DSpace Repository

Welcome to the NWU Repository, the open access Institutional Repository of the North-West University (NWU-IR). This is a digital archive that collects, preserves and distributes research material created by members of NWU. The aim of the NWU-IR is to increase the visibility, availability and impact of the research output of the North-West University through Open Access, search engine indexing and harvesting by several initiatives.

Communities in NWU Repository

Select a community to browse its collections.

Now showing 1 - 5 of 18

Recent Submissions

Bridging the gap: Nurturing self-directedness in higher education teacher training and teachers’ job demands
(Aosis, 2024) van Tonder, Gideon (Deon) P; van Deventer, Nicolaas
This chapter2 focused on insights into how teacher training can be improved to better prepare novice teachers for the complexities of modern education and the integration of self-directed learning (SDL) strategies. This chapter emphasised the significance of equipping novice teachers with the necessary competencies and methodologies to facilitate SDL among their learners. Self-directed learning is an essential element of education that empowers learners and teachers to take charge of their learning and teaching and develop proficiencies in critical thinking, problem-solving and continuous learning. Integrating SDL into the academic syllabus and providing sufficient assistance for novice teachers to execute it competently can enhance learner involvement and incentive and cultivate an atmosphere of independent learning and self-motivated enterprise. Consequently, this can lead to more substantial educational encounters and enhanced scholastic accomplishments.
An overview of advanced oxidation processes using copper-based catalytic degradation of organic pollutants in water.
(Elsevier B.V., 2024) Enyioma C. Okpara; Olanrewaju B. Wojuola; Taiwo W. Quadri; Craig E. Banks
Organic pollutants are harmful to the environment due to their bio-accumulative and long-persistent nature, causing adverse effects on plants, animals, and humans. Their rapid spread beyond target applications in the ecosystem could be responsible for various fatal diseases and eco imbalances. Conventional techniques for removing these pollutants are ineffective because of their high solubility in water and nonbiodegradability. In contemporary times, we have witnessed a notable surge in interest in advanced oxidation processes (AOPs) for water treatment processes. This heightened attention is attributed to their exceptional degradation efficiency for recalcitrant organic pollutants. This review, therefore, focuses on copper-based homogeneous and heterogeneous catalysts for AOPs that offer both cost-effectiveness and high performance. Emphasis is placed on the use of copper-based catalysts in photocatalysis, Fenton-like process (including photo-Fenton (Fe2+/UV/H2O2)), persulfates activation, and ultrasonic irradiation. The catalytic performance, mechanism, and pathway for the abatement of the target pollutants by the copper-based catalysts in each AOP are described in detail. The reusability, stability, and factors affecting the AOPs are briefly highlighted. We further provide perspectives on the key opportunities and challenges associated with copper-based catalysts in AOPs, recommending further exploration for enhanced applications in future studies.
Radiological assessment of commonly food crops in Southwestern Nigeria.
(IOP Publishing Ltd., 2024) Olaoye, Morohunfoluwa Adeola; SA Abd El-Azeem; Olagbaju, Peter Oluwadamilare; Lawal, Rianat Yewande; Akanbi, Ajitokewu Ridwan; YAMostafa, Mostafa; Khalaf, Hyam
Natural radionuclides are present in food items at different levels and are influenced by factors like background radiation, climate, and agricultural practices. These radionuclides play a crucial role in humans' internal radiation exposure. Notably, radionuclides within the decay series 238U and 232Th as well as 40K are significant concerns in radiation protection due to their prevalence and potential health risks. The activity concentrations of radionuclides 238U, 232Th, and 40K in several food crops consumed within Lagos city in Nigeria were measured using gamma spectrometry. The concentrations of 238U, 232Th, and 40K ranged from 0.90 to 55.30, BDL (Below Detection Limit) to 161.60 and 10.30 to 1075.20 Bqkg−1, respectively. The average radionuclide activity concentrations are below the acceptable global level, or the worldwide average values set by the United Nations Scientific Committee on the Effects of Atomic Radiation in 2000 (UNSCEAR, 2000), which are 35, 30, and 400 Bqkg−1 for 238U, 232Th, and 40K, respectively. The study calculated the annual effective dose for individuals consuming the studied food items, and the annual internal dose from ingesting was found to be 8.95 × 10–04 μSvy−1. It’s noteworthy that this computed value is below the worldwide value of 0.32 mSv y−1 set for the public. Additionally, the excess lifetime cancer risk (ELCR) value was 3.13 × 10−3 μSvy−1, which is within the world safe limit value (2.9 × 10−4 μSvy−1). Therefore, there is no potential radiological risk associated with the measured data.
Environmental assessment of toxic heavy metals and natural radionuclides in irrigation water from Rustenburg, South Africa.
(Elsevier Ltd., 2024) Olagbaju, Peter Oluwadamilare; Wojuola, Olanrewaju Bola
Water is a transparent, tasteless and odourless inorganic compound, essential for life and sustainable development. It is important for food and energy production, socio-economic growth, healthy ecosystems and human existence. Global attention is given to water quality monitoring due to the role it plays in human exposure to different kinds of contaminants, including radioactive and toxic contaminants from industrial, agrochemicals, mining and other anthropogenic activities. This work presents the results of measured natural radionuclides and toxic heavy metals in Rustenburg, and their associated non-carcinogenic and carcinogenic risk. The average concentrations of Cd, Cu, Co, Fe, Ni, Mn, Pb and Zn are 0.00007 mg/l, 0.0087 mg/l, 0.0033 mg/l, 0.0636 mg/l, 0.0052 mg/l, 0.0217 mg/l, 0.0003 mg/l and 0.0047 mg/l respectively and are below the safe limit of toxic heavy metals in water. The activity concentration of 40K and 238U ranges from 7.07 Bq/l to 13.2 Bq/l and 1.24 × 10􀀀 04 Bq/l to 1.09 × 10􀀀 02 Bq/l, with a mean activity concentration of 11.6 Bq/l and 2.78 × 10􀀀 03 Bq/l respectively. 232Th was not found in all measured water samples. The estimated average committed effective dose from ingestion of natural radionuclides was observed to be below 170 μSv/yr for 40K, 120 μSv/yr for 232Th and 238U, and a total of 290 μSv/yr reported by the United Nations Scientific Committee on the Effects of Atomic Radiation. The assessment of human health risks resulting from exposure to toxic heavy metals shows negligible carcinogenic and non-carcinogenic health risks to the exposed population, making the water sources from which the sample was collected, safe for agricultural and domestic use. The obtained results will also serve as reference data for future environmental studies.
Synthesis of p-n GCN/CuBi2O4 heterostructures for enhanced visible light photocatalysis
(Elsevier B.V., 2024) Onwudiwe, Damian C.; Olatunde, Olalekan C; Nkwe, Violet M.; Oyewo, Opeyemi A; Muliwa, Anthony M; Ferjani, Hela; Yousef, Tarek A
The fabrication of heterojunction structures is a well-established strategy for achieving efficient separation of charge carriers and their migration in photocatalysis in order to enhance photocatalytic activity. In this study, a series of g-C3N4/CuBi2O4 heterostructure photocatalysts were prepared through a solvothermal process. The obtained products were characterized using different techniques and their photocatalytic properties were evaluated for the degradation of methyl orange under the irradiation of visible light. Compared with the pristine g- C3N4 and CuBi2O4, the g-C3N4/CuBi2O4 heterojunction composites showed improved activity in the photocatalytic degradation of methylene orange, due to the formation of p-n junction, which resulted in improved charge carrier migration and separation. Furthermore, photogenerated O•􀀀 2 and h+ account for the effective degradation of methyl orange (MO) by the photocatalyst. The g-C3N4/CuBi2O4 heterojunction is therefore a promising photocatalyst for the effective degradation of MO.