Abstract

This paper presents measurements of carbon dioxide (CO2) emission and efficiency of stop/start technology on a diesel vehicle in urban traffic. Two four-wheel-drive diesel vehicles with on-board exhaust emission and vehicle activity measurement systems were tested in two urban driving circuits representative of downtown Madrid. The vehicles had similar turbocharged and intercooled diesel engines fulfilling the same Euro 4 emissions regulation; but one had an improved engine incorporating stop/start technology. CO2 emission reduction of more than 20% for the car equipped with the stop/start system was obtained. Regardless of the variability in driving style, the grade and type of streets, traffic congestion, and the engine operating temperature, the car equipped with the stop/start system has intrinsically a lower CO2 emission factor. Document type: Article

Abstract

Reducing defects in manufacturing processes is one of the greatest challenges in the composites industry. This reduction mean an increment in the mechanical properties, repeatability and optimized structural weight. It is known the relationship between the impregnation velocity and the amount of defects, especially air entrapment in liquid impregnation processes. Its consequences are highlighted in the resin infusion process, where the flow velocity is not constant throughout the process. Such heterogeneity leads to non-homogeneous mechanical properties in the material.

This work is base on the development of a methodology to control the impregnation process. It has demonstrated a substantial improvement in the mechanical properties when the flow velocity is controlled and kept around the optimum value.The methodology aims to identify the optimum impregnation velocity value through experimentation, and then, this value is applied during during the whole infusion process. For this purpose, an artificial vision system has been used, which allows keeping the flow velocity constant and near to the optimum value which optimize the mechanical properties.

Its experimental application in both conventional and stitched laminates has shown an increase in the tensile and impact mechanical properties. At the same time, level of control of the infusion process has been enhanced.