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of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

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Author: Gabriel Peev

  • TECHNOLOGIES

    Composite modifications obtained through various technological approaches based on inorganic binders and foam glass materials

    • Lyuben Lakov
    • Bojidar Jivov
    • Gabriel Peev
    • Dimo Mihaylov
    • Mariya Georgieva
    Machines. Technologies. Materials., Vol. 19 (2025), Issue 3, pg(s) 101-104
    • Abstract
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    Composite structural modifications based on hydraulic inorganic binders and foam glass aggregate fractions were prepared. Formwork moulds were developed for the moulding of composite test bodies using different technological approaches. A series of experimental specimens meeting the requirements for standard laboratory tests were obtained. The role of the technological regimes used in the formation of the structural characteristics and performance of the composites is examined. The existing possibilities for further modification and potential application of the obtained composite materials are analysed.

  • MECHANIZATION IN AGRICULTURE

    Prospects for the application of ceramic beehives in modern apiculture farms

    • Lyuben Lakov
    • Bojidar Jivov
    • Todorka Lepkova
    • Marieta Gacheva
    • Gabriel Peev
    Mechanization in agriculture & Conserving of the resources, Vol. 68 (2024), Issue 3, pg(s) 79-82
    • Abstract
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    A brief review of the design characteristics of the main construction types of standard movable frame and traditional beehives applicable in beekeeping farms is presented. The performance of a newly developed innovative movable frame beehive constructed of durable, heat-resistant hollow chamber ceramic structural elements is discussed. A comparison of the functional characteristics of prepared experimental ceramic hive prototypes and the prevailing types of standard beehives made of other materials is carried out. The existing requirements and prospects for equipping beekeeping farms with ceramic hives providing prolonged service life, higher yields and increased sustainability in diverse climatic environments and critical conditions are analysed.

  • TECHNOLOGIES

    Technological characteristics of composite mixtures for the preparation of thermal insulation structural elements

    • Lyuben Lakov
    • Krasimira Toncheva
    • Bojidar Jivov
    • Marieta Gacheva
    • Gabriel Peev
    • Dimo Mihaylov
    Machines. Technologies. Materials., Vol. 18 (2024), Issue 1, pg(s) 21-24
    • Abstract
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    The technological characteristics of suspensions used in the development of new thermal insulation composite structural elements based on foam materials and inorganic binders (Portland cement) are investigated. The role of the components of the compositions, the parameters of the technological regime and other factors in ensuring adequate workability of the prepared cementitious solutions is considered. Determination of the necessary technological characteristics of composite mixtures ensures their effective distribution in the formwork moulds when forming the specimens, cost-effective performance at production stage and obtaining products with the planned
    functional properties. The existing opportunities for potential application in modern construction of the developed composite elements are analyzed.

  • TECHNOLOGIES

    Technology and technological scheme of a workshop for the production of beehives made of amorphous quartz ceramics

    • Lyuben Lakov
    • Todorka Lepkova
    • Marieta Gacheva
    • Krasimira Toncheva
    • Gabriel Peev
    • Dimo Mihaylov
    Machines. Technologies. Materials., Vol. 17 (2023), Issue 2, pg(s) 73-75
    • Abstract
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    The development refers to an innovative technology and technological scheme of a workshop for the production of beehives made of amorphous quartz ceramics. The conditions for obtaining stable suspensions from quartz glass are emphasized and investigated. The time for the treatment of the glass in the grinding device, the amount of water, the influence of the modifiers in stabilizing the suspension by adjusting the pH level, as well as the most suitable sedimentary composition of the glass particles are established. The factors determining the speed and degree of sintering of the ceramics are investigated and established. They include the density of the raw products, the dispersion of the quartz glass particles and its purity, as well as the environment in the furnace and the sintering mode.

  • INNOVATIVE SOLUTIONS

    Results from the plastic pressing of experimental ceramic pavers of “yellow” paving stone type

    • Gergana Mutafchieva
    • Lyuben Lakov
    • Gabriel Peev
    • Dimo Mihaylov
    Innovations, Vol. 11 (2023), Issue 1, pg(s) 34-36
    • Abstract
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    The results of the plastic forming of ceramic pavers with a large volume and size are observed to produce better compaction of the raw material. The used ceramic mixture is based on a sedimentary rock with relatively high moisture content and firing shrinkage which gives the common yellow colour after a high-temperature liquid phase synthesis. The results of one-fold pressing revealed the occurrence of deformation processes in the drying stage and during the temperature regime. As a consequence, the pressing pressure should be increased and the residual water amount needs to be reduced to an optimal content.

  • MATERIALS

    Phase and Petrographic Analysis of Petrurgical Materials Obtained on the Base of Metamorphic Rocks

    • Lyuben Lakov
    • Momchil Dyulgerov
    • Gergana Mutafchieva
    • Gabriel Peev
    • Dimo Mihaylov
    Machines. Technologies. Materials., Vol. 16 (2022), Issue 11, pg(s) 391-393
    • Abstract
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    The phase and petrographic analysis of a part of previously prepared test samples of coloured petrographic materials coloured with different contents of CuO, SnO2, CoO, Cr2O3 were studied. The raw materials are based on metamorphic rocks – dolomite marbles from the village of Ustrem and the village of Mramor, processed by melting at 1450°C, so that after crystallization, petrographic phases are obtained, which are confirmed by X-ray phase and petrographic analysis. The main characteristics of the colouring aggregates and their effect on the mineral composition and crystal structure are described.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    Development and Production of Molding Equipment and Plastic masses using new compounding formulations, plastic pressing, drying, high-temperature liquid-phase synthesis and properties of a prototype batch of “yellow” paving stones

    • Gergana Mutafchieva
    • Lyuben Lakov
    • Mihaela Aleksandrova
    • Marieta Gacheva
    • Gabriel Peev
    • Dimo Mihaylov
    Industry 4.0, Vol. 7 (2022), Issue 6, pg(s) 228-231
    • Abstract
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    The research is related to the creation of new compounding formulations for the production of “yellow” paving stones. This was necessary due to denied access to a potential source of suitable raw material from the deposit near the village of Svetlen, Popovo municipality. Marlstone raw material from this deposit has the necessary qualities for such production, as a result of which, after hightemperature liquid-phase synthesis, new petrurgic phases with high physicochemical and mechanical properties can be formed. The new compounding formulation of the molding mass was developed on the basis of marlstone sedimentary rock from the Alexandra deposit, located near the village of Lovets, Targovishte district. The use of this compounding formulation makes it possible to obtain appropriate physicochemical and mechanical properties and a yellow coloring equivalent to that of the reference samples.

  • MATERIALS

    Foam ceramic blocks with low thermal conductivity suitable for the construction of roads and urban square pavements and non-load-bearing partition walls

    • Gergana Mutafchieva
    • Lyuben Lakov
    • Mihaela Aleksandrova
    • Rositza Dimitrova
    • Gabriel Peev
    Machines. Technologies. Materials., Vol. 16 (2022), Issue 5, pg(s) 186-188
    • Abstract
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    Lightweight porous ceramic has a number of advantages over the tightly sintered one depending on the field of application. As a building material with low thermal conductivity and good sound insulation properties, foam ceramic is a suitable material for the production of thermal and sound insulation panels, partition walls, as well as for layers laid under asphalt to protect road and urban square pavements from freezing. As a filling, foamed ceramic materials are also added during the production of lightweight concrete used in construction and architecture and in the manufacture of decorative and non-structural insulation elements. In the present study we consider the characteristics of marl clay, found around the village of Lovets near the town of Shumen, with coal as a foaming additive, and the technological regulation for the manufacture of foam ceramic blocks.

  • INNOVATIVE SOLUTIONS

    Innovative technologies for the production of high-oxide corundum and boron carbide ceramics

    • Lyuben Lakov
    • Mihaela Aleksandrova
    • Gergana Mutafchieva
    • Gabriel Peev
    Innovations, Vol. 10 (2022), Issue 1, pg(s) 40-45
    • Abstract
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    In this publication, the authors present an in-depth justification on the technology for the production of high-oxide ceramics. Indepth research on international markets on the supply and use of raw materials is presented. The various design developments related to the ways of pressing products are described. The physico-mechanical parameters of the synthesized corundum and boron-ceramic ceramics were also studied.

  • TECHNOLOGIES

    Technology for production of reduced yellow paving stones on the basis of modified marl clay from the Alexandra quarry, the village of Lovets, Bulgaria (Part 1)

    • Gergana Mutafchieva
    • Lyuben Lakov
    • Mihaela Aleksandrova
    • Gabriel Peev
    Machines. Technologies. Materials., Vol. 16 (2022), Issue 3, pg(s) 96-99
    • Abstract
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    Due to the specifics of marl clays, research to date has shown the need to stabilize these clays with respect to their critical melting point. The research is based on a previous analysis of pure raw material from marl clay, located in the area of the village of Lovets, which is modified by various additives. On the one hand, the modification is used to stabilize the ceramic mass and on the other hand, by adding various agents, the aim is to lighten the composition and obtain the required color pattern. For the purposes of production, the experimental part includes laboratory development of a scale model of yellow paving stone. The development presents the entire process of creating instrumental equipment – model making and matrix construction, and molding of finished products – pressing process for paving stones productionfrom modified marl clay. The technological cycle that can be implemented in the real conditions for yellow paving stones production will rely on the present study.

  • Physicochemical and technological researches of marls from the area of the village Lovets related to the production of the new “Yellow paving stones”

    • Lyuben Lakov
    • Gergana Mutafchieva
    • Gabriel Peev
    • Mihaela Aleksandrova
    • Bojidar Jivov
    Materials Science. Non-Equilibrium Phase Transformations., Vol. 7 (2021), Issue 3, pg(s) 107-109
    • Abstract
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    Due to force majeure circumstances, new researches of marls from the Alexandra deposit to the village of Lovets (Shumen region) were carried out to replace the marls from the village Svetlen (Targovishte region), which are part of a plastic mass for the production of large, fine-ceramic parts (yellow paving stones) from peturgical phases. Marls are characterized in terms of mineral and chemical composition. Their properties, characterizing them as a ceramic raw material, have been determined. Three test masses with a chemical composition similar to the one with the participation of marls from the village of Svetlen were developed. The test specimens are characterized in terms of sintering and strength characteristics. It has been established that the marls can be used to repla ce the marl from the village Svetlen in the composition of the plastic fine-ceramic masses for the production of yellow pavers.

  • DOMINANT TECHNOLOGIES IN “INDUSTRY 4.0”

    Technology for production of technical products with fixed thickness and made of quartz ceramics by means of a moulding matrix with a silicone insert

    • Gabriel Peev
    • Lyuben Lakov
    • Gergana Mutafchieva
    • Mihaela Aleksandrova
    Industry 4.0, Vol. 6 (2021), Issue 6, pg(s) 222-224
    • Abstract
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    Molding of technical products with fixed thickness by casting quartz ceramics, based on pure quartz glass, requires specific technological regulations both in the preparation of the ceramic mass and in the process of molding itself. Due to the specif ic characteristics of the colloidal system such as low shrinkage and viscosity, casting in molds made only of gypsum is practically unworkable. A solution lies in developing a technology in which the dismantling of the die is supported so that the molded product can be easily removed. Proposed here is a gypsum mold developed in such a way that a silicone insert is mounted where the lower part of the cast product will be. The technological process presented here in detail includes the main stages of preparing a model according to pre-set parameters, making a gypsum mold consisting of two-parts and with a silicone insert, casting and high-temperature synthesis of the finished product made of quartz ceramics. The development is suitable for complex and large-size technical products made not only of quartz ceramics, but also of other silicate colloidal systems characterized by low and almost zero air shrinkage.

Congresses and conferences

  • IX International Scientific Conference
    "High Technologies. Business. Society"
    04.-07.03.2024 - Borovets, Bulgaria
  • XXI International Congress
    "Machinеs. Technolоgies. Materials."
    Winter session
    06.-09.03.2024 - Borovets, Bulgaria
  • XIX International Scientific Technical Conference
    "Foundry"
    17.-19.04.2024 - Pleven, Bulgaria
  • XXXI International Scientific Conference
    "trans&MOTAUTO"
    24.-27.06.2024 - Varna, Bulgaria
  • IX International Scientific Congress
    "Innovations"
    24.-27.06.2024 - Varna, Bulgaria
  • IX International Scientific Conference
    "Industry 4.0"
    Summer session
    26.-29.06.2024 - Varna, Bulgaria
  • XII International Scientific Congress
    "Agricultural Machinery"
    26.-29.06.2024 - Varna, Bulgaria
  • XI International Scientific Conference
    "Engineering. Technologies. Education. Safety"
    02.-05.09.2024 - Varna, Bulgaria
  • X International Scientific Conference
    "Materials Science. Non-Equilibrium Phase Transformations"
    02.-05.09.2024 - Varna, Bulgaria
  • XVII International Conference for Young Researchers
    "Technical Sciences. Industrial Management"
    04.-07.09.2024 - Varna, Bulgaria
  • XXI International Congress
    "Machines. Technologies. Materials"
    Summer session
    04.-07.09.2024 - Varna, Bulgaria
  • IX International Scientific Conference
    "Conserving Soils and Water"
    09.-12.12.2024 - Borovets, Bulgaria
  • VIII International Scientific Conference on Security
    "Confsec"
    09.-12.12.2024 - Borovets, Bulgaria
  • IX International Scientific Conference
    "Industry 4.0"
    Winter session
    11.-14.12.2024 - Borovets, Bulgaria
  • VI International Scientific Conference
    "Mathematical Modeling"
    11.-14.12.2024 - Borovets, Bulgaria

Scientific Technical Union of Mechanical Engineering "Industry-4.0"

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tel. (+359 2) 987 72 90, tel./fax (+359 2) 986 22 40,
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