Framework for software architecture visualization assessment.

In order to assess software architecture visualisation strategies, we qualitatively characterize then construct an assessment framework with 7 key areas and 31 features. The framework is used for evaluation and comparison of various strategies from multiple stakeholder perspectives. Six existing software architecture visualisation tools and a seventh research tool were evaluated. All tools exhibited shortcomings when evaluated in the framework

Magnetohydrodynamics (MHD) Engineering Test Facility (ETF) 200 MWe power plant. Design Requirements Document (DRD)

A description and the design requirements for the 200 MWe (nominal) net output MHD Engineering Test Facility (ETF) Conceptual Design, are presented. Performance requirements for the plant are identified and process conditions are indicated at interface stations between the major systems comprising the plant. Also included are the description, functions, interfaces and requirements for each of these major systems. The lastest information (1980-1981) from the MHD technology program are integrated with elements of a conventional steam electric power generating plant

Electron Power-Law Spectra in Solar and Space Plasmas

Particles are accelerated to very high, non-thermal energies in solar and space plasma environments. While energy spectra of accelerated electrons often exhibit a power law, it remains unclear how electrons are accelerated to high energies and what processes determine the power-law index $\delta$. Here, we review previous observations of the power-law index $\delta$ in a variety of different plasma environments with a particular focus on sub-relativistic electrons. It appears that in regions more closely related to magnetic reconnection (such as the `above-the-looptop' solar hard X-ray source and the plasma sheet in Earth's magnetotail), the spectra are typically soft ($\delta \gtrsim$ 4). This is in contrast to the typically hard spectra ($\delta \lesssim$ 4) that are observed in coincidence with shocks. The difference implies that shocks are more efficient in producing a larger non-thermal fraction of electron energies when compared to magnetic reconnection. A caveat is that during active times in Earth's magnetotail, $\delta$ values seem spatially uniform in the plasma sheet, while power-law distributions still exist even in quiet times. The role of magnetotail reconnection in the electron power-law formation could therefore be confounded with these background conditions. Because different regions have been studied with different instrumentations and methodologies, we point out a need for more systematic and coordinated studies of power-law distributions for a better understanding of possible scaling laws in particle acceleration as well as their universality.Comment: 67 pages, 15 figures; submitted to Space Science Reviews; comments welcom

The free energy balance equation applied to gyrokinetic instabilities, the effect of the charge flux constraint, and application to simplified kinetic models

The free energy balance equation for gyrokinetic fluctuations is derived and applied to instabilities. An additional term due to electromagnetic sources is included. This can provide a simpler way to compute the free energy balance in practical applications, and is also conceptually clarifying. The free energy balance, by itself, is not sufficient to determine an eigenfrequency. The preceding results are derived in general geometry. The charge flux constraint in gyrokinetics can provide a necessary additional relation, and the combination of these two can be equivalent to a dispersion relation. The charge flux constraint can prevent the appearance of an unstable eigenmode even though the free energy balance would allow strongly growing fluctuations. The application of these concepts to simplified kinetic models in simplified geometry is also indicated.Comment: 5 page

Influence of Geometry and Flow Variation on Jet Mixing and NO Formation in a Model Staged Combustor Mixer with Eight Orifices

A series of non-reacting parametric experiments was conducted to investigate the effect of geometric and flow variations on mixing of cold jets in an axis-symmetric, heated cross flow. The confined, cylindrical geometries tested represent the quick mix region of a Rich-Burn/Quick-Mix/Lean-Burn (RQL) combustor. The experiments show that orifice geometry and jet to mainstream momentum-flux ratio significantly impact the mixing characteristic of jets in a cylindrical cross stream. A computational code was used to extrapolate the results of the non-reacting experiments to reacting conditions in order to examine the nitric oxide (NO) formation potential of the configurations examined. The results show that the rate of NO formation is highest immediately downstream of the injection plane. For a given momentum-flux ratio, the orifice geometry that mixes effectively in both the immediate vicinity of the injection plane, and in the wall regions at downstream locations, has the potential to produce the lowest NO emissions. The results suggest that further study may not necessarily lead to a universal guideline for designing a low NO mixer. Instead, an assessment of each application may be required to determine the optimum combination of momentum-flux ratio and orifice geometry to minimize NO formation. Experiments at reacting conditions are needed to verify the present results

Challenges in researching migration status, health and health service use: an intersectional analysis of a South London community.

OBJECTIVES: This study aimed to investigate the associations between migration status and health-related outcomes and to examine whether and how the effect of migration status changes when it is disaggregated by length of residence, first language, reason for migration and combined with ethnicity. DESIGN: A total of 1698 adults were interviewed from 1076 randomly selected households in two South London boroughs. We described the socio-demographic and socio-economic differences between migrants and non-migrants and compared the prevalence of health-related outcomes by migration status, length of residence, first language, reason for migration and migration status within ethnic groups. Unadjusted models and models adjusted for socio-demographic and socio-economic indicators are presented. RESULTS: Migrants were disadvantaged in terms of socio-economic status but few differences were found between migrant and non-migrants regarding health or health service use indicators; migration status was associated with decreased hazardous alcohol use, functional limitations due to poor mental health and not being registered with a general practitioner. Important differences emerged when migration status was disaggregated by length of residence in the UK, first language, reason for migration and intersected with ethnicity. The association between migration status and functional limitations due to poor mental health was only seen in White migrants, migrants whose first language was not English and migrants who had moved to the UK for work or a better life or for asylum or political reasons. There was no association between migration status and self-rated health overall, but Black African migrants had decreased odds for reporting poor health compared to their non-migrant counterparts [odds ratio = 0.15 (0.05-0.48), p < 0.01]. CONCLUSIONS: Disaggregating migration status by length of residence, first language and reason for migration as well as intersecting it with ethnicity leads to better understanding of the effect migration status has on health and health service use