Natural materials-based composites with superior mechanical properties were produced by utilizing waste black limestone as a filler and jute fibers in the epoxy matrix. The present effort investigates the mechanical properties of the epoxy composite reinforced by varying the weight percentages of the black limestone and the length of the jute fibers. Nine composites comprising black limestone with weight percentages of 0%, 5%, 10%, and short jute fibers having different lengths of 15 mm, 30 mm, and 45 mm were fabricated by a hand lay-up technique. It was found that the composites with optimal content filler material exhibited better performance than higher filler content-based and without fillers composites. The ultimate tensile strength of the 5% black limestone filled with 30 mm jute fiber was 54.8 MPa, similarly higher ultimate flexural and compression strength values. Fractography studies were performed using a scanning electron microscope to elucidate the characteristics of the mechanically tested composite.

The current study deals with the investigation on the performance characteristics of varying composition of coating mixture comprising carbon nano-tube, alumina and titanium dioxide on the thermal spray coating on mild steel. The performance properties, namely tensile and microhardness, were measured for the varying composition of coating mixture based thermal coating on mild steel. Response surface methodology was adopted to access the interdependencies prevailing between various dependent and independent parameters, namely composition of the mixture, tensile and microhardness. Scanning Electron Microscope coupled with elemental mapping were used to show the melting zones features and composition. The experimental results and response graphs indicated that increased weight percentages of carbon nano-tube and TiO2 with an optimal value of alumina at 87.5 percent of total weight showed better performance properties due to better dispersion leading to good bonding suitable for protective coatings. Scanning Electron Microscope images reveal partially melted zones that were restricted to smaller regions, and all particles tend to solidify beginning with a fully molten phase.

The present study investigated the effect of alkali treatment on the enhancement of Physico-chemical, tensile, thermal and surface properties of Symphirema involucratum stem fiber (SISF). The investigation of chemical constituents of optimally alkalized SISF revealed that ideal increment of cellulose content (68.69 wt%) and desired modification of other chemical components was accomplished through 60 min immersion period. An increase in the crystallinity index to 33.33% and small crystallite size to 3.21 nm was noted by X-ray diffraction analysis. Moreover, the treated fiber was found suitable for light-weight applications since physical analysis acknowledges that the density of the fiber augmented to 1424 kg/m3after surface treatment that reduces total weight percentage. The enhancements in tensile strength (471.2 ± 19.8 MPa), tensile modulus (5.82 ± 0.77 GPa) and thermal stability (371 °C) were noted that ensures the treated fiber has good mechanical and thermal properties required for composite preparation. These findings validated that the optimally surface-modified SISF is a suitable material for lightweight composite structures, for the time being.

The current study deals with the effective usage ofPortunus sanguinolentusshell, which is a solid waste in the seafood industry. ThisPortunus sanguinolentusshell waste was powdered and used as untreated fillers in jute fabrics reinforced epoxy composites. ThenPortunus sanguinolentusshell waste powder was treated with chemicals to perform fat removal, deproteination, decarbonization and deacetylation to obtain treatedPortunus sanguinolentusshell filler. Three different composites were developed with traditional hand layup process consisting of four layers jute fabrics that were filled with 10 wt% untreatedPortunus sanguinolentusshell filler, chemical treated 10 wt%Portunus sanguinolentusshell filler and unfilled one. The thermo-mechanical and fracture morphologies were assessed by tensile, flexural, compression, shear, impact, hardness thermogravimetric analysis, Fourier-transform infrared spectroscopy and scanning electron microscopy analysis. The results showed an increase in the thermo-mechanical property of chemical-treatedPortunus sanguinolentusshell powder-filled jute fabrics-based epoxy composite. This phenomenon is due to the increase in the chitosan, mineral contents and decrease in the organic content in thePortunus sanguinolentusshell powder due to chemical treatment, thus enhancing the bonding between the filler and fiber matrix with reduction of the void. A showcase stand was developed with the best performer, as an attempt in the perfection of application. The application is then analyzed using ANSYS to predict the deformation behavior when subjected to 0.25 kg, 0.5 kg and 1 kg loads.

The present work deals with the influence of wood dust namely Rosewood and Padauk in the jute fiber-based epoxy composites. The work involves the fabrication of four different laminates of jute-epoxy composites using hand layup process with varying proportions of Rosewood and Padauk wood dust fillers compared with the composite in the absence of filler. The characterization of the mechanical and thermal properties was carried out by tensile, compression, flexural, shore D hardness, impact and thermogravimetric analysis as per ASTM. It is inferred from the test results that the mechanical properties got enhanced by the fine distribution of Padauk wood dust particles by improved adhesion with the matrix. The coarse structure of Rosewood dust over the composite improved thermal stability. Scanning Electron Microscopy was utilized to study the fractured interfaces of the mechanically tested composites. Furthermore, the developed composites affinity towards moisture and biodegradation were studied using water adsorption and biodegradability tests.

A high dielectric stable epoxy composite was prepared and characterized for their dielectric response and charge transfer properties at elevated temperatures. The principal aim of this work is to develop high stable (insulative) particle dispersed epoxy composites for high temperature and structural applications. The Fe-O single crystal was prepared via co-precipitation and surface capped by capping agent to restrict the abrupt mobility of electrons. The dielectric results show that addition of Fe-O into epoxy resin increase the charge transfer up to 7.4 (dielectric constant). Whereas addition of silane capped FeO particles not altered the dielectric constant and conductance. The increase of temperature on dielectric fetched more dissipation but in surface capped FeO dispersed composite its lower. The addition of surface capped Fe-O particle dispersed epoxy resin composite gives improved mechanical strength than as-received one. The SEM and TEM morphological behaviour confirms the uniform dispersion and adhesion of Fe-O particles on matrix. These mechanically toughened high stable dielectric epoxy composites could be used in VLSI and embedded board fabrication industries because of their better insulation properties even in high temperature.

The idealization of this research work is to extend the utilization of the naturally available fibers as a key ingredient in the development of a non-asbestos free brake pad. The fibers used in this work are Caryota urens, which is found all over the Asian regions and abundantly available. The compression molding machine was used to develop the non-asbestos free brake pad. The fibers were added in weight percentages of 5, 10 and 15. The various physical, chemical, and mechanical properties were evaluated. Chase test rig was used to evaluate the tribological properties. The combination of Caryota urens fiber with the barytes had a more significant influence on the tribological properties. The brake pad composites with ten weight percent of Caryota urens fibers based brake pads possessed a good coefficient of friction values with less fade values and less fluctuations. Increasing the weight percentage of Caryota urens fibers in the brake pad formulation had a decreasing trend in the wear performance but increased recovery properties.

The present work deals with the coating of mild steel using plasma spray coating technique to improve surface properties for various industrial applications. Three different composite coating powders namely Al2O3: TiO2, Al2O3: TiO2: CNT and Al2O3: CNT were coated on the surface of mild steel for a thickness of 0.25 mm. Subsequently, the coated samples were tested for their mechanical characteristics namely tensile, compression and hardness followed by tribological investigations primarily comprising of wear analysis. Further, metallurgical analysis engrossing the Scanning electron microscopy, X-Ray diffraction and Energy-dispersive X-ray spectroscopy analysis were carried out to assess the homogeneity, spread uniformity and bond integrity of the developed samples. The test results revealed that the performance measure of Al2O3: TiO2: CNT is way ahead than other two powder coatings while carbon nanotube majorly contributes to the strength and quality of the surface coating.

Diesel engines produce high thermal efficiency and low CO2but release more particulate matters (PM) and NOx which are harmful to atmosphere as well as human beings. In India, these emissions are controlled by after exhaust gas treatment and are regulated by Bharat Stage Emission Standards. The effective technology for NOx reduction is Selective Catalytic Reduction (SCR). In this study selective catalysis is carried out over Mn/Ce/Al2O3 catalysts which were prepared by sol-gel and combustion synthesis methods. These catalysts were coated on honeycomb ceramic samples and characterized by SEM. The coated samples were tested in Single cylinder Diesel Engine. The results showed nearly 60%NO conversion.

In LNT Catalysts, oxidizing agents are added for reducing the levels of NOxemission. In the current work three sets of LNT catalysts were prepared by dipping them in three independent solutions containing i) Barium nitrate, ii) Copper nitrate + Silver nitrate, iii) Copper nitrate + Ferric nitrate + Barium nitrate. These three catalysts were then tested in dual-cylinder four-stroke Simpson 217 DI Diesel engine coupled to electrical dynamometer with wire wound resistance loading device. LNT process was studied and performance of the various chemicals used to reduce the NOx emission under various load conditions in lean burn engine was evaluated. 60% NOx conversion was obtained for LNT catalyst coated with barium + copper +ferric nitrate.