A comparison of selected quality features of the tissue and slaughter yield of wild and cultivated pikeperch<Emphasis Type="Italic"> Sander lucioperca</Emphasis> (L.)

The study focused on the comparison of carcass and fillet yields, fillet color, the content of basic components, and the fatty acid composition of tissue from cultivated and wild pikeperch. There was no variation in yield between carcasses and fillets. The brightness and redness of the color of the fillet surfaces of both types of fish were comparable, although the yellowness, chromaticity and shade of color differed. The tissue of cultivated fish had three times more fat (2.87%) than did that of wild fish; the difference was compensated for by water content. The protein and mineral component contents did not vary significantly. The total levels of saturated and monounsaturated acids in the tissue lipids in 1 g of fat varied. No differences were observed between the total amount of polyunsaturated fatty acids (PUFA), PUFAn-3, PUFAn-6, or in the n-3/n-6 proportion. One consequence of the higher fat content in cultivated pikeperch tissue was that the contents of eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3) acids per 100 g of fillet were significantly higher than in the tissue of wild pikeperch.     

The Use of a Novel Ferulic Acid Esterase from Lactobacillus acidophilus K1 for the Release of Phenolic Acids from Brewer's Spent Grain

In this work, an extracellular ferulic acid esterase was produced in bioreactor cultivations of Lactobacillus acidophilus K1 strain. The enzyme was partially purified using ultrafiltration (10 kDa), dialysis (4–6 kDa) and Fast Protein Liquid Chromatography (Sepharose CM, Sephacryl S‐300). A considerable increment of enzyme activity (31‐fold) in the final preparation was achieved. Two distinct bands (approx. 21.5 kDa and 39 kDa) were obtained after SDS‐PAGE. A high similarity of the purified enzyme (LC‐MS/MS analysis) to tannase and ferulic acid esterase from Burkholderia ambifaria MEX‐5 was obtained. The optimal pH and temperature for the enzyme activity were 6.3 and 37°C, respectively. The enzyme preparation effectively released phenolic acids (mainly ferulic and p‐coumaric acid) from brewer's spent grain. This novel enzyme preparation can be used for the utilisation of a valuable and inexpensive by‐product of the brewing industry.     

On nanotube carbon deposition at equilibrium in catalytic partial oxidation of selected hydrocarbon fuels

Computations of thermodynamic equilibrium conditions for depositing carbon in various crystallographic forms are carried out for C-H-O reformates from methane and LPG. Selected examples of reactions accompanying oxidation or thermal decomposition of C₁ to C₄ hydrocarbons are presented, followed by theoretical fundamentals for chemical equilibrium. Table values of the standard chemical potential of the reactants are cited along with respective reaction equilibrium constants. Thermodynamic critical conditions for deposition of several carbon allotropes from gaseous reformates originated from partial oxidation with either air or pure oxygen are also quantified. Computation results are presented graphically in terms of the oxygen-to-carbon ratio, O/C, against temperature for varied pressure and oxidant. Zones of either carbon deposition or carbon-free are specified for graphite or one of the two carbon nanotubes, CNTs. The maximum effect of increase in the critical O/C for a CNT against pure graphite is estimated at 85%.     

Rudiments of rough sets

Worldwide, there has been a rapid growth in interest in rough set theory and its applications in recent years. Evidence of this can be found in the increasing number of high-quality articles on rough sets and related topics that have been published in a variety of international journals, symposia, workshops, and international conferences in recent years. In addition, many international workshops and conferences have included special sessions on the theory and applications of rough sets in their programs. Rough set theory has led to many interesting applications and extensions. It seems that the rough set approach is fundamentally important in artificial intelligence and cognitive sciences, especially in research areas such as machine learning, intelligent systems, inductive reasoning, pattern recognition, mereology, knowledge discovery, decision analysis, and expert systems. In the article, we present the basic concepts of rough set theory and point out some rough set-based research directions and applications.     

Accurate Implicit–Explicit General Linear Methods with Inherent Runge–Kutta Stability

We investigate implicit–explicit (IMEX) general linear methods (GLMs) with inherent Runge–Kutta stability (IRKS) for differential systems with non-stiff and stiff processes. The construction of such formulas starts with implicit GLMs with IRKS which are A- and L-stable, and then we ‘remove’ implicitness in non-stiff terms by extrapolating unknown stage derivatives by stage derivatives which are already computed by the method. Then we search for IMEX schemes with large regions of absolute stability of the ‘explicit part’ of the method assuming that the ‘implicit part’ of the scheme is \(A(\alpha )\)-stable for some \(\alpha \in (0,\pi /2]\). Examples of highly stable IMEX GLMs are provided of order \(1\le p\le 4\). Numerical examples are also given which illustrate good performance of these schemes.     

Changes in the location and function of small water bodies in the upper Sanna River catchment—case study (SE Poland)

The article summarises the results of analyses of temporal and spatial changes in the location of small water bodies in the upper Sanna River catchment between the fifteenth and twenty-first centuries. The investigations were conducted on historical sources and cartographic data using GIS tools and inventory files. Natural (location of springs, groundwater depth, geomorphology of valleys), anthropogenic factors (quarries, excavations) and historical determinants of construction of the water reservoirs are presented. Additionally, changes in the economic (fish farming, mills), defence and industrial (paper and steel mills, bloomeries, fulleries) functions of the water bodies have been analysed. The changes in the functions of the water bodies were often influenced by the changing ownership. The results have application significance on a local and regional scale.     

Electrically active defects in SiC Schottky barrier diodes

The electrical properties of deep-level defects in real packaged SiC Schottky barrier rectifiers were studied by deep level transient spectroscopy (DLTS). One deep-level trap with an activation energy in the 0.29–0.30 eV range was revealed to be present in all the tested samples. The electrical characteristics of the trap indicate it is probably attributed to dislocations or to metastable defects, which can be responsible for discrepancies observed in I-V characteristics (see Ref. [2]).     

High temperature deformation of ceramic particle composites

The particle composites Al₂O₃/(2 and 3Y)TZP and MgAl₂O₄/3Y-TZP were tested in bending at temperature of 1280 °C over strain rates from 3.4 × 10⁻⁷ to 1 × 10⁻⁴ s⁻¹ and over stresses from 23 to 85 MPa. Strain rate of the composites decreased as a volume fraction of Al₂O₃ or MgAl₂O₄ increased. MgAl₂O₄/3Y-TZP composites deformed easier under the comparable conditions than alumina/zirconia composites. Four models of composite creep behaviour were compared to the experimental data. All the models were unsuitable for MgAl₂O₄/3Y-TZP, in turn an isostress, an isostrain and a constrained isostrain models provide the good predictions for creep rates for alumina/zirconia ceramics, but the rheological model appeared not good. The threshold stresses approach seems to be useful for describing superplastic flow of MgAl₂O₄/3Y-TZP composites.     

Properties of sucrose-free chocolates enriched with viable lactic acid bacteria

Chocolate formulated with isomalt and enriched with lactic acid bacteria Streptococcus thermophilus MK-10 and Lactobacillus delbrueckii subsp. bulgaricus 151, added in the form of powdered yoghurt, prepared by spray-drying is a sucrose-free, low-calorie product with functional properties. The technique of the production of chocolate sweetened with isomalt and containing live cells of the aforementioned bacterial strains has been established. Physicochemical and sensory properties of this product as well as survival of cells during 6-months storage at 4 and 18 °C have been determined. The isomalt-containing yoghurt chocolates displayed satisfactory sensory attributes. Their calorific value and consistency (hardness) were similar to those of control sucrose-free chocolates. The total acidity of yoghurt and standard milk chocolates was also similar, whereas yoghurt-containing dark chocolates displayed higher acidity. The characteristics of yoghurt-containing chocolates were a relatively low solid substance content (96.82–96.91% w/w), low Casson viscosity and yield value for milk chocolate masses, and enhanced rheological parameters for dark chocolate masses compared with control sucrose-free chocolates. Because the total number of lactic acid bacteria after 6-months storage at 4 and 18 °C was high (approximately 10⁷ cfu/g), the sucrose-free yoghurt-containing chocolates can be regarded as functional foods.