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Surface Waves along the Martian Ionopause

100%

Chmielewski P., Murawski K., Kumar N.

Acta Physica Polonica A

2013

vol. 123

issue 1

156-161

We study the behaviour of surface waves propagating along the ionopause of the planet Mars and derive the onset criteria for unstable Kelvin-Helmholtz modes and negative energy waves at the Martian ionopause. Growth rate of unstable Kelvin-Helmholtz mode decreases with wavelength. The backward propagating waves became negative energy waves for the ionosheath velocity higher than critical velocity. It is found that short wavelength surface waves propagating along the Martian ionopause are less dispersive than long waves.

Dimerization of 1-butene in liquid phase over H-NK-MM-BEA type embedded mesoporous materials

52%

Kumar N., Mäki-Arvela P., Fugleberg S., Yläsalmi T., Villegas J., Heikkilä T., Leino A.-R., Kordás K., Tiitta M., Österholm H., Salmi T., Murzin D.

Catalysis for Sustainable Energy

2012

vol. 1

1-10

Dimerization of 1-butene in the liquid phase was studied at relatively mild conditions, 523 K under 20 bar over both microporous and embedded microporous mesoporous catalysts. Embedded catalysts were prepared by introducing Beta zeolite nuclei into the gel synthesis of mesoporous material. Three different embedded catalysts with different acidities were prepared and characterized by XRD, nitrogen adsorption, TEM, SEM, pyridine adsorption desorption and ammonia TPD. The embedded materials were shown to be thermally stable up to 1173 K, containing both micro- and mesopores and uniform pores with regular periodicity. According to ammonia TPD the acidity increased with increasing aluminium content. Due to the relatively low reaction temperature, the highest yields of C8 hydrocarbons, 33 mol% at the conversion level of 81% were achieved over an embedded micro-mesoporous catalyst containing Beta zeolite inside the mesoporous and totally 2.4 wt.% aluminium.

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1 Acta Physica Polonica A

1 Catalysis for Sustainable Energy

1 2013

1 2012

2 Kumar N.

1 Chmielewski P.

1 Fugleberg S.

1 Heikkilä T.

1 Kordás K.

1 Leino A.-R.

1 Murawski K.

1 Murzin D.

1 Mäki-Arvela P.

1 Salmi T.

1 Tiitta M.

1 Villegas J.

1 Yläsalmi T.

1 Österholm H.

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Surface Waves along the Martian Ionopause

Dimerization of 1-butene in liquid phase over H-NK-MM-BEA type embedded mesoporous materials