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| Registros recuperados: 15 | |
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| Luoma, S. |
| It has been established that direct uptake of (at least some) trace metals from sediments contributes to metal concentrations in benthic organisms. Important controls on metal uptake from sediment are the concentration of the exposure, the partitioning of the metals among components of the sediment, and the redox potential of the sediment. Important problems in ecology, physiology, geochemistry and biogeochemistry remain unresolved, however, and a concentrated interdisciplinary research effort will be necessary before a complete understanding of the fate and impact of sediment-bound metals will be possible. |
| Tipo: Text |
Palavras-chave: Bioaccumulation; Benthos; Food webs; Biogeochemical cycle; Sediments; Availability; Trace metals. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/acte-1302.pdf |
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| Brunetto,Gustavo; Comin,Jucinei Jose; Miotto,Alcione; Moraes,Marcel Pires de; Sete,Paula Beatriz; Schmitt,Djalma Eugênio; Gatiboni,Luciano Colpo; Melo,George Wellington Bastos de; Morais,Gildean Portela. |
| ABSTRACT The purpose of this study was to evaluate Cu and Zn migration and fractions in sandy soil of vineyards. In Urussanga (SC), Brazil, soil samples were collected from a 4-year-old and 15-yearold vineyard, and from a forested area. In the soils, the chemical characteristics of Cu and Zn were analyzed by the EDTA method, which determines the fraction available in soil; 3050B method of the USEPA for total concentrations, which represents the pseudo-soil contents in the soil; and chemical fractionation, which estimates soluble fraction, exchangeable fraction, fraction associated with clay minerals, fraction associated with organic matter and residual fraction. The results show that there is accumulation of Cu and Zn in sandy soils cultivated with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Availability; Chemical fractionation; Toxicity; Environmental contamination; Vitisvinifera. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000100141 |
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| Tapia, M.E.; Torres Ch., G.. |
| El principal objetivo fue de conocer la disponibilidad de la reserva alimenticia (fitoplancton), como un factor que puede influenciar la distribución y abundancia del krill antártico, registrados durante la VII Expedición Ecuatoriana a la Antártida en enero/1998 en el B/I ORION (INOCAR). La biomasa fitoplanctónica en el Estrecho Bransfield, registró altas concentraciones hacia el sur oeste del estrecho dominado principalmente por Cryptomonas spp. entre 1000.000 a 2200.000 cel/l, las menores concentraciones se registraron hacia las Islas Shetland del Sur entre 575.000 a 693.000 cel/l. compuestas principalmente por las diatomeas, Nitzschia delicatissima, N. longissima, Thalassiosira spp., y el Dinoflagelado gymnodinium spp., los cuales se presentaron... |
| Tipo: Journal Contribution |
Palavras-chave: Distribution; Availability; Abundance; Diatoms; Phytoplankton; El Nino phenomena; Distribution; Phytoplankton; Diatoms. |
| Ano: 1998 |
URL: http://hdl.handle.net/1834/3852 |
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| Pinnegar, J; Trenkel, Verena; Tidd, A; Dawson, W; Du Buit, M. |
| Feeding preferences of Celtic Sea fishes were investigated using a database of stomach content records, collected between 1977 and 1994. The diet of cod Gadus morhua, hake Merluccius merluccius, megrim Lepidorhombus whiffiagonis, whiting Merlangius merlangus and saithe Pollachius virens changed markedly as the animals grew larger, and although large predators generally chose larger bodied prey, the variability of prey sizes consumed also increased. Large predators continued to select small, low value, benthic prey (e.g. Callionymus spp. and Trisopterus spp.) which were easier to catch, rather than larger, more energy lucrative pelagic prey (e.g. mackerel Scomber scombrus), even though these pelagic prey-fishes were nearly always available and were often... |
| Tipo: Text |
Palavras-chave: Stomach contents; Preference; Diet; Celtic Sea; Availability. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-607.pdf |
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| Doray, Mathieu; Mahevas, Stephanie; Trenkel, Verena. |
| Few analyses have been performed to estimate the efficiency of trawls targeting demersal fish using the ratio of catches and acoustic densities. In summer 2006, acoustic and fishing data were collected simultaneously over 3 d by three fishing vessels equipped with identical pelagic trawls in the Bay of Biscay. Variography identified moderate spatial autocorrelation in the acoustic backscatter at a mean scale of 3 km, a scale slightly smaller than the mean haul length (3.5 km), indicating that fish horizontal availability did not influence trawl efficiency. Acoustic backscattering densities expressed as nautical area scattering coefficients (NASCs) recorded in the trawled layer were compared with equivalent NASC (ENASC) values calculated from the species... |
| Tipo: Text |
Palavras-chave: Availability; Bay of Biscay; Catchability; Generalized linear model; Geostatistics; Hake; Vulnerability. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11372/7980.pdf |
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| najafi, payam; marzban, afshin; hormozi, mohammad ali. |
| Evaluation of maintenance strategies is an issue which must widely be considered. This paper describes failure rate, mean time between failures (MTBF) and availability analysis for Austoft 7000 sugarcane harvesters series used in agro-industries in southwestern Iran. Sugarcane harvester was divided into three subsystems and the failures were studied for 1800 working hours. The failure rate of subsystems including hydraulic, mechanical and electrical were calculated 0.087, 0.052 and 0.012 h-1, respectively and the total failure rate was 0.15 h-1. MTBF after 1800 working hours were obtained 11.46 h, 19.35 h and 85.71 h for the aforementioned subsystems and machine MTBF was 6.64 h. Among the three studied subsystems, hydraulic with maximum failure rate and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Availability; Failure rate; MTBF; Sugarcane harvester. |
| Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3101 |
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| Silva, Maria Anita Gonçalves da; UEM; Muniz, Antonio Saraiva; UEM; Noda, Antonio Yoshinori; UEM; Marchetti, Marlene Estevão; UFGD; Mata, José de Deus Viana da; UEM; Lourente, Elaine Reis Pinheiro; UFGD. |
| Estudos de correlação foram usados para avaliar a metodologias de extração para micronutrientes em solos do Paraná, visando à padronização dos métodos. Foram avaliados extratores ácidos (Mehlich 1), na proporção solo/extrator de 1:5 e 1:10, um extrator ácido complexantes (Mehlich 3), na proporção de 1:10, e um complexante (DTPA), na proporção 1:2. O Mehlich 1 e Mehlich 3 foram extraídos: a) filtragem imediata após a agitação e b) filtragem após decantação de 16h. As correlações foram estabelecidas entre os teores no solo e em plantas de milho. Os maiores teores de Zn e Cu ocorreram com o uso do Mehlich 1 (1:10), com filtragem após decantação, e Mehlich 3 (1:10), com filtragem imediata e filtragem após decantação. Nos estudos de correlação entre os... |
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Palavras-chave: Micronutrients; Availability; Paraná State soils 5.01.00.00-9 Agronomia micronutrientes; Disponibilidade; Solos paranaenses. |
| Ano: 2009 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/736 |
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| Nogueira,Marco Antonio; Cardoso,Elke Jurandy Bran Nogueira. |
| Mycorrhizal plants may present Mn toxicity alleviation and this depends on the plant-endophyte-environment interaction. The effectiveness of three arbuscular mycorrhizal fungi (AMF) (Glomus macrocarpum, G. etunicatum, G. intraradices) and a control without AMF in two soils: Typic Rhodudalf with high Mn availability and a Typic Quartzipsamment, with low Mn availability, was evaluated in a time-course experiment at 3, 6, 9 and 12 weeks after soybean (Glycine max L.) seedling emergence. The objective was to select the most effective AMF species to enhance plant growth and to assess its effects upon Mn uptake by plants and Mn availability in the soil. For the sandy soil, AMF inoculation resulted in increased plant biomass, especially with G. intraradices and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mn; Availability; Metal; Mycorrhiza; Toxicity; Uptake. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000200018 |
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| Pires,Adriana Marlene Moreno; Marchi,Giuliano; Mattiazzo,Maria Emília; Guilherme,Luiz Roberto Guimarães. |
| The aim of this work was to quantify low molecular weight organic acids in the rhizosphere of plants grown in a sewage sludge-treated media, and to assess the correlation between the release of the acids and the concentrations of trace-elements in the shoots of the plants. The species utilized in the experiment were cultivated in sand and sewage sludge-treated sand. The acetic, citric, lactic, and oxalic acids, were identified and quantified by high performance liquid chromatography in samples collected from a hydroponics system. Averages obtained from each treatment, concentration of trace elements in shoots and concentration of organic acids in the rhizosphere, were compared by Tukey test, at 5% of probability. Linear correlation analysis was applied to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biosolid; Exudates; Heavy metals; Availability. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2007000700002 |
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| Toral Juárez, Marco Antonio. |
| En este trabajo se caracteriza el patrón alimentario de las familias peri-urbanas de ciudad Cardel, Veracruz y se determina su asociación con el nivel socioeconómico familiar, de la misma forma se identifican factores que influyen en la disposición de las madres de familia para practicar la horticultura peri-urbana y por último se estima la rentabilidad de la producción de hortalizas en diversos tipos de contenedores de material reciclados. Se realizó en dos etapas: diagnóstico y experimental. En la etapa de diagnóstico se entrevistó a 114 madres de familia clasificadas de acuerdo a su nivel socioeconómicos por el método Graffar, se analizó una serie de variables que permitieron conocer el patrón alimentario: diversidad alimentaria se determinó por el... |
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Palavras-chave: Hábito; Alimento; Diversidad; Disponibilidad; Rentabilidad; Madres; Habit; Food; Diversity; Availability; Profitability; Mothers; Agroecositemas Tropicales; Maestría. |
| Ano: 2012 |
URL: http://hdl.handle.net/10521/1831 |
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| Couto,Rafael da Rosa; Ferreira,Paulo Ademar Avelar; Ceretta,Carlos Alberto; Lourenzi,Cledimar Rogério; Facco,Daniela Basso; Tassinari,Adriele; Piccin,Rogério; Conti,Lessandro De; Gatiboni,Luciano Colpo; Schapanski,Denis; Brunetto,Gustavo. |
| ABSTRACT Applications for long periods of organic animal waste as a source of nutrients to crops can contaminate the soil and the surface and subsurface waters. This study aimed to evaluate how the utilization of organic waste, after successive applications, affects P fractions in the soil and consequently environmental contamination. In an experiment conducted for 8 years, totaling 12 applications with pig slurry manure (PSM), liquid cattle manure (LCM), swine deep bedding (SDB), and mineral fertilizer (NPK), 460; 505; 1.111; and 535 kg P∙ha−1 were added to the soil through PSM, LCM, SDB, and NPK, respectively. In September 2012, soil samples were collected in the layers 0.0 – 0.04; 0.04 – 0.08; 0.08 – 0.12; 0.12 – 0.16; 0.16 – 0.20 m, prepared and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal manure; Availability; P fractionation; Environmental contamination. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052017000100155 |
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| najafi, payam; asoodar, mohammad amin; marzban, afshin; hormozi, mohammad ali. |
| the performance of agricultural machines depends on the reliability of the machinery used, the operating environment, the maintenance efficiency, the operating process, the technical expertise of the farmers and etc. As the size and complexity of farm equipment continue to increase, the implications of equipment failure become over more critical. Therefore, reliability analysis is required to identify the bottlenecks in the system and to find the components or subsystems with low reliability for a given designed performance. It is important to select a suitable method for data collection as well as for reliability analysis. This paper presents a case study describing reliability and availability analysis of the sugarcane 7000 series chopper harvester at... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agricultural machinery; Availability; Reliability analysis; Sugarcane harvester. |
| Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3104 |
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| SANTOS,MARIA O.; ALMEIDA,BIANCA V. DE; RIBEIRO,DAIANY A.; MACÊDO,DELMACIA G. DE; MACÊDO,MÁRCIA J.F.; MACEDO,JULIMERY G.F.; SOUSA,FRANCISCA F.S. DE; OLIVEIRA,LIANA G.S. DE; SARAIVA,MANUELE E.; ARAÚJO,THATIANE M.S.; SOUZA,MARTA M.A.. |
| ABSTRACT Much of the Brazilian semiarid region faces a considerable process of degradation of natural resources, and ethnobotanical studies have collaborated with important information about the use and traditional knowledge, serving as a tool to design conservation strategies of native plant species. Thus, this study aimed to determine medicinal species meriting conservation priorities in a “Caatinga” area in the northeastern of Brazilian territory. The ethnobotanical data were collected through semi-structured interviews with key subjects selected through the “snowball” technique. The availability and species conservation priority was verified by relative density, risk of collection, local use and use of diversity in the forest fragment sampled. It was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Availability; Biodiversity conservation; Therapeutic practices. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000602675 |
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| Registros recuperados: 15 | |
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