Introduction. The task of high-quality cleaning of root crops from soil is relevant at all stages of preparing roots for further processing, feeding to animals, and selling. In the machines for cleaning root crops from soil, there is mostly used water. With the water consumption for washing a unit of mass of soiled root crops up to 200-400%, the use of water creates a huge problem including soiled water treatment. The dry method of cleaning root crops is most common in practice and involves the use of appropriate machines, which are not always able to provide the required quality of the finished product. Therefore, the problem of developing a root crop cleaner by the dry cleaning method and substantiating the cleaner optimal parameters to ensure the required quality of the finished product is important and relevant. Aim of the Study. The study is aimed at substantiating theoretically the parameters of a root cleaner with adjacent rollers rotating at different frequencies. Materials and Methods. The subject of the study is the technological process of cleaning root crops with the dry method. To realize this process, there has been developed a cleaner of root crops from soil, the key features of which are the use of a roller transport-cleaning working element and the ability of adjacent rollers rotate at different frequencies. Individual design parameters of the proposed cleaner have been substantiated theoretically. Results. There have been determined the forces acting on the root crop when it is located on rotating rollers. There has been found the dependence of the angular displacement phi(t), angular velocity omega(t) of the root crop located on rotating rollers, and the dependence of the coefficient of root crop sliding friction on the rollers on the angle alpha, which determines the relationship between the main design parameters of the working element, in particular, the diameter of the rollers and the distance between them, and the physical and mechanical properties of the root crops. Discussion and Conclusion. The studies of the root crop cleaner conducted in laboratory conditions have confirmed the results of theoretical studies and showed that with a length of the transport-cleaning working element of 2 m within a time of 34,4 s it is possible to achieve an efficient cleaning of 78% when the cleaner is equipped with 16 rollers and the ratio of the rotation frequencies for odd and even rollers is 220/250 min-1. The study results are useful for creating and modernizing technical means for post-harvest processing of root crops, conducting further studies on technological improvement of similar means of mechanization of agricultural processes, and for using in the educational process to train technical specialists.

Nowadays, for soil stabilisation and cleaner production of geo-composites, the possibility of utilizing waste rubber is in vogue. The present paper deals with experimentally investigating the mechanical and microstructural characteristics of weak Indian clayey soil partially substituted with lime (0-3.5%) and waste rubber tyre powder (0-15%). It was observed that, with increasing lime and rubber powder content, the plasticity index of the soil decreases. The shear strength and compaction testing results reveal that adding lime and rubber tyre powder (RTP) enhances the geotechnical performance of clayey soil up to an optimum dosage value. Also, the triaxial shear testing was performed to obtain stress-strain curves for all considered soil mixes. For modified clayey soil containing 3% lime and 12.5% rubber powder, the cohesion values and bearing capacities improved phenomenally by 36.1% and 88.6% respectively, when compared to clayey soil. Further for this mix, SEM analysis reveals a compacted microstructure which improves dry-density and California's bearing ratio among all modified mixes. The novel co-relations upon regression analysis are found able to predict plasticity index, dry density, bearing capacity and shear strength with higher confidence levels. Overall, the cost-benefit analysis worked out to obtain the optimum cost of construction of footings and flexible pavement shows cost deductions up to 19% and 39% respectively while utilizing modified clay soil mixes containing 3% lime and 12.5% rubber powder in subgrade, ultimately making production stronger, cheaper and environment friendly.

The aim of this study is to investigate the properties of biodegradable plantable pots made from biomaterials. Specifically, rapeseed straw and cow manure biomaterials were studied here because these biomaterials add nutrients to the soil during their biodegradation and are readily available agricultural by-products. Furthermore, the use of biomaterials helps in replacing the plastic materials which are currently used to make pots and decreases the environmental impact by producing a cleaner product. The physical and mechanical properties of biocomposites pots were investigated and optimized in the present work. The effect of mixing ratio (straw: cow manure) in the composite, straw particle size, and chemical pre-treatments of straw by 1% HCl or 2% NaOH on the physical and mechanical properties of biodegradable pots was investigated. Additionally, the Taguchi method and ANOVA statistical analyses were employed for parameters optimization. The results indicated the straw to cow manure ratio exhibited a significant effect on the compression strength (CS), penetration strength (PS), and water absorption (WA) of pots. While the CS and PS of pots decreased with increasing the ratio of straw from 2 to 10% and increasing the particle size of straw from 1.5 to 3.0 mm, these changes increased the water absorption of pots (126.52-141.21% for 1.5-mm untreated straw). Chemical pre-treatments of straw investigated here resulted in decreased CS and PS of pots. The straw ratio in the straw/manure mixture is the most significant factor affecting the characteristics of biodegradable pots.