Differences in soil stability, especially in visually comparable soils can occur due to microstructural processes and interactions. By investigating these microstructural processes with rheological investigations, it is possible to achieve a better understanding of soil behaviour from the mesoscale (soil aggregates) to macroscale (bulk soil). In this paper, a rheological investigation of the factors influencing microstructural stability of riparian soils was conducted. Homogenized samples of Marshland soils from the riparian zone of the Elbe River (North Germany) were analyzed with amplitude sweeps (AS) under controlled shear deformation in a modular compact rheometer MCR 300 (Anton Paar, Germany) at different matric potentials. A range physicochemical parameters were determined (texture, pH, organic matter, CaCO3 etc.) and these factors were used to parameterize pedotransfer functions.
The results indicate a clear dependence of microstructural elasticity on texture and water content. Although the influence of individual physicochemical factors varies depending on texture, the relevant features were identified taking combined effects into account. Thus, stabilizing factors are: organic matter, calcium ions, CaCO3 and pedogenic iron oxides; whereas sodium ions and water content represent structurally unfavorable factors. Based on the determined statistical relationships between rheological and physicochemical parameters, pedotransfer functions (PTF) have been developed.
According to the positivists, all our knowledge is based on experience which is the foundation not only of every empirical science, but also of those disciplines that are usually considered to be a priori. The paper consists of two main parts. Firstly, a positivist concept of number defended by J. S. Mill is presented; secondly, it is shown how this conception can settle some objections coming from apriori-oriented philosophers. Mill’s theory of number is interesting for at least two historical reasons. It is developed in connection with a relatively rich scholastic logic which is why its methodology is similar to the contemporary philosophy of language; it is indispensable for an appropriate comprehension of the concept of number that was proposed by Mill’s most famous opponent G. Frege., Podle pozitivistů jsou všechny naše znalosti založeny na zkušenostech, které jsou základem nejen každé empirické vědy, ale také těch oborů, které jsou obvykle považovány za a priori . Příspěvek se skládá ze dvou hlavních částí. Nejprve je prezentován pozitivistický koncept počtu obhajovaných JS Millem; Za druhé, je ukázáno, jak tato koncepce může vyřešit některé námitky z apriori-orientovaných filozofů. Millova teorie čísel je zajímavá alespoň ze dvou historických důvodů. Je rozvíjena v souvislosti s relativně bohatou akademickou logikou, proto je její metodika podobná současné filosofii jazyka; je nepostradatelné pro vhodné pochopení pojmu čísla, který navrhl nejslavnější oponent ml. G. Frege., and Prokop Sousedík, David Svoboda