Browsing by Issue Date, starting with "2019-06-06"
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- Procedimentos de manutenção na indústria aeronáuticaPublication . Fernandes, Salomão Marques da Silva Duarte; Calado, João Manuel Ferreira; Roque, António AfonsoNo presente Trabalho Final de Mestrado, tratar-se-á num contexto aeronáutico, de alguns processos de manutenção associados à prática de equilibragens e análise vibratória em motores Turbo Fan CFM56. Dar-se-á uma abordagem ao funcionamento do motor turbofan para que se entenda o comportamento das suas componentes rotativas e como estas estão interligadas. Tendo como base, toda a metodologia da manutenção condicionada e os seus propósitos, toda a prática de equilibragem associada a componentes rotativos principais do motor como é o caso dos compressores e turbinas, será detalhadamente explanado, bem como a sua real contribuição para um bom funcionamento dos motores. Particular atenção também será dada ao procedimento do alinhamento dos rotores, no entanto, não há evidência de anomalias que resultem num aumento de vibração em banco de ensaio de motores proveniente do respetivo processo de alinhamento. Pretende-se entender a importância da contribuição das equilibragens dos rotores na aprovação do motor, no parâmetro de amplitude de vibração em banco de ensaio. Será ainda apresentada uma metodologia no processo de equilibragem que até então não era executada, que visa mitigar eventuais condições latentes que estejam intrinsecamente relacionadas com a identidade do rotor (comportamento mecânico) ou, fatores externos que induzam situações anómalas, de forma a aferir um desequilíbrio o mais residual e satisfatório possível no processo de equilibragem.
- Positioning and advertising in large indoor environments using visible light communicationPublication . Vieira, Manuela; Vieira, Manuel; Louro, Paula; Vieira, PedroWe investigate the applicability of an intuitive advertising system for large indoor environments using visible light communication (VLC). This VLC-based positioning system includes the use of the visible light signals to light the space and to transmit information for traveler positioning and for advertising campaigns in the surroundings. As transmitters, white RGB-LEDs were used. Although their original function is to provide illumination, due to the ability of each individual chip to switch quickly enough to transfer data, they were used to broadcast information. This functionality is used for communication where multiplexed data can be encoded in the emitting light. The light signals emitted by the LEDs, positioned in the area of an advertising campaign are interpreted directly by the customers’ receivers. A silicon carbide optical sensor with light filtering and demultiplexing properties receives the modulated signals containing the ID, the geographical position of the LED, and other information, and then it demultiplexes and decodes the data and locates the mobile device within the environment. Different layouts are analyzed; square and hexagonal meshes are tested, and a two-dimensional localization design, demonstrated by a prototype implementation, is presented. The key differences between both topologies are discussed. For both, the transmitted information, indoor position, and motion direction of the customer are determined. The results show that the LED-aided VLC navigation system enables to determine the position of a mobile target inside the network, to infer the travel direction as a function of time, and to interact with the received information.
- Corporate Citizenship or when ethics belongs to the organisations DNAPublication . Eiró-Gomes, Mafalda; Raposo, Ana Luísa Canelas Rasquilho; Simão, JoãoIn the first decades of the 21st century companies have been confronted with new challenges and risks. No one expects anymore to hear from a CEO that the only responsibility of a business is to improve profits but we don’t seem to hear often which are the specific responsibilities organizations are willing to take in our contemporaneity. Do they go beyond philanthropic and voluntary work? How concerned are they with Internal Corporate Social Responsibility (CSR) activities? What constrai nts to they impose on the supply chain practices? What are their environmental practices? What about innovation and specially responsible innovation? The option for the concept of "Corporate Citizenship" (Woot, 2013 and 2016) in the context of this article is not altogether innocent. The authors by using it in detriment of some other notions as those of “Enterprise Social Responsibility” or “CSR” wish to emphasize their concern with aspects other than those that could be subsumed under the idea of hands - out philanthropy. They want also to consider aspects that can belong to the realm of organizations being seen precisely as social and political actors in our globalized societies. The main research question is precisely what do the organizations that belong t o the portuguese association for the development of corporate citizenship (GRACE), define as being their main social responsible principles, policies and practices. To paraphrase Lord Chris Patten, in a theoretical framework that we can call of an "ethics of duty," a clear modern paradigm, to act well is still, and in the end, to act in our best interest. Do these organisations act according to this idea? What do they consider as belonging to the realm of CSR? What is the role of strategic communications in these processes (Hallahan et al., 2007)? How do they report, and moreover, how do they express their practices? In accordance to an interpretivist point of view, an exploratory study and a qualitative research design both in what concerns the data recolle ction as well as the data analysis was developed. Researchers studied the main communicative instruments used to report social responsible practices and afterwards face - to - face interviews (20) with the CSR responsible in each organization were conducted. A qualitative content analysis was applied to the data recollected.