• Antibacterial Coatings Containing Nanodiamonds

    pg(s) 272-274

    The aim of this research is to obtain coatings with high antibacterial properties and low toxicity, for various applications. Solgel method was employed to manufacture coating comprising carbon nanoparticles (CNP) of nanodiamonds (ND). Methods of dip-coating and spraying were developed and optimized. The technology was adopted to automatic process using designed and manufactured laboratory and semi-industrial spraying and curing apparatus.

  • New optical method in laser phototherapy

    pg(s) 270-271

    In this study we investigate the kinetics of oxygen tension pО2) in skin tissue under the influence of the transcutaneous laser irradiation. The results of in vivo experimental measurements of pО2 by a method of transcutaneous oxygen monitoring (TcOM) are presented. The results show that under laser irradiation the value of tissue oxygenation increases and after approximately 10 minutes of exposure exceeds its initial level up to 1.6 times. The observed increase in pO2 indicates the process of photodissociation of oxyhemoglobin (HbO2) in skin blood vessels, which results in local O2 increase in the tissue. Such laser-induced enrichment of tissue oxygenation can be used in phototherapy of pathologies, where the elimination of local tissue hypoxia is critical.

  • Thermal decomposition of biomass, significance of biochar

    pg(s) 267-269

    Biochar is an uniquely useful renewable resource that has significant advantages in solving many environmental problems. It helps to mitigate the harmful soil degradation experienced in recent years (decades), including the restoration of the balance of pollutants in the soil, water and gaseous medium. After all, synergistically, with proper use, it can improve soil, water and air quality, carbon dioxide sequestration and moderate greenhouse gas emissions. We designed and implemented laboratory equipment (with a total weight of 0.5 kg) and industrial equipment (50 – 100 kg of coal/hour) and validated the laboratory results with this industrial equipment.
    Our equipment is a so-called resting-bed design. Drying and carbonization are also carried out by direct heat transfer. The carbonizing material is continuously rotated in the interior due to the material movement with the stirrer lever. As a result, the quality of the material leaving and entering the reactor is balanced. Better heat transfer and uniform distribution of thermal energy is facilitated by the circulation of the hot gas that fills the space. The high-temperature gas is supplied with a gas jet pump. The energy obtained by burning the pyrolysis gases produced during carbonization ensures the heating of the system, so there is no need for significant external energy input.
    According to our results, the quality and other characteristics of biochar vary significantly depending on the type of raw material and pyrolysis conditions. In order to ensure the quality of the created material, the production process must be closely monitored in every detail of the equipment. The continuous quality control of the products cannot be neglected either. According to the opinion of international associations and research groups, significant development of the use of biochar is expected in the future. There is growing interest in the use of biochar to remove pollutants from soil, water and gas, and its potential to replace expensive commercial activated carbon.

  • Application of reverse engineering techniques in automotive component design

    pg(s) 264-266

    The aim of the work was to digitize an automotive component using reverse engineering. To apply the procedures by which an automotive component can be designed. Reverse engineering belongs in the field of innovation among the first established knowledgeintensive services. Together with the advancing development of technology and utilizing of 3D scanning, the reverse engineering is becoming an important tool for accelerating the product innovation cycles and increasing the potential of lean approach and agility of development processes in Product Design. The paper illustrates the possibilities of using and experience with these tools on examples of the scanning of the geometry of the selected automotive components.

  • AFM morphology of sol gel coatings on glass for photovoltaics

    pg(s) 262-263

    In this paper, we present the results of atomic force microscopy (AFM) characterizing the surface morphology of nanostructured coatings on photovoltaic glass obtained by the sol-gel method. Two organic titanium precursors were used to prepare the TiO2 deposition solution: Titanium isopropoxide (TTIP) and titanium tetrabutoxide – Ti (OC4H9). The hydrolyzing agent is distilled water and the stabilizer is nitric acid /HNO3/and acetylacetone (AcAc). Many samples were obtained at different ratios of the components involved, rate of application of the solution on the glass substrate, and different curing and holding temperatures. The samples were characterized by AFM analysis.

  • Renovation of moulds for high-pressure casting of aluminium by laser cladding

    pg(s) 259-261

    The paper presents the results of an investigation focused on the analysis of the wear of moulds for high-pressure casting with Al alloy. In order to repair and refurbish the mould parts of moulds for high-pressure casting of aluminium alloys, samples of experimental welds were prepared on the base material of grade 1.2343 (Dievar) of dimensions 150x130x30 mm refined to the hardness value of 44-48 HRC. A TruDisk 4002 solid-state disk laser with BEO D70 focusing optics was used for surfacing. Mat.No.1.2343 (Dievar), Mat.No.1.6356 (Dratec) and Mat.No.1.6356 (UTPA 702 and NIFIL NiCu7/Dievar) wires were used as additional material. Light microscopy technique was used to inspect the microstructures on the cross-sections of the welds. Microhardness measurements were performed with a Vickers indenter at a load of 500 g and a mutual indentation distance of 0.4 mm between the indenter impressions.

  • Development of Software Application in the Evaluation of Erythrocyte Aggregation Studied with Microfluidic Device

    pg(s) 228-231

    The main focus of this research is on the elaboration of the combined experimental approach and image analysis (based on the specialized software environments) to the research of erythrocyte aggregation, which is evaluated by the microfluidic device BioFlux. To realize a precise evaluation of the erythrocyte aggregation index based on the obtained, during the experiment images, are applied image processing toolbox from ImageJ and an elaborated computer program in IntelliJ IDEA (integrated development environment) as well. The obtained results for the index of erythrocyte aggregation, based on the developed methodology, show a statistically significant difference between the two studied groups with preeclampsia and healthy pregnant women.

  • Effect of production technique on a high silicon al-si-ni sintered alloy structure and properties

    pg(s) 224-227

    An experimental study was carried out to develop a technique for manufacturing a high silicon Al-Si-Ni sintered alloy with a coefficient of thermal expansion close to steels. A stage of hot forging was added to overcome porosity and improve silicon inclusions morphology to obtain better mechanical properties. Liquid and solid phase regimes of sintering were studied for the material made of the elemental components powders mixture as well as of a pre-alloyed powder. The impracticality of liquid-phase sintering modes is shown for this type of material primarily because of the tendency to liquid-phase exudation. It was proposed to carry out a solid-state vacuum sintering with subsequent hot deformation. Only the pre-alloyed powder is suitable for the technique; the other way, it leads to the course and sometimes, not equilibrium intermetallic inclusions will form in place of nickel particles because of the insolubility of Ni in solid Al. It is shown the possibility of successful plastic deformation of this material after sintering despite its extremely low ductility, which helps successfully overcome porosity and improve the characteristics of the microstructure of the material.

  • Determination of the quality of welded joints after repairs of hot water pipes

    pg(s) 219-223

    The paper presents the results of an investigation aimed at analysing the current state of the art in the construction of hot water piping systems. Weld joint analysis and evaluation is an essential part of the inspection of hot water pipelines to ensure their safe operation. The practical part of this work is focused on the analysis and evaluation of the weld joint of original and new hot water piping. Destructive and non-destructive weld joint testing methods were applied to carry out the evaluation and analysis, the results of which were used to compare the welded joints on the hot water pipeline

  • Manufacturing Principals of Metal processing Lasers

    pg(s) 216-218

    This paper provides a concise overview of the manufacturing principles of metal processing lasers. Metal processing lasers are advanced tools used in various manufacturing industries for cutting, welding, and shaping metal materials. The presented highlights include the fundamental principles governing laser-based metal processing techniques, including laser beam generation, focusing, and interaction with metal surfaces. It also emphasizes the importance of precise control parameters, such as power, pulse duration, and wavelength, to achieve optimal processing results. Understanding these principles is crucial for enhancing productivity, quality, and efficiency in metal manufacturing processes.

  • The influence of electric discharge and solutions of surfactants on the filtration characteristics of porous, liquid-saturated media

    pg(s) 212-215

    The results of studies of the behavior of rocks with fluids under impulse pressure, which is induced by an electric discharge in solutions of surface-active substances (surfactants), are given. The mechanism of influence of high-voltage electric discharges and mechanical waves induced by them on the behavior of combined objects (porous rocks, hydrocarbon fluids filling their pores – oil and hydrogen surfactant solution, solid mineral sediment) is revealed.
    It was found out that the use of a water-oil emulsion as a working medium for high-voltage electric discharge significantly (2 times for sandstones and 1.5 times for carbonates) increases the efficiency of the electric discharge effect compared to water.
    The complex action of the electric discharge and the aqueous 0.3% solution of NMK-21, used as a working medium, leads to a synergistic effect in increasing the permeability of rocks by twice the sum of the effects for each component.
    Work results can be used in the development of scientific foundations of managing the filtration properties of porous materials of various origins.

  • 3D Design and Prototyping of a Microfluidic Device for Blood Cells’ Investigations

    pg(s) 194-197

    The present study offers an important technological approach for the development of a disposable microfluidic channel using 3D nanoprinter – Photonic Professional GT2 (Nanoscribe, Germany). This publication aims to present 3D modelling, simulation, and prototype of a 3D nanoprinted microfluidic device for the investigation of blood cells. The design of 3D model of a microchannel is realized by the 3D CAD analysis software – SOLIDWORKS. A suitable laminar flow is generated by using computational fluid dynamics (CFD) software. As a result, the critical points of the pressure, velocity and wall shear stress into the microfluidic channel are obtained. An actual physical prototype of the proposed microfluidic device is developed, using a highly innovative technology of 3D nanoprinting by two-photon polymerization. Experimental studies with dilute erythrocyte suspensions are conducted to test the functionality of the developed real-world prototype of nano 3D printed microchannel.