Case Studies and Benchmark Examples for the Use of Grading Entropy in Geotechnics

The grading entropy concept can be adapted to the field of geotechnics, to establish criteria for phenomena such as particle packing, particle migration and filtering, through a quantified expression of the order/disorder in the grain size distribution, in terms of two entropy-based parameters. In this paper, the grading entropy theory is applied in some geotechnical case studies, which serve as benchmark examples to illustrate its application to the characterisation of piping, softening and dispersive soils, and to filtering problems in the context of a leachate collection system for a landfill site. Further, since unstable cohesive (dispersive) soils are generally improved by lime, the effect of lime addition is also considered, on the basis of some measurements and a further application of the grading entropy concept, which allows evolutions in the entropy of a soil to be considered as its grading is modified. The examples described support the hypothesis that the potential for soil erosion and particle migration can be reliably identified using grading entropy parameters derived from grading curve data, and applied through an established soil structure stability criteria and a filtering rule. It is shown that lime modification is not necessarily helpful in stabilizing against particle migration

Some Notes on Granular Mixtures with Finite, Discrete Fractal Distribution

Why fractal distribution is so frequent? It is true that fractal dimension is always less than 3? Why fractal dimension of 2.5 to 2.9 seems to be steady-state or stable? Why the fractal distributions are the limit distributions of the degradation path? Is there an ultimate distribution? It is shown that the finite fractal grain size distributions occurring in the nature are identical to the optimal grading curves of the grading entropy theory and, the fractal dimension n varies between-¥ and ¥. It is shown that the fractal dimensions 2.2-2.9 may be situated in the transitional stability zone, verifying the internal stability criterion of the grading entropy theory. Micro computed tomography (μCT) images and DEM (distinct element method) studies are presented to show the link between stable microstructure and internal stability. On the other hand, it is shown that the optimal grading curves are mean position grading curves that can be used to represent all possible grading curves

EXPRESSION OF RECOMBINANT BOVINE LACTOFERRIN IN PICHIA PASTORIS AND ANTIMICROBIAL ACTIVITY OF ITS HYDROLYSATE

The bovine lactoferrin (bLf) has been well-characterized as a multifunctional glycoprotein, which belongs to the transferrin family exhibiting multifunctional immunoregulation of antibacterial, antioxidant, anti-tumour and antiviral activities. In this study, the structure of pPICZαA::bLfopt was transformed into Pichia pastoris KM71H for heterologous production of lactoferrin under the control of the AOX1 promoter. The antimicrobial activity of the full rbLF and the pepsin-hydrolyzed rbLf against some pathogens were tested. The results showed that the optimized bLf gene encoding bovine lactoferrin was successfully transferred and expressed in Pichia pastoris KM71H. The expression of recombinant bovine lactoferrin was detected by SDS PAGE analysis and confirmed by Western blot. The recombinant bovine lactoferrin digested by Pepsin showed a higher percentage of inhibition than the whole molecular for three strains Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538P and Escherichia coli ATCC 11303 with the highest proportion of 50.71%; 56.76% and 21.11%, respectively. The successful expression of the rbLfopt genes in Pichia pastoris KM71H opens a prospect for developing research in natural antimicrobial agents

mednarodna urbanistično-arhitekturna delavnica

This paper deals with three grading entropy-based rules that describe different soil structure stability phenomena: an internal stability rule, a filtering rule and a segregation rule. These rules are elaborated on the basis of a large amount of laboratory testing and from existing knowledge in the field. Use is made of the theory of grading entropy to derive parameters which incorporate all of the information of the grading curve into a pair of entropy-based parameters that allow soils with common behaviours to be grouped into domains on an entropy diagram. Applications of the derived entropy-based rules are presented by examining the reason of a dam failure, by testing against the existing filter rules from the literature, and by giving some examples for the design of non-segregating grading curves (discrete particle size distributions by dry weight). A physical basis for the internal stability rule is established, wherein the higher values of base entropy required for granular stability are shown to reflect the closeness between the mean and maximum grain diameters, which explains how there are sufficient coarser grains to achieve a stable grain skeleton

Goa, India A General Density Law for Sands

ABSTRACT: A new transfer function generation method was applied in the simplest form to find the relationship between the grading curve and the dry density. The method is based on the grading entropy concept. Some laboratory e max test data were made for the generation of a preliminary dry density transfer function using “optimal ” soils. The goodness of results was tested on the basis of an independent data set related to some “non-optimal ” soils mixtures. The agreement between the two preliminary transfer functions was surprisingly good. The measured data were evaluated with respect to the densest packing problem.

The characterisation of the grains and the pores, applications

The paper addresses the following topics in relation to the grading curve: (i) the densest – loosest packing problem, (ii) pore characterisation and pore size distribution curve, (iii) the calculation of the unsaturated soil functions from the grain size or pore size distribution curve

A general dry density law for sands

The direct interpolation of a transfer function needs exponentially many data in terms of the number of the fractions in the grading curve. The suggested transfer function construction method - based on a double approximation technique, the grading entropy concept and at most quadratic many data in terms of the fraction number – is tested on the example of the dry density of sands here using some previously measured data. In the first approximation step a “preliminary transfer function” is interpolated in the nonnormalized grading entropy diagram on the basis of some “optimal” soil data. In the second approximation step the preliminary transfer function is extended to the space of the possible grading curves with the constant function. The so determined transfer function is tested against an independent “non-optimal” data set, measured on some soil series with basically continuous (i.e., not gap-graded) grading curves. The aim of this paper is to present the main results of the study supporting the goodness of the method and the predictability of the dry density transfer function

Case Studies and Benchmark Examples for the Use of Grading Entropy in Geotechnics

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