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Search Results: 1 - 10 of 58724 matches for " Antonio Fernando Monteiro; "
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A Novel Approach for Inferring the Proportion of Terrestrial Organic Matter Input to Marine Sediments on the Basis of TOC:TN and δ13Corg Signatures  [PDF]
Antonio Fernando Menezes Freire, Marcelo Costa Monteiro
Open Journal of Marine Science (OJMS) , 2013, DOI: 10.4236/ojms.2013.32009
Abstract:

The ratio of total organic carbon to total nitrogen (TOC:TN) and the stable carbon isotope ratio of organic matter (δ13Corg) are widely applied for inferring the origin of organic matter (OM) in Quaternary marine sediments. A plot of TOC:TN vs. δ13Corg is useful for such studies but is strongly based on qualitative constraints. This study is based on the qualitative characterization of the source of Quaternary OM via analysis of TOC:TN and δ13Corg signatures, but also proposes a probability parameter, which combines both signatures, to infer the amount of Terrestrial OM Input (TOMI). This index provides a method for quantifying the proportion of terrestrial OM vs. marine OMin a more comprehensive manner. The TOMI index concept was applied to a study area in theJoetsuBasin, eastern margin of theJapanSea, where previous studies have characterized theOMfrom the Last Glacial Maximum (LGM) to the present. The upwards increase in TOC indicates thatOMproduction during the Holocene was higher than during the LGM. The enriched δ13Corg signature upwards and decrease in TOC:TN suggest predominantly marine phytoplankton OM during the Holocene. Throughout the LGM, low OM production with depleted δ13C

Editorial Editorial
Antonio Fernando Monteiro Camargo
Acta Limnologica Brasiliensia , 2012,
Abstract:
Editorial
Antonio Fernando Monteiro Camargo
Acta Limnologica Brasiliensia , 2011, DOI: 10.1590/s2179-975x2011000400001
Abstract:
Editorial
Antonio Fernando Monteiro Camargo
Acta Limnologica Brasiliensia , 2012,
Abstract:
Characterization and evaluation of the impact of feed management on the effluents of Nile tilapia (Oreochromis niloticus) culture
Baccarin, Ana Eliza;Camargo, Antonio Fernando Monteiro;
Brazilian Archives of Biology and Technology , 2005, DOI: 10.1590/S1516-89132005000100012
Abstract: the objective of this study was to evaluate the effect of different feed management on the quality of effluent water generated in nile tilapia (oreochromis niloticus) culture ponds. feed was supplied as follows: natural food, and pelleted, extruded or minced ration. the study was conducted during 19 weeks in 12 continuous water exchange ponds of 300 m2 each, with a population of male nile tilapia juveniles, in a density equal to 1.7 fish m-2. feeds contained 30% crude protein, 3,000 kcal digestible energy, and were supplied twice a day. natural food consisted of chicken manure. temperature, dissolved oxygen, ph, total phosphorus, total nitrogen, chlorophyll a and suspended solids were monitored weekly in the supplying and effluent water. water residence time was also determined for the ponds. in general, effluent water quality decreased in all treatments.
Photosynthetic rate of the aquatic macrophyte Egeria densa Planch. (Hydrocharitaceae) in two rivers from the Itanhaém River Basin in S?o Paulo State, Brazil
Pezzato, Maura Maria;Camargo, Antonio Fernando Monteiro;
Brazilian Archives of Biology and Technology , 2004, DOI: 10.1590/S1516-89132004000100021
Abstract: egeria densa is a submerged aquatic macrophyte which, in brazil, causes problems specially for electric energy generation. the purpose of this study was to evaluate the photosynthetic rate of e. densa in two rivers (aguapeú and mambu) with different limnological features, both located in the itanhaém river basin. this species is abundant in both rivers without causing damages to their multiple uses. photosynthetic rates were analysed in february, may, august and november 1998 and limnological variables of the water and sediment were also measured. the highest value of gross photosynthesis (gp) was detected in may (10.06 in aguapeú and 6.10 mgo2/gdw/h in mambu), when under-water photosynthetic active radiation (par) was also high (1,126.7 and 895.8 m mol/m/s, respectively). gp, total phosphorous, total co2 and par were always higher in aguapeú river.
Tratamento de efluentes de carcinicultura por macrófitas aquáticas flutuantes
Henry-Silva, Gustavo Gonzaga;Camargo, Antonio Fernando Monteiro;
Revista Brasileira de Zootecnia , 2008, DOI: 10.1590/S1516-35982008000200002
Abstract: the efficiency of systems composed of two species of floating aquatic macrophyte (eichhornia crassipes and pistia stratiotes) to treat effluents from shrimp culture was evaluated in this research. the effluent originated from a pond populated with macrobrachium amazonicum. treatment systems consisted of 12 experimental tanks with aquatic macrophyte and three tanks without plants (control). water samples were collected from the fresh water supply and before and after passing through the treatment systems. there are no differences in the removal of nutrients between the two species. the higher nutrient removal was observed for total phosphorus (41.9% by control; 71.6% by e. crassipes; 69.9 by p. stratiotes; 72.5% by e. crassipes + p. stratiotes and 72.1 by p. stratiotes + e. crassipes) and turbidity (30.6% by control; 80.2% by e. crassipes; 75.2 by p. stratiotes; 79.8% by e. crassipes + p. stratiotes and 81.5 by p. stratiotes + e. crassipes). the systems containing aquatic macrophytes were efficient in nitrogen and phosphorus removal from m. amazonicum culture.
Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents
Henry-Silva, Gustavo Gonzaga;Camargo, Antonio Fernando Monteiro;
Scientia Agricola , 2006, DOI: 10.1590/S0103-90162006000500003
Abstract: the effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. in this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (eichhornia crassipes, pistia stratiotes and salvinia molesta) to treat effluents from nile tilapia culture ponds. the effluent originated from a 1,000-m2 pond stocked with 2,000 male nile tilapia oreochromis niloticus. the treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants). water samples were collected from the: (i) fish pond source water, (ii) effluent from fish pond and (iii) effluents from the treatment tanks. the following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-n, nitrate-n, nitrite-n, total phosphorus and dissolved phosphorus. e. crassipes and p. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively) and total nitrogen removal (46.1% and 43.9%, respectively) than the s. molesta (72.1% total phosphorus and 42.7% total nitrogen) and the control (50.3% total phosphorus and 22.8% total nitrogen), indicating that the treated effluents may be reused in the aquaculture activity.
Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents
Henry-Silva Gustavo Gonzaga,Camargo Antonio Fernando Monteiro
Scientia Agricola , 2006,
Abstract: The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta) to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m2 pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants). Water samples were collected from the: (i) fish pond source water, (ii) effluent from fish pond and (iii) effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively) and total nitrogen removal (46.1% and 43.9%, respectively) than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen) and the control (50.3% total phosphorus and 22.8% total nitrogen), indicating that the treated effluents may be reused in the aquaculture activity.
The Effects of Negative Values of Apparent Resistivity in TEM Surveys  [PDF]
Cassiano Antonio Bortolozo, Julian David Realpe Campa?a, Marco Antonio Couto Junior, Jorge Luis Porsani, Fernando Acácio Monteiro dos Santos
International Journal of Geosciences (IJG) , 2016, DOI: 10.4236/ijg.2016.710088
Abstract: The calculation of apparent resistivity in electrical methods is relatively simple and consolidated in the literature. Furthermore, in the case of DC methods, the apparent resistivity values are for the most part, intuitive and enable an initial interpretation of the results. On the other hand, in TEM method the apparent resistivity values are not very intuitive and interpretation based only on the apparent resistivity values cannot be done reasonably. In this way, this paper presents a discussion about the reasons and effects of the negatives values of apparent resistivity in TEM soundings. The main objective of this paper is to clarify the meanings of these negatives values and the possible effects in TEM inversion.
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