The direct conversion of methane to C2 hydrocarbons, in a quartz tube reactor enforced by a DC corona discharge, was investigated at atmospheric pressure. The process was carried out in the presence of metal oxide catalysts of Mn/W/SiO2, Mn/W/SiO2 (tetraethyl orthosilicate, TEOS), and Mn/W/CNT (supported on carbon nanotubes). The total yield to C2 hydrocarbons in the presence of metal oxide cat...

The presented work focuses on the synthesis of silica-based macroporous aggregates composed silica nanoparticles using a template-free method. To improve mechanical strength prepared fractal-like aggregates, precursor tetraethyl orthosilicate (TEOS) is used during nanoparticle aggregation. obtained results confirm possibility to tailor pore size distribution (PSD) simply by primary particles va...

The energy density of layered oxide cathode materials increases with their Ni content, while the stability decreases and degradation becomes more severe. A common strategy to mitigate or prevent is application protective coatings on particle surfaces. In this article, a room-temperature, liquid-phase reaction trimethylaluminum (TMA) tetraethyl orthosilicate (TEOS) adsorbed moisture either LiNi0...

Johdatus tieto-oppiin on dosentti Markus Lammenrannan tiivistys urastaan Helsingin yliopiston tietoteoriasta vastaavana opettajana. Teos yleiskatsaus analyyttisen tieto-opin keskeisiin ongelmiin, paradokseihin ja yrityksiin ratkaista niitä. Kirja opas ihmettelyyn, filosofiseen ajatteluun. Se ei anna yhtä ratkaisua eikä edes väitä mitään lopulliseksi.

This paper focuses on the comparison of calibrated models for teos deposition in a cvd process according to sem images of SiO2 layers. We describe the applied models and the parameters which lead to the best results for each model. The simulations have been performed using our topography simulator elsa (Enhanced Level Set Applications) which follows the surface evolution by solving the level se...

We revisit the Tidally Excited Oscillations (TEOs) in A-type, main-sequence, eccentric binary KOI-54, prototype of heartbeat stars. Although linear tidal response star is a series orbital-harmonic frequencies which are not stellar eigenfrequencies, we show that non-linearly excited non-orbital-harmonic TEOs eigenmodes. By carefully choosing modes satisfy mode-coupling selection rules, period sp...

The silica xerogel is prepared using copper source; 0.02 mol of Cu(NO3)2.3H2O that has been added to 1 mol TEOS (tetraethyl orthosilicate). The Copper ions are doped to silica matrix by the sol gel method and determination of total molar ratio of components with a reported molar ratio of H2O /TEOS(R) = 6.2. In this method, the acidity the of reaction (pH) depends on the catalyst type in the hyd...

Classical xerogels are robust, inexpensive and nontoxic materials with low-ordered nanoporous structures. In water streams where the pH is higher than the Point of Zero Charge, the surface of classical xerogels such as tetraethoxy orthosilan (TEOS) xerogel is negatively charged. It was assumed that a xerogel can work as a strong adsorbent for metal ions without further modification. Therefore, ...

various concentrations of copper are embedded into silica matrix to xerogel form using copper source - cu(no3)2∙3h2o. the xerogel samples are prepared by hydrolysis and condensation of tetraethyl orthosilicate (teos) by the sol-gel method  and with determination of new molar ratio of components h2o/teos to be 6.2. in this investigation, the necessary amount of trihydrated copper nitrate is adde...