84 resultados para óleo essencial

em Universidade Federal do Rio Grande do Norte(UFRN)


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The extraction with pressurized fluids has become an attractive process for the extraction of essential oils, mainly due the specific characteristics of the fluids near the critical region. This work presents results of the extraction process of the essential oil of Cymbopogon winterianus J. with CO2 under high pressures. The effect of the following variables was evaluated: solvent flow rate (from 0.37 to 1.5 g CO2/min), pressure (66.7 and 75 bar) and temperature (8, 10, 15, 20 and 25 ºC) on the extraction kinetics and the total yield of the process, as well as in the solubility and composition of the C. winterianus essential oil. The experimental apparatus consisted of an extractor of fixed bed and the dynamic method was adopted for the calculation of the oil solubility. Extractions were also accomplished by conventional techniques (steam and organic solvent extraction). The determination and identification of extract composition were done by gas chromatography coupled with a mass spectrometer (GC-MS). The extract composition varied in function of the studied operational conditions and also related to the used extraction method. The main components obtained in the CO2 extraction were elemol, geraniol, citronellol and citronellal. For the steam extraction were the citronellal, citronellol and geraniol and for the organic solvent extraction were the azulene and the hexadecane. The most yield values (2.76%) and oil solubility (2.49x10-2 g oil/ g CO2) were obtained through the CO2 extraction in the operational conditions of T = 10°C, P = 66.7 bar and solvent flow rate 0.85 g CO2/min

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The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

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Malaria, also popularly known as maleita , intermittent fever, paludism, impaludism, third fever or fourth fever, is an acute infectious febrile disease, which, in human beings, is caused by four species: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. Malaria, one of the main infectious diseases in the world, is the most important parasitoses, with 250 million annual cases and more than 1 million deaths per year, mainly in children younger than live years of age. The prophylactic and therapeutic arsenal against malaria is quite restricted, since all the antimalarials currently in use have some limitation. Many plant species belonging to several families have been tested in vivo, using the murine experimental model Plasmodium berghei or in vitro against P. falciparum, and this search has been directed toward plants with antithermal, antimalarial or antiinflammatory properties used in popular Brazilian bolk medicine. Studies assessing the biological activity of medicinal plant essential oils have revealed activities of interest, such as insecticidal, spasmolytic and antiplasmodic action. It has also been scientifically established that around 60% of essential oils have antifungal properties and that 35% exhibit antibacterial properties. In our investigation, essential oils were obtained from the species Vanillosmopsis arborea, Lippia sidoides and Croton zethneri which are found in the bioregion of Araripe-Ceará. The chemical composition of these essential oils was partially characterized and the presence of monoterpenes and sesquiterpenes. The acute toxicity of these oils was assessed in healthy mice at different doses applied on a single day and on four consecutive days, and in vitro cytotoxicity in HeLa and Raw cell lines was determined at different concentrations. The in vivo tests obtained lethal dose values of 7,1 mg/Kg (doses administered on a single day) and 1,8 mg/Kg (doses administered over four days) for 50% of the animals. In the in vitro tests, the inhibitory concentration for 50% of cell growth in Hela cell lines was 588 μg/mL (essential oil from C. zethneri after 48 h), from 340-555 μg/mL (essential oil from L. sidoides, after 24 and 48 h). The essential oil from V. arborea showed no cytotoxicity and none of the essential oils were cytotoxic in Raw cell lines. These data suggest a moderate toxicity in the essential XVIII oils under study, a finding that does not impede their testing in in vivo antimalarial assays. Was shown the antimalarial activity of the essential oils in mice infected with P. berghei was assessed. The three species showed antimalarial activity from 36%-57% for the essential oil from the stem of V. arborea; from 32%-82% for the essential oil from the leaves of L. sidoides and from 40%-70% of reduction for the essential oil from the leaves of C. zethneri. This is the first study showing evidence of antimalarial activity with these species from northeast Brazil. Further studies to isolate the active ingredients of these oils are needed to determine if a single active ingredient accounts for the antimalarial activity or if a complex integration of all the compounds present occurs, a situation reflected in their biological activity

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Natural oils have shown a scientific importance due to its pharmacological activity and renewable character. The copaiba (Copaifera langsdorffii) and Bullfrog (Rana catesbeiana Shaw) oils are used in folk medicine particularly because the anti-inflammatory and antimicrobial activities. Emulsion could be eligible systems to improve the palatability and fragrance, enhance the pharmacological activities and reduce the toxicological effects of these oils. The aim of this work was to investigate the antimicrobial activity of emulsions based on copaiba (resin-oil and essential-oil) and bullfrog oils against fungi and bacteria which cause skin diseases. Firstly, the essential oil was extracted from copaiba oil-resin and the oils were characterized by gas chromatography coupled to a mass spectrometry (GC-MS). Secondly, emulsion systems were produced. A microbiological screening test with all products was performed followed (the minimum inhibitory concentration, the bioautography method and the antibiofilm determination). Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Candida albicans, C. parapsilosis, C. glabrata, C. krusei and C. tropicalis American Type Culture Collection (ATCC) and clinical samples were used. The emulsions based on copaiba oil-resin and essential oil improved the antimicrobial activity of the pure oils, especially against Staphylococcus e Candida resistant to azoles. The bullfrog oil emulsion and the pure bullfrog oil showed a lower effect on the microorganisms when compared to the copaiba samples. All the emulsions showed a significant antibiofilm activity by inhibiting the cell adhesion. Thus, it may be concluded that emulsions based on copaiba and bullfrog oils are promising candidates to treatment of fungal and bacterial skin infections

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Helicobacter pylori is a spiral, Gram negative, mobile, and microaerophilic bacteria recognized as a major cause of gastritis, ulcer, gastric cancer, and gastric low grade, B cell, mucosa – associated lymphoid tissue (MALT) lymphoma, constituting an important microorganism in medical microbiology. Its importance comes from the difficulty of treatment because the requirement of multiple drugs use, besides the increasing emergence of resistant and multiresistant strains to antibiotics used in th e clinic. In order to expand safe and effective therapeutic options , chemical studies on medicinal plants by obtaining extracts, fractions, isolated compounds or essential oils with some biological activity has been intensified . Given the above, the objective was to evaluate the inhi bitory activity of organic extracts derived from Syzygium cumini and Encholirium spectabile, with antiulcer history, and the essential oil, obtained from S. cumini, against H. pylori (ATCC 43504) by the disk diffusion method, for qualitative evaluation, an d determination of minimum inhibitory concentration (MIC) using the broth microdilution method, for quantitative analysis. Also was evaluated the extracts in vitro toxicity by a hemolytic assay using sheep red blood cells, and VERO and HeLa cells using the MTT assay to analyze cell viability. The extracts of both plant used in antimicrobial assays did not inhibit bacterial growth, however the essential oil of S. cumini (SCFO) proved effective, showing MIC value of 205 μg/mL (0.024 % dilution of the original oil). In the hemolytic assay, the same oil shows moderate toxicity, by promote 25% hemolysis at 1000 μg/mL. Regarding the cytotoxicity in cell culture, the SCFO, at 260 μg/mL, affected the cell viability around 80% of HeLa and 50% of VERO cells. So the oi l obtained from S. cumini leaves has antimicrobial activity against H. pylori and cytotoxicity potential, suggesting a source of new molecule drug candidates, since new stages of toxicity in vitro and in vivo, as well, chemical characterization be evaluate d. Moreover, the development of a prospective drug delivery system can result in a prototype to be used in preclinical tests.

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The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

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Malaria, also popularly known as maleita , intermittent fever, paludism, impaludism, third fever or fourth fever, is an acute infectious febrile disease, which, in human beings, is caused by four species: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. Malaria, one of the main infectious diseases in the world, is the most important parasitoses, with 250 million annual cases and more than 1 million deaths per year, mainly in children younger than live years of age. The prophylactic and therapeutic arsenal against malaria is quite restricted, since all the antimalarials currently in use have some limitation. Many plant species belonging to several families have been tested in vivo, using the murine experimental model Plasmodium berghei or in vitro against P. falciparum, and this search has been directed toward plants with antithermal, antimalarial or antiinflammatory properties used in popular Brazilian bolk medicine. Studies assessing the biological activity of medicinal plant essential oils have revealed activities of interest, such as insecticidal, spasmolytic and antiplasmodic action. It has also been scientifically established that around 60% of essential oils have antifungal properties and that 35% exhibit antibacterial properties. In our investigation, essential oils were obtained from the species Vanillosmopsis arborea, Lippia sidoides and Croton zethneri which are found in the bioregion of Araripe-Ceará. The chemical composition of these essential oils was partially characterized and the presence of monoterpenes and sesquiterpenes. The acute toxicity of these oils was assessed in healthy mice at different doses applied on a single day and on four consecutive days, and in vitro cytotoxicity in HeLa and Raw cell lines was determined at different concentrations. The in vivo tests obtained lethal dose values of 7,1 mg/Kg (doses administered on a single day) and 1,8 mg/Kg (doses administered over four days) for 50% of the animals. In the in vitro tests, the inhibitory concentration for 50% of cell growth in Hela cell lines was 588 μg/mL (essential oil from C. zethneri after 48 h), from 340-555 μg/mL (essential oil from L. sidoides, after 24 and 48 h). The essential oil from V. arborea showed no cytotoxicity and none of the essential oils were cytotoxic in Raw cell lines. These data suggest a moderate toxicity in the essential XVIII oils under study, a finding that does not impede their testing in in vivo antimalarial assays. Was shown the antimalarial activity of the essential oils in mice infected with P. berghei was assessed. The three species showed antimalarial activity from 36%-57% for the essential oil from the stem of V. arborea; from 32%-82% for the essential oil from the leaves of L. sidoides and from 40%-70% of reduction for the essential oil from the leaves of C. zethneri. This is the first study showing evidence of antimalarial activity with these species from northeast Brazil. Further studies to isolate the active ingredients of these oils are needed to determine if a single active ingredient accounts for the antimalarial activity or if a complex integration of all the compounds present occurs, a situation reflected in their biological activity

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Lubricant is responsible for reducing the wear on the friction protect the metal against oxidation, corrosion and dissipates excess heat, making it essential for the balance of a mechanical system, consequently prolonging the useful life of such a system. The origin of lubricating oils is usually mineral being extracted from the petroleum. But the search for a new source of production of lubricants and fuels it is necessary to meet future demands and reduce the possible environmental damage. For this reason, looking alternative means to produce certain products derived from petroleum, such as biodiesel, for example. Returning to the realm of lubricants, also one realizes this need for new raw materials for their production. Vegetable oil is a renewable resource and biodegradable, and its use entails advantages in environmental, social and economic. The development of this project aims to characterize the carnauba oil as a lubricant plant, or biolubricant. To analyze the oil carnauba tests as checking density, flash point, fire point, viscosity, viscosity, acid number, pH, copper corrosion, thermal conductivity and thermal resistivity were developed. In addition, for conducting the wear on the friction and the gradient of the system temperature, the analysis equipment is designed for wear on the friction. Based on these results, it is observed that the oil carnauba show good correlation to its application as biolubricant

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O objetivo deste estudo foi avaliar a atividade antibacteriana in vitro e cicatrizante do óleo de buriti (M. flexuosa) em feridas realizadas em ratos (Rattus norvegicus albinus). Para a avaliação antibacteriana in vitro, foram utilizados cinco patógenos bacterianos incluindo espécies gram-positivas e espécies gram-negativas mediante o uso do método de difusão em ágar. Para a avaliação da atividade cicatrizante, foram utilizados 40 ratos da linhagem Wistar, divididos em dois grupos: o grupo I, composto por 20 ratos com feridas cutâneas, tratados com aplicação tópica do creme base com 10% de óleo de buriti, e o grupo II, controle, com o mesmo número de animais que receberam a aplicação tópica do creme base. A aplicação do produto foi realizada em feridas padronizadas, circulares de 1cm de diâmetro na região dorsolombar. As avaliações clínica, morfométrica e histopatológica das feridas foram realizadas no 3°, 7°, 14° e 21° dias. Em relação à avaliação da atividade antibacteriana, os resultados mostraram que houve inibição do crescimento bacteriano em quatro dos cinco patógenos testados. Em relação à área da ferida, foi observada redução significativa da área no 14o dia e maior percentual de contração das feridas do grupo tratado em relação ao controle. No décimo quarto dia, as feridas tratadas com o óleo do buriti apresentavam aumento significativo na contagem de fibroblastos e fibras colágenas, além de completo processo de reepitelização, enquanto o grupo controle necessitava de mais tempo para resolução do processo cicatricial

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Currently a resource more and more used by the petroleum industry to increase the efficiency of steam flood mechanism is the addition of solvents. The process can be understood as a combination of a thermal method (steam injection) with a miscible method (solvent injection), promoting, thus, the reduction of interfacial tensions and oil viscosity. The use of solvent alone tends to be limited because of its high cost. When co-injected with steam, the vaporized solvent condenses in the cooler regions of the reservoir and mixes with the oil, creating a zone of low viscosity between the steam and the heavy oil. The mobility of the displaced fluid is then improved, resulting in an increase of oil recovery. To better understand this improved oil recovery method, a numerical study of the process was done contemplating the effects of some operational parameters (distance between wells, injection steam rate, kind of solvent and injected solvent volume)on the accumulated production of oil, recovery factor and oil-steam rate. Semisynthetic models were used in this study but reservoir data can be extrapolated for practical applications situations on Potiguar Basin. Simulations were performed in STARS (CMG, 2007.11). It was found that injected solvent volumes increased oil recovery and oil rates. Further the majority of the injected solvent was produced and can be recycled

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The gas injection has become the most important IOR process in the United States. Furthermore, the year 2006 marks the first time the gas injection IOR production has surpassed that of steam injection. In Brazil, the installation of a petrochemical complex in the Northeast of Brazil (Bahia State) offers opportunities for the injection of gases in the fields located in the Recôncavo Basin. Field-scale gas injection applications have almost always been associated with design and operational difficulties. The mobility ratio, which controls the volumetric sweep, between the injected gas and displaced oil bank in gas processes, is typically unfavorable due to the relatively low viscosity of the injected gas. Furthermore, the difference between their densities results in severe gravity segregation of fluids in the reservoirs, consequently leading to poor control in the volumetric sweep. Nowadays, from the above applications of gas injection, the WAG process is most popular. However, in attempting to solve the mobility problems, the WAG process gives rise to other problems associated with increased water saturation in the reservoir including diminished gas injectivity and increased competition to the flow of oil. The low field performance of WAG floods with oil recoveries in the range of 5-10% is a clear indication of these problems. In order to find na effective alternative to WAG, the Gas Assisted Gravity Drainage (GAGD) was developed. This process is designed to take advantage of gravity force to allow vertical segregation between the injected CO2 and reservoir crude oil due to their density difference. This process consists of placing horizontal producers near the bottom of the pay zone and injecting gás through existing vertical wells in field. Homogeneous models were used in this work which can be extrapolated to commercial application for fields located in the Northeast of Brazil. The simulations were performed in a CMG simulator, the STARS 2007.11, where some parameters and their interactions were analyzed. The results have shown that the CO2 injection in GAGD process increased significantly the rate and the final recovery of oil

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Waterflooding is a technique largely applied in the oil industry. The injected water displaces oil to the producer wells and avoid reservoir pressure decline. However, suspended particles in the injected water may cause plugging of pore throats causing formation damage (permeability reduction) and injectivity decline during waterflooding. When injectivity decline occurs it is necessary to increase the injection pressure in order to maintain water flow injection. Therefore, a reliable prediction of injectivity decline is essential in waterflooding projects. In this dissertation, a simulator based on the traditional porous medium filtration model (including deep bed filtration and external filter cake formation) was developed and applied to predict injectivity decline in perforated wells (this prediction was made from history data). Experimental modeling and injectivity decline in open-hole wells is also discussed. The injectivity of modeling showed good agreement with field data, which can be used to support plan stimulation injection wells

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The application of thermal methods, to increase the recovery of heavy oil in mature fields through drainage with multilateral and horizontal wells, has been thoroughly studied, theorically, experimentally, testing new tools and methods. The continuous injection of steam, through a steam injector well and a horizontal producer well in order to improve horizontal sweep of the fluid reservoir, it is an efficient method. Starting from an heterogeneous model, geologically characterized, modeling geostatistics, set history and identification of the best path of permeability, with seismic 3D, has been dubbed a studying model. It was studied horizontal wells in various directions in relation to the steam and the channel of higher permeability, in eight different depths. Into in the same area were studied, the sensitivity of the trajectories of horizontal wells, according to the depth of navigation. With the purpose of obtaining the highest output of oil to a particular flow, quality, temperature and time for the injection of steam. The wells studied showed a significant improvement in the cumulative oil recovery in one of the paths by promoting an alternative to application in mature fields or under development fields with heavy oil

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Biomass is considered the largest renewable energy source that can be used in an environmentally sustainable. From the pyrolysis of biomass is possible to obtain products with higher energy density and better use properties. The liquid resultant of this process is traditionally called bio-oil. The use of infrared burners in industrial applications has many advantages in terms of technical-operational, for example, uniformity in the heat supply in the form of radiation and convection, with a greater control of emissions due to the passage of exhaust gases through a macroporous ceramic bed. This paper presents a commercial infrared burner adapted with an ejector proposed able to burn a hybrid configuration of liquefied petroleum gas (LPG) and bio-oil diluted. The dilution of bio-oil with absolute ethanol aimed to decrease the viscosity of the fluid, and improving the stability and atomization. It was introduced a temperature controller with thermocouple modulating two stages (low heat / high heat), and solenoid valves for fuels supply. The infrared burner has been tested, being the diluted bio-oil atomized, and evaluated its performance by conducting energy balance. The method of thermodynamic analysis to estimate the load was used an aluminum plate located at the exit of combustion gases and the distribution of temperatures measured by thermocouples. The dilution reduced the viscosity of the bio-oil in 75.4% and increased by 11% the lower heating value (LHV) of the same, providing a stable combustion to the burner through the atomizing with compressed air and burns combined with LPG. Injecting the hybrid fuel there was increase in the heat transfer from the plate to the environment in 21.6% and gain useful benefit of 26.7%, due to the improved in the efficiency of the 1st Law of Thermodynamics of infrared burner

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The State of Paraíba is one of the most dynamic states of Brazil, strategically located in the northeast, is notable for the excellent potential for integration of different transportation modes forming the states of Rio Grande do Norte, Pernambuco and Alagoas. The dynamic that occurs with port activity causes changes in the space where it is installed. And the elements of this space are always more than suffering direct or indirect influences as the flow in the port is expanded. Therefore, this region became subject to the accidental spillage of oil, because it presents a heavy traffic of ships of various sizes that can run aground or collide with oil causing accidental events. The study of geomorphological and sedimentological compositions of seafloor becomes important as more is known about the relationships between these parameters and associated fauna, and can identify their preferred habitats. The database background, acoustically collected along the proposed study area, is a wealth of information, which were duly examined, cataloged and made available. Such information can serve as an important tool, providing a geomorphological survey of the sedimentary area studied, and come to subsidize, in a flexible, future decision making. With the study area Port of Cabedelo, Paraíba - Brazil, this research aimed to evaluate the influence of the tidal surface and background in modeling the seabed, including the acquisition of information about the location of submerged rocky bodies and the depth of these bodies may turn out to be natural traps for the trapping of oil in case of leaks, and obtain the relationship between types of bed and the hydrodynamic conditions present in the region. In this context, for this study were collected bathymetric data (depth) and physical oceanographic (height of water column, water temperature, intensity and direction of currents, waves and turbidity), meteorological (rainfall, air temperature, humidity, winds and barometric pressure) of the access channel to the Port of Cabedelo / PB and its basin evolution (where the cruise ships dock), and includes tools of remote sensing (Landsat 7 ETM +, 2001), so that images and the results are integrated into Geographic Information Systems and used in the elaboration of measures aimed at environmental protection areas under the influence of this scale facilities, serving as a grant to prepare a contingency plan in case of oil spills in the region. The main findings highlight the techniques of using hydroacoustic data acquisition together bathymetric surveys of high and low frequency. From there, five were prepared in bathymetric pattern of Directorate of Hydrography and Navigation - DHN, with the depth in meters, on a scale of 1:2500 (Channel and Basin Evolution of Access to Port of Cabedelo), where there is a large extent possible beachrocks that hinder the movement of vessels in the port area, which can cause collisions, running aground and leaking oil. From the scatter diagram of the vectors of currents, it can be seen as the tidal stream and undergoes a channeling effect caused by the bidirectional effect of the tide (ebb and flood) in the basin of the Port of Cabedelo evolution in NW-direction SE and the highest speed of the currents occurs at low tide. The characterization weather for the period from 28/02 to 04/07/2010 values was within the expected average for the region of study. The multidisciplinary integration of products (digital maps and remote sensing images), proved to be efficient for the characterization of underwater geomorphological study area, reaching the aim to discriminate and enhance submerged structures, previously not visible in the images