Health risk related to the presence of metals in drinking water from different types of sources

The aim of the paper is to assess health risk related to the exposure of people to contact with water contaminated with chosen metals, via ingestion and dermal routes. The results of analyses performed in 2012–2017 using water samples collected from a surface water intake point on the Dunajec, from infiltration wells and samples of treated water supplied to the water distribution system were used as the basis for calculations. Exposure assessment was performed for children and adults. It was demonstrated that treated water supplied directly into the water distribution system had superior parameters. In the case of adults, the calculated HI values were two or three times higher than for children over the entire analysed period in all three risk assessment scenarios. Health risk resulting from the presence of metals in water is mostly related to the ingestion exposure route. Dermal contact does not produce a considerable risk.     

Control of Underactuated Skid Steering Mobile Platforms Based on Extended Factitious Force Concept

In the paper new control method of skid steering mobile platforms has been presented. Such platforms are robotic objects with deficit of control inputs in dynamic model, i.e. they are dynamically under-actuated. To compensate lack of controls, it has been assumed that there are additional factitious inputs to dynamics (so-called factitious forces), which preserve possibility to control dynamical model of skid steering mobile platform, expressed in auxiliary velocities. Factitious inputs do not exist in reality therefore it was assumed that they are equal to zero equivalently. Signals calculated from implicit functions defining factitious forces make possible to approximate slipping effects and they can be taken into account by construction of control law.     

Experimental investigations of a decentralized system for heating and hot water generation in a residential building

Nowadays, modern heat supply technologies are preferred by the decentralized municipal sector because they considerably reduce heat transfer losses. One such solution is a heating system using residential thermal stations (RTS). The advantages of a heating system with RTS, as compared with hot water storage vessels, include stabilizing heat costs, saving energy and a decrease in heat transfer losses.This paper presents the results of an experiment investigating heat consumption in a residential building using RTS. The building, located in Lublin, Poland, was supplied by the local district heating network. The energy consumption was monitored from April 2007 to April 2009. The efficiency of this system was 71.4% during the period when heat was required (winter) and 61.5% during the summer; an annual average efficiency of 67.1%. The energy consumption of the space heating system varied from 0.03 to 0.53 GJ m⁻² of the flat's surface area, with the average value being 0.22 GJ m⁻². The influences of the location of the flat within the building and the surface area of the flat on the quantity of heat required for space heating were analysed. Specific attention was paid to the occurrence of local heat flows between flats.     

Catalytic reduction of N2O by ethylbenzene over novel hydrotalcite-derived Mg–Cr–Fe–O as an alternative route for simultaneous N2O abatement and styrene production

New hydrotalcite-like materials containing magnesium, chromium, and/or iron were synthesized by the coprecipitation method and then thermally transformed into mixed metal oxides. The obtained catalysts were characterized with respect to chemical composition (XRF), structural (XRD, Mössbauer spectroscopy) and textural (BET) properties. The catalytic performance of the hydrotalcite-derived oxides was tested in the N₂O decomposition and the N₂O reduction by ethylbenzene. An influence of N₂O/ethylbenzene molar ratio on the process selectivity was studied. The relationship between catalytic performance and structure of catalysts was discussed.     

Crystallization characteristics of amorphous Fe-Si-B alloys

Crystallization of soft magnetic Fe-Si-B glasses was investigated by transmission electron microscopy and X-ray diffraction. Electron micrographs of the successive crystallization stages of some Fe-Si-B glasses were obtained and the morphology variations for different alloy compositions were determined. The compositional dependence of the crystallization mode exhibited by the Fe-Si-B glasses was analysed, and on this basis some suggestions about crystallization rules in these glasses are proposed. Two kinds of iron—silicon phases occurred, depending on the Fe-Si-B alloy composition: bcc Fe(Si) solid solution and an ordered solid solution on the structural basis of Fe₃Si iron suicide. It is suggested that the metastable Fe₃B phase (observed during crystallization of only few glasses) was not a simple consequence of boron content. Crystallization of the Fe₃B phase was related to the formation of the iron—silicon phase which was produced during the first crystallization stage.     

Effect of irradiation and storage on patulin disappearance and some chemical constituents of apple juice concentrate

Summary The effect of irradiation on the patulin content and on the chemical composition of apple juice concentrate during storage at 4 °C over a period of several weeks was investigated. The radiation-induced disappearance of the mycotoxin in relation to the absorbed dose followed an exponential relationship. The radiation dose (D₅₀), i.e., the dose which reduced the patulin content to 50% of its initial value was equal to 0.35 kGy. Storage of the irradiated concentrate had no effect on the patulin content; however, storage did lead to a slight increase in the titratable acidity and a decrease in the amounts of the carbonyl compound and the ascorbic acid concentration. The development of non-enzymatic browning during storage of the irradiated samples followed the same kinetics as that of the non-irradiated samples.

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Einfluß der Bestrahlung und Lagerung auf den Patulinverlust und auf die chemische Zusammensetzung des Apfelsaftkonzentrates

Zusammenfassung Es wurde der Einfluß der Bestrahlung auf den Patulingehalt und die chemische Zusammensetzung des Apfelsaftkonzentrates während der Lagerung im Laufe von mehreren Wochen bei 4 °C untersucht. Der durch die -Strahlen induzierte Verlust des Toxins folgte einer Exponentialverteilung. Die Bestrahlungsdosis D₅₀ verursachte eine 50%ige Abnahme der Anfangskonzentration von Patulin und war gleich 0,35 kGy. Die Lagerung der bestrahlten Proben des Konzentrates hatte keinen Einfluß auf den Patulinverlust. Während der Lagerung des Konzentrates nahm die zu titrierende Acidität zu und die Konzentration der Carbonylverbindungen und der Ascrobinsäure ab. Die Entwicklung der nichtenzymatischen Bräunung während der Lagerung der bestrahlten Proben hatte die gleiche Kinetik wie die der nicht bestrahlten.

     

Content of anthocyanins and glycoalkaloids in blue‐fleshed potatoes and changes in the content of α‐solanine and α‐chaconine during manufacture of fried and dried products

In the last ten or so years, potatoes with purple or blue‐flesh and derivative products, for example chips, have appeared on the European markets. The interest in this raw material and these products is increasing among both producers and consumers searching for novel and attractive choices. The anthocyanin content of the analysed potato varieties differed; a higher content of these pigments was determined in Blaue Elise var. potatoes. In blue‐flesh varieties, the prevailing anthocyanins were acylated glycosides: petunidin and malvidin. The production process of French fries, chips and puree caused a decrease in the content of glycoalkaloids in semi‐products and finished products, compared to the raw material. The greatest losses of α‐chaconine and α‐solanine were observed after tuber peeling (ca. 70%) and after frying (ca. 90%). French fries contained 3%, chips 16% and puree 17% of the initial amount of total glycoalkaloids. The losses of α‐chaconine and α‐solanine in the analysed semi‐products and finished products were at the same level, regardless of the processing technology applied.     

Development of volatile profile of Kumpiak podlaski dry-cured ham during traditional ripening

Main aim of this research was to trace the development of volatile profile of Kumpiak podlaski dry-cured ham during traditional curing and ripening for 30 weeks. Volatiles were extracted from each 6-week period of ripening, and overall fifty-three aroma compounds were identified. Changes in chemical groups share between cured and fully ripened ham were observed: aldehydes (35.49 → 31.37%), ketones (25.18 → 14.62%), alcohols (17.97 → 15.74%), esters (3.37 → 12.04%), hydrocarbons (7.69 → 6.81%), fatty acids (0.02 → 0.53%), terpenes (2.26 → 9.70%) and heterocyclic aromatic compounds (0.99 → 0.78%). The 18th week of ripening is crucial for the aroma of Kumpiak podlaski ham due to start of continuous decrease in ketones and increase in esters’ and terpenes’ share. Formation of esters and terpenes originated from the presence of local herbs and the development of microflora. Principal component analysis (PCA) showed clear separation of samples from each 6-week period of ripening. Obtained results relying on thirty-seven compounds enabled to make a preliminary determination of ripening markers.     

Thermal stability of polyurethanes with carbon-carbon crosslinks

Thermal properties of polyurethanes based on 4,4′-diphenylmethane diisocyanate and poly(ethylene adipate) crosslinked only by C? C linkages were studied by isothermal and non-isothermal thermogravimetry carried out in nitrogen atmosphere. Previously studied polyurethanes crosslinked only with allophanate groups were used for comparison. It was found that the structure of crosslinks determines the initial stage of degradation process.