Avaliação do efeito de particulados sólidos na eficiência de um inibidor de corrosão recomendado para meios salinos com CO2

The main problem on the exploration activity on petroleum industry is the formation water resulted on the fields producing. The aggravating of this problem is correlated with the advancing technologies used on the petroleum extractions and on its secondary approach objecting the reobtainment of this oil. Among the main contaminants of the water formation are corrosives gases such as: O2, CO2 and H2S, some solids in suspension and dissolved salts. Concerning to those gases the CO2 is the one that produce significant damage for carbon steel on corrosion process of the petroleum and gas industries. Corrosion inhibitors for carbon steel in formation water is one of the most used agents in control of those damages. In this context, the poor investigations of carbon steel corrosion proceeding from solids in suspension is an opened field for studies. On this work the inhibitor effect of the commercial CORRTREAT 703 was evaluated on some specific solids in suspension at saline medium containing 10.000 ppm of de-aerated chloride using CO2 until non oxygen atmosphere been present. For that, quartz, calcium carbonate, magnetite and iron sulphide were subjected to this investigation as the selected solids. The effect of this inhibitor on corrosion process correlated with those specific solids, was measured using electrochemical (resistance of linear polarization and galvanic pair) and gravimetrical techniques. During all the experimental work important parameters were monitored such as: pH, dissolved oxygen, temperature, instantaneous corrosion rate and galvanic current. According to the obtained results it was proved that the suspension solids calcium carbonate and iron sulphide decrease the corrosion process in higher pH medium. Meanwhile the quartz and magnetite been hardness increase corrosion by broking of the passive layer for erosion. In the other hand, the tested inhibitor in concentration of 50 ppm, showed to be effective (91%) in this corrosion process

Cinemática de partículas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo: avaliação durante paradas operacionais

The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well

Avaliação ambiental de manguezais adjacentes aos campos petrolíferos de Macau e Serra (RN), como subsídio às medidas mitigadoras ao processo erosivo

Among the various effects caused by the climate change and human intervention, the mangrove ecosystem changes through of the years has been worth mentioning, which hasn t known which are the pros and cons for the adjacent coastal and estuarine environments yet. It happens due to the present dynamism in these areas, besides of the difficult understanding of the processes associated with evolution. This study aimed to environmentally evaluate adjacent mangroves from the Macau and Serra oil fields, located on Rio Grande do Norte northern coast, to support the mitigating actions related to the containment of the erosive process, as well as, according to the principles of the Clean Development Mechanism (CDM), to assess the amount of atmospheric carbon sequestered by the studied ecosystem. An inventory was conducted through mangrouve mapping which has supplied this research, especially regarding to the structural characterization of mangrove areas. To understand the local mangrove behavior in a greater level detail, techniques of remote sensing, GIS and GPS were used to make an analogy between the current and past states of the mangrove studied, allowing to make anticipated projections for the future impacts or changes in that region. This study combined data from multispectral LANDSAT 5 TM, Landsat 7 ETM+ with radar microwave data from SAR RADARSAT-1, which increased the interpretation capacity of the data from optical sensor systems. The interpretations have been supported by the data field, representing a better and innovative methodology for the environmental and taxonomic characterization of mangrove forests considered. The results reveal that mangroves of the Ponta do Tubarão Sustainable Development Reserve are biologically representative areas and providing a variety of benefits, especially for local communities, constituting the priority sites for actions development aimed at conservation. They also have been showing the necessity to make mitigating measures in order to recover degraded areas through reforestation or creating new areas of mangrove, as currently 7.1% of the mangrove forests studied are dead or in an advanced state of decomposition. The amount of atmospheric carbon sequestered proved very significant when analyzed for the whole area, which is able to sequester atmospheric 4,294,458 Ton CO2 per year

Avaliação da espécie vegetal Croton cajucara Benth como inibidor de biocorrosão em aço carbono Aisi 1020

Actually in the oil industry biotechnological approaches represent a challenge. In that, attention to metal structures affected by electrochemical corrosive processes, as well as by the interference of microorganisms (biocorrosion) which affect the kinetics of the environment / metal interface. Regarding to economical and environmental impacts reduction let to the use of natural products as an alternative to toxic synthetic inhibitors. This study aims the employment of green chemistry by evaluating the stem bark extracts (EHC, hydroalcoholic extract) and leaves (ECF, chloroform extract) of plant species Croton cajucara Benth as a corrosion inhibitor. In addition the effectiveness of corrosion inhibition of bioactive trans-clerodane dehydrocrotonin (DCTN) isolated from the stem bark of this Croton was also evaluated. For this purpose, carbon steel AISI 1020 was immersed in saline media (3,5 % NaCl) in the presence and absence of a microorganism recovered from a pipeline oil sample. Corrosion inhibition efficiency and its mechanisms were investigated by linear sweep voltammetry and electrochemical impedance. Culture-dependent and molecular biology techniques were used to characterize and identify bacterial species present in oil samples. The tested natural products EHC, ECF and DCTN (DMSO as solvent) in abiotic environment presented respectively, corrosion inhibition efficiencies of 57.6% (500 ppm), 86.1% (500 ppm) and 54.5% (62.5 ppm). Adsorption phenomena showed that EHC best fit Frumkin isotherm and ECF to Temkin isotherm. EHC extract (250 ppm) dissolved in a polar microemulsion system (MES-EHC) showed significant maximum inhibition efficiency (93.8%) fitting Langmuir isotherm. In the presence of the isolated Pseudomonas sp, EHC and ECF were able to form eco-compatible organic films with anti-corrosive properties

Avaliação de parâmetros de estresse oxidativo em plantas de cana-de-açúcar tratadas com peróxico de hidrogênio

The genus Saccharum belongs to Poaceae family. Sugarcane has become important monocultures in Brazil due to their products: ethanol and sugar. The production may change between different regions from Brazil. This difference is related to soil, climatic conditions and temperature that promotes oxidative stress that may induce an early flowering. The aim of this work was to identify the effects of oxidative stress. In order to analyse this, sugarcane plants were submitted to oxidative stress using hydrogen peroxide. After this treatment, the oxidative stress were analyzed Then, the plant responses were analyzed under different approaches, using morphophysiological, biochemical and molecular tools. Thus, sugarcane plants were grown under controlled conditions and until two months they were subjected first to a hydroponics condition for 24 hours in order to acclimation. After this period, these plants were submitted to oxidative stresse using 0 mM, 10 mM, 20 mM and 30 mM hydrogen peroxide during 8 hours. The histomorphometric analysis allowed us to verify that both root and leaf tissues had a structural changes as it was observed by the increased in cell volume, lignin accumulation in cell walls. Besides, this observation suggested that there was a change in redox balance. Also, it was analyzed the activity of the SOD, CAT and APX enzymes. It was observed an increase in the SOD activity in roots and it was also observed a lipid peroxidation in leaves and roots. Then, in order to identify proteins that were differently expressed in this conditions it was used the proteomic tool either by bidimensional gel or by direct sequencing using the Q-TOF EZI. The results obtained with this approach identified more than 3.000 proteins with the score ranging from 100-5000 ions. Some of the proteins identified were: light Harvesting; oxygenevolving; Thioredoxin; Ftsh-like protein Pftf precusor; Luminal-binding protein; 2 cys peroxiredoxin e Lipoxygenase. All these proteins are involved in oxidative stress response, photsynthetic pathways, and some were classified hypothetical proteins and/or unknown (30% of total). Thus, our data allows us to propose that this treatment induced an oxidative stress and the plant in response changed its physiological process, it made changes in tissue, changed the redox response in order to survival to this new condition

Avaliação da incontinência urinária de esforço em mulheres na pós-menopausa com e sem queixa de perda urinária através da aplicação do pad-test de 1 hora

Stress urinary incontinence (SUI) is defined as "involuntary loss of urine" due to several processes that alter the ability of the bladder to hold urine properly, regarded as a social and hygienic problem that adversely affects quality of life. In postmenopausal women, IU is associated with atrophy and weakness of the pelvic floor muscles. The objective this study was investigate, using the onehour pad test, stress urinary leakage (SUI), evaluate and compare their results in postmenopausal and premenopausal women. The survey was characterized as a cross-sectional study. The study consisted of 60 postmenopausal women were divided into GIU - consisting of 34 volunteers complaining of involuntary loss of urine during stress - and GSIU - consisting of 26 volunteers without complaints of loss of urine during stress, and 15 women, during the premenopausal (GPM), and ovulatory with normal menstrual cycle. All volunteers were evaluated clinically, subjected to one-hour pad test, after the biochemical evaluation of blood and sex hormones. Statistical analysis was performed by descriptive analysis, ANOVA, Turkey´s post-test and Pearson correlation. The results showed that 100% of postmenopausal patients had involuntary loss of urine during one hour pad test (GIU: 4.0 g; GSIU: 4.5 g). GPM remained continent after an hour pad test (GPM: 0.4 g). In addition, Pearson showed a strong correlation between urine loss with time since menopause (r = 0.8, p <0.01) and body mass index - BMI (r = 0.7; p = 0.01). These data suggest that the one-hour pad test is a useful test to assess and quantify urinary leakage, including those volunteers who had no previous complaint of SUI

Avaliação neuropsicológica de crianças com hemiparesia congênita e adquirida

A hemiparesia consiste no déficit da força muscular, com consequente debilidade na mão e no pé, afetando um dos lados do corpo. A literatura mostra poucos estudos enfocando detalhadamente as funções cognitivas e emocionais de crianças afetadas por essa condição neurológica. Este estudo teve como objetivo realizar avaliação neuropsicológica de 23 crianças e adolescentes, de ambos os gêneros, com idades entre 5 anos e 4 meses e 16 anos e 6 meses, com hemiparesia congênita e adquirida. Aplicou-se uma bateria de testes específica para avaliação de funções cognitivas superiores incluindo processos intelectuais, atenção, função perceptiva, função motora, praxias, gnosias, linguagem, memória e função visuomotora. Em relação aos aspectos emocionais, foi usado o teste do desenho da figura humana, visando-se a avaliação da percepção da imagem corporal dos pacientes. Os resultados mostraram que a hemiparesia da criança conduz a déficits em funções neuropsicológicas importantes, além de déficit motor e alterações na esfera emocional, mais precisamente aquelas relacionadas com a representação da imagem corporal. A abrangência multidisciplinar, envolvendo a neurologia pediátrica e a psicologia, engrandeceu o trabalho, referendando os resultados obtidos em todos os seus aspectos

Avaliação de concentrações do C-Telopeptideo de Colágeno (CTX) em mulheres no climatério

Fundação de Apoio à Pesquisa do Estado do Rio Grande do Norte

Avaliação da expressão das moléculas HLA de classe I não clássicas HLA-G E HLA-E em espécimes gástricas de pacientes acometidos com a bactéria Helicobacter Pylori

The expression of human leukocyte antigen G (HLA-G) and human leukocyte antigen E (HLA-E) in physiological and pathological processes remains unknown, it is believed that these molecules play a fundamental role in the establishment and maintenance of immune tolerance by inhibiting the functions of immunocompetent cells. In literature we found no published study involving the bacterium Helicobacter pylori (H. pylori) with expression of HLA-G and HLA-E. The objective this study is investigated the expression of this protein in gastric biopsies of patients with the bacterium H. pylori. Sixty-four biopsies of the patients with diagnosis of infection by H. pylori were evaluated to expression of HLA-G and HLA-E. The samples were stratified according to the presence of carcinoma or peptic ulcers. Patients without H. pylori were used to control. To investigate the expression of this protein were used immunohistochemistry technique with monoclonal antibody anti-HLA-G and anti-HLA-E. Other criteria such as analysis of the inflammatory infiltrate (hematoxylin-eosin) and identification of H. pylori (Giemsa) were analyzed. We detected HLA-G and HLA-E molecules in the most samples containing ulcer and gastric carcinoma. In negative control group was not detected the presence of HLA-G and HLA-E. The presence of H. pylori seems modulate the expression of HLA-G and HLA-E, favoring the evolution of infection, giving different degrees of gastric lesion in epithelium of these patients

Avaliação dos efeitos de um extrato bruto de cianobactérias contendo microcistinas sobre o desempenho reprodutivo e a embriofetotoxicidade de ratos

The presence of cyanobacterial blooms in reservoirs intended for supply to the population can create public health problems for many species could produce potentially toxic compounds and these are not eliminated in the conventional procedures used in water treatment plants. So even in amounts less than the maximum allowable limit imposed by MS, cyanotoxins can be present in drinking water distributed to the population, creating a chronic exposure. There is little information about the long-term effects of oral exposure to cyanotoxins. This work aimed to show the exposure orally (v.o) of animals to a crude extract of cyanobacteria containing cyanotoxins to evaluate the reproductive performance of pregnant rats and their offspring and fertility of male rats. The presence of microcystins (MCs) in samples collected during the flowering processes in freshwater reservoirs in the Rio Grande do Norte, was analyzed by enzyme immunoassay and its variants have been identified and quantified by chromatographic methods. It was observed that by administration v.o. cyanobacterial extract containing MCs (40, 100 or 250 ng of MCs / kg / day) did not cause systemic toxicity in adult rats or effect on reproductive performance of male and female rats treated. It was also not observed any changes in skeletal study in the offspring of pregnant rats treated with the extract above. Because the solutions used contained MCs in a concentration equal to or greater than the tolerable daily intake for MCs, the results suggest, therefore, that the development of this work contributed to better assess public health risk as the oral exposure to cyanotoxins, increasing thus the credibility of the maximum allowable limit (LMP) of MCs in drinking water distributed to the population of several countries that use the LMP established by WHO in its legislation

Avaliação da composição química, atividade antioxidante, antibacteriana, antinoceptiva, antiinflamatória e toxicidade do extrato metanólico e frações de folhas de Spondias sp. (Anacardiaceae)

Spondias sp. (Anacardiaceae), popularly known as cajá-umbu, is an endemic plant from Northeastern Brazil, where their leaves are widely used in folk medicine to treat inflammatory processes, while their fruits have a great agro industrial potential. This study was designed to evaluate hepatoprotective, antinociceptive, antioxidant, antimicrobial and anti-inflammatory properties, as well as the acute toxicity and repeated dose 28, using a methanolic extract (MES), a fraction rich in flavonoids (FRF) and a precipitate from Spondias sp.leaves. The antioxidant activity of them was valued to evaluate their free radical scavenger capacity by DPPH test, whereas MES and FRF were used to evaluate while the preventive action on carbon tetrachloride (CCl4)-induced hepatotoxicity. Seven groups (n=5) of female Wistar rats were used as follows: control group, CCl4-intoxicated group treated with EMS (500 mg/kg) for 7 days, three CCl4-intoxicated groups treated with FRF (25, 50 and 75 mg/kg) for 7 days and the CCl4-intoxicated group treated with Legalon ® (silimarina; (phytotherapeutic reference) (50 mg/kg; 7 days). MES and FRF showed a protective action against liver injury induced by CCl4, being observed a significant reduction of serum enzyme activity marker of liver damage (alanine transaminase and aspartate transaminase). On the other hand, the lipid peroxidation (SRAT) decrease, as well as the increase of glutathione content and enzyme activity of antioxidant defense system (SOD, CAT, GPx) toward near normal values indicated the ability of EMS to restore the oxidative imbalance induced by CCl4. The histological analysis confirmed the hepatoprotection, compared to degenerative changes in CCl4-treated group. This hepatoprotetor effect was similar to that shown by Legalon®. The in vitro high antioxidant capacity of extract (93.16 ± 1.00%) showed analogous results to those obtained by Carduus marianus BHT (reference standard). This fact explains the obtained results in vivo. Although no antimicrobial activity was detected, EMS and FRF promoted the antinociceptive effect induced in the second phase by the intraplantar formalin test, evidencing the anti-inflammatory action; confirmed by the carrageenan-induced peritonitis model. The evaluation of the mechanical allodynia (CFA a 80%) demonstrated the involvement of the Spondias sp. chemical composition in the anti-inflammatory activity toward the acute processes. The acute exposure and repeated dose during 28 days did not produce significant changes in the parameters that evaluate toxicity. Together the experimental results reveal, that Spondias sp. leaf extracts have a promising potential in pharmaceutical area, and due to its non-toxic condition present efficiency and security

Avaliação de características morfométricas na relação solo-superfície da Bacia Hidrográfica do Córrego Rico, Jaboticabal (SP)

Com a análise das características morfométricas procura-se entender a relação solo-superfície, em decorrência dos processos erosivos sobre estruturas e litologias variadas. Neste trabalho, objetivou-se avaliar as características morfométricas do padrão de drenagem e do relevo em microbacias hidrográficas de 2ª ordem de magnitude, em Latossolo Vermelho-Escuro e Argissolo Vermelho-Amarelo, com vistas ao planejamento agroambiental da Bacia Hidrográfica do Córrego Rico, município de Jaboticabal, SP. O estudo foi baseado em fotografias aéreas, pancromáticas, verticais na escala 1:35.000 da região administrativa de Ribeirão Preto. Com técnicas de fotointerpretação, foram traçadas a rede de drenagem e respectivas microbacias hidrográficas, onde as variáveis selecionadas foram determinadas. As classes de risco de degradação, resultando no uso potencial do solo, foram determinadas de acordo com o coeficiente de rugosidade. As características do padrão de drenagem e do relevo repercutiram no comportamento hidrológico e litológico das microbacias hidrográficas, possibilitando a diferenciação entre as unidades de solos. A densidade de drenagem e a amplitude altimétrica foram as características que mais contribuíram para o poder discriminatório na relação solo-superfície. Na análise conjunta do potencial de uso do solo, verificou-se, principalmente, adequação para agricultura nos Latossolos e pecuária e, ou, reflorestamento nos Argissolos.

Avaliação de efetividade do centro de reabilitação de adultos - CRA/NATAL/RN

Public services with an emphasis on rehabilitation treatment of disabled people, as established law, have aimed to ensure quality and equity assistance in a rehabilitation way to the segment highlighted. As for people with physical disabilities, the Unified Health System (hereby SUS) through the directive GM/ MS No. 818 of 2001, requires the creation of hierarchical and regionalized services networks at different levels of complexity to ensure appropriate assistance. This study whose title is Evaluation of effectiveness of the Adult Rehabilitation Center in Rn: elements for a discussion aimed to evaluate the effectiveness of rehabilitation services that institution, reference in the State of Rio Grande do Norte, has directed its patients, more specifically those who have had a stroke and therefore are disabled ones. From the standpoint of methodological conduction, it was prioritized a qualitative and empirical theoretical research which was carried out from the following courses: literature references with authors who are the themes pertaining to rehabilitation, inclusion, public policy evaluation, health policy and disability; documentary research through Regulation of Technical Procedures, files, records, informative booklets that were of great importance to the knowledge of the institution, as well as its functioning and dynamics of field research that was materialized with the managers, rehabilitation staff and Center s users, through the application of semi-structured interviews as a tool for data collection. The information obtained was analyzed from the critical analysis of discourse. As a result, it was identified some technical, administrative and financial difficulties which have obliterated the effectiveness of services provided, such as: lack of many professionals to meet existing demand, poor quality of equipment and the physical structure, limits on autonomy management as a result of dependence along with the SESAP/RN; besides the excessive bureaucratization in the administrative processes compromising Center s problem-solving needs. However, in the narratives of managers, rehabilitation staff of patients, despite the difficulties, treatment made by Centre has effectiveness to the extent that has been contributing even in a limited way to improve their quality of life

Gestão de centros históricos: uma avaliação da política de requalificação urbana de Natal/RN

From the second half of the century XX, in many Brazilian cities, the "historic centers" stop being the most densely populated areas of the city, accumulate degradation of the built environment and its functions have physical, social and economic resignified when also intensified interventions in these same centers Historic focused its redevelopment. This work aims to reflect on the experience of urban regeneration in the historic center of Natal, addressing the strategies adopted in the implementation of public policies and how these improve the effectiveness of actions, processes and outcomes for which turn the management of the historic center in question. In Natal, is identified in the neighborhoods of the Upper Town and Ribeira, the historic city center, a large distortion of their ancient architectural complex, the use of sub-urban infrastructure and emptying in the evenings and weekends. Shares redevelopment of the historic center of Natal are considered late, it is only recently that these neighborhoods were objects of policies and projects generally aimed at enhancing the cultural attraction of the area, and not always, it can be said that they have relevance in development process of the city. Added to this, there is the slowness of the interventions, although the zoning as an area of historic preservation has been done for over two decade. In Natal, the ideas of sustainable development articulated a proposed redevelopment of its historic center is still far from being achieved, but on the other hand, the latest phase of implementation of plans and projects in the area, indicating the intention to transform practical experience in the formulations and proposals in relation to these ideals

Utilizando processos geométricos da história da matemática para o ensino de equações do 2º grau

The present work had as principal objective to analyze the, 9th grade students understanding about the solutions of an equation of the 2° degree, using geometric processes of the History of the Mathematics. To do so, the research had as base the elaboration and application of a group of teaching activities, based on Jean Piaget's construtivism. The research consisted of a methodological intervention, that has as subjects the students of a group of 9th grade of the State School José Martins de Vasconcelos, located in the municipal district of Mossoró, Rio Grande do Norte. The intervention was divided in three stages: application of an initial evaluation; development of activities‟ module with emphasis in constructive teaching; and the application of the final evaluation. The data presented in the initial evaluation revealed a low level of the students' understanding with relationship to the calculation of areas of rectangles, resolution of equations of the 1st and 2nd degrees, and they were to subsidize the elaboration of the teaching module. The data collected in the initial evaluation were commented and presented under descriptive statistics form. The results of the final evaluation were analyzed under the qualitative point of view, based on Richard Skemp's theory on the understanding of mathematical concepts. The general results showed a qualitative increase with relationship to the students' understanding on the mathematical concepts approached in the intervention. Such results indicate that a methodology using the previous student‟s knowledge and the development of teaching activities, learning in the construtivist theory, make possible an understanding on the part of the students concerning the thematic proposal