Percorrer por data de Publicação, começado por "2022-05-11"
A mostrar 1 - 4 de 4
Resultados por página
Opções de ordenação
- The role of higher education towards sustainable consumption behavioural change: topics discussed in sustainable consumption educationPublication . João, Isabel; Silva, JoãoMany factors have contributed to the urgency of adopting sustainable consumption patterns. The main challenges related to sustainable consumption include respecting our planet in all its complexity and diversity, taking care of communities and life and, to this end, adopting consumption and production patterns that protect human rights and the well-being of communities. The theme of education for sustainable consumption is multidisciplinary with elements from different curriculum topics and addresses all aspects of everyday life. Establishing a common understanding of sustainable consumption education will create a shared understanding of the topic and improve the necessary cooperation between educators and students, making sustainable consumption education an established and more understandable topic. The objective of this study is to identify the main topics within sustainable consumption education teaching and learning, the main barriers and propose some actions that contribute to a sustainable behavioural change in higher education. A literature review was carried out to categorize the main topics related to teaching and learning processes in higher education environments to fill the gap in this underrepresented research topic of education for sustainable consumption. The review allowed the collection of information reported in this new millennium and the identification, selection and critical evaluation of research related to education for sustainable consumption.
- Substrate integrated waveguide cavity backed slot antennas for millimeter-wave applicationsPublication . Finich, Sanaâ; Salgado, Henrique; Pinho, PedroA low-cost single-layer substrate-integrated waveg uide (SIW) cavity-backed slot antenna is proposed for millimeter wave applications. The structure is designed to operate at the W-band. The T-shaped slot antenna is placed on the back-side of the SIW and fed by a grounded coplanar waveguide (GCPW) transmission line. A transition between the (GCPW) and the SIW is also designed. The simulated results provide that the antenna has a stable gain over the frequency range (98.79-100.56) GHz with a maximum value of around 6 dBi also high radiation efficiency.
- Limits of WPT through the human body using Radio FrequencyPublication . Duarte, Rodrigo; Gouveia, Carolina; Pinho, Pedro; Albuquerque, DanielRecently, the medical community has been devel oping new technologies to enhance medical treatments and diagnosis means, having in mind the patients’ comfort and safety. Implantable medical devices are an example of such solutions. Nonetheless, these devices present some disadvantages, namely need of batteries. Hence, these implants have a limited lifetime, and require periodical surgical interventions to change or to recharge. In order to solve this problem, systems based on Radio Frequency (RF) has been developed to transfer energy inside the organism. However, transmitting power to inside the human body must be performed carefully, since high power levels might be prejudicial to the subject. In this context, the goal of this work is to study the performance of the Wireless Power Transfer (WPT) to inside the human body, while respecting the Specific Absorption Rate (SAR) limits. Therefore, the levels of absorbed power in different body parts were verified by simulation, in order to reach conclusions about the user’s safety. More specifically, two biological models that represent the thigh and the arm were considered. The simulation results led us to conclude that it is possible to transmit approximately 140 mW on the limbs location, while respecting the SAR limits. In turn, it is possible to receive a power superior to 93 µW inside the human body. Additionally, real tests were also carried out in three subjects to verify the power attenuation related to each body structure.
- Dosimetrical studies for error acceptance in FLASH proton therapy. An MCNPX studyPublication . Correia, Jéssica Mestre; Ferreira, Pedro Miguel Martins; Labarbe, RudiAbstract Radiation therapy is a treatment that uses ionizing radiation to treat tumors. Among the particles used, protons stand out for their characteristic behavior, known as Bragg peak, when interacting with matter. These particles make it possible to decrease the dose deposited on adjacent healthy tissues and increase the conformation of the energy deposition to the irradiation target volume. In recent years a huge scientific effort has gone into the knowledge and development of the ultrafast therapy technique, known as FLASH therapy. This investment is due to the observation of differentiating responses compared to conventional techniques, since it has been observed in pre-clinical studies that healthy tissues react in a different way. The most promising features of this technique are the observation of less damage to adjacent healthy tissues after irradiation, concomitant with an anti-tumor efficacy similar to that achieved with more conventional techniques. However, the biological and cellular mechanisms behind these responses remain unknown and further research is needed. The possibility of combining the benefits of proton therapy with the FLASH technique is extremely promising and the objective of this final master's thesis is related to the dosimetric study of a device that presents potential for its implementation. The conformational energy filter is a hardware solution suggested for the implementation of this technique since it allows modulating the proton beam to the characteristics of the target volume during an ultra-fast irradiation (about 200 milliseconds). In order to study the influence of different uncertainties on the dose distribution inside the patient, a Monte Carlo simulator, Monte Carlo N-particles Extended (MCNPX), was used. Several scenarios and uncertainties in beam position, beam angulation, changes in beam size, and changes in the lateral dimensions of the conformal energy filter were simulated. The result of these simulations was compared with a reference simulation, and it was possible to verify that the factor that most influences the dose distribution is the beam translation and angulation. Since the production of neutrons is one of the factors to be taken into account when performing proton therapy, several scenarios were also simulated in order to study the materials for the composition of the accessory and the effects of introducing other accessories in the beam path.