38 results for 1950, Doctoral

  • The geography of manufacturing of Auckland : a study in economic geography

    Linge, G. J. R. (1959)

    Doctoral thesis
    University of Canterbury Library

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  • The contemporary New Zealand town: A study in urban geography

    Pownall, L. L. (1955)

    Doctoral thesis
    University of Canterbury Library

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  • The absorption spectra of lead halides in water-methanol mixtures and the dissociation constants of intermediate ions.

    Panckhurst, M. H. (1953)

    Doctoral thesis
    University of Canterbury Library

    Garrels and Gucker have discussed the deviation of the behaviour of lead chloride solutions from that of a strong electrolyte in terms of both of the Gronwall-La Mer-Sandved extension of the Dbye-Huckel theory and of incomplete dissociation. They conclude that the postulate of incomplete dissociation leads to the more satisfactory treatment of the data but reveal that the various methods of determining the degree of dissociation of the intermediate ion PbCl+ are not in agreement. We here report an extensive investigation of the absorption spectra of lead halides in a range of water methanol mixtures form which we derive dissociation constants for the species Pbcl+, PbBr+, PbI+ in water and mixed solvent at 18°C. We will review the methods which have been used and will later discuss their validity in some detail. Having established the presence of intermediate ions in solution w will discuss the nature of these ions, particularly as regards their bond type and stability in solution. We will also discuss the nature of the absorption process and will attempt a correlation of observed absorption spectra in the crystalline and liquid phases, in terms of a proposed mechanism for the absorption process, and of a proposed absorption spectrum criterion for the nature of complex ions in solution.

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  • A microcalorimetric study of the influence of lead ions on the heat of dilution of potassium halides, and the derived thermodynamics of ion association in solutions of the lead halides.

    Austin, J. M. (1956)

    Doctoral thesis
    University of Canterbury Library

    Recently the association constants for the formation of the complex ions PbCl+, PbBr+, PbI+ have been determined by measurements of the ultraviolet absorption spectra of the corresponding lead halide solutions. In determining these association constants no assumptions are made about the nature of the complex ion except that a chemical potential may be assigned to it and that the law of Mass Action is applicable to the equilibrium Fb++ + X- [] PbX+ where X- = Cl=, Br-, or I-. According to the Bjerrum theory of ion association it is considered that complex ions are formed by electrostatic forces between pairs of ions separated by any distance between that of the minimum distance of closest approach å of a pair of ions and the Bjerrum minimum distance q. When the association constants for the above reaction were used in conjunction with Bjerrum theory to calculate values of the minimum distance of closest approach å they were found to give results much smaller than the sum of the ionic radii of the lead and halide ions. It has been usual to explain such an observation by suggesting that the bonding in the complex is predominatly covalent. From a review of the theory of electrolyte solutions with reference to ion association, however, it is concluded that such an assumption is not valid because of the rather arbitrary value of the Bjerrum minimum distance q. In order to find more evidence for the formation of complex ions in solution and to try and elucidate the nature of such ions, a microcalorimeter has been used to investigate the influence of lead ions on the heat of dilution of potassium halide solutions. If the complex ion PbX+ exists in lead halide solutions then the complex should be formed when a solution of lead perchlorate is mixed with a potassium halide solution. From the properties of lead perchlorate, potassium halide and perchloric acid solutions one would expect that any difference between the heat of dilution of a potassium halide solution in lead perchlorate and perchloric acid solutions should be due to the formation of complex ions, provided the ionic strength of the undiluted and final solutions are the same in each case. A twin differential microcalorimetric system has been designed and built to measure the heat effects associated with the above dilutions. Because of the small heat effects usually associated with the dilution of an electrolyte, temperature changes were measured by an eighty junction copper-constantan thermal and a Paschen galvanometer circuit sensitive to 2x10-6°C or 10-3 cal. The calorimeters were housed in an air-bath which was immersed in a thermostat electronically regulated to maintain the temperature constant to within 0.001°C. Measurements of the heat of solution of potassium chloride crystals were made to check the apparatus and calorimetric technique.

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  • The effect of angularity on the shearing strength of sands

    Gentry, S. C. (1956)

    Doctoral thesis
    University of Canterbury Library

    An attempt has been made in this thesis to analyse the factors which affect the shearing strength of dry sand, as given by Coulomb’s Equation S = p tan φ. Experiments have been carried out using sands of varying angularities and comparing results with those for glass beads. Uniform and ungraded samples were also considered.

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  • Cylindrical aerial radiation and propagation.

    Cummins, J. D. (1955)

    Doctoral thesis
    University of Canterbury Library

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  • The effect of a fused benzene ring on the reactivity of benzene derivatives

    Wilson, A. F. (1957)

    Doctoral thesis
    University of Canterbury Library

    In applying the Hammet equation the naphthyl derivatives, the fused benzene ring may be regarded as a group attached to a corresponding phenyl derivative, and its influence on reactivity may be discussed in terms of the Hammet substituent constant δ. Such discussion, in the case of a 1-naphthyl derivative is severely limited because the electronic effect (which is measured by δ) is masked by steric effects, the magnitude of which cannot normally be determined. Simple reactions of 2-naphthyl derivatives are free from such steric complication. The Analysis of date already published has revealed that, although the 3:4-benzo substituent has almost invariably been assigned a single δ value, there is apparently marked variation in the δ values required for different reactions. In the present investigation three reactions have been studied. The reactions were so chosen that (a) any past studies aided the interpretation of the present results and (b) the required δ values covered the range indicated by the analysis of data available in the literature. The reactions studied were as follows: (1) The reaction of benzoyl chloride with 1- and 2-naphthylanine in benzene was studied at 10°, 25°, 35°and 45°. (2) The solvolysis in ethanol of phenyl-1-naphthylcarbinyl chloride and of phenyl-2-naphthylcarbinyl chloride was examined at four temperatures over the range 5°-25°. For this reaction other data available were insufficient to obtain an accurate value of the reaction constant ρ, which is required for the calculation of a δ₃:₄-benzo value. Consequently the reaction kinetics of phenyl-m-bromophenyl-, phenyl-m-chlorophenyl-, phenyl-m-methylphenyl, phenyl-m-nitrophenyl- and diphenylcarbinyl chloride, were also examined in this reaction. These compounds were studied over the range 25°-75°. (3) The kinetics of the hydrolysis of ethyl 1-naphthyl-ethyl 2-naphthyl- and ethyl phenylacetate were investigated at four temperatures over the range of 20°-50°. It was clear from the present results, taken in conjunction with other data, that the δ values required for the 3:4-benzo substituent fall into significantly different classes. The difference may be linked ti the type and extent of conjugation possible between the substituent and the functional group in the reactant and transition states of these reactions. The reality of the differences in δ values, and the explanation for such differences, are discussed. For the reactions of 1-naphthyl derivatives studies in the present work, discussion of the 2:3-benzo substituent in terms of δ values is not meaningful without the accurate assessment of steric effects.

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  • Steric effects on reactivity in some naphthalene derivatives

    Wong, E. (1957)

    Doctoral thesis
    University of Canterbury Library

    In order that a better understanding of the relative reactivity of α- and β-naphthalene derivatives be attained, two approaches have been made to evaluate the magnitude of steric effects associated with some α-naphthalene derivatives. The rates of reaction in nitrobenzene of methyl iodide with pyridine, quinoline, isoquinoline, 2-methylquinoline, and 8-methylquinoline, have been studied over the temperature range 10 - 50°. In following the kinetics of these slow reactions, a convenient and precise conductometric method has been used. Relative heats of activation were taken as quantitative measures of steric strains present in the activated complexes in these reactions. Using evidence advanced by H.C. Brown and his co-workers in their work on strained homomorphs, kinetics results obtained from the quinoline series have been used to evaluate steric strains present in the structures: 1-methylnaphthalene, 1 , 2-dimetlwlnaphthalene, and 1,8-dimethylnaphthalene.. Steric strains associated with these structures were found to be larger than those of comparable alkyl-benzene structures. This has been attributed to the rigidity of the fused ring system as compared with an alkyl group. The rates of acid-catalysed esterification of benzoic, α-naphthoic, and β-naphthoic acids in absolute methanol, and the rates of alkaline hydrolysis in 56% (w) acetone-water mixture of the methyl and ethyl esters of these acids have also been studied over the temperature range 15 - 60°. Rates were followed by acid-base titrations. For the α-derivatives the methods of R.W. Taft have been adopted to separate quantitatively the effect of the fused ring into polar and nonpolar factors. A σ*value for the fused ring in the a-naphthyl system was calculated. The apparent absence of a steric strain effect in these reactions of the α-naphthyl derivatives has been explained through considerations of steric inhibition of resonance. .An estimate of the magnitude of the steric strain in the transition states of these reactions has been made. This value is of the same order as the steric strains found for the quinoline bases in their reaction with methyl iodide. Results for the (3-derivatives were analysed by means of the Hammett equation and α σ value for the fused ring in the β-naphthyl system has been calculated. From a comparison of the σ and σ * values the conclusion was reached that the polar effects of the fused ring system on the reactivity of α- and β-naphthalene derivatives are very similar.

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  • The heats of solution of rare gases in water

    Alexander, D. M. (1954)

    Doctoral thesis
    University of Canterbury Library

    The intercorrelation of data obtained from the measurement of quantities connected with the solution of gases in liquids has led to a number of empirical laws (e.g. Henry’s Law, Just’s Law) which in turn have led to attempts at theoretical justification. Attention has of course been devoted to the theoretical justification for deviation from these laws. The measurable quantities have been: (a) Solubility under various conditions (b) Molal volumes of gases in liquids These appear to have been the only quantities used. The limited scope of the data has the effect of placing great strain on the accuracy. Much of the data is discordant. Reviews of interrelationships of these quantities and the relation of the quantities to the properties of the pure components of the mixture have been published.

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  • The effect of alkyl substituent-groups on the base-catalysed hydrolysis of amides

    Thomson, A. L. (1954)

    Doctoral thesis
    University of Canterbury Library

    The alkaline hydrolysis of amides follows a simple two stage mechanism, the first stage being addition of a hydroxyl ion and the second being addition of a hydroxyl ion and the second being decomposition to form the reaction products. The mechanism may be represented wither as a addition and retrogression reaction or as a nucleophilic substitution reaction. The addition reaction requires an intermediate with definite independent existence while the substitution reaction requires a transition complex with no finite period of existence. Ingold has discussed this question and has concluded that the position actually assumed is probably between the two extremes with an intermediate stabilised by mesomerism. The existence of an intermediate with a finite life has been experimentally established in the case of ester hydrolysis which is in many ways a similar reaction. The status of the intermediate in the amide reaction, as a molecule, can be assumed by analogy. The reaction is thus not a simple substitution reaction but on the other hand it is not necessarily an addition reaction as normally understood. The most acceptable interpretation of experimental results appears to be given by assuming a resonant intermediate of the dual reaction mechanism as suggested by Ingold. The rate-controlling step in the reaction mechanism is the addition of the hydroxyl ion and it is thus found that electron-attracting substituent groups on the amide accelerate, and electron-repelling groups retard, the reaction. Bevan, Hughes and Ingold have found that in some nucleophilic substitution reactions the loss of the displaced group constitutes the rate-controlling step in the reaction but experimental evidence shows that this is not so for the base-catalysed hydrolysis of amides. Alkyl-groups are electron-repelling in nature and, as expected, are found to reduce the rate of hydrolysis when compared with the unsubstituted amide. The electronic properties of alkyl groups are the sum of two different effects brought about in different ways, an inductive effect and a hyperconjugative effect. In the series methyl, ethyl, iso-propyl and tert-butyl, the inductive effect increases while the hyperconjugative effect decreases through the series. Published data on similar compounds suggests that, in the simple aliphatic amides where the alkyl groups are directly bonded to the reacting group, the order of reactivity should be dictated almost entirely by the inductive effects of the alkyl groups. In the para-substituted benzamides on the other hand, where the amide group is separated from the substituent by the conjugated unsaturated system of the benzene ring, the conditions for hyperconjugation are comparatively much more favourable. The reactivity order may then be either inductive, hyperconjugative, or a mixture of both. All three of these reactivity series have been observed experimentally for different compounds which were not greatly different structurally from the p-alkylbenzamides. The actual reactivity order existing in these amides under a give set of experimental conditions cannot be forecast in any way. In p-alkyl-aromatic compounds, the order or reactivity as well as being considerably effected by minor structural changes may also be altered by changing experimental conditions. This has been observed in ethyl p-alkylbenzoates when the solvent was changed from aqueous ethanol to aqueous acetone. In the work here reported, as study of the kinetics of hydrolysis, in excess of sodium hydroxide in water, of alkyl-substituted acetamides and of p-alkylbenzamides has been carried out. The significance of the experimental results so obtained is discussed.

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  • Heats of mixing

    Adcock, D. S. (1954)

    Doctoral thesis
    University of Canterbury Library

    The object of this investigation was to test some recent theories of the equilibrium behaviour of liquid mixtures. Much theoretical work has been done on this subject, but very few experimental measurements have been made on mixtures simple enough to be satisfactorily described by the models proposed. This work was undertaken to provide data for simple mixtures that could be expected to be reasonably well described by the theoretical models.

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  • The K-series emission spectrum of neon : a study on the excitation of X-radiation in some gaseous elements by means of an electrodeless discharge, and an analysis of the radiation, in the case of the inert gas neon, with a bent crystal vacuum spectrograph

    Moore, Horace Raymond (1954)

    Doctoral thesis
    University of Canterbury Library

    Experiments are reported in which the inert gases argon and neon were subjected to a high-voltage electrodeless discharge. The characteristics of the discharge were studied, and a theory of the mechanism of origin of the emitted x-radiation is proposed. The construction of a composite X-ray, incorporating both orthodox electrodes and an electrodeless discharge tube is described. This involved the building of a vacuum evaporating unit. Details are given of the construction of a photographically recording bent crystal vacuum spectrograph. Using a mica crystal, the working range of the instrument is about 5-19kX in the first order of reflection, the inverse linear dispersion being about 37 X/mm at 15 kX. A spectroscopic analysis of the X-radiation emitted by the inert gas neon is described. Twenty-one K-series lines were recorded, many of them for the first time. The majority of the lines have been identified and the wavelengths measured in all cases. The shapes of the main neon lines were obtained on an intensity scale, and their half-width values, uncorrected for possible diffraction breadth, were determined. As the result of these investigations certain conclusions are drawn.

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  • The kinetics of the substitution of mesitylene and 1,3-dimethyl-5-tertiary butyl benzene with nitric acid, iodine monochloride and iodine

    Barwell, M. R. (1954)

    Doctoral thesis
    University of Canterbury Library

    While the hyperconjugative effect has been established in benzene ring substitution (1), the conditions under which it occurs have not been fully investigated. In the present work a series of rate measurements were made dilatometrically on the reactions of the two compounds mesitylene and 1,3 dimethyl 5 tertiary butylbenzene with the substituting reagents nitric acid, bromine, iodine monochloride and iodine.

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  • A geiger counter concave grating spectrometer for measuring intensities of X-rays of wavelengths between 20 and 400A

    Rogers, J. L. (1952)

    Doctoral thesis
    University of Canterbury Library

    It was decided to attempt the construction of a spectrometer which would make possible the precise measurement of intensities of x-rays in the wavelength range 20-400A. A Geiger counter was chosen as the detector and it was decided to use a concave grating so that a resolving power comparable to that of modern photographic spectrographs could be obtained. The spectrometer was constructed and adjusted and an estimation was made of the effect on the focus of errors in the adjustment. A Geiger counter was constructed and was fitted with a thin celluloid window to permit the entry of the soft X-radiation. When it was found that the plateau position the counter drifted seriously, an electronic method was designed to overcome this drift. Several tests were made on the performance of the spectrometer. After a further adjustment the error in focus was found to be negligible. It was shown that the counting rate, when corrected by a calibration obtained with two radium needles, was accurately proportional to the intensity of X-radiation received. An attempt was made to measure the broadening, by the instrument, of an X-ray line – only partial success was obtained. And finally, the width of the two principle lines of the tungsten emission doublet NIV,V – NVI,VII were measured and a previously unreported component of this spectrum was found. There is some evidence that this line is a satellite of the NIV – NVI transition

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  • Some effects of desiccation of clays in relation to their compression

    Kidson, C. B. (1956)

    Doctoral thesis
    University of Canterbury Library

    Laboratory tests of compression, shrinkage under air drying conditions and measurements of negative pore water pressures were made on some clays in the natural and remoulded states, with a view to gaining information on the effects of desiccation on the compression characteristics of fine grained soils and the relationship between negative pore water and effective pressures.

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  • Maupassant the man, as revealed in his works

    Whale, Patricia F. D. (1950)

    Doctoral thesis
    University of Canterbury Library

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  • The significance of method in intellectual tasks : a study based upon an analysis of intelligence test errors

    Lawrence, Philip John (1955)

    Doctoral thesis
    University of Canterbury Library

    Some years ago, the writer completed a thesis, in the course of which an attempt was made to clarify some of the psychological problems involved in the concept of “work", and to relate these to educational techniques . This led to a consideration of the relationship between "output" and "method", and an appraisal of some of the outstanding studies in industrial psychology in so far as they were relevant to educational problems of the same general type. One of the problems centred around the study of work methods - e.g. study habits and skills, and some of the implications of these methods of improving performance, for example the relation of performance to capacity in intellectual tasks. Since that time, the problem has undergone several stages of transformation and has finally materialised in the form of this thesis. A brief account of these transformations will put the present thesis topic in perspective, and account for the particular way in which it has been handled.

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  • The Historical and Psychological Significance of the Unorganized Games of New Zealand Primary School Children

    Sutton-Smith, Brian (1953)

    Doctoral thesis
    Victoria University of Wellington

    In the Spring of 1948 while teaching at a primary school, I observed a small group of girls playing a game called "Tip the Finger". During the game one of the players chanted the following rhyme: "Draw a snake upon your back And this is the way it went North, South, East, West, Who tipped your finger?" I recognized immediately and with some surprise that this rhyme contained elements which were not invented by the children and were probably of some antiquity. I knew, for example, though only in a vague and unlearned manner, that the four pattern of the North, South, East and West and the Snake symbolism were recurrent motifs in mythology and folklore. I was aware also that there did not exits any specialized attempt to explain the part that games of this nature played in the lives of the players.

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  • A fractionation of acid-soluble non-exchangeable potassium in some New Zealand soils into available and non-available forms : a thesis presented for the degree of Doctor of Philosophy, University of New Zealand [Massey Agricultural College]

    Haylock, Owen Fillbridge (1956)

    Doctoral thesis
    Massey University

    One of the most ubiquitous of the mineral elements present in plants, potassium plays on important and essential rôle in their nutrition, being required in large amounts for healthy plant growth. Unlike nitrogen, phosphorus, calcium and magnesium, potassium does not enter into premanent organic combinations in plants but appears to exist in solution as potassium ions in conjunction with soluble inorganic and organic anions. Consequently, specific rôles in the growth of plants are difficult to assign to potassium and only by inference from comparisons of normal and potassium deficient plants can functions he attributed to potassium. The following summary of the effects of potassium on the physiology of plants, abstracted from the review made by Lawton & Cock (1955), shows that potassium affects the following processes.

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  • Physiological investigations on regeneration from bulb scale leaves of Lilium speciosum Thun. : thesis presented for the degree of Doctor of Philosophy, University of New Zealand

    Robb, Sheila M. (1954)

    Doctoral thesis
    Massey University

    During the past twenty years a vast amount of research work has been carried out on the culture of plant tissues or organs excised from parent bodies. Haberlandt's (53) theories in 1902 on the possibility of procuring growth in such isolated tissues were not put into practice until some twenty years later, when the work of Kotte (63,64) and Robbins (97,98) was partially successful and encouraged further research along these lines. Later work by white (123-125) on excised roots, and by Gautheret (43-46), Nobecourt (84-87), and white (126) on cambial tissue proved that excised plant material could be cultured on a suitable synthetic medium. From that time, an ever-increasing volume of research work has been done on the culture of plant tissue, and the technique has found application in the investigation of a variety of problems in plant physiology.

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