849 resultados para Null values
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Tuberculosis is a disease of great impact on the world context today. In Brazil, the disease management was directed to the Primary Health Care, due to the determination of the Ministry of Health to decentralize health actions for primary care. Thus, since the actions of diagnosis, treatment and control of the disease should happen in this context, however, there are still many barriers that may hinder the realization of these determinations. This study aims to analyze the development of tuberculosis control activities conducted in the services of primary health care from the patient's vision. This is a descriptive, cross-sectional and quantitative study. The population consists of 517 tuberculosis patients treated in units of Primary Health Care in the city of Natal-RN; the sample consists of 93 TB patients. The collect instrument is structured, based in The Primary Care Assessment Tool (PCAT), validated in Brazil and adapted to assess attention to TB in Brazil, with modifications. This instrument was divided into blocks: the first one describes the socio-demographic information of patients with TB and the second one describes the health services working in control, diagnosis and treatment of TB, and includes issues related to the dimensions of primary care: access, bond, services, coordination of care, guidance to the community and family focus. For quantitative analysis, were built indicators for each item of the instrument. The response patterns are followed according to the Likert scale, which was assigned a value between one and five meant that the degree of preference relation (or agreement) of the statements. Values between 1 and 3 were considered unsatisfactory for the indicator, between 3 and less than 4, regular, and between 4 and 5, satisfactory. The results indicate that 62.37% of patients are male, 27.96% aged 41 to 50 years old, and 34.41% unemployed, with low education and low family income. It was found that the reference hospital services are the front door to the patient (59.14%), and are also the local diagnosis of the disease (72.04%). On access, the conditions satisfactory found are: the number of times the patients need to pick up the health care issue, the marking and the facility to get a consultancy in the HS, assistance provided without harm to the individual's attendance labor and facilities related to the proximity between the residence and services; were considered unsatisfactory conditions related to travel to the HS, and on hours and days of operation of services. As for the cast of services were satisfactory and regular actions related to the request for examination to become viable in the first HS, the availability of pot to perform smear and medicines for the treatment, as well as consultations control and receiving information about the disease and the treatment performed; it is considered unsatisfactory the performance of the home care for patients with TB by the HS that acts as a front door, for implementation of the Directly Observed Treatment (DOT), home visits during treatment, the provision of transportation allowance to the patient and the existence of groups for TB patients. Regarding the coordination of care, resulted in regular the action of referring the patient to other HS to obtain examinations, and as unsatisfactory referral to obtain medications. The relationship bond between patient and health team were considered satisfactory in the majority or regular. As for the family and community focus, is satisfactory only the indicator relating to questions from professionals to the patient about the existence of respiratory symptoms in the family. It is considered that there is need for greater commitment from government entities to the incentives required to TB control, as well as the availability of necessary inputs and training of human resources working in the PHC in the ongoing quest to strengthen primary care, as a place of broader host needs to contact the user with the actions and health professionals. It is recommended the adoption of management mechanisms possible to expand the capacity of the health PHC, promoting the service delivery to the user and ensuring attention to population health.
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This study aimed to validate the contents of an Instrument for Nursing Consultation in the Home Visit of people with Spinal Cord Injury (INCEVDOP-LM), based on the Self-Care Deficit Theory. The methodological development study was conducted with spinal cord injured (SCI) people ascribed in the Family Health Units the city of Natal/RN/Brazil, and with the nurses of these institutions. The study was conducted from Januray 2012 to January 2013 in two phases: the first aimed to identify the need for self-care of persons with SCI, and the second to develop and validate the INCEVDOP-LM. The first phase consisted of a census study of people with SCI living in Natal/RN. In the second phase, a non-probabilistic convencience sample of subjects was selected to form two groups: First stage - Group 1 of the first stage was comprised by 73 adults with SCI diagnosed with paraplegia or tetraplegia, with cognitive function preserved and that were registered to some family health unit; Group 2 of the Second phase was composed of six experts that were nurses with doctoral formation, scientific experience in the area of technology development or assistance to persons with SCI, and with publications in periodicals Qualis A2. Data collection of the first phase was conducted through home visits of people with SCI that responded three instruments: Questionnaire I (comprised of demographic and socioeconomic variables), The Competency Rating Scale for Self-care (ASA) and the Barthel Index (an instrument for evaluation of functional capacity). The research for the second phase was conducted in two stages: I-construction of the INCEVDOP LM; II-validation of the INCEVDOP-LM. The instrument and an evaluation form were forwarded to the experts for the validation. The correlations between the responses were analyzed by the Kappa test, with accepting values of>0.75. The evaluation criteria were: organization, clarity, simplicity, readability, appropriateness of vocabulary, objectivity, accuracy, reliability and suitability and the positive responses with frequency values of≥90% were considered excellent. The chi-square test was used to investigate the differences between proportions. The study attended to the principles of Human Rights CNS Resolution 196/96. Results were reported by means of four articles derived from the study. The findings indicate that the items that showed disagreement among experts (k=0.02) were diagnoses, interventions and evaluation of the nursing features pertaining to the domains of Nutrition, Hygiene, Elimination, Physical, Social and Psychological, and of the Ability to perform work activities feature. Agreement among the experts were reported for the other items, with kappa ranging from 0.72 to 1. After removing items with disagreement, all criteria achieved excellent rates and no significant differences were observed between the proportions of responses of evaluation of experts (p>0.05). We conclude that the instrument shows validity to serve as a guide for nurses to conduct a systematic consultation during the home visit to people with spinal cord injury, with emphasis on self-care. The instrument must go through other levels of validation when applied in the clinical setting
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The problem facing the incidence of pressure ulcers (UP) in the hospital environment especially in the intensive care unit (ICU), although it is an old and frequent event in our professional practice, it is not notified in the researches as much as it should be. We observed a tendency to invest in therapeutical and in studies about the production of sophisticated new bandages. Few, however, are the investments in research on preventive measures in order to prevent or at least slow down the development of lesions. In this sense, the study aimed to analyze the correlation between nursing care and the risk of developing UP measured by the Braden scale in ICU patients. This is a descriptive study of longitudinal quantitative approach. The project obtained a favourable opinion from the Ethics Committee of HUOL (no 486/10). Data collection was carried out in the Hospital of Unimed in Natal during six months in 2011. The sample was of 32 patients hospitalized in ICU for over four days. The results were processed in SPSS 15.0 for descriptive statistics and inferential statistics. We identified that, only 9.4% of our sample developed UP, being predominantly male, elderly people aged above 60 years, Caucasian, with diagnostic hypothesis at the time of hospitalization of sepsis, were clinical patients, who presented hemodynamic instability, using orotracheal tube (TOT), enteral probe (SNE), vesical probe delay (SVD) and had values of albumin and hemoglobin levels below normal. In addition, these patients had a longer hospital stay, longer usage of TOT, SNE, SVD, increased use of sedation and drain than those who did not develop UP and were all at risk for developing these injuries second Braden scores. 66.7% of the lesions developed were located in the sacral region, limiting the degree I and all patients that developed were considered serious, 100.0% of them have evolved since the death. Small were the differences between the averages of Braden scores between patients with and without UP, 11,9+2,4 against 12,4+2,6 with p = 0.627. The clinical aspects of the patients in the study were instrumental in the development of UP, once, these findings were statistically significant through the Mann-Whitney test, and appropriateness of nursing conduct was decisive for the prevention of pressure ulcers in critical patients, since many were those classified as at risk (28) and few who have developed lesions (03)
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That study had the aim to validate an instrument to evaluate the knowledge about the Urinary Catheterization (UC) in males. Cross-sectional, descriptive, quantitative and methodological study, accomplished in Universidade Federal do Rio Grande do Norte (UFRN), Universidade do Estado do Rio Grande do Norte (UERN) and a private university from Rio Grande do Norte. Sample of 27 judges selected from the inclusion criteria: registered nurses, discipline of semiology and/or semiotics teachers, with at least 1 year of experience in the disciplines, to work at UFRN, UERN or in private university and agree to participate voluntarily with the signing of the Consent Form. Study developed in three stages: a) elaboration of twos instruments based on the scientific literature, resulting in a structured observation script type checklist consisting of 36 items and a knowledge questionnaire with 12 questions; b) submission of instruments to judges from June to September 2012, which should evaluate each item in "adequate," "adequate with changes" and "inappropriate", and make an overall evaluation of each instrument based on 10 requirements; c) and validation with a verification of the agreement level among the judges, through the application of Kappa Index (K) and Content Validity Index (CVI). It was used the consensus level higher than 0.60 (good) for Kappa Index and higher than 0.70 for CVI. The research project had favorable opinion from the Ethics in Research/HUOL (CAAE n. 0002.0.294.000-10). After being coded and tabulated, the data were analyzed using descriptive statistics. Of the 27 judges who evaluated the instrument, 77.8% are female, with a mean age of 36.6 (± 9.0) years, 63.0% worked in UFRN, 74.1% had master degree and 63.0% worked exclusively on teaching. The experience time mean in teaching was 7.9 (± 8.0) years and in the disciplines of semiology and/or semiotics in nursing was 5.5 (± 6.7) years. In judgment of the checklist and knowledge questionnaire, no step/question was considered inappropriate, since all achieved level of agreement within the established values. All the checklist steps obtained good to excellent K (between 0.60 and 1.00). Of the 36 items, 25 had excellent K (0.75 ≤ K <1.00) and excellent total K (K = 0.83). Regarding the IVC, all steps reached levels above 0.70 (between 0.74 and 1.00) and CVI total was 0.90. All questionnaire questions evaluated separately (K from 0.60 to 0.93 and CVI from 0.74 to 0.96) and generally (K from 0.79 to 1.00 and CVI from 0.89 to 1.00) had evaluation levels of content validity within the established values. The instruments were reformulated based on the agreement levels between judges and international guidelines, dissertations and scientific articles. Both instruments proved to be valid regarding to their content, allowing a clear and objective evaluation of knowledge and skills about UC, both nursing students as well as other students and health professionals, since the use of valid measures seeking the reduction of the risk of the results distorted
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Trasnversal study, with the objective of evaluating the accuracy of clinical indicators of nursing diagnosis excessive fluid volume in patients undergoing hemodialysis. The study occurred in two stages, the first consisted of the evaluation of the diagnostic indicators in study; and the second, the diagnostic inference conducted by nurse diagnosticians. The first stage occurred from december 2012 to april 2013, in a University Hospital and a Hemodialysis Clinic in Northeastern of Brazil, with a sample of 100 chronic renal failure patients on hemodialysis. The data were selected through an interview form and a physical examination, organized into spreadsheets and analyzed as to the presence or absence of the indicators of diagnosis excessive fluid volume. In the second step, the spreadsheets were sent to three nurses diagnosticians, who judged the presence or absence of diagnosis in the clientele searched. This step was conducted from july to september 2013. For analysis of the data, we used descriptive and inferential statistics. In the descriptive analysis, we used measures of central tendency and dispersion. In inferential analysis, we used the tests Chi- square, Fisher and prevalence ratios. The accuracy of the clinical indicators pertaining to the diagnosis were measured as to the specificity, sensitivity, predictive values, likelihood ratios and Diagnostic Odds Ratio. Also developed a logistic regression. The results were organized in tables and discussed with literature. This study was approved by the Ethics Committee in Research of the Federal University of Rio Grande do Norte, with Presentation Certificate for Ethics Appreciation nº 08696212.7.0000.5537. The results revealed that the diagnosis studied was present in 82% of patients. The characteristics with prevalence above 50 % that stood out were: azotemia, decreased hematocrit, electrolyte imbalance, intake exceeds output, anxiety, edema, decreased hemoglobin, oliguria and blood pressure changes. Eight defining characteristics were presented statistically significant association with the nursing diagnosis investigated: pulmonary congestion, intake exceeds output, electrolytes imbalance, jugular vein distension, edema, weight gain over short period of time, agitation and adventitious breath sounds. Among these, the 10 characteristics which showed higher prevalence ratios were: edema and weight gain over short period of time. The features with the highest sensitivity were edema, electrolytes imbalance and intake exceeds output and the standing out with greater specificity were: anasarca, weight gain over short period of time, change in respiratory pattern, adventitious breath sounds, pulmonary congestion, agitation and jugular vein distension. The indicators jugular vein distension, electrolytes imbalance, intake exceeds output, increased central venous pressure and edema, together, were identified in the logistic regression model as the most significant predictors. It is concluded that the identification of accurate clinical indicators allow a good prediction of the nursing diagnosis of excessive fluid volume in patients undergoing hemodialysis in order to assist the nurse in the inference process, which will contribute to the success of patient care. In addition, nurses will consider for diagnostic inference not only his clinical experience, but also scientific evidence of the occurrence of excessive fluid volume, contributing to the control of volemia in these patients
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Empathy is a basic facilitating element of the therapeutic helping relationship and the humanization process in health care. The objectives of this study were to identify the empathy level of health professionals working in the obstetrical sector of a university hospital recognized for its humanistic care and the perceptions of the women under their care regarding the empathic behavior shown by these professionals during hospitalization. We conducted a quanti/qualitative study with 47 health professionals that worked in the obstetrical sector (13 obstetricians, 12 nurses, 22 nurse technicians) and an intentional sample of 101 women that received cared from these professionals during the study period. We collected data by means of the Jefferson Empathy Scale for Health Professioals (JEPS-HR) and the Patient´s Perception of Health Professional Empathy (PPHPE), and two additional open questions designed to obtain the subjective opinion about the empathic behavior during the care. We utilized thematic analysis for the data obtained through the open questions and descriptive and inferential statistics for the quantitative data. We identified five thematic categories that represent the aspects valued by the professionals in their relationship with the women under their care: emotional involvement, communication, warm environment, integral vision and technical/scientific knowledge. The mean score on the JEPS-HR reported for the health professionals was 120,40, being that the maximum possible was 140.The Cronbach Alpha for the JEPS-HR was 0,83, indicating an acceptable level of reliability for this population. We consider therefore, that these professionals presented an acceptable empathy level when compared to other populations observed with the JEPS-HR. The results also indicated that women had statistically significant (p ≤ 0,05) higher scores than men and that professionals with higher working hours tended to have lower scores in the empathy scale (r = -0,288; p ≤ 0,05). The analysis of the subjective responses of the women indicated that they were satisfied with the humanistic care provided by the professionals but they also point out the existence of some power relationships. There were no significant differences in the empathy level of the medical or nursing team perceived by the women who registered means of 41,90 and 41,20 respectively on the PPHPE. In view of these results and considering the relevance of the element of empathy for care based on humanistic values, we reiterate the importance of further in-service training for the health team of the hospital in focus, on the topics of empathy and global aspects of humanized care for the implementation of its mission
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This work focuses on the relationship between organizational culture and quality culture in the hotel sector of NATAL/RN with respect to employee performance. The themes organizational culture and quality have been the research focus of administration theorists and a constant concern of professional managers, since the Japanese demonstrated effective forms or western management. In this study, the Competing Values Model (C.V.M.) (Quinn e Cameron, 1996; Quinn, 1998; Santos, 1998, 2000; Teixeira, 2001), which was tested on north-American organizations and considered a high value academic and professional instrument, was applied. The model maps the organizational culture on a profile with four elements: clan, adhocracy, market and hierarchy. The C.V.M., associated with the taximetrics created by Cameron (which classifies quality culture in for levels: status quo, error detection, error prevention and perpetual creative quality) has been related with organizational performance. In this study, these two models are used jointly and tested in the hotel sector. The results indicate that the strongest element of the profile is clan, which is characterized by internal focus, participation and people involvement, followed by the adhocracy element, which has an external focus, emphasizes flexibility and is characterized by dynamic enterprising and creativity. Regarding the level of the culture s quality in the hotel, the highest level, that of perpetual improvement and creativity, which attempts to enchant and to surprise the clients, was most frequently cited, followed by the error detection level, which has as its goal to discover and correct mistakes, trying, consequently, to reduce waste. The results suggest that employee performance as measured on some indicators is related to elements of the organizational culture profile and quality level
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Genomewide marker information can improve the reliability of breeding value predictions for young selection candidates in genomic selection. However, the cost of genotyping limits its use to elite animals, and how such selective genotyping affects predictive ability of genomic selection models is an open question. We performed a simulation study to evaluate the quality of breeding value predictions for selection candidates based on different selective genotyping strategies in a population undergoing selection. The genome consisted of 10 chromosomes of 100 cM each. After 5,000 generations of random mating with a population size of 100 (50 males and 50 females), generation G(0) (reference population) was produced via a full factorial mating between the 50 males and 50 females from generation 5,000. Different levels of selection intensities (animals with the largest yield deviation value) in G(0) or random sampling (no selection) were used to produce offspring of G(0) generation (G(1)). Five genotyping strategies were used to choose 500 animals in G(0) to be genotyped: 1) Random: randomly selected animals, 2) Top: animals with largest yield deviation values, 3) Bottom: animals with lowest yield deviations values, 4) Extreme: animals with the 250 largest and the 250 lowest yield deviations values, and 5) Less Related: less genetically related animals. The number of individuals in G(0) and G(1) was fixed at 2,500 each, and different levels of heritability were considered (0.10, 0.25, and 0.50). Additionally, all 5 selective genotyping strategies (Random, Top, Bottom, Extreme, and Less Related) were applied to an indicator trait in generation G(0), and the results were evaluated for the target trait in generation G(1), with the genetic correlation between the 2 traits set to 0.50. The 5 genotyping strategies applied to individuals in G(0) (reference population) were compared in terms of their ability to predict the genetic values of the animals in G(1) (selection candidates). Lower correlations between genomic-based estimates of breeding values (GEBV) and true breeding values (TBV) were obtained when using the Bottom strategy. For Random, Extreme, and Less Related strategies, the correlation between GEBV and TBV became slightly larger as selection intensity decreased and was largest when no selection occurred. These 3 strategies were better than the Top approach. In addition, the Extreme, Random, and Less Related strategies had smaller predictive mean squared errors (PMSE) followed by the Top and Bottom methods. Overall, the Extreme genotyping strategy led to the best predictive ability of breeding values, indicating that animals with extreme yield deviations values in a reference population are the most informative when training genomic selection models.
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Foram estimados os coeficientes de herdabilidade e a mudança genética para peso à desmama (PD), peso ao sobreano (PS), ganho de peso do nascimento à desmama (GND), ganho de peso da desmama ao sobreano (GDS), perímetro escrotal (PE) e idade ao primeiro parto (IPP) em animais da raça Nelore. Foram utilizados dados de 128.148 animais nascidos entre 1984 e 2006. Os componentes de variância foram estimados pelo método da máxima verossimilhança restrita, e os valores genéticos foram preditos por modelos mistos aplicando-se modelo animal bicaracterística, incluindo peso à desmama em todas as análises. As tendências genéticas foram estimadas pela regressão dos valores genéticos sobre o ano de nascimento dos animais. Os coeficientes de herdabilidade do efeito direto estimados foram de 0,23 (0,07) (PD); 0,24 (0,02) (PS); 0,21 (0,01) (GND); 0,23 (0,01) (GDS); 0,46 (0,02) (PE) e 0,15 (0,01) (IPP). As tendências genéticas diretas estimadas foram de 0,171 (0,01); 0,219 (0,02); 0,186 (0,03) e 0,224 (0,02) kg/ano para PD, PS, GND e GDS, respectivamente, o que representa incrementos de 0,10; 0,08; 0,13 e 0,22% nas médias das mesmas características ao ano, respectivamente. Para o PE e a IPP no período de 1984 a 1995, as tendências genéticas foram nulas, com valores de 0,011 (0,03) cm/ano e -0,003 (0,06) dias/ano, respectivamente. No segundo período considerado (1996 a 2006), as tendências genéticas para PE e IPP foram de 0,069 (0,01) cm/ano e -3,024 (0,04) dias/ano, respectivamente, indicando melhorias consideráveis em tais características. Esses valores sugerem que características produtivas e reprodutivas, quando utilizadas como critério de seleção, proporcionam progresso genético no rebanho, sendo indicadas para seleção de animais da raça Nelore.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Petroleum can be associated or not with natural gas, but in both cases water is always present in its formation. The presence of water causes several problems, such as the difficulty of removing the petroleum from the reservoir rock and the formation of waterin-oil and oil-in-water emulsions. The produced water causes environmental problems, which should be solved to reduce the effect of petroleum industry in the environment. The main objective of this work is to remove simultaneously from the produced water the dispersed petroleum and dissolved metals. The process is made possible through the use of anionic surfactants that with its hydrophilic heads interacts with ionized metals and with its lipophilic tails interacts with the oil. The studied metals were: calcium, magnesium, barium, and cadmium. The surfactants used in this research were derived from: soy oil, sunflower oil, coconut oil, and a soap obtained from a mixture of 5wt.% coconut oil and 95wt.% animal fat. It was used a sample of produced water from Terminal de São Sebastião, São Paulo. As the concentration of the studied metals in produced water presented values close to 300 mg/L, it was decided to use this concentration as reference for the development of this research. Molecular absorption and atomic absorption spectroscopy were used to determine petroleum and metals concentrations in the water sample, respectively. A constant pressure filtration system was used to promote the separation of solid and liquid phases. To represent the behavior of the studied systems it was developed an equilibrium model and a mathematical one. The obtained results showed that all used surfactants presented similar behavior with relation to metals extraction, being selected the surfactant derived from soy oil for this purpose. The values of the partition coefficients between the solid and liquid phases " D " for the studied metals varied from 0.2 to 1.1, while the coefficients for equilibrium model " K " varied from 0.0002 and 0.0009. The removal percentile for oil with all metals associated was near 100%, showing the efficiency of the process
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The generation of effluent from the finishing process in textile industry is a serious environmental problem and turned into an object of study in several scientific papers. Contamination with dyes and the presences of substances that are toxic to the environment characterize this difficult treatment effluent. Several processes have already been evaluated to remove and even degrade such pollutants are examples: coagulation-flocculation, biological treatment and advanced oxidative processes, but not yet sufficient to enable the recovery of dye or at least of the recovery agent. An alternative to this problem is the cloud point extraction that involves the application of nonionic surfactants at temperatures above the cloud point, making the water a weak solvent to the surfactant, providing the agglomeration of those molecules around the dyes molecules by affinity with the organic phase. After that, the formation of two phases occurred: the diluted one, poor in dye and surfactant, and the other one, coacervate, with higher concentrations of dye and surfactants than the other one. The later use of the coacervate as a dye and surfactant recycle shows the technical and economic viability of this process. In this paper, the cloud point extraction is used to remove the dye Reactive Blue from the water, using nonionic surfactant nonyl phenol with 9,5 etoxilations. The aim is to solubilize the dye molecules in surfactant, varying the concentration and temperature to study its effects. Evaluating the dye concentration in dilute phase after extraction, it is possible to analyze thermodynamic variables, build Langmuir isotherms, determine the behavior of the coacervate volume for a surfactant concentration and temperature, the distribution coefficient and the dye removal efficiency. The concentration of surfactant proved itself to be crucial to the success of the treatment. The results of removal efficiency reached values of 91,38%, 90,69%, 89,58%, 87,22% and 84,18% to temperatures of 65,0, 67,5, 70,0, 72,5 and 75,0°C, respectively, showing that the cloud point extraction is an efficient alternative for the treatment of wastewater containing Reactive Blue
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Naphthenic lubricating oils are used in transformers with the purpose of promoting electrical insulation and dissipating heat. The working temperature range of these oils typically lies between 60°C and 90°C and their useful life is 40 years in average. In that temperature range, the oils are decomposed during operation, whereby a small fraction of polar compounds are formed. The presence of these compounds may induce failure and loss of physical, chemical and electrical properties of the oil, thus impairing the transformer operation. By removing these contaminants, one allows the oxidized insulating oil to be reused without damaging the equipment. In view of this, an investigation on the use of surfactants and microemulsions as extracting agents, and modified diatomite as adsorbent, has been proprosed in this work aiming to remove polar substances detected in oxidized transformer oils. The extraction was carried out by a simple-contact technique at room temperature. The system under examination was stirred for about 10 minutes, after which it was allowed to settle at 25°C until complete phase separation. In another experimental approach, adsorption equilibrium data were obtained by using a batch system operating at temperatures of 60, 80 and 100°C. Analytical techniques involving determination of the Total Acidity Number (TAN) and infrared spectrophotometry have been employed when monitoring the decomposition and recovery processes of the oils. The acquired results indicated that the microemulsion extraction system comprising Triton® X114 as surfactant proved to be more effective in removing polar compounds, with a decrease in TAN index from 0.19 to 0.01 mg KOH/g, which is consistent with the limits established for new transformer oils (maximal TAN = 0.03 mg KOH/g). In the adsorption studies, the best adsorption capacity values were as high as 0.1606 meq.g/g during conventional adsoprtion procedures using natural bauxite, and as high as 0.016 meq.g/g for the system diatomite/Tensiofix® 8426. Comparatively in this case, a negative effect could be observed on the adsorption phenomenon due to microemulsion impregnation on the surface of the diatomite
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The main objective of this research was the development and characterization of conventional and modified cationic asphalt emulsions. The asphalt emulsions were developed by using the Petroleum Asphalt Cement (CAP 50-70) from Fazenda Belém (Petrobras -Aracati-Ce). The first step in this research was the development of the oil phase (asphalt + solvent) and the aqueous phase (water + emulsifying agent + acid + additives), separately. During the experiments for the obtaining of the conventional asphalt emulsion, the concentration of each constituent was evaluated. For the obtaining of the oil phase, kerosene was used as solvent at 15 and 20 wt.%. For the development of the aqueous phase, the emulsifying agent was used at 0.3 and 3.0 wt.%, whereas the acid and the additive were set at 0.3 wt.%. The percentage of asphalt in the asphalt emulsion was varied in 50, 55, and 60 wt.% and the heating temperature was set at 120 °C. The aqueous phase in the asphalt emulsion was varied from 16.4 to 34.1 wt.% and the heating temperature was set at 60 °C. After the obtaining of the oil and the aqueous phases, they were added at a colloidal mill, remaining under constant stirring and heating during 15 minutes. Each asphalt emulsion was evaluated considering: sieve analysis, Saybolt Furol viscosity, pH determination, settlement and storage stability, residue by evaporation, and penetration of residue. After the characterization of conventional emulsions, it was chosen the one that presented all properties in accordance with Brazilian specifications (DNER-EM 369/97). This emulsion was used for the development of all modified asphalt emulsions. Three polymeric industrial residues were used as modifier agents: one from a clothing button industry (cutouts of clothing buttons) and two from a footwear industry (cutouts of sandals and tennis shoes soles), all industries located at Rio Grande do Norte State (Brazil).The polymeric residues were added into the asphalt emulsion (1 to 6 wt.%) and the same characterization rehearsals were accomplished. After characterization, it were developed the cold-mix asphalts. It was used the Marshall mix design. For cold-mix asphalt using the conventional emulsion, it was used 5, 6 and 7 wt.% asphalt emulsion. The conventional mixtures presented stability values according Brazilian specification (DNER-369/97). For mixtures containing asphalt modified emulsions, it was observed that the best results were obtained with emulsions modified by button residue