentials for renewable fuel production. But, there are environmental impacts during the fuel ethanol lifecycle, which this paper intents to analyze, including addressing the main activities responsible for such impacts and indicating some suggestions to minimize the impacts. This study is classified as an applied quantitative research, and the technical procedure to achieve the exploratory goal is based on bibliographic revision, documental research, primary data collection, and study cases at sugarcane farms and fuel ethanol industries in the northeast of SA o pound Paulo State, Brazil. The methodological structure for this LCA study is in agreement with the International Standardization Organization, and the method used is the Environmental Design of Industrial Products. The lifecycle impact assessment (LCIA) covers the following emission-related impact categories: global warming, ozone formation, acidification, nutrient enrichment, ecotoxicity, and human toxicity. The results of the fuel ethanol LCI demonstrate that even though alcohol is considered a renewable fuel because it comes from biomass (sugarcane), it uses a high quantity and diversity of nonrenewable resources over its lifecycle. The input of renewable resources is also high mainly because of the water consumption in the industrial phases, due to the sugarcane washing process. During the lifecycle of alcohol, there is a surplus of electric energy due to the cogeneration activity. Another focus point is the quantity of emissions to the atmosphere and the diversity of the substances emitted. Harvesting is the unit process that contributes most to global warming. For photochemical ozone formation, harvesting is also the activity with the strongest contributions due to the burning in harvesting and the emissions from using diesel fuel. The acidification impact potential is mostly due to the NOx emitted by the combustion of ethanol during use, on account of the sulfuric acid use in the industrial process and because of the NOx emitted by the burning in harvesting. The main consequence of the intensive use of fertilizers to the field is the high nutrient enrichment impact potential associated with this activity. The main contributions to the ecotoxicity impact potential come from chemical applications during crop growth. The activity that presents the highest impact potential for human toxicity (HT) via air and via soil is harvesting. Via water, HT potential is high in harvesting due to lubricant use on the machines. The normalization results indicate that nutrient enrichment, acidification, and human toxicity via air and via water are the most significant impact potentials for the lifecycle of fuel ethanol. The fuel ethanol lifecycle contributes negatively to all the impact potentials analyzed: global warming, ozone formation, acidification, nutrient enrichment, ecotoxicity, and human toxicity. Concerning energy consumption, it consumes less energy than its own production largely because of the electricity cogeneration system, but this process is highly dependent on water. The main causes for the biggest impact potential indicated by the normalization is the nutrient application, the burning in harvesting and the use of diesel fuel. The recommendations for the ethanol lifecycle are: harvesting the sugarcane without burning; more environmentally benign agricultural practices; renewable fuel rather than diesel; not washing sugarcane and implementing water recycling systems during the industrial processing; and improving the system of gases emissions control during the use of ethanol in cars, mainly for NOx. Other studies on the fuel ethanol from sugarcane may analyze in more details the social aspects, the biodiversity, and the land use impact.
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The photodegradation of the herbicide clomazone in the presence of S(2)O(8)(2-) or of humic substances of different origin was investigated. A value of (9.4 +/- 0.4) x 10(8) m(-1) s(-1) was measured for the bimolecular rate constant for the reaction of sulfate radicals with clomazone in flash-photolysis experiments. Steady state photolysis of peroxydisulfate, leading to the formation of the sulfate radicals, in the presence of clomazone was shown to be an efficient photodegradation method of the herbicide. This is a relevant result regarding the in situ chemical oxidation procedures involving peroxydisulfate as the oxidant. The main reaction products are 2-chlorobenzylalcohol and 2-chlorobenzaldehyde. The degradation kinetics of clomazone was also studied under steady state conditions induced by photolysis of Aldrich humic acid or a vermicompost extract (VCE). The results indicate that singlet oxygen is the main species responsible for clomazone degradation. The quantum yield of O(2)(a(1)Delta(g)) generation (lambda = 400 nm) for the VCE in D(2)O, Phi(Delta) = (1.3 +/- 0.1) x 10(-3), was determined by measuring the O(2)(a(1)Delta(g)) phosphorescence at 1270 nm. The value of the overall quenching constant of O(2)(a(1)Delta(g)) by clomazone was found to be (5.7 +/- 0.3) x 10(7) m(-1) s(-1) in D(2)O. The bimolecular rate constant for the reaction of clomazone with singlet oxygen was k(r) = (5.4 +/- 0.1) x 10(7) m(-1) s(-1), which means that the quenching process is mainly reactive.
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The aim of this work was the development of miniaturized structures useful for retention and/or selection of particles and viscous substances from a liquid flow. The proposed low costs structures are similar to macroscopic wastewater treatment systems, named baffles, and allow disassemble. They were simulated using FEMLAB 3.2b package and manufactured in acrylic with conventional tools. Tests for retention or selection of particles in water or air and viscous fluids in water were carried out. Either in air or water particles with 50 mu m diameter will be retained but not with 13 mu m diameter. In aqueous flow, it is also possible the retention of viscous samples, such as silicone 350 cSt. The simulated results showed good agreement with experimental measurements. These miniaturized structures can be useful in sample pretreatment for chemical analysis and microorganism manipulation. (C) 2007 Elsevier B.V. All rights reserved.
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The TCP/IP architecture was consolidated as a standard to the distributed systems. However, there are several researches and discussions about alternatives to the evolution of this architecture and, in this study area, this work presents the Title Model to contribute with the application needs support by the cross layer ontology use and the horizontal addressing, in a next generation Internet. For a practical viewpoint, is showed the network cost reduction for the distributed programming example, in networks with layer 2 connectivity. To prove the title model enhancement, it is presented the network analysis performed for the message passing interface, sending a vector of integers and returning its sum. By this analysis, it is confirmed that the current proposal allows, in this environment, a reduction of 15,23% over the total network traffic, in bytes.
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Aqueous extract of mate (dried leaves of Ilex paraguariensis) added to drinking water for broilers for the last 14 days prior to slaughter did not affect performance at 25 days of age, but improved oxidative stability of the chicken meat. Oxidative stability of precooked breast meat made from control meat (CON) and from meat of broilers raised on water with mate added was investigated during chill storage for up to 7 days. The use of mate showed no influence on the content of lipids in chicken breast meat; however, lipid oxidation measured as thiobarbituric acid-reactive substances (TBARS) was significantly lower for meat from broilers raised on water with mate extracts in different concentrations (MA0.1, MA0.5, and MA1.0 corresponding to 0.1, 0.5, and 1.0% of mate dried leaves). The relative effect was largest at 1 day of storage with more than 50% reduction on TBARS; the result was still significant after 3 days, but almost vanished after 7 days, when oxidative rancidity was very high in all samples. In meat from broilers raised on water with mate extract, vitamin E was protected during cooking, although in the very rancid meat balls at 7 days of storage, the protection almost disappeared. Nevertheless, mate can be an interesting natural alternative to be used in chicken diets to improve lipid stability of the meat.
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In contrast with the abundance of anatomical studies of secretory structures on aerial vegetative organs of Asteraceae species, the information about secretory structures on thickened subterranean organs is sparse. The aim of this study was to investigate the occurrence of secretory structures on thickened and nonthickened subterranean organs of seven Asteraceae species from three tribes: Eupatorieae (Chromolaena squalida and Gyptis lanigera), Vernonieae (Chresta sphaerocephala, Lessingianthus bardanoides, L. glabratus and Orthopappus angustifolius), and Plucheeae (Pterocaulon angustifolium). The specimens were collected in areas of cerrado, from the State of Sao Paulo, Brazil. All species of the tribe Vernonieae studied exhibited endodermic cells, other than the epithelial cells of the canal, with secretory activity in the roots. In C. sphaerocephala roots, two types of endodermic cell were found, but only one had secretory activity. Secretory canals were found in the tuberous and nontuberous roots of all studied species. These data agree with the results from the literature for Asteraceae species. Here, we describe for the first time in Asteraceae the presence of secretory idioblasts in C. sphaerocephala. Secretory trichomes are present in the Orthopappus angustifolius rhizophore. Histochemical tests have shown that all types of secretory structure possess substances containing lipids. (C) 2008 The Linnean Society of London.
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Underground systems of Asteraceac species from the Brazilian Cerrado. The aim or this study was to describe the underground systems structure, the origin of the shoot buds, and to identify the storage reserve of seven Asteraceae species in order to understand the adaptive strategies of these species in burned Cerrado areas and their higher frequency in the floristic Surveys for herbaceous and undershrub layers of this biome. The subterranean systems types-diffuse underground system, rhizophore, tuberous roots, and xylopodium-varied among the studied species, but all of them have high shoot bud-forming potential. Fructans of the inulin type were detected as storage substances. The presence of these characteristics on the underground systems Could explain the frequency of these species in the floristic surveys from the Brazilian Cerrado, in which Fire and seasonal drought are frequent. It is possible that the belowground bud banks in the Cerrado biome are as important as demonstrated in North American prairies where fire is also frequent. However, in the Cerrado, as demonstrated here, there are types of underground systems other than rhizomes that are usually described in the prairie. Understanding the anatomical features of these plants is one of the steps to appropriate conservation management of these species in the Cerrado.
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We progressively reduced the complexity of humic matter by a mild sequential removal of unbound or free components, weakly, and strongly bound molecules. The auxin-like response of residues from each step was tested using tomato (cv. Micro-Tom) seedlings expressing DR5 auxin synthetic promoter fused to the beta-glucuronidase (GUS) reporter gene and the low auxin-sensitivity diageotropica (dgt) mutant. Both exogenous auxin and humic matter promoted lateral root emergence in the control, but failed to induce lateral roots in the dgt mutant. When strongly bound components were removed from humic matter by breaking the ester and ether bonds, the humic residues lost their ability to induce the DR5
Resumo:
Endophytic microorganisms reside asymptomatically within plants and are a source of new bioactive products for use in medicine, agriculture, and industry. Colletotrichum (teleomorph Glomerella) is a fungus widely cited in the literature as a producer of antimicrobial substances. Identification at the species level, however, has been a problem in this type of study. Several authors have reported the presence of endophytic fungi from the medicinal plant Maytenus ilicifolia (espinheira-santa) in Brazil that has antimicrobial activity against various pathogens. Therefore, Colletotrichum strains were isolated from M. ilicifolia and identified based on morphology, RAPD markers, sequence data of the internal transcribed spacer regions (ITS-1 and ITS-2), the 5.8S gene, and species-specific PCR. The analyses suggested the presence of 2 species, Colletotrichum gloeosporioides and Colletotrichum boninense. Two morphological markers were characterized to allow C. gloeosporioides and C. boninense to be distinguished quickly and accurately. The molecular diagnosis of C. boninense was confirmed by using Coll and ITS4 primers. This species of Colletotrichum is reported for the first time in M. ilicifolia.
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The short-term effects of surface lime application and black oat (Avena strigosa Schreb.) residues, with or without N fertilization, were evaluated in a long-term no-till (NT) system on a sandy clay loam, a kaolinitic, thermic Typic Hapludox from the state of Parana, Brazil. The main plot treatments were: control and dolomitic lime applied on soil surface at 8 Mg ha(-1). Three treatments with crop residues were evaluated on the subplots: (i) fallow, (ii) black oat residues, and (iii) black oat residues aft er N fertilization at 180 kg ha(-1). Black oat dry biomass was not affected by the treatments during 3 yr. Surface liming increased soil pH, microbial biomass, microbial activity, and bacterial/fungal ratio at the soil surface (0-5 cm), resulting in increased amino acid turnover, water-soluble humic substances formation, and N mineralization and nitrification. While the application of black oat did increase the soil pH, overall it had much less effect on soil biological processes and C and N pools than did lime. We concluded that black oat cannot replace the need for lime to optimize crop production in these tropical NT systems. In the long term, however, black oat should aid in the amelioration of acidity and replenishment of soil organic C pools and should help reduce erosion. Overall, this study suggests that overapplication of inorganic fertilizer N may occur in some tropical NT systems. Further experiments are required in NT systems to investigate the use of slow-release N fertilizers in combination with lime and black oat as a mechanism to reduce acidification and promote sustainability.
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The soil organic matter (SOM) extracted under different vegetation types from a Brazilian mangrove (Pai Matos Island, Sao Paulo State) and from three Spanish salt marshes (Betanzos Ria and Corrubedo Natural Parks, Galicia, and the Albufera Natural Park, Valencia) was investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The chemical variation was larger in SOM from the Spanish marshes than in the SOM of the Brazilian mangroves, possibly because the marshes included sites with both tidal and nontidal variation, whereas the mangrove forest underwent just tidal variation. Thus, plant-derived organic matter was better preserved under permanently anoxic environments. Moreover, given the low number of studied profiles and sedimentary-vegetation sequences in both areas, depth trends remain unclear. The chemical data also allow distinction between the contributions of woody and nonwoody vegetation inputs. Soil organic matter decomposition was found to cause: (i) a decrease in lignin contents and a relative increase in aliphatics; (ii) an increase in short-chain aliphatics at the expense of longer ones; (iii) a loss of odd-over-even dominance in alkanes and alkenes; and (iv) an increase in microbial products, including proteins, sterols, short-chain fatty acids, and alkanes. Pyrolysis-gas chromatography/mass spectrometry is a useful tool to study the behavior and composition of SOM in wetland environments such as mangroves and salt marshes. Additional profiles need to be studied for each vegetation type, however, to improve the interpretability of the chemical data.
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Nile tilapia social position (Oreochromis niloticus) can be mediated by multiple channels, including chemical communication. Absence of chemical cues in the environment prevents hierarchical settlement among pairs, and enhances time spent in confrontations. The aim of this study was to test the effect of continuously renewed water flow on the establishment of hierarchical dominance in Nile tilapia juveniles. In this condition, a high frequency of attacks and disruption on hierarchical stability were expected because chemical cues for hierarchy maintenance could be washed out. After 3 days in isolation, the fish were paired by standard size but not by sex, and submitted to two conditions: continuously renewed water flow (RENEWED, n = 7) and non-renewed water flow (NONRENEWED n = 8). The paired fish were placed in an aquarium (40 cm x 30 cm x 40 cm) for 3 h; four 10-min sessions were video-recorded: the first, immediately after the fish were paired and the others 1, 2, and 3 h after pairing. Hierarchy was identified by a dominance index (DI = given attacks/received + given attacks) For each fish. The hierarchical stability was achieved by analyzing the difference between dominant DI and subordinate DI (DI-D). Hierarchy was established in both groups after second session because the DI was significantly higher for one fish of the pair. The frequency of attacks of the dominant fish in RENEWED and NONRENEWED conditions was similar in all observation sessions. The attack frequency by subordinate fish was also similar during the first three sessions (2-h pairing). However, the frequency of attacks by subordinate fish in the RENEWED condition was higher than in the NONRENEWED situation at the fourth observation session (means +/- S.E.: RENEWED = 2.83 +/- 0.94 x 10 min(-1) and NONRENEWED = 0.25 +/- 0.16 x 10 min(-1); Mann-Whitney, p = 0.04). At this point, a significant reduction of the DI-D was observed (means +/- S.E.: RENEWED = 0.70 +/- 0.11 and NONRENEWED = 1,00 +/- 0.002; Mann-Whitney, p = 0.04). The changes in DI-D were related to more frequent attacks by the subordinated fish in renewed water flow. According to our results, the unsteady agonistic interaction under renewed water flow leads to social instability. Thus, continuous water renewing can wash out relevant chemical substances and therefore disturb the dominance recognition by subordinate fish. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
Connectivity of the glycocalyx covering of small communities of Acidithiobacillus ferrooxidans bacteria deposited on hydrophilic mica plates was imaged by atomic force microscopy. When part of the coverage was removed by water rinsing, an insoluble structure formed by corrals surrounding each individual bacterium was observed. A collective ring structure with clustered bacteria (>= 3) was observed, which indicates that the bacteria perceived the neighborhood in order to grow a protective structure that results in smaller production of exopolysaccharides material. The most surprising aspect of these collective corral structures was that they occur at a low bacterial cell density. The deposited layers were also analyzed by confocal Raman microscopy and shown to contain polysaccharides, protein, and glucoronic acid.
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In this study, 73 South American red wines (Vitis vinifera) from 5 varietals were classified based on sensory quality, retail price and antioxidant activity and characterised in relation to their phenolic composition. ORAC and DPPH assays were assessed to determine the antioxidant activity, and sensory analysis was conducted by seven professional tasters using the Wine Spirits Education Trust`s structured scales. The use of multivariate statistical techniques allowed the identification of wines with the best combination of sensory characteristics, price and antioxidant activity. The most favourable varieties were Malbec, Cabernet Sauvignon, and Syrah produced in Chile and Argentina. Conversely, Pinot Noir wines displayed the lowest sensory characteristics and antioxidant activity. These results suggest that the volatile compounds may be the main substances responsible for differentiating red wines on the basis of sensory evaluation. (C) 2011 Elsevier Ltd. All rights reserved.