scholarly journals National Physical Laboratory Radiocarbon Measurements VI

Radiocarbon ◽  
1969 ◽  
Vol 11 (01) ◽  
pp. 130-136 ◽  
Author(s):  
W. J. Callow ◽  
Geraldine I. Hassall
Keyword(s):  
Measurement Technique ◽  
National Physical Laboratory ◽  
Physical Laboratory ◽  
Made In

The following list comprises measurements made since those reported in NPL V.No changes have been made in measurement technique or in the method of calculating results described in NPL III.

scholarly journals National Physical Laboratory Radiocarbon Measurements VII

Radiocarbon ◽  
1970 ◽  
Vol 12 (1) ◽  
pp. 181-186 ◽  
Author(s):  
W. J. Callow ◽  
Geraldine I. Hassall
Keyword(s):  
Measurement Technique ◽  
National Physical Laboratory ◽  
Term Stability ◽  
Long Term Stability ◽  
Physical Laboratory ◽  
Made In

The following list comprises measurements made since those reported in Radiocarbon, 1969, v. 11, p. 130–136. No changes have been made in measurement technique or in the method of calculating the results described in Radiocarbon, 1965, v. 7, p. 156–161. It was necessary during 1968 to replace all the geiger counters used in the anti-coincidence rings, but the long term stability of background and standard count rates implicit in the use of a 20-week rolling mean has been maintained.

scholarly journals National Physical Laboratory Radiocarbon Measurements V

Radiocarbon ◽  
1968 ◽  
Vol 10 (1) ◽  
pp. 115-118 ◽  
Author(s):  
W. J. Callow ◽  
Geraldine I. Hassall
Keyword(s):  
Measurement Technique ◽  
National Physical Laboratory ◽  
Physical Laboratory ◽  
Made In

The following list comprises measurements made since those reported in NPL IV.No changes have been made in measurement technique or in the method of calculating results

scholarly journals An account of the pendulum observations connecting kew and greenwich observatories made in 1903

1906 ◽  
Vol 78 (524) ◽  
pp. 241-247
Keyword(s):  
National Physical Laboratory ◽  
Base Station ◽  
Central Bureau ◽  
Geodetic Institute ◽  
Secretary Of State ◽  
Physical Laboratory ◽  
The Government ◽  
Made In

1. The observations, of which a brief account is here given, had their origin in the decision of the Government of India to resume the pendulum work which was brought to a close in 1870. Professor F. R. Helmert, Director of the Central Bureau of the International Geodetic Association, to whose advice the India Office is much indebted, recommended the use of a half-seconds pendulum equipment as designed by Colonel von Sterneck. This equipment was ordered through the Geodetic Institute at Potsdam, and the constants for the necessary pressure and temperature corrections were determined there by Professor L. Haasemann, under Professor Helmert’s direction. A redetermination of these constants was made at Kew, at Professor Helmert’s suggestion, and results were obtained in very close accordance with those found at Potsdam. The apparatus gives only relative determinations of gravity; it was thus necessary to select a base station. As Kew Observatory had been the base station of the older Indian pendulum observations it was again selected, Dr. Glazebrook, Director of the National Physical Laboratory, having given permission and promised all necessary assistance. Meantime, a suggestion was made by the Astronomer Royal, and accepted by the Secretary of State for India, that the opportunity should be taken of swinging the pendulums also at Greenwich, thus allowing of a fresh intercomparison of g at Greenwich and Kew.

scholarly journals Leonard Bairstow, 1880-1963

1965 ◽  
Vol 11 ◽  
pp. 22-40
Keyword(s):  
Wind Tunnel ◽  
National Physical Laboratory ◽  
Practical Applications ◽  
Aerodynamic Derivatives ◽  
Physical Laboratory ◽  
Engineering Department ◽  
Tunnel Design ◽  
Wide Experience ◽  
Wind Tunnel Design ◽  
Made In

Leonard Bairstow was born at Halifax in Yorkshire on 25 June 1880 and began his education in the elementary and secondary schools of Halifax. In 1898 he obtained a scholarship at the Royal College of Science, London, where he was a fellow student of H . E. Wimperis, who declared in later years: ‘I remember that, for several decades there, the most brilliant student that had been produced by the College was Professor Bairstow. He had an uncanny faculty of making himself acquainted with and making completely original suggestions on subjects which we did not think he knew anything about.' He became a Whitworth Scholar in 1902 and took prizes in mechanics and astrophysics. In 1904 he entered the Engineering Department of the National Physical Laboratory. There he worked under Dr T. E. (later Sir Thomas) Stanton on problem s of fatigue and of aerodynamics. In 1909 he was appointed to the staff of the new section of Aerodynamics (later called the Aerodynamics Division), of which he became the Assistant (or Principal) in charge. During this period he carried out some pioneer investigations into wind-tunnel design, and made important developments and practical applications of the theory of aircraft stability due to G. H. Bryan. This theory he illustrated by the use of small mica models of aircraft, and the necessary measurements of aerodynamic derivatives were made in the wind tunnel. In 1917 he was elected a Fellow of the Royal Society and made a G.B.E. Glazebrook had offered him the post of Superintendent of the Aerodynamics Department at the N.P.L. but Bairstow resigned and was appointed to the Air Board to work for Sir David Henderson on the design of aircraft and on aerodynamics research. There Bairstow worked at the Hotel Cecil as deputy to Alec Ogilvie and, with his wide experience, was able to co-ordinate the departmental work on structural strength, aerodynamics, performance and air screws.

scholarly journals A centrifugal method of making small pots of electrically fused refractory materials

1925 ◽  
Vol 107 (742) ◽  
pp. 287-290
Keyword(s):  
Internal Surface ◽  
National Physical Laboratory ◽  
Research Committee ◽  
Ferrous Alloys ◽  
Iron And Steel ◽  
Glazed Surface ◽  
Physical Laboratory ◽  
Usual Manner ◽  
Time Required ◽  
Made In

The present paper describes portion of a research on the alloys of iron, which being carried out at the National Physical Laboratory, under the direction Dr. W. Rosenhain, for the Ferrous Alloys Research Committee. Papers dealing with other portions of the work have been published in the ‘Journal the Iron and Steel Institute.’ In the course of a research on the alloys of iron and oxygen, it became necessary to hold two immiscible layers of molten iron and iron oxide at a temperature of 1,540°C. It was not found possible to hold the liquid oxide at this temperature in any pot made by bonding together previously shrunk fractory material in the usual manner; such refractories as were not directly attacked became “wetted” by the oxide, which was absorbed and an out through the pores of the pot. Experimental melts of very small quantities of oxide were made in small hollows in pieces of solid fused magnesia having a glazed surface; these showed practically no absorption of the oxide by the magnesia. Attempts were therefore made to produce a pot of pure magnesia, having an inner surface completely glazed by fusion, in the heat of a electric arc. The experiments were ultimately successful, and a method as been developed for making well-shaped pots having a glazed internal surface of fused material not only in magnesia (M. P. 2,800°C.), but also in alumina (M. P. 2,050°C.), zirconia (M. P. 2,700°C.) and tungsten metal (M. P. 3,300°C.). The time required to produce a pot (having procured the material to be fused in the form of a powder) is about 15 minutes, the time actual fusion under the arc being about 2 minutes. Two views and ertical section of magnesia pots made by the method to be described are hown in fig. 1 (p. 288).

scholarly journals Iron of high purity

1935 ◽  
Vol 153 (878) ◽  
pp. 172-200 ◽  
Keyword(s):  
High Purity ◽  
National Physical Laboratory ◽  
The Past ◽  
Oxygen System ◽  
Physical Laboratory ◽  
Metallurgy Department ◽  
Purity Iron ◽  
High Purity Iron ◽  
Commercial Iron ◽  
Made In

During the past eleven years (1925-35) several equilibrium diagrams involving iron as one of the components have been investigated at the National Physical Laboratory. The provision of the numerous alloys required for these researches has necessitated the production of quantities of high purity iron. Tritton and Hanson, when they began work on the iron-oxygen system at the National physical Laboratory, considered that the best commercial iron then obtainable was unsuitable for their work, and in the period 1922-24 prepared iron electronically according to the method of Cain, Schram, and Cleaves. At first the present authors produced iron in a somewhat similar manner, but when improvements in analytical methods revealed impurities in samples originally considered satisfactory, alterations were made in the method of preparation. Comprehensive analyses indicate that the latent batch of iron prepared the authors is very low in impurities, yet the physical properties of this material suggest that some disturbing factor may still be present. The problem is apparently complex and a rapid solution appears unlikely In these circumstances it was thought that the present publication of data concerning several batches of iron prepared at the National Physical Laboratory would serve a useful purpose. In addition to information obtained by the authors, particulars of a batch of iron prepared by Mr. W. E. Prytherch, M. Sc., also of the Metallurgy Department, N. P. L., are included, together with occasional results obtained by older members of tde staff. The results of Tritton and Hanson ( loc. cit .) are omitted, how-ever, as these have already been published.

scholarly journals X. The aerodynamics of a spinning shell

1921 ◽  
Vol 221 (582-593) ◽  
pp. 295-387 ◽  
Keyword(s):  
National Physical Laboratory ◽  
The Other ◽  
Scientific Interest ◽  
Physical Laboratory ◽  
Heavy Work ◽  
General Scientific ◽  
Made In

This paper contains the results, theoretical and experimental, of work undertaken, at the request of the Ordnance Committee, by the authors as Technical Officers of the Munitions Inventions Department. Permission to publish such parts as appear to be of general scientific interest has now been granted by the Ordnance Committee and the Director of Artillery. The publication of this paper has received their sanction. The experiments in question were carried out at the firing ground of H. M. S. “Excellent,” Portsmouth; the Experimental Department, H. M. S. “Excellent,” also provided the 3-inch guns used and the material for the construction of the range. The authors’ best thanks are due to the officers of this department, especially Lieut.-Commander R. F. P. Maton, O. B. E., R. N., without whose cordial co-operation these experiments could never have been carried out; also to the other officers of the Munitions Inventions Department who assisted in the heavy work of making and analysing the observations. The aeronautical measurements at low velocities, required for comparison, were made in the wind channels of the National Physical Laboratory, by arrangement with the Director and the Superintendent of the Aero­nautical Department, to whom also we wish to express our thanks.

The Drag Effects of Roughness at High Sub-Critical Speeds

1950 ◽  
Vol 54 (476) ◽  
pp. 534-540 ◽  
Author(s):  
A. D. Young
Keyword(s):  
Surface Roughness ◽  
Reynolds Number ◽  
High Speed ◽  
National Physical Laboratory ◽  
Appreciable Effect ◽  
Drag Effect ◽  
Physical Laboratory ◽  
Mach Numbers ◽  
Constant Mach Number ◽  
Made In

Measurements were made in the Royal Aircraft Establishment High Speed Tunnel of the drag of a wing with various grades of surface roughness in the form of camouflage paint. The measurements were made for a range, of Reynolds number from about 4.5 × 106 to about 15 × 106 at a constant Mach number of 0.2, and for a range of Mach numbers from 0.2 to about 0.7 at a constant Reynolds number of 4.5 × 106 and to about 0.6 at a constant Reynolds number of 6.0 × 106. It was found that for the range of Mach numbers tested compressibility had no appreciable effect on the drag increase due to roughness (Figs. 2 and 3). Further, the drag effect of each roughness tested was such that an equivalent size of sand roughness Ke, of the type tested by Nikuradse, could be readily associated with it. For each finish tested a number of roughness records were taken by means of a roughness gauge developed by Dr. Tomlinson, of the National Physical Laboratory (Fig. 5).

The Design and Work of the Farnborough High Speed Tunnel

1948 ◽  
Vol 52 (448) ◽  
pp. 205-250 ◽  
Author(s):  
A. Thom ◽  
W. G. A. Perring
Keyword(s):  
High Pressure ◽  
Wind Tunnel ◽  
High Speed ◽  
Laboratory Tests ◽  
National Physical Laboratory ◽  
Two Dimensional ◽  
Physical Laboratory ◽  
Made In

The importance of the effects of compressibility on the performance and behaviour of high speed aircraft has been appreciated for a great many years, but in this country it was not until 1937 that serious attention was given to the design of a wind tunnel that would enable the study of compressibility to be undertaken by tests on models of reasonable scale. Prior to 1937 the work which had gone on had established the characteristics of a few aerofoils and simple shapes; at Farnborough the work mainly related to the testing of high tip speed propellers, while at the National Physical Laboratory tests had been made of a two-dimensional character on aerofoils, these tests being made in a small wind tunnel driven on the injector principle, by air discharged from a high pressure reservoir.

scholarly journals Investigations in absolute radiometry

1937 ◽  
Vol 161 (904) ◽  
pp. 1-38 ◽  
Keyword(s):  
Radiation Intensity ◽  
National Physical Laboratory ◽  
Independent Evidence ◽  
Late Professor ◽  
Physical Laboratory ◽  
The Subject ◽  
Improved Design ◽  
Single Instrument ◽  
New Instruments ◽  
Made In

Of modern British work seeking to establish a scale of radiation intensity the most important is that of the late Professor H. L. Callendar (1910), who developed a very accurate instrument, the Callendar Radio-balance, for measuring radiation. Subsequently Callendar used the radio-balance to calibrate various types of radiometer produced by British instrument makers. After his death, arrangements were made for this work to be continued at the National Physical Laboratory. The instrument used to establish a scale of radiation intensity at this Laboratory was a radio-balance made to an improved design of Callendar’s shortly before his death. It was made in the Physics workshops of the Imperial College of Science and calibrated at the National Physical Laboratory as described in the second of these papers. Other scales, notably those known as the Smithsonian Scale of 1913 and the Ångström Scale, have also been employed in this and other countries, particularly for the calibration of meteorological instruments; and it has been recognized for some time that these scales are not in agreement. The discrepancies indicated the importance of obtaining independent evidence of the accuracy of the N. P. L. scale rather than continuing to rely on the properties of a single instrument. Accordingly, the first steps taken in a long investigation, which ultimately led to complete justification of the faith reposed in the radio-balance, concerned the development of absolute radio-meters of an entirely different type. Descriptions of these new instruments, and of the method of using them, form the subject of this first paper.

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