Shan Liu¹, Chengbin Chi¹, Fengze Han², Yanan Wu¹, Lin Zhu¹, Tuo Wang^2,*

Energy Engineering, Vol.121, No.8, pp. 2257-2273, 2024, DOI:10.32604/ee.2024.049861

Abstract Voltage source converter based high voltage direct current (VSC-HVDC) can participate in voltage regulation by flexible control to help maintain the voltage stability of the power grid. In order to quantitatively evaluate its influence on the voltage interaction between VSC-HVDC and line commutated converter based high voltage direct current (LCC-HVDC), this paper proposes a hybrid multi-infeed interaction factor (HMIIF) calculation method considering the voltage regulation control characteristics of VSC-HVDC. Firstly, for a hybrid multi-infeed high voltage direct current system, an additional equivalent operating admittance matrix is constructed to characterize HVDC equipment characteristics under small disturbance.… More >

Shaokun Liu¹, Zhiying Gao^1,2,*, Rina Su^1,2, Mengmeng Yan¹, Jianwen Wang^1,2

Energy Engineering, Vol.121, No.8, pp. 2213-2229, 2024, DOI:10.32604/ee.2024.049616

Abstract Although the aerodynamic loading of wind turbine blades under various conditions has been widely studied, the radial distribution of load along the blade under various yaw conditions and with blade flapping phenomena is poorly understood. This study aims to investigate the effects of second-order flapwise vibration on the mean and fluctuation characteristics of the torque and axial thrust of wind turbines under yaw conditions using computational fluid dynamics (CFD). In the CFD model, the blades are segmented radially to comprehensively analyze the distribution patterns of torque, axial load, and tangential load. The following results are… More >

Qin Qian¹, Mingjing Lu^1,2,*, Anhai Zhong¹, Feng Yang¹, Wenjun He¹, Min Li¹

Energy Engineering, Vol.121, No.8, pp. 2167-2190, 2024, DOI:10.32604/ee.2024.049430

Abstract The production capacity of shale oil reservoirs after hydraulic fracturing is influenced by a complex interplay involving geological characteristics, engineering quality, and well conditions. These relationships, nonlinear in nature, pose challenges for accurate description through physical models. While field data provides insights into real-world effects, its limited volume and quality restrict its utility. Complementing this, numerical simulation models offer effective support. To harness the strengths of both data-driven and model-driven approaches, this study established a shale oil production capacity prediction model based on a machine learning combination model. Leveraging fracturing development data from 236 wells… More >

Liqiong Chen¹, Kui Zhao¹, Kai Zhang^1,*, Duo Xv¹, Hongxvan Hu², Guoguang Ma¹, Wenwen Zhan³

Energy Engineering, Vol.121, No.8, pp. 2143-2165, 2024, DOI:10.32604/ee.2024.049362

Abstract The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment. In this study, computational fluid dynamics (CFD) method was applied to investigate the diffusion law and hazard range of buried natural gas pipeline leakage in mountainous environment. Based on cloud chart, concentration at the monitoring site and hazard range of lower explosion limit (LEL) and upper explosion limit (UEL), the influences of leakage hole direction and shape, soil property, burial depth, obstacle type on the diffusion law… More >

Zeyi Wang¹, Mingxi Jiao¹, Daliang Wang¹, Minxu Liu¹, Minglei Jiang², He Wang³, Shiqiang Li^3,*

Energy Engineering, Vol.121, No.8, pp. 2275-2291, 2024, DOI:10.32604/ee.2024.028223

Abstract This paper addresses the problem of complex and challenging disturbance localization in the current power system operation environment by proposing a disturbance localization method for power systems based on group sparse representation and entropy weight method. Three different electrical quantities are selected as observations in the compressed sensing algorithm. The entropy weighting method is employed to calculate the weights of different observations based on their relative disturbance levels. Subsequently, by leveraging the topological information of the power system and pre-designing an overcomplete dictionary of disturbances based on the corresponding system parameter variations caused by disturbances,… More >

Adelya Khayrova^*, Sergey Lopatin, Valery Varlamov

Journal of Renewable Materials, Vol.12, No.5, pp. 923-950, 2024, DOI:10.32604/jrm.2024.050033

Abstract Due to the expected rise in the world population, an increase in the requirements for quality and safety of food and feed is expected, which leads to the growing demand for new sources of sustainable and renewable protein. Insect protein is gaining importance as a renewable material for several reasons, reflecting its potential contributions to sustainability, resource efficiency, and environmental conservation. Some insect species are known to be able to efficiently convert organic waste into high-value products such as protein, requiring less land and water compared to traditional livestock. In addition, insect farming produces fewer… More > Graphic Abstract

Xujing Zhang¹, Hatem Abushammala², Debora Puglia³, Binbao Lu¹, Pengwu Xu¹, Weijun Yang^1,*, Piming Ma¹

Journal of Renewable Materials, Vol.12, No.5, pp. 895-908, 2024, DOI:10.32604/jrm.2024.049810

Abstract Fluorescent nanomaterials have attracted much attention, due to their unique luminescent properties and promising applications in biomedical areas. In this study, lignin based fluorescent nanoparticles (LFNP) with high yield (up to 32.4%) were prepared from lignin nanoparticles (LNP) by one-pot hydrothermal method with ethylenediamine (EDA) and citric acid. Morphology and chemical structure of LFNP were investigated by SEM, FT-IR, and zeta potential, and it was found that the structure of LFNP changed with the increase of citric acid addition. LFNP showed the highest fluorescence intensity under UV excitation at wavelengths of 375–385 nm, with emission More > Graphic Abstract

Soumia Mounir^1,2,*, Miloudia Slaoui², Youssef Maaloufa^1,2, Fatima Zohra El Wardi^2,3, Yakubu Aminu Dodo^4,5, Sara Ibn-Elhaj², Abdelhamid Khabbazi²

Journal of Renewable Materials, Vol.12, No.5, pp. 1007-1027, 2024, DOI:10.32604/jrm.2024.049392

Abstract Creating sustainable cities is the only way to live in a clean environment, and this problem can be solved by using bio-sourced and recycled materials. For this purpose, the authors contribute to the valuation of sheep wool waste as an eco-friendly material to be used in insulation. The paper investigates the thermal, hygrothermal, and biological aspects of sheep wool by testing a traditional treatment. The biological method of aerobic mesophilic flora has been applied. Fluorescence X was used to determine the chemical composition of the materials used. Also, thermal characterization has been conducted. The thermal… More >

Nabila Eka Yuningsih, Latifa Ariani, Suprapto Suprapto, Ita Ulfin, Harmami Harmami, Hendro Juwono, Yatim Lailun Ni’mah^*

Journal of Renewable Materials, Vol.12, No.5, pp. 981-992, 2024, DOI:10.32604/jrm.2024.049109

Abstract In this research, activated carbon from mangosteen peel has been synthesized using sulfuric acid as an activator. The adsorption performance of the activated carbon was optimized using malachite green dye as absorbate. Malachite green dye waste is a toxic and non-biodegradable material that damages the environment. Optimization of adsorption processes was carried out using Response Surface Methodology (RSM) with a Box-Behnken Design (BBD). The synthesized activated carbon was characterized using FTIR and SEM instruments. The FTIR spectra confirmed the presence of a sulfonate group (-SOH) in the activated carbon, indicating that the activation process using… More >

Retno Asih^1,*, Haniffudin Nurdiansah², Mochamad Zainuri¹, Deni S. Khaerudini^3,4, Angelinus T. Setiawan⁴, A. Y. Dias⁴, Pudji Untoro^4,5, Ahmad Sholih¹, Darminto^1,*

Journal of Renewable Materials, Vol.12, No.5, pp. 969-979, 2024, DOI:10.32604/jrm.2024.049097

Abstract Biomass has become of recent interest as a raw material for ‘green’ graphenic carbon (GC) since it promotes an environmentally friendly approach. Here, we investigate a single pyrolysis route to synthesize GC from coconut shells which provides a simple method and can produce a high yield, thus being convenient for large-scale production. The pyrolysis involves a stepped holding process at 350°C for 1 h and at 650°C or 900°C for 3 h. The GC sample resulted at the 900°C pyrolysis has a thinner sheet, a less porous structure, a higher C/O ratio, and an enhanced More > Graphic Abstract