Explore the vast range of titles available.

PurposeMicroalgae biodiesel has attracted considerable attention as a potential substitute for fossil fuels and biodiesel from food crops. Nevertheless, its reported climate impacts in the scientific literature vary significantly. This article describes and synthesizes the range of results found in the life cycle assessment (LCA) literature regarding microalgae biodiesel studies to investigate whether particular parameters, e.g. technologies, were associated with higher or lower greenhouse gas (GHG) emissions so that a best practice can be inferred from currently available LCA data and thereby recommended.MethodsA systematic literature review and meta-regression analysis (MRA) of 36 LCA studies that report on the GHG emissions of microalgae biodiesel was conducted. An assessment of key aspects, including modelling choices and technologies, was performed. Furthermore, MRA models were formulated considering several variables of interest describing both technical and modelling choices to identify the main causes for the variability in GHG emissions per MJ of biodiesel. Variables chosen include: microalgae species; culture medium; cultivation system; source of CO2; extraction technology; conversion technology; system boundary; geographical scope; inclusion or exclusion of capital goods; and how multifunctionality was handled.Results and discussionThe reviewed studies altogether reported 308 results ranging from −0.7 to 3.8 kg CO2 eq. MJ−1biodiesel, portraying 19 different system configurations. Despite the comprehensive range of variables assessed, the models generated could not plausibly explain that the variability in GHG emissions depends either on the technologies considered or on the methodological choices adopted. However, the following relationships could be observed: location in Europe and high oil productivity were associated with lower emissions, whilst dry extraction should be avoided for leading to higher GHG emissions, on average.ConclusionsThere is a large degree of variability within the technologies considered, as well as the methodological choices adopted, so that no robust conclusions could be drawn from the MRA. Notwithstanding, average GHG emissions reported were more than twice as high as fossil diesel and, while there are some studies showing large benefits, none of the various algae technologies performed consistently better than fossil diesel, questioning the climate-mitigation potential of microalgae biodiesel.

This article contributes to the assessment of the hygrothermal conditions of residential buildings in the Azores archipelago and defines strategies that may contribute to the improvement in indoor air quality. These objectives were fulfilled by in situ monitoring of the hygrothermal conditions of a typical building on Terceira Island. Complementary tests to determine the thermal conductivity of exterior walls and ventilation rates were also conducted. The results were used to validate a simulation model, and different ventilation strategies were simulated using the combined heat, air, and moisture transfer model in EnergyPlus. The model took into account the typical construction methods and materials of the archipelago, as well as the reference weather data sets available for the region. The monitoring campaign showed that the percentage of time in which thermal comfort conditions were achieved was very low, varying from 5% to 32%, being the main cause for discomfort in the humidity level in the indoor environment. The simulation results pointed out the sensitivity of the problem, showing that ventilation may not always be, by itself, beneficial to thermal comfort. In particular, ventilation strategies should be established taking into account additional criteria other than the air change rate, namely the periods of the day and year in which ventilation should be performed, as well as the duration of these periods.

Global warming and security of energy supply are main concerns in the international agenda. Renewable energy sources, including biofuels, are being promoted as possible contributions to address these problems. Nevertheless, significant disagreement and controversies exist regarding the actual benefits of biofuels displacing fossil fuels, as shown by a large number of publications that analyze the life-cycle of biofuels and that have varying and sometimes contradictory conclusions, even for the same biofuel type and pathway. A comprehensive assessment of the key issues that cause uncertainty and variability of the results is thus needed to ensure reliable outcomes and guarantee the environmental sustainability of policies and regulations at this level. Against this background, this dissertation aims to respond to the following questions: How do different (and alternative) European biofuel production systems compare each other? Are they equally efficient in terms of energy balance, GHG intensity, and land use? And how do biofuels compare with the fossil fuels they displace? These issues are assessed by providing a thorough review on European biofuel systems from an energy and greenhouse gas (GHG) life-cycle perspective, including detailed assessment of relevant aspects, namely data used, major assumptions, modeling choices and the extent to which they influence the results. The main sources of uncertainty impacting the life- cycle of biofuels are investigated and a robust framework for incorporating uncertainty issues in the modeling is implemented. To demonstrate the application of the methodology, life-cycle models for five European first-generation biofuel systems are developed, explicitly addressing uncertainty. Finally, the benefits and drawbacks of European biofuel systems-modeled under uncertainty- are presented and discussed in terms of energy renewability efficiency and GHG intensity. It has been concluded that: land use change dominates the GHG intensity of biofuels, although with a high level of uncertainty; optimum use of co-products is required to improve the energy efficiency and GHG intensity of biofuels; conversion of full- or low-tillage croplands to energy crops results in biofuel life-cycle GHG emissions lower than equivalent fossil fuel emissions, whereas conversion of (improved) grassland to energy crops does not contribute to GHG savings over fossil fuels in the short- to mid-term. Calculated carbon payback times of the latter option are always above 50 years for the majority of biofuel systems

Global warming and security of energy supply are main concerns in the international agenda. Renewable energy sources, including biofuels, are being promoted as possible contributions to address these problems. Nevertheless, significant disagreement and controversies exist regarding the actual benefits of biofuels displacing fossil fuels, as shown by a large number of publications that analyze the life-cycle of biofuels and that have varying and sometimes contradictory conclusions, even for the same biofuel type and pathway. A comprehensive assessment of the key issues that cause uncertainty and variability of the results is thus needed to ensure reliable outcomes and guarantee the environmental sustainability of policies and regulations at this level Against this background, this dissertation aims to respond to the following questions: How do different (and alternative) European biofuel production systems compare each other? Are they equally efficient in terms of energy balance, GHG intensity, and land use? And how do biofuels compare with the fossil fuels they displace? These issues are assessed by providing a thorough review on European biofuel systems from an energy and greenhouse gas (GHG) life-cycle perspective, including detailed assessment of relevant aspects, namely data used, major assumptions, modeling choices and the extent to which they influence the results. The main sources of uncertainty impacting the life-cycle of biofuels are investigated and a robust framework for incorporating uncertainty issues in the modeling is implemented. To demonstrate the application of the methodology, life-cycle models for five European first-generation biofuel systems are developed, explicitly addressing uncertainty. Finally, the benefits and drawbacks of European biofuel systems-modeled under uncertainty-are presented and discussed in terms of energy renewability efficiency and GHG intensity. It has been concluded that: land use change dominates the GHG intensity of biofuels, although with a high level of uncertainty; optimum use of co-products is required to improve the energy efficiency and GHG intensity of biofuels, conversion of full-or low-tillage croplands to energy crops results in biofuel ife-cycle GHG emissions lower than equivalent fossil fuel emissions, bx whereas conversion of (improved) grassland to energy crops does not contribute to GHG savings over fossil fuels in the short- to mid-term. Calculated carbon payback times of the latter option are always above 50 years for the majority of biofuel systems. As a closing remark for this dissertation: Robust life-cycle modeling approaches incorporating uncertainty are essential to improve the transparency and reliability of life-cycle studies and better support decisions on whether or not to support specific biofuel pathways.

The ageing process involves a natural degeneration of physiological function and can imply life constraints, namely during activities of daily life (ADL). Walking can be strongly affected by strength, gait, and balance changes, which affect quality of life. The quality of life of the older adult is associated with available solutions that contribute to an active and safe ageing process. Most of these solutions involve technical aids that should be adapted to older adults' conditions. : To identify the advantages and disadvantages of two-wheeled walkers and of two different self-locking systems designed and developed by the authors. : Two studies were performed based on the possible walker combinations used, using a walker with no wheels (classic fixed walker), a two-wheeled walker with self-locking mechanism made of gears and a spring (Approach 1), and a two-wheeled walker with a self-locking mechanism which uses a single spring (Approach 2). These combinations were tested in two quasi-experimental studies with pre-post test design. : No significant differences in duration, gait speed, and Expanded Timed Get Up and Go (ETGUG) were found between the walkers, but there was a marginally significant difference in Physiological Cost Index (PCIs), which means that the energetic cost with Approach 1 was greater than that with Approach 2. Users reported a feeling of insecurity and more weight, although no significant differences were observed and they were found to be equivalent in terms of safety. Study 2 found an improvement in duration and gait speed in the ETGUG between the different types of self-locking systems. : The PCI is higher in the two-wheeled walker models and with the self-locking mechanism. Approach 2 did not show better conditions of use than the other two walkers, and participants did not highlight its braking system. Although safety is similar among the three walkers, further studies are needed, and the braking system of the two-wheeled walker needs to be improved (Approach 2).

Bedridden patients usually stay in bed for long periods, presenting several problems caused by immobility, leading to a long recovery process. Thus, identifying physical rehabilitation programs for bedridden patients with prolonged immobility requires urgent research. Therefore, this scoping review aimed to map existing physical rehabilitation programs for bedridden patients with prolonged immobility, the rehabilitation domains, the devices used, the parameters accessed, and the context in which these programs were performed. This scoping review, guided by the Joanna Briggs Institute’s (JBI) methodology and conducted in different databases (including grey literature), identified 475 articles, of which 27 were included in this review. The observed contexts included research institutes, hospitals, rehabilitation units, nursing homes, long-term units, and palliative care units. Most of the programs were directed to the musculoskeletal domain, predominantly toward the lower limbs. The devices used included lower limb mobilization, electrical stimulation, inclined planes, and cycle ergometers. Most of the evaluated parameters were musculoskeletal, cardiorespiratory, or vital signs. The variability of the programs, domains, devices and parameters found in this scoping review revealed no uniformity, a consequence of the personalization and individualization of care, which makes the development of a standard intervention program challenging.

Bedridden patients usually stay in bed for long periods, presenting several motor problems caused by immobility, such as reductions in muscle mass, bone mineral density and physical impairment, resulting in a long recovery process. Thus, identifying physical rehabilitation programs for bedridden patients with prolonged immobility is a matter of urgent research for a solution that will help health professionals and stakeholders to develop more adjusted programs and identify possible gaps. To date, no previous scoping reviews addressing this purpose have been found. This scoping review will be guided by the Joanna Briggs Institute (JBI) methodology, will focus on physical rehabilitation programs for bedridden patients with prolonged immobility and aims to map the programs, the devices used, and the parameters assessed. A relevant set of electronic databases and grey literature will be searched. Data extraction will be conducted using a tool developed by the research team that will address the review objectives and questions. Data synthesis will be presented in tabular form and a narrative summary aligned with the review’s objective. This scoping review will contribute to the improvement of clinical practice, identifying key challenges that might justify the need to develop new programs suitable in clinical and organizational contexts.

This work focuses on studying the possibility of 3D printing of composite materials composed by cork and a polymer matrix (CPC). Initially the cork was mixed with two types of polymers (HDPE and PP) in different proportions and later processed using extrusion and injection. The composites were tested to study the physical, chemical and mechanical properties. The material was then tested on a large-scale 3D printer to study its feasibility and the ability to produce new products through 3D printing. Attention was focused on the use of pure cork, varying the concentration of cork and coupling agent in thermoplastic matrix composites of PP and HDPE. It was demonstrated that the increase of 5wt.% of coupling agent in the two types of polymers significantly improved the mechanical properties and adhesion between the phases but the increase in cork concentration decreased mechanical properties and crystallinity. The CPCs with PP showed to have better mechanical properties, better aesthetic and internal structural quality, and easier processability than those with HDPE matrix. Nevertheless, the HDPE CPCs showed a high degree of crystallization. Concerning 3D printing, with the filament obtained was demonstrated the possibility of making new products based on natural cork fibers, showing promising results, although additional research is still needed to optimize the process.

Enquadramento: Ao envelhecimento associam-se problemas agudos e crónicos que interferem com a mobilidade da pessoa idosa e a sua independência. Atualmente, existem no mercado diversas tipologias de andarilho com diferentes perfis de desempenho funcional do idoso, que visam compensar limitações físicas e prevenir quedas. Objetivo: Comparar o perfil de desempenho funcional de pessoas idosas institucionalizadas tendo em conta o tempo percorrido, velocidade de marcha, variância frequência cardíaca e custo energético despendido aquando da realização do teste Expanded Timed Get-up-and-Go no uso de três tipologias de um andarilho: fixo, duas rodas e quatro rodas. Metodologia: Estudo quasi-experimental antes e após de grupo único, numa amostra de conveniência de 40 pessoas idosas institucionalizadas. Resultados: Foram identificadas diferenças significativas no tempo percorrido (X2 = 15,65; p < 0,001) e na velocidade de marcha (X2 = 15,80; p < 0,001). Conclusão: Não existe uma solução ideal única entre as tipologias do andarilho analisadas, sendo, portanto, desejável uma solução personalizada às características e necessidades da pessoa idosa institucionalizada. Background: Aging is associated with acute and chronic problems that interfere with older adults’ mobility and independence. There are several types of walkers available in the market with different functional performance profiles of older people which aim to compensate for physical limitations and prevent falls. Objective: To compare the functional performance profile of institutionalized older adults taking into account the total time, gait speed, heart rate variability, and energy cost during the Expanded Timed Get-up-and-Go test using three types of walkers: fixed, two-wheeled, and four-wheeled walkers. Methodology: One-group pretest and posttest quasi-experimental study in a convenience sample of 40 institutionalized older people. Results: Significant differences were found in the total time (X2 = 15.65; p < 0.001) and gait speed (X2 = 15.80, p < 0.001). Conclusion: There is no unique ideal solution among the types of walkers analyzed in this study, thus a tailored solution is desirable to meet institutionalized older adults’ characteristics and specific needs. Marco contextual: El envejecimiento está asociado com problemas agudos y crónicos que interfieren en la movilidad de la persona mayor y su independencia. En la actualidad, existen en el mercado varios tipos de andadores com diferentes perfiles de rendimiento funcional de las personas mayores, que tienen como objetivo compensar las limitaciones físicas y prevenir las caídas. Objetivo: Comparar el perfil de rendimiento funcional de las personas mayores institucionalizadas teniendo en cuenta el tiempo recorrido, la velocidad de la marcha, la variancia de la frecuencia cardíaca y el coste energético gastado durante la prueba Expanded Timed Get-up-and-Go en el uso de tres tipologías de andador: fijo, de dos ruedas y de cuatro ruedas. Metodología: Estudio cuasiexperimental antes y después de un solo grupo, en una muestra de conveniencia de 40 personas mayores institucionalizadas. Resultados: Se identificaron diferencias significativas en el tiempo recorrido (X2 = 15,65; p < 0,001) y en la velocidade de la marcha (X2 = 15,80; p < 0,001). Conclusión: No existe una única solución ideal entre las tipologías de andador analizadas, por lo que lo mejor es una solución personalizada a las características y necessidades de la persona mayor institucionalizada.