Fundamental Physical Parameters Research Articles

Modeling of ion cyclotron resonance frequency heating of proton-boron plasmas in EHL-2 spherical tokamak

Ion cyclotron resonance heating (ICRH) stands out as a widely utilized and cost-effective auxiliary method for plasma heating, bearing significant importance in achieving high-performance discharges in p-11B plasmas. In light of the specific context of p-11B plasma in the EHL-2 device, we conducted a comprehensive scan of the fundamental physical parameters of the antenna using the full-wave simulation program TORIC. Our preliminary result indicated that for p-11B plasma, optimal ion heating parameters include a frequency of 40 MHz, with a high toroidal mode number like to heat the majority H ions. In addition, we discussed the impact of concentration of minority ion species on ion cyclotron resonance heating when 11B serves as the heavy minority species. The significant difference in charge-to-mass ratio between boron and hydrogen ions results in a considerable distance between the hybrid resonance layer and the tow inverted cyclotron resonance layer, necessitating a quite low boron ion concentration to achieve effective minority heating. We also considered another method of direct heating of hydrogen ions in the presence of boron ion minority. It is found that at appropriate boron ion concentrations ( ), the position of the hybrid resonance layer approaches that of the hydrogen ion cyclotron resonance layer, thereby altering the polarization at this position and significantly enhancing hydrogen ion fundamental absorption.

Strain Effects in the Work Function and Charge Transfer of the Au(111) Surface.

Work function (WF) is one of the most fundamental physical parameters of metal surfaces, which can not only reflect the electronic structure of metal surfaces but is also very sensitive to the surface microstructure. In this paper, we use first-principles calculations to systematically study the strain effects on the vacuum level, Fermi level, and WF of the Au(111) surface. We find that the vacuum level and Fermi level of the Au(111) surface increase under compressive strain and decrease under tensile strain, and the effects of biaxial strain on the vacuum level and Fermi level can be equivalent to the superposition of two perpendicular uniaxial strains. These strain effects are attributed to the charge transfer induced by the strain. However, the change of WF with strain is the result of the competition between the strain effects of the vacuum level and Fermi level. That leads to the WF increasing with compressive uniaxial strain and decreasing with tensile uniaxial strain. Moreover, because the Fermi level is more responsive to compressive uniaxial strain, the Fermi level changes faster than the vacuum level under compressive biaxial strain. Consequently, the WF decreases with increasing tensile biaxial strain and slightly increases before decreasing with increasing compressive biaxial strain.

Investigation of a W UMa-type contact binary GZ And in a physical triple system

GZ And is a variable star within the visually observed multiple-star system ADS 1693. Recent observations have yielded new light curves for GZ And, obtained using the Xinglong 85-cm telescope and the Transiting Exoplanet Survey Satellite (TESS) satellite. These light curves, along with radial velocity curves, were analyzed simultaneously to ascertain the fundamental physical parameters of GZ And’s components. The findings indicate that the primary star has a mass of M1 = 0.57 (4)M⊙, radius of R1 = 0.75 (2)R⊙, and luminosity of L1 = 0.42 (2)L⊙. The secondary star is characterized by a mass of M2 = 1.19 (9)M⊙, radius of R2 = 1.04 (3)R⊙, and luminosity of L2 = 0.63 (3)L⊙. Their orbital separation is determined to be a = 2.30 (6)R⊙. An analysis of the accumulated times of light minima reveals that GZ And is undergoing orbital period variations at a rate of dP/dt = −7.58 (7) × 10−8day ⋅ year−1, likely due to mass transfer from the more massive component to its lighter counterpart at a rate of dM2/dt = −9.06 (8) × 10−8M⊙⋅ year−1. Additionally, distance measurements for the component stars in ADS 1693, derived from Gaia DR3 astrometric data, suggest that ADS 1693A (GZ And) and ADS 1693B are gravitationally bound and likely originated from the same molecular cloud, sharing similar ages. This evidence supports the classification of GZ And as a W UMa-type contact binary within a physically associated triple system.

Instrumental broadening and the radial pair distribution function with 2D detectors.

The atomic pair distribution function (PDF) is a real-space representation of the structure of a material. Experimental PDFs are obtained using a Fourier transform from total scattering data which may or may not have Bragg diffraction peaks. The determination of Bragg peak resolution in scattering data from the fundamental physical parameters of the diffractometer used is well established, but after the Fourier transform from reciprocal to direct space, these contributions are harder to identify. Starting from an existing definition of the resolution function of large-area detectors for X-ray diffraction, this approach is expanded into direct space. The effect of instrumental parameters on PDF peak resolution is developed mathematically, then studied with modelling and comparison with experimental PDFs of LaB6 from measurements made in different-sized capillaries.

Impact of inclined magnetic field on natural convection in ferrofluid within a semi-circular enclosure with a heated wavy surface

Ferrofluids are liquids that exhibit distinctive magnetic properties when subjected to a magnetic field. Due to their magnetic susceptibility, ferrofluids have recently gained considerable scientific attention. They find tools in different fields, such as electronics, mechanical engineering, and materials science. The inclusion of the semi-circular enclosure inscribed around a heated wavy cylinder provides innovative perspectives essential for engineering applications involving induction furnaces and cancer therapy devices. This paper aims to conduct a computational investigation into the influence of an inclined magnetic field on the free convection within a semi-circular cage stuffed with a ferrofluid featuring an internally undulating surface. It is considered that the interior wavy cylinder was warmed ( T h ) , and the outer semi-circular enclosure is cold ( T c ) . The analyzed system’s governing equations are computed using the Galerkin finite element method (GFEM). The ferrofluid’s flow pattern and thermal transport rate are investigated about relevant non-dimensional values, such as the wave numbers, the number of Hartmann ( 0 ≤ Ha ≤ 20 ) , the number of Rayleigh ( 10 3 ≤ Ra ≤ 10 6 ) , and the volume fraction ( 0.00 ≤ ϕ ≤ 0.09 ) . Evaluating the results involves examining isotherms, analyzing the distribution of flow velocities, and calculating the Nu avg , all while considering variations in fundamental physical parameters. As the Hartmann number ( Ha ) decreases and both the number of Rayleigh ( Ra ) and volume fraction ( ϕ ) rises, the Nu avg of the ferrofluid exhibits an increased. As a result of incorporating ferroparticles, the simulation identifies a maximum value of 35.86 for the Nu avg . It is worth noting that an enhance in Hartmann numbers is associated with an 80% decrease in the velocity stream function. On the other hand, an escalation in ferroparticle values leads to a 9.7% reduction, while elevated Rayleigh numbers result in a 60.8% surge in the stream function. Moreover, the irreversibility stemming from fluid friction, transfer of heat, and the magnetic field can be minimized for ferrofluid fluids ( n = 1 ), by employing the optimal parametric combination.

Impact of Pediococcus pentosaceus containing multicopper oxidase gene on biogenic amine accumulation and quality of Xinjiang sausage during ripening

Herein, we investigated the impact of Pediococcus pentosaceus containing the multicopper oxidase (MCO) gene on fundamental physical and chemical parameters, biogenic amines (BAs) accumulation, MCO gene expression levels, and the quality of Xinjiang sausage. Our findings revealed that the introduction of Pediococcus pentosaceus altered the predominant microbial composition in the sausage, establishing itself as the dominant species during the fermentation process. Moreover, Pediococcus pentosaceus demonstrated the ability to suppress the accumulation of BAs in the sausage by inhibiting the growth of Enterobacteria and upregulating the expression of the MCO gene. Additionally, the incorporation of Pediococcus pentosaceus facilitated the degradation of protein in the sausage, resulting in an increased content of free amino acids, and also increased the appearance, color, texture and overall acceptability scores of sausages. Overall, our results highlight the potential of Pediococcus pentosaceus containing MCO gene in reducing BAs accumulation and improving the sensory quality of Xinjiang sausage.

A rotating magneto-photothermoelastic effect with moisture diffusivity of nonlocal semiconductor medium

This study focuses on investigating the deformation of a one-dimensional elastic nonlocal semiconductor medium. The aim is to understand how the magnetic field and moisture diffusivity affect this deformation. The research aims to analyze the connection between plasma and moisture diffusivity processes in a rotational field, as well as thermo-elastic waves. The study examines the transport process of photo-thermoelasticity while considering the influence of moisture diffusivity. To derive the governing equations of the photo-thermo-elastic medium, Laplace’s transformation technique is used. These equations encompass the carrier density, elastic waves, moisture transport, heat conduction, and constitutive relationships. The fundamental physical parameters in the Laplace domain, such as mechanical stresses, thermal conditions, and plasma boundary conditions, are calculated. Numerical techniques are employed to invert the Laplace transform and obtain complete time-domain solutions for the various physical domains under investigation. The analysis takes into account reference moisture, nonlocality, magnetic field and rotation field. The effects of applied forces on displacement, moisture concentration, carrier density, stress resulting from forces, and temperature distribution are considered through graphical analysis.

Multifunctional Optical Sensing with Lanthanide-Doped Upconverting Nanomaterials: Improving Detection Performance of Temperature and Pressure in the Visible and NIR Ranges.

Temperature and pressure are fundamental physical parameters in the field of materials science, making their monitoring of utmost significance for scientists and engineers. Here, the NaSrY(MoO4)3:0.02Er3+/0.01Tm3+/0.15Yb3+ nanophosphor is developed as an optical sensor material. Under 975 nm laser excitation, the upconversion characteristics and optical detection performance of the multifunctional sensing platform of temperature and pressure (vacuum) are investigated. We have successfully developed a novel detection platform that enables optical detection of pressure (vacuum) and temperature. This platform utilizes thermally coupled levels (TCLs) and non-TCLs of Er3+ and Tm3+ to achieve ratiometric detection. The multimodal optical temperature and pressure detection based on TCLs and non-TCLs is successfully realized by using different emission bands of double emission centers, which makes it possible for self-referencing optical temperature and pressure measurement modes. These results indicate that the developed nanophosphor is a promising candidate for optical sensors, and our findings suggest potential strategies for modulating the sensor properties of luminescent materials doped with rare-earth ions.

Evaporative Drying Induced Self-Assembly of Epicuticular Wax: A Biomimetic Approach in Tuning Surface Roughness.

Epicuticular wax is an example of a naturally created functional material that forms a layer on the outermost surface of plants with the objective to protect them from adverse environmental conditions, such as UV-solar radiation, uncontrolled water loss, microbial attacks, and so forth. Their functionalities are often attributed to the chemical composition of the wax as well as the physical structuration formed by the wax crystals on the surface. With this work, we present a simple, one-step biomimetic approach to replicate similar surface structures, on model substrate, using wax extracted from Euphorbia Cerifera (Candelilla wax). First, we describe formation of structured wax due to self-assembly induced by evaporative drying on quartz plates. Subsequently, we highlight the fundamental physical parameters required to tune the surface morphology. Our experiments reveal that it is possible to achieve considerably diverse surface morphologies depending on the solvent properties and deposition temperature. This diversity is due to the kinetics of recrystallization of wax during evaporation of solvent which, in turn, is primarily driven by the solubility of wax as well as evaporation rate of the solvent. Thus, the final morphology that we obtain is an interplay between recrystallization kinetics and solvent evaporation. Additionally, the degree of crystallinity of the structured films could also be tuned by solvent polarity. Surprisingly, X-ray diffraction indicates that the crystalline structure at the molecular level remains similar to that of bulk Candelilla wax. Our results provide fundamental insights into the replication of epicuticular wax films and identification of tuning parameters to obtain different surface morphologies with the same wax material for potential bioinspired multifunctional coatings in cosmetic applications.

How Can the Optical Variation Properties of Active Galactic Nuclei Be Unbiasedly Measured?

The variability of active galactic nuclei (AGNs) is ubiquitous, but has not yet been understood. Measuring the optical variation properties of AGNs, such as the variation timescale and amplitude, and then correlating them with their fundamental physical parameters has long served as a critical way of exploring the origin of AGN variability and the associated physics of the accretion process in AGNs. Obtaining accurate variation properties of AGNs is thus essential. It has been found that the damped random walk process can describe the AGN optical variation well, but there is a controversy over how long a minimal monitoring baseline is required to obtain unbiased variation properties. In this work, we settle the controversy by exhaustively scrutinizing the complex combination of assumed priors, adopted best-fit values, ensemble averaging methods, and fitting methods. The new proposal is then an optimized solution where unbiased variation properties of an AGN sample possessing the same variation timescale can be obtained with a minimal baseline of about 10 times their variation timescale. Finally, the new optimized solution is used to demonstrate the positive role of the time-domain surveys to be conducted by the Wide Field Survey Telescope in improving constraints on AGN variation properties.

Supersensitive visual pressure sensor based on the exciton luminescence of a perovskite material.

Accurate, rapid, and remote detection of pressure, one of the fundamental physical parameters, is vital for scientific, industrial, and daily life purposes. However, due to the limited sensitivity of luminescent manometers, the optical pressure monitoring has been applied mainly in scientific studies. Here, we developed the first supersensitive optical pressure sensor based on the exciton-type luminescence of the Bi3+-doped, double perovskite material Cs2Ag0.6Na0.4InCl6. The designed luminescent manometer exhibits an extremely high sensitivity, i.e. dλ/dp = 112 nm GPa-1. It also allows multi-parameter sensing, using both blue-shift and rarely observed band narrowing with pressure. Importantly, this material has small temperature dependence for the manometric parameter used, i.e. spectral shift, allowing detection under extreme pressure and temperature conditions. The developed sensor operates in the visible range, and its emission shifts from orange to blue with pressure. This approach allowed us to demonstrate the real-world application of this sensor in detecting small changes in pressure with a designed uniaxial pressure device, with unprecedented resolution of the order of a few bars, demonstrating the technological potential of this sensor for remote, online monitoring of cracks and strains in heavy construction facilities.

Effects of heat-treatment on physical and mechanical properties of limestone

The susceptibility of buildings to fire makes it crucial to examine the physical and mechanical (P&M) properties of building stones under high temperature, which is necessary to predict and evaluate the safety and stability of stone structures. In this study, uniaxial compression (UC) and Brazilian splitting (BS) tests were performed on heat-treated limestone specimens and digital image correction (DIC) techniques were utilized to measure specimen deformation. Correlation analysis (CA) and principal component analysis (PCA) were conducted on the mechanical parameters obtained from the UC and BS tests, resulting in the establishment of three principal components (y1c, y2c and y1t) that comprehensively reflect the compressive and tensile properties; these were then utilized to analyze the sensitivity of mechanical properties to temperature changes. Furthermore, based on prior experimental data regarding the fundamental physical parameters of granite, one principal component (y1w) that comprehensively reflects fundamental physical characteristics was established and utilized to predict the uniaxial compression strength (σc) and tensile strength (σt). The results indicate that the compressive properties (σc, Poisson's ratio, elastic modulus and principal compressive strain) and tensile properties (σt and tensile strain) are all affected by temperature changes; as tensile strength is sensitive to temperature changes, special attention should be paid to fire and high temperature of stone buildings with the components subjected to the tensile stress; basic mechanical properties (σc and σt) can be well predicted by a principal component (y1w) which provides a new idea for calculating indirectly the residual mechanical properties of building stones after high temperature or fire.

Variable gravity effects on penetrative porous convection

The effect of variable gravity on the onset of penetrative convection in a horizontal fluid-saturated porous layer is studied, performing the linear instability analysis and the nonlinear stability analysis (via the weighted energy method) of the thermal conduction solution. The linear and nonlinear critical Rayleigh numbers for the onset of penetrative porous convection are determined and their behaviour with respect to the fundamental physical parameters of the model is studied. In particular, we found that there exists a region of subcritical instabilities and that the increase of the upper bounding plane temperature and the decrease of gravity have a stabilizing effect on the onset of convection.

Evaluation of Austenite-Ferrite Phase Transformation in Carbon Steel Using Bayesian Optimized Cellular Automaton Simulation.

Austenite-ferrite phase transformation is a crucial metallurgical tool to tailor the properties of steels required for particular applications. Extensive simulation and modeling studies have been conducted to evaluate the phase transformation behaviors; however, some fundamental physical parameters still need to be optimized for better understanding. In this study, the austenite-ferrite phase transformation was evaluated in carbon steels with three carbon concentrations during isothermal annealing at various temperatures using a developed cellular automaton simulation model combined with Bayesian optimization. The simulation results show that the incubation period for nucleation is an essential factor that needs to be considered during austenite-ferrite phase transformation simulation. The incubation period constant is mainly affected by carbon concentration and the optimized values have been obtained as 10-24, 10-19, and 10-21 corresponding to carbon concentrations of 0.2 wt%, 0.35 wt%, and 0.5 wt%, respectively. The average ferrite grain size after phase transformation completion could decrease with the decreasing initial austenite grain size. Some other parameters were also analyzed in detail. The developed cellular automaton simulation model combined with Bayesian optimization in this study could conduct an in-depth exploration of critical and optimal parameters and provide deeper insights into understanding the fundamental physical characteristics during austenite-ferrite phase transformation.

A novel electrochemical method determining pKa and transport parameters of buffers using acid-base transport limitation response

Dissociation constant (logarithmic form, pKa) and diffusion coefficient (D) are two fundamental physical parameters for weak acids and bases (buffers). Their effortless determinations from one method are not available yet. Herein, we propose an innovative method to determine pKa and D values based on a brand-new principle of electrochemical acid-base transport limitation (eABTL). The significance of eABTL lies in its ability to relate inert buffers to electrode reactions, enabling the acquisition of electrochemical responses for inert species. Acid-base transport limiting current (jl) is the only variable that needs to be measured. The pKa and transport coefficient (m) are determined from the relationship of jl vs. solution pH and jl vs. buffer concentration, respectively. Three ways are available for D determinations by introducing the expressions of diffusion layer thickness. The method is demonstrated using rotating disc electrodes to implement hydrogen evolution reaction. The pKa, m and D values exhibit good repeatability in multiple determinations. A well-defined electrode geometry is necessary for accurate D determination. This method can be developed to a family of methods with the advantages for fast estimating practical parameter values of buffers.

Electronic structure, theoretical power conversion efficiency, and thermoelectric properties of bismuth-based alkaline earth antiperovskites.

This research paper investigates the properties and potential applications of antiperovskite materials. Antiperovskites are a class of materials with a unique crystal structure, where the central atom is surrounded by a cage of anions. We review recent research on antiperovskite-based materials for energy storage, photovoltaics, catalysis, and sensors. We discovered that these materials display direct band gap semiconductors, strong absorption in the visible (VIS), ultra-violet (UV), and near infrared regions (NIR) based on their fundamental features, which is the most admirable quality that may be found in many optoelectronic devices. Both mechanical and thermodynamic stability have been confirmed for these materials. We discovered that these materials exhibit high figures of merit through the calculation of transport properties, which makes them a promising candidate for thermoelectric devices. It is anticipated that the proposed material BiPMg3, which has a theoretical efficiency of 11.5%, will make a suitable photovoltaic absorber. This paper highlights the potential of these materials for future technological advancements. Herein, we have used most authentic techniques to compute fundamental physical properties of these antiperovskites. Full-potential linear augmented plane wave (FP-LAPW) method has been used to investigate electronic, magnetic, optical properties, and make antiperovskites attractive for a variety of applications. In light of its implementation, we have checked the theoretical power conversion efficiency by first principles spectroscopic screening methodology, and inspect the fundamental physical parameters of antiperovskites, focusing on their potential as functional materials for energy and information technologies.

Lightweight pumice mortars for repair of historic buildings –Assessment of physical parameters, engineering properties and durability

The subject of the presented research was an experimental analysis of physical, engineering and durability parameters of lightweight mortars intended for the repair of historical buildings. Compatibility criteria, the requirements of technical standards and guidelines, and last but not least, previously published research results dealing with the development of mortars for repair delicate historic structures were taken into account in the design of mortar composition. Crushed pumice of a similar grain size was used to lighten the reference lime-based mortar and natural hydraulic lime mortar with quartz filler. Replacement of quartz sand with pumice was 25, 50, 75 and 100% by volume. The use of pumice allowed the fundamental physical, mechanical, hygric, thermal and durability parameters of the lightweight mortars to be such that they met the standard requirements for repair mortars and the heritage conservation requirements for compatibility with the original materials of historic masonry. The main finding was the fact that by replacing sand with pumice, a significant increase in the porosity of the mortars was achieved, while maintaining sufficient mechanical strength due to the pozzolanic reaction of the pumice. Mortars based on natural hydraulic lime have become more resistant to frost and salt crystallization. The advantage of the developed mortars was their low thermal conductivity and high water vapor permeability, which made them suitable for use on damp masonry, which is a substantial scientific contribution of the manuscript.

Dynamic Analysis and Safety Assessment of Ships and Cables during Salvage Operations

The International Maritime Organization (IMO) emphasizes that shipwreck accidents frequently occur at sea and advocates for the safe recovery of shipwrecks. This paper examines the case of the Korean “Sewol” ferry salvage, where two lifting barges were symmetrically utilized to retrieve a substantial shipwreck. The dynamic analysis of the salvage operation is based on the computational fluid dynamics (CFD) approach. The main investigation covers two fundamental physical parameters: the motion response of the lifting barges and shipwreck and the tension response of the lifting cables. Using the parameters of the maximum absolute value (MA), root mean square (RMS), and coefficient of variation (CV), a unified criterion is established to quantitatively evaluate the safety of the salvage operation under different working conditions. The study demonstrates that by carefully considering the enhancement of safety and stability for the three vessels involved in the salvage process and by optimizing the safety performance of the lifting cables, suitable operating windows are determined at wave intervals of (115°, 155°) and (205°, 245°). Under most working conditions, curves illustrating the maximum tensions of lifting cables No. 1–15 and No. 16–30 show a distribution with a “middle part drooping” shape. The placement of connecting cables on the water’s surface at 1.1–1.2 times the salvage spacing between the two lifting barges or the arrangement of inclined lifting cables underwater proves advantageous in constraining the motion response of the three vessels. Reinforcing the lifting cables at the bow and stern ends is recommended. This study presents a methodology for salvaging a shipwreck using two lifting barges, which can be used as a reference for designing related salvage approaches.

Optically detected magnetic resonance spectroscopic analyses on the role of magnetic ions in colloidal nanocrystals.

Incorporating magnetic ions into semiconductor nanocrystals has emerged as a prominent research field for manipulating spin-related properties. The magnetic ions within the host semiconductor experience spin-exchange interactions with photogenerated carriers and are often involved in the recombination routes, stimulating special magneto-optical effects. The current account presents a comparative study, emphasizing the impact of engineering nanostructures and selecting magnetic ions in shaping carrier-magnetic ion interactions. Various host materials, including the II-VI group, halide perovskites, and I-III-VI2 in diverse structural configurations such as core/shell quantum dots, seeded nanorods, and nanoplatelets, incorporated with magnetic ions such as Mn2+, Ni2+, and Cu1+/2+ are highlighted. These materials have recently been investigated by us using state-of-the-art steady-state and transient optically detected magnetic resonance (ODMR) spectroscopy to explore individual spin-dynamics between the photogenerated carriers and magnetic ions and their dependence on morphology, location, crystal composition, and type of the magnetic ion. The information extracted from the analyses of the ODMR spectra in those studies exposes fundamental physical parameters, such as g-factors, exchange coupling constants, and hyperfine interactions, together providing insights into the nature of the carrier (electron, hole, dopant), its local surroundings (isotropic/anisotropic), and spin dynamics. The findings illuminate the importance of ODMR spectroscopy in advancing our understanding of the role of magnetic ions in semiconductor nanocrystals and offer valuable knowledge for designing magnetic materials intended for various spin-related technologies.

Kepler Light Curve Modeling of KIC 9788457

Eclipsing binary systems are significant objects for astrophysical studies since they offer more accurate fundamental stellar parameters (mass, radius). Therefore, in this study, the first binary modeling of KIC 9788457 is presented to estimated the fundamental stellar parameters of the system. The photometric data of the system were taken from Kepler that provides high-quality data. When the light curve was checked it was found that the more luminous massive component has a significant light contribution into total. Therefore, using the spectral energy distribution and also B-V values Teff value was estimated for the primary component. Utilizing this Teff value, the binary modeling of the system was carried out. As a result, fundamental physical parameters of KIC9788457 were obtained. The radius (R) and mass (M) values of the components are M1=1.89 ± 0.05 Msun and R1= 2.03 ± 0.02 Rsun for the massive component and M2=0.81 ± 0.02 Msun and R2= 1.74 ± 0.03 Rsun for the less massive component, respectively. Additionally, the distance of the system was determined to be 1407 ± 85 pc.