Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given.
The aim of this study was to describe the audiometric results following surgery in a consecutive series of pediatric patients with a congenital middle ear disorder. Retrospective chart review was performed for 29 consecutive children who underwent 33 middle ear surgeries for congenital ossicular chain anomaly between 1990 and 2012. Anomalies were classified into four groups according to the Teunissen and Cremers classification. Audiological parameters using four frequency averages (0.5, 1, 2 and 4 kHz) were assessed pre- and postoperatively. Clinical and audiometric follow-up times were, respectively, 49 ± 8 and 35 ± 5 months (mean ± SEM). Fifty-eight percent of all patients achieved an air-bone gap (ABG) ≤20 dB, 62.5% in class I, 50% in class II and 57.9% in class III. The improvement of the mean ABG was 13.6 dB, 19.2 dB for class I, 0.2 dB in class II and 15.4 dB in class III. Overall mean pure-tone averages improved 14.8 dB with 13.9 dB for class I; there was no improvement for class II and 20.2 dB for class III. The sensorineural hearing loss rate was 9%. This pediatric series showed that hearing results depend on type of anomaly. Class I and class III showed better hearing improvement than class II.
Additive manufacturing offers many advantages, especially in terms of creativity and design freedom. However, this emerging technology is disrupting the way design is carried out and creativity is often limited by the cognitive barriers installed through years of traditional manufacturing processes. Likewise, as this manufacturing process is relatively recent and quite unknown to designers, its specificities are not always considered during the design phase, which leads to manufactured parts happening to differ from CAD models in terms of sizing or surface quality. Consequently, microwave components nowadays manufactured layer-by-layer do not exhibit operational electromagnetic performances. In this way, it is necessary to guide designers throughout the development of a product by drawing their attention to the different steps they must consider in order to design an additive manufactured optimised part.
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