Xiaojun Li, Fuyong Su^*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 719-732, 2024, DOI:10.32604/fhmt.2024.051950

Abstract In order to study the effect of oxygen-enriched combustion technology on the temperature field and NO emission in the continuous heating furnace, this paper studies the oxygen-enriched combustion of a pushing steel continuous heating furnace in a domestic company. This study utilizes numerical simulation method, establishes the mathematical models of flow, combustion and NO generation combustion process in the furnace and analyzes the heat transfer process and NO generation in the furnace under different air oxygen content and different wind ratio. The research results show that with the increase of oxygen content in the air, More > Graphic Abstract

Zhisheng Xu^*, Sohail Mahmood, Zihan Yu

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 791-816, 2024, DOI:10.32604/fhmt.2024.051058

Abstract The centralized smoke exhaust system of shield tunnel is an important determinant for tunnel fire safety, and the use of different design parameters of the tunnel smoke exhaust system will affect the smoke exhaust effect in the tunnel, and the influence of different design parameters on the smoke exhaust effect and temperature attenuation of the tunnel can help engineers in designing a more effective centralized smoke exhaust system for the tunnel. In this paper, the Fire Dynamic Simulator (FDS) is utilized to examine smoke exhaust vent settings for a centralized exhaust system in shield tunnel… More >

Xiao Yan^1,2,3, Di Wang^1,2,4, Haitao Yu^1,2,3,5,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 3051-3071, 2024, DOI:10.32604/cmes.2024.051832

Abstract The existence of high-density bedding planes is a typical characteristic of shale oil reservoirs. Understanding the behavior of hydraulic fracturing in high-density laminated rocks is significant for promoting shale oil production. In this study, a hydraulic fracturing model considering tensile failure and frictional slip of the bedding planes is established within the framework of the unified pipe-interface element method (UP-IEM). The model developed for simulating the interaction between the hydraulic fracture and the bedding plane is validated by comparison with experimental results. The hydraulic fracturing patterns in sealed and unsealed bedding planes are compared. Additionally,… More >

Meng Zhang^1,2, Xiangyang Luo^1,2,*, Ningbo Huang²

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2513-2532, 2024, DOI:10.32604/cmes.2024.050517

Abstract Geolocating social media users aims to discover the real geographical locations of users from their publicly available data, which can support online location-based applications such as disaster alerts and local content recommendations. Social relationship-based methods represent a classical approach for geolocating social media. However, geographically proximate relationships are sparse and challenging to discern within social networks, thereby affecting the accuracy of user geolocation. To address this challenge, we propose user geolocation methods that integrate neighborhood geographical distribution and social structure influence (NGSI) to improve geolocation accuracy. Firstly, we propose a method for evaluating the homophily… More >

Heng Zhang^1,2, Chao Su^2,*, Xiaohu Chen¹, Zhizhong Song¹, Weijie Zhan³

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2977-3000, 2024, DOI:10.32604/cmes.2024.047972

Abstract Temperature-induced cracking during the construction of mass concrete is a significant concern. Numerical simulations of concrete temperature have primarily assumed that the concrete is placed in an open environment. The problem of heat transfer between the air and concrete has been simplified to the concrete’s heat dissipation boundary. However, in the case of tubular concrete structures, where air inlet and outlet are relatively limited, the internal air temperature does not dissipate promptly to the external environment as it rises. To accurately simulate the temperature and creep stress in tubular concrete structures with enclosed air spaces… More >

Yuanqing He^*, Xinyue Yu, Yu Xia, Yanhua Cao

International Journal of Mental Health Promotion, Vol.26, No.6, pp. 463-474, 2024, DOI:10.32604/ijmhp.2024.051909

Abstract Background: Teacher burnout is a serious issue in the field of education, particularly in early childhood education, where teachers face high levels of work stress and emotional labor, leading to emotional exhaustion and job burnout. However, past research has not sufficiently explored the mechanisms of social skills, empathy, and mindfulness in mitigating teacher burnout. Therefore, this study aims to investigate the relationship between preschool teachers’ social skills, empathy, and mindfulness with job burnout, in order to provide theoretical basis and practical guidance for reducing teacher burnout. Methods: This research utilized a convenience sampling approach to… More >

Yuetan Wang^1,2,*, Xianle Yan^1,2, Lili Liu^1,2, Xiran Lu^1,2, Lan Luo^1,2, Xiaobin Ding^1,2,*

International Journal of Mental Health Promotion, Vol.26, No.6, pp. 429-438, 2024, DOI:10.32604/ijmhp.2024.050445

Abstract Social anxiety (SA) is a prevalent mental health issue among adolescents, and vulnerable narcissism (VN) can exacerbate this condition. This study aims to investigate the impact of vulnerable narcissism on social anxiety in adolescents, specifically focusing on the mediating effects of self-concept clarity (SCC) and self-esteem (SE) in the relationship between vulnerable narcissism and social anxiety. Through cluster sampling, a questionnaire survey was conducted among 982 students from three secondary schools in two provinces. The data was analyzed using structural equation modeling (SEM). The results revealed that there was a significant negative correlation between vulnerable More >

Ping Xu^1,*, Zhiwei Zhang¹, Zhenguo Hou^2,3, Mankui Zheng¹, Jin Tong¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1299-1312, 2024, DOI:10.32604/fdmp.2023.046183

Abstract In this paper, cement and dechlorinated Polyaluminum Chloride Residue (PACR) have been used to prepare a net slurry and mortar specimens. Two hydration activity indicators have been used to quantitatively analyze the dechlorinated PACR hydration activity. In particular, the effect of dechlorinated PACR content on the compressive strength of mortar has been assessed by means of compressive strength tests. Moreover, X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been employed to observe the microstructure of the considered hydration products. The following results have been obtained. The 28th day activity index of the dechlorinated PACR… More >

Vladimir Ya. Modorskii, Ivan E. Cherepanov^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 1031-1043, 2024, DOI:10.32604/fdmp.2024.048494

Abstract A transition to clean hydrogen energy will not be possible until the issues related to its production, transportation, storage, etc., are adequately resolved. Currently, however, it is possible to use methane-hydrogen mixtures. Natural gas can be transported using a pipeline system with the required pressure being maintained by gas compression stations. This method, however, is affected by some problems too. Compressors emergency stops can be induced by vibrations because in some cases, mechanical methods are not able to reduce the vibration amplitude. As an example, it is known that a gas-dynamic flow effect in labyrinth… More >

Wei Chen^*, Dingdan Liu, Yue Liang

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.5, pp. 915-938, 2024, DOI:10.32604/fdmp.2024.046335

Abstract This study focuses on the effect of ultrafine waste glass powder on cement strength, gas permeability and pore structure. Varying contents were considered, with particle sizes ranging from 2 to 20 μm. Moreover, alkali activation was considered to ameliorate the reactivity and cementitious properties, which were assessed by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and specific surface area pore size distribution analysis. According to the results, without the addition of alkali activators, the performance of glass powder mortar decreases as the amount of glass powder increases, affecting various aspects such as strength… More >