Sources and depositional changes of aliphatic hydrocarbons recorded in sedimentary cores from Admiralty Bay, South Shetland Archipelago, Antarctica during last decades

2021 ◽  
pp. 148881
Author(s):  
César C. Martins ◽  
Michelle Alves de Abreu-Mota ◽  
Mylene Giseli do Nascimento ◽  
Ana Lúcia L. Dauner ◽  
Rafael André Lourenço ◽  
...  
Keyword(s):  
Aliphatic Hydrocarbons ◽  
Admiralty Bay

scholarly journals TEMPORAL VARIATIONS IN ALIPHATIC HYDROCARBONS IN SEDIMENT CORES FROM ADMIRALTY BAY AND DECEPTION ISLAND, ANTARCTICA

2015 ◽  
pp. 96-99
Author(s):  
Michelle Alves de Abreu Mota ◽  
Mylene Giseli do Nascimento ◽  
César de Castro Martins
Keyword(s):  
Sediment Cores ◽  
Temporal Variations ◽  
Aliphatic Hydrocarbons ◽  
Deception Island ◽  
Admiralty Bay

Transformation of methanol to hydrocarbons over Y zeolites with varying Si/Al ratio

1987 ◽  
Vol 52 (7) ◽  
pp. 1701-1707 ◽  
Author(s):  
Miloslav Křivánek ◽  
Nguyen Thiet Dung ◽  
Pavel Jírů
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Coke Formation ◽  
Aliphatic Hydrocarbons ◽  
Y Zeolite ◽  
Y Zeolites ◽  
Methanol To Hydrocarbons

The catalytic activity of Na, H-Y zeolite samples with a varying Si/Al ratio (2·5 to 20) in the transformation of methanol was determined. The amounts of formed individual aliphatic hydrocarbons as function of reaction time were correlated with the amount of Bronsted and Lewis centres on the catalysts. The effect of coke formation on the over-all course of the reaction has been demonstrated.

Aromatization of C2-C6 Aliphatic Hydrocarbons on Copper-Containing ZSM-5 Zeolites

1992 ◽  
Vol 57 (12) ◽  
pp. 2553-2560
Author(s):  
Zdravka Popova ◽  
Katia Aristirova ◽  
Christo Dimitrov
Keyword(s):  
Copper Content ◽  
Acid Strength ◽  
The State ◽  
Aliphatic Hydrocarbons ◽  
Bronsted Acid ◽  
Ion Formation ◽  
Brönsted Acid ◽  
Wide Range ◽  
Carbenium Ion ◽  
Acid Centers

The aromatization of a wide range of model aliphatic and cycloaliphatic hydrocarbons (ethene, ethane, propene, n-hexane, 1-hexene, methylcyclopentane, cyclohexane, cyclohexene) on copper-containing NaZSM-5 and HZSM-5 zeolites has been investigated. It was established that the degree of aromatization is related to carbenium ion formation and depends on the acid strength and copper content of zeolite. Experiments with copper-containing samples reduced prior to use indicated the possibility to enhance the selectivity to aromatization. The change of the state of Cu2+ ions during catalytic experiments confirmed the assumption about participation of Cu0 simultaneously with the Bronsted acid centers in the dehydrogenation/hydrogenation steps.

Molecular orientation of liquid aliphatic hydrocarbons on the surface and at the interface with water

1989 ◽  
Vol 54 (12) ◽  
pp. 3171-3186 ◽  
Author(s):  
Jan Kloubek
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Molecular Orientation ◽  
Phase Changes ◽  
Aliphatic Hydrocarbons ◽  
Water Molecules ◽  
Free Energies ◽  
Dispersion Component ◽  
System Water ◽  
Orientation Of Molecules

The validity of the Fowkes theory for the interaction of dispersion forces at interfaces was inspected for the system water-aliphatic hydrocarbons with 5 to 16 C atoms. The obtained results lead to the conclusion that the hydrocarbon molecules cannot lie in a parallel position or be randomly arranged on the surface but that orientation of molecules increases there the ration of CH3 to CH2 groups with respect to that in the bulk. This ratio is changed at the interface with water so that the surface free energy of the hydrocarbon, γH, rises to a higher value, γ’H, which is effective in the interaction with water molecules. Not only the orientation of molecules depends on the adjoining phase and on the temperature but also the density of hydrocarbons on the surface of the liquid phase changes. It is lower than in the bulk and at the interface with water. Moreover, the volume occupied by the CH3 group increases on the surface more than that of the CH2 group. The dispersion component of the surface free energy of water, γdW = 19.09 mJ/m2, the non-dispersion component, γnW = 53.66 mJ/m2, and the surface free energies of the CH2 and CH3 groups, γ(CH2) = 32.94 mJ/m2 and γ(CH3) = 15.87 mJ/m2, were determined at 20 °C. The dependence of these values on the temperature in the range 15-40 °C was also evaluated.

Distribution and sources of aliphatic hydrocarbons in surface sediments of Sergipe River estuarine system

2012 ◽  
Vol 64 (8) ◽  
pp. 1721-1725 ◽  
Author(s):  
Manoel B. Lima ◽  
Elaine A. Feitosa ◽  
Elissandro S. Emídio ◽  
Haroldo S. Dórea ◽  
Marcelo R. Alexandre
Keyword(s):  
Surface Sediments ◽  
Aliphatic Hydrocarbons ◽  
Estuarine System ◽  
River Estuarine

Multiscale exploration of hydrocarbons adsorption and hopping through the ZSM-5 channels - from Monte Carlo modelling to experiment

2021 ◽  
Author(s):  
Maciej Strzempek ◽  
Karolina A. Tarach ◽  
Kinga Góra-Marek ◽  
Fernando Rey ◽  
Miguel Palomino ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ir Spectroscopy ◽  
Aliphatic Hydrocarbons ◽  
Adsorption Studies ◽  
Ft Ir ◽  
Gravimetric Adsorption ◽  
Hydrocarbons Adsorption ◽  
Ft Ir Spectroscopy

Abstract In this article the results of the statistical MC modelling corroborated by the FT-IR spectroscopy and gravimetric adsorption studies of the low aliphatic hydrocarbons in ZSM-5 (Si/Al =28 or...

Seashore sediment and water chemistry at the Admiralty Bay (King George Island, Maritime Antarctica) – Geochemical analysis and correlations between the concentrations of chemical species

2020 ◽  
Vol 152 ◽  
pp. 110888
Author(s):  
Joanna Potapowicz ◽  
Danuta Szumińska ◽  
Małgorzata Szopińska ◽  
Robert Józef Bialik ◽  
Katarzyna Machowiak ◽  
...  
Keyword(s):  
Water Chemistry ◽  
Chemical Species ◽  
Geochemical Analysis ◽  
King George Island ◽  
Maritime Antarctica ◽  
Admiralty Bay
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