The present work investigates the production of biodiesel from Euglena sanguinea microalgal bio-oil using calcium methoxide as a heterogeneous catalyst. The catalyst was synthesized and characterized by Fourier Transform Infra-red (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), basicity, and basic site strength analysis. Initially, bio-oil was extracted from mass-cultivated biomass obtained from Euglena sanguinea algae. It is further pretreated and transesterified using calcium methoxide catalyst at various experimental conditions through which an optimum yield of 94.83% was achieved. The catalyst yielded above 90% up to 5 cycles of recovery and recycling. The kinetic studies were investigated at various reaction temperatures to find the rate of reaction. It confirms that the reaction follows pseudo-first-order reaction. The activation energy and pre-exponential factor for the transesterification reaction were found to be 99.33 kJ mol⁻¹ and 1.07 × 10¹⁴ min⁻¹ respectively. The properties of the produced biodiesel were within the limits of ASTM D6751 standard.

A novel solid acid catalyst was prepared from the palm-fruit-bunch by in-situ incomplete sulphonation carbonization method. The prepared catalyst was characterized to determine its physical and chemical properties which are determine its performance in a reaction. The catalyst was then subjected to esterification and transesterification reactions to produce biodiesel from high free fatty acid (FFA) Calophyllum inophyllum (C. inophyllum) oil. An optimum yield of 88.5 wt% methyl ester was achieved at 4 wt% of catalyst, methanol to oil molar ratio of 21:1 and a reaction temperature of 60ºC in 180 min. The fuel properties of the biodiesel were analyzed as per ASTM standard methods, and their properties were found to be in accordance with ASTM D6751.

The present paper describes a methodology devised to study the engine block displacement of an internal combustion engine in the radial direction due to combustion force and inertia forces. The combustion force produced in in-cylinder is a substantial function of angular displacement and then correlated with pressure and temperature. Other than the substantial function, combustion force depends on chamber design, injection parameters, flow patterns and fuels. But inertia is a function of angular displacement and a mass of reciprocating parts. Speed is directly related to combustion by means of indicated pressure and the indicated torque respectively. The engine was taken for an analysis along with speed and load as the design variables. The engine block displacement, time-domain frequency, wave form, side thrust and in-cylinder force were examined for the analysis. The results obtained provide the combined effect of combustion force and inertia force induced displacement, uncertainty in combustion processes, nonlinear vibration of the engine block, and vibration spectra. This new approach in engine parameter design bestows insight with the combustion force and inertia induced vibration and source of noise in the diesel engine.

It is essential to determine the most suitable machining method for magnesite-reinforced Aluminium 6061 composites, which possess excellent mechanical properties, especially notable tensile strength and hardness. The composites were produced using a stir-casting technique, incorporating reinforcements of lightly-calcined magnesite, dead burnt magnesite, and waste magnesite in weight fractions of 2.5%, 5%, and 7.5% within an aluminium 6061 matrix. Wire electrical discharge machining was employed to investigate the machining characteristics of these composites, using controllable process parameters such as cutting speed, pulse-on and pulse-off times, and the weight fraction of magnesites. Two performance indicators such as surface roughness and material removal rate were tested for various parameter combinations by central composite design. To comprehend the impact of the study parameters, contour charts were drawn. MRR increases at a high cutting speed of 2 mm/min when the pulse-on time changes from 120 μs to 125 μs. SR increases when the pulse-on times above 120 μs at all cutting speeds. High cutting speeds make high MRR irrespective of the weight fractions of reinforcement. High pulse-on times make the material melt more, which increases the material removal rate. Because specimen surface material erodes quickly and forms microcracks, high pulse-on time also results in high surface roughness. To optimize the WEDM machining conditions for each composite, hybrid SSO-DF and DFO-DF optimizers were developed by combining the desirability function with Salp-swarm optimization and Dragonfly optimization algorithms. The cutting speed of 2 mm/min and the pulse-on time of 114 μs produce the best performances on the composites.