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Public acceptance in direct potable water reuse: a call for incorporating responsible research and innovation
No full textAs global issues such as climate change and diminishing resources become increasingly pressing, water recycling has moved into the focus. However, the successful implementation of Direct Potable Water Reuse (DPR) projects hinges on securing public acceptance, which remains challenging. This paper aims to flesh out possible reasons for the lingering public rejection of DPR. We will do so by conducting a literature review on how public acceptance is understood and what approaches are proposed to enhance it. These approaches are analyzed using Responsible Research and Innovation principles and the `opening up', `closing down' and `leaving ajar' approaches. Our research identifies an overreliance on the controversial information deficit model, closing down large parts of public engagement. We advocate for becoming more inclusive through the `leaving ajar' approach. Particularly, attention should be paid to reflexivity and responsiveness to public concerns to ensure meaningful public engagement.Values Technology and Innovatio
Hygrothermal ageing of dry gelatine adhesive films: Microstructure-property relationships
No full textGelatine adhesives, also known as animal glues, are collagen-based water-soluble biopolymers derived from vertebrate connective tissues. One of the various fields in which gelatine adhesives are widely used is the conservation of cultural heritage such as decorated furniture and panel paintings. It is observed that, with time, the failure in these objects often occurs along the adhesive bondlines. Given the moisture and temperature sensitivity of these adhesives, obtaining knowledge of their long-term behaviour, when exposed to climate variations, is pivotal. Here, the influence of hygrothermal ageing (exposure to a combination of elevated temperature and relative humidity (RH) cycling) on the microstructure and macroscopic properties of four different types of gelatine adhesives is investigated. These adhesives were selected from different animal origins namely bovine, rabbit, and fish with different Bloom strengths. It was observed that ageing cycles interfere with the most critical structural feature of protein chains namely triple helices. A clear decay in triple helix content at the micro-scale, determined by Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD) techniques, was observed which had implications on the macroscopic properties of these adhesives such as reduction of strain to failure and toughness (strain energy density to failure). The rate of decay in properties was revealed to be the highest in the adhesives with the lowest triple helix content. This study provides a scientific view of microstructure-property relationships in gelatinous adhesives as a function of environmental ageing, and stipulates the underlying mechanism of the degradation of mechanical properties as the loss of structural triple helices, regardless of the animal origin.Bio-based Structures & MaterialsStructural Integrity & CompositesAdhesion Institut
Nudging human drivers via implicit communication by automated vehicles: Empirical evidence and computational cognitive modeling
No full textUnderstanding behavior of human drivers in interactions with automated vehicles (AV) can aid the development of future AVs. Existing investigations of such behavior have predominantly focused on situations in which an AV a priori needs to take action because the human has the right of way. However, future AVs might need to proactively manage interactions even if they have the right of way over humans, e.g., a human driver taking a left turn in front of the approaching AV. Yet it remains unclear how AVs could behave in such interactions and how humans would react to them. To address this issue, here we investigated behavior of human drivers (N = 19) when interacting with an oncoming AV during unprotected left turns in a driving simulator experiment. We measured the outcomes (Go or Stay) and timing of participants’ decisions when interacting with an AV which performed subtle longitudinal nudging maneuvers, e.g. briefly decelerating and then accelerating back to its original speed. We found that participants’ behavior was sensitive to deceleration nudges but not acceleration nudges. We compared the obtained data to predictions of several variants of a drift-diffusion model of human decision making. The most parsimonious model that captured the data hypothesized noisy integration of dynamic information on time-to-arrival and distance to a fixed decision boundary, with an initial accumulation bias towards the Go decision. Our model not only accounts for the observed behavior but can also flexibly generate predictions of human responses to arbitrary longitudinal AV maneuvers, and can be used for both informing future studies of human behavior and incorporating insights from such studies into computational frameworks for AV interaction planning.Human-Robot InteractionHuman-Centred Artificial IntelligenceInteractive Intelligenc
Multifaceted Functionalities of Bridge-Type DC Reactor Fault Current Limiters: An Experimentally Validated Investigation
No full textWith the ongoing expansion and interconnection of electrical power systems, alongside the rapid proliferation of renewable distributed generations (DGs), the short-circuit extent in the power grid is experiencing a significant rise. Fault current limiters (FCLs) have been introduced in an effort to address this issue, ensuring the robustness and sustainability of expensive power system components when confronted with short-circuit faults. Among the various types of FCLs, bridge-type DC reactor fault current limiters (BDCR-FCLs) have emerged as one of the most promising options. While BDCR-FCLs have shown excellent properties in limiting harmful short-circuit currents, they are also advantageous in other respects. This paper investigates the supplementary functionalities of BDCR-FCLs as a multifaceted device towards the enhancement of the quality of supplied energy in terms of total harmonic distortion (THD) reduction, power factor (PF) correction, peak current reduction for nonlinear loads, and soft load variation effects, as well as their capability to limit fault current. To this aim, the capabilities of BDCR-FCLs have been studied through various simulated case studies in PSCAD/EMTDC software V5.0.1, in addition to experimental tests considering an AC microgrid connected to a DC system. The experimental and simulation investigations verify the superior multifaceted functionalities BDCR-FCLs introduce in addition to their excellent fault current-limiting capabilities. The results show that PF improved by 6.7% and 7%, respectively, in simulation and experimental tests. Furthermore, the current THD decreased by 20% and 18% in the simulation and experiment, respectively.Intelligent Electrical Power Grid
Process design and downstream optimization of the direct synthesis route for cleaner production of dimethyl ether from biogas
No full textThis study investigates an innovative method to produce dimethyl ether (DME) by direct synthesis from syngas derived from biogas. The proposed process was rigorously simulated in Aspen Plus, highlighting the main sections: (i) biogas tri-reforming, (ii) dimethyl-ether synthesis, and (iii) DME purification. The tri-reforming section has a CO2 and CH4 conversion of 27.3% and 96.2%, respectively A novel catalyst suitable for CO2-rich feed was chosen for the DME production to allow 60% conversion of CO2. Product separation is achieved via several absorption and distillation columns, ensuring that the operating conditions are kept mild to avoid expensive refrigeration. An optimization analysis was performed to identify the most suitable layout of the downstream process. This was identified through the evaluation of performance indicators such as utility usage and operating expenses. A wide range of purification strategies have been evaluated, and two scenarios are proposed based on the results. Configuration A produces 5.34 ktpy DME and 1.26 ktpy methanol, while Configuration B produces exclusively 6.21 ktpy DME. The process configurations were analysed by means of key techno-economic indicators and sustainability metrics. Both processes have an energy intensity of 14.5 kWh/kg. The reforming unit has a negligible footprint as it is thermally sustained from biogas combustion, but the reboilers are the main contributors for plant CO2 emissions. Configuration B has the best economic value with 11,634 k€ of NPV after 25 years and a payback time of 4 years.ChemE/Product and Process Engineerin
Autonomous Sailing with Sim-to-Real Reinforcement Learning
No full textFacing the critical challenge of reducing greenhouse gas (GHG) emissions in the maritime industry, this thesis explores the potential of smart control systems using Reinforcement Learning (RL) for autonomous sailing. Traditional controls for sailing fall short in navigating the complex, dynamic conditions of maritime environments. RL has shown to be effective for continuous control applications in these types of conditions, however, primarily in simulated environments. Therefore, this study aims to show the potential of RL for autonomous sailing control (ASC) by means of a small scale project. A fast-time simulation of an Optimist is used to train the sailing controls required to reach an upwind target. The controls are then transferred to a robotized Optimist in a real-world environment to test the transferability of the simulation trained controls. First, the reality gap, or modelling error, between the simulation and real-world environment is quantified to be able to assess the performance of the used techniques to bridge the existing gap. The sim-to-real techniques of Domain Randomization (DR) and the addition of observation noise (ON) are applied during the training process. To test the effectiveness of the trained RL controls, the best performing ones in the simulation are selected and tested in the real-world environment. The performance of the RL controlled Optimist is compared to state-of-the-art controls in robotic sailing. Their performances are measured and compared by means of success rate and a physics-based metric that calculates the efficiency of the sailboat to use the power of the wind to propel itself, called the energy ratio. The results show that the RL controls are highly successful in the sailing simulation, however, the transfer to the real-world remains a major challenge. DR does improve the sim-to-real transfer, resulting in an agent that is able to reach a 100% success rate throughout 12 runs in the real-world environment.Supplementary data and information about this thesis can be found here: https://www.marin.nl/en/research/artificial-intelligence-applicationsMarine Technology | Ship Hydrodynamic
Rethinking Youth Participation in Policymaking: A Frame Innovation Approach
No full textYouth participation is becoming increasingly important in municipal governance. However, despite the introduction of new tools, podcasts, and events designed to foster participation, engaging young voices in policy-making remains a challenge. This project explores whether a different perspective on this challenge can lead to more meaningful engagement.This project is part of Healthy Start, a collaborative initiative between the Delft University of Technology, Erasmus Medisch Centrum and the Erasmus University Rotterdam, which seeks to enhance the well-being of young individuals. Among its ambitions is the enhancement of youth participation. The project will emphasize youth participation in municipal policy in Rotterdam.Using the Frame Innovation method, a design approach focused on redefining problems to uncover innovative solutions, this study aims to discover unique insights by ‘reframing’ the issue of youth participation. Achieving an understanding of the stakeholders and their values was accomplished through a Research through Design approach. A variety of design activities were undertaken, including engaging policy advisors in creative sessions at Het Timmerhuis, and deploying cultural probes during dialogues with young individuals in a sounding board group and at the Rotterdam Blaak library.The findings reveal that stakeholders have diverse needs. Not all officials view participation the same way, and differences among young people are significant. Four main themes emerged, reflecting the values of these diverse groups:Open Hearts, Open Minds: This theme underscores the importance of genuine interactions and empathy, highlighting how prejudices can complicate matters. For example, officials may fear being perceived negatively by the public, while young people worry about being seen as inexperienced.Navigating the Unknown: Participatory processes involve uncertainties, requiring both youths and officials to venture into unfamiliar territory. This theme explores how they can feel in control despite these uncertainties.Driven by Responsibility: This focuses on the sense of duty and how it affects engagement. It questions when stakeholders consider something important enough to warrant their involvement.What You Do Matters: This theme emphasizes the significance of feeling that one’s contributions are impactful and explores the dynamics of power within participation. Both youths and officials can feel powerless, doubting the impact of their efforts and not seeing the success of their actions.Reframing the problem based on these themes offers new perspectives on addressing the challenges of youth participation. Navigating the Unknown might suggest a future with a municipal “travel agency” for participation, providing guidance, resources, and connections to make the participatory process less daunting and more accessible. Or adopting an “open hearts, open minds” approach one could imagine facilitating transparent discussions about roles and aspirations, enhancing engagement and ensuring participation leads to meaningful outcomes. This report proposes new strategic approaches to youth participation in Rotterdam’s policymaking. By gaining a deeper understanding of the problem space and reframing it, these new perspectives offer avenues for further exploration. Insights into the frame innovation methodology are also shared to inform future studies. Healthy StartStrategic Product Desig
Security risk assessment: Exploring real-life praxis
No full textFacing a (security) threat, what is the best thing to do? The overall research questions driving this study are about how security professionals assess, reason, and decide about security risks, and where their justification is founded on. The presented results are explorative, based on trying primarily to understand individual professional judgment and secondary, if possible, to explain the reasons behind this judgement. This work will not answer all the questions, it is, however, a valuable start to understand the difficult task the professionals in this domain are facing: preparing for, and thus predicting possible security threats....Safety and Security Scienc
Adaptive Reuse of Urban Heritage in Contested Urban Contexts
No full textThe world is facing global challenges that are dramatically changing the social and physical environments, resulting in cultural confrontation. Rapid urban growth, and gentrification increase urban pressure while jeopardizing social cohesion, multicultural values and local economies. Moreover, environmental factors associated with climate change challenge the way cities respondand adapt, as their assets have to be re-designed to meet the current and future generation needs.One response to these challenges is adaptive reuse, the transformation of the function of an underused structure into a new use. This process turns the cities’ elements in decline into development catalysers. The adaptation to these changes is often a source of conflict, as urban policies lack citizen engagement in the redefinition of public space, resulting in more disagreement. This is particularly acute when addressing contested communities, as their continuous evolution directly influence the adaptation of cultural heritage.Considering these aspects, this research question is responded: ‘How can socio-spatial conflicts that result from contested identities be mitigated through the adaptive reuse of urban heritage?’.The relations between Adaptive Reuse, Urban Heritage and Contested Identities are studied, resulting in the research’s objective: to develop an integrative methodology to evaluate urban heritage adaptive reuse alternatives in contested urban contexts, using the case of Acre (Israel). This final outcome is proposed as a tool for decision-makers and urban planners that provides information-based results to be applied in urban design practice, aiming to translate the theory into practice, and to bridge the gap between global goals and local issues.Heritage & Architectur
Towards a Reliable Design of Geopolymer Concrete for Green Landscapes: A Comparative Study of Tree-Based and Regression-Based Models
No full textThe design of geopolymer concrete must meet more stringent requirements for the landscape, so understanding and designing geopolymer concrete with a higher compressive strength challenging. In the performance prediction of geopolymer concrete compressive strength, machine learning models have the advantage of being more accurate and faster. However, only a single machine learning model is usually used at present, there are few applications of ensemble learning models, and model optimization processes is lacking. Therefore, this paper proposes to use the Firefly Algorithm (AF) as an optimization tool to perform hyperparameter tuning on Logistic Regression (LR), Multiple Logistic Regression (MLR), decision tree (DT), and Random Forest (RF) models. At the same time, the reliability and efficiency of four integrated learning models were analyzed. The model was used to analyze the influencing factors of geopolymer concrete and determine the strength of their influencing ability. According to the experimental data, the RF-AF model had the lowest RMSE value. The RMSE value of the training set and test set were 4.0364 and 8.7202, respectively. The R value of the training set and test set were 0.9774 and 0.8915, respectively. Therefore, compared with the other three models, RF-AF has a stronger generalization ability and higher prediction accuracy. In addition, the molar concentration of NaOH was the most important influencing factors, and its influence was far greater than the other possible factors including NaOH content. Therefore, it is necessary to pay more attention to NaOH molarity when designing geopolymer concrete.Pavement Engineerin
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