bluuebunny/crossref_metadata_2025_split huggingface dataset:
New productide brachiopods (Productoidea) from the Carboniferous of Ixtaltepec Formation, Oaxaca, Mexico
Authors: Torres-Martínez Miguel A. , Sour-Tovar Francisco 
Published: July 2016

AbstractFrom the Santiago Ixtaltepec area, in Oaxaca State, southern Mexico, 11 species of productoid brachiopods, including a new genus and five new species, are described.Semicostellasp.,Antiquatoniasp.,Keokukia? sp.,Inflatia inflata,Reticulatiacf.R.huecoensis,Buxtonia websteri,Weberproductus donajiaen. gen. n. sp.,Dictyoclostus transversumn. sp.,Inflatia coodzavuiin. sp.,Buxtonia inexpletucostan. sp., andFlexaria magnan. sp. were collected from eight stratigraphic levels of the Ixtaltepec Formation. The presence ofSemicostellasp.,Keokukia? sp. andInflatia inflatain the basal strata, Units 1 to 3, of the formation indicate a Viséan-Serpukhovian (Late Mississippian) age.Reticulatiacf.R.huecoensisandBuxtonia websteri, found in Units 6 to 8, confirm the Pennsylvanian age for upper strata of the Ixtaltepec Formation.InflatiaandFlexariaare present in the uppermost beds of the formation so it is possible to extend their upper stratigraphic range to the Middle Pennsylvanian. All these taxa also occur in the United States Midcontinent, suggesting that during the Carboniferous the epicontinental sea extended at least to central Mexico.
The Australian View
Authors: Cumming R. W. 
Published: July 2016

In both civil and military flying take-off and landing accidents represent a major part of all accidents. In both take-off and landing, the problems are becoming more acute with the current change to larger and faster aircraft, and even more significantly with the change to jet engines.The majority of accidents occurring in these two phases of flight are attributed to “ human error,” or “ pilot's error of judgment,” but recent human engineering studies have shown that in many cases the real cause has been due to the engineering situation overloading the pilot in some way, or requiring him to make judgments based on insufficient information.
THE PROTEAN PRINCIPLE OF PROPORTIONALITY: HOW DIFFERENT IS PROPORTIONALITY IN EU CONTEXTS?
Authors: Bjorge Eirik , Williams Jack R. 
Published: July 2016

THE Legal Services Board, tasked with the supervision of approved regulators of persons carrying on legal activities, granted an application (by the Bar Standards Board, Solicitors Regulation Authority, and ILEX Professional Standards Board) for approval of alterations to their regulatory arrangements to give effect to the so-called Quality Assurance Scheme for Advocates (“the decision”). The Scheme provides for judicial assessment of criminal advocates in England and Wales: only those deemed “competent” would gain full accreditation for upper levels of criminal work. Judicial review had been sought, unsuccessfully in the courts below, by barristers practising criminal law. The question in R. (on the application of Lumsdon and others) v Legal Services Board [2015] UKSC 41; [2015] 3 W.L.R. 121 was whether the decision was contrary to Regulation 14 of the Provision of Service Regulations 2009 (SI 2999/2009), which implemented Directive 2006/123/EC (O.J. No. L 376, p. 36). Regulation 14 requires that any authorisation scheme cannot be set unless, inter alia, the need for such a scheme is “justified by an overriding reason relating to the public interest” and the scheme's objective “cannot be attained by means of a less restrictive measure” (see Regulation 14(2)).
Temperature Distributions in Aircraft Structures and the Influence of Mechanical and Physical Material Properties
Authors: Legg K. L. C. , Stevens G. 
Published: July 2016

Summary:Thermal effects in aircraft may arise from kinetic heating, engine installations and auxiliary systems. The first source is potentially of greater importance, although problems in connection with the second source can be severe, especially with vertical take-off aircraft of the “flying bedstead” type. The difficulty encountered in a formal analysis of heat conduction problems when practical boundary conditions are to be satisfied frequently suggests a finite difference approach. This may take the form of direct numerical integration or the use of digital or analogue computers or network analysers in which electrical circuits are arranged to be analogous to the thermal system. Several examples illustrating the use of these finite difference methods are instanced, such as the growth of temperature in a thick plate, the transient distribution of temperature in a rib carrying a hot duct; the chordwise distribution of temperature and transient loss in torsional stiffness in a thin wing due to kinetic heating, and the distribution of temperature and spanwise thermal stress due to kinetic heating in a bay of an integrally stiffened panel. The importance of experimental methods is emphasised and a brief description and illustration of a model fuel tank for simulated kinetic heating tests is given. An urgent plea is made for correlated data on thermal contact resistance of typical aircraft joints, some examples of which are also illustrated. Data is given on some physical and mechanical properties of materials likely to be used for airframes where thermal effects are expected. These include thermal expansion, conductivity, diffusivity, creep, fatigue, specific strength and stiffness, and a parameter called here the “Thermal Stress Efficiency.”
Recent Advances in the Design of Aircraft Tyres and Brakes
Authors: Trevaskis H. W. 
Published: July 2016

Ten years ago take-off speeds rarely exceeded 130 m.p.h. and the maximum inflation pressure used in aircraft tyres was about 120 lb./in2. Today tyres have to cater for speeds up to 230 m.p.h. and pressures of 350 lb./in.2. The increased requirements have produced serious problems of heat generation within the tread and carcass of tyres, which, if not solved, result in disintegration. Fig. 1 shows the effect of speed on tyre temperature and also, the effect of lightening the tyre construction.Beyond the speed range shown, the temperature rises rapidly and tyre failures would occur. To meet these conditions, improved materials with lower hysteresis losses, and capable of operating at higher temperatures, have been produced. Control can also be obtained by modifying casing cord angles, reducing casing and tread thicknesses and so on.
A Simplified Form of the Auxiliary Equation for Use in the Calculation of Turbulent Boundary Layers
Authors: Black T. J. 
Published: July 2016

A New type of auxiliary equation is given for calculating the development of the form-parameter H in turbulent boundary layers with adverse pressure gradients. The chief advantage of this new method lies in the rapidity and ease of calculation which has been achieved, without apparent sacrifice of accuracy.Whereas the growth of momentum thickness in the turbulent boundary layer can now be rapidly calculated by methods involving only simple quadrature, the prediction of the form parameter development remains a laborious task, while the results obtained do not always appear to justify the complexity of the calculations.
Note on Matching a Supersonic Intake to an Aircraft Gas Turbine
Authors: Stephenson J. M. 
Published: July 2016

The Function of the air intake of a gas turbine engine is to deliver whatever air mass flow is required, with the best recovery of ram stagnation pressure, over the desired range of flight speeds and altitudes.Although it is generally shown in other forms, the performance of an air intake for supersonic flight can be represented on charts very similar to those of a rotating compressor. In Fig. 1 the ratio between ambient (static) pressure and stagnation pressure at the diffuser of a typical intake is shown as a function of corrected inlet and outlet air mass flow (which are themselves functions of the local flow Mach numbers), for a series of flight Mach numbers.
Rotary Stability Derivatives from Distorted Models
Authors: Chan Y. Y. , Ward John R. 
Published: July 2016

Foster and Haynes recently suggested the possibility of measuring the rotary stability derivatives of an aeroplane by testing a suitably distorted model in a wind tunnel. This possibility has been examined for an isolated wing by the authors and has been found to be in error for the derivatives due to rolling and yawing.In what follows it will be assumed that thin aerofoil theory and Prandtl’s lifting line theory may be applied.
Rear-Engined Air Liners
Authors: Smith A. W. J. 
Published: July 2016

I Should like to raise a point on the projected rear-engined jet air liners now under active consideration by several major British firms and of which “artists’ impressions” have recently been published, the latest being the V.C.10.The rear-engine layout has so many advantages that its use seems entirely logical, but I am curious to know whether or not such a design has been investigated with a noseplane layout in preference to the conventional tailplane. I have been interested in this possible configuration for some years and put the idea forward in a short Branch lecture at Derby when it appeared that quite a few of those then present agreed in broad principle.
Fail-Safe Structural Design
Authors: Harpur N. F. 
Published: July 2016

Around the end of the fifteenth century were written what must have been about the first set of airworthiness requirements ever compiled. These were notebooks of Leonardo da Vinci in which he discussed the physics of flight and the design of flying machines. In one of these notebooks he wrote:—“ In constructing wings one should make one cord to bear the strain and a looser one in the same position so that if the one breaks under the strain the other is in position to serve the same function.”
Francis Herbert Wenham, Honorary Member 1824—1908
Authors: Laurence Pritchard J. 
Published: July 2016

In December 1905 Wilbur Wright wrote to Octave Chanute, “ We were indeed very much gratified at the commendation of Mr. Wenham, whom we regard as one of the ablest and most useful men who have laboured in the cause of human flight.”Wenham had written to Chanute expressing his delight at the success of the two brothers and adding, “It removes me from the list of cranks who always stated I was advocating an impossibility.”
The Man-Powered Aircraft
Authors: Nonweiler T. R. F. 
Published: July 2016

SummaryAn appreciation is made of recent experimental and project work of relevance to the design of a very light weight aircraft capable of being taken off and flown by two men. The emphasis is on the aerodynamic problems involved. It is concluded that, although there are many difficulties still needing attention, all the information supports previous assertions that flight by muscular power alone is possible. The merits and de-merits of a particular projected design are studied, and its performance and stability assessed.
Strut Testing
Authors: Crawshaw A. H. 
Published: July 2016

In the July JOURNAL, page 528, Dr. H. Fessler describes a method of testing struts using links in tension to apply the load.A much easier and cheaper method is to use sharpened rods as struts tested between hard flat plates. As the load increases the ends continually crush so that there is no restraint and the equivalent to a pin joint is obtained.Eccentricities can easily be obtained by bending the rods and the amount can be checked by mounting between female centres and rotating. At least three specimens of each length should be tested. A strut curve consisting of failing stress plotted against length divided by radius of gyration can then easily be obtained for use with the material, without the use of theory.
Aeroelastic Problems Associated with High Speeds and High Temperature
Authors: Broadbent E. G. 
Published: July 2016

SummaryTwo simple examples of aeroelastic effect are given in which chordwise distortion is important. The first relates to static distortion of a solid wing at high temperature using non-linear relations derived by Mansfield. It is shown that the chordwise distortion is stabilising as regards divergence, but leads to considerable loss of lift. The second example shows that chordwise distortion can reduce the flutter speed of a flat plate.
The Eddy Dijfiisivity in Annular Flow
Authors: Barrow Henry 
Published: July 2016

An investigation into the turbulent flow characteristics in a smooth-walled annulus has been continued. Velocity and its correlation has already been dealt with in the author's note in the November 1958 JOURNAL (p. 830). In the work presented here, the eddy diffusivity in gas flow is discussed, its distribution predicted, and experimental results for the eddy difiusivity of heat in an insulated annulus with a heated inner wall are included in support.The distributions of velocity, shear, temperature and heat flux for an annular flow with heat transfer at the inner boundary are shown diagrammatically in Fig. 1. The features of the turbulent velocity profile and methods of correlating velocity distribution are outlined in Ref. 1. The shearing stress T is given by the equation
Stress Corrosion—The Engineer̕ s View
Authors: Wall P. H. 
Published: July 2016

Of all those forms of corrosion with which the engineer must deal, such as atmospheric corrosion, galvanic and fretting, stress corrosion is perhaps the most difficult to understand, to predict and to prevent.Unlike that other troublesome characteristic of metals, namely fatigue, which also defies exact analysis, it is caused by static tensile stress acting in a corrosive environment (in many cases, the atmosphere). This may be due to internal residual stress or externally applied assembly stress and under such circumstances the possibility of stress corrosion occurring is ever present and is not necessarily removed by the cessation of the working loads.Most alloys are susceptible to some degree ranging from those which suffer in practice to those which only exhibit the phenomena under exaggerated laboratory conditions. Some examples are railway locomotive boilers, stainless steel construction, commercial spot-welded construction and, of course, aeroplane structures in light alloy.
Approximate Solution of Linear Second Order Differential Equations
Authors: Squire William 
Published: July 2016

In a recent paper(1) Collar discussed some aeronautical applications of linear differential equations with variable coefficients. Part of the paper deals with the approximate solution:of the differential equationThis asymptotic approximation, which dates back at least to Liouville, has an interesting history(2). It is widely known as the WKB approximation because of its use in quantum theory by Wentzel, Kramers and Brillouin. It has been applied to compressible flow by Imai(3).While very useful it breaks down at the zeros of n(t) and there are problems in joining solutions passing through such points. Recently(2,4,5) extensions of the approximation which circumvent this difficulty have been developed. This note deals with the extension due to Bailey.This approximation can be developed from the equivalence of equation (2) and the Riccati equation: —
Safe Mechanisms
Authors: Crawshaw A. H. 
Published: July 2016

I should like to thank Mr. Hafner for his paper on “ Safe Mechanisms ” published in the May Journal (p. 273). There is much scope for thought and invention along the lines he suggests and such thought will result in increased safety.In Section 3.1 on page 276 “ Safety Standard,” it is suggested that accident statistics should be quoted on an hourly basis and not per mile. A man expects to live three score years and ten; it is, therefore, the risk of spending a proportion of this time in a given occupation which is significant. It is then possible to compare the relative risks of lying in bed, train travel, air travel, space travel and so on.
An Estimate of the Suction Peak on Infinite Sheared Wings
Authors: Weber J. 
Published: July 2016

It is shown that, for infinite sheared wings with symmetrical aerofoil sections, the value of the suction peak near the nose in incompressible flow depends primarily on the value of the lift coefficient and the nose radius and not on the angle of sweep.When investigating the suitability of a basic wing section for an aircraft design with comparatively large aspect ratio, it is useful to know up to which lift coefficient one can expect the flow to be attached over the wing surface, and separation to occur at the trailing edge only. For aerofoils of small or moderate thickness-chord ratio, flow separation tends to occur first near the leading edge.
Problems of Hypersonic Aerodynamics— A Survey
Authors: Monaghan R. J. 
Published: July 2016

SummaryReal gas effects are among the major complications of hypersonic flow and this is illustrated by examples of the temperatures and pressures attained when a flow is brought to rest. Once dissociation appears, these depend to a marked extent on the type of compression.In designing for the alleviation of aerodynamic heating there are two distinct cases. The first is the uncontrolled re-entry of a freely falling body, for which it is best to have a shape with a high pressure drag. The second is sustained flight, for which a shape with low pressure drag could be better, radiation giving appreciable control of surface temperature.Low pressure drag accords with design for aerodynamic efficiency and there is scope for research on three-dimensional lifting shapes. There is some discussion of this and also of the philosophy of securing maximum amounts of separated flow.Finally, there is continual emphasis on the need for experimental research, since hypersonic flow fields may differ considerably from those that would be expected by extrapolation of
conventional supersonic experience.
Agricultural Aviation
Authors: Wheeler A. H. 
Published: July 2016

The first International Agricultural Aviation Conference, held at the College of Aeronautics at Cranfield between the 15th and 18th of September 1959, was well timed to mark one stage in the development of the art of airborne farming—it was the stage when the art ceased to be mainly experimental and became essentially a commercial business.Intermittently for the past thirty years, in various parts of the world, attempts have been made with varying degrees of economic and practical success to do certain operations connected with farming, forestry or other allied activities. Two main factors within the past decade have served to intensify the interest and activity in the art. One important factor is the general improvement in aircraft, including helicopters, coupled with the very large number of relatively suitable ones which became redundant (and therefore cheap) at the end of the Second World War. The other factor, equal in importance, concerns the development of the science of agricultural chemistry which has given the farmer a new and wide range of fertilisers, selective weed killers and other chemical forms of pest control which are effective in reasonably small bulk.
Operational Requirements for Aircraft in Australian Territories
Authors: Coombes L. P. , Munro J. 
Published: July 2016

At its fifth meeting, the Commonwealth Advisory Aeronautical Research Council discussed the need for a better understanding of the operational requirements for aircraft in different parts of the Commonwealth. It therefore asked for papers from the respective countries, bearing in mind particularly the possibilities of V.T.O.L. and S.T.O.L. aircraft.A survey has been made in Australia. The general impression gained is that within the Australian continent there are no outstanding future operational needs, if the term outstanding is interpreted in the sense of V.T.O.L. or S.T.O.L. or other extraordinary condition of operation. This is not surprising since Australia has, on the whole, excellent conditions for flying; there are no high mountains, very little icing or fog, and the country tends generally to be flat and low. In external operations conditions are not so favourable and certain definite requirements emerge. Theses together with some general observations, have been recorded as of interest to designers. It is clear that simpler forms of V.T.O.L. aircraft than rotary winged types are needed, and this may well indicate a need for more research.
The Low Speed Approach and Catapult Launch Problems in High Performance Naval Aircraft
Authors: Whitehead D. J. 
Published: July 2016

In the first half of the paper some of the basic aerodynamic engineering and piloting problems that have been encountered during the design and development of modern naval deck landing aircraft are enumerated and described. Such aircraft, of basically swept-wing configurations and high transonic or supersonic performance, have to be capable of being flown comfortably under full pilot control at the low speeds expected for carrier deck landings.In Part II, the many devices of aerodynamic and engineering design will be described which have been evolved in an attempt to overcome or minimise the problems.
Vertical Transport Business
Authors: Cummings Robert L. 
Published: July 2016

SummaryTurbine-powered helicopters mark the most important step taken thus far in the transition from development to business for that segment of the transportation industry which utilises the capability for vertical flight.Completing more than a year ot detailed study and evaluation, New York Airways recently announced its commitment to purchase ten multi-turbine Vertol 107 aircraft designed to cruise in excess of 150 miles per hour with 25 passengers. They will be introduced into service in the spring of 1961. With these machines commercial revenues could, for the first time, offset all operating charges and produce a fair return on the capital investment—without government financial support. The availability of the Fairey Rotodyne in 1964 will place New York Airways in a position to offer the public a substantially enlarged and even more useful service operating on a business basis.
Approximate Solution of the “Inverse Problem” of Boundary Layer Theory
Authors: Bradshaw P. 
Published: July 2016

Existing approximate formulae for the thickness of laminar and turbulent boundary layers are used to derive a method of calculating the free-stream velocity distribution corresponding to a given variation of shape parameter.Thwaites has given the formulafor the momentum thickness of a laminar boundary layer with free-stream velocity u (x). This is the integral form of the empirical equation
Elementary Stress Analysis of Circular Frames in a Cylinder Partially Filled with Fluid
Authors: Halliwell A. R. 
Published: July 2016

Expressions are found and curves given for the bending moment, direct force and shear force around a circular frame, in a cylinder partially filled with fluid. The maximum bending moment is found to occur when the cylinder is half full, and its position to be at the level of the fluid surface.The analysis is an elementary one, that is, engineer's bending theory is assumed to hold in the cylinder. Hence the resultant pressure of fluid on the frame is balanced by a sinusoidal varying shear flow around the frame.
Buckling of Unstiffened Shear Webs with Flanged Lightening Holes
Authors: Michael Maureen E. 
Published: July 2016

Although many investigators have set out to find a method of determining the buckling and failing stresses for unstiffened shear webs with flanged or unflanged lightening holes, it seems that so far no really satisfactory method has been found.A number of empirical and semi-empirical expressions have appeared over the years which agree closely with the limited series of tests on which they are based, but which the writer has found not to agree with the general mass of experimental data which is now available on this subject.Following a recent examination of the available data another attempt has been made to derive some expressions or formulae that would help the designer to estimate buckling and failing stresses of such panels, and as a first step a semi-empirical formula has been derived that appears to fit the test results reasonably well for the initial buckling case. It applies to panels with edges fixed.