Pure Mixtures Research Articles

Application of whole-cell biosensors for analysis and improvement of L- and D-lactic acid fermentation by Lactobacillus spp. from the waste of glucose syrup production

BackgroundLactic acid is one of the most important organic acids, with various applications in the food, beverage, pharmaceutical, cosmetic, and chemical industries. Optically pure forms of L- and D-lactic acid produced via microbial fermentation play an important role in the synthesis of biodegradable polylactic acid. Alternative substrates, including by-products and residues from the agro-food industry, provide a cost-effective solution for lactic acid production and are a promising avenue for the circular economy.ResultsIn this study, the transcription factor (TF)-based whole-cell biosensor strategy was developed for the L- and D-lactic acid determination. It was cross validated with commonly used high-performance liquid chromatography and enzymatic methods. The utility of biosensors as an efficient analytical tool was demonstrated by their application for the lactic acid determination and fermentation improvement. We explored the ability of Lacticaseibacillus paracasei subsp. paracasei, Lactobacillus delbrueckii subsp. lactis, and Lactobacillus amylovorus to biosynthesize optically pure L-lactic acid, D-lactic acid or mixture of both from organic-rich residual fraction (ORRF), a waste of glucose syrup production from wheat starch. The fermentation of this complex industrial waste allowed the production of lactic acid without additional pretreatment obtaining yields from 0.5 to 0.9 Cmol/Cmol glucose.ConclusionsThis study highlights the utility of whole cell biosensors for the determination of L- and D-forms of lactic acid. The fermentation of L-lactic acid, D-lactic acid and mixture of both by L. paracasei, L. lactis, and L. amylovorus, respectively, was demonstrated using waste of glucose syrup production, the ORRF.

CO2 Dissociation in Barrier Corona Discharges: Effect of Elevated Pressures in CO2/Ar Mixtures

The formation of carbon monoxide, oxygen and ozone in a barrier corona discharge (BCD) operating in pure carbon dioxide (CO2) and binary mixtures of CO2 and argon is studied. The asymmetric electrode configuration of the BCDs allows plasma operation at pressures exceeding 1 atm, up to 6 bar, at moderate high-voltage amplitudes below 15 kV. Charge–voltage plots and an equivalent circuit model are employed to characterize the electrical parameters at different pressures and gas compositions. Depending on these conditions and the voltage amplitude, full or partial coverage of the electrodes with plasma is obtained. The existence of an optimum pressure for power dissipation for each given operation voltage amplitude and gas composition can be confirmed and explained by the equivalent circuit model. Increasing the CO2 concentration in the working gas increases the mean reduced electric field strength E/N while pressure reduces it in the BCD. The CO2 conversion shows a maximum efficiency of about 4% at 1.5 bar for the gas mixture Ar/CO2 = 1:1 and a voltage amplitude of about 10 kV. The calculation of thermodynamic equilibrium parameters reveals that a relatively small increase in pressure can affect both, the equilibrium parameters and the reaction rates. As a result, the specific required energy for the reaction (ΔH/SEI\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta \\mathrm{H}/\\mathrm{SEI}$$\\end{document}) shows an optimum, but only 8% of the electrical input energy is spent for CO2 dissociation at these optimum conditions.

Treatment of Mixture Pollutants with Combined Plasma Photocatalysis in Continuous Tubular Reactors with Atmospheric-Pressure Environment: Understanding Synergetic Effect Sources.

This study investigates the pilot-scale combination of nonthermal plasma and photocatalysis for removing Toluene and dimethyl sulfur (DMDS), examining the influence of plasma energy and initial pollutant concentration on the performance and by-product formation in both pure compounds and mixtures. The results indicate a consistent 15% synergy effect, improving Toluene conversion rates compared to single systems. Ozone reduction and enhanced CO2 selectivity were observed when combining plasma and photocatalysis. This process effectively treats pollutant mixtures, even those containing sulfur compounds. Furthermore, tests confirm nonthermal plasma's in-situ regeneration of the photocatalytic surface, providing a constant synergy effect.

High-gradient magnetic separation mechanism for separation of chalcopyrite from molybdenite

Removing molybdenite from chalcopyrite by flotation has long been a challenge due to their similar floatability as sulfide minerals. However, the difference in the magnetic susceptibility of the two minerals may be employed to address this challenge. Recently, pulsating high-gradient magnetic separation (PHGMS) has been reported effective as an environmentally friendly and economical strategy for separating chalcopyrite from molybdenite, but the mechanism of their magnetic differences is unclear. The current investigation employed crystal field theory and density functional theory calculations to theoretically elucidate the magnetic properties of these two minerals, and their difference was further demonstrated by experimental investigations. Under optimized conditions in a SLon-100 cyclic PHGMS separator, a chalcopyrite concentrate assaying 31.47% Cu and 0.44% Mo at 81.93% Cu and 5.56% Mo recoveries was produced from a pure chalcopyrite-molybdenite mixture that initially contained 26.29% Cu and 5.42% Mo. After the separation process, the Cu grade decreased to 15.06%, whereas the Mo grade increased to 16.22% in the nonmagnetic product. These findings have potential implications for the separation of chalcopyrite from molybdenite using PHGMS.

Preparation and Characterization of Carvedilol Solid Dispersion by Kneading Method

Solid dispersion using hydrophilic carrier is one of the approaches that has a potential to increase solubility, dissolution rate and consequently the oral bioavailability of poorly-water soluble drugs. In this study, class II drug "Carvedilol" (CVD) was used because of its poor solubility, it serves as a model drug that contributes to irregular dissolution and limited bioavailability. CVD: PVP K30 solid dispersion formulations SD1, SD2 and SD3 were prepared by kneading method at different weight ratios ,1:1; 1:2 and 1:4 respectively and evaluated for drug content, solubility and dissolution rate. Kneading method enhances the stability of drugs and suitable for processing thermolabile substances. The optimum solid dispersion ratio was characterized also for drug-carrier interaction by FTIR spectroscopy, and crystallinity by SEM and PXRD and compared with physical mixture and pure drug powder.
 The results showed that the solubility of carvedilol increased by increasing the proportion of PVP K30 used in the dispersion of the drug. On the other hand, dissolution study revealed a significant enhancement in the dissolution rate of the drug using solid dispersion compared to pure drug and physical mixture. X-ray diffraction of the solid dispersion suggest that the drug's transformation from crystalline to amorphous form may be responsible for the observed improvement in dissolving rate. The carvedilol solid dispersion improved the solubility and dissolution, which depend on the carrier concentration ratio. The dissolution of drugs increased with an increase in carrier content. The studies of PXRD, SEM, and FTIR revealed the amorphous nature of the drug in solid dispersion. The solid dispersion by kneading approach using PVP K30 as a carrier is a potential method for improving CVD's solubility and dissolution rate.

Development of Green HPTLC method for simultaneous determination of a promising combination Tamsulosin and Mirabegron: stability-indicating assay was examined

Recently, mirabegron has been added to tamsulosin to treat overactive bladder in men with benign prostatic hypertrophy. A Rapid, selective, sensitive, and green high-performance thin-layer chromatography (HPTLC) approach was developed for the simultaneous determination of tamsulosin (TAM) and mirabegron (MIR) in pure and laboratory-prepared mixture. Complete separation was obtained on silica gel F254 using the solvent system methanol-ethyl acetate-ammonia (3:7:0.1, v/v). Short-wave ultraviolet light at 270 nm was used to view the chromatographic bands. For MIR and TAM, the suggested technique revealed compact spots with retention factor Rf values of 0.42 and 0.63, respectively. Within concentration ranges of 0.15–7.5 µg/band and 0.05–2.5 µg/band, good linearity was observed, with mean percentage recoveries of 100.04 ± 0.56 and 99.98% ± 0.95 for MIR and TAM, respectively. Green assessment of the developed HPTLC technique was estimated using different green analytical chemistry metrics such as Analytical eco-scale Analytical GREEness (AGREE), and Green Analytical Procedure Index (GAPI) metrics. The proposed method was effectively used as a stability-indicating assay to assess the presence of MIR and TAM in the pharmaceutical dosage form in the presence of their degradation product. The statistical analysis showed high precision and accuracy.

Наукоёмкие технологии в материаловедении: высокотемпературное сквозное азотирование жаростойкой стали

The topicality of the research is occasioned by exaggeration of working conditions of products used at high temperatures and made of heat-resistant sheet alloys, including in particular austenitic chromium-nickel steels. When steel parts under load are operated in an oxidizing atmosphere and aggressive environments, besides resistance to electrochemical and gas corrosion, they require increased strength, hardness, and heat resistance. The increase in the characteristics of these proper-ties is achieved by three-dimensional and surface hardening techniques, which include the nitration process. The applica-tion of traditional technologies of furnace gas nitriding for chromium-nickel steels is complicated due to the problems of the low rate of the nitrogen saturation, which significantly increases the process time, and the formation of chromium nitrides, which negatively affects corrosion and heat resistance. The development of new technologies for nitrogen hardening of high-alloyed chromium-containing steels is carried out in the direction of saturation process intensification and regulation of the phase composition of the nitrided layer to minimize the formation of chromium nitrides. The article is aimed at defin-ing rational technological options and modes of gas austenitic nitriding of austenic steel, making it possible to increase strength characteristics at RT and higher temperatures without sacrificing its heat resistance. Thermodynamic modeling of the phase composition based on the CALPHAD technique shows that primary ways for minimizing the release of chromium nitrides on the nitrided surface are to increase the concentration of titanium in steel and to reduce the activity of the saturat-ing gas atmosphere, which is achieved by inert gas dilution of nitrogen. Experimental studies were carried out on sheet samples of 1.5 mm thick austenic steel of the type X18N10T with a standard (0.5%Ti) and increased (1%Ti) titane content. The experiments were carried out on a laboratory installation for high-temperature nitriding (900.1200 °); pure nitrogen and mixtures of nitrogen with argon were used as saturating media. Two-stage processes consisting of nitrogen hardening in nitrogen followed by argon afterburning were also investigated. Metallographic analysis showed that at the same nitrid-ing temperature, the amount of chromium nitrides decreases in experimental steel with an increased titanium content, and dilution of nitrogen with argon reduces the temperature of chromium nitride release. According to the study of saturation process kinetic, the time of through-the-thickness nitriding of a sheet sample under different saturation modes was deter-mined, as well as the duration of de-nitriding annealing, calculated on the basis of the known thickness of the chromium nitride zone. It was found that the dispersion hardening of the zones of internal nitriding with titanium nitrides leads to an increase in the strength characteristics of steels both at RT and higher temperatures compared to the characteristics of base steel 08X18N10T after typical heat treatment, while the greatest hardening effect is achieved due to through-the-thickness nitriding of steel with 1%Ti. Recommended options for the processes of through-the-thickness nitriding of 1.5 mm sheet of experimental steel: tn=1050 ℃, N2, 16 h; tn= 1100 ℃, 50%N2 + 50%Ar, 22 h; tn=1100 ℃, N2, 5 h + tann=1200 ℃, Ar, 9 h. The temporary passive hardness of nitrided steel at RT increases by 45...50%, and when tested at 800 ℃ - by 40... 65%, de-pending on the process mode. Through-the-thickness nitriding makes it possible to raise the working temperature of steels by 100.150 ° with the same long-term strength. The heat resistance at 900 ℃ remains at the level of non-carbonated steel after two-stage processes that ensure maximum chromium nitrides removal from the surface at the annealing stage.

Adaptive physics-informed neural operator for coarse-grained non-equilibrium flows

This work proposes a new machine learning (ML)-based paradigm aiming to enhance the computational efficiency of non-equilibrium reacting flow simulations while ensuring compliance with the underlying physics. The framework combines dimensionality reduction and neural operators through a hierarchical and adaptive deep learning strategy to learn the solution of multi-scale coarse-grained governing equations for chemical kinetics. The proposed surrogate’s architecture is structured as a tree, with leaf nodes representing separate neural operator blocks where physics is embedded in the form of multiple soft and hard constraints. The hierarchical attribute has two advantages: (i) It allows the simplification of the training phase via transfer learning, starting from the slowest temporal scales; (ii) It accelerates the prediction step by enabling adaptivity as the surrogate’s evaluation is limited to the necessary leaf nodes based on the local degree of non-equilibrium of the gas. The model is applied to the study of chemical kinetics relevant for application to hypersonic flight, and it is tested here on pure oxygen gas mixtures. In 0-textrm{D} scenarios, the proposed ML framework can adaptively predict the dynamics of almost thirty species with a maximum relative error of 4.5% for a wide range of initial conditions. Furthermore, when employed in 1-textrm{D} shock simulations, the approach shows accuracy ranging from 1% to 4.5% and a speedup of one order of magnitude compared to conventional implicit schemes employed in an operator-splitting integration framework. Given the results presented in the paper, this work lays the foundation for constructing an efficient ML-based surrogate coupled with reactive Navier-Stokes solvers for accurately characterizing non-equilibrium phenomena in multi-dimensional computational fluid dynamics simulations.

Probing molecular interactions in mixed system of green solvent ethyl lactate with oligomers of polyethylene glycol

Polyethylene glycol and its oligomers are potential hydrogen bond donors that act as a green, effective, non-toxic, non-corrosive and recyclable molecular component for extractive desulfurization of liquid fuels and variety of other applications. The aim of this investigation is to explore the molecular interactions via variations in viscosity that occur on mixing these glycols with green solvent ethyl lactate. Dynamic viscosities (η) for pure solvents and binary mixtures of ethyl lactate and glycols oligomers (mono/di/tri/tetra-ethylene glycol) were measured at varying temperatures T/(K) = (298.15–313.15; with an interval of 5). Viscosity deviations (Δη) along with excess thermodynamic parameters of activation for viscous flow as Gibbs free energy (ΔG∗E), Enthalpy (ΔH∗E) and Entropy (ΔS∗E) were derived from experimental data. The Δη and ΔG∗E values were further correlated using Redlich-Kister polynomial expression. The experimentally obtained viscosity values were compared with 10 generalised literature models (Arrhenius, Kendall, Kendall-Monroe, Grunberg-Nissan, Hind, Katti-Chaudhri, Heric, McAllister three-body, McAllister four-body and Jouyban-Acree models). The average standard deviation percentages (ASD %) were calculated for all the models to compare the quality of correlation with experimental data. The minimal ASD % for McAllister four-body and Jouyban-Acree models in the working systems indicate that the multiparameter relations have the best capability of reproducing the experimental values. The temperature induced variations were also discussed together with molecular interactions. Further, quantum mechanical density-functional theory and graph theoretical approaches were used to explore the extent of interactions among the components.

Bubbling fluidized bed co-combustion and co-gasification of sewage sludge with agricultural residues with a focus on the fate of phosphorus

In this work, the fate of the ash-forming elements during bubbling fluidized bed combustion and gasification of P-rich sewage sludge (SS) and mixtures with either Si-K-rich wheat straw (WS) or K-Ca-rich sunflower husks (SH) were investigated. The focus of the study was assessing the feasibility of using fuel blends in fluidized bed systems and potential P recovery from the resulting ashes. The used fuels were pure SS and mixtures including 90 wt.% WS (WSS) and 85 wt.% SH (SHS). The analyzed operating conditions were combustion (930–960 °C, λ: 1.2–1.5) and gasification (780–810 °C, λ: 0.4–0.7) in a 5 kW bench-scale reactor. Residual ash and char fractions were collected from different parts of the 5 kW bubbling fluidized bed (bed, cyclone, filter) and analyzed by CHN, SEM/EDS, XRD, and ICP-AES.The conversion of the fuel mixtures achieved a steady state under the used process conditions except for the combustion of WSS, which led to the formation of large bed agglomerates with the bed material. The morphology of ash samples after combustion showed that SS fuel pellets mostly maintained their integrity during the experiment. In contrast, the ash and char particles from fuel mixtures were fragmented, and larger quantities were found in the cyclone, the filter, or on interior reactor surfaces. The fate of P was dominated by crystalline Ca-dominated whitlockites in all ash fractions, partially including K for the fuel mixtures SHS and WSS. 76–81 % of ingoing P was found in the bed residue after combustion and gasification of the SS-fuel. After conversion of the fuel mixtures SHS and WSS, the share was lower at 22–48 %, with larger shares of P in the entrained fractions (25–34 %). The quantity of identified crystalline compounds was lower after gasification than combustion, likely due to the limited interaction of ash-forming elements in the residual CHN matrix. Altogether, the results show that fuel mixtures of sewage sludge with agricultural residues could expand the fuel feedstock and enable P recovery. This may be used in the fuel and process design of upscaled fluidized bed processes or systems employing both combustion and gasification.

Some experimental and theoretical studies of diethylene glycol diethyl ether and 2-alkanol mixtures

Experimental density and dynamic viscosity data for the diethylene glycol diethyl ether +2-alkanol (C3 to C6) mixtures have been published at 293.15 K, 303.15 K, 313.15 K, and 323.15 K and at pressure of 0.1 MPa. Excess molar volume and deviation in dynamic viscosity were obtained from experimental data and correlated with Redlich–Kister equation, from the values obtained, the interaction forces were studied. Perturbed chain-statistical associating fluid theory equation of state was used for modeling the density for pure fluids and mixtures. Free volume theory coupled to Perturbed chain-statistical associating fluid theory equation of state was used to modeling the viscosity of pure fluids and mixtures; in the case of binary mixtures, we proposed a simple mixing rule and used the Pourabadeh et al. mixing rule. Good results in the prediction and correlation of experimental liquid density and dynamic viscosity for binary mixtures were obtained, 0.12% and 2.28%, respectively.

Role of sesquiterpenes in biogenic new particle formation.

Biogenic vapors form new particles in the atmosphere, affecting global climate. The contributions of monoterpenes and isoprene to new particle formation (NPF) have been extensively studied. However, sesquiterpenes have received little attention despite a potentially important role due to their high molecular weight. Via chamber experiments performed under atmospheric conditions, we report biogenic NPF resulting from the oxidation of pure mixtures of β-caryophyllene, α-pinene, and isoprene, which produces oxygenated compounds over a wide range of volatilities. We find that a class of vapors termed ultralow-volatility organic compounds (ULVOCs) are highly efficient nucleators and quantitatively determine NPF efficiency. When compared with a mixture of isoprene and monoterpene alone, adding only 2% sesquiterpene increases the ULVOC yield and doubles the formation rate. Thus, sesquiterpene emissions need to be included in assessments of global aerosol concentrations in pristine climates where biogenic NPF is expected to be a major source of cloud condensation nuclei.

Effects of reseeding with perennial ryegrass, chicory or tyfon in pure stands or mixtures on lamb performance postweaning.

Many producers reseed old pasture (OP) with the objective of improving lamb performance. Old pasture was reseeded with perennial ryegrass plus white clover (RGC), RGC plus chicory (CG), RGC plus tyfon (TG), chicory (C), or tyfon (T) to generate five treatments. In addition, a contiguous block of OP was included in the study for comparative purposes. Lambs (n=286) were assigned to one of the five treatments plus the section of OP from just after weaning until slaughter. Grazing commenced 45days after the desiccation of OP for reseeding. All lambs were managed by rotational grazing and drafted for slaughter at a specified target BW. No concentrate supplement was offered during the study. For the RGC, CG, TG, C and T treatments and the OP section, the average herbage NDF concentrations were 524, 473, 402, 352, 256 and 565 (SE 15.4) g/kg DM; total grazing days were 5213, 4005, 4466, 2262, 3496 and 3677 (SE 629.3); BW gain to slaughter was 211, 175, 205, 211, 199 and 203 (SE 9.5) g/day; days to slaughter were 91, 100, 84, 86, 78 and 88 (SE 4.8). Compared to RGC, the C, T, CG and TG treatments had lower herbage NDF concentrations (P<0.05), and there was no difference (P>0.05) for BW gain or days to slaughter. Chicory yielded significantly fewer (P<0.05) grazing days, but tended to give a higher (P<0.06) carcass weight than RGC. It is concluded that neither reseeding OP with RGC, including either C or T with RGC as a multispecies sward, nor growing pure stands of C or T increased (P<0.05) lamb BW gain from weaning to slaughter or reduced days to slaughter.

Effective Separation of Raman Signals from Fluorescence Interference in Undyed and Dyed Textiles Using Shifted Excitation Raman Difference Spectroscopy (SERDS)

Textiles are an integral part of our everyday lives, e.g., in the form of clothing and furniture. Consequently, their analysis is of great interest in a wide range of application areas including quality control, textile recycling, forensics, and cultural heritage studies. Optical methods offer a large potential for rapid and nondestructive textile inspection. Raman spectroscopy is a particularly promising candidate for this task as it delivers a fingerprint of the sample on the molecular level, thus giving insights into the textile material composition. Currently, a major challenge preventing the widespread use of Raman spectroscopy for textile analysis is the strong fluorescence background originating from additives, e.g., dyes or the fiber material itself. To address this main limitation, this study applies shifted excitation Raman difference spectroscopy (SERDS) for the effective separation of Raman signals from interfering backgrounds. Using a customized Raman setup based on a dual-wavelength diode laser emitting at 785.2 and 784.6 nm, we present investigations for textile analysis and identification on a set of 22 dyed and undyed pure textiles and binary textile mixtures made of cotton, viscose, wool, polyester, and elastane. SERDS in combination with multivariate analysis is demonstrated as a powerful tool for a distinction between different fiber types and fibers of one material colored with various dyes. These results highlight the large potential of SERDS for textile material identification in selected application areas.

Characterization and Optimization of Plasma Electrolytic Process for Conversion of Molecular Nitrogen to Ammonia in Aqueous Water at Atmospheric Pressure

Ammonia (NH3) is widely used in the chemical and agricultural industries and is of growing interest as a potential energy carrier. Most of the current global NH3 production utilizes the Haber-Bosch process which has a large environmental and physical footprint. For this reason, there have been substantial efforts to develop an alternative process that can be sustainable and distributed. Recently, plasma-based electrolysis reactors have shown promise to convert molecular nitrogen to various forms of fixed nitrogen such as ammonia, nitrate, and nitrite in water at atmospheric pressure. However, selectivity and control over the products has not been adequately demonstrated. In this work, we studied a plasma formed in pure nitrogen gas or mixtures containing nitrogen gas at the surface of liquid water. Various products were characterized in the liquid phase including ammonium ions, nitrate ions, nitrite ions, and hydrogen peroxide as a function of pH, discharge current, and time. In addition, continuous direct current (DC) was compared to pulsed DC voltage plasma operation. We find that the selectivity to different nitrogen products depends on the solution conditions. These results could be used to inform optimization and scale up of similar plasma-liquid systems for sustainable nitrogen fixation.

TITANOMAGNETITE CONCENTRATE PROCESSING BY SORPTION CONVERSION

A hydrometallurgical technology for processing titanomagnetite concentrate has been proposed and justified. It includes the decomposition of the concentrate in low-concentration sulfur-acidic solution in the presence of sulfonic cation exchanger in H+ form with the transfer of the main part of the metals of the titanomagnetite concentrate into the sorbent and obtaining a residue enriched with ilmenite, desorption of metals from the saturated sulfonic cation exchanger with a 5 M sodium chloride solution, fractional hydrolytic precipitation and separation of titanium hydroxide, vanadium-enriched iron hydroxide, pure hydroxide iron and mixtures of iron and manganese hydroxides, regeneration of sulfonic cation exchange resin. The optimal parameters for carrying out individual processes have been determined. The technology practically does not consume sulfuric acid and does not generate liquid waste.

Hydration, mechanical and transfer properties of blended cement pastes and mortars prepared with recycled powder or limestone filler

The fine fraction (<80 μm) of recycled aggregates from construction and demolition wastes, currently considered as waste, is investigated as a candidate mineral additive for partial replacement of Ordinary Portland Cement (OPC) to reduce the environmental impact of cementitious materials. Although recycled powder could affect hydration reactions due to the presence of residual anhydrous cement particles and to its high specific surface area, very few studies are available in literature concerning these aspects. Cement pastes and mortars prepared with 0%, 10%, and 20% replacement by weight of OPC by either Recycled Powder (RP) or Limestone Filler (LF) are compared in terms of hydration degree, mechanical and transport properties using several techniques, including Isothermal Calorimetry (IC), Thermogravimetric Analysis (TGA), water porosity, mercury intrusion porosimetry and gas permeability. The results revealed that mixtures blended with RP or LF have a similar decrease in the overall hydration degree compared to the hydration degree of pure OPC mixture due to a dilution effect, although both additives have a small reactivity. A moderate increase in porosity and intrinsic permeability with the replacement rate is observed. Pastes and mortars blended with RP have a compressive strength and a Young modulus nearly identical to those with the same amount of LF, despite RP having worse properties than LF. A multiscale micromechanical model is established and reproduces faithfully these experimental results for the elastic moduli, based on the simplified assumptions that LF is nearly inert while RP reduces the effective water to binder ratio by both absorption of water and internal hydration reactions.

Targeted dosing for susceptible heteroresistant subpopulations may improve rational dosage regimen prediction for colistin in broiler chickens

The dosage of colistin for the treatment of enteric E. coli in animals necessitates considering the heteroresistant (HR) nature of the targeted inoculum, described by the presence of a major susceptible population (S1, representing 99.95% of total population) mixed with an initial minor subpopulation of less susceptible bacteria (S2). Herein, we report the 1-compartment population pharmacokinetics (PK) of colistin in chicken intestine (jejunum and ileum) and combined it with a previously established pharmacodynamic (PD) model of HR in E. coli. We then computed probabilities of target attainment (PTA) with a pharmacodynamic target (AUC24h/MIC) that achieves 50% of the maximal kill of bacterial populations (considering inoculums of pure S1, S2 or HR mixture of S1 + S2). For an MIC of 1 mg/L, PTA > 95% was achieved with the registered dose (75,000 IU/kg BW/day in drinking water) for the HR mixture of S1 + S2 E. coli, whether they harboured mcr or not. For an MIC of 2 mg/L (ECOFF), we predicted PTA > 90% against the dominant susceptible sub-population (S1) with this clinical dose given (i) over 24 h for mcr-negative isolates or (ii) over 6 h for mcr-positive isolates (pulse dosing). Colistin clinical breakpoint S ≤ 2 mg/L (EUCAST rules) should be confirmed clinically.

Study of pure Ni, NiO, and mixture of Ni-NiO thin films on piezoelectric lithium niobate substrate by pulsed laser deposition

The crystallographic orientation plays a significant role in the modern magnetic heterostructure devices, especially in the arena of spintronics. In terms of magnetic property, domain orientation is solely dependent on structural homogeneity. This research work deals with the development of pure Ni, NiO, and mixture of Ni-NiO thin films on a single-crystalline piezoelectric lithium niobate substrate. Pulsed laser deposition technique was used at 650 °C in a reduction and oxidation atmosphere for pure Ni and NiO deposition respectively, whereas deposited NiO was reduction annealed to achieve mixture of Ni (ferromagnetic)-NiO (antiferromagnetic) thin film on a piezoelectric lithium niobate substrate. X-ray diffraction along with x-ray reflectometry was carried out for better understanding of surface nature and thickness of the film. Morphological analysis of the films was conducted using scanning electron microscopy with energy dispersive X-ray spectrum. Atomic force microscopy as well as ferromagnetic resonance were used to understand the magnetic characteristics of the thin films. Additionally, surface properties of the films with Ni and O oxidation states were investigated by X-ray photoelectron spectroscopy. Our findings indicate that Ni and mixture of Ni-NiO thin films exhibit similar dynamic magnetic characteristics, making Ni-NiO films a more attractive option for spintronic applications because of their adjustable magnetic properties.

Investigation of the usage of waste materials and By-Products as grinding aids in calcite grinding

Along with the increasing importance of water worldwide, it is thought that developments in fine grinding processes performed by dry grinding and using grinding aids are too essential to be ignored. Indeed, grinding chemicals in the form of pure or commercial mixtures are intensively used in mineral processing plants in dry grinding systems to micronized sizes, e.g., dry grinding of calcite to micronized sizes. This study investigated the usage of olive pomace oil (OPO) and olive waste water (OWW), waste/by-products of the olive oil industry, as grinding aids in the dry grinding of calcite to micronized sizes using a laboratory-scale stirred ball mill and compared them with pure and commercial grinding aids. The test results were evaluated in terms of product fineness, powder flowability, color factor, surface adsorption characteristics, and agglomeration behavior. The study revealed that using any of the grinding aids tested improved the grinding process in comparison with the no aid condition. It was understood from the experiments and analyses that using OPO and OWW as grinding aids positively affected grinding performance. Particularly, the particle size analyses showed that the product fineness obtained in dry grinding tests was close to that obtained with commercial and pure grinding aids. Considering all the investigated grinding aids (except for OWW), powder flowability increased with the increasing concentration of the grinding aid. Remarkably, the OWW results demonstrated that the increase in dosage was not beneficial in terms of the ffp index. However, the enhancement of particle size was obvious. When evaluated in terms of product quality, four types of grinding aids increased total color differences with respect to feeding material and no aid test. Furthermore, the Fourier transform infrared spectroscopy (FTIR) conducted to determine the interaction between particle surfaces and grinding aids indicated that the grinding aids used in this study were adsorbed on the calcite surfaces by their non-polar, polar functional group and hydroxyl group. The analysis, in which the agglomeration phenomenon was examined with SEM (scanning electron microscopy) images, revealed that using grinding aids reduced the formation of agglomerates in comparison with the no grinding aid condition.