Characterization of Carbonaceous Deposits on an End-of-Life Engines for Effective Cleaning for Remanufacturing

Remanufacturing is one of the most effective strategies to achieve sustainable manufacturing and restore the performance of end-of-life products. However, the lack of an effective cleaning method to clean carbonaceous deposits severely hampers the remanufacturing of end-of-life engines. To explore an appropriate cleaning method, it is necessary to first study the characterization of the carbonaceous deposits. A broad range of analyses including X-ray fluorescence spectrometry, thermogravimetric analysis, 1H-nuclear magnetic resonance study, X-ray diffraction analysis, and scanning electron microscopy were performed to conduct an in-depth characterization of the carbonaceous deposits. The results showed that a hybrid structure composed of organics and inorganics is the most distinguishing feature of the carbonaceous deposit in end-of-life engines. The inorganics form the skeleton on which organics get attached, thereby resulting in a strong adhesion of the deposit and increasing the difficulty of cleaning. Therefore, a method in which several cleaning forces can be simultaneously applied is more suitable for the present purpose. Molten salt cleaning was chosen to verify the feasibility of this proposal. This method was shown to have the potential to effectively clean the carbonaceous deposit. This finding could contribute towards promoting the effective remanufacturing of end-of-life engines.

A facile chemical cross-linking approach toward the fabrication of a sustainable porous ulvan scaffold

Ulvans represent one of the most abundant marine-derived macromolecular sulfated polysaccharides accounting for numerous biological applications including in one of the fastest growing field of biomedical sciences. Tissue engineering based on biologically inspired and naturally derived polymers has been one of the prime focuses of regenerative medicine. The present investigation is intended to explore an ionic cross-linking approach at higher pH lead by the calcium ions for casting cell growth promoting scaffolds out of the raw ulvan. The characterization studies using attenuated total reflectance infrared spectroscopy represent specific absorptions at 2950, 980, and 600 cm−1, whereas the x-ray diffraction showed a total absence of major crystalline peaks presenting significant shift to an amorphous state. The 1H nuclear magnetic resonance study revealed functional group modifications in the backbone that might be potentially derived from calcium interactions with glucurorhamnose 3-sulfate and iduronorhamnose 3-sulfate. The atomic force microscopy together with field emission scanning electron microscopy and energy dispersive x-ray spectroscopy mapping revealed the resultant surface changes, whereas confocal microscopy z-stacking showed the cell proliferative activity as evident by the attainment of complete morphology. The combined chemical and biological response of the scaffold makes it a well suitable support for its cell culture and tissue engineering applications.