bluuebunny/crossref_metadata_2025 huggingface dataset:
The Developing Scene in British Light Aviation
Authors: Stinton D.
Published: July 2022

I am delighted as a test pilot, to have been asked to talk to the Test Pilots’ Group on the subject of light aviation. Originally I was asked to talk about the design of homebuilt aircraft; but, since, leaving the Service and joining the Air Registration Board, to look after all aeroplanes weighing less than 6000 lb, it seems appropriate to take a look at a wider field at this time, without focusing on any specific class of light aircraft.
The Stability of a Wind Tunnel Model on Flexible Supports
Authors: Molyneux W. G.
Published: July 2022

A convenient aid to the investigation of the aeroelastic properties of aircraft is provided by wind tunnel tests on scale representative aeroelastic models. A wide variety of tests is commonly made ranging from tests on models of component parts of an aircraft (wing, tailplane, fin, etc.) to tests on models of the whole aircraft. In many of these tests it is adequate to mount the model structure rigidly to the tunnel wall or sting, but in other cases the model must be provided with rigid body freedoms for representative results to be obtained. This is generally necessary for aeroelastic models of complete aircraft, and particularly for models of slender configuration.
Vibration Testing in Helicopters—A Practical Aspect
Authors: Jackson C. E. P.
Published: July 2022

The fundamental mechanics of the helicopter involving a number of rotating components make the machine subject to vibration. The prime source of excitation is the main rotor and at the design stage of a new helicopter detailed consideration should be given to the level of forcing produced at the hub. Up to the present time, designers using sophisticated mathematical models have not been completely successful in predicting, for a complicated airframe, the vibratory response to this forcing.
Vibration Testing of Helicopters
Authors: Balmford D. E. H.
Published: July 2022

The purpose of my contribution is to explain the need for dynamic testing in terms of defining the design problems where testing is required to assist or substantiate decisions made in the light of mainly theoretical evidence in the initial stages of design before hardware becomes available for testing.

I have interpreted the title in the broadest sense of the word vibration so as not to restrict the presentation only to testing associated with assessing or minimising the vibration of helicopters, but to include problem areas which result in dynamic testing requirements.
Flutter of Skew Panels by the Matrix Displacement Approach
Authors: Kariappa V. , Somashekar B. R.
Published: July 2022

In spite of the large number of published works on panel flutter there appears to be a wide gap in the literature concerning the flutter of skew panels. For instance, recently the flutter behaviour of skew panels in supersonic flow has been presented for a simply-supported boundary condition using double Fourier sine series to represent the deflection surface. Apart from this publication there is practically no literature concerning flutter of skew panels except refs. 3-4 which consider the flutter of skew panels clamped on all the edges. The method used in ref. 3 is the common 4-mode analysis by using the Iguchi functions for representing the deflections and in ref. 4 the same problem is solved by the use of beam characteristic functions. One inherent difficulty in these conventional methods, was that no single function could be chosen to represent the deformation which satisfied various boundary conditions, with the result that the entire analysis may have to be repeated with different assumed functions for accommodating different boundary conditions. Hence, a general method was proposed in ref. 5 for the study of panel flutter problems of arbitrary geometry by the Matrix Displacement Method, which permits application to problems with practically any geometrical boundary conditions on any or all the sides.
Passenger Seaplanes and Their Bases
Authors: Bell R. A.
Published: July 2022

The history of the seaplane is almost as old as flying itself, dating back to man-carrying Box Kites only two years after the Wright brothers memorable flight at Kittyhawk.

The First World War greatly increased the pace of development, which continued to its peak just before the Second World War, when the flying boat became a mainspring in the opening of routes to the Empire. During the Second World War seaplanes played a major part in the Allied war“* effort but decline was already evident, and increased during the early post-war years.

The relative numbers of landplanes and seaplanes used by one principal carrier are shown on Fig. 1, which indicates the rise and fall of the popularity of the seaplane passenger aircraft relative to other aircraft. This paper attempts to analyse the seaplane's virtues and drawbacks, reviews its past and attempts to anticipate its future. The problems and characteristics of the seaplane base are also examined together with some past solutions.
An Extension of the Validity of Beam Theory Beyond its Classical Bounds
Authors: van der Neut A.
Published: July 2022

The elementary beam theory for shell structures yields the exact solution for normal and shear stress, if the three following conditions are fulfilled:

(a)

the shell must be prismatic;

(b)

the cross section must not deform in its plane;

(c)

the centres of rotation of the different cross sections must form an axis of rotation parallel to the longitudinal axis of the beam.
Russian Helicopters
Authors: Free F. W.
Published: July 2022

During the past decade we have seen many notable achievements in aviation by Russian scientists, engineers and technicians. The first man in space, the first supersonic air liner, and the rapid growth of Aeroflot are but three of their more prominent successes.

In a rather less spectacular manner, the Russians have developed a very powerful helicopter industry and it is probably correct to say that no other country in the world has utilised the helicopter so extensively on such a wide variety of uses as have the Russians.

In this lecture, I will endeavour to briefly trace out the historical development of the helicopter in Russia and to review some of the current types in service.
Accident and Maintenance Recording for Civil Aircraft
Authors: Matthews N. O.
Published: July 2022

The recording of aircraft operational data in service has long been considered to be a desirable addition to the data available to an airline. A limited amount of this information has always been provided by the pilot's log, but the capability of recording this data automatically has been delayed until recent years by the lack of recording systems which were both reliable and yet not too costly to the airline's overheads. The availability of possible systems in the immediate post-war years led to attempts to introduce governmental regulations covering the provision of such systems, but it was not until 1958 that the design of reliable airborne systems led to the introduction by the CAB of the first American regulations for this type of equipment. These American regulations were followed by other countries, notably France, Australia and the UK. The mandatory use of aircraft flight recorders derived from government requirements to record a limited number of flight parameters to assist in the evaluation of aircraft accidents.
Secondary Gas Injection into Rocket Nozzles through Ports Mutually at Right Angles
Authors: Neilson J. H. , Gilchrist A. , Lee C. K.
Published: July 2022

The side force produced by gas injection through a single port into the supersonic regime of a rocket nozzle is composed of the natural reaction of the fluid leaving the port and the force due to pressure fields set up within the nozzle by the interaction of the secondary and primary flows. The obstruction presented to the main flow by the entering secondary fluid produces a shock system originating from the vicinity of the injection port. The pitch and yaw of a rocket can be controlled by simultaneous secondary gas injection from two ports mutually at right angles. With two ports operating, the respective shock wave systems produced can interact and hence cause an alteration of the side forces which would be produced if the ports were operating independently.
Serendipity
Authors: Russell A. E.
Published: July 2022

An historical survey gives an opportunity to reflect on a few selected episodes which seem to have had a significant influence on shaping later events. I need not remind you that reflections on aircraft mostly having two-dimensional curvature with surface finish falling short of mirror standards, and not only is the image probably distorted but also the perspective depends very much on where the observer stands. Moreover, also, quite important objects can be thrown right out of vision.
The Analysis of Cooling Towers by the Matrix Finite Element Method
Authors: Chan A. S. L. , Firmin A.
Published: July 2022

As a necessary first step towards the large displacement analysis of the cooling tower structure by the finite element method, an account of the small displacement theory of the SABA family of elements has been given in the first part of the paper. It may be worth repeating the basic considerations which influenced the philosophy in the design of the element: for an economical large displacement analysis to be successful it is essential that the structure should be represented by as few displacement parameters as possible, consistent with an accurate description of the structural behaviour. The SABA element is an axi-symmetrical thin shell element which describes the displacement variation in the circumferential direction by a Fourier series, each term of which is associated with a polynomial for interpolation in the meridional direction. By the devise of interpolating the meridional geometry in the same way, no strain is induced in a rigid-body movement, thus achieving true equilibrium and avoiding serious error in a large displacement calculation. Results of the small displacement analysis by this element for various examples given in Part I agreed accurately with existing solutions by other methods.
Structural Testing, Testing Philosophy and Loads Prediction for Rotary Wing Vehicle Components
Authors: Cowgill Lee C.
Published: July 2022

The high cost of new weapon systems and the loss of tactical capability when vehicles are out of operation for unscheduled repairs are forcing the military services to require a higher order of structural reliability. Fleets are being kept in operation for many years beyond the time originally anticipated during design, resulting in many cases, in the need for costly structural repairs and modification to cure fatigue problems. Consequently, new weapon system procurement contracts are being written with a “fatigue-life” guarantee as a contractual requirement. This situation calls for careful attention to details during the design phase. More testing, both exploratory to aid in detail design decisions, and confirmatory to validate the design and demonstrate compliance with the contractual requirements, is required. Better test methods and more meaningful test results are demanded from the test laboratory. Methods for more accurate predictions of the loads experience during the entire service usage are required of the structural analysts.
Aerodynamic Characteristics of Thick Sharp Edged Cropped Delta and Gothic Wings giving Low Lift-Dependent Drag
Authors: Shaw G. W.
Published: July 2022

For some years now an increasing amount of experimental and theoretical work has been done to obtain a deeper understanding of separated vortex flow associated with slender wings. Most of it has been concerned with flat plates or thin wings.

Slender thin wings with leading-edge separation have high lift-dependent or vortex drags, and lift-dependent drag factors are usually well above unity. Thick symmetrical wings also have high values of lift-dependent drag factor. On a slender wing with leading edge separation, no leading edge thrust is obtained but by suitable! addition of thickness, the high suction peak underneath the main vortex can be made to act on a forward facing surface to give a reduction in drag.
Development of the Bendix/Air Equipment RDR-IDM Radar as an Approach Aid for Helicopters
Authors: Van Der Harten R. J.
Published: July 2022

KLM Noordzee Helikopters exists primarily to serve North Sea oil rigs. The service is available on a 24-hr basis without restrictions. The main base of the company is situated at Schiphol Airport.

In the Netherlands helicopters are not permitted to fly VMC at night, while VMC at day is often not possible because the cloudbase over land, except for a few low flying routes, has to be over 1000 ft.

So our company was from the start of operations committed to instrument flying with helicopters as the weather in the Netherlands is usually very bad in the wintertime, which lasts for 6-8 months.
Stability and control of STOVL aircraft: The design of longitudinal flight control laws
Authors: Fielding C. , Lodge M.
Published: July 2022

Over the past three decades, the UK aerospace industry has carried out significant research into the development of short take-off and vertical landing (STOVL) technology, to enhance the performance and operation of the Harrier aircraft, and for possible application to future aircraft such as those being developed under the Joint Strike Fighter (JSF) programme. Some of this research has focused on aircraft handling and flight control for the transition between wing-borne and jet-borne flight. Following on from internal research at British Aircraft Corporation/British Aerospace (now part of BAE Systems) in the mid to late 1970s, further development work has been carried out in the 1980s and 90s in support of the UK’s Vectored thrust Advanced Aircraft flight Control (VAAC) Harrier and Integrated Flight and Propulsion Control System (IFPCS) programmes. This paper contains a short review of STOVL aircraft longitudinal flight control law design, and how basic feedback control schemes can be used to influence the aircraft’s response and hence its handling qualities.
The use of fuzzy logic in adaptive flight control systems
Authors: Mengali G.
Published: July 2022

A two step procedure is proposed for the design of nonlinear aircraft control systems. A classical design is first denned, based on a linearised aircraft model, and easily optimised by means of standard approaches. An outer-loop nonlinear controller is then used to enhance the whole control system. This latter controller is based on fuzzy logic rules and is of fixed structure. Its behaviour is based on the choice of a set of parameters that may be tuned by means a genetic algorithm based routine. The whole methodology is simple to handle and may be effectively used to give quick and efficient responses to the designer. The procedure has been verified with a couple of examples: the obtained results clearly show important improvements with respect to a classical methodology.
The future of defence and aerospace research: a view from the front
Authors: Green J. E.
Published: July 2022

This paper considers defence and aerospace research in the UK from the perspective of a research worker. The distinction between research, technology demonstration and development, the particular characteristics of research and the qualities required in a research worker are discussed. The important influence of the research environment, both within an organisation and nationally, is highlighted. The contribution of the past environment to the research underlying the present strength of UK technology, and subsequent adverse changes in the environment, are noted. The decline of UK research funding and of the UK research base is contrasted with the situation of our main industrial competitors. Finally, the author lists the actions which he believes are needed to rebuild research to a level which will underwrite the long-term future of UK defence and aerospace.
Space
Authors: Gibson R.
Published: July 2022

The turn of the century produced the expected crop of articles listing space achievements over the past 30-40 years. Many of them, particularly those connected with the Moon landing, made the front pages of newspapers all over the world, and are still regularly served up in television programmes. Nevertheless, they constitute an inadequate basis on which to make an assessment as to where — if the expression can be permitted — we now stand in space. It is no longer sufficient to look at progress in the individual space segments: satellites, launchers and the often neglected ground segment. The springs of action are now to be found elsewhere: the uptake of space applications by the end-users (most of whom have no knowledge of, or interest in, space); the increasing role of the private sector in financing space systems; the inter-twining of the civilian and defence programmes; political and international trade considerations, etc. This.article is an attempt to review progress against the background of these external factors and to present a balance sheet. In order to leave posterity with further palpable proof of the author's fallability, the article will close with a few thoughts on future trends and technological developments.

Although small in comparison with some other global activites, civil and military space operations account for about $50bn annually. Of this, slightly less than 10% can be identified as European, compared to just over 50% for the United States. This volume has been stable for several years and promises to continue at least for the near future, although the distribution between the various sectors is changing. Space is therefore an activity of considerable importance to public and private sectors alike, even though it has lost its high place on the political agendas of many countries.
Low speed control of a second generation supersonic transport aircraft using integrated thrust vectoring
Authors: Steer A. J.
Published: July 2022

Various control options, using both conventional and novel control motivators, may be available to the designer of a second-generation supersonic commercial transport (SCT) aircraft. A number of tradeoff studies using conventional control surfaces have already been addressed and, more specifically, the low-speed performance benefits deriving from a second pitch control surface quantified. However, a combination of limited rudder control power together with the continuing need to improve overall aircraft performance through reduced fin and control surface sizing has resulted in this assessment of alternative methods of control power generation. Specifically, using the foreplane asymmetrically to generate yawing moments for directional control and deflecting the engine exhaust nozzles for thrust vector control (TVC) about all three rotational axes. At low-speed the effectiveness of TVC will be enhanced due to the high engine thrust required by an SST to overcome the large lift-induced drag generated at approach angles of attack where, conversely aerodynamic control power will be at a minimum due to low dynamic pressure.

This paper begins with a statement of the technical background to the work together with an overview of TVC and its current applications. This is followed by a description of the aerodynamic mathematical model, thrust vector control implementation and the accompanying flight control system. A comparison of aerodynamic and thrust vector control at low speed is then made using established manoeuvres about all three rotational axes. Aircraft speed, take-off performance and the effect of fin area reduction are also addressed. Finally, the major results are summarised and conclusions drawn on a selection of control options and the associated implementation issues. It should be noted that issues relating to high speed and supersonic cruise are not specifically addressed nor are the implications of engine failure conditions.
Exact modal analysis of an idealised whole aircraft using symbolic computation
Authors: Banerjee J. R.
Published: July 2022

Exact expressions for the frequency equations and mode shapes of an idealised whole aircraft are derived using the symbolic computation package REDUCE. The aircraft is idealised as a bending-torsion coupled beam for the wing with the associated mass and inertia of the fuselage, tail-plane, fin and rudder assembly being concentrated at the root. The governing differential equation of motion of the aircraft is then solved in its most general form. The analysis is split into symmetric and anti-symmetric cases to formulate the equations from which the natural frequencies and the corresponding mode shapes of the unrestrained aircraft are derived. The analytical approach used here is of great significance, particularly from an aeroelastic optimization point of view, for which repetitive calculations of natural frequencies and mode shapes are often required. The application of the theory is demonstrated by numerical results. These results have been compared with those obtained from the dynamic stiffness and finite element methods.
Airline emissions of carbon dioxide – The opportunity for voluntary agreement
Authors:   Greener by Design Group
Published: July 2022

This paper reviews some of the options for limiting emissions from aircraft engine exhausts. Its main purpose however, is, to investigate the possibility of a Government-airline partnership and to this end, the issues are reviewed along with a summary of the possible approaches that have been identified to date.
Aerospace and the environment what contribution can aerodynamics make?
Authors: Poll D. I. A.
Published: July 2022

For the past 50 years civil air transport has been dominated by the combination of the gas turbine and the B-47 airframe configuration. Both these machines owed their creation to WW2 and both represented revolutionary concepts at the time. Oyer the years, the engine and the airframe have undergone considerable detailed refinement. The changes have resulted in very impressive improvements in performance. However, it is now very clear that both are close to some well defined asymptotic limits that bound their performance. The result is that further potential improvements are smaller in percentage terms, become harder to achieve technically and, consequently, come at increasingly higher cost.

A hugely successful global industry has developed around this standard configuration. Increasingly, more and more companies use aircraft and, as their businesses grow, the demand for aircraft and air transport increases. However, the ability of the environment to absorb this growth is beginning to be questioned and new ideas are required if aviation is to be regarded as an unbounded and a truly sustainable activity.
International collaboration in super/hypersonic propulsion system research project (HYPR)
Authors: Ito M.
Published: July 2022

A ten-year engineering research project on a super/hypersonic transport propulsion system (HYPR) initiated by AIST (Agency of Industrial Science and Technology) in 1989 has been successfully completed. The HYPR project was aimed at establishing the technology base for a propulsion system of supersonic/hypersonic transport (SST/HST) aircraft that will fly as fast as Mach 5. The project proved the feasibility of a combined cycle engine (CCE) for SST/HST by developing and running the world's first CCE , a combination of a variable cycle turbofan engine (VCE) and a methane-fuelled ramjet. The development of the CCE began with a variety of component tests, followed by the development of the high temperature core engine (HTCE) and VCE. This step-by-step approach led to steady and solid success.

Based on this success, a new project was started in 1999, titled "Research and development of environmentally compatible propulsion system for next generation supersonic transport (ESPR)."

This paper introduces the various achievements during the ten years of the HYPR project, and the prospects of the upcoming ESPR project.
Micro adaptive flow control
Authors: Wlezien R.
Published: July 2022

The Defense Advanced Research Projects Agency (DARPA) Micro Adaptive Flow Control programme is described using a series of illustrative examples. Adaptive flow control is defined to be the active modification of aerodynamic flows using small, time-dependent actuators in judiciously chosen locations. A diverse set of large-scale applications is described, in which micro adaptive flow control has a substantial overall system benefit.
The United Kingdom's contributions to the development of aeronautics: Part 2. The development of the practical aeroplane (1900-1920)
Authors: Ackroyd J. A. D.
Published: July 2022

The first part of this survey dealt mainly with the development of the earliest ideas on air resistance and their application to flight. That part of the survey paused at the achievement of powered flight during the early years of the twentieth century. Even then, the main problem remained as that of aerodynamics, a subject only vaguely understood by those aviation pioneers endeavouring to get off the ground. For them theoretical guidelines, as yet, could offer little help. One of the earliest of those very few analytically based results to achieve general acceptance was the statement that resistance is proportional to the product of fluid density, a characteristic body area and the square of the flow's speed. This result had appeared during the seventeenth century in Newton's work and had received some experimental confirmation. Newton's concurrent ‘rare medium’ concept, viewing fluid flow as a stream of disconnected particles, gained credence at that time since its results agreed with the above resistance proportionality. Yet this concept became mistakenly applied to airflow so as to predict plate resistances proportional to the square of the sine of the plates' incidence angles, a misleading result which caused confusion for at least the next century.
Light aviation - past, present and future
Authors: Welch A. C.
Published: July 2022

To attempt to predict the future of light and sporting aviation in Britain is not possible without a study of how it has arrived at where it is today. How, in the early days, it was the enterprise of the individual enthusiast which was the driving force in all aviation progress, to the present where ‘private’ flying, in all its many forms, has been massively outgrown by commercial airline operations.

The 1903 flights of the Wrights did not appear out of the blue. They were just one more exciting happening at a time of great engineering ventures. Trains were running regularly all over Britain, the internal combustion engine was reliable enough to power private motor cars and city buses. Gliders had been successfully flown, telephones were in regular use. There were passenger ships powered by 70,000hp engines crossing the Atlantic at speeds of 25kt. The world was wide open for anything new and in 1903 aviation quickly took pride of place.

Light aviation was the name given to ‘amateur’ flying in the 1920s, to distinguish it from military and commercial aviation. It is still the valuable entry into aviation generally, as it is a relatively inexpensive way to try out new ideas. But to fulfil its potential it has to remain attractive and affordable, particularly to the young. This paper endeavours to speculate how light aviation will fare during aviation’s second century in Britain - or at least for the next 20-30 years, in an increasingly complex world in which global accessibility is commonplace.
Physical modelling of a flight control system
Authors: Sadovnychiy S.
Published: July 2022

This paper deals with the methods of physical modelling of Flight Control Systems (FCS) by means of Dynamically Similar free-flying Models (DSM) for the investigation of stability and controllability of aircraft at subsonic flight speeds. The subsonic flight regime allows us to avoid Mach number similarity considerations. The large scale of the DSM meets autosimilarity of Reynolds numbers, whilst Froude similarity is assured during the development and manufacturing of the DSM. This paper proves the presence of necessary and sufficient conditions of similarity for the FCS of an aircraft, and that of its DSM. The existence of necessary conditions have been proved both mathematically (by means of the π – Theorem from the theory of dimensions), and with equations involving physical quantities. The generalised scale coefficients for transitioning from the FCS’s aircraft gain factors, to those of the FCS of the DSM have been obtained, and it is shown that the coefficients depend only on the linear scale of the DSM.
Licensing Aspects
Authors: Martin P.
Published: July 2022

It is my intention to be severely critical of the report insofar as it concerns licensing, but I hope that what I have to say will not set the tone for this symposium! It is extremely easy to be critical of the work of others, particularly in a field in which one feels one has some experience, but I shall do my best only to offer constructive criticism.
Air Safety and Insurance
Authors: Caplan H.
Published: July 2022

The terms of reference required the Committee to take account of safety when formulating its proposals. As a starting point the Committee had the report of a Special Review (published in 1968) entitled “The Safety Performance of United Kingdom airline operators”.

With this in mind, Edwards formulated as part of the long-term objectives of civil aviation policy that safety should be “equal to the best in the world” (paragraph 1053) —but although a great deal of attention was given to air safety, the Committee admitted that it had “not felt competent to consider the technical aspects of safety in depth” (paragraph 840).
An Investigation of the Effects of Working Pressure on Aircraft Hydraulic Systems
Authors: Walsh R. H.
Published: July 2022

Hydraulic systems are used extensively in aircraft for actuating flight control and other surfaces and in retraction, steering and braking mechanisms. Their weight is of the order of 9% to 13% of the payload in present day civil aircraft and about twice these values in military aircraft. This investigation is aimed at finding whether lighter and more compact systems would result from a change of working pressure and at providing general relationships in the form of dimensionless curves to enable designers readily to optimise aircraft hydraulic systems.
Economics of Propulsion Systems for Air Transport
Authors: Huddie David
Published: July 2022

Compared with most other industries a distinguishing feature of the air transport business throughout its history has been the rapid development and replacement of its flying equipment. Aircraft have evolved to meet the needs of expanding traffic and each generation has been succeeded by different, newer and better versions. The thirties saw the appearance of the all-metal monoplane with piston engines and propellers.
The Edwards Report and Civil Aviation in the 1970s
Authors: Ellison A. P.
Published: July 2022

The Edwards Report is the first comprehensive survey of British Civil Aviation for over thirty years, and it recognises this fact by supplying detailed examination of many aspects of the industry. In this review of the report selection will be made of what appears to be the salient policies of the report and around which the other recommendations follow.

Central to the report's recommendations is the view that controlled oligopoly, in which fares are fixed by a Licensing Authority, will lead to the provision of a more desirable air service than either monopoly operation of “uncontrolled” competition in which freedom of entry and fare fixing is allowed so long as basic safety requirements are satisfied.
Elastic and Equilibrium Matrices of General Semi-Monocoque Membrane Elements
Authors: Robinson J. , Williams R. , Haggenmacher G. W.
Published: July 2022

Many structures are made up of skin material which is stiffened by reinforcing members. Configurations of this type are predominant in the aircraft industry where they are referred to as semi-monocoque structures. When analysing such structures, using finite element techniques, the reinforcing members (stringers) are lumped together to form pure axial elements and the skin is then represented by isotropic plane stress elements.
A Non-Linear Solution to a Tab-Aileron Flutter Problem
Authors: D. L. Birdsall
Published: July 2022

In a decade when aircraft design procedures involve analyses which display ever increasing accuracy to satisfy growing operational demands, it is not surprising that the boundaries of compromise rapidly converge upon the envelope of acceptability. A finished aircraft becomes the unique solution to a well-defined design problem–or what is even more frightening, it becomes a solution to a unique problem. If the problem changes after the solution has been produced… c'est la vie.
Buckling interaction in regular arrays of distorted hexagonal plates
Authors: York C. B.
Published: July 2022

Linear elastic buckling strength assessments are presented for a range of thin plate arrays with optimal strength to weight ratio configurations subject to a range of arbitrary in-plane stress states. The outcomes of the assessment are presented as design curves demonstrating relative buckling strength increases with respect to the classical square plate datum of equal mass.

A stiffness matrix method is adopted for the initial buckling strength predictions. The method is based on exact flat plate theory and assumes that the plate is continuous over supports, whereby deformations in one cell of the plate array influence the deformations in adjacent cells. The supporting webs of each cell are approximated in this study by simple rigid supports that enforce nodal lines or lines of zero out-of-plane displacement in the buckled panel, i.e. the bending and torsional stiffness provided by the supporting webs of the real structure are ignored. Selected results are validated by FEM prediction.
Dietary vitamins, carotenoids and their sources in relation to age-related macular degeneration risk in China: a population-based case–control study
Authors: Jiang Hong , Wang Lina , Li Juan , Fan Yahui , Li Zhaofang , Ma Mei , Liu Sijiao , Li Baoyu , Shi Jia , Li Chao , Mi Baibing , Chen Fangyao , Wang Duolao , Pei Cheng , Ma Le
Published: July 2022

Mechanistic studies have suggested that antioxidants have beneficial effects on age-related macular degeneration (AMD). This study aimed to investigate the association between the types and sources of dietary vitamin and carotenoid intakes and AMD risk in China. A matched case–control study of 260 AMD cases and 260 matched controls was performed. The participants were interviewed for dietary information and potential confounders, and comprehensive ophthalmic examinations were performed. Conditional logistic models were used to estimate the odds ratio (OR) and 95 % confidence interval (CI) of specific vitamins and carotenoids and their main sources. When comparing the extreme quartiles, the ORs (95 % CI) were 0·30 (0·10, 0·88) for lutein and 0·28 (0·11, 0·74) for β-cryptoxanthin. The associations for other dietary vitamin and carotenoid intakes were generally weaker and non-significant. Higher intakes of spinach and egg, which are important sources of lutein, were associated with a reduced odds of AMD. ORs (95% CIs) comparing extreme categories were 0·42 (0·20, 0·88) for spinach and 0·52 (95% CI: 0·27, 0·98) for egg. Participants who were in the highest category of both egg intake and spinach intake had a much greater reduced odds of having AMD (OR: 0·23; 95% CI: 0·08, 0·71) than those in the lowest category of egg intake and spinach intake. In conclusion, a higher intake of lutein and lutein-rich foods was associated with a significantly decreased odds of AMD. These findings provide further evidence of the benefits of lutein and lutein-rich foods in the prevention of AMD.
Scale discrepancy paradox between observation and modelling in fractured reservoir models in oil and gas industry
Authors: Richard P.D. , Bazalgette L. , Volery C. , Toukhi A.
Published: July 2022

The appraisal and development of fractured reservoirs are challenging tasks because of the combined variations in reservoir quality and natural fracture distribution. Fracture models are built routinely to support both appraisal and development decisions for such reservoirs. One of the key objectives of these models is to generate three-dimensional (3D) fracture properties for dynamic flow simulations. In this paper, we illustrate the discrepancy between the scale of observation required to build a thorough geological understanding of the subsurface and the simplification imposed by modelling. We use a case study carried out in the context of an exploration campaign of a Cretaceous carbonate reservoir in Egypt. After describing the regional geological setting of the area, we share a series of detailed observations on open-hole logs, cores, thin-sections and borehole images. These observations are focused on reservoir architecture, fracture typology and fracture connectivity. Observations are then integrated with the regional geological context to build a conceptual fracture model and to characterize the uncertainty affecting the essential parameters of this model. The conceptual model, combined with 3D seismic data, is used to define a fracture modelling strategy. This strategy includes a drastic simplification of the conceptual model to generate 3D discrete fracture network scenarios that are calibrated using pressure communication data from the exploration wells. Another extreme simplification is then necessary to populate 3D simulation grids. In the case study presented, the key tuning parameters to obtain a dynamic match are the grid cell orientation and the width of the modelled fault damage zone.
Particles from Comet Kohoutek Detected by the Micrometeoroid Experiment On HEOS 2
Authors: Hoffmann H.-J. , Fechtig H. , Grün E. , Kissel J.
Published: July 2022

The HEOS 2 satellite was launched into a highly eccentric orbit around the earth on January 31, 1972 and re-entered the earth’s atmosphere after a successful mission on August 2, 1974. Due to the orbit (apogee: 240 000 km, perigee: 300 – 5000 km) the satellite spent most of the time in the interplanetary region where the influence of the earth’s gravitation field is negligible with regard to its effect on interplanetary dust particles.
Assessing the effects of Language for all
Authors: Reichrath Enid , Moonen Xavier
Published: July 2022

Language for all is a method developed in the Netherlands for providing information in such a way that as many intended readers as possible both comprehend and accept this information. Readers include people with a large variety of reading abilities including people with low literacy skills. Language for all can be characterized as a more accessible variant of plain language with some characteristics of easy language.

In three studies the comprehension and acceptance of and preference for texts written in Language for all was evaluated, comparing original texts with a version in Language for all.

Information written in Language for all was significantly better understood and accepted, and was preferable to the original version.

In conclusion, Language for all is a promising effective, inclusive, and comprehensive method to provide information to people with and without low literacy skills. Further research is recommended.
Lessons learned from linking two complementary databases: the Society of Thoracic Surgeons Congenital Heart Surgery Database and The Vermont Oxford Network Expanded Database
Authors: Archer Jeremy M. , Nixon Connie S. , Sura Livia , Neal Dan , Jacobs Jeffrey P.
Published: July 2022

The Society of Thoracic Surgeons Congenital Heart Surgery Database and the Vermont Oxford Network Expanded Database are both large, international, well-established quality and outcomes databases with high penetration in their respective fields of congenital heart surgery and neonatology. Previous studies have shown the value of combining large databases for research purposes. Our aim was to examine the feasibility and value of combining these databases on a local level.

We included patients from both databases, cared for at our centre and born from 2015–2020, who had cardiac surgery as neonates or during the birth hospitalisation. We examined the number of patients from each database and overlap between the two. We compared cardiac diagnoses, surgeries performed, pre-operative factors, mortality, and length of stay between databases.

Of the 255 patients meeting criteria, 209 (81.9%) had records in both databases. The most common diagnoses in both were hypoplastic left heart syndrome, coarctation, and transposition of the great arteries. Surgical data were incompletely recorded in Vermont Oxford. Gestational age, birth weight, multiple gestation, mortality, and length of stay did not differ significantly between the databases, while the percentage of patients with an extracardiac malformation or genetic syndrome recorded was higher in the Society for Thoracic Surgeons group.

Larger-scale matching and comparison studies using these databases are feasible and desirable; for some variables, a record with data from both databases may be more complete. Specific attention should be given to inclusion criteria, reconciling different schema of diagnoses, and formulating questions relying on each database’s relative strengths.
Learning lessons from the COVID-19 pandemic
Authors: Powell Martin
Published: July 2022

This study examines the literature on learning lessons from the coronavirus disease 2019 (COVID-19) pandemic to make a conceptual and empirical contribution. The conceptual contribution suggests a simplified policy transfer framework for learning lessons from the proliferation of approaches involving an expanding and confusing mix of hypotheses, questions, criteria, domains, constructs, factors and criteria. This is then used to review the literature of lessons from COVID-19. This fuses the three reasons for transfer failure and the context-mechanism- outcome configuration of realist approaches to suggest three simple criteria of informed transfer (outcomes); complete transfer (mechanisms); and appropriate transfer (context). The empirical contribution suggests that it is difficult to learn lessons from the existing literature. The conceptual framework suggests that lessons about successful transfer involve a clear idea of policy success, understanding how the policy instrument or mechanism links with success in the original context, and how ‘fungible’ it is to the new context. Put another way, the ‘COVID lessons industry’ may itself need to learn that lessons about policy transfer should be informed, complete and appropriate.
How challenger party issue entrepreneurship and mainstream party strategies drive public issue salience: evidence from radical-right parties and the issue of immigration
Authors: Williams Christopher J. , Hunger Sophia
Published: July 2022

When mainstream parties accommodate radical-right parties, do citizens grow more concerned about immigration? Based on a rich literature, we argue that challenger parties’ ability to affect mainstream party positions, particularly on immigration, is associated with greater public salience of immigration and voter positivity towards challengers exists. We use Comparative Manifesto Project and Comparative Study of Electoral Systems data in order to show that challenger issue entrepreneurship, and mainstream accommodation are associated with greater public concern for challenger issues. These factors do not result in greater public positivity towards challengers. Our findings thus support the argument that a mainstream party accommodative strategy might not be as beneficial for them as often expected by pundit and political scientists alike. This has implications for understanding the effect of indirect party strategies on public attitudes, since mainstream accommodation changes public concern regarding issues, which may bolster challengers’ positions, including radical-right parties.
Investigating Measurement Invariance of the Psychological Entitlement Scale – Grandiose-Based and Vulnerable-Based
Authors: Hart William , Lambert Joshua T. , Kinrade Charlotte
Published: July 2022

Abstract. Entitlement has attracted interest across various social science disciplines due to its broad connection to selfish decision-making outcomes and mental health. Although unidimensional entitlement scales have been widely used, these scales conflate vulnerable- and grandiose-based entitlement forms. The Psychological Entitlement Scale – Grandiose-Based and Vulnerable-Based (PES-G/V) was recently devised to measure these entitlement forms. Prior work has supported the structure and construct validity of the PES-G/V, but no research has addressed the measurement invariance (MI) of the PES-G/V. Hence, we examined MI in relation to gender, two popular sampling frames in psychology studies (US MTurk participants and US college participants), and age. Results supported scalar MI across levels of each of the grouping variables. In sum, the structural properties of the PES-G/V seemed robust to the group distinctions.
Jimena D�az Leiva: Changing Conservation Narratives
Authors: Rocheleau Jackie
Published: July 2022

D�az Leiva has been to Peru and beyond as she works on environmental and social justice projects.
Stretching Crust Explains Earth’s 170,000-Year-Long Heat Wave
Authors: Schmidt Jennifer
Published: July 2022

During a brief period in Earth’s past, a massive emission of carbon abruptly raised global temperatures, acidified oceans, and stamped out species. New data may help explain how it happened.
Are micro enemas administered with a squeeze tube and a 5 cm-long nozzle as good or better than micro enemas administered with a 10 cm-long catheter attached to a syringe in people with a recent spinal cord injury? A non-inferiority, crossover randomised controlled trial
Authors: Kelly Louise C. , Glinsky Joanne V. , Nier Lianne M. , Garrett Gillian , Harvey Lisa A.
Published: July 2022

Study design

Double blind, non-inferiority crossover randomised controlled trial.

Objectives

To determine if micro enemas administered with a squeeze-tube and a 5 cm-long nozzle (squeeze-tube method) are as good or better than micro enemas administered with a 10 cm-long catheter attached to a syringe (catheter method) in people with a recent spinal cord injury.

Setting

Two inpatient spinal cord injury units located in Sydney, Australia.

Methods

Twenty people admitted to hospital with recent spinal cord injury were randomly assigned to two treatment sequences; 4 weeks of micro enemas delivered by the squeeze-tube method followed by 4 weeks of micro enemas delivered by the catheter method, or vice versa. Each treatment sequence was 8 weeks with a crossover at the end of week 4. The primary outcome was time to complete bowel care. Secondary outcomes reflected faecal incontinence, quality of life, perception of treatment effectiveness and participant reported time to complete bowel care. The primary and secondary outcomes were measured by blinded assessors in week 4 and week 8. A non-inferiority margin of 10 min for time to complete bowel care was set a priori.

Results

The mean between group difference (95% confidence interval) for the time to complete bowel care was −0.5 min (−2.8 to 1.8), where a negative value favours the catheter method. Results were similar for all secondary outcomes.

Conclusions

Micro enemas delivered by the squeeze-tube method are as good or better than micro enemas delivered by the catheter method in people with a recent spinal cord injury.
Development of AIEE active fluorescent and colorimetric probe for the solid, solution, and vapor phase detection of cyanide: smartphone and food applications
Authors: Majeed Shumaila , Waseem Muhammad Tahir , Khan Gul Shahzada , Junaid Hafiz Muhammad , Imran Muhammad , Nawazish Shamyla , Khan Tausif Ahmad , Mahmood Tariq , Shahzad Sohail Anjum
Published: July 2022

Piezofluorochromic and AIEE active probe is highly responsive to cyanide in its solid, solution, and vapor phase.