Efficacy of Fly Ash as Additive on the Physical Properties of Biodiesel Extracted from Neem Oil (M. M. Zakari, A. Musa, F. Ahmad, U. I. Isma`il, S. G. D. Iya, M. Uzair, & I. G. Shitu, Trans.). (2026). Nigerian Journal of Applied Physics, 2(2), 213-221. https://doi.org/10.62292/njap-v2i2-2026-90