Structural Properties Of System Research Articles

Study of Structural, Thermal and Electrical Properties of Sr-Doped CaMnO<sub>3</sub>

Sr-doped CaMnO3 materials have wide applications due to their thermal and electrical properties. The importance of the synthesis of Sr-doped CaMnO3 material for various applications encourages researchers to evaluate and refine the synthesis process. In this study, Ca1-xSrxMnO3 (x = 0; 0.05; 0.1; 0.15; 0.2) system has been prepared by sol-gel method followed by conventional sintering process at 850°C for 8 hr. A thorough discussion has been made on the outcomes derived from the investigation on the structural, electrical, and thermal properties of Sr-doped CaMnO3 system using powder x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, DC fourprobe method, thermal expansion studies, and thermoelectric power analyses. The XRD patterns of all prepared samples exhibited single phase with orthorhombic crystal structure (space group Pnma). Rietveld refinements were performed for all the patterns by using Fullprof software to extract the structural properties. The values of unit cell volume of samples tend to increase with the increment of dopant concentration, whereas the crystallite size values were decreased with dopant concentration. The microstructures of all the samples were studied using SEM, and elemental compositions were confirmed from the EDS results. Linear thermal expansion coefficients of all the samples were found to have moderate values in the temperature range from 30°C to 800°C. The electrical properties of all the system of samples were studied in the temperature range from 30°C to 400°C using DC fourprobe conductivity setup. It was found that all the samples exhibited semiconductor nature. Sr-content on the A-site suppress the electrical resistivity up to 10% of concentration and 5% dopant content exhibited the lowest electrical resistivity. The values of Seebeck coefficient found to vary from -160 µV/K to -124 µV/K with the increase of dopant content in the parent compound.

Exploring the diverse modifiers influence on the structural, physical, and mechanical properties of a zinc oxide-based boro-tellurite glass system for enhancing radiation shielding performance

This work is meant to fabricate zinc boro-tellurite (ZnO–TeO2–B2O3) glass systems with various modifiers, including MoO3, Bi2O3, and PbO, using the melt quench technique. Four glass samples were produced, each comprising 20 % of a specific modifier from the total weight percent of the neat glass system. Each glass sample is given a code: TBZn, TBZMo, TBZBi, and TBZPb. The XRD results showed an amorphous nature for all glass samples. The FTIR results showed the functional groups for borate and tellurite oxide. The mechanical properties were reduced when different oxides were added instead of ZnO. For example, Young's modulus decreased for glass samples; their recorded values for Young's modulus are 74.516, 72.569, 60.526, and 59.272 GPa for TBZn, TBZMo, TBZBi, and TBZPb, respectively. On the other hand, adding Bi2O3 and PbO led to enhanced shielding properties. For instance, the linear attenuation coefficient values for TBZn, TBZMo, TBZBi, and TBZPb at 0.015 MeV are 168.739, 115.656, 380.711, and 279.162, respectively. Also, the radiation protection efficiency (RPE) at 5 cm and 600 keV is 83.220 %, 79.299 %, 93.919 %, and 90.222 % for TBZn, TBZMo, TBZBi, and TBZPb, respectively. While adding different oxides decreased stability in the current glasses, it also enhanced their shielding properties, recommending their use in the radiation shielding field.

Impact of Zn-Ion Doping on the Structural and Optical Properties of Cobalt Chromite System

The structural and optical properties of Zn-ion doped CoCr2O4 multiferroic materials were investigated in this work. We successfully synthesized Co[Formula: see text]ZnxCr2O4 ([Formula: see text], 0.2 and 0.4) polycrystalline samples using the conventional solid-state reaction route method. The XRD pattern confirmed the cubic spinel structure of the Zn-doped CoCr2O4 samples, with the Fd3m space group. The Williamson–Hall (W–H) and Debye–Scherrer techniques were employed to determine the crystalline size of the cobalt chromite system. The average crystalline sizes, calculated using the Debye–Scherrer formula, were found to be 35[Formula: see text]nm, 34[Formula: see text]nm and 32[Formula: see text]nm, for the CoCr2O4, Co[Formula: see text]Zn[Formula: see text]Cr2O4, and Co[Formula: see text]Zn[Formula: see text]Cr2O4 samples, respectively. These results show that the crystalline size calculated using the Debye–Scherrer formula decreased with an increase in Zn doping. We observed from the Raman spectra, the presence of three distinct bands at 188[Formula: see text]cm[Formula: see text] (F2g), 504[Formula: see text]cm[Formula: see text] (F2g), 662[Formula: see text]cm[Formula: see text] (A1g) and one weak band at 434[Formula: see text]cm[Formula: see text](Eg). These Raman bands are also present in the Zn-doped CoCr2O4 system, indicating structural stability even with doping. The energy band gap, calculated using the tauc plot, was determined as 3.15[Formula: see text]eV, 3.24[Formula: see text]eV and 3.27[Formula: see text]eV for CoCr2O4, Co[Formula: see text]Zn[Formula: see text]Cr2O4 and Co[Formula: see text]Zn[Formula: see text]Cr2O4 samples, respectively. The formation of the cobalt chromite spinel system was further confirmed by the FT-IR spectra.

Computational insights into the structural, thermodynamic and transport properties of CaF2-MgF2 binary fluoride system at high temperatures

The structural, thermodynamic and transport properties of the CaF2-MgF2 molten salt system were investigated with ab initio molecular dynamics (AIMD), system-specific neural network interatomic potentials (NNIPs) and universal PreFerred Potentials (PFP). We trained an NNIP model using AIMD data as input and used this potential to efficiently simulate the interactions within a large supercell in a temperature range of 1273–1773 K. The Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) code was employed to validate our trained NNIP model. The Matlantis software with universal PFP is also presented to prove its feasibility for MD calculations and can be considered as a useful alternative simulation tool for higher-order systems where existing potentials are not readily available. We calculated structural and thermodynamic properties including radial distribution function (RDF), angular distribution function (ADF), specific heat capacity, ionic self-diffusivity, and viscosity. Our results indicate that the system exhibited a high degree of structural disorder, with the Ca, Mg, and F ions forming a liquid solution. Using PFP, the positions of the first peak in RDFs for Ca-F and Mg-F pairs are only slightly left-shifted (<0.05 Å), and the estimated viscosity of the melt decreases from 4.613 mPa·s to 1.846 mPa·s with an increase in temperature from 1273 K to 1773 K, in agreement with the NNIP trained specifically for CaF2-MgF2. Our results provide valuable insights into the properties of the CaF2-MgF2 system at high temperatures and serve as predictive models for the development of new electrolytes that could be used for silicon epitaxy by adding silica.

Impact of low frequency ultrasound on physicochemical and structural properties of protein-lactose systems with varying caseins, whey proteins and calcium

This study examines the impact of low-frequency ultrasound on the physicochemical attributes of milk proteins, focusing on various casein-to-whey protein ratios and their interactions with lactose and calcium. Milk systems with varying casein-to-whey protein ratios (0:100, 50:50, 60:40, 80:20), lactose, and various calcium chloride (CaCl2) concentrations (0–30 mM), were exposed to 20 kHz ultrasound for different durations (0, 1, 5, 10 min). A range of physicochemical factors, including particle size, zeta potential, calcium ion activity, pH, and water-holding capacity, were examined. The results revealed that calcium concentration and pH significantly (P < 0.05) influenced the physicochemical and structural properties of milk protein-lactose-calcium systems. FTIR analyses indicated that ultrasound promoted secondary structural changes in milk proteins and enabled the creation of lactose-protein and calcium-lactose complexes. The intermolecular and intramolecular interactions through hydrophobic and covalent bonding prevailed. Understanding these three-way interactions is crucial for innovating stable and shelf-stable dairy formulations, which is essential for advancing dairy processing.

Structural, thermal and X-ray photoelectron spectroscopic properties of boro-tellurite based quaternary glass system

The structural, functional and thermal properties of the TeZnCaB glass system were investigated in this work. The thermal properties of the glass system were studied using DSC (differential scanning calorimetry), and the glass transition temperature (Tg) decreased from 470 °C to 438 °C with increasing TeO2 concentration. The vibrational and bending modes of the TeZnCaB glass samples were depicted by Raman spectroscopy analysis. FTIR (Fourier-transform infrared spectroscopy) was performed to investigate the functional groups of TeO2 and B2O3 in the samples. The TeZnCaB glass samples consist of TeO3, TeO4, BO4 and BO3 structural units. XPS (X-ray photoelectron spectroscopy) was investigated to reveal information about the chemical environment and the creation of NBO (non-bridging oxygen) and BO (bridging oxygen) for the different glass systems. The high-resolution Te3d spectrum confirms the presence of various tellurium-based structural units such as TeO4, TeO3, and TeO3+1. The deconvolution of B1s spectra confirmed the existence of two forms of boron (B) such as BO4 (four coordination) and BO3 (three coordination) in the TeZnCaB glass system.

Study of Electronic and Optical Properties of Low-Dimensional Nanosystems by First Principles Calculations

The development of new techniques for material manipulation at the nanoscale, as well as advanced numerical tools for material design, has opened up new prospects in the engineering of novel low-dimensional systems with properties specifically designed for applications in different fields, from photonics to energy conversion. Zero-, one-, and two-dimensional nanosystems show unique electronic, optical, and transport properties that can be tuned, for instance, by size reduction, passivation, and doping. In this talk, we discuss ab-initio results obtained in the study of structural, electronic, and optical properties of low-dimensional systems, in particular focusing on silicon, germanium, and silicon/germanium nanostructures. The analysis of mechanisms that can be exploited to tune Auger recombination and carrier multiplication processes, as well as of those that affect the formation of the band offset (Type I and Type II) at the nanoscale, will be discussed. At the end, effects induced by anion ordering on electronic and optical properties of metal oxynitrides will be analyzed.

Investigation of structural, electrical, dynamical, optical, and thermoelectric properties of Sr-doped Mg2Si systems using first-principles calculations

Investigation of structural, electrical, dynamical, optical, and thermoelectric properties of Sr-doped Mg2Si systems using first-principles calculations

Effect of Active Phase Precursor on Structural, Textural and Catalytic Properties of the Model NiOx/CeO2 System Active in Dry Reforming of Methane

The current paper is devoted to the synthesis of ceria-supported nickel-based catalysts starting from different precursors of the nickel active phase. Thermal decomposition of metal-containing precursors, deposited onto stable supports by dry impregnation, belongs to the industrially preferred, simple ways of catalyst preparation. The synthesized series of NiOx/CeO2 catalysts have been tested in dry methane reforming (DMR), in which two greenhouse gases, i.e., CO2 and CH4, are simultaneously converted into syngas. Both reaction progress and stability of the catalyst strongly depend on nickel speciation, which in turn can be determined by the nature of the chosen precursor. Contrary to relatively many studies focused on the importance of synthetic methods and conditions on nickel speciation, the effect of precursor nature on structural, textural, and functional properties of catalytic systems has neither been discussed much nor fully understood. The main goal of this paper was to elucidate the effect of precursors on the properties of NiOx/CeO2. Consequences of the use of various nickel precursors (simple inorganic salts, organometallic complexes, and chelates) have been analyzed in detail from the viewpoint of their beneficial influence on the catalytic performance of NiOx/CeO2 system (containing 3 wt. % of Ni) tested in DMR.

Rate Lifting for Stochastic Process Algebra by Transition Context Augmentation

This article presents an algorithm for determining the unknown rates in the sequential processes of a Stochastic Process Algebra (SPA) model, provided that the rates in the combined flat model are given. Such a rate lifting is useful for model reverse engineering and model repair. Technically, the algorithm works by solving systems of nonlinear equations and—if necessary—adjusting the model’s synchronisation structure, without changing its transition system. The adjustments cause an augmentation of a transition’s context and thus enable additional control over the transition rate. The complete pseudo-code of the rate lifting algorithm is included and discussed in the article, and its practical usefulness is demonstrated by two case studies. The approach taken by the algorithm exploits some structural and behavioural properties of SPA systems, which are formulated here for the first time and could be very beneficial also in other contexts, such as compositional system verification.

Tailoring structural and optical properties of ZnO system through elemental Mn Doping through First-principles calculations

In this study, band structure and optical properties of Manganese (Mn) doped ZnO are investigated adopting first-principles study calculations. It is observed that, by addition of Mn in ZnO crystal, the electrical properties like conductivity and dielectric function of material have been improved. The elastic constants for the elements are also calculated which shows that the element is stable after addition of dopant. The computational study is done on CASTEP and Material Studio. The ZnO system is simulated and atoms of Mn has been added replacing Zn atoms. The properties that studied are band structure and optics including conductivity, reflectivity, dielectric function, absorption and refractive index. Furthermore, this study also includes calculation of Elastic constants, XRD Spectra, Phonon dispersion and Temperature profile of doped ZnO systems. The computational study produced promising results and experimental approach can be adopted to reinforce the outcomes of this study.

A comparative study of polyethylene oxide (PEO) using different coarse-graining methods.

Polyethylene oxide (PEO) holds significant importance in the field of batteries due to its high processability, intrinsic properties, and potential for high ionic conductivity. Achieving simulation at different scales is crucial for gaining a comprehensive understanding of its properties and thus improving them. In this context, we conducted a comparative study on the molecular physical structure, thermodynamic, and dynamic properties of PEO using three distinct coarse-grained (CG) procedures and all-atom (AA) simulations. The three CG simulation procedures involved modeling with MARTINI forcefield, SPICA forcefield, and an IBI derived potential from AA simulations. The AA simulation has been performed using the class 2 pcff+ forcefield. The ensuing simulated densities align significantly with the literature data, indicating the reliability of our approach. The solubility parameter from the AA simulation closely corresponds to literature reported values. MARTINI and SPICA yield almost similar solubility parameters, consistent with the similar density predicted by both the forcefields. Notably, SPICA forcefield closely reproduces the intermolecular structure of atomistic systems, as evidenced by radial distribution function (RDF). It also comprehensively replicates the distribution of radius of gyration (Rg) and the end-to-end distance (Re) of the atomistic samples. IBI ranks second to SPICA in emulating the structural properties of the atomistic systems, such as Rg, Re, and RDF. However, IBI falls short in accurately representing the solubility parameter of the amorphous PEO samples, while MARTINI does not provide an accurate representation of the structural properties of the systems. The use of SPICA forcefield results in enhanced dynamics of the systems in comparison with IBI and MARTINI.

The influence of MgO on the physical, structural, mechanical, optical, and radiation absorption properties of the boro-germanate glass system

To study non-traditional glass materials, this investigation created four glass samples composed of (70-x)B2O3–20TeO2-10GeO2-xMgO, where x represents the percentage of MgO with values of 20, 25, 30, and 35 mol%. Glasses with high transparency were produced via the accepted melt quenching and annealing method. The samples underwent X-ray diffraction analysis to confirm their glassy structure. Fourier transform infrared spectroscopy was utilized to examine the glass network's various structural groups. The measuring methodology and theoretical calculations were used to calculate a range of physical and mechanical parameters. The cut-off wavelength, as well as the direct and indirect bandgap, and other optical characteristics of the S1–S4 samples were observed using optical absorption. The work utilized Phy-X to acquire the ionizing absorption parameters. The paper demonstrates various glasses' radiation shielding properties, including the effective atomic number, half- and tenth-value layers, linear attenuation coefficient, mass attenuation coefficient, and mean free path.

Structural properties of linear discrete periodic systems based on fully actuated system approaches

AbstractIn this paper, the structural properties of linear discrete‐periodic systems are investigated using fully actuated system approaches and the related criteria are presented, with emphasis on the observability and controllability criteria based on fully actuated system approaches. Both the high‐order fully measured and high‐order fully actuated models of linear discrete periodic time‐varying systems are constructed, and it is shown that a sufficient and necessary condition for the linear discrete periodic system to be observable (controllable) is that it can be equivalently transformed into a step‐forward high‐order fully measured (fully actuated) model and a step‐backward high‐order fully measured (fully actuated) model. Finally, a numerical example is offered to demonstrate the validity and feasibility of the approach.

Glass-Forming Ability, Chemical Durability, and Structural Properties of Lead Dioxide-Silicate Glass System

The present study aimed to test the solubility of SiO2 in a PbO2 host glass matrix. The new glass system with chemical composition xSiO2∙(100-x)∙PbO2 (in mol%) was obtained at low temperature using the melt-quenching technique. The method proposed for the characterization of the glass system includes X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), inductively coupled plasma mass spectrometry (ICP-Ms), Fourier Transform Infrared (FTIR), and Electron Spin Resonance (ESR) spectroscopy. Understanding the relationship between the oxide composition, structure, chemical durability, and thermal characteristics of obtained materials is essential for further developing the new glass crystalline material (GCM) compositions with specific desired properties.

A sub-100 nm thickness flat jet for extreme ultraviolet to soft X-ray absorption spectroscopy.

Experimental characterization of the structural, electronic and dynamic properties of dilute systems in aqueous solvents, such as nanoparticles, molecules and proteins, are nowadays an open challenge. X-ray absorption spectroscopy (XAS) is probably one of the most established approaches to this aim as it is element-specific. However, typical dilute systems of interest are often composed of light elements that require extreme-ultraviolet to soft X-ray photons. In this spectral regime, water and other solvents are rather opaque, thus demanding radical reduction of the solvent volume and removal of the liquid to minimize background absorption. Here, we present an experimental endstation designed to operate a liquid flat jet of sub-micrometre thickness in a vacuum environment compatible with extreme ultraviolet/soft XAS measurements in transmission geometry. The apparatus developed can be easily connected to synchrotron and free-electron-laser user-facility beamlines dedicated to XAS experiments. The conditions for stable generation and control of the liquid flat jet are analyzed and discussed. Preliminary soft XAS measurements on some test solutions are shown.

Transmission Electron Microscopy and Dynamic Light Scattering-Fundamental Perspective

Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) are fundamental tools in nanotechnology and materials science, providing information about the structural and dynamic properties of nanomaterials and colloidal systems. This review provides a thorough examination of TEM and DLS, beginning with a discussion of their fundamental principles. It discusses the interaction of electron beams in TEM and the dynamics of scattered light in DLS, followed by an examination of instrumentation and experimental setups, including recent advances for increased resolution and sensitivity. The article then discusses the numerous applications of TEM and DLS in nanomaterial characterization. It includes analyses of nanoparticle size, shape, morphology, and distribution, as well as research into colloidal system dynamics such as nanoparticle aggregation, diffusion, and stability. The review concludes with a forward-looking perspective on emerging trends and future directions in nanomaterial characterization. It emphasizes the potential of TEM and DLS to overcome current challenges and advance our understanding of nanoscale phenomena. Overall, this comprehensive review provides researchers and practitioners with a solid understanding of the TEM and DLS principles, methodologies, and applications, as well as valuable fundamental insights.

Modulation of Phospholipase A2 Membrane Activity by Anti-inflammatory Drugs.

The phospholipase A2 (PLA2) superfamily consists of lipolytic enzymes that hydrolyze specific cell membrane phospholipids and have long been considered a central hub of biosynthetic pathways, where their lipid metabolites exert a variety of physiological roles. A misregulated PLA2 activity is associated with mainly inflammatory-derived pathologies and thus has shown relevant therapeutic potential. Many natural and synthetic anti-inflammatory drugs (AIDs) have been proposed as direct modulators of PLA2 activity. However, despite the specific chemical properties that these drugs share in common, little is known about the indirect modulation able to finely tune membrane structural changes at the precise lipid-binding site. Here, we use a novel experimental strategy based on differential scanning calorimetry to systematically study the structural properties of lipid membrane systems during PLA2 cleavage and under the influence of several AIDs. For a better understanding of the AIDs-membrane interaction, we present a comprehensive and comparative set of molecular dynamics (MD) simulations. Our thermodynamic results clearly demonstrate that PLA2 cleavage is hindered by those AIDs that significantly reduce the lipid membrane cooperativity, while the rest of the AIDs oppositely tend to catalyze PLA2 activity to different extents. On the other hand, our MD simulations support experimental results by providing atomistic details on the binding, insertion, and dynamics of each AID on a pure lipid system; the drug efficacy to impact membrane cooperativity is related to the lipid order perturbation. This work suggests a membrane-based mechanism of action for diverse AIDs against PLA2 activity and provides relevant clues that must be considered in its modulation.

NMR Relaxation of Gas Adsorbed in Microporous Material.

NMR relaxometry has been widely applied to characterize fluid confined in porous media because of its versatility, chemical selectivity, and noninvasive nature. Here we extend its usage to gas adsorbed in microporous materials by establishing a new quantitative model based on the molecular level NMR relaxation mechanism revealed by the molecular simulation of a prototypical adsorption system, CH4 adsorbed in ZIF-8. The model enables new NMR relaxometry-based characterization methods for thermodynamic, dynamic, and structural properties of adsorption systems, as demonstrated and validated by the experiments where the adsorption capacity and self-diffusivity of H2, CH4, and small alcohols adsorbed in ZIF-8 are deduced from the NMR relaxation data. The findings can serve for a better understanding of the composition-structure-properties relationships of a wide range of adsorption systems which is essential for the development and application of new functional microporous materials.

Influence of Sm2O3/AgNPs Addition on the Properties of Lithium-Borate Glass-Ceramic System

This work reports the effect of adding Sm2O3 and silver nanoparticles, in small quantities up to 1 mol%, on the optical and structural properties of the B2O3-Li2O glass-ceramic system. The X-ray diffraction patterns of the samples show the presence of small quantities of the B2O3 crystalline phase, in addition to a major amorphous phase. Various structural units like BO3, BO4, and LiO4, present in the samples network, are responsible for the absorption bands from the FT-IR spectra. The optical spectra provided valuable information such as the identification of the observed electronic transitions, the energy gap, the refractive index, and metallization values. The luminescence data show the fact that with the addition of metallic NPs the quenching phenomenon can be observed after 0.5 mol% samarium ions. The studied systems are interesting for optical and semiconducting devices.