Present Method Research Articles

A Chemical Kinetic Mechanism Reduction Method with Autoencoder for Hydrocarbon Fuels

ABSTRACT A chemical kinetic mechanism reduction method based on autoencoder (CRAE) is proposed to obtain the skeletal mechanism of hydrocarbon fuels. Based on the network architecture of autoencoder, a computational network structure is constructed using the species molar concentration as the input and output layers. The training datasets are generated from numerical simulations of zero-dimensional homogeneous ignition process using detailed chemical kinetic mechanisms under diverse operating conditions, and the autoencoder is optimized by using back-propagation algorithm and gradient descent algorithm. Subsequently, the weight coefficients connecting the input layer to the first hidden layer are calculated to assess the importance of chemical species, which in turn determines whether a species and its associated elementary reactions can be removed. The skeletal mechanisms for methane and n-heptane generated by using the present CRAE method are compared to those produced by the path flux analysis (PFA) method and the detailed mechanism. The comparisons of the ignition delay time, temperature profiles, and the concentration of important species show that with significantly smaller number of species, the skeletal mechanisms generated by the present CRAE method are more accurate than those of PFA in a broad range of initial pressures, temperatures and equivalence ratios. The CRAE method provides a new and effective means for reduction complex combustion kinetic mechanism of hydrocarbon fuels.

Accurate Cancer Diagnosis and Treatment Monitoring through Multiplexed Profiling of Protein Markers on Small Extracellular Vesicles.

The detection of small extracellular vesicles (sEVs) is currently a pivotal liquid biopsy approach for noninvasive cancer diagnosis. However, the lack of adequate specificity and sensitivity, as well as labor-intensive purification and analysis procedures, present challenges in isolating and profiling sEVs. Here, we present a protein-specific enzymatic optical reporter deposition-based liquid biopsy assay for the rapid and efficient capture and ultrasensitive detection of sEVs using a minimal volume of initial biofluids (10 μL). Biotin aptamers were employed to label sEV proteins for peroxidase conjugation, catalyzing the conversion of fluorescein tyramine into highly reactive free radicals. Efficient signal conversion was achieved by depositing nanoheterolayers composed of covalent tyraminated complexes onto sEV surfaces. The present method offers a detection limit of 6.4 × 103 particles mL-1 with a linear range of 104-1010 particles mL-1 for sEVs. Two machine learning algorithms, principal coordinates analysis and principal component analysis, were subsequently applied for dimensionality reduction. In a clinical cohort of 84 patients, including 6 cancer types and noncancer cases, the assay achieved an overall accuracy of 100% (95% confidence interval) in distinguishing between cancer and noncancer controls and 96% in classifying cancer types. As drugs are frequently administered to patients to modulate the activity of tumor cells, we investigated the efficacy of this strategy in treatment monitoring, achieving an overall accuracy of 100%. This strategy demonstrates a cost-effective, rapid, and low sample volume consumption approach that holds significant potential for precise cancer diagnosis and auxiliary assessment of drug response in clinical settings.

Serine-Grafted Cu2O Electrode Enabling Specific β-Hydroxybutyrate Detection by Surface Sensitization-Promoted Electrolysis in Amperometry.

As the global prevalence of diabetes continues to rise, the home health testing market has experienced rapid growth. Although blood glucose monitoring is widespread among diabetic patients, there remains a significant lack of testing methods for diabetic ketoacidosis. The present study developed a feasible electrochemical technique for ketoacid detection using serine-immobilized copper(I) oxide nanoparticles (Cu2O NPs) as the primary electrode material. Given that the serine on the nanoparticle surface enables conjugation with β-hydroxybutyrate (β-HBA) through an esterification reaction between the hydroxyl group of serine and carboxylic acid of β-HBA and another intramolecular nucleophilic acyl substitution between amine and ester groups to form irreversible amide bonding, thus resulting in the β-HBA deposition on the surface of the Cu2O NP-coated electrode. The quantification of β-HBA can be determined through current variations in amperometry measurement. The results showed a highly linear relationship between reductive current and β-HBA concentration at 0-20 mM, with a reasonable detection limit of 0.1 mM. Moreover, a reasonable mechanism involving the NP surface covering-mediated electrolysis enhancement was proposed. The present method reveals a promising direction in developing sensors for small molecule detection with high specificity and sensitivity.

Drowsiness Detection System in Real Time Based on Behavioral Characteristics of Driver using Machine Learning Approach

Abstract: Drowsiness is among the primary reasons for driver caused traffic accidents. The interactive systems that have been designed to minimize road accidents by notifying the drivers are referred to as Advanced Driver Assistance Systems (ADAS). Most significant ADAS include Lane Departure Warning System, Front Collision Warning System and Driver Drowsiness Systems. In the current research, an eye state detection based ADAS system is introduced to identify driver drowsiness. To start, Viola-Jones algorithm method is utilized for identifying the face and eye regions in the current work. The eye region, detected in the present method, is classified into open or closed through utilization of a machine learning approach. Ultimately, eye conditions are inspected at time domain using percentage of eyelid closure (PERCLOS) metric and drowsiness states are calculated by Support Vector Machine (SVM). The above proposed methods are tested on 7 real individuals and drowsiness conditions are detected better accuracy, respectively.

Description and Convergence Order Analysis of the Finite Element‐Volume Spatial Discretization Method

ABSTRACTThis article reviews the Finite Element‐Volume spatial discretization method on tetrahedral meshes implemented in the TrioCFD code. TrioCFD is a computational fluid dynamics software specifically designed for simulating turbulent flows and heat transfer, with a primary focus on nuclear engineering applications. Its versatility also extends to a wide range of engineering applications. This article presents the principles of Finite Element‐Volume discretization and conducts an analysis of its properties and convergence orders. The time scheme can be explicit or semi‐implicit, and the velocity and pressure are updated based on a projection‐correction scheme. The discretization ensures local mass conservation, second‐order convergence for velocity, and first‐order convergence for pressure. Moreover, a super‐convergence is achieved in two‐dimension when the source term is a gradient. The accuracy and convergence rate of the numerical method is rigorously assessed in a variety of two‐ and three‐dimensional test cases, including steady Stokes and Navier–Stokes problems with manufactured solutions. The classical lid‐driven cavity flow is also addressed, and the results of comparisons between the solutions from the present numerical method and the results of reference literature are provided.

Mechanochemistry‐Driven Synthetic Approach for Halogenated Derivatives of 2‐Amino‐1,4‐Naphthoquinones, Indoles, Indazoles, and Coumarins

AbstractWe, in this work, disclose a practical and straightforward alternative mechanochemistry‐driven strategy for the halogenation of a diverse series of bio‐relevant molecular scaffolds, such as 2‐(alkyl/aryl‐amino)naphthalene‐1,4‐diones, indoles, 1H‐ and 2H‐indazoles and coumarins, under additive‐ and reaction solvent‐free conditions. The salient features of the present method are additive‐ and solvent‐free synthesis, avoidance of using any external oxidants and heating, good to excellent yields, shorter reaction times in minutes, reusability of the solid surface, and gram‐scale synthetic applicability. In addition, we have extended the synthetic applications of the synthesized halo‐derivatives.

A consistent axisymmetric multiphase lattice Boltzmann flux solver for flows with super-large density ratio

Despite the development of numerous axisymmetric models for hydrodynamic fields within the context of Lattice Boltzmann flux solvers, a common challenge remains: the governing equations at the cell centers are often inconsistent with those at the cell interfaces. To solve this problem for the simulation of flow field, this study adopts the kinetic-theory-based axisymmetric lattice Boltzmann method and a consistent finite-volume axisymmetric multiphase lattice Boltzmann flux solver (LBFS) is proposed on the cylindrical coordinates. Through this strategy, the present solver follows the same governing equations both at the cell centers and at the cell interfaces. Specifically, the interface fluxes are numerically reconstructed by the distribution functions and the macroscopic flow variables are tracked at the cell centers. Naturally, the present method does not involve with any complicated velocity gradients which are common in previous axisymmetric LBFS. Due to these striking features, the proposed hydrodynamic model is accurate and stable enough for simulating axisymmetric multiphase flows with superlarge density ratio and large viscosity ratio.

An Enhanced Double‐Unet Segmentation Framework for the Early Detection of Diabetic Retinopathy

ABSTRACTA segmentation method for diabetic retinopathy images utilizing an enhanced Double‐Unet can assist clinicians in analyzing the length, curvature, and branching angles of blood vessels, among other parameters, to facilitate the early detection of diabetic retinopathy. Thin blood veins have little contrast, which makes it simple to lose spatial information. By adding the attention gates of fusion channel attention and spatial attention in the decoder section, the enhanced Double‐Unet network highlights the vascular features and recovers the features lost during the coding stage. Additionally, multi‐scale context information may be efficiently extracted, and blood vessel feature information can be enhanced by substituting the Dense Atrous Spatial Pyramid Pooling (Dense ASPP) module for the ASPP module. The proposed method was assessed using retinal vascular datasets (DRIVE, CHASEDB1, STARE, HRF) and fundus images from 40 patients at a leading hospital in Fujian Province of China. The results show that the present method is fast and has high accuracy and can achieve high accuracy, recall, and F1 scores on most of the above datasets with fewer parameters. The segmentation results offer a solid foundation for more vascular reconstruction research while also successfully overcoming the interference of thin vessels and low‐contrast textures.

Particle Swarm Optimization Support Vector Machine-Based Grounding Fault Detection Method in Distribution Network

With the present fault detection method for low-voltage distribution networks, it is difficult to detect single-phase grounding faults under complex working conditions. In this paper, a particle swarm optimization (PSO) support vector machine (SVM)-based grounding fault detection method is proposed for distribution networks. By improving the inertia weight value and introducing a flight-time factor, the PSO algorithm can be improved. The parameters C and g of the SVM can be optimized based on the improved PSO algorithm. Based on the PSO-SVM-based method, a grounding fault detection method can be established. By testing the proposed model in the simulation and experiment, its effectiveness and detection accuracy is validated.

Stability-indicating UPLC method for quantification of alpelisib in bulk and tablet formulation by QbD approach

BackgroundIn the present study, a new and sensitive UPLC method for stability-indicating study has been established and validated as per the ICH guidelines. To date, no work has been reported on the forced degradation studies of alpelisib using the UPLC technique. Box–Behnken design was used to study the response surface for method optimisation to achieve a good separation with a minimum number of experimental trials. Three independent parameters selected were mobile phase ratio, flow rate of the mobile phase and temperature of the column. Retention time and tailing factor were taken as two responses to obtain mathematical models.ResultsThe chromatography was executed using Waters BEH C18 UPLC column (2.1 × 50 mm, 1.7micron) at wavelength detection of 246 nm. The optimised assay conditions predicted were isocratic mobile solvent system using 0.1% formic acid buffer solution and acetonitrile in the ratio of 50:50 (V/V), with a flow rate of 0.25 mL per min and injection volume of 4 µL. The method has shown a good response with a total run time of 4 min, retention time was found to be 1.49 min and tailing factor was 0.99 for alpelisib, showing good peak symmetry. The linearity of the method developed is at a range of 10–50 µg/mL with R2 0.9955, while the percentage mean recovery for accuracy was of 99.25%. The method developed was precise as % RSD of inter-day and intra-day precision was 0.3 and 0.1, respectively, meeting the specified limits.ConclusionThe developed UPLC work is quick and simple with an increased level of linearity, precision, specificity and accuracy as per the ICH criteria and can find application in industries as a regular method for quantification of alpelisib.

A Frequency-Domain Method to Assess the Dynamic Buffeting Response of Transmission Lines Under Downburst

A downburst is a short-term, sudden, and strong wind event that causes numerous transmission line failures worldwide. This paper applies random vibration theory to investigate the dynamic buffeting response of transmission lines subjected to downbursts. The total response is decomposed into static and dynamic components, with the time-varying mean response calculated analytically. In contrast, the dynamic response is considered as the quasi-static background response and is computed by the influence function. Based on the quasi-static assumption, equations for calculating the mean square deviation of the time-varying mean response and the pulsation response of transmission lines under both equal and unequal elevation conditions are derived through coordinate transformation. A case study is conducted in the frequency domain using simulated downburst wind velocity time histories. Further analyses are carried out by the time-domain nonlinear finite element method (FEM) to investigate the effects of structural geometrical nonlinearity and aerodynamic damping on the response of the transmission line to downbursts. The time-domain results are compared with the analytical solution to verify the correctness and applicability of the present method.

My Husband! Please Keep your Promise to Give the Warm Words to me, to your Wife! (Tcheonzamun 241st-256th)

French Missionary Dallet (1874) wrote in his book that there are differences between Chinese culture and Korean culture. However, the thousand character essay was commonly utilized for the education of their children for Chinese character (Dallet, 1874). The thousand character essay is in Korea called as Tcheonzamun (Han, 1583). Tcheonzamun (千字文) means the thousand(千) character(字) essay(文). It is firmly believed that the origin of Tcheonzamun is Chinese people (Han, 1583). However, several researchers denied this common belief, and they thought that the author(s) of this great work in Asia is Korean people or Korean language-speaking people (Park et al., 2021; Kim, 2023). Therefore, the present researchers will try to prove these recent suggestions of Park et al., (2021) and of Kim (2023). To study which country is responsible for creating Tcheonzamun is not easy. However, there is a method. It is to know the difference of language. The Korean language has the order as follows. It is SOV (Subject + Object + Verb) style. Supposing the order, for example, (241-244 資(Za) 父(Bu) 事(Sa) 君(Gun)) were ABCD. During the recent researches (Park et al., 2021; Kim, 2023), it was known that there are two forms as the Korean style.’ The first and the major form of the translation is B A D C. The translation on the first form will be done as follows. In order to make B (Object) to do A (Verb), we must make D (Object) to do C (Verb). The second and the minor form of the translation is CDAB. The translation on the second form will be carried out as follows. In order to make C (Object) to do D (Verb), we must make A (Object) to do B (Verb). And the present researchers will continue this study on this viewpoint. The range of this study is (Tcheonzamun 241st-256th). The present method for this work is through the meaning of Chinese character on Tcheonzamun poem (Park et al., 2021). The title of this study is ‘My husband! Please keep your promise to give the warm words to me, to your wife! (Tcheonzamun 241st-256th)’. <Number in Tcheonzamun. Chinese character (Pronunciation shown in Korean language on English alphabet)>. 241-244 資(Za) 父(Bu) 事(Sa) 君(Gun). My husband! I am your wife, and I want to cry to you as follows. “My husband! You treated (事) other person as the king or the queen (君)! In order

Chemoselective thioamidation of potassium acyltrifluoroborates (KATs) and amines using elemental sulfur in aqueous solution

Bioisosteres serve as valuable design elements for medicinal chemists, enabling the adjustment of the structural and pharmacokinetic properties of bioactive compounds to develop viable drug candidates. Thioamides hold promise as bioisosteres for the commonly used amide pharmacophores. This paper presents a synthesis method for thioamides, achieved through the reaction of potassium acyltrifluoroborates with amines in the presence of elemental sulfur in aqueous solution. The process is simple, mild, and accommodates various polar functional groups, making it ideal for creating amide and thioamide drug libraries. Furthermore, we have synthesized seven bioactive thioamides and their corresponding marketed drug analogs using present method.

A Chemo‐Damage‐Mechanical Coupled Phase‐Field Model for Three‐Dimensional Hydrogen‐Assisted Dynamic Cracking

ABSTRACTThis study develops a chemo‐damage‐mechanical coupled phase‐field method for modeling two‐dimensional and/or three‐dimensional hydrogen‐assisted transient dynamic cracking in metallic materials. In this method, hydrogen diffusion in solids is described by the evolution of bulk hydrogen concentration governed by the diffusion equation with an extended Fick's law. The hydrogen concentration and the inertial force of solids are incorporated into the governing equations of a non‐standard quasi‐brittle phase‐field model (known as the phase‐field regularized cohesive zone model, PF‐CZM) capable of modeling complicated multiple crack nucleation, initiation, and propagation with insensitivity to mesh size and length scale. The resultant displacement‐damage‐hydrogen concentration coupled three‐field equation is derived by the finite element Galerkin method and solved using a staggered Newton–Raphson iteration algorithm with an unconditionally stable implicit Newmark integration scheme. The new method was verified by four benchmark examples with hydrogen‐free numerical/experimental results for comparison, including quasi‐static/dynamic fracture of a notched plate under uniaxial tension, a dynamic crack branching experiment under constant traction, the Kalthoff‐Winkler impact fracture experiment, and dynamic fragmentation of a cylinder under internal pressures, with the effects of loading velocity, initial bulk hydrogen concentration, and diffusion time on crack propagation investigated in detail. It is found that the present method is capable of modeling complex 2D and 3D hydrogen‐assisted dynamic crack propagation and bifurcation under impact or internal pressure loadings, and thus holds the potential to be used for the structural design of hydrogen storage.

Baker’s yeast bio-catalyzed green and efficient synthesis of 3-indolylmethanamine via Aza-Friedel Crafts Reaction of indole with imines

An efficient and facile method has been developed for the synthesis of 3-indolylmethanamine via the Aza-Friedel Crafts Reaction of indole with imines by using Baker’s Yeast as biocatalyst. The reaction is very facile and works under mild and eco-friendly environment condition as ethyl alcohol (C2H5OH) is used as green solvent and Baker's Yeast as biocatalyst. Furthermore, the present method is very efficient as it requires simple work up and gives the products in good to excellent yields. It is anticipated that the present newly developed method will open a new route for the chemists to prepare the 3-indolylmethanamine via the Aza-Friedel Crafts Reaction of indole with imines in facile and eco-friendly environment.

Biomagnetic field effects on pulsatile blood flow with gold nanoparticles through bifurcated artery with stenosis and aneurysm

PurposeThis article provides a theoretical analysis and numerical simulation of bio-magnetic non-Newtonian pulsatile blood flow through a bifurcated artery with both stenosis and aneurysm, incorporating nanoparticles (Au). Blood flow is taken into account to be unsteady, incompressible, biomagnetic and non-Newtonian.Design/methodology/approachThese flow processes are modeled mathematically by use of the continuity, momentum and energy partial differential equations. The finite element method (FEM) is then accustomed to numerically resolve the dimensionless governing equations.FindingsThe average Nusselt number (Nu¯), local Nusselt number (Nu), local wall shear stress (WSS), isotherm and velocity profile are among the important blood flow parameters that are the primary concern of the study. These characteristics are thoroughly investigated and found to be largely consistent with existing literature. The results, presented graphically, include velocity profiles, isotherms, local Nu, local WSS and average Nu for a range of magnetic numbers (Mnf = 0.0, 0.1, 0.2, 0.3), Reynolds numbers (Re = 50, 100, 150, 200, 250, 300), power law indices (n = 0.8, 0.9, 1.0) and nanoparticle volume fraction coefficients (Φ = 0, 0.02, 0.04, 0.06). The Prandtl number for the biofluid (blood) is assumed constant at Pr = 21. The findings suggest that the magnetic field, nanoparticle volume fraction, power law index and Reynolds number significantly influence the isotherms, velocity, heat transfer coefficients and WSS in pulsatile blood circulation across an artery that is bifurcated and has aneurysm and stenosis.Research limitations/implicationsOne limitation of this study is that fluid–structure interaction was not taken into account. Additionally, we modeled the computational domain in 2D rather than 3D. While we assumed a homogeneous distribution of nanoparticles, this is not always accurate.Originality/valueThe investigation of the non-Newtonian biomagnetic fluid flow of blood with gold nanoparticles in arterial stenosis and aneurysm is novel. The present numerical method is validated for the nanofluids in an aneurysm-shaped computational domain which confirmed the results accuracy.

A Proposed Method for Deep Learning-Based Automatic Tracking with Minimal Training Data for Sports Biomechanics Research

Background: This technical note proposes a deep learning-based, few-shot automatic key point tracking technique tailored to sports biomechanics research. Methods: The present method facilitates the arbitrary definition of key points on athletes’ bodies or sports equipment. Initially, a limited number of video frames are manually digitized to mark the points of interest. These annotated frames are subsequently used to train a deep learning model that leverages a pre-trained VGG16 network as its backbone and incorporates an additional convolutional head. Feature maps extracted from three intermediate layers of VGG16 are processed by the head network to generate a probability map, highlighting the most likely locations of the key points. Transfer learning is implemented by freezing the backbone weights and training only the head network. By restricting the training data generation to regions surrounding the manually annotated points and training specifically for each video, this approach minimizes training time while maintaining high precision. Conclusions: This technique substantially reduces the time and effort required compared to frame-by-frame manual digitization in various sports settings, and enables customized training tailored to specific analytical needs and video environments.

The Synergy of Microwave-Irradiation and Water Surface: A Fast Access to C-2 Functionalized Indolizines Via Baylis-Hillman Reaction.

Herein, we report a sustainable, rapid, and cost-effective methodology for the synthesis of 2-functionalized indolizines from pyridine-2-carboxaldehydes by coupling with α,β-unsaturated compounds via the Baylis-Hillman pathway followed by cyclization in one-pot using DBU as the organocatalyst "on-water" under microwave irradiation. The water as the medium played a pivotal role in achieving quick conversion to the products in just 1 min in good to high yields (up to 78%). The method is further validated on several 2-acylpyridines; however, in these cases a longer time (up to 1 h) was required for complete conversion due to steric bulk at the reaction center and 1,2-functionalized indolizines are obtained in similar yields (up to 74%). The substituent variation in pyridine and α,β-unsaturated compounds show negligible electronic effect and a diverse functional group tolerance is observed. Furthermore, the scalability of the method is studied at the gram-scale with representative examples, which afford products in comparable yields to that of the small-scale reactions. The present method tick multiple sustainability matrices like metal-free synthesis, water as reaction medium, cost-effectiveness, and low E-factor.

Piecewise fractional interpolation with application to the Coupled System of Nonlinear Fractional Ordinary Differential Equations

In this paper, we consider the numerical method for the fractional differential equations. It is based on the piecewise fractional interpolants (PFIs), which is a new family of interpolants. We extend the technique to solve the Coupled system of fractional ordinary differential equations (FODEs) and present a predictor-corrector methods for the numerical solution of the coupled system of FODEs. By using the present method, we are able to solve efficiently the case that the solution of FODEs has lower smoothness. The stability and convergence of the present method is rigorously established. Some numerical examples are provided to confirm the theoretical claims.

Improved heavy-ion PID using scintillation light detector with neural network analysis: a Monte Carlo simulation study

The photon collection efficiency of gaseous scintillator detectors varies according to the position of the impinging charged particles in the medium that generates scintillation light. Thus, when impinging particles are distributed over a large area, the intrinsic photon-number resolution of the system is affected by a large variation.This work presents and discusses a method for adjusting the total number of detected photons to account for variation in the photon collection efficiency as a function of the position of the light source within the scintillating medium. The method was developed and validated by processing data from systematic simulation studies based on GEANT4 that model the response of the Energy Loss Optical Scintillation System (ELOSS) detector.The position of the charged particle is calculated using a deep neural network algorithm. This is accomplished by analyzing the distribution of scintillation light recorded by the array of photosensors. The estimated particle position is then used to calculate the correction factor and adjust the amount of captured light to account for variations in the photon collection efficiency.The neural network algorithm provides excellent tracking capabilities, achieving sub-millimeter position resolution and an angular resolution of 12 mrad, approaching the performance of traditional tracking detectors (e.g., drift chambers).The present method can be generalized to any optical scintillation system where the photon collection efficiency depends on the position of the impinging particle.