NuSpace

NuSpace is the official repository platform of the National University of Science and Technology that enables researchers in:

  • obtaining easy access to a wide range of academic materials,
  • promoting knowledge dissemination and facilitating interdisciplinary collaboration.

Explore our repository to discover a wealth of knowledge across various disciplines.

Photo by @inspiredimages
 

Communities in NuSpace

Select a community to browse its collections.

Now showing 1 - 5 of 12

Recent Submissions

No Thumbnail Available
Item
Influence of Organic Material and Biofilms on Disinfectant Efficacy Against Listeria monocytogenes
(ISEKI-Food Association (IFA), 2012-04-18) Nyati, H.; Beumer, R.; Van der Veen, S.; Hazeleger, W.; Abee, T.
The effects of organic material and biofilm formation on the efficacy of Suma Tab D4 chlorine tablets and Suma Bac D10 quaternary ammonium compound (QAC) against Listeria monocytogenes was determined in suspension and on stainless steel and polystyrene surfaces according to standard disinfectant test methodology. Exposure to 200 and 740 mg L-1 QAC and to 150 mg L-1 active chlorine resulted in a> 5.0 log10 CFU mL-1 and> 5.0 log10 CFU/coupon reduction of six L. monocytogenes strains within one minute, in suspension tests, and on stainless steel surfaces, respectively. Additionally, there was a reduction by as much as 5 log10 CFU/coupon or 5 log10 CFU/well of reference strains EGDe and Scott A biofilms within five minutes on stainless steel and polystyrene surfaces. Organic material, added as bovine serum albumin at 0.3%(w/v) completely prevented the inactivation of L. monocytogenes in 150 mg L-1 chlorine, while reductions of only 0.6+-0.1 log10 CFU mL-1 were recorded in the presence of UHT milk at 3%(v/v). In contrast, reductions of 5 log10 CFU mL-1 were recorded within one minute on exposure to 740 mg L-1 QAC in the presence of 0.3%(w/v) bovine serum albumin and within two minutes in the presence of 20%(v/v) UHT milk. Although Suma D4 chlorine tablets and Suma Bac D10 QAC are effective listericidal agents at recommended concentrations, Suma Tab D4 chlorine efficacy against L. monocytogenes is impaired by the presence of low concentrations of organic material, while Suma Bac D10 QAC maintains its listericidal activity in high organic loads.
No Thumbnail Available
Item
Integrating Entrepreneurship into the University Curriculum: Perceptions of 4th Year Students in One Public University in Zimbabwe
(Taylor and Francis, 2018) Nani, G.V.
This study was conducted to find out what the students’ views were regarding the right time to introduce Entrepreneurship into the university curriculum. The issue of when Entrepreneurship should be taught at university level has been a topic for debate amongst students, with some raising concerns that the course is not given adequate time to complete the entire entrepreneurial process. From a population of 477 students studying Entrepreneurship as a service course, 221 randomly selected fourth and final year students of one public university in Zimbabwe participated. The study employed a case survey approach which used semi-structured questionnaires to collect data. Thematic coding was used to analyse qualitative data. Findings were two-fold: that at the university under study, Entrepreneurship was introduced at fourth and final year level and that students felt that the course should be embedded into the curriculum earlier. Recommendations were that Entrepreneurship be taught from first year level to enable coverage of both the theoretical and practical components of the Entrepreneurship course. Alternatively, the study recommended that a specialised degree program be developed which would allow for the introduction of the Entrepreneurship course from first year university level.
No Thumbnail Available
Item
Use of coal fly ash to manufacture a corrosion resistant brick.
(Elsevier, 2019) Moyo, V.; Mguni, N.G.; Hlabangana, N.; Danha, G.
In this article, we investigate the use of an environmental waste (coal fly ash) in the manufacture of an ammonium nitrate corrosion resistant brick. Ammonium nitrate (AN) fertilizer spillages and vapors continuously corrode the civil structures in a fertilizer manufacturing plant situated in Zimbabwe. This situation is a safety hazard to more than a hundred plant personnel and hence a priority area for research. Our experimental results show that addition of sodium silicate improved the performance of the brick. Water absorption of bricks generally decreased with an increase in the amount of sodium silicate added. Our results also show that the compressive strength generally increased with increase in amount of sodium silicate added and that the corrosion resistance increases with the amount of sodium silicate added to the coal ash bricks.
No Thumbnail Available
Item
The use of calcium sulphate dihydrate (CaSO4. 2H2O) as a bleaching agent for crude soya bean vegetable oil.
(Elsevier, 2019) Chakawa, D.P.; Nkala, M.; Hlabangana, N.; Muzenda, E.
The use of calcium sulphate dihydrate (CaSO4.2H2O) as a bleaching agent during the refining of crude soya bean vegetable oil was investigated. Different weight ratios of CaSO4.2H2O bleaching agent relative to crude oil (2, 4, 5, 10, 20 and 30 wt. %) were prepared. One sample of raw crude without any bleaching agent added was isolated as a control. Each of the 7 crude oil samples were preheated at a temperature range of 80ºC - 120ºC.The different weight compositions of CaSO4.2H2O were added and the respective slurries agitated for 30minutes.The agitated slurry was then filtered. The experimental results for red color were recorded and % free fatty acids (ffa) and % bleachability were calculated. The results indicated that there was decrease in red color of crude oil from 14R-4.3R with increase in weight ratio of bleaching agent. There was also an increase in red color bleachability from 24.285 % - 60.714% with increase in weight ratio. % ffa and solid nonfat (SNF) remained constant at 0.56% and nil respectively. The results indicate that calcium sulphate dihydrate (CaSO4.2H2O) is an effective bleaching agent in bleaching of crude soya bean vegetable oil.
No Thumbnail Available
Item
Micro-spatial distribution of malaria cases and control strategies at ward level in Gwanda district, Matabeleland South, Zimbabwe
(BioMed Central, 2017) Manyangadze, T.; Chimbari, M.J.; Macherera, M.; Mukaratirwa, S.
Background Although there has been a decline in the number of malaria cases in Zimbabwe since 2010, the disease remains the biggest public health threat in the country. Gwanda district, located in Matabeleland South Province of Zimbabwe has progressed to the malaria pre-elimination phase. The aim of this study was to determine the spatial distribution of malaria incidence at ward level for improving the planning and implementation of malaria elimination in the district. Methods The Poisson purely spatial model was used to detect malaria clusters and their properties, including relative risk and significance levels at ward level. The geographically weighted Poisson regression (GWPR) model was used to explore the potential role and significance of environmental variables [rainfall, minimum and maximum temperature, altitude, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), rural/urban] and malaria control strategies [indoor residual spraying (IRS) and long-lasting insecticide-treated nets (LLINs)] on the spatial patterns of malaria incidence at ward level. Results Two significant clusters (p < 0.05) of malaria cases were identified: (1) ward 24 south of Gwanda district and (2) ward 9 in the urban municipality, with relative risks of 5.583 and 4.316, respectively. The semiparametric-GWPR model with both local and global variables had higher performance based on AICc (70.882) compared to global regression (74.390) and GWPR which assumed that all variables varied locally (73.364). The semiparametric-GWPR captured the spatially non-stationary relationship between malaria cases and minimum temperature, NDVI, NDWI, and altitude at the ward level. The influence of LLINs, IRS and rural or urban did not vary and remained in the model as global terms. NDWI (positive coefficients) and NDVI (range from negative to positive coefficients) showed significant association with malaria cases in some of the wards. The IRS had a protection effect on malaria incidence as expected. Conclusions Malaria incidence is heterogeneous even in low-transmission zones including those in pre-elimination phase. The relationship between malaria cases and NDWI, NDVI, altitude, and minimum temperature may vary at local level. The results of this study can be used in planning and implementation of malaria control strategies at district and ward levels.