151 research outputs found

    From dark to bright: First-order perturbation theory with analytical mode normalization for plasmonic nanoantenna arrays applied to refractive index sensing

    Get PDF
    We present a first-order perturbation theory to calculate the frequency shift and linewidth change of photonic resonances in one- and two-dimensional periodic structures under modifications of the surrounding refractive index. Our method is based on the resonant state expansion, for which we extend the analytical mode normalization to periodic structures. We apply this theory to calculate the sensitivity of bright dipolar and much darker quadrupolar plasmonic modes by determining the maximum shift and optimal sensing volume

    Photobase Generator Enabled Pitch Division: A Progress Report

    Get PDF
    Pitch division lithography (PDL) with a photobase generator (PBG) allows printing of grating images with twice the pitch of a mask. The proof-of-concept has been published in the previous paper[1, 2] and demonstrated by others[1]. Forty five nm half-pitch (HP) patterns were produced using a 90nm HP mask, but the image had line edge roughness (LER) that does not meet requirements. Efforts have been made to understand and improve the LER in this process. Challenges were summarized toward low LER and good performing pitch division. Simulations and analysis showed the necessity for an optical image that is uniform in the z direction in order for pitch division to be successful. Two-stage PBGs were designed for enhancement of resist chemical contrast. New pitch division resists with polymer-bound PAGs and PBGs, and various PBGs were tested. This paper focuses on analysis of the LER problems and efforts to improve patterning performance in pitch division lithography.Chemical Engineerin

    Plotting the motivation of student volunteers in sports-based outreach work in the North East of England

    Get PDF
    This paper examines the evolution of student volunteers’ motivation during their participation in a sports-based outreach project and how their experiences during the programme serve to influence their commitment and retention to it. The Sport Universities North East England (SUNEE) project is a university-led community outreach initiative that provides the region's student volunteers with vast opportunities to gain both experience and qualifications as sports coaches, mentors and leaders by working with a range of hard-to-reach groups. This work draws on qualitative data generated from semi-structured interviews (n = 40) and describes a sequence of motivational transitions undergone by student volunteers over the course of their involvement in the project. In order to illustrate this, the paper applies the socio-psychological framework of Self-Determination Theory (SDT) to not only index the type of motivations that compel students to volunteer on the SUNEE project, but to also track motivational adaptation and reveal the features occurring within the project, which serve to either facilitate volunteer motivation or retention (Deci & Ryan, 1985, 2000). By using the example of the SUNEE project, this research demonstrates how students’ motivation to volunteer changes from the extrinsic (i.e., instrumental reasons such as enhancing one's employability profile) to the intrinsic (i.e., enjoying the experience) motivations the longer the person has taken part in the project. The findings demonstrate the utility of the SDT as a framework with which to understand student motivation to volunteer within a university-led sports-based community outreach setting. The theoretical contributions of the study to the literature on student volunteering are outlined, and implications are drawn for practice and future research

    Perpetrators, victims, bystanders and up standers: cyber bullying in a special school context.

    Get PDF
    This study offers a multi-dimensional analysis of ‘real world’ cyberbullying between members of a special school community. The purpose of this article is to analyse the social and educational contexts within which interactions of this nature are embedded.The interview both illuminated a number of themes pertinent to the current literature and extended those related to the call for further analysis of the contextual determinants of cyberbullying.The influence of the conditions experienced by the children involved (Attention Deficit Hyperactivity Disorder (ADHD) and Autistic Spectrum Condition (ASC)) is discussed and demonstrated. This use of natural observation provides a current and ‘real world’ illustration of teacher perceptions of the complex behaviours and interactions occurring in cyberspace, which hold potential for grave consequences. A hopeful tone is maintained as the potential for selfless upstander behaviour and resolution via the involvement of supportive and knowledgeable pastoral staff is realised in the article’s conclusion.<br/

    Viscum album L. extracts in breast and gynaecological cancers: a systematic review of clinical and preclinical research

    Get PDF
    <p>Abstract</p> <p>Background</p> <p><it>Viscum album </it>L. extracts (VAE, European mistletoe) are a widely used medicinal plant extract in gynaecological and breast-cancer treatment.</p> <p>Methods</p> <p>Systematic review to evaluate clinical studies and preclinical research on the therapeutic effectiveness and biological effects of VAE on gynaecological and breast cancer. Search of databases, reference lists and expert consultations. Criteria-based assessment of methodological study quality.</p> <p>Results</p> <p>19 randomized (RCT), 16 non-randomized (non-RCT) controlled studies, and 11 single-arm cohort studies were identified that investigated VAE treatment of breast or gynaecological cancer. They included 2420, 6399 and 1130 patients respectively. 8 RCTs and 8 non-RCTs were embedded in the same large epidemiological cohort study. 9 RCTs and 13 non-RCTs assessed survival; 12 reported a statistically significant benefit, the others either a trend or no difference. 3 RCTs and 6 non-RCTs assessed tumour behaviour (remission or time to relapse); 3 reported statistically significant benefit, the others either a trend, no difference or mixed results. Quality of life (QoL) and tolerability of chemotherapy, radiotherapy or surgery was assessed in 15 RCTs and 9 non-RCTs. 21 reported a statistically significant positive result, the others either a trend, no difference, or mixed results. Methodological quality of the studies differed substantially; some had major limitations, especially RCTs on survival and tumour behaviour had very small sample sizes. Some recent studies, however, especially on QoL were reasonably well conducted. Single-arm cohort studies investigated tumour behaviour, QoL, pharmacokinetics and safety of VAE. Tumour remission was observed after high dosage and local application. VAE application was well tolerated. 34 animal experiments investigated VAE and isolated or recombinant compounds in various breast and gynaecological cancer models in mice and rats. VAE showed increase of survival and tumour remission especially in mice, while application in rats as well as application of VAE compounds had mixed results. <it>In vitro </it>VAE and its compounds have strong cytotoxic effects on cancer cells.</p> <p>Conclusion</p> <p>VAE shows some positive effects in breast and gynaecological cancer. More research into clinical efficacy is warranted.</p

    What makes a bully a cyberbully? Unravelling the characteristics of cyberbullies across twenty-five European countries

    Get PDF
    The characteristics of bullies who act face-to-face and those who do so in cyberspace were compared directly in one sample across twenty-five countries. The role of cross-country differences in technological infrastructure was also explored. Cyberbullies compared to face-to-face bullies were more likely to engage in risky online activities, spend more time online, and found it easier to be themselves online. Private access to the internet did not make a difference. Gender differences showed girls more likely to be cyber- than face-to-face bullies if they have a profile on a social networking site. Age and internet ability beliefs were also positively but not independently associated with cyberbullying. Cross-country differences were small and patterns remained mostly stable across countries, suggesting that individual and not country-level characteristics are pivotal in explaining cyberbullying

    Serving the Public Interest in Several Ways: Theory and Empirics

    Get PDF
    We develop a model where people differ in their altruistic preferences and can serve the public interest in two ways: by making donations to charity and by taking a public service job and exerting effort on the job. Our theory predicts that people who are more altruistic are more likely to take a public service job and, for a given job, make higher donations to charity. Comparing equally altruistic workers, those with a regular job make higher donations to charity than those with a public service job by a simple substitution argument. We subsequently test these predictions using cross-sectional data from Germany on self-reported altruism, sector of employment, and donations to charity. In addition, we use panel data from the Netherlands on volunteering and sector of employment. We find support for most of our predictions.Hervorming Sociale Regelgevin

    Solids flow measurement by correlation methods

    No full text
    • 

    corecore