Osmotic, hydromechanic and energetic properties of modified Münch's model.

In the present work have been made some modifications of Münch's model, which concerns the explanation of biophysical bases of the problem of transport of water and assimilates. Then, by using the thermodynamic formalism of Kedem and Katchalsky (1958), we have made a mathematical description of the model. On this basis it is shown that the model has a series of specific osmotic and hydromechanic properties. Next with the use of the description, the energetic aspect of the model is treated. In this study has been employed an analytical method previously developed (Kargol 1985, 1990, 1993) for studying osmotic and diffusive energy conversion of solutions of different concentrations. The energetic aspect of the study follows from the fact that the phloem transport of water and dissolved assimilates occurring against various forces (including the viscous friction) requires definite expenditure of energy on the part of the plant. Adequate power and energetic efficiency equations have been derived. The equations derived in this work, concerned with Münch's model, offer concrete possibilities for qualitative studies of transport of water and assimilates by phloem in plants.