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Food which is consumed by living organisms contains many antioxidants often with different antioxidant abilities. In the case of antioxidants mixture its potential is not always an additive value of antioxidant properties of their individual ingredients. Despite the extensive research there is still no knowledge about the reasons for observing the antioxidant antagonism and synergism in mixtures. The paper is a review which contains the literature information available about the antioxidant activity of binary mixtures. The manuscript presents different examples of natural mixtures with the literature proposed explanation of the observed antioxidant effects. It also describes different factors (i.e.: applied method, mechanisms of radical neutralization, composition of reacting mixture—chemical structures of antioxidants, concentration and molecular ratio, applied solvent, treatment of sample or reaction time) which have influence on the observed antioxidant effects. Additionally, the ways of expressing of the antioxidant effects are presented.

It is acknowledged that injecting CO2 into oil reservoirs and saline aquifers for storage is a practical and affordable method for CO2 sequestration. Most CO2 produced from industrial exhaust contains impurity gases such as H2S that might impact CO2 sequestration due to competitive adsorption. This study makes a commendable effort to explore the adsorption behavior of CO2/H2S mixtures in calcite slit nanopores. Grand Canonical Monte Carlo (GCMC) simulation is employed to reveal the adsorption of CO2, H2S as well as their binary mixtures in calcite nanopores. Results show that the increase in pressure and temperature can promote and inhibit the adsorption capacity of CO2 and H2S in calcite nanopores, respectively. CO2 exhibits stronger adsorption on calcite surface than H2S. Electrostatic energy plays the dominating role in the adsorption behavior. Electrostatic energy accounts for 97.11% of the CO2-calcite interaction energy and 56.33% of the H2S-calcite interaction energy at 10 MPa and 323.15 K. The presence of H2S inhibits the CO2 adsorption in calcite nanopores due to competitive adsorption, and a higher mole fraction of H2S leads to less CO2 adsorption. The quantity of CO2 adsorbed is lessened by approximately 33% when the mole fraction of H2S reaches 0.25. CO2 molecules preferentially occupy the regions near the pore wall and H2S molecules tend to reside at the center of nanopore even when the molar ratio of CO2 is low, indicating that CO2 has an adsorption priority on the calcite surface over H2S. In addition, moisture can weaken the adsorption of both CO2 and H2S, while CO2 is more affected. More interestingly, we find that pure CO2 is more suitable to be sequestrated in the shallower formations, i.e., 500–1500 m, whereas CO2 with H2S impurity should be settled in the deeper reservoirs.

The collective properties of a binary mixture of A- and B-type self-steering particles endowed with visual perception are studied by computer simulations. Active Brownian particles (ABPs) are employed with an additional steering mechanism, which enables them to adjust their propulsion direction relative to the instantaneous positions of neighboring particles, depending on the species, either steering toward or away from them. Steering can be nonreciprocal, in particular between the A- and B-type particles. The underlying dynamical and structural properties of the system are governed by the strength and polarity of the maneuverabilities (i.e. maximum reorientation torques) associated with the vision-induced steering. The model predicts the emergence of a large variety of nonequilibrium behaviors, which we systematically characterize for all nine principal sign combinations of AA, BB, AB and BA maneuverabilites. In particular, we observe the formation of multimers, encapsulated aggregates, honeycomb lattices, and predator-prey pursuit. Notably, for a predator-prey system, the maneuverability and vision angle employed by a predator significantly impacts the spatial distribution of the surrounding prey particles. For systems with electric-charge-like interactions (i.e. like-particles repel, unlike attract) and nonstoichiometric composition (i.e. small number excess of one component), we obtain at intermediate activity levels an enhanced diffusion compared to non-steering ABPs.

This research aims to remove two phenothiazines, promazine (PRO) and promethazine (PMT), from their individual and binary mixtures using olive tree pruning biochar (BC-OTPR). The impact of individual and combinatory effects of operational variables was evaluated for the first time using central composite design (CCD). Simultaneous removal of both drugs was maximized utilizing the composite desirability function. At low concentrations, the uptake of PRO and PMT from their individual solutions was achieved with high efficiency of 98.64%, 47.20 mg/g and 95.87%, 38.16 mg/g, respectively. No major differences in the removal capacity were observed for the binary mixtures. Characterization of BC-OTPR confirmed successful adsorption and showed that the OTPR surface was predominantly mesoporous. Equilibrium investigations revealed that the Langmuir isotherm model best describes the sorption of PRO/PMT from their individual solutions with maximum adsorption capacities of 640.7 and 346.95 mg/g, respectively. The sorption of PRO/PMT conforms to the pseudo-second-order kinetic model. Regeneration of the adsorbent surface was successfully done with desorption efficiencies of 94.06% and 98.54% for PRO and PMT, respectively, for six cycles. Graphical abstract

Despite the benefits derived from the use of pharmaceuticals, these compounds are currently considered contaminants of emerging concern because of their presence and persistence in the environment. This study aimed to determine the toxicity of 27 pharmaceuticals and the interaction effects of binary mixtures of selected compounds towards two model organisms: the microcrustacean Daphnia magna and the bacterium Aliivibrio fischeri (Microtox test). Six compounds, namely polymyxin B, polymyxin E, fluoxetine, diphenhydramine, clenbuterol and ketoprofen exhibited moderate toxicity towards D. magna. Additionally, three compounds (cefotaxime, polymyxin B, polymyxin E) also showed a moderate toxic effect on A. fischeri. The comparison of such results with model estimations showed inaccuracy in the predicted data, highlighting the relevance of experimental ecotoxicological assays. The assayed mixtures contained four selected drugs of high-hazard according to their reported concentrations in wastewater and surface water (diphenhydramine, trimethoprim, ketoprofen, and fluoxetine); data revealed interactions only in the fluoxetine-containing mixtures for D. magna, while all mixtures showed interactions (mostly synergistic) for Microtox. Chronic effects on the reproduction of D. magna were observed after exposure to fluoxetine and diphenhydramine, although higher sensitivity was determined for the latter, while the mixture of these compounds (which showed acute synergy in both models) also affected the reproduction patterns. Nonetheless, all the effects described at the acute or chronic level (for individual compounds or mixtures) were determined at concentrations higher than commonly reported at environmental levels. This work provides valuable ecotoxicological information for the risk assessment of pharmaceuticals and their mixtures in the environment.

In the present work, the density, speed of sound, and refractive index of binary mixtures of propiophenone (PP) with 3-amino-1-propanol (AP), propylamine (PA), or isobutanol (IB) were measured over whole composition range at temperatures 298.15 to 308.15 K and ambient pressure (0.1 MPa). From these experimental data the excess molar volume, V m E , excess isoentropic compressibility, κ S E , and excess refractive index, n D E , were calculated. The calculated excess molar properties were correlated by Redlich–Kister equation, and their coefficients and standard deviations were calculated. The results show that the V m E values of PP + AP are positive in the entire composition range and at all temperatures, while the V m E values of PP + PA and PP + IB mixtures are negative over whole composition range and at all temperatures. The obtained V m E values were also correlated by Prigogine–Flory–Patterson (PFP) theory which show good agreement between experimental and predicted data.

The relationship between the acute toxicity and feeding deterrent activity of ten compounds occurring commonly in essential oils was explored in order to determine whether they are acute toxins or antifeedants against stored-grain pests. Simultaneously, the objective was also to demonstrate the comparative efficacy against three post-harvest stored-grain pests. Thymol, carvacrol, eugenol and trans -anethole were specifically toxic, and linalool was a generalist feeding deterrent against all three species studied. Thymol was most toxic to Tribolium castaneum and Rhyzopertha dominica compared to carvacrol and eugenol but was least toxic to Sitophilus oryzae . Similarly, linalool deterred feeding of S. oryzae (FI 50  = 0.025 mg/g of the wafer diet), T. castaneum (FI 50  = 0.207 mg/g of the wafer diet) and R. dominica (FI 50  = 0.482 mg/g of the wafer diet) at different concentrations; R. dominica beetles required about 20 times the concentration to deter feeding compared to S. oryzae and more than twice compared to T. castaneum . Comparison of toxicity and deterrent activity with respective artificial blends as binary mixtures revealed that synergism was not a generalized phenomenon, and the variations were both species as well as blend specific. Individual compound efficacy correlations were not ascertained, which suggests that artificial blends could be prepared to obtain potential mixtures for substantial control of stored-grain insect pests. The present study also implies that the compounds are mostly acute toxins, and whatever inhibition in feeding was obtained could be due to physiological toxicity rather than any interaction with gustatory receptors.

Essential oils (EOs) are plant natural products typically composed of a complex mixture of molecules, many of them recognized for their antibacterial potential. EOs have different benefits in contrast to synthetic agrochemicals, like no persistence on the environment, compatibility with classical biocontrol agents and natural enemies, and no toxicity for most non-target organisms. The aim of this work was to evaluate the antibacterial effect of lemon (Citrus limon) and orange (Citrus sinensis) EOs and their combinations with mint (Mentha x piperita) or oregano (Origanum vulgare) EOs against Streptomyces scabiei, the main causal agent of the potato common scab. The EOs were characterized by GC-MS. The antibacterial activity of citrus EOs and combinations were evaluated using the broth microdilution method and the effect of the EOs on the S. scabiei envelope was analyzed by scanning electron microscopy. The lowest EO antibacterial concentrations were obtained for the combination of lemon and mint EOs, mixed in equal quantities. The application of this combination of lemon EO on S. scabiei cultures caused cell envelope damage, causing changes in the superficial hyphae anatomy and narrowing their thickness. Additionally, orange EO efficacy was enhanced in combination with oregano EO, suggesting that this binary mixture could improve their utilization as bactericidal agents against S. scabiei. These results position citrus EOs and some of their combinations as promising sustainable alternatives for potato common scab control.

Due to the complexity of extrusion 3D printing objects and lack of universal parameters, there are few classified statistics or quantitative description for the “extrudability” of material with shear thinning properties. In order to systematically study the rheological properties of extrudable materials and establish a unified criterion or quality evaluation standard from the basic process theory, a Nishihara rheological constitutive model based on visco-elastic and visco-plastic characteristics of materials is explored to predict and investigate the extrusion performance of four typical dispersed-continuous phase binary mixture. The creep model result shows that, expect for the gelatin network-water system with almost complete elastic behavior, the material with shear thinning property based on Nishihara model is in good agreement with the experimental results. In the extrusion process, the shear stress is related to the advancing speed, material viscosity, and nozzle size. The effects of advancing speed and nozzle size on shear stress show antagonistic characteristics in a certain range; that is, the velocity gradient is the dominant factor at lower extrusion speed, and the dynamic viscosity is the dominant factor at higher extrusion speed. In terms of extrusion properties, the material system with smaller yield strain/stress has the least obvious extrusion delay characteristics, and is easier to extrude under the condition of the same material strength.

The processes that control binary mixing of two sizes of grains have been investigated theoretically and validated by comparison with experimental data. These seemingly simple experiments are difficult to carry out with the degree of precision needed to test the models. We have developed a methodology allowing porosity and permeability to be measured to within ± 4.415% and ± 4.989% (at a flow rate of 5.13 cm 3 /s) of each value, respectively. Theoretical considerations recognise mixing processes: (1) an interstitiation process whereby small grains fit between larger grains and (2) a replacement process whereby large grains replace smaller grains and the porosity associated with them. A major result of this work is that the theoretical models describing these two processes are independent of grain size and grain shape. The latter of these two findings infers that the models developed in this work are applicable to any shape of grain or type of packing, providing that a representative porosity of each size of grain pack is known independently, either experimentally or theoretically. Experimental validation has shown that the newly developed relationships for porosity described measurements of porosity for near-ideal binary mixtures extremely well, confirming that porosity is always reduced by binary mixing, and that the degree of reduction depends upon the size of the ratio between the two grain sizes. Calculation of permeability from the packing model has also been done. Six different permeability estimation methods have been used. It was found that the most accurate representations of the experimental permeability were obtained (1) when the exact RGPZ (Revil, Glover, Pezard, Zamora) method was used with the porosity mixing models developed in this work and (2) when the exact RGPZ method was used with the weighted geometric mean to calculate a representative grain size.