• Influence of ultrasound in the production of Frass extracts

    Materials Science. Non-Equilibrium Phase Transformations., Vol. 10 (2024), Issue 1, pg(s) 39-39

    The current direction of development is the Green Deal, the main objective of which is to create a sustainable and modern economy without harming the environment. In order to avoid the negative effects of intensive farming, various options for sustainable agriculture are often proposed such as partially replacing synthetic fertilizers and replacing chemical plant protection measures with biological ones [1]. Residues from other agricultural branches can be used as an alternative raw material to produce fertilizers. The current trends in insect breeding, which are gaining wider applicability and legalization for use in the food industry, also create opportunities for the development of waste treatment methods. In Lithuania, the cultivation of insects is developing rapidly, which means that the amount of frass will also grow rapidly, so finding effective ways to use it are essential.

  • MATERIALS

    Microcrystallites, granularity and agglomerates of detonation nanodiamonds

    Machines. Technologies. Materials., Vol. 15 (2021), Issue 6, pg(s) 241-243

    Energy-saturated materials are considered to be a source of cheap energy, while detonation synthesis is a new promising form of the basic technology for producing nanodiamonds and other super hard and ceramic nanomaterials. Nanodiamonds is a unique product that combines both the properties of diamond and the advantages of nanostructures. The given work investigated the synthesis products, obtained under industrial conditions, while having detonation of a mixture of trinitrotoluene (TNT) with gecsogen (RDX) and RDX with graphite. The sizes of microcrystallites were, estimated by X-ray diffraction analysis and particle grain size according to the measurement of specific surface area, agglomerate in water suspension after treatment by ultrasound. There was, shown the evolution of nanod iamonds particle sizes and microstructures, both in the primary synthesis products and after enrichment from non-diamond forms of carbon and technological impurities. Changes in the microstructure indicate a high reactivity of nanodiamonds. The obtained results can be useful for studying the mechanism of synthesis and practical application of detonation nanodiamonds.

  • TECHNOLOGIES

    Influence of complex ultrasound vibrations and composite lubricants on wear resistance of materials of endoprosthesis

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 3, pg(s) 117-119

    As a rule, parts that are made of titanium alloys are critical parts that can work in corrosive medium, accept alternating loads, have certain parameters of surface quality and surface layer. A finite-element simulation of a burnishing process of titanium alloy Ti-6Al-4V (an alloy that is widely used in medicine, as an example in endoprostheses) with/without ultrasonic loading at various processing speeds was carried out. It is established that when burnishing with ultrasonic vibrations of the tool, it is possible to obtain a qualitatively different picture of the distribution of residual stresses in the surface layer of the part. The features of the contact interaction of the tool with the workpiece surface were established for ultrasonic vibrations of the tool. For finite element simulation two types of ultrasonic vibrations were chosen (according to real ultrasonic tool): longitudinal and longitudinal-torsion vibrations. It is shown that the use of ultrasound can reduce the temperature of the deformation zone, which is extremely important when processing titanium alloys. It was also found that the use of metal-containing lubricant can improve the surface quality  arameters after ultrasonic burnishing.

  • PROBLEMS RELATED TO MAINTENANCE OF AGRICULTURAL EQUIPMENT IN BULGARIA

    Mechanization in agriculture & Conserving of the resources, Vol. 61 (2015), Issue 12, pg(s) 25-27

    Maintenance of agricultural equipment is carried out by agricultural equipment dealer in Bulgaria. Their business interests forbid them to implement strategies that decrease maintenance costs, such as proactive maintenance or condition based maintenance. For this reason farmers incur unnecessary financial losses. This article shows the necessity and effectiveness of implementing early diagnosis in agricultural equipment maintenance.