Abstract Structural adhesives are increasingly being used in the aerospace and automotive industries. They allow for light weight vehicles, fuel savings and reduced emissions. However, the environmental degradation of adhesive joints is a major setback in its wide implementation. Moisture degradation of adhesive joints includes plasticization, attacking of the interface, swelling of the adhesive and consequent creation of residual stresses. This may lead to reversible and irreversible damage. In this work double cantilever beam (DCB) specimens using two different adhesives for the automotive industry were subjected to two different ageing environments. They were tested periodically until the toughness of the adhesives stabilized, which means that they were fully degraded. An association was made between the toughness of the adhesive and the amount of water that it had absorbed. This way it was possible to indirectly measure the water uptake in an adhesive joint taking into account the water uptake properties of the adhesives studied, which had been determined in another study. It was found that diffusion of water into the studied adhesive joints was faster than diffusion through the bulk adhesive alone. A model that takes into account diffusion through the interface between the adhesive and the adherends was proposed.

Abstract The present work focuses on the effects of water degradation on the fatigue behaviour of adhesive joints bonded with aluminium adherends. The objective of this study is to measure the influence that humidity has on the fatigue crack growth velocity of two distinct adhesives characterized using the Paris Law, using double cantilever beam (DCB) specimens in unaged and various aged conditions loaded in mode I in order to understand the influence that water content has on the Paris Law constants. It was found that the slope of the Paris Law curve is not heavily changed with the presence of water, but a shift in the curves does occur, generally resulting in a crack initiating at a lower threshold than in the unaged adhesive. Based on this behaviour, it can be concluded that an increase in water content reduces the fatigue joint strength and lifespan of adhesive joints bonded with the studied adhesives.

O presente trabalho teve por objetivo verificar a ocorrência de demência senil em amostra de pessoas de 65 e mais anos de idade residentes no Município de Fortaleza. Foram testados 865 idosos, a partir do teste de Informação, Memória e Concentração, IMC (teste de Hachinski, modificado), que aborda aspectos concernentes à identificação da pessoa, à memória de fatos atuais e remotos e à concentração, determinando os estados demenciais em função do número e grau de respostas numa seqüência programada e previamente testada quanto à sensibilidade e especificidade. Analisando-se os resultados quanto a idade, sexo e condição social, evidenciou-se uma prevalência de 8,4% de demência senil no conjunto geral, com diferença não-significativa na faixa de 75 e mais anos de idade (9,3%), comparada ao grupo de 65 a 74 anos (7,5%). Os percentuais foram semelhantes para homens e mulheres: 8,7% e 8,3%, respectivamente. Quanto à condição social, foi verificado um aumento progressivo nas proporções de estados demenciais, desde 4,2% para o estrato A/B (abastados), 6,9% para o grupo C (nível intermediário) e 10,3% no nível D/E correspondente ao estrato de pessoas economicamente desprivilegiadas. Estes resultados, entretanto, deverão ser vistos com cena reserva, dado o grau de recusa por ocasião das entrevistas, especialmente nos estratros A/B (19,3%) e D/E (9,3%).

The objective of the present paper was to verify the occurrence of senile dementia in the city of Fortaleza, Brazil. A screening test, the Information, Memory and Concentration Test (IMC), was applied to 865 persons (65 years old and older). The Test includes questions on personal identification, recent and remote memory and concentration. Dementia was determined as a function of the total score obtained by the person in the test previously examined as far as sensitivity and specificity are concerned. The results were analysed according to age, sex and social strata. It was demonstrated a prevalence of dementia of 8.4% in the sample studied with no significant difference in the proportions of cases among people 75 years old or older (9.3%) as compared to the group younger, 65 to 74 years old, (7.5%). The percentage of dementia was similar between men (8.7%) and women (8.3%). It was verified a progressive increase in the frequence of dementia ranging from 5.2% for the higher social classes (A/B) to 6.9% and 10.3% for medium (C) and lower (D/E) ones respectively, with a significant difference between the social classes A/B and D/E. These results, however, should be seen with caution because of the percentage of refuse especially in the higher, A/B (19.3%) and lower D/E (9.3%) social classes.

O presente trabalho teve por objetivo verificar a ocorrência de demência senil em amostra de pessoas de 65 e mais anos de idade residentes no Município de Fortaleza. Foram testados 865 idosos, a partir do teste de Informação, Memória e Concentração, IMC (teste de Hachinski, modificado), que aborda aspectos concernentes à identificação da pessoa, à memória de fatos atuais e remotos e à concentração, determinando os estados demenciais em função do número e grau de respostas numa seqüência programada e previamente testada quanto à sensibilidade e especificidade. Analisando-se os resultados quanto a idade, sexo e condição social, evidenciou-se uma prevalência de 8,4% de demência senil no conjunto geral, com diferença não-significativa na faixa de 75 e mais anos de idade (9,3%), comparada ao grupo de 65 a 74 anos (7,5%). Os percentuais foram semelhantes para homens e mulheres: 8,7% e 8,3%, respectivamente. Quanto à condição social, foi verificado um aumento progressivo nas proporções de estados demenciais, desde 4,2% para o estrato A/B (abastados), 6,9% para o grupo C (nível intermediário) e 10,3% no nível D/E correspondente ao estrato de pessoas economicamente desprivilegiadas. Estes resultados, entretanto, deverão ser vistos com cena reserva, dado o grau de recusa por ocasião das entrevistas, especialmente nos estratros A/B (19,3%) e D/E (9,3%).

The objective of the present paper was to verify the occurrence of senile dementia in the city of Fortaleza, Brazil. A screening test, the Information, Memory and Concentration Test (IMC), was applied to 865 persons (65 years old and older). The Test includes questions on personal identification, recent and remote memory and concentration. Dementia was determined as a function of the total score obtained by the person in the test previously examined as far as sensitivity and specificity are concerned. The results were analysed according to age, sex and social strata. It was demonstrated a prevalence of dementia of 8.4% in the sample studied with no significant difference in the proportions of cases among people 75 years old or older (9.3%) as compared to the group younger, 65 to 74 years old, (7.5%). The percentage of dementia was similar between men (8.7%) and women (8.3%). It was verified a progressive increase in the frequence of dementia ranging from 5.2% for the higher social classes (A/B) to 6.9% and 10.3% for medium (C) and lower (D/E) ones respectively, with a significant difference between the social classes A/B and D/E. These results, however, should be seen with caution because of the percentage of refuse especially in the higher, A/B (19.3%) and lower D/E (9.3%) social classes.