Small urban water bodies, like ponds or canals, are often assumed to cool their surroundings during hot periods, when water bodies remain cooler than air during daytime. However, during the night they may be warmer. Sufficient fetch is required for thermal effects to reach a height of 1–2 m, relevant for humans. In the ‘Really cooling water bodies in cities’ (REALCOOL) project thermal effects of typical Dutch urban water bodies were explored, using ENVI-met 4.1.3. This model version enables users to specify intensity of turbulent mixing and light absorption of the water, offering improved water temperature simulations. Local thermal effects near individual water bodies were assessed as differences in air temperature and Physiological Equivalent Temperature (PET). The simulations suggest that local thermal effects of small water bodies can be considered negligible in design practice. Afternoon air temperatures in surrounding spaces were reduced by typically 0.2 °C and the maximum cooling effect was 0.6 °C. Typical PET reduction was 0.6 °C, with a maximum of 1.9 °C. Night-time warming effects are even smaller. However, the immediate surroundings of small water bodies can become cooler by means of shading from trees, fountains or water mists, and natural ventilation. Such interventions induce favorable changes in daytime PET.
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This paper presents five design prototypes for cool urban water environments developed in the 'Really cooling water bodies in cities' (REALCOOL) project. The REALCOOL prototypes address an urgent need: urban water bodies, such as ponds or canals, are often assumed to cool down their surroundings during days with heat stress, whereas recent research shows that this is not always the case and that urban water bodies may actually have warming effects too. There are, however, indications that shading, vaporising water, and proper ventilation can keep water bodies and their surroundings cooler. Yet, it is necessary to explore how these strategies can be optimally combined and how the resulting design guidelines can be communicated to design professionals. The REALCOOL prototypes communicate the spatial layout and biometeorological effects of such combinations and assist design decisions dealing with urban water environments. The micrometeorological simulations with Envimet showed that the prototypes led to local reductions on daytime PET from 1 °C to 7 °C, upon introducing shade. Water mist and fountains were also cooling solutions. The important role of ventilation was confirmed. The paper discusses and concludes about the use of the prototypes as tools for urban design practice.
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Wageningen ligt in een Nederlands fiets- en waterlandschap. In warme zomers zijn de strandjes aan de Nederrijn een geliefde plek waar veel mensen naartoe trekken om te zwemmen en te recreëren. Zwemmen wordt gedoogd, maar is niet zonder gevaar. Veel vluchtelingen kunnen niet of slecht zwemmen en onderschatten het risico van zwemmen in de rivier. Het project WoW! Wageningen richtte zich op veilig en inclusief sporten en bewegen in de openbare ruimte. We wilden achterhalen hoe het COA kan voorkomen dat vluchtelingen zichzelf in gevaar brengen of soms zelfs verdrinken. Dat leverde deze informatiefolder op, waarmee COA-medewerkers (of vrijwilligers) op een zeer laagdrempelige manier toegang krijgen tot alle verschillende voorlichtingsmaterialen en -mogelijkheden.
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Zand en andere grove grondstoffen worden steeds schaarser door intensief gebruik in infrastructuur en industrie, terwijl miljarden kubieke meters slib wereldwijd worden uitgebaggerd om vaargeulen en havens operationeel te houden. Vanwege dit groeiende tekort aan traditionele grondstoffen is er behoefte aan het ontwikkelen van nieuwe methodieken voor hergebruik van slib en lokaal sediment, onder andere voor dijkversterking en ophoging van landbouwgronden. Echter wordt gebaggerd slib volgens de regelgeving nog als een van de grootste potentiële afvalstromen gezien. Ook is slib complexer in het gebruik omdat het bestaat uit een heterogeen mengsel van onder meer water, zand, organisch materiaal, fijnstof en gas. Vanwege schaarste in bouwmaterialen lopen er steeds meer initiatieven voor het nuttig hergebruiken van gebaggerd slib, maar de optimale laagdikte en aanlegtechnieken moeten nog worden onderzocht. Met dit project zoeken lectoraat Sustainable River Management samen met Hogeschool Van Hall Larenstein en de praktijkpartners Klaei B.V., Waterschap Noorderzijlvest en EcoShape naar de best practices voor het produceren van waardevol klei uit havenslib. Via laboratoriumexperimenten en veldproeven binnen grootschalige pilots worden mechanische eigenschappen van havenslib uit de Lauwersoog haven in beeld gebracht. Er wordt gezocht naar de optimale dikte van havenslib om bruikbare klei te produceren. Daarbij wordt onderzocht of de mechanische eigenschappen van de geproduceerde klei afhankelijk zijn van de laagdikte van de initiële laag of havenslib. De resultaten verbinden de laagdikte in rijpingscompartimenten met materiaaleigenschappen en monitoren de initiële verouderingsprocessen na de aanleg van de klei in een proefdijk. Het eindresultaat biedt inzicht in de best practices voor toepassing van havenslib en de daarbij horende materiaaleigenschappen. Dit project draagt daarmee direct bij aan de ontwikkeling van een nieuw, duurzaam materiaal voor gebruik in dijkversterkingen en landbouw en een circulaire economie in Nederland in 2050.
The European eel (Anguilla anguilla) is a delicacy fish and an integral part of the Dutch culinary history. However, the stock of adult eel has decreased significantly due to a precipitous recruitment of glass eel fall. This relates to multiple factors including obstacles in migration pathways, loss of habitat and chemical pollution. Consequently, Anguilla anguilla has become a critically endangered species and is protected under European legislation. One possible solution, explored on laboratory scale, is the captive reproduction of eels and growth of glass eel in aquaculture. A big challenge of this technique is the limiting aspect of possible nutrients for the eels in the larval stage, as the diet must be delivered in micrometric capsules (< 20 µm) with a high protein content. Such diets are not yet available on the market. Electrohydrodynamic atomization (EHDA) is a novel option to prepare a micro-diet suitable for eel larvae. EHDA is especially interesting for its narrow size distribution capabilities and for applications which require submicrometric sizes. This project aims to evaluate the use of EHDA to produce high protein content micrometric size capsules for feeding larval eels. If successful, this would assist in the captivity production of glass eel and to make the eel culture independent of wild catches, restoring the culinary market. The project will be conducted in two phases. Firstly, tests will be conducted to evaluate the necessary conditions of the capsules using EHDA. Subsequently, the obtained capsules will be tested as feed for eel larvae. The main objective is to favour the development of a more sustainable eel culture, regarding the possibilities of investigating the current fish in natura option and exchanging it for a captivity one.
The ENCHANT project aims to clarify the differences between circular Calcium Carbonate (CCC) and grounded Calcium Carbonate (GCC), in order to expand the applications of the circular alternative CCC in the paint and coating industry. CCC is produced by pyrolysis from paper waste in an innovative process developed by the company Alucha Works B.V., and it can be applied again as filler or binder in consumer products (e.g. plastics, rubbers, paints and coatings) in a cost-effective manner. Products containing CCC have a higher content of circular resources, which minimizes their carbon footprint, and reduces the exploitation of primary resources. Performances of CCC in oil-based paints, however, is not optimal, due to a larger oil adsorption as compared to GCC. A physical and chemical characterization of CCC and GCC samples, including competitive oil-water adsorption measurements, would help Alucha to formulate a solution to match the properties of CCC and GCC, either adjusting the recycling process or applying a surface modification treatment to CCC. This would enable Alucha to expand the market for CCC, making oil-based formulation products more circular.
