Técnicas estendidas na obra Traçado Íntimo e Hesitante para violoncelo solo de Bruno Ângelo e sua utilização na iniciação ao violoncelo

This works sheds light on the technical challenges regarding the use of extended techniques at the piece “Traçado Íntimo e Hesitante” by Bruno Angelo and the use of some of these techniques in the cello initiation. The main goal of the research is to provide cellists interested in the performance of the piece with ideas to surpass the technical difficulties as well as to introduce new ideas of using sound materials of contemporary music in the beginner cello teaching.

Performance comparativa entre R437A e R134A paradrop-in em um condicionador de ar automotivo

The reduction in energy consumption is the main requirement to be satisfied in refrigeration and air conditioning by mechanical vapor compression system. In automotive system isn´t different. Thermal analyses in these systems are crucial for a better performance in automotive air conditioner. This work aims to evaluate the conditions of use of R134A refrigerant (used in vehicles) and compare with R437A (alternative refrigerant), varying the speed of the electric fan in the evaporator. All tests were performed in automotive air conditioning unit ATR600, simulating the thermal conditions of the system. The equipment is instrumented for data acquisition temperature, condensation and evaporation pressures and electrical power consumed to determine the coefficient of performance of the cycle. The system was tested under rotations of 800, 1600 and 2400 rpm with constant load of R- 134a. It occurred with the same conditions with R437A. Both recommended by the manufacturer. The results show that the best system performance occurs in the rotation of 800 RPM for both refrigerants.