International Research Award on Civil and Environmental Engineering

INTRODUCTION This study explores how differing irrigation regimes and organic amendments shape selenium (Se) behaviour in naturally Se‑rich paddy soils. By comparing continuous flooding (CF) with alternating wet‑dry (AWD) cycles and evaluating cotton‑straw biochar (BC) versus sheep manure (SM) at two dosage levels, the work seeks to clarify why Se sometimes remains locked in soil and how it can be mobilised for healthier rice production. WATER‑MANAGEMENT STRATEGIES Switching from CF to AWD proved pivotal: periodic drainage not only elevated root‑surface iron‑plaque formation but also boosted rhizospheric affinity for Se. AWD further hastened the shift from weakly organic‑bound forms toward soluble and exchangeable fractions, creating a more plant‑available Se pool without relying solely on chemical inputs. ORGANIC AMENDMENTS AND RATES Amendment chemistry mattered. A modest 10 g kg⁻¹ SM dose maximised Se bioavailability—especially under AWD—while BC repeatedly suppressed it. Manure’s...

  INTRODUCTION The development of sustainable construction materials has led to growing interest in the use of autoclaved aerated concrete (AAC) incorporating industrial by-products. This research investigates the effects of autoclaving parameters on AAC made from recycled concrete powder (RCP), calcium carbide slag (CCS), fly ash (FA), and phosphogypsum (PG). These materials offer environmental and economic advantages, aligning with the goals of green construction. Understanding how curing time impacts AAC’s properties is crucial to optimize its performance and durability in structural applications. HYDRATION PRODUCT TRANSFORMATIONS The hydration process during autoclaving plays a critical role in determining the mechanical strength of AAC. The study reveals that C-(A)-S-H phases gradually transform into tobermorite as the curing time increases. Tobermorite, especially in its fibrous form, enhances structural integrity. However, prolonged curing beyond 9 hours promotes the conv...