Suchergebnisse

Le Bitcoin et les crypto-monnaie sont des monnaies numériques et ont comme singularité d'être décentralisé et fonctionne sans autorité hiérarchique. Ces monnaies digitales (ainsi que la Blockchain, qui est issue de ces dernières) possèdent leurs caractéristiques propres pouvant déboucher sur de nombreuses applications et utilisations dans toutes sortes de secteurs ou industriels. Néanmoins, ces innovations présentent des risques qui nous amènent à nous interroger sur les cadres juridiques, politiques, sociaux et éthiques qui devraient les limiter. Le Bitcoin et les crypto-monnaies présentent également des limites technologiques : par exemple, la volatilité de certaines valeurs boursières de ces monnaies digitales pose des problèmes qu'il importe de résoudre, si ces nouvelles technologies veulent gagner en notoriété et confiance auprès du grand public et si elles veulent devenir des alternatives crédibles au système centralisé que nous connaissons aujourd'hui. Les attributs innovants des crypto-monnaies poussent les gouvernements à proposer des mesures de régulation qui sont, au niveau international, peu homogènes.

The additive manufacturing technology, also known as 3D printing, is gaining popularity amongst the general public, the media, and in the industries. It is believed to be a disruptive technology, and so the assessment of social impacts is very important. There are still very few works in this area and social impacts are yet to be identified. The first objective of this dissertation was to identify the possible social impacts caused by the implementation of this technology. There were found eleven social strands that were impacted with the additive manufacturing technology. These strands were: educational; commercial; intellectual property; employment and labour; access to the technology; economic; environment and energy; supply chain; health and occupational hazards; healthcare and safety; and governmental approach. There were found twenty-six social impacts amongst these social components. The second objective was to determine who are the stakeholders by those social impacts. For this we analyze the categories of stakeholders in a product life cycle assessment perspective, and matched the social impacts to the stakeholders' categories, creating a typology for the additive manufacturing social impacts. Amongst every stakeholder category, a set of sub-categories is proposed for each stakeholder too. The third, and last, objective, fulfilled by this dissertation, was to propose social indicators for the additive manufacturing impacts identified. A list of proposed indicators is found in the dissertation. This dissertation results in a conceptual model to analyze the additive manufacturing social impacts.

The use of alternative feedstock as waste cooking oils (WCO) and bovine tallow for biodiesel production has some advantages. It is cheaper than edible vegetable oils and it is a way to valorize a sub-product. Nevertheless, these oils possess some contaminants, specially free fatty acid (FFA) content, which can reduce the quality and yield of biodiesel production. This problem was solved by testing different operating conditions and different transesterification procedure and equipments for each stage of processing. Technological assessment of process was carried out to evaluate their technical benefits, limitations and quality of final product. In this work biodiesel was produced by an alkali-catalyzed transesterification and by a two step esterification/alkali-catalysed transesterification in cases which FFA content has above 3%. Evaluation of quality from raw materials and final biodiesel was performed according to standard EN 14214. Results show that all parameters analyzed meet the standard and legislation requirements. This evidence proves that in those operational conditions the biodiesel produced from WCO and bovine tallow can substitute petroleum-based ...

As word society has grown exponentially it was created more and more wastes. Each year European Union throws away 3 billion tons of waste, and some 90 million tons of that are hazardous. It is clear that treating and disposing of all this material - without harming the environment becomes a major trouble. In the early years 90 the amount of waste generated in Europe increased by 10%. Most of that was thrown away in incinerators, or dumped into landfill creating environmental damage. Landfill disposal not only takes valuable land space but also causes air, water and soil pollution, discharging carbon dioxide (CO2) and methane (CH4) into the atmosphere and chemicals and pesticides into the earth and groundwater. This situation is harmful to human health as well as to plants and animals. These events triggered urgency for a responsibility and appropriate legislation for correct waste management. EU and Portuguese policy main objective in the waste management are prevent and reduce waste production, and reduce their toxicity, through the reuse and modification of production processes, adopting cleaner technologies. Waste management must also avoid or at least reduce its risk to human health and to environment. In Portugal, wastes sector was suffered a revolution on the last years, due to the appearance of the Strategic Plan for Solid Waste I (PERSU I) in 1997 and by the constant pressure from the EU for their state members and waste producers. In December 2006 was created the PERSU II to correct all mistakes made in the previous plan. However soon realized that PERSU II had very ambitious goals and so unattainable that triggered the need to reformulate these objectives. The aim of this overview in waste management was to follow the goals outlined in PERSU II, identifying the progress of each operational system over the years. It was also the target compare those results to European statistics tracing possible ways to permit compliance with EU objectives in ...

Biodiesel, as an alternative fuel, has many benefits. It is biodegradable, non-toxic and compared to petroleum-based diesel, has a more favorable combustion emission profile, such as low emissions of carbon monoxide, particulate matter and unburned hydrocarbons. In brief, these merits make biodiesel a good alternative to petroleum based fuel. Biodiesel feedstocks derived from microalgae and macroalgae have emerged as one of the most promising alternative sources of lipid for use in biodiesel production because of their high photosynthetic efficiency to produce biomass and their higher growth rates and productivity compared to conventional crops. In addition to their fast reproduction, they are easier to cultivate than many other types of plants and can produce a higher yield of oil for biodiesel production. In this work biodiesel was produced using the species of microalgae Chlorella emersonii and Botrycoccus braunii due to its high oil content. Biodiesel productions through macroalgae oil are in preliminary phase. Therefore, results and methodology will not be presented in this work. Technological assessment of process was carried out to evaluate their technical benefits, limitations and quality of final product. In this work biodiesel from microalgae oil was produced by an alkali-catalyzed transesterification and it was achieved 93% of mass conversion. The evaluation of quality from raw materials and final biodiesel was performed according to standard EN 14214. Results show that all parameters analyzed meet the standard and legislation requirements. This evidence proves that in those operational conditions the biodiesel produced from microalgae can substitute petroleum-based ...

The project EcoGreenRoofs - EGR aims to develop ecological substrates for application in green roofs, which include in their formulation industrial waste of organic and inorganic base. The substrates are tentatively produced exclusively from industrial waste and / or materials derived from waste treated, and tested at a facility to be studied, developed and built on pilot scale. The substrates produced will be tested under real conditions for their validation and inherent production process. This project aims also to evaluate the commercialization of substrates by analyzing the technical, economic and environmental components. The project is being carried out in co-promotion by two enterprises, one with know-how in the execution of green roofs (Neoturf) and the other with knowledge to implementation of industrial solutions aiming waste management (W2V), and by two SI & I entities with the knowledge and means to develop waste recovery studies (CVR) and roof solutions (Itecons). ; This work has been co-financed by Compete 2020, Portugal 2020 and the European Union through the European Regional Development Fund – FEDER within the scope of the project EGR - EcoGreenRoof: Desenvolvimento de eco-materiais para coberturas verdes (POCI-01-0247-FEDER- ...

This review aimed to analyze the findings in the literature related to Mixed Martial Arts (MMA) through an exploratory systematic review and to present the state of the art from a multifactorial perspective. The review was conducted in accordance with the PRISMA statement, with a search performed in the Scopus, PubMed, and Web of Science databases. Participants were competitive athletes (amateurs or professionals) of regional, national, or international levels. Of the 2763 registries identified, 112 studies met the eligibility criteria. The pooled sample size and age were 20,784 participants, with a mean age of 27.7 ± 6 years for male and 28.9 ± 3 years for female, with the vast majority of athletes being male (94.9%). MMA athletes were 17.2% amateurs, 73.8% professionals, and 9% were not reported. The scientific literature related to MMA reported injuries (n = 28), weight loss (n = 21), technical and tactical analysis (n = 23), physical fitness (n = 8), physiological responses and training characteristics (n = 13), psychobiological parameters (n = 12), and interventions applied to MMA athletes (n = 7). Therefore, this exploratory systematic review presents practitioners and researchers with seven broad summaries of each facet of performance of importance in this population of athletes.