RIOFH - Repository of Institute of General and Physical Chemistry
Not a member yet
1118 research outputs found
Sort by
RE-SYNTHESIZING CATHODE MATERIAL FROM SPENT LI-ION BATTERIES AND ITS EXAMINATION IN AN AQUEOUS SOLUTION OF NANO3
No full textIn vitro antibiofilm effect and cytotoxicity, and in vivo toxicity of Persicaria maculosa and Bistorta officinalis ethanolic extracts
No full text
Validation of energy-dispersive X-ray fluorescence procedure for determination of major and trace elements present in the cement based composites
No full textAdjustment and subsequent validation of energy-dispersive X-ray fluorescence (ED-XRF) method for cement based binders with addition of mineral raw materials (fly ash, zeolite and bentonite) was conducted. Eighteen chemical elements present in the material composition were analyzed: ten major elements (Si, Al, Fe, Ca, Mg, S, Na, K, Ti, P) and eight trace elements (Cr, Zn, Cu, As, Ni, Pb, Sr, Mn). Thirty-five samples of either certified reference materials or reference materials of cement, fly ash and clay were utilized during adjustment and optimization of the investigated ED-XRF procedure. The method was consecutively validated in terms of selectivity, precision, working range, linearity, accuracy, robustness, limits of detection and quantification. Thirty-two samples in total, i.e. three certified reference materials and twenty-nine reference materials, were simultaneously analyzed by ED-XRF and inductively coupled plasma optical emission spectrometry (ICP-OES). Comparison of the outputs of monitored methods showed infinitesimally small differences, as correlation coefficients were extremely good (approximate to 1), which highlighted ED-XRF as highly satiable alternative for ICP-OES for the chemical analysis of cement binders
Effect of Atmospheric Cold Plasma Treatments on Reduction of Alternaria Toxins Content in Wheat Flour
No full textBeside Fusarium toxins, Alternaria toxins are among the most commonly found mycotoxins in wheat and wheat products. Currently, investigations of possibilities of reduction of Alternaria toxins in the wheat-processing chain are limited. Therefore, the aim of this study was to explore the potency of cold atmospheric plasma treatments, as a new non-thermal approach, for reduction of alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) content in spiked white wheat flour samples. Samples were treated with plasma generated in the air during 30 s to 180 s, with an increment step of 30 s, and at four varying distances from the cold plasma source (6 mm, 21 mm, 36 mm and 51 mm). The reduction of the Alternaria toxins content in samples after treatment was monitored by high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The maximum reduction of the examined Alternaria toxins was obtained by treatment performed at 6 mm distance from the plasma source, lasting 180 s, resulting in reductions of 60.6%, 73.8% and 54.5% for AOH, AME and TEN, respectively. According to the obtained experimental results, five empirical models in the form of the second-order polynomials were developed for the prediction of AOH, AME and TEN reduction, as well as the temperature and the moisture content of the wheat flour, that gave a good fit to experimental data and were able to predict the response variables successfully. The developed second-order polynomial models showed high coefficients of determination for prediction of experimental results (between 0.918 and 0.961)
An insight into in vitro antioxidant activity of Cantharellus cibarius hot water extract for the potential application in meat products
No full textThe current research was undertaken to estimate the in vitro antioxidant activity of Cantharellus cibarius mushroom extracted by boiling in water for 30 minutes. Several previous studies have shown that the addition of edible mushrooms in meat products affects the reduction of lipid oxidation and prolongs the shelf-life of the final products. Antioxidant capacity of C. cibarius was measured using the following methods: reducing power ability, lipid peroxidation assay, cupric ion reducing antioxidant capacity (CUPRAC) and DPPH free radical scavenging activity. Reducing power and antioxidant activity assays of C. cibarius hot water extract showed low antioxidant activity. CUPRAC assay demonstrated positive effect only at the concentration of 10 mg/mL, whereas DPPH radical scavenging activity showed moderate antioxidant activity in comparison with culinary-medicinal mushrooms, with the effective concentration (EC50) from 7.41 mg/mL
Hydroxymethylfurfural content and colour parameters of cookies with defatted wheat germ
No full textDefatted wheat germ was used to substitute wheat flour by 5-15% to produce cookies enriched with protein, fat, sugar and minerals. The effects of different level of substitution of wheat flour by defatted wheat germ and dough moisture content (20-24%) on hydroxymethylfurfural (HMF) formation in cookies were investigated. Colour parameters (L*, a*, and b*) were also measured, total colour difference (Delta E) and browning index (BI) were calculated and their correlations with HMF content were studied. The substitution of wheat flour by defatted wheat germ led to a higher HMF content compared to control cookies (P LT 0.05). However, its formation was more strongly influenced by the dough moisture content than by the level of substitution. HMF content is positively correlated to the a* (r = 0.890; P LT 0.01), b* (r = 0.605; P LT 0.01) and BI (r = 0.710; P LT 0.01) values, and negatively correlated to the L* (r = -0.624; P LT 0.01). Results of the HMF formation and the correlation between HMF content and colour parameters were confirmed by the PCA analysis
Colour and fluorescence emission of Euchroea auripigmenta beetle
No full textIn nature, many natural organisms display very conspicuous visual appearances. Most of these appearances are due to pigments located within the biological tissues. In addition, fluorescence emission is also known to arise from several organisms. Upon contact with liquids, the colours and fluorescence of some species such as a few from the class Insecta were reported to change reversibly. However, these optical effects are so far not totally elucidated. In this study, the colour and fluorescence properties of Euchroea auripigmenta beetle were investigated. This insect exhibits a yellow visual appearance on its head, thorax and elytra when it is illuminated by either visible white light or UV light. After soaking into liquids, both the colour and the fluorescence emission from its integuments are modified. The displayed colour turns from yellow to brown. Using optical, fluorescence and electron microscopy techniques, we morphologically characterised the beetle's integuments. This allowed to observe spike-like protuberances covering the yellow areas of the beetle and from where the yellow visual appearance originates. These protuberances are thought to give rise to further light scattering in addition to the scattering by pigments. Thanks to spectrophotometry, imaging scatterometry and spectrofluorimetry observations, the reflectance and fluorescence properties of this beetle were characterised. Whereas the liquid-induced colour change is attributed to a change in the scattering pattern, the fluorescence emission is most likely due to a chemical influence of the liquids on the two different types of embedded fluorophores
Experimental and DFT study of CoCuMo ternary ionic activator for alkaline HER on Ni cathode
No full textIn this work, nickel (Ni) cathode for hydrogen evolution reaction (HER) in alkaline medium, was modified by a combination of in situ ionic activators, based on three d-metals (Co, Cu and Mo). Catalytic performance of new Co-Cu-Mo cathode was improved compared to pure Ni in view of both increased HER reaction rate and improved energy efficiency - reduction of energy consumption of a model electrolytic cell by 15%. We discussed obtained results in comparison with previously investigated similar systems (Ni-Co-Mo and Ni-Cu-Mo). In addition, we perform a detailed surface characterization by a series of experimental techniques (XRF, XRD, SEM, profilometry and EIS) and employ DFT calculations to provide a more detailed discussion of the origin of obtained catalytic performance
Colour and fluorescence emission of Euchroea auripigmenta beetle
No full textIn nature, many natural organisms display very conspicuous visual appearances. Most of there appearances are due to pigment located within the biological tissues. In addition, fluorescence emission is also known to arise from several organisms. Upon contact with liquids, the colours and fluorescence of some species such as few from the class Insecta were reported to change reversibly. However, the optical effects are so far not totally elucidated. In this study, the colour and fluorescence properties of Euchroea auripigmenta beetle were investigated. This insect exhibits a yellow visual appearance on its head, thorax and elytra when it is illuminated by either visible white light or UV light. After soaking into liquids, both the colour and the fluorescence emission from its interguments are modified. The displayed colour turns from yellow to brown. Using optical, fluorescence and electron microscopy techniques, we morphologically characterised the beetle's interguments. This allowed to observe spike-like protuberance covering the yellow areas of the beetle from where the yellow visual appearance originates. These protuberance are thought to give rise to the further light scattering in addition to the scattering by pigments. Thanks to spectrophotometry, imaging scatterometry and spectrofluorimetry observations, the reflectance and fluorescence properties of this beetle were characterised. Whereas the liquid-induced colour change is attributed to a change in the scattering pattern, the fluorescence emission is most likely due to a chemical influence of the liquids on the two different types of embedded fluorophores