The age estimation of biological traces is one of the holy grails in forensic investigations. We developed a method for the age estimation of semen stains using fluorescence spectroscopy in conjunction with a stoichiometric ageing model. The model describes the degradation and generation rate of proteins and fluorescent oxidation products (FOX) over time. The previously used fluorimeter is a large benchtop device and requires system optimization for forensic applications. In situ applications have the advantage that measurements can be performed directly at the crime scene, without additional sampling or storage steps. Therefore, a portable fiber-based fluorimeter was developed, consisting of two optimized light-emitting diodes (LEDs) and two spectrometers to allow the fluorescence protein and FOX measurements. The handheld fiber can be used without touching the traces, avoiding the destruction or contamination of the trace. In this study, we have measured the ageing kinetics of semen stains over time using both our portable fluorimeter and a laboratory benchtop fluorimeter and compared their accuracies for the age estimation of semen stains. Successful age estimation was possible up to 11 days, with a mean absolute error of 1.0 days and 0.9 days for the portable and the benchtop fluorimeters, respectively. These results demonstrate the potential of using the portable fluorimeter for in situ applications.
The impact of the construction industry on the natural environment is severe, natural areas are changedinto predominantly hard solid surfaces, the energy use in the built environment is high and the industryputs huge claims on materials.
MULTIFILE
In het artikel staat beschreven hoe binnen de opleiding Applied Science van Fontys Hogeschool Toegepaste Natuurwetenschappen in Eindhoven een Overall Toets ontwikkeld is die aansluit bij het competentiegerichte leren. In deze toets staat een casus over een actuele beroepssituatie centraal waarbij de vakgebieden chemie, biologie en technologie in de propedeuse geïntegreerd competentiegericht getoetst worden. De samenstellers laten zien hoe deze toets er uit ziet en geven aan wat de ervaringen er mee zijn.
Unwanted tomatoes represent ~20% of the European market, meaning that ~3 million metric tons of tomatoes are wasted every year. On a national scale, this translates to 7000 tons of tomato waste every year. Considering the challenge that food spillage represents worldwide and that the Netherlands wants to be circular by 2050, it is important to find a way to circularize these tomatoes back into the food chain. Moreover, tomatoes are the largest greenhouse crop in the Netherlands, which means that reducing the waste of this crop will positively and significantly affect the circularity and sustainability of the Dutch food system. A way to bring these tomatoes back into the food chain is through fermentation with lactic acid bacteria (LAB), which are already used in many food applications. In this project, we will assemble a unique new mix (co-culture) of LAB bacteria, which will lead to a stable fermented product with low sugar, low pH and a fresh taste, without compromising its nutritional value. This fermentation will prevent the contamination of the product with other microorganisms, providing the product with a prolonged shelf life, and will have a positive impact on the health of the consumers. Up until now, only non-fermented products have been produced from rejected tomatoes. This solution allows for an in-between product that can be used towards many different applications. This process will be upscaled to pilot scale with our consortium partners HAN BioCentre, Keep Food Simple, LLTB and Kramer B.V. The aim is to optimize the process and taste the end result of the different fermentations, so the end product is an attractive, circular, and tasty fermented tomato paste. These results will help to advance the circularity and sustainability of our food system, both at a national and European level.
Even though considerable amounts of valuable wood are collected at waste collection sites, most of it remains unused and is burned: it is too labor-intensive to sort, process and upcycle useable parts. Valuable wood thus becomes worthless waste, against circular economy principles. In MoBot-Wood, waste collection organizations HVC and the municipality of Amsterdam, together with Rolan Robotics, Metabolic and AUAS investigate how waste wood can be sorted and processed at waste collection sites, using an easy-to-deploy robotic solution. In various preceding and on-going projects, AUAS and partners are exploring circular wood intake, sorting and processing using industrial robots, including processes like machine vision, 3D scanning, sawing, and milling. These projects show that harvesting waste wood is a challenging matter. Generally, the wood is only partially useable due to the presence of metal, excessive paint, deterioration by fungi and water, or other contamination and damages. To harvest useable wood thus requires intensive sorting and processing. The solution of transporting all the waste wood from collection sites to a central processing station might be too expensive and have a negative environmental impact. Considering that much of collected wood will need to be discarded, often no wood is harvested at all, due to the costs for collection and shipping. Speaking with several partners in related projects, the idea emerged to develop a mobile robotic station, which can be (temporarily) deployed at waste collection sites, to intake, sort and process wood for upcycling. In MoBot-Wood, research entails the design of such station, its deployment conditions, and a general assessment of its potential impact. The project investigates robotic sorting and processing on location as a new approach to increase the amount of valuable, useable wood harvested at waste collection sites, by avoiding material transport and reducing the volume of remaining waste.
Polycotton textiles are fabrics made from cotton and polyester. It is used in many textile applications such as sporting cloths, nursery uniforms and bed sheets. As cotton and polyester are quite different in their polymer nature, polycotton textiles are hard to recycle and therefore mostly incinerated. Incineration of discarded polycotton, and substitution by virgin polycotton, create a significant environmental impact. However, textile manufacturers and brand owners will become obliged to apply recycled content in clothing from 2023 onwards. Therefore, the development of more sustainable recycling alternatives for the separation and purification of polycotton into its monomers and cellulose is vital. In a recently approved GoChem project, it has been shown that cotton can be separated from polyester successfully, using a chemical recycling process. The generated solution is a mixture of suspended and partially decolorized cotton (cellulose) and a liquid fraction produced from the depolymerization of the polyester (monomers). A necessary further step of this work is the investigation of possible separation methods to recover the cotton and purify the obtained polyester monomers into polymer-grade pure products suitable for repolymerization. Repolymerize is a new consortium, composed of the first project members, plus a separation and purification process group, to investigate efficient and high yield purification steps to recover these products. The project will focus on possible steps to separate the suspended fraction (cotton) and further recover of high purity ethylene glycol from the rest fraction (polyester depolymerization solution). The main objective is to create essential knowledge so the private partners can evaluate whether such process is technologically and economically feasible.
