Showing papers by "Imperial Chemical Industries published in 1965"
TL;DR: In this article, the authors derived a flow equation for pseudoplastic flow that is associated with the formation and rupture of structural linkages in both aqueous and nonaqueous media.
1,703 citations
TL;DR: A new method for finding the maximum of a general non-linear function of several variables within a constrained region is described, and shown to be efficient compared with existing methods when the required optimum lies on one or more constraints.
Abstract: A new method for finding the maximum of a general non-linear function of several variables within a constrained region is described, and shown to be efficient compared with existing methods when the required optimum lies on one or more constraints. The efficacy of using effective constraints to eliminate variables is demonstrated, and a program to achieve this easily and automatically is described. Finally, the performance of the new method (the "Complex" method) with unconstrained problems, is compared with those of the Simplex method, from which it was evolved, and Rosenbrock's method.
1,285 citations
488 citations
241 citations
TL;DR: This paper describes a variant of the generalized secant method for solving simultaneous nonlinear equations and it is shown that for suitable problems the method is considerably superior.
Abstract: This paper describes a variant of the generalized secant method for solving simultaneous nonlinear equations. The method is of particular value in cases where the evaluation of the residuals for imputed values of the unknowns is tedious, or a good approximation to the solution and the Jacobian at the solution are available. Experiments are described comparing the method with the Newton-Raphson process. It is shown that for suitable problems the method is considerably superior.
123 citations
TL;DR: In this article, it was shown that the meta-stable peaks in mass spectra are abnormally wide and that this extra width is associated with release of kinetic energy during fragmentation.
Abstract: Certain of the “meta-stable peaks” in mass spectra are abnormally wide. This extra width is shown to be associated with release of kinetic energy during fragmentation. Methods are presented for measuring this energy release and values are given for various transitions in the spectra of aromatic nitro compounds.
98 citations
TL;DR: The differences in biosynthesis between mycobactin T and P are discussed and their components have fatty acid side chains that are mostly different from the side chains of the components in myc Cobactin P preparations.
Abstract: 1. A growth factor for Mycobacterium johnei has been isolated from Mycobacterium tuberculosis as an iron complex; it has been named ferric mycobactin T. 2. Ferric mycobactin T as isolated is a mixture of at least four closely related components differing only in their fatty acid side chains. 3. Mycobactin T resembles mycobactin P in structure but differs in the following respects: (a) the aromatic acid residue is salicylic acid in place of 2-hydroxy-6-methylbenzoic acid; (b) the hydroxy acid residue is (+)-beta-hydroxybutyric acid in place of (-)-3-hydroxy-2-methylpentanoic acid; (c) its components have fatty acid side chains that are mostly different from the side chains of the components in mycobactin P preparations. One minor component in mycobactin T has probably a cis-octadec-2-enoyl side chain. The major side-chain components correspond to acids of chain length C(18)-C(21) that are not n-saturated or n-Delta(2)-unsaturated acids. 4. The differences in biosynthesis between mycobactins T and P are discussed.
83 citations
TL;DR: In this paper, the authors derived a theoretical solution for the contact area of a cylinder compressed between two rigid planes when the cylinder is a transversely isotropic elastic body, given in terms of the elastic constants, the radius of the cylinder and the applied load and was found to hold experimentally.
Abstract: A synthetic fibre monofilament was compressed between transparent fiats mounted on a microscope stage, and an image of the contact area thrown onto a screen. The contact area was determined as a function of load for polyethylene terephthalate, polypropylene and nylon monofilaments. These monofilaments can be regarded as transversely isotropic elastic cylinders and show considerable anisotropy, the extensional modulus being at least six times the transverse modulus. A theoretical solution was therefore derived for the contact area of a cylinder compressed between two rigid planes when the cylinder is a transversely isotropic elastic body. The solution is given in terms of the elastic constants, the radius of the cylinder and the applied load and was found to hold experimentally. The theory was used together with measurements of Poisson’s ratio and extensional modulus to derive the transverse modulus of the filaments from the compression experiments. In polyethylene terephthalate and polypropylene the calculated moduli are in reasonable agreement with those obtained directly from uniaxially oriented films.
73 citations
TL;DR: The concentration of butylated hydroxytoluene in the fat and liver of rats fed on diets containing 0·5 and 1·0% BHT for up to 50 days has been determined by a colorimetric method, and it is probable that the excretion of BHT metabolites is delayed by an enterohepatic circulation.
69 citations
62 citations
TL;DR: A technique of back-flushing gas chromatographic columns is described which avoids the use of taps in the sample path and can be located outside the oven at ambient temperature, consequently the apparatus is easy to construct and existing chromatographs can be readily modified.
TL;DR: In this article, the photochemical degradation of gramoxone herbicide was studied and a complete understanding of the behaviour of its active constituent, paraquat, in all circumstances was provided.
Abstract: THE establishment of world-wide and varied uses of ‘Gramoxone’1 herbicide requires a complete understanding of the behaviour of its active constituent, paraquat, in all circumstances. The present report is concerned with the photochemical degradation of the chemical.
TL;DR: In this article, the effects of dilution in various organic solvents on the proton and 13C chemical shifts (at natural abundance) of the methyl group have been measured for the polar solutes methyl iodide and acetonitrile.
Abstract: The effects of dilution in various organic solvents on the proton and 13C chemical shifts (at natural abundance) of the methyl group have been measured for the polar solutes methyl iodide and acetonitrile. The results are discussed in terms of the distortion of the solute molecule by its electrostatic interaction with the surrounding medium (reaction field effect). Using an expression for the reaction field derived from the spherical cavity model of Onsager, it is found that the results cannot be accounted for by inserting the static dielectric constants e for the solvents. The results are, however, consistent with effective dielectric constants intermediate between the static values e and the optical values n 2; this suggests that the correlation times for random re-orientation of the solute molecules are comparable with the dielectric relaxation times of some of the solvents. Dielectric saturation in the immediate neighbourhood of a solute molecule must also be considered as reducing the effective diele...
01 Jun 1965
TL;DR: Measurement of liver weight/bodyweight ratios and a quantitative sampling of the extent of liver damage indicated that the maximum amount of damage in all groups of infected rats was present approximately 6 weeks after infection, indicating a degree of competitive inhibition among flukes in the heavier infections.
TL;DR: By the use of x-ray diffraction techniques a method is proposed for the measurement of the "smectic" content (interpreted here as material of intermediate order) of undrawn polypropylene filaments as discussed by the authors.
Abstract: By the use of x-ray diffraction techniques a method is proposed for the measurement of the “smectic” content (interpreted here as material of intermediate order) of undrawn polypropylene filaments. The method involves two estimates of crystallinity by x-ray methods. One is considered to measure the amount of diffraction from the normal crystalline monoclinic lattice and the other the total amount of diffraction from crystalline, “smectic” and noncrystalline material. By separation of these various quantities the amount of “smectic” polypropylene can be deduced. It was found by this technique that the “smectic” content of quenched polypropylene samples decreased from 40°C. onward and approached zero at about 85°C.
TL;DR: Huothane is one of the purest anaesthetics but Fluothane contains traces of four unsaturated hydrocarbons that are relatively toxic and therefore cannot be administered in toxic concentrations.
Abstract: Fluothane (halothane BP), one of the purest anaesthetics, contains traces of some impurities amounting to a total of 0·05 per cent w/w, none of them exceeding 0·01 per cent w/w. Once these impurities had been identified they were synthesized and tested for anaesthetic activity and toxicity. The results of these experiments showed that most of these impurities have low toxicity but Fluothane contains traces of four unsaturated hydrocarbons that are relatively toxic. When Huothane is administered in anaesthetic concentrations, its impurities are diluted to the same extent and therefore cannot be administered in toxic concentrations.
TL;DR: There appears to be no close correlation between the broad-leaved weed species present in the original pasture, the viable seeds in the soil, or the volunteer species in the new sward, and the potential weed flora which may occur in chemically-renewed swards.
Abstract: The viable-seed content of soils under grass swards was investigated in relation to the potential weed flora which may occur in chemically-renewed swards. The viable-seed populations in the top 6 in. of the soils ranged from 46 million per acre for a 1-year ryegrass ley to 1·7 million in an old permanent pasture. On the limited evidence available, there appears to be no close correlation between the broad-leaved weed species present in the original pasture, the viable seeds in the soil, or the volunteer species in the new sward. Large populations of viable seeds of indigenous grass species occurred in most swards, while there was an almost complete lack of seeds of cultivated grasses. The effect of surface cultivation following the application of paraquat to a grass sward is to stimulate the dormant weed seeds in the upper layers of the soil to germinate. If these layers were left undisturbed a relatively weed-free environment would eventually be achieved.
TL;DR: 'Inderal' (II)' (propranolol) has been shown to be about five times more potent than 'Alderlin' as a (3-adrenergic receptor blocking agent and non-carcinogenic to mice•, rats, guinea-pigs or dog.
Abstract: 'ALDERLIN' (1)1 was shown by Black and Stephenson• in 1962 to block specifically cardiac and other (3-adrenergic receptors in laboratory animals. In 1964, Alcock and Bond3 described the production in mice of thymic tumours and other sarcomata a ssociated with the administration of 'Alderlin' , which had not appeared to be carcinogenic to rats, guinea-pigs or doge. 'Inderal' (II)' (propranolol) has recen tly been shown5 to be about t en times more potent than 'Alderlin' as a (3-adrenergic receptor blocking agent and non-carcinogenic to mice•, rats, guinea-pigs or dog.>".
TL;DR: In this article, the synthesis of poly(arylene sulphones) by self-condensation of dinuclear arylsulphonyl chlorides, catalysed by ferric chloride, is described.
TL;DR: A study of the distribution of the antigens in F. hepatica at various stages of development, and in the liver and spleen of experimentally infected rats using globulins labelled with fluorescein isothiocyanate is described.
Abstract: The results are described of a study of the distribution of the antigens in F. hepatica at various stages of development, and in the liver and spleen of experimentally infected rats using globulins labelled with fluorescein isothiocyanate, from rats and sheep infected with F. hepatica . Possible uses of this technique in aiding the diagnosis of fascioliasis are indicated. I wish to thank Dr A. W. J. Broome for a supply of the metacercariae of F. hepatica , and Dr J. S. S. Lowe who kindly isolated and labelled the globulins with fluorescein isothiocyanate. Miss Enid Eccleston gave valuable technical assistance.