Browsing by Author "Silva, Jorge"
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- Air transportation: perception and impact of passengers with reduced mobilityPublication . Zorro, Sara; Macário, Rosário; Silva, JorgeAir transport has many restrictions for persons with reduced mobility (PRM). This study aims to better understand the needs of PRMs and the main constraints they face within airports and aircraft. The passengers’ air rights and how they are being met for PRMs were analysed. An online survey was used to gather information about accessibility constraints and PRMs’ perception of air travel. The specific regulations for these passengers are not being properly complied with. There is still room for both airports and airlines to improve PRM experience during air travel.
- Airports Catchment Area Size Definition: a Portuguese Case StudyPublication . Baltazar, Maria Emilia; Silva, JorgeThe definition of the Catchment Area of an airport is very broad and current literature suggests doing it in combination with certain pre-defined criteria: the assessment of the impact or effectiveness of a certain airport, or from the perspective of competition between airports. This paper aims to assess the validity of the hinterland defined by the Portuguese airport manager, ANA - Aeroportos de Portugal. A case study was developed involving the three main national airports: Lisbon (LIS), Oporto (OPO) and Faro (FAO). ANA defined the hinterland of each airport. Thus, a survey was developed to the companies located within the hinterland of every airport aiming to understand the existence of any relationship between them and the closest airport. We followed a stratified sample method to determine the size of the survey. We only considered import and export companies with the highest business volumes. Data analysis was performed using GIS (Geographic Information System), that is a software, spatial data and computational procedures system that enables and facilitates the analysis, management and representation of space and phenomena that occur in it. We collected a total of 243 surveys. The main conclusion of the study was that the calculation of an airport’s hinterland based exclusively on the travel time or distance is, potentially, misleading. It is proposed the use of other factors. The validity of such a method and practice raises some doubts. The actual distribution of economic activities and population is ignored as well as the mutual influence of several airports. Further research is now needed to calculate airports actual influence.
- CDM description and operational implementation challengesPublication . Netto, Omar; Silva, Jorge; Baltazar, Maria EmiliaThe purpose of this research is to discuss a subject that, today, is a significant challenger of all the International Civil Aviation Organization (ICAO) signatory countries: the implementation of the Performance Improvement Areas preconized in the Global Air Navigation Plan (GANP). To achieve the objective of providing a better understanding of Airport Collaborative Decision Making (A-CDM) processes the strategy chosen was to present the vision and implementation of the main entities representing the aviation area, such as the didactic form as the article is sequenced and the case studies discussed will present solutions for countries that aren’t so advanced in the implementation of their A-CDM operational processes. Also, the article will act as a guide for all stakeholders. The contribution of the research will be to provide further support to all stakeholders in the air transport sector, regarding basic knowledge and more technical approaches of compliance with the recommended guidelines for the next decades in GANP. ICAO. In this specific case, regarding Performance Improvement Area: Airport Operations and the A-CDM module.
- Development of a new chitosan hydrogel for wound dressingPublication . Ribeiro, MP.; Espiga, Ana; Silva, Daniela; Baptista, Patrícia; Henriques, Joaquim; Ferreira, Catarina L.; Silva, Jorge; Borges, João; Pires, Eduardo; Chaves, Paula; Correia, Ilídio Joaquim SobreiraWound healing is a complex process involving an integrated response by many different cell types and growth factors in order to achieve rapid restoration of skin architecture and function. The present study evaluated the applicability of a chitosan hydrogel (CH) as a wound dressing. Scanning electron microscopy analysis was used to characterize CH morphology. Fibroblast cells isolated from rat skin were used to assess the cytotoxicity of the hydrogel. CH was able to promote cell adhesion and proliferation. Cell viability studies showed that the hydrogel and its degradation by-products are noncytotoxic. The evaluation of the applicability of CH in the treatment of dermal burns in Wistar rats was performed by induction of full-thickness transcutaneous dermal wounds. Wound healing was monitored through macroscopic and histological analysis. From macroscopic analysis, the wound beds of the animals treated with CH were considerably smaller than those of the controls. Histological analysis revealed lack of a reactive or a granulomatous inflammatory reaction in skin lesions with CH and the absence of pathological abnormalities in the organs obtained by necropsy, which supported the local and systemic histocompatibility of the biomaterial. The present results suggest that this biomaterial may aid the re-establishment of skin architecture.
- Fuel Burn Benefits of Altitude Optimization Strategies in the Cruise Phase of LongHaul FlightsPublication . Silva, JorgeThis paper focuses on the vertical profile of the cruise phase of long-haul commercial flights covering legislation, operational standards, communications, surveillance, flight planning and performance aspects. Two case studies are presented: the first one describes and compares an actual vertical profile of a flight and an optimised one, with detailed calculations as well as results estimation; the second one compares two vertical profile optimization procedures strategies. Small modifications in how cruise phase of a flight is operated airlines can achieve cost reductions, mitigate environmental impacts, and contribute to airspace efficiency.
- Global decision support for airport performance and efficiency assessmentPublication . Baltazar, Maria; Rosa, Tiago; Silva, JorgeAirport benchmarking depends on airport performance and efficiency indicators, and it is an important issue for business, operational management, regulatory agencies, airlines and passengers. Using the MACBETH (Measuring Attractiveness by a Categorical Based Evaluation Technique) approach, a hierarchical additive value model is constructed with criteria weights and value scales derived from expert's judgments (obtained by an online survey) and by comparison of different reference levels and profiles of performance. This model measures airport performance and efficiency and also peer benchmarks it within a set of direct competitors or self-benchmarks itself during a specified period. GDS (Global Decision Support) model outputs, integrated into a management system, allows the identification of deficiencies requiring urgent intervention and corrective measures for its continuous improvement.
- Low-Cost Carriers Socio-Economic Impact in Tourism Development: The Case of Faro’s Airport HinterlandPublication . Rosado, Tiago; Baltazar, Maria; Silva, JorgeDue to airline market deregulation in Europe LCC’s (Low-Cost Carriers) depicts a fast growth in the last decade and it’s expected that this growth continues in the next years. Also, thisEuropean airline market change has affected the way many airports operate and it’s likely that thischange impacts not only airports performance and efficiency, but also its hinterland. Tourism development is one of the main beneficiaries of this new paradigm. Airport hinterland definition is very broad.Traditionally hinterland is measured by several kilometres’ radiuscentred on the airport or a certain travel time from one pointto the airport. However, this definition may be considered too simplistic because there are other indicators that can determine such influence area.Therefore, current literature prefers to do it in combination with certain pre-defined criteria: airport impact or effectiveness assessment, or a tourism destination perspective. This paper presents a study on airport hinterland socio-economic activity, with emphasis on tourism development due to LCC operations. Thestudy analyses socio-economic indicators from 2006 to 2012, a period whichrepresents the full operation entry and evolution of LCC’s in the Portuguese south airport of Faro. Results are aligned with the expectations created by literature review as well by the empirical preliminary analysis from the case study, showing a possible correlation between LCC movements and some hinterland indicators with direct impact on the tourism sector.
- Mechanical Properties of Fused Filament Fabrication MaterialsPublication . Santos, João; Silva, Jorge; Gamboa, Pedro; Neves, JoãoThe last decades have witnessed a significant development and increased usage of additive manufacturing (AM) technologies. Among these technologies, the fused filament fabrication (FFF) is being characterized by a massive worldwide spreading, from specialized companies with high-quality equipment to the hobbyist with home-made 3D printers. Thus, and aiming to help the user achieving the best results, it is essential to continuously perform studies and analyses concerning the mechanical properties resulting from different feedstock materials and printing settings. This study covers the execution and the subsequent comparative analysis of the results of flexural and tensile tests on three different types of FFF materials: polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and CarbonFilTM. It also comprehends a parallel study of the infill setting, more specifically the testing of specimens with a 50% infill reduction. All tests were executed according to the corresponding American Society for Testing and Materials (ASTM) standards. This work aims to clarify the properties of three different materials and the effect of the internal material reduction on the mechanical properties of 3D printed objects.
- Perdendo Altitude: Ascensão e Declínio da INFRAEROPublication . Arantes, Elaine; Netto, Omar; Silva, JorgeO cenário brasileiro de gestão de aeroportos indica que a Empresa Brasileira de Infraestrutura Aeroportuária (INFRAERO) vem perdendo receita com seus principais aeroportos. O objetivo deste artigo é entender o que contribuiu para a ascensão e o declínio da INFRAERO. Este estudo é apoiado pelas teorias da complexidade, dos sistemas e do interesse público. Considera a base teórica e legal da privatização, regulação e desregulamentação. Trata-se de um estudo exploratório-descritivo de natureza aplicada, seguindo a estratégia do estudo de caso. Os dados primários foram coletados em entrevistas com especialistas do setor aeroportuário. Os dados secundários obtidos através da análise documental dos relatórios da INFRAERO, bem como de estudos realizados no setor aeroportuário. Até 2003, a INFRAERO era uma operadora lucrativa e respeitada em todo o mundo. A recente concessão aeroportuária brasileira levou a INFRAERO a perder receita com seus principais aeroportos e terminais de carga. O moral de seus funcionários foi profundamente abalado. Espera-se que esta pesquisa indique os motivos do declínio da INFRAERO. Os dados primários e secundários coletados também permitirão uma discussão teórico-empírica. A pesquisa apresenta relevância empírica, teórica e acadêmica. Empiricamente, os resultados desta pesquisa permitirão aos membros do setor aéreo aprender, compreendendo os fatores que transformaram uma empresa respeitada e lucrativa a entrar em um processo de declínio. Teoricamente, retomará aspectos específicos das teorias no contexto organizacional do aeroporto. Academicamente, este estudo fornecerá subsídios para a continuação da pesquisa no setor aeroportuário em todo o mundo.
- Pilots performance and flight safety: the case of cognitive fatigue in unpressurized aircraft cabinsPublication . Rocha, João Artur de Freitas; Silva, JorgeThe purpose of this study is to understand the impact, evolution and perception of cognitive fatigue as a contributory factor on the occurrence of incidents and accidents, on unpressurized aircraft. This study use the science principles present in the Fatigue Management Guide for Airline Operators (FMG) [1] to evaluate data obtained by four methods of measuring cognitive fatigue [2] These consist in two objective measures, Psychomotor Vigilance Test (PVT) and an actiwatch (Readiband 5), and two subjective measures Samn-Perelli 7-point fatigue Scale (SPS) and sleep diaries. It is also obtained results from a survey related to this theme. From this research are draw conclusions of the influence and evolution of cognitive fatigue on the operations of unpressurized aircrafts and it is understood the difference between perceived cognitive fatigue and the real cognitive fatigue accumulated by the pilot. Is also drawn findings from a launched survey related to this theme. In this case study the focus will fall upon general aviation where there are no way to control and monitor the fatigue element, the cause of most incidents and accidents that occur in Portugal as concluded by analyzing several GPIAAF final reports using HFACS [3]. Normally this type of research is conducted within airline operators, that are already a very restricted and controlled domain of civil aviation, instead of within general aviation.