Standard Particle Research Articles

Incoherent frequency-selective phase coded holography and axial overlap information stripping

In the paper, we proposed frequency-selective carrier coded aperture correlation holography (FSC-COACH). Incoherent frequency selection technique is introduced into coded aperture correlation holography for the first time, and mask scattering imaging of arbitrary branches is realized. This represents a novel form of non-visual imaging technology capable of effectively suppressing background noise and facilitating holographic separation and reconstruction beneath the obstruction of multiple opaque mediums. Experimental analysis explores the impact of virtual point spread function filter radius on the quality of reconstruction. Through the reconstruction of standard particles and the overlapping dual-path reconstruction of the USAF chart under mask obstruction, the feasibility of our technology is demonstrated. We are confident that the proposed approach will pioneer paradigm shifts in incoherent imaging, wavefront acquisition through scattering mediums, astronomical imaging, and rapid object recognition applications.

Improved particle swarm optimization based on multi-strategy fusion for UAV path planning

PurposePath planning is an important part of UAV mission planning. The main purpose of this paper is to overcome the shortcomings of the standard particle swarm optimization (PSO) such as easy to fall into the local optimum, so that the improved PSO applied to the UAV path planning can enable the UAV to plan a better quality path.Design/methodology/approachFirstly, the adaptation function is formulated by comprehensively considering the performance constraints of the flight target as well as the UAV itself. Secondly, the standard PSO is improved, and the improved particle swarm optimization with multi-strategy fusion (MFIPSO) is proposed. The method introduces class sigmoid inertia weight, adaptively adjusts the learning factors and at the same time incorporates K-means clustering ideas and introduces the Cauchy perturbation factor. Finally, MFIPSO is applied to UAV path planning.FindingsSimulation experiments are conducted in simple and complex scenarios, respectively, and the quality of the path is measured by the fitness value and straight line rate, and the experimental results show that MFIPSO enables the UAV to plan a path with better quality.Originality/valueAiming at the standard PSO is prone to problems such as premature convergence, MFIPSO is proposed, which introduces class sigmoid inertia weight and adaptively adjusts the learning factor, balancing the global search ability and local convergence ability of the algorithm. The idea of K-means clustering algorithm is also incorporated to reduce the complexity of the algorithm while maintaining the diversity of particle swarm. In addition, the Cauchy perturbation is used to avoid the algorithm from falling into local optimum. Finally, the adaptability function is formulated by comprehensively considering the performance constraints of the flight target as well as the UAV itself, which improves the accuracy of the evaluation model.

ZAFG Method for Quantitative Characterization of Spherical Particles: Deriving a Universal Equation for Geometrical Correction.

This study introduces a universal equation to calculate the geometrical correction factor (G) as the fourth factor in the conventional ZAF method for quantifying spherical particles (specifically, NIST-K411 glass microspheres mounted on bulk carbon substrate). Note that the fluorescence correction factor (F) is not considered in this study. Our findings demonstrate that the G factor, as a function of the particle diameter (D) and the range of emitted X-rays in a bulk sample (Xe), provides the best model. Xe depends on the chemical composition and accelerating voltage. We observed excellent agreement between the G factor predicted by our model and experimental data obtained from NIST-K411 standard particles. Our results show that when Xe is greater than D, the G factor decays exponentially, independent of the incident electron energy, X-ray lines, and chemical composition of the particles. We also found that when DXe > 1, the particle behaves as a bulk sample, and G = 1. Notably, our data indicate that the G factor depends only on DXe, not on the chemical composition or beam energy.

Quantitative analysis of antibody aggregates by combination of pinched-flow fractionation and coulter method

For the pharmaceutical development of proteins, multiple methods of analysis are recommended for evaluating aggregation, and the development of more quantitative and simpler analytical techniques for subvisible particles is expected. This study introduces the Pinched-Flow Fractionation (PFF)-Coulter method, which combines the Pinched-flow fractionation (PFF) and Coulter methods to analyze the concentration of submicron-sized particles. The PFF method separates the particles by size. Separated particles were individually detected using the Coulter method. We have utilized the PFF-Coulter method to quantitatively analyze particle concentrations using standard particles, evaluate detection limits, variability, and correlation between theoretical and measured values, and analyze mixtures of different particle sizes. The PFF-Coulter method allows for quantitatively analyzing of particle sizes from 0.2 to 2.0 μm. The quantifiable weight concentration range was 2.5 × 10−2 – 50 μg/mL, and the number concentration range was 104–1010 particles/mL. The sample volume was small (<10 μL). The PFF-Coulter method is capable of quantitative analysis that complements data from conventional measurement techniques, and when used in conjunction with existing submicron-size particle analysis techniques, will enable more accurate particle analysis.

The Higgs boson couplings: past, present, and future. The relationships between Higgs boson and other known particles as measured by current and future experiments

The discovery of the Higgs boson, a fundamental particle of the Standard Model, at the Large Hadron Collider (LHC) in 2012, marked a monumental milestone in the field of particle physics. Since then, extensive research has been conducted to understand the properties and interactions of the Higgs boson, particularly its couplings with other known particles. This article provides a review of the past, present, and future measurements of the Higgs boson couplings, with a focus on the most recent experimental developments. It discusses the experimental techniques and methods used to study the Higgs boson couplings, including the production and decay channels employed in various experiments. The article highlights the important relationships between the Higgs boson and other known particles, including the gauge bosons (W and Z bosons), quarks, and leptons and the Higgs boson itself, through its self-interaction. After discussing the channels used by ATLAS and CMS collaborations to measure the Higgs boson coupling to the other standard model particles, the article will present an overview of the latest results obtained at the LHC, commenting on how various measurements have evolved over time along with a better comprehension of the detectors and ever more refined analysis techniques. Future collider developments and expectation for the measurement of the Higgs boson couplings and double-Higgs boson production with increased precision and accuracy will be discussed along with the main challenges faced by future experiments.

A boosted muon collider

A muon collider could produce the heavier Standard Model particles with a boost, for example in resonant processes such as μ−μ+→ h or μ−μ → Z. We propose machine configurations that produce the boost (asymmetric beam energies, tilted beams) and estimate how much the luminosity is reduced or perhaps enhanced. The feasibility of the proposed configurations, as well as an estimation of the beam-induced backgrounds and beam energy spread, needs to be evaluated in order to derive more solid conclusions on the physics potential of such boosted collider configurations. If achievable, the boost can provide new interesting observational opportunities. For example it can significantly enhance the sensitivity to long-lived new particles decaying in a far-away detector, such as dark higgses or sterile neutrinos produced in h or Z decays.

Sterile neutrinos from dark matter: a ν nightmare?

We provide a comprehensive study of observable spectra from dark matter pair-annihilation or decay into sterile (right-handed) neutrinos. This occurs, for instance, in neutrino portal dark matter models, where a sterile neutrino acts as the portal between dark matter and the Standard Model sector. The subsequent decays of right-handed neutrinos produce detectable Standard Model particles, notably photons, positrons, and neutrinos. We study the phenomenology of models where the right-handed neutrino masses are below the GeV scale, as well as models where they are at, or significantly heavier than, the TeV scale. In both instances, and for different reasons, the standard tools, including Monte Carlo simulations, are both inadequate and inaccurate. We present the complete framework to compute the relevant branching ratios for right-handed neutrino decays and the spectra of secondary photons, positrons, and neutrinos for a broad range of dark matter and right-handed neutrino masses. We discuss the general features of such signals, and compare the spectra to standard signals from dark matter annihilation/decay into bottom quarks. Additionally, we provide open source code (The code is available at https://github.com/LoganAMorrison/blackthorn) that can be used to compute such spectra.

The evaluation of university management performance using the CS-RBM algorithm.

Amidst the ongoing higher education reforms in China, the escalated investments in colleges and universities underscore the need for an effective assessment of their performance to ensure sustainable development. However, traditional evaluation methods have proven time-consuming and labor-intensive. In response, a novel approach called CS-RBM (Crow Search Restricted Boltzmann Machine) prediction algorithm has been proposed for the educational management of these institutions. By integrating the CS algorithm and an enhanced RBM algorithm, this method facilitates the scoring of project performance indicators, bolstered by insights from user evaluation form reports. The comprehensive project performance is ultimately derived from this combination. Comparative analysis with the standard particle swarm optimization algorithm on public data sets demonstrates a remarkable 45.6% reduction in prediction errors and an impressive 34.7% increase in iteration speed using the CS-RBM algorithm. The accuracy of the tested data set surpasses 98%, validating the efficacy of the CS-RBM algorithm in achieving precise predictions and effective assessments. Consequently, this innovative approach exhibits promising potential for expediting and enhancing the performance evaluation of colleges and universities, contributing significantly to their sustainable development.

A global analysis of axion-like particle interactions using SMEFT fits

In the presence of axions or axion-like particles (ALPs) that couple to the Standard Model via dimension-five interactions, dimension-six SMEFT interactions are generated via renormalization-group evolution. As many of these SMEFT contributions are experimentally tightly constrained, this “ALP-SMEFT interference” can be used to derive indirect bounds on the ALP couplings to the Standard Model particles. We present a global analysis of the Wilson coefficients of the ALP effective Lagrangian based on Higgs, top, and low-energy data. The obtained bounds are model independent and are competitive or even stronger than direct bounds in the GeV to TeV ALP-mass range.

DM-SM interactions mediated by spin-one particles: EFT study

Standard model-dark matter particles, mediated by spin one fields, are analyzed within the effective field theory framework. We [1, 2] consider dark particles masses from few MeV to 6.4 TeV. We restrict the EFT using bounds from relic density, Z invisible decay width, direct and indirect detection limits and collider constraints. Solutions below mZ are found for two operators. Others, around the electroweak scale or slightly above, are also compatible with all present limits.

Application of a Modified Particle Swarm Optimization for Maximum Power Point Tracking for Solar Photovoltaic Systems

The maximum power point extraction at any instant of time on photovoltaic (PV) systems has attracted attention. This study introduces a novel DC-DC converter-based power point tracking (PPT) algorithm for solar PV systems. The proposed optimization technique is a modified form of the standard particle swarm optimization (PSO), where the limitations of the standard PSO algorithm, like random number assignment of the acceleration factors and constant weight, are modified. The main goal of the suggested modified particle swarm optimization (MPSO) algorithm is to change the particle weight within a range of values and remove the random number from the acceleration factors. As a result, some of the contributions to this work are: First, when the weight is within some interval values, velocity restriction with a constant number improves. It offers the chance to expedite the search without limitation because of the constantly shifting environmental conditions. Second, the solution shows that the lack of acceleration constants predicts the particle's behavior. Thirdly, the algorithm's input parameters are incredibly minimal. The MATLAB/Simulink simulation of a modeled standalone 2.9 kW solar PV system in shading and non-shading conditions proved the proposed algorithm's performance. Thus, the average efficiency and time tracking of the global maximum power point (GMPP) is 99.45% and 6.285 s, respectively. Generally, the proposed MPPT method is more straightforward and adaptable than perturb and observe (P&amp;O), the cuckoo search algorithm, and standard PSO.

Traveling Salesman Problem Solving Based on Hybrid Particle Swarm Optimization Algorithm

Genetic algorithms all the methods used to solve the Traveling Agent (TSP) problem, the use of genetic algorithms on TSP problems is more common than other methods, and it is also possible to achieve global search and obtain the best values. Compared with the traditional genetic algorithm, the particle swarm algorithm is not only easy to be applied, but also can be widely used because of the function of rapid search, but at the same time, the shortcomings of the traditional standard particle swarm algorithm are more prominent, and it is easy to fall into the situation of optimal solution of local problems. So first of all, we use the classical TSP algorithm to propose a mixed particle swarm algorithm, which solves the TSP problem by using the selection, crossover, variation and other operators of the traditional genetic algorithm, and through the conclusion of the solution, it can be shown that the method not only greatly improves the search function of the traditional standard particle swarm, but also greatly improves the convergence speed while obtaining the approximate optimal solution.

Circumventing volumetric locking in explicit material point methods: A simple, efficient, and general approach

AbstractThe material point method (MPM) is frequently used to simulate large deformations of nearly incompressible materials such as water, rubber, and undrained porous media. However, MPM solutions to nearly incompressible materials are susceptible to volumetric locking, that is, overly stiff behavior with erroneous strain and stress fields. While several approaches have been devised to mitigate volumetric locking in the MPM, they require significant modifications of the existing MPM machinery, often tailored to certain basis functions or material types. In this work, we propose a locking‐mitigation approach featuring an unprecedented combination of simplicity, efficacy, and generality for a family of explicit MPM formulations. The approach combines the assumed deformation gradient () method with a volume‐averaging operation built on the standard particle–grid transfer scheme in the MPM. Upon explicit time integration, this combination yields a new and simple algorithm for updating the deformation gradient, preserving all other MPM procedures. The proposed approach is thus easy to implement, low‐cost, and compatible with the existing machinery in the MPM. Through various types of nearly incompressible problems in solid and fluid mechanics, we verify that the proposed approach efficiently circumvents volumetric locking in the explicit MPM, regardless of the basis functions and material types.

Effect of particle size distribution on the laminar flame speed of iron aerosols

Iron particles in air burn in heterogeneous combustion mode and the flame speed is very sensitive to particle size. Previous numerical work on the propagation of flames in iron dust was based on average particle sizes. However, in practice, experiments are conducted with particle size distributions (PSD). This makes it challenging to compare different experiments as the samples used in those studies vary (the average particle size might be similar but not the particle size distribution). It is the aim of the current work to provide insight into the effect of particle size distribution on flame propagation. This involves identifying the minimum number of discrete averaged particle sizes (bins) required in the simulations to capture the burning characteristics of the PSD. Then, flame speed and flame structure for a narrow and broad distribution are investigated. It is shown that the equivalence ratio at which the maximum flame speed occurs for certain mean particle sizes varies with the width of the particle size distribution. The difference in the flame speed between the same average particle size but different standard deviation varies as a function of β (ratio between standard deviation and average particle size), not just the average particle size itself. For a constant β at a particular equivalence ratio, the difference in the flame speed between PSD and mono-dispersed aerosols is approximately the same irrespective of the particle size. The effects of the smaller and bigger particles in the PSD on the flame speed and flame structure are also systematically investigated. The findings in this study confirm that the particle width of the PSD plays a crucial role and that experiments and simulations can not be readily compared if different PSDs are used.

Effective portals to heavy neutral leptons

The existence of right-handed neutrinos, or heavy neutral leptons (HNLs), is strongly motivated by the observation of neutrino masses and mixing. The mass of these new particles could lie below the electroweak scale, making them accessible to low-energy laboratory experiments. Additional new physics at high energies can mediate new interactions between the Standard Model particles and HNLs, and is most conveniently parametrized by the neutrino Standard Model Effective Field Theory, or νSMEFT for short. In this work, we consider the dimension six νSMEFT operators involving one HNL field in the mass range of 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}(1) MeV < MN<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}(100) GeV. By recasting existing experimental limits on the production and decay of new light particles, we constrain the Wilson coefficients and new physics scale of each operator as a function of the HNL mass.1

Testing BSM physics with gravitational waves

The Cosmic Gravitational Wave Background (CGWB) is an irreducible background of gravitational waves generated by particle exchange in the early Universe plasma. Standard Model particles contribute to such a stochastic background with a peak at f∼80 GHz. Any physics beyond the Standard Model (BSM) may modify the CGWB spectrum, making it a potential testing ground for BSM physics.We consider the impact of general BSM scenarios on the CGWB, including an arbitrary number of hidden sectors.We find that the largest amplitude of the CGWB comes from the sector that dominates the energy density after reheating and confirm the dominance of the SM for standard cosmological histories.For non-standard cosmological histories, such as those with a stiff equation of state ω > 1/3, like in kination, BSM physics may dominate and modify the spectrum substantially.We conclude that, if the CGWB is detected at lower frequencies and amplitudes compared to that of the SM, it will hint at extra massive degrees of freedom or hidden sectors.If it is instead measured at higher values, it will imply a period with ω > 1/3.We argue that for scenarios with periods of kination in the early Universe, a significant fraction of the parameter space can be ruled out from dark radiation bounds at BBN.

Inhalation devices and inhaled corticosteroids particle size influence on severe pneumonia in patients with chronic obstructive pulmonary disease: a nationwide cohort study

BackgroundInhaled corticosteroids (ICSs) are associated with an increased risk of pneumonia among patients with chronic obstructive pulmonary disease (COPD). The introduction of extrafine particle ICS has aimed to improve the...

An improved dissipative particle dynamics method for the liquid-particle two-phase flow in microchannels

Liquid-particle two-phase flow in microchannel widely exists in the fields of biomedical and environmental monitoring, such as the lab-chip device for disease diagnosis. The standard dissipative particle dynamics (DPD) method has been previously employed to study the liquid-particle two-phase flow in microchannel, but it cannot accurately simulate the real process because of the unsuitable DPD parameters. In the present study, an improved DPD method was developed by changing the system energy and fitting the characteristic curve between the random force coefficient and the Schmidt number. In addition, a new logarithmic relationship between the conservative force coefficient and the particle size was found. The result demonstrated that the improved DPD method enabled more accurate simulation on the liquid-particle two-phase flow in microchannels than the standard DPD method. For instance, in the simulation of particle sedimentation, the relative deviation between the value obtained by the improved DPD method and the theoretical value was less than 6% while the relative deviation was more than 20% for the standard DPD method. The simulated result of the particle migration in microchannel was in good agreement with the result obtained by Matas et al, and the relative deviation was less than 1.5%. Therefore, the improved DPD method would have great potentials in the study on the liquid-particle two-phase flow in microchannels.

Cannabis sativa mediated palladium nanoparticles as an effective nanodrug against multi-drug resistant bacteria and A549 lung cancer cells

The present paper reports a biogenic synthesis of palladium nanoparticles (PdNPs) involving Cannabis sativa leaf extract. The physicochemical characterisations of biogenic synthesised PdNPs were carried out to determine size, shape, morphology, atomic composition, and crystal structure via different techniques involving Ultraviolet–visible (UV–vis), Fourier transform infrared (FT-IR), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), and X-ray diffraction (XRD). The standard particle size of the synthesized PdNPs was found to be 3.49 ± 0.5 nm from the TEM analysis, while XRD analysis showed a crystal size of 4.6 nm with a face-centred-cubic (fcc) structure. FT-IR study of the green synthesis confirmed the presence of phytochemicals which act as reducing and stabilising agents. The synthesised biogenic PdNPs were subjected to antimicrobial analysis for isolated strains of multi-drug resistant (MDR) Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Salmonella abony where minimum inhibitory concentration (MIC) was found in the range of 52.04–68.3 μg/mL. Moreover, for the cytotoxic effects of biogenic PdNPs, A549 lung cell lines were used, and the half-maximal inhibitory concentration (IC50) value was evaluated as 22.17 µg/mL. The present investigation suggests the possible role of C. sativa extract capped PdNPs in the clinical management of lung cancer cells and MDR pathogens.

Novel zone elution mode in coiled tube field-flow fractionation for online separation and characterization of environmental submicron particles.

Coiled tube field-flow fractionation (CTFFF) is currently applied to environmental and material studies. In the present work, a novel zone elution mode in CTFFF has been proposed and developed. Zone elution mode is based on the separation of particles by stepwise decreasing the flow rate of the carrier fluid and their subsequent elution at a constant flow rate. The fractionation parameters were optimized using a mixture of standard silica submicron particles (150, 390, and 900nm). Taking samples of volcanic ash as examples, it has been demonstrated that zone elution mode can be successfully used for the fractionation of environmental nano- and submicron particles. For the first time, CTFFF was coupled online with a dynamic light scattering detector for the size characterization of eluted particles. Zone elution in CTFFF can serve for the further development of hyphenated techniques enabling efficient fractionation and size/elemental characterization of environmental particles in nano- and submicrometric size ranges.