Indra Mamad Gandidi^1,2,*, Sukarni Sukarni^3,4, Avita Ayu Permanasari³, Purnami Purnami⁵, Tuan Amran Tuan Abdullah⁶, Anwar Johari⁶, Nugroho Agung Pambudi^7,*

Energy Engineering, Vol.121, No.12, pp. 3635-3648, 2024, DOI:10.32604/ee.2024.054943 - 22 November 2024

Abstract The use of catalysts has significantly enhanced the yield and quality of in-situ pyrolysis products. However, there is a lack of understanding regarding pyrolysis approaches that utilize several low-cost natural catalysts (LCC) and their placement within the reactor. Therefore, this study aims to examine the effects of various LCC on the in-situ pyrolysis of spirulina platensis microalgae (SPM) and investigate the impact of different types of catalysts. We employed LCC such as zeolite, dolomite, kaolin, and activated carbon, with both layered and uniformly mixed LCC-SPM placements. Each experiment was conducted at a constant temperature of 500°C… More > Graphic Abstract

Tao Yan¹, Javed Rashid^2,3, Muhammad Shoaib Saleem^3,4, Sajjad Ahmad⁴, Muhammad Faheem^5,*

CMC-Computers, Materials & Continua, Vol.81, No.2, pp. 2685-2708, 2024, DOI:10.32604/cmc.2024.058186 - 18 November 2024

Abstract Electricity is essential for keeping power networks balanced between supply and demand, especially since it costs a lot to store. The article talks about different deep learning methods that are used to guess how much green energy different Asian countries will produce. The main goal is to make reliable and accurate predictions that can help with the planning of new power plants to meet rising demand. There is a new deep learning model called the Green-electrical Production Ensemble (GP-Ensemble). It combines three types of neural networks: convolutional neural networks (CNNs), gated recurrent units (GRUs), and… More >

Nataliya Shakhovska^1,2,*, Mykola Medykovskyi¹, Oleksandr Gurbych^1,3, Mykhailo Mamchur^1,3, Mykhailo Melnyk¹

CMC-Computers, Materials & Continua, Vol.81, No.2, pp. 3147-3163, 2024, DOI:10.32604/cmc.2024.056542 - 18 November 2024

Abstract The increasing adoption of solar photovoltaic systems necessitates accurate forecasting of solar energy production to enhance grid stability, reliability, and economic benefits. This study explores advanced machine learning (ML) and deep learning (DL) techniques for predicting solar energy generation, emphasizing the significant impact of meteorological data. A comprehensive dataset, encompassing detailed weather conditions and solar energy metrics, was collected and preprocessed to improve model accuracy. Various models were developed and trained with different preprocessing stages. Finally, three datasets were prepared. A novel hour-based prediction wrapper was introduced, utilizing external sunrise and sunset data to restrict… More >

Junrong Wang^1,2,*, Kuang He¹, Botao Xie³, Chunlei He¹, Wenbin Wu^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.30, No.2, pp. 1-1, 2024, DOI:10.32604/icces.2024.011711

Abstract Internal solitary waves (ISWs) a serious threat to moored floating structures in deep water, especially in South China Sea. On predicating dynamic response of a moored structure subjected to ISWs, previous researchers directly apply the pre-calculated ISW loading to the structure, which ignores the coupling effects between the structure and the ISW. To address this issue, this paper develops a coupled dynamic analysis model for moored structures, where the determination of ISW loading considers the effects of dynamic responses of floating structures. This model can simulate the action of various loading components on the floating… More >

Xingbin Zhao¹, Neng Yang², Hao Liang³, Mingqiang Wei^2,*, Benteng Ma², Dongling Qiu²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2523-2540, 2024, DOI:10.32604/fdmp.2024.052766 - 28 October 2024

Abstract The transient flow testing of ultra-deepwater gas wells is greatly impacted by the low temperatures of seawater encountered over extended distances. This leads to a redistribution of temperature within the wellbore, which in turn influences the flow behavior. To accurately predict such a temperature distribution, in this study a comprehensive model of the flowing temperature and pressure fields is developed. This model is based on principles of fluid mechanics, heat transfer, mass conservation, and energy conservation and relies on the Runge-Kutta method for accurate integration in time of the resulting equations. The analysis includes the… More >

Saeed Ismaeilimoghadam^1,*, Saeed Mahdavi¹, Mehdi Pourhashemi², Afsaneh Shahraki³, Mehdi Jonoobi^4,*

Journal of Renewable Materials, Vol.12, No.10, pp. 1771-1789, 2024, DOI:10.32604/jrm.2024.054888 - 23 October 2024

Abstract This research aimed to investigate the effect of pulping conditions and refining intensities of wheat straw to be recommended for fluff pulp production. For this purpose, mono ethanol amine (MEA) was selected as a de-lignification agent at three levels of 50:50, 25:75, and 15:85 (MEA/water, W/V %), and soda-AQ 14 W/V % was used as a reference pulping. To investigate the optimal refining intensity, the obtained pulp was passed through a single disk laboratory refiner from 0 to 6 times and in two different consistencies (1.5 and 2.5 W/V %). Total yield, kappa number, ash… More > Graphic Abstract

Peyman Ahmadi^1,*, Davood Efhamisisi^1,*, Marie-France Thévenon^2,3, Hamid Zarea Hosseinabadi¹, Reza Oladi¹, Jean Gerard^2,3

Journal of Renewable Materials, Vol.12, No.10, pp. 1715-1728, 2024, DOI:10.32604/jrm.2024.054076 - 23 October 2024

Abstract Sugarcane bagasse is an agro-waste that could replace timber resources for the production of bio-composites. Composite boards such as particleboard offer an issue for the use and recycling of poor quality timber, and these engineered products can overcome some solid wood limitations such as heterogeneity and dimension. Bagasse offers an alternative to wood chips for particleboard production but present some disadvantages as well, such as poor physico-mechanical properties. To address these issues, bagasse fibers were treated with an innovative natural resin formulated with tannin and furfural. Impregnated particles with different concentrations of resin (5%, 10%,… More > Graphic Abstract

Zhenjiang Zhao¹, Lei Jiang¹, Ling Bai^2,*, Bo Pan³, Ling Zhou^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1111-1136, 2024, DOI:10.32604/cmes.2024.055399 - 27 September 2024

Abstract The fluid’s viscosity significantly affects the performance of a centrifugal pump. The entropy production method and leakage are employed to analyze the performance changes under various viscosities by numerical simulation and validated by experiments. The results showed that increasing viscosity reduces both the pump head and efficiency. In addition, the optimal operating point shifts to the left. Leakage is influenced by vortex distribution in the front chamber and boundary layer thickness in wear-ring clearance, leading to an initial increase and subsequent decrease in leakage with increasing viscosity. The total entropy production inside the pump rises More >

Agatha E. R. Prado Gárate^1,2, Fernando E. Felissia², María Cristina Area², Teresa Suirezs³, María Evangelina Vallejos^2,*

Journal of Renewable Materials, Vol.12, No.9, pp. 1541-1555, 2024, DOI:10.32604/jrm.2024.052481 - 25 September 2024

Abstract Non-traditional lignocellulosic materials are a significant resource for producing high-value products, including nanocellulose. This work studied the nanocellulose obtention from chemical pulps of the two fast-growing bamboo species, Guadua trinii, and Guadua angustifolia. Chemical pulps were produced by soda-anthraquinone (S) pulping from both autohydrolysis-pretreated (H) and unpretreated bamboo chips. Autohydrolysis-pretreated (SHP) and unpretreated soda-anthraquinone (AQ) (SP) pulps were characterized by yield, Kappa number, alpha, beta, and gamma cellulose, degree of polymerization, water retention value, and crystallinity. The nanocellulose was produced by a sequential chemical oxidation treatment (2,2,6,6-tetramethylpiperidine-1-oxyl, TEMPO reagent) and mechanical nanofibrillation. Nanocellulose was characterized by carboxylic… More > Graphic Abstract

Qiang Liu¹, Rujun Wang¹, Yintao Zhang¹, Chong Sun¹, Meichun Yang¹, Yuliang Su^2,*, Wendong Wang², Ying Shi², Zheng Chen²

Energy Engineering, Vol.121, No.10, pp. 2797-2823, 2024, DOI:10.32604/ee.2024.052007 - 11 September 2024

Abstract Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors, making it crucial to understand the relationship between fluid phase states and flow patterns. This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China. Combining phase behavior analysis and CMG software simulations, the study systematically investigates phase transitions, viscosity, and density changes in the gas and liquid phases under different pressure conditions, with a reservoir temperature of 165°C. The research covers three crucial depletion stages of the reservoir: single-phase flow,… More >