Performance characteristics of an isolated coannular plug nozzle at transonic speeds

The Langley 16-Foot Transonic Tunnel was used to evaluate the performance characteristics of a coannular plug nozzle at static conditions (Mach number of 0) and at Mach numbers from 0.65 to 1.20. Jet total pressure ratio was varied from 1.0 (jet off) to 10.0. Thirty-seven configurations generated by the combination of three geometric variables - plug angle, shroud boattail length (fixed exit radius), and shroud extension length - were tested

An Investigation into the Critical Factors of on-site Waste Segregation in the UK Construction and Demolition Sector.

This paper provides an in-depth exploration into critical factors affecting the use of on-site waste segregation strategies in the UK C&D market. Utilising data from two separate survey questionnaires; this study confirms usage of on-site segregation strategies by many UK contractors where physical site space and project budgets allow. However, through assessment of stakeholder perceptions, this paper also identifies several key barriers that are impeding overall effectiveness. Amongst many factors, this study indicates how issues such as poor attitude and a lack of knowledge of the benefits amongst workers, could be having a profound effect on successful adaptation of ground level recycling initiatives. This research project then finishes by ranking existent barriers by importance, with the goal of suggesting proposals for overcoming these challenges. Ultimately, weighing the critical factors and prospective barriers to on-site segregation in the UK C&D sector, this study makes recommendation of multiple incentives, but suggests that enhanced training initiatives could be a crucial element for instigating long-term industry improvement in respect of recycling and on-site waste segregation strategies

Physical soil quality indicators for monitoring British soils

The condition or quality of soils determines its ability to deliver a range of functions that support ecosystem services, human health and wellbeing. The increasing policy imperative to implement successful soil monitoring programmes has resulted in the demand for reliable soil quality indicators (SQIs) for physical, biological and chemical soil properties. The selection of these indicators needs to ensure that they are sensitive and responsive to pressure and change e.g. they change across space and time in relation to natural perturbations and land management practices. Using a logical sieve approach based on key policy-related soil functions, this research assessed whether physical soil properties can be used to indicate the quality of British soils in terms of its capacity to deliver ecosystem goods and services. The resultant prioritised list of physical SQIs were tested for robustness, spatial and temporal variability and expected rate of change using statistical analysis and modelling. Six SQIs were prioritised; packing density, soil water retention characteristics, aggregate stability, rate of erosion, depth of soil and soil sealing. These all have direct relevance to current and likely future soil and environmental policy and are appropriate for implementation in soil monitoring programs

Adaptive Engine Technologies for Aviation CO2 Emissions Reduction

Adaptive turbine engine technologies are assessed for their potential to reduce carbon dioxide emissions from commercial air transports.Technologies including inlet, fan, and compressor flow control, compressor stall control, blade clearance control, combustion control, active bearings and enabling technologies such as active materials and wireless sensors are discussed. The method of systems assessment is described, including strengths and weaknesses of the approach. Performance benefit estimates are presented for each technology, with a summary of potential emissions reduction possible from the development of new, adaptively controlled engine components

Combustion waves in a model with chain branching reaction and their stability

In this paper the travelling wave solutions in the adiabatic model with two-step chain branching reaction mechanism are investigated both numerically and analytically in the limit of equal diffusivity of reactant, radicals and heat. The properties of these solutions and their stability are investigated in detail. The behaviour of combustion waves are demonstrated to have similarities with the properties of nonadiabatic one-step combustion waves in that there is a residual amount of fuel left behind the travelling waves and the solutions can exhibit extinction. The difference between the nonadiabatic one-step and adiabatic two-step models is found in the behaviour of the combustion waves near the extinction condition. It is shown that the flame velocity drops down to zero and a standing combustion wave is formed as the extinction condition is reached. Prospects of further work are also discussed.Comment: pages 32, figures 2

Humanism and the Ideology of Work

This thesis argues that humanism, despite being subject to a sustained critique within the social sciences over the past fifty years or more, continues to limit the critical and explanatory power of the sociology of work, preventing a fuller understanding of the nature of work under contemporary capitalism. Developing Louis Althusser’s (1996) critique of humanism and ideology, humanism is shown to be an ideological problem for the sociology of work insofar as it brackets, obfuscates or mystifies key social relations of work and, by extension, the class struggles reflected in those relations. Humanism presents a persistent and pervasive problem for the sociology of work, as both an explanatory and critical framework. Because of the persistence of humanism in the sociology of work, the problems of contemporary work – and the proposed ‘solutions’ to these problems – are located not in an analysis of the social relations of these realities, but in ideological discourses of human alienation and human self-affirmation. The thesis explores the extent of this ideological problem across three contemporary debates within the sociology of work: ‘postcapitalist’ discourse (Srnicek & Williams, 2015) and the emergence of a contemporary post-work imaginary; feminist discourses on the ‘bioeconomy’ (Cooper & Waldby, 2014) and theories of social reproduction in the context of sex work, tissue donation and surrogacy; and the figuration of labour and work within contemporary social scientific discourses of the ‘Anthropocene’ (Bonneuil & Fressoz, 2016). In each of these areas, the thesis demonstrates how much of the sociology of work continues to rely on humanistic ideas to provide a normative theoretical foundation and a critical edge. If the sociology of work is to provide a genuinely critical orientation for understanding the changing world of work, this thesis argues, then the critique of humanism remains a central task