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The Advanced Learning Platform for Analog Circuits and Automation for hybrid electronic practicals
No full textTo maintain experimental lab course work during the COVID-19 lockdowns, we chose a hybrid approach for our electronic instrumentation course and developed thereto the Advanced Learning Platform for Analog Circuits and Automation (ALPACA). To further meet our goals and standards, the ALPACA platform has been updated, using a Raspberry Pi Pico with Python instead of an Arduino. Our educational materials and approach are illustrated here through the typical example of a relaxation oscillator assignment. As student's feedback was overall positive and grades remained comparable, we continue the use of the ALPACA in the non-COVID era.BN/AfdelingsbureauElectronic Instrumentatio
A systematic methodology for changeable and reconfigurable manufacturing systems development
No full textPursuing manufacturing competitiveness in the dynamic industrial landscape necessitates implementing changeable and reconfigurable manufacturing systems (RMS) capable of rapid adaptation to varying functionalities and capacities. However, current manufacturing system development methods often overlook product-driven changes during the system's life cycle, hindering companies from effectively responding to shifting demands and technological advancements. Consequently, this research paper proposes a systematic methodology for designing and developing changeable and reconfigurable manufacturing systems to address this gap. The proposed methodology is derived from a synthesis of design theory, reconfigurability theory, and practical insights to guide the development process from conception to implementation. The four-step development method adopts a system life cycle-wide perspective, encompassing (i) identification and clarification of the need for reconfigurability, (ii) formulation of reconfigurable concepts, (iii) detailed design of the reconfigurable system, and (iv) successful implementation and utilization of reconfigurability. Crucially, the development method blends existing RMS development tools and novel tools co-created with industry partners, ensuring its pragmatic and holistic applicability. Each step incorporates specific activities and supporting tools, rendering the methodology flexible and adaptable to diverse manufacturing environments. The proposed methodology was validated through case studies in seven diverse manufacturing companies. The primary contributions of this research lie in integrating new and existing development tools into a comprehensive and practical development method, facilitating a system life cycle-wide approach to RMS design, and promoting industry-specific adaptability. The validation across multiple manufacturing companies ensures the effectiveness and broad applicability of the proposed methodology. Consequently, this paper is a valuable resource for manufacturing companies aiming to enhance competitiveness by adopting changeable and reconfigurable manufacturing systems.Transport Engineering and Logistic
LCA of Passive Smart Windows: A framework for assessing and comparing the environmental impact of Auto-Responsive glazing
No full textThe building sector is increasingly acknowledging the necessity to mitigate its environmental impact in response to the challenges posed by climate change. Adaptive facades specifically are used to develop a dynamic control of the envelope’s properties, modifying their behaviour in response to outdoor conditions and indoor stimuli. Thermochromic and photochromic technologies, also known as Passive Smart Windows (PSW) are passive solutions that aim to regulate solar gains through the integration of an Auto-Responsive (AR) layer, particularly for cooling purposes, to reduce energy consumption and minimize the operational impact of buildings.Existing literature predominantly concentrates on the performance aspects of these technologies, mainly due to their early development stages. However, there remains a gap in assessing the overall environmental impact, both in terms of impact perspective, thus considering several possible effectson the environment, and from a life cycle perspective, thus including both embodied and operational dimensions. The embodied impact, in particular, lacks comprehensive examination beyond considerations of Global Warming Potential (GWP). Furthermore, the dynamic landscape of materials and principles utilized in these technologies adds complexity to their evaluation.This thesis project aims to bridge these gaps by establishing a comprehensive framework for evaluating the total impact of PSW, encompassing both embodied and operational stages. Through comparative analysis with alternative Dynamic Window Systems (DWS), comprising static windows paired with dynamic shading devices, the framework facilitates a thorough examination. Operational energy calculations are grounded in energy simulations of a standard office space with an exposed facade, while the description of the embodied stages gives an overview of the life cycle of PSW, with focus on different possibilities integrating the AR layer and their consequences.The application of the framework in a case study reveals nuanced findings. While the GWP of PSW decreases of 1,1%, most of the other impact of PSW increase, including a growth of 0,1% of the Single Score. PSW has a lower impact compared to DWS due to the increased energy demand of the latter but, contrary to the initial expectations, the PSW does not consistently outperform static glazing due to conservative assumptions in energy simulation and a higher replacement rate, which significantly escalates embodied impact. Notably, challenges arise in defining materials for the AR layer, necessitating collaboration with manufacturers to improve data availability.The study identifies replacement as a critical factor in determining overall impact, underscoring the importance of extending the lifespan of PSW or to consider a detachable layer to enhance its environmental sustainability. However, criticisms regarding the partial nature of the analysis emerge, particularly in neglecting user comfort and control over the facade, as well as the temporal flexibility of the technology. Future research directions should incorporate these aspects for a more comprehensive evaluation.Ultimately, this thesis emphasizes the interdependency between the LCA approach, the energy simulation and the context of the PSW’s application. This highlights that the environmental impact assessment of such building elements can not leave the contextual application out of consideration in order to provide a sufficiently reliable result, thus limiting the use of this framework mainly to defined projects rather than to the estimation of generic impact for a PSW product.Civil Engineering | Building Engineering | Building Physics and Technolog
Revisiting interior microclimates: adaptive practices and the shifting paradigm of comfort: In the context of climate change, how can we redefine the modern notion of comfort in interior microclimates, and what insights can be gained from historical vernacular practices to guide the development of adaptive and resilient living environments?
No full text“Comfort […] is in short supply. Not because the world is running out of it but because, in the face of the climate crisis, we have to collectively adjust to its going away” (Barber, 2019, p. 44). During the last century, the Western hemisphere has grown accustomed to high standards of comfort reliably enabled by the built environment. Within the realm of thermal comfort, fossil-fueled mechanical HVAC systems are expected to mitigate heat during warmer seasons and provide warmth throughout living and working spaces in winter months. However, the understanding of and measures to achieve thermal comfort are a construct of modern societies. And they come at a price: cooling and heating accounts for approximately 20% respectively 50% of building energy (Wang et al., 2023). Facing the challenges and implications of climate change, this paper aligns with Professor Barber's contention that the status quo on comfort needs to be revisited and it is architects who are “on the front lines”, who are responsible for “exploring life after” and to explore and build noncarbon possibilities for “a world at the edge of discomfort” (Barber, 2019, p.50). The thesis delves into the historical evolution of comfort in the built environment, with a primary focus on thermal comfort and the overlooked influence of microclimates in our lives. The study explores the historical transition from vernacular ways of shaping interior microclimates through today's prevailing practices that are dependent on fossil fuels to contemporary movements to redefine our understanding and way of achieving thermal comfort. The exploration of thermal comfort has evolved throughout history, from ancient attempts of individuals who sought refuge from extreme climate conditions to sophisticated scientific models using multidisciplinary methods to answer simple questions – when do we feel comfortable and what is the amount of discomfort we can acclimatize to and embrace? Barber, D. A. (2019). After Comfort, 45–50. https://doi.org/http://dx.doi.org/10.17613/a32k-mg16 Wang, F., Yang, B., Deng, Q., & Luo, M. (Eds.). (2023). Personal Comfort Systems for improving indoor thermal comfort and air quality. Springer Verlag, Singapor.AR2A011Architectural History ThesisArchitecture, Urbanism and Building Science
Ports, Portscapes and Port Landscapes: The 100 year vision and strategy for circular and just spaces
No full textPortscapes are one of the most important hubs in the global economic system that facilitate the movement of goods and shape the socio-economic conditions of their surroundings. However, in times of climate change, they face unprec- edented challenges to completely transform their current ways of operating and fully reduce their contribution to a linear economy and socio-spatial injustice. These challenges go far beyond purely economic considerations and calls for a closer analysis of their current spatial impacts and system flows.Despite their significance, the spatial effects of Portscapes and their role in a shift towards sustainability and circularity is rarely the main focus of urban and regional design efforts. Drawing upon key theories such as circularity, decentralisation, socio-spatial justice, and sustainable land use, our approach involves a multidisciplinary analysis of ports and Portscapes in the Eurodelta portlandscape in North-Western Europe. Through analysis we have identified the different functioning of portscapes, the stakeholders they encompass and the spatial dynamics shaping ports, Portscapes and Port Landscapes.Our goal is to develop a strategy for the future of the European Portscape after a successful transition towards circular and just development to create a sustainable Eurodelta. This is achieved through a set of five objectives; integrating the ports, Portscapes and portlandscapes; increasing the resource efficiency of Portscapes; regenerating Portscapes for humans and nature; embracing technological innovation; facilitating a socially just transition.The spatial implications of these five objectives should not be neglected, and our strategy outlines what changes need to happen and when. In four Phases of spatial interventions and regulatory frameworks, we propose to build a just and truly circular Portscape, in harmony with the Eurodelta Port Landscape.This report holds key implications for both academia and practice, as further light is being shed on the spatial dynamics of Portscapes and potential transition pathways. By understanding the interplay of ports with their surrounding environments better, policymakers, urbanists and other related stakeholders can make informed decisions that promote sustainability and resilience. Ultimately, our efforts regarding the creation of more sustainable Portscapes contribute to broader (global) goals of addressing climate change, promoting socio-spatial justice and ensuring inclusive development.AR2U086 R&D Studio – Spatial Strategies for the Global MetropolisAR2U088 R&D Methodology for UrbanismArchitecture, Urbanism and Building Sciences | Urbanis
Impact of Water Quality on Biofilm in Drinking Water Distribution Systems
No full textMicrobial drinking water quality is of great importance to human health. Drinking water distribution systems (DWDSs) are designed as the final barriers for delivering and maintaining the biosafety of drinking water. Though the drinking water produced is usually safe and clean, it is common that the water quality deteriorates during the distribution. Such deteriorations can be linked to the establishment of biofilm in DWDSs, where the majority of the biomass is residing (> 95%). The formed biofilms are reportedly leading causes of the undesired taste, odor, and color of the drinking water, corrosion of the pipes, decay of the disinfectants, and proliferation of pathogenic microbes, giving rise to public health concerns. In the Netherlands, the control of the biofilm growth in DWDSs is achieved by producing bio-stable drinking water with extremely low nutrients (e.g., AOC < 10 µg C/l). On the other hand, water utilities in many countries usually apply chemical disinfectants (e.g., free chlorine, monochloramine) to control the biofilm growth in DWDSs. Nevertheless, biofilm formation is inevitable, regardless of the strategy. Additionally, there is no standard method to monitor the biofilm growth in DWDSs, which makes the understanding and management of DWDS biofilms more challenging. Efforts have been made to explore the biofilm formation and structure through pilot studies. However, most of these investigations have been conducted in a short time frame (e.g., within weeks to a max of 84 days), where the developed biofilms were far from mature and significantly different from those in the real DWDSs. To uncover how biofilm develops and what roles disinfectants play during the biofilm development, a newly-built pilot system was followed for a 64-weeks period under different disinfection regimes: no disinfectants (NC), free chlorine (FC), and monochloramine (MC) (Chapter 2). The results showed that residual disinfectants presented intensive suppression of the biofilm growth and shaped the biofilm communities. Specifically, MC exhibited stronger suppression of the biofilm activity (i.e., ATP), whereas FC expressed intense selection pressure on the microbes and established more homogenous and less complex biofilm community, with Proteobacteria comprising on average 82% of the relative abundance. The temporal trends highlighted the essential developmental stages in biofilm formation from initial colonization to accumulation and selection and stabilization, which occurred at different rates under each of the conditions, and were associated with significant dynamic changes in biofilm bacterial communities. Reaching stabilization took longest in the MC condition (> 64 weeks), followed by the NC (~ 36 weeks) and FC (~ 19 weeks) conditions. Holistically, the early stages in the biofilm formation in the NC condition were primarily dominated by stochastic processes where colonizers originating from treated water randomly attached to and settled on the pipes, while deterministic processes progressively increased in their relative contributions at the end of the accumulation stage and became predominant at the later stages. In the MC condition, the biofilm succession was governed by stochastic processes during the entire test, even though some deterministic processes occurred during the accumulation stage. Conversely, in the FC condition the biofilm succession was driven by deterministic processes already from the initial development stage. DWDSs are highly dynamic ecosystems, where the liquid (i.e., bulk water, suspended particles) and solid (i.e., biofilm, loose deposits) phases interact intensively during transport of the water from treatment to consumer. The cells and/or particles that were introduced with the treated water may attach to and/or settle on the pipes, forming biofilm/loose deposits when the hydraulic forces are weak. Conversely, the biofilm/loose deposits might release cells/particles to the bulk water during hydraulic disturbances, affecting the drinking water quality negatively. The hydraulic conditions in DWDSs are very complex and dynamic. They exhibit daily patterns, with high flow rates at high water demand periods (e.g., morning and/or evening hours) and long stagnancy or low flows during the night. However, most monitoring occurs using grab samples at one point in time. Thus, continuous online sampling is required to obtain a representative image of the particles and microbes in drinking water. In Chapter 3, a novel online monitoring and sampling system (OMSS) was developed to investigate the spatiotemporal variations of the planktonic and particle-associated bacteria in an unchlorinated DWDSs. The 16S rRNA gene sequencing combined with SourceTracker2 was used to trace and reveal the origin of the changes in the planktonic and particle-associated bacteria, assigning sampled biofilm and loose deposits as sources. The results showed that, spatially, the particle loads significantly increased from treatment plant within distribution networks, while the trend in the quantity of the particle-associated bacteria was the opposite. Similar to the trend of particle loads, the number of the observed OTUs in both planktonic and particle-associated bacteria increased from the treatment plant within the distribution network. The spatial results implied a dominant role of sedimentation of particles entering the DWDS from the treatment plant, while the observed increases in particles and the associated bacteria primarily originated from the distribution network, which were confirmed by the increased contributions from loose deposits and biofilm determined by SourceTracker2. Temporally, daily peaks in the water quality, including particle-associated bacterial quantity, observed operational taxonomic unit (OTU) number, and contributions of biofilm and loose deposits, were sensitively captured during the high water demand (morning/evening peaks). The temporal results revealed clear dynamic interactions between the liquid (i.e., bulk water, suspended particles) and solid (i.e., biofilm, loose deposits) phases in DWDSs. Driven by increasingly stringent drinking water regulations and challenges to drinking water quality, efforts are underway to further improve water quality. These initiatives include source water switching, upgrading treatment processes, and implementing changes to disinfectant strategies. Such actions change the quality and composition of the treated water that enters the DWDS. This may have transition effects, which in this thesis refers to the water quality deteriorations contributed by the release of cells and particles from biofilm and/or loose deposits due to the irregular changes in supply-water quality. It is largely unknown whether, where and when the transition effects will happen. In Chapter 4, transition effects were investigated through characterizing the particles before (T0), during (T3-weeks) and after (T6-months) introducing additional treatment steps (softening, second rapid sand filtration and adding carbon dioxide) to the existing treatment. The results showed that the upgraded treatment significantly improved the water quality after 6 months’ time. However, significant water quality deterioration was observed at the initial stage (T3-weeks) when the quality-improved treated water entered into the network. This manifested as a significant increase in total suspended solids (TSS) by 50-260%, active biomass (ATP) by 95-230%, and Mn by 130-250%. Furthermore, pyrosequencing results revealed sharp differences in microbial community composition and structure of the bacteria associated with particles between T0 and T3-weeks, implying the potential contributions from biofilm or loose deposits in the DWDS. Interestingly, the domination of Nitrospira spp. and Polaromonas spp. in the distribution system at T3-weeks, which were detected at rather low relative abundance at treatment plant, further confirmed the potential contributions from biofilm or loose deposits. Though the study in Chapter 4 confirmed the occurrence of the transition effects, the question how fast/how long the transition effects will occur/last, where the deteriorations originate from, and what actions can be carried out to minimize the transition effects is not clear. The sampling was conducted in a relatively short time frame (i.e., 6 months), with only a few time points (i.e., T0, T3-weeks, T6-months) and without the collection of biofilm and loose deposit samples. Additionally, as what we can see from the results from Chapter 3, it could be imagined that the transition effects might be enhanced during high water demand when shear forces are high. In order to fill the knowledge gaps, the OMSS was applied, accompanied with SourceTracker2, in an unchlorinated DWDS where partial RO was introduced (Chapter 5). The study was conducted before (TB), immediately after (T0), one month (T1M), two month (T2M), one year (T1Y) and two years (T2Y) after the partial RO introduction. Noticeably, significant transition effects in DWDS were captured right after the RO introduction, with increases in the particle loads, bacterial quantity, community diversity, and significant differences between bacterial communities in particles at treatment plant and distribution network. The disturbances lasted one month until T1M, after which they ceased to be observable around T2M. The captured deteriorations were confirmed by the increased contributions of loose deposits and biofilm (both the number of the immigrants and their abundance) at T0 and T1M determined by SourceTracker2 and neutral community model. While the peak transition window spanned about one month, it took considerably longer, until one year (T1Y) and two years (T2Y) later, for the microbial ecology to re-stabilize and for improvements in water quality to become noticeable. In addition, the peaks in the water quality deteriorations were enlarged during the high water demand (morning/evening peaks), which implies that current monitoring could potentially underestimate the extent of the quality deterioration. Remarkably, the observation that loose deposits contributed more to the transition effects than biofilm challenges the traditional standpoint, and provided new insights into the management of the transition effects, where the risks of the transition effects can be largely reduced by conducting flushing before the introduction of treatment changes to remove the loose deposits. In light of the destabilization caused by the changed water quality, flushing with new-quality water might be more rewarding. To conclude, through conducting studies at both field and pilot scales, the effects of the (changes in) operational conditions on the microbial drinking water quality in DWDSs were comprehensively explored. The findings in the thesis offer novel insights into the drinking water quality management. The knowledge gained from investigating the biofilm succession dynamics under different disinfectant regimes has significantly deepened our understanding of managing drinking water biofilms. These insights serve as valuable information when making informed decisions about the appropriate strategies to employ. The implementation of the developed OMSS is capable of capturing both periodic and aperiodic changes in drinking water quality, making it an essential tool in minimizing assessment deviations and ensuring accurate evaluations of drinking water quality. Moreover, the established methodology holds promise for application in various systems, including those that utilize chlorination. By identifying and characterizing the transition effects resulting from changes in supply water quality, such as treatment upgrades or the introduction of reverse osmosis, the study highlights the significance of considering these effects in water management practices. These observations underscore the importance of addressing the impact of transition effects on drinking water quality and provide practical implications for minimizing their negative consequences.Sanitary Engineerin
