An image-processing algorithm for morphological characterisation of soot agglomerates from TEM micrographs: Development and functional description

Merits photocatalytic activity of rGO/zinc copper ferrite magnetic nanocatalyst for photodegradation of methylene blue (MB) dye

The world is now facing a water scarcity crisis due to waste, pollution, and uneven distribution of freshwater resources, which are limited. Thus, the creation of innovative, economical, and effective methods for purifying water is crucial. Here, the photo-assisted degradation of methylene blue (MB) dye under visible light and UV was achieved by using RGO photocatalyst loaded with Zn0.5Cu0.5Fe2O4 in three different loaded 10%, 20%, and 30% called MRGO 10, MRGO 20, and MRGO 30. Furthermore, all prepared samples was characterized by X-ray diffraction (XRD), fourier transformation infrared (FTIR), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and Raman analysis. After 40 min, the high photocatalytic efficacy effectively eliminated about 95.2% of the 10 ppm MB using 20 mg of MRGO 20 NPs at pH9 Visible light. From the results, the photocatalytic activity of MRGO 20 reduced to 54.6% after five cycles of methylene blue (MB) dye degradation. The produced samples' observed efficacy in both UV and visible light may encourage continued research into more effective photocatalysts for the filtration of water.

Harnessing Short-Range Surface Plasmons in Planar Silver Films via Disorder-Engineered Metasurfaces

Short-range surface plasmon polaritons (SR-SPPs) can arise due to the hybridization of surface plasmon polaritons propagating along the two interfaces of a thin metal slab. In optics, they have gained particular interest for imaging and sensing applications because of their short wavelengths at optical frequencies along with strong field enhancement. However, mediating the interaction of SR-SPPs with photons in planar films is difficult because of the large momentum mismatch. For efficient coupling, nanostructuring such thin films (∼20 nm thickness), or placing metallic nanostructures in close proximity to the planar film, is technologically challenging and can strongly influence the SR-SPP properties. In this article, harnessing SR-SPPs in planar silver films is demonstrated using disorder-engineered metasurfaces. Disorder-engineering is realized by the light-controlled growth of silver nanoparticles. The dispersion of the hybrid modes with the silver thickness is measured and compared with simulations. We anticipate these results to introduce a facile method for harnessing SR-SPPs in planar optical systems and make use of their promising properties for imaging, sensing, and nonlinear optics.

Experimental evaluation of the effect of ozone treatment on the oxidation and removal of dry soot deposits of the exhaust gas recirculation system

The integration of alternative energy sources as a replacement for fossil fuels across various industrial sectors, including power generation, emergency systems, or marine applications, is uncertain. As a result, the utilization of traditional fuels is not anticipated to be fully phased out in the near future. To address this, new technologies, such as those that employ oxidising atmospheres, have been explored as a means to enhance the pollution control capabilities of existing technologies, as the Exhaust Gas Recirculation (EGR) system. In this regard, the present study has assessed the efficacy of ozone atmosphere exposure in mitigating the formation of undesired fouling deposits within the system, with the aim of facilitating more efficient operation of EGR devices and extending their service life. To this end, dry soot samples have been exposed to various ozone atmospheres at different temperatures and ozone concentrations through the utilization of an experimental test bench. The oxidation potential of these atmospheres has been evaluated through the analysis of the deposit mass loss. Likewise, confocal microscopy techniques have been employed to obtain the 3D topography of the fouling samples before and after the ozone treatment, allowing the assessment of the deposit thickness reduction, as well as the surface roughness variation. Additionally, thermogravimetric analysis has been conducted to examine the effects of the oxidation processes on fouling samples composition. The findings of this study have revealed that ozone atmospheres have been effective in reducing deposit mass at ozone treatment temperatures above 100 °C. The reduction in mass has reached 78.5% and 91.8% with treatment temperature of 140 °C with ozone concentrations of 30 gO3/m³ and 50 gO3/m³, respectively. It has also been established that treatment conditions with ozone concentrations of 30 gO3/m³ and 50 gO3/m³ are effective in reducing the thickness of deposits even at intermediate treatment temperatures, resulting in a thickness reduction of 78.6% and 81.1% at 80 °C, respectively. Additionally, it has been observed that the ozone exposure leads to the increase in the proportion of volatile material within the deposit.