Thèse--Droit--Lausanne, 1976. / Bibliogr. p. 172-189.

Fifty years have elapsed since Hadley Cantril (1965) published his work on the Pattern of Human Concerns. His line of inquiry has stood the test of time. In late 2012, the nationally representative South African Social Attitudes Survey (SASAS) replicated Cantril’s 1960s questions and methodology to elicit South Africans’ hopes and aspirations and worries and fears for self and country and their ratings of where self and country stood – past, present and will stand in future. Although Cantril’s ‘ladder‐of‐life’ scale is still regularly used as a measure of subjective well‐being, to our knowledge his full line of preliminary questioning has not been fielded again to date. Our study found that South African aspirations for self were mainly material ones for a decent standard of living and the means to achieve this goal. Hopes for the nation concentrated on economic and political progress to consolidate South Africa’s democracy. A large number of personal and national hopes were mirrored in fears that these aspirations might not be met. Cantril’s method also allowed us to review the main concerns and ratings across the diverse groups of citizens that make up the ‘rainbow nation’. There was a substantial degree of consensus on top hopes and fears but levels of standing on the Cantril ladder of life were still graded according to apartheid‐era inequalities with black South Africans scoring lower than other race groups. Nonetheless, the majority of South Africans rated their present life better than five years ago and projected life to get better in future. Such optimism may place considerable pressure on the state to deliver on personal and societal hopes as the country enters its third decade of democracy.

Kinetocardiograms of 507 patients whose clinical records, physical examinations, and electrocardiograms were normal or essentially normal, and who demonstrated one of seven conduction defects, were classified into eight cardiac disease categories, one of which was a normal control. The kinetocardiogram wave patterns were then studied as a single basis for deriving a computer-assisted method of cardiac disease diagnosis. [See document for full abstract.] / Ph. D.

The effect of riveted and uniformly spaced stringers on the stress intensity actor of a centrally cracked sheet is determined. Also obtained is the force in the critical rivet and stringer. The results are presented for two symmetrical cases of crack location: the crack initiating at a rivet, and the crack initiating between two stringers. / M. S.

The problem of an interacting electron gas in a static lattice (an inhomogeneous electron gas) at zero temperature is treated by use of field theoretic perturbation theory. The unperturbed system is taken to be a non-interacting electron gas in a static lattice. The electron-electron interactions are then treated as a perturbation or;. this system. One-particle basis functions, Bloch functions, are introduced explicitly into the perturbation series for the Green functions, and diagrams associated with the various terms are defined. Certain formal results in integral equation form are noted. Using the method of DuBois, the plasmon excited state is studied. In particular, plasmon energies and lifetimes are calculated in the pair approximation for several insulators. / Ph. D.

We have studied 2250 events with 6 charged tracks in the final state from 7.0 GeV/c π⁻p film taken at the BNL 80-inch bubble chamber. The events were fitted to the final states π⁻p → π⁻π⁻π⁻π⁺π⁺p 211 events (1) π⁻p → π⁻π⁻π⁻π⁺π⁺pπ⁰ 535 events (2) π⁻p → π⁻π⁻π⁻π⁺π⁺π⁺n 230 events (3) We find the total six-prong cross section to be 2.40 ± 0.27 mb. The partial cross sections are: 0.22 ± 0.04 mb for reaction (1), 0.58 ± 0.09 mb for reaction (2), and 0.24 ± 0.05 mb for reaction (3). Final state (1) shows significant ρ(760) and Δ⁺⁺(1238) production. In reaction (2) there is Δ⁺⁺(1238) production and a u bump at 1540 ± 20 MeV/c² with width 100 ± 40 MeV/c² in the pπ⁰ mass distribution (interpreted as N*(l520)). The π⁺π⁻π⁺π⁻ mass plot shows peaks at 1085 ± 20 MeV/c² and 1470 ± 20 MeV/c² with widths 70 ± 30 MeV/c² and 60 ± 25 MeV/c². These peaks appear less prominently in reaction (3). The transverse momentum distributions are analyzed in terms of statistical model predictions. In particular the Hagedorn statistical thermodynamical model gives temperatures of 120 MeV for pions and 150 MeV for nucleons. The influence of Bose-Einstein statistics as found by Goldhaber is observed in the angles between pion pairs. / Ph. D.

The problem of ductile fracture in anisotropic and viscoelastic solids is an important engineering problem. In this paper the Dugdale model is assumed, that is, the yielded zone is replaced by a constant yield stress. Solutions are presented for anisotropic static, orthotropic dynamic and anisotropic viscoelastic solids. The anisotropic static and orthotropic dynamic solutions were obtained by the complex variable approach. Stress functions which must satisfy a generalized bi-harmonic equation, are represented in terms of two analytic functions of two different complex variables. In this way boundary value problems can be reduced to problems of complex function theory. The anisotropic and dynamic solutions are thus seen to be completely analogous and thus similar relations are obtained for both cases. The yield stress is assumed to follow a Von Mises' yield criterion which was adopted to the anisotropic-dynamic case. For the static anisotropic and the orthotropic dynamic cases the following results were obtained; 1. The plastic zone is given by the same relation as in the isotropic - static case, (𝒍/a) = cos [ (πT)/ (2Y) ] 2. Any anisotropic or corresponding dynamic function may.be obtained from the corresponding isotropic or static function by simply multiplying the isotropic or static function by a coefficient. 3. A limit on yielding along the line of the crack, and therefore a limit on the anisotropy and the velocity are derived. The anisotropic viscoelastic solution is obtained from the static solution from Graham's extension of the correspondence principle after it is shown that the problem fits the restriction set by this technique. The effects of anisotropy in the material are handled by the inclusion of the generalized creep compliance and relaxation modulus. Once these terms are evaluated for each material an approximate inversion method for the Laplace transform may have to be used. For the case of constant external load it is shown that the a xx stress may be separated into a time variation and a space variation. Several different viscoelastic materials are assumed and the stresses solved for. In the limit all results reduce to the isotropic and static solutions. Finally, a large bibliography is included to serve those who wish to investigate the area further. / Ph. D.

Many workers have attempted to determine neutron absorption cross sections and average resonance parameters with varying degrees of success. Values of the latter parameters for a given isotope often vary as much as a factor of two or three from one worker to another. This dissertation is an attempt to remove some of this uncertainty. Natural silver and the isotopes ¹⁰⁷Ag, ¹⁰⁹Ag, ¹¹⁵In, ¹²⁷I have been irradiated by the monoenergetic neutrons emitted at 90° to a proton beam striking a ⁷Li target. These samples were then counted for their β and γ activity and their absolute cross sections relative to the cross section of ¹²⁷I at 24 keV were calculated over the energy range of from 3 to 155 keV. These measured cross section versus energy curves were used to determine the γ-ray strength functions, (r_γ)/( D_o), the s-wave neutron strength functions, (r¹_n)/(D), and the p-wave neutron strength functions (r¹_n)/(D). Because of data limitations it has been assumed that the γ-ray strength function is the same for both s- and p-wave neutrons. The cross sections determined are in general good agreement with the values previously reported but differ somewhat in shape. This shape variance results in values for the average resonance parameters which are somewhat higher than values reported by other workers. / Ph. D.

Estimators are investigated which provide alternatives to the usual unbiased estimators for the mean and variance. It is assumed that the experimental situation is one in which the statistician has at his disposal some information concerning the parameter space. In particular, the experimenter may have reason to believe that the parameter is in a certain region of the parameter space. The first estimator examined is reasonably close to the natural origin. The admissibility of θ̂ with respect to x̅ is also exhibited. The final estimator examined is a preliminary test estimator for the variance when the mean is also unknown. The estimator chooses between functions of the form cs², where s² is the usual unbiased estimator, and functions of the form kw², where w² is a crude sum of squares, as the final estimator of the variance on the basis of a preliminary t-test on the mean. S² is apparently made inadmissible by several of these intermediate values of θ, while the MSE(θ̂p|θ) and MSE(x̅|θ) are shown to be approximately the same for relatively large values of θ. θ̂p is shown to be inadmissible universally but admissible with respect to x̅. In order to improve upon θ̂p in the areas in which it performs poorly a new estimator, θ̂, is proposed. θ̂ is a weighted estimator between x̅ and kx̅ and its weighting functions are fiducial probabilities. The MSE(θ̂|θ) function is shown to be smaller than the MSE(θ̂p|θ) for values of θ so-called preliminary test estimator for an unknown mean θ with the variance known and is defined by θ̂p = x̅ , if x̅ ε R = kx̅, if x̅ ε R̅, where 0 < k < 1, R is the region of θ̂ in which MSE(x̅|θ) < MSE(kx̅|θ̂) and R̅ is the complement of R. Procedures are given for determining optimal values of k. Bias and MSE for θ̂p are found. The MSE(θ̂p|θ) function is found to be smaller than that for x̅ around the "natural origin", larger than MSE(x̅|θ) for estimators as is (n-1/n+1) s² which has uniformly minimum MSE among estimators of the form c². Formulas are given for calculation of the MSE in closed form when the mean is actually the same as the hypothesized value. / Ph. D.

Ph. D.