Geopolymer recycled pervious concrete (GRPC) provides a promising solution for low-carbon construction through the utilization of industrial by-products and recycled coarse aggregates (RCA). However, the influence of RCA quality on the durability performance of GRPC remains insufficiently understood. In this study, GRPC was prepared using RCA of high, medium, and low quality, denoted as H-GRPC, M-GRPC, and L-GRPC, respectively. The mechanical properties, permeability, fatigue resistance, freeze-thaw resistance, and microstructural characteristics were systematically investigated. The results showed that RCA quality had a limited effect on permeability, whereas the mechanical performance and durability of GRPC were strongly dependent on RCA quality. The initial compressive strengths of H-GRPC, M-GRPC, and L-GRPC were 79.2, 75.3, and 60.0 MPa, respectively, with corresponding flexural strengths of 7.3, 6.7, and 6.2 MPa. After 100,000 fatigue cycles, compressive strength increased by 3.7%, 4.4%, and 3.0%, respectively. After 200 freeze-thaw cycles, the overall freeze-thaw durability followed the order H-GRPC > M-GRPC > L-GRPC. Microstructural analysis revealed that higher RCA quality promoted a denser matrix, a more intact interfacial transition zone, and a higher degree of geopolymerization. These findings provide guidance on selecting appropriate RCA quality for durable GRPC design.
Africa harbors unparalleled genetic and cultural diversity. Yet, despite cancer being a major global non-communicable disease, African populations, particularly Indigenous groups, remain remarkably underrepresented in cancer genomics research. This review examines the current landscape of cancer genomics studies across Africa, with emphasis on population diversity and the extent to which Indigenous populations have been included. The genetic heterogeneity across African populations is discussed, and how it can influence cancer susceptibility, tumor biology, and therapeutic response, underscoring the fact that findings from non-African cohorts may not have the same significance in African cohorts. A substantial knowledge gap persists, and expanding studies in Africa could significantly provide valuable insights for global cancer biology. These factors emphasize the urgency of an African-based and African-owned biobanking infrastructure to support equitable research, strengthen local capacity and ethical stewardship of genomic resources towards the promotion of precision oncology and health equity on the continent.
China, with its vast territory, harbors abundant regional food resources with multiple values in nutrition, ecology, and anthropology. However, simply adopting the World Trade Organization’s (WTO) Geographical Indication (GI) system for classifying and managing these agricultural products fails to fully reflect their authentic natural and anthropological attributes, which cannot support the development of local characteristic economies and food cultural ecosystems. Therefore, there is an urgent need to establish a hierarchical classification standard system for regional food resources tailored to China’s national conditions. This paper proposed a new definition for China’s endemic and characteristic food resources and summarizes interdisciplinary research methods for exploring their biological and cultural attributes. Additionally, the economic and sociological values of these resources were discussed. The proposed classification standards provide guidance for the industrialization of regional food resources in China and offer new ideas for transforming biodiversity into novel productive forces in characteristic industries.
Tetraamminecopper(II) sulfate monohydrate, [Cu(NH3)4]SO4·H2O, can be used as a thermochemical energy storage material. When heated, [Cu(NH3)4]SO4·H2O releases ammonia gas and water, leaving behind CuSO4. When CuSO4 is cooled and exposed to ammonia, the reverse reaction occurs, forming [Cu(NH3)4]SO4 and releasing the stored heat. The reaction occurs at medium temperatures, can store a significant amount of thermal energy, and is highly reversible, allowing repeated cycles of heat storage and release without significant material degradation. This type of thermochemical energy storage can be used in various applications, particularly industrial waste heat recovery and solar thermal energy storage. In this study, tetraamminecopper(II) sulfate monohydrate was synthesized by chemical precipitation and thoroughly characterized via various techniques. Phase identification was performed by powder X-ray diffraction (PXRD) and Fourier transformed infrared spectroscopy (FTIR). The morphology of the sample was examined by scanning electron microscopy (SEM), and its chemical composition and elemental distribution were analyzed by energy-dispersive X-ray spectroscopy (EDS). Thermal properties were investigated via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). UV-Vis diffuse reflectance spectroscopy of the solid sample revealed a broad absorption band characteristic of [Cu(NH3)4]SO4·H2O, consistent with its dark blue color. XRD and FTIR analyses confirmed that the obtained sample is [Cu(NH3)4]SO4·H2O. SEM investigation showed that the prepared material consists of agglomerated particles of varying sizes. The process of thermal decomposition of the examined tetraamine copper(II) sulfate monohydrate takes place in three steps below 350 °C, followed by two additional steps at higher temperatures. Thermochemical energy storage potential of the prepared material is assessed on the basis of operating temperature range (20–200 °C), water elimination during the initial cycle, and volume changes in the course of charging/discharging process, yielding volumetric energy storage density estimation of 382 MJ·m−3.
Stoebe vulgaris is a declared indigenous bush encroacher species in South Africa. It has invaded over 11 million ha of grasslands. It is commonly called bankrupt bush due to its ability to outcompete other indigenous forb and grass species, decreasing grazing capacity, biodiversity, and ecosystem functioning, eventually leading to financial ruin for farmers. Landowners are legally required to control the plant. A herbicide trial was set up in a severely encroached camp at Dundee Research Station in KwaZulu-Natal, South Africa, to test the effectiveness of metsulfuron-methyl (50 g active ingredient ha−1) in controlling S. vulgaris. Applying metsulfuron-methyl provided a significant long-term reduction in S. vulgaris cover over six years. However, effective monitoring and management strategies depend on knowledge of the spatial distribution and expansion patterns of invasive species. We evaluated the ability of UAV-based imagery and machine learning, using Picterra, to detect and map S. vulgaris, while determining the optimal parameters to maximise detection accuracy. The best season for image acquisition was late summer when vegetation was at peak growth and maturity, providing the best spectral distinction between species, under light overcast and mild wind conditions. We recommend careful consideration of the flight orientation to the solar angle. We achieved 92% detector accuracy, with multispectral imagery enhancing the discrimination of similarly coloured plants. Plants smaller than 10 cm were not detected by the model. Our approach, using high-resolution drone imagery and AI, is capable of individual plant detection suited to a farm scale. This opens the way for using advances in drone technology for targeted, spot-application of herbicide.
