Bulk Properties Research Articles

Symmetry energy effect on hot nuclear matter and proto-neutron stars

Abstract We examine the effects of symmetry energy on proto-neutron stars (PNSs) by employing equation of state (EOS) described by the relativistic mean-field (RMF) model.
The thermal properties of dense matter and the bulk properties of PNSs are investigated under the assumptions of isothermy, isentropy, and fixed lepton fractions.
The polytropic index is calculated at finite temperature, 
revealing a negative correlation with the PNS maximum mass that the EOS can support.
The properties of PNSs during the heating and cooling stages along their evolution line are explored under different combinations of lepton fraction and entropy.
We investigate the correlation between the symmetry energy slope $L$ and the properties of PNSs. As $L$ increases, the PNS radius also increases; however, this effect diminishes with a growing lepton fraction for the isentropic case.
These results indicate that the nuclear symmetry energy and its density dependence play crucial roles in determining the properties of PNSs and their evolution stages.

NMR and MD Simulations of Non-Ionic Surfactants

Non-ionic surfactants are an important solvent in the field of green chemistry with tremendous application potential. Understanding their phase properties in bulk or in confined environments is of high commercial value. In recent years, the combination of molecular dynamics (MD) simulations with multinuclear solid-state NMR spectroscopy and calorimetric techniques has evolved into the most powerful tool for their investigation. Showing recent examples from our groups, the present review demonstrates the power and versatility of this approach, which can handle both small model-surfactants like octanol and large technical surfactants like technical polyethylene glycol (PEG) mixtures and reveals otherwise unobtainable knowledge about their phase behavior and the underlying molecular arrangements.

Role of polymer graft stiffness in electrostatic-driven self-assembly of nanoparticles in solutions.

Self-assembly of nanoparticles (NPs) in solution has garnered tremendous attention among researchers because of their electrical, chemical, and optoelectronic properties at the macroscale with potential applications in bio-imaging, bio-medicine, and therapeutics. Control of size, shape, and composition at the nanoscale is important in tuning the material's bulk properties. The grafting of NPs with polymers enables us to tune such bulk material properties at the nano level by controlling their assemblies, especially in solutions. The stiffness of grafts plays a crucial role in tuning the self-assembly of spherical NPs grafted with polyions (PGNs). Many recent studies based on single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) showed the potential applications of such assemblies. In this work, we have performed coarse-grained molecular dynamics (MD) simulations to understand the charge-driven self-assembly of PGNs by varying stiffness of polymer grafts, the grafting density, and graft length. Self-assembly of these PGNs leads to the formation of different structures driven by the rigidity of polyion chains and the electrostatic interactions. A dramatic change in morphological transitions can be achieved, ranging from rings, strings, and percolated structures and ordered to disordered aggregates by tuning the control parameters. The percolated structures form disordered structures upon annealing with potential applications in thermal under filling, neuromorphic devices, and biological systems including drug delivery, and therapeutics.

Increasing the Wear Resistance of Stamping Tools for Coordinate Punching of Sheet Steel Using CrAlSiN and DLC:Si Coatings

The punching of holes or recesses on computer numerical control coordinate presses occurs in sheets at high speeds (up to 1200 strokes/min) with an accuracy of ~0.05 mm. One of the most effective approaches to the wear rate reduction of stamping tools is the use of solid lubricants, such as wear-resistant coatings, where the bulk properties of the tool are combined with high microhardness and lubricating ability to eliminate waste disposal and remove oil contaminants from liquid lubricants. This work describes the efficiency of complex CrAlSiN/DLC:Si coatings deposited using a hybrid unit combining physical vapor deposition and plasma-assisted chemical vapor deposition technologies to increase the wear resistance of a punch tool made of X165CrMoV12 die steel during coordinate punching of 4.0 mm thick 41Cr4 carbon structural steel sheets. The antifriction layer of DLC:Si allows for minimizing the wear under thermal exposure of 200 °C. The wear criterion of the lateral surface was 250 μm. The tribological tests allow us to consider the CrAlSiN/DLC:Si coatings as effective in increasing the wear resistance of stamping tools (21,000 strokes for the uncoated tool and 48,000 strokes for the coated one) when solving a wide range of technological problems in sheet stamping of structural steels.

Stabilizing bicontinuous particle-stabilized emulsions formed via solvent transfer-induced phase separation.

Bicontinuous particle-stabilized emulsions (bijels) are unique soft materials that combine the bulk properties of two immiscible fluids into a single interconnected structure. This structure is achieved through the formation of two interwoven fluid networks, stabilized by an interfacial layer of colloidal particles. Bijels with submicron-scale domain networks can be synthesized via solvent transfer-induced phase separation (STrIPS). However, the fluid network structure in STrIPS-bijels tends to degrade over time, limiting their practical applications. In this study, we identify that the destabilization of STrIPS-bijels is driven by the exchange of matter between the bijel and the surrounding oil phase. Confocal laser scanning microscopy reveals that over time, aqueous components from the bijel dissolve into the surrounding oil, leading to an inward flow of oil into the bijel. This process disrupts the fluid bicontinuous structure within hours. To extend the stability of the bijel to several weeks, we explore strategies to reduce the dissolution of the aqueous phase and the inflow of oil. Specifically, we investigate the effects of the oil's chemical composition and properties, as well as modifications to the surface chemistry of the supporting glass substrates. Our results show that while the particle scaffold of STrIPS-bijels exhibits long-term stability, the maintenance of the fluid bicontinuous network depends on minimizing the loss of aqueous components. The enhanced control over the stability of the fluid bicontinuous structure developed in this work is critical for advancing STrIPS-bijels as functional materials for applications in catalysis, separations, and energy storage.

Intrinsic and defect-related magnetism of MnBi2Te4(Bi2Te3)n family from the Bulk to two-dimensional limit

Abstract The van der Waals MnBi2Te4(Bi2Te3) n family, encompassing MnBi2Te4(n = 0), MnBi4Te7(n = 1), MnBi6Te10(n = 2), and MnBi8Te13(n = 3) etc, has attracted considerable interest owing to its intriguing combination of intrinsic magnetism and non-trivial band topology. This unique blend offers a fertile ground for investigating the engineering of magnetic states and the interplay between magnetism and topology. A comprehensive understanding and manipulation of their magnetic properties in single-crystal bulk and two-dimensional (2D) forms are imperative for the advancement of applications in quantum technology. This review presents an extensive overview of recent experimental and theoretical inquiries into the magnetic characteristics of MnBi2Te4(Bi2Te3) n (n = 0, 1, 2, 3) spanning from the bulk to the 2D realm. It delves into intrinsic and defect-related magnetism and its modulation under diverse external fields. The elucidations provided herein aspire to enhance the understanding of magnetic phenomena in magnetic topological insulators, underscoring the potential for tailoring magnetic states to propel future quantum devices.

Transiting Jupiters around M Dwarfs Have Similar Masses to FGK Warm Jupiters

Abstract This paper presents a comparative analysis of the bulk properties (mass and radius) of transiting giant planets (≳8R ⊕) orbiting FGKM stars. Our findings suggest that the average mass of M-dwarf Jupiters is lower than that of their solar-type counterparts, primarily due to the scarcity of super-Jupiters (≳2 M J) around M dwarfs. However, when super-Jupiters are excluded from the analysis, we observe a striking similarity in the average masses of M-dwarf and FGK warm-Jupiters. We propose that these trends can be explained by a minimum disk dust mass threshold required for Jovian formation through core accretion, which is likely to be satisfied more often around higher-mass stars. This simplistic explanation suggests that the disk mass has more of an influence on giant planet formation than other factors, such as the host star mass, formation location, metallicity, radiation environment, etc., and also accounts for the lower occurrence of giant planets around M-dwarf stars. Additionally, we explore the possibility of an abrupt transition in the ratio of super-Jupiters to Jupiters around F-type stars at the Kraft break, which could be a product of vsini-related detection biases, but requires additional data from an unbiased sample with published nondetections to confirm. Overall, our results provide valuable insights into the formation and evolution of giant exoplanets across a diverse range of stellar environments.

Impact of solid content on the bulk properties of lyophilized powders.

Interest in oral delivery of biological drug products, commonly prepared through lyophilization, is surging. Typically, low solid content solutions are employed for lyophilization to enhance mass transfer and minimize drying time. Yet, this approach often results in lyophilized powders with low bulk density and poor flowability, challenging downstream processing steps that are required for oral product development. Increasing solid content in a starting solution can, in theory, increase the density of lyophilized cakes and powders with higher bulk density post-milling. However, the effectiveness of improving powder density and flowability using a higher solid content has not been experimentally verified. In addition, the impact of using a higher solid content on other physicochemical properties of lyophilized materials remains uncertain. To address the knowledge gaps, we lyophilized three common bulk cryoprotectants at two different solid contents (5% and 10%) and systematically evaluated their solid-state properties, bulk density, flowability, compaction characteristics, and physical stability. We found that powders prepared at a higher solid content (10%) exhibited higher bulk density, but they still failed to meet the requirements for easy oral product development. A change in solid content also leads to different solid-state properties, compaction behaviors, and stability, highlighting the importance of thorough characterization of lyophilized materials when solid content is changed in the course of oral solid dosage formulation development.

Optimizing proton acceleration using hollow laser pulses and a double-layer target: effects of focal spot position and polarization

Abstract We study the influence of hollow laser pulse settings, specifically adjustments to the focal plane and the phase structure and polarization, on the acceleration of high-energy, low-divergence proton beams from a double-layer target using a feasible laser energy (~ 3.7 J). We investigate the laser's relativistic self-focusing dynamics in the near-critical plasma layer of the target and examine hot electron generation and proton acceleration using three-dimensional particle-in-cell (PIC) simulations. First, we vary the focal spot position of a tightly focused twisted driver, leading to distinct laser beam width evolution that impacts hot electron generation in the near-critical plasma, particularly in the transverse direction. The resulting proton beams differ in maximum longitudinal momentum (0.29-0.35 mi c) and transverse profile. The most efficient acceleration, with a cutoff energy of 40 MeV and ultra-low divergence (~25 mrad), occurs when the driver is focused at the center of the target.
Next, we modify the phase structure and polarization of the laser pulse, transitioning from a linearly polarized twisted beam to cylindrical vector beams with radial and azimuthal polarization, all exhibiting hollow, cylindrically symmetric intensity profiles. This change primarily affects the proton beam's maximum energies, influenced by the ultra-relativistic direct laser-accelerated (DLA) electrons, efficiently generated only by the radially polarized and twisted laser pulses. However, the bulk properties of the proton beam remain similar, as the relativistic mid-energy electrons (< 25 MeV), which sustain a strong sheath field, are the main contributors to proton acceleration in this setup.

Synthesis and Physicochemical, Electrical and Magnetic Properties of Bulk and Film Samples of Ferromagnetic MnSb (Review)

Synthesis and Physicochemical, Electrical and Magnetic Properties of Bulk and Film Samples of Ferromagnetic MnSb (Review)

ON IDENTIFICATION OF PARAMETERS OF A NONLINEAR CONSOLIDATION MODEL OF SANDY SOIL

Previously, the authors of this article formulated a physically and geometrically nonlinear formulation of the problem of porous fluid-saturated medium deformation during fluid filtration (consolidation problem) in terms of the rate of solid phase displacement and the change in pore pressure in differential and variational forms. The developed consolidation model takes into account changes in the porosity and permeability of the medium during deformation. Deformation-type constitutive relations are used in the model. The developed consolidation model can be used to simulate non-stationary processes in the soil, for example, the formation of ruts and unevenness of dirt roads, as well as to calculate the uneven settlement of engineering structures. This work is devoted to the experimental determination of the deformation and strength properties of water-saturated sandy soils, which is the next stage in the consolidation process simulation. The results of the experimental determination of the bulk and shear properties of sandy soil using the ASIS automated complex (OOO NPP “Geotek”) are presented. The studies were carried out on three quartz sands of various grain sizes. To determine the volumetric moduli of dry and water-saturated sandy soils, compression tests were carried out under a continuously growing vertical load at a constant strain rate. The experiments were carried out for various strain rates in the range from 3·10–6 to 3·10–3 s–1. According to the experimental results, the bulk properties do not depend on the strain rate in the specified range. Deformation and strength shear characteristics of sandy soils were determined by the method of multiplanar shear, approximating a simple shear. The tests were carried out under a kinematically applied shear load with a given constant strain rate according to the scheme of consolidated-drained shear. The dependences of the deformation and strength properties of coarse and fine quartz sands on the shear strain rate in the range from 2·10–4 tо 4·10–3 s–1 were studied. Increasing, decreasing and nonmonotonic dependences of the internal friction angle on the shear strain rate were obtained for dry and water-saturated sands of various grain sizes. For water-saturated sands, the maximum spread in the values of the internal friction angle for different strain rates does not exceed 7 %. A technique has been developed for recalculating the obtained properties and experimental dependences into the parameters of the proposed sandy soil consolidation model.

­­­­­­Exploring surface diversification of polyvinyl alcohol/polyethylene glycol Composites by cold plasma: Ompact of Argon and oxygen plasmas on biomedical application

Tetraethyl orthosilicate was used as a crosslinker to create composites made of polyvinyl alcohol and polyethylene glycol (PVA/PEG (PP)). The composites were exposed to non-thermal plasma (NTP) treatment with an Argon and oxygen gas mixture. The NTP treatment resulted in an improvement in surface hydrophilicity. Physiographical investigations indicated surface nanotexturing, but bulk properties were unaffected. After twenty days of exposure to air, there was no detectable ageing effect, showing that the NTP-modified composites were extremely robust. The composites swelled more in intestinal pH than at gastric pH. The NTP-modified composites shown significant Biofilm eradication activity against E. coli. Plasma treated composites shown Greater antibacterial activity against E.coli and enterobacilous bacteria. Mechanical properties enhances with application of different carrier gases in the non-thermal plasma process. Release characteristics of the composites validated the controlled delivery of anticancer drug sulforaphane to the intestine. Biodegradability character increases for the plasma treated composites over the subsequent days. It was also discovered that the hydrogels were biodegradable. PVA/PEG composites treated with O and Ar plasma are therefore effective for a variety of biomedical applications.

Polymeric innovations in drug delivery: Enhancing therapeutic efficacy

Drug delivery is the method or process of administering pharmaceutical compounds to achieve a therapeutic effect in humans or animals. Drug delivery technologies are designed to modify the release, absorption, distribution, and elimination of drugs to enhance therapeutic effectiveness, safety, and patient adherence. Innovative drug delivery systems provide a variety of approaches, such as oral, injectable, implantable, pulmonary, nasal, transmucosal, transdermal, and topical routes, along with options for delivering proteins and peptides. Polymers, due to their large molecular structure and diverse functional groups, play a pivotal role in these systems. Progress in polymer science has paved the way for the development of advanced drug delivery platforms. To optimize polymer-based drug delivery, it is essential to carefully evaluate both surface and bulk properties during the design process. This review explores the use of natural and synthetic polymers in oral drug delivery systems. Natural polymers include protein-based polymers like collagen, albumin, and gelatin, and polysaccharides such as alginate, chitosan, dextran, gums, hyaluronic acid, starch, and cellulose. Synthetic polymers are classified into biodegradable types, which include polyesters such as polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxybutyrate-co-valerate (PHBV), polycaprolactone (PCL), and poly(lactide-co-glycolide) (PLGA). Additionally, they encompass poly anhydrides like poly sebacic acid and poly adipic acid. Non-biodegradable synthetic polymers include silicones, cellulose derivatives, synthetic carbonates, acrylics, and others like vinyl chloride polymer and copolymers, styrene acrylonitrile polymer (SAN), acrylonitrile butadiene styrene polymer (ABS), and polystyrenes. This review focuses on summarizing recent progress in polymer-based drug delivery systems, emphasizing their capability to improve therapeutic effectiveness and promote patient adherence.

Ameliorating Defects in Wide Bandgap Tin Perovskite Solar Cells Using Fluorinated Solvent and Hydrazide.

Surface passivation with multifunctional molecules is an effective strategy to mitigate the defect and improve the performance and stability of perovskite solar cells (PSCs). Here, the fabrication of awide bandgap-PSC is reported with tin perovskite (WB-Sn-HP; bandgap: 1.68 eV), followed by molecular surface passivation using 4-Fluoro-benzohydrazide (F-BHZ). WB-Sn-PSC has demonstrated a promising device efficiency of 11.14% with improved device stability. The key to enhancing device performance lies in the meticulous engineering of both surface and bulk properties of WB-Sn-HP film with F-BHZ treatment as a consequence of stronger electrostatic potential and molecular interaction with hydrazine and carbonyl functionalities. A compact perovskite film and highly crystalline film growth results in a longer carrier lifetime and surface defect mitigation with the control of Sn2+ oxidation as supported by theoretical calculations. This work underlines the promising potential of chemical engineering to improve the device performance of WB-Sn-PSC and stabilityusing multifunctional passivating molecules.

Atmospheric Abundances and Bulk Properties of the Binary Brown Dwarf Gliese 229Bab from JWST/MIRI Spectroscopy

Atmospheric Abundances and Bulk Properties of the Binary Brown Dwarf Gliese 229Bab from JWST/MIRI Spectroscopy

Surface Characterization of Bone-Level and Tissue-Level PEEK and Titanium Dental Implant Scan Bodies After Repeated Autoclave Sterilization Cycles.

Background: Sterilization is required for any biomedical device intended to be used in contact with the human body. Several studies have reported alterations in the bulk and surface properties of such devices after repeated sterilization cycles. These surface modifications may influence other clinical parameters. Therefore, the aim of this study was to investigate the surface and chemical properties of implant scan bodies (SBs) after consecutive autoclave sterilization procedures. Methods: The objective was to analyze the scan bodies using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) for chemical analysis and an optical profilometer to analyze the surface roughness. Results: FTIR spectra depicted the appearance of peak at 1741 and 1100 cm-1 due to the diphenyl ether band disappearance. The XPS spectra showed alterations in the elemental composition after autoclaving and roughness were significantly reduced in PEEK BL and TL SBs. Conclusions: These results indicated that some surface modifications were induced by repeated sterilization cycles.

Halogenated Anils of Sulfanilamide: Structural, Hirshfeld, and Optical Studies

AbstractChemistry of functional organic materials is interesting in terms of design and applications. Halogen functionalization of organic molecules is intriguing as besides affecting the intramolecular electronic properties, their presence triggers intermolecular halogen bonds, affecting both packing and bulk properties. We report the rationally substituted halogenated anils of sulfanilamide 1–3 to understand the influence of halogens on molecular packing and bulk properties. The products 1 and 2 exhibit thermal stability beyond 300 ⁰C, whereas 3 undergoes early weight loss, indicating the presence of lattice solvent. The phase purity of the products has been confirmed with powder X‐ray analyses. Products have been further characterized through single‐crystal diffraction studies to understand crystal packing with further support from Hirshfeld studies. X⋯O interactions are predominant interactions and significant interhalogen X⋯X interactions are observed only in 2. The products are feebly emissive in solid‐state. Interestingly, 2 and 3 in thin film forms undergo emission quenching, whereas 1 exhibits augmented emission. AIE active anil 1 has been used for the sensing of explosive aromatic compound like picric acid.

Characterisation of TOI-406 as a showcase of the THIRSTEE program

Context. The exoplanet sub-Neptune population currently poses a conundrum, as to whether small-size planets are volatile-rich cores without an atmosphere, or rocky cores surrounded by a H-He envelope. To test the different hypotheses from an observational point of view, a large sample of small-size planets with precise mass and radius measurements is the first necessary step. On top of that, much more information will likely be needed, including atmospheric characterisation and a demographic perspective on their bulk properties. Aims. We present here the concept and strategy of the THIRSTEE project, which aims to shed light on the composition of the sub-Neptune population across stellar types by increasing their number and improving the accuracy of bulk density measurements, as well as investigating their atmospheres and performing statistical, demographic analysis. We report the first results of the program, characterising a new two-planet system around the M-dwarf TOI-406. Methods. We analysed TESS and ground-based photometry together with high-precision ESPRESSO and NIRPS/HARPS radial velocities to derive the orbital parameters and investigate the internal composition of the two planets orbiting TOI-406. Results. TOI-406 hosts two planets with radii and masses of Rc = 1.32 ± 0.12 R⊕, Mc = 2.08−0.22+0.23 M⊕ and Rb = 2.08−0.15+0.16 R⊕, Mb = 6.57−0.90+1.00 M⊕, orbiting with periods of 3.3 and 13.2 days, respectively. The inner planet is consistent with an Earth-like composition, while the external one is compatible with multiple internal composition models, including volatile-rich planets without H/He atmospheres. The two planets are located in two distinct regions in the mass-density diagram, supporting the existence of a density gap among small exoplanets around M dwarfs. With an equilibrium temperature of only Teq = 368 K, TOI-406 b stands up as a particularly interesting target for atmospheric characterisation with JWST in the low-temperature regime.

Unveiling the Influence of Natural Weathering on the Nanomechanical Properties of Magnetorheological Elastomers

Examining the physical aging of materials is essential for assessing their long-term performance and determining their suitability for specific applications. Material aging involves changes from their initial state, including deterioration or degradation. A key example of such a progressive, continuous process is the aging of materials in response to natural weathering conditions. While extensive research has focused on macro- and micro-scale aging, further investigation at the nanoscale could provide a more detailed understanding of material deterioration. This study explores the nanomechanical properties of magnetorheological elastomers (MREs) after nine months of natural weathering, focusing on stiffness, elasticity, surface roughness, and adhesion at the nanometer scale. Atomic Force Microscopy (AFM) with a sharp tip affixed to a cantilever was employed to characterize these properties. After nine months of exposure to natural weathering, MREs exhibited unique nanomechanical changes compared to their bulk properties, highlighting the significance of nanoscale analysis. At the nanoscale, the nanomechanical properties of MREs, including stiffness and elasticity, exhibited noticeable alterations within the first month of exposure, followed by a gradual reduction, and slight increments observed up to the nine-month mark. Surface roughness steadily increased over the nine months, while adhesion energy initially rose during the first month before gradually decreasing by the end of the study. These findings provide valuable insights into the material's mechanical behavior and offer a deeper understanding of its structural and functional properties at the nanoscale.

Liquid phase exfoliation of α-SnSe nanosheets: Exploring the role of solvents

Abstract In this study, we used a top-down approach to fabricate 2D SnSe nanosheets via the liquid phase exfoliation (LPE) technique. Bulk SnSe was dispersed in six different solvents: isopropyl alcohol (IPA), absolute ethanol, N-Methyl-2-pyrrolidone (NMP), acetone, methanol, and deionized (DI) water. The solutions containing bulk SnSe were ultrasonicated and subjected to high-speed centrifugation. Comprehensive characterization of both the bulk and exfoliated samples was conducted using various techniques. X-ray diffraction (XRD) analysis confirmed the orthorhombic crystal structure of bulk SnSe. Raman spectroscopy was used to examine the vibrational properties of both bulk and exfoliated SnSe, showing distinct B 3g and A g 3 modes at ~115.6 and 150 cm−1, respectively. Morphological analysis using both Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) revealed the formation of few-layer nanosheets. Additionally, UV-visible spectroscopy was employed to investigate the optical properties and the stability of the exfoliated SnSe nanosheets.