Li Niu¹, Yang Wang^1,*, Nan Lin², Yaoying Yue¹, Wenbin Fu¹, Elzat Tuhanjiang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.6, pp. 1473-1487, 2025, DOI:10.32604/fdmp.2025.062623 - 30 June 2025

Abstract With the widespread use of polyethylene (PE) materials in gas pipelines, the problem related to the aging of these pipes has attracted increasing attention. Especially under complex environmental conditions involving temperature, humidity, and pressure changes, PE pipes are prone to oxidative degradation, which adversely affects their performance and service life. This study investigates the aging behavior of PE pipes used for gas transport under the combined effects of temperature (ranging from 80°C to 110°C) and pressure (0, 0.1, 0.2, and 0.3 MPa). By assessing the characteristics and thermal stability of the aged pipes, relevant efforts… More >

Ans Ahmed Memon¹, Laveet Kumar^1,2,*, Abdul Ghafoor Memon¹, Khanji Harijan¹, Ahmad K. Sleiti²

Frontiers in Heat and Mass Transfer, Vol.23, No.3, pp. 833-856, 2025, DOI:10.32604/fhmt.2025.064805 - 30 June 2025

Abstract Climate change, rising fuel prices, and fuel security are some challenges that have emerged and have grown worldwide. Therefore, to overcome these obstacles, highly efficient thermodynamic devices and heat recovery systems must be introduced. According to reports, much industrial waste heat is lost as flue gas from boilers, heating plants, etc. The primary objective of this study is to investigate and compare unary (Al₂O₃) thermodynamically, binary with three different combinations of nanoparticles namely (Al₂O₃ + TiO₂, TiO₂ + ZnO, Al₂O₃ + ZnO) and ternary (Al₂O₃ + TiO₂ + ZnO) as a heat transfer fluid. Initially, three different types of… More > Graphic Abstract

Ahmad Mola¹, Sahira H. Ibrahim¹, Nagham Q. Shari², Hasanain A. Abdul Wahhab^3,*

Energy Engineering, Vol.122, No.6, pp. 2239-2255, 2025, DOI:10.32604/ee.2025.061590 - 29 May 2025

Abstract High-efficiency solar energy systems are characterized by their designs, which primarily rely on effective concentration and conversion methods of solar radiation. Evaluation of the performance enhancement of flat plate solar collectors by integration with thermal energy storage could be achieved through simulation of proposed designs. The work aims to analyze a new solar collector integrated with a porous medium and shell and coiled tube heat exchanger. The heat transfer enhancement was investigated by varying the geometrical parameters in shell and helically coiled tubes operating with CuFe₂O₄/water with different volume fractions of 0.02%, 0.05%, and 0.1 vol.%.… More >

Baoping Zou^1,2, Jiahao Yin^1,2, Chunhui Cao^1,2,*, Xu Long^3,*

Journal of Polymer Materials, Vol.42, No.1, pp. 255-275, 2025, DOI:10.32604/jpm.2025.062081 - 27 March 2025

Abstract The ongoing operation of subway systems makes existing tunnels vulnerable to deformations and structural damage caused by adjacent foundation pit construction. Such deformations-manifesting as horizontal displacement, heightened lateral convergence, and internal force redistribution-may significantly compromise subway operational safety. Grouting remediation has become a widely adopted solution for tunnel deformation control and structural reinforcement. Developing optimized grouting materials is crucial for improving remediation effectiveness, ensuring structural integrity, and maintaining uninterrupted subway operations. This investigation explores the substitution of fine mortar aggregates with 0.1 mm discarded rubber particles at varying concentrations (0%, 3%, 6%, 9%, 12%, and More >

Xuegang Zhang^1,*, Yingjie Dong², Xian Wei^1,*, Ruiqi Wang¹, Qi Zhang³

CMES-Computer Modeling in Engineering & Sciences, Vol.142, No.2, pp. 1585-1609, 2025, DOI:10.32604/cmes.2025.059580 - 27 January 2025

Abstract The fixed-setting face-milled curvilinear cylindrical gear features teeth that are arc-shaped along the longitudinal direction. Some researchers hypothesize that this arc-tooth may enhance the lubrication conditions of the gear. This study focuses on this type of gear, employing both finite element analysis (FEA) and analytical methods to determine the input parameters required for elastohydrodynamic lubrication (EHL) analysis. The effects of assembly errors, tooth surface modifications, load, and face-milling cutter radius on the lubrication performance of these gears are systematically investigated. The finite element model (FEM) of the gear pair is utilized to calculate the coordinates… More >

Mohammad Al-Omari¹, Qasem Abu Al-Haija^2,*

Computer Systems Science and Engineering, Vol.48, No.6, pp. 1537-1555, 2024, DOI:10.32604/csse.2024.056257 - 22 November 2024

Abstract More businesses are deploying powerful Intrusion Detection Systems (IDS) to secure their data and physical assets. Improved cyber-attack detection and prevention in these systems requires machine learning (ML) approaches. This paper examines a cyber-attack prediction system combining feature selection (FS) and ML. Our technique’s foundation was based on Correlation Analysis (CA), Mutual Information (MI), and recursive feature reduction with cross-validation. To optimize the IDS performance, the security features must be carefully selected from multiple-dimensional datasets, and our hybrid FS technique must be extended to validate our methodology using the improved UNSW-NB 15 and TON_IoT datasets. More >

Mohammed A. Alhartomi^1,*, Mohammad F. L. Abdullah², Wafi A. B. Mabrouk², Mohammed S. M. Gismalla³, Ahmed Alzahmi¹, Saeed Alzahrani¹, Mohammad R. Altimania¹, Mohammed S. Alsawat⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.3, pp. 2087-2105, 2024, DOI:10.32604/cmes.2024.055679 - 31 October 2024

Abstract The demand for broadband data services on high-speed trains is rapidly growing as more people commute between their homes and workplaces. However, current radio frequency (RF) technology cannot adequately meet this demand. In order to address the bandwidth constraint, a technique known as free space optics (FSO) has been proposed. This paper presents a mathematical derivation and formulation of curve track G2T-FSO (Ground-to-train Free Space Optical) model, where the track radius characteristics is 2667 m, divergence angle track is 1.5° for train velocity at V = 250 km/h. Multiple transmitter configurations are proposed to maximize More >

Dattu Ghane^*, Vishnu Wakchaure

Energy Engineering, Vol.121, No.11, pp. 3199-3220, 2024, DOI:10.32604/ee.2024.050952 - 21 October 2024

Abstract Wind energy provides a sustainable solution to the ever-increasing demand for energy. Micro-wind turbines offer a promising solution for low-wind speed, decentralized power generation in urban and remote areas. Earlier researchers have explored the design, development, and performance analysis of a micro-wind turbine system tailored for small-scale renewable energy generation. Researchers have investigated various aspects such as aerodynamic considerations, structural integrity, efficiency optimization to ensure reliable and cost-effective operation, blade design, generator selection, and control strategies to enhance the overall performance of the system. The objective of this paper is to provide a comprehensive design… More >

Tajim Md. Niamat Ullah Akhund^1,2,*, Waleed M. Al-Nuwaiser³

CMC-Computers, Materials & Continua, Vol.80, No.3, pp. 3485-3506, 2024, DOI:10.32604/cmc.2024.054222 - 12 September 2024

Abstract This study explores the impact of hyperparameter optimization on machine learning models for predicting cardiovascular disease using data from an IoST (Internet of Sensing Things) device. Ten distinct machine learning approaches were implemented and systematically evaluated before and after hyperparameter tuning. Significant improvements were observed across various models, with SVM and Neural Networks consistently showing enhanced performance metrics such as F1-Score, recall, and precision. The study underscores the critical role of tailored hyperparameter tuning in optimizing these models, revealing diverse outcomes among algorithms. Decision Trees and Random Forests exhibited stable performance throughout the evaluation. While More >

Abdul Sattar Laghari¹, Mohammad Waqas Chandio¹, Laveet Kumar^2,*, Mamdouh El Haj Assad³

Energy Engineering, Vol.121, No.8, pp. 2023-2038, 2024, DOI:10.32604/ee.2024.051082 - 19 July 2024

Abstract The selection of working fluid significantly impacts the geothermal ORC’s Efficiency. Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC. In the current study, modelling and thermodynamic analysis of ORC, using geothermal as a heat source, is carried out at fixed operating conditions. The model is simulated in the Engineering Equation Solver (EES). An environment-friendly mixture of fluids, i.e., R245fa/R600a, with a suitable mole fraction, is used as the operating fluid. The mixture provided the most convenient results compared to the pure working fluid under fixed operating More >