This paper provides a discussion concerning results of CO2 removal from a gas mixture by the application of aqueous solutions of ethanoloamine (MEA) and 2-amino-2-methyl-1-propanol (AMP) promoted with piperazine (PZ). The studies were conducted using a process development unit. Research of such a scale provides far more reliable representation of the actual industrial process than modelling and laboratory tests. The studies comprised comparative analyses entailing identical energy supplied to a reboiler as well as tests conducted at similar process efficiencies for both solvents. The results thus obtained imply that using AMP/PZ enables reduction of the solvent heat duty. Moreover, while using AMP/PZ temperature decrease was also observed in the columns.

The article presents a new modification of the the least squares Prony method. The so-called variable-frequency Prony method can be a useful tool for estimating parameters of sinusoidal components, which, in the analyzed signal, are characterized by time-dependent frequencies. The authors propose use of the presented method for testing the quality of electric energy. It allows observation of phenomena which, when using traditional methods, are averaged in the analysis window. The proposed modification of least squares Prony method is based on introduction and specific selection of a frequency matrix. This matrix represents frequencies of estimated components and their variability in time.

In the article, Author tries to find connections between the way of thinking in traditional societies and methods of constructing narration in modern historiography.

In situ time series measurements of ocean ambient noise, have been made in deep waters of the Arabian Sea, using an autonomous passive acoustic monitoring system deployed as part of the Ocean Moored buoy network in the Northern Indian Ocean (OMNI) buoy mooring operated by the National Institute of Ocean Technology (NIOT), in Chennai during November 2018 to November 2019. The analysis of ambient noise records during the spring (April–June) showed the presence of dolphin whistles but contaminated by unwanted impulsive shackle noise. The frequency contours of the dolphin whistles occur in narrow band in the range 4–16 kHz. However, the unwanted impulsive shackle noise occurs in broad band with the noise level higher by ∼20 dB over the dolphin signals, and it reduces the quality of dolphin whistles. A wavelet based threshold denoising technique followed by a subtraction method is implemented. Reduction of unwanted shackle noise is effectively done and different dolphin whistle types are identified. This wavelet denoising approach is demonstrated for extraction of dolphin whistles in the presence of challenging impulsive shackle noise. Furthermore, this study should be useful for identifying other cetacean species when the signal of interest is interrupted by unwanted mechanical noise.