Wrocław University of Technology

About: Wrocław University of Technology is a education organization based out in Wrocław, Poland. It is known for research contribution in the topics: Laser & Computer science. The organization has 13115 authors who have published 31279 publications receiving 338694 citations.

Determination of the Elemental Composition of Coffee Using Instrumental Methods

Abstract: Although the content of elements in coffee is only about 5 % (m/m), it seems to be a good indicator of the coffee authenticity. Apparently, it can bring the useful information about individual elemental patterns that are distinctive to the origin of growing soils for coffee plants in addition to cultivation and environmental conditions used. The elemental analysis of coffee by means of instrumental measurement methods may have other uses. It can be used to prove the high quality and safety of raw coffee beans, various coffee byproducts, and the final coffee product in the market. Commonly, different atomic absorption and emission spectrometry and instrumental neutron activation analysis methods are used to determine concentrations of various elements in green, roasted, and ground or instant coffees and coffee infusions, but these samples have to be suitably prepared prior to the analysis.

Fractal market hypothesis and two power-laws

Abstract: A fractal approach is used to analyze financial time series by applying different degrees of time resolutions. This leads to the heterogenous market hypothesis (HMH), where different market participants analyze past events and news with different time horizons. A new general model for asset returns is studied in the framework of the fractal market hypothesis (FMH). It concerns capital market systems in which the conditionally exponential dependence (CED) property can be attached to each investor on the market.

Vanadium catalyzed enantioselective oxidation of sulfides: easy transformation of bis(arylthio)alkanes into C2 symmetric chiral sulfoxides

Abstract: A facile and selective method for the title transformation is described. The two-phase oxidation of bis-sulfides with hydrogen peroxide catalyzed by vanadium complex of chiral Schiff base leads to the corresponding chiral mono- and bis-sulfoxides. In the case of 1,2-bis(arylthio)ethanes the respective optically active bis-sulfoxides are formed in up to over 95% e.e.