In Sweden, a preliminary investigation of the contamination situation of igneous rock surrounding underground storage facilities of diesel showed that the situation was severe. The diesel was believed to have penetrated into the rock as far as 50 m from the walls of the vaults. Consequently, the risk for contamination of groundwater and recipients could not be neglected. To be able to assess the fate of diesel components in rock, both a suitable drilling method and a method for the determination of a wide range of diesel components were needed. The analytical method presented made it possible to quantify a number of hydrocarbons in rock samples collected with triple-tube core drilling. The samples were dissolved in hydrofluoric acid (HF) with hexane in Teflon centrifuge tubes. After digestion of the rock, extraction of the analytes with hexane was performed. Determination of the individual hydrocarbons present was done with gas chromatography-mass spectrometry (GC-MS). The method was used to study the environmental impact of the underground storage of diesel. The drilling method enabled sampling without contamination risks. Our data show that the major transport of diesel components in rock occurs through fracture systems and that diffusion of diesel through the rock is of minor importance. The results have drastically changed the view of the contamination situation of diesel in the vicinity of storage facilities in hard rock in Sweden.
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http://dx.doi.org/10.1021/es991168r | DOI Listing |
Sci Rep
January 2025
Department of Electrical Engineering, Arak University of Technology, Arāk, Iran.
This paper introduces an optimal sizing approach for battery energy storage systems (BESS) that integrates frequency regulation via an advanced frequency droop model (AFDM). In addition, based on the AFDM, a new formulation for charging/discharging of the battery with the purpose of system frequency control is presented. The studied MG system that consists of PV units, a diesel generator (DG), a combined heat and power (CHP) unit, a gas boiler, and a BESS is designed to meet the consumers' thermal and electrical load requirements as well as system frequency regulation.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
Introduction: Exposure to particulate matter ≤2.5 μm in diameter (PM) is associated with adverse respiratory outcomes, including alterations to lung morphology and function. These associations were reported even at concentrations lower than the current annual limit of PM.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2BX, United Kingdom.
Engine deposits can reduce performance and increase emissions, particularly for modern direct-injection fuel delivery systems. Surfactants known as deposit control additives (DCAs) adsorb and self-assemble on the surface of deposit precursors to keep them suspended in the fuel. Here, we show how molecular simulations can be used to virtually screen the ability of surfactants to bind to polyaromatic hydrocarbons, comprising a major class of carbonaceous deposits.
View Article and Find Full Text PDFHeliyon
January 2025
Faculty of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran.
In this paper, a hybrid optimization method based on a technique for order of preference by similarity to an ideal solution (TOPSIS) is used for the simultaneous site selection and sizing of a hybrid photovoltaic (PV) water pumping/diesel generator energy system. Various sites in Iran are analyzed for the establishment of the photovoltaic water pumping power plants. Key geographical and climatic criteria are used for optimal site selection across different sites.
View Article and Find Full Text PDFSensors (Basel)
December 2024
School of Automation, Jiangsu University of Science and Technology, Zhenjiang 212100, China.
The fuel system serves as the core component of marine diesel engines, and timely and effective fault diagnosis is the prerequisite for the safe navigation of ships. To address the challenge of current data-driven fault-diagnosis-based methods, which have difficulty in feature extraction and low accuracy under small samples, this paper proposes a fault diagnosis method based on digital twin (DT), Siamese Vision Transformer (SViT), and K-Nearest Neighbor (KNN). Firstly, a diesel engine DT model is constructed by integrating the mathematical, mechanism, and three-dimensional physical models of the Medium-speed diesel engines of 6L21/31 Marine, completing the mapping from physical entity to virtual entity.
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