Oman has adopted e-government services, but according to the United Nations E-Government Development Index classification, such services are not fully utilised. E-government classification of Oman shows a lack that motivated this research. The aim is to provide a framework that can help the Omani government to better implement e-government services. As a result, Oman classification is expected to be improved. Such framework may also help similar developing countries in implementing their e-government services. This work aimed to address both; government and citizens prospective, also aiming to help conducting a sold research a good implementable framework. Therefore, an interview with 21 government participations from different institutions was conducted followed by citizens that attracted 400 qualified responses. The research process has led to the suggestion of using another approach of e-government services, the unified e-services portals. The outcomes of this research show; both government and citizens are in favour of using unified definitions in portals. In addition, a proposed framework is presented based on supported findings that is believed to better utilising e government services hence leading to improve ranking. It is also believed that the UN assessing committees would benefit from the unified approach. Simply, it unifies the definition of each service based on the published academic definitions and work. The evaluation of the proposed framework is outside this research and can be addressed by a further research as recommended. Implementing the unified approach portals is another front that attracts implementation and evaluation.

Made available in DSpace on 2017-07-10T17:11:52Z (GMT). No. of bitstreams: 1 dissert Final Marcel Araujo.pdf: 10392408 bytes, checksum: 3344b21a2f98d64347dd0aea895a4444 (MD5) Previous issue date: 2013-03-01 / The use of piezoelectric devices to harvest vibration energy has found applications in several areas, especially in structural health monitoring, either to recharge batteries or to directly feed sensors and also electronic devices. In general, the practical use of the energy converted by these devices requires, first, converting the alternating current (AC) produced to direct current (DC). This is normally done by using rectifier circuits. However, modeling the harvesting system, usually a PZT sensor bonded on a cantilever micro-beam and coupled to a rectifier circuit, using the same software package is pointed out by some authors as a drawback to overcome, due to its multidisciplinary requirements, involving topics of both mechanical and electrical engineering. In this sense, the main goal of this dissertation is to describe a comprehensive and simple modeling strategy, which considers a single computational platform and, simultaneously, account for both the electromechanical model of a clamped piezoelectric beam and the practical energy harvesting circuit, seeking ways to facilitate the analysis and design of energy harvesting systems. Numerical simulations and experimental tests are performed to illustrate the proposed approach, considering a full-wave diode bridge as the non-controlled rectifier circuit and a resistive load, which are directly connected to the cantilevered piezoelectric beam. Additionally, experimental tests carried out with a commercial harvesting system are presented, aiming to characterize and compare its performance with a full-wave diode bridge and a resistive circuit, both developed by the author. A single degree of freedom model of this system is also presented. The results showed that the model is suitable to perform simulations of systemshaving the characteristics described in this dissertation and confirmed the need of using active circuits to better use the produced energy. / A utilização de dispositivos piezelétricos para reaproveitamento de energia vibratória tem en- contrado aplicações em várias áreas, sobretudo em monitoramento de integridade estrutural, seja para recarregar baterias ou alimentar diretamente sensores e outros dispositivos eletrôni- cos. Em geral, o uso prático da energia convertida por estes transdutores requer, primeiramente, a transformação da corrente alternada (CA) produzida em corrente contínua (CC). Isto é fre- quentemente obtido por meio da utilização de circuitos retificadores. Entretanto, utilizar o mesmo pacote de software para modelar sistemas de energy harvesting, geralmente compostos por um sensor piezelétrico acoplado em uma microviga e conectados a um circuito retificador, é apontado por alguns autores como um grande desafio a ser superado, pois necessita de requisi- tos multidisciplinares que incluem tópicos de engenharia elétrica e mecânica. Neste sentido, o principal objetivo deste trabalho é apresentar uma estratégia de modelagem simples, que utilize apenas uma plataforma computacional e considere, simultaneamente, os modelos de uma viga piezelétrica e um circuito prático de extração/armazenamento de energia, buscando meios de facilitar a análise e o projeto de sistemas de energy harvesting. Simulações numéricas e testes experimentais são realizados para ilustrar a abordagem proposta, considerando um circuito retificador de onda completa e uma carga resistiva conectados diretamente a uma viga piezelétrica sob condição engastada-livre. Além disso, são apresentados testes experimentais realizados com um sistema comercial de energy harvesting visando caracterizar e comparar seu desempenho frente aos circuitos retificadores de onda completa e resistivo, ambos confeccionados pelo autor. Um modelo de um grau de liberdade deste sistema também é apresentado. Os resultados mostraram que o modelo é adequado para realizar simulações de sistemas que possuam as características descritas neste trabalho e comprovaram a necessidade de se utilizar um circuito ativo para se ter um melhor reaproveitamento da energia gerada.