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关键词： MATLAB  

摘要： In this study, we investigate the negative electromagnetic properties and negative refractive index in yttrium iron garnet (YIG) -based nanocomposites, specifically Cu/YIG and nickel-doped Cu/YIG, synthesized through an in situ synthesis method. Field Emission Scanning Electron Microscopy (FESEM) confirmed that the synthesis process was successfully executed, yielding the desired nanostructures. Histogram analysis of particle size distribution revealed an approximately normal and uniform size distribution within the YIG nanoparticles. Furthermore, UV spectroscopy verified that the electronic structure and optical properties of these samples aligned with the predicted outcomes. The dielectric permittivity and magnetic permeability parameters were measured at room temperature using scattering parameters obtained from a Vector Network Analyzer (VNA) and subsequently calculated through MATLAB software. Results demonstrated that in certain frequency regions, both Ε and μ were simultaneously negative, indicating the feasibility of producing structures with a negative refractive index. This property has the potential to open new avenues for electromagnetic wave control, paving the way for significant advancements in optical, communication, and electronic technologies. © 2025 Elsevier B.V.

关键词： MATLAB  

摘要： Background: Microorganisms make biofuel production and synthesizing various compounds and enzymes possible. They serve as excellent model organisms for study. They have been turned into weapons and are occasionally utilised in bioterrorism and combat. Novelty: The study's novelty is exploring spectacular features of microorganisms, such as Cattaneo-Christov radiative flux over a permeable geometry. Approach: The shooting method with MATLAB built-in BVP4C solver has been utilised. Conclusions: According to the results of the present study, as Weissenberg's number rises, so does the fluid velocity. To strengthen the temperature description, the temperature-ratio parameter values rise. The field of concentration decreases for a significant Lewis number. © 2025 The Authors

关键词： MATLAB  

摘要： The NSTX-U Shorted Turn Protection (STP) system is a vital safety feature designed to protect the tokamak's coils during operations. It employs a Kalman filter-based algorithm to monitor coil currents and detect faults in real-time. If an anomaly is detected, the system swiftly terminates the tokamak pulse to prevent damage. Developed with Matlab and Simulink, the STP system has been validated through real-time simulations, ensuring its effectiveness for the upcoming upgrades of the NSTX-U facility. This article presents the theory for implementation of the STP algorithm and the results from simulation and real-time implementation. © 2024

关键词： MATLAB  

摘要： We perform twenty experiments on an acoustically-forced laminar premixed Bunsen flame and assimilate high-speed footage of the natural emission into a physics-based model containing seven parameters. The experimental rig is a ducted Bunsen flame supplied by a mixture of methane and ethylene. A high-speed camera captures the natural emission of the flame, from which we extract the position of the flame front. We use Bayesian inference to combine this experimental data with our prior knowledge of this flame's behaviour. This prior knowledge is expressed through (i) a model of the kinematics of a flame front moving through a model of the perturbed velocity field, and (ii) a priori estimates of the parameters of the above model with quantified uncertainties. We find the most probable a posteriori model parameters using Bayesian parameter inference, and quantify their uncertainties using Laplace's method combined with first-order adjoint methods. This is substantially cheaper than other common Bayesian inference frameworks, such as Markov Chain Monte Carlo. This process results in a quantitatively-accurate physics-based reduced-order model of the acoustically forced Bunsen flame for injection velocities ranging from 1.75m/s to 2.99m/s and equivalence ratio values ranging from 1.26 to 1.47, using seven parameters. We use this model to evaluate the heat release rate between experimental snapshots, to extrapolate to different experimental conditions, and to calculate the flame transfer function and its uncertainty for all the flames. Since the proposed model relies on only seven parameters, it can be trained with little data and successfully extrapolates beyond the training dataset. Matlab code is provided so that the reader can apply it to assimilate further flame images into the model. Novelty and Significance Statement Thermoacoustic systems tend to be extremely sensitive to small parameter changes, which makes them difficult to model a priori from existing models in the

关键词： MATLAB  

摘要： Gasification is an effective way of converting biomass into electricity. However, determining optimal conditions to reach higher temperature gradients and ensure thermal stability of the reactors for syngas production is challenging. This paper presents a hybrid static and dynamic model for optimizing fixed-bed biomass gasification using experimental data. A reduction-model has been developed and simulated using MATLAB to optimize the reduction process, which involves the most important reactions in syngas production. The analytical results show significant improvements, with the volume fractions of CO increasing from the initial value of 15.10 % to the simulated value of 30.77 % between 650 °C and 1000 °C, and H2 rising from 7.39 % to 18.76 % at the same temperatures. Thus, the increase in temperature leads to a slight increase in the volume fraction of CH4 from its initial value of 3.16 % to the maximum simulated value of 4.33 %. Cold gas efficiency (CGE) rises from the initial value 36.60 % to the calculated value of 71.53 % and carbon conversion efficiency (CCE) increases from 62.37 % to 97.99 % between 650 °C and 1000 °C. The reduction kinetic model identified an optimum 1000 °C initial reduction-zone temperature and 0.3m minimum reduction-zone depth. This model is applicable for determining optimal operational parameters in fixed-bed gasification process. © 2025 The Authors

关键词： MATLAB  

摘要： SAE 10W-30 synthetic blended over-based oil with hybrid nano coolants and magnetic dipole effects provides enhanced thermal characteristics and lubricating properties for sophisticated vehicle systems. This study examines the convective flow of Maxwell hybrid nanofluid in inclined and vertical cylinders, highlighting the influence of magnetic dipoles. New governing equations are formulated using SAE 10W-30 as the base fluid, incorporating ferrous ferric oxide (Fe₃O₄) and graphene oxide (GO) nanoparticles, along with thermal and solutal stratification boundary conditions. The implementation of MATLAB with its built-in bvp4c numerical solver converts the partial differential equations into ordinary differential equations, and a multilayer perception -artificial neural network (ANN) using the Levenberg-Marquardt algorithm predicts skin friction, Nusselt, and Sherwood numbers. Numerical data consisting of 110 points is obtained via bvp4c and implemented in the ANN model, where the training, validation, and testing are 70 %, 15 %, and 15 % respectively as the input data. The ANN accurately predicts performance metrics for inclined and vertical cylinders validated through mean square error (MSE), regression analysis, and error distribution. Results highlight that higher reciprocal magnetic prandtl numbers decrease flow velocity and induced magnetic profiles while increasing temperature and concentration fields. From the result of ANN, applied performance metrics include the mean square error (MSE) = 0.0081488, coefficient of determination (R) = 0.99858 while MSE = 0.000031011and R = 1 for the inclined and vertical cylinders respectively. Comparing the findings of this study with those of previous studies shows much similarity. This predictive analysis optimizes engine cooling and lubrication under varying thermal and flow conditions. The addition of Magnetic dipole effects enhances heat transfer, reduces drag, and improves lubrication, offering better engine protection th

关键词： MATLAB  

摘要： The hybrid energy storage system (HESS) is an effective solution for managing power and utilizing unpredictable renewable energy resources in isolated DC microgrids. This paper proposes a new approach that combines RST control with filter-based (RST-FB) technology. The RST controller is based on a polynomial structure comprising three polynomials: R (Regulation), S (Sensitivity), and T (Tracking). The aim of this approach is twofold: firstly, to prevent state-of-charge (SoC) violations of the supercapacitor (SC) within the HESS in an isolated DC microgrid, and secondly, to ensure uninterrupted operation of the SC when the system experiences a significant constant power load (CPL) or abrupt load changes that cannot be effectively mitigated using conventional filter-based (CFB)schemes. By preventing SoC violations and ensuring uninterrupted operation, this approach ensures that the SC operates within its safe and efficient range and minimizes stress on the battery. This approach enhances overall system performance by improving transient response and voltage stability. Furthermore, the proposed method extends the lifespan of both the SC and the battery by efficiently managing power distribution among system components, thereby increasing operational efficiency during load fluctuations. These results highlight the method's effectiveness in optimizing reliability and durability within an isolated DC microgrid incorporating a HESS. The proposed RST-FB scheme was evaluated and compared with the CFB scheme via MATLAB simulation conducted on an isolated DC microgrid incorporating HESS. The results indicate that the RST-FB scheme outperforms the CFB scheme by effectively preventing SoC violations, ensuring continuous operation, improving power sharing between the HESS, and maintining stable regulation of the DC bus voltage. Furthormore, the efficacy of the proposed scheme was validated through real-time hardware-in-the-loop (HIL) simulations. © 2025 Elsevier Ltd

关键词： 流塑土   钢架-土工材料系统   预加固   极限承载力   抗拉强度  

摘要： 在港口建设的围海造陆工程中，吹填流塑土的预加固至关重要，能够促进深层排水固结、提升地基承载力。针对传统填土法成本高、效率低的局限，文章提出一种“钢架-土工材料系统”预加固工艺，该工艺以高效、低成本及材料循环利用为显著优势。文章深入分析了该工艺的力学机理，通过引入关键物理力学参数修正承载力公式，揭示了预加固后极限承载力与土工材料参数的敏感性关系，探讨了该预加固工艺的科学性。结果表明：（1）高变形模量比的双地基结构有效分散上部荷载，减少流塑土附加应力;（2）土工材料在荷载作用下产生变形，通过摩阻力和锚固效应提升流塑土承载力。预加固效果与土工材料等效抗拉强度呈线性正相关，与极限应变呈指数负相关，前者影响更显著。工程实践应选择抗拉强度略高的材料，以应对施工扰动，防止预加固失效。通过工程实例分析，若采用传统填土法以达到该工艺相同的加固成效，所需填土层厚度至少9.13 m，因此该方法具有极大的优越性和推广前景。研究结果可为流塑土插板排水施工预加固提供方案和理论指导。

摘要： 随着《义务教育数学课程标准》的实施，对学生综合能力的培养已经成为课堂教学的核心目标。小学数学教学中，为了提升学生的综合素养，实验成为小学数学课堂不可或缺的组成部分。在数学课堂开展数学实验，能够激发学生的学习热情，帮助他们明晰知识的形成过程，让学生了解数学知识在生活中的应用价值。对此，为了让学生更加深刻、透彻地掌握数学知识点，教师应结合课程内容，引入具有多元性的实验，解放学生的手脑，让他们调动多重感官探索数学知识，感受数学之美。本文阐述了实验在小学数学课堂中的应用策略，旨在帮助学生健全学习体系，构建更加高效的数学课堂。

关键词： MATLAB  

摘要： Lighting is an art and technology is its canvas. In modern interior architectural designs lighting systems have evolved beyond their primary function to integrate communication capabilities through Visible Light Communication (VLC). This work explores the dual role of LED (Light Emitting Diode) lighting in providing illumination and enabling data transmission. A number of lighting models have been analyzed such as flush mount lighting, recessed lighting, hanging pendant, chandeliers, slide rails, pendant light cluster, diagonal linear strips, linear strips across y-axis, random LED lighting patterns and wall fixture LEDs. Performance metrics such as illuminance levels, uniformity, ISO compliance, received power, signal-to-noise ratio (SNR) and mobility area coverage were analyzed to assess lighting efficiency and VLC data transmission quality. The work employs MATLAB and DIALux Evo software to simulate and analyze the performance of various lighting configurations. Additionally, four specific LED products 726.70 PANTALLA 4000 K, 726.80 PANTALLA 3000 K, ELIA PL M2 DALI and MOLNPRO 4400LM 840 MP were evaluated for their dual capabilities in illumination and Visible Light Communication (VLC). The work offers valuable insights into designing multifunctional, energy-efficient indoor environments that integrate advanced lighting and communication technologies.