An assessment of the strength and durability characteristics of recycled plastic pavers.

Masters Degree. University of KwaZulu-Natal, Durban.The generation of waste is reaching record highs and displays a consistent uptrend over the last decade, and despite high generation rates, landfilling is still the dominant disposal method for waste in South Africa. However, these materials may have potential for reuse in several applications, and industries are considering their viability. One such industry is the construction and engineering industry, which has seen an increase in research into the application of waste materials. This study explores the use of HDPE, PP, and glass waste as an alternative material for making concrete pavers. The study uses local waste materials to assess the density, durability, and mechanical strengths of the resulting paver, called Eco-pavers, and compares them to regular concrete pavers for accuracy. The pavers are made of a 50/50 blend of recycled plastic and glass aggregate, which has not been widely studied as a replacement for cement or stone aggregate. The Eco-pavers demonstrate a low water absorption rate of 0.28%, compared to the 4.5% of concrete pavers. After immersion testing in various chemicals over a 180-day period, the pavers show no signs of degradation either structurally or visually. The Eco-pavers are suitable for use as impermeable pavers, as they did not allow any infiltration during the permeability test. The flexural strength assessment resulted in an average breaking stress of 7.9 MPa, which is greater than the prescribed minimum. However, the pavers' average compressive strength is 12.47 MPa, which is below the minimum criterion of 35 MPa for pavers, and therefore needs improvement. In summary, this study explored the use of recycled plastic and glass waste in manufacturing Eco-pavers as an alternative to traditional concrete pavers. The resulting pavers demonstrated low water absorption, chemical resistance, and impermeability, making them suitable for impermeable applications. However, the compressive strength of the pavers needs improvement. While their short-term use is unlikely to release microplastics, further research is needed to determine their long-term impact

Barbarians at the British Museum: Anglo-Saxon Art, Race and Religion

A critical historiographical overview of art historical approaches to early medieval material culture, with a focus on the British Museum collections and their connections to religion

Bionomics of Anopheles arabiensis from Mamfene in KwaZulu-Natal (South Africa): an area of high malaria transmission in the province

Abstract Background Although great strides have been made in controlling malaria, the disease is of significant public health importance. Historically, efforts to control the vector has concentrated on adult vector control targeting the female Anopheles mosquitoes. As there is now a focus on eliminating residual malaria from KwaZulu-Natal, new strategies are being investigated to increase the impact of malaria elimination strategies. Greater attention is now being given to larval control, as a complementary measure to indoor residual spraying. However, there is a large gap in knowledge of the bionomics of the larval stages of this mosquito vector of malaria in South Africa. In order to focus on both larval and adult mosquito control methods, larval development and the reproductive stages of the vector were investigated since these variables influences our ability to impact mosquito populations through larval control. This study was therefore conducted to determine the peak eruption times and the emergent sex ratios, as well as the peak egg oviposition time in order to attack the mosquito when it is at its most vulnerable and when control interventions will have the most impact. Results Oviposition studies showed two peaks corresponding with late evening and again just before dawn. Most eggs were also laid in the first half of the night (18h00 – midnight). Most mosquitoes erupted just after sunset and the sex ratios showed that twice as many females as males emerged. Females readily took a bloodmeal after oviposition or just after erupting. Hatch rate to viable first instar larvae was 74.5%. Conclusions The results of this study have provided information as to when interventions would be most effective in controlling mosquito populations and have provided information that highlights the value of larval control as a complementary measure to adult mosquito control. The most vulnerable stages of the female Anopheles arabiensis are when they have just emerged or when they have just oviposited. Vector control strategies should be designed to target these vulnerable stages at the breeding sites in order to have maximum impact.</jats:p

Bionomics of Anopheles Arabiensis from Mamfene in KwaZulu-Natal (South Africa): An Area of High Malaria Transmission in the Province

Abstract Background: Although great strides have been made in controlling malaria, the disease is of significant public health importance. Historically, efforts to control the vector has concentrated on adult vector control targeting the female Anopheles mosquitoes. As there is now a focus on eliminating residual malaria from KwaZulu-Natal, new strategies are being investigated to increase the impact of malaria elimination strategies. Greater attention is now being given to larval control, as a complementary measure to indoor residual spraying. However, there is a large gap in knowledge of the bionomics of the larval stages of this mosquito vector of malaria in South Africa. In order to focus on both larval and adult mosquito control methods, larval development and the reproductive stages of the vector were investigated since these variables influences our ability to impact mosquito populations through larval control. This study was therefore conducted to determine the peak eruption times and the emergent sex ratios, as well as the peak egg oviposition time in order to attack the mosquito when it is at its most vulnerable and when control interventions will have the most impact.Results: Oviposition studies showed two peaks corresponding with late evening and again just before dawn. Most eggs were also laid in the first half of the night (18h00 – midnight). Most mosquitoes erupted just after sunset and the sex ratios showed that twice as many females as males emerged. Females readily took a bloodmeal after oviposition or just after erupting. Hatch rate to viable first instar larvae was 74.5%.Conclusions: The results of this study have provided information as to when interventions would be most effective in controlling mosquito populations and have provided information that highlights the value of larval control as a complementary measure to adult mosquito control. The most vulnerable stages of the female Anopheles arabiensis are when they have just emerged or when they have just oviposited. Vector control strategies should be designed to target these vulnerable stages at the breeding sites in order to have maximum impact.</jats:p

Emergence, feeding and oviposition behaviour of Anopheles arabiensis: a vector from Mamfene in KwaZulu-Natal (South Africa)

Abstract Background Malaria is a disease of public health importance. To eliminate malaria from KwaZulu-Natal, new strategies are needed to increase the impact of existing interventions. Greater attention is being given to controlling the larval stages, as a complementary measure to indoor residual spraying. However, there is limited information available on bionomics of this South Africa mosquito vector. To fill ithe knowledge gaps in vector bionomics, this study interrogated the emergence, feeding and oviposition behaviour of Anopheles arabiensis. Methods To observe the number of eggs laid per F1 An. arabiensis female, 300 fully gravid mosquitoes were individually placed into breeding tubes which were observed hourly from 18h00 to 06h00 and number of eggs laid by each female was recorded. Egg hatch rate was measured. Immediately after oviposition, the female mosquitoes were offered a blood meal to determine the duration post laying it took to refeed. To observe emergence times and sex ratios, a total of 4000 F1 pupa were placed in large containers which were observed hourly from 18h00 to 06h00. The newly erupted mosquitoes were collected and placed in bug-dorm cages. A sample of the newly erupted female mosquitoes were removed from the cages and placed individually into a test container and offered a blood meal. The female was then observed for a probing behaviour indicating its willingness to feed. Results Oviposition studies revealed two peaks corresponding with late evening and just before dawn. Most eggs were laid in the first half of the night (18h00 – midnight). Most mosquitoes erupted just after sunset and the sex ratios showed twice as many females as males emerged from pupae. Females readily took a bloodmeal after oviposition or just after emerging. Hatch rate to viable first instar larvae was 74.5%. Conclusions This study provided information on egg laying, hatch rates, emergence times, feeding behavior and sex ratios. The sex ratio of emerging mosquitoes is biased to females. The feeding behaviour suggests that the use of control interventions close to known vector breeding sites would be a tool to eliminate many males and females seeking sustenance soon after emergence or oviposition.</jats:p