Nanodiamonds: From biology to engineering

Whilst diamond nanoparticles have been synthesised by the detonation method since the middle of the 20th century, it was not until the development of their fully dispersed form in 2008 that the hugely varied array of potential applications opened up. These prospective uses are described in chapter 2, spanning the breadth of the sciences; from the chemical (ion sensors and electrochemical electrodes), the biological (drug delivery and intracellular monitoring), to the physical (composite materials and growth nucleation seeds). Highlighting this versatility, chapter 5 of this thesis covers the use of ND as a neuronal biomaterial, investigating for the first time the role of the size, production method and surface functionalisation on neurite extension, where it was found that the only significant variable was the size of the ND used, suggesting the curvature of particle is of high importance. A patterned ND surface was also fabricated and this resulted in the successful growth of neuronal networks along the ND patterning, down to ND track widths of 10 μm. Chapter 6 presents a study into the electrical characteristics of nanodiamond. Here for the first time, ND layers with various surface terminations were produced and verified using Fourier transform infrared spectroscopy. These layers were then probed using impedance spectroscopy to obtain modelled values of the layers’ resistance and capacitance as a function of measurement temperature. This data was manipulated into Arrhenius plots to extract activation energies of the observed conduction paths. The hydrogen terminated ND layers were shown for the first time to be stable for short heating durations up to 475°C, although longer heating duration at this temperature did cause permanent damage to the ND layer. Oxygen terminated ND was found to be less stable when heated in atmospheric conditions, with permanent degradation occurring at 200°C. However when measured in vacuum, these layers showed resilience similar to that seen on the hydrogen terminated ND, suggesting the hydrogen termination is providing protection against oxidative degradation in atmospheric conditions. The next chapter documents the attempts to fabricate thin, conformal layers of ND within the channels of a microchannel plate (MCP) – the electron amplification stage of a night vision device. This work resulted in the first successful seeding of ND throughout the first 60 μm of the MCP channel, as requested by the industrial sponsor of this work, Photonis. This chapter also presents the iterative designs of a custom cooler and sample mount for the microwave plasma enhanced chemical vapour deposition chamber used for low temperature diamond growth both in this chapter and the final experimental chapter. The last experimental chapter details a novel investigation into the optimal conditions for ND to be grown into a thin film for use as a secondary electron emitter. The results presented include Raman spectroscopy (for film quality assessment), scanning electron micrographs (to provide topographical information), atomic force microscope line scans (to estimate film thickness) and finally secondary electron yield experiments upon each of the films. It was found that the films grown with the highest applied microwave power -­‐ resulting from the most aggressive cooling -­‐ gave the highest secondary electron emission yield, slightly under 10 (meeting the objective set by Photonis) along with a sharper sp3 peak at 1333cm-­‐1

Singing and Social Identity in Young Children

A range of studies suggest that singing activities with young children can have a beneficial impact on other aspects of their development. However, there is little research examining the relationship between young children’s singing and their developing social identity. In the current study, data were captured of young children’s singing and social identity as part of a larger-scale, longitudinal evaluation of the nationwide Sing Up programme in England. Participants were 720 children aged 5-8 years old. The assessment of young children’s singing ability employed an established measure and was undertaken individually. With adult support, the children were also asked to complete a simple questionnaire that focused on selected aspects of their social identity, both in general terms and also related to singing. Key themes embraced their attitudes to singing (at home, in school and in informal settings), singer identity (emotional engagement with singing and self-concept), and perceptions of self (self-efficacy, self-esteem, social integration). Comparative data were collected from young children of a similar age outside the programme. Findings suggested that the programme had a positive impact on children’s singing ability, both overall and including the youngest children. The data analyses suggest that children could be identified as either “pupils with positive singing identity” or “pupils with less positive, or still developing singing identity.” Overall, pupils with a more positive singer identity—irrespective of Sing Up-related experience—tended to report more positive attitudes toward singing at school and other settings, had higher perceived levels of self-esteem and social integration, as well as more positive evaluations of their singing ability. Furthermore, the research suggests that successful participation in high-quality singing activities is likely to have a positive impact on young children’s singing ability and, by implication, such positive singing development will also be associated with aspects of self that are related to contexualised singer identity and their sense of social inclusion

III-V arsenide-nitride semiconductor

III-V arsenide-nitride semiconductor are disclosed. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V materials varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V material can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired

A Study of Nontraditional Referral and Screening of Culturally Different Gifted Children.

The purpose of this study was to determine the effectiveness of using nontraditional referral and screening procedures to identify culturally different (minority) gifted children. The extreme disparity of representative frequencies of these groups within gifted programs nationally and in Louisiana prompted research in four parishes (counties) to compare nontraditional with traditional identification procedures. The nontraditional referral procedures included child search methods and parent and teacher training about the characteristics of giftedness among culturally different populations. Nontraditional screening procedures included the use of creativity and leadership checklists, analysis of achievement in all academic areas, and the use of the Matrix Analogies Test-Short Form (MAT-SF) as an intelligence measure. Chi-square tests of association and qualitative analyses were used to analyze data. Among the referral sample (N = 276) of students in grades 1-5, larger numbers of minorities were referred and screened using nontraditional methods. A significant difference was found (p $\u3c$.001) in the proportion of minorities ultimately identified as gifted. Final eligibility for program placement was based on achievement tests and intelligence tests. A significant difference (p $\u3c$.05) was found between teacher and parent ratings on the creativity checklist. In the qualitative analysis of parent/teacher narrative comments on the Creativity and Leadership Checklists (n = 17), parents named significantly more indicators of creativity than did teachers. Similarities were found in parents\u27 and teachers\u27 observations of students concerning creativity and leadership behaviors. Using qualitative analysis, three categorical patterns in leadership and creativity indicators were identified: cognitive, affective and behavioral. Further research should investigate specific nontraditional assessment procedures that include measures to determine cultural characteristics of minority gifted children. Particular attention should be given to the areas of creativity and leadership as a part of the total assessment process. Additionally, such research should attempt to determine the effectiveness of the assessment procedures to provide a description of the child\u27s abilities socially, creatively, academically and intellectually

Methods for forming group III-V arsenide-nitride semiconductor materials

Methods are disclosed for forming Group III--arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired

Methods for forming group III-arsenide-nitride semiconductor materials

Methods are disclosed for forming Group III-arsenide-nitride semiconductor materials. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired

III-V aresenide-nitride semiconductor materials and devices

III-V arsenide-nitride semiconductor crystals, methods for producing such crystals and devices employing such crystals. Group III elements are combined with group V elements, including at least nitrogen and arsenic, in concentrations chosen to lattice match commercially available crystalline substrates. Epitaxial growth of these III-V crystals results in direct bandgap materials, which can be used in applications such as light emitting diodes and lasers. Varying the concentrations of the elements in the III-V crystals varies the bandgaps, such that materials emitting light spanning the visible spectra, as well as mid-IR and near-UV emitters, can be created. Conversely, such material can be used to create devices that acquire light and convert the light to electricity, for applications such as full color photodetectors and solar energy collectors. The growth of the III-V crystals can be accomplished by growing thin layers of elements or compounds in sequences that result in the overall lattice match and bandgap desired

The National Singing Programme for primary schools in England: an initial baseline study

The ‘Sing Up’ National Singing Programme for Primary schools in England was launched in November 2007 under the UK Government’s ‘Music Manifesto’. ‘Sing Up’ is a four-year programme whose overall aim is to raise the status of singing and increase opportunities for children throughout the country to enjoy singing as part of their everyday lives, in and out of school. As part of the Programme’s research evaluation, a key focus has been to build an initial picture of singing in Primary schools across England. This information could then be used as a ‘baseline’ by which the programme’s subsequent impact could be judged, including ‘before’ and ‘after’ measures of schools that receive particular ‘Sing Up’ input. This paper reports an overview of key outcomes of first five months of baseline profiling (October, 2007 to February 2008), embracing analyses of the singing behaviours of 3,472 children in 76 Primary schools. These findings are complimented by additional analyses of children’s views on singing in and out of school; and the self-efficacy of their class teachers’ (n=90), both as singers and as teachers of singing

Researching the Impact of the National Singing Programme 'Sing Up' in England : Diverse Approaches to Successful Singing in Primary Settings

This report presents findings from research carried out with seven Chorister Outreach Projects from Cathedrals across England as part of the Choir School Association's Chorister Outreach Programme (COP). In total, data were collected from fifteen Primary Schools working with these Chorister Outreach Projects. This data set was supplemented by similar teaching and learning of singing data from an additional five (non-COP) Primary Schools who were working with aspects of the SingUp Programme. In total, 48 singing sessions were observed, of which 28 (58.3%) were in COP schools and 20 (41.7%) in non-COP schools. Overall, the observation data on learning and teaching of singing within and outside the COP school sessions demonstrate that high 'quality' experiences can be found in any school context, whether urban or rural, with older or younger children, ethnically diverse or not, and whether led by musical specialists or generalists