In certain conditions, (part of) an oil spill can disappear from the water surface through a process called natural dispersion. One available oil spill response option is to enhance this process by addition of dispersants (chemical dispersion). An informed decision for such response requires insight in the oil slick size WITH and WITHOUT treatment. This thesis aims to enable such assessment of net effectiveness, by providing a strategy for modelling the dispersion process. A plunging jet test was developed for investigating entrainment and droplet breakup. Using this set up the relevance of oil layer thickness was proven and an algorithm to model droplet sizes of dispersed oil was defined. The findings were applied in a model simulating dispersion and resurfacing as well as the wind-driven differential transport between the floating slick and suspended droplets. The simulation outputs help assess the added value (or not) of dispersant application in reducing the surface oil slick size for different oil types and conditions.
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Active antifungal packaging is a technological solution for reducing the postharvest losses of fruits and vegetables associated with phytopathogens. Anthracnose (Colletotrichum gloeosporioides) is the principal fungus that causes post-harvest avocado fruit decay. In this study, antifungal sachets filled with oregano oil-starch capsules were prepared, and their active effects were demonstrated on Hass avocado fruits. Oregano oil (31 % of carvacrol) was encapsulated with corn starch by spray drying. Tyvek sachets (4 × 4 cm) filled with 80 (T1) and 160 mg (T2) of oregano oil-starch capsules (99.35 ± 1.86 mg g − 1) were fabricated. The antifungal effects of the sachets were tested in vitro and in vivo using a humidity chamber (90–95 % relative humidity (RH)) on fruits inoculated with anthracnose. The results showed that T1 and T2 inhibited 75.21 ± 2.81 and 100 % in vitro growth of anthracnose at 25 °C for 12 days. Furthermore, Hass avocado fruits stored in a humidity chamber at 25 °C for 6 days showed that only T2 significantly (p < 0.05) reduced the area of lesion produced by artificial inoculation of Hass avocado fruits with anthracnose. On average, the lesion area in the Hass avocado fruits treated with T2 was 13.94 % smaller than that in the control fruit.
MULTIFILE
The aim of the present work was to control phytopathogens associated to mango decay by exposure to antifungal thyme oil-starch/agave fructans microcapsules in Nylon sachets. Fusarium pseudocircinatum, Alternaria alternata, Neofusicocum kwambonambiense, Cladosporium pseudocladosporioides, and Colletotrichum gloeosporioides were isolated from mango fruits and its mycelial growth was 100% inhibited with 5 μL of thyme oil. Thyme oil was microencapsulated with modified starch/agave fructans by spray drying. Thymol content, size, and shape of microcapsules were evaluated. Antifungal sachets were prepared by filling Nylon bags (4 × 4 cm) with different doses of thyme oil microcapsules: 0.10, 0.15 and 0.20 g. The mycelial growth of all microorganisms was controlled with 0.10, 0.15 and 0.20 g of antifungal sachets. The incidence (75 and 65%) and severity (77 and 41%) of C. gloeosporioides were effectively reduced in mango, respectively, using 0.10 and 0.20 g of antifungal sachets.
DOCUMENT
Due to the existing pressure for a more rational use of the water, many public managers and industries have to re-think/adapt their processes towards a more circular approach. Such pressure is even more critical in the Rio Doce region, Minas Gerais, due to the large environmental accident occurred in 2015. Cenibra (pulp mill) is an example of such industries due to the fact that it is situated in the river basin and that it has a water demanding process. The current proposal is meant as an academic and engineering study to propose possible solutions to decrease the total water consumption of the mill and, thus, decrease the total stress on the Rio Doce basin. The work will be divided in three working packages, namely: (i) evaluation (modelling) of the mill process and water balance (ii) application and operation of a pilot scale wastewater treatment plant (iii) analysis of the impacts caused by the improvement of the process. The second work package will also be conducted (in parallel) with a lab scale setup in The Netherlands to allow fast adjustments and broaden evaluation of the setup/process performance. The actions will focus on reducing the mill total water consumption in 20%.
De ambitie is het ontwikkelen van een toegespitste homogeniserende egalisatiemachine inclusief een in de grond flexibel in te bouwen sensorisch meetsysteem voor het implementeren van een innovatieve meetopstelling in het Aeres Innovation Centre (Bodem Band Bassin). In het Bodem Band Bassin wordt in kaart gebracht welke bodemdruk ontstaat door banden- of trackkeus en band/track afstelling bij inzet van machines en werktuigen. Essentie bij onderzoek in het BBB is het preventief zoeken naar de mogelijkheden om de ondergrondverdichting te minimaliseren. Dit stimuleert duurzaam bodembeheer in de landbouw en maakt ondernemers bewust van hoe de afstelling tussen bandformaat, bandafstelling, gewicht werktuig en bodemgesteldheid op elkaar afgestemd kunnen worden. In dit project wordt een, eerder zelf ontwikkelt, sensorisch meetsysteem doorontwikkeld en toepasbaar gemaakt voor vertalingen naar praktijksituaties. Na één test is de bodem in het bassin verstoord en daarom moet na elke meting de voorgaande bodemsituatie hersteld worden. Daarvoor wordt in dit project via een morfologische analyse een werktuigbouwkundig constructieplan ontwikkeld zodat na afronding van dit project een dergelijke homogeniserende egalisatiemachine gebouwd kan worden. De essentie van de onderzoeksvraag van dit project ligt in het uitwerken van de zelf ontwikkelde meetopstelling en daarbij gebruik maken van bestaande kennis rondom band- en sensortechniek en bodemkunde. Door de meetopstelling en het egalisatiewerktuig op de tekentafel samen met de telers en mechanisatiebedrijven door te ontwikkelen in een praktijksetting vergroten we het inzicht in de (on)mogelijkheden van deze toepassing en kunnen we een innovatie ontwikkelen die nauw aansluit op de wens van telers zo min mogelijk bodemdruk te veroorzaken. Het ultieme doel is om ondergrondverdichting in de landbouw een halt toe te roepen. Op basis van dit project wordt een groter onderzoeksvoorstel geschreven waar de lectoraten Precisielandbouw (Aeres), Duurzaam Bodembeheer (Aeres) en Mechatronica (Saxion) samen het initiatief in nemen.
Plastic products are currently been critically reviewed due to the growing awareness on the related problems, such as the “plastic soup”. EU has introduced a ban for a number of single-use consumer products and fossil-based polymers coming in force in 2021. The list of banned products are expected to be extended, for example for single-use, non-compostable plastics in horticulture and agriculture. Therefore, it is crucial to develop sustainable, biodegradable alternatives. A significant amount of research has been performed on biobased polymers. However, plastics are made from a polymer mixed with other materials, additives, which are essential for the plastics production and performance. Development of biodegradable solutions for these additives is lacking, but is urgently needed. Biocarbon (Biochar), is a high-carbon, fine-grained residue that is produced through pyrolysis processes. This natural product is currently used to produce energy, but the recent research indicate that it has a great potential in enhancing biopolymer properties. The biocarbon-biopolymer composite could provide a much needed fully biodegradable solution. This would be especially interesting in agricultural and horticultural applications, since biocarbon has been found to be effective at retaining water and water-soluble nutrients and to increase micro-organism activity in soil. Biocarbon-biocomposite may also be used for other markets, where biodegradability is essential, including packaging and disposable consumer articles. The BioADD consortium consists of 9 industrial partners, a branch organization and 3 research partners. The partner companies form a complementary team, including biomass providers, pyrolysis technology manufacturers and companies producing products to the relevant markets of horticulture, agriculture and packaging. For each of the companies the successful result from the project will lead to concrete business opportunities. The support of Avans, University of Groningen and Eindhoven University of Technology is essential in developing the know-how and the first product development making the innovation possible.
Lectoraat, onderdeel van Saxion
