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The effects of in‑plane strains on the electrochemical properties of Li adatoms on the ZrS2 monolayer : a first-principles study
Mahapane, B.D.; Fwalo, Chewe; Bekeur, Craig Arthur; Mapasha, Refilwe Edwin (Springer, 2025-12)
In this study, we use density functional theory (DFT) with a Hubbard (U) parameter, implemented in the Quantum Espresso code, to investigate the interactions between Li-ions and the ZrS2 monolayer under the influence of in-plane uniaxial and biaxial strains, specifically within the context of lithium-ion batteries. This is to ensure the ZrS2 monolayer is more robust against the Coulomb forces arising from interactions between multiple lithium ions. This study objectively examines the impact of tensile and compressive strains ranging from − 5% to 5% on the energetic stability and electrochemical properties of the lithiated ZrS2 electrode monolayer. For a single Li adatom on a 3 × 3 ZrS2 monolayer, the compressed structure (at − 5% strain) becomes more energetically favorable, exhibiting a low adsorption energy of − 1.41 eV. In contrast, the stretched structure (at + 5% strain) has a higher adsorption energy of − 0.95 eV compared to the unstrained structure (− 1.16 eV), although exothermic interaction is maintained. The ZrS2 electrode monolayer has a shallow energy barrier of 0.23 eV for Li-ion diffusion, indicating greater mobility, which is slightly enhanced by compressive strain. The application of − 5% (compressive strain) resulted in an average OCV of 0.93 V, and 0.78 V for unstrained, while + 5% (tensile strain) yielded an OCV of 0.69 V, which is in the range of commercial anode materials. The tensile strain on a ZrS2 electrode monolayer would be more effective in mitigating the dendrite formation. The introduction of a Li adatom rearranged the conduction band minimum, leading to the hybridized Zr d orbital states crossing the Fermi level and becoming more populated as the number of Li adatoms increases, leading to a more conductive electrode. Additionally, the strain reduced the band gap, causing the induced electronic states to be continuous from the VBM to the CBM edges, which enhances the electronic conductivity of the material, ensuring the excellent LIBs operation during the charge and discharge processes.
Expansion and deepening of social support systems for female caregivers who attended a group-based HIV prevention programme in Soweto, South Africa
Gunda, Sabastian; Sibanda, Sipho (Taylor and Francis, 2025-06-05)
The steady rise of family-based interventions to prevent HIV infections among adolescent girls has necessitated the need for empirical evidence to gauge their acceptability and impact. This qualitative study explored the experiences of female caregivers who attended the “Let’s Talk,” HIV prevention Programme. The study used semi-structured interviews with caregivers who participated in the Let’s Talk Programme. Twelve caregivers were purposively sampled to participate in the study. Data was analyzed using a thematic analysis approach, which entailed manual categorization and coding the data into themes and subthemes using a deductive approach. The findings indicate that through attending Let’s Talk sessions, the caregivers’ social support networks widened and deepened, ultimately leading to sharing and transference of problem solving and parenting skills. The conclusion is that the expansion and deepening of the caregivers’ social networks provide empirical evidence of Let’s Talk’s efficacy in facilitating desired outcomes. It is recommended that the Let’s Talk Programme needs to be up scaled in its current format within South Africa and other resource limited settings of Africa. This study only covered a small geographic area of Soweto, there is therefore scope for further research incorporating a bigger sample of participants drawn from a larger geographic area.
Improving post-award grant management efficiency through process mapping and activity-based costing
Kotzee, Ninette; Du Toit, Elda (Society of Research Administrators International, 2025)
This case study details how the University of Pretoria’s Grant Management Unit improved post-award grant management efficiency and compliance. Using process mapping and Activity-Based Costing, the Unit identified and addressed inefficiencies, high compliance costs, and process bottlenecks. Activity-Based Costing provides valuable insights into resource allocation and cost optimization. This integrated approach offers a practical model for enhancing efficiency and compliance in resource constrained universities.
Evaluation of phosphite to protect a South African Proteaceae from Phytophthora root rot
Msweli, Dumsani; Geerts, Sjirk; Nndanduleni, Mashudu; Paap, Trudy (Springer, 2025-11)
Phytophthora cinnamomi is a globally recognised invasive plant pathogen, affecting approximately 5000 host species. In South Africa, previous research has linked P. cinnamomi to root rot in endemic Proteaceae, including Leucadendron argenteum. Recent observations have noted high mortality rates in L. argenteum, with P. cinnamomi readily isolated from the roots and collars of dying trees. Phosphite is commonly used to control Phytophthora diseases, but its efficacy in protecting native South African flora remains uncertain. To address this, trials were conducted to evaluate phosphite’s effectiveness against P. cinnamomi infection in L. argenteum. In the glasshouse trial, four-month-old seedlings were treated with 5 g/L phosphite and then inoculated with P. cinnamomi. Non-treated inoculated seedlings exhibited rapid wilting within three weeks, while treated seedlings showed significant disease reduction, with no difference in root weight and seedling height compared to non-inoculated controls. In the field trial, L. argenteum trees treated with 40 g/L and 50 g/L phosphite injections over 30 months showed no significant difference in survival rates compared to untreated controls. The lack of phosphite efficacy in the field trial was attributed to the presence of Armillaria spp. The study underscores the threat P. cinnamomi poses to L. argenteum populations and highlights the additional risk from Armillaria. While phosphite has demonstrated effectiveness against Phytophthora root rot, further investigation is needed to determine if P. cinnamomi and Armillaria spp. have synergistic effects on L. argenteum mortality. Additionally, exploring phosphite’s potential to protect plants from A. mellea at the seedling stage is warranted.
Crafting teacher-time for tea and art : the participatory development of a social connectedness intervention with teachers in an unequal space
Versfeld, Jessica; Ferreira, Ronel; Ebersohn, L. (Liesel) (University of Cincinnati Office of Innovation and Community Engagement, 2025)
This study explores the development and evaluation of the Isithebe Social Connectedness intervention, an expressive arts-based initiative co-created with teachers in resource-constrained primary schools in South Africa. Using Participatory Reflection and Action (PRA) principles, the intervention was designed to be culturally relevant, contextually responsive, and aligned with Afrocentric values such as Ubuntu. By involving teachers as active co-creators of the intervention, rather than mere recipients, the intervention fosters relevant science by fitting the unique contextual and conceptual needs of the educational space, responsive science by addressing challenges with local resources, and responsible science by empowering participants as agents of change within their communities. This study highlights the participatory processes and adaptive strategies that underpinned the intervention’s development. Findings underscore the potential of community-driven, culturally resonant interventions to enhance teacher resilience and well-being in resource-limited settings.