Correct quantitative determination of ethanol and volatile compounds in alcohol products

Determination of the volume content of ethanol in the alcohol products in practice is usually determined by pycnometry, electronic densimetry, or densimetry using a hydrostatic balance in accordance with Commission Regulation No 2870/2000. However, these methods determine directly only density of the tested liquid sample and does not take into account the effects of other volatile components such as aldehydes, esters and higher alcohols. So they are appropriate only for binary water-ethanol solutions in accordance with international table adopted by the International Legal Metrology Organization in its Recommendation No 22. Availability notable concentrations of the higher alcohols and ethers in different alcohol-based products, e. g. in whisky, cognac, brandy, wine as well as in waste alcohol and alcohol beverage production, leads to the significant contribution of these compounds in the value of the density of tested alcohol-containing sample. As a result, determination of the volume of ethanol content for such alcohol products in gives the value of the strength, which may significantly differ from the true one. Using incorrectly calculated volume content of ethyl alcohol leads to incorrect results determining the quantities of volatile compounds in the alcohol-containing products, expressed in milligrams per liter of absolute alcohol. We propose experimental results of the method of correct determination of ethanol and other volatile compounds content in waste products of alcohol and alcoholic beverage industry by gas chromatography. Calculations are based on the measured value of sample density and volatile compound concentrations expressed in mg per liter of absolute alcohol [JAFC 61(2013)2950]. The method can be easily incorporated into daily practice of analytical and control laboratories with no additional material, financial or time costs.Comment: 4 pages, 2 figures, submitted to Proc. of the Wine Active Compounds (WAC) 2014 international conference (Beaune, France, March 26-28, 2014

Nonstationary stage of quasi‐cherenkov beam instability in periodical structures

Analysis of nonstationary stage of quasi‐Cherenkov instability of electron beam in the case of two‐wave distributed feedback is carried out. Mathematical models and numerical methods of nonstationary quasi‐Cherenkov electron beam instability are proposed. Results of numerical experiments are proposed. Bifurcations of nonstationary solution are discussed. Straipsnyje analizuojama nestacionariosios fazes kvazi‐Cherenkovo elektronu spinduliuotes nestabilumas esant dvieju bangu saveikai su grižtamo ryšio pernešimu. Pasiūlyti šios elektronu spinduliuotes nestacionariosios fazes atveju matematiniai ir skaitiniai sprendimo metodai. Pateikti skaitinio eksperimento rezultatai. Aptartos nestacionariojo sprendinio bifurkacijos. First Published Online: 14 Oct 201

Communication 5 generation

The article discusses the directions of implementation of metallographic research. Analysis of grain counting methods and the use of these methods in metallographic analysis. The principles of implementing a web application are given

Communication 5 generation

The article discusses the directions of implementation of metallographic research. Analysis of grain counting methods and the use of these methods in metallographic analysis. The principles of implementing a web application are given

Reflectometer with Spectral Separation of Signals

The characteristics of a reflectometer with spectral separation of the signal are studied. The measurements and parameters of the optical fiber in the operating wavelength range of 1550 nm are analyzed. The perspective of the use of the study results in telecommunication systems for servicing fiber optic communication lines is considered