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New Cemetery: A museum of memories
No full textWhat relationship can a cemetery have with the city? Since the first garden cemetery was built in the early nineteenth century, this concept spread rapidly throughout Europe. Until now garden cemetery is still the common form of cemeteries in European cities. With the concept of garden cemetery, cemeteries exist in the urban fabric as a public space represented by nature and landscape attributes. The emergence of this relationship is closely related to the demand for burialbased burial forms. For a long time, this relationship has given the cemetery a natural and green identity, which is also the common perception of the cemetery among citizens. Has this relationship changed? In the context of the Complex Project, Building Body Berlin course, this research design will focus specifically on Berlin, Germany. The existence of the German cemetery law, known as “Der Friedhofszwang“, makes cemetery burial mandatory in Germany. Along with this law of compulsory burials, the demand for cemeteries has a huge quantitative basis in Germany. However, according to the research of cemetery development plan of Berlin in 2006, since the end of the 20th century, the cemeteries (mainly garden cemetery) in Berlin have roduced a large amount of vacancy. These idle cemeteries consume a lot of operating and maintenance costs. This phenomenon does not mean that the demand for cemeteries has declined. On the contrary, the demand for cemeteries in Berlin is still increasing. Moreover, with the aging of the population in Germany, the death rate and the number of deaths have risen, and Berliners’ demand for cemeteries will continue to increase in the future. The increase in demand for cemeteries does not appear to coincide with the reduction in cemetery size. It is this inconsistency that helps us see the problem for what it is. The reason for this lies in the transformation of the form of burials. As cremation has grown in popularity, people have increasingly turned to other forms of burial, such as burial of ashes and placement in columbariums. According to statistics, the proportion of cremation in Germany has reached more than 75%. Compared with the traditional form of burying coffins, the land area required for the new burial form represented by cremation is greatly reduced. Statistics show that compared with the average area of 12 square meters in traditional burial coffins, the average area of urns placed in columbariums is only 0.5 square meters. This huge change has also led to a continuous reduction in the core space actually used in the cemetery. Therefore, more and more cemeteries can no longer assume the role of urban public green space due to the reduction of the core use area. Although this phenomenon of quantitative change has not accumulated to produce qualitative change, we can still see the urgent need for the transformation of the cemetery. So how can the cemetery provide a new value as an urban public space? This research design process will ask questions around this question and offer a possible solution.Architecture, Urbanism and Building Sciences | Complex Project
Berlin's Kitchenlab
No full textThe Berlin’s Kitchenlab bridges the gap between highly specialised culinary education and the community. As a school that acts like a social catalyst for its surroundings. The building is located in Otto Park in Alt Moabit, an upcoming area, surrounded by food venues at the end of a public axis. The building consists of a central street with a public program surrounded by other specialised programs, resulting in a building that is easily accessible by the public while still tailored towards the program’s specific needs, like the distribution of food and support functions. All functions are situated on the façade making the building a frame that displays all contents. This makes the culinary university move past a traditional cooking school and become valuable for its immediate and broader surroundings.Architecture, Urbanism and Building Sciences | Complex Project
Fortress Without Barriers: Maintaining Accessibility in the Face of Security
No full textIn an era when rising threats put increasing pressure on security demands in state office buildings, the public trust in these same governmental institutions is on the decline, owing to a sense of detachment and lack of transparency.This detachment partially stems from the functional and physical separation of people’s civic and political lives, leaving public officials as uncountable, a separated class unresponsive to the everyday people, who in turn can glance little of the everyday working of their government. In other words: it is easier to pass unfavourable legislation when you never interact with the common people and sit in your fortress hidden from protests. For these reasons, the future must see the creation of new governmental spaces that are public in nature, but also safeguarded from new dynamic threads. New design approaches in established typologies need to be sought to answer these relationship questions that stem from new state, societal, and technological developments.The Graduation Project ‘Fortress Without Barriers‘ seek to explore these issues of security and accessibility by using a scenario involving the design of a new Federal Ministry of Defence headquarters in Berlin. At first glance this typology might be perceived as ill suited to the integration of public life, even agitative. But rather the project places it as the ultimate test for whether these values can be effectively expressed in an urban context. Defence Ministry being the most prime domain of security, on the scale of city within a city, and placing the most private and secured programme imaginable alongside the proposed public functions.Architecture, Urbanism and Building Sciences | Complex Project
Magnetic fluid film enables almost complete drag reduction across laminar and turbulent flow regimes
No full textIn the race to curb energy and oil consumption, zeroing of wall frictional forces is highly desirable. The turbulent skin friction drag at the solid/liquid interface is responsible for substantial energy losses when conveying liquids through hydraulic networks, contributing approximately 10% to the global electric energy consumption. Despite extensive research, efficient drag reduction strategies effectively applicable in different flow regimes are still unavailable. Here, we use a wall-attached magnetic fluid film to achieve a wall drag reduction of up to 90% in channel flow. Using optical measurements supported by modelling, we find that the strong damping of wall friction emerges from the co-existence of slip and waviness at the coating interface, and the latter is a key factor to obtain almost complete wall drag reduction across laminar and turbulent flow regimes. Our magnetic fluid film is promising and ready to be applied in energy-saving and antifouling strategies in fluid transport and medical devices.Rivers, Ports, Waterways and Dredging Engineerin
100 000 biobased top-ups: Quickest route to Paris Proof housing
No full textIn the light of climate change and environmental challenges such as a nitrogen crisis, a decreasing biodiversity and waterlogging, the Dutch government is trying to build 900 000 homes by 2030 while aiming for a reduction of 55% of CO2 in the construction industry. Biobased topping-up of existing tenement flats is proposed as a solution to tackle several issues. A literature review revealed that a top-up structure has the ability to limit the Global Warming Potential (GWP) of housing. From a set of seven biobased resources, wood, hemp, flax, straw, miscanthus, cattail and seaweed, it was concluded that the current Dutch stock is not sufficient to construct all 100 000 required top-ups with locally sourced biobased materials. Scaling up to a sufficient amount of resources by 2030 requires the right allocation of material over the Dutch landscape, and for the region of Zuid-Holland the right allocation over a peat region, a clay region and a sand region. This is necessary because this cultivation can help break the nitrogen impasse and boost the biodiversity. Furthermore, most resources do not compete with food production. A design for a top-up could be constructed with materials that were sourced within 50km reach. The comparison of GWPs of different variations on the design for the top-up showed that the variations with biobased insulation do not always perform better as an additional layer of fire-proofing had to be added to the construction. Biobased materials do however have the capacity to store biogenic carbon which should be taken into account. Knowing this, the Dutch government and the province of Zuid-Holland should try to construct as many top-ups with locally sourced biobased materials as possible, since it is the quickest way to Paris-proof housing.Architecture, Urbanism and Building Sciences | Building Technolog
Acoustic streaming-based calibration of ultrasound transducers
No full textThe accurate determination of the transfer function of ultrasound transducers is important for their design and operational performance. However, conventional methods for quantifying the transfer function, such as hydrophone measurements, radiation force balance, and pulse-echo measurements, are costly and complex due to specialized equipment required. In this study, we introduce a novel approach to estimate the transfer function of ultrasound transducers by measuring the acoustic streaming velocity generated by the transducer. We utilize an experimental setup consisting of a water tank with a millimeter scale, an ink-filled syringe, and a camera for recording the streaming phenomenon. Through streaming velocity measurements in the frequency range from 2 to 8 MHz, we determined the transfer function of an unfocused circular transducer with a center frequency of 5 MHz and a radius of 5.6 mm. We compared the performance of our method with hydrophone and pulse-echo measurements. At the center frequency, we measured a transmit efficiency of 1.9 kPa/V using the streaming approach, while hydrophone and pulse-echo measurements yielded transmit efficiencies of 2.1 kPa/V and 1.8 kPa/V, respectively. These findings demonstrate that the proposed method for estimating the transfer function of ultrasound transducers achieves a sufficient level of accuracy comparable to pulse-echo and hydrophone measurements.ImPhys/Verweij groupImPhys/Medical ImagingImPhys/De Jong grou
Investigation into the resonance behaviour of the internal water column of an open-ended monopile
No full textThe offshore wind industry is increasingly constructing wind turbines farther from the coast, in deeper water, and under more extreme conditions. This requires larger (monopile) foundations and necessitates new installation methods. An important factor affecting workability is the dynamic behavior of the monopile during installation. The objective of this thesis is to develop a method for determining the hydrodynamic loads caused by internal sloshing in an open-ended monopile (MP) as it transitions from a horizontal to a vertical position in the splash zone. First, the resonance frequencies of the internal water column are predicted with analytical approximations based on linear theory. Distinction is made between piston mode and sloshing. Two numerical methods, linear potential flow (LPF), and computational fluid dynamics (CFD) are used to verify the resonance frequencies. Since the CFD analysis is done in 2D, a 2D representation of the open-ended monopile is considered. Due to the presence of viscous effects in CFD, the resonance observed with CFD consistently occurs at a lower frequency than for the analytical and LPF methods. Also it is found that an decrease in inclination angle of the monopile with respect to the horizontal, while maintaining the same submerged length, results in lower resonance frequency for both piston mode and sloshing in both LPF and CFD. To assess the accuracy of LPF in describing the motion of the internal water column, it is compared to the CFD model. Input excitation in the CFD model is low enough to avoid non-linear sloshing modes and other non-linear behaviour of the free-surface. The ComFLOW 2D CFD model has been validated against various works from the literature for the accurate representation of gap resonance frequencies. For both the piston mode and sloshing resonance, discrepancies between the two numerical methods are found, which can be attributed to viscous effects. At resonance viscous effects are nonnegligible, therefore the LPF method over-predicts the severity of the piston mode and sloshing. The influence of both the submergence of the monopile and its inclination angle with respect to the horizontal is considered. The hydrodynamic coefficients for added mass and damping are found with forced oscillation for both upright and inclined geometries. While good agreement is found between the LPF and CFD results away from resonance, the CFD results in the vicinity of the resonance frequency are used to tune the LPF model, by way of additional linear damping, to achieve more accurate results.It can be concluded from the present work that the resonance of the internal water column near the first sloshing mode significantly affects the overall hydrodynamic force and must be taken into account. At the peak hydrodynamic force observed during the first sloshing mode, the sloshing induces forces 5.59 times higher (submergence of 5 meters), 3.62 times higher (submergence of 10 meters), and 2.33 times higher (submergence of 15 meters) compared to cases where sloshing is not considered.Looking forward, it is strongly advised to conduct forced oscillation tests with larger amplitudes, as this explores the effect of non-linear chaotic sloshing. Additionally, expanding the CFD analyses to 3D, where more non-linear sloshing effects are expected, such as swirling, is recommended. Furthermore, given the differences in results between LPF and CFD, it is valuable to validate the findings through model experiments.Offshore and Dredging Engineerin
Layout Optimisation of Floating Offshore Wind Farms
No full textThis study presents an innovative algorithm designed to optimise the layout of floating offshore wind farms (FOWFs), addressing inter-array cable length and the number of anchor structures required. This research is particularly noteworthy as no prior work has been conducted on wind farm layout optimisation for FOWFs. The Local-Search-Inspired Layout Optimisation (LSILO) algorithm was developed, incorporating a variety of novel heuristics such as Edge Impact Destroy (EID), diversifying repair, and neighbourhood tabu search, most of which were innovatively designed for this research. The LSILO algorithm is capable of optimising cable routing while facilitating anchor-sharing and minimising cable length. In comparison to the industry standard, LSILO displayed promising results, outperforming the random benchmark by a 24% improvement in cable length. However, the algorithm does plateau at a certain turbine density. Turbine density has a substantial influence on the algorithm’s speed and rationality. Therefore, we recommend utilising LSILO with an EID of three turbines, diverse repair without alternatives, and traditional tabu search, on current floating wind turbine sites.Aerospace Engineerin
Substrate-Specific Evolution of Amine Dehydrogenases for Accessing Structurally Diverse Enantiopure (R)-β-Amino Alcohols
No full textThe biocatalytic oxidative deamination of β-amino alcohols holds significant practical potential in kinetic resolution and/or deracemization process to access (R)-β-amino alcohols. This study exemplifies a notable instance of acquisition and utilization of this valuable oxidative deamination activity. Initially, the mutation N261M (M0) was identified to endow a native valine dehydrogenase with oxidative deamination activity toward a few (S)-β-amino alcohols. Subsequently, a phylogenetic analysis-guided, double-code saturation mutagenesis strategy was proposed to engineer M0's side-chain binding site. This strategy facilitated the substrate-specific evolution of M0, resulting in the creation of a panel of mutants (M1-M4) with noteworthy oxidative deamination activity toward structurally diverse (S)-β-amino alcohols. Using these engineered amine dehydrogenases, termed as β-amino alcohol dehydrogenases (β-AADHs), the complete kinetic resolution and even deracemization of a range of β-amino alcohols have been achieved. This work reports distinct biocatalysts and a synthetic strategy for the synthesis of enantiopure (R)-β-amino alcohols and offers an innovative approach for substrate-specificity engineering of enzymes.BT/Biocatalysi
Potential Impacts of Transit-Shared Bike Integration on Equity in Job Accessibility: A Case Study in the Amsterdam Transport Region
No full textTravelling to work is one of the essential activities in individuals’ daily lives. However, commuters who depend on public transport often face significant challenges in accessing job opportunities, resulting in transport-related social exclusion risks. In recent years, shared mobility services have gained popularity as a solution, offering greater flexibility in first/last-mile segments of multimodal trips. These services have promising potential to improve accessibility for those who rely on public transport, thereby addressing issues of accessibility inequity. Such an intervention aligns well with the unique Dutch cycling culture, where cycling already accounts for a substantial portion of transit journeys. However, limited bike availability at the egress side diminishes the utilization of bikes for the last mile of a trip. To address this issue, integrating shared bikes with transit as an egress mode could be an effective intervention.This thesis conducted a ”what-if analysis” in the Amsterdam Transport Region to investigate the impacts on job accessibility for different commuters and the equity of the whole transportation system if shared bikes are provided at transit stations as the egress mode. The results highlight the considerable potential of this integration in improving job accessibility and promoting social equity.Implications drawn from the analysis provide valuable insights. Statistically, groups without car access can benefit more than groups with car access from integrating transit and shared bikes, but benefits might favour high-income groups. Geographically, accessibility improvements are mainly distributed to commuters living next to transit stations, while equity improvements are concentrated in areas with dense and developed public transport systems. Additionally, commuters living close to transit stations are more likely to contribute significantly to the overall accessibility deficiency, even though they have convenient first-mile segments. These implications guide policymakers in prioritizing interventions for targeted groups or regions, and facilitating the creation of a more equitable transportation system.Civil Engineering | Transport and Plannin
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