Analysis of epoxy composites reinforced with jute, banana, and coconut fibers and enhanced with Rubik's layer: Tensile, bending, and impact performance evaluation

This research paper presents a comprehensive analysis of epoxy composites fortified with natural fibers such as jute, banana, and coconut, further augmented by the incorporation of Rubik's layer, aimed at evaluating their mechanical performance in terms of tensile, bending, and impact properties. As sustainable alternatives to traditional reinforcement materials, these natural fibers offer the advantage of low environmental impact, renewability, and biodegradability. The Rubik's layer, known for its three-dimensional interlocking structure, holds promise in enhancing composite properties due to its unique geometry and material characteristics. The study involves the fabrication of composite specimens through a systematic layering process, varying the composition of natural fibers and Rubik's layer. A comprehensive experimental campaign is conducted to assess the tensile strength, bending modulus, and impact resistance of the resultant composites. The results are systematically compared against those of pristine epoxy composites to ascertain the influence of the added reinforcements and enhancement layer. The findings reveal distinctive trends in mechanical behavior based on the type and proportion of natural fibers employed. Notably, the jute-reinforced composites exhibit commendable tensile and bending properties, while banana and coconut reinforcements contribute to improved impact resistance. The introduction of the Rubik's layer further refines these properties, with discernible variations based on its placement within the composite structure. This paper offers valuable insights into the multifaceted impact of natural fiber reinforcements and Rubik's layer incorporation on epoxy composites. The systematic evaluation of mechanical attributes provides a comprehensive understanding of the synergistic effects among these constituents. As the demand for sustainable and high-performance materials escalates, this research contributes to the growing body of knowledge on composite design, catering to diverse engineering applications that prioritize mechanical excellence and ecological responsibility.

Physical soil architectural traits are functionally linked to carbon decomposition and bacterial diversity

Aggregates play a key role in protecting soil organic carbon (SOC) from microbial decomposition. The objectives of this study were to investigate the influence of pore geometry on the organic carbon decomposition rate and bacterial diversity in both macro- (250–2000 μm) and micro-aggregates (53–250 μm) using field samples. Four sites of contrasting land use on Alfisols (i.e. native pasture, crop/pasture rotation, woodland) were investigated. 3D Pore geometry of the micro-aggregates and macro-aggregates were examined by X-ray computed tomography (μCT). The occluded particulate organic carbon (oPOC) of aggregates was measured by size and density fractionation methods. Micro-aggregates had 54% less μCT observed porosity but 64% more oPOC compared with macro-aggregates. In addition, the pore connectivity in micro-aggregates was lower than macro-aggregates. Despite both lower μCT observed porosity and pore connectivity in micro-aggregates, the organic carbon decomposition rate constant (Ksoc) was similar in both aggregate size ranges. Structural equation modelling showed a strong positive relationship of the concentration of oPOC with bacterial diversity in aggregates. We use these findings to propose a conceptual model that illustrates the dynamic links between substrate, bacterial diversity, and pore geometry that suggests a structural explanation for differences in bacterial diversity across aggregate sizes.

Climate and soil properties limit the positive effects of land use reversion on carbon storage in Eastern Australia

Australia’s “Direct Action” climate change policy relies on purchasing greenhouse gas abatement from projects undertaking approved abatement activities. Management of soil organic carbon (SOC) in agricultural soils is an approved activity, based on the expectation that land use change can deliver significant changes in SOC. However, there are concerns that climate, topography and soil texture will limit changes in SOC stocks. This work analyses data from 1482 sites surveyed across the major agricultural regions of Eastern Australia to determine the relative importance of land use vs. other drivers of SOC. Variation in land use explained only 1.4% of the total variation in SOC, with aridity and soil texture the main regulators of SOC stock under different land uses. Results suggest the greatest potential for increasing SOC stocks in Eastern Australian agricultural regions lies in converting from cropping to pasture on heavy textured soils in the humid regions.