Mass Ratio Of Components Research Articles

Propagation gap for shear waves in binary liquids: Analytical and simulation study.

Transverse collective excitations in 50-50 and 80-20 Lennard-Jones binary liquid mixtures are studied for different mass ratio of components R at fixed numerical densities. Increasing the mass ratio results in a growing difference between frequencies of shear waves and transverse optic modes. We report an increase in the propagation gap width for shear waves with mass ratio of components and compare it to the gap width expression, known from the transverse dynamics of simple liquids. A four-variable dynamic model of transverse dynamics in binary liquids with an account of cross correlations between total-mass and mass-concentration transverse current fluctuations is solved analytically in the long-wavelength region. An equation for the propagation gap of shear waves for binary liquids is reported and analyzed.

Dyeing of Mixed Cotton and Polyester Fabrics with New Dyes—Complexes of Collagen with Transition Metal Ions

Uniform, stable, one-step dyeing of textile fabrics made from a mixture of natural and synthetic fibers using traditional methods remains problematic to this day. As an alternative to traditional methods, a one-step method for dyeing mixed cotton and polyester fabrics with a new natural dye—a complex of collagen and [Formula: see text] and [Formula: see text] ions—was proposed for the first time. Dyeing of pre-prepared cotton, polyester, and cotton–polyester fabrics is carried out by dipping in an aqueous dye solution, squeezing, drying, and heat setting. The influence of the mass ratio of dye components, fixation temperature, and pH of the solution on the degree of dye fixation was determined. A degree of sorption of dyes (14–25%) from the solution onto the surface of fabrics was established, which after heat fixation decreases slightly (1–3%). During washing processes, the copper complex is almost completely washed out from polyester and blended fabrics and remains in small quantities (2.4–3.8%) on the surface of cotton fabrics. After water washing, the degree of fixation of the collagen–chrome complex in fabrics is as follows: in cotton—8–10%, in polyester—10–12%, and in cotton–polyester—8–9%. The color coordinates of cotton and cotton–polyester fabrics hardly change before and after washing, but for polyester fabric, the changes are significant. The mechanism of interaction of the complex dye with the fibers was studied using the Fourier transform infrared method, and the morphology and distribution of the dye on the surface of the samples using the SEM-EDS method. The dye binds to cellulose through ionic and coordination bonds, and to polyester through joint melting. Therefore, unlike pure polyester fabric, cotton and cotton–polyester fabrics demonstrated high color fastness to washing and light fastness. The use of production waste, the exclusion of synthetic dyes and harmful chemicals, and single-stage dyeing of the material reduce the environmental burden.

Improving the electrical conductivity of multiwalled carbon nanotubes‐containing micromoldings via in situ construction of electrically conductive networks

AbstractMicroinjection molding (μIM) is characterized by high shearing and cooling rates, resulting in higher a degree of filler orientation which impairs the electrical conductivity (σ) of conductive filler‐containing polymer composites when compared with that of compression molding and conventional injection molding processes. In this study, polypropylene/polyamide 6/multiwalled carbon nanotubes (PP/PA6/CNT) composites were used as the model system to investigate how blending sequence, injection speed, and component mass ratios affected the morphology and σ of PP/PA6/CNT microparts. The results demonstrated that CNTs exhibited a higher affinity for the polar PA6 phase and they tended to be preferentially distributed in PA6 domains. The deformation and coalescence of CNT‐rich PA6 phase promoted the creation of an intact and continuous filler network structure along the flow direction under the influence of high shearing conditions in μIM. When the mass ratio of PP:PA6 was 70:30 and the concentration of CNT was 7 wt%, the micropart possessed the highest σ (1.2 × 10−6 S/m) when compared with their PP/CNT (4.4 × 10−9 S/m) and PA6/CNT (3.4 × 10−10 S/m) counterparts. Higher injection speeds resulted in higher degree of CNT orientation, which negatively affected the σ of subsequent moldings. This work established an approach for producing electrically conductive microparts that demonstrate promising applications in the fields of electronics, automotive, and microsystems among others.Highlights PP/PA6/CNT composites were used as model systems for microinjection molding. The electrical conductivity was improved by shear‐induced deformation of CNT‐rich phase. The properties of PP/PA6/CNT microparts were affected by process parameters.

Comparison of the Properties and Structure of Montmorillonites Modified with Polyvinylpyrrolidone

The modification method of aluminosilicate clays and the modifier content have a decisive influence on the structure and properties of the obtained nanocomposites. Therefore, the development and research of new techniques of nanoclays modification are of great importance for polymer nano-chemistry. The work studied the modification of montmorillonite (MMT) using polyvinylpyrrolidone (PVP) in an aqueous colloidal solution with the subsequent separation of three separate fractions of the solution according to the previously developed method. The influence of the initial mass ratio of components (MMT/PVP) on the structure and thermal properties of the modified MMT in each solution layer was determined. Scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal gravimetry (TG), differential scanning calorimetry (DSC), and Fourier-transform infrared (FTIR) spectroscopy were used for research. It was established that the mass ratio of components in the initial solution has almost no effect on the structure of MMT in the top and middle solution layers, but significantly affects the yield of final products. Different structures can be obtained in the bottom layer of the solution. Still, intercalated MMT was obtained exclusively at the mass ratio of MMT/PVP = 1:2. In addition, the work investigated the structure and thermal properties of modified montmorillonites with the same PVP content, and it has been proven that such composites have dissimilar structures and properties when obtained by different methods.

Physical Properties of the Young Asteroid Pair 2010 UM26 and 2010 RN221

The main belt asteroids 458271 (2010 UM26) and 2010 RN221 share almost identical orbital elements, and currently appear as comoving objects ∼30″ apart in the plane of the sky. They are products of the breakup of a parent object, or the splitting of a binary, with a separation age measured in decades rather than thousands or millions of years as for most other asteroid pairs. The nature of the precursor body and the details of the breakup and separation of the components are unknown. We obtained deep, high-resolution imaging using the Hubble Space Telescope to characterize the pair and to search for material in addition to the main components that might have been released upon breakup. The primary and secondary have absolute magnitudes H = 17.98 and 19.69, respectively, and effective diameters 760 and 350 m (assuming geometric albedo 0.20). The secondary/primary mass ratio is 0.1, assuming equal densities. Time-series photometry shows that the primary rotates with period ∼5.9 hr and has a small photometric range (0.15 mag), while the period of the secondary is undetermined (but ≳20 hr) and its lightcurve range is at least 1 mag. The primary rotation period and component mass ratio are consistent with a simple model for the breakup of a rotationally unstable precursor. However, unlike other observationally supported instances of asteroid breakup, neither macroscopic fragments nor unresolved material are found remaining in the vicinity of this asteroid pair. We suggest that the pair is a recently dissociated binary, itself formed earlier by rotational instability of 2010 UM26.

Gaia BH1: A Key for Understanding the Demography of Low-q Binaries in the Milky Way Galaxy

The recently discovered Gaia BH1 binary system, a Sun-like star and a dark object (presumably a black hole), may significantly change our understanding of the population of binaries. The paper presents the components mass ratio (q) distributions of binary systems of different observational classes. They all show a significant shortage of low-q systems. In this work, I demonstrate (quantitatively) how our ignorance extends, and point out the importance of discovering and studying systems like Gaia BH1. In addition, an approximate mass–temperature relation and mass ratio–magnitude difference relation for main-sequence stars are presented here.

Preparation and characterization of wheat gluten nanofiber films based on electrospinning and Maillard crosslinking

In the present study, composite nanofiber films were fabricated using a combination of electrospinning and Maillard crosslinking. The nanofiber films were comprised of polyvinyl alcohol/wheat gluten/glucose (PVA/WG/G) in various ratios. The determination of the optimal mass ratio of the nanofiber film components (PVA/WG = 1/4) and the proportion of glucose (20 g/hg, PWG144) was based on the physicochemical properties of the spinning solution and the analysis of scanning electron microscopy (SEM) images of the nanofiber films before and after crosslinking. Fourier transform infrared (FTIR) not only showed the presence of hydrogen bond interaction between WG and PVA, but also confirmed the occurrence of Maillard crosslinking. X-Ray Diffraction (XRD) analysis revealed that the crystal structure of the PWG144+ nanofiber films changed after Maillard crosslinking. Maillard crosslinking increased the thermal decomposition temperature and hydrophobicity of the PWG144+ nanofiber film, as well as improved its water stability and mechanical properties. This study suggests that the PWG144+ nanofiber film had the potential to be used as active food packaging after Maillard crosslinking reaction.

Thermal response of double network hydrogels with varied composition

Abstract The series of double network (DN) hydrogels, based on poly(N,N′-diethylacrylamide) (PDEAAm), polyacrylamide (PAAm), or poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) were synthesized with various mass ratios of components and their thermal response was investigated. The formation of DN structure in studied hydrogels results in significant increase in Young’s modulus. PDEAAm/PAMPS hydrogels exhibited rather high swelling ratio and consequently their temperature sensitivity was not detected. DN hydrogels PDEAAm/PAAm and PDEAAm/PDEAAm displayed thermo-responsive behavior, and the dependence of transition parameters on the feed molar concentration of acrylamide and N,N′-diethylacrylamide monomers, respectively, was determined through deswelling, NMR, and Differential scanning calorimetry (DSC) experiments. A two-state process model was employed to describe the phase transition of hydrogels. By utilizing a modified van’t Hoff equation with data from deswelling, NMR, and DSC experiments, we were able to obtain thermodynamic parameters of the transition and determine the size of the cooperative domains consisting of polymer units and water molecules.

Thermal Stabilization of Nafion with Nanocarbon Materials.

The stability of Nafion-carbon composites is important for the efficient functioning of fuel cells. The thermal decomposition of Nafion, nanostructured carbon materials, such as multi-walled carbon nanotubes, graphene-like materials, and their composites, have been studied using constant heating rate thermogravimetry in air. Materials were characterized by quantitative and qualitative analysis methods, such as thermogravimetry, X-ray photoelectron spectroscopy, scanning, and transmission electron microscopy with field emission. In Nafion-carbon composites, an increase in the thermal stability of the Nafion polymer is observed due to the formation of surface compounds at the Nafion-carbon interface. In this case, the degree of stabilization is affected by both the component composition of the composite and the structure of the nanocarbon material. The greatest effect was obtained in the case of using thermally expanded graphite (few-layer graphene). Nafion is distributed to a greater extent over the surface of the carbon material due to its high structural accessibility. The most thermally stable composite is Nafion-graphene in a mass ratio of components 1:4 with one stage Nafion degradation at 422 °C, whereas the degradation of pristine Nafion occurs in three stages at 341, 413, and 430 °C. The dependences of thermal stability and features of thermal degradation on the composition and structure of composites are discussed.

Hydrogen-bonding interaction promoted supercapacitance of polylactic acid-graphene-microcrystalline cellulose/polyaniline nanofiber

Electrospinning polylactic acid-graphene-microcrystalline cellulose/polyaniline (PLA-GN-MCC/PANI) nanofiber is fabricated as superior supercapacitor electrode material, which involves flexible substrate of PLA, conductivity additive of GN, GN dispersion additive of MCC and electroactive substance of PANI. PLA-GN-MCC is optimized as a component mass ratio of 10:0.6:1 to achieve superior interface affinity properties. The ultimate tensile strength and the elongation at break of the optimized PLA-GN-MCC are 568 kPa and 93%, better than the 496 kPa and 87% of PLA, exhibiting both superior strength and flexibility. The PLA, PLA-GN-MCC and PLA-GN-MCC/PANI keep the reduced ohmic resistance from 18.73 to 9.58 to 8.00 Ω, the dwindled charge transfer resistance from 323.2 to 181.7 to 17.8 Ω, the declined electronic band gap from 4.084 to 0.557 to 0.142 eV, the reduced Frontier molecular orbitals energy gap from 3.6505 to 0.7964 to 0.7694 eV, the increased density of states from 4.7983 to 5.7842 to 8.6671 electrons eV−1. These results indicate more feasible electron transition and highly improved electronic conductivity. The hydrogen bonding interaction between PLA-GN-MCC and PANI contributes to increasing interface affinity and decreasing total surface energy, achieving superior electrochemical capacitance increased from 2.72 to 3.72 up to 221.64 mF/cm2. Experimental measurement and simulation calculation keep consistent results, demonstrating the promise of PLA-GN-MCC/PANI nanofibers for electrochemical energy storage.

Composite Granular Fuel

Currently, the topical trend in the development of energy complexes in a number of countries is the expansion of the solid fuel use, which is largely provided by the use of various types of local renewable fuels. The latter often have high thermal properties (heat of combustion, ash content, etc.), but have low or poorly predicted physical and mechanical characteristics (strength, granulometric composition, etc.). These circumstances practically make stable and efficient operation of automation systems, mechanization of transportation of pellets, and technological processes of boilers impossible. The formation of a composite fuel with specified physical and mechanical properties provides a solution to this problem. The structure of the composite fuel based on peat, sawdust, cellulose and modifier was established at the previous stages of our work. However, in case of a given composition, the physical and mechanical characteristics depend on the operating and technological conditions for obtaining granules. In this paper, a statistical and experimental study was carried out aimed at finding rational technological conditions for granulating and drying composite fuel particles with a given mass ratio of components. To prepare fuel pellets of a given size from the initial fine-fraction components, a laboratory installation was used, the main elements of which were a Z-shaped mixer, a screw granulator, and a fixed bed dryer. The influence of independent variables on the strength and final moisture content of finished pellets of composite fuel was determined within the framework of a full factor experiment. The paper presents graphical images of response surfaces characterizing the specified influence of variable factors. The obtained regression dependences describing the influence of factors on the target properties of granules are linear in nature. The latter limits the possibility of using gradient optimization methods and creates the need to search for rational conditions, taking into account the limitations caused by the technical and economic parameters of obtaining finished fuel pellets.

High adhesive and mechanically stable SR/PU IPNs coating with dual-functional antifouling/anticorrosive performances

Silicone rubber (SR) based coatings with remarkable antifouling performances have received tremendous interests due to their prominent merits of environmental adaptability, stability, non-toxicity. However, it still remains a great challenge to fabricate SR-based antifouling coatings with both high mechanical properties for the bulk coating and high adhesion properties to substrates. Herein, a dual-functional SR-based coating with both antifouling and anticorrosive performances was developed by incorporating polyurethane (PU) chains into the SR framework to form SR/PU interpenetrating polymer networks (SR/PU IPNs), to maintain its high adhesion to metal substrate without compromising surface antifouling properties. By adjusting the mass ratio of SR and PU components, the adhesion of the SR/PU IPNs to the substrate as well as its mechanical properties can be remarkably improved. Compared with the pristine SR, the SR/PU75 IPNs possessed the optimized mechanical properties, with the increases in the Young's modulus and compression modulus, by ~312 % and ~289 % respectively. Additionally, the adhesion strength of the composite was increased by 369 %. Owing to the synergistic effect of SR/PU IPNs, the SR/PU75 IPNs realized synchronous enhancement of antifouling and anticorrosion performance. After 28-day immersion in 3.5 % NaCl solution, the SR/PU75 IPNs coating was tightly bonded with the substrate, and exhibited a maximum |Z|0.01Hz value of 1.254 × 108 Ω·cm2.This proposed dual-functional SR/PU IPNs coating may provide a novel strategy for the future development of marine instruments and equipment, where both strong mechanical performances and high antifouling/anticorrosion performances are acquired.

Unresolved Binaries and Multiples in the Intermediate Mass Range in Open Clusters: Pleiades, Alpha Per, Praesepe, and NGC 1039

In this study, we continue our project to search for unresolved binary and multiple systems in open clusters exploiting the photometric diagram (H–W2)–W1 versus W2–(BP–K) first introduced in Malofeeva et al. In particular, here we estimate the binary and multiple star ratios and the distribution of the component mass ratio q in the Galactic clusters Alpha Persei, Praesepe, and NGC 1039. We have modified the procedure outlined in our first study making star counts automatic and by introducing bootstrapping for error estimation. Basing on this, we reinvestigated the Pleiades star cluster in the same mass range as in our previous work and corrected an inaccuracy in the mass ratio q distribution. The binary and multiple star ratio in the four clusters is then found to lie between 0.45 ± 0.03 and 0.73 ± 0.03. On the other hand, the ratio of systems with multiplicity more than 2 is between 0.06 ± 0.01 and 0.09 ± 0.02. The distribution of the component mass ratio q is well fitted with a Gaussian having the mode between 0.22 ± 0.04 and 0.52 ± 0.01 and the dispersion between 0.10 ± 0.02 and 0.35 ± 0.07. All clusters show a large number of the very low-mass secondary components in the binary systems with primary components below 0.5 M ⊙.

Структура и физико-химические свойства наноструктурированного сорбционного материала на основе оксида графена, модифицированного органическими полимерами

A synthesis of a new hybrid nanostructured sorbent based on graphene oxide modified with organic polymers of biological origin, such as chitosan and lignin, were developed. The effect of different mass ratios of the initial components (graphene oxide, lignosulfonate, chitosan) on the final sorbent properties was considered as applied to the liquid-phase sorption of organic dyes and heavy metal ions. Using scanning and transmission electron microscopy, X-ray diffractometry, thermogravimetry, infrared spectroscopy and Raman spectroscopy, the resulting compositions properties were evaluated. Presumably, during the nanocomposites formation, the macromolecules of chitosan and lignosulfonate were located between the layers of graphene oxide. The materials sorption capacity from different batches was studied under static conditions using as example of the lead ions and the organic dye — methylene blue (MB), sorption. It has been established that the sorption capacity for the composition 20:1:1 was the maximum value in the considered samples line — 1849.8 mg/g for MB and 324.6 mg/g for lead ions at a sorption time of 15 min. Thus, the study showed that the synthesized nanostructured composites modified with environmentally friendly and economical additives are suitable for removing various nature pollutants from water.

Two-dimensional (PEA)2PbBr4 perovskite modified with conductive network for high-performance electromagnetic wave absorber

Two-dimensional (2D) hybrid halide perovskites have shown great potential for application in the field of electromagnetic wave (EMW) absorption thanks to their inherent high-equilibrium electron hole and electron mobility as well as enhanced water-resistance and photo-stability. However, research on the application in EMW absorption has never been reported. Here, we first design the (PEA)2PbBr4/CNTs wave-absorption system. By adjusting the component ratio, the 2D perovskite-based composite shows an excellent wave absorbing performance. The maximum effective absorption bandwidth reaches 5.12 GHz at 1.74 mm (12.28–17.40 GHz) and a minimum reflection loss of −56.88 dB at 1.90 mm, respectively, as the component mass ratio is 12:1. This outstanding performance is attributed to the combined action of multiple loss mechanisms and provide a great potential of 2D perovskite for application in EMW absorption.

Three-Dimensionally Conducting Network in Graphene-Based Composite Fibers toward Enhanced Electrochemical and Toughness Performance in Fibrous Supercapacitors

As one of the most promising energy storage devices, graphene-based fibrous supercapacitors (FSSCs) are attracting intensive attention. However, the conflict between specific capacitance and intrinsic brittleness of pure graphene fibers hinders their practical applications. Herein, we develop a strategy to fabricate graphene-based ternary composite CNT/MXene/graphene (CMG) fiber electrodes with high toughness and high electrical and electrochemical performance. These resulting properties are attributed to the three-dimensional cross-linked conducting network within graphene sheets through covalent bonding and π–π interaction among acidified carbon nanotubes, graphene sheets, and MXene, which greatly contributes to the enhanced tensile strength, toughness, and electrical transport in the CMG fiber. The CMG fiber with the optimized mass ratio of different components shows a high toughness of ∼1.7 MJ m–3 and an electrical conductivity of 420 S cm–1, which is 4- and 2-fold that of reduced graphene oxide fiber, respectively. The assembled FSSC based on the optimized CMG fiber exhibits an areal capacitance of 237 mF cm–2 and a good rate performance of 85%.

Properties of Compacts from Mixtures of Calcium Fluoride Micro- and Nanopowders

In this work, compacts from mechanical mixtures of CaF2 micron powder (MCP) with CaF2 nanopowder (NP) additives were produced, with mass ratios of the mixture components ranging from 10:0.125 to 10:1, respectively, using magnetic pulse (MP) and static pressing (SP) methods. The effects of pressure (Pp) and pressing temperature (Tp), concentration and phase composition of the additive on the density and color of compacts were studied, taking into account the properties of the initial components of the mixtures. The evolution of pulsed cathodoluminescence (PCL) spectra and photoluminescence (PL) of compacts from pure powders and their mixtures depending on Pp, Tp and characteristics of initial CaF2 NP was also studied. A new near-infrared (NIR) band associated with fluoride vacancies was discovered with a maximum at ~765 nm in PCL spectra of compacts produced by MP at a temperature of 425 °C. A blue band at 435 nm associated with impurity oxygen vacancies in the CaF2 lattice was found in PL spectra compacts of pure NP and powder mixtures. The density of compacts of pure NP and MCP reached 89% of the theoretical density, and the density of compacts of mixtures did not exceed 78%. The defective structure and phase composition of the CaF2 NP had a decisive effect on the luminescent properties of compacts from mixtures of micro- and nanopowders.

Development Of the Software Program That Can Account the Combustion, Emission and Engine Performance Values of Internal Combustion Engines

In this study, a simulation program was developed that can calculate combustion, emission and engine performance values depended on variable parameters for internal combustion engines by mathematical modelling. This simulation program was created with the Java programming language. Graphical user interface (GUI) was used in this simulation program. With the simulation program created, it can calculate many values such as in-cylinder pressure, temperature, gas amounts generated as a result of combustion, power, torque, specific fuel consumption, both in spark ignition engines and compression ignition engines. This simulation program presents the results both numerically and graphically. The calculations are obtained at every crankshaft angle at 0.25 ˚ intervals. With this simulation program, analyses were made in different excess air coefficients (0.9-1-1.1-1.2) and the effects of in-cylinder pressure, temperature, mass ratios of gas components and engine performance values were compared. According to the simulation results, as the excess air coefficient increases, the temperature and pressure values decrease. 〖CO〗_2 and NO mass ratios decrease as the excess air coefficient increases in case the excess air coefficient is greater than 1. H_2 O mass ratio increased as the excess air coefficient increased.

Research of the residual content of aromatic hydrocarbons in the composition of diesel fuel after extraction cleaning

In paper the results of luminescent studies mixture of the straight-run diesel fraction with the product secondary oil refining — light gas oil coking at a mass ratio of components of 70:30% of the masses and raffinates obtained by extraction purification of the indicated feedstock with N-methylpyrrolidone and an ionic liquid - N-methylpyrrolidoneacetate synthesized based on N- methylpyrrolidone and acetic acid have been presented. A series of studies has established a relatively high extraction ability of the ionic liquid, compared with N-methylpyrrolidone. Since under similar conditions of selective purification using the specified ionic liquid as the extractant, bicyclic aromatic hydrocarbons are almost completely removed from the composition of the test mixture of the diesel fraction. Keywords: raffinate; luminescent studies; extraction purification; UV spectral analysis; ionic liquid; N-methylpyrrolidone.

Magnetic CoNi nanoparticles-decoated Ti3C2Tx MXene as excellent electromagnetic wave absorber

Due to their unique two-dimensional layered structure and high dielectric loss, transition metal carbides (MXene) are noticed in microwave absorption. To improve the poor impedance matching and single loss mechanism of pure MXene materials, the CoNi/Ti3C2Tx composite with a particle-anchored multilayered structure was successfully fabricated. CoNi alloy particles were uniformly anchored between the Ti3C2Tx film layers. By changing the mass ratio of different components, the influence of CoNi alloy content on the microwave absorption performance of composites was explored. When the mass ratio of MXene to CoNi alloy is 1:6, the RLmin reach −42.5 dB at 8.99 GHz and the effective absorption bandwidth (RL < -10 dB) reaches 5.61 GHz. Compared with the same type of composite materials, CoNi/Ti3C2Tx possess better microwave absorption performance at low frequency. The loss mechanism of CoNi/Ti3C2Tx is systematically analyzed. The results show that CoNi/Ti3C2Tx is an absorber with excellent performance and controllable effective absorption bandwidth.