The effect of probiotics (Lactobacillus rhamnosus HN001, Lactobacillus paracasei LPC-37, and Lactobacillus acidophilus NCFM) on the availability of minerals from Dutch-type cheese

The use of probiotic cultures in the production of Dutch-type cheeses did not lead to significant changes in their chemical composition but it lowered their acidity. The availability of calcium and magnesium analyzed by in vitro enzymatic hydrolysis was 19 and 35%, respectively; the availability of phosphorus was significantly higher, at >90%. The use of probiotic cultures significantly increased the availability of calcium (~2.5%), phosphorus (~6%), and magnesium (~18%). The in vitro method supports accurate determination of the effect of the Lactobacillus spp. cultures on the availability of mineral compounds ingested with Dutch-type cheese.     

Sandwich structures with textile-reinforced composite foldcores under impact loads

The mechanical behaviour of composite sandwich structures with textile-reinforced composite foldcores, which are produced by folding prepreg sheets to three-dimensional zigzag structures, is evaluated under compression, shear and impact loads. While foldcores made of woven aramid fibres are characterised by a rather ductile behaviour, carbon foldcores with their brittle nature absorb energy by crushing, showing extremely high weight-specific stiffness and strength properties. The impact damage under low and high velocity impact loads tends to be very localised. In addition to regular single-core sandwich structures, a dual-core configuration with two foldcores is also investigated, showing the potential of a two-phase energy absorption behaviour. In addition to experimental testing, finite element models for impact simulations with LS-DYNA have been developed. Despite the high degree of complexity of the models due to the various skin and core failure modes that have to be covered, the results correlate well with test data, allowing for efficient parameter studies or detailed evaluations of damage patterns and energy absorption mechanisms.     

AN ANALYSIS OF EXPERIENCE REPLAY IN TEMPORAL DIFFERENCE LEARNING

Temporal difference TD methods are used by reinforcement learning algorithms for predicting future rewards. This article analyzes theoretically and illustrates experimentally the effects of performing TD lambda prediction udpates backwards for a number of past experiences. More exactly, two related techniques described in the literature are examined, referred to as replayed TD and backwards TD. The former is essentially an online learning method which performs at each time step a regular TD 0 update, and then replays updates backwards for a number of previous states. The latter operates in offline mode, after the end of a trial updating backwards the predictions for all visited states. They are both shown to be approximately equivalent to TD lambda with variable lambda values selected in a particular way. This is true even if they perform only TD 0 updates. The experimental results show that replayed TD 0 is competitive to TD lambda with regard to learning speed and quality.     

Evaluation of conductive-to-resistive layers interaction in thick-film resistors

Low-frequency noise spectroscopy is used to examine the interactions between resistive and conductive films that take place during thick-film resistor (TFR) fabrication. Two noise parameters are introduced to quantitatively describe the strength of these interactions. They refer to intensity and repeatability of the noise generated in the resistor interfaces. Extensive experimental studies performed on ruthenium dioxide and bismuth ruthenate TFRs terminated with gold, platinum–gold, palladium–silver and platinum–silver contacts from various manufacturers allow to establish criteria of pastes compatibility and to evaluate compatible systems of pastes for standard “on-alumina” and low-temperature co-fired ceramic (LTCC) resistors. It is found that gold contacts form low-size-effect, stable, low-noise interfaces both with ruthenium dioxide and bismuth ruthenate TFRs. Silver-containing terminations can be used with bismuth ruthenate but not with ruthenium dioxide resistors. Manufacturer optimized system of pastes for LTCC technology works best when used to produce high-resistive, co-fired devices.     

Biocomposites of Epoxidized Natural Rubber/Poly(lactic acid) Modified with Natural Fillers (Part I)

The study aimed to prepare sustainable and degradable elastic blends of epoxidized natural rubber (ENR) with poly(lactic acid) (PLA) that were reinforced with flax fiber (FF) and montmorillonite (MMT), simultaneously filling the gap in the literature regarding the PLA-containing polymer blends filled with natural additives. The performed study reveals that FF incorporation into ENR/PLA blend may cause a significant improvement in tensile strength from (10 ± 1) MPa for the reference material to (19 ± 2) MPa for the fibers-filled blend. Additionally, it was found that MMT employment in the role of the filler might contribute to ENR/PLA plasticization and considerably promote the blend elongation up to 600%. This proves the successful creation of the unique and eco-friendly PLA-containing polymer blend exhibiting high elasticity. Moreover, thanks to the performed accelerated thermo-oxidative and ultraviolet (UV) aging, it was established that MMT incorporation may delay the degradation of ENR/PLA blends under the abovementioned conditions. Additionally, mold tests revealed that plant-derived fiber addition might highly enhance the ENR/PLA blend’s biodeterioration potential enabling faster and more efficient growth of microorganisms. Therefore, materials presented in this research may become competitive and eco-friendly alternatives to commonly utilized petro-based polymeric products.     

Comparison of Aging Resistance and Antimicrobial Properties of Ethylene–Norbornene Copolymer and Poly(Lactic Acid) Impregnated with Phytochemicals Embodied in Thyme (Thymus vulgaris) and Clove (Syzygium aromaticum)

The effects of plant-based extracts on the solar aging and antimicrobial properties of impregnated ethylene–norbornene (EN) copolymer and poly(lactic acid) (PLA) were investigated. In this study, the impregnation yield of polyolefin, lacking in active centers capable of phytochemical bonding, and polyester, abundant in active sides, was measured. Moreover, two different extracts plentiful in phytochemicals—thyme (TE) and clove (CE)—were employed in the solvent-based impregnation process. The effect of thymol and eugenol, the two main compounds embodied in the extracts, was studied as well. Interestingly, oxidation induction times (OIT) for the impregnation of EN with thyme and clove extracts were established to be, respectively, 27.7 and 39.02 min, which are higher than for thymol (18.4 min) and eugenol (21.1 min). Therefore, an aging experiment, mimicking the full spectrum of sunlight, was carried out to investigate the resistance to common radiation of materials impregnated with antioxidative substances. As expected, the experiment revealed that the natural extracts increased the shelf-life of the polymer matrix by inhibiting the degradation processes. The aging resistance was assessed based on detected changes in the materials’ behavior and structure that were examined with Fourier-transform infrared spectroscopy, contact angle measurements, color quantification, tensile tests, and hardness investigation. Such broad results of solar aging regarding materials impregnated with thyme and clove extracts have not been reported to date. Moreover, CE was found to be the most effective modifying agent for enabling material with antimicrobial activity against Escherichia coli to be obtained.     

Renewable energy in the Kujawsko-Pomorskie Voivodeship (Poland)

In this article we presented the current state and prospects for development of renewable energy in the Kujawsko-Pomorskie Voivodeship, in which the greatest amount of renewable energy in Poland is obtained. In this area there are 96 wind power plants, 103 water power plants, 7 biogas power plants, 4 biofuel producing plants, 3 big energy willow (Salix viminalis) plantations as well as numerous biomass boilers (mostly using wood). In the near future it is planned to further develop renewable energy based on wind, water and biomass.     

Agricultural biogas plants in Poland: Investment process,economical and environmental aspects,biogas potential

The formal and legal requirements as well as the support system for building agricultural biogas plants in Poland have been presented. There are currently 24 agricultural biogas plants operating in Poland. The fermentation substrates are slurry, food waste and maize silage. It is most often mesophilic fermentation. Produced biogas is combusted in cogeneration and thus obtained electrical and thermal energy is used for the biogas plant's own needs and sold. The support system for biogas plants' operation in Poland is based on a system of certificates. In this system it is cost-effective to use waste for fermentation whilst it is not cost-effective for a biogas plant to run on maize silage. It has been calculated that in Poland the theoretical annual biogas potential for cattle slurry is 3646 million m³, for pig slurry it is 2581 million m³, for poultry manure it is 717 million m³, from maize after seed harvest it is 1044 million m³, from municipal waste biofraction it is 100 million m³ of biogas.     

Can energy self-sufficiency be achieved? Case study of Warmińsko-Mazurskie Voivodeship (Poland)

Clean Technologies and Environmental Policy - An analysis was carried out to show whether the Warmińsko-Mazurskie Voivodeship (Poland) could become energy self-sufficient. The technical...     

Effect of paracasein degradation on sensory properties of Gouda cheese

The relation between the sensory quality of Gouda cheese and the extent of paracasein degradation, i. e., the content of soluble N, peptide N, amino acid N and amine N, was studied. The above-mentioned parameters of paracasein degradation differently determined the sensory properties of Gouda cheese. The flavour of cheese after 6-week ripening depended to the largest extent on the content of amine N and soluble N. The effect of the content of peptide N on cheese flavour was smaller but statistically significant. Also the smell of Gouda cheese was to the largest extent correlated to the content of amine N. A dependence between smell and the content of peptide N was found only in the cheeses after 4-week ripening. None of the sensory quality parameters of the examined cheeses depended on the content of amino acid N.