Perception of Recycled Plastics for Improved Consumer Acceptance through Self-Reported and Physiological Measures.

This article aims to provide in-depth insight into how consumers perceive recycled materials in comparison with natural raw materials at both the perceptual and attitudinal levels. To this end, we combined classic self-reported measures of sensory aspects, preferences, environmental attitudes, and consumption habits together with physiological measures of cognitive-emotional processing. Three different materials-two recycled materials, M2 and M3, and one raw material, M1-were chosen for inspection through three different sensory conditions, which we refer to as channels -visual, tactile, and visuo-tactile. The assignation of materials to sensory channels was counterbalanced so that each participant evaluated only one of the materials per channel. Although participants in general were not very accurate in discriminating between the materials, self-reported sensory evaluations showed that M3 (a recycled material that is made to look non-recycled), was clearly less liked. Meanwhile, the psychophysiological analyses revealed higher levels of electrodermal activity for the tactile evaluations of both recycled materials (M2 and M3). Finally, the results from the attitudes and habits evaluations indicate that the participants had positive environmental attitudes yet poor consumption habits. Altogether, these results suggest that some sensorial properties differ between recycled materials and natural raw materials and that there is a chance to improve and implement new consumption habits. The implications of these results are further discussed both in terms of suggestions for designers and methodological recommendations for researchers.

Perception evaluation kit: a case study with materials and learning styles.

Materials are elements that configure our built environment and are key components in design and engineering education. This research aims to understand learners' sensorial perception of materials as stimuli and what constitutes the most appropriate communication channel for learning about their characteristics without losing information in accordance with their VAK learning styles-visual, auditory and kinaesthetic-. Seventy-five people participated in this workshop. Using evaluation tools in a test format, they evaluated all the sensory properties of the following materials: Alusion™, PolarMoss, and Silkworms. These three materials were presented in various interaction formats, called channels: a text plus image-C1-, video-C2-, and a physical sample plus audio-C3-. Two types of experiments were carried out: mixed per person-interaction with the three materials in a different channel each time in random order-and blocked per person-interaction with the same material in the three channels, in an order of C1-C3. The data obtained was analysed using mixed models with the channel as a fixed factor and the individuals and material as the random factors. The most relevant results indicate significant differences between channels in accordance with the sensory property, normally C2 and C3. The level of responses between the two experiments is similar, therefore showing that the order C1-C2-C3 does not affect perception. Although the three learning styles-visual, auditory, and kinaesthetic-coexist in the participants, the vast majority agree that they prefer C3 as easier to evaluate, more entertaining and the best way to learn.

Optimization and Sensitivity Analysis of the Cutting Conditions in Rough, Semi-Finish and Finish Honing.

Honing processes are currently employed to obtain a cross-hatched pattern on the internal surfaces of cylinders that favors oil flow in combustion engines or hydraulic cylinders. The main aim of the present paper is to optimize the machining conditions in honing processes with respect to surface roughness, material removal rate and tool wear by means of the desirability function. Five process variables are considered: grain size, density, pressure, linear speed and tangential speed. Later, a sensitivity analysis is performed to determine the effect of the variation of the importance given to each response on the results of the optimization process. In the rough and semi-finish honing steps, variations of less than 5% of the importance value do not cause substantial changes in the optimization process. On the contrary, in the finish honing step, small changes in the importance values lead to modifications in the optimization process, mainly regarding pressure. Thus, the finish honing phase is more sensitive to changes in the optimization process than the rough and the semi-finish honing phases. The present paper will help users of honing machines to select proper values for the process variables.