Concentration Ratio Of Components Research Articles

Features of Wetting with Water Hydrophobic Powders of Methyl Silica and Composite Systems Based on it.

The phase state of heterogeneous systems prepared on the basis of mixtures of hydrophobic and hydrophilic silica and water, depending on the ratio of component concentrations, and their using as thixotropic agents has been studied. It was found that the dependence of the interfacial energy of water with the surface of the particles of the composite system made on the basis of hydrophilic and hydrophobic silica taken in the proportion of 1:1 as for the individually taken AM-1 has a bell-shaped form with peaks at h=3 and 1.5 g/g, respectively. The type of dependence is due to the complex processes involved in the formation of the composite system involving solid particles, water, and air.

Predicting the occurrence of antagonism within ternary guanidine mixture pollutants based on the concentration ratio of components

The widespread prevalence and coexistence of diverse guanidine compounds pose substantial risks of potential toxicity interactions, synergism or antagonism, to environmental organisms. This complexity presents a formidable challenge in assessing the risks associated with various pollutants. Hence, a method that is both accurate and universally applicable for predicting toxicity interactions within mixtures is crucial, given the unimaginable diversity of potential combinations. A toxicity interaction prediction method (TIPM) developed in our past research was employed to predict the toxicity interaction, within guanidine compound mixtures. Here, antagonism were found in the mixtures of three guanidine compounds including chlorhexidine (CHL), metformin (MET), and chlorhexidine digluconate (CDE) by selecting Escherichia coli (E. coli) as the test organism. The antagonism in the mixture was probably due to the competitive binding of all three guanidine compounds to the anionic phosphates of E. coli cell membranes, which eventually lead to cell membrane rupture. Then, a good correlation between toxicity interactions (antagonisms) and components' concentration ratios (pis) within binary mixtures (CHL-MET, CHL-CDE, MET-CDE) was established. Based on the correlation, the TIPM was constructed and accurately predicted the antagonism in the CHL-MET-CDE ternary mixture, which once again proved the accuracy and applicability of the TIPM method. Therefore, TIPM can be suggested to identify or screen rapidly the toxicity interaction within ternary mixtures exerting potentially adverse effects on the environment.

Optimization of Plasma Electrolytic Oxidation Technological Parameters of Deformed Aluminum Alloy D16T in Flowing Electrolyte

The prospects of plasma electrolytic oxidation (PEO) technology applied for surface hardening of aluminum alloys are substantiated. The work aims to optimize the technological process of PEO for aluminum in flowing electrolyte. The design of the equipment and the technological process of the PEO for aluminum deformed alloy D16T in flowing silicate–alkaline electrolyte have been developed. Oxide coatings were formed according to various technological parameters of the PEO process. The properties of the oxide coatings were evaluated, respectively, by measurements of coating thickness, geometric dimensions of the samples, microhardness, wear tests, and optical and scanning electron microscopy. To study the influence of the technological parameters of the PEO process of forming oxide coatings on geometrical, physical, and mechanical properties, planning of the experiment was used. According to the results of the conducted experiments, a regression equation of the second order was obtained and the response surfaces were constructed. We determined the optimal values of the technological parameters of the PEO process: component concentration ratio (Na2SiO3/KOH), current density, flow rate, and electrolyte temperature, which provide the oxide coating with minimal wear and sufficiently high physical and mechanical properties and indicators of the accuracy of the shape of the parts. The research results showed that the properties of oxide coatings mainly depend on almost all constituent modes of the PEO process. Samples with Al2O3 oxide coating were tested during dry friction according to the “ring–ring” scheme. It was established that the temperature in the friction zone of aluminum samples with an oxide coating is lower compared to steel samples without a coating, and this indicates high frictional heat resistance of the oxide coating.

Retrieval of aerosol optical depth from GF-6 wide field of view 16-m data based on deep blue algorithm

Aerosol optical depth (AOD) is an important indicator for air pollution monitoring. We obtain AOD from the GF-6 satellite, which was launched on June 2, 2018 by China. Beijing is selected as the study area. Based on the deep blue algorithm, the moderate-resolution imaging spectroradiometer surface reflectance product is used to correct and establish the surface reflectance library, and the AOD is retrieved from the GF-6 wide field of view (WFV) blue band. So, the application of the deep blue algorithm in a GF-6 WFV camera is realized. The aerosol is divided into three models: a custom model, a continental model, and an urban model in second simulation of the satellite signal in the solar spectrum model. To improve the accuracy of retrieval results, we recalculated the aerosol component concentration ratio based on GF-6 WFV data and ground observation as the custom model. The retrieval results of the three aerosol models show that the central and southern urban areas are higher than the mountainous areas in the northwest, indicating that human emission is the main source of air pollution in Beijing. The retrieval results of the custom model, continental model, and urban model are compared with the ground observation. The error of urban model retrieval is large, and the determination coefficient R2 is only 0.3671. The results of the custom model and continental model are similar. The R2 of the custom is 0.8942, which is higher than that of the continental (0.8872). We analyze the relationship between the retrieved AOD of the three aerosol models and top of atmosphere (TOA) reflectance and find that the custom AOD has the best sensitivity to TOA reflectance, whereas the urban AOD has the worst sensitivity. So, the custom aerosol model is closer to the real aerosol situation in Beijing.

Composite materials based on dispersed sodium hydrosilicate in enhanced oil recovery technologies

A gel-forming composition based on dispersed sodium hydrosilicate, an acid modifier and a polymer additive has been developed. Тhe concentration ratios of components in it allow varying within a wide range the properties of the compositions and the formed gels, ensuring the possibility of their successful use at facilities with different geological and physical conditions (type of treated collector, degree rock permeability, temperature, etc.).

Toxicological Interactions of Organophosphorus Pesticides Mixtures to Chlorella pyrenoidosa

The toxicity effects of combined pesticides pollution have potential risks to aquatic environment. To investigate the combined toxicity effects of organophosphorus pesticides (OPs) mixtures on green algae in freshwater ecosystems, five OPs, i.e. malathion (MIT), dichlorvos (DDVP), trichlorfon (TRC), dimethoate (DIT) and omethoate (OMT), were selected as the mixture components. Nine OPs binary mixture systems contained 45 mixture rays were designed by a direct equipartition ray design (EquRay) method. The growth inhibition toxicities of the five single OPs and 45 binary mixture rays to Chlorella pyrenoidosa (C. pyrenoidosa) were determined using the 96-well microplate. Combination index based on the confidence intervals method was applied to analyze the toxicological interactions in OPs binary mixtures. Taking the negative logarithm of median effective concentration (pEC50) as toxicity index, the toxicity order of five OPs was as follows: TRC > MIT > DDVP > OMT > DIT. The toxicity of single OPs to C. pyrenoidosa was affected by the electropositivity of its phosphorus. The combined toxicity of some OPs mixtures depended on component concentrations. The toxicological interactions of OPs mixtures on C. pyrenoidosa were dominated by additive action, and some mixtures presented antagonism behavior. In addition, the mixture systems with antagonism displayed additive effects at low-effect regions and showed antagonistic effects at high-effect regions. The antagonism of the mixture systems containing MIT were strengthened with the increasing of MIT concentration ratio. It was worth noting that the toxicological interactions of OPs mixtures were related to component concentration ratio. Meanwhile, the concentration-ratio-dependent interactions of OPs mixtures were not associated with their concentration-ratio-dependent toxicity.

Dendritic Cells Targeting and pH-Responsive Multi-layered Nanocomplexes for Smart Delivery of DNA Vaccines.

Specific and effective delivery of DNA vaccines into dendritic cells (DCs) to express antigens is a precondition for induction of immune responses. Construction of a new DNA vaccine delivery system with the ability of programmed gene transfection may achieve this objective. In this study, we successfully integrated dendritic lipopeptide, charge-reversible polymer, and APC-targeted material into DNA vaccine delivery system through layer-by-layer (LBL) assembly. By the means of adjusting the weight ratios and concentration ratios of components, stable complexes were formulated with a particle size of 256.8 ± 10.7nm and zeta potential of 25.1 ± 2.3mV. Moreover, this DNA vaccine delivery system could achieve specific delivery into DCs, high transfection efficiency and low cytotoxicity, holding great promise for immunotherapy.

Polymerization of styrene in the presence of carboxyl-containing polydimethylsiloxane and its mixture with oxyethylated poly(propylene glycol)

The effect of synthesis conditions, such as the phase and concentration ratios of components, on the mechanism of styrene polymerization in the presence of the water-insoluble organosilicon surfactant α,ω-bis(10-carboxydecyl)polydimethylsiloxane and its mixture with the nonionic surfactant Pluronic F-68 is studied.

Electrochromic properties of Prussian blue–polypyrrole composite films in dependence on parameters of synthetic procedure

Composite materials of Prussian blue–polypyrrole (PB/PPy) on the surface of indium tin oxide (ITO)-coated glasses were obtained via one-step chemical (redox) and one-stage electrochemical procedures in mixed solution of iron (III), hexacyanoferrate (III), and pyrrole with various concentration ratios of components in nitrate supporting electrolyte. Electrochemical stability of composite films depends on the amount of Py in synthetic solution, whereas color contrast coefficient values depend on the type of synthetic procedure. PB/PPy film electrochromic response (tested by spectroelectrochemical potentiodynamic measurements) was compared with response of both pure PB and pure PPy films. It was shown that degradation of composite films occurs due to PB component instability in Prussian white form. The highest value of color contrast coefficient and great electrochemical stability were revealed for composite films obtained via redox-synthesis procedure from solution with 0.1 mM [Fe3+ + Fe(CN)63−] and 1.0 mM Ру (PB/PPy-Ch-1:1:10 system).

Correlation analysis between formation process of SF6 decomposed components and partial discharge qualities

To obtain relationship between concentration of SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposed characteristic components (or their concentration ratio) during the formation process and partial discharge qualities and pulse repetition rate, this paper used needle-plate electrode to simulate outthrust insulation fault and conducted a serial of experiments. First, the SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition characteristic under different PD strengths is obtained. Then this paper defines average discharge qualities per second as Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SEC</sub> . It considers both apparent discharge qualities and discharge pulse repetition rate, and analyzes the relation feature between SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> decomposition characteristic (both concentration of component and their effective formation rates RRMS) and Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SEC</sub> . Besides, it proposes C(SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> )/C(SOF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) as the energy characteristic ratio (ER) to represent PD energy, and defines the effective energy characteristic ratio as (ER <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RMS</sub> ). Moreover, it achieves the inner correlation feature between Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SEC</sub> and all the characteristic component concentration, the RRMS of each characteristic component and ERRMS. The results show that: since number of C atoms from stainless steel surface and content of trace H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O and O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> in gas chamber were limited, both decomposed component concentration and component concentration ratio accords with the famous "Logistic Population Model" growth trend in ecology, which means they present "S"-curve increase with Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SEC</sub> . The proposed ER can effectively indicate the amount of PD energy and the defined ER <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RMS</sub> can objectively reveal the variance regularity of PD energy with Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SEC</sub> . Hence, the correlation mathematic formula between ER <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RMS</sub> and Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SEC</sub> is obtained and ER <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RMS</sub> can be used as the new characteristic parameter to represent PD energy. It establishes the foundation for the further fault diagnosis research.

Investigation of Microemulsion System for Transdermal Delivery of Matrine

A new O/W microemulsion system for transdermal matrine delivery was developed in order to provide clinical medication of matrine with a more convenient,reasonable and effective new form.Various factors were investigated including solubility of matrine,the skin permeability of matrine in various components, and the compatibility among surfactants, cosurfactants and oils, aiming to choose suitable surfactants, cosurfactants and oils.The pseudo-ternary phase diagrams were constructed to determine the concentration ratio of components in the microemulsion. The formulation of microemulsion was optimized by using the simplex lattice method.The optimum formulation with the highest skin permeation rate (1239.56 μg /cm2/h) consisted of 7.2% matrine,4.5% ethyl oleate- ethyl butyrate(4:1), 23 % EL-OP(1:1) ,15 % PEG-400 and water.

Competition-Based Model of Pheromone Component Ratio Detection in the Moth

For some moth species, especially those closely interrelated and sympatric, recognizing a specific pheromone component concentration ratio is essential for males to successfully locate conspecific females. We propose and determine the properties of a minimalist competition-based feed-forward neuronal model capable of detecting a certain ratio of pheromone components independently of overall concentration. This model represents an elementary recognition unit for the ratio of binary mixtures which we propose is entirely contained in the macroglomerular complex (MGC) of the male moth. A set of such units, along with projection neurons (PNs), can provide the input to higher brain centres. We found that (1) accuracy is mainly achieved by maintaining a certain ratio of connection strengths between olfactory receptor neurons (ORN) and local neurons (LN), much less by properties of the interconnections between the competing LNs proper. An exception to this rule is that it is beneficial if connections between generalist LNs (i.e. excited by either pheromone component) and specialist LNs (i.e. excited by one component only) have the same strength as the reciprocal specialist to generalist connections. (2) successful ratio recognition is achieved using latency-to-first-spike in the LN populations which, in contrast to expectations with a population rate code, leads to a broadening of responses for higher overall concentrations consistent with experimental observations. (3) when longer durations of the competition between LNs were observed it did not lead to higher recognition accuracy.

Application of principal component analysis to the extraction of pure mass spectra in chemical analysis by gas chromatography/mass spectrometry

In this work, we investigated the possibility of the purification of mass spectra of coeluted substances containing at least one characteristic value of m/z using principal component analysis. Simulated and real gas chromatographic/mass spectrometric data were analyzed. For the simulated data, the resolution of the chromatographic peaks varied from 0.075 to 0.75, and the ratio of component concentrations ranged from 0.01 to 100. Noise-free simulated data and simulated data with randomly distributed noise were considered. It was shown that the method gave satisfactory results even when the chromatographic resolution (R s ) was less than 0.05.

Modeling of the dynamics of diffusion crystal growth from a cooling magmatic melt

The process of diffusion growth of a single crystal of plagioclase (consisting of two components: albite and anorthite) from a cooling magma melt is considered. Crystallization starts when the temperature becomes lower than the melting (liquidus) temperature and occurs as a result of the diffusion of melt components to the boundary of the growing crystal. The crystallization process is simulated by solving a system of nonlinear, linked by cross terms, nonstationary diffusion equations for albite, anorthite, and residual melt in the coordinate system moving with the growing crystal boundary. The dependence of the crystal growth rate on undercooling and temperature and of its composition on temperature and pressure is taken into account. Both quantities substantially depend on the component concentration ratio in the melt on the crystal-melt interface. The competition between the diffusion and crystal growth processes and the complex dependence of these processes on the current melt and crystal compositions and the system temperature lead to a strong nonlinearity of the problem. As a result of numerical simulation, it is established that with a linear decrease in temperature the growing crystal composition changes nonmonotonically. This makes it possible to propose a novel interpretation of the crystal zoning typical of natural magmatic systems.

Sedimentation stability of mixed dispersions of kaolin and synthetic latexes

Sedimentation stability of mixed dispersions of kaolin and synthetic latexes was studied in relation to the chemical nature of the phase boundary, particle size, pH of the dispersion medium, and concentration ratio of components of the dispersed phase.

Maximum acceptable deviations from additivity in the photometric analysis of two-component mixtures by Firordt’s method

Photometric analysis of mixtures by Firordt’s method yields relative errors that do not exceed the specified limits only if the deviations from additivity at the analytical wavelengths do not exceed (in their numerical value) their own critical values (δA crit). These deviations depend on the ratio of component concentrations. By virtue of the analytical geometry technique, we derived equations for the evaluation of δA crit. These equations allow one to predict the possibility of the precise determination of two components in a mixture under investigation at one and the same set of wavelengths. The developed algorithm was verified on 40 model mixtures of organic compounds.

Predictors of Effect of Ampicillin-Sulbactam against TEM-1 β-Lactamase-Producing Escherichia coli in an In Vitro Dynamic Model: Enzyme Activity versus MIC

The clinical outcome in patients treated with ampicillin-sulbactam may not always be predictable by disc susceptibility testing or with the MIC as determined with a constant level (4 micrograms/ml) of the beta-lactamase inhibitor (MIC1). The enzyme activities (EA) and the MICs estimated at a constant ratio of ampicillin to sulbactam of 2:1 (MIC2) for 15 TEM-1 beta-lactamase-producing strains of Escherichia coli were examined as alternatives to MIC1 as predictors of the antibacterial effects of this combined drug as studied in an in vitro model which simulates ampicillin-sulbactam pharmacokinetic profiles observed in human peripheral tissues. Integral parameters describing the area under the bacterial count-time curve (AUBC), the area between the normal growth curve, and the killing curve of bacteria exposed to antibiotic (ABBC), and the second parameter expressed as a percentage of its maximal hypothetical value (ABBC/ABBCmax) were calculated. All three parameters correlated well with EA (AUBC, r = 0.93; ABBC, r = -0.88; ABBC/ABBCmax, r = -0.91) and with MIC2 (r = 0.94, -0.94, and -0.95, respectively) but not with MIC1. Both EA and MIC2 can be considered reliable predictors of the antibacterial effect of ampicillin-sulbactam in an in vitro model. These correlations suggest that in vitro kinetic-dynamic models might be useful to reexamine established susceptibility breakpoints obtained with data based on the MIC1 (MICs obtained with constant levels of beta-lactamase inhibitors). These data also suggest that quantitative determinations of bacterial beta-lactamase production and MICs based on the component concentration ratio observed in vivo might be useful predictors of the effect of ampicillin-sulbactam and other beta-lactam-inhibitor combinations.

Evidence for Two Ferryl Species in Chloroperoxidase Compound II

Using a combination of density functional calculations and Mössbauer spectroscopy, we have examined chloroperoxidase compound II (CPO-II). The Mössbauer spectrum of CPO-II suggests the presence of two distinct ferryl species in an approximately 70:30 ratio. Density functional calculations and cryogenic reduction and annealing experiments allow us to assign the major species as an Fe(IV)OH intermediate. The Mössbauer parameters of the minor component are indicative of an authentic iron(IV)oxo species, but we have found the 70:30 ratio to be pH invariant. The unchanging ratio of component concentrations is in agreement with CPO-II's visible absorption spectrum, which shows no change over the enzyme's range of pH stability.

Potentiometric p Ka determination of standard substances in binary solvent systems

A new method has been developed for the determination in binary solvent systems of acid dissociation constants of compounds (molecular acids or phenols) used as p K a standards in potentiometric measurements. In the first step, a rough p K a value of a standard is estimated from the difference in e.m.f. of equimolar solutions of acidic and basic buffer components in the binary solvent mixture and in one of the single solvents of the binary system. The p K a value of the standard substance estimated in this way provides subsequently the basis for the determination of the accurate value by using a procedure based on the ‘general’ Kostrowicki and Liwo method for the determination of equilibrium constants in solutions. By this novel method, p K a values have been determined in binary systems of acetonitrile–dimethyl sulfoxide, acetonitrile–acetone and acetonitrile–methanol for compounds frequently used as standards in potentiometric measurements (picric acid and 2,6-dinitrophenol). The solvent mixtures consisted of both polar aprotic solvents (the protophobic acetonitrile and acetone, as well as the protophilic dimethyl sulfoxide) and the amphiprotic methanol. In each of the binary solvent systems studied, similar as in individual solvents, the relationship between e.m.f. and the logarithm of the concentration ratio of components of the standardising system (tetra- n-butylammonium picrate–picric acid or tetra- n-butylammonium 2,6-dinitrophenolate–2,6-dinitrophenol) has been found to be linear, and the slope of the glass electrode characteristics was close to the theoretical Nernst value of 59.14 mV. On the other hand, a relationship between p K a of the standards and molar fraction was non-linear in all the solvent systems studied, thus revealing the absence of additivity of the p K a values in the solvent mixtures.

Polymorphism of CaCO3, precipitated in a constant‐composition environment

AbstractPolymorphism of calcium carbonate was investigated using a constant‐composition method, and three polymorphs—calcite, aragonite, and vaterite—are produced. Factors that affect the formation of polymorphs are studied over a wide range, including solution pH, temperature, concentration ratio of components, supersaturation, ionic strength, and type and concentration of additives. At room temperature, solution pH is the most significant factor, and high yield polymorphs are present at different pH values. At a high temperature, aragonite becomes the major product at a pH below 12. The effects of the additive are complicated, depending on its type and concentration as well as the operating conditions. The influence of concentration ratio and supersaturation on the formation of polymorphs is less significant, Besides, various particle morphologies of CaCO3 polymorphs are observed, depending on the operating conditions.