bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Influencing the Radiocarbon Dating of Human Skeletal Remains from the Dnieper River System: Archaeological and Stable Isotope Evidence of Diet from the Epipaleolithic to Eneolithic Periods
Authors: Lillie Malcolm , Henderson Rowena , Budd Chelsea , Potekhina Inna 
Published: July 2016

AbstractRecent research has identified the existence of a freshwater reservoir effect influencing the radiocarbon dating of human skeletal remains from the Dnieper region of Ukraine (Lillie et al. 2009). The current study outlines the evidence for freshwater resource exploitation throughout the period ~10,200–3700 cal BC, and presents the available evidence for the existence of dietary offsets in the14C dates obtained. We have obtained human skeletal material from 54 Epipaleolithic to Mesolithic period individuals and 267 Neolithic to Eneolithic individuals, from 13 cemeteries, since our research in Ukraine began in 1992. Here, we present the initial results of stable isotope analysis of Eneolithic individuals from the Igren VIII cemetery alongside the Epipaleolithic to Eneolithic samples that have previously been analyzed. When contrasted against the evidence from the prehistoric fauna and fish remains studied, and modern fish species from the Dnieper region, we continue to see variability in diets at the population level, both internally and across cemeteries. We also observed temporal variability in human diets across these chronological periods. The fish samples (both archaeological and modern) show a wide range of isotope ratios for both δ13C and δ15N, which could prove significant when interpreting the dietary sources being exploited. This information directly informs the14C dating program as an inherent degree of complexity is introduced into the dating of individuals whose diets combine freshwater and terrestrial sources in differing quantities and at differing temporal and/or spatial scales (e.g. Bronk Ramsey et al. 2014).
Studies of the flow field near a IMACA 4412 aerofoil at nearly maximum lift
Authors: Hastings R. C. , Williams B. R. 
Published: July 2016

SummaryMeasurements made at a Mach number of 0.18 and a chord-based Reynolds number of 4·2 x 106 on a constant-chord model having a NACA 4412 aerofoil section are described and compared with the results of flow field calculations.Both the experimental arrangement and the difficulties initially experienced in achieving an adequate approximation to two-dimensional flow above the wing are briefly outlined.The measurements include static pressure distributions on the wing surface and on the wind-tunnel walls above and below the mid-span section of the wing. The main emphasis in the experiment was, however, on defining the development of the upper surface boundary layer through separation (at about 20% chord ahead of the trailing-edge) and on into the wake, making extensive use of laser anemometry to measure mean velocities. In addition, Reynolds stresses were measured in certain parts of the flow field by hot-wire anemometry.The flow field calculations are of the semi-inverse kind in which an inverse momentum-integral treatment of the shear flow, used to avoid difficulties at separation, is coupled to a direct solution of the inviscid flow problem. The main features of the method are outlined.
Design features which influence flow separations on aircraft
Authors: Mabey D. G. 
Published: July 2016

SummaryFeatures of aircraft which influence flow separations, and hence the onset of buffeting, should be always of interest to an aerodynamicist. The present compilation of such features is based on notes made during a visit to the USAF Aircraft Museum in Dayton, Ohio. Although two low-speed aircraft with high aspect ratio wings are considered, the emphasis is primarily on transonic and supersonic military aircraft, with wings of lower aspect ratio.Some recommendations are made to stimulate research into improved methods to control flow separation, particularly for future transonic and supersonic aircraft.
Large deflections of a spring-hinged tapered cantilever beam with a rotational distributed loading
Authors: Nageswara Rao B. , Venkateswara Rao G. 
Published: July 2016

SummaryLarge deflection problem of a spring loaded hinged nonuniform cantilever beam subjected to a rotational distributed loading is formulated by means of a second-order non-linear integro-differential equation. The problem is examined by considering the beam of rectangular cross-section with linear depth taper subjected to a uniform rotational distributed load. The elastic curves of a beam for this special case are presented.
The reliability of inspection techniques in relation to damage tolerant design
Authors: Stone D. E. W. 
Published: July 2016

This paper is concerned especially with the reliability of inspection in the nondestructive testing of military aircraft structures. The first part considers design philosophies, examines how the requirements for inspection arise and highlights the difference between the approaches being adopted in the USA and in the UK.The second part examines what data are already available on the reliability of inspection and discusses the UK programmes that are aimed at gathering more data.
The use and potential use of reliability engineering for offshore structures
Authors: Mowatt G. A. , Loader D. J. , Arbuthnot C. H. 
Published: July 2016

This paper presents a review of the current status and potential future use of reliability methods in the design, fabrication and operation of offshore oil production platforms.An overview of the traditional design process is presented and key areas where reliability methods have contributed to the development of codes of practice are described. Future applications in the design stage include the optimisation of framing configurations and the treatment of uncertainties in basic design parameters.
Premature boundary layer transition caused by surface static pressure tappings
Authors: Roach P. E. , Turner J. T. 
Published: July 2016

SummaryExperiments have been performed to study the influence of multiple surface static pressure tappings on transition of the boundary layer on a circular cylinder in cross-flow. A wide range of tapping and cylinder dimensions have been examined to demonstrate that the tappings can act in the same way as trip wires or other surface roughness to reduce the Reynolds number at which transition occurs. Hence, the pressure distribution around the cylinder may be influenced by the presence of the tappings, leading to incorrect measurements. Examination of the data has resulted in a correlation which should make it possible to avoid this tapping/boundary layer interaction in future experiments involving similar cylindrical bodies.
Precision Hovering by Light Helicopters at Moderate Altitudes
Authors: Clark B. A. , Gross K. A. 
Published: July 2016

SummaryUsing television as an instrumental aid, light helicopters can be hovered with considerable accuracy above a known ground point at altitudes of the order of a thousand metres above ground level. The image from a vertically-aimed ground-based television camera is transmitted to the helicopter and displayed on a receiver placed in front of the pilot, who uses the image of the helicopter for guidance to the hover point. With this system, the hover point has been maintained within ±1.2 m (4 feet) for periods of up to 2.5 minutes at 1200 m (4000 feet) above ground level.
Flow Separation in an Aerofoil Cascade
Authors: Clayton B. R. , Massey B. S. 
Published: July 2016

SummaryThe pattern of flow at low Reynolds Numbers about an aerofoil in a cascade has been illustrated by the hydrogen-bubble flow-visualisation technique. The method has also been adapted tor the accurate experimental determination of the position of boundary-layer separation. Results of the investigation are presented graphically together with photographs showing the general behaviour of the flow in the wake.
The Influence of Added Narrow Band Noises and Tones on the Subjective Response to Shaped “White” Noise
Authors: Hargest T. J. , Pinker R. A. 
Published: July 2016

SummaryExperiments on the influence of added narrow band sounds on the subjective assessment of noise were conducted at the NGTE 1966 Open Week and at the 1966 SBAC Show, with over two thousand people participating. The results clarify the apparently conflicting observations of earlier workers and show definitely that the presence of a narrow band content can significantly influence the degree of disturbance caused by noise of the type generated by aircraft near an airport.
A Two-Parameter Method for Calculating the Two-Dimensional Incompressible Laminar Boundary Layer
Authors: Curle N. 
Published: July 2016

Summary:In most one-parameter methods of calculating laminar boundary layers it is assumed that the non-dimensional parameters H=δ1/δ2, I=δ2τW/μu1 and L = 2{I−λ(H+2)}, depend only upon the pressure gradient parameter λ=u1δ22/v. In this paper it is shown theoretically that a more accurate, two-parameter representation isL=F0(λ)−μG0(λ)I2=F1(λ)−μG1(λ),where μ=λ2U1U1/(U1)2. Careful examination of the available range of exact solutions of the boundary layer equations has enabled the four functions F0, G0, F1, G1, to be tabulated, and the above functional forms agree with the exact solutions to a remarkable accuracy.In view of the fact that a reasonable first approximation to L is usually , we write,and it is then shown that the momentum integral equation becomesThis equation is easily solved by iteration, setting g=0 in the first approximation, and convergence is extremely rapid.The method is, in effect, a refinement of that due to Thwaites, which is universally accepted as one of the better of the existing calculation methods. Detailed calculations made by the present method indicate that the errors are only 5% of those given by the Thwaites method.
The Refractory Metals
Authors: Llewelyn G. 
Published: July 2016

The refractory metals are usually referred to as metals which have melting points equal to, or higher than, chromium. A number of these metals, such as chromium, molybdenum, niobium, and tungsten are already being used quite extensively as alloying elements in both ferrous and non-ferrous alloys. Tungsten has been used in the lamp industry for many years, while molybdenum has been used for heating elements and niobium has been of interest in the atomic energy field.The advancements in design and efficiency of aero engines has been associated with an increase in engine temperature. If this advancement is to continue, it will be necessary for a new family of alloys to be made available to the engineer. The current nickel-base high temperature alloys are now approaching their limit. It is difficult to be precise about these temperatures because the applications in terms of stress vary widely.
Internal Aerodynamics Problems
Authors: Livesey J. L. 
Published: July 2016

SummaryThis paper defines Internal Aerodynamics and via similarity generalises the concept to include internal flows of fluids other than air.Variable area ducted flows are considered distinguishing one, two and three-dimensional treatments and the difference between accelerating and diffusing flows is stressed. The design of variable area ducts using ideal inviscid fluid theory, ideal fluid plus boundary layer theory and inviscid but rotational fluid theory is discussed. The success and limitations of these theories with reference to contractions and diffusers is surveyed The particular difficulty of a diffusing flow as affected by entry velocity profile and turbulence is considered.From the problem of simulating entry velocity profiles arises the need for the generation of required velocity profiles in duct systems. Examples of methods of generation and difficulties are discussed.Next follows a series of examples of internal flow problems.The radial flow diffuser is considered as an example of the interaction of viscous and inertia effects. An approximate theoretical treatment is given and the real flow, with the occurrence of reverse transition, is described.The deliberate production of a reversed flow regime for flame stabilisation is described with reference to a marine boiler register Aspects of pressure drop and stability are considered.Secondary flow is defined and the origin in the distortion of the upstream vorticity field is described. The case of a strut wall junction is given with details of the downstream flow where the secondary flow produces apparent multiple wakes from a single strut.Air flow excited vibration of heat exchanger tubes is described. Different mechanisms resulting in transverse or streamwise oscillations and the coupled modes of tube rows are discussed.Finally the paper emphasises the large available body of information in internal aerodynamics, largely of aeronautical origin, and considers its usefulness and limitations for the problems discussed.
Early Days with Aircraft Design and Development
Authors: Jones T. 
Published: July 2016

In my boyhood days I well remember seeing balloon ascents at the Crystal Palace, which sowed the seed for my ideas of man being supported and carried in the air. Many times, when flying my kite, it passed through my mind that if, instead of holding it against the wind to keep it in an elevated position, the kite would rise and keep elevated if it were moved through the air at a speed equal to that of the wind, but this boyish reasoning into matters of heavier-than-air flying machines remained dormant while I carried on with my general engineering training.Between the years 1905 and 1910, I took serious notice of the experiments made with gliders, particularly those by Wilbur and Orville Wright. Thus, my interest in aviation was revived, and with the experiments with engine-powered gliders, and the very early flying machines, I definitely decided that Aviation was to be my future occupation.
A Simple Correlation of Turbine Efficiency
Authors: Smith S. F. 
Published: July 2016

SummaryFor a number of years it has been the practice at Rolls-Royce to determine the basic aerodynamic characteristics of the turbines of our engines by tests of model turbines. The first model of the single-stage Derwent I turbine was tested In 1945 and a design point efficiency of 75 per cent was measured. Since then over 600 different turbine configurations have been tested and many of the more recent turbines have achieved efficiencies appreciably better than 90 per cent. Typical of modern turbines is the Spey two-shaft turbine in which the four stages reach a design point efficiency of a little over 92 per cent. This paper presents a description of the test techniques which are used in this work and also a simple method of correlation which relates the efficiency of some 70 turbine stages to the velocity triangles and enables the efficiency of those turbines, which fall within the scope of the correlation, to be predicted with an accuracy better than ± 2 per cent. The measured value of turbine efficiency can be markedly influenced by the measurement technique, so the way in which the turbines are manufactured and tested is described in some detail.
Hovercraft Noise and its Suppression
Authors: Richards E. J. , Sharland I. J. 
Published: July 2016

Although the science of Hovercraft is still in its infancy, sufficient promise is already being shown to indicate a commercial and military future as alternative means of transportation. Since transportation involves power, and power involves noise, it is imperative that even at this early stage, development does not proceed in a direction which involves excessive noise and in so doing builds up the embarrassing situation for itself of the kind now occurring with aircraft at London Airport.To give an example, one of the major problems in establishing a third airport for London is obtaining a quick method of communication between such an airport and the centre of the city. Unless this can be achieved, the advantages of supersonic travel will be nullified. The roadways and railroads are already full and alternative forms of travel must be found.
Airline Engineering and Maintenance: Reduction of Costs by Job Control and Time Standards
Authors: Bennett W. L. 
Published: July 2016

Is there a danger of trying to over-simplify the manner in which costs can be reduced? Has the colour grey been deleted from our dictionary, and is everything really black or white? It would seem to me there is a tendency for the technical man to over-rule completely the practical man or vice versa, and maybe there is room for the colour grey to return and be high-lighted in our dictionaries.A number of subjects come readily to mind where, in my opinion, neither the purely theoretical nor the purely practical approach can achieve the best results, and the only efficient way is a combination of both. Job control and time standards is, I consider, a subject which comes into this category.
On the Bending of Clamped Skewed Plates Under Uniform Pressure
Authors: Kennedy J. B. 
Published: July 2016

SummaryA simplified approximate solution for clamped skewed plates under uniform pressure is presented. Variations in maximum edge and centre moments with skew angle and sides ratio are shown plotted. The convergency of the solution is checked and results compared with the limited available data. Results were verified by an experimental investigation.
The Calculation of the Discharge Coefficient of Profiled Choked Nozzles and the Optimum Profile for Absolute Air Flow Measurement
Authors: Stratford B. S. 
Published: July 2016

SummaryA choked nozzle with an appropriate wall contour has adischarge coefficient, CD, so close to unity that a theoretical calculation of (I—CD) would allow the nozzle to be used as an absolute meter for air flow. The high discharge coefficient results basically from the fact that ∂(ρv)∂p=0 at M=1.Simplified calculations yield formulae for the boundary layer displacement thickness and for the flow reduction resulting from the variation in static pressure across the throat. The optimum profile for the wall at the throat of an absolute meter is suggested to be a circular arc of radius of curvature equal to about twice the throat diameter. For such a meter the theoretical discharge coefficient is found to be within ¼ per cent of 0·995 over a wide range of Reynolds numbers.The uncertainty in the discharge coefficient for a steady flow at Reynolds numbers of 106 and over appears to be less than ±0·15 per cent, both when the boundary layer is known to be entirely turbulent and when it is known to be entirely laminar. When the state of the boundary layer is not known the corresponding figure appears to be ±0·25 per cent. Experimental information might therefore be helpful on transition—under the appropriate conditions of flow unsteadiness and rig vibration. Available experimental results with known boundary layers tend to confirm the theoretical discharge coefficients down to a Reynolds number of 0·4x106.A pressure ratio of about 1·1/1 or less would probably be sufficient to establish fully supersonic flow if the nozzle were followed by a suitable diffuser.
The Investigation of Aircraft Accidents With Particular Reference To Those Caused By Mechanical Failure, Their Diagnosis And Lessons Learnt From Them
Authors: Newton E. 
Published: July 2016

Since the mythical dawn of man's attempt to emulate birds and fly, and some believe this started with Icarus, man has been frustrated by his apparent inability to predict or prevent occasional disaster arising from failure of his mechanical aids to flight. From ancient Icarus with his ultimate and disastrous thermal structural failure, to the present and future aircraft the same problem although now in a more sophisticated and complex form, confronts the aircraft designer and engineer of today.This paper is not intended to be a comprehensive treatise on Aircraft Accident Investigation as a whole because this is a subject of many facets and problems, but rather is it intended to draw attention in basic and elementary form to some types of mechanical failures or inadequate design criteria which have caused accidents to aircraft in the past, the methods used in their diagnosis and, what is perhaps more important, some lessons that have been learnt from them.
The Wallis Ultra-Light Autogyro
Authors: Wallis K. H. 
Published: July 2016

The speaker has no specialist knowledge of agricultural aviation and will therefore briefly describe the aircraft, and provide thoughts on possible uses in aid of agriculture.The ultra-light autogyro is probably the smallest practical aircraft of any type. Happily it does not need to be correspondingly fragile or delicate and it is little affected by turbulence or inclement weather, in the air or on the ground.Some thought has already been given to an agricultural autogyro, although a somewhat larger machine than the Wallis autogyro was envisaged. While advantages would undoubtedly ensue from the larger size, such an aircraft would probably be in competition with comparable helicopters and fixed - wing machines. By the time development was complete there might be no great saving in first cost or maintenance.
The Airlines’ Point of View
Authors: Marking Henry 
Published: July 2016

My Talk will be Brief because Mr. Kean has covered the field extensively and extremely well.What is Interchange? Mr. Kean indicated that it is not a very satisfactory description of what takes place because it is not a word which describes it accurately, and I think a good deal of confusion about interchange exists in the minds of many laymen because, unlike most air transport words which had their roots in surface transport, interchange so far as I know is peculiar to air transport; hence people are apt to think that it is something special, and that special rules must apply to it. In fact I suggest that it is nothing of the kind; all it is is a certain kind of charter, and the same rules apply to interchange of aircraft as to any other kind of charter, and the reason that it has been singled out as a special problem for lawyers is that its characteristics make it extremely difficult to work satisfactorily, internationally particularly, if the normal rules are applied.
Optimum Elastic Restraint for Pressurised Circular Plates
Authors: Bert Charles W. 
Published: July 2016

SummaryFor uniform-thickness, solid circular plates made of isotropic elastic material and elastically restrained at the edge, expressions are derived for the optimum support stiffness to minimise the following quantities:1.The largest effective stress based on several different strength theories.2.The largest effective stress per unit of maximum deflection or per unit volume displaced.
Education of the Airline Engineer
Authors: Walls A. J. 
Published: July 2016

Mr. Wilkinson's paper (July 1963 Journal, pp. 421-6) will doubtless be universally applauded by airline management. One can only hope that it receives equal attention from those responsible for the education of Graduate Engineers.His point about economic training is basic. It is extraordinary how, as professions evolve, certain fundamentals appear to be lost. From the earliest days of Engineering, an Engineer was denned at “a man who could do for a penny what any fool can do for twopence.” I think if the point were raised with most Engineers they would all admit that economy is at the very root of the profession. Nevertheless, how true Mr. Wilkinson is when he points how that Engineers receive little or no formal economic training in their basic education.
Study of the Human Pilot as a Servo-Element
Authors: Hall I. A. M. 
Published: July 2016

SummaryA method for describing the action of a pilot in mathematical terms is presented. The method applies for tracking tasks and gives a pilot describing function which can be used in conventional servo-analysis. Flight simulator data obtained in this way for a wide variety of aircraft longitudinal response characteristics are presented and the effect of these characteristics on the pilot's action is discussed fully. In order to illustrate that work of this kind can lead to a quantitative understanding of pilot's “handling qualities” opinion, the recorded pilot opinions are “predicted” from a knowledge of three simple aircraft characteristics.