Spectroscopic analysis of chia seeds

Chia seeds are becoming more and more popular in modern diets. In this contribution NIR and 2D-fluorescence spectroscopy were used to determine their nutritional values, mainly fat and protein content. 25 samples of chia seeds were analysed, whereof 9 samples were obtained from different regions in Kenya, 16 samples were purchased in stores in Germany and originated mostly from South America. For the purchased samples the nutritional information of the package was taken in addition to the values obtained for fat and protein, which were determined at the Hohenheim Core Facility. For the first time the NIR and fluorescence spectroscopy were used for the analysis of chia. For the spectral evaluation two different pre-processing methods were tested. Baseline correction with subsequent mean-centring lead to the best results for NIR spectra whereas SNV (standard normal variate transformation) was sufficient for the evaluation of fluorescence spectra. When combining NIR and fluorescence spectra, the fluorescence spectra were also multiplied with a factor to adjust the intensity levels. The best prediction results for the evaluation of the combined spectra were obtained for Kenyan samples with prediction errors below 0.2 g/100 g. For all other samples the absolute prediction error was 0.51 g/100 g for fat and 0.62 g/100 g for protein. It is possible to determine the amount of protein and fat of chia seeds by fluorescence and NIR spectroscopy. The combination of both methods is beneficial for the predictions. Chia seeds from Kenya had similar protein and lipid contents as South American seeds.

COMPARATIVE EVALUATION OF RESISTANCE OF HEATING EXCHANGE APPARATUS FOR NEW CONSTRUCTIONS FOR GAS COMPRESSOR STATIONS

The main volume of gas produced in the Republic of Azerbaijan is formed in offshore fields. Some of this gas is transported to the shore, and the other part is used in gas-operated wells. In both cases, multi-stage compressors on SOCAR's balance sheet are used. In the process of compressing gas in compressor stations, its temperature rises (T = 115 ÷ 118 ℃) and it is important to cool it to T = 35 ÷ 38 ℃ before sending it to the outlet. The heat exchanger proposed by the authors differs in this respect by its simplicity and functional advantages. The article provides a comparative analysis of the durability of existing and newly constructed heat exchangers used in compressor stations. Keywords: heat exchanger, selection, flicker noise spectroscopy, multitaper spectral evaluation.

New Pair of 2-Amino-naphthoxazoles Derived from β-Lapachone: Synthesis, Spectral Evaluation and Crystal Structure

This work describes a novel synthetic route for obtaining 2-amino-naphthoxazoles derived from β-lapachone, which consists of a condensation reaction between β-lapachone and thiourea in a basic medium. This synthetic approach can be seen as a potential route for obtaining 2-amino-oxazoles from quinones. The obtained amino-naphthoxazoles were characterized by spectroscopic techniques and the crystal structure of one of them was resolved by X-ray diffraction. The experimental results were compared to that obtained through density functional theory (DFT) calculations, revealing high correlation coefficients.

SPECTRAL EVALUATION OF SLEEP EEG IN PATIENTS WITH CHRONIC DISORDERS OF CONSCIOUSNESS BY MULTI-WINDOW DISCRETE FOURIER TRANSFORM

In recent years, EEG spectral analysis has become increasingly popular due to the development of computer technologies. Among the methods of spectral analysis, various variants of the window Fourier transform are most often used, taking into account the non-stationary nature of the EEG signal. In this article, the spectral composition of the sleep EEG of 32 patients with impaired consciousness was studied using a discrete Fourier transform with Windows in the form of elongated spheroidal sequences. The classification of the received gipropischeprom patients with CHF on the dynamics of the spectral composition of the detected correlation characteristic changes in the spectral composition of sleep EEG with the level of consciousness and the etiology of the disease

On the application of frequency tagging

To detect a weak signal in human electrophysiology that is a response of a periodic external stimulus, spectral evaluation is mostly used. The recorded signal’s amplitude and phase noise components of the signal are statistically independent from each other, but both of them are decreasing the signal-to-noise ratio, which results in a lower probability of successful signal detection. Provided that the phase information of the stimuli is preserved, we found that a way to reject an additional phase noise component, which improves the detection probability considerably, by analysing the signal’s phase coherency instead of its spectrum.