Newborns and new schools: critical times in women's employment

This report presents the findings of research into how and when differences in work behaviour between men and women develop, focusing on the evolution of the gender gaps immediately after childbirth and during the initial years of family development. The analysis presented focuses on two crucial periods in family development: when a new baby arrives and when a child starts school. The study uses two data sources: the first thirteen waves from the British Household Panel Survey covering the years 1991 to 2003 and the first five waves from the Families and Children Study covering the years 1999 to 2003

The consistency and reliability of the activity history data in the Families and Children Study (FACS)

The purpose of this report is to examine the consistency and reliability of the activity history data collected in the FACS. Using data from the first five waves of the FACS and from the first thirteen waves of the British Household Panel Survey (BHPS) as a comparison survey, carefully matched samples have been analysed to calibrate the completeness and consistency of the activity history data collected in the FACS and to test whether the FACS generates labour market statistics similar to the comparison survey

Submission to the Work and Pensions Select Committee Inquiry: 'How can suitable, affordable childcare be provided for all parents who need it to enable them to work?'

This briefing note is provided as evidence to the Work and Pensions Select Committee as to whether childcare could be provided for all parents who need it to help them to work. It looks at the ways in which this could be achieved

Families and Children Strategic Analysis Programme (FACSAP): Reviewing approaches to understanding the link between childcare use and mothers' employment

This report was commissioned through the Department for Work and Pensions' Families and Children Strategic Analysis Programme (FACSAP). It examines methods that could potentially be used to explore the link between mothers' demand for childcare and their employment. Several approaches are examined, including: learning from evaluations of existing programmes; the scope for natural experiments and the potential for reduced form and structural modelling of key relationships. The report focuses on methodology but in doing so presents findings from existing studies in the area, most of which are from the United States

The living standards of families with children reporting low incomes

The Government has high-profile child poverty targets which are assessed using a measure of income, as recorded in the Household Below Average Income series (HBAI). However, income is an imperfect measure of living standards. Previous analysis suggests that some children in households with low income do not have commensurately low living standards. This report aims to document the extent to which this is true, focusing on whether children in low-income households have different living standards depending on whether their parents are employed, self-employed, or workless

Noise diffraction patterns eliminated in coherent optical systems

Lens rotation technique of noise diffraction pattern elimination spreads diffracted energy, normally concentrated over small area of image, over much larger annular area. Technique advantages include simplified lens selecting process, reduced clean room requirements, and low cost equipment requirements

Scramjet sidewall burning: Preliminary shock tunnel results

Experiments performed with a two dimensional model scramjet with particular emphasis on the effect of fuel injection from a wall are reported. Air low with a nominal Mach number of 3.5 and varied enthalpies was produced. It was found that neither hydrogen injection angle nor combustor divergence angle had any appreciable effect on thrust values while increased combustor length appeared to increase thrust levels. Specific impulse was observed to peak when hydrogen was injected at an equivalence ratio of about 2. Lowering the Mach number of the injected hydrogen at low equivalence ratios, less than 4, appeared to benefit specific impulse while hydrogen Mach number had little effect at higher equivalence ratios. When a 1:1 mixture by volume of nitrogen and oxygen is used instead of air as a test gas, it is found that hydrogen combustion is enhanced but only at high enthalpies

Further shock tunnel studies of scramjet phenomena

Scramjet phenomena were studied using the shock tunnel T3 at the Australian National University. Simple two dimensional models were used with a combination of wall and central injectors. Silane as an additive to hydrogen fuel was studied over a range of temperatures and pressures to evaluate its effect as an ignition aid. The film cooling effect of surface injected hydrogen was measured over a wide range of equivalence. Heat transfer measurements without injection were repeated to confirm previous indications of heating rates lower than simple flat plate predictions for laminar boundary layers in equilibrium flow. The previous results were reproduced and the discrepancies are discussed in terms of the model geometry and departures of the flow from equilibrium. In the thrust producing mode, attempts were made to increase specific impulse with wall injection. Some preliminary tests were also performed on shock induced ignition, to investigate the possibility in flight of injecting fuel upstream of the combustion chamber, where it could mix but not burn

Elimination of coherent noise in a coherent light imaging system

Optical imaging systems using coherent light introduce objectionable noise into the output image plane. Dust and bubbles on and in lenses cause most of the noise in the output image. This noise usually appears as bull's-eye diffraction patterns in the image. By rotating the lens about the optical axis these diffraction patterns can be essentially eliminated. The technique does not destroy the spatial coherence of the light and permits spatial filtering of the input plane

Preliminary calibration of a generic scramjet combustor

The results of a preliminary investigation of the combustion of hydrogen fuel at hypersonic flow conditions are provided. The tests were performed in a generic, constant-area combustor model with test gas supplied by a free-piston-driven reflected-shock tunnel. Static pressure measurements along the combustor wall indicated that burning did occur for combustor inlet conditions of P(static) approximately equal to 19kPa, T(static) approximately equal to 1080 K, and U approximately equal to 3630 m/s with a fuel equivalence ratio approximately equal to 0.9. These inlet conditions were obtained by operating the tunnel with stagnation enthalpy approximately equal to 8.1 MJ/kg, stagnation pressure approximately equal to 52 MPa, and a contoured nozzle with a nominal exit Mach number of 5.5