ABSTRACT The structure is a component that plays an extremely important role in the equipment’s performance, it must withstand efforts without compromising the function, receive and transfer heat, dampen vibrations and position the elements, as well as promote ergonomics and aesthetics. In lightweight and precision equipment’s the raw material used must also allow thin walls, rigid, resistant and low density. The objective of the present work is the development of a synthetic granite composite for manufacturing of equipment’s structures. For this, an abundant Brazilian granite, a high strength epoxy resin and segmented carbon fibers were selected as materials. Test specimens, with maximized packing with granite gravel less than 2.0 mm were fabricated and tested for tensile strength, compression, flexural, damping, hardness, dilatometry, thermal conductivity and density. The maximized composition supported flexural stresses above 42 MPa, without fiber reinforcement and 51 MPa with carbon fiber reinforcement. The damping coefficient was about 7 times higher than cast iron, coefficient of thermal expansion of 1.4E-05 m/m.K, thermal conductivity coefficient of 1.2 W/m.K and density of 2.1 g/cm3. The developed composite showed potential for refining structures, with ease of molding of thin-walled elements, use of inserts, re-machining, providing economical manufacture of single parts, and is still able to perform the function with high damping coefficient and low weight.

Existe um crescimento elevado da oferta de produtos e serviços das empresas de teleatendimento. Porém, os operadores usuários de fones de ouvido mostram-se afetados pela exposição a ruído, podendo estar sujeitos à perda auditiva permanente e irreversível devido à exposição acima dos limites permissíveis. Os métodos tradicionais de medição da exposição a ruído não são adequados quando a fonte sonora é instalada diretamente sobre o sistema auditivo externo (orelha) através do uso de fones. Neste trabalho, a norma ISO 11904 é usada para avaliar a exposição a ruído em operadores de teleatendimento, considerando duas técnicas: cabeça artificial padronizada e microfone em ouvido real. Os resultados obtidos demonstraram que os dois métodos aplicados são eficientes e efetivos, podendo contribuir na avaliação apropriada da exposição a ruído em usuários de fones de ouvido de teleatendimento.

There is a fast expansion in the number of products and services offered by telemarketing companies. However, operators using earphones showed to be affected and could have been subjected to permanent and irreversible auditory loss due to exposure above the permitted levels. The traditional methods for measuring noise exposure have not proved to be efficient when the sound source (earphones) is placed directly on the external auditory system (ears). In this study ISO 11904 was used as a standard to evaluate telemarketing operators' exposure to noise. Two technical approaches were taken into consideration: a standardized artificial head and a microphone placed at operator's ear. Final results demonstrated that both techniques are efficient and effective, and can contribute to evaluating adequately the earphone users' exposure to noise in telemarketing.