Resource-efficient Systems Research Articles

Robust optimisation of combined rainwater harvesting and flood mitigation systems

Combined large-scale rainwater harvesting (RWH) and flood mitigation systems are promising as a sustainable water management strategy in urban areas. These are multi-purpose infrastructure that not only provide a secondary, localised water resource, but can also reduce discharge and hence loads on any downstream wastewater networks if these are integrated into the wider water network. However, the performance of these systems is dependent on the specific design used for its local catchment which can vary significantly between different implementations. A multitude of design strategies exist, however there is no universally accepted standard framework. To tackle these issues, this paper presents a two-player optimisation framework which utilises a stochastic design optimisation model and a competing, high-intensity rainfall design model to optimise passively-operated RWH systems. A customisable tool set is provided, under which optimisation models specific to a given catchment can be built quickly. This reduces the barriers to implementing computationally complex sizing strategies and encouraging more resource-efficient systems to be built. The framework was applied to a densely populated high-rise residential estate, eliminating overflow events from historical rainfall. The optimised configuration resulted in a 32% increase in harvested water yield, but its ability to meet irrigation demands was limited by the operational levels of the treatment pump. Hence, with the inclusion of operational levels in the optimisation model, the framework can provide an efficient large-scale RWH system that is capable of simultaneously meeting water demands and reducing stresses within and beyond its local catchment.

Industrial symbiosis marketplace concept for waste valorization pathways

Acceleration of raw materials’ depletion and waste accumulation create a need for stakeholders to shift from linear to circular business models by adopting novel strategies. Circular economy (CE) and industrial symbiosis (IS) offer a direction towards sustainable, resource efficient systems and eco-friendly waste management approaches. IS encompasses all types of interfirm cooperation in order to achieve a green, waste-free supply chain and at the same time to attain profits. However, among other barriers hampering widespread adoption of IS is lack of information exchange. Digital tools have emerged as facilitators of IS, since they enable real-time data sharing, identification and evaluation of symbiotic opportunities, while continuous progress of those tools is necessary for the digital transformation of IS. Important elements for the functionality and success of such tools are the criteria determining the matching of potential stakeholders and the support of the decision-making process. In the ongoing research that is presented, these matching criteria and benchmarks for waste valorization pathways are investigated and a matchmaking framework is proposed. The objective of the framework is to identify the most suitable collaborators to be deployed later to an automated matchmaking process, revealing latent possibilities (e.g. by suggesting indirect matches) and advantages of symbiotic actions from a holistic perspective. This tailor-made assessment is aspired to evaluate stakeholders’ compatibility based on more than a mere waste streams’ valorization match. Stakeholders’ specific requirements and motivations are incorporated in the potential partnership evaluation, thereby a multicriterion approach is proposed considering the potential cooperators’ relevance in terms of aspects like strategic goals, the level of IS embracement or synergy’s environmental impact.

Comparative Study of Layout Analysis of Tabulated Historical Documents

Nowadays, the field of multimedia retrieval system has earned a lot of attention as it helps retrieve information more efficiently and accelerates daily tasks. Within this context, image processing techniques such as layout analysis and word recognition play an important role in transcribing content in printed or handwritten documents into digital data that can be further processed. This transcription procedure is called document digitization. This work stems from an industrial need, namely, a Swedish company (ArkivDigital AB) has scanned more than 80 million pages of Swedish historical documents from all over the country and there is a high demand to transcribe the contents into digital data. Such process starts by figuring out text location which, seen from another angle, is merely table layout analysis. In this study, the aim is to reveal the most effective solution to extract document layout w.r.t Swedish handwritten historical documents that are featured by their tabular forms. In short, outcome of public tools (i.e., Breuel's OCRopus method), traditional image processing techniques (e.g., Hessian/Gabor filters, Hough transform, Histograms of oriented gradients -HOG- features), machine learning techniques (e.g., support vector machines, transfer learning) are studied and compared. Results show that the existing OCR tool cannot carry layout analysis task on our Swedish historical handwritten documents. Traditional image processing techniques are mildly capable of extracting the general table layout in these documents, but the accuracy is enhanced by introducing machine learning techniques. The best performing approach will be used in our future document mining research to allow for the development of scalable resource-efficient systems for big data analytics.

Ex-ante quantification of nutrient, total solids, and water flows in sanitation systems

To prioritise sustainable sanitation systems in strategic sanitation planning, indicators such as local appropriateness or resource recovery have to be known at the pre-planning phase. The quantification of resource recovery remains a challenge because existing substance flow models require large amounts of input data and can therefore only be applied for a few options at a time for which implementation examples exist. This paper aims to answer two questions: How can we predict resource recovery and losses of sanitation systems ex-ante at the pre-planning phase? And how can we do this efficiently to consider the entire sanitation system option space? The approach builds on an existing model to create all valid sanitation systems from a set of conventional and emerging technologies and to evaluate their appropriateness for a given application case. It complements the previous model with a Substance Flow Model (SFM) and with transfer coefficients from a technology library to quantify nutrients (phosphorus and nitrogen), total solids (as an indicator for energy and organics), and water flows in sanitation systems ex ante. The transfer coefficients are based on literature data and expert judgement. Uncertainties resulting from the variability of literature data or ignorance of experts are explicitly considered, allowing to assess the robustness of the model output. Any (future) technologies or additional products can easily be added to the library. The model is illustrated with a small didactic example showing how 12 valid system configurations are generated from a few technologies, and how substance flows, recovery ratios, and losses to soil, air, and water are quantified considering uncertainties. The recovery ratios vary between 0 and 28% for phosphorus, 0–10% for nitrogen, 0–26% for total solids, and 0–12% for water. The uncertainties reflect the high variability of the literature data but are comparable to those obtained in studies using a conventional post-ante material flow analysis (generally about 30% variability at the scale of a an urban area). Because the model is fully automated and based on literature data, it can be applied ex-ante to a large and diverse set of possible sanitation systems as shown with a real application case. From the 41 technologies available in the library, 101,548 systems are generated and substance flows are modelled. The resulting recovery ratios range from nothing to almost 100%. The two examples also show that recovery depend on technology interactions and has therefore to be assessed for all possible system configurations and not at the single technology level only. The examples also show that there exist trade-offs among different types of reuse (e.g. energy versus nutrients) or different sustainability indicators (e.g. local appropriateness versus resource recovery). These results show that there is a need for such an automated and generic approach that provides recovery data for all system configurations already at the pre-planning phase. The approach presented enables to integrate transparently the best available knowledge for a growing number of sanitation technologies into a planning process. The resulting resource recovery and loss ratios can be used to prioritise resource efficient systems in sanitation planning, either for the pre-selection or the detailed evaluation of options using e.g. MCDA. The results can also be used to guide future development of technology and system innovations. As resource recovery becomes more relevant and novel sanitation technologies and system options emerge, the approach presents itself as a useful tool for strategic sanitation planning in line with the Sustainable Development Goals (SDGs).

Developing sanitation planning options: A tool for systematic consideration of novel technologies and systems

To provide access to sustainable sanitation for the entire world population, novel technologies and systems have been developed. These options are often independent of sewers, water, and energy and therefore promise to be more appropriate for fast-growing urban areas. They also allow for resource recovery and and are adaptable to changing environmental and demographic conditions what makes them more sustainable. More options, however, also enhance planning complexity. Structured decision making (SDM) can help balance opposing interests. Yet, most of the current research focuses on the selection of a preferred option, assuming that a set of appropriate options is available. There is a lack of reproducible methods for the identification of sanitation system planning options that can consider the growing number of available technology and the many possible system configurations. Additionally, there is a lack of data, particularly for novel options, to evaluate the various sustainability criteria for sanitation.To overcome this limitation, we present a novel software supported approach: the SANitation sysTem Alternative GeneratOr (Santiago). To be optimally effective, Santiago is required to be integrated into an SDM approach. In this paper, we present all the elements that such an integration requires and illustrate these methods at the case of Arba Minch, a fast growing town in Ethiopia. Based on this example and experiences from other cases, we discuss the lessons learnt and present the advantages potentially brought by Santiago for sanitation planning The integration requires four elements: a set of technologies to be looked at, decision objectives for sustainable sanitation, screening criteria to evalute technology appropriateness, and about the technologies and the casea. The main output is a set of sanitation system options that is locally appropriate, diverse in order to reveal trade-offs, and of a manageable size. To support the definition of decision objectives, we developed a generic objective hierarchy for sustainable sanitation. Because one of the main challenges lies in the quantification of screening criteria, we established the data for 27 criteria and 41 technologies in a library.The case studies showed, that if the integration is successful, then Santiago can provide substantial benefits: (i) it is systematic and reproducible; (ii) it opens up the decision space with novel and potentially more appropriate solutions; (iii) it makes international data accessible for more empirical decision making; (iv) it enables decisions based on strategic objectives in line with the sustainable development goals; (v) it allows to prioritise appropriate and resource efficient systems right from the beginning (vi) and it contributes to a more citywide inclusive approach by bridging strategic objectives with an area-based appropriateness assessment. The here presented approach enables the prioritisation of appropriate and resource efficient sanitation technologies and systems in strategic planning. Thereby this approach contributes to SDG 6.2, 6.3, and 11, sustainable sanitation for all.

Roller Burnishing of Particle Reinforced Aluminium Matrix Composites

Energy and resource efficient systems often demand the use of light-weight materials with a specific combination of properties. However, these requirements usually cannot be achieved with homogeneous materials. Consequently, composites enabling tailored properties gain more and more importance. A special kind of these materials is aluminium matrix composites (AMCs), which offer elevated strength and wear resistance in comparison to the matrix alloy. However, machining of these materials involves high tool wear and surface imperfections. An approach to producing high-quality surfaces consists in roller burnishing of AMCs. Furthermore, such forming technologies allow for the generation of strong compressive residual stresses. The investigations address the surface properties in the roller burnishing of AMCs by applying different contact forces and feeds. For the experiments, specimens of the alloy AA2124 reinforced with 25% volume proportion of SiC particles are used. Because of the high hardness of the ceramic particles, roller bodies were manufactured from cemented carbide. The results show that roller burnishing enables the generation of smooth surfaces with strong compressive residual stresses in the matrix alloy. The lowest surface roughness values are achieved with the smallest feed (0.05 mm) and the highest contact force (750 N) tested. Such surfaces are supposed to be beneficial for components exposed to dynamic loads.

Multidisciplinary and Historical Perspectives for Developing Intelligent and Resource-Efficient Systems

As communication and computation systems become more complex and target at higher performance, the fundamental limits of nature can be expected to constrain their development and optimization. This calls for intelligent use of basic resources, that is, materials, energy, information, time, frequency, and space. We present a multidisciplinary and historical review on the body of knowledge that can be applied in researching, such as intelligent and resource-efficient systems. We review general system theory, decision theory, control theory, computer science, and communication theory. While multidisciplinarity has been recognized as important, there are no earlier reviews covering all these five disciplines. Based on the review, we build a chronology of intelligent systems and identify connections between the disciplines. Optimization, decision-making, open- and closed-loop control, hierarchy, and degree of centralization turn out to be recurring themes in these disciplines, which have converged to similar solutions that are based on remote control, automation, autonomy, and self-organization. We use future wireless networks as an example to illustrate the open questions and how they can be addressed by applying multidisciplinary knowledge. This paper can help researchers to use knowledge outside their own field and avoid repeating the work done already. The resulting consolidated view can speed up research and is especially important when the fundamental limits of nature are approached and new insights are required to overcome the challenges. The general, long-standing problem to be tackled is multiobjective optimization with autonomous and distributed decision-making in an uncertain, dynamic, and nonlinear environment where the objectives are mutually conflicting.

A Study of Resource-efficient Technologies for Cities of the Future to be Sustainable

The urbanization process presents enormous challenges to governments, companies, and environmental planners of the megacities. The rapid growth of megacity causes severe social, environmental and economic problems, which are difficult to manage in a sustainable way. Traffic jams, poor air quality, and health risks make life in megacities even more difficult. On the other hand, in developing world, urban impoverished face enormous challenges with inadequate services which become even more challenging. Therefore, resource-efficient systems will be highly needed to tackle the social, economic and environment pressures in a sustainable way for cities. This paper improves the awareness of some resource-efficient technologies and investigates their contributions to tackling environmental and social challenges for megacities of the future. Some sustainability principles are investigated to guide technology development to better deliver social equity, environmental protection, and economic prosperity for cities of the future.

Overcoming institutional barriers in the development of novel process industry residue based symbiosis products – Case study at the EU level

The development of novel symbiosis products based on primary industrial residues in accordance with the systemic approaches of Industrial Ecology (IE) and Industrial Symbiosis (IS) has significant potential to increase the environmental performance of process industry, including more material and energy efficient processes and with lower environmental impacts. What is more, functionally innovative symbiosis products have the potential to promote residue utilisation and recovery and to prevent or reduce waste generation in line with the EU level ‘recycling society’ concept. However, successful product development requires an enabling institutionally aligned environmental approach that includes appropriate market incentives and regulatory instruments. This paper aims to identify the possible institutional barriers in the EU legal framework that have to be addressed to promote the development of such primary residue based process industry symbiosis products, with thorough consideration of full product life-cycles. Recommendations for overcoming these barriers and on the design of new approaches that support industrial symbiosis and contribute to progress towards sustainable societies are also outlined. These include enhanced focus on creating an enabling institutional environment for industrial innovations and the promotion of material efficiency through incentives policies and regulations, as well as soft law guidance on novel uses of materials and closure of resource cycles. Making a wider system more sustainable on an eco-efficiency basis also calls the definition of system boundaries into question. Applying a systemic approach, such as that offered by both IE and IS, which cover sustainability and recycling to achieve more resource efficient systems, appears to offer a way forward. We argue that the development of process industry residue based products can be significantly promoted and advanced by co-operative and joint design of appropriate incentives, policies and regulations. A major question is whether the REACH Regulation would apply to residue based symbiosis products if their creation makes them no longer legally classified as waste under end-of-waste legislation. We use a synthetic symbiosis product group concept based on the utilisation of steel, paper and pulp process industry primary residues as a case study to assess the development potential of such products against legal requirements and policy objectives.

Retrofitting sustainability to historic city core areas

Historic, mixed-use, core urban areas such as Soho in Central London have proved remarkably resilient with building stock that is adaptable to changes of use over time. Such districts contribute significantly to the social fabric and cultural character of cities and are highly valued by their resident and user populations. In the UK, buildings, according to various estimates, contribute between 44 and 52% of the total carbon emissions and there is now considerable pressure to retrofit existing urban areas to make them more environmentally sustainable. The built fabric in the historic areas is relatively energy- and resource-inefficient, although embodied energy and carbon is high owing to the long working life of buildings. At the same time the existing buildings, because of their use, have high energy demands. Guiding retrofitting requires an integrated urban design and management approach at the district or neighbourhood scale that addresses both buildings and urban spaces. A methodology is outlined that meets the needs of cultural preservation while facilitating retrofitting of resource-efficient systems.