Aerodynamics of an Aerofoil in Transonic Ground Effect: Numerical Study at Full-scale Reynolds Numbers

The potential positive effects of ground proximity on the aerodynamic performance of a wing or aerofoil have long been established, but at transonic speeds the formation of shock waves between the body and the ground plane would have significant consequences. A numerical study of the aerodynamics of an RAE2822 aerofoil section in ground effect flight was conducted at freestream Mach numbers from 0·5 to 0·9, at a range of ground clearances and angles of incidence. It was found that in general the aerofoil\u27s lifting capability was still improved with decreasing ground clearance up until the point at which a lower surface shock wave formed (most commonly at the lowest clearances). The critical Mach number for the section was reached considerably earlier in ground effect than it would be in freest ream, and the buffet boundary was therefore also reached at an earlier stage. The flowfields observed were relatively sensitive to changes in any given variable, and the lower surface shock had a destabilizing effect on the pitching characteristics of the wing, indicating that sudden changes in both altii11de and attitude would be experienced during sustained transonic flight close to the ground plane. Since ground proximity hastens the lower surface shock formation, no gain in aerodynamic efficiency can be gained by flying in ground effect once that shock is present

How can firms in the UK be encouraged to create more value? A discussion and review paper

This paper investigates how firms in the UK might be encouraged to create more value through strategic innovation. Our approach is an integrative one, drawing on both the extant literature - covering the value chain, innovation and the low skill/low quality equilibrium debate - and the two systematic reviews completed by the AIM Scholars - covering promising practices and networks. In the paper we argue that there are three basic strategies that firms can adopt to create more value through strategic innovation: Increasing efficiency and effectiveness through the adoption of better practices; Innovating to produce products or services that generate more revenue — through either higher prices or larger volumes — but realised while remaining at the same position in the value chain. Fundamentally changing position in the value chain and moving to a position where the products and services that are being delivered inherently generate more value. We contend that increased value is likely to be created if firms adopt one or more of these three strategies. However, adoption is likely to represent significant challenges to management. Such challenges are linked to the levels of firm competency and their ability to construct, acquire and communicate knowledge during the innovation and subsequent implementation process. Addressing these challenges form the basis of our policy and research implications

Soft X-ray harmonic comb from relativistic electron spikes

We demonstrate a new high-order harmonic generation mechanism reaching the `water window' spectral region in experiments with multi-terawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving uJ/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a cavity and bow wave created by a relativistically self-focusing laser in underdense plasma. The spike sharpness and stability are explained by catastrophe theory. The mechanism is corroborated by particle-in-cell simulations

Measuring Servitization Progress and Outcome:The Case of ‘Advanced Services’

The purpose of this paper is to establish a framework for assessing the progress and outcome of a manufacturer’s transformation towards becoming a provider of ‘advanced services’ – a complex bundling of products and services, whereby manufacturers offer capabilities and outcomes instead of products alone. ‘Advanced services’ represent the most complex offering in the current servitization trend among manufacturers. However, current performance measures lack the breadth and focus to assess progress or outcomes, and so support research and practice of organisational transformation efforts required. To address this gap the paper investigates how a manufacturer’s efforts to become an ‘advanced services’ provider can be comprehensively measured, and develops a framework for assessing the transformation journey towards becoming an ‘advanced services’ provider. The research method is based on (1) a systematic literature review process to create a comprehensive set of service-related performance measures that are available to assess a manufacturer’s servitization efforts, followed by (2) an engagement with an expert panel to synthesise the identified measures and create a set of ‘advanced services’ performance measures. The proposed framework is presented as a scorecard that can be used in practice to assess the progress and outcome of a manufacturer’s transformation towards becoming a provider of ‘advanced services’

Miscellaneous Fish Helminth Parasite (Trematoda, Cestoidea, Nematoda, Acanthocephala) Records from Arkansas

Between June 2012 and January 2014, 147 fishes (10 species) within five families were collected from watersheds in 8 counties of Arkansas and examined for helminth parasites. Almost every fish species examined harbored at least one or more helminth parasite, including 5 trematodes (Alloglossidium sp., Plagioporus sp., Crepidostomum sp., Clinostomum marginatum and unknown metacercaria), 2 cestodes (unknown cyclophyllidean cysticerci and Corallotaenia parva), 3 nematodes (Spiroxys sp., Capillaria catostomi, and Eustrongylides sp.), and 3 acanthocephalans (unknown cystacanths, Neoechinorhynchus sp., and Leptorhynchoides sp.). We document 16 new host and 2 new distributional records for these helminths. In addition, this is the first time any helminth has been reported from the Blackspot Shiner, Notropis atrocaudalis and Caddo Madtom, Noturus taylori