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Pollutants generally exist as mixtures in the environment. Their cumulative toxicity and toxicity interactions are potential risks. Therefore, this study aimed to examine the variation of joint toxicity of a multi-component mixture system, which consisted of six common quaternary ammonium salt surfactants in the environment, on Vibrio qinghaiensis sp.-Q67 (Q67). Vibrio qinghaiensis sp. -Q67 (Vqin-Q67) is a freshwater luminescent bacterium that continuously emits blue-green light (485 nm). The bacterium has been widely used for detecting toxic contaminants. In the mixture system, the luminescent toxicity of each component of the mixture to Q67 was determined by the microplate toxicity analysis method, and the toxicity interaction of the mixture was determined by the toxicity unit method (TU). The combined toxicity of the mixture system was investigated from four aspects, including the number of components, key components, concentration (toxicity) ratio, and exposure time. The results showed that the combined toxic effect of the same mixture system tends to be an additive effect with the increase of the number of components. The combined toxicity of the mixture system was close to that of the key components. Antagonism was presented in the equal toxicity mixture, while synergism was presented in the non-equal toxicity mixture. The combined toxic effect of the multi-component mixture system was not only related to the concentration of the pollutant but also related to the exposure time of the pollutant.

Essential oils (EOs) and their individual volatile organic constituents have been an inherent part of our civilization for thousands of years. They are widely used as fragrances in perfumes and cosmetics and contribute to a healthy diet, but also act as active ingredients of pharmaceutical products. Their antibacterial, antiviral, and anti-inflammatory properties have qualified EOs early on for both, the causal and symptomatic therapy of a number of diseases, but also for prevention. Obtained from natural, mostly plant materials, EOs constitute a typical example of a multicomponent mixture (more than one constituent substances, MOCS) with up to several hundreds of individual compounds, which in a sophisticated composition make up the property of a particular complete EO. The integrative use of EOs as MOCS will play a major role in human and veterinary medicine now and in the future and is already widely used in some cases, e.g. , in aromatherapy for the treatment of psychosomatic complaints, for inhalation in the treatment of respiratory diseases, or topically administered to manage adverse skin diseases. The diversity of molecules with different functionalities exhibits a broad range of multiple physical and chemical properties, which are the base of their multi-target activity as opposed to single isolated compounds. Whether and how such a broad-spectrum effect is reflected in natural mixtures and which kind of pharmacological potential they provide will be considered in the context of ONE Health in more detail in this review.

Orthoconic antiferroelectric liquid crystals (OAFLCs) represent unique self-organized materials with significant potential for applications in photonic devices due to their sub-microsecond switching times and high optical contrast in electro-optical effects. However, almost all known OALFCs suffer from low chemical stability and short helical pitch values. This paper presents the synthesis and study results of two chiral AFLCs, featuring a four-ring structure in the rigid core and high chemical stability. The mesomorphic properties of these compounds were investigated using polarizing optical microscopy and differential scanning calorimetry. Spectrometry and electro-optical studies were employed to estimate the helical pitch, tilt angle, and spontaneous polarization of the synthesized compounds and the prepared mixtures. All studied compounds exhibit enantiotropic chiral smectic mesophases including the SmA*, the SmC*, and a very broad temperature range of the SmCA* phase. Doping top-modern antiferroelectric mixture with synthesized compounds offers benefits such as increased helical pitch and tilt angle values without significantly influencing spontaneous polarization. This allows the prepared mixture to be regarded as an OAFLC with high optical contrast, characterized by an almost perfect dark state. These valuable physicochemical and optical properties suggest significant potential of studied materials for practical applications.

Natural gas is one of the most common forms of energy in our daily life, and it is composed of multicomponent hydrocarbon gas mixtures (mainly of methane, ethane and propane). It is of great significant to reveal the condensation mechanism of multicomponent mixtures for the development and utilization of natural gas. A numerical model was adopted to analyze the heat and mass transfer characteristics of propane condensation in binary and ternary gas mixtures on a vertical cold plate. Multicomponent diffusion equations and the volume of fluid method (VOF) are used to describe the in-phase and inter-phase transportation. The conditions of different wall sub-cooled temperatures (temperature difference between the wall and saturated gas mixture) and the inlet molar fraction of methane/ethane are discussed. The numerical results show that ethane gas is more likely to accumulate near the wall compared with the lighter methane gas. The thermal resistance in the gas boundary layer is one hundred times higher than that of the liquid film, revealing the importance of diffusion resistance. The heat transfer coefficients increased about 11% (at ΔT = 10 K) and 7% (at ΔT = 40 K), as the molar fraction of ethane increased from 0 to 40%. Meanwhile, the condensation heat transfer coefficient decreased by 53~56% as the wall sub-cooled temperature increased from 10 K to 40 K.

Medicinal mushrooms are multicomponent mixtures (MOCSs). They consist of a large number of individual compounds, each with different chemical structures, functions, and possible pharmacological activities. In contrast to the activity of an isolated pure substance, the effects of the individual substances in a mushroom or its extracts can influence each other; they can strengthen, weaken, or complement each other. This results in both advantages and disadvantages for the use of either a pure substance or a multicomponent mixture. The review describes the differences and challenges in the preparation, characterization, and application of complex mixtures compared to pure substances, both obtained from the same species. As an example, we use the medicinal and culinary mushroom Lentinula edodes, shiitake, and some of its isolated compounds, mainly lentinan and eritadenine.

Hydrogen is a promising energy vector; however, its storage in solid-state materials is still an unresolved problem. Hydrogen storage on Mg-based materials is an ongoing research area. Here, five materials, Mg2(Co1/3Fe1/3Ni1/3), Mg2(Cu1/3Fe1/3Ni1/3), Mg2(Co1/3Cu1/3Fe1/3), Mg2(Co1/3Cu1/3Ni1/3), and Mg2(Co1/4Cu1/4Fe1/4Ni1/4), are reported for hydrogen storage. The hydriding and dehydriding reactions in these materials proceed via two steps. The first step is associated with the Mg/MgH2 equilibrium, while the second step is related to the simultaneous formation of mixtures of hydrided Mg-intermetallics. All of the studied materials demonstrate easy hydriding in mild conditions (15 bar, 300 °C). Mg2(Co1/3Fe1/3Ni1/3) can be considered the best material among the studied series, with a hydrogen storage capacity of 3.8 wt. % and a dehydriding onset temperature of 243 °C. The presence of Cu modified the equilibrium pressure of the second hydriding step and induced partial dehydriding at 250 °C in pressure-composition isothermal testing. The presence of Fe favored the hydrogen uptake in the first hydriding reaction, from 0.5 wt. % at the material without Fe to 1.1–2.2 wt. % in the Fe materials. The elements Co, Co, Cu, and Fe demonstrated synergistic effects on hydriding/dehydriding reactions.

In many professional and industrial settings, liquid multicomponent mixtures are used as solvents, additives, coatings, biocidal products, etc. Since, in all of these examples, hazardous liquids can evaporate in the form of vapours, for risk assessments it is important to know the amount of chemicals in the surrounding air. Although several models are available in legal contexts, the current implementations seem to be unable to correctly simulate concentration changes that actually occur in volatile mixtures and in particular in thin films. In this research, the estimation of evaporation rates is based on models that take into account non-ideal behaviour of components in liquids and backpressure effects as well. The corresponding system of differential equations is solved numerically using an extended Euler algorithm that is based on a discretisation of time and space. Regarding air dispersion of volatile components, the model builds upon one-box and two-box mass balance models, because there is some evidence that these models, when selected and applied appropriately, can predict occupational exposures with sufficient precision. That way, numerical solutions for a wide variety of exposure scenarios with instantaneous and continuous/intermittent application, even considering “moving worker situations”, can be obtained. A number of example calculations have been carried out on scenarios where binary aqueous solutions of hydrogen peroxide or glutaraldehyde are applied as a biocidal product to surfaces by wiping. The results reveal that backpressure effects caused by large emission sources as well as deviations from liquid-phase ideality can influence the shape of the concentration time curves significantly. The results also provide some evidence that near-/far-field models should be used to avoid underestimation of exposure in large rooms when small/medium areas are applied. However, the near-field/far-field model should not be used to estimate peak exposure assuming instantaneous application, because then the models tend to overestimate peak exposure significantly. Although the example calculations are restricted to aqueous binary mixtures, the proposed approach is general and can be used for arbitrary liquid multicomponent mixtures, as long as backpressure effects and liquid-phase non-idealities are addressed adequately.

The article reviews the most common analytical methods for calculating the parameters of minimum reflux condition during fractionation of multicomponent mixtures, taking account of the specified separation products quality requirements. A calculation procedure that makes it possible to simplify determination of minimum reflux or vapor ratios as well as of distillate or residue compositions under minimum reflux condition compared to the known methods is proposed and described.

This work presents a model based on multilayer perceptron neural network (MLPNN) for the prediction of hydrate equilibrium conditions in hydrocarbon systems. The model heuristics are based on an extensive experimental dataset found in the open literature (consisting of 2883 data points for pure component, 993 data points binary component and 484 data points for multicomponent systems, for a wide range of temperature, compositions, and considering different equilibrium phases and presence of inhibitors). Absolute average relative deviation (AARD), mean squared error (MSE) and the regression coefficient ( R 2 ) are used as the evaluation criteria to test the efficacy and accuracy of the model’s performance. Results were validated with data points not used to develop the proposed model and found to be in close agreement. The model’s performance was also compared to well-known rigorous equilibrium models (Ng–Robinson and Colorado School of Mines models) and found superior in terms of accuracy with a AARD value as low as 0.60 MPa for the same experimental dataset. The results and comparison indicate that the proposed MLPNN model can be confidently used to predict hydrate equilibrium conditions for various hydrocarbon systems.

The problem on the optimum organization of the rectification of a multicomponent mixture in a rectifying column was considered. It is shown that, in the case where heat is supplied to the boiler of the column and is removed from its dephlegmator, the boundary of the realizable-load range of the column represents a parabola convex upwards with two characteristic parameters. The interrelation between the indicated characteristic parameters and the kinetics of the heat- and mass-transfer processes in the column, the composition of the mixture separated in it, and the mixture separation boundary selected was determined. The consequences of the possibility of parametrization of the boundary of the realizable-load range of a rectifying column are discussed. A rule for the choice of the boundary of separating a multicomponent mixture has been formulated.