Adherend effect on the peel strength of a brittle adhesive

Peel tests are widely used to characterize the peel strength of bonded joints and control adhesion quality. There are various configurations of peel test, such as the T-peel test, peel testing at 180°, the floating roller peel test, and the climbing drum peel test. These methods have been widely used mainly in the aeronautical industry, as a way of assessing the peel strength of metallic joints. However, with the growing use of composite materials in industry, it is necessary to characterize bonded joints with these materials when subjected to peeling loads. In this research, the adherend effect on the peel strength of a brittle adhesive is experimentally studied using the floating roller peel test with the aim of evaluating how adherend changes affect adhesion properties of brittle adhesives and also to assess the viability of using the floating roller peel test in composite-to-composite and composite-to-aluminum joints, as well as make a comparison with aluminum-aluminum joint performance. It is also intended to prove the applicability of this test for quality control of adhesion and determination of peel strength in joints with composite materials. The results show the Araldite® AV138 performance falls within the characteristic values of peel strength of other structural adhesives, particularly when composite adherends are concerned, and with reasonable repeatability considering it is a brittle adhesive.info:eu-repo/semantics/publishedVersio

Equine infectious anemia : prevalence in working equids of livestock herds, in Minas Gerais, Brazil

Estimaram-se, no estado de Minas Gerais, a prevalência e a distribuição espacial da anemia infecciosa eqüina (AIE) em propriedades com eqüídeos de serviço. As amostras de sangue, de 6540 eqüídeos de 1940 rebanhos foram coletadas no período de setembro de 2003 a março de 2004, nos 853 municípios do estado. Utilizaram-se dois testes de laboratório em seqüência: ELISA, usando-se antígeno recombinante gp90, e imunodifusão em gel de ágar (IDGA). As prevalências foram de 5,3% [IC=4,3 a 6,3%] para rebanhos e de 3,1% [IC=2,2 a 3,9%] para animais. O estado de Minas Gerais foi considerado área endêmica para AIE. As mais altas prevalências para rebanhos e para animais foram encontradas na região Norte/Noroeste, seguida pela região Vale do Mucuri/Jequitinhonha. ___________________________________________________________________________________________________________ ABSTRACTThe prevalence and spatial distribution of equine infectious anemia (EIA) were estimated in livestock herds where equids were used as draft power and for transportation in the State of Minas Gerais, Brazil. Serum samples were collected from September/2003 to March/2004 in 853 municipalities of the state. The sample comprised 6,540 equids from 1,940 herds. Two laboratorial tests were performed in sequence: ELISA using a recombinant gp90 protein, following by the AGID. The prevalence in the herds was estimated in 5.3% [CI = 4.3 to 6.3%], and 3.1% [CI = 2.2 to 3.9%] of the animals tested were positive. Minas Gerais was considered an endemic region for EIA. The highest prevalence for herds and animals was found in North/Northwest region (strata) followed by Vale do Mucuri/Jequitinhonha region

A validation study of the CarerQol instrument in informal caregivers of people with dementia from eight European countries

Purpose: Informal care constitutes an important part of the total care for people with dementia. Therefore, the impact of the syndrome on their caregivers as well as that of health and social care services for people with dementia should be considered. This study investigated the convergent and clinical validity of the CarerQol instrument, which measures and values the impact of providing informal care, in a multi-country sample of caregivers for people with dementia. Methods: Cross-sectional data from a sample of 451 respondents in eight European countries, collected by the Actifcare project, were evaluated. Convergent validity was analysed with Spearman's correlation coefficients and multivariate correlations between the CarerQol-7D utility score and dimension scores, and other similar quality of life measures such as CarerQol-VAS, ICECAP-O, and EQ-5D. Clinical validity was evaluated by bivariate and multivariate analyses of the degree to which the CarerQol instrument can differentiate between characteristics of caregivers, care receivers and caregiving situation. Country dummies were added to test CarerQol score differences between countries. Results: The mean CarerQol utility score was 77.6 and varied across countries from 74.3 (Italy) to 82.3 (Norway). The scores showed moderate to strong positive correlations with the CarerQol-VAS, ICECAP-O, and EQ-5D health problems score of the caregiver. Multivariate regression analysis showed that various characteristics of the caregiver, care receiver and caregiving situation were associated with caregiver outcomes, but there was no evidence of a country-level effect. Conclusion: This study demonstrates the convergent and clinical validity of the CarerQol instrument to evaluate the impact of providing informal care for people with dementia

Prevalence and risk factors for bovine leptospirosis in Mato Grosso do Sul, Brazil

Foi investigada a prevalência de anticorpos antileptospira em fêmeas bovinas com idade igual ou superior a 24 meses, provenientes de 178 rebanhos de 22 municípios do estado de Mato Grosso do Sul, bem como identificados fatores de risco associados à infecção. Foram analisadas 2.573 amostras de soro sangüíneo por meio do teste de soroaglutinação microscópica perante 10 sorovares de leptospira. Títulos iguais ou superiores a 100 para um ou mais sorovares foram detectados em 1.801 fêmeas (98,8%) de 161 (96,5%) rebanhos. O sorovar Hardjo (65,6%) foi apontado como o mais provável, seguido do sorovar Wolffi (12,3%). Os resultados demonstram que a leptospirose bovina se encontra presente em todos os municípios estudados, com alta prevalência, tanto em animais como em rebanhos. Os fatores de risco identificados neste estudo e associados à infecção por bactérias do gênero lepstopira foram o tipo de exploração pecuária de corte e a raça Zebu. _____________________________________________________________________________________________________________ ABSTRACTThe prevalence of anti-Leptospira spp. antibodies was estimated for female cattle aged 24 months or older. The sample comprised 178 herds from 22 counties in the state of Mato Grosso do Sul, Brazil. The risk factors associated with the presence of infeccion were investigated. A total of 2,573 blood serum samples were tested against 10 leptospira serovars using the microagglutination test (MAT). Titers of 100 or higher for one or more serovars were detected in 1,801 females (98.8%) from 161 herds (96.5%). Serovar Hardjo (65.6%) was the most frequent, followed by serovar Wolffi (12.3%). These results suggest that bovine leptospirosis is widespread in all the counties under study, with a high prevalence both at the animal and the herd level. Beef farms and the Zebu breed were associated to the higher risk of herd infection by leptospiras