Element Mass Research Articles

Correction: Certification of the total element mass fractions in UME EnvCRM 03 soil sample via a joint research project

Correction: Certification of the total element mass fractions in UME EnvCRM 03 soil sample via a joint research project

Band structure study of pure and doped anatase titanium dioxide (TiO2) using first-principle-calculations: role of atomic mass of transition metal elements (TME) on band gap reduction

Band structure study of pure and doped anatase titanium dioxide (TiO2) using first-principle-calculations: role of atomic mass of transition metal elements (TME) on band gap reduction

Zinc oxide coating impact on corrosion of ZK60 magnesium alloys in simulated body fluid

Magnesium alloys offer an alternative for applications in biodegradable implant devices within human body, eliminating the need for subsequent surgeries to remove metallic parts. Nevertheless, the uniform degradation rate of magnesium (Mg) alloys must be enhanced by applying surface coatings, preferably incorporating bactericidal and biocompatible agents, to improve the implant properties. In this study, magnesium alloys ZK60 (Mg, Zn, and Zr) and ZK60-Mm (Mg, Zn, and Zr with 1.5 % mass of rare-earth elements - mischmetal), both having a specific mass close to the bone, were investigated. The surfaces were coated with ZnO using physical vapor deposition (PVD) in the HiPIMS (High Power Impulse Magnetron Sputtering) mode. The corrosion resistance and degradation of the alloys were studied using electrochemical and immersion tests in simulated body fluid. Surface analysis and microstructures were characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and X-ray Diffraction (XRD). The results showed that the ZnO coating favors osseointegration with hydroxyapatite formation after immersion in SBF. Moreover, electrochemical analysis indicates an enhancement in corrosion resistance. On average, the corrosion current density decreases by a factor of four for the ZK60 alloy and two for the ZK60-Mm alloy post-coating. The corrosion rate of ZnO-coated alloys is lower compared to that of uncoated alloys, showcasing the promising utility of this coating.

Earth-catalyzed detection of magnetic inelastic dark matter with photons in large underground detectors

Inelastic dark matter with moderate splittings, O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\mathcal{O} $$\\end{document}(few to 150) keV, can upscatter to an excited state in the Earth, with the excited state subsequently decaying, leaving a distinctive monoenergetic photon signal in large underground detectors. The photon signal can exhibit sidereal-daily modulation, providing excellent separation from backgrounds. Using a detailed numerical simulation, we examine this process as a search strategy for magnetic inelastic dark matter with the dark matter mass near the weak scale, where the upscatter to the excited state and decay proceed through the same magnetic dipole transition operator. At lower inelastic splittings, the scattering is dominated by moderate mass elements in the Earth with high spin, especially 27Al, while at larger splittings, 56Fe becomes the dominant target. We show that the proposed large volume gaseous detector CYGNUS will have excellent sensitivity to this signal. Xenon detectors also provide excellent sensitivity through the inelastic nuclear recoil signal, and if a future signal is seen, we show that the synergy among both types of detection can provide strong evidence for magnetic inelastic dark matter. In the course we have calculated nuclear response functions for elements relevant for scattering in the Earth, which are publicly available on GitHub.

Theoretical Analysis of Light-Actuated Self-Sliding Mass on a Circular Track Facilitated by a Liquid Crystal Elastomer Fiber.

Self-vibrating systems obtaining energy from their surroundings to sustain motion can offer great potential in micro-robots, biomedicine, radar systems, and amusement equipment owing to their adaptability, efficiency, and sustainability. However, there is a growing need for simpler, faster-responding, and easier-to-control systems. In the study, we theoretically present an advanced light-actuated liquid crystal elastomer (LCE) fiber-mass system which can initiate self-sliding motion along a rigid circular track under constant light exposure. Based on an LCE dynamic model and the theorem of angular momentum, the equations for dynamic control of the system are deduced to investigate the dynamic behavior of self-sliding. Numerical analyses show that the theoretical LCE fiber-mass system operates in two distinct states: a static state and a self-sliding state. The impact of various dimensionless variables on the self-sliding amplitude and frequency is further investigated, specifically considering variables like light intensity, initial tangential velocity, the angle of the non-illuminated zone, and the inherent properties of the LCE material. For every increment of π/180 in the amplitude, the elastic coefficient increases by 0.25% and the angle of the non-illuminated zone by 1.63%, while the light intensity contributes to a 20.88% increase. Our findings reveal that, under constant light exposure, the mass element exhibits a robust self-sliding response, indicating its potential for use in energy harvesting and other applications that require sustained periodic motion. Additionally, this system can be extended to other non-circular curved tracks, highlighting its adaptability and versatility.

Modeling and vibration analysis of an aero-engine dual-rotor-support-casing system with inter-shaft rub-impact

In order to reveal the nonlinear dynamics of dual-rotor-support-casing system, a numerical procedure is proposed using the finite element method and the component mode synthesis method. Especially, the casing system is subdivided into the casings, struts and housings, which are modeled by shell elements, beam elements and rigid regions with mass elements, respectively. Furthermore, the inter-shaft rub-impact, which may occur in the aero-engine because of imbalance and other faulty, is considered in the dynamic model as a nonlinear excitation. The modal analysis verified the validity of the dual-rotor-support-casing system model. The motion equations are established using the reduced-order model and solved by Newmark-β method with Newton-Raphson iteration. The results show that larger rubbing stiffness will cause the rubbing to enter a self-excited vibration state, and the rotational speed ratio will change the speed region where the self-excited vibration occurs. Finally, the experiment is performed based on a real dual-rotor aeroengine under inter-shaft rub-impact and the results are consistent with the theoretical results, which proves the effectiveness of dual-rotor-support-casing system dynamic model.

Study of New CGSP‐P Series Phosphate Matrix Reference Materials for LA‐ICP‐MS

A series of three CGSP‐P phosphate matrix reference materials, with variable element mass fractions, were synthesised by co‐precipitation with CaCl2 and (NH4)3PO4 to form a hydroxylapatite matrix. Each powder sample was packaged into multiple bottles and pressed into tablets as replicates. The within‐bottle homogeneity was evaluated by the repeatability of element mass fractions of six spots in per tablet of CGSP‐Ps by LA‐ICP‐MS. For the between‐bottle homogeneity evaluation, one approach adopted the % RSD of element mass fractions in twelve different tablets from twelve bottles in the same reference material in comparison with the repeatability field of LA‐ICP‐MS analyses obtained from homogeneous glasses, and the other used a one‐way analysis of variance (ANOVA) approach. Most of the elements (e.g., Mg, Ca, P, Mn and REE) were homogenous within 10% RSD, and other elements (e.g., Si, Al, K, Rb, Cs and Ni) were considered heterogeneous (with > 20% RSD). All of the elements passed the t‐test except Ni in CGSP‐P3, and V, Cr, Ni, Zr, Gd, Dy and Th in CGSP‐P4 after a 29‐month period stability examination by LA‐ICP‐MS. The preliminary reference values and standard uncertainties for CGSP‐Ps are given with a network of methods and eight laboratories by bulk analysis according to ISO Guide 35:2006 and JJF 1343‐2012.

Indonesian experience in providing accuracy-based proficiency testing scheme using metrologically traceable reference values for elements mass fraction in drinking water

Indonesian experience in providing accuracy-based proficiency testing scheme using metrologically traceable reference values for elements mass fraction in drinking water

Ultra-low frequency vibration energy harvesting of piezoelectric vibration systems with an adjustable device

Energy harvesting from external Ultra-low frequency vibrations is currently attracting a lot of attention. However, for the same system, it is difficult to satisfy the need for more efficient energy harvesting in a variety of external environments. Accordingly, an adjustable gearing device connected to the energy harvesting system is used herein for adapting energy harvesting to a wide range of external environments. The device uses four symmetrical inclined springs. One end of the springs is connected to a gear and the other end to a mass element. The geometrical parameters of the system can be varied by rotating the gears, thus varying the dynamic stiffness of the system. The kinetic equations of the system are derived and their nonlinear terms are Taylor-expanded. The amplitude-frequency response curve of the system is obtained by solving using the harmonic balance method. Multi-color plots of RMS values of induced voltage and electric power are obtained using the fourth-order Runge-Kutta method. The results show that the device has excellent adjustable performance. Adjusting the rotation angle of the gears can change the soft and hard characteristics of the system's dynamic stiffness and the intrinsic frequency, thus improving the system's energy harvesting performance in different environments.

An unstructured body-of-revolution electromagnetic particle-in-cell algorithm with radial perfectly matched layers and dual polarizations

A novel electromagnetic particle-in-cell algorithm has been developed for fully kinetic plasma simulations on unstructured (irregular) meshes in complex body-of-revolution geometries. The algorithm, implemented in the BORPIC++ code, utilizes a set of field scalings and a coordinate mapping, reducing the Maxwell field problem in a cylindrical system to a Cartesian finite element Maxwell solver in the meridian plane. The latter obviates the cylindrical coordinate singularity in the symmetry axis. The choice of an unstructured finite element discretization enhances the geometrical flexibility of the BORPIC++ solver compared to the more traditional finite difference solvers. Symmetries in Maxwell's equations are explored to decompose the problem into two dual polarization states with isomorphic representations that enable code reuse. The particle-in-cell scatter and gather steps preserve charge-conservation at the discrete level. Our previous algorithm (BORPIC+) discretized the E and B field components of TEϕ and TMϕ polarizations on the finite element (primal) mesh [1,2]. Here, we employ a new field-update scheme. Using the same finite element (primal) mesh, this scheme advances two sets of field components independently: (1) E and B of TEϕ polarized fields, (Ez,Eρ,Bϕ) and (2) D and H of TMϕ polarized fields, (Dϕ,Hz,Hρ). Since these field updates are not explicitly coupled, the new field solver obviates the coordinate singularity, which otherwise arises at the cylindrical symmetric axis, ρ=0 when defining the discrete Hodge matrices (generalized finite element mass matrices). A cylindrical perfectly matched layer is implemented as a boundary condition in the radial direction to simulate open space problems, with periodic boundary conditions in the axial direction. We investigate effects of charged particles moving next to the cylindrical perfectly matched layer. We model azimuthal currents arising from rotational motion of charged rings, which produce TMϕ polarized fields. Several numerical examples are provided to illustrate the first application of the algorithm.

Evaluation of pretreatment methods for filamentous fungal detection

In order to obtain the best mass spectrometry identification results for using the most appropriate methods in clinical practice, we explore the optimal pretreatment methods for different species and morphologies of filamentous fungi. 98 fungal strains were treated with formic acid sandwich method, dispersion method, extraction method, and other methods using a medium element mass spectrometer (EXS3000) as a platform. Each strain had three targets, and the identification rates and confidence differences under different pre-treatment methods were compared to evaluate the identification effects of these methods. The mass spectrometry identification rates of 98 filamentous fungi obtained after pre-treatment with formic acid sandwich method, dispersion method, and extraction method were 85.71%, 82.65%, and 75.51%, respectively. The identification rate of the formic acid sandwich method was significantly higher than the other two methods (P < 0 005) has the best identification ability and the obtained confidence is also higher than the other two methods. The use of formic acid sandwich method for mass spectrometry identification of filamentous fungi can achieve ideal identification results, which is suitable for mass spectrometry identification of filamentous fungi in conventional laboratories.

Analysis of nonlinear wave propagation within architected materials consisting of nonlinear Timoshenko beam structural elements

In the present work, a full nonlinear Timoshenko beam employing nonlinear shape functions is developed. The extended Hamilton principle is employed for deriving the differential equations of motion and the associated boundary conditions. The general form of the boundary conditions is then utilized to determine the static solution of the beam motion. Using this solution for the deformation and rotation of the beam, the nonlinear shape functions of the beam are identified, which leads to the linear and nonlinear mass and stiffness matrices of the Timoshenko beam element. The nonlinear dispersion diagram incorporating the non-linear corrections is obtained using the Linstedt–Poincaré perturbation method. An analysis of the effect of internal transverse shear and bending on the nonlinear dispersion characteristics of wave propagation in two-dimensional periodic network materials made of nonlinear Timoshenko beams is done. The formulated theory shows that the percentage of correction factor of the nonlinear kinematics versus the linear dynamical behavior is inversely proportional to the frequency amplitude. The shear and extension modes are shown to have the higher effect in the non-linear correction term in comparison to the flexural mode.

Vibration Analysis of Uniform Flexible Beams under Large Deformation with Uniformly Continuous Mass Elements Using the Equivalent Pseudolinear System

This paper analyses vibration of uniform flexible simply supported rectangular isotropic beam under large deformation with uniformly distributed mass elements. The method of equivalent pseudolinear systems was employed. The deformation of the beam was assumed to be large and the beam was also assumed to be inextensible. The expressions for elastic and nonlinear bending moments were determined. The numerical values of horizontal displacements of the movable support, and the equivalent lengths at various depth-to-breadth (aspect) ratios were determined. The corresponding equivalent pseudolinear systems for various nonlinear bending moment diagrams at various aspect ratios were determined. Consequently the concentrated loads yielding the equivalent pseudolinear systems were converted to point masses using the gravitational acceleration; and subsequently a unit load system was applied successively and independently at each mass point. The Vereshchagin’s method was applied to determine the displacements for canonical equations of motion. Non-trivial solution of the canonical equations at each aspect ratio was sought for the desired eigenvalues. The first mode frequencies at aspect ratios, β = 1.00 and β = 1.25 are complex eigenvalues. Also the natural frequencies exhibit hard-spring type with aspect ratios; and the fundamental frequencies for all the aspect ratios are at seventh mode. Conclusively, the dynamic stability of the flexible rectangular beam of 0.25m-breadth and 15m-undeformed length is not guaranteed when the aspect ratio is less than or equal to 1.25. It is also concluded that deepness of the flexible rectangular beam loaded with uniformly distributed mass elements influences the vibratory characteristics.

Theory-guided deep neural network for boiler 3-D NOx concentration distribution prediction

Timely and accurate three-dimensional (3-D) NOx concentration distribution prediction is essential for achieving low-emission and efficient operation in power plants. This study proposed a theory-guided data-driven prediction method for the 3-D NOx concentration distribution prediction. Firstly, the method created a foundational dataset by fusing numerical simulation data from the computational fluid dynamics (CFD) with operational data from the distributed control system (DCS). Then, the data was classified into three load condition categories, and the center operating conditions for each category were computed separately. Subsequently, the K-means algorithm was employed to extract representative data to address the computational challenges associated with big data. Finally, a Theory-Guided Deep Neural Network model (TG-DNN) was established leveraging the principle of carbon element mass conservation and deep neural network. Experimental results demonstrate that the method effectively monitors the 3-D NOx concentration distribution, potentially facilitating efficient production processes.

Single particle inductively coupled plasma mass spectrometry metrology: Revisiting the transport efficiency paradigm

Transport efficiency has become a critical parameter in single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) since it is involved in the calibrations to determine different measurands (element mass per particle, particle size and particle number concentration). Specific methods for its determination based on the use of particle standards have been developed and widely applied (particle frequency and particle size methods). A refined indirect method not relying on particle standards is also available (dynamic mass flow method). A number of discrepancies on the accuracy of these methods and their adequacy have become evident, making a revision of the topic pertinent. In fact, the application of the particle frequency and particle size methods determine the transport efficiencies corresponding to the particles or the dissolved element respectively, whereas the solvent transport efficiency is actually measured by the dynamic mass flow method. The use of each of these methods requires assuming different conditions that must be considered. These conditions, together with the sources of bias associated to each method are critically discussed to provide a holistic and harmonized view of transport efficiency in the context of SP-ICP-MS metrology.

Kinerja Analitik Mikrokapsul Magnetit - Alginat (MNPs-ALG) untuk Analisis Ion Logam Cu(II) dan Aplikasinya pada Sampel Alam

Research has been carried out regarding the synthesis of Magnetite-Alginate microcapsules (MNPs-ALG) and applied to Cu (II) metal ions. The nature of magnetic nanoparticles, Fe3O4 which easily form aggregations can be overcome by this encapsulation process, but a very efficient separation process is also very much needed in the analytical separation process.The process of making magnetite nanoparticle compounds is carried out first using FeCl2.4H2O and FeCl3.6H2O and adding concentrated ammonia at a temperature of 90οC until the solution becomes blackish in color. The dry magnetite, Fe3O4, nanoparticles were then dissolved in distilled water and thickened with Na-Alginate then dropped slowly into a 1 M CaCl2 solution. The results of characterization using SEM showed that there were differences in morphology before and after contact, and there was 0.98% mass of Cu elements on the EDS results.The microcapsule adsorption optimization test gave results for the best adsorption percentage &gt;90% on a mass variation of magnetite (MNPs) of 0.3 grams; pH 5; contact time of 30 minutes and retention capacity of 185.95 mg/gram, at a Cu(II) concentration of 800 ppm. Analytical performance shows the best results with linearity parameters with a correlation coefficient of 0.999; the detection limit and quantitation limit are 0.0516 ppb and 0.1720 ppb with a lifetime of four times. The application of samples in the form of river water samples shows a percent recovery value of around &gt;90%, indicating that there is no matrix that significantly influences the measurements.

Impact of Ejecta Temperature and Mass on the Strength of Heavy Element Signatures in Kilonovae

A kilonova, the electromagnetic emission produced by compact binary mergers, is formed through a delicate interplay of physical processes, involving r-process nucleosynthesis and interactions between heavy elements and photons through radiative transfer. This complexity makes it difficult to achieve a comprehensive understanding of kilonova spectra. In this study, we aim to enhance our understanding and establish connections between physical parameters and observables through radiative-transfer simulations. Specifically, we investigate how ejecta temperature and element mass influence the resulting kilonova spectrum. For each species, the strength of its line features depends on these parameters, leading to the formation of a distinct region in the parameter space, dubbed the resonance island, where the line signature of that species is notably evident in the kilonova spectrum. We explore its origin and applications. Among explored r-process elements (31 ≤ Z ≤ 92), we find that four species—SrII, YII, BaII, and CeII—exhibit large and strong resonance islands, suggesting their significant contributions to kilonova spectra at specific wavelengths. In addition, we discuss potential challenges and future perspectives in observable heavy elements and their masses in the context of the resonance island.

Dynamics Responses of a Block Machine Foundation and a Pile Group Foundation Systems on Stratified Residual Soils in Indonesia by Lumped Mass and Finite Element Methods

This paper presents a comprehensive study of the dynamic responses of machine foundations, both block and pile foundations, on stratified residual soils in Duri and Ulubelu, Indonesia. The evaluation was conducted using two widely recognized methods: the lumped mass method (LMM) and the finite element method (FEM). LMM and FEM were performed by utilizing DYNA and ABAQUS, respectively. The analysis results showed that LMM generally predicted more conservative displacements compared to FEM. This conservatism in predicted displacement was more pronounced for pile group foundations, which are inherently more flexible than block foundations. Additionally, this study found that the resonance frequencies obtained through both analysis methods were not the same. Furthermore, this paper includes a parametric study and presents its results to assess the influence of key factors, i.e., pile cap thickness, pile diameter, number of piles, and vertical dynamic loads, on displacement.

Research on cable dynamic response of a catenary anchor leg mooring system based on ANCF

This paper presents a dynamic analysis model for a catenary anchor leg mooring (CALM) system based on the absolute nodal coordinate formulation (ANCF) method, combined with continuum mechanics and finite element theory. This model uses absolute slope coordinates instead of traditional angle coordinates to better describe the large deformation and large displacement of the cables. The paper derives the element mass matrix, generalized stiffness matrix, and the element external load matrix, including the Morison force transformed into the ANCF framework, based on the virtual work principle. The accuracy and reliability of the ANCF program are validated using static and dynamic beam models, as well as submerged tether models. Furthermore, a comparative analysis of the ANCF mooring cable model with OpenFAST and MoorDyn accentuates the program's practical value in real engineering applications. Finally, we systematically analyzed the dynamic characteristics of a CALM single-point mooring system, revealing that the mooring forces in the cables significantly influence the high-frequency motion of the buoy. Additionally, the reduction in the length of the mooring cables, to an appropriate extent, enhances the stability of the system, which further attests to the effectiveness and practicality of the ANCF model that has been developed.

Transient vibration of a fractional viscoelastic cantilever beam with an eccentric mass element at the end

Transient vibration of a fractional viscoelastic cantilever beam with an eccentric mass element at the end