Elaboração e avaliação de indicadores comportamentais de aderência ao tratamento hemodialítico

Introduction: This work intents to characterize behavioral indicators of tack to the hemodialysis treatment in a sample of carrying patients of chronic kidney failure (CKF) in the great Natal/RN. The therapeutical adherence represents the agreement degree between the patient behavior and the health team lapsings. The CKF is the gradual and irreversible loss of the renal function, being the hemodialysis treatment an important alternative to assist or to substitute the kidneys. Method: The sample consisted in 80 chronic kidney patients in hemodialysis treatment in two located clinical centers in the region of the great Natal, RN. It was used as instruments (a) a protocol of clinical data collection, (b) the Millon Index of Personality Styles (MIPS) and (c) a script of halfstructuralized interview. Results: The results show a balance between the genders (51% of female and 48.8% of the male sex), average age and equal average time of dialysis respectively to the 43,4 years (±13,25 years) and 22,04 years (±4,24 years). The marital status of half of the sample is married, predominating basic education (43.6%) and a familiar income until a minimum wage (43.8%). It had been defined six physicianlaboratorial indicators to evaluate the therapeutical adherence, further the use of the evaluation of the health team and the patient themselves. Thus, there was an average adherence around 55.97% of the sample ±18.37%). However only between selfassessment of the patients about the adherence and the assessment made by blood pressure post-dialysis indicated a significant association (p=0,029, qui-square test). On the other hand, there was a significant association (p <0.05, chi-square test) among the criteria for treatment adherence and issues investigated in the interview - the perception on the quality of the health services provided to patients, the difficulties following the prescribed diet, the characterization of the days between dialysis sessions and the perception of patients about the dialysis sessions. It was also noted a significant association (p <0.05, Levene test) between adherence to therapy and scales that constitute the MIPS. The health team characterized the patients more adherent behavior as an attitude of acceptance of the treatment, looking actively for their implementation, for more information and knowledge, and establishing a positive communication with the team and with other patients. Similar results were confirmed by the MIPS evaluation. According to that assessment the more compliant patients adopt a more optimistic attitude, trying to act or adapt themselves to their environment, processing cognitively both concrete and objective information, such as more speculative and symbolic information. In addition they establish a gregarious, cooperative, submissive and flexibly pattern of interpersonal relationships to social demands. These characteristics managed to explain 55.7% of the adherence variation according the health team and 23.3% of the variation according the CaxP laboratory indicator. Conclusions: The MIPS shown to be able to identify the most and least adherent to therapy patients. The use of different adherence indicators is important for an evaluation covering the different facets of this process. The adhesion levels are observed within registered by the relevant literature. There is need for further studies with a larger sample to deepen the data findings in this work

Publicação e avaliação de periódicos científicos: paradoxos da classificação Qualis em Psicologia

Recently, Brazilian scientific production has increased greatly, due to demands for productivity from scientific agencies. However, this high increases requires a more qualified production, since it s essential that publications are relevant and original. In the psychological field, the assessment scientific journals of the CAPES/ANPEPP Commission had a strong effect on the scientific community and raised questions about the chosen evaluation method. Considering this impact, the aim of this research is a meta-analysis on the assessment of Psychological journals by CAPES to update the Qualis database. For this research, Psychology scientific editors (38 questionnaires were applied by e-mail) were consulted, also 5 librarians who work with scientific journals assessment (semi-structured interviews) and 8 members who acted as referees in the CAPES/ANPEPP Commission (open questions were sent by e-mail). The results are shown through 3 analysis: general evaluation of the Qualis process (including the Assessment Committee constitution), evaluation criteria used in the process and the effect of the evaluation on the scientific community (changes on the editing scene included). Some important points emerged: disagreement among different actors about the suitability of this evaluation model; the recognition of the improvement of scientific journals, mainly toward normalization and diffusion; the verification that the model does not point the quality of the journal, i.e., the content of the scientific articles published in the journal; the disagreement with the criteria used, seemed necessary and useful but needed to be discussed and cleared between the scientific community. Despite these points, the scientific journals evaluation still is the main method to assure quality for Psychology publications

Critérios comportamentais utilizados por técnicos na avaliação do desempenho esportivo de futebolista das categorias de base

Currently one of the major concerns in sports is to identify, select, discover and reveal talents in soccer. As principal reasons is perceived the search direct or indirect for resources for players, clubs, media, sports brands and their sponsors. However, high salaries are an exception and not a rule, because the majority of professional players in Brazil receives 1 minimum salary per month. It is also known that on professional clubs, daily, arriving several players to try to be a professional soccer player, however, the majority of clubs - almost all does not present methodological, systematic and analytical aspects to select promising players. The selective processes ("sieves" or "big sieves") developed by technical observers ( olheiros") summarized in the observation of the sportive performance of a big group of players in a period of few minutes given to each player. In this period the target behavior is the ability with the ball. If promising players are identified on that selection, they are referred to the club for a new observation, which will be conducted by the responsible coach of base category in question. It is understood by base categories, the amateur categories (not professional), to serve as a "base" for the formation of the cast of professional clubs. What are sub-13 (under 13 years), sub-15 (under 15 years), sub-17 (under 17 years) and sub-20 (under 20 years). The absence of common criterias and performance indicators of these professionals may hamper the evaluation of promising players, and be a costly activity for the club. This study proposes to identify, characterize and categorize the criterias and methods of behavioral evaluation, used by coaches of base categories of Rio Grande do Norte (RN) to evaluate the sportive performance of young soccer players, with the purpose of to compare the criterias of evaluation of sportive performance of young soccer players, used by coaches with different time of experience in function. The proposal had 2 pilot studies, the first (June and July, 2007) were interviewed 29 coaches, 17 of category sub-13 and 12 of category sub-17. The data were tabulated and organized into spreadsheets in order to describe, and developed a set of descriptors of behavior. And the second (May and June, 2008), with revisions made based on observations, analysis and descriptions found in the first, were interviewed 14 technical of category sub-15. After the results found in pilots, it was possible to outline the study in question, which had 46 coaches base categories of the RN. And from the results show that the characteristic of greatest importance, according to the interviewees was the behavior, the 2nd most important characteristic considered was the motivation, the 3rd was the ability and the 4th was the physical condition and the last was the affiliation. And by analyzing the results to the methods of evaluation of sportive performance used by coaches, it was noted clearly that most uses only the observation to select young soccer players. Therefore, needs a systematization to the selection of soccer players, since there is complexity in the verification of characteristics and aspects involved with purpose to avoid wrong evaluations and selections and the results negligible

Aplicabilidade do Rorshach na avaliação psicológica do autismo

This study investigates the applicability of the Rorschach Method for evaluating the personality of people with Autism Spectrum Disorder (ASD).The relevance of this study is justified by the limited number of investigations published in the research literature concerning the use of psychological tests used for evaluating the personality of individuals with ASD. The Rorschach Method was chosen as an appropriate instrument considering it reveals the personality s basic structure, including characteristics of the affectivity, sensuality, inner life, mental resources, psychic energy and general characteristics and intellectual state of the individual. The general objective of this investigation consisted of verifying the applicability of the use the Rorschach Method in the evaluation of the characteristics of people's personality with autism spectrum disorder (ASD).The study also sought to identify perceptive factors of the personality structure of individuals with ASD, provide contributions of the understanding of this syndrome, seeking the establishment of possible therapeutic interventions starting from diagnostic by Rorschach Method. In addition, this investigation aims at verifying the adequacy of using the Rorschach Method as an instrument for evaluating the personality characteristics of individuals with ASD and its possible use in Brazil, starting from preliminary normative results. Participants consisted of 44 youngsters and adults, both genders with age range 14 - 39 years-old (average: 23.5 years-old) distributed in 2 groups. Group 1: composed with 22 youngsters and adults with clinical diagnosis of autism spectrum disorder (communication impairments, social interaction deficits, restricted and repetitive interests and activities); Group 2: composed with 22 youngsters and adults with typical behavior. The participants were paired to gender and age, individually. The Mann-Whitney and Wilcoxon tests were applied to evaluate statistical differences between the groups, considering demographic and social data. The results indicate the presence of restricted interest or difficulty in the expression of the social and affective interaction of people with ASD. However, the need of broader normative studies concerning the use of personality evaluation instruments for people with ASD is warranted. These investigations could help understand the psychic dynamism of this population, offering subsidies that can be added to the current techniques of diagnosis. The Rorschach Method is susceptible to application but it is necessary to respect the individual limitations of these people and to establish more criterions about the spectrum

Mães de neonatos pré-termo hospitalizados: avaliação do apoio social e da sintomatologia ansiogênica

Social support is an important factor throughout one s life, especially in times of crisis. Premature delivery can be considered a crisis, followed by neonatal hospitalization. This type of birth is associated with elevated anxiety, representing risks to maternal mental health and mother-infant relationship. This research aims to investigate whether a relationship exists between perceived social support and the expression of anxiety in mothers of premature, hospitalized newborns. This is a cross-sectional, correlational study, conducted during the period of April to October 2011, using a convenience sample. The sample consisted of seventy mothers with preterm, hospitalized newborns and seventy mothers of full-term newborns. The instruments used were the State-Trait Anxiety Inventory and the Social Support Scale. The results demonstrated a weak negative relationship between intensity-State Anxiety and emotional support as well as a negative relationship in intensity between low to moderate-Trait Anxiety, social support and its dimensions (material support, emotional, information, interaction positive social and emotional). These suggest that the better the perception of social support, the less severe anxiogenic symptoms will be, and the converse is also true. It is noteworthy, therefore, the importance of social support, as well as the importance of health professionals to be aware not only of the physical health of the newborn, but also the psychosocial aspects that pervade the context of preterm birth followed by hospitalization

Avaliação da relação entre qualidade de sono e uma intervenção com jogos para o desempenho de crianças e adolescentes

The sleep is an active brain process that allows the efficient realization of daily tasks. The changes on sleep patterns may influence the different cognitive processes performance. Many recent studies show the possibility of cognitive performance improvement, through the cognitive training with the use of computer games. The question is if these interventions may be influenced by the sleep quality. Thus, we evaluated the sleep quality effect about the efficacy of an intervention with computers games based on the working memory and attention for a cognitive performance training of elementary school students. The sample was constituted by 42 students with average age of 10,43 years old (SD=1,23), with 22 male participants and 20 female participants. We used to evaluate the sleep with the parents a sleep questionnaire, a sleep diary and the Sleep Behavior Questionnaire. In regard to intervention, the subjectives were distributed in an experimental and in a control group, both with 21 participants. In the first group occurred the intervention that consisted in the working memory and attention training with two cognitive tasks (Safari e Brain Workshop) during 30 daily minutes, for a 6 weeks period. In an equal period, the students from the control group should reproduce an artwork using drawing software. To evaluate the cognitive performance we applied before and after the intervention period the Wechsler Intelligence Scale for Children (WISC-III). The results showed that in both the groups the performance of the intelligence, working memory, attention and visuospatial skills was below of the mean. The cognitive processes evaluated after of intervention in the experimental group had a performance significantly higher in the Perceptual Reasoning Index (t = -6,24; p < 0,01) and in the Full Scale IQ (t = -5,09; p < 0,01) and Performance IQ (t = -6,52; p < 0,01), suggesting a improvement on the visuospatial skills, attention, working memory and processing speed. On the control group, the performance was significantly higher in the Coding subtest (t = -5,38; p< 0,01) and in the Perceptual Reasoning Index (t = -3,66; p = 0,01), suggesting a improvement on the visuospatial skills and attention. The mean obtained with the Sleep Behavior Questionnaire was 53,76 (SD=14,96) for an experimental group and 61,19 (SD=12,82) for a control group, indicating tendency for a bad sleep quality in that last one. Not only during the first days, but also in the last fifteen days of the intervention we verified in the two groups an adequate time to sleep, duration and regularity, in the weekdays and on the weekends. We didn t find significant differences between the two groups in none of the sleep variables. We verified statistically meaningful improvement on the performance of the experimental group with the intervention in the two games. We didn t verify significant correlations between the games performance index and in the sleep variables of the experimental group individuals. We verified significant correlations among the performance on the Brain Workshop and the Cubes subtest, the Perceptual Reasoning Index and the Scale Performance IQ, suggesting that the significant improvement of the visuospatial skills and of the attention was correlated with the performance in the Brain Workshop. Although the absence of correlations with the performance in the Safari, possibly it also has relieved in the improvement of the cognitive performance. The findings support the hypothesis that the computer games might be a satisfactory tool for the improvement of the performance in visuospatial skills and attention. This can be resulted of the insertion of visuospatial stimulations in the task, for example, graphical elements with thematic for children that increase the interest. The IQ below mean the individuals might have influenced the improvement absence on the cognitive processes like the working memory with games. Moreover, it wasn t verified a relation between the sleep quality and the intervention efficacy. It might have been influenced by the n of the sample. Future studies must focalize in the improvement of the effect of the interventions with games

Evidências de validade do Millon Behavioral Medicine Diagnostic (MBMD) na avaliação psicológica de candidatos à cirurgia bariátrica

the Millon Behavioral Medicine Diagnostic is an instrument, developed from a consensus among health professionals, to identify psychological factors that may compromise the conducting of medical treatment in order to allow a better adhesion. As it has been one of the most used tools to assess bariatric surgery, the objective of this research is to verify the evidence validity of Millon Behavioral Medicine Diagnostic (MBMD) for psychological assessment of candidates for bariatric surgery. Method: males and females volunteers, aged 18 to 70, grouped in 150 patients admitted for surgical procedures or suffering from chronic diseases (control group) and 426 patients candidates for bariatric surgery, contacted in person or by the internet. For the study in the face group were also administered Millon Index of Personality Styles (MIPS), the Millon Clinical Multiaxial Inventory-III (MCMI-III) and the General Health Questionnaire of Goldberg, just in bariatric surgery patients. Results: there are indicators of semantic adaptation of the instrument, with 27 factors in five areas of the instrument, all with satisfactory levels of validity. The reliabitity indicators were satisfactory in 18 of the 32 scales that comprise the MBMD, while relations with the other three instruments showed significant variations compared to the original indicators. The MBMD was sensitive to differences between groups about gender, age, education, marital status, body mass index, comorbidities and chronic disease patients and with or without obesity. The use of this instrument in the assessment of candidates for bariatric surgery presents indicators of validity in view the limitations as to the realiability of certain scales

Contribuições do Programa Institucional de Bolsas de Iniciação Científica (PIBIC) para a formação do aluno de psicologia

The undergraduate courses in Psychology have been historically pointed as defective in aspects related to the critical education and the integration between theory and practice. Hence, the scientific education has been considered a possibility to overcome those lacks. Therefore, this study has investigated the undergraduate education process of Psychology students with PIBIC (Portuguese acronym for Undergraduate Scientific Research Scholarships Institutional Program) scholarships from CNPq (Portuguese acronym Brazilian National Council of Scientific and Technological Development). The scholarship program has been a strategic tool for the undergraduate scientific research. Electronic questionnaires have been sent to all the PIBIC scholarship students of Psychology in Brazil (622; 104 have answered), containing questions about the program developed activities, tutoring and advising, PIBIC evaluation and other ones. The students scientific and academic production has also been investigated through their Lattes (CNPq s Platform in which researchers have their academic résumés). The major part of the participants (70%) has stated that the first motivation to be in the program had been their interest in the research or in the academic career. Furthermore, 60% of the scholarship students has worked as volunteers before receiving PIBIC scholarship. Among the students who have answered the research, 65,4% has reported they are tutored directly by their advisors, and 80% of them attends one or more than one advising meeting every fifteen days. It has been identified that the Psychology scholarship students do not participate in all the research activities and that the proximity with the advisor is related to the accomplishment of tasks which contributes with the student critical and reflexive education. Finally, less than 25% of the students has published scientific articles or book chapters during the scholarship, what XI demonstrates a possible exclusion of them in that phase of the process. In general, the scholarship students evaluate the program positively by revealing that it contributes with their professional and academic education. For those reasons, it is observed PIBIC s potential role for the undergraduate education in order to develop more critical psychologists able to propose innovations and contextualized practices. However, the results obtained in programs like the studied one denounce the disqualification of the provided undergraduate education for the major part of the university students, who do not have a PIBIC scholarship. As a result, it is emphasized that it there should be more investment for improving the quality of the undergraduate education itself and not only for programs which are available for few students

Avaliação das habilidades neurocognitivas em crianças e adolescentes sobreviventes da Leucemia Linfoide Aguda - LLA

The present study investigated the impact of the treatment modalities of Acute Lymphoblastic Leukemia on neurocognitive abilities of children and adolescents survivors, aged between 6 and 16 years of age, accompanied in pediatric oncology sectors of public health services in the cities of Campina Grande-PB and Natal-RN. The study included 52 children, 13 of these being children and adolescents diagnosed with leukemia and 39 healthy children matched in relation to the study group considering gender, age, school type and level of maternal education. Later the group of children with leukemia was subdivided into two subgroups depending on treatment modality which were submitted: Group 1A (only chemotherapy) and 1B (chemotherapy and radiotherapy). All participants were subjected to a battery of neuropsychological tests that investigated the following neurocognitive abilities: intellectual ability, memory system, attention, visuospatiality and visuoconstruction, processing speed and executive functions. Data were analyzed using descriptive and inferential measurements with the aid of the U test of Mann-Whitney and T test, considering the influence of the variables: sex, age at diagnosis, time since completion of treatment and level of schooling mothers, on the performance of children. Overall, it is concluded that the illness and the treatment of acute lymphoblastic leukemia significantly favors the emergence of cognitive deficits, particularly in terms of visuospatial skills, and executive skills visoconstrutivas. In turn, the treatment modality of radiotherapy is associated with the presence of more severe deficits, highlighting the significant impact on the speed of information processing. It is hoped that the results presented here will contribute to a better understanding of the nature and extent of neurocognitive effects arising ALL treatment

Tomada de decisão de Psicólogos em avaliação Psicologica

Psychological assessment is a procedure that is inserted in all areas of a psychologist s professional field of work. When starting any psychological intervention, it is necessary to carry an analysis of how individual operate in order to identify and define their demands to adequately meet them. It is important to study this practice because the choice of instruments, techniques and procedures to be employed influences the efficiency and effectiveness of the work and the image of the profession towards society in general, also impacting the scientific community. This study aimed to identify, in the subjects, the percentage of professionals in psychology who make use of the Psychological Assessment in the Northeastern region of Brazil; another objectives were to analyze the profile of these professionals in terms of gender, time after graduation, additional training in PA, the state of the country where he/she works; to check how psychologists do their planning when using PA as well as to identify which differences can be observed in terms of time from graduation and additional training in the process of planning the assessment different extents. The instrument used was an online questionnaire and the sample was by adhesion to the application. The attendance was of 159 professionals and most of them were females with a specialist degree. It was found that the majority of the professionals perform the planning of the PA, establishing a method and choosing the most appropriate strategies to be used. It was also verified that most of the subjects fulfill the steps of the whole process, and when planning the techniques of data collection, integrating database from different sources, reporting the results and returning the information, the professional demonstrates his/her goals to understand their demands and accomplish the decision making and/or proposed intervention for individuals assessed. It was found that the undergraduate degree may not have produced a more complete effect in the professional qualification and therefore, of the quality of the actions in PA, and that there is a need for training and continuing education

Participação de moradores no programa de coleta seletiva em três bairros de Natal/RN: explorando determinantes psico-socio-ambientais

The general purpose of the study was the analysis of residents' participation in the program of door-by-door collection of recyclable residuals in Natal, Rio Grande do Norte. Even though the conception of such program by municipal managers was basically aimed at providing job opportunities and income for the collectors, the main objective of the investigation was to verify whether residents' participation could be attributed to their environmental commitment. Data collection involved three municipal districts and was performed in three stages, with complementary methodological strategies (observation, questionnaire, and interview), and characterized by selfevaluation, by residents, and hetero-evaluation, by collectors. Social, demographic, situational/contextual, and dispositional data were identified to help in the analysis of residents' adherence to the program. Separating and delivering recyclable residuals was the most frequent type of residents' participation, which demonstrates their low level of appropriation of decisions related to the program, taking part on it as passive agents. Two forms of motivation towards participating in the program were found: environmental and social. Despite the first being more frequent, it was associated to lack of environmental awareness related to the process, which may very well imply a mere reproduction of pro-environmental discourse. Motivation towards social issues was strongly connected to philanthropic forms of help. Knowledge was revealed as na important predictor for participation, as well as social networks, formed by neighbors, relatives and friends. Despite the social emphasis in the design of the program, it is possible to conclude that some residents also perceive its environmental benefits, possibly as consequence of a knowledge originated outside the program. Initiatives of environmental education should be promoted in order to minimize the allegation of lack of knowledge as justification for non-participation. Similarly, actions to put together municipal management and population would be welcome, to promote joint decisions towards sustainable styles of life

Avaliação do comportamento termoanalítico e oxidativo do biodiesel de mamona

In this work biodiesel was gotten through the transesterification reaction using the oil of castor as source of triglycerides and using the methylic route for obtaining of esters. For the characterization of biodiesel and its mixtures with mineral diesel oil, physical chemical parameters and several analytical techniques had been used, as well as: gas chromatography (GC), nuclear magnetic resonance of proton (1H NMR), infrared spectroscopy (IR) and thermal analysis. The chromatography confirmed the complete reaction of esters in biodiesel presenting a 97,08% conversion. The 1H - NMR presented singlet in 3,6 ppm corresponding to the hydrogen of the group ester RCOO CH3. The infrared presented a strong band in 1741 cm-1 referring to stretching C=O of ester and an average band in 1175 cm-1 referring C O deformation. With the data of thermal analysis it was possible to observe the thermal and oxidative stability of the samples changing the atmospheres of synthetic air and nitrogen, where stages of the thermal decomposition had been verified and had been attributed to the volatilization and/or decomposition of the triacylglycerides. The thermal degradation of the samples was carried through 150 and 210°C during 1, 12, 24 and 48 hours and was observed change in the thermogravimetric profile, therefore an increase in the number of stages of the thermal decomposition also occurred indicating characteristic intermediate composites of polymerization, being this confirmed through the rheological study that presented brusque increase of viscosity. The kinetic study showed that the activation energy has the following order: biodiesel > mineral diesel oil > mixtures biodiesel/diesel

Síntese, caracterização e avaliação catalítica do silicoaluminofosfato SAPO-11 sulfatado

Due to environmental restrictions around the world, clean catalytic technology are of fundamental importance in the petrochemical industry and refineries. Creating the face of this a great interest in replacing the liquid acids for solid acids, so as molecular sieves have been extensively studied in reactions involving the acid catalysis to produce chemical substances with a high potential of quality. Being the activity of the catalysts involved in the reaction attributed to the acid character of them involved for the Lewis and Brönsted acid sites. Based on this context, this study aimed to prepare catalysts acids using a molecular sieve silicoalumino-phosphate (SAPO-11) synthesized in hidrotermical conditions and sulphated with sulphuric acid at different concentrations, using to it the method of controlled impregnating. The samples resulting from this process were characterized by x-ray difratometry (DRX), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TG-DTG) and determination of total acidity (by n-butilamin adsorption). The results show that the synthesis method used was efficient in the formation of AEL structure of SAPO-11 and when being incorporated the sulfate groups in this structure the acidity of the material was increased, pointing out that to very high concentrations of acid there is a trend of decrease the main peaks that form the structure. Finally they were tested catalytictly by the reaction model of conversion of m-xylene which showed favorable results of conversion for this catalyst, showing to be more selective of cracking products than isomerization, as expected, in order that for the o-xylene selectivity there was no positive change when to sulfate a sample of SAPO-11, while for light gases of C1-C4 this selectivity was remarkably observed

Avaliação termoanalítica da eficiência de antioxidantes na estabilidade oxidativa do biodiesel de mamona

The biodiesel is defined as the mono-alkyl ester derived from long-chain fatty acids, from renewable sources such as vegetable oils or animal fat, whose use is associated with the replacement of fossil fuels in diesel engine cycle. The biodiesel is susceptible to oxidation when exposed to air and this process of oxidation affects the quality of fuel, mainly due to long periods of storage. Because of this, the oxidation stability has been the focus of numerous researches since it directly affects the producers, distributors and users of fuel. One of the possibilities to increase the resistance of biodiesel is the autoxidation treatment with inhibitors of oxidation. The antioxidants can be used as potential inhibitors of the effects of oxidation on the kinematic viscosity and the index of acidity of biodiesel, thereby increasing oxidative stability. This work aims to examine the efficiency of antioxidants, α-tocopherol and butylated hydroxy-toluene (BHT), added the biodiesel content of remembrance through Pressurized-Differential Scanning Calorimetry (P-DSC), Thermogravimetry (TG) and Petrology. The results showed that the use of antioxidant BHT, at the concentration of 2000ppm, increased resistance to oxidation of the biodiesel and oxidative induction time (OIT), which is a better result as antioxidant than the α-tocopherol. With the thermogravimetric analysis, it was observed that the biodiesel presented an initial decomposition temperature of lower tendency than that of oil, demonstrating to be more volatile, bearing great similarity to the diesel and being characterized as an alternative fuel. The rheological analysis indicated that each sample of biodiesel behaved as a Newtonian fluid

Avaliação do comportamento de argila ativada na presença de água destilada, soluções salinas e inibidores de hidratação catiônicos

The clay swelling is today one of the major problems during the well drilling. Nearly 50% of clays that constitute shale expand easily in the presence of water molecules. During the drilling of a geological formation containing swelling clays, when is feasible the use of water base fluids, it is necessary to apply clay inhibitors. This avoids the incorporation of the cutting to the drilling fluid which is responsible for the wall swelling and crumbling. The aim of this work was to evaluate the synergistic behavior that occurs when swelling clay inhibitors are associated to NaCl and KCl salts. Three swelling clay inhibitors samples, INIB A, INIB B and INIB C, were analyzed. Each inhibitor was characterized by the amount of chlorides and active matter content. For the water-clay interaction evaluation in the presence of various fluids, it was used the Capillary Suction Timer (CST, Fann) and Linear Swell Meter (LSM 2000, Fann). For better interpretation of results, a Design of Experiments (DOE, Umetrics MODDE 7.0 TM) through Result Surface Methodology (RSM) was employed, taking into account the type, the swelling inhibitors concentration and the contact time with the clay. The results showed different efficiencies among the inhibitors employed, and the salt-inhibitors mixtures were more efficient than those products alone. However, for field operation, other parameters should be taking into account, as operational cost, environmental requests and time of application for each product