An analytical and experimental study of injection-locked two-port oscillators

A Ku-band IMPATT oscillator with two distinct output power ports was injection-locked alternately at both ports. The transmission locking bandwidth was nearly the same for either port. The lower free running power port had a reflection locking bandwidth that was narrower than its transmission locking one. Just the opposite was found at the other port. A detailed analytical model for two-port injection-locked oscillators is presented, and its results agree quite well with the experiments. A critique of the literature on this topic is included to clear up misconceptions and errors. It is concluded that two-port injection-locked oscillators may prove useful in certain communication systems

What can we infer about the underlying physics from burst distributions observed in an RMHD simulation ?

We determine that the sizes of bursts in mean-square current density in a reduced magnetohydrodynamic (RMHD)simulation follow power-law probability density function (PDF). The PDFs for burst durations and waiting time between bursts are clearly not exponential and could also be power-law. This suffices to distinguish their behaviour from the original Bak et al. sandpile model which had exponential waiting time PDFs. However, it is not sufficient to distinguish between turbulence, some other SOC-like models, and other red noise sources.Comment: In press, Planetary and Space Science. Proceedings of a session at European Geophysical Society General Assembly, Nice, 200

Power law burst and inter-burst interval distributions in the solar wind: turbulence or dissipative SOC ?

We calculate for the first time the probability density functions (PDFs) P of burst energy e, duration T and inter-burst interval tau for a known turbulent system in nature. Bursts in the earth-sun component of the Poynting flux at 1 AU in the solar wind were measured using the MFI and SWE experiments on the NASA WIND spacecraft. We find P(e) and P(T) to be power laws, consistent with self-organised criticality (SOC). We find also a power law form for P(tau) that distinguishes this turbulent cascade from the exponential P(tau) of ideal SOC, but not from some other SOC-like sandpile models. We discuss the implications for the relation between SOC and turbulence.Comment: 3 pages, 1 figure. Submitted to PRL on 25th February 2000. Revised version re-submitted on 9th May 2000. Second revised version submitted Phys. Rev. E on 26th June, 200

Domestic Violence and Child Participation: Contemporary Challenge for the 1980 Hague Child Abduction Convention

This article addresses two contemporary challenges for the 1980 Hague Child Abduction Convention: (i) domestic violence and (ii) child participation. It also outlines three components of a global socio-legal policy and research initiative undertaken to address these issues and, where relevant, their intersection. The published literature on these topics, including the children’s objections exception, is explored, as are the ways in which these challenges are addressed within some of the 101 Contracting States to the Convention and through the Guide to Good Practice on Article 13(1)(b) of the Convention. Regard is paid to the data provided by the statistical analysis of applications made under the Convention in 2015 by Lowe and Stephens, and the changes which will occur once the Recast of The European Brussels 11a Regulation comes into operation. The likely impact of the UK leaving the European Union, currently due to occur on 31 October 2019, for 1980 Hague Convention abduction proceedings is contemplated. Other current international initiatives are discussed, including the development of a child-friendly version of the Convention through The International Association of Child Law Researchers. Training is a key to changing attitudes and upskilling family justice professionals to ensure the Convention operates in a fully child-centric way. This will maintain and strengthen the Convention by keeping it ‘fit for purpose’

Colorectal Cancer Brochure Development for African Americans

Introduction: African Americans are more likely to die from colorectal cancer (CRC) than any other racial/ethnic group in the United States. Unfortunately, African Americans are also less likely to undergo screening for CRC than their White counterparts. Focus groups methodology was used to refine educational brochures designed to increase CRC screening among African Americans. Methods: Two series of focus groups were completed, with a total of seven groups and 39 participants. Six different brochures (stage-matched and culturally sensitive) designed to promote CRC screening among African Americans were evaluated. Results: All participants thought that the brochures motivated them to talk with their health care providers about screening. Cost, pain, medical mistrust and fear were identified as major barriers and the brochures were modified to address these concerns. Conclusions: Focus groups methodology with African Americans can be used to inform brochures designed to increase African Americans CRC screening that addresses their major concerns

Online peer support for students

While many UK higher education institutions have websites offering information and advice on common student problems, interactive online support is less common. This article describes a project developing internet-based mutual support for students experiencing psychological problems at University College London

Educational Research Association

n/