The forgotten topological index was defined to be used in the analysis of chemical structures which often appear in drug molecular graphs. In this paper, we studied the F-index and F-coindex for certain important physico chemical structures such as V-Phenylenic Nanotube V PHX [m; n] and V-Phenylenic Nanotorus V PHY [m; n] and their molecular complement graph. Moreover, we computed F-polynomial of the V-Phenylenic Nanotubes and Nanotorus. These explicit formulae can correlate the chemical structure of molecular graphs of Nanotubes and Nanotorus to information about their physicochemical structure.

This work devoted to construction of the Matrix-Green’s functions of initial-boundary value problems for the time-fractional diffusion equation on the metric star graph with equal bonds. In the case of Dirichlet and mixed boundary conditions we constructed Green’s functions explicitly. The uniqueness of the solutions of the considered problems were proved by the method of energy integrals. Some possible applications in branched nanostructures were discussed.

The transmission spectra of a composite material obtained by introducing magnetite nanoparticles into a polyvinyl alcohol matrix are studied. The samples were films on the glass substrate prepared by drying an aqueous solution of polymer and a ferrofluid. A number of them were made in a constant magnetic field, which led to the formation of extended aggregates. The features of these spectra and possible causes of their appearance are discussed.

The multifaceted enzyme-like activity of CeO₂ nanoparticles (CeNPs) expands the prospects for their potential biomedical applications. In this regard, there is a need for a comprehensive analysis of the redox behavior of CeO₂ nanoparticles in relation to key molecules of free radical homeostasis. Here, the prooxidant potential of CeNPs towards H2O2 was investigated to elucidate both prooxidant capacity and prooxidant activity of CeNPs. To describe the kinetics in the luminol–H₂O₂ system at pH 8.5 upon the addition of citrate-stabilized CeO2 sol (3 nm), a numerical model of three reactions is proposed. The rate constants being a measure of prooxidant activity, were k₁ = 9,0 * 10⁴ _M^-1min^-1, k₂ = 2,0 * 10^-6 _M^-1min^-1, k₃ = 2,9 * 10^-5 _M^-1min^-1. The functionalization of CeO₂ nanoparticles surface with ammonium citrate increases their prooxidant capacity by two-fold, while modification with maltodextrin decreases it by six-fold. It was shown that the prooxidant capacity of citrate-stabilized CeO₂ sol in Tris-HCl is approximately four-fold higher than in phosphate buffer solution at pH 7.4.

Ultra high sensitive room temperature gas sensor based on Ni-doped WO₃ nanoparticles (hereafter NPs) has been reported here. The synthesis of pure and Ni-doped WO₃ NPs was done by facile precipitation route. XRD studies revealed the polycrystalline monoclinic structure of the prepared samples with the preferential growth orientation along (002) crystal plane. Analysis via SEM and FE–SEM was conducted, and the micrographs showed that the synthesized samples were found to have highly porous structure with excellent dispersibility. The successful incorporation of Ni²+ions in to WO₃ lattice has been confirmed by XPS analysis. The highly improved room temperature gas sensing characteristics of WO₃ by Ni doping is also studied using a high sensitive electrometer. Compared to undoped WO₃, 3 mol. % Ni-doped WO₃ sensor showed nearly 20-fold greater sensitivity (2641 – 200 ppm ammonia, room temperature) with rapid response/recovery times of 40/97 s.

The dependence of cobalt ferrite nanosized powder production process on the synthesis method and conditions was studied. The paper shows the possibility for producing nanocrystalline CoFe₂O₄ with an average particle size of 12 nm under conditions of an impinging-jets microreactor at room temperature. The influence exerted by the parameters of process implementation in the microreactor on phase formation in the CoO–Fe₂O₃–H₂O system was analyzed.

TiO₂/SiO₂ alternative thin films (stacks) were deposited on silicon substrates using sol-gel spin-coating techniques. The prepared samples had their corresponding optical properties analyzed by UV-Visible spectrophotometry (UV-Vis), X-ray diffractometry (XRD), a surface profilometer, and Raman spectroscopy. The optical and crystallization properties of thin films were varied and compared by changing the number of stacks. UV-Vis spectrum showed high reflectance and shifting towards the infrared region with effect of increased TiO₂/SiO₂ stacks. XRD spectra confirmed the existence of anatase TiO₂ and SiO₂ diffraction peaks. The multilayer film thickness was calculated at 109 and 151 nm at two and four stacks by a surface profilometer. The Raman spectra confirmed the Si–O–Si and TiO₂ stretching modes at 2600, 980, and 519 cm^-1. This investigation reveals the promising and effective UV-Visible reflective property of alternative TiO₂/SiO₂ thin films on a silicon substrate.

Zinc sulfide (ZnS) thin films were deposited onto microscopic silica slides through the cost-effective chemical bath deposition (CBD) method. The optimized bath parameters were: 25 ml of 0.1 M zinc precursors (ZnCl₂, Zn(CH₃COO)₂, ZnSO₄), 25 ml of 1 M thiourea and 3 ml of 3.75 M triethanolamine (TEA). The effects of different zinc precursors (ZnCl₂, Zn(CH₃COO)₂, ZnSO₄) on the growth mechanism of ZnS thin film were investigated using thermal, structural, morphological, optical and electrical studies. The XRD pattern has shown Miller indexing peaks corresponding to the hexagonal phase of as-grown ZnS thin film with the estimated grain size of 22 – 27 nm. The change in physical properties (weight loss) of ZnS powder as a function of temperature was recorded using thermogravimetry (TGA/DTA). Scanning electron microscopy (SEM) revealed the effect of ZnCl₂, Zn(CH₃COO)₂ and ZnSO₄ precursors on growth mechanism. UV/visible optical transmission/absorption spectra displayed the transmittance between 10 to 29 % of as-grown ZnS thin film with a band gap in the range of 4.10 – 4.25 eV. Photoluminescence (PL) analyses demonstrated broad blue emission around ~ 459 nm was attributed to recombination of electron-hole pair from donor-acceptor trap levels to valance band. Raman spectra of ZnS powder prepared using different zinc precursors were also reported. The values of electrical parameters (resistivity, conductivity, activation energy, Hall coefficient, carrier concentration, mobility) were investigated using the two-point probe method and Hall-effect apparatus.

This paper is aimed at the experimental study (in animal models) of acute toxicity and irritating properties of polysaccharide hydrogel modified with cerium oxide nanoparticles. In the acute experiment, there were no indications of irritating action of the gel at the site of application when the hydrogel was administered intragastrically or epicutaneously. No lethal effects were registered during this experiment even at the highest concentration. The results obtained demonstrate the lack of acute toxicity and local irritability of the synthesized hybrid hydrogel, which allows to classify the developed hybrid hydrogel as the relatively low-risk drug.

The article is devoted to the covalent modification of the surface of titanium dioxide nanoparticles with polymethacrylic acid using the method of controlled atom transfer radical polymerization. For the first time, core-shell titanium dioxide nanoparticles with water-soluble shell of poly(methacrylic acid) were obtained.

Catalytic fullerenol C₆₀(OH)₂₄ action on Chlorella Vulgaris growth in the conditions of limited resource growth base and in the conditions of oxidative stress are reported. Chlorella growth or oppression were investigated in open transparent in the visible area cylindrical polystyrene test tubes at room temperature under illumination by standard incandescent lamp for the period 9 days. Catalyst concentration were varied in the range 0.01 – 1.0 g/dm³. Oxidative stress was organized by the addition of hydrogen peroxide with the concentration 1.0 g/dm³. Chlorella Vulgaris concentrations were determined by the method of turbidimetry – by the determination of optical density of scattered light in the direction of propagation of the incident beam at wavelength 664 nm. Obtained kinetic data were processed by the method of formal classical kinetics. The pseudo-order of the process Chlorella Vulgaris growth in the conditions of limited resource, according to Chlorella, is -2; the curve of the dependence of Chlorella concentration against time is concave at all fullerenol concentrations. The pseudo-order of the process Chlorella Vulgaris suppression in the conditions of oxidative stress, according to Chlorella, is +2, the curve of the dependence of Chlorella concentration against time is convex at all fullerenol concentrations. The kinetics of Chlorella Vulgaris growth in the conditions of limited resource was also processed by model Verhulst equation of logisitic growth, and this equation describes the kinetics as accurately and adequately as possible. The authors have established, that in the case of the conditions of limited resource, fullerenol at low concentrations (less than 0.1 g/dm³) catalyzes-accelerates Chlorella growth and at higher concentrations (0.1 – 1.0 g/dm³) inhibits Chlorella growth. For the conditions of oxidative stress, authors have established, that at all fullerenol concentrations, it considerably inhibits suppression-depopulation of Chlorella processes, so fullerenol proves enough strong anti-oxidant action. It was demonstrated, that Verhulst equation maybe satisfactory used for the description of different natural process.

In this study, Carbon nano particles (C NPs) from neem leaves were synthesized for adsorption and photo catalytic degradation of Auramine–O (Au–O) dye used in paper industries. The synthesized C NPs were characterized by powder X-ray diffraction and scanning electron microscopy. Dye adsorption and photo catalytic properties of C NPs were examined by studying the decolorization of dye Au–O at 5 minutes time interval using a UV-Visible spectrophotometer. The results show that C NPs acts as a better adsorbent even with shorter time and lower concentration than as photocatalysts.

In this paper, the achievements, problems and prospects of creating personalized energy systems based on nanostructured materials are analysed. Various concepts of developing methods and ways of personalized energy provision for autonomous human survival in remote natural habitat, emergency situations of natural disasters and technogenic catastrophes when centralized power supply is unavailable or in an effort to reduce the economic and environmental costs of remote energy production and transportation are also considered. The possibilities and limitations of using traditional and renewable alternative energy sources, processes and devices for extracting, storing and converting their energy into the necessary consumer forms due to fundamental physical laws are discussed as well. The article covers the new nanostructured materials with special functional properties for personalized energy systems development. The mechanisms for formation of the required nanostructures in synthesized materials, especially those with a high content of fractal interfacial formations, are considered as well as methods for studying their structural and phase characteristics that determine the achievability of the specified parameters of model converters and energy storage devices.