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Seaweed fibre is usually discarded as biomass waste after extraction of useful ingredients from seaweed. However this seaweed fibre, a natural abundant cellulose material with uniform dimensions 10 times smaller than other plant-based fibre can be utilized as electrode material for energy storage. In this work, we converted seaweed fibre into conductive carbon electrodes by a thermal carbonisation method. The morphology, chemical composition and conductivity are highly influenced by the carbonisation temperature. In comparison to other biomass sources such as cotton pulp, seaweed fibre is finer, smoother and more conductive at low carbonisation temperature. These carbonized seaweeds were then used as a supercapacitor, giving a high supercapacitance (226.3 Fg−1) at the carbonisation temperature of 900°C, and good stability within 2400 cycles. This specific capacitance is significantly higher than values obtained from filter paper or cotton pulp.

An important limitation of polymer electrolyte fuel cell technology is the low mechanical strength and dimensional instability with changes of water content of proton exchange membranes (PEMs). A range of different approaches to more stable PEMs based on Nafion have been studied of which composite materials of Nafion with mechanically stronger polymers is one of the most promising directions. If successful, they will lead to thinner composite PEMs with enhanced fuel cell performance, life span, and cost-effectiveness. Developed in this thesis are electrospinning conditions for the fabrication of electrospun mats for potential application in PEMs. Polysulfone (PSU), poly vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), and polyvinylidene fluoride (PVDF) were tested as mechanically stronger but inert (minimal contribution to proton transport) polymers that can tolerate the fuel cell condition. PVDF-HFP generated defect free electrospun mats over a wide range of spinning conditions, while PSU required very specific conditions and no successful conditions were found for PVDF mostly due to over-wetting. These mats might function as mechanical support and could be tested as PEMs when filled with Nafion, but the complete filling of electrospun mats with Nafion has been proven difficult. Instead, the electrospinning of Nafion was tested to explore options of electrospinning mixed mats of two different polymers and co-electrospinning of core-sheath fibers. Two commercial Nafion solutions D520 and D2020 with 5 wt% and 20 wt% content of Nafion were electrospun together with polyethylene oxide of two different molecular weights as a carrier polymer. Mats of sufficient quality for PEM tests were obtained with solutions based on 20 wt% content of Nafion, a low flow rate of 0.2 mL/h, and the lower molecular weight polyethylene oxide as the carrier. Finally, coaxial electrospinning conditions for the formation of core-sheath fibers were developed for Nafion as sheath material and PVDF-HFP or PSU as the core material. Defect-free, core-sheath fibers were generated when the concentration of both solutions was high (20 wt%), the Nafion flow rate was about 0.2 mL/h for the sheath, and the core flow rate was below the flow rate of the sheath (0.1-0.15 mL/h for PVDF-HFP and 0.15 mL/h for PSU). Mats of these core-sheath fibers should provide good mechanical strength combined with much better compatibility with Nafion. A straightforward pore filling with Nafion solutions is expected and their investigation as PEMs in fuel cells is planned as future work.

Resumen: En este Trabajo de Final de Grado se aborda, como principal objetivo la reducción del consumo energético, en una bodega construida en el año 1965 con posteriores modificaciones para adaptarse a las demandas de la producción, en la actualidad tiene capacidad para procesa un máximo de 10 millones de kilos de uva por vendimia. Una de las modificaciones fue el cambio de ubicación de la zona de recepción del mosto, pasando de la cota más alta a la parte más baja de la finca, de unos depósitos de cemento a los de acero inoxidable i de estar ubicados en el interior de la bodega a la intemperie. Como se ha apuntado anteriormente, el principal objetivo de este proyecto es la reducción del consumo energético y concretamente de la zona de recepción, para tal fin se construirá un cofre aislante con las siguientes medidas 35 x 16 x 14 m, albergando en su interior los depósitos y el intercambiador de calor, ejecutándose la obra con dichos elementos inamovibles. Se han realizado los cálculos pertinentes para el dimensionado de la estructura metálica del cofre, de los cabales y dimensiones de los nuevos circuitos de refrigeración, calculando la potencia frigorífica necesaria para mantener la temperatura deseada, con una entrada máxima diaria de 200 tn de uva por día. Los cerramientos se realizarán con paneles aislantes que permitan mantener la temperatura del mosto refrigerado inicialmente hasta su clarificación y trasiego. Se ha calculado un presupuesto de ejecución de obra por contrato y se han elaborado los planos correspondientes. Así pues el proyecto consta de los siguientes documentos: Documento N.º 1 Memoria y 9 Anejos Documento N.º 2 Planos Documento N.º 4 Presupuesto detallado Como conclusión, podemos afirmar que con este proyecto se espera una reducción del 55% en el consumo energético de la zona de Recepción del mosto, mejoraría el rendimiento, tanto energético como en eficiencia con la automatización de las instalaciones entre la zona de Recepción y el Lagar. Abstract: This Final Degree Work addresses the reduction of energy consumption, mainly electricity, of a winery built in 1965, with subsequent modifications adapting to production circumstances, with the capacity to process 10 million kilos of grapes. One of the modifications was the change in location of the must reception area, moving from the highest to the lowest level of the farm, from cement tanks to stainless steel tanks and to be located inside the cellar in the open air. The objective of the project is the reduction of energy consumption in the must reception area, through the construction of an insulating box of 35 x 16 x 14 m, closing the six tanks and the tubular heat exchanger inside. the work being carried out with said immovable elements inside. The necessary calculations have been made for the dimensioning of the metal structure of the chest, the flow rates and the dimensions of the new refrigeration circuits, as well as the refrigeration power necessary to maintain them at the desired temperature, with a daily input of 200 t of grape The enclosures will be made with insulating panels that allow the temperature of the initially cooled must to be maintained until its clarification by gravity. A contract execution budget has been calculated and the corresponding plans have been drawn up. So, the project consists of the following documents: Document Nº1: Memory and 9 chapters. Document No. 2: 19 plans Document Nº4: Detailed budget. As a conclusion we will say that this project is expected to reduce energy consumption in the reception area by 55% and we can affirm that the performance, both energy and efficiency, would improve if the facilities between the Reception area and the Presses. Resum: En aquest treball de Final de Grau s'aborda la reducció del consum energètic d'un celler construït l'any 1965, amb posteriors modificacions per adaptar-se a les circumstancies de la producció, amb capacitat per processar 10 milions de quilos de raïm . Una d'elles va ser el canvi d'ubicació de la zona de recepció del most, passant de la cota mes alta a la part mes baixa de la finca, d'uns dipòsits de ciment a uns d'acer inoxidable i d'estar en el interior del celler al intempèrie. L'objectiu del projecte serà doncs, la reducció del consum energètic de la zona de recepció del most, mitjançant la construcció d'un cofre aïllant de 35 x 16 x 14 m, tancant en el seu interior els dipòsits i l'intercanviador de calor que romandran en el seu lloc mentre s'executi el projecte. S'han realitzat els càlculs necessaris per dimensionar l'estructura metàl·lica del cofre, dels cabals i dimensions dels nous circuits de refrigeració i de la potencia frigorífica necessària per mantenir-los, amb una entrada màxima diària de 200 tn de raïm per dia. Els tancaments es realitzaran amb panells aïllants que permetin mantenir la temperatura del most refredat inicialment, fins al seu desfangat estàtic. S'ha calculat un pressupost d'execució d'obra per contracta i s'han elaborat els plànols corresponents. Així doncs, el projecte consta del: Document Nº 1: Memòria i 9 Annexes. Document Nº 2: 19 plànols Document Nº 4: Pressupost detallat Com a conclusió direm que d'aquest projecte s'espera una reducció del 55% en el consum energètic a la zona de recepció del most i que es milloraria el rendiment, tant energètic com en eficiència amb l'automatització de les instal·lacions entre la Recepció i el Lagar. Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables

The optical and photovoltaic properties of Si NCs / SiC multilayers (MLs) are investigated using a membrane-based solar cell structure. By removing the Si substrate in the active cell area, the MLs are studied without any bulk Si substrate contribution. The occurrence is confirmed by scanning electron microscopy and light-beam induced current mapping . Optical characterization combined with simulations allows us to determine the absorption within the ML absorber layer, isolated from the other cell stack layers. The results indicate that the absorption at wavelengths longer than 800 nm is only due to the SiC matrix. The measured short-circuit current is significantly lower than that theoretically obtained from absorption within the ML absorber, which is ascribed to losses that limit carrier extraction. The origin of these losses is discussed in terms of the material regions where recombination takes place. Our results indicate that carrier extraction is most efficient from the Si NCs themselves, whereas recombination is strongest in SiC and residual a-Si domains . Together with the observed onset of the external quantum efficiency (EQE) at 700-800 nm, this fact is an evidence of quantum confinement in Si NCs embedded in SiC on device level.

The aggravating global problems of energy crisis, rising atmospheric greenhouse gas concentrations and accumulation of persistent waste have attracted the attention of scientists, policy-makers and global organisations to come up with effective and expeditious solutions to address these challenges. In this context, the development of sustainable technologies driven by renewable energy sources for the production of clean fuels and commodity chemicals from diverse waste feedstocks is an appealing approach towards creating a circular economy. Over the years, semiconductor photocatalysts based on TiO₂, CdS, carbon-nitrides (CNx) and carbon dots (CDs) have been widely used for the photocatalytic reforming (PC reforming) of pre-treated waste substrates to organic products, accompanied with clean hydrogen (H₂) generation. However, these conventional solar-driven processes suffer from major drawbacks such as low production rates, poor product selectivity, CO₂ release, challenging process and catalyst optimisation, and harsh waste pre-treatment conditions, which limit their commercial applicability. These challenges are tackled in this thesis with the introduction of new and efficient photoelectrochemical (PEC) and chemoenzymatic processes for reforming a diverse range of waste feedstocks to sustainable fuels. Solar-driven PEC reforming based on halide perovskite light-absorber is first developed as an attractive alternative to PC reforming. The PEC systems consist of a perovskite|Pt photocathode for clean H₂ production and a Cu-Pd alloy anode for reforming diverse waste streams, including pre-treated cellulosic biomass, polyethylene terephthalate (PET) plastics, and industrial by-product glycerol into industrially-relevant, value-added chemicals (gluconic acid, glycolic acid and glyceric acid) without any externally applied bias or voltage. Additionally, the single light-absorber PEC systems can also convert the airborne waste stream and greenhouse gas CO₂ to diverse products with the simultaneous reforming of PET plastics with no applied voltage. The perovskite-based photocathode enables the integration of different CO₂ reduction catalysts such as a molecular cobalt porphyrin, a Cu-In alloy and formate dehydrogenase enzyme, which produce CO, syngas and formate, respectively. The versatile PEC systems, which can be assembled in either a ‘two-compartment’ or standalone ‘artificial leaf’ configurations achieve 60‒90% oxidation product selectivity (with no over-oxidation) and >100 µmol cm‾² h‾¹ product formation rates, corresponding to 10²‒10⁴ times higher activity than conventional PC reforming systems. In addition to developing PEC platforms, this thesis also explores avenues for circumventing the harsh alkaline pre-treatment strategies (pH >13, 60‒80 ºC) adopted for photoreforming waste substrates. For this purpose, a chemoenzymatic pathway is introduced whereby PET and polycaprolactone plastics were deconstructed using functional enzymes under benign conditions (pH 6‒8, 37‒65 ºC), followed by PC reforming using Pt loaded TiO₂ (TiO₂|Pt) or Ni₂P loaded carbon-nitride (CNx|Ni₂P) photocatalysts. The chemoenzymatic reforming process demonstrates versatility in upcycling polyester films and nanoplastics for H₂ production at high yields reaching ∼10³‒10⁴ µmol gsub‾¹ and activities at >500 µmol gcat‾¹ h‾¹. The utilisation of enzyme pre-treated plastics also allowed the coupling of plastic reforming with photocatalytic CO₂-to-syngas conversion using a phosphonated cobalt bis(terpyridine) co-catalyst immobilised on TiO₂ (TiO₂|CotpyP). Finally, moving beyond solar-driven systems, a bio-electrocatalytic flow process is demonstrated for the conversion of microbe pre-treated food waste to ethylene (an important feedstock in the chemical industry) on graphitic carbon electrodes via succinic acid as the central intermediate. In conclusion, with its focus on improving efficiencies, achieving selective product formation, building versatile platforms, diversifying substrate and product scope, and reducing carbon footprint and economic strain, this thesis aims to bring sustainable waste-to-fuel technologies a step closer to commercial implementation.

The accurate training of a wind power forecasting (WPF) model for a newly built wind farm is difficult because of limited historical data. This study established a multitask learning architecture wherein the WPF in different wind farms represents an independent task. Subsequently, a novel short-term WPF model based on a multitask learning architecture was proposed. In this model, a multitask Gaussian process is used to capture the intertask conjunction, which contributed to the training of each task. The proposed methodological framework employs dependencies from other tasks wherein older wind farms contain substantial historical data to enhance the performance of tasks in which there is a newly built wind farm. Several numerical experiments were conducted using datasets from seven independent wind farms in Australia. The results show that the proposed scheme not only obtains improved point forecasting results but also produces better probabilistic forecasting results, thus demonstrating the superiority of the proposed method.

The stability of winter wheat-flowering-date is crucial for ensuring consistent and robust crop performance across diverse climatic conditions. However, the impact of climate change on wheat-flowering-dates remains uncertain. This study aims to elucidate the influence of climate change on wheat-flowering-dates, predict how projected future climate conditions will affect flowering date stability, and identify the most stable wheat genotypes in the study region. We applied a multi-locus genotype-based (MLG-based) model for simulating wheat-flowering-dates, which we calibrated and evaluated using observed data from the Northern China winter wheat region (NCWWR). This MLG-based model was employed to project flowering dates under different climate scenarios. The simulated flowering dates were then used to assess the stability of flowering dates under varying allelic combinations in projected climatic conditions. Our MLG-based model effectively simulated flowering dates, with a root mean square error (RMSE) of 2.3 days, explaining approximately 88.5 % of the genotypic variation in flowering dates among 100 wheat genotypes. We found that, in comparison to the baseline climate, wheat-flowering-dates are expected to shift earlier within the target sowing window by approximately 11 and 14 days by 2050 under the Representative Concentration Pathways 4.5 (RCP4.5) and RCP8.5 climate scenarios, respectively. Furthermore, our analysis revealed that wheat-flowering-date stability is likely to be further strengthened under projected climate scenarios due to early flowering trends. Ultimately, we demonstrate that the combination of Vrn and Ppd genes, rather than individual Vrn or Ppd genes, plays a critical role in wheat-flowering-date stability. Our results suggest that the combination of Ppd-D1a with winter genotypes carrying the vrn-D1 allele significantly contributes to flowering date stability under current and projected climate scenarios. These findings provide valuable insights for wheat breeders and producers under future climatic conditions.