Statistical turbulence theory and turbulence phenomenology

The application of deductive turbulence theory for validity determination of turbulence phenomenology at the level of second-order, single-point moments is considered. Particular emphasis is placed on the phenomenological formula relating the dissipation to the turbulence energy and the Rotta-type formula for the return to isotropy. Methods which deal directly with most or all the scales of motion explicitly are reviewed briefly. The statistical theory of turbulence is presented as an expansion about randomness. Two concepts are involved: (1) a modeling of the turbulence as nearly multipoint Gaussian, and (2) a simultaneous introduction of a generalized eddy viscosity operator

Time and frequency stability for the Crustal Dynamics Project

Very long base interferometry (VLBI) and laser ranging to artificial satellites and the Moon were used to determined vector baselines between stations with precisions of about one part in 10 to the 8th power. Deformations and strain accumulations in active earthquake regions were determined by making frequent measurements of baselines between many stations in active areas near plate boundaries

Materials processing in space: Early experiments

The characteristics of the space environment were reviewed. Potential applications of space processing are discussed and include metallurgical processing, and processing of semiconductor materials. The behavior of fluid in low gravity is described. The evolution of apparatus for materials processing in space was reviewed

Infrared ground-based astronomy with the Hughes 256 X 256 PtSi array

It is shown that large format PtSi Schottky diode infrared arrays, the Hughes 256 X 256 hybrid Schottky array in particular, are competitive alternatives to the smaller format photovoltaic arrays for ground-based astronomy. The modest quantum efficiency of the PtSi compared to the photovoltaic devices is more than compensated for by the larger format. The use of hybrid technology yields effective fill factors of nearly 100 percent, and the low dark current, noise, excellent imaging characteristics, cost, and solid nitrogen operating temperature add to the effectiveness of this array for ground-based imaging. In addition to discussing the characteristics of this array, researchers present laboratory test data and astronomical results achieved at Kitt Peak

Delivering alcohol identification and brief advice (IBA) in housing settings: a step too far or opening doors?

Within the UK, there is a drive to encourage the delivery of alcohol screening (or identification) and brief advice (IBA) in a range of contexts beyond primary care and hospitals where the evidence is strongest. However, the evidence base for effectiveness in non-health contexts is not currently established. This paper considers the case of housing provided by social landlords, drawing on two research studies which were conducted concurrently. One study examined the feasibility of delivering alcohol IBA in housing settings and the other the role of training in delivering IBA in non-health contexts including housing. This paper draws mainly on the qualitative data collected for both studies to examine the appropriateness and feasibility of delivering IBA in a range of social housing settings by the housing workforce. Findings suggest that while it is feasible to deliver IBA in housing settings, there are similar challenges and barriers to those already identified in relation to primary care. These include issues around role inadequacy, role legitimacy and the lack of support to work with people with alcohol problems. Results indicate that the potential may lie in focusing training efforts on specific roles to deliver IBA rather than it being expected of all staff

Implementation of the Licensing Act 2003: a national survey

The Licensing Act 2003 came into force in November 2005 and transferred responsibility for alcohol licensing to Local Authorities. This reports the findings of a nation wide survey of 225 (63%) local authority chairs of licensing committees/senior members of licensing teams in England evaluating the short-term impact of the Act

Design of linear and nonlinear control systems via state variable feedback, with applications in nuclear reactor control

Linear and nonlinear control systems via state variable feedback with applications in nuclear reactor contro

Thermal design for areas of interference heating on actively cooled hypersonic aircraft

Numerous actively cooled panel design alternatives for application in regions on high speed aircraft that are subject to interference heating effects were studied. Candidate design concepts were evaluated using mass, producibility, reliability and inspectability/maintainability as figures of merit. Three design approaches were identified as superior within certain regimes of the matrix of design heating conditions considered. Only minor modifications to basic actively cooled panel design are required to withstand minor interference heating effects. Designs incorporating internally finned coolant tubes to augment heat transfer are recommended for moderate design heating conditions. At severe heating conditions, an insulated panel concept is required

Alcohol harm reduction in Europe.

This chapter provides an overview of harm reduction approaches to alcohol in Europe. First, definitions ascribed to alcohol harm reduction are outlined. Then, evaluated alcohol harm reduction interventions in European countries are described and the evidence for their effectiveness examined. These include multi-component programmes, improvements to the drinking environment, and initiatives to reduce the harms associated with drink-driving. Third, harm reduction activities that have been recorded and described but not yet evaluated are briefly outlined. These include ‘grassroots’ initiatives and more formal local initiatives. To conclude, the chapter raises questions about how alcohol harm reduction is defined and put into practice, the evidence-base that is available for policymakers, and how information is shared. It highlights the need to develop systems to facilitate knowledge transfer on alcohol harm reduction between researchers, policymakers and practitioners in Europe but stresses the importance of respecting local and cultural diversity in the development and implementation of harm reduction initiatives

Direct Statistical Simulation of Jets and Vortices in 2D Flows

In this paper we perform Direct Statistical Simulations of a model of two-dimensional flow that exhibits a transition from jets to vortices. The model employs two-scale Kolmogorov forcing, with energy injected directly into the zonal mean of the flow. We compare these results with those from Direct Numerical Simulations. For square domains the solution takes the form of jets, but as the aspect ratio is increased a transition to isolated coherent vortices is found. We find that a truncation at second order in the equal-time but nonlocal cumulants that employs zonal averaging (zonal CE2) is capable of capturing the form of the jets for a range of Reynolds numbers as well as the transition to the vortex state, but, unsurprisingly, is unable to reproduce the correlations found for the fully nonlinear (non-zonally symmetric) vortex state. This result continues the program of promising advances in statistical theories of turbulence championed by Kraichnan