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  • Author: Romuald Górski x
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Usefulness assessment of standard measuring instruments installed on sea-going ships to perform energy measurements

The presented work is a contribution to discussion on usefulness of application of measurement instrumentation used on sea-going ships for energy measurement and scientific research purposes. Contemporary sea-going ships are equipped as a rule with up-to-date measurement instrumentation usually based on electronic data processing and computer technique. These authors have made many times use of such instruments in their research work. This way it was not necessary to install any special instruments, that significantly reduced measurement cost. In such cases to obtain a sufficient accuracy of measurements constitutes a crucial problem. In this paper was presented an analysis of measurement errors of some operational parameters of ship and its main propulsion system, elaborated within the frame of the KBN research project no. 9 T12D 033 17. Results of the analysis confirm usefulness of the standard measurement instrumentation installed on ships, and its sufficient accuracy.

Abstract

Investigations concerning the effect of hemp oil on mortality of the foxglove aphid (Aulacorthum solani Kalt.) and the two spotted spider mite (Tetranychus urticae Koch) were conducted in the years 2014-2015. The tested essential oil was produced at the Institute of Natural Fibers and Medicinal Plants in Poznan. It was obtained by steam distillation of fresh panicles of Polish hemp cultivars, Beniko, Bialobrzeskie and Silesia, with low cannabinoid contents, including THC (max. 0.2% plant fresh matter). The effect of essential oil on the investigated pests was determined following the application of aqueous emulsion solution at 0.02, 0.05 and 0.1%. Mortality of agrophages was determined 24, 48 and 72 h after treatment. In this study a very high efficacy of the essential oil produced from hemp panicles was found in the reduction of population size of the foxglove aphid (A. solani). Already at 24 h after its application at a concentration of 0.1% pest mortality rate was 98.20%, while after 48 h it reached 100%. A significant, although much lesser effect of oil on the aphid population was recorded when applying it at 0.05%, with the mortality rate of the true bug after 72 h amounting to 57.33%. Essential oil also showed an effect on the two spotted spider mite (T. urticae). Following the oil application, irrespective of its concentration, a significant effect on mite mortality was observed. Its action was the strongest at its highest concentration, ie 0.1%, while mortality of the pest at 24, 48 and 72 h after treatment was 83.28, 95.83 and 98.72%, respectively.

Abstract

The aim of the study was to determine the effect of electromagnetic fields and their shielding on carrot seed quality. Three sectors were separated on the device emitting electromagnetic fields: “E” - sector emitting electromagnetic radiation with the predominance of the electrical component, “EM” - sector emitting electromagnetic radiation without domination of its components and “M” - sector with a predominance of magnetic component. Fields generated by the device were also shielded with ADR TEX screen, based on a nanocomposite in which the electric component of the electromagnetic radiation is absorbed by water dispersed in a dielectric matrix in various ways. The composites exhibit high dielectric absorption and shield electric fields within the frequency range from ~100 mHz to ~100 kHz. Seed germination and vigour were evaluated at 20 °C in darkness. Mycological analysis was performed using a deep-freeze blotter test. Exposure of seeds to radiation with the predominance of the electrical component and electromagnetic radiation without domination of its components combined with shielding of electromagnetic fields with ADR TEX (E+ADR TEX and EM+ADR TEX) increased seed germination energy and germination capacity compared to these treatments without shielding and control. The percentage of abnormal diseased seedlings in treatments with shielding of electromagnetic fields with ADR TEX (E+ADR TEX, EM+ADR TEX and M+ADR TEX) was significantly lower than in the treatments without shielding and in control. None of the treatments affected seed vigour. Generally, exposure of seeds to electromagnetic radiation did not influence the incidence of fungi.

Abstract

The two-phase flow (water-air) occurring in square minichannel (3x3 mm) has been analysed. In the minichannel it has been observed: bubbly flow, flow of confined bubbles, flow of elongated bubbles, slug flow and semi-annular flow. The time series recorded by laser-phototransistor sensor was analysed using the recurrence quantification analysis. The two coefficients:Recurrence rate (RR) and Determinism (DET) have been used for identification of differences between the dynamics of two-phase flow patterns. The algorithm which has been used normalizes the analysed time series before calculating the recurrence plots.Therefore in analysis the quantitative signal characteristicswas neglected. Despite of the neglect of quantitative signal characteristics the analysis of its dynamics (chart of DET vs. RR) allows to identify the two-phase flow patterns. This confirms that this type of analysis can be used to identify the two-phase flow patterns in minichannels.

An Esr Study of Free Radicals Scavenging by Red Tea

Herbal tea is known to exhibit the scavenging of free radicals responsible for cellular damage. We studied the effect of water treated with reverse osmotic filter equipped with a special dielectric ceramic composite on the antioxidant activity of red tea. Methanol solution of DPPH was added to the tea extract and the RT decay of DPPH free radicals was studied by ESR spectroscopy. Red tea brewed from tap water treated with the composite filter was found to exhibit higher radical scavenging efficiency in comparison with that of the tea brewed from tap water, mineral water and reverse osmosis water.

Abstract

The aim of the research was to assess the influence of calcium chloride and calcium lactate irrigation on the yield volume and dry matter content in two champignon strains, ie Amycel 2200 and Italspawn F59. When both strains were irrigated with calcium lactate, there was a significant decrease observed in the yield when the concentration of the solution was 0.6%. On the other hand, when calcium chloride was applied to the Italspawn F59 strain, there was a significant decrease in the yield when the concentration was as low as 0.4%, whereas the yield of the Amycel 2200 strain dropped when the concentration of calcium chloride was 0.6%. The irrigation with calcium chloride and calcium lactate had influence on the content of dry matter in the champignon carpophores. When the solutions under investigation were applied at concentrations of 0.4 and 0.6%, there was a significant increase observed in the content of dry matter in both strains.

Abstract

By changing the air and water flow relative rates in the two-phase (air-water) flow through a minichannel, we observe aggregation and partitioning of air bubbles and slugs of different sizes. An air bubble arrangement, which show non-periodic and periodic patterns. The spatiotemporal behaviour was recorded by a digital camera. Multiscale entropy analysis is a method of measuring the time series complexity. The main aim of the paper was testing the possibility of implementation of multiscale entropy for two-phase flow patterns classification. For better understanding, the dynamics of the two-phase flow patterns inside the minichannel histograms and wavelet methods were also used. In particular, we found a clear distinction between bubbles and slugs formations in terms of multiscale entropy. On the other hand, the intermediate region was effected by appearance of both forms in non-periodic and periodic sequences. The preliminary results were confirmed by using histograms and wavelets.