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Drone logistics is a novel method of distribution that will become prevalent. The advantageous location of the logistics hub enables quicker customer deliveries and lower fuel consumption, resulting in cost savings for the company's transportation operations. Logistics firms must discern the ideal location for establishing a logistics hub, which is challenging due to the simplicity of existing models and the intricate delivery factors. To simulate the drone logistics environment, this study presents a new mathematical model. The model not only retains the aspects of the current models, but also considers the degree of transportation difficulty from the logistics hub to the village, the capacity of drones for transportation, and the distribution of logistics hub locations.Moreover, this paper proposes an improved particle swarm optimization (PSO) algorithm which is a diversity-based hybrid PSO (DHPSO) algorithm to solve this model. In DHPSO, the Gaussian random walk can enhance global search in the model space, while the bubble-net attacking strategy can speed convergence. Besides, Archimedes spiral strategy is employed to overcome the local optima trap in the model and improve the exploitation of the algorithm. DHPSO maintains a balance between exploration and exploitation while better defining the distribution of logistics hub locations Numerical experiments show that the newly proposed model always achieves better locations than the current model. Comparing DHPSO with other state-of-the-art intelligent algorithms, the efficiency of the scheme can be improved by 42.58%. This means that logistics companies can reduce distribution costs and consumers can enjoy a more enjoyable shopping experience by using DHPSO's location selection. All the results show the location of the drone logistics hub is solved by DHPSO effectively. [ABSTRACT FROM AUTHOR]

SiC reinforced aluminum matrix composites are widely used in aerospace, electronic packaging and transportation due to their high specific strength, high thermal conductivity and high wear resistance. In this paper, SiC particle reinforced aluminum matrix composites were prepared by hot pressing sintering. The effects of SiC content on the microstructure and mechanical properties of aluminum matrix composites were studied. The phase composition, apparent density and mechanical properties of the samples were determined by X-ray diffraction, Archimedes drainage method, Rockwell hardness analysis and three-point bending method. The microstructure of the samples was analyzed by SEM. The thermal conductivity was measured by laser flash method. The results show that the hardness of the samples increases first and then decreases with the increase of the volume fraction of SiC particles from 0% to 60%, and reaches the maximum value of 90 HRB when the volume fraction of SiC is 50%. The thermal conductivity of the samples increases first and then decreases, and reaches the maximum value of 324.05 W/(m ⋅ K) when the volume fraction of SiC is 30%. With the increase of SiC volume fraction, the metal matrix and the reinforcement are closely combined without obvious pores. When the volume fraction of SiC increases to 60%, the porosity of the samples increases, the consistency decreases, and the strength decreases. [ABSTRACT FROM AUTHOR]

Over the past decade, significant research has focused on detecting abnormalities in metal laser powder bed fusion (L-PBF) additive manufacturing. Effective online monitoring systems are crucial for enhancing process stability, repeatability, and the quality of final components. Therefore, the development of in situ detection mechanisms has become essential for metal L-PBF systems, making efficient closed-loop control strategies to adjust process parameters in real time vital. This paper presents an overview of current in situ monitoring systems used in metal L-PBF, complemented by ex situ characterizations. It discusses in situ techniques employed in L-PBF and evaluates the applicability of commercial systems. The review covers optical, thermal, acoustic, and X-ray in situ methods, along with destructive and non-destructive ex situ methods like optical, Archimedes, and X-ray characterization techniques. Each technique is analyzed based on the sensor used for defect detection and the type or size of defects. Optical in situ monitoring primarily identifies large defects from powder bed abnormalities, while thermal methods detect defects as small as 100 µm and keyholes. Thermal in situ detection techniques are notable for their applicability to commercial devices and efficacy in detecting subsurface defects. Computed tomography scanning excels in locating porosity in 3D space with high accuracy. This study also explores the advantages of multi-sensor in situ techniques, such as combining optical and thermal sensors, and concludes by addressing current research needs and potential applications of multi-sensor systems. [ABSTRACT FROM AUTHOR]

As the applications for freeform optical surfaces continue to grow, the need for high-precision machining methods is becoming more and more of a necessity. Different toolpath strategies for the ultra-high precision turning of freeform surfaces can have a significant impact on the quality of the machined surfaces. This paper presents a novel toolpath planning method for ultra-precision slow tool servo diamond turning based on the curvature of freeform surfaces. The method analyzes the differential geometric properties of freeform surfaces by reconstructing NURBS freeform surfaces. A mathematical model is constructed based on the parameters of different positions of the freeform surface, toolpath parameters, and tool residual height. Appropriate toolpath parameters can be calculated to generate the optical freeform ultra-precision slow tool servo diamond turning toolpath. Compared with the toolpaths generated by the traditional Archimedes spiral method, the ultra-precision slow tool servo diamond turning toolpath planning method proposed in this paper can generate more uniform toolpaths on the freeform surfaces and keep the residual tool height within a small range. [ABSTRACT FROM AUTHOR]

Contemporary erasure poetry and the poetics of remediated forms are often taken as serving as political battlegrounds and sites of epistemic transference. At the same time, what is missing from the literature is a discussion of medieval manuscripts and the history of palimpsests. This paper explores two topics: (1) how the Archimedes palimpsest allows us to understand blackout poems as sites of knowledge production as well as conversations between polemic positions and (2) how poetic remediation can inform our valuation of the erasures situated in the Archimedes palimpsest. Through analysis of Travis Macdonald's The O Mission Repo, Rachel Stempel's "Natal Girl (& Other Repeat Offenses)," Molly R. Sullivan's "Levonorgestrel," and the Archimedes palimpsest, this paper explores how both medieval manuscripts and modern forms of poetry serve us as classroom realia, illustrating that their value extends beyond disciplinary boundaries to reveal new ways of conceiving artistic and pedagogical praxes. [ABSTRACT FROM AUTHOR]

The performance of the existing underdetermined blind source separation methods is very sensitive to the initial parameters, meanwhile, the existing setting or selection methods of initial parameters need to be improved. Consequently, an effective underdetermined blind source separation method is proposed in this paper to solve the above engineering problems. Based on the Archimedes optimization algorithm and quantum computing theory, this paper proposes a novel intelligent algorithm named quantum Archimedes optimization algorithm, which solves the objective functions for engineering problems. Then the optimal solution obtained through the quantum Archimedes optimization algorithm is used as the initial clustering centers of the K-means clustering algorithm to achieve mixing matrix estimation. In addition, the original initial estimation signal setting of the source recovery based on radial basis function network is converted into an initial solution in population for quantum Archimedes optimization algorithm. The optimal solution obtained through the quantum Archimedes optimization algorithm is used as the new initial estimation signal setting to achieve source recovery. The simulation results show that the proposed underdetermined blind source separation method has higher accuracy than previous methods. The proposed method that is more robust and applicable makes the setting and selection of initial parameters more reasonable so that the performance is no longer limited to the initial parameters. [ABSTRACT FROM AUTHOR]

The rapid growth of smart cities and industry causes an increase in waste production. The amount of municipal solid waste (MSW) increases by several factors, including population growth, economic status, and consumption trends. The inadequacy of basic trash data is a major issue for managing MSW. Numerous existing models based on solid waste prediction have been presented so far, but none of them predict solid waste accurately and also it consumes more time. To address these concerns, a deep convolutional spiking neural network for solid waste prediction (DCSNN-SWP) is proposed in this paper. Here, the real-time solid waste prediction data are gathered from the quantity of municipal corporation of Chennai (MCC), landfill, garden garbage, and coconut shell reports in Tamil Nadu (Chennai), such as Zone 9 (Nungambakkam), Zone 10 (Kodambakkam) and Zone 13 (Adyar). Then the collected solid waste data are pre-processed using the kernel correlation model. Then the pre-processing data is given to DCSNN-hybrid BCMO and Archimedes optimization algorithm which accurately predicts the solid waste as wet waste, dry waste, horticulture waste, and dumping yard for 2022-2032 years. The proposed DCSNN-SWP method has been implemented in Python. [ABSTRACT FROM AUTHOR]

This paper introduces a novel neural network model predictive controller based on Archimedes optimization algorithm to control constrained nonlinear systems, namely robot manipulators. Neural network models of a simple structure are used to accurately predict the system's future outputs. The new Archimedes optimization algorithm is utilized to solve the optimization problem of model predictive control and compute the optimal control action; this algorithm was widely used in different engineering fields due to its good accuracy and convergence speed. The performances of the suggested control algorithm are investigated by simulating a two-degrees-of-freedom robot manipulator. The obtained results are compared with those of various techniques, namely the PID controller, the computed torque controller, and the neural network-based model predictive control using the teaching–learning-based optimization and the particle swarm optimization. To complete the study, the developed controller is implemented on a DSP board and used to control a three-degrees-of-freedom robot manipulator; its results are compared to the neural network-based model predictive control based on the teaching–learning-based optimization and the particle swarm optimization. The simulation and the experimental results demonstrate that the proposed controller provides satisfactory robustness and accuracy, can handle constraints, and can be used to control systems with fast dynamics. [ABSTRACT FROM AUTHOR]

Facing the two major challenges of just-in-time (JIT) and energy-saving in part-feeding system for mixed-model assembly lines in automotive industry, this paper focuses on optimizing the part-feeding process by investigating the autonomous guided vehicles (AGV) routing and scheduling problem. A hybrid feeding policy, called dual-distribution, is proposed, which considers the utilization of different types of AGVs in various part-feeding policies. The problem is formulated as a mixed-integer programming model with the objectives of simultaneously minimizing the line-side inventory and AGV energy consumption in the part-feeding system. To solve this problem, a Q-learning-based multi-objective quantum-inspired Archimedes optimization algorithm (QMQAOA) is developed with a customized encoding and decoding approach to solve the problem. Besides, the quantum rotation gate initialization mechanism, the Q-learning-based neighborhood search strategy, and the neighboring distance calculation are integrated into the algorithm to improve both solution quality and convergence rate. Finally, numerical experiments are conducted to evaluate the performance of QMQAOA by comparing it with the Gurobi solver and other benchmark algorithms. The results demonstrate the superiority of QMQAOA, with performance superiority rates of 90/90, 77/90, and 90/90 achieved for degree of Pareto optimality (DPO), evenness of solutions (ES), and inverted generational distance (IGD) indicators, respectively. From managerial insights, the application of different types of AGVs in the part-feeding system is shown to enhance efficiency when compared to using a single type of AGV in several instances. These findings provide valuable insights for optimizing the automotive part-feeding system. [ABSTRACT FROM AUTHOR]

Diabetic Retinopathy (DR) primarily affects a set of lesions in the eyes, causing retinal degeneration and loss of vision. The DR features serve as a crucial component for ophthalmologists to diagnose DR at an earlier stage. This paper presents an automatic DR screening tool using a hybrid GAN-RCNN architecture formulated to categorize and identify different DR grades from the fundus images captured at various resolutions. The hybrid GAN-RCNN architecture is formulated by replacing the discriminator in the GAN with the RCNN classifier. The RCNN model can handle the complex inter-class and intra-class variations present in the fundus retina images and classify them into different classes such as mild, moderate, severe, and nonproliferative DR. The RCNN model not only extracts the pixels present in the fundus image but also focuses on the significant relationship that exists between different DR classes. The Archimedes optimization Algorithm (AOA) is used to optimize the different GAN and RCNN hyperparameters. When compared to the existing techniques the proposed model offers an accuracy of 99%, 98.5%, and 99.4% in the APTOS, Kaggle, and Messidor datasets which is comparatively high. The experimental outcome reveals that the introduced model serves as a concrete baseline for the diagnosis and treatment of DR patients. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging has emerged as a prominent area of research in the field of remote sensing science. However, hyperspectral images (HSIs) pose a notable challenge due to the presence of numerous irrelevant and redundant spectral bands exhibiting high correlation. Therefore, it is necessary to enhance the classification performance for HSI processing by selecting the most relevant discriminative spectral bands. To this end, this paper introduces a metaheuristic search method called enhancing exploration-exploitation in harmony search (E3HS). The standard harmony search suffers from many weaknesses, such as premature convergence and falling easily into the local optimum. Consequently, E3HS was proposed to evade falling into the local optimum by creating a balance between exploration and exploitation strategies to accelerate convergence toward the global optimum solution. Finally, two machine learning classifiers (k-nearest neighbor and support vector machine) were employed for hyperspectral image classification at the pixel level. Moreover, the proposed method was compared with the bat algorithm, Archimedes optimization algorithm, particle swarm optimization, standard harmony search, genetic algorithm, and krill herd algorithm. The experimental results demonstrated significant improvement with overall accuracy equal to 87.49%, 94.85%, and 94.41% for the Indian Pines, Pavia University, and Salinas datasets, respectively. [ABSTRACT FROM AUTHOR]

During the Scientific Revolution, the works of Archimedes played a momentous role. The geometers and natural philosophers of seventeenth-century Europe used Archimedes as a resource for tasks that varied considerably. In this paper, after some introductory remarks, I will consider and contrast the different readings of Archimedes provided by Leibniz and Newton. Leibniz's Archimedes is a precursor of calculus because of his use of exhaustion methods and infinitesimal magnitudes for the calculation of the dimension (area or volume) of curvilinear figures. In Newton's mathematical writings, Archimedes is invoked not to provide a rigorous foundation to the infinitesimal methods of the Moderns, but as an alternative to the symbolic approach to geometry championed by Descartes. [ABSTRACT FROM AUTHOR]

Laser processing has its advantages of high energy density, good controllability, and high flexibility; it has shown its importance in advancing modern manufacturing. Laser processing is used in this paper to fabricate an end grinding wheel with orderly arranged abrasive particles, and the performance of the fabricated grinding wheel is compared with that of a conventional grinding wheel. Our experiment and comparative studies have drawn the conclusions of (1) active laser brazing has been successfully used to arrange diamond particles in Archimedes' spirals; (2) the resulted grinding wheel has shown the enhanced effectiveness in comparison with the conventional grinding wheel in terms of reduced grinding force; when the spiral change rate i is set 0.25, the tangential grinding force has been reduced by up to 60%; (3) for a grinding wheel with specific spiral change rate, ground debris are discharged from the grinding zone in a certain direction, and the grinding temperature can be reduced; (4) in high-speed grinding, the surface quality by the grinding wheel with orderly arranged abrasive particles is better than that of conventional grinding wheel; under the tested grinding conditions, the roughness of the ground surface has been reduced up to 47% of that by conventional grinding wheels; (5) the grinding wheel with orderly arranged abrasive particles has shown the better wear resistance that conventional grinding wheels; abrasive particles of all four conventional grinding wheels are damaged to certain extent but orderly arranged abrasive particles on the fabricated wheel maintain mostly their protruded heights. [ABSTRACT FROM AUTHOR]

This paper presents a strategy to evaluate the performances of converter stations under the optimized operating points of hybrid AC-DC power systems with a reduced number of DC link variables. Compared to previous works reported with five DC-side control variables (CVs), the uniqueness of the presented optimal power flow (OPF) formulation lies within the selection of only two DC-side control variables (CVs), such as the inverter voltage and current in the DC link, apart from the conventional AC-side variables. Previous research has mainly been focused on optimizing hybrid power system performance through OPF-based formulations, but has mostly ignored the associated converter performances. Hence, in this study, converter performance, in terms of ripple and harmonics in DC voltage and AC current and the utilization of the converter infrastructure, is evaluated. The minimization of active power loss is taken as an objective function, and the problem is solved for a modified IEEE 30 bus system using a recently developed and very efficient Archimedes optimization algorithm (AOA). Case studies are performed to assess the efficacy of the presented OPF model in power systems, as well as converter performance. Furthermore, the results are extended to assess the applicability of the proposed model to the allocation of photovoltaic (PV)-type distributed generations (DGs) in hybrid AC-DC systems. The average improvement in power loss is found to be around 7.5% compared to the reported results. Furthermore, an approximate 10% improvement in converter power factor and an approximate 50% reduction in ripple factor are achieved. [ABSTRACT FROM AUTHOR]

In the 3rd century B.C.E., Archimedes wrote his treatise on the quadrature of the parabola, in which he laid out his solution to the problem of finding the area of a parabolic segment. Archimedes attacks the problem from two sides; first, he uses classical mechanics to derive an area formula, and then he uses pure geometry to prove his formula is correct. In this paper, we will present two modern approaches to this problem using calculus. The first approach can be presented to a calculus class that has learned about optimization methods and convergent geometric sequences, and the second can be presented after they have learned the Fundamental Theorem of Calculus. [ABSTRACT FROM AUTHOR]

Cassius Dio's fragmentary Roman History 15 contains an account of Archimedes' role in defending Syracuse during the Roman siege of 213–212 b.c., incorporating a legendary tale about a solar reflector Archimedes constructed to burn Roman warships, and including details of his death when the city fell. The textual basis of this famous episode depends on two derivative twelfth-century works: Zonaras' Epitome of Histories (9.4–5) and Tzetzes' Chiliades (2.35). After clarifying the present state of enquiry, this paper introduces two new witnesses, overlooked by editors of Dio and extensive scholarship on Archimedes, and assesses their value for reconstructing Dio's text. Comparative analysis of corresponding Dio-derived material in Tzetzes' Carmina Iliaca and Hypomnema in S. Luciam , especially verbal correspondences with Zonaras' Epitome , demonstrates that they are independent and, sometimes, superior witnesses to Dio's wording and content, reflecting Tzetzes' selective use of the Roman History in different verse and prose compositions over several decades. The study considers editorial implications for this section of Dio's work and general characteristics of Tzetzes' writings as repositories of testimonia and fragments. [ABSTRACT FROM AUTHOR]

The study of trigonometric functions traces back to Hellenistic mathematicians such as Pythagoras, Euclid, and Archimedes. Many fundamental methods of analysis use trigonometric functions to describe and understand cyclical phenomena. It was Fourier in the early years of the 19th century who pioneered the additive usage of trigonometric functions and first expressed various types of functions in terms of the sum of constant-amplitude constant-frequency trigonometric functions of different periods, now called the Fourier Transform. Unfortunately, Fourier's sum does not explicitly express nonlinear interactions between trigonometric components of different periods. To seek a remedy, a multiplicative perspective of using trigonometric functions in quantifying nonlinear interaction in any time series has been developed, starting with the invention of the Empirical Mode Decomposition methodology in the late 1990s by Norden E Huang. The most recent development is a multi-dimensional spectral representation of a time series, which is termed in this paper as the Huang Spectrum. Huang Spectral Analysis explicitly identifies the interactions among time-varying amplitude and frequency oscillatory components of different periods of a time series and quantifies nonlinear interactions explicitly. This paper introduces the intuitions and physical rationales behind the Huang Spectrum and Huang Spectral Analysis. Various synthetic and climatic time series with known time series characteristics are used to demonstrate the power of Huang Spectral Analysis. • Fourier Spectral Analysis takes an additive perspective on representing data and cannot resolve nonlinearity explicitly. • Huang Spectral Analysis takes a multiplicative perspective on representing data and resolves nonlinearity explicitly. • The combination of additive and multiplicative perspectives provides unprecedented power for extracting data information. [ABSTRACT FROM AUTHOR]

The field of research considered in this work is that of mechanisms generating inverse curves. We were motivated to approach this field, proposing variants of mechanisms based on Artobolevsky's inversor, in blocking conditions, due to the lack of recent applications related to inversor mechanisms that draw curves other than straight lines. Based on Crawford's inversor, Artobolevsky's inversor is structurally and kinematically analysed in what follows. Hence, we carried out the kinematic analysis and simulation of four inversor mechanisms derived from Artobolevsky's inversor, which draw different initial curves (a circle, a straight line, an ellipse and an Archimedes' spiral) were performed. Inverse curves were generated under limited operating conditions due to geometrical dimensions and kinematic parameters. Given the researchers' increasing interest in the development of applications related to inversor mechanisms (in fields such as: robotics, machine tools, visual arts and symbolic languages), as well as expanding databases of planar and spatial mechanisms, it is suggested that there is a need to create new mechanisms similar to those studied in this paper and to analyse their mode of operation. [ABSTRACT FROM AUTHOR]

Foam glasses are novel materials in engineering that have found a special place in various industries during recent decades. Foam glass is generally produced using recycled glass. By using waste materials, in addition to reducing the amount of waste glass that can harm the environment, it is possible to achieve a lightweight foam that is resistant to compression, corrosion, and heat transfer. The foam glass structure consists of cells that are filled with gas, and the walls of these bubbles are made of solid glass. One of the challenges is to measure its density. Because the samples made in the laboratory generally do not have a conventional shape, and therefore it is difficult to find the volume of the samples geometrically. In this paper, a new, simple, and practical method to find the density of foam glass is presented. The result of the tests showed a very good coincidence between geometrical volume measurements and volumes measured by using this novel method. [ABSTRACT FROM AUTHOR]

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Introduction: The ratio of Triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) is a crucial indicator for diabetes diagnosis. Methods: This study utilizes the Copula function to model and fit the non-linear correlation among fasting blood glucose (Glu), glycosylated hemoglobin (HbA1C), and TG/HDL-C in patients with diabetes. The Copula function chosen for this study includes the two-dimensional Archimedes and Elliptical distribution family, as well as the multidimensional Vine Copula function, for fitting the data. The evaluation of the fitting effect is performed using the mean absolute error (MAE) and mean square error (MSE). Results: The results indicate that the Clayton Copula exhibits the highest effectiveness in fitting the pairwise relationship between Glu and TG/HDL-C, as well as HbA1C and TG/HDL-C, displaying the smallest fitting error. Additionally, the Vine Copula function produces a satisfactory fit for the relationship among all three indicators. Compared to linear analysis methods, the Copula function more accurately depicts the correlation among these three types of indicators. Discussion: Moreover, our findings indicate a stronger correlation in the lower tail between Glu and HbA1C, as well as TG/HDL-C, suggesting that the Copula function provides greater accuracy and applicability in depicting the relationship among these indicators. As a result, it can offer a more precise auxiliary diagnosis and serve as a valuable reference in clinical judgment. [ABSTRACT FROM AUTHOR]

Titanium and its alloys are used to make dental implants because of its low density, high strength, and corrosion resistance. This paper describes the development of a potential biomaterial Ti‐10Nb by powder metallurgy utilizing four different compaction pressures and analyses its microstructural, physical, mechanical, electrochemical, biological, and tribological behavior under various situations. The alloys were fabricated using four different compaction pressures, that is, 600, 650, 700, and 750 MPa, and sintered in a vacuum atmosphere at 1000°C for 1.5 h. The density of the samples was measured using Archimedes principle. X‐ray diffraction and scanning electron microscopy equipped with energy dispersive spectroscopy were used to investigate the phase composition and microstructure, and a profilometer was used to examine the surface roughness of various samples. Vickers hardness tester was used to evaluate hardness, and a universal testing machine was used for compression testing. Corrosion and wear behavior were examined using a potentiostat and a Bio‐Tribometer, respectively. This Ti‐10Nb alloys consist of α + β phase, and have 16% highest porosity in sample compacted at 600 MPa. The samples compacted at 750 MPa achieved highest hardness, yield strength, compressive strength, and elastic modulus of 450 ± 29.72 HV, 718.22 ± 16.37 MPa, 1543.59 ± 24.37 MPa, and 41.27 ± 3.29 GPa, respectively. In addition, it also possesses highest corrosion and wear resistance with lowest icorr of 0.3954 ± 0.008 μA/cm2 and wear volume of (31.25 ± 0.206) × 10−3 mm3. These results indicate that the developed alloys have a variety of desirable properties, including high hardness, adequate compressive strength, good corrosion and wear resistance, apatite‐forming capability, and a low elastic modulus, which is advantageous for avoiding stress shielding. Therefore, it may be recommended to use it as a dental implant material. [ABSTRACT FROM AUTHOR]

The number of electric vehicle charging stations (EVCSs) is increasing alongside electric vehicles (EVs). The unplanned rollout of EVCSs can lead to problems such as deterioration of the voltage profile, increased active power losses, and maximum load demand in distribution networks (DNs). Therefore, EVCSs should be placed in optimum locations on the DNs. The complexity of the problem requires efficiency and performance. In this paper, a novel modified Archimedes optimization algorithm (MAOA) is proposed for optimal placement of EVCSs in DNs. Five parameters of the AOA were modified using the Honey Badger Algorithm (HBA). This placement is based on a combination of indexes: power loss, voltage deviation, and voltage stability index (VSI). Next, Newton-Raphson based load flow analysis is used to compute the minimum cost. MAOA, AOA and eight other optimization algorithms are compared. The results provide the most appropriate buses in the DN. The efficiency of the proposed algorithm was tested on IEEE 33, 69, and 10-bus Hatay power network systems. In all test systems, the proposed MAOA provided the best results with consistently low standard deviation values. The results suggest that the proposed method is more effective in the integration of EVCSs into the DN. © 2017 Elsevier Inc. All rights reserved. [ABSTRACT FROM AUTHOR]

The Proposition 4 from the 11-th volume (called Book of Lemmas) of „Great Books of the Western World" (printed in USA in 1952) presents the properties of a remarkable curve from Antiquity. This curve was studied by Archimedes, who called it Arbelos and it looks like a shoemaker's knife. It consists of 3 semicircles. The first part of the paper is dedicated to the description of an original mechanism, conceived to plot the above-mentioned curve. It is made of a rotating driving element and two dyads of RRR type. The curve plotted by the mechanism checks the equality of areas described by Archimedes. He proved (by using geometric reasonings) that the area of a circle whose diameter is equal to the height of the right triangle inscribed in the Arbelos curve's big semicircle is equal to the Arbelos curve's area. In the second part of the paper, the authors modified the mechanism's parameters and obtained 3 particular cases of Arbelos curves. These particular curves, plotted with the modified mechanism, are also composed of 3 semicircles whilst exhibiting other equalities between areas. The authors used geometric reasonings to prove the equality between the area of each particular curve and the area of a circle whose diameter is equal to the leg of a right triangle inscribed in the big semicircle of the studied particular curve. [ABSTRACT FROM AUTHOR]

Summary: The issue of underwater sensor network (UWSN) localization has led to the aim of techniques presented in recent years. In this paper, we develop Doppler shift with Archimedes Optimization Algorithm for localizing unknown nodes in UWSN. The projected method predicts that sink node plays a major function in managing the computational load contrasted with the remaining nodes in the network of underwater. This node localization is proceeding with frequency shifts of sound waves contrasted toward real, which are present once observer in addition source can be mobile as they do in a marine atmosphere. The proposed technique is utilized to compute the estimated position of an unknown sensor node; here Archimedes' optimization algorithm is utilized to reduce the error during localization of nodes in UWSNs. This proposed technique can be enhancing the accuracy of the localization of nodes in UWSNs. This proposed methodology can be implemented and evaluated with the help of performance metrics. To validate the proposed technique's efficiency, it is contrasted with conventional techniques like Particle Swarm Optimization (PSO) and Whale Optimization Algorithm (WOA). [ABSTRACT FROM AUTHOR]

The plane supporting spring commonly referred as flexural spring is used in isolation instruments such as astronautics, aeronautics, auto industries, micro-stereolithography and bulk lithography. All the applications require significant amount of radial stiffness which is used for isolation and providing friction-less motion. The proposed paper is targeted to derive a forced-based mathematical model for evaluating radial stiffness provided by the plane support spring. The springs are mounted in the flexural mechanism assembled in spindle head body clamped on micro drilling machine tool. The numerical equation for computing the radial stiffness is evaluated on the basis of solving various force components and the radial displacement generated by of each spring/arm using the "force–energy method." The finite element solution is done in ANSYS, whereas the theoretical answers are solved using PTC-MATHCAD solution. The results obtained by numerical analysis done in MATHCAD are validated by the finite element solution. The relationship between the radial stiffness and the key geometrical parameters are analyzed and confirmed. [ABSTRACT FROM AUTHOR]

Soil fertility and environmental factors play an important role in improving productivity and cropland quality in the agricultural sector. A new prediction and classification model for the potential of soil nutrients and hydrogen (pH) levels is proposed. The proposed model, Hybrid Whale Archimedes Optimization–based Multilayer Perceptron Neural Network (HWAO-MLPNN), is utilized for soil features classification of pH levels, and the soils are collected from the villages such as phosphorous (P), organic carbon (OC), boron (B), and potassium (K). The village-wise soil fertility prediction and classification model aims to improve soil health, reduce harmful fertilizer usage, enhance environmental quality, and achieve more profits. The proposed model combines the Multilayer Perceptron Neural Network (MLPNN) model and the Hybrid Whale Archimedes Optimization (HWAO) algorithm to enhance the classification performance on the validation data. The Marathwada dataset is selected to validate the soil nutrient prediction and classification model, and various measuring units such as cross-validation accuracy, Area Under Curve (AUC), accuracy, Mean Squared Error (MSE), G-mean, precision, specificity, and sensitivity are used for evaluation. The comparative study of this paper shows that the proposed HWAO-MLPNN achieved more classification accuracy of 98.1%, cross-validation accuracy of 98.3% for pH classification, and cross-validation accuracy of 97.9% for soil nutrient classification. The proposed model can be utilized to accurately classify soil nutrients and pH levels, which can have a significant impact on improving soil health, reducing harmful fertilizer usage, enhancing environmental quality, and ultimately increasing profitability in the agricultural sector. [ABSTRACT FROM AUTHOR]

Dropping a water-filled cup with a ping-pong ball inside to the ground expels the ball much higher than its initial height. During free fall, the absence of gravity in the reference frame of the cup makes capillary forces dominant, causing the ball to be sucked into water. At impact, the high velocity ejection is due to the strong Archimedes' force caused by vertical acceleration. In this paper, we study the dynamics of the capillary sinking of the ball during free fall and the ejection speed at impact, using tracking and high-speed imaging. In particular, we show that at short-time, the sinking is governed by capillary and added mass forces. [ABSTRACT FROM AUTHOR]

Analyzing the landing dynamics response is essential for enhancing the success rate of surface explorations on celestial bodies like Mars, the moon, and asteroids. This paper develops a comprehensive dynamics model for a space lander equipped with four sets of buffer legs. Each set comprises a primary strut, two secondary struts, and a footpad. The compression force of the buffer struts is determined through interpolation of real experimental data, while the contact force between the footpad and the ground is calculated using Archimedes law for granular media. The Lagrange equation of the second kind is employed to construct the dynamical model for the lander with minimal degrees of freedom. The proposed dynamics model is validated through experiments involving touchdowns of a single legged lander and a four legged lander. Moreover, key physical quantities such as the buffer force, energy absorption and body acceleration are computed for both 1-2-1 and 2-2 landing configurations. The results indicate that the buffer strut is capable of absorbing approximately half of the impact energy, leading to a 50-fold reduction in the shock acceleration of the main body in both landing configurations. However, it is observed that the maximum compression of the buffer strut is greater in the 1-2-1 landing configuration than in the 2-2 landing configuration. Furthermore, these simulations can be completed within seconds, enabling extensive simulations for the design and optimization of soft landing processes. [ABSTRACT FROM AUTHOR]

Through an activation reaction sintering method, porous (Mo2/3Y1/3)2AlC ceramics were prepared by Mo, Y, Al, and graphite powders as raw materials. The phase composition, microstructure, element distribution, and pore structure characteristics were comprehensively studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), Archimedes method, and bubble point method. A detailed investigation was conducted on the influence of sintering temperature on the phase composition. Possible routes of phase transition and pore formation mechanisms during the sintering process were provided. The experimental results reveal that at 650–850 °C, transition metals react with aluminum, forming aluminum-containing intermetallics and a small amount of carbides. At 850–1250 °C, transition metals collaborate with graphite, producing transition metal carbides. Then, at 1250–1450 °C, these aluminum intermetallics interact with transition metal carbides and remaining unreacted Y, Al, and C, yielding the final product (Mo2/3Y1/3) 2AlC. Simultaneously, the pore structure alters correspondingly with the solid-phase reaction at different reaction temperatures. [ABSTRACT FROM AUTHOR]

In modern textbooks, π is defined as the ratio C/d, where C is the length of a circumference and d its diameter. Since π is presented as a constant, we are led to the question in the title. A complete answer is not found in Euclid nor in Archimedes works, as they did not define the length of a plane curve explicitly, which impedes us to put their writings into a formal proof. In this paper, we point out the disadvantages of the integral definition of length found in calculus textbooks and then we introduce a definition that allows for a simple proof that C/d is the same for all circles, which demands only basic notions of geometry and sequences. [ABSTRACT FROM AUTHOR]

Reducing the dependence on traditional energy sources and shifting towards the utilization of renewable energy sources (RES) of energy in the maritime sector is imperative for reducing greenhouse gas emissions. Inherently, RES sources like solar and wind are intermittent and variable, resulting in inconsistent power availability and hence leading to energy supply fluctuations and potential shortages. In this respect, an efficient control strategy to maintain system stability and address intermittency effectively is essential. This work considers a hybrid marine microgrid with various energy sources like photovoltaics (PV), wind energy conversion system (WECS), marine biodiesel generator, Archimedes wave power generation, solid oxide fuel cell, and batteries. A 2-degree of freedom (2DOF) structure is designed and implemented with the tilt-integral-derivative filter (TIDN) to address frequency variations. Furthermore, an Archimedes optimization algorithm (AOA) is used to optimize the 2DOF-TIDN controller. The stability of the proposed microgrid system is assessed under various combinations of RES availabilities, including real-time data from WECS and PV. The AOA-based 2DOF-TIDN performance is compared to the following algorithms: genetic, Jaya, bat, grasshopper optimization, particle swarm optimization, and moth flame optimization. Simulation results obtained show that the AOA-based 2DOF-TIDN control strategy achieves shorter settling times in mitigating the changes of marine microgrid systems under different dynamic conditions as compared to the other algorithms. Finally, the controller being proposed in this paper was tested for robustness with parameter deviations of +25%, −20%, and − 40% from the nominal values, and proved to be the proposed 2DOF-TIDN controller parameters demonstrate significant robustness in effectively managing the uncertainties and parametric variations. • Maritime Microgrid system is designed for investigations with RE & storage units. • PV, Wind, MBG, AWPG, SOFC, and battery storage units are considered. • 2DOF-TIDN controller is developed to mitigate the changes in the system. • The AOA method is proposed for optimal gains of the 2DOF-TIDN under uncertainties. • Sensitivity analysis, Time delay analysis, and stability analysis are performed [ABSTRACT FROM AUTHOR]

This paper proposes an efficient method for calculating the dynamic behaviour and seismic performance of reciprocal structures by introducing the generalized displacements at the hinge point to describe the displacements of the nodes at the beam ends. The whole structural nodal coding system is condensed by replacing the two codes at the beam end nodes with code at the hinge point based on the traditional space rigid frame matrix displacement method. On the basis of the principle of virtual work, the system natural vibration equation of the structure in the condensed nodal coding system is obtained; from the mode-superposition response spectrum method and the time history analysis method, the system seismic response equation of the structure in the condensed nodal coding system is derived. Then, the dynamic behaviour and seismic performance of the structure can be achieved by solving the obtained system dynamic equations. Finally, two numerical examples, a space L-shaped articulated reciprocal rigid frame and a reciprocal configuration transformed from the 36 type of Archimedes paving, are adopted to demonstrate the effectiveness of the proposed method. From the numerical results, the reciprocal structure transformed from the 36 type of Archimedes paving has a large whole stiffness, and the seismic response generated by vertical earthquake excitation is the most significant, which should be the focus of the seismic design of reciprocal structures. The proposed method effectively reduces the number of computational degrees of freedom of the whole structure and is more efficient in calculating the reciprocal structure. • A new method for dynamic calculation of reciprocal structures is proposed. • The condensed nodal coding system is introduced. • The beam end nodal displacements are described by the generalized displacements at the hinge point. • The natural vibration equation and seismic response equation in the condensed nodal coding system is derived. • The dynamic behaviour and seismic performance of reciprocal structures are investigated. [ABSTRACT FROM AUTHOR]

• A novel MSSAO-ERNN technique is proposed to detect the PTSD symptom from speech. • The MSSAO-ERNN technique efficiently identifies PTSD symptoms from the dataset. • Three datasets namely NNE, FME hospital as well as TIMIT datasets are employed. • PTSD is mental illness that affects people when they experience traumatic events. • Performance is determined by computing various metrics for PTSD identification. Post-traumatic stress disorder (PTSD) is a stress-based disorder that occurs when a person is vulnerable to undesirable traumatic events like injury or harm. Numerous research works reported dissimilar complex issues for detecting PTSD severity in patients which makes the PTSD diagnosis process a complicated task. So, a novel Multi-Strategy Seeker Archimedes Optimization-based Elman Recurrent Neural Network (MSSAO-ERNN) technique to detect PTSD symptoms in earlier stages using speech samples. Our proposed MSSAO-ERNN technique efficiently identifies PTSD symptoms from the dataset and helps the physician to diagnose accurately. The proposed approach constitutes various significant phases that include the pre-processing phase, feature extraction phase, and classification phase to detect the presence of PTSD in the datasets. The performance of the proposed method is determined by computing various metrics for the accurate identification of PTSD. Finally, three different datasets namely the NNE dataset, the FME hospital dataset as well as TIMIT dataset are employed in this paper for PTSD diagnosis. The experimental results revealed that the proposed method attained a superior accuracy of 97% under different PTSD techniques. [ABSTRACT FROM AUTHOR]

With a growing interest on inorganic ceramics based solid-state electrolytes for all-solid-state batteries, there is a need to maximise their density to optimise electrochemical performance and fuel impermeability. In this paper, we demonstrate the sensitivity of terahertz time-domain spectroscopy (THz-TDS) combined with effective medium theory to quantify the porosity or density of sodium superionic conductor (NaSICON)-based solid-state electrolyte (SSEs) pellets prepared at densities in the range of 2.2–2.9 g cm−3, corresponding to 50–90 % relative densities sintered at 900–1150 °C. The results of which, have been validated against complementary Archimedes analysis and mercury porosimetry highlighting the potential of THz-TDS for rapid, contactless, non-destructive electrolyte characterisation. • Demonstrated sensitivity of terahertz radiation to NaSICON-based electrolyte. • NaSICON densities quantified using effective medium theory. • Estimated densities correlates to Archimedes analysis. • Estimated densities agrees with to mercury porosimetry data. [ABSTRACT FROM AUTHOR]

The impedance matching control, also known as approximate complex conjugate control (ACC), is one of the main strategies for improving the capture of energy by point absorber wave energy converters. Such a strategy shapes the mechanical impedance related to the floater dynamics via the control law. Since the traditional ACC is given by a linear control law, this work proposes a generalization denoted as nonlinear complex conjugate control (NCC) that considers the presence of nonlinear viscous damping in addition to the usual linear damping and stiffness. The energy maximization conditions for the proposed NCC are derived in the frequency domain through the describing function method. These conditions show that the ACC is a special case of the NCC when the total damping on the floater is approximated as a linear function of its velocity. From numerical simulations of a point absorber wave energy converters with nonlinear damping, which is based on the Archimedes wave swing prototype, it is shown that the NCC provides greater energy conversion than the ACC, as well as a robust performance in the presence of variations of the damping coefficient and the excitation force peak frequency. [ABSTRACT FROM AUTHOR]

The evolution of belt conveyors, as an important type of continuous conveying machinery, is examined here in a historical perspective. For this purpose, the selected period is from the ancient time, i.e. occurrence of conveying equipment, and up to the end of the nineteenth century. The basic postulation of a modern machine, including conveyors, is often interlinked to that of its ancestor, which may be simple and primitive. Ancient machines and principles of their work were the basis for later improvements which also brought the inventions in engineering. For instance, Archimedes lifted water to high altitude with a screw, which was regarded as the ancestor of today's screw conveyor and essentially his design has not changed since then. Bucket elevators also have their predecessors dating back to ancient times. In the concrete case of belt conveyors, a first trace can be found in the beginning of the seventeenth century, even classified as primitive example. During the Industrial Revolutions, various machines, such conveyors, appeared. The first modern-like belt conveyors are dedicated to the late eighteenth century due to the invention of Oliver Evans in USA and to the nineteenth century, by Lyster in England, Lopatine in Russia and Thomas Robins in USA. The technical solutions developed by the end of the nineteenth century were forerunners of the today's belt conveyors, while the key operational principles have not changed. [ABSTRACT FROM AUTHOR]

Archimedean spirals are common in various fields such as biology, engineering, astronomy, and space physics. Here we report the discovery of patterns resembling the general Archimedean spirals in particle distributions in the Earth radiation belt. Our analytic theory and numerical simulations demonstrate that electrons with initially asymmetric spatial distributions form such spirals in the inner magnetosphere, where particles at smaller radial distances move more slowly in angular velocity. These spirals result in time‐varying peaks and valleys in particle fluxes, referred to as "zebra stripes," which are well consistent with Van Allen Probes measurements. Although the initial asymmetric distribution may be seeded by the electric field in the magnetosphere, the spiral formation does not require them. Furthermore, we show that, due to the same fundamental motion of charged particles in regions dominated by dipole fields, this spiral phenomenon may also appear in the proton distributions, as well as in planetary magnetospheres. Plain Language Summary: The Archimedean spiral is named after the 3rd‐century BC Greek mathematician Archimedes. Such spirals have been seen from the sunflower head, Iridogorgia to galactic arms. Throughout the solar system, the average configuration of the background magnetic field also aligns with Archimedean spirals, as it is dragged by charged particles that are ejected radially from the surface of the rotating Sun, a fundamental discovery made by E. N. Parker. However, it remains unknown whether an Archimedean spiral exists in the near‐Earth space. Here we report for the first time the discovery of patterns similar to the general Archimedean spirals in particle distributions in the radiation belt, a region filled with energetic charged particles surrounding Earth. This happens because electrons closer to the Earth move slower in the angular direction. These spirals manifest as time‐varying peaks and valleys in the electron spectagrams, named as "zebra stripes." Our theory and simulation results are well consistent with the measurements of the Van Allen Probes. Besides, our theory predicts that these spirals could occur on protons and other planets with similar magnetic fields. Key Points: The first known discussion and discovery of Archimedean spiral structures in Earth's magnetosphereElectrons' general Archimedean spiral‐like distribution results in the formation of "zebra stripes" in the inner radiation beltOur findings hold exciting implications for understanding magnetospheric physics beyond our planet [ABSTRACT FROM AUTHOR]

A novel methodology for determining the singular point of an enveloped surface is put forward. Unlike some existing methods, the presented method starts directly from the equation of the enveloped surface instead of that of the generating surface, and it is thus called a direct method. The calculation for the normal vector of the enveloped surface is well simplified with the help of the moving frame approach, which makes the presented method feasible. The singularity condition equation is extracted by using the theory of linear algebra. For singular points with different properties, proper solving techniques are established, including resultant elimination and simple elimination. Applying the developed method, the undercutting characteristics of the Archimedes worm wheel are investigated from the perspective of spatial meshing. The numerical results demonstrate that the worm wheel generally has one undercutting limit line, whose trend is along the tooth width of the wheel. Locating on one side of the tooth surface and near the tooth root is a dangerous part of the worm wheel undercutting. The proposed method is beneficial for the development of gear meshing science. [ABSTRACT FROM AUTHOR]

A symbolic analysis of Archimedes's periodical number system is developed, from which a natural link emerges with the modern positional number systems with zero. After the publication of Fibonacci's Liber Abaci, the decimal Indo-Arabic positional system was the basis of the algorithmic and algebraic trend of modern mathematics, but even if zero plays a crucial role in algebra and mathematical analysis, zeroless positional systems show the same capability of producing efficient arithmetical algorithms based on operation tables over digits. The crucial role of digits is assessed, by considering a representation of numbers based on strings in lexicographic order. A new algorithm for the determination of decimal periods is presented by remarking on the cruciality of this topic in number theory. Periods of ordinal numbers and enumerations of recursive enumerability are shortly recalled. Concluding remarks are formulated about the deep relationship between numbers and information, which shed new light on a red line passing through the whole history of mathematics. [ABSTRACT FROM AUTHOR]

In this study, a nonlinear Archimedes wave swing (AWS) energy conversion system was employed to enable the use of irregular sea waves to provide useful electricity. Instead of the conventional PI controllers used in prior research, this study employed fractional-order PID (FOPID) controllers to control the back-to-back configuration of AWS. The aim was to maximize the energy yield from waves and maintain the grid voltage and the capacitor DC link voltage at predetermined values. In this study, six FOPID controllers were used to accomplish the control goals, leading to an array of thirty parameters required to be fine-tuned. In this regard, a hybrid jellyfish search optimizer and particle swarm optimization (HJSPSO) algorithm was adopted to select the optimal control gains. Verification of the performance of the proposed FOPID control system was achieved by comparing the system results to two conventional PID controllers and one FOPID controller. The conventional PID controllers were tuned using a recently presented metaheuristic algorithm called the Coot optimization algorithm (COOT) and the classical particle swarm optimization algorithm (PSO). Moreover, the FOPID was also tuned using the well-known genetic algorithm (GA). The system investigated in this study was subjected to various unsymmetrical and symmetrical fault disturbances. When compared with the standard COOT-PID, PSO-PID, and GA-FOPID controllers, the HJSPSO-FOPID results show a significant improvement in terms of performance and preserving control goals during system instability [ABSTRACT FROM AUTHOR]

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This study analyses the alteration of refractory bricks after 96 baking cycles of anodes baking furnace. A decrease of compressive strength from 48.45 to 32 MPa, respectively, for unused and used bricks were observed. The bulk density obtained by mercury intrusion porosimeter method decreased from 2.48 to 2.38 g/cm3for unused and used bricks; while the bulk density by archimedes method increased from 2.29 to 2.49 g/cm3. The water absorption by Archimedes method is decreased from 6.65 to 5.05 wt.%. While the total porosity obtained by mercury intrusion porosimeter increased from 15.41 to 17.21 wt.% for unused and used bricks. In the same way the total cumulative pore increased from 62.05 to 72.35 mm3/g. While the average pore radius decreased from 5.65 to 1.06 µm, respectively, for unused and used brick. The anode side of brick is deterioted rapidly than hot side of brick. The instrusion porosimetry method seems to be the best method to characterize bulk density and porosimetry of refractory bricks than Archimedes method. Mullite peak seems to be not change, suggesting that a very compacted brick with high mullite content seems to be the best matrix for bricks in anode baking furnace. Silica corrosion is mostly affected in refractory brick than alumina in anodes baking furnace. [ABSTRACT FROM AUTHOR]

Optimization problem, as a hot research field, is applied to many industries in the real world. Due to the complexity of different search spaces, metaheuristic optimization algorithms are proposed to solve this problem. As a recently introduced optimization method inspired by physics, Archimedes Optimization Algorithm (AOA) is an efficient metaheuristic algorithm based on Archimedes' law. It has the advantages of fast convergence speed and balance between local and global search ability when solving continuous problems. However, discrete problems exist more in practical applications. AOA needs to be further improved in dealing with such problems. On this basis, to make Archimedes Optimization Algorithm better applied to solve discrete problems, a Binary Archimedes Optimization Algorithm (BAOA) is proposed in this paper, which incorporates a novel V-shaped transfer function. The proposed method applies the BAOA to COVID-19 classification of medical data, segmentation of real brain lesion, and the knapsack problem. The experimental results show that the proposed BAOA can solve the discrete problem well. [ABSTRACT FROM AUTHOR]

Traditional power system stabilizer (PSS) is an effective controller to damp out low frequency oscillation (LFO) through the excitation system. Adding proportional integral derivative (PID) controller improves the performance of PSS controller. This paper propose Archimedes optimization algorithm (AOA) to improve the performance of series PSS-PID controller through adjusting the tuning parameters to effectively damp out LFO and improve power system transient stability in western system coordinate council (WSCC) power system. AOA is used to optimize the system based on minimizing the integral time absolute error (ITAE) of rotor angular speed. A nonlinear model of WSCC system and PSS-PID controller are simulated under three phase short circuit fault applied at terminals of machines. The system has been tested without PSS-PID controller. Then, PSS-PID controller is optimized using AOA algorithm and whale optimization algorithm (WOA) to compare between their performances. The system under study is simulated in time-domain using MATLAB software. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bi-DCB specimens were designed and manufactured by the vacuum bag method, and bistable deformation processes of Bi-DCB specimens were achieved. • Based on the Tsai-Hill and maximum stress criteria, two nonlinear explicit finite element models were established for predicting the folding stable state of the Bi-DCB. • Numerical results of two finite element models were compared with experiments, and the three were in good agreement. The bistable deployable composite boom (Bi-DCB) can realize the bistable function by storing and releasing strain energy, which has a good application prospect in the aerospace field. In this paper, the folding stable state of the Bi-DCB was investigated using experimental and numerical approaches. Using the vacuum bag method, six Bi-DCB specimens were prepared. Bistable experiments of Bi-DCB specimens were conducted and linear fitting with Archimedes' helix was performed to determine the folding stable configuration. In addition, two Finite Element Models (FEMs) were established for predicting the folding stable state of the Bi-DCB. Two classical failure criteria were utilized to analyze the stress level of the folding stable state of the Bi-DCB. Numerical results of two FEMs agreed well with experimental results, including the bistable deformation process and the folding stable state. [ABSTRACT FROM AUTHOR]

PbO glass has an adverse effect on the environment; the bismuth glass has a high refractive index, low melting temperature, softening temperature, and glass transition temperature (Tg), so that it can be used as a lead-free glass, used in optoelectronics, electronics, optics, and other components, which bismuth glass has been proved to be an important replacement material. Due to the higher melting temperature, Bi3+ ions tend to partially reduce to the low valence state of Bi0, which in turn causes coloration of the glass. In this experiment, the absorption peaks of glass oxidized brown color were observed at about 470 nm at 1,100°C (Bi2O3 = 40, 45 mol%) and 1,000°C (Bi2O3 = 40 mol%) for these three curves. The bismuth glass produced by high-temperature melting is not suitable for optical applications; by adding an oxidant (Sb2O3), which inhibits the reduction reaction of bismuth ions and maintains the ions in the state of Bi3+, the glass becomes more transparent in appearance and the transmittance is also improved and raised to approximately 75%–80%, which proves that appropriate additives are sufficient to greatly improve the application of bismuth glass for optical components. In the research process, the density and molar volume were measured by Archimedes method, Raman analysis was used to explore the influence of its structural changes, UV/Vis spectroscopy was used to measure the transmittance and absorption spectra for analysis and discussion, and TMA was used to observe the thermal properties, in the hope of developing a good optical properties of the glass, and the present experiments have confirmed that the addition of a small amount of Sb2O3 changes the color of the glass from black to a light yellow, which can be better used in the optical glass. [ABSTRACT FROM AUTHOR]

This work has developed and simulated a planar complementary Archimedes-based metamaterial absorber with the goal of its application in refractive index sensing. Unlike designs that employ multiple layers or numerous resonators within a single unit cell, our proposed absorber adopts a more streamlined approach. It consists of three layers, with an FR4 dielectric substrate sandwiched between two copper layers. It's important to note that the absorption characteristics of this design are polarization-dependent. This polarization dependence arises from the asymmetrical resonance behavior observed in both the x and y directions. The absorber exhibits impressive absorption rates at various resonance frequencies, namely 98.5% at f1 = 8.49 GHz, 77.1% at f2 = 8.88 GHz, 88.7% at f3 = 9.3 GHz, 98.2% at f4 = 9.87 GHz, 99.7% at f5 = 10.65 GHz, 83.4% at f6 = 11.58 GHz, and 99.9% at f7 = 12.24 GHz. Furthermore, the article explored the refractive index sensing capabilities of this structure by introducing a 1 mm analyte layer on top of the patch structure. Through refractive index sensing analysis, we've determined that this absorber-based sensor yields an impressive high-quality factor value of 84.5, highlighting its remarkable sensitivity and precision. A more profound comprehension of the physical mechanisms in action has been attained by examining the distribution of surface currents. Furthermore, the behavior of the absorber has been investigated under varying polarization and incident angle conditions, ranging from zero degrees to sixty degrees. The thorough characterization establishes this absorber as a promising choice for microwave sensing applications. [ABSTRACT FROM AUTHOR]