D. Butler, P. Jowitt, R. Ashley, D. Blackwood, J. Davies, C. Oltean‐Dumbrava, G. McIlkenny, T. Foxon, D. Gilmour, H. Smith, S. Cavill, M. Leach, P. Pearson, H. Gouda, W. Samson, N. Souter, S. Hendry, J. Moir and F. Bouchart
In industrialised countries water service providers (WSPs) must provide an appropriate level of service with an acceptable performance at an acceptable cost to customers. In the…
Abstract
In industrialised countries water service providers (WSPs) must provide an appropriate level of service with an acceptable performance at an acceptable cost to customers. In the UK a move towards sustainable development is now also a major goal for WSPs. However, the imposition of institutional systems and regulatory targets still encourage the adoption of less sustainable technologies or solutions by the water industry. It is within this context, that the Sustainable Water industry Asset Resource Decisions (SWARD) project has developed a set of decision support processes that allow WSPs to assess the relative sustainability of water/wastewater system asset development decisions. A Guidebook has been produced that takes the WSP and its stakeholders through the processes essential to incorporating sustainability in asset investment decision‐making. Several case studies that demonstrate the SWARD principles in application are included within the Guidebook, the experience of which is described in this paper.
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The Basic Design Philosophy as it Applies to all Load‐Carrying Elements including a Description of Fuel Tank Design, Flap Structure and Floor Layout. FROM the structural viewpoint…
Abstract
The Basic Design Philosophy as it Applies to all Load‐Carrying Elements including a Description of Fuel Tank Design, Flap Structure and Floor Layout. FROM the structural viewpoint the aircraft had to suit the needs of the small or medium‐sized airline having difficult operating conditions. Structural integrity would have to be maintained with limited servicing facilities and the aircraft must be capable of operating in remote areas from rough airstrips. Therefore, this meant that the aircraft had to have a high degree of reliability and serviceability, be of rugged construction with a long fatigue life, be designed for easy maintenance on a scheduled inspection basis, and have quick turn round times using the minimum of staff and facilities.
Ronald L. Simons, Steven R.H. Beach and Ashley B. Barr
Purpose – The goal of this chapter is to demonstrate the importance of incorporating gene by environment (G×E) interactions into behavioral science theory and…
Abstract
Purpose – The goal of this chapter is to demonstrate the importance of incorporating gene by environment (G×E) interactions into behavioral science theory and research.
Design/methodology/approach – We critique behavioral genetics, discuss the emergence of epigenetics, review findings on G×E effects, and present the differential susceptibility model of gene–environment interplay.
Findings – The studies reviewed demonstrate that genetic variation often interacts with environmental context to influence the probability of various behaviors. Importantly, in many, and perhaps most, of the studies reviewed, the genetic variable, unlike the environmental variable, has little if any main effect on the outcome of interest. Rather, the influence of the genetic variable is limited to its moderation of the effect of the environmental construct.
Research limitations/implications – Molecular G×E research does not undermine the importance of environmental factors; rather it shows how social scientific explanations of human behavior might be made more precise by incorporating genetic information. This suggests expanded research opportunities for those interested in social causation.
Social implications – This model of molecular G×E research presented suggests that a substantial proportion of the population is genetically predisposed to be more susceptible than others to environmental influence. We argue that this model of G×E is particularly relevant to sociologists and psychologists and has the potential to enhance the development of theory in both areas.
Originality/value – This chapter will be of particular interest to sociologists and psychologists who have found the behavioral genetic paradigm off-putting because of its emphasis on genetic main effects and genetic determinism. The current chapter offers an alternative model that may better capture the available data and better integrate social processes with genetic and biological processes.
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FOR the last twenty years aircraft manufacturers throughout the world have been preoccupied with one specific object—the design and development of a successful replacement for the…
Abstract
FOR the last twenty years aircraft manufacturers throughout the world have been preoccupied with one specific object—the design and development of a successful replacement for the Douglas DC.3/Dakota. Well over twenty different aircraft have been designed with the primary aim of fulfilling this requirement and although one or two types have achieved sales success to the tune of orders for more than a hundred aircraft, it can be argued that these types are not true DC.3 replacements at all but highly sophisticated short‐haul airliners primarily intended for operation on comparatively high‐density routes between city airfields possessing long concrete runways.
The analysis of the wing/fuselage and fuselage/tail unit interaction forces is extended to cover the case when the attached component is more conveniently analysed by the Matrix…
Abstract
The analysis of the wing/fuselage and fuselage/tail unit interaction forces is extended to cover the case when the attached component is more conveniently analysed by the Matrix Displacement Method. The flexibility matrix of the complete aircraft, supported on the wing/fuselage attachment points, follows from the results derived in this and previous sections and takes into account the elastic interaction between the various components. The dynamical matrix of the complete free aircraft is set up and for completeness the theory and properties of the normal modes of vibration are given. A final sub‐section discusses some points of detail in the mass distribution and the definition of the forces on the aircraft.
THE power plant for the Concord supersonic transport has evolved from an optimization study which showed that a medium‐pressure ratio turbojet would be the best compromise for a…
Abstract
THE power plant for the Concord supersonic transport has evolved from an optimization study which showed that a medium‐pressure ratio turbojet would be the best compromise for a transatlantic M=2•2 civil aircraft. The detail design of the engine intake and nozzle systems is currently proceeding in the Design Offices of British Aircraft Corporation and Bristol Siddeley Engines in England and S.N.E.C.M.A. in France.
A LARGE class of aircraft and missile structural vibration problems, and also dynamics problems associated with missile test stands and launch equipment, may be represented…
Abstract
A LARGE class of aircraft and missile structural vibration problems, and also dynamics problems associated with missile test stands and launch equipment, may be represented ideally by masses inter‐connected by extensional and rotational springs. Generally the spring constants, which represent stiffnesses of structural sections, may be determined analytically; however, experiments are sometimes necessary to determine the magnitude of the spring constants when boundary conditions or end restraints of members are neither pinned nor clamped. In some problems one may measure frequencies, without damaging the structure, and work backwards to determine equivalent spring constants which then may be used in solving static problems.
Levent Ünlüsoy and Yavuz Yaman
The purpose of this paper is to analyse the effects of morphing on the aeroelastic behaviour of unmanned aerial vehicle (UAV) wings to make an emphasis on the required aeroelastic…
Abstract
Purpose
The purpose of this paper is to analyse the effects of morphing on the aeroelastic behaviour of unmanned aerial vehicle (UAV) wings to make an emphasis on the required aeroelastic tailoring starting from the conceptual design of the morphing mechanisms.
Design/methodology/approach
In this study, flutter and divergence characteristics of a fully morphing wing design were discussed to show the dilapidating effect of morphing on the related parameters. The morphing wings were intended to achieve a high efficiency at different flight phases; thus, various morphing concepts were integrated into a UAV wing structure. Although it is considered beneficial to have the morphing capabilities to avoid the failure due to a possible wear out in flutter and divergence parameters; it is necessary to include the aeroelastic analyses at the early design phases. This study utilizes a combination of a reduced order structural model and Theodorsen unsteady aerodynamic model as primary analyses tools for flutter and divergence. The analyses were conducted by using an in-house developed pk-algorithm coupled with a commercial finite element analysis (FEA) tool. This approach yielded a fast solution capacity because of the state-space form used.
Findings
Analyses conducted showed that transition between take-off, climb, cruise and loiter phases yield a change in the flutter and divergence speeds as high as 138 and 305 per cent, respectively.
Practical implications
The research showed that an extensive aeroelastic investigation was required for morphing wing designs to achieve a failure safe design.
Originality/value
The research intends to highlight the possible deteriorating effects on structural design of morphing UAV wings by focusing on the aeroelastic characteristics. In addition to that, fundamental morphing concepts are compared in terms of the order of magnitude of their deteriorating effects.
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A.F. Newell and D. Howe
MUCH has been written about possible developments in the next decade, but any forecasting must of necessity be conjectural. As far as the next generation of military aircraft is…
Abstract
MUCH has been written about possible developments in the next decade, but any forecasting must of necessity be conjectural. As far as the next generation of military aircraft is concerned the situation is very obscure, except for the fact that it is known that fewer types will be required. Developments in the civil field are rather easier to foresee, these being based on the anticipated travelling habits of the world's population.
The use in aircraft construction of sandwich panels with balsa wood cores gives a saving in weight with very high tensile and compressive strength, which is maintained over a wide…
Abstract
The use in aircraft construction of sandwich panels with balsa wood cores gives a saving in weight with very high tensile and compressive strength, which is maintained over a wide range of temperatures and is uniform in all planar directions. The core is stable under changing temperature conditions, and absorbs little moisture through its exposed faces. Panels made with it can be produced in flat sheets and with single or double curvature, are very stiff, and have a smooth aerodynamic surface. They em be fixed by almost any of the conventional methods.