Volume 21 (2019): Issue 1 (March 2019)

The purpose of the conducted study was to analyse new materials intended for contact with the human body in view of their physical, chemical and biological properties. The authors have put to test six commercially available materials, four out of which were composite polyamide 12-based materials, while two were polyurethanes. The examined materials were assessed in terms of the surface. Subsequently, their hardness and biocompatibility were tested. The authors devoted major attention to the tests of absorption and emissivity of water, the pH = 7.4 PBS buffer solution and pH = 4.3 artificial sweat in temperatures of 21°C and 37°C. The results of the tests have confirmed the non-toxicity of all the tested materials and allowed to provide their characteristics in terms of their surface, hardness, as well as absorption and emissivity of various body fluids. Both polyamide 12 and the tested polyurethanes are classified as thermoplastics that may be used in additive technology.

This article describes the influence of various design modifications of the ammonia oxidation reactor operating in nitric acid plant TKIV in Kędzierzyn-Koźle on flow distribution of an air-ammonia mixture. The CFD (Computational Fluid Dynamics) simulations of turbulent flow were carried out with SST k-ω turbulence model to close the system of RANS (Reynolds Averaged Navier-Stokes) equations. The simulation results show that the properly selected perforated plate screen and the conical diffuser ensure uniform flow of gas on the ammonia oxidation catalysts and on the catalysts for nitrous oxide decomposition. It was proved experimentally achieving uniform temperature of nitrous gases in different locations under the catalytic gauzes and high efficiency of ammonia oxidation and nitrous oxide decomposition

Fruit and vegetable processing by-products, undervalued until recently, are rich sources of nutrients. This study investigated properties of extruded corn puffs with addition (5–20%) of blackcurrant or chokeberry pressings. We assessed expansion rate, water absorption index (WAI) and water solubility index (WSI) of the produced extru-dates, the concentration of polyphenols, and antioxidant activity measured by FRAP method and ABTS method. The puffs with addition of chokeberry pressings had higher WSI values, higher phenolic acids, flavonols, and anthocyanins content, and higher antioxidant activity than puffcorn with addition of blackcurrant pressings. The corn puffs with addition of fruit pressings contained much higher concentrations of phenolic compounds and were characterized by much higher antioxidant activity than pure puffcorn. This confirms the usefulness of addition of such fruit processing by-products in order to manufacture functional food.

Many studies have been carried out in the direction of improvement of the effectiveness of commonly utilized phosphate corrosion inhibitors. For this purpose various types of modifications are realized, e.g. introduction of different cations to the pigment composition or replacement of phosphate anions with others. In the presented work, anticorrosive pigments containing calcium hydrogen phosphate, and/or calcium hydroxyphosphate, and calcium molybdate were obtained. The phase and chemical composition and the oil absorption number of those materials were determined. The anticorrosive properties were investigated by an electrochemical noise method. The obtained results were compared with previously published studies concerning pigments containing (NH₄)₃Al₂(PO₄)₃ and/or AlPO₄, and CaMoO₄. It was found that the pigment containing only calcium molybdate(VI) is not an effective corrosion inhibitor. However, the pigments comprising a mixture of CaHPO₄ and CaMoO4 exhibited good anticorrosive properties and they were characterized by higher effectiveness in the corrosion protection than compared materials.

The polyphosphoric acids (PPA) were synthesized in a cascade reactors system from P₂O₅ obtained from the burning of Kazakh phosphorus. Presented system provides guidelines for the PPA production process using phosphoric acids only at concentrations above 100% (in conversion to H₃PO₄). Polyphosphoric acids are processed in a cascade reactors system, where the in 1^st concentration of PPA is increased by addition of P2O₅, while in the 2^nd reactor PPA is diluted with the use of 85% phosphoric acid. Produced PPA can be obtained in the 100–118% range and is characterized by high chemical purity due to the reduction of the corrosivity of the reaction, which results in very low content of iron (below 2 ppm Fe).

Flaky graphene oxide was activated with divinylsulfone followed by immobilization of the β-galactosidase enzyme. An active and stable preparation was obtained. β-galactosidase stability after immobilization was much higher than with the native enzyme. The half-life time of the immobilized enzyme was estimated as 165 hours, while for the native form, the estimate was only 5 hours. The developed procedure for the preparation of flaked graphene and its use in the chemical immobilization of enzymes can be used for any enzyme. A processing solution for continuous operation was proposed and verified using cow’s milk, with lactose as the hydrolysed substrate, as a dosing stream. Lactose, a milk sugar, was effectively hydrolysed. Product for allergy sufferers who cannot digest lactose has been obtained in this way.

The objective of the study was to develop a steady-state system model in Aspen TECH using user-defined subroutines to predict the SOFC electrochemical performance. In order to achieve high overall fuel utilization and thus high electrical efficiency, a concept of Combined Heat and Power system with two-stage SOFC stacks of different number of cells was analyzed. The concept of two-stage SOFC stacks based system was developed in the framework of the FP7 EU-funded project STAGE-SOFC. The model was validated against data gathered during the operation of the proof-of-concept showing good agreement with the comparative simulation data. Following model validation, further simulations were performed for different values of fuel utilization to analyze its influence on system electrical performance. Simulation results showed that the concept of two-stage SOFC stacks configuration was viable and reliable. The model can be useful for development the optimal control strategy for system under safe conditions.

Jerusalem artichoke (Helianthus tuberosus) and chicory (Cichorium intybus) are valuable pharmaceutical raw materials on account of their high content of inulin, a natural prebiotic. Inulin-rich plants are also increasingly employed in the formulation of cosmetic products. The paper presents the biological properties of aqueous and aqueous-ethanolic extracts of Jerusalem artichoke and chicory. The extracts have been found to have a high free radical scavenging ability, with the most beneficial antioxidant properties being observed for the aqueous-ethanolic extract of Jerusalem artichoke. Inulin isolated from both plant types is a safe and non-toxic raw material. Inulin added to model body wash gel formulations markedly reduces their potential to cause skin irritation and sensitization.

α-Damascone is widely used in perfumes. However, the manufacture of α-damascone remains challenging owing to the limitations of current production processes. Herein, α-damascone was successfully synthesized from α-ionone using a new route involving only four steps, namely oximization, epoxidation, dehydration, and reduction. The total yield was 54.9% with a final chemical purity of 97% (by GC). Only water, cyclohexane, and ethanol were used in the reactions except in the purification step, and all solvents could be recycled. The structures of the intermediates and target compound were identified by ¹H NMR and ¹³C NMR analyses and MS experiments. This route is a simple and successful method for the industrial preparation of α-damascone.

Ethylcellulose polymer was used as a coating material in the preparation of controlled release fertilizers. The materials have been prepared with the use of an immersion method. The mass ratio of polymer to fertilizer was in the range of 0.165–0.285 and the layer thickness was in the range of 204–244 μm. Mechanical properties of the prepared materials were significantly better in comparison with the initial fertilizer. Measurements of time and the degree of release of mineral components from the obtained materials were determined with a standard method. Ethylcellulose-coated materials have met the requirements of controlled release fertilizers.

Activated carbons (ACs) prepared from common nettle (Urtica Dioica L.) were studied in terms of carbon dioxide adsorption. ACs were prepared by KOH chemical activation in a nitrogen atmosphere at temperatures (ranging from 500 to 850°C). The pore structure and the surface characterization of the ACs were specified based on adsorption-desorption isotherms of nitrogen measured at –196°C and carbon dioxide at 0°C. The specific surface area was calculated according to the BET equation. The pore volume was estimated using the DFT method. The highest values of the specific surface area (SSA) showed activated carbons produced at higher carbonization temperatures. All samples revealed presence of micropores and mesopores with a diameter range of 0.3–10 nm. The highest value of the CO₂ adsorption, 4.22 mmol/g, was found for the material activated at 700°C.