• Energy Research
• Restricted close
• Open Source close
• Embargo close
• ES close
• CA close
• US close
• PL close
• English close

Engineered cementitious composites (ECCs) are special types of fibre-reinforced cementitious composites (FRCC) with higher strain capacity which can be achieved with low fibre volume as low as 2% and total elimination of coarse aggregates. Due to the outstanding performance of ECCs, they are suitable for various construction and repair applications. However, in order for ECCs to achieve their properties; a high amount of binder which is primarily composed of Portland cement (PC) is used alongside a special type of ultrafine silica sand (USS) which is different from the conventional natural fine aggregates. The production of PC is known to be detrimental to the environment due to its high carbon dioxide emissions coupled with the high consumption of natural resources. Thus, the high use of PC content in ECCs posed a sustainability threat. Similarly, the USS used in ECCs are not readily available everywhere and are expensive. The processing of the USS coupled with its transportation over long distances would also increase the cost and embodied carbon of ECCs. Hence, in order to promote more development and applications of ECCs for various applications; this dissertation aims to provide innovative ways to improve the sustainability of ECCs and their performances. This dissertation offers four solutions to improve the sustainability of ECCs which are (i) use of unconventional industrial by-products as partial replacement of PC (ii) total replacement of PC in ECCs with alternative sustainable binders (iii) replacement of USS in ECCs with recycled materials and (iv) the use of supplementary cementitious materials to replace a high volume of PC. The findings from this study revealed sustainable ECCs with acceptable mechanical and durability performance can be achieved with the use of alternative binders or replacement of the conventional USS used in ECC mixtures. The sustainability and cost assessment of the ECCs indicated that the incorporation of industrial by-products such as blast furnace slag (BFS) especially at higher content is beneficial to reducing the negative environmental impact and economic burden associated with ECCs compared to the conventional ECC. The sustainability index and cost index of the ECCs further showed that the use of BFS is more beneficial when the sustainability and cost of the ECCs are compared with the corresponding performance. Similarly, the use of recycled materials as an alternative to USS was found to result in a significant reduction in the embodied carbon and cost of ECCs. The use of recycled materials such as expanded glass (EG) as aggregates in ECCs was also found to improve the thermal insulation properties of ECCs making such ECC suitable for the production of building envelope elements.

Engineered cementitious composites (ECCs) are special types of fibre-reinforced cementitious composites (FRCC) with higher strain capacity which can be achieved with low fibre volume as low as 2% and total elimination of coarse aggregates. Due to the outstanding performance of ECCs, they are suitable for various construction and repair applications. However, in order for ECCs to achieve their properties; a high amount of binder which is primarily composed of Portland cement (PC) is used alongside a special type of ultrafine silica sand (USS) which is different from the conventional natural fine aggregates. The production of PC is known to be detrimental to the environment due to its high carbon dioxide emissions coupled with the high consumption of natural resources. Thus, the high use of PC content in ECCs posed a sustainability threat. Similarly, the USS used in ECCs are not readily available everywhere and are expensive. The processing of the USS coupled with its transportation over long distances would also increase the cost and embodied carbon of ECCs. Hence, in order to promote more development and applications of ECCs for various applications; this dissertation aims to provide innovative ways to improve the sustainability of ECCs and their performances. This dissertation offers four solutions to improve the sustainability of ECCs which are (i) use of unconventional industrial by-products as partial replacement of PC (ii) total replacement of PC in ECCs with alternative sustainable binders (iii) replacement of USS in ECCs with recycled materials and (iv) the use of supplementary cementitious materials to replace a high volume of PC. The findings from this study revealed sustainable ECCs with acceptable mechanical and durability performance can be achieved with the use of alternative binders or replacement of the conventional USS used in ECC mixtures. The sustainability and cost assessment of the ECCs indicated that the incorporation of industrial by-products such as blast furnace slag (BFS) especially at higher content is beneficial to reducing the negative environmental impact and economic burden associated with ECCs compared to the conventional ECC. The sustainability index and cost index of the ECCs further showed that the use of BFS is more beneficial when the sustainability and cost of the ECCs are compared with the corresponding performance. Similarly, the use of recycled materials as an alternative to USS was found to result in a significant reduction in the embodied carbon and cost of ECCs. The use of recycled materials such as expanded glass (EG) as aggregates in ECCs was also found to improve the thermal insulation properties of ECCs making such ECC suitable for the production of building envelope elements.

This study aimed to evaluate the potential of microalgae grown in wastewater to recover carotenoids and biogas in a biorefinery approach. To this end, two pilot raceway ponds treating real wastewater were operated with a hydraulic retention time (HRT) of 8 and 6 days. The maximum total carotenoid content in harvested biomass was 4.3 mg·gDW-1 with a HRT of 8 days, while it stabilized at 1.5–2.2 mg·gDW-1 with a HRT of 6 days. Biochemical methane potential tests were then run to quantify the biogas production from carotenoid-extracted biomass (136.3 mLCH4·gVS-1), which corresponded to 86% of the methane yield achievable from raw microalgal biomass. Co-digestion with primary sludge increased the methane yield production both for raw and carotenoid-extracted biomass by 58 and 86%, respectively, when a 75:25 ratio was employed and by 28 and 44%, respectively, when a 50:50 ratio (VS basis) was used. This approach is promising for recovering resources (bio-based products and bioenergy) in the framework of a circular bioeconomy. This research has received funding from MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe’’ under the projects AL4BIO (RTI2018-099495-B-C21) and Cyan2Bio (PID2021-126564OB-C32). E. Ruales acknowledges her grant 2020 FISDUR 00592 funded by AGAUR (Generalitat de Catalunya). M. Bellver acknowledges her grant PRE2019-091552 funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”.

This study aimed to evaluate the potential of microalgae grown in wastewater to recover carotenoids and biogas in a biorefinery approach. To this end, two pilot raceway ponds treating real wastewater were operated with a hydraulic retention time (HRT) of 8 and 6 days. The maximum total carotenoid content in harvested biomass was 4.3 mg·gDW-1 with a HRT of 8 days, while it stabilized at 1.5–2.2 mg·gDW-1 with a HRT of 6 days. Biochemical methane potential tests were then run to quantify the biogas production from carotenoid-extracted biomass (136.3 mLCH4·gVS-1), which corresponded to 86% of the methane yield achievable from raw microalgal biomass. Co-digestion with primary sludge increased the methane yield production both for raw and carotenoid-extracted biomass by 58 and 86%, respectively, when a 75:25 ratio was employed and by 28 and 44%, respectively, when a 50:50 ratio (VS basis) was used. This approach is promising for recovering resources (bio-based products and bioenergy) in the framework of a circular bioeconomy. This research has received funding from MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe’’ under the projects AL4BIO (RTI2018-099495-B-C21) and Cyan2Bio (PID2021-126564OB-C32). E. Ruales acknowledges her grant 2020 FISDUR 00592 funded by AGAUR (Generalitat de Catalunya). M. Bellver acknowledges her grant PRE2019-091552 funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”.

Treball Final de Màster Universitari en Estudis Internacionals de Pau, Conflictes i Desenvolupament (Pla de 2013). Codi: SBG120. Curs acadèmic: 2019/2020 Menstruation is a natural phenomenon in women and girl’s life and yet millions of menstruators are denied the right to manage their period in dignity and in a healthy manner around the world. From taboos within religious practices to the modern corporate taxes on menstrual products in the western world, menstrual health and hygiene is linked to gender inequality, discriminatory social norms, cultural taboos, poverty, conflicts, lack of basic services and access to health care and health products. Afghan women and girls are not spared from these insecurities, menstruation in the Afghan society is a subject that cannot be mentioned publicly nor privately. According to the available data, Afghan women do not have access to menstrual products due to poverty, market proximity, and lack of subject knowledge. In fact, it is sadly documented that a girl misses one week of school due to her menstruation. This pilot project aims to change the current approach on menstruation and accessibility of menstrual products through stakeholders and civil societies that run Human shelters, family guidance centers, family protection centers and other health facilities by awareness sessions within the community, trainings and economic empowerment on pads productions and various other menstrual products. The outcome of this pilot project is to give back the dignity to afghan menstruators by allowing them to have access to products but mainly to understand that menstruation is not a shame and also get familiar with what is available for them. The activities are carried out in socially acceptable manner in order to reach remote areas of Afghanistan once the pilot project becomes eventually a national project.

Treball Final de Màster Universitari en Estudis Internacionals de Pau, Conflictes i Desenvolupament (Pla de 2013). Codi: SBG120. Curs acadèmic: 2019/2020 Menstruation is a natural phenomenon in women and girl’s life and yet millions of menstruators are denied the right to manage their period in dignity and in a healthy manner around the world. From taboos within religious practices to the modern corporate taxes on menstrual products in the western world, menstrual health and hygiene is linked to gender inequality, discriminatory social norms, cultural taboos, poverty, conflicts, lack of basic services and access to health care and health products. Afghan women and girls are not spared from these insecurities, menstruation in the Afghan society is a subject that cannot be mentioned publicly nor privately. According to the available data, Afghan women do not have access to menstrual products due to poverty, market proximity, and lack of subject knowledge. In fact, it is sadly documented that a girl misses one week of school due to her menstruation. This pilot project aims to change the current approach on menstruation and accessibility of menstrual products through stakeholders and civil societies that run Human shelters, family guidance centers, family protection centers and other health facilities by awareness sessions within the community, trainings and economic empowerment on pads productions and various other menstrual products. The outcome of this pilot project is to give back the dignity to afghan menstruators by allowing them to have access to products but mainly to understand that menstruation is not a shame and also get familiar with what is available for them. The activities are carried out in socially acceptable manner in order to reach remote areas of Afghanistan once the pilot project becomes eventually a national project.

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.