Dienst van SURF
© 2025 SURF
Abstract: Electronic and electrical waste (e-waste) is growing fast. The purpose of this study is to examine young consumers’ purchase intention of refurbished electronic devices (REDs) such as laptop, tablet, mobile phone and game console. From literature review the factors that influence young consumers’ purchase intention were identified as ‘environmental awareness’, ‘social acceptance’, ‘seller/brand reputation and availability’, and ‘affordability and value’. For each factor a few statements were developed and used as independent variables in a questionnaire. One statement was added about purchase intention as dependent variable. A Pearson correlation coefficient test us showed a clear positive correlation of ‘environmental awareness’ and ‘affordability and value’ with the intention to purchase REDs, but not for the other two factors. This analysis contributes to knowledge on young consumers’ perceptions of refurbished electronic devices and can inform the design of innovative value propositions and new business models for REDs that contribute to a circular economy
MULTIFILE
OBJECTIVES: This systematic and meta-analytic review aimed to quantify the association of psychosocial correlates with oral hygiene behaviour among 9- to 19-year olds. METHODS: A systematic search up to August 2015 was carried out using the following databases: PubMed, PsycInfo, Embase, CINAHL and Web of Science. If necessary, authors of studies were contacted to obtain unpublished statistical information. A study was eligible for inclusion when it evaluated the association between the psychosocial correlates and oral hygiene behaviour varying from self-reports to clinical measurements, including plaque and bleeding scores. A modified New Castle Ottawa Scale was applied to examine the quality of the included studies. RESULTS: Twenty-seven data sets (k) presented in 22 publications, addressing nine psychosocial correlates, were found to be eligible for the meta-analysis. For both tooth brushing and oral hygiene behaviour, random effect models revealed significant weighted average correlation (r+ ) for the psychosocial factors: 'intention', 'self-efficacy', 'attitude' (not significant for tooth brushing), 'social influence', 'coping planning' and 'action planning' (r+ ranging from 0.18 to 0.57). Little or no associations were found for 'locus of control', 'self-esteem' and 'sense of coherence' (r+ ranges from 0.01 to 0.08). CONCLUSIONS: The data at present indicates that 'self-efficacy', 'intention', 'social influences', 'coping planning' and 'action planning' are potential psychosocial determinants of oral health behaviour. Future studies should consider a range of psychological factors that have not been studied, but have shown to be important psychosocial determinants of health behaviours, such as 'self-determination', 'anticipated regret', 'action control' and 'self-identity'. Effectiveness of addressing these potential determinants to induce behaviour change should be further examined by intervention trials.
MULTIFILE
Dit project richt zich op de ontwikkeling van de biotechnologische en chemische procesvoering om op basis van mycelium een alternatief voor leer te produceren. In vergelijking met leer is het voordeel van mycelium dat geen runderen nodig zijn, de productie kan plaatsvinden onder industriële condities en met gebruik van reststromen, de CO2 uitstoot alsook hoeveelheid afval verlaagd wordt, en het gebruik van toxische stoffen zoals chroom wordt vervangen door biobased alternatieven. In het project zullen de procescondities worden bepaald die leiden tot de vorming van optimaal mycelium. Daartoe zullen twee verschillende schimmels worden gekweekt in bioreactoren bij de Hogeschool Arnhem Nijmegen (HAN), waarbij specifiek de effecten van de procescondities (temperatuur, pH, shear, beluchting) en de samenstelling van het kweekmedium op groei van het mycelium en materiaal eigenschappen zullen worden onderzocht. De meest optimale condities zullen vervolgens worden opgeschaald. Op het op deze wijze verkregen materiaal zal Mylium BV een aantal nabehandelingsstappen uitvoeren om de sterkte, elasticiteit, en duurzaamheid van het product te vergroten. Daartoe worden biobased plasticizers, cross-linkers en/of flexibility agents gebruikt. Het resulterende eindproduct zal middels specifiek fysieke testen vergeleken worden met leer alsook worden voorgelegd aan mogelijke klanten. Indien beide resultaten positief zijn kan het betreffende proces na het project verder worden opgeschaald voor toepassing naar de markt.
Paper sludge contains papermaking mineral additives and fibers, which could be reused or recycled, thus enhancing the circularity. One of the promising technologies is the fast pyrolysis of paper sludge, which is capable of recovering > 99 wt.% of the fine minerals in the paper sludge and also affording a bio-liquid. The fine minerals (e.g., ‘circular’ CaCO3) can be reused as filler in consumer products thereby reducing the required primary resources. However, the bio-liquid has a lower quality compared to fossil fuels, and only a limited application, e.g., for heat generation, has been applied. This could be significantly improved by catalytic upgrading of the fast pyrolysis vapor, known as an ex-situ catalytic pyrolysis approach. We have recently found that a high-quality bio-oil (mainly ‘bio-based’ paraffins and low-molecular-weight aromatics, carbon yield of 21%, and HHV of 41.1 MJ kg-1) was produced (Chem. Eng. J., 420 (2021), 129714). Nevertheless, catalyst deactivation occurred after a few hours’ of reaction. As such, catalyst stability and regenerability are of research interest and also of high relevance for industrial implementation. This project aims to study the potential of the add-on catalytic upgrading step to the industrial fast pyrolysis of paper sludge process. One important performance metric for sustainable catalysis in the industry is the level of catalyst consumption (kgcat tprod-1) for catalytic pyrolysis of paper sludge. Another important research topic is to establish the correlation between yield and selectivity of the bio-chemicals and the catalyst characteristics. For this, different types of catalysts (e.g., FCC-type E-Cat) will be tested and several reaction-regeneration cycles will be performed. These studies will determine under which conditions catalytic fast pyrolysis of paper sludge is technically and economically viable.
Resistance to damage, fracture and failure is critical for high performance polymers, especially so in safety applications where they protect equipment or human life. In this project we investigate the use of molecular mechanochemistry tools for the measurement and analysis of mechanical impact in high performance polymers and their composites. While typically performed in a laboratory setting, these measurements hold promise for studying damage in large scale realistic samples. For this we will to develop fluorescent imaging techniques and chemistry, necessary to produce mechanoresponsive samples. This proposal will also draw correlations between imaging and mechanical testing, which can ultimately allow us to study realistic samples and recover the history of the impact they have sustained during operation.