Publikace vydané Univerzitou Pardubice / Published by the University of Pardubice
Stálý URI pro tuto komunituhttps://hdl.handle.net/10195/37631
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Článek Otevřený přístup peer-reviewedpublished Effect of concentration of zinc-powder in epoxy-ester based anticorrosive coatings(University of Pardubice, 2023) Raycha, Yash; Kohl, Miroslav; Kalendová, Andréa; Adam, MartinThe present work is directed to study the effect of zinc powder concentration on anticorrosive efficiency of epoxy ester resin-based anticorrosive coatings. A high performance of zinc coating for metal protection is of vital importance depending on the concentration of zinc incorporated into coating formulation. Zinc pigment gives protection against corrosion by cathodic protection and barrier protection mechanism; however, it is necessary to keep adequate dosage of zinc. A lower dosage of zinc is insufficient to obtain sufficient cathodic protection while much higher concentration leads to the pores in the film which may influence corrosion. Therefore, this study was focused on the development of highly effective zinc coatings for excellent anticorrosion protection, as well as mechanical performance, when using standardized tests on corrosion, mechanical and chemical properties.Článek Otevřený přístup peer-reviewedpublished Polyfluorene derivatives as a promising candidate for coating application(University of Pardubice, 2023) Mechergui, Imen; Piana, Francesco; Kohl, Miroslav; Kalendová, Andréa; Adam, MartinThis paper is focused on the synthesis and the characterization of one of the cationic water-soluble conjugated polymers based on polyfluorene (PF) derivatives with terminal amino-groups named poly(9,9-bis(2-(N-ethan(pyrolin-1-yl))ethan)fluorene dibromide (shortly abbreviated as "para phenyl") synthesized by Suzuki-Miyaura coupling reaction and quaternized through a bromoalkylation on pyrrolidine groups, giving rise to a conjugated ammonium polyelectrolyte (P2). The structure of the obtained polyfluorene derivatives (P1 and P2) was confirmed by 1H NMR and FTIR and their photophysical, electrical, and electrochemical properties fully investigated. The results show that the new polyfluorene electrolyte could be a strong candidate as a coating material thanks to its chemical stability and high conductivity.Článek Otevřený přístup peer-reviewedpublished Changes in concentrations of 5-hydroxymethylfurfural, carbohydrates, and ethanol during the mead production(University of Pardubice, 2022) Klikarová, Jitka; Melicharová, Šárka; Řezková, Soňa; Česlová, Lenka; Adam, MartinThis work is focused on monitoring changes in the concentrations of 5-hydroxymethylfurfural, ethanol, and carbohydrates during the mead production using various analytical techniques, namely micellar electrokinetic chromatography with spectrophotometric detection, gas chromatography coupled to flame-ionization detector, and hydrophilic interaction liquid chromatography with refractive-index detector, respectively. In this study, production of three mead samples made by different Czech beekeepers has been monitored. The individual mead fractions were regularly sampled for two months of fermentation and always analysed with the aid of the optimised analytical approach.Článek Otevřený přístup peer-reviewedpublished Gadolinium of anthropogenic origin in food crops(University of Pardubice, 2022) Josefová, Dominika; Mišíková, Frederika; Krejčová, Anna; Patočka, Jan; Adam, MartinThe study is focused on the monitoring of rare earth elements (REE) in food crops with particular interest paid to the evaluation of gadolinium of anthropogenic origin. Macroscopic fungi were used as they are culinary processed and being also a good indicator of environmental pollution. In total, 46 dried mushroom samples originating from the Czech Republic and Slovakia were analysed. When using microwave decomposition of samples and the elemental analysis of Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, Y, Yb using inductively coupled plasma mass spectrometry (ICP-MS), the respective analytical procedure was optimised and validated. The study also included the calculation of the gadolinium anomaly in the processed samples, as well as the calculation of the amount of anthropogenic gadolinium. In the case of the gadolinium monitored, the minimum value found was 1.41 μg kg−1; the maximum being 361 μg kg−1, and the average 33.7 μg kg−1. The contribution of gadolinium of the anthropogenic origin ranged from 0.77 to 270 g kg−1.Článek Otevřený přístup peer-reviewedpublished Advances in perovskite doping – SrTiO3 with cobalt ions(University of Pardubice, 2022) Fejk, Jiří; Dohnalová, Žaneta; Honcová, Pavla; Adam, MartinThis paper supports the point of research on doping of inorganic materials – in this case, pigments – with various elements. Compounds on the basis of SrTiO3 with individually substituted titanium positions for the cobalt ions have been prepared by the solid-state reaction boosted by the prior-to-made mechanoactivation. Calcination temperature and the molar ratio of reactants were varied in order to study their effect on the pigment synthesis. Powdered materials were characterised in terms of thermal behaviour and the phase composition. Particle size distribution and application possibilities in ceramic glaze and organic binder along with colour properties were subsequently determined for selected samples. The prepared set of pigments SrTi1–xCoxO3 (x = 0.1–0.9) differed in characteristics according to a diverse range of substitution and conditions of the synthesis.Článek Otevřený přístup peer-reviewed Comprehensive customer solutions in selected chemical product lines in the Czech Republic(University of Pardubice, 2022) Jelínková, Martina; Lošťáková, Hana; Adam, MartinThis paper aims to summarize the results of quantitative research striving to determine the importance of providing a comprehensive solution to the needs and requirements of buyers of the selected chemical products. It also aims to investigate the role of different components of products, services, and other aspects of offerings play as parts of a comprehensive solution designed for customers processing chemical products. The respondents were managers of enterprises purchasing the examined categories of chemical products in the Czech Republic and our research took place in 2021. Its outcomes show that a comprehensive solution of the needs and requirements of customers in the case of chemical products is perceived far more broadly than those hitherto presented in the literature. In general, it differs especially in the phase of research and development of delivered products, in the phase of consulting and cooperation with customers in harmonizing the technology of processing the products, as well as in the aspects of providing additional services and waste disposal.Článek Otevřený přístup peer-reviewedpublished Voltammetry with a carbon paste electroactive electrode used for the quality assessment of vegetable oils(University of Pardubice, 2021) Horská, Anna; Švancara, Ivan; Sýs, Milan; Adam, MartinThis article introduces carbon paste electroactive electrodes in combination with voltammetric measurements as a useful tool for simple, low-cost, efficient, and semi-quantitative assessment of the quality of various vegetable oils. The respective method is based on anodic oxidation of electroactive organic compounds (namely: phenolic compounds and lipophilic vitamins) that naturally occur in the samples of interest and, in this case, being admixed in a small quantity directly into the carbon paste bulk. All the experiments were performed in 0.1 mol L−1 acetate buffer (pH 4.5) in the square-wave voltammetric mode. The results obtained have shown that the proposed procedure can be applied in food control to authenticate - as an electrochemical fingerprinting - the kind and the quality of a vegetable oil, including its freshness.Článek Otevřený přístup peer-reviewedpublished HILIC-MS analysis of common artificial sweeteners in food and beverages(University of Pardubice, 2021) Klikarová, Jitka; Štěpánová, Hana; Šimorová, Lenka; Česlová, Lenka; Fischer, Jan; Adam, MartinThe five most common artificial sweeteners were analysed in various samples of food and beverages and other products using hydrophilic-interaction liquid chromatography coupled with mass spectrometry. The optimised method employed Hypersil Gold HILIC analytical column combined with a binary mobile phase of 50 mmol/L ammonium acetate in water (pH 5; A)/acetonitrile (B) operating at a gradient program of 90–65 % B for 10 min. The individual sweeteners were quantified by the calibration curve method and the data obtained compared with the data declared on the packaging.Článek Otevřený přístup peer-reviewedpublished Multi-elemental analysis of wine samples using ICP-OES and ICP-MS methods. Anthropogenic gadolinium in wine(University of Pardubice, 2021) Mišíková, Frederika; Patočka, Jan; Krejčová, Anna; Adam, MartinThe study presented in this article has been focused on developing a method for elemental analysis of wine samples. A wide sample set of 200 wines contained white, rosé and red still wines; the wine vintages being 2013, 2014, 2015, 2016, 2017 and 2019. Samples were taken from wine festivals in Pardubice and Hradec Králové and private wineries in the Czech Republic. The analysis was performed using inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS); the determined elements being As, Ba, Ca, Cd, Ce, Co, Cu, Dy, Er, Eu, Fe, Gd, Ho, K, La, Lu, Mg, Mn, Na, Nd, Ni, P, Pb, Pr, S, Sm, Sr, Tb, Tm, Y, Yb, and Zn. The data obtained were processed statistically and the Sr/Ba, Sr/Ca and Sr/Mg ratios were determined as potential indicators for the identification and classification of the wine origin. The existence of the so-called gadolinium anomaly for selected wine samples was investigated as evidence of the presence of anthropogenic gadolinium.Článek Otevřený přístup peer-reviewedpublished Effects of crystal habit modifiers on characterization parameters of tetrazene(University of Pardubice, 2021) Ryšavý, Jan; Matyáš, Robert; Adam, MartinThis work has studied the effects of modifying agents on the behavior of industrially important primary explosive – tetrazene. Namely, of interest were the powder characteristics (particle size, bulk density and angle of repose) and sensitivities to external stimuli (friction, impact). The agents consisted of a wide group of materials when the following ten were selected: dextrin, sodium carboxymethylcellulose, gum arabic, sodium layrylsulfate, p-toluenesulfonic acid, polystyrenesulfonic acid, 1,6-diaminohexane, polyacrylamide, sunflower lecithin, and bone glue. No general correlation between the agent structure and the results were found, but some partial behavior patterns could be identified. The bulk density ranged from 0.2 g∙cm–3 at the low end for unmodified samples to 0.5 g∙cm–3 at the highest improvement. The angle of repose shifted from 60° for the unmodified form to 52° at best flowability (for the ball ammonium perchlorate as a reference value of 30°). The effect on the friction sensitivity is minuscule and all the samples had their F50 values within 3–7 N range. Three different groups separated for the impact-stimulus behavior – unaffected, sensitivity lowered to that of PETN or RDX, and erratic behavior. The particle size was generally in the 100 μm scale, but the crystal habit varied significantly.