[Darya]
[Yu Long]
[Amir]
[Anh]
[Mais]
[Darya]
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2 место - продано (договор 12) 3 место - продано (договор 13) Дополнительно по статье: At temperatures below 600 K, the isotherms of hydrogen absorption by Pd exhibit hysteresis loops related to the first-order phase transition or, more specifically, to separation of a diluted phase and hydride. According to the experiments, addition of even small amount of the second metal, e.g. Au or Ta, can appreciably suppress hysteresis. This interesting effect is important in various applications, e.g., in the context of fabrication of efficient hydrogen sensors. To clarify its physical background, we present statistical calculations of the hydrogen absorption isotherms for a series of binary alloys of Pd with Mg, Cu, Ag, Ta, Pt, or Au by using the values of the H-metal interaction provided by the density functional theory (DFT). Aiming at the situations with small amount (15%) of the second metal, the metal atoms in an alloy are considered to be located at random or with short-range correlations. In the random alloy approximation, appreciable suppression of hysteresis is predicted for all the additives under consideration except Cu. Concerning the correlations, we show that the tendency of metals to mixing (as, e.g., predicted for the Pd?Au or Pd?Ta alloy) is in favour of additional suppression of hysteresis whereas the tendency to segregation (as, e.g., predicted for the Pd-Ag alloy) makes the hysteresis loops wider. For Au and Ta, our findings are in good agreement with available experimental data. Ключевые слова: Absorption isotherms; Binary alloys; First-order phase transitions; Hydride; Palladium Заказать публикацию № 1 Номер заказа № 1 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 22) 3 место - продано (договор 23) 4 место - продано (договор 24) 5 место - продано (договор 25) 6 место - продано (договор 26) Дополнительно по статье: Abstract: This paper deals with the additive manufacture of magnesium alloy products of the magnesium-aluminum-manganese-zinc system by plasma surfacing with a reverse polarity current. Special attention was paid to the following points: studying the influence of evaporation of alloying elements during plasma additive surfacing on the material quality; studying the influence of surfacing modes (continuous filling and layer-by-layer filling with cooling at different thermal cycles) on the formation of structure and properties of the synthesized material; specifying the influence of the heat treatment on the structure and properties of the deposited metal. A correct selection of plasma surfacing parameters eliminates porosity and cracks in deposited layers. It is established that plasma surfacing provides a relative structural and phase stability of the previous layers under the influence of subsequent thermal cycles during the workpiece manufacture. In general, the dispersion of the structure of the deposited MA5 alloy is significantly higher than that of the cast and heat-treated metal structures produced by conventional technologies. Plasma surfacing with a reverse polarity current provides a deposited metal with high mechanical properties, i.e. a unique 5?9-fold increase in ductility compared to the cast material with an increase in ultimate strength by 7?10%, both with and without heat treatment. Ключевые слова: layered materials; magnesium alloys; plasma deposition with a reverse polarity current; properties; structure Заказать публикацию № 2 Номер заказа № 2 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 32) 3 место - продано (договор 33) 4 место - продано (договор 34) 5 место - продано (договор 35) Дополнительно по статье: Three-dimensional printed nitinol (NiTi) alloys have broad prospects for application in medicine due to their unique mechanical properties (shape memory effect and superplasticity) and the possibilities of additive technologies. However, in addition to mechanical properties, specific physicochemical characteristics of the surface are necessary for successful medical applications. In this work, a comparative study of additively manufactured (AM) NiTi samples etched in H2SO4/H2O2, HCl/H2SO4, and NH4OH/H2O2 mixtures was performed. The morphology, topography, wettability, free surface energy, and chemical composition of the surface were studied in detail. It was found that etching in H2SO4/H2O2 practically does not change the surface morphology, while HCl/H2SO4 treatment leads to the formation of a developed morphology and topography. In addition, exposure of nitinol to H2SO4/H2O2 and HCl/H2SO4 contaminated its surface with sulfur and made the surface wettability unstable in air. Etching in NH4OH/H2O2 results in surface cracking and formation of flat plates (10?20 microns) due to the dissolution of titanium, but clearly increases the hydrophilicity of the surface (values of water contact angles are 32?58?). The etch duration (30 min or 120 min) significantly affects the morphology, topography, wettability and free surface energy for the HCl/H2SO4 and NH4OH/H2O2 etched samples, but has almost no effect on surface composition. Ключевые слова: Additive manufacturing; Biomaterials; Chemical etching; Nitinol; Surfaces; Wettability Заказать публикацию № 3 Номер заказа № 3 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 42) 3 место - продано (договор 43) 4 место - продано (договор 44) 5 место - продано (договор 45) Дополнительно по статье: Alginate is a common agent used for microencapsulation; however, the formed capsule is easily damaged. Therefore, alginate requires blending with other biopolymers to reduce capsule vulnerability. Whey protein is one polymer that can be incorporated with alginate to improve microcapsule structure. In this study, three different encapsulation methods (extrusion, emulsification, and spray drying) were tested for their ability to stabilize microencapsulated Pseudomonas strain VUPF506. Extrusion and emulsification methods enhanced encapsulation efficiency by up to 80% and gave the best release patterns over two months. A greenhouse experiment using potato plants treated with alginate?whey protein microcapsules showed a decrease in Rhizoctonia disease intensity of up to 70%. This is because whey protein is rich in amino acids and can serve as a resistance induction agent for the plant. In this study, the use of CNT in the ALG?WP system increased the rooting and proliferation and reduced physiological complication. The results of this study showed that the technique used in encapsulation could have a significant effect on the efficiency and persistence of probiotic bacteria. Whole genome sequence analysis of strain VUPF506 identified it as Pseudomonas chlororaphis and revealed some genes that control pathogens. Ключевые слова: Alginate; Carbon nanotubes; Emulsification; Extrusion; Pseudomonas; Spray drying; Whey protein; Whole genome sequence Заказать публикацию № 4 Номер заказа № 4 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 52) 3 место - продано (договор 53) Дополнительно по статье: The most promising source of alumina in the 21st century is the coal fly ash (CFA) waste of coal-fired thermal plants. The methods of alumina extraction from CFA are often based on the pressure alkaline or acid leaching or preliminary roasting with different additives followed by water leaching. The efficiency of the alumina extraction from CFA under atmospheric pressure leaching is low due to the high content of acid-insoluble alumina phase mullite (3Al2O3?2SiO2). This research for the first time shows the possibility of mullite leaching under atmospheric pressure after preliminary desilication using high liquid to solid ratios (L:S ratio) and Na2O concentration. The analysis of the desilicated CFA (DCFA) chemical and phase composition before and after leaching has been carried out by inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray diffraction (XRD). The morphology and elemental composition of solid product particles has been carried out by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). An auto-mated neural network and a shrinking core model (SCM) were used to evaluate experimental data. The Al extraction efficiency from DCFA has been more than 84% at T = 120C, leaching time 60 min, the L/S ratio 20, and concentration of Na2O-400 g L1. The kinetics analysis by SCM has shown that the surface chemical reaction controls the leaching process rate at T 110C, and, at T 110C after 15 min of leaching, the process is limited by diffusion through the product layer, which can be represented by titanium compounds. According to the SEM-EDX analysis of the solid residue, the magnetite spheres and mullite acicular particles were the main phases that remained after NaOH leaching. The spheric agglomerates of mullite particles with non-porous surface have also been found. Ключевые слова: Alkaline; Coal fly ash; Kinetics; Leaching; Machine learning; Mullite; Neural network; Shrinking core model Заказать публикацию № 5 Номер заказа № 5 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 62) 3 место - продано (договор 63) 4 место - продано (договор 64) 5 место - продано (договор 65) 6 место - продано (договор 66) 7 место - продано (договор 67) Дополнительно по статье: This article dwells upon the additive manufacturing of high-energy materials (HEM) with regards to the problems of this technology?s development. This work is aimed at identifying and describing the main problems currently arising in the use of AM for nanostructured high-energy materials and gives an idea of the valuable opportunities that it provides in the hope of promoting further development in this area. Original approaches are proposed for solving one of the main problems in the production of nanostructured HEM?safety and viscosity reduction of the polymer-nanopowder system. Studies have shown an almost complete degree of deagglomeration of microencapsulated aluminum powders. Such powders have the potential to create new systems for safe 3D printing using high-energy materials. Ключевые слова: 3D printing; Additive manufacturing; High-energy materials; Thermite Заказать публикацию № 6 Номер заказа № 6 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 72) 3 место - продано (договор 73) 4 место - продано (договор 74) Дополнительно по статье: An analytical model has been developed for calculating three-dimensional transient temperature fields arising in the direct deposition process to study the thermal behavior of multi-track walls with various configurations. The model allows the calculation of all characteristics of the temperature fields (thermal cycles, cooling rates, temperature gradients) in the wall during the direct deposition process at any time. The solution of the non-stationary heat conduction equation for a moving heat source is used to determine the temperature field in the deposited wall, taking into account heat transfer to the environment. The method considers the size of the wall and the sub-strate, the change in power from layer to layer, the change in the cladding speed, the interpass dwell time (pause time), and the heat source trajectory. Experiments on the deposition of multi-track block samples are carried out, as a result of which the values of the temperatures are obtained at fixed points. The proposed model makes it possible to reproduce temperature fields at various values of the technological process parameters. It is confirmed by comparisons with experimental thermo-couple data. The relative difference in the interlayer temperature does not exceed 15%. Ключевые слова: Additive manufacturing; Analytical modeling; Direct laser deposition; Transient temperature field Заказать публикацию № 7 Номер заказа № 7 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 82) 3 место - продано (договор 83) 4 место - продано (договор 84) Дополнительно по статье: Our study clarifies the nature of the exceptional impact of the ultra-low content of silica (SiO2) units on the properties of the heterocyclic cyanate ester resin (CER) network matrix in the subnano- or nanocomposites. To this effect, we have performed a series of calculations of average distances between SiO2 units and the interfacial area values in the composites as functions of the content and size of SiO2 units. The estimates were made for the CER composites with SiO2 and POSS additives, based on these calculations and the composites previously measured structural characteristics. It was found that the aforementioned unusual effect was controlled by the constrained interfacial matrix dynamics in the composites. Thus, when (a) the SiO2 content was 0.03?0.1 wt%, (b) SiO2 units and the matrix network had covalent bonding, and (c) SiO2 units had quasi-regular distribution in the amorphous matrix (as found for the subnanocomposites), we found that distances between SiO2 units equaled 6 and 10 nm, that is, these distances were commensurable with the lengths of Kuhn segments in heterocyclic macromolecules. Ключевые слова: interfaces; nanocomposites; thermosets Заказать публикацию № 8 Номер заказа № 8 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 92) 3 место - продано (договор 93) Дополнительно по статье: Proteases are one of the most innovative products used to improve the efficiency of feed additives. Due to their hydrolytic properties, they enhance the absorption of amino acids, which can reduce the protein content and the cost of feeds. The subtilisin-like proteinase of Bacillus pumilus 3?19 is a promising candidate for industrial use as a feed additive. However, in order to obtain a high yield of the enzyme, it is necessary to develop a highly efficient expression system. The aim of the study was to obtain stable expression of the optimized B. pumilus 3?19 protease gene in the Pichia pastoris expression system and evaluate the correlation of enzyme activity with the choice of vector type and signal peptides. The efficient secretion of subtilisin-like protease into the culture fluid of the recombinant yeast strains was confirmed. The study showed that the incubation time affects the synthesis of protease in P. pastoris, and the maximum activity of the enzyme was observed at 72 h of growth of the yeast culture. Yeast strains with constructs based on the low-copy vector pPINK-LC showed higher protease activity (U/mL) in the hydrolysis of azocasein (2.63 ? 0.16 for killer signal peptide (SP), 2.49 ? 0.08 for -mating factor presequence, 2.19 ? 0.11 for lysozyme SP) than strains with constructs based on the pPINK-HC vector (1.86 ? 0.09 for killer SP, 2.21 ? 0.07 for -mating factor presequence, 1.31 ? 0.11 for lysozyme SP), regardless of which signal peptide was used. The ability of the recombinant protease to hydrolyze a specific substrate confirms that the enzyme is a member of the subtilisin family. The maximum protease activity was obtained for yeast strains with pPINK-LC-killer-aprBp (5.75 ? 0.08 U/mL) and pPINK-LC--mat.factor-aprBp (4.33 ? 0.07 U/mL) constructs. This study demonstrated that the subtilisin-like protease from recombinant P. pastoris strains exhibits proteolytic activity, which depends on the incubation time and the choice of signal peptide and vector. The production of bacillary protease by the heterologous yeast-based expression system makes this system promising for the development of new feed additives for animal husbandry. Ключевые слова: Bacillus pumilus; Feed additive; Heterological expression system; Pichia pastoris; Protease Заказать публикацию № 9 Номер заказа № 9 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 102) 3 место - продано (договор 103) 4 место - продано (договор 104) 5 место - продано (договор 105) 6 место - продано (договор 106) Дополнительно по статье: The modification of the mesoporous carbon sorbent with 3-phenylpropanoic acid was carried out in order to create preparations of complex, prolonged action, exhibiting detoxifying, antibacterial, and antifungal properties due to the applied modifier, which is capable of migrating into the solution and exhibiting its own biospecific properties. A technique was developed for fixing 3-phenylpropionic acid (PhPA) on a carbon support by its adsorption from solution. Three types of sorbents with various content of the modifier (PhPA) and the sorbent without modifier were studied. The sorption activity of new sorbents was studied using liquid-liquid extraction and gas chromatography-mass spectrometry methods on model experiments with plasma and aqueous additives of hydroxylated phenyl-containing acids (PhCAs) in various concentrations. The specific surface area was significantly changed for sorbent, modified with 1 103 mol/L of PhPA solution, and was 25% less than the area of unmodified sorbent. Potentially toxic biologically active hydroxylated PhCAs were used to create model solutions. The degrees of sorption of these compounds were close to 100%, except phenyllactic acid (over 80%). The sorbent without modifier and two sorbents with the lowest content of the modifier are considered to be more effective for the purification of the plasma from the hydroxylated PhCAs than the sorbent with the highest concentration of the modifier. Simultaneous adsorption of toxic metabolites from the bloodstream and desorption of beneficial ones can be used for a more subtle correction of the patient?s condition. Ключевые слова: 2-(4-hydroxyphenyl)acetic acid; 3-(4-hydroxyphenyl)lactic acid; 3-phenyllactic acid; 3-phenylpropionic acid; carbon sorbents; gas chromatography-mass spectrometry; Microbial metabolites; phenyl-containing acids; sepsis Заказать публикацию № 10 Номер заказа № 10 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 112) 3 место - продано (договор 113) 4 место - продано (договор 114) 5 место - продано (договор 115) Дополнительно по статье: Eco-friendly alternative binders for asphalt were studied, utilizing green bio-additives (GBA) with different compositions. These GBA were prepared using the waste of cooking oil (WCO) in different ratios ranged from 10 to 40% from the whole composite; on the other hand, the waste polymer (WP), which formed from styrene?butadiene rubber (WSBR) and waste polystyrene (WPS) in a ratio ranged from 90 to 60% from the GBA composite, was used. The optimum composition of GBA has been chosen based on the physical and curing properties, which define that the [60% WP (WSBR and WPS separately) with 40% WCO] is the optimum composite. Asphalt 60/70 (A) and 80/100 (B) were used in this study, GBA with different ratios ranged from 10 to 50% from the applied asphalt were added to prepare green alternative binder (GAB), and physical and rheological properties before and after curing were investigated. The physical properties of the GAB including penetration, softening point, penetration index and penetration temperature susceptibility before and after curing were studied. Rheological properties of pure asphalt and the prepared GAB were studied using dynamic shear rheometer. Herein, data revealed that the GAB consisting of equal proportions between WCO and WP is simulated to original asphalt in the physical and rheological properties. The results showed that in case of asphalt 60/70, when using the 40% WSBR, the softening point increased by 17.7% and penetration decreased by 15.4%, and when using the 40% WPS, the softening point increased by 24.4% and penetration decreased by 16.9%. In case of 50% GAB, when using asphalt 60/70 + 40% WPS, the softening point increased by 17.7%, while using asphalt 80/100 + 40% WPS the softening point increased by 28.9%. Additionally, these materials are a promising candidate to replacement the non-renewable asphalt binders which used in the construction of road infrastructure, with a healthy environment and reduce the cost of road construction. Ключевые слова: Asphalt; Eco-friendly; Green alternative binder; Waste oil and waste polymer Заказать публикацию № 11 Номер заказа № 11 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 122) 3 место - продано (договор 123) 4 место - продано (договор 124) 5 место - продано (договор 125) Дополнительно по статье: The growth of surface oxide films on binary aluminium alloys with transition metal (TM) Ti, Zr and Hf additives at temperatures 600 and 620? ? in air was studied using the single-wave ellipsometry method (wavelength 0.6328 ?m). It was shown that the annealing temperature affects the growth rate and extinction coefficient of surface oxide films for alloys having 5 at.% and 18 at.% TM in aluminium. Alloys with hafnium demonstrated the most active growth of oxide films during heating. A considerable increase in the extinction coefficients of oxide films was observed during oxidation of Al 18 at.% TM alloys. The optical properties of alloys (substrates) were found to correlate with their chemical composition. The aluminium alloys with 6 and 18.5 at.% Ti retain their resistance to thermal oxidation in air at the indicated temperatures. Ключевые слова: Aluminum-Hafnium alloy; Aluminum-Titanium alloy; Aluminum-Zirconium alloy; Ellipsometry; Intermetallics; Surface oxidation; Surface oxide layers Заказать публикацию № 12 Номер заказа № 12 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 132) 3 место - продано (договор 133) Дополнительно по статье: A new approach to produce biodegradable low-temperature greases, based on cellulose acetate butyrate (CAB) that dissolves in the medium of acetyl tributyl citrate (ATBC) at high temperatures and produces a gel during cooling because of phase separation, is proposed. Rheological properties of CAB solutions and gels in a wide temperature range from 80 ?C to 160 ?C were investigated with characterization of their viscoelasticity and viscoplasticity that arise because of the sol-gel transition of CAB/ATBC systems at 55 ?C. CAB gelation reduces the wear coefficient tenfold when using ATBC as a lubricant but leads to a noticeable increase in the friction coefficient. To improve tribological properties of gel greases, additives of various solid particles were used: hexagonal boron nitride, graphite, and polytetrafluoroethylene (PTFE). The introduction of 10% to 30% additives in a gel grease containing 10% CAB has shown the preference of PTFE at a concentration of 10% for improving grease tribological characteristics. Ключевые слова: Acetyl tributyl citrate; Cellulose acetate butyrate; Gel; Greases; Rheology; Tribology Заказать публикацию № 13 Номер заказа № 13 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 142) 3 место - продано (договор 143) 4 место - продано (договор 144) 5 место - продано (договор 145) Дополнительно по статье: The current work considers the effect of the low Al fraction (x = 0.01, 0.05, and 0.1) on the microstructure and phase composition of the CrFeCoNiAlx high-entropy alloy in-situ manufactured by powder bed fusion additive technique. The influence of a homogenization annealing at 1200 ?C is also presented. The presence of Al powder in the pre-mixed blend decreased the porosity in the as-built samples, while the microhardness did not change significantly. All samples with different Al content demonstrated the chemical inhomogeneity, additionally the Al volatilization was observed. The annealing homogenized the material but led to the Al-rich precipitates. Additionally, the microhardness did not drop significantly for annealed CrFeCoNiAlx samples. The fraction of annealing twins in CrFeCoNiAlx was much lower than in CrFeCoNi after annealing at 1200 ?C. According to XRD analyses, only the fcc phase was determined for all conditions. Ключевые слова: Additive manufacturing; Annealing; High-entropy alloys; In-situ alloying; Microstructure; Phase composition Заказать публикацию № 14 Номер заказа № 14 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 152) 3 место - продано (договор 153) Дополнительно по статье: This article describes the process of assimilation of additive technologies at PJSC UEC-Saturn, introduced and advanced domestic materials for various areas of additive production, the results of manufacturing critical parts of the gas turbine engine by this technology. Заказать публикацию № 15 Номер заказа № 15 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 162) 3 место - продано (договор 163) 4 место - продано (договор 164) 5 место - продано (договор 165) Дополнительно по статье: The article presents the research of adhesive properties of various polymers used in additive manufacturing by fused deposition modeling. Tensile tests of additively manufactured samples of various polymers are carried out, electro-microscopic photographs of the working area are taken before and after tests, and studies on the manufacturability of printing are performed to exclude further typical errors identified during these tests. Samples of the following polymers are studied: thermoplastic resin acrylonitrile butadiene styrene (ABS +), thermoplastic resin acrylonitrile butadiene styrene with the addition of titanium nitrite as a dye (ABS + TiN), thermoplastic resin acrylonitrile butadiene styrene with the addition of polyester inserts (ABS polylactide (PLA), polylactide based compound (PLA HP), thermoplastic polyethylene terephthalate glycol (PETG), and nylon with carbon inserts (NSC). The work reveals the advantages and disadvantages of the investigated plastics. For example, deformations occur when the part is cooled down during printing process of ABS +, and a crack could form in stress concentrators as a result of the influence of cold air flows. Заказать публикацию № 16 Номер заказа № 16 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 172) 3 место - продано (договор 173) 4 место - продано (договор 174) 5 место - продано (договор 175) Дополнительно по статье: The article deals with the development of shell-and-tube heat exchangers for the needs of power engineering, based on additive technologies, in particular, selective laser sintering technology with new configurations of heat exchange surfaces. The role of heat exchangers in microturbines, the most common units of power plants of small distributed power generation, is considered. To intensify heat transfer and increase the efficiency of microturbines, it is proposed to use various configurations of flow channels of shell-and-tube heat exchangers made on the basis of additive technologies. Mathematical modeling and experimental study of a gas medium flow in the tubes of a heat exchanger are carried out. The dependences of the coefficient of hydraulic resistance between the surface of inlet and outlet of gas from tubes of various configurations on the Reynolds number are obtained. The results of the experiment allow us to conclude that the resistance of spiral-shaped tubes is slightly higher than the resistance of tubes with three ribs. Заказать публикацию № 17 Номер заказа № 17 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 182) 3 место - продано (договор 183) 4 место - продано (договор 184) 5 место - продано (договор 185) Дополнительно по статье: A systematic study of the effect of nanoparticles of various concentrations and sizes on the rheological properties of various oil-based drilling fluids with nanoparticle additives has been carried out. The concentration of nanoparticles in drilling emulsions varied from 0.25 to 2 wt%, and the average size of nanoparticles ranged from 18 to 100 nm. As a result of numerous laboratory experiments, formulations and technology for the preparation of stable oil-based drilling fluids with additives of nanoparticles have been developed. The effect of nanoparticles on the viscosity and rheological properties of these drilling fluids has been studied. Заказать публикацию № 18 Номер заказа № 18 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 192) 3 место - продано (договор 193) Дополнительно по статье: Abstract: The effect of the fusion temperature for powder obtained by means of the electric-discharge erosive dispersion of cobalt?chromium alloy waste in alcohol exerted on the porosity, microhardness, and roughness of additive products is considered. It is noted that the increasing fusion temperature positively affects the change in the properties mentioned. Ключевые слова: additive products; cobalt?chromium alloys; electric-discharge erosive dispersion; powder; properties; temperature Заказать публикацию № 19 Номер заказа № 19 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 202) 3 место - продано (договор 203) Дополнительно по статье: Abstract: The influence of additive coloring on the electrical conductivity of CaF2 crystals of special purity grade, used in photolithography optics, has been studied for the first time. The additive coloring of fluorite crystals was performed in a reducing calcium atmosphere. A significant increase in the crystal conductivity after additive coloring is observed. The electrotransfer in additively colored CaF2 crystals is due to mobile anion vacancies; the ionic conductivity reaches 1.5 10?7 S/cm at 573 K and exceeds the intrinsic electric conductivity of the initial crystal by a factor of 2 103. Заказать публикацию № 20 Номер заказа № 20 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 212) 3 место - продано (договор 213) 4 место - продано (договор 214) 5 место - продано (договор 215) Дополнительно по статье: Abstract: Optimization of the synthesis procedure for a layer of lithium carbonate on the surface of a lithium electrode has been carried out. As a result, a number of samples without additives and with the addition of polyvinylidene fluoride were obtained. Testing in air showed that the sample with a layer of lithium carbonate doped with polyvinylidene fluoride performed better in air than samples of pure lithium and lithium coated with a layer of lithium carbonate. Possible causes of this phenomenon are described. Ключевые слова: lithium anode; lithium carbonate; lithium?air battery; polyvinylidene fluoride; protective layer Заказать публикацию № 21 Номер заказа № 21 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 222) 3 место - продано (договор 223) Дополнительно по статье: The effect of carbonaceous materials (e.g., graphite, shungite carbon, and acetylene black) on the properties of composites and coatings based on the Si?B4C?ZrB2 glass-forming system has been studied. The results of thermogravimetric and differential thermal analyzes, as well as thermal resistance tests are provided. The phase composition and surface morphology of the coatings were also studied. It is shown that the introduction of carbonaceous additives results in an increase in the vitrified surface area of the coating, thus causing an improved material resistance to high temperatures and other aggressive factors. Ключевые слова: acetylene black; boron carbide; glass-forming melt; graphite; heat resistance; heat-resistant coating; shungite; silicon; zirconium boride Заказать публикацию № 22 Номер заказа № 22 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 232) 3 место - продано (договор 233) 4 место - продано (договор 234) Дополнительно по статье: Abstract: The cold strength and low-temperature failure of 3D-printed 08?2? and 07?25?13 steels are considered. Specifically, the metals are produced by electric arc surfacing. With decrease in temperature, the impact strength of the steels falls. The impact strength is higher for samples cut along the surfacing direction than for those cut in the transverse direction. The brittle component predominates in the fracture of 08?2? steel below 40?C. By contrast, the ductile component is seen in the fracture of 07?25?13 steel at any temperature. A relationship is established between the fractal dimensionality of the fracture surface and the quantity of ductile component. Ключевые слова: 3D printing; cold strength; ductilebrittle transition; failure mechanisms; fractal dimensionality; metal fracture; steel Заказать публикацию № 23 Номер заказа № 23 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 242) 3 место - продано (договор 243) 4 место - продано (договор 244) 5 место - продано (договор 245) 6 место - продано (договор 246) Дополнительно по статье: Copper matrix composites (CMC) are frequently used in the automotive, aerospace, construction, and electrical-electronics industries. Properties such as low density, improved fatigue strength, high hardness, and high specific strength are the factors that make copper matrix composites important. The development of these factors is important for the industrial use of copper matrix composites. SiCp doped metal matrix composites have better mechanical properties than pure alloys. It is also known that Ti, B powder particle additives improve the mechanical properties of the main matrix. In this study, Cu hybrid composites reinforced with Ti?B-SiCp powders, which were not produced before, were obtained and their microstructure, density, hardness, and wear behavior were investigated. Composite materials produced by powder metallurgy method were prepared at 2?8 wt. % mixing ratios. Then each material was sintered at temperatures of 950?100-1050 ?C. Microstructural images showed homogenous distribution in the composite material. The highest relative density of 93% was obtained in the composite material with a 2% reinforcement rate at 1050 ?C. It was found that the hardness increased with the increase of the reinforcement rate up to 6 wt.% and then decreased after that. It was observed that the specific wear rate increased with the increasing reinforcement ratio. In addition, the lowest friction coefficient and wear temperature occurred at a sintering temperature of 1050 ?C. In this study, it was reported that the sinter temperature value of 1050 ?C is the optimum temperature value in terms of the tribological and mechanical performance of the materials. Ключевые слова: Copper matrix composites (CMC); Hardness; Hybrid composites; Powder metallurgy; Wear Заказать публикацию № 24 Номер заказа № 24 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 252) 3 место - продано (договор 253) 4 место - продано (договор 254) 5 место - продано (договор 255) 6 место - продано (договор 256) 7 место - продано (договор 257) Дополнительно по статье: Technology for producing alumina-periclase-carbon refractories of the brands APUK-D and APU-D is developed and implemented. Use of complex antioxidant and carbon-binding additives makes it possible to improve strength properties for these refractories after reduction firing. Pilot plant tests of the refractories developed in the lining of the working layer of steel-pouring ladles confirmed a reduction in lining wear rate compared with that of standard series periclase-carbon refractories by a factor of 1.2 ? 1.5. Ключевые слова: alumina-periclase-carbon (APC) refractories; antioxidant; carbon binder additive; lining; lining wear rate; periclase-carbon (PC) refractories; steel pouring ladle Заказать публикацию № 25 Номер заказа № 25 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 262) 3 место - продано (договор 263) 4 место - продано (договор 264) Дополнительно по статье: All-solid-state lithium-ion batteries raise the issue of high resistance at the interface between solid electrolyte and electrode materials that needs to be addressed. The article investigates the effect of a low-melting Li3 BO3 additive introduced into LiCoO2-and Li4 Ti5 O12-based composite electrodes on the interface resistance with a Li7 La3 Zr2 O12 solid electrolyte. According to DSC analysis, interaction in the studied mixtures with Li3 BO3 begins at 768 and 725 C for LiCoO2 and Li4 Ti5 O12, respectively. The resistance of half-cells with different contents of Li3 BO3 additive after heating at 700 and 720 C was studied by impedance spectroscopy in the temperature range of 25?340 C. It was established that the introduction of 5 wt% Li3 BO3 into LiCoO2 and heat treatment at 720 C led to the greatest decrease in the interface resistance from 260 to 40 cm2 at 300 C in comparison with pure LiCoO2. An SEM study demonstrated that the addition of the low-melting component to electrode mass gave better contact with ceramics. It was shown that an increase in the annealing temperature of unmodified cells with Li4 Ti5 O12 led to a decrease in the interface resistance. It was found that the interface resistance between composite anodes and solid electrolyte had lower values compared to Li4 Ti5 O12 |Li7 La3 Zr2 O12 half-cells. It was established that the resistance of cells with the Li4 Ti5 O12 /Li3 BO3 composite anode annealed at 720 C decreased from 97.2 (x = 0) to 7.0 k cm2 (x = 5 wt% Li3 BO3) at 150 C. Ключевые слова: All-solid-state lithium-ion batteries; Interface; Li4 Ti5 O12; LiCoO2; Solid electrolytes Заказать публикацию № 26 Номер заказа № 26 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 272) 3 место - продано (договор 273) Дополнительно по статье: This work aimed to study the effect of a microfibrillated cellulose additive on strength, elastic modulus, heat release, and shrinkage of mortar and concrete. The dosage of the additive varies from 0.4 to 4.5% by weight of the cement. The change in strength with an increase in the dosage of the additive occurred in a wave-like manner. The uneven character of the change in the results also took place in the determination of heat release and shrinkage. In general, heat release and shrinkage decreased at increasing additive dosage. The additive showed the greatest decrease in the heat release of concrete at a content of 2%. The heat release of concrete practically differed little from the exotherm of the standard at an additive content of 1 and 1.5%. The addition of microfibrillated cellulose additive in small (0.5%) and large (1.5%) amounts reduced shrinkage compared to the reference, and at an intermediate content (1%), the shrinkage was higher than in the reference specimens. In this case, the water evaporation rate from concrete increased with an increase in the additive. With an increase in the additive dosage, the modulus of elasticity decreases. Thus, the microfibrillated cellulose additive provides concrete with lower values of the modulus of elasticity, heat release, and shrinkage, and the additive is recommended for use in concretes with increased crack resistance during the hardening period. The recommended additive content is 0.5% by weight of cement. At the specified dosage, it is possible to provide the class of concrete in terms of compressive strength C35/45. Ключевые слова: Concrete; Heat release; Mortar; Nano/microfiber cellulose; Shrinkage; Strengths; Tensile modulus; Testing Заказать публикацию № 27 Номер заказа № 27 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 282) 3 место - продано (договор 283) Дополнительно по статье: Exhibiting strong optical absorption in the visible - near-infrared, plasmonic nanomaterials can be used as transducers in optical biosensing, contrast agents in bioimaging and synthesizers of photothermal therapy. Such functionalities promise their employment as functional elements in tissue engineering platforms, but such applications typically require ultraclean nanomaterials to minimize toxicity problems, which is not easy using conventional chemical synthesis routes. We recently demonstrated the possibility of fabricating ultraclean bare (ligand-free) plasmonic Au and TiN nanoparticles by ultrashort laser ablation in liquid ambient. Exempt of any toxic contaminants and exhibiting a series of imaging and therapeutic functionalities, these nanomaterials present promising objects for various biomedical applications. Here, we review our recent progress in the co-electrospinning of laser-synthesized Au and TiN nanoparticles with polymers to form functionalized matrices for tissue engineering. Заказать публикацию № 28 Номер заказа № 28 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 292) 3 место - продано (договор 293) 4 место - продано (договор 294) Дополнительно по статье: Abstract: Compositions of Russian glasses of the 18th century manufactured at state-own factories have almost not been investigated so far. This work presents the results of studies of the composition of glasses found in 2020 on the place of Lava Factories (1730?1760th). The composition of glasses was determined using complementary analytical methods: X-ray fluorescence spectrometry, energy-dispersive X-ray electron probe microanalysis, and optical spectroscopy. The general type of glasses (K2O?CaO?SiO2) was revealed and also groups of glasses corresponding to various melting formulations were distinguished. The role of various functional additives to the studied glasses is discussed. Ключевые слова: determination of the composition of silicate glasses; historical sites; optical spectroscopy; X-ray electron probe microanalysis; X-ray fluorescence spectrometry Заказать публикацию № 29 Номер заказа № 29 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |
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2 место - продано (договор 302) 3 место - продано (договор 303) Дополнительно по статье: The electrochemical synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) was first carried out in the presence of mixtures of flexible-chain and rigid-chain polyacids and their Na-salts. Earlier on with the example of polyaniline, we have shown the non-additive effect of the rigid-chain component of polyacid mixtures on the electrodeposition of polyaniline films, their morphology and spectroelectrochemical properties. In this study, we confirmed the non-additive effect and showed that such mixed PEDOT?polyelectrolyte films possess unique morphology, spectroelectro-chemical and ammonia sensing properties. The electrosynthesis was carried out in potential cycling, galvanostatic and potentiostatic regimes and monitored by in situ UV?Vis spectroscopy. UV?Vis spectroelectrochemistry of the obtained PEDOT?polyelectrolyte films revealed the dominating influence of the rigid-chain polyacid on the electronic structure of the mixed complexes. The mixed PEDOT?polyacid films demonstrated the best ammonia sensing performance (in the range of 5 to 25 ppm) as compared to the films of individual PEDOT?polyelectrolyte films. Ключевые слова: Ammonia sensor; Electropolymerization; PEDOT; Polyelectrolyte; Spectroelectrochemistry Заказать публикацию № 30 Номер заказа № 30 Самый быстрый и простой способ заказать или задать вопрос, написать нам: Все контакты |