Aplicação de sistemas microemulsionados ácidos em acidificação de poços

Stimulation operations have with main objective restore or improve the productivity or injectivity rate in wells. Acidizing is one of the most important operations of well stimulation, consist in inject acid solutions in the formation under fracture formation pressure. Acidizing have like main purpose remove near wellbore damage, caused by drilling or workover operations, can be use in sandstones and in carbonate formations. A critical step in acidizing operation is the control of acid-formation reaction. The high kinetic rate of this reaction, promotes the consumed of the acid in region near well, causing that the acid treatment not achive the desired distance. In this way, the damage zone can not be bypassed. The main objective of this work was obtain stable systems resistant to the different conditions found in field application, evaluate the kinetic of calcite dissolution in microemulsion systems and simulate the injection of this systems by performing experiments in plugs. The systems were obtained from two non ionic surfactants, Unitol L90 and Renex 110, with sec-butanol and n-butanol like cosurfactants. The oily component of the microemlsion was xilene and kerosene. The acqueous component was a solution of HCl 15-26,1%. The results shown that the microemulsion systems obtained were stable to temperature until 100ºC, high calcium concentrations, salinity until 35000 ppm and HCl concentrations until 25%. The time for calcite dissolution in microemulsion media was 14 times slower than in aqueous HCl 15%. The simulation in plugs showed that microemulsion systems promote a distributed flux and promoted longer channels. The permeability enhancement was between 177 - 890%. The results showed that the microemulsion systems obtained have potential to be applied in matrix acidizing

Perfil epidemiológico dos distúrbios hipertensivos na gravidez

The preeclampsia is a disease that evolves to high death rate for the mother and for the fetus. The incidence of this disease in the world is variable and there are no data of this disturb in the Brazilian population. This paper had the objective to determine the incidence and risk factors for development of hypertensive disorders of pregnancy in a neighborhood in Natal, RN, Brazil, taking place a prospective study, cohort type, with the objective of evaluating the entire pregnancy of 242 women that got pregnant between 2004-2007. The incidence of hypertensive disorders was of 17%, while the incidence of preeclampsia was of 13.8%. The age average of women that developed the hypertensive disorders was of 27.4 years (SD±.9), whilst those that developed preeclampsia was of 26.6 (SD ±7.8) years and the normotensive was of 23.9 (SD±5.8) (p=0.002). It is noted a significant increase of the hypertensive disorder with age (p=0.0265). The gestational age for those who developed preeclampsia was lower than the women that developed normotensive pregnancy (p=0.0002). The body mass index (BMI) of the group of women that developed the hypertensive disorder was of 25.8 (SD±3.9), significantly higher than the group of normotensive women with 23.5 (SD±3.7) (p=0.02). The levels of triglycerides and cholesterol tended to be higher on women with preeclampsia than on normotensive, p=0.0502 and p=0.0566, respectively. Six (6) women presented with severe preeclampsia and one (1) developed HELLP Syndrome. The resolution of the pregnancy was performed by cesarean section in 70% of women that developed hypertensive disorders, whilst the normotensive was of 23.6% (p<0.0001). A subgroup of the studied subjects was reassessed one year after labor, revealing that 50% of the patients were still hypertensive. There were no larger complications nor mother death during labor. The incidence of hypertensive disorders are above the levels noted in other studies and 30% of the women were within the poles of greater risk for the hypertensive disorders; the elevated BMI in the beginning of the pregnancy is a risk factor for hypertensive disorder. The risk of severe complication in preeclampsia is high, with imminence of eclampsia occurring in 20.1% of women who developed hypertensive disorder of pregnancy. The adequate prenatal care and the opportune labor assistance may minimize the complications of the pregnancy hypertension and avoid mother death, although the risk of women remaining hypertensive is elevated

Educação de jovens e adultos na cidade do Natal: uma reflexão sobre sucesso e insucesso

This essay proposes to research the success and failure in Education for Youth and Adults (known as EJA), based on the approval, failure and evasion rates in public schools belonging to the city of Natal, RN. Reflecting upon the reasons why some pupils from this program were dropping out of school while others kept on studying was a necessity. Therefore, we seek to know these subjects and their school environment. In the search this data, we set off by approaching the EJA politics, going through a historical path, highlighting significant facts to Brazilian and Natal history. While bringing together the pieces of information for this essay, we were lead to the State and City Education Department, in search of approval, failure and evasion rates from the year 2009. Based on these rates, two schools have been chosen: the first with a high failure rate and the second with a failure rate lower than the city average. The schools work was researched throughout the year 2010, through interviews with pupils, teachers, managers and employees; school files analysis; the analysis of files the establish the rules for EJA programs in the city of Natal. Nethertheless, this essay points to inner and outer factors which might come to contribute to the failure or success of pupils from the researched schools, emphasizing that the difference between those are in the team work present in the school with low failure rate

Integração dos processos de flotação e foto-fenton para redução de óleos e graxas de água produzida em campos de petróleo

During production of oil and gas, there is also the production of an aqueous effluent called produced water. This byproduct has in its composition salts, organic compounds, gases and heavy metals. This research aimed to evaluate the integration of processes Induced Air Flotation (IAF) and photo-Fenton for reducing the Total Oils and Greases (TOG) present in produced water. Experiments were performed with synthetic wastewater prepared from the dispersion of crude oil in saline solution. The system was stirred for 25 min at 33,000 rpm and then allowed to stand for 50 min to allow free oil separation. The initial oil concentration in synthetic wastewater was 300 ppm and 35 ppm for the flotation and the photo-Fenton steps, respectively. These values of initial oil concentration were established based on average values of primary processing units in Potiguar Basin. The processes were studied individually and then the integration was performed considering the best experimental conditions found in each individual step. The separation by flotation showed high removal rate of oil with first-order kinetic behavior. The flotation kinetics was dependent on both the concentration and the hydrophilic-lipophilic balance (HLB) of the surfactant. The best result was obtained for the concentration of 4.06.10-3 mM (k = 0.7719 min-1) of surfactant EO 2, which represents 86% of reduction in TOG after 4 min. For series of surfactants evaluated, the separation efficiency was found to be improved by the use of surfactants with low HLB. Regarding the TOG reduction step by photo-Fenton, the largest oil removal reached was 84% after 45 min of reaction, using 0.44 mM and 10 mM of ferrous ions and hydrogen peroxide, respectively. The best experimental conditions encountered in the integrated process was 10 min of flotation followed by 45 min of photo-Fenton with overall TOG reduction of 99%, which represents 5 ppm of TOG in the treated effluent. The integration of processes flotation and photo-Fenton proved to be highly effective in reducing TOG of produced water in oilfields

Concepção de um secador rotatório para secagem do cefalotórax do camarão

The present work has as objective the knowledge of the process of drying of the cephalothorax of shrimp to give support the industry to make possible the use of this byproduct. In this sense, the process conditions in this tray dryer and spouted bed were analyzed. With these results, it was projected and constructs a dryer with specific characteristics for the drying of the cephalothorax. The desorption isotherms were obtained by the dynamic method in the temperatures of 20, 35 and 50º C and in the interval of 10-90% of relative humidity. It was observed that the product in form of powder can be conserved with larger stability for lower relative humidity to 40%. The curves of drying of the dryer of fixed bed were adjusted for the models: single exponential, biparametric exponential and Page. The model biparametric exponential more adequately described all the drying conditions studied. The tests carry out in spouted bed showed high drying rate for the material in the paste form in beds active dynamicly-fluid, provely the necessity of a feeding in shorter intervals of time to increase the thermal efficiency of the process. The projected dryer, be considered the obtained results, it was a rotary dryer with inert bed, feed co-current, discharge in cyclone to take place the separation gas-solid, and feed carry out in intervals of 2 minutes. The optimization of the equipment projected it was accomplished used the complete factorial experimental design 24, this had as independent variables temperature velocity of the air, feed flow rate and encapsulated concentration (albumin), as variables answers the thermal efficiency, the moisture content of obtained powder, total time of test and the efficiency of production of powder in several points of processing. The results showed that the rotary dryer with inert bed can present, also, good results if applied industrially

Avaliação de indicadores de impactos ambientais no perímetro irrigado Cruzeta-Região semi-árida do RN

Environmental impacts are defined as the processes of social and ecological changes caused by nuisance ambient. In agriculture are diverse, and the intensive use of land and inappropriate agricultural practices causes negative effect on the environment besides affecting crop productivity and quality of life of man. So this study was objective to analyze parameters indicators of environmental impacts in the Cruzeta the Discrict Irrigation. During the period July 2007 to March 2008 samples were collected in lot 01 and 02 of the irrigation district. The monitoring was conducted in four sampling points, three (3) located in the irrigation channels and 1 (one) located in a cacimbão. Were monitored pH, CE, STD, SS, NO3-, OD, DT, PST, RAS, CT, Ca+2, Mg+2, Na+ and K+ and heavy metals. Analysis was performed, soil fertility, determining the infiltration rate, moisture content of soil and flow measurement. The results showed that the parameters considered most effective in evaluating the indicators of environmental impacts were: Suspended solid, turbidity, dissolved oxygen and Coliform termotelerantes. The concentrations of nitrate were below the limit established by CONAMA (2005). High levels of STD were found in the point P4. The risk of salinity in cacimbão Lot 02, the water was classified as Class II, or medium risk of salinity in the remaining points was classified as Class I. The iron and aluminum were found high concentrations in four sampling points independent of the dry or rainy. On the ground, found high levels of phosphorus in both samples collected in the batch 01, as the lot 02. The pH levels found in samples of soil, the soil can be classified as neutral and moderate alkalinity. The high infiltration rate obtained in the tests performed in lots 01 and 02 indicated the high permeability of soil at these points

A humanização no parto e no nascimento: os saberes e as práticas no contexto de uma maternidade pública brasileira

The practice of medicine related to the gestational processes tend to be organized according to the context and the place of work, being thus dependent of the conditions both social and economical, and of the physical structure and the functionality of the services. The high mortality rate in this process has diminished, since 1986, the study made by the World Health Organization (WHO) as to the technical aspects and the social inequalities that influence this situation in different geographical contexts. This culminated recommendations that proposed the reorientation of the dynamical practice of medicine, with a focus on the safety of maternities. Brazil adopted, in the year 2000, the suggestions of the OMS, emphasizing the humanization as the main reason for these actions. However, this discussion tends to not consider the problems caused by the social inequalities and the epidemiological and social conditionings that define the actions of the Unified Health System (Sistema Único de Saúde SUS). In this area, this research seeks to analyze the practices, cares taken, and the universal symbol that promotes and rewards the assistance to the birth of children by the SUS. Besides the analysis of the public documents that deal with this subject, an ethnographic study was developed in a maternity in Natal/RN, considered a model of humanization after receiving the Galba de Araújo prize in 2002. In this stage, the methodological strategies were observed, and the focus of the individual interviews with workers and users of this service. In the analysis of the data, it became evident that the different professional workers and women who gave birth, tend to show concern of the standards the delimit production and reproduction of the practice of medicine, as they favor the absence of a critical posture of the actions destined to the population. Besides this, if became evident that the institutional difficulties associated to the economical, cultural, and political problems also difficult the involvement and the reflection of the workers in favor of assisting changes of the process. There is also a utilization of a perspective prescriptive of humanization in the everyday life of the social workers, without reflection of its meaning. Some workers present, in their statements, a preoccupation with the social and economical aspects that affect the practice of medicine, and with the limitations of the humanization discourse that disarticulates the necessities of those involved in the process of formation, and soon tend to return to the discussion of humanization while a kind practice characterized by the minimization of the interventionist actions. Now the users of the system show themselves before the dynamic of the services, submitting themselves to what is offered while assistance, without questioning and/or reflecting about their usual shortages. Therefore, to think of changes in the know and do of the practice of medicine destined to the birth of children implies reflection on the quotidian production of these practices and of the social contexts that influence the process of assistance in the practice of medicine. Herein it would be possible to predict the appropriation, by different workers concerning their exasperations and necessities, making them active in the pursuit of their rights as citizens

Avaliação clínica de pacientes submetidos à colocação de implantes zigomáticos pela técnica de Stella & Warner

This study aimed to evaluate patients who underwent placement of zygomatic implants technique by Stella & Warner, considering the survival of conventional and zygomatic implants, sinus health and level of patient satisfaction in relation to oral rehabilitation. We evaluated 28 patients where 14 had received conventional and zygomatic implants, being rehabilitated with implant-fixed dentures (group 1) and 14 were rehabilitated only with conventional implants and implant-fixed dentures (group 2). The study had four phases, represented by radiographic evaluation of implants (stage I), clinical evaluation (stage II), assessing the health of the maxillary sinus (stage III) and a questionnaire to measure satisfaction of rehabilitation with fixed prosthesis implant Total -backed (stage IV). Group 2 underwent only stage IV, while group 1 participated in all stages. Descriptive analysis and statistics were performed, using the t test for independent samples in the evaluation of phase IV. The results demonstrated that the technique of Stella & Warner proved effective, allowing a high survival rate of conventional implants and zygomatic (100%), considering a minimum follow-up of 15 months and maximum 53 months after prosthetic rehabilitation. There were no pathological changes in tissues periimplants conventional and zygomatic implants analyzed. Radiographic findings showed satisfactory levels bone implants in the oral rehabilitation with conventional zygomatic implants and a good positioning of the apex of the zygomatic implants over the zygomatic bone. The presence of the zygomatic implant did not cause sinus and the t test showed a satisfaction index lower in group 1 compared with group 2. The zygomatic implant placement technique by Stella & Warner proved to be a predictable technique with high survival rate in patients with atrophic jaws, necessitating long-term follow-up to confirm the initial findings of the study

Algoritmos e Arquiteturas VLSI para Detectores MIMO com Decisão Suave

The use of Multiple Input Multiple Output (MIMO) systems has permitted the recent evolution of wireless communication standards. The Spatial Multiplexing MIMO technique, in particular, provides a linear gain at the transmission capacity with the minimum between the numbers of transmit and receive antennas. To obtain a near capacity performance in SM-MIMO systems a soft decision Maximum A Posteriori Probability MIMO detector is necessary. However, such detector is too complex for practical solutions. Hence, the goal of a MIMO detector algorithm aimed for implementation is to get a good approximation of the ideal detector while keeping an acceptable complexity. Moreover, the algorithm needs to be mapped to a VLSI architecture with small area and high data rate. Since Spatial Multiplexing is a recent technique, it is argued that there is still much room for development of related algorithms and architectures. Therefore, this thesis focused on the study of sub optimum algorithms and VLSI architectures for broadband MIMO detector with soft decision. As a result, novel algorithms have been developed starting from proposals of optimizations for already established algorithms. Based on these results, new MIMO detector architectures with configurable modulation and competitive area, performance and data rate parameters are here proposed. The developed algorithms have been extensively simulated and the architectures were synthesized so that the results can serve as a reference for other works in the area