Previous studies have shown that the incidence rate of intervening strong Mg II absorbers towards gamma-ray bursts (GRBs) were a factor of 2-4 higher than towards quasars. Exploring the similar sized and uniformly selected legacy data sets XQ-100 and XSGRB, each consisting of 100 quasar and 81 GRB afterglow spectra obtained with a single instrument (VLT/X-shooter), we demonstrate that there is no disagreement in the number density of strong Mg II absorbers with rest-frame equivalent widths W-r(lambda 2796) > 1 angstrom towards GRBs and quasars in the redshift range 0.1 less than or similar to z less than or similar to 5. With large and similar sample sizes, and path length coverages of Delta z = 57.8 and 254 : 4 for GRBs and quasars, respectively, the incidences of intervening absorbers are consistent within 1 sigma uncertainty levels at all redshifts. For absorbers at z < 2.3, the incidence towards GRBs is a factor of 1.5 +/- 0.4 higher than the expected number of strong Mg II absorbers in Sloan Digital Sky Survey (SDSS) quasar spectra, while for quasar absorbers observed with X-shooter we find an excess factor of 1.4 +/- 0.2 relative to SDSS quasars. Conversely, the incidence rates agree at all redshifts with reported high-spectral-resolution quasar data, and no excess is found. The only remaining discrepancy in incidences is between SDSS Mg II catalogues and high-spectral-resolution studies. The rest-frame equivalent-width distribution also agrees to within 1 sigma uncertainty levels between the GRB and quasar samples. Intervening strong Mg II absorbers towards GRBs are therefore neither unusually frequent, nor unusually strong.

Magister Scientiae - MSc / High-spin states in the oblate deformed odd-odd thallium nucleus ( ) 109 190 81 Tl have been investigated through the reaction 175Lu(20Ne, 5n)190Tl at a beam energy of 115 MeV. The gamma rays emitted from 190Tl nucleus were detected with Ge detectors using the AFRODITE array at iThemba LABS, South Africa. Gamma-gamma coincidence data were obtained and used to construct the level scheme. In this work, Directional Correlations from Oriented (DCO) state ratios and linear polarization anisotropies were measured in order to deduce spin and parity of energy levels in the decay scheme. It was possible to determine the spin and parity of two additional signature-partner bands which decay to the ground-state band. / South Africa

No description available.

Ph.D. (Biochemistry) / This study consistsof two parts namely: • Phosphoproteins in ripening mango fruit tissue: Effect of y-irradiation and various effectors on protein phosphorylation during the climacteric rise, climacteric peak and post-climacteric stages of ripening. • Protein kinase (EC 2.7.10 and EC 2.7.11) activities in ripening mango fruit tissue: Classification, purification and characterisation.

The purpose of this investigation was to observe the excited states of the Cs¹³³ nucleus when neutrons are inelastically scattered from the nucleus.

No description available.

No description available.

<p> A variety of experiments has been performed in order to establish and identify the states in 191Ir and 193Ir. From radioactive decay, the energies and intensities of the gamma rays and internal conversion electrons have been measured with high precision using Ge(Li) detectors and the Chalk River π√2 spectrometer. A series of gamma-gamma coincidence experiments were performed using Ge(Li) detectors. The gamma rays following Coulomb excitation of 191Ir and 193Ir were also measured with Ge(Li) detectors. In addition, (3He,d) and (α,t) transfer reactions were performed and the reaction products analyzed by means of an Enge split-pole spectrograph. From these data, the energies, spins, parities and spectroscopic factors for the states in 191Ir and 193Ir have been established and interpreted in terms of the Nilsson model with band mixing.</p> / Thesis / Doctor of Philosophy (PhD)

<p> Twenty-two energy levels of 105Ru populated in the beta decay of 105Ru have been determined. The internal conversion coefficients of the eighteen strongest transitions were measured using a magnetic spectrometer and were used to obtain their multipole assignments. The energies and intensities of seventy gamma rays were measured using germanium detectors and scintillation counters. Gamma-gamma and beta-gamma coincidence measurements carried out with magnetic spectrometers, NaI(Tl) and Ge(Li) detectors were used with these energy measurements to establish a decay scheme. An interpretation of the decay scheme in the light of current nuclear models was attempted.</p> / Thesis / Doctor of Philosophy (PhD)

No description available.