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    Optimization of Interplant Water Reuse in Industrial Parks: Considering Water Treatment Systems

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    Reusing water is a crucial part of the solution for addressing the growing concern regarding the risk of water scarcity in industrialized and urbanized areas. This study introduces a tool for the design of water networks, focusing on water reuse in industrial parks. Utilizing a mixed-integer nonlinear programming (MINLP) model developed earlier, this tool is the first in water network design models that operates with open-source software, while considering water treatment systems and multiple constituents. A literature study is conducted to discover shortcomings in water network design models and to find a foundational model to use to develop the tool. The developed tool creates a water network based on the optimization of the costs of water obtained from water sources, the costs of treatment systems, and optionally the piping costs. The treatment systems are used to regenerate the water for reuse in industrial plants and to meet environmental discharge limits. The tool develops local optimal solutions as an output. Additionally, this study is the first to integrate a water treatment systems database into a water network design model. However, this database needs to be expanded before it is usable. This study demonstrates the tool through three case studies.Civil Engineerin

    Railway sleeper vibration measurement by train-borne laser Doppler vibrometer and its speed-dependent characteristics

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    A train-borne laser Doppler vibrometer (LDV) directly measures the dynamic response of railway track components from a moving train, which has the potential to complement existing train-borne technologies for railway track monitoring. This paper proposes a holistic methodology to characterize train-borne LDV measurements by combining computer-aided approaches and real-life measurements. The focus is on the speed-dependent characteristics because the train speed affects the intensity of railway sleeper vibrations and the intensity of speckle noise, which further affects the quality and usability of the measured signals. First, numerical models are established and validated to simulate sleeper vibrations and speckle noise separately. Then, a vibration–noise separation method is proposed to effectively extract speckle noise and structural vibrations from LDV signals measured at different speeds. The parameters of the separation method are tuned using simulation signals. The method is then validated using laboratory measurements in a vehicle-track test rig and applied to field measurements on a railway track in Rotterdam, the Netherlands. Further, the speed-dependent characteristics of train-borne LDV measurement are determined by analyzing the competition between sleeper vibrations and speckle noise at different speeds. Simulation and measurement results show that an optimal speed range yields the highest signal-to-noise ratio, which varies for different track structures, measurement configurations, and operational conditions. The findings demonstrate the potential of train-borne LDV for large-scale rail infrastructure monitoring.Reservoir EngineeringRailway Engineerin

    Criminal, Cosmopolitan, Commodified: How Rotterdam’s Interwar Amusement Street, the Schiedamsedijk, Became a Safe Mirror Image of Itself

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    This chapter develops a layered analysis of the Schiedamsedijk, Rotterdam’s interwar amusement street. It links the street’s split socio-cultural character to that of port cities in general, and investigates this along the lines of a similar divide in perceptions of safety and security. Based on an historical bird’s-eye view of the pleasure area, the Schiedamsedijk’s criminal and cosmopolitan sides are discussed. Both of these maritime urban traits were neutralised when the Schiedamsedijk reinvented itself as a domestic tourist attraction in the late 1930s. Through visual sources, interchanges are foregrounded between contrasting internal and external perspectives on safety, which ultimately help to nuance and reframe the stereotypical characters and ambiguous nature traditionally ascribed to this historical environment of pleasure culture.'The Cultural Construction of Safety and Security' was made possible by a grant from: Open Access Stimuleringsfonds; HERA project ‘Governing the Narcotic City. Imaginaries, Practices, Discourses and Consequences of Public Drug Use’; Faculty CW Open UniversiteitHistory, Form & Aesthetic

    Installation of perforated monopiles: And the associated fatigue damage

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    The European offshore wind industry has experienced significant growth in the past decade, mainly focusing on shallow areas in the North Sea to reduce the Levelised Cost of Electricity (LCoE) and compete with fossil fuels. However, as shallow areas become scarcer and the industry seeks greater independence from government subsidies, a shift towards deeper waters is anticipated, and already observed in Europe. In the northern part of the North Sea (60-120 meters deep), jacket foundations are currently favoured, despite drawbacks such as extensive engineering efforts, weld requirements, challenging series production, and high costs. This misalignment with the industry's LCoE reduction goal highlights the need for a technologically viable and economically attractive foundation concept for waters in the 60-120-meter range. To combat this challenge, perforated monopiles are being developed. The perforated monopile consists of a monopile with perforations, either circular or elliptical, around the splash zone, with the goal of reducing the frontal area, and thus reducing the hydrodynamic loads on the structure. These concepts aim to combine the ease of manufacturing of a monopile, with the reduced area affected by hydrodynamic loads that are common for jacket structures. The research done so far on these perforated monopiles has only looked at the reduction in hydrodynamic loads, which have proven significant. These reductions in hydrodynamic loads should enable the perforated monopiles to be used in deeper waters compared to regular, non-perforated, monopiles. They could provide a tempting alternative for the more expensive jacket structures, but more research is necessary, especially in analyzing other loads that the perforated monopile may be subject to. This thesis aims to look at one such different load that affects this perforated monopile, namely the installation loads induced by hammering. The first part of this thesis will look at stresses and fatigue damage during the installation of non-perforated monopiles. The second part will analyze the increased stresses, possible losses in hammer energy, and increased fatigue damage, all due to the presence of perforations. Finally, several alternatives, such as different geometries of perforations and different hammer loads will be analyzed with regard to their effect on fatigue damage. The fatigue damage due to installation is found to increase significantly due to the presence of perforations, increasing from 5% for non-perforated monopiles, to up to 118% and 112% for the two most promising geometries analyzed, thus proving a show-stopper for installation via impact hammer, if no measures are taken. Changing certain parameters, however, either the geometries of the perforations, or the characteristics of the hammer used, shows that installation is indeed possible. Using different geometries of perforations, that maintain a significant reduction in area, shows installation is possible, whilst limiting the fatigue damage to 53%. A reduction in hammer force by a factor of 2, also decreases the fatigue damage by 34% on average. The use of a so-called vibro-hammer also shows promising, resulting in a halving of the fatigue damage compared to the use of an impact hammer, but more research needs to be done to confirm this final finding. To conclude, this research shows that installation of a perforated monopile is possible, although most, if not all of the reduction in fatigue damage due to hydrodynamic loading is cancelled out by the increase in fatigue damage due to installation. Geometries and installation methods may exist that improve the fatigue life of the structure, but this research was unable to find them. Future research may be able to find geometries and installation loads that do reduce overall fatigue damage. Further research is also necessary before perforated monopiles can be taken into service, such as the confirmation of the energy losses in installation due to perforations. Also, several other load cases need to be analyzed, to ensure the perforated monopile survives its designed lifetime.Offshore and Dredging Engineerin

    Drivers for optimum sizing of wind turbines for offshore wind farms

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    Large-scale exploitation of offshore wind energy is deemed essential to provide its expected share to electricity needs of the future. To achieve the same, turbine and farm-level optimizations play a significant role. Over the past few years, the growth in the size of turbines has massively contributed to the reduction in costs. However, growing turbine sizes come with challenges in rotor design, turbine installation, supply chain, etc. It is, therefore, important to understand how to size wind turbines when minimizing the levelized cost of electricity (LCoE) of an offshore wind farm. Hence, this study looks at how the rated power and rotor diameter of a turbine affect various turbine and farm-level metrics and uses this information in order to identify the key design drivers and how their impact changes with setup. A multi-disciplinary design optimization and analysis (MDAO) framework is used to perform the analysis. The framework uses low-fidelity models that capture the core dependencies of the outputs on the design variables while also including the trade-offs between various disciplines of the offshore wind farm. The framework is used, not to estimate the LCoE or the optimum turbine size accurately, but to provide insights into various design drivers and trends. A baseline case, for a typical setup in the North Sea, is defined where LCoE is minimized for a given farm power and area constraint with the International Energy Agency 15 MW reference turbine as a starting point. It is found that the global optimum design, for this baseline case, is a turbine with a rated power of 16 MW and a rotor diameter of 236 m. This is already close to the state-of-the-art designs observed in the industry and close enough to the starting design to justify the applied scaling. A sensitivity study is also performed that identifies the design drivers and quantifies the impact of model uncertainties, technology/cost developments, varying farm design conditions, and different farm constraints on the optimum turbine design. To give an example, certain scenarios, like a change in the wind regime or the removal of farm power constraint, result in a significant shift in the scale of the optimum design and/or the specific power of the optimum design. Redesigning the turbine for these scenarios is found to result in an LCoE benefit of the order of 1 %–2 % over the already optimized baseline. The work presented shows how a simplified approach can be applied to a complex turbine sizing problem, which can also be extended to metrics beyond LCoE. It also gives insights into designers, project developers, and policy makers as to how their decision may impact the optimum turbine scale.Wind Energ

    Design and Analysis of Macro-Economic Models in the Laplace Domain: An Economic-Engineering Approach

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    In this thesis, we demonstrate the efficiency of Laplace domain techniques for the design and analysis of economic systems. To make the techniques applicable to economic modeling, we establish the economic analogs to the various tools and nomenclature in the engineering literature. We show that the Laplace domain provides an alternative description of economic systems, offering insights into behavior not apparent in the time domain. This allows economic discounting and cycles to be efficiently analyzed using pole-zero maps, Bode plots, and similar techniques. In addition, we demonstrate that transforming the linear differential equations of economic engineering into algebraic equations in the Laplace domain simplifies the design of economic systems.We use the Laplace domain techniques to design and analyze a macroeconomic model. By designing the model in the Laplace domain, we are able to integrate supply chain dynamics and the housing market using two-port network theory.By analyzing the model using a pole-zero map, we show that the economy's discount rates and business cycles are represented by complex poles and the economy's transmission blocking rates by complex zeros. Additionally, we demonstrate that the Bullwhip effect, a supply chain phenomenon, can be intuitively visualized using a Bode plot. These applications illustrate how Laplace-domain techniques enable the efficient design and analysis of economic systems.Mechanical Engineering | Systems and Contro

    Enabling Technologies for the Navigation and Communication of UAS Operating in the Context of BVLOS

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    Unmanned Aerial Systems (UAS) have rapidly gained attraction in recent years as a promising solution to revolutionize numerous applications and meet the growing demand for efficient and timely delivery services due to their highly automated operation framework. Beyond Visual Line of Sight (BVLOS) operations, in particular, offer new means of delivering added-value services via a wide range of applications. This "plateau of productivity" holds enormous promise, but it is challenging to equip the drone with affordable technologies which support the BVLOS use case. To close this gap, this work showcases the convergence of the automotive and aviation industries to advance BVLOS aviation for UAS in a practical setting by studying a combination of Commercial Off-The-Shelf (COTS) technologies and systems. A novel risk-based approach of investigating the key technological components, architectures, algorithms, and protocols is proposed that facilitate highly reliable and autonomous BVLOS operations, aiming to enhance the alignment between market and operational needs and to better identify integration requirements between the different capabilities to be developed.Signal Processing System

    Isolating a Tree’s Skeleton using a 3-Dimensional Reconstruction

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    L-Systems allow for the efficient procedeural generation of trees to be used for rendering in video games and simulations. Currently, however, it is difficult to engineer grammars that mimic the behaviours of real life trees in 3 dimensions. To be able to deduce them, the skeleton of a tree can be used to train a model and generate an L-system for a given tree in particular. The aim of this paper is to provide a pipeline to isolate these skeletons from images of a tree, using Neural Radiance Fields (NeRFs) to reconstruct the tree, and using Laplacian Based Contraction to retrieve the underlying skeleton. We find that this approach leads to 3-dimensional topologies that very closely resemble the given tree.CSE3000 Research ProjectComputer Science and Engineerin

    A Toolkit To Spark Interest In Engineering Among Young Adults

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    This project aims to introduce engineering in a way that captures students' interest. In order to motivate studernts to try it out, instead of limited by their past experience. Therefore, expanding the original knowledge of engineering during the design ideation process becomes crucial. Beginning with the identification of factors contributing to the underrepresentation of female students in the field. Additionally, this study collaborates with Cities of Things Lab 010, which strives to incorporate citizens' opinions into the neighbourhood robot design process. Hosting the workshop and making robot development accessible to all citizens. For me, I narrowed down the scope to focus on students. To address the research questions, I conducted a literature review and identified two gaps: limited research on gender learning in STEM for ages above 18 and a scarcity of studies on the male perspective. I conducted surveys to address these gaps. One focused on the educational robotics toolkit, utilizing experiences of female Industrial Design Engineering (IDE) bachelor students (aged 18 to 21). The other survey aimed to understand the male perspective on the current situation in the engineering field. Involving both males and females in crafting the solution creates awareness of the responsibility that everyone plays a role in this situation. It is crucial to emphasize that this thesis does not aim to generate conflict between genders. Instead, its message has the ambition of shaping a world where everyone can choose what they want to do based on their interests, free from gender stereotypes. Furthermore, I defined the design goal of the toolkit based on this message.The design goal of the toolkit is to make everyone feel involved and comfortable to share their opinion in the group discussion. Encouraging the incorporation of different viewpoints and getting inspired by other people’s ideas. Ultimately, broadens the existing original impression of robotics. To visualise the design goal and validate the final concept, I developed a prototype of an inspirational toolkit with fellow students mainly from the DP3 course in the IDE bachelor program. Since the group assignment of the DP3 course is to design a cleaning robot for the campus. Utilising this toolkit to inspire students in the early stages of robot design can have a positive impact on the design process. I conducted multiple user testings to improve the prototype, considering the interplay of aesthetics, form, user experience and assembly.Final design HiveMind, I conducted user testing with a group of students to validate whether the after-use effect of the prototype aligns with the design goal. All participants agreed that they feel encouraged and comfortable expressing their ideas, and the toolkit helps them get on the same page. Furthermore, the toolkit improves group discussions in the early stages of the design process, especially when everyone in the group is not familiar with each other. The validation result shows that each participant has a more diverse impression of robots after using the toolkit. However, I observed that the shape of the robot they drew for the assignment still adheres to a traditional representation of how a robot should be. This suggests that future design recommendations could focus on the relationship between picture cognitive association, the impact of different game rules, and using the toolkit before or after hands-on activities.Integrated Product Desig

    An analysis of Java release practices on GitHub

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    This paper examines the release practices of Java Maven Repositories on GitHub. Most prior research in this vein has been done on Maven Central, the largest Maven package repository. However, GitHub hosts 15.5 million Java repositories, and is left untapped. Additionally of interest is the fact that GitHub provides a competitor to Maven Central, GitHub packages. To this end, the paper establishes an index of all Java repositories on GitHub. Furthermore, this dataset also includes Maven configuration (POM.xml) files. Additionally, an in-depth analysis is done of a sample of 500 000 of those 15.5 million repositories. This sample ended up containing 170 798 Java Maven repositories that had those POM.xml files. In this sample we discovered that of those 170 798, 6 507 (≈ 3.8%) had set up distribution configuration. Maven Central ended up being the most popular but GitHub packages and others ended up being quite popular as well. In the external repositories configured in those Java projects we notice a distinct lack of GitHub packages, other repositories were still present. We theorize that the lower popularity of GitHub packages is because it requires authentication, which is not trivial to set up. We discuss several approaches that can improve this situation.CSE3000 Research ProjectComputer Science and Engineerin


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