Studies on antimicrobial and wound healing applications of gauze coated with CHX–Ag hybrid NPs

In this study, chlorhexidine (CHX)–silver (Ag) hybrid nanoparticles (NPs) coated gauze was developed, and their bactericidal effect and in vivo wound healing capacities were tested. A new method was developed to synthesise the NPs, wherein Ag nitrate mixed with sodium (Na) metaphosphate and reduced using Na borohydride. Finally, CHX digluconate was added to form the hybrid NPs. To study the antibacterial efficacy of particles, the minimal inhibition concentration and biofilm degradation capacity against Gram‐positive and Gram‐negative bacteria was studied using Escherichia coli and Staphylococcus aureus. The results indicated that the NP inhibited biofilm formation and was bactericidal as well. The gauze was doped with NPs, and its wound healing property was evaluated using mice model. Results indicated that the wound healing process was fastened by using the NPs gauze doped with NPs without the administration of antibiotics.Inspec keywords: nanomedicine, nanoparticles, wounds, silver, cellular biophysics, biomedical materials, nanofabrication, microorganisms, antibacterial activityOther keywords: NPs gauze, antimicrobial wound healing applications, hybrid NPs, chlorhexidine–silver hybrid nanoparticles, CHX, coated gauze, bactericidal effect, minimal inhibition concentration, biofilm degradation capacity, Gram‐negative bacteria, wound healing property, wound healing process, in vivo wound healing capacities, Staphylococcus aureus, Escherichia coli, antibiotics administration, Na borohydride, Ag nitrate mixing, sodium metaphosphate, CHX digluconate, NP inhibited biofilm formation, Ag     

Selective catalytic reduction converter design: The effect of ammonia nonuniformity at inlet

A three-dimensional CFD model of SCR converter with detailed chemistry is developed. The model is used to study the effects of radial variation in inlet ammonia profile on SCR emission performance at different temperatures. The model shows that radial variation in inlet ammonia concentration affects the SCR performance in the operating range of 200–400 °C. In automotive SCR systems, ammonia is non-uniformly distributed due to evaporation/reaction of injected urea, and using a 1D model or a 3D model with flat ammonia profile at inlet for these conditions can result in erroneous emission prediction. The 3D SCR model is also used to study the effect of converter design parameters like inlet cone angle and monolith cell density on the SCR performance for a non-uniform ammonia concentration profile at the inlet. The performance of SCR is evaluated using DeNO _x efficiency and ammonia slip.     

Large-scale synthesis of centrifugally spun tantalum oxynitride fiber electrocatalysts for hydrogen evolution reaction

Tantalum oxynitride (TaO_xN_1−x) fibers were synthesized and evaluated for their electrocatalytic hydrogen activity using an in-house developed centrifugal spinning setup. By tailoring the composition of the spinning solution and optimizing collector distance and rotation speed of the spinneret, bead-free TaO_xN_1−x fibers with a diameter of 800 nm were obtained. The fibers were structurally characterized through phase and elemental analysis, confirming the formation of monoclinic TaO_xN_1−x with clear splitting of the X-ray photoelectron spectroscopy peaks indicating Ta was in +5 oxidation state. The resulting oxynitride fibers exhibited superior electrocatalytic performance with low overpotentials (250 mV) to generate 10 mA/cm² compared to Ta₂O₅ oxide fibers. Interestingly, the enhanced activity of oxynitride fibers was observed to be suppressed in basic medium due to the high oxophilicity of tantalum ions and a negative Gibbs adsorption-free energy, leading to poisoning of the active sites. This work demonstrates a facile pathway for the fabrication of high-performance electrocatalysts, based on TaO_xN_1−x fibers, from a cost-effective and energy-efficient centrifugal spinning technique.     

Screening Maize Hybrids for Silicon Efficiency to Improve the Growth and Yield on Silicon Deficient Soils

Silicon - Silicon is a metalloid that hardly finds a place among the nutritional elixir required for plants. However, in recent times, silicon fertilizers have been gaining popularity for their...