International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Dynamically developing plant growing continuously sets challenges to the system for training specialists, who have to be able to develop competitive and sustainable agriculture. In the conditions of market economy and various forms of land management, for the development of plant growing are needed managers and executives, who will be able to apply successfully the scientific principles of research, analysis, support and management of cost-effective agricultural production units. The degree programme Plant Growing provides preparation of such specialists. Education in Crop Science and Production offers such kind of training by application of innovation moments such as practical semester and development of integrated project.

The paper is devoted to a mathematical model of land-use change proposed by Dobson et. al. We formulate and investigate some quantitative properties of the corresponding Cauchy problem. We construct a numerical algorithm for approximate solution of the problem and present some of the numerical results. Their meaning is explained and discussed.

After mechanized whole-plant threshing of sesame a mixture of seeds, seed-cases and stems is obtained. The separation of the seeds is done by means of a unit, consisting of a sieve and a fan with combined movement and adjustment of the air flow rate and the slope of the sieve cradle. The results of the testing of the separation unit with different crop shows the possibility to obtain sesame seed purity 94 … 97%.

A comparison has been made of four technologies for mechanized sesame harvesting in conditions of Bulgaria. The first is one- stage harvesting with grain harvester. The second is two- stages whole-plant harvesting. The third is two- stages harvesting where the first stage is collecting the sesame capsules and the second – threshing the capsules after draying. The last technology is one – stage seeds harvest- ing while the plants are "on roots". The first technology has been recommended for large and flat fields. The third technology has been the most suitable for production of seeds. The forth technology is suitable for small-size fields. For such conditions has been elaborated a prototype which harvests sesame at a humidity which is twice times higher than the optimal for grain harvester and at several times less consumption of energy.

In the following, well-founded a method and is proposed preliminary version of the device for stationary whole plant threshing of sesame. Presented a methodology for calculation of basic geometric and kinematic parameters of crushing and grinding mechanism consists of a pair of metallic corrugated rollers, for threshing of sesame.

We suggest a method and a device for inverting sugar solution by using invertase enzyme and using it for feeding bees. The results suggest that when using the device for enzyme hydrolysis of sugars, the process of inverting the polysaccharides is the strongest until the ninth day, regardless of the quantity of honey added. After this period, the enzyme-driven process slows down significantly. The percentage of the monosaccharides triose, D-glucose, and fructose rises in the inversion process after the quantity of natural honey has been increased (from 1,5 kg to 3,0 kg respectively).