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The aim of the research is to develop a method for betulin integration into electrospinning solutions to electrospun qualitative nanofibers webs morphology with high surface area and increase bioavailability. The main challenge in this study is to prepare betulin - containing electrospinning solutions with suitable concentrations due to limited betulin solubility in water and low alcohol concentrations. Tree concentrations of betulin extracts were obtained. The operation sequence to obtain electrospinning solution...

Gold and iron nanoparticles were generated via environmentally safe metal-vapor synthesis method applying acetone or toluene as organic dispersion medium. Biological properties of the nanoparticles were analyzed by the agar disc diffusion method using Gram-positive and Gram-negative bacteria and via in vitro cytotoxicity assays with different human cell lines. The obtained results revealed distinct biological activity profiles of the studied specimens. Fe nanoparticles (Fe NPs) demonstrated inhibitory effects agai...

The mechanism for the selective adsorption of zirconium ions in a highly acidic medium by sodium-modified titanium dioxide was proposed. The mechanism of adsorption of zirconium ions in an acidic medium by this adsorbent is similar to the mechanism of adsorption of strontium ions in a neutral medium. The selectivity of Na-TiO2 is due to the positively charged surface of the adsorbent in the highly acidic medium.

In the last years, composite materials are increasingly used in automotive, aeronautic, aerospace, construction applications. Composite materials have been used in aerospace in applications such as engine blades, brackets, interiors, nacelles, propellers/rotors, single aisle wings, wide body wings. The fields of use of composite materials have multiplied with the improvement of material properties, such as stability and adaptation to the environment, mechanical tests, wear resistance, moisture resistance, etc. The...

Although the volumes of fiber reinforced polymer composites (FRPs) used for aircraft applications is a relatively small percentage of total use, the materials often find their most sophisticated applications in this industry. In aerospace the performance criteria placed upon materials can be far greater than in other areas - key aspects are lightweight, high-strength, high-stiffness and good fatigue resistance. Composites were first used by the military before the technology was applied to commercial planes. Nowad...

The evolution of technology in the field of unmanned aerial vehicles (UAVs) has led to the miniaturization of the equipment on board these aircraft. The most used equipment mounted on a UAV is still the video sensor, with the help of which the video image from the aerial vehicle can be processed for dedicated applications (facility inspection, surveying and mapping, operational oversight, traffic control, etc.). In this paper, we present the prototyping of a three-axis gimbal using the direct drive technology to r...

In this paper were obtained waste/polymeric nanocomposites - polyamide waste (PAW) and polystyrene (PS), compatibilized with maleic anhydride grafted polystyrene, and reinforced with carbon nanofibers (CF). PolyamideWaste / polystyrene (PAW / PS) composites are studied because both components are relatively cheap, with beneficial properties, and can be processed by injection. Compatibility of polymer and waste compounds can be achieved by adding a grafted copolymer, the segments of which have physical or chemical ...

The article deals with the research of thermal insulation properties of thin-layer insulating material made of hollow glass-ceramic microspheres in relation to technical building installations. Until now, there has been a lack of scientific studies describing the effectiveness of thermal insulation properties of thin-layer insulation materials on distribution systems or technical equipment. In this particular case, the insulation material was applied in a two-millimeter layer to a heat storage tank and the heat lo...

A designed protection system should not fail once or under a small number of hits. Tests to assess ballistic protection are expensive and numerous. The simulations support engineers in limiting the number and complexity of impact tests. This paper discusses the failure mechanisms and simulated impact phases between a bullet (similar to 9 mm FMJ) and a panel made of 8-layers, 12-layers and 16-layers, at two impact velocities, 373 m/s and 420 m/s. respectively. The 8-layers and 16-layers simulations are compared to ...

Purification of aqueous solutions from radionuclide contamination is an extremely problematic topic, which is the subject of many scientific papers. This scientific topic is very relevant to Ukraine. In particular, the synthetic adsorbents - activated carbon, zeolites, metal oxide-adsorbents TiO2, titanium or zirconium phosphates, ion exchange resins, etc., are often used for the removal of heavy metal cations Pb (II), Cd (II), Ba (II), Hg (II), Sr (II) as well as some anions Cl-, F- from the aquatic environment. ...

The rapeseed oil is a promising eco-friendly lubricant for applications involving environment protection. But any vegetal oil has shortcuts especially related to low viscosity and thermal stability. Research in additivation with nanoparticles is of interest for improving load capability of the contact and for reducing wear. Other tribological characteristics, as friction coefficient, could oscillate around values offered by the neat vegetal oil, with more or less influence of the system behavior. The four-ball tes...