Pupil mobility, attainment and progress in secondary school

This paper is the second of two articles arising from a study of the association between pupil mobility and attainment in national tests and examinations in an inner London borough. The first article (Strand & Demie, 2006) examined the association of pupil mobility with attainment and progress during primary school. It concluded that pupil mobility had little impact on performance in national tests at age 11, once pupils’ prior attainment at age 7 and other pupil background factors such as age, sex, special educational needs, stage of fluency in English and socio-economic disadvantage were taken into account. The present article reports the results for secondary schools (age 11-16). The results indicate that pupil mobility continues to have a significant negative association with performance in public examinations at age 16, even after including statistical controls for prior attainment at age 11 and other pupil background factors. Possible reasons for the contrasting results across school phases are explored. The implications for policy and further research are discussed

Solid propellant rocket motor

The characteristics of a solid propellant rocket engine with a controlled rate of thrust buildup to a desired thrust level are discussed. The engine uses a regressive burning controlled flow solid propellant igniter and a progressive burning main solid propellant charge. The igniter is capable of operating in a vacuum and sustains the burning of the propellant below its normal combustion limit until the burning propellant surface and combustion chamber pressure have increased sufficiently to provide a stable chamber pressure

Double precision trajectory program /DPTRAJ 2.2C/

Four part program computes trajectory of space probe moving in solar system and subject to variety of forces

The limits of social class in explaining ethnic gaps in educational attainment

This paper reports an analysis of the educational attainment and progress between age 11 and age 14 of over 14,500 students from the nationally representative Longitudinal Study of Young People in England (LSYPE). The mean attainment gap in national tests at age 14 between White British and several ethnic minority groups were large, more than three times the size of the gender gap, but at the same time only about one-third of the size of the social class gap. Socio-economic variables could account for the attainment gaps for Black African, Pakistani and Bangladeshi students, but not for Black Caribbean students. Further controls for parental and student attitudes, expectations and behaviours indicated minority ethnic groups were on average more advantaged on these measures than White British students, but this was not reflected proportionately in their levels of attainment. Black Caribbean students were distinctive as the only group making less progress than White British students between age 11 and 14 and this could not be accounted for by any of the measured contextual variables. Possible explanations for the White British-Black Caribbean gap are considered

Role of long-range exact exchange in polaron charge transition levels: The case of MgO

Predicting the degree of localization and calculating the trapping energies of polarons in insulators by density functional theory (DFT) is challenging. Hybrid functionals are often reparametrized to obtain accurate results and the a priori selection of these parameters is still an open question. Here we test the accuracy of several range-separated hybrid functionals, all reparametrized to produce an accurate band gap, by calculating the charge transition levels (CTLs) of experimentally well-studied hole polaron defect centers in MgO. We show that the functional with screened long-range exact exchange is moderately but consistently more accurate than functionals which do not include long-range exact exchange. We provide evidence that the source of the improved accuracy is the eigenvalue associated with the valence band maximum of the bulk material. We discuss the extent to which this accuracy relates to Koopmans' compliance of the defect energy level

Insect feeds in salmon aquaculture : sociotechnical imagination and responsible story-telling

Unidad de excelencia María de Maeztu CEX2019-000940-MSalmon aquaculture is a growing industry with increasing challenges of feed sustainability and availability. This global sustainability issue has led to calls for novel feeds. Aquafly, a Norwegian research project, has performed small-scale tests using the black soldier fly as an ingredient in salmon diet. However, in order for insect feeds to become a reality on the industrial scale, workable scientific, technical and political solutions have to be envisioned in tandem. In this study, we studied, elicited and assessed sociotechnical imaginaries in the Aquafly research consortium, using the approaches of concomitant ELSA research, the Ethical Matrix and Quantitative Story-Telling. We show how the sociotechnical imaginaries develop together with the scientific trajectory of the project, and how this also affects the assessment of the ethical and environmental impacts of the technology, including issues of food and feed safety and security, fish health and welfare, pollution and efficient use of waste streams. We show how there are intrinsic challenges when dealing with global sustainability issues in the research project. For instance, overcoming the problem of salmon feed scarcity may aggravate the challenges caused by intensive aquaculture. We report the results of a Quantitative Story-Telling exercise that indicates that Aquafly can be seen as part of a larger economy of technological promise, and discuss if and how this critique can be employed and integrated into scientific and technical imagination in a research project, contributing to Responsible Research and Innovation