Iron doped zircon – phase composition and environmental aspects

W artykule zawarto wyniki badań składu chemicznego i fazowego pigmentu cyrkonowo-żelazowego otrzymanego z zastosowaniem różnych surowców żelazowych i dodatków mineralizujących. Do badań zastosowano dyfrakcję rentgenowską (XRD), fluorescencyjną spektrometrię rentgenowską (XRF-WD) oraz skaningową mikroskopię elektronową wraz z analizą składu pierwiastkowego w mikroobszarach (SEM-EDS). Stwierdzono występowanie faz krystalicznych (neighborytu, gryceitu i egirynu litowego), które dotychczas nie były opisywane dla omawianych pigmentów cyrkonowo-żelazowych. W dyskusji odniesiono się również do znaczenia powstających faz dla efektów środowiskowych mających miejsce podczas wytwarzania pigmentów cyrkonowych.The chemical and phase composition of irondoped ZrSiO4 ceramic pigments synthesized from different iron raw materials and mineralizing agents were studied. The results were obtained using X-rays powder diffaction, X-rays fluorescence spectroscopy and scanning electron microscopy techniques. It was revealed for the first time for this pigment that fluorine forms its own stable phases (neighborite and gryceite) accompanied by lithium aegirine. The environmental meaning of the presence of these phases in ceramic pigment was discussed

Wykorzystanie rentgenowskiej analizy dyfrakcyjnej do oceny stałości składu zestawu surowcowego do syntezy C3S

W pracy przedstawiono badania odpowiednie do wytworzenia głównego składnika cementu portlandzkiego − krzemianu trójwapnia. Przeprowadzone badania obejmowały ujednorodnienie zestawu, ocenę stałości jego składu z wykorzystaniem rentgenowskiej analizy fazowej w połączeniu z metodą Rietvelda oraz wyniki XRD wytworzonego spieku. Zaprezentowane wyniki potwierdzają adekwatność przyjętych metod badawczych do wytworzenia jednorodnego spieku zawierającego alit (krzemian trójwapnia).The paper presents tests suitable for the production of the main component of Portland cement - tricalcium silicate. The tests carried out included homogenization of the batch of raw material sets, assessment of the constancy of its composition with the use of X-ray phase analysis in conjunction with the analysis of the results using the Rietveld method, and the XRD results of the sinter produced. The presented results confirm the adequacy of the adopted research methods for the production of a homogeneous sintered alite (tricalcium silicate)

Application of machine learning methods in the analysis of the microscopic image of ceramic tiles

Współczesne metody badań stosowane w nowoczesnych technikach badawczych spowodowały, że zbierane są ogromne ilości danych, które muszą być poddane dalszej analizie. Uczenie maszynowe pomaga interpretować zgromadzone dane, a po ich przetworzeniu może pomóc podjąć dalsze decyzje. Metoda ta ma coraz większe zastosowanie w kontroli jakości wyrobów. W artykule przedstawiono zastosowanie nadzorowanej wersji uczenia maszynowego w badaniach nad optymalizacją rozpoznawania faz chemicznych z obrazów mikroskopowych i obrazów składu chemicznego dla płytek ceramicznych. Stwierdzono, że w przypadku opracowanych danych z elektronowej mikroskopii skaningowej, najlepsze wyniki uzyskano dla algorytmu CART (drzewo decyzyjne). Zastosowana metodyka znacznie usprawnia przeprowadzenie badań i poprawia jakość uzyskanych analiz obrazu w odniesieniu do standardowego oprogramowania mikroskopów.Contemporary research methods used in modern research techniques often result in the collection of huge amounts of data that must be further analyzed. Machine learning helps to interpret the collected data, and after their processing, it can help you make further decisions. The article presents the use of the supervised machine learning in research on the optimization of the recognition of chemical phases from microscopic images and chemical composition images for ceramic tiles. It was found that in the case of the developed data from scanning electron microscopy, the best results were obtained for the CART algorithm (decision tree structure). The applied methodology significantly improve the conduct of research and ameliorate the quality of the obtained image analyzes

Dawsonite as an indicator of multistage deformation and fluid pathways within fault zones: Insights from the Fore-Dukla Thrust Sheet, Outer Carpathians, Poland

The structural pattern developed within metre to microscopic scale thrust and strike-slip fault zones exposed in the Palaeogene flysch rocks of the Fore-Dukla Thrust Sheet in the south-eastern part of the Silesian Nappe, Outer Carpathians, Poland, reveals evidence for upper crustal deformation and fluid flow. Syntectonic dawsonite [NaAlCO3(OH)2] indicates the following series of deformational events within the fault zones: i) detachment and buckle folding resulting from movement along thrust faults; ii) faulting as a compensation of the shortening, resulting in the fault propagation folding, breakthrough thrust faulting and imbrications; and iii) strike-slip faulting. The microstructural pattern coupled with the growth of a related sequence of carbonate minerals within the fault zones, followed by present-day dawsonite precipitation and tufa formation, indicate a continuing influence of fluids within the Silesian Nappe up to and including modern time. Structural observations at metre to microscopic scales coupled with EDS mapping of rocks indicate that dawsonite is a unique tool for the reconstruction of subsequent deformation in the Fore-Dukla Thrust Sheet

Płytki ceramiczne. Badania mikroskopowe tekstur w odniesieniu do wytrzymałości na zginanie

Płytki gresowe są wytwarzane głównie z glinki kaolinowej, kwarcu i skaleni. Wiele właściwości technicznych, w tym odporność na zginanie, są związane z teksturą materiału w skali mikroskopowej. Najważniejszymi cechami są: zawartość, rozmiar i kształt różnych ziaren, w tym większych ziaren kwarcu, kryształów mullitu, fazy amorficznej bogatej w krzemionką i porowatości. Zrozumienie zależności pomiędzy mikrostrukturą a odpornością na zginanie może prowadzić do opracowania efektywniejszych metod wytwarzania cieńszych płytek o większych wymiarach.Porcelain tiles are sintered ceramic material made mainly from ball clays, quartz and feldspars. Many technical feateurs, including bending strength, are related to the microtexture of porcelain stoneware. Most important features are content, size and shape of different grains. These include large particles of filler (quartz), mullite crystals, a silica-rich amorphous phase and porosity. The understanding of the relationship between the microstructure and the bending strength of porcelain stoneware can lead to the development the manufacturing of thinner tiles with higher dimensions

Synthesis of SiC/Ag/Cellulose Nanocomposite and Its Antibacterial Activity by Reactive Oxygen Species Generation

We describe the synthesis of nanocomposites, based on nanofibers of silicon carbide, silver nanoparticles, and cellulose. Silver nanoparticle synthesis was achieved with chemical reduction using hydrazine by adding two different surfactants to obtain a nanocomposite with silver nanoparticles of different diameters. Determination of antibacterial activity was based on respiration tests. Enzymatic analysis indicates oxidative stress, and viability testing was conducted using an epifluorescence microscope. Strong bactericidal activity of nanocomposites was found against bacteria Escherichia coli and Bacillus cereus, which were used in the study as typical Gram-negative and Gram-positive bacteria, respectively. It is assumed that reactive oxygen species generation was responsible for the observed antibacterial effect of the investigated materials. Due to the properties of silicon carbide nanofiber, the obtained nanocomposite may have potential use in technology related to water and air purification. Cellulose addition prevented silver nanoparticle release and probably enhanced bacterial adsorption onto aggregates of the nanocomposite material

Technogenic soils (Technosols) developed from fly ash and bottom ash from thermal power stations combusting bituminous coal and lignite : part II : mineral transformations and soil evolution

Fly ash and bottom ash from thermal power stations are industrial wastes which are susceptible to weathering in the environment. First manifestations of transformations occur immediately after deposition of ashes in a disposal site and they continue in technogenic soils (Technosols) developing from the ashes on surfaces of such sites. Technosols developed from bituminous coal and lignite ashes in Poland were studied in order (a) to identify the most important mineral transformations during the first several decades of soil development, and (b) to discuss the evolution of these soils. Mineral transformations can serve as good indicators of pedogenesis in the studied Technosols. Quantitative X-ray diffraction analyses, Fourier transform infrared spectroscopy, optical microscopy, and scanning electron microscope-energy dispersive spectroscopy studies showed that the mineral transformations proceeded more dynamically in Technosols developed from lignite ashes, whereas they were less expressed in soils formed from bituminous coal ashes. Technosols developed from bituminous coal ashes contained mineral phases inherited from ashes (aluminosilicate glass, mullite, quartz, magnetite, hematite, and traces of maghemite and barite) as predominating constituents. Small contents of pedogenic calcite, iron oxyhydroxides, and most likely short-range order Si- and Al-containing phases originated within ~ 60 years of pedogenesis. Technosols developed from lignite ashes contained aluminosilicate glass, quartz, hematite inherited from fly ash, as well as a variety of secondary minerals (vaterite, calcite, bassanite, gypsum, ettringite, hydrotalcite, and brucite) which were formed as an effect of rapid mineral transformations after ash deposition. After about 40 years, pedogenesis (accelerated by reclamation and a few years of intense cultivation) led to the formation of a new mineral assemblage with the predomination of calcite, gypsum, and hydrotalcite. A concept of evolution of the studied Technosols comprising four stages of evolution was proposed: I - formation of ash during combustion of fuel (coal or lignite) in a thermal power station, II - transport and deposition of ash in a disposal site accompanied by the first weathering alterations, III - early pedogenesis, and IV - further (predicted) evolution

Air Purification Performance of Photocatalytic Concrete Paving Blocks after Seven Years of Service

This paper presents the results of laboratory tests on photocatalytic pavement blocks from a bicycle lane in Poland after seven years of service. Air purification performance was tested on dusty and clean samples using different light sources and setups, with non-laminar gas circulation. Secondary Electrons Secondary Ions (SESI) and InLens detectors combined with SEM−EDS and X-ray analyses were applied to confirm the presence of TiO2 in the studied blocks. The obtained results show that TiO2 was present in the form of agglomerates with a diameter of 0.25−5 µm and was bonded to the cement matrix components. The tested samples still maintained nitric oxide (NO) removal capability with a NO reduction rate of 4−45%, depending on light source and surface cleanliness

MTA-type cement based on ZnO-enriched tricalcium silicate – evaluation of cytotoxicity and bactericidal activity

W artykule przedstawiono wyniki badań in vitro dotyczące cytotoksyczności i działania bakteriobójczego materiału do stosowania w endodoncji – cementu typu MTA (ang. Mineral Trioxide Aggregate) o nowym składzie chemicznym. Cement wytworzono na bazie krzemianu trójwapnia wzbogaconego ZnO i płynu będącego 15% roztworem CaCl2 , a jako czynnik wprowadzający kontrast RTG zastosowano ZrO2 . Wytworzony cement MTA oceniono poprzez scharakteryzowanie właściwości fizykochemicznych obejmujących: czas wiązania, wytrzymałość na ściskanie, a także kontrast RTG i bioaktywność w roztworze symulującym osocze (SBF). Do zbadania wpływu ziaren ZrO2 na ilość i wielkość porów w cemencie wykorzystano technikę mikrotomografii komputerowej (µCT). Działanie cytotoksyczne cementów oceniano przez zastosowanie referencyjnej linii komórkowej L-929. Warunki hodowli komórkowej w kontakcie z badanymi materiałami lub ekstraktami z cementów oceniano za pomocą analizy obrazu lub testu kolorymetrycznego MTT. Do badania aktywności przeciwbakteryjnej wykorzystano dwa szczepy paciorkowców: Streptococcus mutans i Streptococcus sanguinis. Opracowany cement typu MTA charakteryzuje się odpowiednimi właściwościami użytkowymi i spełnia wymagania zawarte w normie PN-EN ISO 10993-5:2009 „Biologiczna ocena wyrobów medycznych, część 5: Badania cytotoksyczności in vitro”. Jednak, aby mógł być rozważany jako bezpieczny wyrób medyczny do wypełniania wstecznego kanałów korzeniowych, wymaga dalszych badań.The article presents the results of in vitro cytotoxicity and bactericidal activity of MTA-type cement (Mineral Trioxide Aggregate) for endodontics with a new chemical composition. The cement was made on the basis of ZnO-enriched tricalcium silicate and a liquid being a 15% CaCl2 solution. ZrO2 was used as an X-ray radiopacity agent in the cement. The produced MTA-type cement was assessed by characterizing the physicochemical properties including: setting time, compressive strength, as well as X-ray radiopacity and bioactivity in a simulated body fluid (SBF). Microtomography technique (µCT) was used to investigate the effect of ZrO2 grains on the number and size of pores in the cement. The cytotoxic activity of the cements was assessed by using the reference L-929 cell line. Cell culture conditions in contact with test materials or cement extracts were assessed by image analysis or MTT colorimetric test. Two strains of streptococci were used to test the antibacterial activity: Streptococcus mutans and Streptococcus sanguinis. The developed MTA cement has appropriate functional properties and meets the requirements of the PNEN ISO 10993-5:2009 standard "Biological evaluation of medical devices, Part 5: In vitro cytotoxicity tests". However, in order to be considered a safe medical device for retrograde root canal filling, it requires further research