A study on waste PCB fibres reinforced concrete with and without silica fume made from electronic waste.

This research goal is to appraise the effect of electronic waste on concrete properties by examining the mechanical properties of concrete reinforced with waste printed circuit boards (PCBs). PCB fibres, each 50 mm long, were mixed in varying proportions (1-5% by weight of cement). Silica fume (SF) was used as a 12% weight replacement for cement to conserve the properties of PCB fibre-reinforced concrete while tumbling cement consumption. Following a 28-day curing period, the fresh and hardened characteristics of PCB fibre-reinforced concrete were juxtaposed with those of conventional concrete. The experimental results led to the conclusion that 5% by weight of cement is the most effective proportion of PCB fibres to include in both PCB fibre-reinforced concrete and silica fume-modified PCB fibre-reinforced concrete. The addition of PCB fibres and silica fume significantly increased the mechanical strength of the concrete, making it suitable for high-strength concrete applications. Based on a similar investigational research design, an artificial neural network model was created, and it played a critical role in predicting the mechanical properties of the concrete. The model produced accurate results, with an R-squared (R2) value greater than 0.99.

Recycling and sustainable applications of waste printed circuit board in concrete application and validation using response surface methodology.

The present investigation aims to examine the mechanical and durability properties of concrete that has been reinforced with a waste printed circuit board (WPCB) towards a low-carbon built environment. It assessed the fresh and hardened characteristics of the low-carbon concrete reinforced with WPCB fibres, after a curing period of 7 and 28 days. The evaluation was done by quantifying slump, compressive strength, split tensile strength, flexural strength, sorptivity, rapid, and acid tests. It further analysed eleven discrete concrete mixes with WPCB fibres at a weight percentage ranging from 1 to 5% in the cement mixture. The results indicate that incorporating WPCB fibre into concrete improves its mechanical strength. The results revealed that incorporating 5% WPCB fibre yielded the most favourable outcomes. The properties of WPCB fibre-reinforced concrete have been theoretically validated through Response Surface Methodology (RSM), which employs various statistical and mathematical tools to analyse the experimental data. The results derived from RSM were compared with the experimental results. It was found that the RSM model demonstrated a high level of accuracy (R2 ≥ 0.98) in validating the mechanical properties of WPCB fibre concrete. The statistical model exhibited no indication of prediction bias and demonstrated a statistically significant outcome, with a p-value below 0.5.

In silico approach of azadirachtin binding with actins.

In silico docking analysis reported here suggests that insect cellular cytoskeletal beta-actin could be the target of Azadirachtin A (Aza-the principle bioactive compound of neem seeds). The best docking energy of -40.09 kcal/mol at 8.73 A RMSD and predicted hydrogen bond between Arg210 and carboxymethyl group of Aza accompanied with seven hydrophobic interactions in the proposed binding site strongly support this hypothesis. This is of specific interest due to the non-affinity of Aza to mammalian beta-actins under the same set of conditions, although beta-actins across the species are highly conserved. Our results show that few scattered amino acid changes have caused significant steric hindrance in the binding pocket for mammalian beta-actin, causing a reverse orientation of Aza. These results suggest a model to support the recently observed biological effects caused by Aza in Drosophila cytoskeletal elements and explain why Aza is highly specific to insects than mammals.

Azadirachtin inhibits proliferation of Sf 9 cells in monolayer culture.

Azadirachtin A in ppm quantity inhibits proliferation and monolayer formation of Spodoptera frugiperda (Sf9) insect cells in monolayer culture. The incubated cells demonstrate reduced rates of protein synthesis which finally leads to cell death. This growth inhibiting activity is compared with other botanicals such as ohchinin, salannin and volkensin. The high and specific activity of azadirachtin A on insect cells is discussed in comparison with its effect on a mammalian cell line, based on 2 D PAGE analysis of the total protein contents.

High resolution two-dimensional mapping of tissue-specific polypeptides in the desert locust, Schistocerca gregaria.

High resolution two-dimensional gel electrophoresis (2-DE) using immobilized pH gradients was used to map the tissue-specific polypeptides of the desert locust, Schistocerca gregaria. Highly specific comprehensive 2-DE reference maps ("master gels") were developed for the brain, corpus cardiacum, subesophageal ganglion, and hemolymph. The polypeptides were well resolved within the pH 4-7 range in the first dimension and within the 14-94 kDa molecular mass range in the second dimension.