Plasmon-Enhanced Perovskite Solar Cells Based on Inkjet-Printed Au Nanoparticles Embedded into TiO2 Microdot Arrays

The exceptional property of plasmonic materials to localize light into sub-wavelength regimes has significant importance in various applications, especially in photovoltaics. In this study, we report the localized surface plasmon-enhanced perovskite solar cell (PSC) performance of plasmonic gold nanoparticles (AuNPs) embedded into a titanium oxide (TiO2) microdot array (MDA), which was deposited using the inkjet printing technique. The X-ray (XRD) analysis of MAPI (methyl ammonium lead iodide) perovskite films deposited on glass substrates with and without MDA revealed no destructive effect of MDA on the perovskite structure. Moreover, a 12% increase in the crystallite size of perovskite with MDA was registered. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) techniques revealed the morphology of the TiO2_MDA and TiO2-AuNPs_MDA. The finite-difference time-domain (FDTD) simulation was employed to evaluate the absorption cross-sections and local field enhancement of AuNPs in the TiO2 and TiO2/MAPI surrounding media. Reflectance UV-Vis spectra of the samples comprising glass/TiO2 ETL/TiO2_MDA (ETL-an electron transport layer) with and without AuNPs in TiO2_MDA were studied, and the band gap (Eg) values of MAPI have been calculated using the Kubelka-Munk equation. The MDA introduction did not influence the band gap value, which remained at ~1.6 eV for all the samples. The photovoltaic performance of the fabricated PSC with and without MDA and the corresponding key parameters of the solar cells have also been studied and discussed in detail. The findings indicated a significant power conversion efficiency improvement of over 47% in the PSCs with the introduction of the TiO2-AuNPs_MDA on the ETL/MAPI interface compared to the reference device. Our study demonstrates the significant enhancement achieved in halide PSC by utilizing AuNPs within a TiO2_MDA. This approach holds great promise for advancing the efficiency and performance of photovoltaic devices.

Cleaning Strategies of Synthesized Bioactive Coatings by PEO on Ti-6Al-4V Alloys of Organic Contaminations

The effect of various cleaning methods on coating morphology and their effectiveness in removing organic contaminants has been studied in this research. Bioactive coatings containing titanium oxides and hydroxyapatite (HAP) were obtained through plasma electrolytic oxidation in aqueous electrolytes and molten salts. The cleaning procedure for the coated surface was performed using autoclave (A), ultraviolet light (UV), radio frequency (RF), air plasma (P), and UV-ozone cleaner (O). The samples were characterized using scanning electron microscopy (SEM) with an EDS detector, X-ray photoelectron spectroscopy (XPS), X-ray phase analysis (XRD), and contact angle (CA) measurements. The conducted studies revealed that the samples obtained from molten salt exhibited a finer crystalline structure morphology (275 nm) compared to those obtained from aqueous electrolytes (350 nm). After applying surface cleaning methods, the carbon content decreased from 5.21 at.% to 0.11 at.% (XPS), which directly corresponds to a reduction in organic contaminations and a decrease in the contact angle as follows: A > UV > P > O. This holds true for both coatings obtained in molten salt (25.3° > 19.5° > 10.5° > 7.5°) and coatings obtained in aqueous electrolytes (35.2° > 28.3° > 26.1° > 16.6°). The most effective and moderate cleaning method is ozone treatment.

Improving the Stability of Halide Perovskite Solar Cells Using Nanoparticles of Tungsten Disulfide

Halide perovskites-based solar cells are drawing significant attention due to their high efficiency, versatility, and affordable processing. Hence, halide perovskite solar cells have great potential to be commercialized. However, the halide perovskites (HPs) are not stable in an ambient environment. Thus, the instability of the perovskite is an essential issue that needs to be addressed to allow its rapid commercialization. In this work, WS₂ nanoparticles (NPs) are successfully implemented on methylammonium lead iodide (MAPbI₃) based halide perovskite solar cells. The main role of the WS₂ NPs in the halide perovskite solar cells is as stabilizing agent. Here the WS₂ NPs act as heat dissipater and charge transfer channels, thus allowing an effective charge separation. The electron extraction by the WS₂ NPs from the adjacent MAPbI₃ is efficient and results in a higher current density. In addition, the structural analysis of the MAPbI₃ films indicates that the WS₂ NPs act as nucleation sites, thus promoting the formation of larger grains of MAPbI₃. Remarkably, the absorption and shelf life of the MAPbI₃ layers have increased by 1.7 and 4.5-fold, respectively. Our results demonstrate a significant improvement in stability and solar cell characteristics. This paves the way for the long-term stabilization of HPs solar cells by the implementation of WS₂ NPs.

MILK LIPIDS AND SUBCLINICAL MASTITIS

This article deals with the process of obtaining quality raw milk by analyzing its lipid composition. The lipid composition of raw milk depends on many factors, among which, first of all, is the species, the composition of the diet and the physiological state of the breast. In recent years, a large amount of data has accumulated on the fluctuations of certain lipid parameters of milk depending on the type, age, lactation, diet, time of year, exercise, animal husbandry technology, physiological state of the lactating organism in general and breast status in particular. Factors of regulation of fatty acid composition of raw milk: genetically determined parameters of quality and safety; fatty acid composition of the diet; synthesis of fatty acids by microorganisms of the digestive tract; synthesis of fatty acids in the breast; physiological state of the breast. The milk of each species of productive animals has its own specific lipid profile and is used in the formulation of certain dairy products to obtain the planned technological and nutritional parameters. Diagnosis of productive animals for subclinical mastitis involves the use of auxiliary (thermometry, thermography, electrical conductivity) and laboratory research methods: counting the number of somatic cells; use of specialized tests; microbiological studies of milk; biochemical studies of milk. The biochemical component in the diagnosis of subclinical forms of mastitis is underestimated. An increase in body temperature implies an increase in the intensity of heat release during the oxidation of substrates, sometimes due to a decrease in the intensity of synthesis of energy-intensive compounds. There are simply no other sources of energy in the body. The situation is the same with certain parts of the metabolism, which are aimed at the development of protective reactions to the etiological factor aimed at the defeat of the breast. That is why the biochemical composition of breast secretions in the absence of clinical signs of mastitis undergoes biochemical changes and the task of scientists is to develop mechanisms for clear tracking of such changes, identification of animals with subclinical forms of mastitis and effective treatment.

MYCOTOXINS IN MILK AND DAIRY PRODUCTS

The article gives an overview of modern opinions about the ways of possible contamination of milk and dairy products by mycotoxyn. The key indicator of the presence of mycotoxins in milk  and dairy products is the level to which micromycetes affect productive livestock’s feed. Yet, mycromycetes and mycotoxines do not always occur together: some test samples can contain certain micromycetes, but no mycotoxines. Mycotoxines are synthesised by micromycetes only under certain favourable conditions. The multi-chambered stomach ecosystem of lactating cows utilises most mycotoxins occurring in food. Only a small amount of those is excreted in milk. However, some mycotoxins can bind to milk caseins. In this case, cheese and other dairy products can contain far higher amounts of mycotoxins than at  the initial stage of milk production. The paper compares the maximum permissible levels of mycotoxins in milk and in dairy products  according to the regulations of Ukraine and the EU. It presents the mycotoxins isolated from secretions of mammary glands of humans and productive animals, and describes their effect on the body’s physiology. It also provides a structural diagram of how mycotoxins contaminate milk and dairy products following the path “Animal feed – dairy products.” We suggest four-stage assessment of the risks of mycotoxin contamination of milk and dairy products: Stage I – identifying the producer of mycotoxin (molecule, metabolites in feed, milk, and dairy products). Anamnesis; Stage II – constructing a sequence diagram. Inspecting all production stages to identify the main ways  and periods of contamination, determining and describing the symptoms of contamination; Stage III – assessing how the intensity and duration of exposure to a mycotoxin and its metabolites are likely to effect on the body. Modelling the influence of mycotoxins on the body; Stage IV – assessing the risk and determining measures to eliminate or minimise it. Risk scenario forecast

THE FATTY ACIDS CONTENT IN THE LIVER OF JAPANESE QUAILS AFTER THE CHEMICAL TREATMENT OF HATCHING EGGS

The five groups of Pharaoh quail (100 animals per group) were formed to fulfill the tasks. Quails of the control group were fed by the standard mixed fodder for quail (DSTU 4687:2006). The bird of the research groups (I–IV) received the same feed, but with the addition of 20 g/t of vitamin E. We selected the hatching eggs after 4 weeks of feeding research fodders. Eggs were weighed and laid for incubation using the standard mode after pre-incubation storage of the eggs of the quails obtained in the peak of egg production for 5 days. On the 14th day of incubation, the eggs of the quails were divided into 5 groups. Treatment of eggs I, II and III of the test group was carried out on the 14th day of incubation, respectively, with solutions of 1% sodium hypochlorite 2% perchloric acid 0,5% hydrogen peroxide. Egg of control and IV experimental group were not subject to chemical treatment. The material for research was hatching eggs of quail, liver tissue of 14 daily embryos and 1-day quail. The fatty acid composition of the lipids of tissues and egg yolk was determined in this biological material. Analysis of methyl esters of LC was carried out on a Gas chromatograph Trace GC Ultra (USA) with a flame ionization detector. Identification of fatty acids was carried out using a standard Supelco 37 Component FAME Mix. Quantitative assessment of the spectrum of fatty acids of yolk lipids was carried out by the method of internal normalization, determining their percentage content. Ontogenetic differences in the fatty acid composition of tissues are established. Processing of the eggshell on the fourteenth day of incubation with H2O2 solution is accompanied by an increase in the proportion of stearic acid in the liver of the 1-day quail and a decrease in the proportion of Neukosatrienoic and pre-fatty acids. Treatment of the shell with sodium hypochlorite and HCl is accompanied by an increase in the proportion of stearic acid by 0.96–1.00 % and аrachinic acid, with a decrease in the proportion of gondoinic and eicosatrienic fatty acids. At the same time, when treating with HCl and sodium hypochlorite, the ratio of the sum of saturated to unsaturated fatty acids decreases by 3.2–7.9% (p<0.05). So, the established changes in the fatty acid composition of the liver one-day quail indicate a significant effect of the chemical treatment of the egg shell on the exchange of fatty acids in the embryonic period.

Toward an Understanding of Magnetic Displacement of Floating Diamagnetic Bodies, I: Experimental Findings

Diamagnetic objects (polymer and metallic plates and spheres, ceramic beads, and liquid marbles), floating on water, and a variety of organic liquids may be driven by a steady magnetic field of 0.1 T, registered at the water-vapor surface. Diamagnetic bodies are attracted to the magnet, when the apparent contact angle at the solid/liquid interface is obtuse and repelled from the magnet, when the angle is acute. Cold plasma-treated polyolefin rafts and spheres, demonstrating underwater floating, are repelled by a permanent magnet. Addition of a surfactant to the water, as well as cold plasma treatment of the polyolefin bodies, can turn the attraction into the repulsion. We conjecture that the observed effects are caused by the interplay of two main phenomena. The first is the gravity, which induces sliding of the particle on the deformed liquid/vapor interface (the Moses effect). The second cause is the hysteresis of the contact angle at the bodies' boundaries.