Field-effect transistors based on Zinc oxide nanoparticles

This work reports the development of field-effect transistors (FETs), whose channel is based on zinc oxide (ZnO) nanoparticles (NPs). Using screen-printing as the primary deposition technique, different inks were developed, where the semiconducting ink is based on a ZnO NPs dispersion in ethyl cellulose (EC). These inks were used to print electrolyte-gated transistors (EGTs) in a staggered-top gate structure on glass substrates, using a lithium-based polymeric electrolyte. In another approach, FETs with a staggered-bottom gate structure on paper were developed using a sol-gel method to functionalize the paper’s surface with ZnO NPs, using zinc acetate dihydrate (ZnC4H6O4·2H2O) and sodium hydroxide (NaOH) as precursors. In this case, the paper itself was used as dielectric. The various layers of the two devices were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric and differential scanning calorimetric analyses (TG-DSC). Electrochemical impedance spectroscopy (EIS) was used in order to evaluate the electric double-layer (EDL) formation, in the case of the EGTs. The ZnO NPs EGTs present electrical modulation for annealing temperatures equal or superior to 300 ºC and in terms of electrical properties they showed On/Off ratios in the order of 103, saturation mobilities (μSat) of 1.49x10-1 cm2(Vs)-1 and transconductance (gm) of 10-5 S. On the other hand, the ZnO NPs FETs on paper exhibited On/Off ratios in the order of 102, μSat of 4.83x10- 3 cm2(Vs)-1and gm around 10-8 S.

Relatório de estágio na AXA Portugal

The present report has the goal of enunciating and exposing some of the main judicial subjects that were developed during the period of internship, coming forth in the form of answers to questions properly reformulated as not to injure the confidentiality of data available while in the process of making said report, they deal with different branches of the law, although with a special focus on the field of Insurance Law. It being an academic piece, it was of the utmost importance to focus more sharply on a specific theme, in casu, medical-civil responsibility, causing the interest in this matter due to the curricular internship and a case law research on the subject. The last chapter of this paper focuses mainly on the problematic of seizure by insurance intermediary’s commissions, credits from occupational accidents and illnesses and Retirement and Education Savings Plans (PPR/Es), this being one problematic with which I dealt directly in the early stages of the internship.

Methodology for WSN communication technologies automated field tests

Wireless Sensor Networks(WSN) are networks of devices used to sense and act that applies wireless radios to communicate. To achieve a successful implementation of a wireless device it is necessary to take in consideration the existence of a wide variety of radios available, a large number of communication parameters (payload, duty cycle, etc.) and environmental conditions that may affect the device’s behaviour. However, to evaluate a specific radio towards a unique application it might be necessary to conduct trial experiments, with such a vast amount of devices, communication parameters and environmental conditions to take into consideration the number of trial cases generated can be surprisingly high. Thus, making trial experiments to achieve manual validation of wireless communication technologies becomes unsuitable due to the existence of a high number of trial cases on the field. To overcome this technological issue an automated test methodology was introduced, presenting the possibility to acquire data regarding the device’s behaviour when testing several technologies and parameters that care for a specific analysis. Therefore, this method advances the validation and analysis process of the wireless radios and allows the validation to be done without the need of specific and in depth knowledge about wireless devices.

O estatuto disciplinar da literatura angolana : contributo para uma epistemologia dos estudos literários africanos

A presente investigação procura inscrever-se no domínio da epistemologia dos estudos literários, fazendo apelo a uma abordagem interdisciplinar que aponta para a necessidade de um comparatismo literário africano e, ao mesmo tempo, mundial. O conceito-chave com que operamos neste trabalho é o de disciplinarização, tendo em conta o seu potencial explicativo para entender o processo que nos irá conduzir à integração dos Estudos Literários Africanos no sistema disciplinar actual. Por disciplinarização entendemos o processo de definição que consiste na demarcação de uma determinada disciplina, por força de dinâmicas endógenas e exógenas, durante o qual se transita de uma fase pré-disciplinar para outra disciplinar, admitindo-se a existência de uma compatibilidade entre os fundamentos epistemológicos e metodológicos da produção e transmissão de conhecimentos e, por outro lado, a consagração da institucionalidade da disciplina como objecto de estudo. A profissionalização disciplinar será uma consequência desse processo e da formação de comunidades de agentes epistémicos que, conhecendo profundamente a história e os universos de referência da disciplina, sejam capazes de aplicar as metodologias mais adequadas no domínio da investigação e do ensino. Para compreender os fundamentos epistemológicos dos Estudos Literários Africanos, importa refletir sobre o momento a partir do qual se constituem como campo disciplinar na história da produção do conhecimento sobre o continente africano. Por outro lado, com o presente trabalho pretende-se avaliar o estatuto disciplinar da Literatura Angolana, num exercício que procura justificar as determinações da epistemologia disciplinar, operacionalizando os sentidos em que se pode analisar o conceito de disciplina. Deste modo, a atribuição do referido estatuto pressupõe o domínio de um instrumental teórico que implica a descrição dos tipos de conhecimento veiculados através dos processos de transmissão que caracterizam as disciplinas escolares e as disciplinas académicas.