Rod pump systems are complex nonlinear processes, and conventional efficiency prediction methods for such systems typically rely on high-order fractional partial differential equations, which severely constrain real-time inference. Motivated by the increasing availability of measured electrical power data, this paper introduces a series of prediction models for nonlinear fractional-order PDE systems efficiency based on multimodal feature fusion. First, three single-model predictions—Asymptotic Cross-Fusion, Adaptive-Weight Late-Fusion, and Two-Stage Progressive Feature Fusion—are presented; next, two ensemble approaches—one based on a Parallel-Cascaded Ensemble strategy and the other on Data Envelopment Analysis—are developed; finally, by balancing base-learner diversity with predictive accuracy, a multi-strategy ensemble prediction model is devised for online rod pump system efficiency estimation. Comprehensive experiments and ablation studies on data from 3938 oil wells demonstrate that the proposed methods deliver high predictive accuracy while meeting real-time performance requirements.
In this work, the refractive indices nD, refractive index deviations Δ nD, molar refractions Rm and excess molar refractions REm were determined over the full range of compositions for the Diglycolamine-water binary mixture. Experimental measurements of these properties were carried out at atmospheric pressure and at temperatures ranging from 293.15 to 333.15 K. Excess molar refractions REm and refractive index deviations Δ nD have been fitted to the polynomial Redlich-Kister equation. The refractive indices have been compared with those predicted by the mixing rules proposed by: Lorentz-Lorenz (L-L), Gladstone- Dale (G-L), Eykman (E), Arago-Biot (A-B), Eyring-John (E-J), Bruggeman (B), and Oster (OS), in order to verify their validity for the Diglycolamine-water binary system. The experimental values of the refractive indices agree well with all the previous relationships, with the relationship of Oster (OS) and Gladstone-Dale (G-L) with which better results are obtained.
Vevosa Nakro, Ketiyala Ao, Tsenbeni N. Lotha, Imkongyanger Ao, Lemzila Rudithongru, Chubaakum Pongener, Merangmenla Aier, Aola Supong and Latonglila Jamir
The discharge of large quantities of organic dyes into the environment causes significant harm to humans and the environment. Thus, there is an urgent need to develop cost-effective adsorbents for removing these dyes. In the present study, the synthesis of activated carbon (AC) derived from mixed fish scale waste using KOH activation was investigated for Congo red (CR) dye removal. The finding shows that the obtained biocarbon has a fixed carbon of 42.9% with a crystallinity index of 15.01%. N2 adsorption-desorption isotherm was found to be type IV, signifying mesoporous structure with a surface area and total pore volume of 150.049 m2 g-1 and 0.119 cm3.g-1. Batch adsorption was carried out by various adsorbent doses, initial concentration, contact time, and pH to comprehend the effect of operating parameters on its removal efficacy. The isotherm studies fitted well for Freundlich with an R2 of 0.99%. Adsorption kinetics was best fitted by the pseudo-second-order model and thermodynamic studies revealed the adsorption process to be exothermic and spontaneous. The efficiency of AC was also studied by an amount of sorption and desorption cycles which showed its potential for reusability up to the sixth cycle. Thus, the findings suggest that activated carbon derived from mixed fish scale waste is a promising adsorbent for removing Congo red dye from aqueous solutions.
Environmental effects of industries and plants, Science (General)
The present study explores the potential of dead Aspergillus flavus mycomass (DAFM) as an effective, eco-friendly, and low-cost myco-biosorbent for the removal of Zn2+ ions from contaminated aqueous environments. DAFM, characterized by its chemically diverse surface and abundance of functional groups, offers significant promise for the removal of metal ions. The study systematically optimized key operational parameters − including biomass age, particle size, temperature, contact time, DAFM dosage, and initial Zn2+ concentration − to identify the most favorable conditions for maximum biosorptive efficiency. Advanced characterization techniques, including FT-IR spectroscopy, confirmed the active participation of functional moieties such as hydroxyl, carboxyl, and amide groups in Zn2+ binding, underscoring the role of physicochemical interactions in the adsorption process. The maximum adsorption capacity (qmax = 65.69 mg·g−1) obtained with Langmuir's isotherm model exhibited a close relationship with experimental adsorption capacity. Kinetic analysis supported the pseudo-second-order model, indicating chemisorption as the dominant mechanism, while thermodynamic evaluation revealed that the process is spontaneous and endothermic, with increased randomness at the solid-liquid interface. Furthermore, equilibrium modeling demonstrated the system's conformity to the Langmuir isotherm, highlighting the monolayer adsorption capacity of DAFM. Overall, the findings affirm the potential utility of DAFM in industrial effluent treatment, particularly in sectors releasing zinc-laden wastewater. This study lays the groundwork for scalable applications of fungal biomass in biosorption technologies, contributing to the development of sustainable and cost-effective water purification systems suitable for use in resource-limited settings.
This article investigates the problem of finite-time synchronization of fractional-order complex-valued random multi-layer networks without decomposing them into two real-valued systems. Firstly, by promoting real-valued signum functions, sign functions on the complex-valued domain are introduced. Simultaneously, quantization functions in the complex-valued domain are also introduced, and several related formulas for sign functions and quantization functions in complex-valued domain are established. Under the framework of the given sign function and quantization function, an adaptive quantized control scheme with or without deception attacks is designed. According to the finite-time theorem, Lyapunov function, and graph theory methods, some sufficient criteria for realizing finite-time synchronization in complex-valued fractional-order multi-layer networks have been obtained. Furthermore, the setting time of finite-time synchronization is effectively evaluated. Eventually, the reliability of our results and the practicality of control strategies are verified through numerical examples.
This study provides an innovative and attractive analytical strategy to examine the numerical solution for the time-fractional Schrödinger equation (SE) in the sense of Caputo fractional operator. In this research, we present the Elzaki transform residual power series method (ET-RPSM), which combines the Elzaki transform (ET) with the residual power series method (RPSM). This strategy has the advantage of requiring only the premise of limiting at zero for determining the coefficients of the series, and it uses symbolic computation software to perform the least number of calculations. The results obtained through the considered method are in the form of a series solution and converge rapidly. These outcomes closely match the precise results and are discussed through graphical structures to express the physical representation of the considered equation. The results showed that the suggested strategy is a straightforward, suitable, and practical tool for solving and comprehending a wide range of nonlinear physical models.
Lattice structures such as triply periodic minimal surface (TPMS) structures have gained significance due to advancements in additive manufacturing, particularly 3D printing, which enable their engineering to be tailored to specific applications, such as heat exchangers. While traditional heat exchanger designs have been extensively studied, investigations into the thermal performance of TPMS structures are limited. Considering the extensive range of the geometric design variations in TPMS structures, highly efficient structures on par with the performance of conventional heat exchanger designs can be expected. This study aims to comprehensively evaluate the thermal and flow characteristics of a specific TPMS structure (Fischer Koch S), and, in particular, the impact of various volume fractions on its heat transfer performance and on its friction factor. Another key objective of this study is to develop Nusselt and friction factor correlations as a function of the investigated volume fractions for potential use in future design tools. To this end, a broad CFD study was carried out. Additionally, this study provides insights into the procedures involved in generating Fischer Koch S geometries and the modeling methodology employed in CFD investigations. Based on the results of the CFD study, the thermal and fluid dynamic performances of Fischer Koch unit cells were evaluated, resulting in heat transfer coefficients up to 160 W/m<sup>2</sup>K for the investigated structures. A comparison between the heat transfer coefficient of the examined TPMS structure and a conventional plate heat exchanger suggested a potential increase in the heat transfer coefficient of approximately 35%. The generated CFD data were subsequently utilized to formulate fitting correlations for the Nusselt number and friction factors as a function of the volume fraction. The fitted parameters of these correlations are provided in this work.
In the development of interactive aerodynamic optimization tools, the need to reduce the computational complexity of flow calculations has arisen. Computational complexity can be reduced by estimating the flow variables using machine learning, but that approach has a number of hindrances. Avoiding these hindrances through lowering the computational complexity by stating the assumptions of inviscid incompressible potential flow is the focus of this article. The assumptions used restrict the applicability of this approach to only specific cases, but in engineering practice, these cases are quite widespread. The assumptions allowed the coupling of the adjoint method with parsec parametrization and the panel method, yielding a highly computationally efficient and robust tool for optimizing an airfoil’s lift coefficient (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi></mrow><mrow><mi>y</mi></mrow></msub></mrow></semantics></math></inline-formula>). The optimization of the NREL S809 airfoil was carried out, and the results were verified using the Xfoil 6.99 software. The Xfoil verification showed that by making minimal changes to the airfoil’s shape, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>C</mi></mrow><mrow><mi>y</mi></mrow></msub></mrow></semantics></math></inline-formula> and lift-to-drag ratios were significantly improved. The improvement magnitude was over 94% for a 0 deg angle of attack (AoA) and over 16% for 6.2 deg AoA. This indicates an improvement in performance that is similar to that of some genetic algorithms, but with computational costs that are many orders of magnitude lower.
Arul Joseph Gnanaprakasam, Balaji Ramalingam, Gunaseelan Mani
et al.
In this paper, we introduce the notion of orthogonal <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>–<i>F</i>–convex contraction mapping and prove some fixed-point theorems for self-mapping in orthogonal complete metric spaces. The proven results generalize and extend some of the well-known results in the literature. Following the derivation of these fixed-point results, we propose a solution for the fractional integro-differential equation, utilizing the fixed-point technique within the context of orthogonal complete metric spaces.
The primary objective of this study is to assess the adsorption behavior of boron using a tannin-based biosorbent known as tannic acid resin, synthesized from Turkish acorns (valonia) through the spray-drying method. The resulting biosorbent, named Valex, underwent modification into a tannic acid resin-based structure, rendering it suitable for use as a biosorbent. Comprehensive characterization studies involving Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller analysis were conducted on this biosorbent. The outcomes demonstrated the effectiveness of tannic acid resin, a tannin-based biosorbent, in removing boron from aqueous solutions. Various parameters such as pH, initial boron concentration, and adsorbent dosage were investigated for their impact on boron removal. The study also delved into adsorption kinetics, adsorption isotherm models, and adsorption thermodynamics. Maximum boron removal, reaching 92.9%, was achieved using 1 g of tannic acid resin-based biosorbent with an initial boron concentration of 8 mg L −1 within 6 h at pH 3. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin isotherm models were applied to experimental data, with the Temkin model demonstrating a good fit. Adsorption kinetics were explored using pseudo-first-order, pseudo-second-order, Elovich, first-order, second-order, and intraparticle diffusion models, with the pseudo-second-order kinetic model fitting the data effectively. The negative values of Δ G ° at all temperatures indicated the spontaneous nature of boron adsorption on the tannin resin, and the positive value of Δ H ° suggested the endothermic nature of adsorption. This study shows the efficacy of Valex in boron adsorption and suggests its potential application as an effective method for boron removal. This study's findings on the impact of various parameters on boron removal provide insights for optimizing the boron adsorption process in practical applications.
B.K. Kasenov, Sh.B. Kasenova, Zh.I. Sagintayeva
et al.
By the method of dynamic calorimetry in the range of 298.15-673 K, the heat capacity of titanium-manganite LaСаTiMnO6, obtained by solid-phase interaction at 800-1200oC from lanthanum, titanium (II), manganese (III) and calcium carbonate oxides was studied. On the dependence curve Ср°~¦(T) in the specified temperature range, a λ-shaped effect was detected at 598 K, probably related to the phase transition of the second kind. A fundamental constant is determined — the standard heat capacity of LaСаTiMnO6, equal to 221±14 J /(mol×K). Its standard entropy, equal to 206±6 J/(mol×K), was estimated by the approximate method of ion increments. Based on experimental data, taking into account the temperature of the phase transition, the equations describing the temperature dependences of Ср°~¦(T) and the thermodynamic functions So (T), Ho (T) — Ho (298.15) and Фхх(Т) of the investigated titanium-manganite lanthanum and calcium are calculated. The standard heat capacity of LaСаTiMnO6 is also calculated using the Debye method, the value of which is in good agreement with experimental data. According to the developed methodology, the standard enthalpy of titanium-manganite formation was calculated, equal to — 3867.5 kJ/mol.
Nuclear and particle physics. Atomic energy. Radioactivity, Thermodynamics
Lucas P. Tendela, Christian A. Cuadrado-Laborde, Miguel V. Andrés
In this work, it is demonstrated numerically that an asymmetric Moiré fiber grating operated in reflection can provide the required spectral response to implement an all-optical fractional differentiator. In our case, the accumulated phase shift is not associated with a point phase shift, as when working with fiber Bragg gratings and long-period gratings with punctual defects, but is distributed all over the grating. The proposed device is supported by numerical simulations, and a dimensionless deviation factor is calculated to make quantitative analysis feasible. The performance of the proposed device is analyzed using numerical simulations by computing the fractional time derivatives of the complex field of an arbitrary transform-limited Gaussian pulse. A comparison with the performance given by theoretical differentiation is also presented.
Ratinan Boonklurb, Ampol Duangpan, Udomsak Rakwongwan
et al.
This paper presents an explicit formula of conditional expectation for a product of polynomial functions and the discounted characteristic function based on the Cox–Ingersoll–Ross (CIR) process. We also propose an analytical formula as well as a very efficient and accurate approach, based on the finite integration method with shifted Chebyshev polynomial, to evaluate this expectation under the Extended CIR (ECIR) process. The formulas are derived by solving the equivalent partial differential equations obtained by utilizing the Feynman–Kac representation. In addition, we extend our results to derive an analytical formula of conditional expectation of a product of mixed polynomial functions and the discounted characteristic function. The accuracy and efficiency of the proposed scheme are also numerically shown for various modeling parameters by comparing them with those obtained from Monte Carlo simulations. In addition, to illustrate applications of the obtained formulas in finance, analytical pricing formulas for arrears and vanilla interest rate swaps under the ECIR process are derived. The pricing formulas become explicit under the CIR process. Finally, the fractional ECIR process is also studied as an extended case of our main results.
Isothermal turbulent flow around circular cylinders arranged side-by-side was numerically simulated on a commercial finite-volumes platform, ANSYS<sup>®</sup> CFX, version 2020 R2. The turbulence was modeled by using k-<i>ω</i> shear stress transport (k-ω SST). Three different Reynolds numbers were computed, <i>Re<sub>d</sub></i> = 200, 1000, and 3000, which were based on the cylinder diameter, d, the free stream velocity, <i>U</i><i>∞</i>, and the kinematic viscosity of the fluid, ν. Sided cylinders were spaced apart from each other, forming a <i>p/d</i> ratio equal to 2, which was kept constant throughout the computations regardless of changes in the Reynolds number. The drag coefficient, <i>C<sub>d</sub></i>, as well as its time traces, was evaluated along with the different wake topologies experienced by the cylinders (wide wake <i>WW</i> and narrow wake <i>NW</i>). The simulations were able to predict the bistable flow over the cylinders and the Cd changes associated with the wakes. Whenever a new wake topology was identified, the shape drag changed in accordance with the instantaneous pressure distribution. A laminar simulation was carried out for the lowest Reynolds number case, showing that the adopted turbulence model did not affect the dynamic response of the flow. The <i>Re<sub>d</sub></i> = 3000 case was compared to Afgan’s outcomes, whose simulations were carried out in a 3-D mesh using LES (Large Eddy Simulation), showing great agreement with their results.
Thermodynamics, Descriptive and experimental mechanics
This paper aims at analyzing nonlinear dependence between fractionally integrated, chaotic precious metal and oil prices and volatilities. With this respect, the Markov regime-switching fractionally integrated asymmetric power versions of generalized autoregressive conditional volatility copula (MS-FIAPGARCH-copula) method are further extended to multi-layer perceptron (MLP)-based neural networks copula (MS-FIAPGARCH-MLP-copula). The models are utilized for modeling dependence between daily oil, copper, gold, platinum and silver prices, covering a period from 1 January 1990–25 March 2022. Kolmogorov and Shannon entropy and the largest Lyapunov exponents reveal uncertainty and chaos. Empirical findings show that: i. neural network-augmented nonlinear MS-FIAPGARCH-MLP-copula displayed significant gains in terms of forecasts; ii. asymmetric and nonlinear processes are modeled effectively with the proposed model, iii. important insights are derived with the proposed method, which highlight nonlinear tail dependence. Results suggest, given long memory and chaotic structures, that policy interventions must be kept at lowest levels.
Zaineb Ben Zaid, Amine Tilioua, Ibtissam Lamaamar
et al.
The objective of this new study is to integrate a Phase Change Material (PCM) in a clay-straw wall to reduce the energy consumption of buildings in Saharan regions (Presented by the city of Errachidia in Morocco). The underlying idea is to fully exploit the storage capacity of walls built with clay and straw. In addition, to increase the thermal energy stored in the building envelope, a PCM has been integrated into the walls. To appreciate the importance of integrating a PCM in clay-straw walls instead of cement walls, a comparative study is carried out. This study investigates numerically the thermal performance of clay-straw walls integrating phase change materials (PCM) located in Errachidia city (Morocco). In winter, the results obtained show that the clay-straw wall integrated PCM24 is a good choice for this region in terms of thermal performance. The integration of PCM24 in clay-straw walls increases the interior heat flux density by 33.33%. Contrary, incorporating PCM24 into cement walls reduces the heat flux density by 36.36%. By using the clay-straw construction integrating PCM24 instead of the cement construction, the interior heat flux density is reduced by 72.72%. In summer, in terms of peak heat flux reduction, PCM32 is effective in Errachidia city. The integration of PCM32 in clay-straw walls reduces the interior heat flux density by 13.04% and by 23.68% in cement walls. By using the clay-straw construction incorporating PCM32 instead of the cement construction, the interior heat flux density is reduced by 73.68%.
Materials of engineering and construction. Mechanics of materials