The recent upgrading of the Tidbinbilla two-element interferometer to simultaneous S-band (2.3 GHz) and X-band (8.4 GHz) operation has provided a powerful new astronomical facility for weak radio source measurement in the Southern Hemisphere. The new X-band system has a minimum fringe spacing of 38 arcsec, and about the same positional measurement capability (approximately 2 arcsec) and sensitivity (1 s rms noise of 10 mJy) as the previous S-band system. However, the far lower confusion limit will allow detection and accurate positional measurements for sources as weak as a few millijanskys. This capability will be invaluable for observations of radio stars, X-ray sources and other weak, compact radio sources.

A K-band (18-25 GHz) reflected-wave ruby maser (Moore and Clauss 1979) has been borrowed from the National Radio Astronomy Observatory for radio astronomy use on the NASA 64-m antenna of the Deep Space Network at the Tidbinbilla Tracking Station, near Canberra. The purpose of the installation is to provide additional sensitive spectral line, continuum, and VLBI capabilities in the southern hemisphere. Previous measurements at 22.3 GHz (λ = 13.5 mm) determined that the Tidbinbilla 64-m antenna has a peak aperture efficiency of ˜22%, a well-behaved beam shape and consistent pointing (Fourikis and Jauncey 1979). Before installing the maser on the antenna a cooled (circulator) switch was added to provide a beam-switching capability, and a spectral line receiver following the maser was incorporated. The system was assembled and tested at JPL in late 1980 and installed at Tidbinbilla early in 1981. We give here a brief description and present some of the first line observations made in February and March 1981. Extensive line and continuum observations are planned with the present system and a program is under way to determine the telescope pointing characteristics.

Despite many advances in recent years for patients with critical paediatric and congenital cardiac disease, significant variation in outcomes remains across hospitals. Collaborative quality improvement has enhanced the quality and value of health care across specialties, partly by determining the reasons for variation and targeting strategies to reduce it. Developing an infrastructure for collaborative quality improvement in paediatric cardiac critical care holds promise for developing benchmarks of quality, to reduce preventable mortality and morbidity, optimise the long-term health of patients with critical congenital cardiovascular disease, and reduce unnecessary resource utilisation in the cardiac intensive care unit environment. The Pediatric Cardiac Critical Care Consortium (PC4) has been modelled after successful collaborative quality improvement initiatives, and is positioned to provide the data platform necessary to realise these objectives. We describe the development of PC4 including the philosophical, organisational, and infrastructural components that will facilitate collaborative quality improvement in paediatric cardiac critical care.

Although overall outcomes for children undergoing heart surgery have improved, there is a significant variation in outcomes across hospitals. This review discusses the variation in cost and outcomes across centres performing congenital heart surgery, potential underlying mechanisms, and efforts to reduce variation and improve outcome.

We are exploring a new parameter space of the two-beam acceleration (TBA) scheme based on an ultra-short (~20 ns) rf pulse in a dielectric TBA. All two-beam accelerators (TBAs) use an electron drive beam to generate high-power rf in a decelerator and extract this power to drive an accelerating structure to high gradient. Typically, the rf pulse is on the order of hundreds of ns or greater in order to maintain good rf-to-beam efficiency. However, recent scaling arguments show that the rf breakdown threshold improves with decreasing rf pulse length, so it desirable to find a way to run at short-pulse length with good efficiency. In this paper, we discuss how we chose the design parameters of a short-pulse TBA for a TeV linear collider module. We then present plans for an experimental program to demonstrate TBA at Argonne wakefield accelerator (AWA) facility including high-power rf generation, high-gradient acceleration, and staging.

Over the last 20 years, the French public services’ actions in the field of polluted areas have continuously evolved from the inventory of potentially polluted areas to the statement of a general framework on the management. Initially designed for chemical pollutants, main guidelines have been implemented for radioactive substances. The general framework is presented hereafter and illustrated with a real example.

In-situ transmission electron microscopy (TEM) has developed rapidly over the last decade. In particular, with the inclusion of scanning probes in TEM holders, allows both mechanical and electrical testing to be performed whilst simultaneously imaging the microstructure at high resolution. In-situ TEM nanoindentation and tensile experiments require only an axial displacement perpendicular to the test surface. However, here, through the development of a novel in-situ TEM triboprobe, other surface characterisation experiments are now possible, with the introduction of a fully programmable 3D positioning system.

Programmable lateral displacement control allows scratch tests to be performed at high resolution with simultaneous imaging of the changing microstructure. With the addition of repeated cyclic movements, both nanoscale fatigue and friction experiments can also now be performed. We demonstrate a range of movement profiles for a variety of applications, in particular, lateral sliding wear.

The developed NanoLAB TEM triboprobe also includes a new closed loop vision control system for intuitive control during positioning and alignment. It includes an automated online calibration to ensure that the fine piezotube is controlled accurately throughout any type of test. Both the 3D programmability and the closed loop vision feedback system are demonstrated here.

The Rocketdyne Division of Rockwell International has developed a large scale spray-calcination technique generic to the preparation of ceramic high-temperature superconductor (HTSC) powders. Among the advantages of the technique is that of producing uniformly mixed metal oxides on a fine scale. Production of both yttrium and thallium-based HTSCs has been demonstrated using this technique.

In the spray calciner, solutions of the desired composition are atomized as a fine mist into a hot gas. Evaporation and calcination are instantaneous, yielding an extremely fine, uniform oxide powder. The calciner is 76 cm in diameter and can produce metal oxide powder at relatively large rates (approximately 100 g/h) without contamination.

Bulk samples of thallium-based powder were prepared by spray calcination, collected, cold-pressed, and sintered. An optimized temperature schedule was developed to produce T12Ba2Ca2Cu3Ox. Samples were examined by X-ray diffraction and characterized by measurements of critical transition temperature, Tc. A complete transition to zero resistance at 112 K was measured.

We evaluated the effectiveness of a measles vaccine campaign in rural Kenya, based on oral-fluid surveys and mixture-modelling analysis. Specimens were collected from 886 children aged 9 months to 14 years pre-campaign and from a comparison sample of 598 children aged 6 months post-campaign. Quantitative measles-specific antibody data were obtained by commercial kit. The estimated proportions of measles-specific antibody negative in children aged 0–4, 5–9 and 10–14 years were 51%, 42% and 27%, respectively, pre- campaign and 18%, 14% and 6%, respectively, post-campaign. We estimate a reduction in the proportion susceptible of 65–78%, with ~85% of the population recorded to have received vaccine. The proportion of ‘weak’ positive individuals rose from 35% pre-campaign to 54% post-campaign. Our results confirm the effectiveness of the campaign in reducing susceptibility to measles and demonstrate the potential of oral-fluid studies to monitor the impact of measles vaccination campaigns.

The standard AIC (Achromatic Interfero Coronagraph) has a “coudé” geometry (the output beam leaves at right angle from the input beam). Thus, some extra optical parts are required to fit such a device within the optical train between a telescope and its IR camera. To avoid this drawback, we present two mono-axial variants of the AIC.

We present new laboratory measurements of the intrinsic rejection performances in infrared (1.9 $\mu\,$m to 2.5 $\mu\,$m) for a prototype of Achromatic Interfero Coronagraph (AIC). We first recall basics about the AIC, then describe the prototype under consideration. We give detailed explanations about the experimental setup and the procedures followed to measure the rejection rate. We end up with a discussion of the results obtained.

In continuous hot dip galvanizing, in particular with galvannealing baths, competitive reactions occur between iron, zinc and aluminium that may be affected by other elements such as chromium. Based on thermodynamics modelling and experimental descriptions, the zinc rich corner of the quaternary Fe-Zn-Al-Cr system is investigated at 460°C. The results obtained contribute to a better knowledge of the reactivity of steels in industrial galvanizing or galvannealing baths.

High titres of pertussis toxin (PT) antibody have been shown to be predictive of recent infection with Bordetella pertussis. The seroprevalence of standardized anti-PT antibody was determined in six Western European countries between 1994 and 1998 and related to historical surveillance and vaccine programme data. Standardized anti-PT titres were calculated for a series of whole-cell and acellular pertussis vaccine trials. For the serological surveys, high-titre sera (>125 units/ml) were distributed throughout all age groups in both high- (>90%) and low-coverage (<90%) countries. High-titre sera were more likely in infants in countries using high-titre-producing vaccines in their primary programme (Italy, 11·5%; Western Germany, 13·3%; France, 4·3%; Eastern Germany, 4·0%) compared to other countries (The Netherlands, 0·5%; Finland, 0%). Recent infection was significantly more likely in adolescents (10–19 years old) and adults in high-coverage countries (Finland, The Netherlands, France, East Germany), whereas infection was more likely in children (3–9 years old) than adolescents in low-coverage (<90%; Italy, West Germany, United Kingdom) countries. The impact and role of programmatic changes introduced after these surveys aimed at protecting infants from severe disease by accelerating the primary schedule or vaccinating older children and adolescents with booster doses can be evaluated with this approach.

This paper analyses Streptococcus pneumoniae transmission dynamics in households using longitudinal data on pneumococcal (Pnc) carriage in the United Kingdom. Ten consecutive swabs were taken at 4-week intervals from all members of 121 households. The family status is derived from the observed Pnc carriage status of each family member. Transition matrices are built for each family size and composition containing the observed frequency of transitions between family statuses over a 28-day interval. A density-dependent transmission model is fitted to derive maximum-likelihood estimates of the duration of carriage and acquisition rates from the community and from infected individuals within the household. Parameter values are estimated for children (<5 years) and adults (5+ years). The duration of carriage is longer in children <5 years of age than in older family members (51 vs. 19 days). Children are 3–4 times more likely than adults to acquire Pnc infection from the community. Transmission rates within the household suggest that adults are more infectious but less susceptible than children. Transmission within the household is most important in large families. The proportion of household-acquired infection ranges from 29 to 46% in households of three persons to 38–50% in larger households. Evidence of density-dependent within-household transmission is found, although the strength of this relationship is not clear from the model estimates.

Heat transfer levels have been investigated behind a rearward-facing step in a superorbital expansion tube. The heat transfer was measured along a flat plate and behind 2 and 3mm steps with the same length to step height ratio. Results were obtained with air as the test gas at speeds of 6·76kms-1 and 9·60kms-1 corresponding to stagnation enthalpies of 26MJ/kg and 48MJ/kg respectively. A laminar boundary layer was established on the flat plate and measured heat transfer levels were consistent with classical empirical correlations. In the case of flow behind a step, the measurements showed a gradual rise in heat transfer from the rear of the step to a plateau several step heights downstream for both flow conditions. Reattachment distance was estimated to be approximately 1·6 step heights downstream of the 2mm step at the low enthalpy condition through the use of flow visualisation.