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| Registros recuperados: 154 | |
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| Deroine, Morgan; Le Duigou, Antoine; Corre, Yves-marie; Le Gac, Pierre-yves; Davies, Peter; Cesar, Guy; Bruzaud, Stephane. |
| Pollution of nature by plastics is a major environmental problem and the challenge for the future is to manage the lifetime of polymers better. The aim of this study is to establish a baseline on degradation mechanism and degradation kinetics for lifetime prediction of polylactide (PLA) in a marine environment. The ageing of PLA was accelerated by raising temperature in distilled water, filtered and renewed seawater and natural seawater. Samples were immersed in distilled water for six months at different temperatures (25, 30, 40 and 50°C) in order to evaluate the influence of temperature on PLA degradation kinetics and to predict lifetime. Then, samples were immersed in seawater both in the laboratory and at sea, in order to compare the effects of... |
| Tipo: Text |
Palavras-chave: PLA; Accelerated ageing; Hydrothermal ageing; Degradation. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28376/26689.pdf |
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| Le Gac, Pierre-yves; Le Saux, V.; Paris, M; Marco, Y.. |
| Polymers are widely used in marine environments due to their excellent properties and good weathering resistance. Despite this extensive use, their long term behaviour in such an aggressive environment is still not well known. To assess the polymer durability within reasonable durations, it is essential to perform accelerated ageing tests to accelerate the degradation kinetics but without any modification of the degradation process. This study therefore proposes and validates accelerated ageing tests to study marine ageing of a silica-filled chloroprene rubber (CR) used for offshore applications. Several accelerated ageing protocols are investigated for temperatures ranging from 20 to 80 degrees C in renewed natural seawater. The ageing consequences are... |
| Tipo: Text |
Palavras-chave: Chloroprene rubber; Degradation; Sea water; Silica; Accelerated ageing; Natural ageing. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00073/18429/20232.pdf |
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| HOTT, M. C.; CARVALHO, L. M. T.; ANTURNES, M. A. H.; RESENDE, J. C. de; ROCHA, W. S. D. da. |
| Abstract: There is currently a lot of interest in determining the state of Brazilian grasslands. Governmental actions and programs have recently been implemented for grassland recovery in Brazilian states, with the aim of improving production systems and socioeconomic indicators. The aim of this study is to evaluate the vegetative growth, temporal vigor, and long-term scenarios for the grasslands in Zona da Mata, Minas Gerais State, Brazil, by integrating phenological metrics. We used metrics derived from the normalized difference vegetation index (NDVI) time series from moderate resolution imaging spectroradiometer (MODIS) data, which were analyzed in a geographic information system (GIS), using multicriteria analysis, the analytical hierarchy process,... |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Time series; NDVI; Phenological metrics; Remote sensing; Degradation; Grasslands. |
| Ano: 2019 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1118582 |
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| Moraes,Fillipe Alexandre; Takeda,Othavio Toniasso. |
| ABSTRACT The growing use of Photovoltaic Solar Energy in Brazil, both in power plants and in distributed generation systems, brings with it a series of practical and technical questions that are not limited to the design and project of the systems. Environmental factors and resources related to the use, operation, maintenance, decommissioning and final disposal of the equipment and components that constitute them, should be taken into consideration, so that these systems maintain an adequate performance during their lifespan granting the safety for users, properties and avoid negative environmental impacts. Within the concept of Risk Analysis within the Life Cycle of these systems, the present study addresses a perspective of the growth of the use of Solar... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photovoltaic Installations; Maintenance; Degradation; Reliability. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132018000200234 |
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| VARELI, C. S.; PIZZUTTI, I. R.; GEBLER, L.; CARDOSO, C. D.; GAI, D. S. H.; FONTANA, M. E. Z.. |
| In order to evaluate the efficiency of biobeds on DTC degradation, the aim of this study was to apply, optimize and validate a method to determine dithiocarbamate (mancozeb) in biobeds using gas chromatography-tandem mass spectrometry (GC-MS). The DTC pesticide mancozeb was hydrolysed in a tin (II) chloride solution at 1.5% in HCl (4 mol L−1 ), during 1 h in a water bath at 80 °C, and the CS2 formed was extracted in isooctane. After cooling, 1 mL of the organic layer was transferred to an auto sampler vial and analyzed by GC-MS. A complete validation study was performed and the following parameters were assessed: linearity of the analytical curve (r2 ), estimated method and instrument limits of detection and limits of quantification (LODm, LODi,... |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Biobed; Biomixture; Dithiocarbamates; GC-MS; Biodegradation; Degradation. |
| Ano: 2018 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1102339 |
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| Zheng, Zhou; Jin, Qing; Miao, Jinlai; Liu, Fangming. |
| Two hydrocarbon degrading bacteria NJ276 and NJ341 were screened from 385 Antarctic marine bacteria and their degrading characteristics were studied. Diesel oil as sole carbon source was used in this study. The results showed that the oil degradation rates of Antarctic psychrophile bacteria NJ276 and NJ341 were 23.47 % and 32.15 %, respectively, after 20 days culturation at 5 °C, and the rates were 43.95 % and 62.47 % respectively after 20 days culturation at 15 °C. The oil degradation abilities were enhanced remarkably with the increasing culture temperature. GC - MSs indicated the residual oil contained C15 - C21 7 alkyls after degradation by NJ276, and C16, C17 and C18 3 alkyls after degradation by NJ341. The 16S rDNA gene sequences homology and... |
| Tipo: Journal Contribution |
Palavras-chave: Hydrocarbons; Degradation; Bacteria. |
| Ano: 2008 |
URL: http://hdl.handle.net/1834/5879 |
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| Olivo, Paula Martins; Santos, Geraldo Tadeu dos; Ítavo, Luís Carlos Vinhas; Silva Junior, Ranulfo Combuca da; Leal, Eduardo Souza; Prado, Rodolpho Martin do. |
| Agroindustrial co-products are a viable alternative for use in animal nutrition. Tests were conducted using eight different types of co-products and feed to evaluate the chemical composition, in vitro digestibility of dry matter, crude protein and neutral detergent fiber, and gas production by them. The co-products tested were: coffee hulls; pelleted citrus pulp; grape residue; soybean hulls; cottonseed; cassava foliage; and foods usually supplied to ruminants: corn silage and ground corn concentrate. Data of in vitro digestibility of dry matter, crude protein and neutral detergent fiber were tested by analysis of variance using the least square method; the results of gas production were interpreted by a non-linear regression by the Gauss-Newton method;... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zootecnia; Nutrição de Ruminantes alternative feed; Degradation; Fermentation; Gas production.s. |
| Ano: 2017 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/34024 |
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| Gonçalves,Morgana S.; Sampaio,Silvio C.; Coelho,Silvia R. M.; Suszek,Floriano L.; Cordovil,Claudia M. D. S.. |
| The effects of swine wastewater on atrazine dissipation and formation of bound residues in subtropical clay soil were investigated in this study. The experiment was carried out in laboratory, under room conditions, where samples of Rhodic Hapludox soil received 168.61 mg kg-1 of atrazine and were incubated for 60 days in the following treatments: T1 (sterilized soil + swine wastewater), T2 (sterilized soil + distilled water), T3 (Non sterilized soil + swine wastewater) and T4 (Non sterilized soil + distilled water). The extractable residues and bound residues of atrazine were extracted and analyzed by high performance liquid chromatography. The results showed no effect of swine wastewater on atrazine dissipation. However, the addition of swine wastewater... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Degradation; Sorption; Organic matter. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000600017 |
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| CONSTANT, L. S.; GOMES, F. dos S.; RIBEIRO, A. P. de O.; GODOY, R. L. de O.; CABRAL, L. M. C.. |
| Conhecida por suas agradáveis características sensoriais, a melancia é um fruto muito apreciado para consumo in natura. Ultimamente, tem sido relatada como uma importante fonte de licopeno, um pigmento associado à redução do risco de algumas doenças degenerativas. Diversos processos tem apresentado eficácia em concentrar e aumentar a estabilidade do licopeno a partir de frutas. Entretanto, tal incremento no teor desse composto não, necessariamente, implica em um aumento na quantidade absorvida pelo organismo humano e, consequentemente, na promoção da saúde do indivíduo de forma que a avaliação da liberação do composto durante a digestão, ou seja, a sua bioacessibilidade se faz necessária. Este trabalho objetivou adaptar um modelo de digestão in vitro para... |
| Tipo: Artigo em anais de congresso (ALICE) |
Palavras-chave: Licopeno; Digestão; Beta-caroteno; Degradação; Lycopene; Digestion; Beta-carotene; Degradation. |
| Ano: 2016 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/1057886 |
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| Tallur,Preeti N.; Mulla,Sikandar I.; Megadi,Veena B.; Talwar,Manjunatha P.; Ninnekar,Harichandra Z.. |
| Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Degradation; Immobilization; Cypermethrin; Polyurethane foam; Micrococcus sp. strain CPN 1. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000300667 |
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| Martínez, S.; Acosta, A.. |
| Several predictions have been made, about magnitude and direction of temporal changes in the coral community structure, during the last decade. However, few studies have demonstrated it quantitatively. In order to document such changes, the coral community structure was studied in four continental reefs in the Colombian Caribbean, two in the Santa Marta region: Punta Betín (PB) and Morro Grande Island (MO), and two in the Tayrona National Natural Park (PNNT): Granate cove (GR) and Gayraca bay (GA). Coral composition and cover were quantified in 2002 and compared to base line studies from 1989 (PB, MO & GR) and from 1992 (GA). These variables were quantified by 20 m linear transects between 1.5 m and 29 m depth. After a decade, all reefs lost in average... |
| Tipo: Journal Contribution |
Palavras-chave: Coral reefs; Degradation; Temporal variations; Community composition; Coral reefs; Degradation; Http://aims.fao.org/aos/agrovoc/c_1880; Http://aims.fao.org/aos/agrovoc/c_2159. |
| Ano: 2005 |
URL: http://hdl.handle.net/1834/2012 |
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| ROCHA JUNIOR, P. R. da; DONAGEMMA, G. K.; ANDRADE, F. V.; PASSOS, R. R.; BALIEIRO, F. de C.; MENDONÇA, E. de S.; RUIZ, H. A.. |
| In Brazil, a large part of the Atlantic Forest was deforested in pastures, which were developed on the basis of natural fertility and organic matter content of the new deforested soil. However, as time went by the organic matter content in these areas have been decreasing causing soil degradation. The objective of this study was to evaluate the organic matter as a quality indicator of Ultisols in different levels of pasture degradation in the region of Governador Valadares-MG. Four sites of pastures were chosen at different levels of degradation, observed visually, two capoeiras in different stages of natural recovery and forest site (reference). Soil samples were collected at three depths (0.00-0.05, 0.05-0.10 and 10-0.20 m) in two seasons of the year... |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Soil quality; Organic matter pool; Particulate organic matter; Degradation; Ultisols. |
| Ano: 2014 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/981949 |
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| Registros recuperados: 154 | |
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