Caracterização de propriedades resilientes de três britas graduadas utilizadas em pavimentos no sul do Brasil

Foram analisadas, na presente pesquisa, as características resilientes de um granito de Santa Catarina e de dois tipos de basaltos do Rio Grande do Sul, utilizados como base e sub-base em pavimentos na região sul do país. Os valores de Módulo de Resiliência foram obtidos em laboratório por ensaios triaxiais de carga repetida, com aplicação da norma americana de determinação do módulo de resiliência para materiais granulares (AASHTO TP46-94). Foi analisado seu comportamento resiliente através da variação da umidade de compactação e da variação do grau de compactação das amostras. A influência da umidade foi estudada variando-se a umidade de compactação em relação à umidade ótima relativa à energia modificada, num intervalo correspondente a 2% acima e abaixo da mesma. Apenas o granito foi ensaiado nas três umidades desejadas. Os dois tipos de basalto não foram ensaiados na umidade 2% acima da ótima, por apresentarem uma umidade ótima elevada, dificultando a moldagem. Outro fator estudado foi a influência da densidade no módulo de resiliência, onde o grau de compactação das amostras foi variado em 100%, 98%, 95% e 93%. Os resultados mostraram que a umidade exerce uma influência no módulo de resiliência, influência esta constatada nas amostras de granito. Para este material, o Módulo de Resiliência diminui com o aumento da umidade. Nos três materiais estudados, não foi obtida correlação entre o módulo de resiliência e o grau se compactação, de acordo com a variação considerada.

Os efeitos da auditoria independente (externa) sobre a manipulação da informação contábil por parte das OPS brasileiras

A presente pesquisa busca investigar se a auditoria externa (independente) minimiza a propensão à manipulação das informações contábeis - MIC (medidas pelas acumulações discricionárias correntes) por parte das operadoras de plano privado de assistência à saúde, no que tange às informações econômico-financeiras divulgadas à Agência Nacional de Saúde Suplementar. Após revisão bibliográfica sobre qualidade da informação contábil, auditoria e mercado de saúde suplementar, promoveu-se uma pesquisa empírica com informações prestadas à ANS pelas OPS relativas ao período de 2004 a 2006. Para verificar se há diferença significativa no nível de acumulações discricionárias correntes, medidas pelo modelo AWCA e Jones Modificado (1995), entre as informações auditadas (quarto trimestre de cada ano) e as informações nãoauditadas (três primeiros trimestres de cada ano) para as mesmas empresas foi aplicado o teste não-paramétrico de Mann-Whitney. Os resultados indicam que não existem diferenças estatísticas significativas na propensão à manipulação entre as informações contábeis auditadas e não-auditadas, pelo menos no que tange às informações de 2004 a 2006 prestadas pelas OPS à ANS. Adicionalmente, também foram testadas as influências do tipo de modalidade, porte da firma e situação apresentada do patrimônio líquido sobre as acumulações discricionárias correntes. Observou-se que essas três variáveis influenciam em maior ou menor grau na manipulação da informação contábil gerada pelas OPS à ANS. Neste contexto, as seguintes características sobre a maior propensão a MIC foram diagnosticadas: Cooperativa Odontológica e a Medicina de Grupo (Modalidade); Pequeno (Porte da Firma); e Passivo a Descoberto ou PL Próximo de Zero (Situação do Patrimônio Líquido). Ao passo que as características relacionadas à menor propensão de MIC foram: Cooperativa Médica e Filantropia (Modalidade); Médio e Grande (Porte da Firma); Patrimônio Líquido Favorável (Situação do Patrimônio Líquido).

O tratamento do medo de alturas

Neste artigo, mencionamos as estratégias terapêuticas que julgamos mais apropriadas ao tratamento do medo de alturas. Comparamos vários estudos que usaram várias técnicas e referimos a nossa experiência clínica e de investigação. Considerámos, igualmente, os novos tratamentos que usam ambientes de realidade virtual para o tratamento da acrofobia. Actualmente a realidade virtual (RV) é utilizada pelos governos, indústrias, academias e investigadores individuais, favorecendo uma multiplicidade de possíveis produtos e aplicações em diversas áreas. Estes sistemas têm igualmente inúmeras aplicações no campo da psicologia, por exemplo na avaliação e tratamento de desordens alimentares e diversas fobias, como medo de aranhas, medo de andar de avião e claustrofobia. Concluímos que, até o momento presente, a prática reforçada de Leitenberg (1976) é o tratamento mais bem estudado para a acrofobia. O objectivo principal deste tratamento de fobias é a diminuição do evitamento do estímulo ou situação temida; a moldagem de comportamentos de aproximação apropriados. O terapeuta providencia ao cliente uma exposição gradual ao alvo ameaçador e reforça melhorias sucessivas à habilidade do cliente para interagir com o estímulo alvo. A duração das exposições pode ser baseada numa duração de tempo ou num número de apresentações práticas.

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.

Estudo da adição de argila expandida na formulação de concretos leves

Lightweight concrete has been the subject of several studies towards the development of new building materials. Emphasis has been given on the particle size effect and nature of aggregates used as raw materials. The present study includes an analysis of the materials that make this kind of concrete, analyzes of mechanical properties such as compressive and tensile strength, in addition to assessments of the interface concrete aggregate/matrix interface, porosity and absorption profile of chloride ions in lightweight concrete based on expanded clay. The experiments were carried out by molding cylindrical samples 100 mm in diameter and 200 mm in height. The dosage experiments were performed without additives or with the addition of minerals: (T1) 1: 2.01: 1.10: 0.78 (T2) 1: 2.00: 1.32 : 0.62 - (T3) 1 :1.93 :1.54: 0.47 (cement : sand : expanded clay 0500 : expanded clay 1506).The water to cement ratio was set to 0.43. Expanded clay minerals with different average particle sizes were used, i.e., 9.5 mm/0500 and 19 mm/1506. The larger aggregate was coated by a glassy layer, yielding lower water absorption characteristics to the concrete. The results showed that the use of light expanded clay aggregates is a technically interesting solution to the production of lightweight concrete for construction applications

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

Caracterização Microestrutural e Tribocorrosiva de Sistemas Metalocerâmicos Odontológicos do Tipo Ni-Cr/Porcelana E Ni-Cr/Ti/Porcelana

The partial fixed prosthodontics restoration is used to rehabilitate form and function of partial or total compromised teeth, having to remain permanently joined to remainder tooth. The most useful material on prosthodontics is the feldspar porcelain, commercialized as aluminosilicate powders. Dental porcelains are presented with limited mechanical properties to rehabilitate extensive spaces. The association with Ni-Cr metallic systems (metal-ceramic system) allows that the metallic substructure compensates the fragile porcelain nature, preserving the thermal insulation and aesthetics desirable, as well as reducing the possibility of cracking during matication efforts. Cohesive flaws by low mechanical strength connect the metallic substructure to the oral environment, characterized by a electrolytic solution (saliva), by aggressive temperature, pH cyclic changes and mechanical requests. This process results on ionic liberation that could promote allergic or inflammatory responses, and/or clinical degradation of ceramometal system. The aim of this study was to evaluate the presence of an intermediate titanium layer on the microscopic fracture behavior of porcelains on ceramometal systems. Plasma deposition of titanium films result in regular passivating oxide layers which act as barriers to protect the metallic substrate against the hazardous effects of corrosive saliva. Tribocorrosion tests were performed to simulate the oral environment and mechanical stress, making it possible the early detection of crack formation and growth on metal-ceramic systems, which estimate the adherence between the compounds of this system. Plain samples consisting of dental feldspar porcelain deposited either onto metallic substrates or titanium films were fired and characterized by scanning electron microscopy. The result showed that the titanium film improved the adherence of the system compared to conventional metal-ceramic interfaces, thus holding crack propagation

Estudo da incorporação da cal em composições binárias de solo-cimento para produção de tijolos maciços

The use of binders in the soil for the production of solid bricks is an old construction technique that has been used by several civilizations over time. At the same time, the need for environmental preservation and the tendency of scarcity of natural resources make the construction invest in researching new concepts, methods and materials for building systems for the sustainability of their economic activities. Thus arises the need to obtain building materials with low power consumption, capable of reducing the growing housing shortage of rural and urban population. Currently, research has been conducted on this topic to better understand the cementitious and pozzolanic reactions that occur in the formation of the microstructure of the soil-cement when added to other materials such as, for example, lime, and the relationship between microstructure and formed interfaces with the physical, mechanical and chemical analysis in compounds made from these ternary compositions. In this context, this study aimed to analyze the results of the influence of the incorporation of lime to the soil-cement to form a ternary mixture to produce soil-cement bricks and mortar without structural purposes. From the inclusion of contents of 6 %, 8 %, 10% and 12% lime to the soil, and soil-cement mixes in amounts of 2 %, 3 %, 4 % and 5 % were shaped-bodies of -cylindrical specimens to determine the optimum moisture content and maximum dry apparent specific weight. Then they were cured, and subjected to the tests of compressive strength, absorption and durability modified. Compositions obtained the best results in the tests performed on the bodies-of-proof cylindrical served as a parameter for molding of solid bricks, which underwent the same experimental methodology previously cited. The raw materials used, as well as compositions in which the bricks were molded solid, were characterized by physical and chemical tests, X-ray diffraction and scanning electron microscopy. The results obtained in the study indicate that the compositions studied, that showed the best results in terms of compressive strength, water absorption and durability ternary composition was soil, 10 % cement and 2 % lime

Processamento e caracterização de compósitos Poli(METACRILATO DE METILA)/Sílica (PMMA/SiO2)

Currently the search for new materials with properties suitable for specific applications has increased the number of researches that aim to address market needs. The poly (methyl methacrylate) (PMMA) is one of the most important polymers of the family of polyacrylates and polymethacrylates, especially for its unique optical properties and weathering resistance, and exceptional hardness and gloss. The development of polymer composites by the addition of inorganic fillers to the PMMA matrix increases the potential use of this polymer in various fields of application. The most commonly used inorganic fillers are particles of silica (SiO2), modified clays, graphite and carbon nanotubes. The main objective of this work is the development of PMMA/SiO2 composites at different concentrations of SiO2, for new applications as engineering plastics. The composites were produced by extrusion of tubular film, and obtained via solution for application to commercial PMMA plates, and also by injection molding, for improved the abrasion and scratch resistance of PMMA without compromising transparency. The effects of the addition of silica particles in the polymer matrix properties were evaluated by the maximum tensile strength, hardness, abrasion and scratch resistance, in addition to preliminary characterization by torque rheometry and melt flow rate. The results indicated that it is possible to use silica particles in a PMMA matrix, and a higher silica concentration produced an increase of the abrasion and scratch resistance, hardness, and reduced tensile strength

Novos monômeros obtidos a partir do metacrilato de glicidila, bisfenol A e 4, 4 isopropilidenodicicloexanol : síntese, caracterização estrutural e propriedades de compósitos para utilização em resinas de restauração dental

Nowadays, composite resins are the direct restorative materials more important in dental clinical performance, due to their versatility and aesthetic excellence. Bis-GMA (2,2-bis[4(2-hydroxy-3-metacryloxypropoxy)phenil]propane) is the base monomer more frequently used in restorative composite resins. However, this monomer presents some disadvantages, such as high viscosity and two aromatic rings in its structure that can promote allergic reactions to the humans. In this work, the main purpose was to synthesize new monomers from glycidyl methacrylate to use in dental restorative materials. Structural characterization of the monomers was carried out through FTIR and NMR 1H, and eight composites were produced from the new monomers, by addition of silane-treated alumino silicate particles (inorganic filler) and a photocuring system (camphorquinone and ethyl 4-dimethylaminebenzoate). The composites were analyzed by environmental scanning electronic microscopy and the water sorption and solubility, compressive strength and elastic modulus were determined. A commercial composite resin [Z100 (3M)] was used to comparison effect. The new composites presented general characteristics similar to the commercial ones; however, they didn t present the properties expected. This behavior was attributed to the lower degree of monomer reaction and to the granulometry and size distribution of the mineral filler in the polymeric matrix

Sinterização de matrizes cerâmicas à base de alumina reforçadas por carbetos a partir de precursores poliméricos

Ceramic composites produced with polymerics precursors have been studied for many years, due to the facility of obtaining a complex shape, at low temperature and reduces cost. The main objective of this work is to study the process of sintering of composites of ceramic base consisting of Al2O3 and silicates, reinforced for NbC, through the technique of processing AFCOP, as well as the influence of the addition of LZSA, ICZ and Al as materials infiltration in the physical and mechanical properties of the ceramic composite. Were produced ceramic matrix composites based SiCxOy e Al2O3 reinforced with NbC, by hidrosilylation reaction between D4Vi and D1107 mixtured with Al2O3 as inert filler, Nb and Al as reactive filler. The specimens produced were pyrolised at 1200, 1250 and 1400°C and infiltred with Al, ICZ and LZSA, respectively. Density, porosity, flexural mechanical strength and fracture surface by scanning electron microscopy were evaluated. The microstructure of the composites was investigated by X-ray diffraction to identify the presence of crystalline phases. The composites presented apparent porosity varying of 31 up to 49% and mechanical flexural strength of 14 up to 34 MPa. The infiltration process improviment of the densification and reduction of the porosity, as well as increased the values of mechanical flexural strength. The obtained phases had been identified as being Al3Nb, NbSi2, Nb5S3, Nb3Si and NbC. The samples that were submitted the infiltration process presented a layer next surface with reduced pores number in relation to the total volume

Acesso aos serviços odontológicos e incidência de cárie em adolescentes e fatores de risco em município do Nordeste Brasileiro, 2006

The aims of this study were to analyze the access of dental services by child population, to determine the prevalence of dental caries, gingivitis and malocclusion in resident children from the municipal district of Sobral Ceará and to evaluate the incidence of the dental decay in adolescents associated with the factors related to socioeconomic condition, access to health services and self-perception. This study had as main factor the multidisciplinary represented by the participation of health professional (doctors, dentists, nurses) in the development of the survey's initial reference; student from Human Sciences area to apply the structured questionnaire in domiciliary visits; statistics professionals in the orientation of the analysis to be held and family health team (community health agents, dentists and dental clinic assistants) in the scheduling of domiciliary visits and the accomplishment of oral exam. The sample was determined from the domicile record that included children born between 1990 and 1994 to develop the research Children health conditions in the municipal district of Sobral Ceará . The first sample comprised 3425 parents of children from 5 to 9 years old, living in the urban area at the municipal district of Sobral Ceará, aiming at identifying the most important factors associated to the access to dental service. From this sample, 1021 children were selected in a systematic way, for the accomplishment to the epidemiological study of decay, gingivitis and malocclusion. In the study's third phase, in order to arrange the group to be followed, 688 adolescents were examined and interviewed, by means of the active search from the 1021 individuals that had been previously examined. It was observed that 50.9% of the children had access to dental service at least once in a lifetime. Of this total, 65.3% accomplished it during the last year, and 85.4% of these did in public services, what allows to identify the importance of this sector in the access to dental services. It was observed that the factors that most affected the access to dental 129 services were related to socioeconomic condition, such as the access to health plan, the possession of toothbrush, garbage collecting, mother s schooling, sewerage treatment and malnutrition. In relation to oral diseases, an increase in the DMF-T index according the age was observed, from 0.10 in five years old to 1.66 in the nine years old, while with the dmf-t index, the inverse happened, since the index decreased from 3.59 in five years old to 2.69 in nine years old. In relation to gingivitis, an average 32.7% of the children presented gum bleeding. In what concerns malocclusion, it was observed that 60.3% of the children didn't present any problem, 30.17% had light malocclusion and 9.5% severe malocclusion. The average incidence of dental caries was 1.86 teeth per youngster. Among the studied variables, tooth pain in the last six months, mother's income and school snack, adjusted by the perception about the need of treatment, the mother's schooling and the dentist's appointment at least once in a lifetime, were the variables that presented positive relationship with the high incidence of dental caries on this population by logistic regression. Variables of socioeconomic nature, related to the access to health services and behavior and biological variables presented a relationship with the high caries incidence. The study point out to the need of developing health actions in a humanized way, by an oral health team effectively bound to the population's interest, with the great objective to provide, with the public health services managers, adequate conditions to improve oral health

Avaliação in vitro da atividade antimicrobiana de diferentes soluções a base de hidróxido de cálcio

The science of Dentistry wishes obtains the ideal solution for the dental plaque chemical control. This research evaluated antimicrobial action capacity in calcium hydroxide and tergentol various solutions starting for the CHD 20, a root canals irrigating solution with a reason of 80% calcium hydroxide saturated solution and 20% tergentol detergent with the aim of evaluate this drug mouth rinse indication with prevention or combat objective for dental caries and periodontal diseases. Antibiogram disks and biofilm tests were accomplished for the microorganisms: Streptococcus mutans, Streptococcus sanguis, Streptococcus sobrinus and Lactobacillus casei. Different reasons of detergent for the calcium hydroxide saturated solution, tergentol and distillated water solution, 0,12% clorhexydine digluconate solution was positive control and distillated water was negative control. The results showed better performance of clorhexydine in relation to calcium hydroxide directing to not accept this (CHD20) as mouth rinse solution

Determinação da idade dental de crianças brasileiras nordestinas: novos valores de conversão de maturidade dental para população específica

Since Demirjian's system of estimating dental maturity was first described, many researchers from different countries have tested its accuracy among diverse populations. Some of these studies have pointed out a need to determine population-specific standards. In Brazil, the Northeast region is the one that most suffers the negative impact of exodus, specially related to the increase of abandoned children in the cities. The aim of this study was to test the accuracy of Demirjian's system for assessing the dental maturity of northeastern Brazilian children, so as to present a scale for maturity score conversion into dental age developed specifically for this population. This could be used for forensic, anthropological and legal matters, and also as a model for other countries attempting to formulate their own conversion scales. Panoramic radiographs of 1,491 children (821 females and 670 males), aged 7 to 13 years, from Ceará state, northeast Brazil, were assessed by a single observer to determine dental age (DA) according to Demirjian's system. The mean percentage of intra-observer agreement was 86.6%, with a mean Cohen's Kappa coefficient of 0.67 (substantial agreement). The DA was compared by paired t-test to subjects' chronological age (CA). The differences between CA and DA in all age groups were statistically significant (p<0.0001), demonstrating a great advancement in DA among Brazilians. Scatter plots were drawn for both genders, and the data were fitted to a growth curve, y = 100/ (1 + e-a(x b)). Graphs corresponding to the 50th percentile curves were produced. A table with new values for the conversion of maturity score into dental age for northeastern Brazilian children is presented. The great advancement in DA, as obtained by Demirjian's system in this population, justified the determination of specific scores for dental maturity assessment