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.

Solvent effects on infra-red group frequencies

Abstract: In previous publications we have shown that solvent effects on group frequencies can be studied conveniently by plotting the relative frequency shifts ∆ ν/ν of one solute in a series of solvents, directly against the corresponding values for some other (Bellamy, Hallam & Williams 1958). Thus, ∆ ν/ν the values for the NH stretching frequency of pyrrole yield a linear plot against the ∆ ν/ν values for any other X —H stretching absorption such as the O—H of methanol or the B—H of decaborane. These relations hold over a wide range of different solvents, and each X H compound has a characteristic slope when plotted in this way against a common standard. The slopes measure the relative proton donating powers of the solutes. Similar plots have been obtained for a large number of carbonyl compounds (Bellamy & Williams 1958). Here the pattern of solvent effects is altogether different from that given by X —H links as the dipole available for solvent association is reversed. The sensitivity of individual carbonyl compounds to solvent effects varies widely and seems to depend upon a number of different factors.

The symmetrical vibrations of a thin elastic plate

Abstract: In recent years, the theory of integral transforms—often in the guise of ‘operator calculus'—has been employed to obtain the solutions of a wide variety of problems in mathematical physics, particularly in the theory of vibrations. The most commonly employed transforms are those of Fourier, Laplace and Mellin; in problems where the range of one of the variables is (0, ∞) or (− ∞, ∞) these transforms have often been used with success to reduce a partial differential equation in n independent variables to one in n − 1 variables and hence to simplify the boundary value problem involved. In this paper we consider some simple problems in the theory of elastic vibrations in which the Bessel, or Hankel, transform is more useful than those mentioned above and is consequently employed throughout. In the first instance we consider problems in which the variable to be eliminated from the differential equation ranges from 0 to ∞ so that the theory of Hankel transforms is directly applicable; the application of finite intervals is then extended to the Hankel transform by a method similar to that used by Doetsch in his treatment of the Fourier transform.

The spectrum of modulated pulses

Abstract: Some methods proposed for evaluating the spectra of modulated pulse trains are discussed. The basic pulse-frequency, -phase, -length and -amplitude modulation systems are defined and the spectrum of a train of rectangular pulses sinusoidally modulated in any one of these ways is derived. Modulation by more than one tone is also considered. It is shown that in none of these methods is there any harmonic distortion or audio crosstalk. Anharmonic distortion arises from sidebands of harmonics of the pulse repetition frequency, and graphs are given to illustrate its magnitude. The formulae are extended to cover non-rectangular pulses, and it is shown that the distortions to be expected are practically the same as for rectangular pulses. The reproduction of transients is briefly examined. It seems that they suffer little distortion in form but that their timing is modified by the pulse modulation, the maximum time-shift being half the pulse repetition period.

Oximes and atropine in sarin poisoning

Abstract: Three oximes, monoisonitrosoacetone (MINA), pyridine-2-aldoxime methiodide (PAM) and diacetylmonoxime (DAM), have been examined in combination with atropine as antidotes in sarin poisoning. When treatment was administered 15 min. before sarin, atropine enhanced the protective effect of MINA and DAM 2 to 3 times and of PAM 9 to 10 times in mice and rats. In mice, rats, and guinea-pigs, atropine increased by no more than 2 times the protective effect of all three oximes when given 30 sec. after sarin. Atropine given to monkeys 1 min. after sarin raised the LD50 approximately 3 times. When given in conjunction with MINA or DAM, the LD50 of sarin was raised 7 to 14 times.