Aliphatic (n-C12-n-C40, unresolved complex mixture, resolved peaks) and aromatic hydrocarbons (46 PAH) were investigated in suspended particulate matter (SPM) sampled over eleven months in six of the major rivers and two channels of the Guanabara Bay Basin. PAH flow rates of the most contaminated rivers, the contribution to the PAH sediment load of the receiving bay, and the main sources of hydrocarbons were determined. PAH (38) ranged from 28 ng L(-1) to 11,514 ng L(-1). Hydrocarbon typology and statistical evaluation demonstrated contribution of distinct sources in different regions and allowed quantification of these contributions. Total flow rate for the five major rivers amounts to 3 t year(-1) and responds for 30% of the total PAH annual input into the northern area of the Guanabara Bay. For the first time PAH mass deposited in the bay sediments has been estimated and shall serve as base for decision making and source abatement.
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http://dx.doi.org/10.1016/j.scitotenv.2014.11.033 | DOI Listing |
Sci Rep
January 2025
China University of Mining and Technology (Beijing), Beijing, 100083, China.
This study aims to evaluate the efficiency and energy release characteristics of different types of coal in pulse detonation engines (PDE) to advance the development of deep coal fluidization detonation technology, achieving more efficient and cleaner coal utilization. Using a custom PDE setup, experiments were conducted with four coal types at mass flow rates from 30 to 120 g/s. High-frequency pressure sensors assessed pressure dynamics and detonation wave propagation, complemented by numerical simulations for accuracy.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Chemical Engineering, School of Engineering and Digital Science, Nazarbayev University, Astana 010000, Kazakhstan.
The escalating global energy demand necessitates enhanced oil recovery methods, particularly offshore. Biological nanotechnology offers sustainable, environment-friendly, and cost-effective alternatives to synthetic chemicals. This study explored the synthesis of polysaccharide-based nanoparticles (PNPs) from Corchorus olitorius leaves using a weak acid-assisted ultrasonic method and their application as nanocomposites for oil recovery.
View Article and Find Full Text PDFSci Total Environ
January 2025
Institute of Catalysis for Energy and Environment, College of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang 110034, China; State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Chang Ping, Beijing 102249, China.
The transformation and risk assessment of flavonoids triggered by free radicals deserve extensive attention. In this work, the degradation mechanisms, kinetics, and ecotoxicity of kaempferol and quercetin mediated by ∙OH, ∙OCH, ∙OOH, and O in gaseous and aqueous environments were investigated using cell experiments and quantum chemical calculations. Three radical scavenging mechanisms, including hydrogen atom transfer (HAT), radical adduct formation (RAF) and single electron transfer (SET) were discussed.
View Article and Find Full Text PDFFluids Barriers CNS
January 2025
Medical Image Processing Department, CHU Amiens-Picardie University Hospital, Amiens, France.
Background: The pressure gradient between the ventricles and the subarachnoid space (transmantle pressure) is crucial for understanding CSF circulation and the pathogenesis of certain neurodegenerative diseases. This pressure can be approximated by the pressure difference across the aqueduct (ΔP). Currently, no dedicated platform exists for quantifying ΔP, and no research has been conducted on the impact of breathing on ΔP.
View Article and Find Full Text PDFClin Exp Med
January 2025
Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, China.
Donafenib is an improved version of sorafenib in which deuterium is substituted into the drug's chemical structure, enhancing its stability and antitumor activity. Donafenib exhibits enhanced antitumor activity and better tolerance than sorafenib in preclinical and clinical studies. However, the specific mechanism of its effect on hepatocellular carcinoma has not been reported.
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