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Combining bio-based cementation with cement stabilisation for road construction

(2024-07) Smit, Michelle A; Rust, FC

The growing concerns over climate change and the move towards sustainable, costeffective road development have resulted in the development of bio-based construction methods. Microbial induced calcium carbonate precipitation (MICP) binds material through the formation of calcite bridges between soil grains. Current MICP treatment techniques, however, are not compatible with road construction processes. Due to this the Council for Scientific and Industrial Research (CSIR) has started investigating bio-stabiliser treatment techniques for road construction. The objective of this paper is to present Unconfinded compressive strength (UCS) results for a G8 material stabilised using in-situ bacteria present in the soil. After 10 days of cementation solution treatments a UCS dry result of 1.16MPa was achieved. No wet UCS results were, however, produced as all the samples disintegrated. The decision was made to supplement MICP with 0.7% cement. Not only did UCS wet results show a 100% increase compared with MICP only treated samples, but the UCS dry results were comparable to adding 2.5% cement to the G8 material. Partial replacement of cement with MICP during stabilisation could lead to an overall reduction in the amount of cement used in road construction without compromising strength, which will have a positive environmental and economic impact.

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In vitro antiplasmodium and antitrypanosomal activities, β-haematin formation inhibition, molecular docking and DFT computational studies of quinoline-urea-benzothiazole hybrids

(2024-10) Oyeneyin, OE; Moodley, R; Mashaba, C; Garnie, LF; Omoboyowa, DA; Rakodi, GH; Maphoru, MV; Balogun, Mohammed O; Hoppe, H; Egan, TJ; Tukulula, M

Quinoline-urea-benzothiazole hybrids exhibited low to sub-micromolar in vitro activities against the Plasmodium falciparum (P. falciparum) 3D7 chloroquine (CQ)-sensitive strain, with compounds 5a, 5b and 5f showing activities ranging from 0.33 to 0.97 μM. Against the formation of β-haematin, the majority of the tested compounds were comparable to the reference drug, chloroquine (CQ), with compounds 5c (IC50 = 9.55 ± 0.62 μM) and 5h (IC50 = 9.73 ± 1.38 μM), exhibiting slightly better in vitro efficacy than CQ. The hybrids also exhibited low micromolar to submicromolar activities against Trypanosoma brucei brucei, with 5j-5k being comparable to the reference drug, pentamidine. Compound 5b displayed higher in silico binding energy than CQ when docked against P. falciparum dihydroorotate dehydrogenase enzyme. Compounds 5j and 5k showed higher binding energies than pentamidine within the trypanothione reductase enzyme binding pocket. The root means square deviations of the hit compounds 5b, 5j and 5k were stable throughout the 100 ns simulation period. Post-molecular dynamics MMGBSA binding free energies showed that the selected hybrids bind spontaneously to the respective enzymes. The DFT investigation revealed that the compounds have regions that can bind to the electropositive and electronegative sites of the proteins.

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Towards greener networks: Evaluating power consumption in popular open RAN environments

(2024) Ebrahim, Rozeena; Vilakazi, Mlamuli C; Burger, Chris R; Lysko, Albert A

Energy efficiency, power consumption, and their cost and environmental impacts have become critical considerations in telecommunications, including fifth-generation (5G) and beyond mobile networks. This work investigates power consumption within open Radio Access Network (RAN) implementations for 4G and 5G mobile networks, such as OpenAirInterface (OAI) and Software Radio Systems RAN (srsRAN). Using two measurement tools, a hardware measurement setup and the software tool Turbostat, we evaluate and compare the power consumption across various RAN environments on our inhouse mobile network testbeds. We also compare the power consumption profiles for each RAN environment under different modes/tasks. From this comparison of considered versions, we found that the srsRAN platform consumes less power than the OAI RAN for both 4G and 5G setups potentially resulting in lower operational costs in open RAN deployments.

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Determining the value of different wavelength ranges of non-imaging hyperspectral reflectance to estimate carotenoid content using the PROSPECT-5 model

(2024-12) Sibiya, Bongokuhle; Cho, Moses A; Mutanga, O; Ondidi, J; Masemola, Cecilia R; Bonnet, Wessel J

Carotenoids are important plant attributes offering valuable insights into the physiological condition of vegetation and serve as essential indicators for early identification of plant stress. Generally, carotenoids can be extracted using radiative transfer model (RTM) remote sensing techniques like PROSPECT that utilize the entire spectral domain (400–2500 nm) to retrieve carotenoid information. However, such inversions suffer from ill-posed due to model uncertainties. Literature suggests that selecting appropriate bands improves the RTM inversion. Hence, this study proposed a wavelength selection approach using various regions in the visible portion of the electromagnetic spectrum and bands selected by the random forest algorithm to estimate carotenoids using the PROSPECT-5 model. This study utilized three distinct datasets – savanna, tropical forest, and a combination of two. The green spectral region demonstrated the strongest performance in the tropical forest dataset (R2 = 0.90, RMSE = 0.71) than the savanna (R2 = 0.70, RMSE = 1.19) and combined (R2 = 0.72, RMSE = 1.11) datasets, respectively. The bands (green, yellow, and red-edge) selected by the random forest model produced the highest accuracy in the savanna dataset (R2 = 0.84, RMSE = 0.99), followed by combined (R2 = 0.80, RMSE = 1.20) and tropical forest (R2 = 0.78, RMSE = 1.33), respectively. Lastly, the visible region demonstrated strong performance in the tropical forest (R2 = 0.84, RMSE = 0.85), followed by combined datasets (R2 = 0.72, RMSE = 1.15) and savanna (R2 = 0.68, RMSE = 1.27), respectively. The findings suggest that carotenoid retrieval should be limited to the visible portions of the spectrum as it exhibited strong performance in estimating carotenoid content across the savanna, tropical forest, and combined datasets.

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Solving the privacy and security challenge using ZKP: Its positive impact on the economy

(2024-12) Ntshangase, Cynthia S; Baruni, Kedimotse P; Myaka, Zanele S; Mahlasela, Oyena N

The 4th and 5th industrial revolutions are improving the functioning of the working environment for different industries. However, it also introduces security and privacy challenges that lead to cybercrime which negatively impacts the economy. This article presents a comprehensive analysis of the usage of Zero Knowledge Proofs (ZKP) to protect data in the major technologies for the 4th and 5th industrial revolutions. These technologies include cloud computing, big data, Internet of Things, blockchain, 5G, artificial intelligence, and supply chain. Security and privacy challenges and solutions in these technologies were investigated. ZKP, a cryptographic method that enables verification of a party without revealing confidential details, is one of the promising solutions to fight the problem of data security and privacy. In this study, it was determined that Blockchain is the leading technology in terms of using the ZKP to improve security and enhance privacy. The paper provides the future direction to secure these technologies using cryptographic methods such as ZKP.