Browsing by Author "Pereira, J."
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- Accuracy in detecting prenatal alcohol exposure and error preventionPublication . Xavier, Maria Raúl; Carvalhal, T.; Brizida, A.; Rei, C.; Cruz, J.; Pereira, J.; Bastos, L.; Campos, M.; Costeira, M.
- Migration of two antioxidants from packaging into a solid food and into TenaxPublication . Reinas, I.; Oliveira, J.; Pereira, J.; Machado, P.; Poças, M. F.The migration of chemicals from packaging materials into foods is an important issue in food safety and quality. European legislation sets specific migration limits which compliance must be assessed, surveyed and controlled by industry and authorities. Recently, the new Regulation UE 10/2011 included a new simulant - the Modified Polyphenylene Oxide (Tenax ) for solid dry foods. The objective of this work was to compare the migration kinetics of two antioxidants into Tenax as compared to rice at 3 temperatures: 23, 40 and 70 C. The application of two different solutions of the 2nd Fick’s law to describe and simulate the migration of the migrants to the present systems was studied. Diffusion coefficients ranged between 4.80E-13 and 2.84E-11 cm2/s for the migration into Tenax and between 6.90E-18 and 4.33E-17 cm2/s for the migration into rice. The partition coefficients ranged between 6 and 29 for Tenax and were over 1000 for rice. The activation energy for the migration into rice was half of that for Tenax . The models described relatively well the experimental data (ε < 12% and < 30% for rice and Tenax , respectively). Results indicate that the food simulant tends to overestimate migration values and thus can be safely used to assess materials compliance when materials are intended to contact with rice. However, results also indicate that Tenax is a much more severe simulant in representing rice.
- Performance of wine bag-in-box during storage: loss of oxygen barrierPublication . Fradique, S.; Hogg, T.; Pereira, J.; Poças, M .F. F.Bag-in-box system is a convenient packaging system for wine. Its barrier to oxygen relies, in many cases, in an aluminium metallized polyester film laminated between two polyethylene (PE) layers as the inner bag. One on the most frequently observed system failures is the ingress of wine into the gap between the layers of the double bag. This study aimed at verifying if that influences the barrier of the system to oxygen. The results showed that the contact of wine with this barrier layer, although through a PE layer, promotes the demetallization and consequent loss of barrier properties. The type of wine, in particular its volatile acidity, and the temperatures were two variables assessed. Results showed that wine with higher acidity and stored at higher temperatures tend to yield a higher increase in oxygen transmission rate of the film.
- Using assistive robots to promote inclusive educationPublication . Encarnação, P.; Leite, T.; Nunes, C.; Ponte, M. Nunes da; Adams, K.; Cook, A.; Caiado, A.; Pereira, J.; Piedade, G.; Ribeiro, M.Purpose: This paper describes the development and test of physical and virtual integrated augmentative manipulation and communication assistive technologies (IAMCATs) that enable children with motor and speech impairments to manipulate educational items by controlling a robot with a gripper, while communicating through a speech generating device. Method: Nine children with disabilities, nine regular and nine special education teachers participated in the study. Teachers adapted academic activities so they could also be performed by the children with disabilities using the IAMCAT. An inductive content analysis of the teachers’ interviews before and after the intervention was performed. Results: Teachers considered the IAMCAT to be a useful resource that can be integrated into the regular class dynamics respecting their curricular planning. It had a positive impact on children with disabilities and on the educational community. However, teachers pointed out the difficulties in managing the class, even with another adult present, due to the extra time required by children with disabilities to complete the activities. Conclusions: The developed assistive technologies enable children with disabilities to participate in academic activities but full inclusion would require another adult in class and strategies to deal with the additional time required by children to complete the activities. Implications for Rehabilitation Integrated augmentative manipulation and communication assistive technologies are useful resources to promote the participation of children with motor and speech impairments in classroom activities. Virtual tools, running on a computer screen, may be easier to use but further research is needed in order to evaluate its effectiveness when compared to physical tools. Full participation of children with motor and speech impairments in academic activities using these technologies requires another adult in class and adequate strategies to manage the extra time the child with disabilities may require to complete the activities.