Experimental study of the distribution of the heights of sugar beet root crowns above the soil surface

ArticleThe results of experimental studies and operational tests of the sugar beet harvesting process carried out recently reveal that the latest models of beet harvesters produced in Europe and America cause considerable loss of the sugar-bearing mass. The source of this loss is mainly the poor topping of the crowns of standing sugar beet roots, more specifically the excessively low point at which the tops are cut off, which results in the straight out loss of sugar-bearing mass. Thus, there is need to search for such engineering solutions that would avoid both the loss of sugar-bearing mass and the presence of residual haulm on the roots. The aim of this study was to reduce the loss of sugar-bearing mass in the process of topping sugar beet root crowns. The results of this research into the distribution of the heights that root crowns protrude above the soil surface have confirmed the hypothesis that it follows the normal distribution. Based on the results, it has been established that this distribution has the following statistical parameters: mean deviation a = 20–30 mm, mathematical expectation m = 40...60 mm. The laboratory unit developed for this work and the field studies performed with it have provided sufficient evidence to develop a new system to automatically adjust the topping height on state-of-the-art root crop harvesters

Investigating the possibility of using date kernel ash as supplementary cementitious material in sustainable concrete

The cultivation of dates from palm trees is an important economic activity in Iraq. Date production forms a significant part of the country's agricultural sector, contributing to both local consumption and export markets. The date industry supports many livelihoods and businesses in Iraq. The total number of fertile palm trees in Iraq is over 22 million. In the production of pitted dates, date molasses, date paste and date confectionery, a significant amount of date pits are usually discarded as waste. This study reports chemical analysis investigations conducted to evaluate the potential use of waste date kernel ash (DKA) compared with other pozzolanic material which is fly ash (FA) from bricks factory, tow samples obtained as a partial cement replacement in concrete, the first sample by the calcination of date pits at 500 °C for 4 hours then cooling and continue calcination at 600 °C for 2 hours, and the second sample by calcination at 500 °C for 4 hours. The results of (XRF) tests showed that DKA has low silica oxide and does not qualify as a pozzolanic material compared with a high silica oxide of FA

Теоретическое определение силы счесывания ботвы сахарной свёклы с головки корнеплода

Beet tops harvesting is a complex task of the sugar beet growing industry which forms the qualitative indicators of root crops during their further digging out from the soil and determines the loss of tops and sugar-bearing mass. In the development of theoretical foundations of the optimal tops cutting from heads of sugar beet root by different types of topping working bodies should take into account forces which act at the same time and the rational cutting height. Theoretical researches having been carried out hitherto concerned only the detailed analytical description of the functioning of the new designs of topping working bodies and practically did not concern the general provisions of the separation tops from the head of root crop. The aim of this study is the theoretical determination of the forces that occur at the contact point of cutting working body of topper machines with root crops head of sugar beet root crop. When carrying out theoretical studies are used the methods of mathematics, theoretical mechanics, strength of materials, methods of programming and numerical calculations on PC. As a result, of the theoretical research new analytical dependencies of force describing the processes of crumpling and subsequently cutting of sugar beet heads by topping working body, depending on the size and shape of root crops heads and design parameters of topper have been obtained. As a result, of numerical calculations on PC critical level value of penetration of the cutting element of topping working body into root crops head of sugar beet and maximum value of cutting force at which ejection of root vegetables from the soil doesn’t take place, was defined. The obtained theoretical dependencies and values of normal reaction and cutting forces are the basis for the further working out of a mathematical model of dynamic interaction system of cutting working bodies with the heads of sugar bee

Theory of motion of grain mixture particle in the process of aspiration separation

The paper describes the development of a mathematical model for the motion of a seed mixture particle in the aspiration channel of the separator after the particle passes the cone-shaped spreader and enters the workspace of the aspiration channel in the pneumatic dynamics and vibration unit devised by the authors. The unique feature of the proposed new design is the presence of the central pipe with sail members in the aspiration channel. The sail members in the air stream generate the self-oscillatory mode of motion of the central pipe, which results in the efficient separation of the grain seed mixture into the required fractions. On the basis of the prepared equivalent schematic model, the differential equations of the motion of a seed mixture particle in the process of aspiration separation have been generated. Basing on the results of the PC-assisted numerical modelling of the motion paths, on which the material particles (seeds) of the heavy and medium fractions travel, it has been established that they move on different courses, and the course of the heavy fraction seeds is such that, after they pass the cone-shaped spreader and advance further in the air stream through the space of the aspiration channel, they move closer to the pipe of the aspiration channel. Also, their velocities and accelerations are greater than the same kinematic parameters of the medium fraction seeds. The seeds of the light fraction move upwards under the action of the air stream and leave the aspiration separator at its top

Effect of mineral additives on the adherence strength of reinforced concrete with increased corrosion resistance

The purpose of this study was to evaluate the corrosion resistance of steel reinforcement in concrete samples containing modifying additives using an accelerated electrochemical corrosion method. It was found that the adhesion strength between the reinforcement and the cement stone of concrete largely depends on the corrosion resistance of the reinforcement in concrete. At the same time, the best result from the tested concretes was shown by the developed concrete of optimal composition, in which the adhesion strength between concrete and reinforcement is 1.7 times higher than that of control concrete without mineral additives. The obtained results can be explained by the fact that an increase in the density of concrete due to the modification of its structure with organo-mineral additives leads not only to an increase in its strength, but also to a better protection of steel reinforcement in concrete from corrosion. This will help to increase the durability of reinforced concrete structures of offshore hydraulic structures in Vietnam and increase the period of their maintenance-free operation

Properties of the sugar beet tops during the harvest

All methods of sugar beet tops separation from the roots are based on the difference in the placement tops and root crops relative to the soil surface and their relative placement. Separation of tops residues after cutting is based on the various strength of sugar beet heads and leaves. The aim of the study is to determine the optimal method of mechanical impact on the beet tops in order to improve the quality of its harvest process. To study the form and structure of the sugar beet stalks there was used cuttings used photo-shoot overlaid by coordinate grids. For determine the hardness of various zones was used specially designed hardness tester. Impact action on the root crops head was investigated by a special laboratory facility. As a result of experimental studies there were obtained a new data characterizing the structure, shape and strength of the various zones of the root crops head and leaves with the aim to study the possibilities of effective mechanical destruction of leaves and subsequent separation of them from the head

Spatial quadratic solitons guided by narrow layers of a nonlinear material

We report analytical solutions for spatial solitons supported by layers of a quadratically nonlinear material embedded into a linear planar waveguide. A full set of symmetric, asymmetric, and antisymmetric modes pinned to a symmetric pair of the nonlinear layers is obtained. The solutions describe a bifurcation of the subcritical type, which accounts for the transition from the symmetric to asymmetric modes. The antisymmetric states (which do not undergo the bifurcation) are completely stable (the stability of the solitons pinned to the embedded layers is tested by means of numerical simulations). Exact solutions are also found for nonlinear layers embedded into a nonlinear waveguide, including the case when the uniform and localized nonlinearities have opposite signs (competing nonlinearities). For the layers embedded into the nonlinear medium, stability properties are explained by comparison to the respective cascading limit.Comment: J. Opt. Soc. Am. B, in pres

High-performance concrete produced with locally available materials

Vietnam is one of the countries most severely affected by climate change and sea level rise, especially in the south. High-performance concrete appears to be a better choice for strong and durable structures. The primary objective of this research was to use locally available materials to produce HPC reaching compression strength of over 100 MPa and suitable for Vietnamese climatic conditions and environment. The materials locally available in Vietnam used in the study included: sulfate-resisting Portland cement (PCSR40), crushed granite as coarse aggregate (size 9.5÷19 mm), river sand with fineness modulus of 3.0, Sika®Viscocrete®-151 type superplasticizer, mineral materials (class F fly ash and silica fume), and potable water. All concrete mixtures were designed according to TCVN 10306-2014 standard. For compressive strength, concrete samples were tested after 3, 7, 28, 56, and 450 days, while the tests for splitting tensile and flexural strengths, water absorption and permeability were conducted after 28 days. In this experimental research, the greatest compressive strength values obtained at 450 days of age were 95.426 MPa in a mix containing 10 %SF + 20 %FA + 20 %Qp and 101.597 MPa in a mix containing 12.5 %SF + 20 %FA + 20 %Qp. The results showed that the optimum high-performance concrete mixes used for construction in aggressive corrosive environment of Southern Vietnam contain 7.5 %SF + 30 %FA, 10 %SF + 20 %FA, 10 %SF + 30 %FA, 12.5 %SF + 20 %FA, respectively. This study showed that the HPC produced with locally available materials in Vietnam can have compressive strength exceeding 110 MPa as well as other excellent mechanical properties. All of this can be achieved simply by using materials available at the local markets, provided they are carefully selected and properly mixed to optimize grain size distribution

Theoretical research of cleaner pressure on sugar beet root crop

Technology incompatibility in the sugar beet harvesting process is established. Beet tops removing by follower cutoff with the subsequent root crop heads cleaning is possible at speed no more than 1.5 m·s-1 whereas beet pullers operate at speeds of 1.2... 1.5 times are higher. At a cutting without copier of sugar beet tops a working speed makes more than 1.5 m·s-1, however losses of sugar-bearing plant material exceed agrotechnical requirements twice because of unreasonable height of a cut relative to soil surface. The differential equation of bow-shaped copier movement on a root crop head of sugar beet which is the main equation of functioning root crops heads cleaner is worked out. Components of the differential equation are defined and dependence of normal reaction on design parameters of root crop head cleaner is received. Conditions not of knocking-out of root crops are received and rational values of design parameters and operating modes of root crop head cleaner are proved