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...

sol–gel chemistry is an efficient tool to control the morphology and reactivity of solids. drying is the crucial step due to the capillary forces exerted during the classic ambient drying process, which induces the collapse of the wet gel porosity. the use of n, n-dimethylformamide (dmf), a newly found dcca were found to be effective in the sol–gel synthesis of crack-free silica gel monolith fr...

Materials: Cyclohexane, n-hexanol (98%), ammonia hydroxide (28~30 wt%), tetraethylorthosilicate (TEOS, 98%), (3-aminopropyl)trimethoxysilane (APTS, 95%), polyoxyethylene(10)isooctylphenylether (TritonX-100), fluorescein isothiocyanate isomer I (FITC, 90%), Iron(III) acetyl acetonate (Fe(acac)3, 99+%), and benzyl ether (99%) were purchased from Acrös. 1,2 dodecanediol (90%), oleylamine, and olei...

9 Mesostructured silica phases with lamellar structure were prepared by the liquid crystal templating (LCT) technique, from double chain alkylammonium surfactant and sodium silicate or tetraethylorthosilicate (TEOS) silica precursors. The structural characterization of these phases is presented and compared. Surface modification of the silica layers, together with elimination of the organic tem...