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Abstract

The article shows the methodology and calculation procedures based on Lagrange polynomial interpolation which were used to determine standard performance characteristics of the Polish production engine, type ANDORIA 4CTi90-1BE6. They allow to simplify the experimental research by maintaining a minimum number of measurement points and estimating the remaining data in an analytical way. The methods presented are convenient when it comes to the practical side because they eliminate the need for exploration of mathematical equations describing the various curves, which can be cumbersome and time consuming in the case of nonautomated accounts. The results of analysis were applied to actual experimental results, indicating sufficient accuracy of the resulting approximations. As a result, procedures may be used in bench testing of a similar profile, especially with repeated cycles of the experiment, such as optimization of operating parameters of combustion engines.
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Abstract

The self-consistent optical-electrical-thermal-gain model of the oxide-confined edge-emitting diode laser has been used to simulate the room-temperature operation of the long-wavelength 1.3-µm quantum-dot (InGa)As/GaAs diode laser. The validityof the model has been verified using some experimental results for comparison. An impact of quantum-dot densityon laser operation characteristics as well as on temperature dependence of lasing threshold have been discussed.
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Abstract

It has been found that the vegetable oils are promising substitute, because of their properties are similar to those of diesel fuel and they are renewable and can be easily produced. However, drawbacks associated with crude vegetable oils are high viscosity, low volatility call for low heat rejection combustion chamber, with its significance characteristics of higher operating temperature, maximum heat release, and ability to handle lower calorific value (CV) fuel etc. Experiments were carried out to evaluate the performance of an engine consisting of different low heat rejection (LHR) combustion chambers such as ceramic coated cylinder head-LHR-1, air gap insulated piston with superni (an alloy of nickel) crown and air gap insulated liner with superni insert - LHR-2; and ceramic coated cylinder head, air gap insulated piston and air gap insulated liner - LHR-3 with normal temperature condition of crude rice bran oil (CRBO) with varied injector opening pressure. Performance parameters (brake thermal efficiency, brake specific energy consumption, exhaust gas temperature, coolant load, and volumetric efficiency) and exhaust emissions [smoke levels and oxides of nitrogen [NOx]] were determined at various values of brake mean effective pressure of the engine. Combustion characteristics [peak pressure, time of occurrence of peak pressure, maximum rate of pressure rise] were determined at full load operation of the engine. Conventional engine (CE) showed compatible performance and LHR combustion chambers showed improved performance at recommended injection timing of 27°bTDC and recommend injector opening pressure of 190 bar with CRBO operation, when compared with CE with pure diesel operation. Peak brake thermal efficiencyincreased relatively by 7%, brake specific energy consumption at full load operation decreased relatively by 3.5%, smoke levels at full load decreased relatively by 11% and NOx levels increased relatively by 58% with LHR-3 combustion chamber with CRBO at an injector opening pressure of 190 bar when compared with pure diesel operation on CE.
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