Applied Physics Publications
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- ItemRefinement of the Proposed Gamma-Ray Burst Time Delay Model(International Journal of Astronomy and Astrophysics, 2024-06-28) Abbey, G.F.; Simfukwe, J.; Simpemba, P.C.; Phiri, S.P.; Srivastava, A.; Nyambuya, G.G.This paper is the second instalment in our study of the observed time delay in the arrival times of radio photons emanating from Gamma Ray Bursts (GRBs). The mundane assumption in contemporary physics as to the cause of these pondersome time delays is that they are a result of the photon being endowed with a non-zero mass. While we do not rule out the possibility of a non-zero mass for the photon, our working assumption is that the major cause of these time delays may very well be that these photons are travelling in a rarefied cosmic plasma in which the medium’s electrons interact with the electric component of the Photon, thus generating tiny currents that lead to dispersion, hence, a frequency-dependent speed of Light (FDSL). In the present instalment, we “improve” on the model presented in the first instalment by dropping the assumption that the resultant pairs of these radio photons leave the shock front simultaneously. The new assumption of a non-simultaneous— albeit systematic—emission of these photon pairs allows us to obtain a much more convincing and stronger correlation in the time delay. This new correlation allows us to build a unified model for the four GRBs in our sample using a relative distance correction mechanism. The new unified model allows us to obtain as our most significant result a value for the frequency equivalence of the interstellar medium (ISM)’s conductance ν* ~ 1.500 ± 0.009 Hz and also an independent distance measure to the GRBs where we obtain for our four GRB samples an average distance of: ~69.40 ± 0.10, 40.00 ± 0.00, 58.40 ± 0.40, and 86.00 ± 1.00 Mpc, for GRB 030329, 980425, 000418 and 021004 respectively.
- ItemStrategies to respond to climate change effects in the Zimbabwean construction industry(CRC Press, 2023) James, M.; Moyo, T.The Zimbabwean construction industry is vulnerable to impacts of climate change, but lacks effective responses and policies to strengthen climate change resilience. The effects are characterized by destruction of infrastructure, construction workers’ health and safety concerns, among others, therefore, probing the study. Qualitative methods were incorporated to gather insights from purposively selected seven key informants. Face-to-face interview data, analyzed through thematic analysis revealed common themes including the need to; integrate construction-related policies, improve enforcement of existing regulations, provide adequate funding for climate change requirements, facilitate climate change literacy for construction professionals, and promulgate building by-laws that support construction activities. Findings encompassed the need to deal with climate change throughout the construction process. However, consensus on these issues needs to be made apparent. The major limitation was data collection from only key informants; nevertheless, this augers well with exploratory studies. Future studies should further interrogate identified strategies to establish appropriate interventions.
- ItemPsycho-social well-being programs required for construction workers in Zimbabwe(CRC Press, 2023) Mateza, W.; Moyo, T.Globally, psycho-social well-being is a significant challenge affecting construction workers. While the developed world has made great strides in solving this challenge, developing countries, including Zimbabwe, are lagging behind. This research, sought to determine the psycho-social well-being initiatives required for skilled construction workers in Zimbabwe. Quantitative data was collected using self-administered structured questionnaires for management personnel and interviewer-administered questionnaires for construction workers. Participants were sought from the Construction Industry Federation of Zimbabwe affiliated companies in higher categories. Relative importance index and T-test (two samples) were used for analysis. Both groups ranked counselling and team-building activities as the first and second-best initiatives. Health and safety regulations must address the absence of such initiatives. Further studies can investigate on the structuring and implementation of the initiatives. The study's main limitation was that participants needed to be drawn from all the construction company categories to ascertain the full extent of the challenge.
- ItemA Framework for Monitoring Stability of Tailings Dams in Realtime Using Digital Twin Simulation and Machine Learning(Elsevier, 2024) Mwanza, J.; Mashumba, P.; Telukdarie, A.Tailings dam failures cause catastrophic impact on the environment and surrounding communities. Incidences of failure in the recent past have caused industrialists and researchers to seek innovative ways for proactively managing their safety and disaster mitigation. Given Industry 4.0 technologies now available, researchers are looking to develop digital tools for cost-effective, realtime monitoring of tailings dams. However, published literature indicates that a reliable framework is still lacking. This paper proposes a framework for developing a data-driven system for monitoring tailings dam stability and early warning detection. The framework relies upon digital twin simulation and machine-learning (ML) techniques, and comprises four main components: realtime data collection, digital twin modelling, ML-based early detection and prediction, and intelligence-driven decision-support. Sensors gather real-time geophysical data from monitored structure, and the digital twin uses this data to simulate dam behaviour. ML algorithms analyse the data and simulations to enable early detection of instability and failure prediction. Literature suggests that digital twin and ML-based approaches may have advantages over traditional monitoring techniques and other AI-based methods. The paper concludes with a discussion of the framework's limitations, opportunities for improvement, and potential for application in mining and geotechnical engineering. The paper serves as a basis for model development and future research.
- ItemIntegration of hydrogeophysical and geological investigations in enhancing groundwater potential assessment in Houtriver gneiss crystalline basement formation of South Africa(Elsevier, 2021-03-10) Muchingami, I.; Mkali, A.; Vinqi, L.; Pietersen, K.; Xu, Y.; Whitehead, R.; Karsten, J.; Villholth, K.; Kanyerere, T.Groundwater exploration in crystalline basement aquifers such as the Houtriver gneiss formation in the Limpopo province of South Africa is often described as complex. This is because groundwater availability in such aquifers is largely a consequence of the interaction of several processes related to recharge, underlying geological features and fracture connectivity of the aquifer rock matrix. In this study, an integration of geophysical and geological investigations is applied in inferring potential drill targets within the Houtriver gneiss crystalline basement aquifer system. Results from the magnetic and frequency domain electromagnetic surveys were combined with geological investigations to identify sites where vertical electrical resistivity sounding was applied to infer the thickness and layering of weathered and fractured zones, as well as to identify potential targets where test boreholes were drilled. Constructed geo-resistivity pseudo-sections suggested that groundwater occurrence within this formation is described by a heterogeneous multiple-layered and fractured aquifer system with the main groundwater bearing zones ranging from a depth of 30–72m in most cases. Ten potential drill sites were identified from which three test boreholes were drilled and used to validate the results through a lithostratigraphic conceptual model developed from the correlation of the geophysical results with drill logs. The integration of hydro-geophysical and geological methods thus provided a comprehensive approach for resource assessment in the Houtriver gneiss formation.