Strong Attractive Interaction Research Articles

An ab-initio investigation of Sc and Y doped chalcopyrite MgGeN[formula omitted]

The doping of Scandium and Yttrium within chalcopyrite MgGeN2 were computationally investigated using density function theory (DFT) calculations. By calculating the formation energy, it was shown that independent single Sc and Y dopants energetically favor the occupation of the Mg site, inducing a shallow level within the conduction band. However, in the presence of a substitutional defect, the second dopant will occupy the neighboring Ge site. There is strong attractive interaction between two dopants, so that they are easily combined into a composite defect. In this case a shallow defect level appears above the valence band edge. Similar behavior is observed for the composite defects containing one dopant and an intrinsic cation vacancy, while those with one dopant and a nitrogen vacancy induce a deep defect level and greatly reduce the band gap. The investigation deepens the knowledge of Sc and Y doped II-IV-V2 compounds and may hence lead to more implementations.

Selective adsorption behaviors and mechanisms of benzyl quaternary ammonium salt on quartz and gypsum: A combined experimental and theoretical study

Benzyl quaternary ammonium salt is an effective collector of quartz from gypsum. To investigate the selective collection mechanism of tetradecyl dimethyl benzyl ammonium chloride (TDBAC) for quartz from a microscopic view, the adsorption experiments, first-principles calculations based on density functional theory (DFT), and molecular dynamics (MD) simulation were performed in this work. The adsorption experiment results show that the adsorption capacity of TDBAC on the quartz surface was 1.6 × 10−6 mol/m2, much larger than that on the gypsum surface (1.0 × 10−7 mol/m2). The interaction energy of TDBAC with quartz surface was −20202.98 kJ/mol, much smaller than that with gypsum surface (-78.37 kJ/mol). DFT calculation results indicate that the quartz surface was more likely to interact with TDBAC through electrostatic attraction since the average negative charge and exposure oxygen density of the quartz surface were both greater than those of the gypsum surface. After the adsorption of TDBAC, there were hydrogen bonds formed between the hydrogen atoms in TDBAC and the oxygen atoms on the quartz surface. This work confirmed that the highly selective adsorption of TDBAC on quartz surface was attributed to the strong electrostatic attraction and hydrogen-bond interaction.

Functional renormalisation group approach to the finite-temperature Bose polaron

The functional renormalisation group (FRG) approach is employed to study Bose polarons at finite temperatures in the regime of strong attractive bath-impurity interactions. Both two- and three-dimensional configurations are considered. The appearance of two polaron quasiparticle branches at finite temperatures is revealed, consistent with recent findings by other analytical techniques. Ground-state polaron energies are also reported for selected interactions and temperatures within the gas superfluid phase. The findings of this work present the FRG as a useful tool for studying finite-temperature polarons in quantum gases.

Exploring the suppression methods of helium-induced damage in tungsten by investigating the interaction between beryllium and helium

Abstract Helium (He)-induced damage is a sensitive concern for the performance of tungsten plasma facing materials (W-PFMs). Recent experiments have revealed that trace impurities in He plasma can effectively prevent the formation of He bubbles and fuzz on W surfaces. To explore its plausibility and underlying mechanism, we performed a multiscale computational study that combines density functional theory calculations and object kinetic Monte Carlo simulations to investigate the effects of a small quantity of beryllium (Be) on the evolution of He bubbles. It is found that there is a strong attractive interaction between He and Be, which can be attributed to the decrease in electron density and the lattice distortion induced by embedded Be atoms. Therefore, the co-implantation of Be continuously introduces trapping centers for He. Due to the low implantation depth and high migration energy of Be, the Be atoms are located close to the surface, leading to the trapping of the majority of He within the near-surface region and the development of a shielding layer for He permeation. The presence of Be facilitates the dispersion of the trapped He, skewing the He clusters into smaller sizes. More importantly, the Be trapping centers bring the He clusters closer to the surface, significantly increasing the probability of bubble bursting and the release of He back to the vacuum. This ultimately leads to a lower retention of He in the case of He + Be co-irradiation, compared with the case of He-only irradiation. Consequently, our findings elucidate the suppressive effect of a low flux of Be atoms on the growth of He bubbles, highlighting the need to focus on synergetic effects between plasma species.

FT-IR, UV–Vis, density functional theory and molecular docking studies on 3,7,11,15-Tetramethyl-2hexadecen-1-ol

The organic molecule of 3,7,11,15-Tetramethyl-2-hexadecen-1-ol is frequently present in plant chlorophyll pigment. The title compound possesses antimicrobial, antibacterial, antioxidant, anti-inflammatory, and anticancer characteristics. The 3TMH molecule are being investigated using Gas Chromatography Mass Spectrometry (GC–MS) analysis, Ultraviolet-Visible (UV–Vis), Fourier Transform Infrared Spectroscopy (FT-IR), and Density Functional Theory (DFT) approach with the Becke,3-parameter, Lee–Yang–Parr (B3LYP) method, 6–311++G (d, p) basis set is used to analyse the geometrical parameters, Highest Occupied Molecular Orbital and the Lowest Unoccupied Molecular Orbital (HOMO-LUMO), and Molecular Electrostatic Potential (MEP) mapping. In the 3TMH molecules, the computed Natural Bond Orbital (NBO) analysis exhibit the high stabilization interaction (intra-inter, hydrogen bonding, and charge delocalization) between the donor and acceptor. The UV–Vis spectra of the maximum absorption correlated with different solvents as determined by Time-Dependent Density Functional Theory (TD-DFT). According to Veda 04, the measured FT-IR spectrum and the theoretical spectra of vibrational assignment with Potential energy distribution (PED%) are in good agreement. The Electron Localization Function (ELF) and Localized Orbital Locator (LOL) mapping has provided an explanation for the chemical bonding within fragments, as well as interactions between the atoms. The strong attraction, strong repulsion, and weak interaction have been estimated Reduced Density Gradient (RDG). Furthermore, the molecular docking examined ligand-protein interaction of least binding energy 6.73 kcal/mol against anti-cancer activity.

Torrefaction of Cassia fistula seeds for sequestration of aqueous and gaseous pollutants: Experimental and computational approach

Contamination of water bodies due to pharmaceutical pollutants including antibiotics is growing day by day due to enhanced consumption of these molecules. Biochar is a competent material for wastewater treatment due to ease of preparation as well as high adsorption capability towards desired pollutants. Cassia fistula biochar (CFB) was prepared by torrefaction process in an inert atmosphere. Owing to a large surface area of 672.3 m2/g, the purpose of this work is to carry out adsorption studies of three antibiotics, namely, ciprofloxacin (CFX), levofloxacin (LVX) and diclofenac sodium (DFC) in aqueous phase as well as for the sequestration of carbon dioxide in gaseous phase. The batch adsorption studies were carried and effects of various operational conditions were studied. The maximum adsorption capacities for CFX, LVX, and DFC were found to be 607.86 mg/g, 68.27 mg/g and 160.51 mg/g respectively under the optimum pH 6.0 for all the three adsorbates, contact time of 60 minutes for CFX, LVX and 20 minutes for DFC at room temperature condition of 298 K. Various operational parameters were optimized using Response Surface Methodology (RSM). Isotherm and kinetics studies for the adsorption of all three drugs followed Langmuir model (R2 >0.99) and pseudo-second order kinetics (R2 >0.95). Thermodynamic studies show the adsorption of all three drugs were enthalpy driven spontaneous processes. Fixed bed studies were performed showing the applicability of CFB for larger sample volumes. DFT calculations showed strong attractive interaction of CFB with all the three drug molecules. The same material has been applied for capture of carbon dioxide at different temperatures. The CO2 capture studies showed maximum adsorption capacity of 64.78 cc/g at 273 K owing to activation of CFB with high CO2 selectivity of 14.29 with respect to nitrogen. Hence, a multipurpose adsorbent has been thoroughly studied with environmental sustainability factor of 0.03.

Insights into 5-fluorouracil anti–cancer drug encapsulation within the pristine and palladium-doped carbon, silicon-carbide, and germanium-carbide nanotubes: A DFT investigation for advanced nanomedicine applications

In this study, we investigated the interaction and binding properties of 5-Fluorouracil (5-FU), an anti-cancer drug, encapsulated within pristine and palladium-doped carbon, silicon-carbide, and germanium-carbide nanotubes (CNT, SiCNT, GeCNT). Using density functional theory (DFT), we conducted a comprehensive analysis at both aqueous and gas phases. This included geometrical, structural, electrical, bonding, and thermodynamic properties, optimized geometries, adsorption energies, quantum molecular descriptors, frontier molecular orbitals, and topological parameters at the M06-2X level of theory. Our findings indicate that Pd-doping enhances the encapsulation capabilities of nanotubes, strengthening interactions with 5-FU and improving water solubility. Calculations of recovery time required for drug release suggest that Pd-doped nanotubes effectively control the release of 5-FU. Notably, the decapsulation time of 5-FU from of Pd-doped nanotubes was longer in the gas phase than in aqueous conditions. Using the quantum theory of atoms in molecules (QTAIM) method, we investigated intermolecular interactions and critical bonding points. Natural bond orbital (NBO) analysis revealed enhanced stabilization of the 5-FU molecule post-encapsulation, with charge transfer primarily directed from nanotubes to the 5-FU. Hirshfeld surface analysis highlighted that hydrogen bonds between 5-FU active sites and nanotubes are crucial in encapsulation and fixation. Reduced Density Gradient (RDG) analysis confirmed Pd-doping as a primary source of strong attractive interactions in 5-FU/Pd-doped nanotube complexes compared to pristine nanotubes.

Molecular weight insight into critical component contributing to reverse osmosis membrane fouling in wastewater reclamation

Molecular weight (MW) of organics was one of the important factors influencing membrane fouling propensity. This study identified critical foulants of reverse osmosis (RO) membranes in reclaimed water by MW fractionation. MW > 10 kDa component was identified as the critical fouling contributor (CFC) in secondary effluent (SE), which accounted for only 13 ± 5% of dissolved organic carbon (DOC) but contributed to 86 ± 11% of flux decline. Throughout 12-month monitoring, SE and MW > 10 kDa component showed a similar fouling variation tendency: apparently higher fouling potential in winter and lower in summer, while MW < 10 kDa component presented minor fouling changes. Morphology of membrane fouled by CFC characterized a smooth and thick foulant layer on membrane surface. CFC was mainly composed of proteins and polysaccharides, and a protein-polysaccharide-protein “sandwich” fouling layer structure was preferentially formed on membrane surface. extended Derjaguin–Landau-Verwey–Overbeek (xDLVO) analysis demonstrated that strong attractive interactions between CFC and membrane surface dominated the fouling process. Furthermore, computational fluid dynamics (CFD) simulation revealed strong filtration resistance of CFC, confirming its significant fouling potential. Dual effects including attractive interactions and advantageous ridge-and-valley surface appearance accounted for the significant fouling propensity of MW > 10 kDa component and glean valuable insights into RO fouling mechanisms of reclaimed water in practical application.

Austenite decomposition behavior adjacent to δ-ferrite in a Si-modified Fe-Cr-Ni austenitic stainless steel during thermal aging at 550 °C

The δ-ferrite decomposition has been widely reported in conventional Fe-Cr-Ni austenitic stainless steel during thermal aging. However, a novel phenomenon is found in a Si-modified austenitic stainless steel, that δ-ferrite decomposition is suppressed, replaced by the decomposition of adjacent austenite. Herein, the decomposition behavior of austenite adjacent to δ-ferrite and its effect on impact toughness in a Si-modified austenitic stainless steel during aging at 550 °C up to 3000 h have been investigated. During thermal aging, austenite adjacent to δ-ferrite is decomposed in the following sequence: (1) γ → M23C6 + α transformation takes place. The preferential formation of secondary M23C6 carbides not only rejects Si atoms into the surrounding austenite but also produces a C-depleted zone. The transformation of austenite to ferrite is induced in the Si-riched and C-depleted micro-zone. (2) The growth of secondary M23C6 carbides induces a continuous rejection of Ni and Si atoms into M23C6/γ and M23C6/α interfaces, and the strong attractive interaction between Ni and Si provides the chemical driving force for nucleation of M6C carbides and G-phase. (3) With prolonged aging time, the lower C, high Ni, and high Si concentrations in the frontier of decomposed austenite will promote the preferential precipitation of M6C carbides rather than M23C6 carbides. During impact deformation, microcracks caused by strain incompatibility between secondary M23C6 and α-ferrite, resulting in a slight decrease in impact toughness. As austenite decomposition proceeds, the higher strain incompatibility across M6C/α interfaces leads to brittle cleavage fracture, resulting in a significant decrease in impact toughness.

Spinodal decomposition and phase separation in polar active matter.

We develop and study the hydrodynamic theory of flocking with autochemotaxis. This describes large collections of self-propelled entities all spontaneously moving in the same direction, each emitting a substance which attracts the others (e.g., ants). The theory combines features of the Keller-Segel model for autochemotaxis with the Toner-Tu theory of flocking. We find that sufficiently strong autochemotaxis leads to an instability of the uniformly moving state (the "flock"), in which bands of different density form moving parallel to the mean flock velocity with different speeds. This instability is, therefore, completely different from the well-known "banding instability," in which bands form perpendicular to the mean flock velocity. The bands we find, which are reminiscent of ant trails, coarsen over time to reach a phase-separated state, in which one high-density and one low-density band fill the entire system. The same instability, described by the same hydrodynamic theory, can occur in flocks phase separating due to any microscopic mechanism (e.g., sufficiently strong attractive interactions). Although in many ways analogous to equilibrium phase separation via spinodal decomposition, the two steady-state densities here are determined not by a common tangent construction, as in equilibrium, but by an uncommon tangent construction very similar to that found for motility-induced phase separation of disordered active particles. Our analytic theory agrees well with our numerical simulations of our equationsof motion.

Green leaching of cold filter cakes using choline chloride-maleic acid deep eutectic solvent and molecular dynamics simulation.

Deep eutectic solvents (DESs) represent a novel class of solvents characterized by their favorable biodegradability and compatibility, which have been used for dissolving various metals. In this study, choline chloride-maleic acid (ChCl-Me) DES was synthesized, and the FTIR technique was used to investigate the formation of DES. Then, ChCl-Me DES was applied to dissolve cold filter cakes (CFCs), and FTIR analysis proved the stability of DES during leaching. Response surface methodology (RSM) was used to investigate the effects of time, temperature, DES to CFC ratio, and stirring speed on the leaching efficiency of Zn, Ni, and Cd. Analysis of variance (ANOVA) showed that the leaching time has a significant effect on all three metals' leaching efficiency. Also, the DES to CFC ratio and the interaction between time and the DES to CFC ratio significantly affect Zn leaching efficiency. Moreover, the second order of the DES to CFC ratio significantly affects Cd leaching efficiency. Optimal conditions were determined as follows: a time of 20 hours, a DES to CFC ratio of 70, a temperature of 60 °C, and a stirring speed of 300 rpm. The UV-vis spectra of the leaching solution showed that metals leached as chlorides in DES. Also, CFC characterization by FESEM-EDS before and after leaching via ChCl-Me DES proved almost complete leaching of metals. Therefore, this solvent can be used as a suitable solvent for the cumulative dissolution of Zn, Ni, and Cd metals with a dissolution efficiency of 90%. Molecular dynamics (MD) simulation and density functional theory (DFT) were employed to obtain detailed information about the complexes formed by Zn, Cd, and Ni ions. The surface charge density, obtained from COSMO computations, shows the notable impact of Cl anions and O atoms within ChCl and Me compounds, respectively, on the Zn2+, Cd2+, and Ni2+ complexes. The radial distribution function (RDF) result highlights strong attractive interactions between ions and Cl- in ChCl, extending to bonded atoms. In addition, RDF results show that oxygen atoms in Me have an impact on CFC dissolution in ChCl-Me DES.

Impact of polypyrrole units (pyr*n; n=3, 5, 7, or 9) on the adsorption and excitation dynamics of enrofloxacin antibiotic interaction with hafnium-doped graphene/boron nitride (Hf@GP/BN) heterostructure: A theoretical perspective

This research work focuses on investigating on influence of pyrrole units (pyr) on the structural stability, reactivity, adsorption potential, bonding variation, and the visible-light interactions of enrofloxacin (xacin) antibiotic with hafnium-doped graphene/boron nitride (Hf@GP_BN) heterostructure within the framework of hybrid exchange-correlation functional and the Monte Carlo molecular simulations. The interaction of enrofloxacin (xacin) with the hybrid surface pyr*n_Hf@GP_BN (where n = 3, 5, 7, or 9) provided insights into the effects of changing the polypyrrole (pyr) chain length on the resulting interactions: xacin_pyr3_Hf@GP_BN, xacin_pyr5_Hf@GP_BN, and xacin_pyr7_Hf@GP_BN respectively to gain more efficient degradation capabilities and the influence of the increase polymer chain. The calculated energy gap decreases due to the increase in LUMO energy experienced upon the addition another of ring, nonetheless when the length of the polypyrrole was further adjusted to seven, the energy gap of the composite increased from 2.184 eV to 2.205 eV which is in the range of semi-conductor to support efficient electron excitation. Results of the molecular dynamic (MD) simulation reveal that while the potential energy of the system decreased for all pyr*n_Hf@GP_BN combinations, the magnitude of the potential energy reduction varied with different pyr chain lengths. Pyr3 exhibited the least reduction of 1310.899 ± 36.119 kcal/mol, followed by 1402.128 ± 38.678 for pyr5, 1511.129 ± 40.494 for pyr7, and 1616.720 ± 43.445 kcal/mol for pyr9, which displayed the most substantial reduction. Longer pyr chains (pyr7 and pyr9) seem to have stronger attractive interactions with enrofloxacin, leading to more significant energy reductions. This indicates that longer pyr chains are more effective in stabilizing the interactions between the antibiotic and the hybrid surface. While the UV-excitation analysis revealed that an increase in the polypyrrole chain length led to a decrease in the wavelength for both the adsorbent and the interactions, decreasing order of exciton binding energy is observed as: 0.602585, 0.606008, and 0.597378 for xacin_pyr3_Hf@GP_BN, xacin_pyr5_Hf@GP_BN, and axacin_pyr7_Hf@GP_BN respectively which is below the 1.9 eV benchmark of efficient materials for photodegradation. The findings could contribute to the broader field of photocatalysis, potentially informing the design of more effective photocatalytic materials. Therefore, research contributes to the development of more efficient methods for antibiotic degradation, with potential applications in environmental remediation.

The conformational phase diagram of charged polymers in the presence of attractive bridging crowders.

Using extensive molecular dynamics simulations, we obtain the conformational phase diagram of a charged polymer in the presence of oppositely charged counterions and neutral attractive crowders for monovalent, divalent, and trivalent counterion valencies. We demonstrate that the charged polymer can exist in three phases: (1) an extended phase for low charge densities and weak polymer-crowder attractive interactions [Charged Extended (CE)]; (2) a collapsed phase for high charge densities and weak polymer-crowder attractive interactions, primarily driven by counterion condensation [Charged Collapsed due to Intra-polymer interactions [(CCI)]; and (3) a collapsed phase for strong polymer-crowder attractive interactions, irrespective of the charge density, driven by crowders acting as bridges or cross-links [Charged Collapsed due to Bridging interactions [(CCB)]. Importantly, simulations reveal that the interaction with crowders can induce collapse, despite the presence of strong repulsive electrostatic interactions, and can replace condensed counterions to facilitate a direct transition from the CCI and CE phases to the CCB phase.

Benzoic acid as additive: A route to inhibit the formation of cracks in catalyst layer of proton exchange membrane fuel cells

Cracks are a common defect in the catalyst layers (CLs) of proton exchange membrane fuel cells (PEMFCs), deteriorating their performance. This study proposes benzoic acid as a cracking inhibitor in the catalyst ink. The additive strengthens the network of catalyst particles by promoting attractive interaction within them. Molecular dynamics simulations demonstrate that the inhibitor facilitates the desorption of ionomer from the Pt/carbon surface, weakening the repulsion force within catalyst particles. Rheology experiments indicate that the addition of benzoic acid transforms the catalyst ink from a sol-like to a gel-like, improving its viscosity and storage modulus. The stronger attractive interactions within the inhibitor-added ink impart anti-cracking ability, preventing stress release during the drying process. Furthermore, optical microscopy reveals a significant decrease in both the crack area and the maximum length of cracks in the CL after incorporating the inhibitor. Specifically, the crack area decreases from 13% to 2%, while the maximum crack length decreases from nearly 400 μm to 150 μm. Single cell tests show that the inhibitor-added sample exhibits a higher peak power density of 0.893 W/cm2 compared to the standard sample's 0.873 W/cm2. Overall, this study presents an effective method for manufacturing high-quality CLs in PEMFCs, ensuring improved performance.

Molecular dynamic (MD) simulation and density function theory (DFT) calculation relevant to green leaching of metals from spent lithium-ion battery cathode materials using glucose-based deep eutectic solvent (DES)

Deep eutectic solvents (DES), as environmentally-friendly solvents, have shown potential for recovering metals in the cathodes of spent lithium-ion batteries (LIBs). This study employed a glucose-based DES of choline chloride to recover cobalt, manganese, nickel, and lithium from LIB cathode materials, optimizing temperature and time parameters in the range of 60–110 °C and 2–24 h for leaching the cathode materials. The highest metal recoveries were observed between 60 and 110 °C, with 82.4% for Ni, 94.2% for Co, 97.6% for Ni, and 93.7% for Li after 24 h of leaching at 100 °C. The Co, Mn, Ni, and Li recoveries in the DES solution increased with time at 100 °C. UV–visible spectroscopy analysis investigated the leaching mechanisms for cathode metals, confirming that the spent LIBs leaching in DES (ChCl:G) is not completely associated with the reduction of cobalt. It appears that other metal ions, such as Li, Mn, and Ni, form complexes with chloride ions originating from the choline chloride agent. The results of the MD simulation show that hydrogen of the OH in choline chloride has a very strong attractive interaction with the Cl− ion. Also, H atoms of OH groups in glucose molecules interact considerably with the chloride ion of choline chloride. In addition, all H atoms of OH groups in glucose form hydrogen bonds with O5 of the glucose. All metal ions, including Co3+, Li+, Mn2+, and Ni2+, have very strong electrostatic interactions with the Cl− of the choline chloride molecule. The MD calculations show that metal ions are complexed with some oxygen atoms of the glucose molecule. Results show that the choline chloride molecule (via Cl− ion) and glucose molecule (via oxygen atoms) play a significant role in the leaching of metal ions from LIBs via electronegative atoms. Another finding is that the molecules of choline chloride and glucose have no selectivity towards the leaching of ions, which agrees with the experimental results, so all ions are almost 100% extracted.

Single-molecule-binding studies of antivirals targeting the hepatitis C virus core protein.

The hepatitis C virus is associated with nearly 300,000 deaths annually. At the core of the virus is an RNA-protein complex called the nucleocapsid, which consists of the viral genome and many copies of the core protein. Because the assembly of the nucleocapsid is a critical step in viral replication, a considerable amount of effort has been devoted to identifying antiviral therapeutics that can bind to the core protein and disrupt assembly. Although several candidates have been identified, little is known about how they interact with the core protein or how those interactions alter the structure and thus the function of this viral protein. Our work biochemically characterizes several of these binding interactions, highlighting both similarities and differences as well as strengths and weaknesses. These insights bolster the notion that this viral protein is a viable target for novel therapeutics and will help to guide future developments of these candidate antivirals.

Universal many-body properties of one-dimensional mass-imbalanced highly polarized Fermi gases

We investigate the universal properties of mass-imbalanced highly polarized Fermi gases in one-dimensional scenarios. By treating the mass ratio as a parameter, we delve into the binding energy, quasiparticle residue, and correlation functions of the systems. We provide a thorough momentum distribution for impurities and spin-up atoms within the Fermi sea. When the impurity mass is infinite, we discover that the quasiparticle residue approaches to zero and the systems exhibit the signature of the Anderson orthogonality catastrophe in strong coupling regime. We observe an increase in Tan contact under large mass ratios and study density correlations by applying Fourier transform. Crucially, we demonstrate the existence of the molecular state in one-dimensional polaron system with strong attractive interactions, unlike previous conclusions.

Effects of aluminum and oxygen additions on quenched-in compositional fluctuations, dynamic atomic shuffling, and their resultant diffusionless isothermal [formula omitted] transformation in ternary Ti–V-based alloys with bcc structure

Diffusionless isothermal ω transformation is a recently discovered ω transformation that occurs isothermally during aging near room temperature in Ti alloys with a bcc (β-phase) structure. Unlike conventional displacive phase transitions, the diffusionless isothermal ω transformation occurs in locally unstable nanoscale β-phase regions formed by quenched-in statistical compositional fluctuations. In the present study, the effects of Al and oxygen additions in ternary β-phase Ti–V-based alloys on the diffusionless isothermal ω transformation and its attempt process, called dynamic atomic shuffling, were studied. Elastic constant and internal friction measurements for Ti–16.6V–2.1Al and Ti–17.5V–2.5O (at.%) alloy single crystals and analysis of quenched-in compositional fluctuations using the thermodynamic theory of fluctuations indicated that the oxygen addition increases the β-phase stability, and it selectively increases the activation energy of dynamic atomic shuffling in locally unstable Ti-rich regions, which is caused by the strong attractive interaction between Ti and oxygen elements. As a result, oxygen addition suppresses the diffusionless isothermal ω transformation that occurs during aging at 298 K. In contrast, low β-phase stability, which promotes ω-phase nucleation, is retained by Al addition. Furthermore, dynamic atomic shuffling with a low activation energy is retained even though the average activation energy is enhanced by the Al addition, originating from the relatively weak atomic interaction between Ti and Al. Therefore, the diffusionless isothermal ω transformation cannot be suppressed by Al addition.

New insight into the structure and properties of silver selenate

Given the wide application of silver and selenium nanoparticles in pharmaceutical and biomedical research, we focused on further elucidating the structure and properties of silver selenate. Silver selenate was prepared by the hydrothermal synthesis method. The experimental structure was characterized by X-ray crystallographic techniques, spectroscopic (UV-Vis, FT-IR) and thermal (TG) methods. To discuss the strength of interactions in silver selenate, Hirschfeld surface analysis and fingerprint diagrams were performed. The reduced density gradient (RDG) was used to analyze weak and strong attractive interactions and steric repulsions in the structure.

The ϕ p bound state in the unitary coupled-channel approximation

The strong attractive interaction of the ϕ meson and the proton has recently been reported by the ALICE Collaboration. The corresponding scattering length f 0 is given as and fm. The fact that the real part is significant in contrast to the imaginary part indicates a dominant role of elastic scattering, whereas the inelastic process is less important. In this work, such scattering processes are inspected based on a unitary coupled-channel approach inspired by the Bethe–Salpeter equation. The ϕ p scattering length is calculated based on this approach, and it is found that the experimental value of the ϕ p scattering length can be obtained only if the attractive interaction of the ϕ meson and the proton is taken into account. A significant outcome of such attractive interaction is a two-pole structure in the ϕ p scattering amplitude. One of the poles, located at (1969 − i283) MeV might correspond to N(1895)1/2− or N(1875)3/2− as listed in the review of the Particle Data Group (PDG). The other one, located at 1949 − i3 MeV should be a ϕ N bound state, which has no counterpart in the PDG data.