bluuebunny/crossref_metadata_2025 huggingface dataset:
The Rational Design of Aeroplanes
Authors: Low Archibald R.
Published: February 2017

In dealing with the flow of fluids, and the reactions set up on moving surfaces, water and steam turbine engineers have to deal with definite masses of water or steam flowing along channels whose boundary walls are fixed.

Fig. 1 (reproduced from Stodola's Steam Turbines, 3rd edition) shows the nature of the assumption made for the so–called impulse turbine, assumptions which hold to an equal approximation for water turbines, showing nozzle and moving vanes

Reaction turbines present a more complicated state of affairs, which offers a less direct analogy with aeroplanes and airscrews, and which therefore need not be considered here.

In the figure (1) the mass of working fluid delivered per second is the cross section of the nozzle or channels between vanes, at any point, multiplied by the velocity of the fluid relatively to the walls of the channel at that point.
The Elastic Constants of Spruce as Influenced by Moisture
Authors: Carrington H.
Published: February 2017

Previous investigations on the effect of moisture on the elastic constants of spruce have been confined to its effect on Young's modulus in the direction of the grain. The most important work in this connection is probably that of H. D. Tiemann, who deduced curves for pine spruce and chestnut showing that Young's modulus along the grain decreased as the moisture increased up to the fibre saturation point, and that further addition of moisture had little or no effect on the value of the modulus. Tiemann thus found that the modulus decreased to a minimum at the fibre saturation point and then remained nearly constant and independent of any further addition of moisture. The reason for the independence of the modulus on the moisture beyond the fibre saturation point becomes evident if it is considered that when the fibres are saturated, any further moisture added is retained in the cells and in all probability cannot further affect the stiffness and strength of the wood.
The Technique of Flight
Authors: Hill R. M.
Published: February 2017

In my last lecture I promised to try and show how the pilot can foresee and effectively eliminate practically all the danger which attends the art of flying. You will probably notice that most of the danger arises, at least indirectly, from some misbehaviour of the engine; so that in estimating the danger I shall be compelled to lay considerable emphasis on the possibility of engine failure, in spite of the fact that it is comparatively remote. If we look back to the infancy of any mechanical means of locomotion, we realise how unreliable it was in the initial stages; we may therefore look forward with absolute confidence to the future reliability of the aero engine and its installation.

Every day almost marks an improvement, and if the early pioneers who lost their lives could trace its development what surprise they would express ! At the same time the possibility of one unreasonable engine failure is a menace to the whole of flying, which cannot and must not be blinked at.
Wind Gusts and the Structure of Aerial Disturbances
Authors: Shaw W. N.
Published: February 2017

Aeronautics is certainly the science of the future and its professors and preachers have the qualities of their science. When you were good enough to ask me to read a paper, by way of opening a discussion this evening, you told me beforehand the subject which I should select. It is a new departure, characteristic of these new times. If you will look at the practice of education in this or any other country you will find that hitherto subjects have been selected, not by those who are to hear, but by those who are to speak. They are the subjects upon which the teacher has already made up his mind. The principle of selection is that the teacher must be able to display superior knowledge and the process of education is a sort of wave of superior knowledge going down from the universities into the most elementary recesses without much regard for what it looks like from the point of view of those hungry for the knowledge of “how it goes,” and still more “why it goes?”

You have provoked this digression by giving me the subject, “Wind Gusts
and the Structure of Aerial Disturbances.”
Lessons Accidents have Taught
Authors: Holden H. C. L.
Published: February 2017

When I was asked some six months ago to contribute a paper to this Society dealing with the lessons to be learnt from the study of the causes of accidents when flying, I agreed to do so because it seemed to me that a discussion upon this subject could not fail to be of interest and advantage to pilots, constructors and others by bringing before them in collective form the accidents, preventable and otherwise, which have happened, and in particular those which have been investigated by the Accidents Investigation Committee of the Royal Aero Club, on which your Chairman of Council, General Ruck, and several other Fellows and Members of the Aeronautical Society are very useful workers.
The Value of Ballooning as a Training for Flying
Authors: Brewer Griffith , Fletcher J. N.
Published: February 2017

Members of this Society may be forgiven if, in view of the glorious progress of aviation, they regard the balloon as an extinct species of aeronautical apparatus. The object of this paper is to show that, in spite of the strides aviation has made, the balloon still has its part to play in the navigation and study of the air, and that those who go to the trouble of making balloon ascents not only reap considerable pleasure by employing that means of transit, but they also learn facts about the atmosphere which may be of service to them in becoming more than mere chauffeurs of aeroplanes.

The best sailors who navigate our steamships have served their apprenticeship on sailing vessels, where they learn the true force and effects of winds and gain a knowledge of the sea not so readily acquired under steam power. In the same way, I venture to suggest that the much–despised balloon is a means for acquiring a knowledge of the atmosphere which cannot be gained when tearing through the air at fifty miles an hour.
The Measurement of Air Speed
Authors: Thurston A. P.
Published: February 2017

It is a matter of extreme importance to be able to measure accurately the speed of the air in any situation and under any condition, because all our knowledge of the dynamical properties of the air is dependent upon a correct measurement of its velocity, and because the safety of a pilot depends upon knowing accurately the speed at which he is flying. He is then able to guard himself against the risk of stalling his machine or of attaining too great a speed. An air speed indicator is really as indispensable to a pilot as a foot rule is to a carpenter or a “hooter” to a motorist.

The velocity of the air may be determined by three main methods.

In the first method the velocity is measured directly by the time taken by a particle, body or substance floating in or dragged along by the air to travel from one point to another.
Wing Adjustments of Pterodactyls
Authors: Howard Short G.
Published: February 2017

In view of the very interesting information about pterodactyls contained in the foregoing paper by Dr. Hankin and Mr. Watson it will be worth while to endeavour to reconstruct the animal and to ascertain as far as possible the effect of the various adjustments upon the shape of the membrane which forms the wing.

This can best be accomplished by a study of the drawings accompanying this paper.

In the first place, it is important to remember that the wing membrane (plainly visible in some of the smaller fossils) doubtless resembled that of a bat in being extremely extensible and elastic. Possibly it had muscles attached to it which could tighten it in various directions and possibly increase and diminish camber. Air pressure upon this membrane would be certain to make the back margin of the wing a curved line with the convexity upward and the front margin of the wing (formed chiefly by the supporting bones) would have to follow this curved line more or less closely, otherwise the angle of incidence would vary excessively in different parts of the wing.
The Manoeuvres of Getting off and Landing
Authors: Hill R. M.
Published: February 2017

The manoeuvres of getting off and landing are to me the beginning and the send of flight; they separate the sheep from the goats; the aristocrat of the flying world uses them for the display of his genius, leaving his would-be imitators to find what consolation they can in the amusement with which they innocently provide the onlookers.

In commercial flying the manoeuvres of getting off and landing are still the most obvious calls on the pilot's skill; and who shall deny the splendid response? But a determination to ease the pilot's task is not thereby for an instant to be excused. This, one of the most urgent problems before applied design to-day, lies in the conflicting requirements of ease and safety in getting off and landing and those of economy and usefulness in full flight. To assist in the statement of this problem is the object of my Paper. These are the manoeuvres perhaps about which most has been said, and, from the pilot's point of view, least written. Since first a heavier-than-air machine left the ground, they have never failed as a topic of conversation throughout the whole flying community; and this has tempted me to analyse them on the basis of my own experience and that of the many pilots I have known.
The Design of Aeroplane Control Surfaces, with Special Reference to Balancing
Authors: Irving H. B.
Published: February 2017

In a recent article in “ Engineering ” the writer has given an account of the principles which govern the design of aeroplane control surfaces, making special reference to wing ailerons. Included in the information presented were data on the properties of wing ailerons of the ordinary unbalanced form, but varying in span and chord length and fitted to wing tips of different plan forms. From these data several conclusions of practical importance were drawn, some of them finding general application in the design of control surfaces, and it may be useful to give a résumé of these before proceeding to deal with the balancing of control surfaces.

(i) All ailerons and elevators become relatively inefficient for movements above about 15° to 20° from the normal position, owing to a sudden reduction in the slope of the curve relating moment on machine with angle of aileron or elevator. For movements up to about 15° or 20° the moment is nearly proportional to the angle.
The Rigid Dynamics of Circling Flight
Authors: Bryan G.H.
Published: February 2017

This paper is intended as a sequel to “Stability in Aviation” and deals with* Problem 2 in Chapter XI. (p. 178). The long list of problems there given will show that before the book was written or even commenced, investigations had been projected and contemplated more than sufficient to fill a second volume on the Rigid Dynamics of Aeroplane Motions, my book on stability constituting the fiist. It will be found that the necessity of mathematical investigation in connection with stability, and other aeroplane problems was first mentioned by me in “Science Progress” for October, 1897, and it would have been a great advantageif the completion of most of this work had preceded the first aeroplane flights. With reasonable facilities and assistance, longitudinal stability could have been completed by about ,1900, lateral by 1904; the unwritten second volume would have been in the printers’ hands by January, 1910.
On Observation of Transiently Visible Movements
Authors: Hankin E. H.
Published: February 2017

It is a commonplace of laboratory experience that one or two months' practice may be required to “get one's eye in” for an apparently so simple task as taking the readings of a polarimeter. But it does not seem to be so widely realised that similar practice is necessary to get one's eye in for seeing objects that are only visible for minute periods of time. Consequently, anyone who has had such practice is liable to incur criticism from those who do not realise its nature and value.

Colonel de Villamil is sceptical as to my statement that in certain cases the smoke issuing from a steamer funnel assumes the form of two vortex filaments lying side by side and rotating in opposite directions. The changes of shape of the smoke masses and their rotary movements are so rapid that they are by no means easy to recognise. I have seen the movements in question both on P. and O. steamers and on excursion steamers from Bournemouth. Mr. J. H. Field, of the Agra Aerological Observatory, kindly permits me to state that he has frequently seen the double spiral in steamer smoke as I have described it. His observations were ,made independently of mine and before he had seen my paper. The necessary condition for the formation of the spirals is that a strong wind should be blowing across the top of the funnel.
Note on an Empirical Formula for Aeroplane Strength
Authors: Sutton Pippard A. J.
Published: February 2017

The decision as to what strength shall be given to the structure of an aeroplane is made as a result of previous experience. It is well known that it is quite impossible so to design the structure as to render it unbreakable under any condition of flight without increasing the weight to such an extent that the aeroplane is useless as a flying proposition.

The result has been that load factors have been specified for different types of aeroplanes such as experience has shown will render the structure safe for any reasonable treatment in the air.

The principal factor to be fixed is that for the case when the centre of pressure is in its most forward position. Once this is determined the remainder of the structure can be designed consistently with it.
Note on Flying Boat Hulls
Authors: Hope Linton
Published: February 2017

The following extremely important table, compiled by Major Linton Hope, was inadvertently omitted from the reprint of his lecture in the August issue of the Journal. It should also be noted that the last set of Flying Boat lines, on page 470, is the design which Major Linton Hope made in 1916, after the trials of the 41ft. design, Fig. 2, and to which he refers in his reply to Mr. Baker. It should be noted that the angles of the step tangents to the foreplaning bottom have been increased and the back step reduced in size and moved aft, both of which features appear in C.E.I. designed some considerable time afterwards.
Fourier's Theorem in Aerodynamics
Authors: Bryan G. H.
Published: February 2017

In “Practical Aerodynamics,” Major B. Baden–Powell quotes the following; formulae for the pressure of the air on a moving plane when expressed as a function of the angle of attack α, taking the pressure as unity when α=90°.

I. Duchemin

II. Rayleigh (hydrodynamical)

IIa. Gerlach

III. Renard

IV. Soreau

V. Eiffel, 1907,

VI. Another formula frequently quoted is

and a more complicated formula, depending on the aspect ratio of the plane, has been proposed by Soreau.
Long Tails Versus Short Tails in Aerodynamics
Authors: Bryan G. H. , Brodetsky S.
Published: February 2017

Consider any form of aircraft provided with a small rudder plane placed behind its centre of gravity and at a certain distance l from it, which we may speak of as the length of the tail. When this tail is subjected to a given wind pressure, the moment of this pressure about the centre of gravity, tending to turn the machine round, is proportional to l. From this point of view a long tail is preferable to a short one.

On the other hand, the pressure of the air on the tail plane depends on the normal velocity of the wind relative to it. Hence the normal velocity of the plane itself is limited in magnitude, and the angular velocity with which the machine turns about its centre of gravity must therefore be less when l is large than when lis small; that is, the long–tailed machine turns more slowly than the one with a short tail, and this is a disadvantage.
On the Flight of Locusts
Authors: Hankin H.
Published: February 2017

Some time ago when leaving my laboratory I happened to notice a large number of cheels gliding overhead that seemed to me to show something unusual in their mode of flight. I guessed that they were after locusts, a flight of these insects having passed over Agra three days previously. On reaching my house I found, with the help of my binocular, that my conjecture was correct. The following are the notes that I took at the time:—

IIth August, 1915, 3.0 p.m. A few small thin clouds. Air rather hazy at a height. Wind S, occasionally moving small branches.

A large number of cheels were gliding in a way that seemed to me unusual. They were at heights between 200 and 400 metres. They were generally slow–flex–gliding and did so in all directions and with frequently changing course. Two were seen rapidly losing height, feet foremost. Occasionally they dived or at least glided steeply downwards at speed.
How to Advance the Science of Aeronautics
Authors: Johnson V. E.
Published: February 2017

On commencing the study of .aeronautics it is above all things most important that we should make ourselves thoroughly acquainted with what has already been accomplished in order to save waste of effort on our part in trying experiments or devices already dealt with. Again, it is quite a mistake to suppose that but little, if anything at all, has as yet been accomplished towards the solution of this—the, perhaps, greatest of all mechanical problems. We do possess at last a science, of aeronautics, and a preliminary study of this same science is a sine quâ non; the successes and failures of the past must be carefully studied, as also the apparent causes of such successes and failures; and the principles involved— that is to say, the aerodynamical principles— must be above all things, most carefully studied, in order that the investigator may be perfectly enabled to distinguish between any inadequate proposal, certain to fail, and a design worthy of consideration, investigation, and, perhaps (after careful thought), a practical trial.
Some Aeronautical Experiments
Authors: Wright Wilbur , Dayton O
Published: February 2017

Engineers have, until recent years, fought shy of anything relating to aerial navigation. Those who ventured, in spite of the odium attached to that study, to look into it at all, became very soon satisfied that the great obstacle in the way was the lack of a motor sufficiently light to sustain its weight and that of an aeroplane, upon the air. Fifteen years ago the lightest steam motor was the marine engine weighing 60 pounds to the H.P., while the gas engine weighed very much more; the locomotive weighed 200 pounds per H.P. During the past fifteen years a great change has taken place. Steam motors have been produced weighing only 10 pounds per horse–power, and gas engines have been lightened down to 12½ to 15 pounds per horse–power, so that the status, so far as engineers are concerned, is very greatly changed, and there is some hope that, for some limited purposes at least, man will eventually be able to fly through the air.
What Mouillard Did
Authors: Wright Wilbur
Published: February 2017

The erection at Cairo, Egypt, of a monument to L. P. Mouillard, recalls attention to one of the greatest missionaries of the flying cause which the nineteenth century produced. Mouillard was a Frenchman who passed a large part of his life in Algeria and Egypt, where his attention was attracted, by the wonderful soaring of vultures on fixed wings. His imagination was greatly excited by what he saw, and during the remainder of his life he was like a prophet crying in the wilderness, exhorting the world to repent of its unbelief in the possibility of human flight.In 1881 he published a book called “The Empire of the Air,” which is one of the most remarkable pieces of aeronautical literature that has ever been published.
What Clement Ader Did
Authors: Wright Wilbur
Published: February 2017

Clement Ader was a French electrical engineer, who during the last quarter of the nineteenth century devoted a great deal of study and money to the problem of human flight. In his youth he had become interested in the flight of birds, and at a later period had made a study of bats, with a view to imitating their structure in a flying machine. Between the years 1882 and 1890 he built a number of pieces of apparatus, of which the last, finished in 1890, was fitted with a steam engine.

Having exhausted his own resources, he succeeded in enlisting the aid of the French Government, and proceeded to the construction of a large machine, having a steam motor of 40 horse-power. This apparatus was tried under conditions of great secrecy in October, 1897, at the military field at Satory, near Paris, in the presence of a Commission representing the French Government, but the results were so unsatisfactory that the French Government, which had spent more than $100,000 on the project, refused to advance further funds, and Ader abandoned the attempt to solve the problem.
Appendix G
Authors: Wright Wilbur
Published: February 2017

My brother and I became seriously interested in the problem of flight in 1899, a little more than 12 years ago. Some three years before this the death of Lilienthal, which was mentioned in the newspapers of that day, had brought the subject to our attention and led us to make some inquiry for books relating to flight. But the only serious books we found were by Professor Marey, and these related to the mechanism of bird flight rather than human flight. As our interest at that time was mere curiosity as to what had been done, we did not pursue the subject further when we failed to find books relating to human flight.

Several years later, while reading a book on ornithology, we became interested in studying the appearance and habits of birds, but it soon occurred to us that the really interesting thing about birds was their power of flight. This was a power which seemed to us almost in contradiction of the laws of nature.
Aeroplane Experiments at the Crystal Palace
Authors: Baden-Powell
Published: February 2017

It has often been supposed that one of the greatest difficulties to be overcome before successful aërial navigation can be achieved is the practical balance of the apparatus in mid-air. Whether or not this will really prove a stumbling-block it is impossible, with our present experience, to state with certainty. Several inventors, it is true, have had considerable difficulties in the initial starting of their machines, which have had a way of toppling over as soon as they have been launched into the air. It seems just possible, however, that if the machine could be properly trimmed before starting, all such difficulties might be overcome. We know that small models, if dropped from the hand or lightly thrown forward, will easily upset, if not properly balanced, but which, if the weights be carefully adjusted beforehand, will fly steadily enough on their downward course.
An Airtight Balloon Car for High Ascents
Authors: Short Eustace , Short Horace Leonard
Published: February 2017

It gives us great pleasure to have this opportunity of submitting and explaining to you a specially constructed airtight car which we have designed for the purpose of reaching high altitudes.

In the past many attempts have been made to reach great heights in open cars for the purpose of making scientific observations and experiments, and from these experiments it appears that the only difficulty which has been grappled with is that of the insufficiency of air for respiration purposes. To overcome this difficulty the general plan has been to take up in bags or other receptacles a supply of oxygen.

As no attempt, however, has been made to overcome the great inconvenience suffered by the occupants of the balloon, due to the exceedingly low pressure at these high altitudes, these many attempts, in spite of the oxygen supply taken, have been fraught with great inconvenience and danger.
The Development of the Aëroplane
Authors: Baden-Powell B.
Published: February 2017

The day is undoubtedly drawing near when we shall be utilising the highway of the air for travel, and it is becoming an interesting question as to what form the motor car of the skies is to take.

A great number of abortive attempts to produce a practical apparatus have thrown considerable light on the prospects. During the last few years we have seen a great development in the construction of navigable balloons, and, in my humble opinion, these many attempts have only shown clearly what immense difficulties have to be contended with, and how little hope there is of our attaining any real success in this direction.
War Kites
Authors: Baden–Powell B.
Published: February 2017

They have said there is nothing new under the sun. But then they probably reckoned without such recent discoveries as Rontgen rays, phonographs, and wireless telegraphy, amongst others. Yet, on the other hand, it is very remarkable how people pass by good inventions and good ideas, and won't take to them. Kites, for instance, have been known for hundreds of years. Everyone knows of them all the world over, yet, till a few years ago, no one thought of putting them to any use. When I say no one, I do not mean that exactly, for Franklin and others, of course, used kites for meteorological experiments; Pocock drew a little carriage along with them, and several others suggested their use for lifesaving at sea. But these are the exceptions that prove the rule. They drew attention to the utility of the invention, yet went no further.

Suddenly, and only during the last three or four years, inventors have taken up this longneglected contrivance, land now we hear of new and improved kites being experimented with by many different people in many different countries.
Notes on Some Recent Experiments in Aërodynamics
Authors: Alexander P. Y.
Published: February 2017

On the occasion of the launching of the first balloon in Italy, a very interesting discussion was raised with regard to raising surfaces in the atmosphere and propelling them downwards — as to whether we experienced the same resistance. Professor Hergesell, of Strasburg, very kindly arranged for some experiments to be carried out. The apparatus was rigged up, and we tried spheres and discs of varying diameters; but with the spheres we were very much bothered, and I may say our chief trouble was with the vertical currents in the tower of the Cathedral. However, the experiments are still going on, and so far we have found that the spheres rise vertically quicker than they descend. It is rather difficult to understand this.
Notes on an Aluminium Kite
Authors: Burgoyne Alan H.
Published: February 2017

I have made many kites subsequently, and of many different forms, but always came back to that represented in the photographs before the meeting. It resembles in some particulars that of Mr. Cody, though I had made it long before I had seen or heard of Mr. Cody's kite. The essential difference is in the wings, where I do away with the eccentric protuberances which he favours. One particular feature I would point out is my employment of steel springs to fly the kite from at the kite-end of the connections. Mr. Cody employs all his springs at the winder end, but I find the double use of springs renders the flight of the kite infinitely more steady.
Some Simple Experiments with Aero–Curves
Authors: Merrill A. A.
Published: February 2017

In the summer of 1898 I constructed a full sized gliding machine with which I made many short flights, ranging from fifty to one hundred feet. This machine was constructed on the plans of the Herring soarer used by Mr. Octave Chanute in his experiments on the borders of Lake Michigan during the summer of 1896, and, although I was not able to make so long a flight as Mr. Herring did, I acquired some knowledge of the management of the apparatus and the difficulties to be overcome. I used the Lilienthal form of curve, which is the arc of a circle, and the height of the curve is 1/12 the length of the chord.

My experiments showed not only that the problem of stability is a very great one, but that it ia very necessary to find some more efficient form of curve than the circle, in order to reduce the power necessary to drive the machine through the air at a sustaining speed. I, therefore, determined to experiment with various surfaces, until I found one offering much less resistance than the one I was using.
Some Remarks on Aërial Flight
Authors: Wenham F. H.
Published: February 2017

During the past year considerable advance has been made on the question of Aeronautics relating to flying arrangements heavier than air (exclusive of balloons). I have always maintained that the power required for bird life has been much over-estimated. Take, for example, the flight of the pelican, which I have often witnessed. A dead bird weighed 21 lbs., with an extent of wings of 10 feet from end to end, speed 70 strokes per minute, each stroke averaging about one foot. It is evident that during a period of gliding flight with motionless wings these sustain the whole weight of the bird. The exertion or force will be during the oscilating or downstroke of the wing against this pressure.
The Valveless Balloon Voyage
Authors:   Fellow of the Royal Meteorological Society
Published: February 2017

When the astronomers next announce an exceptionally brilliant display of the Leonids, for the sake of the balloonists who make elaborate and costly preparations, it is to be hoped they will be more accurate in their calculations. The spectacle of seven shooting stars is in itself scarcely worth such a risk to life and limb as the Eev. J. M. Bacon experienced in his ascent in search of the meteors. But the scientific observer gains fresh experience from every journey he makes into the upper strata of the atmosphere, and probably Mr. Bacon has accumulated a sufficient number of facts to repay him for the suspense and discomfort endured.

The ascent was made under exceptional circumstances. Mr. Bacon, his courageous daughter, and Mr. Stanley Spencer, entrusted themselves to a valveless balloon; for if we accept the term valve in its legitimate sense, the arrangement provided for ripping open the top of the balloon and letting the gas out once and for all cannot be called a valve.
Anton Weczera's Flying Machine
Authors: Broadwell L. W.
Published: February 2017

Mr. Chairman and Gentlemen of the Aeronautical Society:—The flying machine—a working model of which I have now the honour to submit to your critical inspection— is the invention of M. Anton Weczera, a Hungarian architect, who has devoted many years to the study of a question which has such a special interest for your Honourable Society.

I, too, have devoted considerable attention to this subject; but whilst studying the construction of the many flying machines that dispense with the use of an air–bag, I have invariably failed to find in any of them an adequate and reliable lifting capacity, which, in my opinion, is the most essential element in all of them, and without which there can be no practical success.
Lifting Power of Air Propellers, being Experiments with Propellers 30 ft. in Diameter
Authors: Walker William George
Published: February 2017

These experiments were carried out during the latter part of 1899, with the expert and financial assistance of Mr. Patrick Y. Alexandsr, of Experimental Works, Bath.

Experimental Apparatus. Five propellers 30 feet in diameter were tried, lettered A., B., C, D., E., the skeleton structure of the blades was also tested, the different propellers were formed by altering the canvas stretched on the skeleton blades. The skeleton propeller was made as light as possible, and for reasons of strength and lightness, a Mangin type of propeller was used of four blades, the blades b3- ing fixed one behind the other, and connected together by diagonal struts and ties; the blades were 3 feet 1½ inches apart. A pair of blades are thus, from a structural point of view, similar to a “warren” or lattice girder supported at one end, the respective blades cf one pair constituting the upper and lower flanges of the girder; therefore, when the propeller is exerting a thrust, the members of one blade will be in compression, and the other in tension.
The Principle of Relativity
Authors: De Villamil R.
Published: February 2017

The question of “relativity” is much to the front at the present day, and the methods of viewing it may be divided, very roughly, into three classes:—

1.The relativity of space, time, motion, etc. Nothing being absolute— everything relative to something else. This view is very old (it certainly dates back as far as the time of Aristotle), and nearly everybody believes it; although there are still a few people who would like to believe in absolute motion, space, or rest. Even truth, however, is really “relative” ; and this was, apparently, Pilate's view when he scornfully asked, “What is truth?”
The Structure of Gusts
Authors: Turner Charles C.
Published: February 2017

Gusts, says Duchêne, are more frequent when the machine is flying into the wind than with the wind, “for the simple reason that the gusts have a certain speed and the aeroplane therefore meets more of them (in the same space of time).” Elsewhere Duchêne refers to the experience of a pedestrian on a tramway route: in a given time a pedestrian meets more cars than those that overtake him.

I can see no parallel here, however, to meeting or following gusts in an aeroplane. Whether the machine is flying with the wind, or in the opposite direction to the stream of air, it has got to maintain its relative speed to the air: increase or decrease means a lift or a dip. So, as regards gusts in either case, the number met or overtaken would be the same. And it would seem that a following lull should have much the same effect on a machine as a head gust, and vice–versâ.
The de Bradsky Airship
Authors: Schneider Baron V.
Published: February 2017

By kind permission of Baron de Bradsky's widow, I am enabled to give an authentic account of his ideas concerning the “ de Bradsky ” balloon, of its construction, and of the causes that produced the lamentable accident on October 13lh, 1902, in which Baron de Bradsky (Fig. 1) [to the left] and his engineer, Morin [to the right], lost their lives. Baroness de Bradsky thought it due to her husband's memory to have this account published, particularly as the details in the papers at the time of the accident were more or less incorrect, and none of their authors had grasped the fundamental idea which actuated Baron de Bradsky in the construction of his airship ; Baroness de Bradsky was also of the opinion that a reliable account would be of interest to aëronauts in general, and might be of use in solving the numerous and difficult problems which assail them.
The Sailing Flight of the Turkey-Buzzard
Authors: Hugo T. H.
Published: February 2017

The central plain of Mexico is at a considerable elevation, ranging from 3,000 ft. at the frontier to 7,300 in the immediate neighbourhood of the City of Mexico. The air is, consequently, considerably rarefied, and one would suppose that birds would find it difficult to practise sailing and circling flight; but that does not seem to be the case, as, at any time during the day, numbers of turkey-buzzards can be seen sailing or floating and circling with only a rare flap of wing; and, as a proof that rarety of atmosphere does not seem to diminish their sailing powers, I have seen at Tres Marias, a station on the Cuemavaca line, as it crosses the hills bounding the southern limit of the plain, at an elevation of over 10,000, these birds sailing equally gracefully and without any appearance of labour. There can be little doubt that the air at this elevation has less supporting power, and, therefore, it must be compensated for by the greater speed if the upward current, and shows how wonderfully adapted the wing of the turkey-buzzard is for sailing flight, and that at a lower elevation the wing could support more than the weight of the bird.
Mechanical Principles of the Helicopter
Authors: Chatley Herbert
Published: February 2017

In spite of the rapid development of aeroplanes there are many experimenters interested in the helicopter; it will perhaps be useful to consider a few theoretical points in connection with this type of machine upon which recent research has thrown a stronger light.

Propeller Thrust with Full Slip.—The principal question that concerns us is the possible value of the propeller thrust, and it should, at once be noted that it is probable that much larger values are obtainable for this than is possible in the case of the propellers of an aeroplane. Each horse-power employed by the propeller produces 550 ft.-lbs. of work per second.
Steel Tubes, Tube Manipulation, and Tubular Structures for Aircraft
Authors: Hackett W. W. , Hackett A. G.
Published: February 2017

The present decade will pass down into history notorious for many things good and bad. It will be styled a time of improvement in many ways. It will be remembered as covering the period of the world's greatest war, but it will also be remembered among all trades appertaining in any way to engineering as the age of progress in the manufacture and manipulation of steel tubing.

Independent altogether of the stimulus given to the use of tubing for structural work by the advent and advance of aeronautics, the uses to which tubing of steel and other metals is put has increased considerably during the past few years. Much, of course, has been due to the large output of cycles and motor-cycles, but in addition an immense quantity of tubing is used in the construction of motorcars, and in a thousand other productions which it is unnecessary to particularise in this paper.
Some Outstanding Problems in Aeronautics
Authors: Durand W. F.
Published: February 2017

Ten years ago the aeroplane was a curiosity—a means wherewith, by a tour de force, a man might lift himself from the ground and make a hazardous flight through quiet air—a means to attract curious crowds to fenced-in county fair grounds to witness the marvel of a body heavier than air actually rising from the ground and moving under some measure of control through the air, and returning safely to its starting point.

What the aeroplane has become in this short but poignant decade of the world's history, and what it stands for to-day, this audience knows too well to need specification in detail.

It is perhaps well within the limits of conservatism to say that no achievement of man's inventive and constructive genius has undergone more intensive, more rapid, or more potentially significant development than has that of flying with an apparatus heavier than the air in which it moves.
A Rare Ile-2041-Thr Mutation in the ACCase Gene Confers Resistance to ACCase-inhibiting Herbicides in Shortawn Foxtail (Alopecurus aequalis)
Authors: Guo Wenlei , Zhang Lele , Wang Hengzhi , Li Qi , Liu Weitang , Wang Jinxin
Published: February 2017

Understanding the mechanism of herbicide resistance is fundamental for designing sustainable weed control strategies and exploiting herbicides rationally. Shortawn foxtail is a problem grass weed infesting several important crops in China. The repeated use of acetyl-CoA carboxylase (ACCase)-inhibiting herbicides has resulted in herbicide resistance in this weed. The ACCase gene of resistant individuals of a shortawn foxtail population (JSLS-1) has an Ile-2041-Thr mutation. F2 generation seeds, originated from the same heterozygous plant, were harvested, and two homozygous mutant (JSLS-1RR) and wild (JSLS-1SS) populations for the Ile-2041-Thr mutation were obtained. In whole plants, the JSLS-1RR population conferred high resistance to fenoxaprop and clodinafop, moderate resistance to haloxyfop, low resistance to pinoxaden, and no obvious resistance to clethodim and sethoxydim, compared with JSLS-1SS and a proven susceptible population (HNXY-1). A derived cleaved amplified polymorphic sequence (dCAPS) marker was developed to rapidly detect the rare Ile-2041-Thr mutation in the shortawn foxtail population. This is the first report of the cross-resistance pattern of Ile-2041-Thr mutation, and the robust dCAPS marker could quickly detect this mutation in shortawn foxtail.
Goal Striving in Adolescents With and Without Emotional and Behavioral Disturbances Attending Different School Types
Authors: Margraf Hannah , Pinquart Martin
Published: February 2017

Abstract. Adolescents with emotional and behavioral disturbances (EBD) and adolescents attending special schools often show poor academic competence and problems with making career choices. In this context, the processes of goal-striving have not been assessed systematically even though they are related to success and failure in goal attainment ( Heckhausen, Wrosch, & Schulz, 2010 ). Thus, the present longitudinal study compared the levels of domain-specific goal engagement (actively pursuing a goal) and goal disengagement (i. e., postponing goals) and the effects of goal engagement on the attainment of academic competence and career choice of adolescents with and without EBD attending regular versus special schools. Adolescents with EBD reported lower levels of goal engagement and higher levels of goal postponement than adolescents without EBD. For all groups of adolescents, goal engagement at the first measurement predicted stronger progress in the perceived attainment of academic competence at the 1-year follow-up. Conclusions are drawn on how to promote the successful development of students with EBD from regular or special schools.
Metal-centred azaphosphatriptycene gear with a photo- and thermally driven mechanical switching function based on coordination isomerism
Authors: Ube Hitoshi , Yasuda Yoshihiro , Sato Hiroyasu , Shionoya Mitsuhiko
Published: February 2017

Metal ions can serve as a centre of molecular motions due to their coordination geometry, reversible bonding nature and external stimuli responsiveness. Such essential features of metal ions have been utilized for metal-mediated molecular machines with the ability to motion switch via metallation/demetallation or coordination number variation at the metal centre; however, motion switching based on the change in coordination geometry remain largely unexplored. Herein, we report a PtII-centred molecular gear that demonstrates control of rotor engagement and disengagement based on photo- and thermally driven cis–trans isomerization at the PtII centre. This molecular rotary motion transmitter has been constructed from two coordinating azaphosphatriptycene rotators and one PtII ion as a stator. Isomerization between an engaged cis-form and a disengaged trans-form is reversibly driven by ultraviolet irradiation and heating. Such a photo- and thermally triggered motional interconversion between engaged/disengaged states on a metal ion would provide a selector switch for more complex interlocking systems.
Meta-Optical Chirality and Emergent Eigen-polarization Modes via Plasmon Interactions
Authors: Moocarme Matthew , Proscia Nicholas V. , Vuong Luat T.
Published: February 2017

The response of an individual meta-atom is often generalized to explain the collective response of a metasurface in a manner that neglects the interactions between meta-atoms. Here, we study a metasurface composed of tilted achiral meta-atoms with no spatial variation of the unit cell that derives appreciable optical chirality solely from the asymmetric interactions between meta-atoms. The interactions between meta-atoms are considered to stem from the Lorentz force arising from the Larmor radiation of adjacent plasmonic resonators because their inclusion in a simple model accurately predicts the bonding/anti- bonding modes that are measured experimentally. We also experimentally observe the emergence of multiple polarization eigenmodes, among other polarization-dependent responses, which cannot be modeled with the conventional formalism of transmission matrices. Our results are vital to the precise characterization and design of metasurfaces.
MFN2 suppresses cancer progression through inhibition of mTORC2/Akt signaling
Authors: Xu Ke , Chen Guo , Li Xiaobo , Wu Xiaoqin , Chang Zhijie , Xu Jianhua , Zhu Yu , Yin Peihao , Liang Xin , Dong Lei
Published: February 2017

The mitochondrial GTPase mitofusin-2 (MFN2) has previously been reported to play a role in regulating cell proliferation, apoptosis and differentiation in a number of cell types. Here, we report that breast cancer patients with low MFN2 expression are associated with poor prognosis as compared to patients with high MFN2 expression. We find that MFN2 knockout from MCF7 and A549 cells via Crispr/Cas9 greatly promotes cell viability, colony formation, and invasion of cancer cells in vitro and in vivo, which were confirmed by colony formation assay, transwell invasion assay, and tumor xenograft model. Signaling analyses suggest the mammalian target of rapamycin complex 2 (mTORC2)/Akt signaling pathway is highly elevated in MFN2 knockout cancer cells. The elevated mTORC2 promotes cancer cell growth and metastasis via AktS437 phosphorylation mediated signaling pathway. Mechanistic studies reveal that MFN2 suppresses mTORC2 through direct interaction by binding its domain HR1. Inhibition of mTORC2 significantly suppresses MFN2 deficient tumor growth. Collectively, this study provides novel insights into the tumor progression associated with MFN2 deficiency and suggests that the importance of mTORC2 inhibitor in the treatment of MFN2 downregulated cancer patients.
Metamaterial study of quasi-three-dimensional bowtie nanoantennas at visible wavelengths
Authors: Zhao Yukun , Yun Feng , Huang Yi , Wang Shuai , Feng Lungang , Li Yufeng , Guo Maofeng , Ding Wen , Zhang Ye
Published: February 2017

In this paper, a novel array of quasi-three-dimensional (quasi-3D) bowtie nanoantennas has been investigated numerically and experimentally. A low-cost and facile method has been designed and implemented to fabricate the quasi-3D bowtie nanoantennas. The fabrication processes containing laser patterning and wet etching have demonstrated the advantages of easily tuning the periodic and diameter of microhole arrays. According to the simulated results, the electric and magnetic resonances at visible wavelengths are obtained in the tips and contours of the metamaterials made of the quasi-3D bowtie nanoantennas, respectively. The effects of the size and gap of quasi-3D bowtie nanoantennas on the array performance have also been studied. The underlying mechanism suggests that different electric and magnetic resonant ranges of the metamaterials could contribute to the broad resonant range for the monolithic metamaterials.
Dipstick proteinuria level is significantly associated with pre-morbid and in-hospital functional status among hospitalized older adults: a preliminary study
Authors: Chao Chia-Ter , Tsai Hung-Bin , Chiang Chih-Kang , Huang Jenq-Wen , Hung Kuan-Yu
Published: February 2017

Although chronic kidney disease (CKD) is associated with functional decline, whether proteinuria alone is associated with functional statuses over the course of acute illnesses independent of CKD is unclear. During 2014, we prospectively enrolled non-dialysis patients aged ≥65 years, and all participants underwent spot dipstick urinalysis on admission, divided into 3 groups according to the results (none, trace to 1 + , and 2 + or higher); functional status was evaluated using the pre-morbid and in-hospital Barthel index (BI) scores. Of 136 community-dwelling elderly patients enrolled (age 80.7 ± 8.2 years, with 19% having CKD), 17%, 57%, and 26% had no, trace to 1 + , or 2 + or higher proteinuria. Overall pre-morbid, on-admission, and on-discharge BI scores were 50.4 ± 41.9, 38.6 ± 31.8, and 38.7 ± 35.3, respectively with significant negative correlations with proteinuric severity on admission. Finally, multivariate linear stepwise regression analysis with backward variable selection found that dipstick proteinuric severity was significantly associated with pre-morbid, on-admission, and on-dischrage BI scores (p = 0.048, <0.01, and <0.01, respectively), independent of diabetes and CKD. This relationship between dipstick proteinuric levels and functional status of hospitalized elderly suggests an under-recognized association. Prospective evaluation of long-term outcome is needed.