The cycling combustion instabilities in a diesel engine have been analyzed based on chaos theory. The objective was to investigate the dynamical characteristics of combustion in diesel engine. In this study, experiments were performed under the entire operating range of a diesel engine (the engine speed was changed from 600 to 1400 rpm and the engine load rate was from 0% to 100%), and acquired real-time series of in-cylinder combustion pressure using a piezoelectric transducer installed on the cylinder head. Several methods were applied to identify and quantitatively analyze the combustion process complexity in the diesel engine including delay-coordinate embedding, recurrence plot (RP), Recurrence Quantification Analysis, correlation dimension (CD), and the largest Lyapunov exponent (LLE) estimation. The results show that the combustion process exhibits some determinism. If LLE is positive, then the combustion system has a fractal dimension and CD is no more than 1.6 and within the diesel engine operating range. We have concluded that the combustion system of diesel engine is a low-dimensional chaotic system and the maximum values of CD and LLE occur at the lowest engine speed and load. This means that combustion system is more complex and sensitive to initial conditions and that poor combustion quality leads to the decrease of fuel economy and the increase of exhaust emissions.
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http://dx.doi.org/10.1063/1.4899056 | DOI Listing |
Heliyon
January 2025
Department of Mechanical Engineering, Addis Ababa Science and Technology University, Addis Ababa, 16417, Ethiopia.
Many approaches have been implemented in order to reduce the emissions of particular pollutants without compromising engine performance. Cotton and castor mixed seed oil was chosen for the current study due to their distinct fatty acid composition and potential as a feedstock for bio-additives. Three fuel samples-99 % diesel and 1 % blended fuel (cottonseed oil + castor seed oil), 99.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Civil, Environmental and Architectural Engineering, University of Padova, Via Marzolo 9, 35131, Padova, Italy.
The materials removed in the oil separation units of wastewater treatment plants can be referred to as fat, oil and grease (FOG) waste. FOG waste accumulation in treatment plants can cause clogging of pipes, production of excessive scums and foams, and negatively affect air/liquid oxygen transfer. While conventional disposal routes of this material can be limited by its water and organic content, FOG can represent a source of bio-energy other than bio-diesel production.
View Article and Find Full Text PDFChemosphere
January 2025
Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), 26504, Patras, Greece. Electronic address:
The goal of the present work is to quantify the performance of ozonation as a method for the in situ remediation of soils polluted at varying degree with different types of hydrocarbons, and assess its applicability, in terms of remediation efficiency, cost factors, and environmental impacts. Ozonation tests are conducted on dry soil beds, for three specific cases: sandy soil contaminated with low, moderate and high concentration of a non-aqueous phase liquid (NAPL) consisting of equal concentrations of n-decane, n-dodecane, and n-hexadecane; sandy soil polluted with diesel fuel; oil-drilling cuttings (ODC). The transient changes of the concentration of the total organic carbon (TOC), total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAHs), and soluble chemical oxygen demand (SCOD) in soil and carbon dioxide (CO), carbon monoxide (CO), volatile organic compounds (VOCs), and ozone (O) in exhaust gases are recorded.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing Normal University, Beijing 100875, China.
Light nonaqueous-phase liquids (LNAPLs) are the main source of organic pollution in soil and groundwater environments. The capillary zone, with varying moisture contents, is the last barrier against the infiltration of LNAPL pollutants into groundwater and plays an important role in their migration and transformation. However, the effect and mechanism of the moisture content in the capillary zone on LNAPL pollutant migration are still unclear.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
MOE Key Laboratory of Groundwater Quality and Health, School of Environmental Studies, China University of Geosciences, Wuhan 430078, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, School of Environmental Studies, China University of Geosciences, Wuhan 430078, China. Electronic address:
Pickering emulsion template has aroused attention in the fabrication of porous composite materials. In this work, six nanoparticles including cellulose nanofiber/nanocrystal (CNF/CNC), chitin nanofiber/nanocrystals (ChNF/ChNC) and waxy/normal corn nanocrystal (WSNC/CSNC) were comparatively studied for their performance in fabricating porous composites with PDMS via Pickering emulsion templates. Among all, CNF and ChNF exhibited best emulsion stabilizing ability, while ChNF and ChNC at optimized concentrations enabled the formation of high internal phase emulsions with long-term stability of over 300 days.
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