Effect of Plant Fibres on the Variability of Cob Materials

Earthen materials have different nature components and present a high variability comparing to conventional materials; researchers try to settle it down for a future normalization as environmentally efficient material. But there is a need in energy to do it, either directly (compaction, organic matter extraction, particle screening to get the best particle size distribution ...) or indirectly by including inefficient materials from an environmental perspective (cement, limestone ...). The aim of this study is to follow the variability problematic of cob materials by comparing and understanding variation level of the hygrothermal characteristics due to fibres nature and fibres content. We found that plant fibres (hemp, flax and hay) act as a stabilizer for dry bulk density; at 1% fibres substitute, hemp fibre composites show the highest coefficient of variation on the thermal properties (6.1% on thermal conductivity, 18.74% on specific heat capacity) but flax fibres show the highest mean values. Increasing hay stalk content induces the spread of the hygrothermal properties inside their range of variaation.

The probability of particles screening on the screen, taking into account the interaction of particles over the meshes of the sieve

The probability of a single particle screening through the mesh of a screen is usually estimated by the A.M. Goden formula. During screening along a screen sieve, a quantity of particles moves. Particles of different sizes interact with each other. Large particles block the meshes of the sieve and reduce the probability of small particles screening. A screening probability formula is proposed that takes into account the interaction of particles over the sieve meshes and the possibility of several particles passing simultaneously through the sieve mesh. The results of modeling the probability of sieving and screening process are presented. An increase in the fraction of “small” particles in the primary product leads to an increase in the probability of sieving. When the material moves along the screen sieve (from the first to the last row of meshes), the probability of particle sieving decreases.

Application of automated particle screening for effective analysis of individual uranium particles by thermal ionization mass spectrometry

Automated particle screening was combined with isotope ratio analysis of individual uranium particles using thermal ionization mass spectrometry.

Theoretical Analysis of Granularity Control of Particles

Splintering substance while using particle screening or grading equipment for screening of particle processing at the same time can meet the needs of the production process Cost-effectively .With screening or grading equipment with mill use, we can use a single parameter,two-parameter and multi-parameter three ways respectively. In this article, we report our theoretical analysis on the conditions of a single parameter, two-parameter and multi-parameter control.