Ministry of Supply

About: Ministry of Supply is a based out in . It is known for research contribution in the topics: Polarography & Bacillus (shape). The organization has 416 authors who have published 355 publications receiving 8951 citations. The organization is also known as: MoS.

Tropospheric Wave Propagation in a Duct of Non-Uniform Height

Abstract: This paper describes an approximate method for extending the simple mode theory of tropospheric refraction (Booker and Walkinshaw 1947) to cover situations where the refractive index profile varies with range The transmission path is divided into a number of zones, in each of which the variation in the refractive index profile is small In each zone the profile is then taken to be independent of range, and given by the mean profile throughout the zone. The duct-width d and the lapse-rate of modified refractive index at infinite height kinfinity are found for each zone and are used, together with published propagation curves, to evaluate the distribution of radio field strength in the region beyond the horizon of a transmitter Although the method is a general one, the final formula refers specifically to situations in which the field can be adequately described by the first mode alone, and where the mean profile of refractive index in each zone may be represented analytically by a one-half power law curve. An example of the application of the method to a practical situation is given This shows good agreement between experiment and theory, and demonstrates the significant effect of changes in the refractive index profile on the level of field strength The limitations of the method are pointed out, and its extension to cover other types of refractive index profile and higher order modes is outlined

The production of DL‐methionine on a semi‐technical and pilot scale

Abstract: Substantial quantities of DL-methionine were urgently required by the Medical Research Council in England during the latter part of the war. The Ministry of Supply undertook the development up to a pilot scale of a process thought to be suitable for quantity production of methionine of high purity. The results of the first stages of this development, i.e., laboratory research, have already been published.1 The present paper is concerned with the semi-technical and pilot scale development of the process.

The Physics of the Solid-State Maser

Abstract: Since the demonstration of the possibility of achieving very low noise amplification of signals in the centimetric wavebands, a great deal of work has been carried out in various laboratories with a view to producing and testing devices. The major part of the present article focuses attention on one particular device, the three-level solid-state maser. The physical principles underlying the process of stimulated emission of radiation are in many cases unfamiliar to electronic engineers, and study of the growing literature on the subject can be confusing without a clear understanding of the physics involved. The present article outlines the general theory of emission and radiation processes, particularly as they apply to the microwave spectrum. A quantum mechanical description is employed throughout, and a brief and not very rigorous account is given of the relevant portions of this theory as it applies to the investigation of transistors between energy levels. Well-known expressions are derived for the operating characteristics of a three-level maser, particular attention being given to the significance of the various factors involved and their relationship to easily measured quantities. Little information is included concerning practical maser amplifiers; at the time of writing, few practical devices had been constructed. A survey of recent literature indicates the rapid progress which has since been made, and shows the interest in the development of masers.