https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:43640 Wed 30 Jun 2021 11:46:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:53880 Wed 27 Jul 2022 11:35:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:58953 Wed 23 Nov 2022 15:34:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:74420 Wed 17 Jul 2024 14:59:13 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30536 Wed 12 May 2021 23:47:02 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27255 Wed 12 May 2021 23:27:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30650 Wed 12 May 2021 22:57:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28479 Wed 12 May 2021 21:48:07 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:38179 Wed 12 May 2021 20:50:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39408 Wed 12 May 2021 20:27:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30542 Wed 12 May 2021 19:54:48 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39405 Wed 12 May 2021 19:41:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27240 Wed 12 May 2021 19:27:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30541 Wed 12 May 2021 18:44:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39605 Wed 12 May 2021 18:39:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29532 Wed 12 May 2021 18:36:10 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29531 Wed 12 May 2021 18:21:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30050 Wed 12 May 2021 18:19:39 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27258 Wed 12 May 2021 17:57:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28902 Wed 12 May 2021 17:54:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36661 Wed 12 May 2021 17:35:54 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29794 Wed 12 May 2021 17:15:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35991 Wed 12 May 2021 17:13:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36654 Wed 12 May 2021 17:12:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35988 Wed 12 May 2021 17:09:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27312 Wed 12 May 2021 17:05:54 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39563 Wed 12 May 2021 16:38:19 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27256 Wed 12 May 2021 16:35:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35990 Wed 12 May 2021 16:32:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29526 Wed 12 May 2021 16:12:20 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:40454 Wed 12 May 2021 15:09:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42050 Wed 12 May 2021 15:09:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:40123 Wed 12 May 2021 15:08:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42111 Wed 12 May 2021 15:04:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:43008 Wed 12 May 2021 15:00:52 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41738 Wed 12 May 2021 14:37:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:40120 Wed 12 May 2021 14:17:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:40115 Wed 12 May 2021 14:13:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42110 Wed 12 May 2021 14:06:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:40117 Wed 12 May 2021 14:02:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42071 Wed 12 May 2021 13:57:02 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:43149 Wed 09 Jun 2021 12:18:02 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65643 Wed 08 Nov 2023 09:23:17 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:52754 Wed 06 Jul 2022 10:32:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:62026 Tue 28 Feb 2023 13:08:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:73240 Tue 11 Jun 2024 10:47:39 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:43216 Tue 06 Jul 2021 11:38:17 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:75239 Thu 29 Aug 2024 10:05:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72728 Thu 23 May 2024 10:00:39 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:73562 7-ONE > 8-ONE > 5-ONE which correlated exactly with results from binary guest/guest competition experiments, where 6-ONE was always preferred by H1, while 5-ONE was consistently disfavoured. Single crystal X-ray diffraction (SCXRD) analyses demonstrated that each guest compound was retained in the crystals by means of a hydrogen bond with an alcohol moiety of the host compound. Furthermore, preferred guests 6- and 7-ONE produced crystals with greater densities than guests less favoured (5- and 8-ONE). A conformational analysis of the guest geometries in the four complexes with H1 revealed that the low energy guest conformers were present. The host selectivity for 6- and 7-ONE was proposed to be due to the improved molecular packing in the crystals of the complexes containing these two guest compounds, observed from their higher crystal densities. Hirshfeld surface analyses were not useful in explaining the preference of H1 for 6-ONE relative to 7-ONE (these types of analyses were not possible for the 5-ONE and 8-ONE-containing inclusion compounds due to the nature and degree of disorder present in the guest molecules). H1 was also crystallized from γ-butyrolactone (GBL), 2-pyrrolidone (NP), N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP), and 1H-NMR spectroscopy revealed that all but GBL were included. The host compound was also presented with these guest solvents in various mixtures, and it was observed that NMP was an extremely favoured guest solvent, followed by NEP and NP, with GBL being consistently disfavoured in every experiment. It was therefore shown that in certain instances, H1 may serve as an alternative tool for separating some of these mixtures through host-guest chemistry strategies. The hydrogen bonding motifs present in each of the successfully formed complexes were extensively investigated through SCXRD analysis, as was the thermal behaviour of these complexes. In the latter instance, the peak temperature of the endotherm (from the DSC trace) representing the guest release was greater for the inclusion compound with favoured NMP (145.5 °C) relative to the complexes with NP (139.8 °C) and NEP (120.5 °C). Host compounds H2 and H3 were revealed to have the ability to include each of pyridine (PYR), 2-methylpyridine (2MP), 3-methylpyridine (3MP) and 4-methylpyridine (4MP). H2 displayed selective behaviour for 3MP and 4MP when presented with mixtures of these guest compounds, whilst H3 preferred PYR. In the latter case, this PYR-containing inclusion compound was also the more stable one (the guest release onset temperature was highest, Ton 66.0 °C). It was demonstrated that H2 has the ability to separate very many binary mixtures of these pyridines on a practical platform, since K (the selectivity coefficient) values were 10 or greater in many instances. However, unfortunately, the more difficult-to-separate mixtures containing 3MP and 4MP cannot be purified or separated by employing H2 and supramolecular chemistry strategies. H3 was also shown to be a likely candidate for binary guest separations in very many of the guest solutions considered here, where K was also 10 or greater, and even infinity in many cases. SCXRD demonstrated that 2MP, 3MP and 4MP were retained in the crystals of their complexes by means of classical hydrogen bonds with the host compound. Satisfyingly, this hydrogen bond between 2MP and H2 (3.0213(18) Å) was significantly longer than that between this host compound and both disorder components of 3MP (2.875(2) and 2.825(9) Å) and that between H2 and 4MP (2.8458(13) Å). This observation explains the affinity of H2 for both 3MP and 4MP, and why 2MP was disfavoured. The results of thermal experiments did not wholly concur with observations from the guest/guest competition experiments. Hirshfeld surface analyses were also conducted but were not entirely conclusive with respect to explaining the host selectivity behaviour. In the case of H3, SCXRD analyses revealed that favoured PYR experienced a classical hydrogen bond with the host compound that was statistically significantly shorter (2.795(2) Å, 165°) than those between the other guest compounds and H3. Additionally, this guest compound was the only one to be involved in a (host)C−H···π(guest) interaction (2.91 Å, 139°) and also a non-classical hydrogen bond with the host compound ((host)C−H···N−C(guest), 2.77 Å (144°)). Finally, Hirshfeld surface analyses showed also that preferred PYR experienced a greater percentage of C···H/H···C (33.1%) and H···N/N···H (11.1%) interactions compared with the complexes with 2MP, 3MP and 4MP. However, it is not clear whether these Hirshfeld observations explain the affinity of H3 for PYR.]]> Thu 20 Jun 2024 15:42:01 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:73554 Thu 20 Jun 2024 14:46:36 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39402 Thu 13 May 2021 14:44:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39403 Thu 13 May 2021 08:54:11 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36623 Thu 13 May 2021 08:05:54 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28215 Thu 13 May 2021 08:04:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29527 Thu 13 May 2021 07:35:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35989 Thu 13 May 2021 07:31:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39395 Thu 13 May 2021 07:07:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30538 Thu 13 May 2021 06:58:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35986 Thu 13 May 2021 06:55:48 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36657 Thu 13 May 2021 06:51:10 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27293 Thu 13 May 2021 06:30:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29410 Thu 13 May 2021 06:28:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28317 Thu 13 May 2021 06:18:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27315 Thu 13 May 2021 06:18:07 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29525 Thu 13 May 2021 05:54:36 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30535 Thu 13 May 2021 05:45:39 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39847 Thu 13 May 2021 05:45:06 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:38132 Thu 13 May 2021 05:24:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30537 B ± 0.1ᵒ and (111) ± 0.1ᵒ] using similar growth conditions yielded a higher dot density on the (100) substrate compared to the (111) substrate. This was attributed to the presence of terraces/atomic steps induced by the misorientation on the (100) substrate, which invariably gives rise to increased adsorption and an enhanced sticking coefficient of adatoms. Studies on the influence of a buffer layer on the morphology of uncapped dots showed that the shape and size of the dots are sensitive to the thickness of the buffer layer. In some case a corrugated buffer surface resulted, which introduced order in the arrangement of the dots, which formed preferentially inside the troughs. An increase in the V/III ratio from 1.0 to 3.0 was found to reduce the areal density of the QDs, while an analysis of the diameter histograms showed a narrowing of the size distribution with an increase in V/III ratio. The larger size distribution at low V/III was ascribed to the increase in indium species and the increased indium adatom migration length. This leads to increased dot density and nucleation sites, and thus triggers an increase in the conversion of tiny QDs into thermodynamically more suitable larger dots via coalescence. However, as the V/III ratio increased, the number of indium adatoms available for growth on the surface reduced, which automatically led to a decrease in the migration length of indium species which is unfavourable for the production of nucleation sites and to a decrease in dot density. Low growth rates were found to be beneficial for the growth of a high density (~5×1010cm-2) of QDs. Photoluminescence (PL) analysis of the capped samples at low temperature (~10 K), using an excitation power of 2 mW, showed a PL peak at ∼732 meV. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV was noticed. This emission typically persisted up to 60–70 K. An increase in the number of InSb QD-layers, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the PL lines, together with an enhancement in the strength of the PL emission. However, high resolution transmission electron microscopy (HRTEM) of the capped dots revealed the formation of an InGaSb quantum well-like structure, ∼10 nm thick, which was responsible for the PL signal mentioned above. The absence of QDs in the capped sample was attributed to inter-diffusion of Ga and In during the deposition of the cap layer, giving rise to a quantum well (QW) instead of the intended QDs. The presence of threading dislocations and stacking faults were also observed in the TEM micrographs of the samples containing multilayers, which can account for the fast quenching of the PL emission with increasing temperature from these samples. Theoretical simulations of the band alignment, wave functions and energy levels were in good agreement with the data collected from the PL spectra of the samples.]]> Thu 13 May 2021 04:56:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30539 Thu 13 May 2021 04:34:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27309 Thu 13 May 2021 03:28:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36685 Thu 13 May 2021 02:43:43 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35984 Thu 13 May 2021 02:17:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29523 Thu 13 May 2021 01:43:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35985 Thu 13 May 2021 00:27:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36624 0.8) for AP, when compared with the non-PA intervention group. No significant differences were found for AP in relation to intervention group comparisons for the health and hygiene education and nutrition intervention groups. Similarly, the intervention group comparisons revealed no significant differences regarding attention for post-intervention and pre- to post-intervention differences. Findings suggest that a school-based PA intervention can positively affect children’s AP. The current study emphasises the necessity of PA and reinforces the importance of PE in the school curriculum. Therefore, it is strongly recommended that PE regains its rightful place and be actively taught within the school curriculum.]]> Thu 13 May 2021 00:16:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36662 Thu 13 May 2021 00:15:20 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:74163 Thu 11 Jul 2024 15:35:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:58058 Thu 03 Nov 2022 11:14:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:62114 Thu 02 Mar 2023 15:25:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:62073 Thu 02 Mar 2023 09:11:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45713 Sat 22 Jan 2022 10:24:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:43148 Mon 21 Jun 2021 12:12:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:43173 Mon 14 Jun 2021 10:33:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:43172 Mon 14 Jun 2021 10:04:42 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:37835 Mon 12 Jun 2023 11:50:57 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:58054 Mon 07 Nov 2022 09:29:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:73586 Fri 21 Jun 2024 12:04:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:73575 Fri 21 Jun 2024 10:32:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35983 Fri 20 Aug 2021 17:34:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27257 Fri 15 Mar 2024 13:07:07 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30949 Fri 15 Mar 2024 13:00:57 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30543 Fri 15 Mar 2024 12:32:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:74185 Fri 12 Jul 2024 08:42:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:51996 Fri 10 Jun 2022 11:50:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:62074 Fri 07 Jul 2023 11:34:06 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:62150 Fri 07 Jul 2023 11:29:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65640 Fri 07 Jul 2023 11:21:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65633 Fri 07 Jul 2023 11:14:51 SAST ]]>