Avaliação das técnicas de soldagem MIG-P CA e MIG-P CC+ aplicadas ao passe de enchimento em liga de alumínio AA5083

For contain beneficial properties, aluminum alloys are gaining more importance in different industrial areas, becoming the subject of study in several academic fields. When related to welding these alloys have some peculiarities that may hinder the union, such as microscopic oxide layer present on the metal surface. The MIG welding process, also known as GMAW, has developed versions that can be effective for welding aluminum. Knowing this, for this paper, two versions of pulsed MIG (CC + and CA) were chosen to evaluate which best suits pass by filling bevel on AA5083 aluminum sheets with 8 and 12 mm thick respectively. Furthermore, two types of wire, ER5087 and ER5183 were evaluated. To evaluate the process and versions of the wires, the high-speed cameras and thermal were used to monitor the metal transfer and the thermal behavior respectively, and the metallographic analysis for macrographic view of the weld beads and non-destructive testing by radiography for observation of possible discontinuities. It was found that the technique of MIG-P CA showed better results ahead of another technique both welding conditions imposed. When connected to the wires, they showed similar results, with uniform cords and seamless

Densificação e microestrutura de um compósito Mo-Cu preparado a partir de um pó de heptamolibidato de amônia e cobre

The Cu-Mo system is a composite used in the electrical industry as material for electrical contact and resistance welding electrode as well as the heat sink and microwave absorber in microelectronic devices. The use of this material in such applications is due to the excellent properties of thermal and electrical conductivity and the possibility of adjustment of its coefficient of thermal expansion to meet those of materials used as substrates in the semiconductor micoreletrônic industry. Powder metallurgy through the processes of milling, pressing shaping and sintering is a viable technique for consolidation of such material. However, the mutual insolubility of both phases and the low wettability of liquid Cu on Mo impede its densification. However, the mutual insolubility of both phases and the low wettability of liquid Cu on Mo impede its densification. The mechanical alloying is a technique for preparation of powders used to produce nanocrystalline composite powder with amorphous phase or extended solid solution, which increases the sinterability immiscible systems such as the Mo-Cu. This paper investigates the influence of ammonium heptamolybdate (HMA) and the mechanical alloying in the preparation of a composite powder HMA-20% Cu and the effect of this preparation on densification and structure of MoCu composite produced. HMA and Cu powders in the proportion of 20% by weight of Cu were prepared by the techniques of mechanical mixing and mechanical alloying in a planetary mill. These were milled for 50 hours. To observe the evolution of the characteristics of the particles, powder samples were taken after 2, 10, 15, 20, 30 and 40 hours of milling. Cylindrical samples 5 to 8 mm in diameter and 3 to 4 mm thickness were obtained by pressing at 200 MPa to the mixed powders so as to ground. These samples were sintered at 1200 ° C for 60 minutes under an atmosphere of H2. To determine the effect of heating rate on the structure of the material during the decomposition and reduction of HMA, rates of 2, 5 and 10 ° C / min were used .. The post and the structures of the sintered samples were characterized by SEM and EDS. The density of the green and sintered bodies was measured using the geometric method (weight / volume). Vickers microhardness with a load of 1 N for 15 s were performed on sintered structures. The density of the sintered structures 10 ° C / min. reached 99% of theoretical density, how the density of sintered structures to 2 ° C / min. reached only 90% of the theoretical density

Padrão epidemiológico das oclusopatias muito graves em adolescentes brasileiros

OBJECTIVE: To describe the distribution of malocclusion and its associated factors in Brazilian adolescents. METHODS: Data from 7,328 subjects aged 12 years and 5,445 adolescents aged 15-19 years were analyzed. The adolescents took part in the Brazilian Oral Health Survey (SBBrasil 2010). The outcome was severe malocclusion according to the dental aesthetic index. The independent variables were sex, skin color, monthly household income, possessions, number of individuals in the household, untreated dental caries, missing teeth and dental appointments or lack thereof, frequency, and reason. Logistical regression analysis was carried out, considering the complex sampling cluster design, based on a hierarchical model. RESULTS: The prevalence of severe malocclusion was 6.5% and 9.1% in the 12-year-olds and the 15-19-year-olds, respectively. After adjustment, those with lighter- skinned black or black skin were 1.59 (95%CI 1.08;2.34) times more likely to present the outcome compared with those with white skin. The loss of one or more first molars increased 2.66 (95%CI 1.26;5.63) the chance to present severe malocclusion by the age of 12. Adolescents aged 15-19 whose household income was below R$ 1,500.00 (OR 2.69 [95%CI 1.62; 4.47]) and those who had seen a dentist for treatment (OR 2.59 [95%CI 2.55;4.34]) had the greatest chance of having severe malocclusion compared with those with higher incomes and those who visited the dentist for prevention.

Levantamentos epidemiológicos em saúde bucal: análise da metodologia proposta pela Organização Mundial da Saúde

Epidemiological surveys are important for obtaining information on the prevalence and etiology of mouth diseases, since the data collected permit health actions to be planned, performed, and assessed. Methodological uniformity is necessary, however, to maintain reproductibility, validity, and reliability, and to allow national and international comparisons. The initiative of the World Health Organization (WHO) as an advisor in ongoing surveys has been extremely useful, stimulating standardization in all countries. In 1991, a Portuguese version of the 1987 third edition of Oral Health Surveys - basic methods, an instruction manual for performing epidemiological surveys, was published and became a reference for many parts of Brazil and the World. The present analysis found conflicting points in relation to the sample size, calibration of the examiners, and criteria for evaluating oral health and treatment needs. In conclusion, due to the dynamic characteristics of scientific knowledge and, considering the regional differences in relation to the development of oral diseases, we recommend that proposals for standardizing surveys be checked periodically. Other important issues may have not been detected in this analysis, urging a thorough discussion within the dentistry community as a whole.

Levantamentos epidemiológicos em saúde bucal: análise da metodologia proposta pela Organização Mundial da Saúde

Epidemiological surveys are important for obtaining information on the prevalence and etiology of mouth diseases, since the data collected permit health actions to be planned, performed, and assessed. Methodological uniformity is necessary, however, to maintain reproductibility, validity, and reliability, and to allow national and international comparisons. The initiative of the World Health Organization (WHO) as an advisor in ongoing surveys has been extremely useful, stimulating standardization in all countries. In 1991, a Portuguese version of the 1987 third edition of Oral Health Surveys - basic methods, an instruction manual for performing epidemiological surveys, was published and became a reference for many parts of Brazil and the World. The present analysis found conflicting points in relation to the sample size, calibration of the examiners, and criteria for evaluating oral health and treatment needs. In conclusion, due to the dynamic characteristics of scientific knowledge and, considering the regional differences in relation to the development of oral diseases, we recommend that proposals for standardizing surveys be checked periodically. Other important issues may have not been detected in this analysis, urging a thorough discussion within the dentistry community as a whole.

Construção e validação do instrumento de investigação do conhecimento de gestantes sobre sua saúde bucal e a do seu bebê: perspectiva do cuidado em saúde

INTRODUCTION: Humanized and quality prenatal and post-partum care is critical to maternal and newborn health, as well as oral health care. Currently, the National Oral Health Policy is aiming at expanding dental care for pregnant women. Thus, the promotion of oral health and attention to prenatal care policies should be integrated; however, there is still limited participation of pregnant women. Thus, it is necessary to verify the knowledge of pregnant women related to oral health, seeking to estimate the quality of dental care provided during prenatal care, being essential for the Family Health strategy to organize personnel, plan costs and to ensure the quality standard of care. OBJECTIVE: To develop and validate a research instrument on the knowledge of pregnant women about their oral health and of their baby. METHOD: This is a construction and validation study with 93 pregnant women in Family Health Units and specialized private clinics in Obstetrics, in the city of Natal / RN. It was authorized by the Onofre Lopes University Hospital Ethics Committee of the Universidade Federal do Rio Grande do Norte (UFRN) under the registration number 421.163/13. The construction of the instrument followed steps so that it was valid, reliable and sensitive: creation and reduction of the items (drafting of the instrument), content validity and testing of the instrument, and hypotheses validation. Once constructed, the instrument was evaluated by experts who suggested modifications. There was consultation with the target population about the new version of the created instrument, which had the instrument validation verified by internal consistency through intra and inter-calibration and test-retest. Next, the hypotheses were validated. A database was built in the Statistical Package for Social Sciences (SPSS), version 22.0. After creating the hypotheses, an association was found for validating the criteria between each of the specific issues for each established criteria, considering a 5% significance level. Data analysis was carried out by describing the absolute and relative frequencies of the variables pertaining to issues relating to their pregnancy knowledge about their oral health and their baby. The Kappa coefficient was used for the calibration process (Inter and Intra-examiner calibration) and Cronbach's alpha coefficient was used to analyze instrument reproducibility (test-retest). In addition, the chi-square test was used to cross the dependent variable with the (dichotomized) independent variables. RESULTS: The intra and inter agreement analysis presented a Kappa coefficient between 0.400 and 1.000. Internal consistency through the analysis showed that 90% of the instrument's questions showed great reliability in the answers (Cronbach α ˃ 0.7). In the investigation of the relationship between the dependent variable (knowledge about oral health) and the independent variables (trimester of pregnancy, education, income and multiparous), it was found that none of these independent variables were significantly associated. All hypotheses had their Ho confirmed. CONCLUSION: The constructed instrument was validated, considering that it showed to be sensitive with good reliability and good accuracy, and therefore can be used to assess pregnant women’s knowledge about their oral health and the oral health of their baby.

Construção e validação do instrumento de investigação do conhecimento de gestantes sobre sua saúde bucal e a do seu bebê: perspectiva do cuidado em saúde

INTRODUCTION: Humanized and quality prenatal and post-partum care is critical to maternal and newborn health, as well as oral health care. Currently, the National Oral Health Policy is aiming at expanding dental care for pregnant women. Thus, the promotion of oral health and attention to prenatal care policies should be integrated; however, there is still limited participation of pregnant women. Thus, it is necessary to verify the knowledge of pregnant women related to oral health, seeking to estimate the quality of dental care provided during prenatal care, being essential for the Family Health strategy to organize personnel, plan costs and to ensure the quality standard of care. OBJECTIVE: To develop and validate a research instrument on the knowledge of pregnant women about their oral health and of their baby. METHOD: This is a construction and validation study with 93 pregnant women in Family Health Units and specialized private clinics in Obstetrics, in the city of Natal / RN. It was authorized by the Onofre Lopes University Hospital Ethics Committee of the Universidade Federal do Rio Grande do Norte (UFRN) under the registration number 421.163/13. The construction of the instrument followed steps so that it was valid, reliable and sensitive: creation and reduction of the items (drafting of the instrument), content validity and testing of the instrument, and hypotheses validation. Once constructed, the instrument was evaluated by experts who suggested modifications. There was consultation with the target population about the new version of the created instrument, which had the instrument validation verified by internal consistency through intra and inter-calibration and test-retest. Next, the hypotheses were validated. A database was built in the Statistical Package for Social Sciences (SPSS), version 22.0. After creating the hypotheses, an association was found for validating the criteria between each of the specific issues for each established criteria, considering a 5% significance level. Data analysis was carried out by describing the absolute and relative frequencies of the variables pertaining to issues relating to their pregnancy knowledge about their oral health and their baby. The Kappa coefficient was used for the calibration process (Inter and Intra-examiner calibration) and Cronbach's alpha coefficient was used to analyze instrument reproducibility (test-retest). In addition, the chi-square test was used to cross the dependent variable with the (dichotomized) independent variables. RESULTS: The intra and inter agreement analysis presented a Kappa coefficient between 0.400 and 1.000. Internal consistency through the analysis showed that 90% of the instrument's questions showed great reliability in the answers (Cronbach α ˃ 0.7). In the investigation of the relationship between the dependent variable (knowledge about oral health) and the independent variables (trimester of pregnancy, education, income and multiparous), it was found that none of these independent variables were significantly associated. All hypotheses had their Ho confirmed. CONCLUSION: The constructed instrument was validated, considering that it showed to be sensitive with good reliability and good accuracy, and therefore can be used to assess pregnant women’s knowledge about their oral health and the oral health of their baby.

Avaliação imunoistoquímica de CD34 e triptase em cistos odontogênicos radiculares e cistos dentígeros inflamados

Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq

Avaliação imunoistoquímica de CD34 e triptase em cistos odontogênicos radiculares e cistos dentígeros inflamados

Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq

Modificação do eletrodo AWS E7018 com adição de filmes finos externos de PVC e Al, para soldagem de aço C-Mn

This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.

Modificação do eletrodo AWS E7018 com adição de filmes finos externos de PVC e Al, para soldagem de aço C-Mn

This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.

Educação ambiental como estratégia para inserção da sustentabilidade na formação em odontologia

This thesis proposes environmental education as a strategy for the inclusion of sustainability in the academic education of higher level. The dentistry course has been the object of study, which is justified by the recognition of the need for reflection on environmental issues in the dental academia, initially based on professional experience of the author as a dental surgeon. The aim of this study is to investigate the scientific production of dentistry and its content related to environmental issues, in addition to expanding discussions and reflections on the need to insert environmental education as academic content. With the specific purpose of verifying the amount and analyze the content of scientific articles involving issues related to sustainability in dentistry, Chapter 01 presents research in leading journals portals available on the internet. Works were surveyed where sustainability and related issues were present and placed in a theoretical framework that analyzes the dental service inclusion in the dominant economic model. These procedures are intended to prove the hypothesis that the dental profession does not produce significant scientific content that relates the profession to the environment and sustainability. A literature review was conducted with the statement of dentistry changes from its origins to the front position to the dominant development model and exemplification of the deleterious effects of this model on the environment. In addition, there was a scientific research in journals portals available on the internet and investigated the amount and content of scientific articles involving issues related to sustainability in dentistry. Chapter 02 has the specific purpose of providing content to expand discussions and reflections on the need to insert environmental education in undergraduate courses in dentistry, such as insertion strategy into a new development model guided by sustainability. In this, students questionnaires were given the 8th dentistry course of the period the Federal University of Rio Grande do Norte (UFRN), to be understood environmental perception of learners and were obtained grants for proof of the thesis that environmental education applied dentistry has the potential to make people aware and willing to act practicing and propagating sustainability in their conduct. The overall results indicate little scientific production, as the research and work that relates to dentistry to sustainability and the issues related to the environment have not significantly been present in the syllabus of the undergraduate courses in dentistry, despite the interest shown by survey respondents When such issues are addressed. In this context, it is proposed fostering actions to environmental education, so that dental professionals are engaged in the construction of a new development model based on sustainability, as despite the environmental theme seems to be little explored in the academic and scientific world of dentistry, there interest from students and great potential multiplier for appropriate environmental behavior. After proving the hypothesis that the environment-related content are poorly explored in the academic and scientific world of dentistry, the main conclusions were recognizing the importance of environmental education as an interdisciplinary tool for environmental thematic approach in undergraduate courses dentistry, in addition to implementing this new pedagogical proposal in the professional practice of dentists, given their potential multiplier for environmental knowledge.

Impacto da Estratégia Saúde da Família com equipe de saúde bucal sobre a utilização de serviços odontológicos

PEREIRA, C. R. S. et al. Impacto da estratégia saúde da família com equipe de saúde bucal sobre a utilização de serviços odontológicos. Cad. Saúde Pública, v. 25, n. 5, p.985-996. Maio, 2009. ISSN 0102-311X.

Impacto da Estratégia Saúde da Família com equipe de saúde bucal sobre a utilização de serviços odontológicos

PEREIRA, Carmen Regina dos Santos et al. Impacto da Estratégia Saúde da Família com equipe de saúde bucal sobre a utilização de serviços odontológicos. Cadernos de Saúde Pública, Rio de Janeiro, v. 25, n. 5, p. 985-996, maio 2009.

Influência do número de refundições da liga Ni-Cr-Mo-Ti sobre as propriedades de próteses metalocerâmicas

A frequently encountered difficulty in oral prosthetics is associated with the loss of metallic alloys during the melting stage of the production of metal-ceramic replacement systems. Remelting such materials could impar their use in oral rehabilitation due to loss in esthetics, as well as in the chemical, physical, electrochemical and mechanical properties. Nowadays, the Ni-Cr-Mo-Ti alloy is widely used in metal-ceramic systems. Manufacturers state that this material can be remelted without significant alterations in its behavior, however little has been established as to the changes in the performance of this alloy after successive remelting, which is common practice in oral prosthetics. Therefore, the objective of this study was to evaluate possible changes in the esthetics and associated properties of metalceramic samples consisting of Ni-Cr-Mo-Ti and dental porcelain. Three to five remelting steps were carried out. The results revealed that Ni-Cr-Mo-Ti can be safely used even after three remelting steps. Further remelting significantly affect the characteristics of the alloys and should not be recommended for the manufacture of metal-ceramic systems