688 research outputs found

    The adsorption of nitric oxide on a silicon (100) 2 × 1 surface studied with Auger electron spectroscopy

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    We present an Auger electron spectroscopy (AES) study of the adsorption of nitric oxide (NO) on a clean Si(100)2 × 1 surface at 300 and 550 K. Accurate measurement reeveal well resolved fine structure at Auger SiL2.3VV transitions at 62 and 83 eV. These peaks can be attributed to Si---O and Si---N bonds. Furthermore, it is argued that the broadening in the SiLi2.3VV Auger transition at 83 eV at 300 K may be composed of two nearby peaks, which could be attributed to two different kinds of chemical bonding, Si---N and Si---O. The absence of a peak at 69 eV at room temperature strongly suggests the NO adsorption on a Si(100)2 × 1 surface to be molecular. Dissociation of NO on the Si(100)2 × 1 surface is observed at 550 K

    Sitting too much: a hierarchy of socio-demographic correlates

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    Too much sitting (extended sedentary time) is recognized as a public health concern in Europe and beyond. Time spent sedentary is influenced and conditioned by clusters of individual-level and contextual (upstream) factors. Identifying population subgroups that sit too much could help to develop targeted interventions to reduce sedentary time. We explored the relative importance of socio-demographic correlates of sedentary time in adults across Europe. We used data from 26,617 adults who participated in the 2013 Special Eurobarometer 412 "Sport and physical activity". Participants from all 28 EU Member States were randomly selected and interviewed face-to-face. Self-reported sedentary time was dichotomized into sitting less or >7.5h/day. A Chi-squared Automatic Interaction Detection (CHAID) algorithm was used to create a tree that hierarchically partitions the data on the basis of the independent variables (i.e., socio-demographic factors) into homogeneous (sub)groups with regard to sedentary time. This allows for the tentative identification of population segments at risk for unhealthy sedentary behaviour. Overall, 18.5% of the respondents reported sitting >7.5h/day. Occupation was the primary discriminator. The subgroup most likely to engage in extensive sitting were higher educated, had white-collar jobs, reported no difficulties with paying bills, and used the internet frequently. Clear socio-demographic profiles were identified for adults across Europe who engage in extended sedentary time. Furthermore, physically active participants were consistently less likely to engage in longer daily sitting times. In general, those with more indicators of higher wealth were more likely to spend more time sitting

    Educational differences in the validity of self-reported physical activity

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    BACKGROUND: The assessment of physical activity for surveillance or population based studies is usually done with self-report questionnaires. However, bias in self-reported physical activity may be greater in lower educated than in higher educated populations. The aim of the present study is to describe educational differences in the validity of self-reported physical activity. METHODS: We included 196 healthy adults (age 57 ± 15.4, of whom 17 % low, 24 % medium and 59 % high educated). Criterion validity of an adapted International Physical Activity Questionnaire was assessed against the ActiGraph GT3X+ accelerometer. RESULTS: While criterion validity of self-reported physical activity was low to moderate in the total sample (Spearman rho ranged from 0.16 to 0.27, depending on the variables used), the validity in lower educated respondents was poor (-0.07 to 0.05). CONCLUSIONS: The results confirm the hypothesis that self-report physical activity questionnaires are less valid in lower educated populations

    Motivation: key to a healthy lifestyle in people with diabetes? Current and emerging knowledge and applications

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    Aim Motivation to take up and maintain a healthy lifestyle is key to diabetes prevention and management. Motivations are driven by factors on the psychological, biological and environmental levels, which have each been studied extensively in various lines of research over the past 25 years. Here, we analyse and reflect on current and emerging knowledge on motivation in relation to lifestyle behaviours, with a focus on people with diabetes or obesity. Structured according to psychological, (neuro‐)biological and broader environmental levels, we provide a scoping review of the literature and highlight frameworks used to structure motivational concepts. Results are then put in perspective of applicability in (clinical) practice. Results Over the past 25 years, research focusing on motivation has grown exponentially. Social–cognitive and self‐determination theories have driven research on the key motivational concepts ‘self‐efficacy’ and ‘self‐determination’. Neuro‐cognitive research has provided insights in the processes that are involved across various layers of a complex cortical network of motivation, reward and cognitive control. On an environmental – more upstream – level, motivations are influenced by characteristics in the built, social, economic and policy environments at various scales, which have provided entry points for environmental approaches influencing behaviour. Conclusions Current evidence shows that motivation is strongly related to a person's self‐efficacy and capability to initiate and maintain healthy choices, and to a health climate that supports autonomous choices. Some approaches targeting motivations have been shown to be promising, but more research is warranted to sustainably reduce the burden of diabetes in individuals and populations

    Transition to a Sustainable Circular Plastics Economy in The Netherlands: Discourse and Policy Analysis

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    The circular economy (CE) has become a key sustainability discourse in the last decade. The Netherlands seeks to become fully circular by 2050 and the EU has set ambitious circularity targets in its CE Action Plan of 2015. The plastics sector, in particular, has gained a lot of attention as it is a priority area of both the EU and Dutch CE policies. However, there has been little research on the different and often contested discourses, governance processes and policy mechanisms guiding the transition to a circular economy and society. This paper aims to fill these gaps by asking what circular discourses and policies are being promoted in the Netherlands and what sustainability implications and recommendations can be drawn from it. It does so through a mix of media analysis, policy analysis, semi-structured interviews, and surveys using Q-methodology. Results indicate a dominance of technocentric imaginaries, and a general lack of discussion on holistic, and transformative visions, which integrate the full social, political, and ecological implication of a circular future. To address those challenges, this research brings key policy insights and recommendations which can help both academics and practitioners better understand and implement the transition towards a sustainable circular plastics economy

    How circular is your tyre: Experiences with extended producer responsibility from a circular economy perspective

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    The circular economy (CE) emphasises closing material loops to retain material value. The current practice of tyre recycling in the Netherlands, through a system of extended producer responsibility (EPR), appears an overwhelming success, with claims of 100% recovery. Yet, there is limited critical understanding regarding the system’s circularity, considering alternative value retention options and resource recovery outcomes. This study analyses this Dutch tyre EPR system and reflects on how it can be improved from a systemic CE perspective. It uses a qualitative case study approach, using interviews and a review of policy, legal and EPR reporting documents. This paper assesses the governance of this sector and reflects on the existing system, including its circularity and value retention outcomes. Our analysis reveals seven central issues concerning how the EPR system currently functions, resulting in limited circularity and sustainability outcomes, despite high material recovery levels. To address these issues we recommend the continuous improvement of recovery and sustainability targets beyond a single product life cycle, a more transparent and inclusive governance system, as well as a greater focus on sufficiency strategies, e.g. design for durability and a broader transformation of transport models. This paper adds a practical understanding of the capacity of EPR to contribute to CE

    European Sitting Championship: Prevalence and Correlates of Self-Reported Sitting Time in the 28 European Union Member States

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    Objective: Sedentary behaviour is increasingly recognized as an important health risk, but comparable data across Europe are scarce. The objective of this study was to explore the prevalence and correlates of self-reported sitting time in adults across and within the 28 European Union Member States. Methods: This study reports data from the Special Eurobarometer 412. In 2013, 27,919 randomly selected Europeans (approximately 1000 per Member State) were interviewed face-to-face. Sitting time on a usual day was self-reported and dichotomised into sitting less- and more than 7.5 hours per day. Uni- and multivariate odds ratios of sitting more than 7.5 hours per day were assessed by country and socio-demographic variables using binary logistic regression analyses. The analyses were stratified by country to study the socio-demographic correlates of sitting time within the different countries. Results: A total of 26,617 respondents were included in the analyses. Median sitting time was five hours per day. Across Europe, 18.5 percent of the respondents reported to sit more than 7.5 hours per day, with substantial variation between countries (ranging from 8.9 to 32.1 percent). In general, northern European countries reported more sitting than countries in the south of Europe. ‘Current occupation’ and ‘age when stopped education’ were found to be the strongest correlates of sitting time, both across Europe and within most Member States. Compared to manual workers, the odds ratio of sitting more than 7.5 hours per day was 5.00 for people with white collar occupations, 3.84 for students, and 3.65 for managers. Conclusions: There is substantial variation in self-reported sitting time among European adults across countries as well as socio-demographic groups. While regular surveillance of (objectively measured) sedentary behaviour is needed, the results of this study provide entry points for developing targeted interventions aimed at highly sedentary populations, such as people with sedentary occupations
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