30 research outputs found

    Modelling, simulation and evaluation of centralised and decentralised food manufacturing scenarios

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    Current long-rigid centralized supply chains, responsible for high energy consumption and environmental impact, might become outdated in a near future. Many theoretical studies, predicting a shift on companies’ strategical approach to the market based on scaling down and decentralization to reach mass differentiation, can be found in literature. This work demonstrates that the shift on manufacturing paradigm can be studied as an engineering problem. Process system engineering methodology is implemented to develop a modelling tool, capable to generate trusted practical data for common and alternative manufacturing scale scenarios with increasing degree of decentralisation, i.e. Single plant production, Multiple plant production, Distributed Manufacturing, Food Incubator, and Home manufacturing. The tool is used to perform a techno-economic and environmental assessment for three food products of distinct characteristics, namely dry cereal porridge, sandwich bread and ice cream. The processing alternatives are first designed and studied separately for each food, to identify the benefits and tradeoffs associated to decentralised production methods. Variations on economic, social and environmental impact parameters along a wide range of production rates –e.g. 0.01 to 50,000 kg/h– are evaluated, and a UK demand framework is used to check the performance of the alternative production methods in a realistic scenario. A final comparison among the three items is performed to study how each scale differently functions for the production of each food studied. The output of this research is to offer a robust tool that might assist companies in the complex decision between centralized or decentralized manufacturing systems for real market opportunities

    Monetization of policy costs and sustainability benefits associated with renewable energy in fossil fuel-rich countries (FFRCs)

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    The electricity sector in Middle Eastern fossil fuel-rich countries (FFRCs) is characterised by the high electricity subsidies that result in a large price gap between Feed-in Tariffs (FiT) and consumer electricity prices, which inhibits electricity generation from renewable energy sources (RES-E). Meanwhile, RES-E development could reduce GHG emissions, allow fossil fuel to be sustainably commercialised or processed, and save water consumption in thermal power plants as an alternative solution in FFRCs. This study aimed at monetarizing those benefits and evaluating the performance of RES-E policy in a FFRCs framework by defining the benefit-cost ratio as a sustainability indicator, considering Iran as a case study scenario. Results showed that the FiT purchase price was seven times higher than the average consumer price of electricity, which implied a US345millioncostforrenewableenergysupportduringthe2009–2019timewindow.Conversely,benefitsfromtheuseofrenewableenergywereestimatedinUS 345 million cost for renewable energy support during the 2009–2019 time window. Conversely, benefits from the use of renewable energy were estimated in US 68 million. The resulting benefit-cost ratio of RES-E policy was found to be 0.2, which indicates that FiT policy was inefficient and only 20% of the expenditure could be recovered. To make RES-E policies more efficient and foster renewable energy deployment, limiting the electricity subsidy that widens the price gap between FiT and market price has been suggested. Furthermore, carbon price was identified to have high impact on the benefit-cost ratio indicator. A policy framework setting a 100 $US/t CO2 would balance RES-E policy costs and benefits. This evidence could aid in decision-making for RES-E implementation in FFRCs

    Predicción del compromiso en Educación Física desde la teoría de la autodeterminación: análisis de invarianza según el nivel de actividad física

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    This study aimed to test a predictive model for behavioral engagement in physical education (PE) in the light of self-determination postulates (basic psychological needs intrinsic motivation behavioral engagement) as well as to analyze the invariance of this model according to physical activity (PA) levels. A sample of 468 12-16 physical education (PE) students completed different validated instruments. The hypothesized sequence was tested through a structural equation model. Fitting indices revealed that the model was suitable to predict engagement (χ2 [112] = 310.65, p .05). Findings from the invariance analyses indicated that competence became more important among adolescents showing higher levels in autonomous motivation and PA while autonomy became more relevant among students showing lower levels in autonomous motivation and PA. Results thus suggest that strategies used to facilitate engagement in PE classes should be adapted to students according to the PA they usually performEl objetivo principal de este trabajo fue testar un modelo predictivo del compromiso comportamental en educación física (EF) desde los postulados de la teoría de la autodeterminación (necesidades psicológicas básicas motivación intrínseca compromiso comportamen-tal) y analizar la estabilidad de dicho modelo en fun-ción del nivel de práctica de actividad física (AF). Una muestra de 468 estudiantes de educación física (EF) de entre 12 y 16 años respondieron diferentes cuestiona-rios validados. La secuencia de relaciones hipotetizada se testó a través de un modelo de ecuaciones estructura-les. Los índices de ajuste indicaron que dicho modelo re-sultó adecuado para predecir el compromiso (χ2 [112] = 310.65, p .05). Los hallazgos del análisis de invarianza señalaron que la satisfacción de competencia cobró más importancia entre los adolescentes con mayor nivel de AF, siendo la satisfacción de autonomía más relevante en los estudiantes de nivel bajo de AF. Los resultados sugieren que las estrategias utilizadas para favorecer el compromiso en las clases de EF deberían adaptarse a los alumnos en función de la práctica de AF que realicenActividad Física y Deport

    Cáncer de Cuello Uterino: La Hipertermia como nuevo pilar en el tratamiento

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    El cáncer de cérvix, constituye una de las neoplasias de mayor importancia en la actualidad, tanto por los datos de incidencia (3.3% de los tumores femeninos, siendo el segundo en frecuencia de las neoplasias en la mujer, por detrás del cáncer de mama), como por los avances introducidos en prevención, diagnóstico y tratamiento. Hoy en día, son diagnosticados alrededor de 2587 nuevos casos al año, con una edad promedio de 48 años, y aunque su prevalencia es elevada, han disminuido enormemente las cifras de mortalidad asociadas a esta neoplasia (alrededor de unas 680 muertes al año). El conocimiento y avance de las técnicas de screening , sobretodo la citologia del Cérvix uterino y el test del Virus de Papiloma Humano (VPH), permite una detección temprana de estas patologías, mejorando así las tasas de supervivencia. Por otro lado, la introducción de medidas profilacticas como, la vacuna del Virus del Papiloma Humano (VPH), han resultado fundamentales para la reducción del número de casos, ya que este virus, se considera uno de los principales agentes causales en el desarrollo de la misma. Con respecto al ámbito terapéutico disponible, además de los ya implantados como la cirugía (histerectomía en la mayor parte de los casos), la aplicación de radioterapia y quimioterapia (como terapia única o combinada), en la actualidad se está apostando por el estudio de los beneficios de la introducción de nuevos pilares terapéuticos entre los que destaca el uso de la hipertermia en combinación con los tratamiento clásicos de dicha enfermedad. Son numerosos los estudios que aportan resultados prometedores en las tasas de respuesta aplicando estas nuevas técnicas sin aumentar los aspectos negativos en el tratamiento de dichos tumores.<br /

    Carbon dioxide removal potential from decentralised bioenergy with carbon capture and storage (BECCS) and the relevance of operational choices

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    Bioenergy with carbon capture and storage (BECCS) technology is expected to support net-zero targets by supplying low carbon energy while providing carbon dioxide removal (CDR). BECCS is estimated to deliver 20 to 70 MtCO2 annual negative emissions by 2050 in the UK, despite there are currently no BECCS operating facility. This research is modelling and demonstrating the flexibility, scalability and attainable immediate application of BECCS. The CDR potential for two out of three BECCS pathways considered by the Intergovernmental Panel on Climate Change (IPCC) scenarios were quantified (i) modular-scale CHP process with post-combustion CCS utilising wheat straw and (ii) hydrogen production in a small-scale gasifier with pre-combustion CCS utilising locally sourced waste wood. Process modelling and lifecycle assessment were used, including a whole supply chain analysis. The investigated BECCS pathways could annually remove between −0.8 and −1.4 tCO2e tbiomass−1 depending on operational decisions. Using all the available wheat straw and waste wood in the UK, a joint CDR capacity for both systems could reach about 23% of the UK's CDR minimum target set for BECCS. Policy frameworks prioritising carbon efficiencies can shape those operational decisions and strongly impact on the overall energy and CDR performance of a BECCS system, but not necessarily maximising the trade-offs between biomass use, energy performance and CDR. A combination of different BECCS pathways will be necessary to reach net-zero targets. Decentralised BECCS deployment could support flexible approaches allowing to maximise positive system trade-offs, enable regional biomass utilisation and provide local energy supply to remote areas

    Opportunities and challenges for Bioenergy with Carbon Capture and Storage (BECCS) systems supporting net-zero emission targets

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    â–ª Anthropogenic GHG emissions have been relentlessly growing for many decades, thus compromising attempts to avoid dangerous climate change and meet net-zero emission targets by 2050. â–ª BECCS technology creates a negative carbon flow from the atmosphere into storage by coupling CO2 removal, low-carbon energy conversion routes, and carbon capture and storage technologies. â–ª Process modelling and life cycle assessment of the entire BECCS value chain must be implemented to determine the net-negative emission potential of this technology. â–ª A better understanding of the implications of large-scale BECCS deployment should be included in climate modelling methodologies such as SSPs and IAMs. â–ª While other renewable energies might be more cost-efficient, BECCS is the only carbon negative renewable energy approach and can provide sustainability co-benefits to various cross-cutting sectors. To enable these benefits, political intervention is needed to attract investment for long-term R&D and implementation of BECCS technologies. â–ª Relying on future BECCS deployment to counterbalance the current excess of CO2 emissions only can risk sustainability benefits and would not enable the full potential and benefits of BECCS. Policy frameworks should go beyond the greenhouse gas removal potential of BECCS and integrate wider sustainability benefits whilst also considering trade-offs, for example in regard to land-use, food security, biodiversity, income opportunities, technology and infrastructure development and social justice

    Reducing the environmental impact of international aviation through sustainable aviation fuel with integrated carbon capture and storage

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    Sustainable aviation fuels (SAFs) represent the short-term solution to reduce fossil carbon emissions from aviation. The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) was globally adopted to foster and make SAFs production economically competitive. Fischer-Tropsch synthetic paraffinic kerosene (FT-SPK) produced from forest residue is a promising CORSIA-eligible fuel. FT conversion pathway permits the integration of carbon capture and storage (CCS) technology, which provides additional carbon offsetting capacities. The FT-SPK with CCS process was modelled to conduct a comprehensive analysis of the conversion pathway. Life-cycle assessment (LCA) with a well-to-wake approach was performed to quantify the SAF's carbon footprint considering both biogenic and fossil carbon dynamics. Results showed that 0.09 kg FT-SPK per kg of dry biomass could be produced, together with other hydrocarbon products. Well-to-wake fossil emissions scored 21.6 gCO2e per MJ of FT-SPK utilised. When considering fossil and biogenic carbon dynamics, a negative carbon flux (-20.0 gCO2eMJ−1) from the atmosphere to permanent storage was generated. However, FT-SPK is limited to a 50 %mass blend with conventional Jet A/A1 fuel. Using the certified blend reduced Jet A/A1 fossil emissions in a 37 %, and the net carbon flux resulted positive (30.9 gCO2eMJ−1). Sensitivity to variations in process assumptions was investigated. The lifecycle fossil-emissions reported in this study resulted 49 % higher than the CORSIA default value for FT-SPK. In a UK framework, only 0.7 % of aviation fuel demand could be covered using national resources, but the emission reduction goal in aviation targeted for 2037 could be satisfied when considering CCS
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