Service-Learning (SL) experiences enable University Social Responsibility (USR) to be worked on in engineering studies as a core of education for Sustainability. The combined use of such experiences with active student-centered teaching methodologies fosters the acquisition of general and specific competences. On the basis of students' perception, this study investigated and sought evidence of empirical foundations to understand whether and how Project Based Learning (PBL) affects the acquisition of USR-related competences when SL experience was implemented as the regular exercise in core courses in engineering studies. This research studied 100 second year undergraduate students in Industrial Design Engineering and Product Development. The students were divided into two groups, one of which experienced Service-Learning only in one class activity while the other group carried out a PBL activity. A survey consisting of 28 items was delivered to all these students and their answers were analyzed from a descriptive statistics viewpoint to understand how the students perceived their degree of attainment of USR competences. The findings suggest a clear difference between the methodologies used, which shows that PBL methodology may lead to a greater acquisition of USR competences than SL activity.
Most hospitalized patients are carriers of biomedical devices. Infections associated with these devices cause great morbidity and mortality, especially in patients in intensive care units. Numerous strategies have been designed to prevent biofilm development on biodevices. However, biofilm formation is a complex process not fully clarified. In the current study, roughness and hydrophobicity of different biomaterials was analyzed to assess their influences on the biofilm formation of four leading etiological causes of healthcare-associated infections, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis and Candida albicans, using a CDC biofilm reactor. Hydrophobic materials allowed the formation of more abundant and profuse biofilms. Roughness had effect on biofilm formation, but its influence was not significant when material hydrophobicity was considered.
Poly(lactic acid) (PLA) is one the most promising bio-based and biodegradable polymer. However, its low thermal stability limits the range of applications and complicates its transformation via the most industrial common processes. The novelty of this work is studying the thermal stability of PLA and PLA/clay nanocomposites during use, as a function of the composition and using a wide range of extrusion and injection moulding processing parameters. To improve the thermal stability of the PLA, laminar silicates containing different organomodifications have been added (Cloisite 20A and Cloisite 30B). The results show that the processing conditions and composition define the morphology of the bio-nanocomposites, which plays key role in defining final thermal properties of the material. In general, clays improve the thermal stability of the processed material, increasing the degradation temperature and decreasing the degradation rate under a wide range of processing conditions. V C 2014 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2014, 131, 40747.
Hybrid acrylic/CeO 2 latexes with solids content as high as 50 wt% and CeO 2 content up to 1 wt% are synthesized by a seeded semibatch emulsion polymerization process. TEM images show that CeO 2 nanoparticles are randomly located within the polymer particles. The 2D trasmission electron microscopy (TEM) images are not conclusive to elucidate if CeO 2 is encapsulated in the hybrid polymer particles. A TEM tomographic analysis is presented here to assess their morphology. The study shows that the latexes synthesized present an encapsulated morphology for CeO 2 nanoparticles regardless of whether these are located at the center or borders of the polymer particles.
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