94 documents found, page 1 of 10
Rational Approach to Design Gold Nanoparticles for Photothermal Therapy: the ef...
Ferreira-Gonçalves, T.; Nunes, D.; Fortunato, E.; Martins, R.; de Almeida, A.P.; Carvalho, L.; Ferreira, D.; Catarino, J.; Faísca, P.; Ferreira, H.A.Among the unique characteristics associated to gold nanoparticles (AuNPs) in biomedicine, their ability to convert light energy into heat opens ventures for improved cancer therapeutic options, such as photothermal therapy (PTT). PTT relies on the local hyperthermia of tumor cells upon irradiation with light beams, and the association of AuNPs with radiation within the near infrared (NIR) range constitutes an a...
A note on the essential numerical range of block diagonal operators
Carvalho, L.; Diogo, C.; Mendes, S.; Soares, H.In this note, we characterize the essential numerical range of a block diagonal operator T = ?i Ti in terms of the numerical ranges {W(Ti)}i of its components. Specifically, the essential numerical range of T is the convex hull of the limit superior of {W(Ti)}i. This characterization can be simplified further. In fact, we prove the existence of a decomposition of T for which the convex hull is not required.
On the convexity of the quaternionic essential numerical range
Carvalho, L.; Diogo, C.; Mendes, S.; Soares, H.The numerical range in the quaternionic setting is, in general, a non-convex subset of the quaternions. The essential numerical range is a refinement of the numerical range that only keeps the elements that have, in a certain sense, infinite multiplicity. We prove that the essential numerical range of a bounded linear operator on a quaternionic Hilbert space is convex. A quaternionic analogue of Lancaster theor...
Quaternionic essential numerical range of complex operators
Carvalho, L.; Diogo, C.; Mendes, S.; Soares, H.We study the essential numerical range of complex operators on a quaternionic Hilbert space and its relation with the essential S-spectrum. We give a new characterization of the essential numerical range relating it to the complex essential numerical range. Moreover, we show that the quaternionic essential numerical range of a normal operator is the convex hull of the essential S-spectrum.
Recommended Practices in Early Childhood Intervention – A Guidebook for profess...
Carvalho, L.; Almeida, I.C.; Felgueiras, I; Leitão, S.; Boavida, J.; Franco, V.This book includes up-to-date information and guidance needed by the early intervention community to build and strengthen practitioner’s capacity to work effectively with young children and their families. This guideline will strengthen an already model system of early intervention in Portugal and serve as model to other countries in Europe and elsewhere.
Mapping the field: A bibliometric analysis for distance education with a focus ...
Castro. C.; Carvalho, L.; Moreira, S.The pandemic context has presented new challenges for education. In a short time, higher education institutions (HEIs) adapted their students, staff, technology, and infrastructures for a fast migration to distance learning. This change brought new challenges but also new opportunities that justify more contributions. The purpose of this paper is to study distance education (DE) methods and approaches, with a f...
The circular economy in corporate reporting: Text mining of energy companies’ m...
Santos, M. R. C.; Rolo, A.; Matos, D.; Carvalho, L.This paper explores the implementation of the circular economy in the energy sector. The research findings contribute to our understanding of the practical application of the circular economy, enabling policymakers and stakeholders to make informed decisions and develop targeted strategies. The study analyzes 88 Portuguese companies’ reports, examining the presence of circular economy strategies and initiatives...
S-spectrum and numerical range of a quaternionic operator
Carvalho, L.; Diogo, C.; Mendes, S.We study the numerical range of bounded linear operators on quaternionic Hilbert spaces and its relation with the S-spectrum. The class of complex operators on quaternionic Hilbert spaces is introduced and the upper bild of normal complex operators is completely characterized in this setting.
Wear behavior of a new composite formulation, with TEOS addition, for abrasive ...
Capela, Paulina Araújo; Costa, Sharlane Maria; Souza, M. S.; Carvalho, Sérgio Manuel Freitas; Pereira, Mário; Carvalho, L.; Gomes, J. R.; Soares, DelfimVitrified grinding wheels are used in many manufacturing industries to shape and finish metals and other materials in an efficient way. This work addresses a new approach with the use of tetraethyl orthosilicate solution (TEOS solution or silica sol), as an additive, in vitrified abrasive composites for grinding wheels. Different types of composite were produced using always the same materials and processing me...
Effect of grooves and their geometry on the wear behavior of structured grindin...
Capela, Paulina Araújo; Costa, Sharlane Maria; Souza, M. S.; Carvalho, Sérgio Manuel Freitas; Carvalho, L.; Pereira, M.; Gomes, J. R.; Soares, DelfimThe dry and wet wear behavior of different structured abrasive grinding wheels, with different grooves geometry, were investigated and compared with an unstructured abrasive composite. It was found that the grooves, as well as their geometry, play a decisive role in the wear behavior of abrasive composites.