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Irrigation of Urban Moss Surfaces: Making Cities Climate Resilient by Enhancing Moss Growth on Façades
No full textMoss covered surfaces are a promising way to mitigate the urban heat island effect. A layer of moss on a building’s façade reduces heat absorption during summer, hence passively cooling the building and its surroundings. The startup Respyre wants to offer such moss layers as a commercial product. A bio-gel mixed with moss fragments is sprayed on a porous concrete outer layer. This is irrigated for several months until the wall is covered by a layer of living moss.The aim of this project is to rethink the existing irrigation system, since it gives a bad water distribution, resulting in high water usage and uneven moss growth.First, the context was analysed. Literature study and an interview with an expert provided a better understanding of what role moss has in mitigating the urban heat island effect and what moss needs from a biological perspective. Further research revealed what solutions for providing moist already exist. A stakeholder analysis provided insight into who has something to say about the irrigation system. All these findings together resulted in a list of requirements.During a brainstorm, a set of ideas was sketched to find as many out-of-the-box solutions as possible. This is a mix of new ideas, existing ideas found during the analysis, and combined ideas.The brainstormed ideas that are feasible were developed into concepts. They were prototyped and their water distributing performance was tested by irrigating them in a green house. The concepts have been assessed on (among others) water distribution, estimated costs, minimum water pressure, ease of installation, and the need for developing new parts.Five promising concepts were further developed and tested on a larger prototype. Their water distribution was quantitively tested, and costs estimated.The finally chosen solution was further improved and detailed in the last stage. The end result is a design and prototype of an irrigation system that gives a slightly more uniform water distribution at a significantly slower rate for comparable costs.Integrated Product Desig
Using inverse imaging in the thermal modelling of LPBF processes for domains with circular boundaries
No full textIn this thesis a new efficient model has been developed in the thermal analysis of Laser Powder Bed Fusion, an Additive Manufacturing (or: 3D-printing) method that is used to manufacture metal products. During this process, a laser is used as a heat source to melt metal powder grains to each other, that are solidified when cooled down. In Laser Powder Bed Fusion high temperatures changes arise at the laser spot, that are in a scale smaller than the scale of the manufactured product. This requires a very fine spatial discretization (or: mesh) if the thermal analysis is done purely numerical. A fine mesh leads to high computational cost. Various methods have been previously developed to reduce this costs, like the semi-analytic method. The new model in this thesis is ased on a the previously developed thermal model that uses the semi-analytic method....Mechanical Engineering | Structural Optimization and Mechanic
Fabrication of a glass microfluidic gas exchanger using a femtosecond laser
No full textOrgan-on-chip (OoC) technology has transformed biomedical research by providing a platform to simulate physiological conditions for drug development and disease modeling. Incubator-free OoC systems offer notable advantages over traditional approaches, including enhanced adaptability and impermeability to gases. Nevertheless, achieving precise oxygen regulation remains a challenge in such systems. This thesis investigates the application of femtosecond (Fs) laser ablation to fabricate a glass microfluidic gas exchange system for accurate oxygen regulation in incubator-free OoCs. Through successful engraving of fluidic channels and integration of an off-the-shelf optical oxygen sensor, this study highlights the efficacy of Fs laser technology in the rapid prototyping of intricate glass microfluidic devices. Despite encountering challenges such as dimensional losses and debris clogging, the study presents a functional gas exchanger prototype. Future research directions include optimization efforts, addressing issues like gas permeation through connectors, and testing under physiological conditions to further advance OoC technology.iMicrofluidicsMechanical Engineering | Micro and Nano Engineering (MNE
Bandgap Dynamics in Locally Resonant Metastructures: A General Theory of Internal Resonator Coupling
No full textThe dynamics of metastructures, incorporating both conventional and internally coupled resonators, are investigated to enhance vibration suppression capabilities through a novel mathematical framework. A close-form formulation and a transfer function methodology are introduced, integrating control system theory with metastructure analysis, offering new insights into the role of internal coupling. The findings reveal that precise internal coupling, when matched exactly to the stiffness of the resonator, enables the clear formation of secondary bandgaps, significantly influencing the vibration isolation efficacy of the metastructure. Although the study primarily focuses on theoretical and numerical analyses, the implications of adjusting mass distribution on resonators are also explored. This formulation methodology enables the adjustment of bandgap characteristics, underscoring the potential for adaptive control over bandgaps in metastructures. Such capabilities are crucial for tailoring the vibration isolation and energy harvesting functionalities in mechanically resonant systems, especially when applied to demanding heavy-duty applications.Mechatronic Systems Desig
Estimating European Transport Investment Needs for completing 2030 Climate Targets
No full text The European Union aims to reduce its emissions by 55% in 2030 compared to 1990 levels, requiring massive investment in the economy and society. Knowing the level of investment to be made is key to understanding the macroeconomic impact of the transition, creating investment policies and prioritizing sectors. However, in the transport sector, accounting for around 30% of the total EU CO2 emissions, no independent assessment of the investment needs has been found. In this master thesis, the level of gross investments required for meeting 2030 transport policies at the European scale is estimated and compared to the historical level. The results show that between 2024 and 2030, making EU targets in the transport sector requires 253 billion euros of investments per year, or 1.6% of the EU GDP. When compared to the current level, 42% of the yearly investment needs are already met. It leaves an investment gap—defined as the extra investment necessary compared to the current level - of 147 billion euros, or 0.9% of the EU GDP. The results show that European policies for generalizing electric vehicles in 2030 were missing ambition compared to climate target. This thesis is also a use case for using the investment gap as an indicator for monitoring policies. Through the proxy of investment, the implementation of the European transport policy can be tracked. p { line-height: 115%; margin-bottom: 0.25cm; background: transparent }Engineering and Policy Analysi
Author Correction: Africa needs context-relevant evidence to shape its clean energy future
No full textCorrection to: Nature Energyhttps://doi.org/10.1038/s41560-022-01152-0, published online 24 October 2022 In the version of the article initially published, Gebrekidan Gebresilassie Eshetu’s name appeared incorrectly as Eshetu Gebrekidan Gebresilassie and has now been corrected in the HTML and PDF versions of the article.Water Resource
Integrating hydrologic modeling and satellite remote sensing to assess the performance of sprinkler irrigation
No full textImproving irrigation water management is a key concern for the agricultural sector, and it requires extensive and comprehensive tools that provide a complete knowledge of crop water use and requirements. This study presents a novel methodology to explicitly estimate daily gross and net crop water requirements, actual crop water use, and irrigation efficiency of center pivot irrigation systems, by mainly utilizing the Sentinel-2 MultiSpectral Instrument (MSI) imagery at the farm scale. ETMonitor model is adapted to estimate actual water use (as the sum of canopy transpiration and evaporation of water intercepted by canopy and evaporation from soil) at daily/10-m resolution, benefiting from the high-resolution Sentinel-2 data and thus to assess the irrigation efficiency at the farm scale. The gross irrigation water requirement is estimated from the net crop water requirement and the water loss, including the water droplet evaporation directly into the air during application before droplets fall on the canopy and canopy interception loss. The method was applied to a pilot farmland with two major crops (wheat and potato) in the Inner Mongolia Autonomous Region of China, where modern equipment and appropriate irrigation methods are deployed for efficient water use. The estimated actual crop water use showed good agreement with the ground observations, e.g. the determination coefficients range from 0.67 to 0.81 and root mean square errors range from 0.56 mm/day to 1.24 mm/day for wheat and potato when comparing the estimated evapotranspiration with the measurement by the eddy covariance system. It also showed that the losses of total irrigated volume were 25.4% for wheat and 23.7% for potato, respectively, and found that the water allocation was insufficient to meet the water requirement in this irrigated area. This suggests that the amount of water applied was insufficient to meet the crop water requirement and the inherent water losses in the center pivot irrigation system, which imply the necessity to improve the irrigation practice to use the water more efficiently.Optical and Laser Remote Sensin
PDRs4All: III. JWST's NIR spectroscopic view of the Orion Bar
No full textContext. JWST has taken the sharpest and most sensitive infrared (IR) spectral imaging observations ever of the Orion Bar photodis-sociation region (PDR), which is part of the nearest massive star-forming region the Orion Nebula, and often considered to be the 'prototypical'strongly illuminated PDR. Aims. We investigate the impact of radiative feedback from massive stars on their natal cloud and focus on the transition from the H II region to the atomic PDR -crossing the ionisation front (IF) -, and the subsequent transition to the molecular PDR -crossing the dissociation front (DF). Given the prevalence of PDRs in the interstellar medium and their dominant contribution to IR radiation, understanding the response of the PDR gas to far-ultraviolet (FUV) photons and the associated physical and chemical processes is fundamental to our understanding of star and planet formation and for the interpretation of any unresolved PDR as seen by JWST. Methods. We used high-resolution near-IR integral field spectroscopic data from NIRSpec on JWST to observe the Orion Bar PDR as part of the PDRs4All JWST Early Release Science programme. We constructed a 3″ × 25″ spatio-spectral mosaic covering 0.97-5.27 μm at a spectral resolution R of ~2700 and an angular resolution of 0.075″-0.173″. To study the properties of key regions captured in this mosaic, we extracted five template spectra in apertures centred on the three H2 dissociation fronts, the atomic PDR, and the H II region. This wealth of detailed spatial-spectral information was analysed in terms of variations in the physical conditions-incident UV field, density, and temperature -of the PDR gas. Results. The NIRSpec data reveal a forest of lines including, but not limited to, He I, H I, and C I recombination lines; ionic lines (e.g. Fe III and Fe II); O I and N I fluorescence lines; aromatic infrared bands (AIBs, including aromatic CH, aliphatic CH, and their CD counterparts); pure rotational and ro-vibrational lines from H2; and ro-vibrational lines from HD, CO, and CH+, with most of them having been detected for the first time towards a PDR. Their spatial distribution resolves the H and He ionisation structure in the Huygens region, gives insight into the geometry of the Bar, and confirms the large-scale stratification of PDRs. In addition, we observed numerous smaller-scale structures whose typical size decreases with distance from θ1 Ori C and IR lines from C I, if solely arising from radiative recombination and cascade, reveal very high gas temperatures (a few 1000 K) consistent with the hot irradiated surface of small-scale dense clumps inside the PDR. The morphology of the Bar, in particular that of the H2 lines, reveals multiple prominent filaments that exhibit different characteristics. This leaves the impression of a 'terraced'transition from the predominantly atomic surface region to the CO-rich molecular zone deeper in. We attribute the different characteristics of the H2 filaments to their varying depth into the PDR and, in some cases, not reaching the C+/C/CO transition. These observations thus reveal what local conditions are required to drive the physical and chemical processes needed to explain the different characteristics of the DFs and the photochemical evolution of the AIB carriers. Conclusions. This study showcases the discovery space created by JWST to further our understanding of the impact radiation from young stars has on their natal molecular cloud and proto-planetary disk, which touches on star and planet formation as well as galaxy evolution.Planetary Exploratio
Factors Associated with Primary Liver Cancer Survival in a Southern Italian Setting in a Changing Epidemiological Scenario
No full textA retrospective observational study utilising cancer incidence data from a population-based registry investigated determinants affecting primary liver cancer survival in a southern Italian region with high hepatitis viral infection rates and obesity prevalence. Among 2687 patients diagnosed between 2006 and 2019 (65.3% male), a flexible hazard-based regression model revealed factors influencing 5-year survival rates. High deprivation levels [HR = 1.41 (95%CI = 1.15–1.76); p < 0.001], poor access to care [HR = 1.99 (95%IC = 1.70–2.35); p < 0.0001], age between 65 and 75 [HR = 1.48 (95%IC = 1.09–2.01); p < 0.05] or >75 [HR = 2.21 (95%CI = 1.62–3.01); p < 0.0001] and residing in non-urban areas [HR = 1.35 (95%CI = 1.08–1.69); p < 0.01] were associated with poorer survival estimates. While deprivation appeared to be a risk factor for primary liver cancer patients residing within the urban area, the geographic distance from specialised treatment centres emerged as a potential determinant of lower survival estimates for residents in the non-urban areas. After balancing the groups of easy and poor access to care using a propensity score approach, poor access to care and a lower socioeconomic status resulted in potentially having a negative impact on primary liver cancer survival, particularly among urban residents. We emphasise the need to interoperate cancer registries with other data sources and to deploy innovative digital solutions to improve cancer prevention.Statistic
Craspase Orthologs Cleave a Nonconserved Site in Target Protein Csx30
No full textThe Craspase CRISPR-Cas effector consists of the RNA-guided ribonuclease gRAMP and the protease TPR-CHAT, coupling target RNA recognition to protease activation. The natural substrate of Craspase is Csx30, a protein cleaved in two fragments that subsequently activates downstream antiviral pathways. Here, we determined the protease substrate specificity of Craspase from Candidatus “Jettenia caeni” (Jc-Craspase). We find that Jc-Craspase cleaves Jc-Csx30 in a target RNA-dependent fashion in A|S, which is different from the sites found in two other studied Craspases (L|D and M|K for Candidatus “Scalindua brodae” and Desulfonema ishimotonii, respectively). The fact that Craspase cleaves a nonconserved site across orthologs indicates the evolution of specific protein interactions between Craspase and its respective Csx30 target protein. The Craspase family thus represents a panel of proteases with different substrate specificities, which we exploited for the development of a readout for multiplexed RNA detection.BN/Stan Brouns LabBT/Environmental Biotechnolog
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