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Приказ резултата 11-20 од 852
Assessment of viscoelastic crack bridging toughening in refractory materials
(Elsevier Sci Ltd, Oxford, 2008)
Viscoelastic bridges can be formed in refractory ceramics while cooling from high temperatures. Such bridges can shield crack tips, thus reducing the effective crack tip stress intensity factors leading to higher resistance ...
Simplex optimization of artificial neural networks for the prediction of minimum detectable activity in gamma-ray spectrometry
(Elsevier, Amsterdam, 2006)
A three-layer feed-forward artificial neural network (ANN) with a back-propagation learning algorithm was used to predict the minimum detectable activity (AD) of radionuclides (Ra-226, U-238, U-235, K-40, Th-232, Cs-134, ...
The effect of substrate polarity on the lipase-catalyzed synthesis of aroma esters in solvent-free systems
(Elsevier, Amsterdam, 2007)
The aim of this study was to compare activities of commercial lipases in synthesis of various esters in solvent-free system and in isooctane. Moreover, the effect of substrate polarity (expressed as log P) on solvent-free ...
Doped gamma-Bi2O3: synthesis of microcrystalline samples and crystal chemical analysis of structural data
(Walter de Gruyter Gmbh, Berlin, 2007)
A series of microcrystalline products containing the gamma-Bi2O3 phase doped with Co, Fe, Mn, Pb, Sb, Si, Ti, V and Zn has been prepared by solid state reaction. Based on the heating temperature and heating time, the ...
Service life prediction for refractory materials
(Springer, New York, 2008)
Ultrasonic pulse velocity testing and image analysis were used to predict the thermal stability of cordierite-mullite refractories. Two compositions used as substrates in fast firing of porcelain whiteware, characterized ...
Estimation of single solute adsorption isotherms applying the nonlinear frequency response method using non-optimal frequencies
(Elsevier, Amsterdam, 2008)
In order to estimate single solute adsorption isotherms, the nonlinear frequency response (FR) of a chromatographic column is analyzed experimentally and evaluated using the concept of higher order frequency response ...
Methanol electrooxidation on supported Pt and PtRu catalysts in acid and alkaline solutions
(Pergamon-Elsevier Science Ltd, Oxford, 2002)
The kinetics of methanol oxidation on supported 47.5 wt.% Pt and 54 wt.% Pt-Ru (with nominal Pt:Ru ratios of 2:3) catalysts are measured in 0.5 M H2SO4 and 0.1 NaOH at 295 and 333 K using thin-film rotating disk electrode ...
Heat transfer coefficient and pressure drop during refrigerant R-134a condensation in a plate heat exchanger
(Versita, Warsaw, 2008)
The condensation heat transfer coefficient and the two-phase pressure drop of refrigerant R-134a in a vertical plate heat exchanger were investigated experimentally. The area of the plate was divided into several segments ...
Supercritical carbon dioxide extraction and fractionation of hyper for in and adhyperforin from St. John's Wort (Hypericum perforatum L.)
(CHISA 2006 - 17th International Congress of Chemical and Process Engineering, 2006)
Plants of the genus Hypericum have been used as traditional medicinal plants in various parts of the world. St. John's Wort (Hypericum perforatum L.) has been reported as an antidepressive, antiviral, antimicrobial, ...
Enhancement of the electrochemical reduction of oxygen at platinum by nickel underpotential deposition
(Springer, New York, 2006)
Polycrystalline Pt electrode was modified by underpotential deposition (upd) of nickel. The modification was performed by potential cycling in phosphate buffer pH 7. 0 containing NiSO4, in which hydrogen and nickel upd ...