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 High-frequency fatigue tests

1925 ◽  
Vol 109 (749) ◽  
pp. 119-143 ◽  
Keyword(s):  
Mild Steel ◽  
High Frequency ◽  
High Speed ◽  
Fatigue Testing ◽  
National Physical Laboratory ◽  
Fatigue Tests ◽  
Research Committee ◽  
Engineering Research ◽  
Physical Laboratory ◽  
The Cost

The experiments on high-frequency fatigue in copper, Armco iron, and mild steel described in the following paper were carried out in the Engineering Laboratory, Oxford, for the Fatigue Panel of the Aeronautical Research Committee. The cost of the apparatus was defrayed by a grant from the Engineering Research Board of the Department of Scientific and Industrial Research. In 1911 Prof. B. Hopkinson called attention to the importance of ascertaining whether the fatigue limit of metals was dependent on the rate of alternation of stress. He designed and made an electric alternating directstress machine, and published the results of tests on mild steel carried out at about 7,000 periods per minute (116 per second), which was more than three times as fast as any tests made up to that time. The results at this speed were compared with those made by Dr. Stanton at the National Physical Laboratory on the same material at 2,000 periods per minute (33 per second). Prof. Hopkinson considered that the results showed that speed had a marked effect, but he did not consider that his tests were conclusive. In the light of the knowledge gained on fatigue testing since that date neither set of tests can be considered satisfactory. The question is of importance to the users of high-speed machinery. It is also of importance when comparisons are made between tests carried out at different speeds, and, finally, it has a bearing on the causes of fatigue failure. For these reasons it appeared to be desirable to make a more thorough investigation, and, if possible, to extend the tests to very much higher speeds.

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.

Alloys Research Committee: The Work of the Alloys of Iron Research Committee

1934 ◽  
Vol 127 (1) ◽  
pp. 277-298 ◽  
Author(s):  
C. H. Desch
Keyword(s):  
National Physical Laboratory ◽  
Basic Material ◽  
High Melting Point ◽  
Research Committee ◽  
Laboratory Methods ◽  
Physical Methods ◽  
X Ray ◽  
Upper Limit ◽  
Physical Laboratory ◽  
Systematic Knowledge

The Alloys Research Committee of The Institution of Mechanical Engineers began its work in 1890, and from 1902 onwards the investigations were conducted in the National Physical Laboratory. The Eleventh Report, published in 1921, dealt very fully with the light alloys of aluminium. At that stage it was decided that further research should be devoted to the alloys of iron with the object of determining the fundamental nature of the alloys of iron with various metals and non-metals to serve as a basis for a more systematic knowledge of the steels used in practice. The investigation has comprised the construction of equilibrium diagrams using thermal, microscopical, X-ray, and other physical methods. Iron being more sensitive to the influence of minute quantities of impurities than most other metals, it was necessary to prepare very pure iron as the basic material. Since 1921, the alloys of iron with oxygen, phosphorus, silicon, chromium, and manganese have been studied. As all the alloys are of high melting point, many new laboratory methods have had to be developed, the technique of experiments at high temperatures becoming more difficult the higher the upper limit is raised. In the course of the research, therefore, it has been necessary to prepare new refractories and to design special forms of apparatus in order to avoid contamination. The paper contains a summary of the results obtained in the course of the work, and it is shown how these bear upon the improvement of steels for structural and engineering purposes. The investigation is being extended to other elements, and ultimately to the influence of more than one solid element when present simultaneously in the alloy.

Steels for Steam Power Plant

1953 ◽  
Vol 167 (1) ◽  
pp. 414-433
Author(s):  
A. M. Sage
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
National Physical Laboratory ◽  
Research Association ◽  
Creep Tests ◽  
Steam Power ◽  
Iron And Steel ◽  
Steam Power Plant ◽  
Physical Laboratory ◽  
High Temperature Steam

A review of the work carried out for the Steels for High Temperature committee of the British Electrical and Allied Industries Research Association between 1930 and 1952.† In this paper the achievements of the J/E committee between the years 1930 and 1952 are reported. Development of steam power plant largely depends on the physical properties of the materials. Realization of the effects of creep in metals has caused creep data to supersede Hooke's law in the determination of design methods for steam power plant. The study of the effects of creep properties in different steels led to the adoption of chromium- molybdenum, and chromium-molybdenum-silicon and, to a less extent, molybdenum-vanadium steel for the high-temperature components; superheater tubes, steam pipes, and superheater headers for plant using temperatures above 900 deg. F. From creep tests made, the stress-time relation for each component was obtained. Methods of creep testing are compared, and abnormally high creep rates are investigated. The testing of the reliability of long-time creep tests deduced from short-time creep tests is described. Relaxation tests carried out enabled a mathematical relation between relaxation time and stress to be derived. Investigations into the effects on the properties of the steel, of the presence of minor elements in the steel, and the method of manufacture, are described, and also the cause and effects of grain growth. The causes of, and means of avoiding, cracking of steel are studied. Future developments are outlined. FOREWORD C. H. Desch, D.Sc, Ph.D., F.R.S. Chairman of the Steels for High Temperature Committee of B.E.A.I.R.A. Since 1930 the Steels for High Temperature committee of the British Electrical and Allied Industries Research Association has fostered work on the properties of steels used in steam power plant. The committee was formed from the committee of the Department of Scientific and Industrial Research on the behaviour of materials at high temperatures, at a time when the importance of the phenomenon of creep in designing high-temperature steam power plant was being realized. The committee has always included in its membership representatives of leading steel makers, tube manufacturers, turbine builders, and boiler makers. The Admiralty has also been well represented and, also since their formation, the British Electricity Authority and the British Iron and Steel Research Association. The views of metallurgists and engineers concerned with the production and use of high-temperature steels have thus been combined in furthering co-operative work which has effectively contributed to advances in the design and efficiency of British steam power plant. The work of this committee has thus formed an integral part of the development of high-temperature steels which has been made by British industry over the last twenty years. The committee has throughout the work had the co-operation of the Engineering and Metallurgy Divisions of the National Physical Laboratory where most of the investigational work has been carried out. This work has been supported financially by the steel-making and the appropriate user industries. Since the inception of the committee in 1930 a number of detailed technical reports have been issued on various problems which it has investigated. The following report has been prepared to provide an overall picture of the major achievements of the committee. Although he has not been concerned with experimental work, Mr. Sage has had access to all reports and papers connected with the research. The value of the contributions of numerous investigators at the National Physical Laboratory is acknowledged, and Dr. Jenkins and Mr. Tapsell should be specially mentioned as having taken a leading part in the investigation since its inception.

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 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 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 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.

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