Sky commons as a basis to explore the touristic potential of the Alqueva area (Portugal)

This paper analyzes the use of an unpolluted night sky as the basis for the differentiation of a rural tourism destination. As it has been pointed out in other studies the use of the commons as part of the tourism offer may lead to situations of overuse and pollution. In the present case it is shown that by having awareness of the tourism potential of this common resource, stakeholders of the Alentejo Region joined efforts to mitigate all the sources of pollution. A resource that was being neglected has become in the center of preservation policies of local public authorities of this region.info:eu-repo/semantics/submittedVersio

Implementation of a program for the analysis of the costs of equipments' maintenance until the end of their useful life

Companies face nowadays a very competitive environment and they have to be well managed to remain sustainable. For being sustainable the company needs either to increase its prices over time or has to reduce the amount of expenses. Reducing costs may be the best option once the global market is very competitive. This work results from the intention of a company (ME-Construction Company) to get a tool to support the decisions related to the equipment management. The aim is to create a model for the analysis of the costs resulting from using MEConstruction Company’s equipments. The studied case is real. This model is the Life Cycle Cost complemented by the Net Present Value and Equivalent Annual Cost. It is worked on a representative sample of the equipment of the company. The application of this model allows the manager to have the estimating tools which may support and justify his decisions in the company. During the equipment’s lifetime, he may have the right perception of the evolution of the expenses and income. The company should develop an equipment costing methodology as much effective as possible in order to consider the expenses that are not included in the equipment value and to consider the equipments which release less greenhouse gases contributing to reduce the global greenhouse effect

Relative Abundance and Compositional Variation of Silicates, Oxides and Phosphates in the W-Sn-Rich Lodes of the Panasqueira Mine (Portugal): Implications for the Ore-Forming Process

Panasqueira is a world-class W-Sn-Cu lode-type deposit located in Portugal. It consists of a dense swarm of subhorizontal quartz lodes criss-crossed by several ENE–WSW and N–S fault zones, bordering Late Variscan granite and hosted in Late Ediacaran—Early Cambrian metasediments. The relative abundance and compositional variation (assessed with EPMA) of the main silicates, oxides and phosphates forming the quartz lodes and their margins were examined, aiming to explore: (i) mineral and geochemical zonation at the mine scale; and (ii) some conclusions on the chemical nature of prevalent fluid inflows and T-conditions of mineral deposition. Quartz lodes nearby or far from the known greisen-granite cupola display significant differences, reflecting multiple fluid influxes of somewhat distinct composition related to various opening and closing events extending for several My, ranging from an early “oxide–silicate stage” (OSS) to a “main sulfide stage” (MSS), and further on to a post-ore carbonate stage (POCS); however, a rejuvenation event occurred after MSS. The onset of OSS was placed at ca. 299 ± 5 Ma and the rejuvenation event at ca. 292 Ma. The OSS was confined to ≈500 ≤ T ≤ 320 °C, following rutile and tourmaline growth under ≈640 ≤ T ≤ 540 °C (depending on aSiO2). The rejuvenation event (≈440–450 °C) preceded a late chlorite growth (≈250–270 °C) and the progression towards POCS.info:eu-repo/semantics/publishedVersio

Credit Guarantee and the Impact in Financial Structure of the Portuguese SMEs

The aim of this work is to show the relevance of guarantees provided by the Mutual Credit Guarantee System (MCGS - the Portuguese Society of Credit Guarantee SPGM) as an instrument used in the financing of SMEs, especially in restructuring long-term debt (LTD) and bank loans. The study provides empirical evidence and puts forward an explanatory model of the influence of the mutual credit guarantees on the financing of SMEs. The results obtained show that long-term debt (LTD) financing is positively influenced by the guarantees provided by the MCGS to SMEs as it allows greater debt capacity, especially in the medium and long term, for firms that usually cannot obtain this type of financing. The results also suggest that this type of guarantees creates an environment of confidence among all stakeholders involved.info:eu-repo/semantics/publishedVersio

Água e saúde: análise do risco da presença de trihalometanos na água para consumo humano

A aplicação de compostos clorados e do ozono na desinfeção da água trouxe enormes benefícios para a preservação da saúde pública, através da obtenção duma água bacteriologicamente segura para consumo humano. Contudo estes compostos podem induzir a formação de subprodutos da desinfeção (SPD) com efeitos cancerígenos e mutagénicos comprovados. Neste trabalho apresenta-se uma síntese do estudo sobre a ocorrência de trihalometanos na água distribuída, realizado nos 14 municípios do distrito de Braga (Portugal), visando a avaliação do risco de cancro (RC) e do risco de efeitos não carcinogénicos (RENC) através do método proposto pela USEPA e IRIS. Num cenário gravoso, o RC deu um valor superior ao limite máximo definido como negligenciável, em todos os municípios analisados, sendo a ingestão a via de exposição mais relevante. O resultado do RENC foi quase sempre inferior à unidade indicando um nível de risco aceitável. O uso de indicadores do risco para a saúde pode constituir uma ferramenta útil quer no apoio à decisão das entidades gestoras de sistemas de abastecimento de água, quer na definição de estratégias e políticas de saúde pública que visem a mitigação deste risco de modo a preservar/aumentar a qualidade de vida das populações

Book of Abstracts of SPE 2021

Book of Abstracts of SPE 202

Evaluating 5G coverage in 3D scenarios under configurable antenna beam patterns

Active Antenna Systems (AASs) play a key role in the performance of 5 th Generation (5G) networks as they enable the use of Massive Multiple-Input Multiple-Output (mMIMO) and directional beamforming. Besides, AASs can be configured with distinct broadcast beams configurations. In this work, the coverage provided by the broadcast beam configurations of a real AAS is evaluated. A 3-Dimensional (3D) configurable synthetic scenario was proposed to evaluate the resulting 5G coverage from all the possible antenna beam configurations. This analysis revealed that beam configurations with several horizontal beams and one vertical are recommended for urban macro deployments. Moreover, it was demonstrated that the percentage of covered area in a real scenario is approximated by an equivalent synthetic scenario with a Pearson correlation of 0.98. The synthetic scenario has the advantage of not requiring 3D building databases. Finally, an interference analysis in multi-site real scenarios was conducted, where it was verified that some antenna configurations introduce excessive interference for the level of coverage provided.info:eu-repo/semantics/publishedVersio

Mobile sensing system for cycling power output control

This paper describes the development of a novel cycling effort control sys-tem that contributes to promote the users’ physical health and mobility. This system controls the motor assistance level of an electric bicycle in order to ensure that the cyclist’s power output remains inside the desired limits, regardless of changes in variables such as the speed of the bicycle or the slope of the terrain. The power output is monitored using a sensor device that provides raw torque and cadence data, whereas a smartphone application processes these data, implements the effort control algorithm and provides the user interface. Modules on the bicycle handle the data acquisition, wire-less communication with the smartphone and driving of the motor assis-tance level. Experimental results validate the effectiveness of the imple-mented power output control system.This work is supported by FCT (Fundação para a Ciência e Tecnologia) with the reference project UID/EEA/04436/2013, and by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941

Adsorption of propane, propylene and isobutane on a metal–organic framework : molecular simulation and experiment

The separation of propane/propylene mixtures is the most energy-intensive operation practiced in the petrochemical industry. Adsorptive processes are currently viewed as a promising alternative to cryogenic distillation for the separation of these mixtures. In this paper, we explore the possibility of using a new metal-organic framework material, CuBTC, in adsorptive separation processes, particularly in a simulated moving bed (SMB) context using isobutane as a potential desorbent. A gravimetric method has been used to measure the adsorption equilibrium isotherms of propylene, propane and isobutane onto a commercial CuBTC powder over a temperature range from 323 to 423K and pressures up to 100kPa. These were complemented by a detailed experimental characterization of the structure of CuBTC using XRD and SEM techniques. Comparison of experimental isotherms with grand canonical Monte Carlo simulations in CuBTC showed that propane adsorption occurs preferentially in small octahedral pockets, while isobutame is excluded from these pockets due to its bulky structure. Propylene was seen to interact strongly with unsaturated metal sites, due to specific pi-Cu bonds. These interactions significantly enhance the affinity of this MOF for unsaturated hydrocarbons. Furthermore, in a range of temperatures and pressures, the affinity of CuBTC for isobutane is intermediate to that of propane and propylene. Our results suggest that CuBTC-isobutane is a very promising adsorbent-desorbent pair for use in SMB processes for propane/propylene separations