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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.

Some Parties (Countries) to the UNFCCC decided to include the carbon uptake by harvested wood products (HWP) in a new general accounting framework after 2012 (post Kyoto). The analysis aims to make a comparison between the cascaded use of HWP and the use of wood for energy. We combine the new HWP framework with an assumed increased 50 million m3harvest level in Canada and evaluate the impact of the GHG emissions over a 100-year period. Our reference case assumes all harvested wood is an immediate CO2emission (IPCC default) and no substitution effects, i.e. annual GHG emissions of 41 million tonnes CO2eq. In our wood utilization scenario's, harvested trees are allocated (in varying shares) to three end-products: construction wood, paper products and pellets for power production. In comparison with our base case, a combination of fossil fuel substitution, material substitution and temporary carbon uptake by HWP leads to significant decreases in GHG emissions. All scenario's show annual GHG emission between 18 and 21 million tonnes CO2eqexcept for triple use without recycling (at least 24 million tonnes CO2eq). We conclude that GHG emissions of our scenarios are substantially lower than IPCC default. However, it is difficult to incorporate one single method to account for GHG uptake and emissions by HWP, due to end use efficiency and recycling options. Further GHG allocation over individual countries is not straightforward and needs further research. © 2013 Elsevier Ltd.

The deep-sea, defined as the area 200 m below the surface, is facing emerging chemical, physical and biological stressors. Currently, very little is known regarding deep-sea ecosystems both globally and in the Arctic. In this thesis I undertook a literature review on the current understanding of global deep-sea ecosystems through the use of stable isotopes. Specifically, I synthesized the available literature on spatial variation, energy pathways, depth, temporal variation, feeding behaviour, niche, trophic position and body size isotopic trends. This thesis then presents a case study examining the isotopic niche of five teleost and two decapod species within Arctic deep-sea food webs across the localized latitudinal gradient of Baffin Island. Spatial variation in isotopic niche was quantified using 13C and 15N for seven deep-sea species at three locations on Baffin Island, Nunavut to determine whether the “Latitudinal Niche Breadth Hypothesis” which states that niche breadth should increase with latitude holds true in the Arctic. Overall, isotopic patterns in global deep-sea ecosystem are variable; consistent trends are not observed across all taxa and habitats. It was concluded that niche breadth did not consistently increase with latitude in the eastern Canadian Arctic; localized conditions (e.g. sea ice, temperature) and individual condition (e.g. hepatosomatic index) may contribute more to a species’ niche than latitude. Overall, this thesis improves our understanding of deep-sea ecosystems globally, contributes baseline data for future monitoring, and by investigating multiple species and locations it will provide input on how climate change may impact Arctic food web diversity, energy dynamics and ecosystem structure to aid in sustainable fishery development.

AbstractSustainable biorefineries have a critical role to play in our common future. The need to provide more goods using renewable resources, combined with advances in science and technology, has provided a receptive environment for biorefinery systems development. Biorefineries offer the promise of using fewer non‐renewable resources, reducing CO2 emissions, creating new employment, and spurring innovation using clean and efficient technologies. Lessons are being learned from the establishment of first‐generation biofuel operations. The factors that are key to answering the question of biorefinery sustainability include: the type of feedstock, the conversion technologies and their respective conversion and energy efficiencies, the types of products (including coproducts) that are manufactured, and what products are substituted by the bioproducts. The BIOPOL review of eight existing biorefineries indicates that new efficient biorefineries can revitalize existing industries and promote regional development, especially in the R&D area. Establishment can be facilitated if existing facilities are used, if there is at least one product which is immediately marketable, and if supportive policies are in place. Economic, environmental, and social dimensions need to be evaluated in an integrated sustainability assessment. Sustainability principles, criteria, and indicators are emerging for bioenergy, biofuels, and bioproducts. Practical assessment methodologies, including data systems, are critical for both sustainable design and to assure consumers, investors, and governments that they are doing the ‘right thing’ by purchasing a certain bioproduct. If designed using lifecycle thinking, biorefineries can be profitable, socially responsible, and produce goods with less environmental impact than conventional products … and potentially even be restorative!. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd

Climate change is a growing concern across the globe, and the Provincial Government of Ontario recognizes that climate change impacts need to be considered in all decision-making. In Southern Ontario, a critical and ongoing challenge is balancing the competing water demands under changing climate for various uses to ensure prosperity and sustainability in the future. A better understanding and quantification of impacts of possible climate change on regional hydrology are necessary for sustainable water resources management and maintaining healthy ecosystems in this region. In order to study the impacts of future climate on the regional water resources, a large-scale hydrologic model was developed for Southern Ontario within the Great Lakes basin using the Soil and Water Assessment Tool (SWAT). The study area includes four basins: Eastern Georgian Bay, Eastern Lake Huron, Northern Lake Erie, and Lake Ontario and Niagara Peninsula basins, covering a total area of about 84,650 km2. The hydrologic model was calibrated and validated using monthly observed streamflow data at 40 gauging stations, and spatially validated at another 40 gauging stations across the study area. The developed model was employed to estimate water budget components for a reference period (1971-2000), and to assess climate change impacts on the hydrologic regime during the mid-century (2041-2070) and the end-century (2071-2100). Projected climate data from five GCM-RCMs simulations for RCP4.5 and RCP8.5 scenarios were obtained from the NA-CORDEX archive. After bias correction, climate data sets were used in the SWAT model for the impact assessment. Based on the model calibration and validation results, the overall performance of the model was found to be satisfactory. Its performance was better in the predominantly agricultural Northern Lake Erie and Eastern Lake Huron basins than the other two basins. The average annual precipitation, evapotranspiration (ET), surface runoff and water yields for the study area over the period 1971-2000 were estimated at 979 mm, 540 mm, 183 mm and 410 mm, respectively. The average annual precipitation in the four basins varied from 923 mm to 1049 mm, and water yields were found to vary between 377 mm and 465 mm. The projected increases in mean annual temperature are 3.0oC and 2.4oC by the mid-century, while the increases are 5.2oC and 3.2oC by the end-century for RCP8.5 and RCP4.5 scenarios, respectively. The average annual precipitation of the study area is projected to increase by 8% to 16%, depending on the scenario and time period. The possible increases in precipitation are relatively high for the RCP8.5 scenario and likely to vary between 13% and 18% in the four basins by the end of the 21st century. By the mid-century, the average annual water yields in the four basins are predicted to increase by 7% to 20%, and 5% to 13% under RCP8.5 and RCP4.5 scenarios, respectively. By the end-century, the projected increases in the annual water yields of the basins are 5% to 26% for RCP8.5 scenario and 3% to 11% for RCP4.5 scenario. In general, the average monthly water yield in the study area is likely to increase during December to February, but decrease in the months of March and April. The results are also presented spatially for the subwatersheds across the study area. The study results would help in planning and management of water resources, and in developing climate change adaptation plans and strategies.

Alternative Food Networks (AFNs) are challenging the traditional food system by leveraging concepts such as self-organisation and self-management aiming to shorten the food supply chain and give cu...

The overarching objective of the Glasgow Climate Pact, a bold and ambitious undertaking, is to lay the groundwork for all the world’s economies, without exception, to decisively and irreversibly achieve the remarkable feat of hitting the net zero greenhouse gas emissions mark by the year 2050. The rationale behind this audacious goal is to arrest and neutralize the increasingly dire, ominous and pervasive impact of global warming on a planetary scale, and ensure that the rise in temperatures does not exceed the precarious 1.5◦ Celsius threshold above pre industrial levels. As such, it becomes crystal clear that it is a matter of utmost urgency that we, as a collective, wholeheartedly embrace and fervently pursue the adoption of green energy technologies, in all their multifarious and sundry forms, to enable us to inexorably advance to wards a state of civilization that leaves no carbon footprint, net or otherwise. However, this formidable challenge can only be surmounted through the vigorous and concerted efforts of the scientific and engi neering communities, who must endeavor to both invent and engineer innovative, cutting-edge low- or zero-carbon energy technologies, while also seeking to optimize and augment the efficiency and efficacy of our current energy systems, all while being mindful of the imperative to optimize cost-effectiveness in the process.

Although nearly zero energy buildings have attracted growing research attention, literature analysis shows that only a limited number of researches try to couple load match/grid interaction issues and environmental impacts in early design stages. The study proposes a novel multidisciplinary design approach that allows to integrate these two conflicting aspects aiming to find trade-offs. The proposed approach has been applied to a building case study, equipped with a photovoltaics system without energy storage. The results show that even though on yearly basis the energy use (5,290 kWhe) is largely overcome by the on-site energy generation (8069 kWhe), an oversized PV system alone may not be the best solution for reducing the environmental impact of the building sector, besides not being very efficient in improving load match. Afterwards, a parametric analysis was carry out analysing three redesign scenarios, obtained varying the sizes of the PV system and installing different sizes of the storage systems. The results show that the use of storage systems, in addition to decrease the grid dependency, can increase the environmental benefits arising from the renewable energy sources (e.g. there is a decrease of global warming potential of 48%, compared to the base case, with 5.28 kWp PV system and 10 kWh storage system). Conflicting results are found according to specific impact categories and this suggests the need for a holistic approach, including different domains and indicators. In this context, the proposed approach can contribute to the transition toward low-carbon energy technologies, by supporting researches and designers to take environmentally sound considerations.

PurposeThe purpose of this paper is to explore the potential impact of food sharing platform business models and to identify the limits and barriers in measuring the impact. Using the “theory of change” (ToC) approach, this paper develops a theoretical framework that captures the activities, outputs and outcomes of food sharing platforms and links them to indicators.Design/methodology/approachThe study employs a two-step methodology, which includes a website content analysis followed by two focus groups. The purpose of the website content analysis was to list a set of activities that are performed by food sharing platforms. The focus groups allow to design the ToC and to discuss limits and barriers in measuring the impact of food sharing platforms.FindingsThe study provides an overview of the main areas of impact of food sharing platforms (environmental, social, economic and political) and identifies the related outcomes. Furthermore, the paper highlights the need for the platform to manage the multifaceted tensions of food waste recovery vs prevention and the benefits of food recovery to helping hungry people vs the actual need to eradicate poverty by addressing social injustices and inequalities.Research limitations/implicationsThe selected sample involved in the focus group comprised a wide but not comprehensive set of stakeholders. Indeed, the obtained information cannot be generalized. In addition, the ToC approach requires a certain discretion of the facilitator and introduces the potential for partiality in conducting the analysis.Practical implicationsThe framework helps to unbundle the complex challenge of measuring the impact of food sharing platforms and it provides managers, practitioners and policy makers with a practical tool to direct their activities toward a better impact.Originality/valueFrom a theoretical perspective the study advances the literature on (food) sharing platforms and contributes to research on the sustainability in the food sector. It indicates the impacts a novel actor relying on digital technology can have in the food sector and points out the tensions between food recovery and prevention and the impact on poverty. The proposed framework could be a useful tool to support practitioners in understanding the trade-offs among the outcomes they aim to attain, and to identify the proper strategies to manage them.