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This paper presents the results of the performance diagnosis of a 6-cylinder engine-generator set, originally designed to run on diesel fuel or natural gas, operating in spark ignition mode and fueled with high butane content liquefied petroleum gas (LPG). In order to assess the steady-state and transient operation of the engine-generator, an original protocol for testing and recording of operating variables was designed, based on a stepped sequence of loads, comprising cold start, idling, operation at some mean load points and at a limited full load. During the tests, the variation of crankshaft rotational speed, warm-up time, engine temperatures, block vibrations, active/reactive power and engine-generator frequency, as well as exhaust emissions were continuously logged. The results show that, during the cold starting process, the engine is slow to reach nominal rated speed, its warm-up time is lengthy and its speed response during load transients is also sluggish, the latter being reflected in the voltage and frequency deviations of the output power; also, during transients, vibration levels are intensified, though the values are within the acceptable ranges according to the regulations. The torque performance of the engine-generator set is good when operating with LPG, satisfying the requirements for class G2 engine-generator units, but during transient processes it does not meet the specifications required for class G1, in terms of frequency and voltage deviations. In light of the emission limits suggested by the Environmental Protection Agency (EPA) for stationary units, it can be concluded that, without appropriate adjustments and regulations particular to LPG, the engine-generator set does not meet the carbon monoxide emission limits. [ABSTRACT FROM AUTHOR]

This article presents the evaluation of the parameters of Electrical Safety in its general requirements, for biomedical equipment and electronic instrumentation, according to the regulations of the International Electrotechnical Commission, IEC, for uncontrolled environmental laboratory conditions, such as the temperature and the percentage of relative humidity. This evaluation is done to implement a protocol for preconformity tests and in situ fault detection for electro-technology equipment. Eighteen equipment were evaluated, including biomedical and instrumentation. After that a correlation analysis of the environmental variables was performed with the measured parameters, to determine the influence of the environmental variables on the Electrical Safety parameters. The results show that such parameters do not present any correlation with the measured environmental variables. [ABSTRACT FROM AUTHOR]

An important part of the population does not have access to public services such as gas and electricity. their main source of energy is coal and wood, particularly for cooking, with negative impacts on environment. It is possible to explore alternatives tomitigate these impacts, such as the use of solar energy. The use of low power solar cookers by poor people is widespread, but from the technical point of view, their thermal behavior is not known. This paper presents a proposal to how to perform the tests based on international protocols evaluation of the thermal performance of solar cookers and submit the results of the linear fit of two variables that arise from the energy balance. First, we selected for evaluation many kinds of solar cookers, takinginto consideration important aspects such as building materials of their components, such as cardboard and aluminum.Results from the data analysis show the difference in thermal behavior between different prototypes and models analyzed. The best thermal performance in our analysis is presented by "fun panel" cooker. [ABSTRACT FROM AUTHOR]