Fast autotuning of a hydrogen maser by cavity Q modulation

A new fast autotuner for the hydrogen maser was implemented. By modulating the cavity, a phase shift in the maser output signal is induced which is proportional to the cavity tuning error. The phase shift is detected and fed back to a varactor tuner to stabilize the cavity against long-term drifts. Also, a PIN-diode cavity modulator which gives no incidental frequency shift over a very wide range of operation was developed. Modulated at over 200 Hz, it allows variations in maser cavity frequency to be compensated with a loop gain greater than 1000. Compensation of incidental amplitude modulation of the output was demonstrated

Is the Water Sector Lagging behind Education and Health on Aid Effectiveness? Lessons from Bangladesh, Ethiopia and Uganda

A study in three countries (Bangladesh, Ethiopia and Uganda) assessed progress against the Paris Principles for Aid Effectiveness (AE) in three sectors – water, health and education – to test the assumption that the water sector is lagging behind. The findings show that it is too simplistic to say that the water sector is lagging, although this may well be the case in some countries. The study found that wider governance issues are more important for AE than having in place sector-specific mechanics such as Sector-Wide Approaches alone. National political leadership and governance are central drivers of sector AE, while national financial and procurement systems and the behaviour of actors who have not signed up to the Paris Principles – at both national and global levels – have implications for progress that cut across sectors. Sectors and sub-sectors do nonetheless have distinct features that must be considered in attempting to improve sector-level AE. In light of these findings, using political economy approaches to better understand and address governance and strengthening sector-level monitoring is recommended as part of efforts to improve AE and development results in the water sector

Exhaust emissions reduction for intermittent combustion aircraft engines

Three concepts which, to an aircraft piston engine, provide reductions in exhaust emissions of hydrocarbons and carbon monoxide while simultaneously improving fuel economy. The three chosen concepts, (1) an improved fuel injection system, (2) an improved cooling cylinder head, and (3) exhaust air injection, when combined, show a synergistic relationship in achieving these goals. In addition, the benefits of variable ignition timing were explored and both dynamometer and flight testing of the final engine configuration were accomplished

Quantum-Dot Cellular Automata using Buried Dopants

The use of buried dopants to construct quantum-dot cellular automata is investigated as an alternative to conventional electronic devices for information transport and elementary computation. This provides a limit in terms of miniaturisation for this type of system as each potential well is formed by a single dopant atom. As an example, phosphorous donors in silicon are found to have good energy level separation with incoherent switching times of the order of microseconds. However, we also illustrate the possibility of ultra-fast quantum coherent switching via adiabatic evolution. The switching speeds are numerically calculated and found to be 10's of picoseconds or less for a single cell. The effect of decoherence is also simulated in the form of a dephasing process and limits are estimated for operation with finite dephasing. The advantages and limitations of this scheme over the more conventional quantum-dot based scheme are discussed. The use of a buried donor cellular automata system is also discussed as an architecture for testing several aspects of buried donor based quantum computing schemes.Comment: Minor changes in response to referees comments. Improved section on scaling and added plot of incoherent switching time

Evaluating the application of research-based guidance to the design of an emergency preparedness leaflet

UNLABELLED: Guidelines for the design of emergency communications were derived from primary research and interrogation of the literature. The guidelines were used to re-design a nuclear emergency preparedness leaflet routinely distributed to households in the local area. Pre-test measures of memory for, and self-reported understanding of, nuclear safety information were collected. The findings revealed high levels of non-receipt of the leaflet, and among those who did receive it, memory for safety advice was poor. Subjective evaluations of the trial leaflet suggested that it was preferred and judged easier to understand than the original. Objective measures of memory for the two leaflets were also recorded, once after the study period, and again one week or four weeks later. Memory for the advice was better, at all time periods, when participants studied the trial leaflet. The findings showcase evaluation of emergency preparedness literature and suggest that extant research findings can be applied to the design of communications to improve memory and understandability. STATEMENT OF RELEVANCE: Studies are described that showcase the use of research-based guidelines to design emergency communications and provide both subjective and objective data to support designing emergency communications in this way. In addition, the research evaluates the effectiveness of emergency preparedness leaflets that are routinely distributed to households. This work is of relevance to academics interested in risk communication and to practitioners involved in civil protection and emergency preparedness

Building Community: A Tool Kit for Youth and Adults in Charting Assets and Creating Change

Extension workers around the country are discovering a new way to help communities become more of what they want to be, and link them to extension resources, through the use of Building Community: A Tool Kit for Youth and Adults In Charting Assets and Creating Change. Developed by the Innovation Center for Community and Youth Development with Extension partners, the tool kit focuses on the gifts that a community brings to their desire for change--gifts of the past, place, people, and relationships--and has proven itself to be a powerful tool for sustainable community development

Spiral cracks in drying precipitates

We investigate the formation of spiral crack patterns during the desiccation of thin layers of precipitates in contact with a substrate. This symmetry-breaking fracturing mode is found to arise naturally not from torsion forces, but from a propagating stress front induced by the fold-up of the fragments. We model their formation mechanism using a coarse-grain model for fragmentation and successfully reproduce the spiral cracks. Fittings of experimental and simulation data show that the spirals are logarithmic, corresponding to constant deviation from a circular crack path. Theoretical aspects of the logarithmic spirals are discussed. In particular we show that this occurs generally when the crack speed is proportional to the propagating speed of stress front.Comment: 4 pages, 5 figures, RevTe

Progression and assessment in foreign languages at Key Stage 2

The teaching of primary languages has been increasing steadily, in response to the future entitlement for all Key Stage 2 (KS2) pupils aged 7-11 to learn a foreign language by 2010. However, there remain concerns about progression both within KS2 and through to secondary school and about how learners' progress is assessed. This paper presents findings on the issues of progression and assessment taken from case studies which formed part of a project funded by the then Department for Education and Skills (DfES), now the Department for Children, Schools and Families (DCSF). This project set out to evaluate 19 local authority (LA) Pathfinders in England that were piloting the introduction of foreign language learning at KS2 between 2003 and 2005. Findings revealed that there was inconsistency between schools, even within each LA Pathfinder, in the use of schemes of work and that assessment was generally underdeveloped in the majority of the Pathfinders. In order to set these findings in context, this paper examines the issues of progression and assessment in foreign language learning in England. Finally, it investigates the challenges English primary schools face in terms of progression and assessment in the light of the new entitlement and discusses implications for the future. Managing progression, both within KS2 and through to secondary school at KS3 (ages 11-14), is one of the key factors in determining the overall success of starting languages in primary school

Using the filaments in the LCRS to test the LambdaCDM model

It has recently been established that the filaments seen in the Las Campanas Redshift Survey (LCRS) are statistically significant at scales as large as 70 to 80 Mpc/h in the $-3^{\circ}$ slice, and 50 to 70 Mpc/h in the five other LCRS slices. The ability to produce such filamentary features is an important test of any model for structure formation. We have tested the LCDM model with a featureless, scale invariant primordial power spectrum by quantitatively comparing the filamentarity in simulated LCRS slices with the actual data. The filamentarity in an unbiased LCDM model, we find, is less than the LCRS. Introducing a bias b=1.15, the model is in rough consistency with the data, though in two of the slices the filamentarity falls below the data at a low level of statistical significance. The filamentarity is very sensitive to the bias parameter and a high value b=1.5, which enhances filamentarity at small scales and suppresses it at large scales, is ruled out. A bump in the power spectrum at k~0.05 Mpc/h is found to have no noticeable effect on the filamentarity.Comment: 16 pages, 3 figures; Minor Changes, Accepted to Ap