Interaction Parameters Research Articles

Apatite–Wollastonite (AW) glass ceramic doped with B2O3: Synthesis, structure, SEM, hardness, XRD, and neutron/charged particle attenuation properties

In the study, the influence of doping apatite-wollastonite (AW) glass-ceramics (GCs) with B2O3 on the structural, physical, microstructural, and light and heavy particle interaction properties is presented. Using the solid-state reaction and the cold isostatic press method, pristine AW, 10 wt% (AW-B10), and 20 wt% (AW-B20) B2O3-doped AW GCs were prepared. The prepared GCs were subject to structural, chemical compositional, and surface morphological investigation through standard experimental processes. Furthermore, the neutron (fast and thermal) and charged radiation (electron, proton, alpha, and carbon ion) interactional parameters of the GCs were obtained through standard theoretical models and software. The density of AW (2.91 gcm−3) increases to about 2.957 and 2.986 gcm−3 as B2O3 increases to 10 and 20 wt%, respectively. The presence of boron oxide supported the wollastonite phase to remain glass and suppressed crystallisation in the AW GCs. Doping AW with B2O3 improved the interaction probabilities of the GCs with fast and thermal neutrons, electrons, protons, alpha particles, and carbon ions. B-rich AW is thus potentially useful as a target material in human tissues for boron neutron capture therapy for the management of cancer and tumours, isolating or shielding specific tissues in ion beam therapy processes, and other techniques that require the exposure of human tissues to irradiation.

Thermoplastic polymers as water substitutes

Background. New applications of 3D printing have recently appeared in the fields of radiotherapy and radiology, but the knowledge of many radiological characteristics of the compounds involved is still limited. Therefore, studies are needed to improve our understanding about the transport and interaction of ionizing radiation in these materials. Purpose. The purpose of this study is to perform an analysis of the most important radiation interaction parameters in thermoplastic materials used in Fused Deposition Modeling 3D printing. Additionally, we propose improvements to bring their characteristics closer to those of water and use them as water substitutes in applications such as radiodiagnosis, external radiotherapy, and brachytherapy. Methods. We have calculated different magnitudes as mass linear attenuation, mass energy absorption coefficients, as well as stopping power and electronic density of several thermoplastic materials along with various compounds that have been used as water substitutes and in a new proposed blend. To perform these computations, we have used the XCOM and ESTAR databases from NIST and the EGSnrc code for Montecarlo simulations. Results. From the representation of the calculated interaction parameters, we have been able to establish relationships between their properties and the proportion of certain chemical elements. In addition, studying these same characteristics in different commercial solutions used as substitutes for water phantoms allows us to extrapolate improvements for these polymers. Conclusion. The radiological characteristics of the analyzed thermoplastic materials can be improved by adding some chemical elements with atomic numbers higher than oxygen and by using polyethylene in new blends.

Investigation of Polymer-Asphalt Compatibility Using Molecular Dynamics Simulation.

Polymer modification is a promising approach to enhancing the performance of asphalt binders. However, a major issue plaguing polymer mixing with asphalt is the phase separation of these two components post-mixing. In the field of polymer science, the Flory-Huggins theory has been long established as the way to describe the conditions under which a mixture is stable or unstable. This Flory-Huggins interaction parameter χ and the molecular weights of the components are required under this theory. This work uses molecular dynamics simulations to calculate χ between various polymers found in waste plastics and asphalt. The compatibility of these polymers with the asphalt binder is discussed as a function of binder composition, molecular weight, and temperature. Four common polymers (polyethylene, polystyrene, polypropylene, and polybutadiene) were tested. While none of the polymers showed good compatibility with asphalt, PE was the most compatible. Stable compatibilization of plastics with asphalt will require additives or chemical modification of the plastic.

A computational analysis on two phase Eyring-Powell (non-Newtonian) dust particles flow for heat and mass transfer phenomenon with variable thermal features

In this instigation, the heat and mass transfer pattern on Eyring-Powell nanofluid with suspension of dust particles is focused. For heat transfer phenomenon, the Eyring-Powell nanofluid capturing the variable thermal conductivity. Furthermore, the variable and mass diffusivity assumptions are entertained for summarizing the observations chemical reaction phenomenon. The flow is endorsed to magnetic force impact. The additional impact of Brownian motion and thermophoresis consequences have been adopted. The numerical computations with shooting technique are performed. The physical aspects of parameters have been observed graphically. Based on depicted observations, it is examined that the fluid velocity reduces due to interaction velocity parameter which reverse trend is noted for dust particles velocity. The temperature profile for dusty fluid particles enhanced due to interaction parameter for temperature. Furthermore, the concentration profile reduces due to concentration interaction parameter. Current results present applications in solar energy, thermal processes, heat transform devices cooling systems, plasma, manufacturing processes, energy systems, etc.

Superfluid fraction tensor of a two-dimensional supersolid

We investigate the superfluid fraction of crystalline stationary states within the framework of mean-field Gross–Pitaevskii theory. Our primary focus is on a two-dimensional Bose–Einstein condensate with a non-local soft-core interaction, where the superfluid fraction is described by a rank-2 tensor. We then calculate the superfluid fraction tensor for crystalline states exhibiting triangular, square, and stripe geometries across a broad range of interaction parameters. Factors leading to an anisotropic superfluid fraction tensor are also considered. We also refine the Leggett bounds for the superfluid fraction of the 2D system. We systematically compare these bounds to our full numerical results, and other results in the literature. This work is of direct relevance to other supersolid systems of current interest, such as supersolids produced using dipolar Bose–Einstein condensates.

Synergistic effects of nonionic surfactants ethoxylated alkylamines and sodium dodecyl sulfate in mixed systems

HypothesisIn general, the performance of surfactant hybrid systems is better than that of single surfactants, so surfactant hybrid systems are widely used in various industries. As a very important class of nonionic surfactants, ethoxylated alkylamines have been widely used in industries such as washing, coating, and pesticide, but little research has been conducted on their mixed systems. In order to improve the utilization efficiency of surfactants and reduce wastage, the surface properties and aggregation behavior of ethoxylated alkylamine mixed systems should be further explored. ExperimentIn this study, the nonionic surfactant ethoxylated dodecylamine (AC-1202) and the anionic surfactant sodium dodecyl sulfate (SDS) were used to form a mixed system. The static surface tension and interaction parameters of the mixed system under the influence of inorganic salt ions were investigated using a KRÜSS K12 surface tensiometer. The diffusion process of the mixed system was investigated using a KRÜSS bubble pressure tensiometer. At the same time, the aggregate behavior of the mixed system was studied by particle size analyzer. In addition, the contact angle and rheological properties of the mixed solution were also investigated. FindingsThe SDS/AC-1202 mixture system formed a synergistic effect that could reduce the CMC value to 24.20 mN/m and the CMC value was as low as 22.89 mN/m after the addition of inorganic salts. The mixed system conforms to the kinetic mechanism of mixing and diffusion and the Ostwald de model for non-Newtonian fluids. Finally, there is a good aggregation pattern in the mixed system, and the stronger synergistic effect will lead to the reduction of the average particle size of the mixture to 45.41 nm.

The role of gaming for information, education and communication of AMR: full review of online education resources.

The first objective of the Global Action Plan on antimicrobial resistance (AMR) is to improve awareness and understanding of AMR through effective communication, education and training. Towards this several efforts have been made to create AMR awareness resources. The aim of these resources is to inform the public about responsible antibiotic use and drive positive behavioural change. Digital media and specifically games can serve as unique innovative platforms in public communication programmes. This study focuses on compiling and evaluating game-based AMR resources. Recognizing the engaging and creative potential of games as learning tools, the primary objective of this study was to identify games that can be used, individually or in combination depending on their unique focus and gameplay experience, for AMR awareness. Furthermore, games are evaluated on five objective criteria and recommendations are made towards further development of gaming resources towards AMR awareness. Meticulous curation was performed to mine information, education and communication resources, with a primary focus on games for AMR awareness and evaluating them based on game design and gameplay, AMR content and learning, engagement and replay appeal, learning outcomes, and level of difficulty and challenges. In this study, we selected 12 AMR games. Our evaluations, spanning various gamification elements and interactive parameters, informed recommendations for future AMR resource development, including multilevel game design, varied graphics, simple-to-understand rules, sustained challenge and a sense of reward, among others. This study generated the first-ever comprehensive catalogue of AMR games that may assist public communication programmes for AMR awareness. Evaluation of these games led to actionable design recommendations for future resources towards effective communication of AMR complexity, enhanced learning and awareness.

Efficacy of Ni2+ on modification the structure, ultrasonic, optical, and radiation shielding behaviors of potassium lead borate glasses

This paper presents the method of preparing (60 − x) B2O3–20 K2O–20 PbO–x NiO, coded as (NiO x), and x = (0–10 mol%) glass systems fabricated through the melt-quench technique. The prepared glass was characterized through X-ray diffraction spectra (XRD); the mechanical behavior of the glass samples was investigated using the ultrasonic technique, Fourier transform infrared (FTIR) spectra, the optical reflectance R(λ), refractive index (n), optical conductivity (σopt), the dispersion parameters of the studied samples were deduced using Wemple and Di-Domenico models. The results obtained were reported in detail. One of the fundamental parameters used to evaluate the interaction of radiation with shielding material was the mass attenuation coefficient (μm), which was obtained using Phy/X software and PHITS code program. It was used to calculate radiation interaction parameters, e.g., linear (μL) attenuation coefficient, effective atomic number (Zeff), half value layer HVL, mean free path (MFP) and the average atomic cross section, σt. Comparing the shielding behavior of the glass samples revealed that (NiO 10) glass demonstrated the highest μm and μL compared to the other samples. The maximum μm values equal 48.13, 48.73, 49.42, 50.59, and 51.08 cm2/g for (NiO 0) to (NiO 10), recorded at 0.015 MeV, respectively. This study shows that increasing the amount of NiO in the preferred glass samples leads to achieving high-performance radiation shielding materials.Graphical abstract

Investigation of superconductivity of A15 type cubic Nb3Os material by using density functional theory

In this study, the structural, elastic, electronic, phonon and electron-phonon interaction properties of A15 type cubic Nb3Os compound were investigated by density functional theory. The lattice constant of this compound was obtained in agreement with experiments, and the investigation of elastic properties revealed its ductile nature. From electronic calculations for Nb3Os, the density of states at Fermi level (N(EF)) was found to be 5.31 states/eV with the largest contribution of Nb 4d orbitals. According to the results obtained from phonon calculations, Nb3Os was found to be dynamically stable in the cubic A15 structure and phonon modes were largely formed by the vibrations of Nb atoms. Using the electronic and phonon properties, we determined the Eliashberg spectral function, which illustrates the electron-phonon interaction. The electron-phonon interaction parameter and average phonon frequency values for Nb3Os were found to be 0.41 and 222.97 K, respectively. The calculated superconducting transition temperature of 1.05 K is in excellent agreement with the experimental value of 1.02 K.

Phase behaviour and internal mechanism of action of two solvents for the separation of butanol isomers from industrial wastewater

Industrial wastewater usually contains large amounts of butanols which form azeotropic mixtures with water. Efficiently and cleanly separating these azeotropes while saving energy is an urgent problem to solve. This study used two types of solvents to measure the ternary liquid-liquid equilibrium (LLE) data for extracting n-butanol, sec-butanol, and tert-butanol from water at 298.2 K and 101.3 kPa. The obtained data was correlated with NRTL and UNIQUAC models to obtain relevant binary interaction parameters. The reliability of the binary interaction parameters was verified using a Gibbs energy topology-based mixture surface analysis method. The root mean square deviations of the two models were less than 0.0061 and 0.0072, respectively, indicating that both the NRTL and UNIQUAC models could correlate the experimental data well. The extraction performance was evaluated using the distribution coefficient (D) and the separation factor (S). Isopentyl acetate showed better extraction performance, and the differences in the molecular structures of butanols also showed regularity during the extraction process. Combined with quantum chemistry calculations, the hydrogen bond donors and acceptors between six ternary systems were analyzed using the COSMO-SAC method. The intermolecular interaction energies were calculated using the Dmol3 module. Finally, through IGMH and AIM analysis, it was proved that the difference in hydrogen bond strength between isopentyl acetate/ethyl acetate and butanols with different molecular structures is the reason for this difference. This study provides basic data and parameters for the design of butanols extraction processes through a combination of experiments and quantum chemistry calculations.

Unsteady MHD dusty fluid flow over a cone in the vicinity of porous medium: a numerical study

This research presents an unsteady free convection magnetohydrodynamics (MHD) dusty fluid flow over a vertical cone enclosed inside a porous medium. The Crank–Nicolson approach is used to get the numerical solutions for these non-linear partial differential equations (PDEs). The velocity and temperature distributions are graphed numerically for a wide range of physical parameters to highlight important characteristics of the solutions. The results showed that increasing the porosity parameter leads to a rise in the velocity profile for the fluid and dust phases, while doing the reverse with the rise of the magnetic parameter, fluid-particle interaction parameter, and mass concentration of the particle phase parameter. Additionally, it is shown that the temperature profile rises as the magnetic parameter and the mass concentration of particle phase parameter grow, whereas the fluid-particle interaction parameter and porosity parameter show the opposite tendency.

State diagram of freeze-dried sardines (Sardinella longiceps, Valenciennes)

State diagram is used to determine the stability of dried and frozen foods during their processing and storage. In this study, state diagram of sardine was developed by measuring the freezing curve, glass line, solids melting line, and maximal-freeze-concentration conditions. Glass transition temperature decreased with the increase in water content and it was adjusted using a modified Gordon-Taylor equation. The glass transition of dry-solids and critical temperature were 184.1 and 12.5oC, and the model parameter of the modified Gordon-Taylor equation was estimated as 4.2, respectively. Solids melting temperature was modeled by Flory-Huggins equation; and dry-solids melting temperature and Flory-Huggins solids-water interaction parameter were determined as 199.4oC and 0.956, respectively. Freezing point of fresh sardine was observed as −1.3oC with ice melting enthalpy of 186.3 kJ/kg, and it decreased with the increase of solids due to the freezing point depression with solutes. Freezing point was adjusted by Chen equation based on Clausius-Clapeyron equation. The ultimate maximal-freeze-concentration temperatures, (Tm′)u and (Tg′′′)u were determined as −18.6 and −25.1oC, respectively and maximal-freeze-concentration solids were estimated as 0.90 g solids/g sample (i.e. un-freezable water 0.10 g water/g sample). This indicated that frozen sardines could be most stable if stored below −25.1oC, and dried fish stored below its glass transition.

A Bayesian approach for exploring person × environment interaction within the environmental sensitivity meta-framework.

For investigating the individual-environment interplay and individual differences in response to environmental exposures as captured by models of environmental sensitivity including Diathesis-stress, Differential Susceptibility, and Vantage Sensitivity, over the last few years, a series of statistical guidelines have been proposed. However, available solutions suffer of computational problems especially relevant when sample size is not sufficiently large, a common condition in observational and clinical studies. In the current contribution, we propose a Bayesian solution for estimating interaction parameters via Monte Carlo Markov Chains (MCMC), adapting Widaman etal. (Psychological Methods, 17, 2012, 615) Nonlinear Least Squares (NLS) approach. Findings from an applied exemplification and a simulation study showed that with relatively big samples both MCMC and NLS estimates converged on the same results. Conversely, MCMC clearly outperformed NLS, resolving estimation problems and providing more accurate estimates, particularly with small samples and greater residual variance. As the body of research exploring the interplay between individual and environmental variables grows, enabling predictions regarding the form of interaction and the extent of effects, the Bayesian approach could emerge as a feasible and readily applicable solution to numerous computational challenges inherent in existing frequentist methods. This approach holds promise for enhancing the trustworthiness of research outcomes, thereby impacting clinical and applied understanding.

Interaction, Surface Activity, and Application of Mixed Systems of Alcohol Ether Sulfate Anionic Surfactants with Multiple Ethylene Oxide Groups and Gemini Quaternary Ammonium Surfactant.

The surface activities and application properties for the mixtures of cationic surfactants tetramethylene-1,4-bis[N,N-bis(hydroxypropyl)-hexa/decyloxypropylammonium] bromide (GC10-P) and tetramethylene-1,4-bis[N,N-bis(hydroxyethyl)-hexa/decyloxypropylammonium] bromide (GC10-E) and anionic surfactant isomeric sodium fatty alcohol ether sulfates (iso-AE9S) were investigated using both the tensiometry and the conductometry. The interaction parameters and thermodynamic micellization parameters of GC10-P/iso-AE9S and GC10-E/iso-AE9S mixtures were evaluated by Clint-Rubingh and Motomura theoretical models. When the mole fraction of α1 for GC10-P/iso-AE9S mixed system was 0.2, the critical micelle concentration (CMC) reached a minimum of 1.61 × 10-4 mol/L, and the minimum critical micelle concentration of the GC10-E/iso-AE9S mixed system is 2.67 × 10-5 mol/L at α1 = 0.6. The CMC value of the mixed system is 1-2 orders of magnitude lower than that of any single component. The results indicate that the synergistic effects of the investigated mixed systems (evaluated by βm) are in order of GC10-P/iso-AE9S < GC10-E/iso-AE9S, with maximum βm values of -17.98 and -9.78, respectively. The change in zeta potential indicates that the poly(ethylene oxide) chain has weakened the charge density of the hydrophilic headgroup of the anionic surfactant. The interfacial tension at the oil-water interface in the mixed system of anionic/cationic surfactants is lower than that of any single component, exhibiting a higher interfacial activity. The mixed system exhibits a decreased contact angle and superior wetting ability over any single component, and it also enhances foam performance, emulsification performance, and degreasing performance.

Insights on Microsomal Prostaglandin E2 Synthase 1 (mPGES-1) Inhibitors using Molecular Dynamics and MM/PBSA Calculations

Background: Despite being a normal body response against invading agents, inflammation, when exaggerated, needs to be controlled to minimize damage to the body. There are several drugs in clinical use against inflammation and other inflammatory conditions. Still, side effects often limit the use of these drugs, such as gastrointestinal effects generated by COX-1 inhibitors and cardiovascular effects by COX-2 inhibitors. Thus, exploring new targets such as mPGES-1 may lead to discovering agents that are more selective against inflammation and generate fewer side effects. Objectives: Here, docking, molecular dynamics, and MM-PBSA studies were performed on a dataset of known mPGES-1 inhibitors to identify helpful information and discover new mPGES-1 inhibitors. Methods: Molecular docking in GOLD software was used to obtain the complexes used in Molecular dynamics simulations (GROMACS software), performed to generate the RMSD, RMSF, Rg, SASA, and H-bond plots to predict the complexes' stability. The most stable conformation was analyzed regarding the most important interactions of the compounds. Finally, MM-PBSA calculations using the tool g_mmpbsa in GROMACS software were performed to determine de-binding affinity, interaction parameters, and per-residue contribution. Results: The main findings of this work were that the molecular dynamics simulation was able to find the open conformation of mPGES-1, which showed a greater preference on compounds in this region, consisting of residues known as "gateways". All compounds showed stability and stable complex formation with mPGES-1, as demonstrated by the results of RMSD, RMSF, Rg, SASA, and H-bond plots generated in a molecular dynamics simulation at 100 ns. The molecular dynamics identified three preferential sites of interaction for the compounds. Thus, the docking and dynamics protocols showed greater affinity of these compounds for cavity-02, interacting with Leu85, Pro81, Gln134, Cys137, Ala138, and Ala141. On the other hand, compound 09 preferred the cavity-03 of the protein, interacting mainly with His72 through Hbond. In addition, MM-PBSA calculations showed binding energies of up to -220,113 KJ/mol for compound 04. Furthermore, MM-PBSA could identify which electrostatic interactions are the most prevalent in the complex formation of the compounds with the highest affinity (04 and 07). Still, the van der Waals interactions are the most important for the others. Finally, the energy contribution per-residue revealed Lys120, Arg122, Arg126, and Tyr130 as the most important for the formation of the complexes. Conclusion: Design mPGES-1 inhibitors based on the residues Leu85, Pro81, Gln134, Cys137, Ala138, and Ala141, in addition to Lys120, Arg122, Arg126, and Tyr130 can provide new promising drugs useful against diseases involving inflammatory conditions.

Structural elucidation of ternary mixtures of L‐valine/glycyl‐L‐valine and water + 1‐decyl‐3‐methylimidazolium bromide: Apparent molar properties at infinite dilution and expansivities

AbstractThis work comprises ternary systems of water + SAIL,1‐decyl‐3‐methylimidazolium bromide, and (S)‐2‐Amino‐3‐methylbutanoic acid generally identified as L‐valine/ (S)‐2‐(2‐Aminoacetamido)‐3‐methylbutanoic acid usually described as glycyl‐L‐valine, densities, and sound speed data have been computed at four operating temperatures, i.e., 288.15 to 318.15 K. Calculated density data have utilized for calculation of various thermodynamic parameters like Vϕ (apparent molar volume), (apparent molar volumes at infinite dilution), and calculated speed of sound statistics used to determine Kϕ,s (apparent molar isentropic compression), Ks (partial molar isentropic compression at infinite dilution). In our systems, the hydrophilic‐ionic interactions that are produced by co‐sphere overlap models are predominant. The Hepler's constant is used to analyze the solute's capacity to create or destroy solvent structures. The interaction parameter is computed using the McMillan‐Mayer theory. Understanding structure‐making, solvation characteristics, and numerous modifications in the ternary system of L‐valine/Glycyl‐L‐valine, water, and [C10MIm] [Br] is aided by a variety of thermodynamic factors.

ENHANCING BRIX VALUE PREDICTION IN STRAWBERRIES USING MACHINE LEARNING: A FUSION OF PHYSIOCHEMICAL AND COLOR-BASED FEATURES FOR IMPROVED SWEETNESS ASSESSMENT

This study contributes to the ongoing wave of artificial intelligence integration by applying machine learning techniques to automate the assessment of strawberry quality. This research focuses on determining if the sweetness of strawberries can be predicted using a combination of physiochemical variables, their interaction parameters, and color-based features extracted from image data. This research used a 150-sample collection of strawberry images and physiochemical characteristics such as salinity, specific gravity, pH, and Brix. Normalized raw and derived feature variables and selected dataset transformations were done. We then split the dataset into mutual exclusivity training and test sets. Exponential Gaussian Process Regression (GPR) suited well due to low validation errors. This best model predicted Brix values for the remaining test samples. The Mean Absolute Percentage Error(MAPE) showed 98.783% forecast accuracy (Acc). We also examined the model's coefficient of determination (R2) values, which were 0.78 and 0.9739 for training and testing, respectively. The Mean Square Error (MSE) and Mean Absolute Error (MAE) obtained after training were 0.32994 and 0.0453, and testing was 0.35286 and 0.0663. Using input characteristics with high Acc and low error rates, deep learning models like Recurrent Neural Network (RNN) and its derivatives were constructed. Using physiochemical and visual data, machine learning and deep learning models successfully predict strawberry sweetness. This prediction accuracy shows the complex link between internal components and Brix readings, enabling high-quality strawberry production.

Building a model of the abrasion grinding mechanism in a tumbling mill based on data visualization

The object of this study is the grinding process in a tumbling mill when the mechanism of destruction by abrasion is implemented, which is caused by the mechanism of shear loading. The abrasive effect due to the impulse interaction during the mutual chaotic movement of granular particles in the shear layer of loading, characterized by the granular temperature, is taken into account. The task solved was determining the parameters of the shear interaction, which is caused by the difficulties of modeling and complexity of the hardware analysis of behavior of the internal loading in the mill. A mathematical model was built based on data visualization for the abrasion grinding mechanism. The power of the shear interaction forces was taken as an analog of the grinding performance. The initial shear characteristic was considered to be the average value of the shear velocity gradient in the central averaged normal section of the shear layer. The impact on productivity of the granular temperature and mass fraction of the shear layer and loading turnover was taken into account. The effect of rotation speed on performance was evaluated by experimental modeling at a chamber filling degree of 0.45 and a relative particle size of 0.0104. The maximum value of the energy and productivity of grinding by abrasion was established at the relative speed of rotation ψω=0.55–0.6. The results have made it possible to establish a rational speed when grinding by abrasion, ψω=0.5–0.6. This value is smaller in comparison with grinding by crushing ψω=0.55–0.65 and breaking ψω=0.75–0.9. The established effect is explained by the detected activation of the chaotic quasi-thermodynamic movement of particles of the shear layer at slow rotation. The model built makes it possible to predict rational technological parameters of the energy-saving process of fine grinding in a tumbling mill by abrasion

Interactions at the interfaces of the H2-brine-cement systems at elevated pressures for H2 storage

There is a global demand on assessment of potential subsurface gas storage sites in view of safely injecting hydrogen or carbon dioxide. One relevant aspect that has already been subject to thorough investigation is the mutual interaction of all participating compounds in terms of the wetting behaviour that on its turn is directly related to the predominating capture mechanisms. Given the diversity of the geophysical and geochemical circumstances, transferability of results from work conducted on one geological site to another location is limited. For instance, there is a large number of publications on wettability of many different rock types in hydrogen atmosphere that are partly controversal and strictly applicable only to the respective reported system. Hence, there is a gap in finding general model approaches that serve for a holistic understanding of predominating mechanisms and building the fundamentals for predicting the behaviour of systems that have not been studied so far. The presented work addresses this gap by quantifying mutual interactions of the participating phases in a solid-liquid-gas systems and determining the respective interfacial tensions, γSV (solid-vapor), γLV, (liquid-vapor) and γSL (solid-liquid).Neumann and Good demonstrated how to determine the solid-fluid interfacial tension based on the contact angle and the liquid-gas interfacial tension by calculating a so-called molecular interaction parameter. Up to date, this method has been applied, among others, for systems containing CO2 and solids such a teflon, glass, and steel. The methodology could be confirmed by testing systems comprising steel - H2O - CH4 /H2 and comparing the results to the aforementioned literature data.As one of the critical parts in H2 underground storage, the completion system containing a common well cement, H2 and brine was subject to this work. The interfacial tension between H2 and brine as well as the contact angle between the fluid phases and the cement were investigated experimentally up to 20 MPa, temperatures from 313.15 to 353.15 K and NaCl – concentrations of up to 10% wt. As a theoretical approach, the interfacial tension of the system H2O+H2 was investigated using the density gradient theory (DGT) in combination with the perturbed chain statistical associating fluid theory equation of state (PC-SAFT). Finally, the H2-cement interfacial tension is determined through the calculation of a so-called molecular interaction parameter. The interfacial tension data of H2O+H2 experimentally and theoretically determined in this work agree among each other as well as with previous literature data. Likewise, agreement was found between the brine+H2 interfacial tension and previous studies. The contact angle appears to be influenced mostly by pressure, producing a less H2O/brine-wet system as pressure increases. The H2-cement interfacial tension decreases from approximately 150 mN/m down to 100 mN/m, as the pressure increases from 0.1 to 20 MPa. The presented data suggest H2 to be slightly adsorbed on the one hand but the capillary entry pressure to decrease on the other, causing concerns regarding the integrity of the completion system.

Thermodynamic and quantum chemical investigation of MIBK as a liquid phase extraction solvent for separating pyridine compounds from water

Pyridine compounds play a crucial role in the synthesis of fine chemicals and pharmaceuticals; however, the generation of a large amount of wastewater may pose a threat to the ecological environment and human health. Considering environmental factors and economic benefits, it is essential to explore efficient methods for separating pyridine compounds from water. In this study, pyridine compounds were separated from water by liquid–liquid extraction using MIBK as solvent. Liquid-liquid equilibrium (LLE) data for the ternary system water + pyridine compounds(pyridine, 2-methylpyridine, 3-methylpyridine, 2,6-dimethylpyridine, and 2,4,6-trimethylpyridine) + MIBK were measured at 303.2 K and 101.3 kPa. Subsequently, the distribution coefficient (D) and separation factor (S) were calculated based on the obtained data, serving as indicators to evaluate the performance of the extractant. The LLE data were then correlated with NRTL and UNIQUAC models to obtain binary interaction parameters. The accuracy of the regressed binary interaction parameters was assessed through Gibbs energy topology analysis. To explore the intrinsic mechanism of extraction between MIBK and pyridine or alkylpyridines, the σ-profile was used to investigate the interaction form between MIBK and pyridine or alkylpyridines. Based on this, quantum chemical calculations and wave function analysis were used to reveal the molecular-level separation mechanism. The interaction behavior of the MIBK and pyridine or alkylpyridines systems was systematically investigated. The results indicate that van der Waals forces are the main intermolecular interactions, and it is through these strong forces that MIBK can efficiently separate pyridine and alkylpyridines from water.