GCSE grades and GNVQ outcomes: results of a pilot study

This paper reports an investigation into the importance of basic skills in literacy and numeracy in the promotion of success on intermediate vocational courses at age 16+. Two measures of attainment in literacy and numeracy are examined; GCSE passes in English and Mathematics analysed by grade awarded and the Adult Literacy and Basic Skills Unit (ALBSU) tests in communication and numeracy. The study examines the relationship between prior attainment as attested by GCSE grades and ALBSU scores and course outcome. The extent to which a consistent relationship is found between GCSE grades and ALBSU scores is also examined. The study uses a random sample of 142 students drawn from a population of all first year 16/7 year old students who enrolled at a London Further Education college in 1994. A sub-sample of students on GNVQ Intermediate and NVQ level 2 courses is examined in greater depth. Data on course outcomes was collected at three points in time, 1995, one year after enrolment and on two occasions in 1996. It was therefore possible to chart the progress of students in the sample who took more than one year to complete an Intermediate (G)NVQ. Initial analysis found that at the GCSE middle grade range (Grades C,D,E,F) there was a wide range of literacy and numeracy outcomes as measured by the ALBSU literacy and numeracy tests. GCSE Maths and English passes at these grades do not appear to guarantee threshold attainment levels in basic numeracy and literacy. No significant relationship is found between prior attainment as measured by GCSE Maths and English grades and course outcomes. The ALBSU test scores proved to be more helpful in predicting student outcomes on the Intermediate GNVQ but were still fairly weak predictors. The high proportion of leaves from the sample, probably influenced by ''pull'' factors from the labour market, gives cause for concern. There is no evidence to indicate that weaker students leave Intermediate GNVQ courses early, if anything, the reverse is true. A significant proportion of Intermediate GNVQ courses early, if anything, the reverse is true. A significant proportion of Intermediate GNVQ students gained their awards after the prescribed one year study period. Commitment and motivation to succeed appear to be as - if not more - important than academic qualifications for success on Intermediate GNVQ. The study offers evidence that, for those motivated to persist with the studies, GNVQ can offer a valuable ''bridge'' to further and higher education opportunities to students who have performed poorly on ''academic'' GCSEs

Study of bonding methods for flip chip and beam leaded devices

The results are presented of a comprehensive study and evaluation for the bonding of flip chip and beam leaded devices onto hybrid microcircuit substrates used in high reliability space applications. The program included the evaluation of aluminum flip chips, solder (silver/tin) bump chips, gold beam leaded devices, and aluminum beam leaded devices

First-principles calculation of mechanical properties of Si <001> nanowires and comparison to nanomechanical theory

We report the results of first-principles density functional theory calculations of the Young's modulus and other mechanical properties of hydrogen-passivated Si nanowires. The nanowires are taken to have predominantly {100} surfaces, with small {110} facets according to the Wulff shape. The Young's modulus, the equilibrium length and the constrained residual stress of a series of prismatic beams of differing sizes are found to have size dependences that scale like the surface area to volume ratio for all but the smallest beam. The results are compared with a continuum model and the results of classical atomistic calculations based on an empirical potential. We attribute the size dependence to specific physical structures and interactions. In particular, the hydrogen interactions on the surface and the charge density variations within the beam are quantified and used both to parameterize the continuum model and to account for the discrepancies between the two models and the first-principles results.Comment: 14 pages, 10 figure

NASA micromin computer Monthly progress letter, Jan. 1967

Microminiature circuit development for flight control computer

Self Calibration of Tomographic Weak Lensing for the Physics of Baryons to Constrain Dark Energy

Numerical studies indicate that uncertainties in the treatment of baryonic physics can affect predictions for shear power spectra at a level that is significant for forthcoming surveys such as DES, SNAP, and LSST. Correspondingly, we show that baryonic effects can significantly bias dark energy parameter measurements. Eliminating such biases by neglecting information in multipoles beyond several hundred leads to weaker parameter constraints by a factor of approximately 2 to 3 compared with using information out to multipoles of several thousand. Fortunately, the same numerical studies that explore the influence of baryons indicate that they primarily affect power spectra by altering halo structure through the relation between halo mass and mean effective halo concentration. We explore the ability of future weak lensing surveys to constrain both the internal structures of halos and the properties of the dark energy simultaneously as a first step toward self calibrating for the physics of baryons. This greatly reduces parameter biases and no parameter constraint is degraded by more than 40% in the case of LSST or 30% in the cases of SNAP or DES. Modest prior knowledge of the halo concentration relation greatly improves even these forecasts. Additionally, we find that these surveys can constrain effective halo concentrations near m~10^14 Msun/h and z~0.2 to better than 10% with shear power spectra alone. These results suggest that inferring dark energy parameters with measurements of shear power spectra can be made robust to baryonic effects and may simultaneously be competitive with other methods to inform models of galaxy formation. (Abridged)Comment: 18 pages, 11 figures. Minor changes reflecting referee's comments. Results and conclusions unchanged. Accepted for publication in Physical Review