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Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl and Rh/Ni–MgO/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl FeCrAlloy wire mesh supported catalysts were prepared via multistep procedure. They were characterized by XRD, SEM and TEM techniques. A comparative study of autothermal reforming (ATR) of isooctane and simulated gasoline (blends of isooctane, ortho-xylene and naphthalene) over Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl and Rh/Ni–MgO/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl was performed. Both catalysts showed excellent performance in ATR of isooctane at molar ratios of O2:C = 0.51 and H2O:C = 2.59, T = 750°С and GHSV = 10000 h−1. In the ATR of isooctane – o-xylene blend in presence of Rh–Ni-containing catalyst carbon formation was observed. Rh-containing catalyst demonstrated rather good activity and stability even in the case of isooctane – o-xylene – naphthalene blend.

One of the main problems in the production of tablets, which has significant negative consequences, is the segregation of the tablet mixture leading to inhomogeneity of dosage units, material losses in the manufacturing process and improperness of the specified pharmaceutical technical characteristics of the mixture. The aim of the research. This work aims at the pharmaceutical technical study of the substances N-acetyl-D-glucosamine and Actimask® Acetaminophen and determination the uniformity of the powder mixture of active pharmaceutical ingredients (APIs) to predict the optimal technology for obtaining a pharmaceutical formulation with the acceptable properties. Materials and methods. N-acetyl-D-glucosamine (Zhejiang Candorly Pharmaceutical, China) and Actimask® Acetaminophen (SpiPharma, USA) were used. Scanning probe microscope Solver P47N-PRO ("NT-MDT", Russia), optical microscope, flowability tester VP-12A, laser diffraction particle size analyzer SALD-2201 ("Shimadzu", Japan), liquid chromatograph Agilent 1260 Infinity II with Diode Array Detector (Agilent Technologies, USA), spectrophotometers Shimadzu UV-1800 ("Shimadzu", Japan) were used. The study of API pharmaceutical technical properties (microscopic characteristics, moisture absorption capacity, flowability, bulk volume and tapped volume, particle size distribution by sieve analysis and laser diffraction), as well as vibration simulation and following chromatographic study were carried out in this work. Results and discussion. The shape of the particles N-acetyl-D-glucosamine and Actimask® Acetaminophen, which was determined by microscopic analysis, demonstrated the possibility of N-acetyl-D-glucosamine particles to stick to Actimask® Acetaminophen ones. The experimental study allowed to reveal the hygroscopicity of both APIs; poor flowability, unsatisfactory Hausner ratio, and Carr index for N-acetyl-D-glucosamine; excellent flowability, Hausner ratio, and Carr index for Actimask®. Vibration caused segregation of the powder mixture. It was found that all layers do not meet the requirements and an excessive content of Actimask® is registered, which indicates the stratification of the powder mixture. Conclusions. The physical properties of the substances were determined and found to have significant differences in their particle size distribution. Segregation of the mixture after vibration was confirmed by laser diffraction and assay analysis. In order to solve the segregation problem, the granulation of N-acetyl-D-glucosamine may be proposed.

The prospect of further use of refractory concrete based on barium-containing alumina cement was justified, with the help of a simplex-lattice method of the experiment planning, the granulometric composition of concrete was selected and its physical, mechanical and technical properties were determined, which exceed the properties of the used analogues.

Granulometric characteristics of structurally inhomogeneous materials based on full-scale mounds of a powder mixture of different fractional composition are established. Regularities of backfilling of powder particles of different shapes and sizes are revealed, and changes in the polydispersity of powder particles within each fraction are justified. It is proved that with a decrease in the average particle size of structurally inhomogeneous AlCu2 materials in a single fraction, the size spread relative to this value of other particles increases. The results of calculating the porosity of backfills with particles of various shapes (round, triangular, and square) depending on the cross-sectional area of the lobules are presented. A three-dimensional diagram is constructed that shows the relationships between the fractional composition of powder particles, their average diameter, and the degree of inhomogeneity of homogeneous bronze AlCu2.

Calculations using the example of a reinforced concrete ribbed slab have shown that if, as a result of an explosion, due to cracks that have arisen, a part of the compressed concrete layer is turned off, then even while maintaining the bearing capacity of the slab, its fire resistance is significantly reduced. It is shown that on the basis of the proposed methodology for studying the behavior of bending elements under the combined effect of "explosion-fire", it is possible to take into account the necessary parameters of reinforced concrete ribbed slabs in the design and operation of structures of hazardous operations industrial facilities. Also, the proposed technique makes it possible to predict a relatively safe amount of explosive in the technological process of an hazardous operations industrial facility, without leading to catastrophic consequences.

Features of creation of porous nanostructured oxides of transition materials on an example of niobium are considered. It has been experimentally shown that variation in anodizing modes makes it possible to obtain non-porous and porous amorphous anodic oxide films (AOF) and films of the crystalline type. It is determined that the process of AOF formation on niobium, as well as its structure and properties depend on such parameters as the type of electrolyte, anodizing voltage, activator concentration, the duration of the process. It is confirmed that the presence of an activator in the electrolyte is a necessary and decisive factor in the process of forming a nanostructured anode oxide layer. To obtain a nanostructured surface of niobium oxide, a necessary condition is the introduction of fluoride into the electrolyte, but also an important task is to determine the type of compound with which F– ions are introduced into the electrolyte. It has been experimentally determined that the optimal solution for the rapid growth of porous crystalline oxide is a solution consisting of a background electrolyte in the form of 1M H2SO4 with the addition of a fluoride ion activator in the form of 0.5M NaF. The increase in the activator accelerates the formation of the crystal structure on the surface of niobium. It is shown that higher voltage and longer anodizing time leads to an increase in the size of microcones and their number on the surface of niobium. Optimal for the formation of porous crystalline oxide is a voltage of 60 V in the electrolyte 1M H2SO4 + 0.5M NaF for 2 hours.

Laser shaping of sheet materials is a flexible process and is carried out without force contact on the material, it allows forming, among other things, brittle, elastic and difficult-to-deformed materials. It is known that the main parameters of laser shaping are the beam power, the size of the focus zone and the speed of beam movement along the surface of the workpiece, however, the range of variation of these parameters is not unlimited, but due to the characteristics of a particular equipment. Therefore, it is necessary to develop an approach to selecting processing modes that can be selected from the range available on the equipment and at the same time obtain a predictable result. There is also a need to investigate a reproducibility of laser shaping results with a lot of pass-through processing. Actually, this study is aimed at solving these issues. In particular, the article formulates a provision on complex formation parameters that allow determining interchangeable modes of laser molding processing and varying parameters in ranges available on equipment. For this, the basic processing mode was chosen, formation was carried out with a fixed number of passes, after which, using complex parameters, alternative modes were determined and formation was carried out under these conditions with the same number of passes. The article also presents the methodology and results of experimental studies of checking the interchangeability of formation modes and the repeatability of formation results during processing along parallel and multi-directional trajectories. It was experimentally found that the deviation of the strain value obtained in alternative modes, compared to the base, and did not exceed 2.46% for a three-pass cycle and 5.8% - for a nine-pass cycle. And the repeatability of the formation results during laser shaping is quite high; the discrepancy in the deformation value did not exceed 5%, and, preferably, was lower.

The operation of the TiN/HfO2/Pt bipolar memristor has been simulated by the finite elements method using the Maxwell steady state equations as a mathematical basis. The simulation provided knowledge of the effect of conductive filament thickness on the shape of the I–V curve. The conductive filament has been considered as the highly conductive Hf ion enriched HfOx phase (x < 2) whose structure is similar to a Magneli phase. In this work a mechanism has been developed describing the formation, growth and dissolution of the HfOx phase in bipolar mode of memristor operation which provides for oxygen vacancy flux control. The conductive filament has a cylindrical shape with the radius varying within 5–10 nm. An increase in the thickness of the conductive filament leads to an increase in the area of the hysteresis loop of the I–V curve due to an increase in the energy output during memristor operation. A model has been developed which allows quantitative calculations and hence can be used for the design of bipolar memristors and assessment of memristor heat loss during operation.

Calcium manganites (CaMnO3) ceramic powders were prepared by sol–gel technique using citric acid as a chelating agent. The polycrystalline powder crystallized in an orthorhombic structure with lattice parameters a = 5.270 A, b = 7.421 A and c = 5.231 A. Dielectric relaxation was observed which can be attributed to Maxwell–Wagner relaxation behavior. The oxidation states of Calcium, Manganese and the presence of oxygen deficiencies in the prepared samples were ascertained by XPS studies.

The world’s experience in using hafnium in two important parts of high-temperature thermal barrier coatings, such as the top thermal barrier layer and bond coat layer, was analyzed. In the top thermal barrier layer, hafnium is present as HfO2 completely or partially stabilized by yttria (or other rare-earth oxides). Another approach is to use hafnium dioxide as an addition to conventional coatings based on ZrO2 stabilized completely or partially. Electron-beam physical vapor deposition (EB-PVD) and air plasma spray process (APS) are most common techniques for applying thermal barrier coatings containing hafnium dioxide. Magnetron sputtering turned out to be successful as well. Compared to the 8YSZ coating, the 7.5YSH coating showed reduced Young’s modulus, 30% lower thermal conductivity (decreased to 0.5–1.1 W/(m · K)) at high temperatures for HfO2 stabilized with 27 wt.% Y2O3, and higher sintering resistance and heat resistance. Doping of ZrO2 and HfO2 by several stabilizers proved to be promising: specifically, doping by a mixture of one trivalent ion larger than Y3+ and another trivalent ion smaller than Y3+, preserving the metastable structure of the t′ phase. The importance of phase diagrams for a correct choice of the top coat composition and doping elements for the bond coat is shown. Doping the bond coat with a small amount (up to 1 wt.%) of hafnium improved its cyclic oxidation resistance and increased the adhesion of the thermally grown oxide layer to the bond coat and strength of the latter.

In the present work, cation doped hydroxyapatite (HAP) synthesized by sol-gel method. The crystal structure and crystallinity of samples confirmed by powder X-ray diffraction and roughness of prepared samples investigated through the atomic force microscopy. The changes in the dielectric with temperature and frequency are analyzed. Temperature-dependent dielectric property was studied and confirmed that the relaxation occurs with non-Debye-type relaxation. Mechanical properties such as hardness, yield strength, and flexural strength of the ion-doped HAP are studied. The significant improvements were shown in the mechanical property with ion doping for various concentrations.

This paper reports an analysis of the process of heating a graphitized hollow electrode (GHE) during steel processing in ladle-furnace. The results of the numerical modeling of electrode operation are given. The data on the temperature field of the electrode were obtained when electricity was supplied and during periods without electrical loading. Values of the Joule heat released at electrode operation during the periods of metal heating in ladle-furnace were calculated; they amounted to 1.11–1.15MW/m3. Coefficients of the heat transfer by convection have been calculated for the inner and outer GHE surface: 1.60 and 1.80, and 5–17W/(m2∙°C), respectively. Values of the electrode temperature gradient in the high-temperature zone were obtained, which, for the first heating period, reached 8,286°C/m, for the third ‒ to 6,571°C/m. It was established that during the cooling periods of the electrode, the temperature gradient is significantly reduced and amounts to the inner surface of 379°C/m; to the outer surface ‒ 3,613°C/m; the vertical plane to the end of the electrode ‒ 1,469°C/m. The directions to improve the installation’s thermal work and reduce its resource intensity during out-of-furnace processing of steel have been defined. It has been determined that during the periods of electrode operation with current supply, significant values of the temperature gradient are observed, which are concentrated in the end part. During the periods of operation without current supply, a locally overheated zone forms, taking the shape of a torus flattened along the axis, which is created as a result of the accumulation of heat from the preceding period. The data have been acquired on the effect exerted by the gas supply through a hollow electrode on the parameters of formation of the high-temperature GHE regions. It has been shown that the supply of neutral gas through a graphitized hollow electrode at a flow rate of 0.05m3/min shifts the high-temperature zone to the periphery by 3.5–4.2mm, as well as reduces its height by 1.0–1.2mm. The study reported here could make it possible to calculate expedient gas and material consumption for controlling the oxidation of metal and slag, to reduce the consumption of graphitized electrodes, to bring down energy- and resource costs for metal production

Annotation. Gauze remains the main dressing. It is used to make swabs for drying wounds and dissecting tissues. The purpose of the work is to establish the optimal density of the swab for drainage of the wound and preparation of tissues. Swabs made of 10x12 cm gauze fragments were investigated. The gauze fragments were weighed before and after immersion in water and the absorption capacity per unit dry weight was calculated. The dissecting properties of the swabs were investigated on plasticine blocks, the surface of which was pressed with a force of 12 N. The formed depressions were filled with gypsum. The volume and weight of the casts were determined. To determine the reliability of the difference between the two mean values used the reliability criterion t (Student’s test). It was found that loose swabs absorbed 913.5±43.9% of water, medium density – 766.3±55.2%, dense – 682.9±70.1 (p˂0.05). This is due to the fact that loose swabs have the largest in radius and length of the capillaries. When studying the recesses formed by embossing the swab on the surface of the block, it was found that when using loose swabs formed a deep conical recess, which indicated the risk of injury. When embossed with dry swabs of medium density received molds weighing 0.034±0.0000011 g, wet – 0.033±0.0000011 g (p>0.05). When using dense swabs – 0.037±0.0000011 g and 0.034±0.0000011 g, respectively (p˂0.05). Dense swabs showed the best dissecting properties. When wet, they are slightly but significantly reduced. Medium density swabs have slightly worse dissecting properties. When wet, they did not change significantly. We attribute the decrease in dissecting properties to the displacement of water from the gauze when pressed. Thus, loose swabs (∆M=913.5%±43.9%) absorb fluid best, which determines their predominant use for wound drying. Dense swabs are characterized by the lowest absorption capacity (682.9±70.1%), the best dissecting properties.

We report on the synthesis of 3D mesoporous fullerene/carbon hybrid materials with ordered porous structure and high surface area by mixing the solution of fullerene and sucrose molecules in the nanochannels of 3D mesoporous silica, KIT-6 via nanotemplating approach. The addition of sucrose molecules in the synthesis offers a thin layer of carbon between the fullerene molecules which enhances not only the specific surface area and the specific pore volume but also the conductivity of the hybrid materials. The prepared hybrids exhibit 3D mesoporous structure and show a much higher specific surface area than that of the pure mesoporous fullerene. The hybrids materials are used as the electrodes for supercapacitor and Li-ion battery applications. The optimised hybrid sample shows an excellent rate capability and a high specific capacitance of 254 F/g at the current density of 0.5 A/g, which is much higher than that of the pure mesoporous fullerene, mesoporous carbon, activated carbon and multiwalled carbon nanotubes. When used as the electrode for Li-ion battery, the sample delivers the largest specific capacity of 1067 mAh/g upon 50 cycles at the current density of 0.1 A/g with stability. These results reveal that the addition of carbon in the mesoporous fullerene with 3D structure makes a significant impact on the electrochemical properties of the hybrid samples, demonstrating their potential for applications in Li-ion battery and supercapacitor devices.

The results of the study into the effect of the wheat-triticale grain grinding mixture ratio on the milling and baking properties of wheat-triticale flour are presented. The flour and baking properties of the initial grain wheat-triticale grain mixture in 80 : 20, 70 : 30, 60 : 40, and 50 : 50 ratios and the control grain of wheat were determined. The milling properties of the initial grain mixtures were determined in MLP-4 laboratory mills with rifled and microrough rollers. It was found that adding triticale grain to the grinding grain mixture reduces the yield of flour from 0.5% when adding 20% triticale grain to 3.2% when adding 50% triticale grain. The addition of triticale grains to the initial grinding grain mixture has the greatest influence on the fall number of wheat-triticale flour. In this case, there is a 3.5-fold decrease in the falling number from 294 s for a control sample of wheat to 80 s in flour obtained from a grain mixture at a 50 : 50 ratio of wheat and triticale. In this case, the addition of triticale grain to the grinding mixture slightly decreases the volumetric yield of bread from 0.2 g/cm3 with a 80 : 20 ratio of wheat and triticale to 0.4 g/cm3 with a 50 : 50 ratio. The shape stability of hearth bread is reduced even less—from 0.1 when the ratio of wheat and triticale is 80 : 20 to 0.2 at a 50 : 50 ratio. The addition of triticale to the grinding grain mixture has the greatest influence on the porosity of the bread. Compared to the control sample of bread from wheat flour, the porosity of bread from wheat and triticale flour in the 80 : 20 ratio decreased by 0.6%, and it decreased by 8.2% from wheat and triticale flour in the 50 : 50 ratio.

The use of compositionally complex ZrO2-based ceramics doped with a mixture of yttrium-subgroup rare-earth metal (REM) oxides for the deposition of thermal barrier coatings (TBCs) was studied. For research, a heavy concentrate (HC) of yttrium-subgroup REM oxides, consisting of (wt.%) 13.3 Y2O3, 1.22 Tb4O7, 33.2 Dy2O3, 8.9 Ho2O3, 21.8 Er2O3, 1.86 Tm2O3, 12.5 Yb2O3, 0.57 Lu2O3, and 6.65 other oxides (including 3.2 Al2O3), and Y2O3 and M-ZrO2 powders were chosen. The targets for depositing electron-beam ceramic TBC layers—both standard and compositionally complex ones—were made of ceramic mixtures including (wt.%) M-ZrO2–7 Y2O3 and 90 M-ZrO2–10 HC. The properties of the compositionally complex and standard yttria-stabilized ZrO2-based ceramic layers in electron-beam TBCs applied in one process cycle were compared. Two-layer metal/ceramic TBCs were deposited onto model blades by directional crystallization from the ZhS-26VI alloy employing an UE-174 industrial electron-beam installation (ELTECHMACH, Vinnytsia). The ceramic M-ZrO2–7 Y2O3 topcoat was denoted as YSZ and 90 M-ZrO2–10 HC as HCSZ. The MZP-6 alloy (nickel–chromium–aluminum–yttrium) was used to form an inner heat-resistant bond coat. This resulted in rough dense glassy coatings differing by color: light-gray YSZ and dark-gray HCSZ. The coatings were 90–95 μm thick on the blade back side and 90 μm thick on the pressure side. Both coatings included the F-ZrO2 phase. Feather-like microstructures emerged in the coatings. The YSZ topcoat contained two types of dense structures, represented by columns and branched formations, and the HCSZ layer was of irregular microstructure with wide feather-like formations growth together. The laminar microstructure of the ceramic topcoat was due to the process features peculiar to electron-beam deposition. The YSZ topcoat had the following microhardness: 3884 MPa on the back side and 6052 MPa on the pressure side. The HCSZ topcoat had much lower microhardness: 1381 MPa on the back side and 1679 MPa on the pressure side. The compositionally complex coating withstood 161 thermal cycles and the standard coating 138 thermal cycles. Previous studies showed that ZrO2 stabilization with concentrates of yttrium-subgroup REM oxides was promising for the microstructural design of TBC ceramic topcoats.

The aim.To conduct the research on the choice of the basis for a mild drug with a semi-solid extract of feverfew for use in dermatology. Materials and methods.In the study of the solubility of a semi-solid extract of feverfew (SSFE) used the method of optical microscopy using a laboratory microscope “Konus Academy”. Determination of pH and homogeneity of the studied samples was performed according to the methods described in SPhU, Vol.1. The bioavailability of the model samples was investigated by diffusion in 3 % agar gel. Colloidal stability and thermal stability were determined according to the methods of GOST 29188.3-91. Measurements of rheological parameters were performed on a rotary viscometer “MYR 3000 V 2R” (Viskotech, Spain). Determination of particle distribution was performed using a laser diffraction analyzer of particle size Mastersizer 3000. Results. The best results in determining the organoleptic properties, stability and degree of release of biologically active substances (BAS) showed samples prepared on emulgel and gel bases. Structural and mechanical parameters of the samples on these bases proved the presence of a non-Newtonian type of flow with plastic and thixotropic properties. When determining the distribution of SSFE particles by optical diffraction, their smaller size was determined in the sample on an emulgel basis in comparison with the gel. Conclusions. Emulgel loaded with specific drugs has been found effective in some topical disorders, and it is emerging as potential drug delivery system in the area of dermatology. Since emu-lgel shows enhanced spreadability, adhesion, viscosity and extrusion. Based on the obtained results, an emulsion gel base was chosen as a carrier for a semi-solid drug with SSFE

Strontium hexaferrite has achieved immense attention in industries, manufacturing crucial components for devices, technological applications, and machine making due to its high coercivity value. The efficient technique of sol–gel auto-combustion was espoused for the synthesis, and the morphological studies affirmed the hexagonal shape of the particles. The magnetic analysis revealed the sample being a potential substance for perpendicular recording media applications. The dielectric studies disclosed relaxations and polarization effects existing in the material. The linkage of structural, magnetic, and dielectric properties and their inter-influences are the remarkable consequences of the research work.

Creep behaviour of Ti modified 14Cr–15Ni austenitic stainless steel (designated as D9I SS), being considered for the cladding material in Prototype Fast Breeder Reactor (PFBR), is analysed using theta (θ) projection method and with a new relation. The material D9I SS, apart from fuel cladding tubes, is also being considered as a clad wrapper tube (long hexagonal tube) of FBRs that houses the fuel clad tubes. The new methodology is found to predict the creep behaviour much better than traditional 4-θ and 6-θ approaches. Further, the minimum creep rate, time to reach various strain levels and rupture life of the alloy D9I SS (with varying Titanium contents) have also been successfully predicted using this new relation.

Nanoporous biocarbons derived from biomass have attracted significant attention owing to their great potential for energy storage and conversion and water purification. However, the fabrication technology for these materials requires high cost and corrosive activating agents such as KOH or ZnCl2 which is a huge hurdle for their potential commercialization. In this study, a low-cost synthesis strategy is introduced for the preparation of O and N functionalized nanoporous biocarbons using non-corrosive and low-cost potassium citrate as an activating agent and casein as a biomass source via a single-step solid-state procedure. The presence of O functional groups in the activating agent and a large amount of N in the biomass precursor facilitated the successful incorporation of both O and N atoms into the final nanoporous biocarbons. A series of O and N functionalized nanoporous biocarbons with tunable porosity, specific surface area, and pore volume was prepared by varying the amount of the activating agent and casein. The optimized material CPC-3, which was synthesized using a 1 : 3 ratio of casein to potassium citrate, showed a high surface area (2212 m2 g-1), a large pore volume (1.11 cm3 g-1), and an appreciable amount of surface oxygen-containing functional groups. With the advantages of excellent surface parameters and the O and N functionalities on the porous surface, the functionalized nanoporous biocarbons achieved a high CO2 adsorption capacity of 25.4 mmol g-1 at 0 °C and 30 bar and showed an impressive specific capacitance of 177 F g-1 in a three-electrode and 95 A g-1 two-electrode system at 0.5 A g-1 using 3 M KOH as an electrolyte. Interestingly, the functionalized nanoporous biocarbon with a high amount of micropores displays a CO2 adsorption capacity of 5.3 mmol g-1 at 1 bar/0 °C, which is much higher than that of the reported activated porous carbon materials and ordered mesoporous carbons. It is surmised that the reported unique fabrication approach and the multifunctionality nature of these fascinating materials offer exciting opportunities for cost-effective CO2 adsorption systems and highly efficient energy storage devices.

Current studies of ceramic topcoat materials for thermal barrier coatings (TBCs) of next generation focus mainly on ternary, quaternary, and more complex oxide systems. The use of high-entropy ZrO2-based ceramics doped with a mixture of rare-earth metal (REM) oxides for TBCs was studied, and the properties of thermal barrier ceramic layers deposited by EB-PVD in one process cycle were examined. For research, a CeO2-based REM concentrate (light concentrate (LC)) with the following composition (wt.%) was chosen: 62.4 CeO2, 13.5 La2O3, 10.9 Nd2O3, 3.9 Pr6O11, 0.92 Sm2O3, 1.2 Gd2O3, 0.24 Eu2O3, 2.66 ZrO2, 1.2 Al2O3, and 1.7SiO2; the total content of other oxides was 1.38. Targets for depositing the thermal barrier ceramic layer were produced by the ceramic synthesis method from the 85 wt.% M-ZrO2–15 wt.% LC mixture. Two-layer metal/ceramic TBCs were deposited employing the UE-174 industrial electron-beam installation operated at ELTECHMACH (Vinnytsia) onto model blades manufactured by directional crystallization from the ZhS-26VI alloy. A rough dense glossy coating was produced. The coating on the blade suction side and leading edge was 85 μm thick and on the blade pressure side was 70 μm thick. The coating phase composition represented a mixture of F-ZrO2 and M-ZrO2. Dense columnar crystallites collected into feather-like structures were observed in the ceramic layer. Vertical pores that formed between the crystallites were located perpendicularly or at an angle to the surface. A complex Al2O3-based spinel layer 2–2.5 μm thick grew between the ceramic topcoat and metallic bond coat layers. The ceramic layer acquired a laminar structure under the synergistic effect of components in the ZrO2–REM concentrate mixture in the vapor deposition process. The microstructural features of the coating determined the microhardness gradient in height. Thermal cycling experiments showed that this coating withstood 161 thermal cycles, which was higher than the standard YSZ coating did (138 thermal cycles). Previous studies showed that ZrO2 stabilization with REM oxide concentrates was promising for the microstructural design of the thermal barrier ceramic layer.

Because of exceptional properties, such-as high unique strength, excellent flexural strength, easy manufacturing and light-in-weight, aluminium alloys and composites are prominently used in the automotive, aerospace and manufacturing industries. Surface treatment appears to be of great significance for the physico-chemical characteristics of metals and alloys, even when their long-term performance has been significantly reduced by wear resistance, and dimensional stability. Laser treatment for an alloy's surface morphology becomes one of the most appropriate and efficient ways of producing accurate microstructures by quick heating and cooling methods. The effect of different input processing factors, including the laser power and scanning speed, on different composite materials such as ceramics, metals, or alloys has greater improvements on the surface morphologies when laser-treated. Delamination removal of such coatings from the substratum is often possible due to the difference in the elastic attachment of film to the substratum connected with the above processes. It is presented in this paper that, the laser treatment impact on surface properties of Al alloys and composites in detail. Besides this, the key challenges have been addressed through laser surface treatment as well as the associated consequences and trends are foreseen with this article that also concludes the directions for future research.

In this study, the preparation of organoclay filled hybrid epoxy composites and the hydrophilic, thermo-mechanical behaviour of organoclay with the incorporation of epoxy resin/unsaturated polyester (UP) was analysed. TGA results reveal that the thermal behaviour of the epoxy matrix increases when it is filled with 5% clay and toughened with 5% unsaturated polyester combined with 3% clay. From the DSC data, the maximum glass transition temperature is observed for epoxy matrix with 1% clay and toughened with 5% unsaturated polyester combined with 3% clay. The significant capacity of water repellent property using organoclay is highlighted.

The objective of this research is to develop the equipment for liquid-jet forming of women's headwear hats, which will allow expanding design assortment of these products. The equipment for cyclic liquid-jet forming of headwear hats in liquid-active working environment (LAWE) with forming element rotation was designed. The mechanism of movement and orientation of liquid -jet forming nozzle was developed, which allows influencing fabric parts by flooded and controlled liquid-jet, repeating the contour at a certain distance and with appropriate angle attack on each technological section of the part. The conducted experimental research allowed to receive semi-spherical forms of headwear hats from six fabrics suit-coat assortments, which are one of the most difficult forms of non-seam forming. Completely formed hats of a given complex configuration were obtained by liquid-jet forming, different from standard semi-spherical ones. The developed equipment provides mobility of the production from the point of view of quick equipment adaptation due to action use of flooded controlled liquid-jet and forming of a significant number of various hats contours, various combinations of technological forming modes.

Variations in the phase composition, specific surface area, and morphology of structural components in the ultrafine powder of composition (wt.%) 70 (90 ZrO2 (3 Y2O3, 2 CeO2)–10 Al2O3)–30 CoAl2O4 (70ZA30CoA), produced by hydrothermal synthesis combined with mechanical mixing, were studied in the heat treatment process up to 1300°C. The study employed Xray diffraction, scanning and transmission electron microscopy, petrography, and BET. The formation of CoAl2O4 in the 70ZA30CoA powder in the heat treatment process was accompanied by reversible phase transformations: T-ZrO2 → M-ZrO2 → T-ZrO2. The M-ZrO2 content increased from 15% to 46% in the temperature range 850–1000°C and decreased to 13% after heat treatment to 1150°C. The process involved slight coarsening of the primary T-ZrO2 particles, while the size of the primary M-ZrO2 particles remained practically unchanged. The phase transformation was due to a decrease in the free energy of the ultrafine 70ZA30CoA powder, representing a thermodynamically nonequilibrium system. The phase composition changed color of the 70ZA30CoA powder in the following sequence: gray → gray blue → dark cyan → bright blue. Morphological analysis of the structural components showed that the CoAl2O4 formation and reversible T-ZrO2 → M-ZrO2 phase transformation were accompanied by shape change, loosening, and subsequent sintering of the agglomerates. The chain-like agglomerates of various shapes and sizes indicate that the 70ZA30CoA powder sinters actively at 1300°C. The decrease in the specific surface area from 46 to 1 m2/g depending on the heat treatment temperature was determined by the development of three structural transformation processes: formation of CoAl2O4, phase transition of the ZrO2 solid solution, and sintering of the 70ZA30CoA powder. The established regularities are of fundamental importance for the microstructural design of ZrO2 composites such as ZrO2–Y2O3–CeO2–Al2O3–CoO materials of blue and other colors for various applied purposes.

This paper presents detection of defects on the tensile specimen of Al6061/SiC composite using active pulsed infrared thermography technique (APIRT) by data and image processing. APIRT is a powerful nondestructive evaluation tool for online monitoring of the real defects of composite which gives an accurate region of defects with respect to temperature variations. Al/SiC composites have high strength, high resistance to wear and low weight properties which increases their demand in many industrial applications. Thirty numbers of Al6061/SiC composite specimens were prepared by stir casting technique, out of which 20 specimens are defect-free with different compositions and the remaining with induced defect and cut, as per ASTM standard B577M-14. The APIRT experimental result shows that the Al/SiC composite tensile surface region with defect reveals higher temperature than region without defect and also cooling process proceeds longer in the region having defect. APIRT clearly shows that internal and external surface defects, defect areas with high thermal concentration, accurate defect area with high revolution, prediction of first failure location in specific region of specimen, coverage with large detection areas, size, depth of defect and material loss percentage of defect area are found with digital image processing.

Effect of content of synthetic aluminosilicates in medium-density polyethylene on the fire hazard characteristics and mechanical properties of compositions is investigated. It has been shown that during decomposition of the filler with the release of water, its effectiveness depends not only on the endothermic effect of decomposition and the content of dehydration products, but also on the correspondence of temperature of the dehydration of the filler and the temperature of intensive decomposition of the polymer. Regardless of the type of fillers, an increase in their content in polymer composite material helps to reduce combustibility. It has been shown that compositions based on epoxy oligomers or medium-density polyethylene and synthetic zeolite have properties of self-extinguish and fairly high physical and mechanical characteristics. It is shown that epoxy polymer composite material with the content of inorganic fillers 40-70 wt.% can be used for sealing building structures and other products operating at elevated temperatures, as well as in a mode where the fire resistance and heat resistance of the sealing compound are decisive. A number of efficiency of flame-suppressing of fillers is presented. Formulations of compositions based on epoxy oligomers or medium-density polyethylene whith synthetic zeolite having an optimal ratio of fire hazard and mechanical properties and not having toxic or carcinogenic effects when heated are recommended.

The problems of reducing combustibility and increasing fire resistance of some polymer building materials are considered. And the toxicity of the gaseous products of their thermal degradation was evaluated both individually and in various combinations with each other. The features of thermal degradation and the loss of mechanical properties under the influence of a flame of polymer building materials were studied. The following samples were used: water pipes based on polyethylene; Tarkett linoleum, Ondex roofing products, Rolvaplast PVC profile panels; structural panels of the company "Polygal"; facing tile based on phenol-formaldehyde oligomers. The processes occurring during pyrolysis and combustion are considered, the results of a study of the combustibility and mechanical properties of polymer building materials based on polyethylene, polyvinyl chloride, polycarbonate, phenol-formaldehyde and epoxy oligomers under the influence of a flame are presented. For the studied building polymer materials, the products of pyrolysis and combustion were studied; their ignition and self-ignition temperatures, and also the flame propagation velocity were measured. The data on the toxicity of the products of their combustion, both individually and under combined action, are summarized. Also, for the studied polymer building materials, the losses of heat resistance, toughness, and flexural strength under the influence of a flame were studied. Thermogravimetric analysis of Rolvaplast PVC panels and Poligal polycarbonate panels allowed us to determine the maximum temperatures and activation energies of the polymer decomposition process. It was concluded that if the material is recognized as non-combustible or slow-burning, it will not always be fire resistant, since its strength and thermal properties can sharply decrease already in the first seconds of flame exposure.

In this work, three systems of the composite were prepared using cured epoxy (CE), unsaturated polyester (UP), and organically changed montmorillonite (OMMT) of CE-UP, CE-OMMT, and CE-UP-OMMT which have been developed and the samples were subjected to Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). EIS shows CE-OMMT composite of sample E3M has maximized the room temperature conductivity of the composite to 3.7976 × 10−5 S/cm. The conductivity was enhanced to 7.5891 × 10−5 S/cm on the addition of 5 wt% UP in CE-OMMT. This conductivity was further enhanced to 1.1023 × 10−4 S/cm on the addition of 15 wt% of UP in CE-OMMT composite. The conductivity enhancement was found due to the long-range movement of charge carriers by folding/unfolding up of polymer chains accumulated in the composite. X-ray diffraction spectroscopy affirms the amorphous nature and FTIR proves the interaction between CE, UP, and OMMT composites. XRD and FTIR confirm the folding/unfolding up of polymer chains. Dielectric and dielectric loss tangent studies confirm the results obtained by conductivity. The SEM reveals aggregate microstructure for CE-UP-OMMT composite and provides the relevant reason for reduction in conductivity. All the outcomes are verifying that the conductivity enhancement in CE-UP-OMMT composite is due to the interaction and the newly formed bonds.

The standard material of the ceramic layer in thermal barrier coatings (TBCs)—a solid solution of ZrO2 stabilized with (6–8 wt.%) Y2O3 (YSZ)—approaches the temperature limit of its application (

The nanosized 90 mol.% ZrO2–2 mol.% Y2O3–8 mol.% CeO2 powder was produced by hydrothermal synthesis in an alkaline environment and heat-treated in the range 400–1300°C. The powder properties were examined by X-ray diffraction (XRD), SEM and TEM, petrography, and BET. According to the XRD data, a low-temperature metastable cubic ZrO2 (F-ZrO2) solid solution formed after hydrothermal synthesis. According to the petrography and electron microscopy data, TZrO2 began to form already in the hydrothermal synthesis process. The F-ZrO2 → T-ZrO2 phase transformation was completed in the range 700–850°C. Some T-ZrO2 particles were characterized by a twin substructure. The T-ZrO2 unit cell volume monotonically increased from 133.58 · 10–3 nm3 to 137.09 · 10–3 nm3 and the degree of tetragonality from 1.0033 to 1.0140. No M-ZrO2 was found to form. The powder specific surface area decreased from 94 to 2 m2/g in the heat treatment process. The sizes of primary powder particles (5–10 nm) remained almost unchanged in heat treatment up to 1150°C. The Vickers hardness of the ceramics produced from the powder treated at 850°C was 3.1 GPa and critical fracture toughness factor KIc was 8.4 MPa · m1/2. The preservation of the tetragonal structure (T-ZrO2), which is capable of the martensitic T-ZrO2 → M-ZrO2 transformation, and the strength characteristics determined open ways for microstructural design of smart materials, including shape memory ones, in the ZrO2–Y2O3–CeO2 system.

The processes of hydrogen production from various types of fossil and renewable fuels are energy-intensive multi-route chemical reactions, and for their efficient implementation it is necessary to use selective and high-performance catalysts that combine high activity, thermal conductivity, and corrosion and thermal resistance. A general strategy for the design of catalytic systems for hydrogen production is outlined; it consists in the use of composite catalysts of the “metal nanoparticles/active oxide nanoparticles/structural oxide component/structured metal support” type; an approach for their directed synthesis is described. The structured metal support provides efficient heat removal or supply for exo- or endothermic reactions, possesses good hydrodynamic characteristics, and facilitates scale transition. The structural oxide component (aluminum oxide) provides thermal and corrosion resistance and a high specific surface area of the catalytic coating, as well as performing a protective function for the metal support. The active oxide component (mainly cerium–zirconium oxides) increases resistance to carbonization due to oxygen mobility and maintains a high dispersion of the active component due to its strong metal–support interaction. Metal nanoparticles 1–2 nm in size are involved in the activation of substrate molecules. FeCrAl alloy wire meshes, formed into cylindrical blocks of specified sizes, to be used as a heat-conducting substrate. By controlled annealing with the formation of a micron α-Al2O3 layer and subsequent deposition of a η-Al2O3 layer according to the Bayer method (through aluminum hydroxide), a structural layer of η-Al2O3 with a “breathing” needle morphology was deposited onto the FeCrAl alloy surface; then the catalytic active component was deposited onto this layer by impregnation and/or deposition. The efficiency of the proposed strategy is shown for Rh/Ce0.75Zr0.25O2 – δ–η-Al2O3/FeCrAl catalysts for methane tri-reforming and Cu–CeO2 – δ/η-Al2O3/FeCrAl catalysts for dimethoxymethane steam reforming.

Additive manufacturing (AM) is used for highly complex structures that can be stable and extremely light weight. AM also enables a design-driven manufacturing process where production is determined by design. Fused deposition modelling (FDM) is one of the mainly used AM technique. It is more easily accessible technique than others and also has advantages like less time consuming, usage with broad range of materials and lower costs. It is also referred to as 3D printing in which objects are produced layer by layer from a CAD model by depositing a thermoplastic filament. Mechanical properties like tensile strength and hardness plays a vital impact when various process parameters are varied on printed parts for different application. Experimental investigation on the FDM printed parts using acrylonitrile butadiene styrene (ABS) material has been carried out by varying the three process parameters namely Infill density, Infill pattern and Layer thickness. Tensile strength and hardness are utilized as response parameters. Experiments are considered by means of central composite design (CCD) of response surface methodology (RSM). The optimization has been carried out by desirability analysis. The study reveals that that infill density and layer thickness is most significant factor.

Digital manufacturing method, in recent times has gained more interest among researchers from the academic world and manufacturing industry, as it is used to build 3D components. In additive manufacturing (AM) especially Fused Deposition Modelling (FDM) has witnessed a rapid development, is used for manufacturing parts from polymer and plastic materials straight away from a digital file. In FDM parts are made by melting, extruding and depositing layers one over the other. Part complexity does not affect the FDM fabrication but other process parameters namely infill density, layer thickness, raster angle, build orientation, air gap, etc., are taken into consideration for productivity. In this paper a study has been carried out to study the effect of infill density on the tensile strength and surface roughness of the FDM component made of Polyethylene Terephthalate Glycol (PETG) and keeping other parameters as constant. Specimens were printed as per the ASTM standard by varying the above mentioned process parameter. It has been observed that the individual process parameters have a considerable influence on the tensile strength and surface roughness of the PETG FDM fabricated parts.

It is shown based on the structural analysis by reciprocal space mapping and the experimental secondary ion mass spectrometry and transmission electron microscopy data that, along with lateral compressive stress, vertical compressive stress is induced in a multilayer epitaxial heterostructure with a metamorphic step-graded buffer. The reason for this stress is that interphase boundaries hinder complete stress removal at strain relaxation. The analysis carried out within the linear elasticity theory showed that the elastically strained state of the heterostructure layers is similar to the state arising during a two-stage deformation process (bulk and biaxial compression). It is shown that the free energy of the system in the metastable state is minimal in this case.

Here we report on the structural characterization and the hydrogen storage performance of naturally derived halloysite nanotubes (HNTs). HNTs were mined from different deposits in Australia and purified with different processes including crushing, blunging, reblunging, sedimentation and filtration. The clay materials were characterized by different techniques such as powder XRD, TGA, XPS, FTIR spectroscopy, SEM, TEM, and N₂ sorption. Characterization results revealed that they are highly porous in nature with tubular morphology and exhibited excellent thermal stability. Among the halloysite materials studied, HNT1 which is having higher halloysite content and less kaolinite exhibited hydrogen uptake of 0.5 wt.% at 1 bar and -196 °C, which is increased to 1.33 wt.% when the pressure raised to 48 bar. High hydrogen uptake was linked with the high surface area, hollow tubular aluminosilicate structure and the large interlayer spacing of the HNTs as they favour physisorption of hydrogen. It was also demonstrated that HNT1 is considered to be better material than some of the materials reported so far in terms of their cost-effectiveness and environmental safety for the hydrogen storage.

Medicated chewing gums (MCGs) represent a beneficial platform for realizing drugs intended for dental prophylaxis and treatment. The present study aimed to investigate the impact of compression force on the mechanical, textural, release, and chewing perception characteristics of compressible MCGs with the combination of lysozyme hydrochloride (LH) and ascorbic acid (AsA). Four batches of MCGs were obtained on a laboratory single-punch tablet machine applying different forces, i.e., 5, 7, 10, and 15 kN, and evaluated by their geometrical parameters, mechanical resistance, surface and internal structure characteristics, texture profile, release behavior, and perception attributes during mastication. It was found that increasing compression force slightly affected resistance to crushing and friability of MCGs, but resulted in surface smoothing and formation of a thicker layer with highly compacted particle arrangement. According to the texture analysis, increasing compression force led to harder and more adhesive gums, indicating possible difficulties in chewing and, therefore, impairment of their consumer properties. Lower compression forces were also found to be preferable in terms of better drug release from the obtained chewing gums. The volunteers’ assessment showed that an increase of compression force led to significantly raising the initial hardness and crumbliness as well as to decreasing the rate of the integral gum mass formation during mastication, which may negatively affect perceptive sensations when using MCGs. Based on the results obtained, the optimal compressing force was selected to be 7 kN, which allows obtaining MCGs with good organoleptic, mechanical, textural, and release properties.

Discovered exactly 200 years ago in 1821, thermoelectricity is nowadays of global interest as it allows to directly interconvert thermal and electrical energy via the Seebeck/Peltier effect, which could be exploited to enhance energy efficiency. In their seminal work, Mahan and Sofo mathematically derived the conditions for ’the best thermoelectric’ − a delta-distribution-shaped electronic transport function, where charge carriers contribute to transport only in an infinitely narrow energy interval. So far, however, only approximations to this concept were expected to really exist in nature. Here, we propose as a physical realisation of this scenario the Anderson transition in an impurity band, i.e. the transition from Anderson-localised to extended quantum states. We obtained a significant enhancement and dramatic change of the thermoelectric properties from p-type to n-type in the stoichiometric Heusler compound Fe2VAl, which we assign to a narrow region of delocalised electrons in the energy spectrum near the Fermi energy. We achieved this through an innovative approach of driving the Anderson transition via continuous disorder tuning: variable amounts of atomic defects are induced in a controlled fashion by thermal quenching from high temperatures (950 − 1380 °C). Based on our experimental electronic transport and magnetisation results, supported by Monte-Carlo and density functional theory calculations, we demonstrate a universal enhancement strategy towards colossal thermoelectric performance that is applicable to diverse material classes.