This research presents a low-cost, easy-to-assemble nondispersive infrared (NDIR) device for monitoring N₂O gas concentration in agricultural soils during field and laboratory experiments. The study aimed to develop a cost-effective instrument with a simple optic structure suitable for detecting a wide range of soil N₂O gas concentrations with a submerged silicone diffusion cell. A commercially available, 59 cm path-length gas cell, microelectromechanical systems (MEMS)-based infrared emitter, pyroelectric detector, two anti-reflective (AR) coated optical windows, and one convex lens were assembled into a simple instrument with secure preciseness and responsivity. Control of the IR emitter and data recording processes was achieved through a microcontroller unit (MCU). Tests on humidity tolerance and the saturation rate of the diffusion cell were carried out to test the instrument function with the soil atmosphere. The developed calibration model was validated by repeatability tests and accuracy tests. The soil N₂O gas concentration was monitored at the laboratory level by a specific experimental setup. The coefficient of determination (R²) of the repeatability tests was more than 0.9995 with a 1–2000 ppm measurability range and no impact of air humidity on the device output. The new device achieved continuous measuring of soil N₂O gas through a submerged diffusion cell.

This study examined plastic waste management in Sri Lanka, concentrating on the contributing factors to plastic waste generation and collection. Data were gathered through a questionnaire survey from registered plastic recycling and management centres. The analysis revealed a positive correlation between tourist arrivals and plastic waste generation, indicating increased plastic waste production due to tourism spanning from 2014 to 2022. However, plastic waste collection negatively correlated with precipitation levels, suggesting heavy rainfall hampers collection efforts. This study found HDPE, PVC, LDPE, and PP to be the most collected and recycled plastic types, whereas PS and PET recycling were less prevalent. The results demonstrate the need for enhanced recycling infrastructure and highlight the necessity for government participation in plastic waste management initiatives. This study recommends increasing waste collection and recycling during the tourist season. In addition to enhancing public and private awareness, there should be additional investment in recycling facilities. The findings offer crucial insights into plastic waste management in Sri Lanka, emphasizing the importance of collaborative efforts and comprehensive strategies to tackle plastic pollution.

Faced with the escalating crisis of global deforestation, including particularly alarming rates in Sri Lanka, researchers have turned their attention to the potential of boronbased preservatives for treating timber. The comprehensive study of the samples has revealed a significant negative correlation between the treatability of timber under pressure and the total area of vessels and wood density. Woods with fewer and smaller vessels are more receptive to boron treatment, making them more suitable for preservation. The study also identified a positive, though somewhat weak, correlation between treatability and the total ray area within the wood, indicating that the internal structure of timber plays a crucial role in its preservation potential. The timber during the research has been categorized based on the depth of boron penetration, with categories ranging from fully penetrated to less than 5 mm. The findings obtained suggest that boron preservatives offer a promising and sustainable alternative to traditional timber treatment methods. By categorizing wood based on the treatability and anatomical properties, we can optimize the treatment processes, thereby maximizing resource utilization and minimizing waste. Thus boron-treated timber could become a cornerstone in the fight against deforestation in future, providing a responsible and environmentally friendly alternative to the untreated wood. In doing so, the research contributes significantly to the preservation of our forests and the overall well-being of our planet, offering a promising trajectory in sustainable forestry practices.

The detection of low gas concentrations from the soil surface demands expensive high-precision devices to estimate nitrous oxide (N₂O) flux. As the prevalence of N₂O concentration in the soil atmosphere is higher than its surface, the present study aimed to simulate N₂O surface flux (CF) from soil gas measured in a soil-interred silicone diffusion cell using a low-cost device. The methodological steps included the determination of the diffusion coefficient of silicone membrane (D_slcn), the measurement of the temporal variations in the N₂O gas in the soil (C_si) and on the surface (MF), and the development of a simulation process for predicting CF. Two experiments varying the procedure and periods of soil moisture saturation in each fertilized soil sample were conducted to detect C_si and MF. Using D_slcn and C_si, the variations in the soil gas (C_soil) were predicted by solving the diffusion equation using the implicit finite difference analysis method. Similarly, using six soil gas diffusivity models, the CF values were simulated from C_soil. For both experiments, statistical tests confirmed the good agreement of CF with MF for soil gas diffusivity models 4 and 5. We suggest that the tested simulation method is appropriate for predicting N₂O surface emissions.