OALib Journal期刊

ISSN: 2333-9721




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2020 ( 58 )

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2018 ( 220 )


匹配條件: “Douglas Marcelo Pinheiro da Silva” ,找到相關結果約92471條。
Caracteriza o física e química de terras pretas arqueológicas e de solos n o antropogênicos na regi o de Manicoré, Amazonas = Physical and chemical characterization of archaeological dark earths and nonanthropogenic soils the Manicore region, Amazon.
Milton César Costa Campos,Luís Ant?nio Coutrim dos Santos,Douglas Marcelo Pinheiro da Silva,Bruno Campos Mantovanelli
Agro@mbiente On-line , 2012,
Abstract: Os solos predominantes na regi o Amaz nica pertencem à classe dos Latossolos e Argissolos, caracterizado por seu alto grau de intemperismo e baixa fertilidade natural, em contraste, ocorrem às terras pretas arqueológicas com elevada fertilidade natural e alto teor de matéria organica. Objetivou-se com este estudo caracterizar quanto aos atributos físicos e químicos as terras pretas arqueológicas e os solos n o antropogênicos da regi o de Manicoré, AM. Foram amostrados quatro sítios de Terras Pretas Arqueológicas e quatro solos n o antropogênicos distribuídos na regi o de Manicoré, sul do Amazonas. Nesses locais foram abertas trincheiras e os perfis foram caracterizados morfologicamente e coletados por horizonte. Foramrealizadas análises físicas (textura e densidade do solo) e químicas (pH em água, Ca, Mg, K, e Al trocáveis, P disponível, e C organico). Os valores de pH, carbono organico, soma de bases e V% das terras pretas arqueológicas foram superiores aos observados para solos n o antropogênicos da regi o de Manicoré, AM. Os solos n o antropogênicos apresentaram maiores valores de densidade do solo quando comparados às áreas de terra preta arqueológica. Os maiores teores de matéria organica do solo foram encontrados nas áreas de terra preta arqueológica. As terras pretas arqueológicas deste estudo apresentam atributos químicos e físico-químicos superiores aos solos n o antropogênicos, conferindo-lhes maior fertilidade.The predominant soils in the Amazon region belong to the class of Oxisols and Ultisols, characterized by its high degree of weathering and low natural fertility, in contrast, occur at Archaeological Dark Earths soils with high fertility and high organic matter content. The aim of this study was the physical and chemical characterization of archaeological dark earths and non-anthropogenic soils in the southern Amazon. Four archaeological sites with dark earths and four non-anthropogenic soils distributed in the Manicoré region, souther Amazon, were sampled. In these locations, open trenches and profiles were characterized morphologically and collected by horizon. Physical (texture and bulk density) and chemical (pH, Ca, Mg, K,and Al, P, and organic C) analyses were realized. The values of pH, organic carbon, total bases and V% in archaeological dark earths were higher than those observed in the non-anthropogenic soils the Manicore, Amazon region. The non-anthropogenic soils showed higher bulk density compared to areas of archaeological dark earths. The highest levels of soil organic matter were found in areas of archaeological dark earth
Lightning risk warnings based on atmospheric electric field measurements in Brazil
Marco Antonio da Silva Ferro*,Jorge Yamasaki,Douglas Roberto M. Pimentel,Kleber Pinheiro Naccarato
Journal of Aerospace Technology and Management , 2011,
Abstract: This paper presents a methodology that employs the electrostatic field variations caused by thundercloud formation or displacement to generate lightning warnings over a region of interest in Southeastern Brazil. These warnings can be used to prevent accidents during hazardous operations, such as the manufacturing, loading, and test of motor-rockets. In these cases, certain equipment may be moved into covered facilities and personnel are required to take shelter. It is also possible to avoid the threat of natural and triggered lightning to launches. The atmospheric electric field database, including the summer seasons of 2007/2008 and 2008/2009 (from November to February), and, for the same period and region, the cloud-to-ground lightning data provided by the Brazilian lightning detection network – BrasilDAT – were used in order to perform a comparative analysis between the lightning warnings and the cloud-to- ground lightning strikes that effectively occurred inside the area of concern. The analysis was done for three areas surrounding the sensor installation defined as circles with 5, 10 and 15 km of radius to determine the most effective detection range. For each area it was done using several critical electric field thresholds: +/- 0.5; +/- 0.8; +/- 0.9; +/- 1.0; +/- 1.2; and +/- 1.5 kV/m. As a result of the reduction of atmospheric electric field data provided by the sensor installed in area of concern and lightning provided by BrasilDAT, it was possible, for each of the areas of alert proposals, to obtain the following parameters: the number of effective alarms; the number of false alarms; and the number of failure to warning. From the analysis of these parameters, it was possible to conclude that, apparently, the most interesting critical electric field threshold to be used is the level of 0.9 kV/m in association with a distance range of 10 km around the point where the sensor is installed.
Dipterofauna do arquipélago de Fernando de Noronha (Pernambuco, Brasil)
Couri, Márcia Souto;Barros, Gabriel Pinto da Silva;Orsini, Marcelo Pinheiro;
Revista Brasileira de Entomologia , 2008, DOI: 10.1590/S0085-56262008000400007
Abstract: this paper records some diptera from the island of fernando de noronha (pernambuco, brazil), presenting the richness of species and their abundance. the material studied was collected in july 1973. eight families of diptera in a total of 11,515 specimens were studied. among the families the following seven are new records: calliphoridae, muscidae, fanniidae, stratiomyidae, sepsidae, otitidae and tabanidae. the first three and the sarcophagidae (previously recorded) were identified to species level. the most abundant families were sepsidae and calliphoridae with more than 80% of the total collected, having cochliomyia macellaria (fabricius, 1775), as the dominant species.
Potencialidades espeleoturísticas da área cárstica do município de Luminárias (MG, Brasil)
Couto Carvalho, Vinícius do,Correia da Silva, Marcelo Alexandre,Veloso Oliveira, Douglas
PASOS : Revista de Turismo y Patrimonio Cultural , 2007,
Abstract: This research intended to verify the potencial of ecotouristic activities developed in the carstics caves of Luminárias-MG town, aiming a future speleotourism projection and management. To develop this research it was possible to count on technical and material support from the Caves Protection and Handling National Studies Center – CECAV/IBAMA – MG, whose headquarters is placed in Lavras’ Sectional Office; and Luminárias’ City Hall. The intended research took as a parameter a guide of actions and subactions and goals to reach, presenting two caves with a big potential to be the city’s future speleotouristic attractions
Oviposi??o de Ascia monuste orseis (Godart) (Lepidoptera, Pieridae) em couve comum
Bastos, Cristina Schetino;Pican?o, Marcelo;L?bo, Ailton Pinheiro;Silva, Edimar Ant?nio da;Neves, Ludmila Lafetá de Melo;
Revista Brasileira de Zoologia , 1997, DOI: 10.1590/S0101-81751997000100017
Abstract: this research was developed in green house of the universidade federal de vi?osa, in vi?osa, minas gerais state, brazil and the objective was to evaluate oviposition patterns of ascia monuste orseis (godart, 1819) (lepidoptera, pieridae) in the canopy of brassica oleracea linnaeus plants. ascia monuste orseis eggs were laid preferable during the morning period, in higher numbers in the stem of these plants and in the leaves of the lower part of the plants. higher number of eggs was found in the lower parts of leaves of plants with no previous oviposition.
Isolation and screening for plant growth-promoting (PGP) actinobacteria from Araucaria angustifolia rhizosphere soil
Vasconcellos, Rafael Leandro Figueiredo de;Silva, Mylenne Calciolari Pinheiro da;Ribeiro, Carlos Marcelo;Cardoso, Elke Jurandy Bran Nogueira;
Scientia Agricola , 2010, DOI: 10.1590/S0103-90162010000600019
Abstract: actinobacteria are capable of playing several different roles in soil ecosystems. these microorganisms affect other organisms by producing secondary metabolites and are responsible for the degradation of different complex and relatively recalcitrant organic compounds. in our survey of actinobacteria isolated from the rhizosphere of araucaria angustifolia, five culture media (ai, wye, yced, mssc and lnms) were compared for their effectiveness in isolating these microorganisms. when summing up all the isolates randomly obtained, we got 103 isolates. after isolation, the phosphate-solubilizing ability and the "in vitro" production of indole-acetic acid and chitinases were evaluated. the ai medium was ineffective for actinobacteria isolation, when it was compared with the other four culture media. indole-acetic acid and chitinase were produced by respectively 36% and 24% of the strains tested. however, only 2% of the 103 strains presented some phosphate-solubilizing ability. these results demonstrate the biotechnological potential of these microorganisms.
Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury
Rocha, Carlos Alberto Machado da;Cunha, Lorena Araújo da;Pinheiro, Raul Henrique da Silva;Bahia, Marcelo de Oliveira;Burbano, Rommel Mario Rodríguez;
Genetics and Molecular Biology , 2011, DOI: 10.1590/S1415-47572011000400024
Abstract: the frequencies of micronuclei (mn) and morphological nuclear abnormalities (na) in erythrocytes in the peripheral blood of tambaqui (colossoma macropomum), treated with 2 mg.l-1 methylmercury (mehg), were analyzed. two groups (nine specimens in each) were exposed to mehg for different periods (group a - 24 h; group b - 120 h). a third group served as negative control (group c, untreated; n = 9). although, when compared to the control group there were no significant differences in mn frequency in the treated groups, for na, the differences between the frequencies of group b (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of mehg on c. macropomum erythrocytes after prolonged exposure.
Lab-scale periphyton-based system for fish culture
Cavalcante, Davi de Holanda;Silva, Suzete Roberta da;Pinheiro, Paloma Damasceno;Martins, ádila da Cunha;Sá, Marcelo Vinícius do Carmo e;
Ciência Rural , 2011, DOI: 10.1590/S0103-84782011005000146
Abstract: the present research aimed to assess a lab-scale model to study periphyton-based systems for fish culture. twenty-five liters plastic aquaria were stocked with three nile tilapia, oreochromis niloticus, juveniles (0.77±0.09g; 12 fish m-2) for 6 weeks in a 2x2 factorial design. small plastic bottles were placed in some aquaria for periphyton development. two feeding regimes were employed: "full-fed" (standard feeding rates were fully adopted) and "half-fed" (50% of standard feeding rates). growth performance and limnological variables were observed in each aquarium. there werefive replicates per treatment. fish have fed actively on periphyton, especially in the half-fed aquaria. the placement of periphyton bottles had no significant effects on the water quality variables, except by the gross primary productivity which became lower. half-fed aquaria presented lower concentrations of ammonia (0.28-0.29mg l-1), nitrite (0.33-0.37mg l-1) and phosphorus (0.42-0.43mg l-1) than full-fed aquaria (0.57-0.60mg l-1; 0.75-0.77mg l-1; 0.67-0.70mg l-1, respectively). the final body weight of fish in half-fed aquaria with periphyton bottles (6.22±0.64g) was significantly higher than in aquaria without bottles (4.65±0.36g). although the growth rate of fish was lower in the half-fed aquaria (4.27-4.72 vs. 5.29-5.61% bw day-1), survival was significantly higher when compared to the full-fed aquaria (93.3-100.0 vs. 80.0-83.4%). only in the aquaria with periphyton the feed conversation ratio was improved by the feeding restriction regime.
Sele??o de atrativos alimentares e toxicidade de inseticidas para o manejo da broca-pequena-do-tomateiro
Fran?a, Solange Maria de;Oliveira, José Vargas de;Pican?o, Marcelo Coutinho;L?bo, Ailton Pinheiro;Silva, ézio Marques da;Gontijo, Pablo da Costa;
Pesquisa Agropecuária Brasileira , 2009, DOI: 10.1590/S0100-204X2009000600003
Abstract: this work aimed at evaluating the food preference, threshold of intake and toxic effect insecticides associated with attractive sources on adults neoleucinodes elegantalis. the following attractive food sources were tested: molasses and honey at 10%, hexanic extract of green tomato fruits at 0.4%, sucrose at 5%, orange and grape juice at 30%, red wine vinegar at 10%, and hydrolyzed protein at 5% concentration. based on the food preference test, sucrose, molasses, honey, and orange juice were selected to determine the threshold concentration capable of stimulating feeding in n. elegantalis adults. the toxic effect of insecticides added to honey at 10% was also tested. sucrose and honey had the best results in terms of number of landings, landing time, and feeding time of adults of n. elegantalis. the insecticides did not affect negatively the attraction of n. elegantalis adults to the food sources. carbaryl, cartap, deltamethrin, fenpropatrin, indoxacarb, lambda-cyhalothrin, and lufenuron caused 100% mortality of adults (males and females), after 24 hours of exposure, which suggests that they are promising for use in toxic baits.
Development of an Analytical Method for Determination of Nitrate in Leafy Vegetables Using Ion Chromatography  [PDF]
Douglas Goncalves da Silva, Anaildes Lago de Carvalho, Evanildo de Jesus Araújo, Marcelo Eca Rocha, Bruno Oliveira Moreira, Dhavid Lucas Silva Santos
Open Access Library Journal (OALib Journal) , 2020, DOI: 10.4236/oalib.1106471
Abstract: The presence of nitrate in food in general may indicate a threat to human health. Nitrate can be converted to nitrite, a toxic species, in saliva and in the gastrointestinal tract. This work describes a precise and sensitive method using ion chromatography to determine nitrate (NO-3) in hardwood vegetables. In the proposed method the extraction of the nitrate of the vegetal matrix was carried out in an aqueous medium at a temperature of 70°C. The limit of detection (LOD) for the determined ion was 0.06 μg·L-1. The accuracy of the method was evaluated as the relative standard deviation (DPR) of the analytical signal area and the retention time, with values of 0.63% and 0.41%, respectively, for a solution of NO-3 5.0 mg·L-1. The detector presented linearity between 0.22 and 10 mg·L-1 with a correlation coefficient of 0.9999. The accuracy of the procedure was evaluated by addition/recovery test using real samples in which values greater than 95% were obtained. The validation of the proposed method was also performed by comparing the NO-3 concentrations obtained using the selective ion electrode method (EIS). The paired Student t test and the F test showed that both methods provide equivalent results concerning accuracy and precision.

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