322 research outputs found

    Spatially and Temporally Explicit Energy System Modelling to Support the Transition to a Low Carbon Energy Infrastructure – Case Study for Wind Energy in the UK

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    Renewable energy sources and electricity demand vary with time and space and the energy system is constrained by the location of the current infrastructure in place. The transitioning to a low carbon energy society can be facilitated by combining long term planning of infrastructure with taking spatial and temporal characteristics of the energy system into account. There is a lack of studies addressing this systemic view. We soft-link two models in order to analyse long term investment decisions in generation, transmission and storage capacities and the effects of short-term fluctuation of renewable supply: The national energy system model UKTM (UK TIMES model) and a dispatch model. The modelling approach combines the benefits of two models: an energy system model to analyse decarbonisation pathways and a power dispatch model that can evaluate the technical feasibility of those pathways and the impact of intermittent renewable energy sources on the power market. Results give us the technical feasibility of the UKTM solution from 2010 until 2050. This allows us to determine lower bounds of flexible elements and feeding them back in an iterative process (e.g. storage, demand side control, balancing). We apply the methodology to study the long-term investments of wind infrastructure in the United Kingdom

    The critical role of the industrial sector in reaching long-term emission reduction, energy efficiency and renewable targets

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    This paper evaluates the critical contribution of the industry sector to long-term decarbonisation, efficiency and renewable energy policy targets. Its methodological novelty is the incorporation of a process-oriented modelling approach based on a comprehensive technology database for the industry sector in a national energy system model for the UK (UKTM), allowing quantification of the role of both decarbonisation of upstream energy vectors and of mitigation options in the industrial sub-categories. This enhanced model is then applied in a comparative policy scenario analysis that explores various target dimensions on emission mitigation, renewable energy and energy efficiency at both a national and European level. The results show that ambitious emission cuts in the industry sector of up to 77% until 2050 compared to 2010 can be achieved. Moreover, with a reduction in industrial energy demand of up to 31% between 2010 and 2050, the sector is essential for achieving the overall efficiency commitments. The industry sector also makes a moderate contribution to the expansion of renewable energies mostly through the use of biomass for low-temperature heating services. However, additional sub-targets on renewable sources and energy efficiency need to be assessed critically, as they can significantly distort the cost-efficiency of the long-term mitigation pathway

    Reinventing the energy modelling-policy interface

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    Achieving net-zero emissions through the reframing of UK national targets in the post-Paris Agreement era

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    The Paris Agreement provides an international framework aimed at limiting average global temperature rise to well below 2 ∘C, implemented through actions determined at the national level. As the Agreement necessitates a ‘net-zero’ emissions energy system by 2100, decarbonization analyses in support of national climate policy should consider the post-2050 period. Focusing solely on mitigation objectives for 2030 or 2050 could lead to blindsiding of the challenge, inadequate ambition in the near term, and poor investment choices in energy infrastructure. Here we show, using the UK as an example, that even an ambitious climate policy is likely to fall short of the challenge of net-zero, and that analysis of the post-2050 period is therefore critical. We find that the analysis of detailed, longer-term national pathways that achieve net-zero is important for future reassessment of ambition under nationally determined contributions (NDCs)

    Impact of Transformational Leadership on Psychological Empowerment and Job Satisfaction Relationship: a Case of Yemeni Banking

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    The banking sector of Yemen is under threat due to the lack of confidence and trust of the prospective clients that hindered economic development of the country. The study aimed to measure a moderating effect of transformational leadership on employees\u27 psychological empowerment and job satisfaction relationship so that attitudes of the Yemeni can be bumped towards banking. In this study, 160 employees were surveyed in different branches of four banks in Yemen. The data were analyzed in four stages namely, reliability and validity analysis, descriptive analysis, multivariate analysis, and hypotheses testing analysis. The study revealed a significant positive relationship between employees\u27 psychological empowerment and transformational leadership towards their job satisfaction level. If the policy makers consider the findings and undertake necessary measures, the Yemeni banking is expected to be accelerated which will contribute to the economy of the country

    Anti-aging potential of extracts from Washingtonia filifera seeds

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    The aim of this study was to test the inhibitory effect of fruit extracts from Washingtonia filifera on skin aging-related enzymes. The pulp extracts did not exert a significant enzyme inhibition while seed extracts from W. filifera exhibit anti-elastase, anti-collagenase, and anti-tyrosinase activities. Tyrosinase was mildly inhibited while a stronger effect was observed with respect to elastase and collagenase inhibition. Alcoholic extracts provided better results than aqueous extracts. Among them, methanol extracts showed the prominent enzyme inhibitory activities being IC50 value for elastase and collagenase comparable and even better than the reference compound. The inhibition mode of the most active extracts was investigated by Lineweaver-Burk plot analysis. Seed extracts from W. filifera were also investigated for their photo-protective effect by Mansur equation and the antioxidant activity of W. filifera extract was evaluated in oxidative-stressed cells. To evaluate the safety of the extract, the effect on cell viability of human keratinocytes cells was analyzed. Methanol extract presented the best photo-protective effect and exerted an antioxidant activity in a cellular system with no cytotoxic effect. The overall results demonstrate that W. filifera extracts are promising sources of bioactive compounds that could be used in cosmetic and pharmaceutical preparation

    Euphorbia characias Extract: Inhibition of Skin Aging-Related Enzymes and Nanoformulation

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    Plant extracts have long served as important sources of bioactive compounds, and they are currently the focus of extensive research in the development of novel preventive and therapeutic strategies. However, their health benefits are often limited by low bioavailability. Nanoparticle delivery systems can represent a solution to such limitations. Euphorbia characias is a Mediterranean shrub known to have biological activities, such as inhibiting tyrosinase and showing a potential role as a skin-whitening agent. In this study, an ethanolic extract from E. characias leaves was tested for its inhibitory activity on skin-related enzymes, such as elastase, collagenase, and hyaluronidase, and for sun protection factors. Moreover, the extract was formulated in phospholipid vesicles to improve its local bioavailability and applicability. The vesicles were characterized by size, surface charge, storage stability, and entrapment efficiency. The nanoformulation was also evaluated for antioxidant activity and assayed for cytocompatibility and anti-tyrosinase activity in melanoma cells. Our findings demonstrated that the extract has a photo-protective effect and enzyme-inhibitory properties. E. characias nanoformulation was also cytocompatible and improved the extract’s activity in the cells, suggesting a potential skin application for antimelanogenic treatments and confirming the key role of nanotechnological approaches to maximize plant extract’s potentialities

    The potential of marine energy technologies in the UK – Evaluation from a systems perspective

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    Accelerated technological change plays a crucial role in enabling the low-carbon energy transition. Quantitative energy modelling exploring alternative long-term decarbonisation pathways can support policy-makers in choosing the most important areas for technology promotion. This study analyses the potential contribution of marine energy in the UK from an energy systems perspective considering the trade-offs between local lead markets and global learning, the uncertainty in the learning potential, competition with alternative technologies and impacts on system balancing. The results indicate that only under very favourable conditions, i.e. with learning rates above 15% and high global deployment, marine energy w ill have a significant contribution to the UK decarbonisation pathway. Alternatively, marine energy could constitute a hedging strategy against multiple failure in other low-carbon options. The early strategic investments into marine energy lead, in most cases, to a slight rise in societal welfare costs compared to the respective cases without attempts to induce marine learning and brings benefits to the electricity system. Thus, on the whole, we conclude that marine energy has the potential to contribute to the UK energy system, but there is a substantial risk that strategic investments in a national lead market will not directly pay off in the long term

    Meiofauna metabarcoding in Lima estuary (Portugal) suggests high taxon replacement within a background of network stability

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    Meiofauna organisms play an important role in ecological and sedimentary processes in estuarine ecosystems. Recently, the application of environmental DNA (eDNA) for investigating meiofauna in different environments, improved the accessibility to its diversity and composition in a scale, frequency and depth previously unattainable. Nevertheless, little attention has been given to the description of baseline patterns of coupled spatial and temporal dynamics of meiobenthic communities. In an earlier study conducted in Lima estuary (NW Portugal), using eDNA metabarcoding of sediment samples, high levels of meiofauna Operational Taxonomic Units (OTUs) turnover were recorded, between sampling points only a few metres apart, and among sampling stations along the estuary. In order to verify the consistency of these patterns, in the current study we re-assessed Lima estuary's meiofauna communities approximately 1 year after, applying the same methodological approach (targeting segments of the COI and 18S rRNA genes), and expanding HTS-data analyses through the use of association networks. A high degree of spatial turnover was found both within and between sampling stations and this was consistent for both markers and years. As a consequence, most of the beta-diversity was accounted by OTU replacement with only a minor contribution from OTU richness. Despite the high levels of OTU replacement, relatively stable network properties were found in meiofaunal communities, irrespective of the sampled year. Network properties appear to shift sharply from the downstream/high salinity area of the estuary to the mesohaline medium-upstream areas, suggesting high resilience and redundancy of meiofaunal communities along the estuarine gradient. The recognition of meiofauna's networks features may improve the understanding of the ecology and dynamics of these communities that apparently hold large portions of variable elements, thereby making difficult their analyses solely based on the OTU/species composition.This study was funded by the project "The NextSea: Next generation monitoring of coastal ecosystems in a scenario of global change'' (operacao NORTE-01-0145-FEDER-000032), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Maria Fais and Sofia Duarte were supported, respectively by a Ph.D. (SFRH/BD/113547/2015) and a post-doc fellowship (SFRH/BPD/109842/2015) from FCT. The authors would like to thank Prof. Jesus Troncoso (University of Vigo) and Prof. Pedro Gomes (University of Minho) for their availability and hospitality for the lab processing; Dr. Bruno Sampieri and Barbara Leite (University of Minho) for the great support during the implementation of the practical stage of the research. The authors would like also to thank the anonymous reviewers for critically reading the manuscript and suggesting substantial improvements

    Tyrosinase Inhibitor Activity of Coumarin-Resveratrol Hybrids

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    In the present work we report on the contribution of the coumarin moiety to tyrosinase inhibition. Coumarin-resveratrol hybrids 1-8 have been resynthesized to investigate the structure-activity relationships and the IC50 values of these compounds were measured. The results showed that these compounds exhibited tyrosinase inhibitory activity. Compound 3-(3’,4’,5’-trihydroxyphenyl)-6,8-dihydroxycoumarin (8) is the most potent compound (0.27 mM), more so than umbelliferone (0.42 mM), used as reference compound. The kinetic studies revealed that compound 8 caused non-competitive tyrosinase inhibition
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