DiTeD (Digital Thesis and Dissertations) Repository
(1.413 recursos)
El servicio DiTeD se destina a gestionar tesis y disertaciones en formato digital, depositadas voluntariamente en la BNP - Biblioteca Nacional de Portugal.
Mostrando recursos 1 - 13 de 13
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Surface plasmon resonance as a tool in the functional analisys of an immunodominant site in foot-and-mouth disease virus - Gomes, Paula Alexandra de Carvalho
A fast and direct surface plasmon resonance (SPR) method for the kinetic analysis of the interactions between peptide antigens and immobilised monoclonal antibodies (mAb) has been established. Protocols have been developed to overcome the problems posed by the small size of the analytes (< 1600 Da). The interactions were well described by a simple 1:1 bimolecular interaction and the rate constants were self-consistent and reproducible. The key features for the accuracy of the kinetic constants measured were high buffer flow rates, medium antibody surface densities and high peptide concentrations. The method was applied to an extensive analysis of over 40...
2.
Cristalização de Biomateriais Vitrocerâmicos e Mineralização em Meio Fisiológico Simulado - Queiroz, Carlos Manuel Gomes de Araújo
We propose new theoretical models, which generalize the classical Avrami-Nakamura models. These models are suitable to describe the kinetics of nucleation and growth in transient regime, and/or with overlapping of nucleation and growth. Simulations and predictions were performed for lithium disilicate based on data reported in the literature. One re-examined the limitations of the models currently used to interpret DTA or DSC results, and to extract the relevant kinetic parameters.
Glasses and glass-ceramics with molar formulation 0.45SiO2? (0.45-x)MgO?xK2O?0.1(3CaO.P2O5) (0?x?0.090) were prepared, crystallized and studied as potential materials for biomedical applications. Substitution of K+ for Mg2+ were used to prevent devritification...
4.
Distributed learning environments in the design and development of the flexible university - Cardoso, Eduardo Luís
Distributed learning environments (DLE), based in e-learning plataforms (eLP), have been presented with the potential to foster innovation and development in the teaching activitiy, at higher education institutions (HEI). However, changes within the teaching and learning processes, due to information and communication technologies (ICT), have showed to be limited and with a weak evolution rate.
The present research work studied the phenomenon of eLP adoption in HEI to support DLE, building understanding about the process of adoption and use of technology and how it is influenced, and how it influence, by the context where it take place. The main goals of...
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Métodos Formais para o Estudo de Protocolos de Segurança - Adão, Pedro Miguel dos Santos Alves Madeira, 1980-
Várias abordagens têm sido propostas nos últimos anos para o estudo de problemas de Criptografia. Visto que o modelo da Criptografia Computacional é bastante complexo e por isso bastante difícil de utilizar, várias abstracções têm sido propostas nos últimos anos sendo a mais bem sucedida a proposta por Dolev-Yao. No entanto, apesar desta abstracção facilitar o tratamento dos problemas, é necessário verificar se estas abstracções são correctas, i.e., se os protocolos cuja correcção foi provada, segundo estas abstracções, são correctos aquando da sua implementação.
Nesta dissertação, começamos por considerar a lógica de indistinguibilidade proposta por Abadi e Rogaway e mostraremos que...
6.
Educação superior no período noturno-impacto do entorno educacional no cotidiano - Terribili Filho, Armando, 1955-
The conduct of university courses at night in Brazil is significant, where this scheduling option is used by more that 60% of undergraduate students. In order to discuss if the surrounding education (issues in the areas of transportation, traffic, public safety and labor law) affects the student day-by-day and can influences the student’s physical and psychological state upon arrival for their studies, it was developed a quantitative and qualitative research conducted with 340 students who attend night classes at three private institutions located in São Paulo State (one in São Paulo city, other institution in a city placed in Campinas...
7.
Digital libraries-The future through the traditional library - Borbinha, José Luís, 1963-
This dissertation addresses the problem of the «Digital Library»
from the point of view of the «Traditional Library». The work comprises an
analytical approach to the problem, being proposed a model for the «Digital
Library» according to the perspective and requirements of the «Traditional
Library» in face of the new emerging technological paradigm. This model is
analysed for the cases of the specialized library and the deposit library, when
facing the problem of the digital publishing. As a result, it is proposed a
strategy for the deposit library based on the identification of scenarios and
publication genres. As a consequence of this process, there were also
identified and analysed...
8.
A model for the simulation of Doppler ultrasound signals from pulsatile blood flow - Bastos, Carlos Alberto da Costa
The Doppler ultrasonic blood flow detector estimates
non-invasively the velocity of blood in the circulatory system. It has been
extensively used in the last four decades for the detection of stenoses in the
circulation.The development of new signal processing techniques for the Doppler
signal requires test signals with known or measurable characteristics. This is
very difficult to achieve with Doppler signals obtained in vivo because of the
variability of blood flow between persons and with physiological state, for
example blood pressure. A model for generating simulated Doppler signals whose
characteristics are controllable and/or measurable is a useful tool because it
permits the test of new processing techniques under controlled...
9.
Metodologias de teste para FPGAs (Field Programmable Gate Arrays) integradas em sistemas reconfiguráveis - Gericota, Manuel Gradim de Oliveira, 1968-
xi
Keywords: programmable logic devices, partial and dynamically reconfigurable FPGAs (Field
Programmable Gate Arrays), active replication, concurrent structural test, IEEE 1149.1 and
IEEE 1532 standards.
Reconfigurable logic devices, namely Field Programmable Gate Arrays (FPGAs), experienced a
considerable expansion in the last few years, due to an increase in their size and complexity. The
introduction of a new type of SRAM-based FPGAs, capable of implementing fast run-time partial
reconfiguration, reinforced the advantages of these devices, wide-spreading their usage as a base for
reconfigurable computing systems.
However, larger dies and smaller submicron scales increase the probability of lifetime operation
failures, requiring new test/fault tolerance strategies, capable of assuring long-term reliability.
This thesis presents...
10.
Automatica parallelization of matricial algorithms - Daniel, Helder Aniceto Amadeu de Sousa, 1967-
The introduction of parallel processing architectures allows the reduction of computation time by mapping the algorithm over a network of cooperating processors. However, to take advantage of the processing power of these architectures, the programmer, due to the lack of appropriate tools, must spend a considerable amount of time in the parallelization of the algorithm. Another problem with the conventional parallel programming model is that the parallelization of these algorithms is strongly dependent on the hardware used, so portability and upgradability are also time consuming steps in the development process. This way, the development time of efficient parallel applications, with...
12.
Logics of Formal Inconsistency - Almeida, João Marcos de, 1974-
According to the classical consistency presupposition, contradictions have an explosive character: Whenever they are present in a theory, anything goes, and no sensible reasoning can thus take place. A logic is paraconsistent if it disallows such presupposition, and allows instead for some inconsistent yet non-trivial theories to make perfect sense. The Logics of Formal Inconsistency, LFIs, form a particularly expressive class of paraconsistent logics in which the metatheoretical notion of consistency can be internalized at the object-language level. As a consequence, the LFIs are able to recapture consistent reasoning by the addition of appropriate consistency assumptions.
The present monograph introduces the...
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