摘要:

The paper describes measurements of the ionisation produced in air by radium sources. Various errors such as scattering from the wall of the ionisation chamber and room, finite size of chamber and source, atomic number of walls of chamber, etc., are discussed in detail.A carefully standardised measuring system is described, and the results of measurements with carbon, magnesium, lead, and paraffin wax chambers are given. A section of the paper is devoted to questions of accurate measurement of radium sources, particularly in relation to the errors which may arise from the use of various types of ionisation chamber.It is concluded that the total charge set free per cubic centimetre of air at N.T.P., at I cm. distance from a point source of I mg. Ra element filtered with 0·5 mm. Pt, is 8·3 electrostatic units per hour.

DOI:10.1259/0007-1285-10-113-365

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

At a meeting of the Institute held on April 15, 1937, the following new member was elected:—Miss J. M. Honeyburne, M.Sc.

DOI:10.1259/0007-1285-10-113-388-a

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

Intervertebral disc defects are readily observed radiologically. Autopsy investigations by the Dresden Clinic have provided more detailed conceptions of the structure, function, and pathology of the discs. The significance of radiological changes both in youth and age may now be more truly assessed.It becomes more and more evident that the adolescent disc frequently reveals a weakness or defect which may have considerable influence on disc integrity in later years.Radiological observations in vertebral epiphysitis are of considerable interest in view of the Schmorl—Scheuermann controversy.

DOI:10.1259/0007-1285-10-113-389

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

The appearance of this second annual will be welcomed by all students of French radiology and electro-therapy, for it gives an excellent epitome of the chief contributions which have been made in that language during the period 1934–5.

DOI:10.1259/0007-1285-10-113-407

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

The Commonwealth X-ray and Radium Laboratory, University of Melbourne, has been established by the Commonwealth Department of Health, in conjunction with the Council of the University of Melbourne, to serve as the Australian centre for the study of the problems of X-ray and radium therapy. The X-ray standardisation equipment which has been set up in the laboratory for the realisation of the röntgen is described. The free-air ionisation chamber, which is of the Bureau of Standards guarded-field type, serves as the primary standard of X-ray dosage in Australia.The methods of measuring the various quantities involved in a determination of the röntgen are outlined. The accuracy with which the unit is realised is believed to be of the order of 0·5 per cent. Although further work will be carried out in an endeavour to improve the accuracy, that at present obtained is considered adequate for the calibration of clinical dosemeters.It has been found that, by a suitable arrangement of diaphragms, with the tube diaphragm within a few centimetres of the focal spot, an X-ray beam of approximately uniform cross-sectional intensity can be obtained. With such a beam the inverse square law has been found to hold over a wide range of working distances. As a result of this, the calibrations of clinical dosemeters is facilitated.The influence of the humidity of the ionised air is discussed, and the suggestion made by other workers that the röntgen might be better defined in terms of the ionisation produced in unit mass of air is supported.

DOI:10.1259/0007-1285-10-113-408

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

University of Cambridge Examination for the Diploma in Medical Radiology and Electrology, Part I. February 1937

DOI:10.1259/0007-1285-10-113-426

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

In a recent paper1in this Journalwe described a simple photographic method of comparing the intensities of two beams of X rays of approximately the same wavelength. This method was based on one used in Ornstein's laboratory at Utrecht for the microphotometric investigation of spectral lines in the visible and ultra-violet region. It involves the use of ray filters which diminish the intensity of the initial X-ray beams by known amounts There is, however, a still simpler method of obtaining a quantitative estimate of the relative intensities of the two beams which is somewhat less accurate since it depends on the ratios of fairly small intervals of time, but which has the advantage of not requiring calibrated ray filters.It is well known that the Roscoe-Bunsen law,i.t= constant (where i = intensity of light andt= time of exposure), holds in many photo-chemical reactions, but not for the effect produced by the action of light on a photographic emulsion. If a plate or film is exposed to a beam of light for a certain time, then doubling the intensity of the beam and halving the time of exposure does not produce the same effect on the same plate (after developing and fixing), or the same “density” (darkening of the film or plate). In the case of X rays, however, this lawdoesapply very closely; the time which depicts the relationship between the photographic density and time is straight and passes through the origin (Fig. 1).*

DOI:10.1259/0007-1285-10-113-427

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

During the course of a recent clinical investigation, a problem arose in which it was necessary to determine the distribution of radiation intensity in the vicinity of a radium ring which had been pressed into contact with a curved surface.The general problem reduces to that in which the radioactive ringBCPDE(Fig. 1), of radiusr1, is wrapped around the surface of a cylinder, the axis of which isOZ, and the radius of which isa.

DOI:10.1259/0007-1285-10-113-430

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

Dr. H. M. Meyrick-Jones, like so many others, started X-ray and electrical work in the early years of the century while he was still in general practice. Qualifying from Guy's Hospital in 1893, he took the degrees of M.B.(Dur.) in 1896 and M.D.(Dur.) in 1898. He acquired X-ray and electro-therapeutic apparatus, and gradually developed an X-ray and electrical practice in Cheltenham. He was appointed Honorary Radiologist to the General and to the Ear, Nose and Throat Hospitals of that town. As usual in those days, he was much hampered by lack of funds, and built up departments in which he showed much ingenuity in providing make-shift apparatus. During the War he was in charge of the X-ray work at a hospital in Alexandria until invalided home for dysentery. He then spent a year in France, but was recalled to Cheltenham, where a radiologist was urgently needed. In 1921–1922 he was President of the Gloucestershire Branch of the B.M.A., and Secretary of the Radiological Section when it met in Manchester in 1929.

DOI:10.1259/0007-1285-10-113-432

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY

摘要:

The Medical Members' Monthly Meeting was held in the Reid Knox Hall of the Institute on Friday, January 15, 1937, and was attended by about fifty members. Dr. Rowden was in the Chair, and the following cases were shown:—Dr. Hooper: (1) Unilateral sclerosis of the temporal bone following trauma.

DOI:10.1259/0007-1285-10-113-433

出版商:The British Institute of Radiology    

年代:1937

数据来源: WILEY