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Showing papers by "University of Reading published in 1968"


Journal ArticleDOI
TL;DR: When not fully saturated with iron, bovine, human and goat lactoferrins were bacteriostatic for Bacillus stearothermophilus and Bacillus subtilis in both the presence and absence of trace amounts of metals.

315 citations


Book ChapterDOI
01 Jan 1968
TL;DR: Some of the ideas associated with process control systems have already been discussed, and the majority of processes may be controlled automatically by adjusting the rate of flow of energy or material entering the process.
Abstract: Some of the ideas associated with process control systems have already been discussed in §1.4. The majority of processes may be controlled automatically by adjusting the rate of flow of energy or material entering the process. In manually-controlled systems the human operator adjusts the rate of flow by means of a hand-operated valve; he will receive information regarding the state of the process from a measuring instrument giving a visual indication. Manual control has numerous disadvantages and indeed manual control of many modern plants would be virtually impossible, owing to their complexity and the speed and precision of control they require for successful operation.

213 citations



Journal ArticleDOI
TL;DR: In this article, various methods for assessing the extent that the protein has spoiled in stored beef are considered in relation to the various criteria discussed in Part I. From the point of view of routine quality control, the macro-distillation of the volatile nitrogen produced appears to be the most reliable method.
Abstract: Various methods for assessing the extent that the protein has spoiled in stored beef are considered in relation to the various criteria discussed in Part I. From the point of view of routine quality control, the macro-distillation of the volatile nitrogen produced appears to be the most reliable method. From statistical correlations with odour scores, most beef can be considered to be acceptable if the total volatile nitrogen (TVN) and TVN/FF (fat-free) figures do not exceed 16.5 and 19.7 mg N/100 g respectively.

96 citations


Journal ArticleDOI
TL;DR: In this article, the Coriolis constants in the E2g species from the work of Callomon et al. have been recalculated for all of the in-plane vibrations of benzene.

93 citations


Journal ArticleDOI
TL;DR: A formula is developed which predicts the expected daily calorie intake for any level of diet, and it is shown that birds fed high energy diets usually “over‐consume” calories and gain more in weight than birds fed lower energy diets.
Abstract: Synopsis This paper summarises evidence taken from the literature to show the effect of dietary energy level on the voluntary food intake of laying birds. Although groups of pullets offered different diets tend to adjust consumption so as to maintain the same calorie intake, this adjustment is imperfect in the majority of cases. Thus birds fed high energy diets usually “over‐consume” calories and gain more in weight than birds fed lower energy diets. The degree of over‐consumption observed when a particular strain is offered a range of diets of differing energy content is correlated with the characteristic calorie intake of that strain (r = 0.667). Strains with characteristically high energy intakes adjust their food consumption to compensate for differences in energy content of the diet less efficiently than the small strains which have characteristically low calorie intakes. From the relationships demonstrated, a formula is developed which predicts the expected daily calorie intake for any level of diet...

92 citations


Journal ArticleDOI
Eric Jones1

91 citations


Journal ArticleDOI
J. N. Hunt1
TL;DR: In this article, it is suggested that the principal features of wave-like welds are consistent with a mechanism in which the waves arise as a result of hydrodynamic instability between the reentrant jet and the surface along which it propagates.
Abstract: The interface between explosively welded metals frequently exhibits a regular wave-like profile. The circumstances under which such a profile develops are not fully understood, and existing theories fail to predict some of its observed characteristics. In the present paper it is suggested that the principal features of wave-like welds are consistent with a mechanism in which the waves arise as a result of hydrodynamic instability between the re-entrant jet and the surface along which it propagates.

88 citations



Journal ArticleDOI
TL;DR: In this article, the following generalisation of Sperner's result was established: / / (A t,..., A ǫ) e S(k, < w, m) then
Abstract: It is quite easy to see that (2) and (3) give best possible results. Upper estimates for n were also given in [2] if either (Alt..., An)eS(k,

65 citations


Journal ArticleDOI
TL;DR: In this article, a review of the role of food spoilage in industrial control is presented, with suggestions for a coordinated program of study which could help in clarifying some of the difficulties inherent in the application of meat spoilage research.
Abstract: Numerous chemical and physical tests have been described which reflect the biochemical and other changes which occur in meat during storage. Although some work has occasionally included the correlation with organoleptic data, there have been few suggestions as to possible critical legal or control limits. In industrial control, however, each method has to be considered in relation to the purpose intended and semi-empirical tests may be of value provided that the procedure is standardised. Critical maxima based on chemical values have been recommended for white fish, which differs, however, from meat in having a negligible fat content. With meat, protein breakdown usually precedes fat spoilage, but in certain circumstances the order of these reactions is reversed. Recommended limits for meat should take into account both types of spoilage. The review concludes with suggestions for a coordinated programme of study which could help in clarifying some of the difficulties inherent in the application of meat spoilage research in industrial control.

Journal ArticleDOI
01 Jan 1968-Nature
TL;DR: Shinozaki and Kira as mentioned in this paper used a logistic equation of population growth with the law of constant final yield to describe the relationship between plant density and yield, and proved the validity of the logistic equations as tested for different crops.
Abstract: Shinozaki and Kira1 by combining a logistic equation of population growth (equation (1)) with the law of constant final yield (equation (2)) derived equation (3) to describe the relationship between plant density and yield. or where at a given time t, w is the dry weight of each plant and W is the asymptote of w, λ is the coefficient of growth which is independent of plant density ρ, k is the integration constant, determined by the initial conditions and independent of plant density, Y is the final yield/unit area, and independent of density, and W0 is w at t = 0. The law of constant final yield, however, may not always be satisfied (data to be published elsewhere) and the yield in higher densities may decline. In these conditions, equation (3) cannot describe the yield–density relationship. The validity of the logistic equation (equation (1)), as tested for different crops1,2, has proved to be justified so far, and it seems that it is the law of constant final yield which needs further modification.

Journal ArticleDOI
01 Jul 1968-Nature
TL;DR: In this paper, a molybdenum-cysteinato-cysteine complex with trihydrate trihydrates was reported, which can be regarded as a model for molybdoflavo-protein enzymes.
Abstract: RECENT measurements of electron spin resonance1 have indicated that, in the reduced form of the molybdoflavo-protein enzyme xanthine oxidase, molybdenum(V) is coordinated with one or more sulphur atoms, probably ionized thiol groups of cysteine. Molybdenum–sulphur complexes have therefore attracted considerable interest as possible models for molybdenum in enzymes2. Although the chemistry of molybdenum–sulphur complexes is becoming well understood3, there has been little work on complexes with cysteine. Stability constants of complexes of molybdenum(V) and (VI) with cysteine have been reported4, but no complexes have been isolated. We now report the preparation and properties of a molybdenum(V)–cysteine complex, sodium di-μ-oxo-bis {oxo[cysteinato(2-)]aquomolybdate(V)} trihydrate, Na2 {Mo2O4[SCH2CH(NH2)CO2]2(H2O)2}3H2O, and discuss how far it can be regarded as a model for molybdenum in enzymes.

Journal ArticleDOI
M. L. Tiku1
TL;DR: In this article, a relation g(z)∼+βz is used to derive estimators μr and sr of the parameters of a truncated normal distribution and estimators σ and sc of the mean and standard deviation of a logistic distribution from doubly censored samples.
Abstract: Summary Let g(z) be the ratio of the ordinate and the probability integral of the distribution of a variate z. The relation g(z)∼+βz is used to derive (i) estimators μr and sr of the parameters of a truncated normal distribution and (ii) estimators μc and sc of the mean and standard deviation of a logistic distribution from doubly censored samples. The variances and eovariances of these estimators are obtained. They are shown to be nearly as efficient as the maximum likelihood estimators and easier to compute.

Journal ArticleDOI
TL;DR: A study of nineteen species of monotocardian veligers belonging to eight different superfamilies revealed the uniformity of structure of the alimentary tract up to the time of metamorphosis as mentioned in this paper.
Abstract: A study of nineteen species of monotocardian veligers belonging to eight different superfamilies reveals the uniformity of structure of the alimentary tract up to the time of metamorphosis. Results of feeding experiments with nineteen species of unicellular algae show that there is also uniformity in the functioning of the gut.


Journal ArticleDOI
TL;DR: From statistical correlations with odour scores, most meats were considered acceptable provided the FFA did not exceed 1.2% (calculated as oleic acid on the extracted fat), and several of the other fat spoilage methods considered gave values which rose during the storage period to a maximum and then either remained constant or decreased steadily to a very low figure.
Abstract: Various methods for assessing the extent to which the fat has deteriorated in stored beef are considered in relation to various criteria discussed in Part I. From the point of view of routine quality control, the titrimetric determination of free fatty acids (FFA) appears to be the most reliable method. From statistical correlations with odour scores, most meats were considered acceptable provided the FFA did not exceed 1.2% (calculated as oleic acid on the extracted fat). Several of the other fat spoilage methods considered gave values which rose during the storage period to a maximum and then either remained constant or decreased steadily to a very low figure. Most fresh samples gave peroxide values of 0.1-1.0 mequiv./kg (on the extracted fat), but a critical limit of 5 might be applied under practical conditions.

Journal ArticleDOI
01 Jul 1968-Nature
TL;DR: Extended-chain lamellae (ECL) as mentioned in this paper is a type of polyethylene polymers that is typically composed of thin (100 A) lambs in which the long (103-105 A) molecules lie transversely in chainfolded configurations.
Abstract: THE texture of crystalline polymers is typically one of thin (100 A thick) lamellae within which the long (103–105 A) molecules lie transversely in chain-folded configurations In certain circumstances, however, much thicker lamellae, often as thick as the molecular length, have been observed in polyethylene1–3 An example is shown in Fig 1 Because a variety of evidence indicates little or no chain-folding in these layers (that is, the molecules, which lie across them, are essentially in extended configuration) they have become known as extended-chain lamellae (ECL) in contrast to the more familiar folded -chain lamellae (FCL) The circumstances in which ECL form are: (i) growth at low supercoolings for long times1 and (ii) by recrystallization under high pressure2,3 The layers themselves vary in thickness, being most regular in slowly crystallized samples1 In pressure crystallized material, thicknesses varying by a factor of two for the same lamella, and ten for different ones, have been observed3 ECL are also mechanically very different from FCL, because the toughening effect of molecules crystallizing through several lamellae must then be small In fact ECL are no longer plastic but waxy as befits their paraffinoid structure It is, however, the growth of ECL that has provided a long standing problem in polymer physics

Journal ArticleDOI
TL;DR: In this article, the rotational band contour of the 0-0 band of phenol at 2750 $\overset{\circ}{\mathrm A}$ has been recorded experimentally with a resolving power of 300 000.
Abstract: The rotational band contour of the 0-0 band of phenol at 2750 $\overset{\circ}{\mathrm A}$ has been recorded experimentally with a resolving power of 300 000. The contour contains many characteristic features of which a series dependent on K$\_a$ has been used to obtain trial sets of rotational constants A', B' and C' in the electronically excited state. The excited state was assumed to be planar. These data together with rotational selection rules were used in an asymmetric rotor band contour computer program and the rotational constants varied until the computed contour matched the observed. The contours were matched only by using type B selection rules. The electronic assignment is therefore $^1$B$\_2$-$^1$A$\_1$ (using the C$\_{2v}$ point group) and the excited state rotational constants are: $A' = 0.1773 \pm 0.0002 cm^{-1}; B' = 0.08751 \pm 0.00006 cm^{-1}; C' = 0.05859 \pm 0.00001 cm^{-1}.$ These constants reflect an appreciable interaction of the hydroxyl group with the ring in the excited state whereas microwave data have shown very little interaction in the ground state. In particular, there is a slight overall contraction of the molecule along the long in-plane inertial axis from the ground to the excited state in contrast to an expected expansion if there were no hydroxyl group interaction. The origin of the 2750 $\overset{\circ}{\mathrm A}$ 0-0 band is at 36 348.7 $\pm$ 0.2 cm$^{-1}$.

Journal ArticleDOI
TL;DR: In this article, a nonlinear analysis of the conditions necessary and sufficient for a function of many variables to have a stationary local minimum when its second variation is only semi-definite is presented.
Abstract: This paper contains an original investigation of the conditions which are necessary and sufficient for a function of many variables to have a stationary local minimum when its second variation is only semi-definite. The approach is to determine the order of contact which the function makes with the space of the variables upon which it depends. The analysis is slanted towards potential energy functions in order to get conditions for the colloquial stability of a conservative system. The sequence of governing equations are shown to be specializations of equations defining equilibrium paths which are explored in part I. They are characterized by variational principles. The classical notions of neutral equilibrium and buckling modes are re-examined in the light of this nonlinear analysis.

Journal ArticleDOI
TL;DR: In this article, a theory of the observed dependence of exciton series spectra on crystal thickness is presented, and the effective confinement of the exciton bound states, by the uncertainty principle, raises the kinetic energy.
Abstract: A theory is presented of the observed dependence of exciton series spectra on crystal thickness [2,3]. When the latter is comparable to the Wannier exciton radius the effective confinement of the exciton bound states, by the uncertainty principle, raises the kinetic energy. This confinement is introduced by the boundary condition which requires the Wannier wave function to vanish outside the crystal. Allowance is made for thick crystal anisotropy, and its effects on the binding energy calculated for the low excited states. Es wird eine Theorie fur die gemessene Abhangigkeit der Exzitonenserienspektren von der Kristalldicke [2,3] vorgeschlagen. Wenn die Kristalldicke mit dem Wannierschen Exzitonenradius vergleichbar ist, so erfordert das Unbestimmtheitsprinzip, das die effektive Beschrankung der angeregten Exzitonenzustande die kinetische Energie erhoht. Diese Beschrankung wird durch die Grenzbedingung eingefuhrt, das die Wannierfunktion auserhalb des Kristalls verschwindet. Die Anisotropie bei dicken Kristallen wird berucksichtigt, und ihr Einflus auf die Bindungsenergie wird fur niedrig liegende, angeregte Zustande berechnet.

Journal ArticleDOI
TL;DR: In this paper, the effect of time of application of nitrogen and potassium on the growth, development and yield of the second early variety Craig's Royal was studied by the technique of growth analysis.
Abstract: The effect of time of application of nitrogen and potassium on the growth, development and yield of the second early variety Craig's Royal was studied by the technique of growth analysis. There was an indication that witholding nutrients led to the earlier initiation of tubers, but this was of no practical consequence and all treatments affected tuber bulking rate rather than the duration of bulking. Compared with early application, late application of nitrogen depressed tuber yield, although total drymatter yield was not affected. Late application of potassium, however, increased tuber yield; this was associated with an improvement in the recovery of applied potassium. Delaying the application of nitrogen also resulted in its more efficient recovery in the crop. Late application of potassium improved the recovery of early applied nitrogen and vice versa. Reasons are put forward to account for these effects.

Journal ArticleDOI
C. J. Summers1, R. B. Dennis1, B. S. Wherrett1, P. G. Harper1, S.D. Smith1 
TL;DR: In this article, the electron-phonon coupling of optical lattice modes to the magnetic states of both conduction and donor electrons in InSb has been made in the Faraday configuration, where no plasma interaction is present.
Abstract: Detailed examination of the electron-phonon (polaron) coupling of optical lattice modes to the magnetic states of both conduction and donor electrons in InSb has been made in the Faraday configuration, where no plasma interaction is present The striking discontinuity observed in linewidth as the cyclotron-resonance frequency (${\ensuremath{\omega}}_{c}$) passes through the longitudinal-optic-mode frequency (${\ensuremath{\omega}}_{\mathrm{LO}}$) has been studied at temperatures of 15 and 88\ifmmode^\circ\else\textdegree\fi{}K for donor concentrations from 5\ifmmode\times\else\texttimes\fi{}${10}^{13}$ to 1\ifmmode\times\else\texttimes\fi{}${10}^{15}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ The smaller effect of a simultaneous shift in the frequency of magnetic absorption is also observed in this configuration Similar effects are found for both conduction and bound electrons, and both are explained on the basis of a one-phonon-interaction model developed by Harper

Journal ArticleDOI
TL;DR: Branchiura sowerbyi Beddard was probably introduced to Britain with exotic plants consigned to botanic gardens and power station effluents and it followed that at 20°–25°C the growth of sexually mature worms was probably depressed by the high rate of cocoon production.
Abstract: Branchiura sowerbyi Beddard was probably introduced to Britain with exotic plants consigned to botanic gardens. The British populations occur mainly in artificially warmed habitats such as lily ponds in botanic gardens and power station effluents but a few are found at natural temperatures. Branchiura completed its life cycle in about a year both in the river Avon, Wiltshire, at natural temperatures and in the warm effluent from a power station discharging into the river Thames. In a worm culture maintained at natural temperatures the rate of cocoon production reached a peak in summer and was closely related to temperature. In the laboratory it was found that the optimum temperature for cocoon laying in mature worms, also growth in sexually immature worms, was near 25°C. The optimum temperature for growth in sexually mature worms, however, was lower (10°C in the Avon population and 15°C in the Thames population). It followed that at 20°–25°C the growth of sexually mature worms was probably depressed by the high rate of cocoon production.

Journal ArticleDOI
TL;DR: The ordinary absorption spectrum of MoS2 contains two series of exciton absorption bands associated with direct optical transitions from a split valence band as discussed by the authors, and the exciton series limit in thin crystals is determined from the oscillatory magneto absorption which occurs to the high energy side of the short wavelength series.
Abstract: The ordinary absorption spectrum of MoS2 contains two series of exciton absorption bands associated with direct optical transitions from a split valence band. In thick crystals the first five members of each exciton series have been detected; these exciton bands move to higher energies and show a diminishing diamagnetic shift with decreasing crystal thickness. The exciton series limit in thin crystals is determined from the oscillatory magneto absorption which occurs to the high energy side of the short wavelength series. Das normale Absorptionsspektrum von MoS2 enthalt zwei Serien von Exzitonenabsorptionsbanden, die mit direkten optischen Ubergangen von einem aufgespaltenen Valenzband verbunden sind. An dicken Kristallen sind die ersten funf Linien beider Serien gemessen worden; bei abnehmender Kristalldicke werden diese Exzitonenbanden zu hoheren Energien hin verschoben und zeigen eine verminderte diamagnetische Verschiebung. Die Grenze der Exzitonenserien wird in dunnen Kristallen von der oszillatorischen Magnetoabsorption bestimmt, die auf der Hochenergieseite der kurzwelligen Serien eintritt.


Journal ArticleDOI
TL;DR: In this article, the one-phonon, band-mode, infrared absorption spectra activated by antimony, arsenic, boron, oxygen and phosphorus in silicon, and by isolated nitrogen atoms and radiation damage centres in diamond have been investigated.
Abstract: The one-phonon, band-mode, infrared absorption spectra activated by antimony, arsenic, boron, oxygen and phosphorus in silicon, and by isolated nitrogen atoms and radiation damage centres in diamond have been investigated. Absorption features attributed to in-band resonances are observed in most cases. Neither the shape nor the strength of the absorption spectra can be accounted for adequately in terms of the isotopic-defect theory of Dawber & Elliott. In the case of silicon, the absorption strengths suggest that the effective charge is not confined exclusively to the impurity atoms.

Journal ArticleDOI
Eric Jones1
TL;DR: The incidence of fire damage in southern England fell off steeply about 1780 as mentioned in this paper, due to a spreading movement to build or rebuild in brick-and-tile instead of "mud", timber and thatch, reinf...
Abstract: The incidence of fire damage in southern England fell off steeply about 1780. This is traced to a spreading movement to build or rebuild in brick-and-tile instead of ‘mud’, timber and thatch, reinf...

Journal ArticleDOI
TL;DR: Recordings of fixation eye movements were made in the presence of flickered illumination using both the optical lever and strain gauge techniques and it was found that for low frequency fucker (⩽3 c/s) the saccade rate increased significantly and that there existed a definite time relationship between the onset of the light phase of the flicker and the occurrence of a saccades.

Journal ArticleDOI
TL;DR: In this article, the theory of Sah, Noyce and Shockley is modified by assuming the recombination centres to be nonuniformly distributed, and a current/voltage relation can be obtained in the form I ∝ exp (eV/mkT), where m lies between 1 and 2.
Abstract: If the theory of Sah, Noyce and Shockley is modified by assuming the recombination centres to be nonuniformly distributed, a current/voltage relation can be obtained in the form I ∝ exp (eV/mkT), where m lies between 1 and 2.