https://commons.ru.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:70172 Wed 29 Nov 2023 21:24:48 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:28548 Wed 01 Dec 2021 08:36:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41124 Wed 01 Dec 2021 08:13:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41018 Tue 30 Nov 2021 08:34:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:69912 Tue 21 Nov 2023 19:54:50 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:50010 Tue 19 Apr 2022 09:01:44 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45279 Tue 16 Nov 2021 10:51:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45276 Tue 16 Nov 2021 10:02:53 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45271 Tue 16 Nov 2021 09:28:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:70631 Tue 12 Dec 2023 17:37:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:70630 Tue 12 Dec 2023 17:25:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45106 99% d.e. for larger alkyl groups. The expected preference for endo-alkylation is supported by NMR (chemical shift, coupling constant and NOE) data and was confirmed by acidic hydrolysis of the pentylated 3-imino lactone to afford the known acid. Computer modelling, with the software package HYPERCHEM®, was used to explore the conformational properties of the alkylated products and their enolate precursors. Exploratory work on the enantiomeric beneficiation of racemic amino acids, using alkylated imino lactone derivatives, revealed preferential exo-protonation of the enolate intermediates. Asymmetric Baylis-Hillman reactions between a novel camphor-derived acrylic ester and a range of aldehydes afforded the corresponding 2-(hydroxyalkyl)acrylates in up to 59% d.e., the observed stereoselectivities being sensitive to both steric and electronic factors. Attempts to prepare imino lactone derivatives from ketopinic acid, although unsuccessful, led to the isolation of two novel W-(carbobenzyloxy)glycinates, whose structures were established by 1- and 2-D NMR spectroscopy. Attempts to prepare "BINAP" analogues from dibomyl ether's also proved unsuccessful, but the investigation led to the discovery of a third, novel dibomyl ether.]]> Tue 09 Nov 2021 15:33:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45103 Tue 09 Nov 2021 12:03:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:50170 Thu 21 Apr 2022 17:19:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:50169 Thu 21 Apr 2022 17:09:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65804 S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-Vis spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO-1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states.]]> Thu 13 Jul 2023 15:22:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65803 Thu 13 Jul 2023 15:14:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65780 Thu 13 Jul 2023 11:50:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65779 Thu 13 Jul 2023 11:36:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65778 Thu 13 Jul 2023 11:29:37 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65776 Thu 13 Jul 2023 10:47:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45273 Thu 01 Feb 2024 09:44:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71629 Sat 17 Feb 2024 12:56:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71628 Sat 17 Feb 2024 12:46:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71627 Sat 17 Feb 2024 12:15:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71626 Sat 17 Feb 2024 11:56:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71965 Sat 06 Apr 2024 15:13:22 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71964 Sat 06 Apr 2024 15:13:06 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71963 Sat 06 Apr 2024 14:59:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71962 0.5 mg/ml). The QDs also retained most of their fluorescence and properties and could easily be tracked in cells and visualized around the nucleus, indicating the successful internalization of the QDs in the cytosol. These results shows that encapsulation of CdTe multi-core-shell QDs in liposomes produce better bio-compatibility compared to multi-core-shell QDs and better than CNP coating. These particles therefore show good promise in cell-labelling, drug delivery studies. Their core-shell nanoparticles have also shown good behavior in enhancing the memory of a device which is based on some recent collaborated works.]]> Sat 06 Apr 2024 14:52:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71961 Sat 06 Apr 2024 14:42:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71960 Sat 06 Apr 2024 14:24:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71958 Sat 06 Apr 2024 13:48:43 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71957 Sat 06 Apr 2024 13:33:28 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71956 4 and Dst_ -50 nT was used as a criterion for geomagnetic disturbed conditions, while the four geomagnetically quiet days were selected each month based on Kp < 3. Observations of TIDs are made using Global Navigational Satellite Systems (GNSS) total electron content derived data. During quiet conditions, seven and two transhemispheric TIDs were identified over the African-European and American sectors, respectively. The observed TIDs originated from the wintertime hemisphere and propagated into the summertime hemisphere. The horizontal velocity, periods, and horizontal wavelengths of TIDs are in range of cH = 120-274 m/s, 48-80 min and _H = 379-1104 km, respectively. These quiet-time equatorward TIDs have been associated with tertiary gravity waves (GWs) from the dissipation of secondary GWs which are in turn generated from the dissipation of mountain waves (MWs) as a result of excited orographic forcing. The poleward TIDs during geomagnetically quiet conditions over the African and American sectors occur mainly during local daytime. Poleward TIDs were observed mostly in the African-European sector than the American sector. Their horizontal propagation velocities and periods range between 129-280 m/s and 39-70 min over African-European and American sectors. Although the mechanisms responsible for launching quiet-time poleward TIDs have not been established in this study, lower atmospheric processes such as convection systems, sudden stratospheric warming and cold weather fronts may have a role in their generation. During geomagnetic storms in the African sector, almost all poleward TIDs (with the exception of two cases) during the main phase were large-scale with horizontal velocities and periods ranging from 250-503 m/s and 30 min to 2 hours. During recovery phase, poleward TIDs fall under the category of medium scale. In the American sector, the majority of poleward TIDs occurred during the storm's main phase, as opposed to the African-European sector, which experienced a significant number of poleward TIDs during the recovery phase. The periods and horizontal velocities of TIDs range from 45 min-1.5 h and 180-296 m/s during main phase. During the recovery phase, the horizontal velocity and period range from 177-271 m/s and 40-1.5 h, respectively. Overall, it has been shown that statistically, changes in equatorial electrodynamics related to enhanced eastward electric _eld and hence increased equatorial electrojet (vertical E_B drift) correlates highly with the reported poleward TIDs.]]> Sat 06 Apr 2024 13:06:52 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71955 Sat 06 Apr 2024 12:42:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:71954 Sat 06 Apr 2024 12:24:44 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45340 Mon 22 Nov 2021 15:55:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45338 Mon 22 Nov 2021 15:20:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65844 Mon 17 Jul 2023 18:43:34 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65843 Mon 17 Jul 2023 18:30:32 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:65841 Mon 17 Jul 2023 18:08:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45267 Mon 15 Nov 2021 15:41:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45266 Mon 15 Nov 2021 15:27:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45264 Mon 15 Nov 2021 15:06:44 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45263 Mon 15 Nov 2021 14:52:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45262 Mon 15 Nov 2021 14:45:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:45247 Mon 15 Nov 2021 11:36:45 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41120 Fri 29 Jul 2022 08:40:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:64492 Fri 14 Jul 2023 09:11:17 SAST ]]>