In this concise yet comprehensive book, the author discusses the principles of mass, momentum, and energy transport, and derives balance equations for single-component fluids and multicomponent mixtures based on the direct application of natural laws and principles of thermodynamics. Transport equations over control volumes are formulated with reference to the Reynolds transport equation, thereby circumventing the need for ad-hoc balances for open systems that are best justified in hindsight. Notable features with regard to mass transport include the interpretation of diffusion in mixtures in terms of species parcel motion and separation, the introduction of Ficks and fractional diffusion laws with reference to random molecular excursions, a detailed account of species and mixture kinematics and dynamics, and the discussion of partial stresses, energies, and entropies of individual mixture components. Key features of this book include: The governing equations are derived from first principles based on the application of natural laws and principles of thermodynamics Balances over control volumes are derived from rigorous equations governing material parcel property evolution Ficks law, a fractional diffusion law, and other diffusion laws are discussed with reference to random walks A detailed account of species and mixture kinematics and dynamics is presented for binary and multicomponent solutions A tabulated summary of transport equations is presented in differential and integral forms, and an overview of classical thermodynamics is given in an appendix for a self-contained discourse C. Pozrikidis has taught at the University of California and the University of Massachusetts. He is the author of several books on theoretical and computational topics in science and engineering, applied mathematics, scientific computing, and computer science.