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1

The margins of the Early Jurassic Trento Platform (Southern Alps)

Riva Alberto, Gianolla Piero, Caggiati Marcello

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

59--59

EN

Examples of Lower Jurassic carbonate platform margins are rare, probably due to the scarcity of good outcrops. One of the major palaeogeographic units of the Mesozoic Tethys, the Trento Platform, however, shows two different margin types facing the Belluno and the Lombardian basins. While the western margin, facing the Lombardian Basin, is showing an ooidal unit with frequent mud mounds (Massone Oolite), the eastern margin was poorly characterized, mainly due to difficult stratigraphic definition and problematic accessibility of outcrops. The eastern platform margin characteristics are strictly controlled by tectonic activity and the type of carbonate factory; the differences between the eastern and the western margin could be linked to windward-leeward position of the platform margin, more protected to the west than to the east. Subsidence increased since Late Triassic, due to the opening of the Alpine Tethys, defining shallow water areas, dominated by subtidal and peritidal muddy carbonates, and deeper basins, such as the Belluno and Lombardian Basin. More than 500 m of mud-dominated carbonates developed until Early Sinemurian, when major switch in the carbonate factory occurred. The Hettangian-Early Sinemurian margin is usually not well exposed and is strongly dolomitized and appears to be a tectonically controlled escarpments. Since Late Early Sinemurian, the carbonate factory changed and led to a huge production of peloids and ooids, promptly shed in the surrounding basin: in the Eastern Trento Platform we recognize a 400/500 m thick wedge of Sinemurian to Pliensbachian ooidal calcarenites pinching-out towards the basin, with scattered bioconstructions made of calcareous sponges across the margin. This wedge pinches out also towards the platform interior, showing that the ooids were poorly preserved on the platform top. The preserved slope shows an angle of about 20-25°. In the western margin, the resedimented ooids are more limited, probably due to the limited size of the marginal carbonate factory. In the Late Pliensbachian, probably in the Margaritatus zone, a drowning phase affected part of the eastern carbonate platform, switching to encrinitic calcarenites, while in the western one carbonate production continued until Bajocian. These encrinites are extremely thin on the platform top, but a resedimented wedge in the proximal basin highlights the position of the topographic margin. The margins of the Trento Platform is a rare example of Early Jurassic carbonate platform margin that can be used as a reference for coeval carbonate platform depositional systems.

2

The earliest Cretaceous carbonate platform destroyed by volcanism from the Ukrainian/Romanian Carpathians – reconstruction based on microfacies

Iwańczuk Joanna, Krobicki Michał, Feldman-Olszewska Anna, Hnyłko Oleh

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

31--31

EN

There is a unique tectonostratigraphic unit called Kaminnyi Potik occur in the Ukrainian-Romanian Carpathian transborder zone. In the Ukrainian part numerous outcrops of this unit can be observed in many streams near Rachiv city, but its most spectacular occurrence is in the Chyvchyn Mountains. The whole complex consists of volcanogenic-sedimentary rocks and is divided into two Berriasian formations: Chyvchyn and Kaminnyi Potik. In the section of the Chyvchyn Formation, at the base, there are pillow lavas (basalts and andesites/trachyandesites) and volcano-sedimentary breccia with clasts of lava, coral limestones and radiolarites (submarine debris flows), and peperites as well. The Kaminnyi Potik Formation is made up of fine-grained hyaloclastic and carbonate debris flows of a flysch character (including organodetrital limestones with fragments of: corals, bryozoans, echinoderms bivalves and foraminifera), which overlying breccias and coral limestones of the Chyvchyn Formation. The profile ends by thin-bedded cherty limestones. The thin sections analysis revealed the following microfacies: oolithic-echinoderm packstone/grainstone; coral lithoclastic quartz packstone/grainstone; oolithic-lithoclastic wackestone/packstone; lithoclastic-echinoderm packestone; lithoclastic packestone; radiolarian echinoderm packestone; radiolarian wackestone; radiolarian-calpionellid wackestone and mudstone. Pyroclastic material is often present in the matrix. The ooids observed in the thin sections and the remains of fauna such as corals, echinoderms and bivalves suggest that the original material came from a carbonate platform that was sheltered by a coral reef. As a result of volcanic eruptions and possibly accompanying earthquakes, the platform has been destroyed and its traces are visible in clasts. Sedimentological character of submarine debris flows, (e.g. fractional graiding, mixture of shallow-water fauna and lithoclasts with deep-marine microfauna (radiolarians and calpionellids) and hyaloclastic material present in the matrix document short-term episodes of a catastrophic nature, leading to the redeposition of shallow-water sediments to the deeper parts of the basin.

3

Wpływ węglanów litu, strontu i baru na fazę belitu tworzoną przy temperaturze 1200°C

Ghorab Hanaa Youssef, Abbas Mostafa, Arafa Ahmed, Hassan Hassan Eid

Cement Wapno Beton

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2023

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R. 28, nr 6

428--437

PL

Worcowy belit został przygotowany poprzez wypalenie kalcytu i kwarcu w stosunku molowym 2 przez 1,5 godziny w temperaturze 1200°C. Zidentyfikowano odmiany polimorficzne belitu utworzone przy dodatku Li2CO3 z 1% Li2O jako topnika i domieszki oraz SrCO3 i BaCO3 w ilościach równoważnych 8% SrO i 8% BaO jako mineralizatorów. Utworzone odmiany polimorficzne zbadano za pomocą dyfraktometrii rentgenowskiej z analizą Rietvelda oraz zbadano pod skaningowym mikroskopem elektronowym. Stwierdzono, że odmiany β i γ równie często powstają w belicie z domieszką strontu, a w obecności baru pojawia się również α’. Rozkład Li2CO3 do Li2O jest opóźniony przez węglany strontu i baru z powodu wzrostu ciśnienia parcjalnego CO2 i w konsekwencji stopiony materiał jest stabilizowany. Konieczne są dalsze badania w celu wyjaśnienia wpływu ciśnienia parcjalnego CO2 węglanów na polimorfizm krzemianu dwuwapniowego.

EN

A reference belite is prepared from burning calcite and quartz at mole ratio = 2, for 1.5 hours at 1200°C. Belite polymorphs formed in the presence of Li2CO3 with 1% Li2O, as a fluxing and doping agent, in addition to SrCO3 and BaCO3 with amounts equivalent to 8% SrO and 8% BaO, as mineralizers, were identified. The thermal behavior of the belite mixes and of the pure carbonates was recorded for temperatures up to 1300°C. The polymorphs formed are defined by means of X-ray Rietveld analysis, and examined under a scanning electron microscope. It is found that the β and γ polymorphs are equally formed in the belite doped with strontium, and in the presence of barium, the α’ appears as well. The decomposition of Li2CO3 to Li2O is depressed by strontium and barium carbonates due to the increase in the partial pressure of CO2 and consequently the melt is stabilized. Further research is needed to explain the effect of CO2 partial pressure of the carbonates on the polymorphism of belite.

4

Półilościowe pomiary zawartości węglanu wapnia w historycznych zaprawach gipsowych, za pomocą fourierowskiej spektroskopii w podczerwieni

Koochakzaei Alireza, Mehrabad Mahsa Saidi, Ajorloo Bahram

Cement Wapno Beton

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2023

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R. 28, nr 2

68--75

PL

Niniejsza praca, wykorzystuje spektroskopię fourierowską w podczerwieni, do półilościowego pomiaru zawartości węglanu wapnia, w historycznych zaprawach gipsowych. Badano 17 próbek historycznych zapraw gipsowych, związanych z Łukiem Alishāha w Tabriz w Iranie, pochodzących z okresu Ilchanidów. W badaniach, zastosowano spektroskopię fourierowską, rozproszonego odbicia w podczerwieni - DRIFTS [ang. diffuse reflectance infrared Fourier transform spectroscopy]. Przygotowano zaprawy gipsowe zawierające od 0 do 6,5% kalcytu i zbadano je za pomocą spektrometru FTIR. Krzywą kalibracji przygotowano na podstawie stosunku intensywności pasma 1485 cm-1, związanego z wibracjami wiązań grup węglanowych w kalcycie do intensywności pasma przy 660 cm-1 odpowiadającego wibracjom grupy siarczanowej w gipsie. Obliczenia zawartości węglanu wapnia w badanych historycznych zaprawach gipsowych pokazują, że jego zawartość mieściła się w zakresie 0,12% do 1,08%. Zgodnie z uzyskanymi wynikami można przyjąć, że ze względu na niewielką ilość węglanu wapnia w zaprawach, węglan dostał się do zapraw, jako zanieczyszczenie z gleby, lub w postaci rozpuszczonych soli. Może to wskazywać, że wbrew początkowym przypuszczeniom na temat niektórych z tych zapraw, mieszanka wapna i gipsu nie była używana, jako główny składnik, w ich produkcji.

EN

This paper uses Fourier transform infrared spectroscopy to semi-quantitatively measure the amount of calcium carbonate in historical gypsum mortars. 17 historical mortar samples related to Arch of Alishāh in Tabriz-Iran, belonging to the Ilkhanid period, were evaluated. The methodology used in this study was diffuse reflectance infrared Fourier transform spectroscopy [DRIFTS]. Gypsum mortars containing 0-6.5% calcite were prepared and analysed using an FTIR spectrometer. The calibration curve was prepared based on the band intensity ratio of 1485 cm-1 related to carbonate vibrations in calcite to 660 cm-1 corresponding to sulphate vibrations in gypsum. Calculating the amount of carbonate in all historical mortars shows the presence of about 0.12 to 1.08% carbonate in gypsum mortar. According to obtained results, it can be acknowledged that due to the meagre amount of carbonate in the mixture of mortars, the existing carbonate has entered the mortar as an impurity through soil or dissolved salts. This can indicate that, contrary to the initial idea about some of these mortars, lime and gypsum mixture was not used as the main component in the making these mortars.

5

Implications of brecciation in Pennsylvanian Atoka Bank complex carbonates, Eddy County, New Mexico

Eren Muhsin

Annales Societatis Geologorum Poloniae

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2023

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Vol. 93, No. 4

345--352

EN

The Pennsylvanian Atoka bank carbonates were deposited on the northwest shelf of the Delaware Basin in Eddy County, New Mexico, forming a stratigraphic trap for natural gas. Brecciation is common in the core samples of some wells. This paper describes the brecciation in the phylloid algal limestones and discusses its origin. In the core samples, brecciated dark areas, consisting of irregularly shaped fragments, are seen together with internal sediment-filled pores, characterized by light gray coloured areas. Detailed examination of the core samples reveals that the brecciated dark areas correspond to open space areas between phylloid algal colonies, on the basis of comparison with the well-preserved primary rock texture in the cores. Brecciation is mainly due to the selective dissolution of phylloid algae that produced phylloid algal moulds, later filled by sandy internal sediments under subaerial conditions. The subsequent compaction of the limestone caused the rock to break up and formed a breccia in situ. The sandy internal sediment prevented the moulds from collapse as well as breccia formation in the pore-filling area, owing to its loose character. Overall, the brecciation process, including the dissolution of phylloid algae and breakage of the rocks, significantly improved the reservoir quality, whereas the internal sediment reduced the reservoir quality, for it reduced the porosity.

6

The pre-Taghanic (Givetian, Middle Devonian) ecosystems of Miłoszów (Holy Cross Mts, Poland)

Halamski Adam T., Baliński Andrzej, Racki Grzegorz, Amler Michael R. W., Basse Martin, Denayer Julien, Dubicka Zofia, Filipiak Paweł, Kondas Marcelina, Krawczyński Wojciech, Mieszkowski Radosław, Narkiewicz Katarzyna, Olempska Ewa, Wrzołek Tomasz, Wyse-Jacson Patrick N., Zapalski Mikołaj K., Zatoń Michał, Kozłowski Wojciech

Annales Societatis Geologorum Poloniae

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2022

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Vol. 92, No. 4

323--379

EN

The middle and upper parts of the Skały Fm, Early to Middle Givetian in age, were investigated in four sections at Miłoszów Wood in the Łysogóry Region (northern region of the Holy Cross Mountains, central Poland). The dating is based on conodonts (Polygnathus timorensis Zone to the later part of the Polygnathus varcus/Polygnathus rhenanus Zone; early Polygnathus ansatus Zone cannot be excluded) and spores (Ex1–2 subzones) and, coupled with cartographic analysis and geophysical investigation, allows correlation within the strongly faulted succession. Significant lateral facies variations within the carbonate ramp depositional system in comparison with the better studied Grzegorzowice–Skały section, about 3 km distant, are documented, thanks to conodont-based correlation of both successions. Foraminifers, fungi, sponges, rugose and tabulate corals, medusozoans, microconchids and cornulitids, polychaetes (scolecodonts), molluscs (bivalves, rostroconchs, and gastropods), arthropods (trilobites and ostracods), bryozoans, hederelloids, ascodictyids, brachiopods, echinoderms (mostly crinoids, rare echinoids, holuthurians, and ophiocistoids), conodonts, fish, plants (prasinophytes, chlorophycophytes, and land plant spores), and acritarchs are present. Brachiopods are the most diverse phylum present (68 species), other richly represented groups are bryozoans and echinoderms; in contrast, cephalopods and trilobites are low in diversity and abundance. The muddy, middle to outer ramp biota (200 marine taxa, including 170 species of marine animals, 22 photoautotrophs, 6 forams) represents a mixture of allochthonous shallower-water communities (upper BA3), including storm- and possibly tsunami-affected coral mounds, and autochthonous deep-water soft-bottom brachiopod (e.g., Bifida–Echinocoelia) communities (BA 4–5). The richness and diversity of the Miłoszów biota is relatively high, comparable with other approximately coeval pre-Taghanic ecosystems during the Devonian climatic deterioration (cooling). Preliminary data indicate that in the Holy Cross Mountains, no large-scale replacement of brachiopod (and probably many other benthic ones, like crinoids) communities took place between the Early–Middle Givetian and the Early Frasnian, in contrast to the demise of the Hamilton/Upper Tully fauna in the Appalachian Basin. Such a similarity of pre- and post-Taghanic faunas does not exclude the occurrence of environmental perturbations and transient community turnovers, caused by immigrations during the Taghanic Biocrisis, but evidences the successful recovery of the indigenous biota.

7

Effect of phosphate quality on foam generation during the phosphoric acid production process

Anouar Islaam, Jouraiphy Rim, Essallaki Hicham, Mazouz Hamid, Yousfi Samia, Boulif Rachid, Essaid Bilal, Bouamrani Mouna L.

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 2

48--57

EN

The presence of organics materials in phosphate ores generates foam during the manufacture of phosphoric acid, thus affecting the production performance and the quality of the products. Today, in the phosphate industry defoamers are used to reduce the negative impact of foam phosphoric production. In the present work, we focused on root cause evaluation for foam generation during the phosphoric acid production process, we evaluated the effect of phosphate rock quality in terms of organic carbon (OC) and carbonate content, on foam generation using a laboratory protocol for foaming ability evaluation. The results show that there is a relationship between the volume of the foam generated and the values of those impurities, while the volume of foam generated is higher when the concentration of OC and Carbonate is high. In our work, we confirm that the foaming ability of the phosphate rock can be avoided if the concentration of organic carbon less than 0.1% and less than 3% for carbonate.

8

Effect of thermal conditions of pyrolysis process on the quality of biochar obtained from vegetable waste

Molenda J., Swat M., Osuch-Słomka E.

Inżynieria i Ochrona Środowiska

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2018

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T. 21, nr 3

289--302

EN

An effective way of managing natural waste, including waste from the agri-food industry or products that are economically useful can be offered by production of biochar. Biochar is used not only as an energy product, but also as a sorption material for e.g. groundwater treatment, sewage treatment, as well as biogas valorization. Therefore, the aim of the study was to determine the effect of the conditions of cascade heating of selected types of vegetable waste in carbon dioxide on the microstructure and chemical composition of the obtained biochar. Wheat straw, corn waste in the form of dried leaves and stems, as well as flax shives and cherry stones were subjected to pyrolysis. Cascading temperature conditions were programmed for a total time of 100 minutes, including 15 minutes of final heating at 500°C in one variant and at 700°C in the other. After final heating, the products were left in the pyrolytic chamber to cool down spontaneously to room temperature. The biochar samples were next subjected to microscopic examinations coupled with X-ray microanalysis (SEM/EDS) and infrared spectral examination (FTIR). It was found that the pyrolysis yielded biochar in the amount from 26 to 32.3% of the initial charge mass, depending on the conditions of the process and the type of waste. Furthermore, the differences observed in the chemical structure of the surface of the biochar concerned mainly the occurrence of organic oxygen functional groups whose type depends on the pyrolysis temperature. An increase in the temperature of pyrolysis leads to a decrease in the oxygen content of the products obtained, which results in a relative increase in the proportion of char in the product. Biochar obtained at temperatures of up to 500°C contains aromatic rings and quinone groups, whereas those obtained at higher temperatures (up to 700°C) have ether groups embedded mainly in aliphatic cyclic groups.

PL

Efektywnym sposobem zagospodarowania odpadów naturalnych, w tym pochodzących z przemysłu rolno-spożywczego, na produkty użyteczne gospodarczo może być wytwarzanie biowęgli. Znajdują one zastosowanie nie tylko jako produkt energetyczny, ale także jako materiał sorpcyjny, wykorzystywany m.in. do uzdatniania wód gruntowych, oczyszczania ścieków, a także waloryzacji biogazu. W związku z powyższym celem przeprowadzonych prac było określenie wpływu warunków kaskadowego ogrzewania wybranych odpadów roślinnych w atmosferze ditlenku węgla na mikrostrukturę i budowę chemiczną powstających biowęgli. Pirolizie poddano słomę pszeniczną, odpady kukurydziane w postaci wysuszonych liści i łodyg, a także paździerze lniane i pestki wiśni. Kaskadowe warunki temperaturowe zaprogramowano na łączny czas 100 minut, w tym 15-minutowe wygrzewanie końcowe w jednym wariancie w temperaturze 500°C, a w drugim wariancie w temperaturze 700°C. Po końcowym wygrzewaniu pozostawiano produkty w komorze pirolitycznej do samoistnego wystudzenia do temperatury pokojowej. Otrzymane biowęgle poddano następnie badaniom mikroskopowym sprzężonym z mikroanalizą rentgenowską (SEM/EDS) oraz badaniom spektralnym w podczerwieni (FTIR). Stwierdzono, że w wyniku pirolizy otrzymuje się biowęgiel w ilości od 26 do 32,3% początkowej masy wsadu, zależnej od warunków prowadzenia procesu oraz rodzaju odpadów. Natomiast obserwowane różnice w budowie chemicznej powierzchni otrzymywanych biowęgli dotyczą w głównej mierze występowania tlenoorganicznych grup funkcyjnych, których typ jest zależny od temperatury procesu pirolizy. Wzrost temperatury pirolizy prowadzi do obniżenia zawartości tlenu w otrzymywanych produktach, co powoduje relatywne zwiększenie udziału węgla w produkcie. Biowęgle otrzymywane w temperaturach do 500°C posiadają w swej strukturze pierścienie aromatyczne oraz ugrupowania chinonowe, natomiast otrzymywane w wyższych temperaturach (do 700°C) posiadają ugrupowania eterowe wbudowane głównie w alifatyczne ugrupowania cykliczne.

9

Geochemical signatures of pervasive meteoric diagenesis of Early Miocene syn-rift carbonate platform, Red Sea, NW Saudi Arabia

Al-Ramadan K.

Geological Quarterly

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2017

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Vol. 61, No. 1

239--250

EN

Different diagenetic environments have been recognized in the Early Miocene carbonate platform of Musayr Formation in the Red Sea rift area. Early marine diagenesis includes micritisation that occurs as thin envelope around skeletal and non-skeletal grains in low-energy mud dominated facies and isopachous fibrous calcite in high-energy grain-dominated facies. Pervasive meteoric water diagenesis resulted in cementation of the carbonates by coarse-crystalline blocky-drusy calcite and meniscus cements. Depletion of oxygen (avg. –9.08‰), carbon (avg. –1.6‰) isotopes and trace elements concentrations (avg. values of Fe: 1387 ppm; Mn: 1444 ppm; Sr: 419 ppm; Na: 1194 ppm) in conjunction with negative correlation between Mn2+ and oxygen isotope data suggest variable degrees of fluid-rock interactions and pervasive meteoric diagenesis. The formation of meteoric diagenesis in the Musayr Formation can be explained by two subsequent mechanisms: (1) the presence of meteoric lenses during the time of deposition might have been associated with active freshwater input from the hinterland (NE) due to fall in the relative sea level; (2) later uplift episode during Plio-Pleistocene may have also contributed to the pervasive meteoric diagenetic alterations of the carbonates of the Musayr Formation. The first mechanism is supported by the cement stratigraphy where the blocky-drusy cements postdate the meniscus cement. The latter mechanism seems to have more pronounced effect on the alteration of Musayr carbonate sequence by observing the occurence of late cements such as blocky calcite in most of the samples. The impact of meteoric diagenesis on the studied samples suggest that dissolution is less severe than cementation, hence the visible porosity is very low. Understanding the timing of meteoric diagenesis provides useful information about the reservoir quality distribution in syn-rift carbonate sequences.

10

Analiza korelacji pomiędzy miąższością serii łupkowej a zasobnością CU serii węglanowej we fragmencie jednego ze złóż CU-AG LGOM

Wójtowicz J.

Górnictwo Odkrywkowe

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2014

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R. 55, nr 2-3

92--96

PL

Wcześniejsze badania nad wykształceniem litologicznym i zasobnością Cu złóż LGOM-u, wskazują na istnienie zależności pomiędzy miąższością serii łupkowej a zasobnością Cu serii węglanowej. Statystyczna analiza miąższości serii łupkowej i zasobności Cu serii węglanowej wskazuje na dużą zmienność tych parametrów oraz występowanie w zbiorze danych wartość anomalnych. Analiza siły korelacji z wykorzystaniem współczynników Pearsona i Spearmana przyniosła na ogół statystyczny istotne, choć relatywnie bardzo małe wartości współczynników korelacji, które na wartość bezwzględną są rzędu 0,15.

EN

Earlier studies on lithological structure and accumulation index of Cu in LGOM deposits showed a relationship between thickness of shale ore and accumulation index of Cu in the carbonate ore. Statistical analysis of the thickness of shale ore and accumulation index of Cu in the carbonate ore indicates a high variability of these parameters and occurrence in the dataset anomalous values. The correlation testing using Pearson and Spearman coefficients generally resulted in a statistically significant but relatively very poor results with correlation coefficients slightly exceeding 0.15.

11

Reactive distillation for multiple-reaction systems: optimisation study using an evolutionary algorithm

Keller T., Dreisewerd B., Górak A.

Chemical and Process Engineering

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2013

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Vol. 34, nr 1

17--38

EN

Reactive distillation (RD) has already demonstrated its potential to significantly increase reactant conversion and the purity of the target product. Our work focuses on the application of RD to reaction systems that feature more than one main reaction. In such multiple-reaction systems, the application of RD would enhance not only the reactant conversion but also the selectivity of the target product. The potential of RD to improve the product selectivity of multiple reaction systems has not yet been fully exploited because of a shortage of available comprehensive experimental and theoretical studies. In the present article, we want to theoretically identify the full potential of RD technology in multiple-reaction systems by performing a detailed optimisation study. An evolutionary algorithm was applied and the obtained results were compared with those of a conventional stirred tank reactor to quantify the potential of RD to improve the target product selectivity of multiple-reaction systems. The consecutive transesterification of dimethyl carbonate with ethanol to form ethyl methyl carbonate and diethyl carbonate was used as a case study.

12

Oxygen isotope analysis of shark teeth phosphates from Bartonian (Eocene) deposits in Mangyshlak peninsula, Kazakhstan

Pelc A., Hałas S., Niedźwiedzki R.

Mineralogia

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2011

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Vol. 42, iss. 1

53--61

EN

We report the results of high-precision (±0.05‰) oxygen isotope analysis of phosphates in 6 teeth of fossil sharks from the Mangyshlak peninsula. This precision was achieved by the offline preparation of CO2 which was then analyzed on a dual-inlet and triple-collector IRMS. The teeth samples were separated from Middle- and Late Bartonian sediments cropping out in two locations, Usak and Kuilus. Seawater temperatures calculated from the δ18O data vary from 23–41oC. However, these temperatures are probably overestimated due to freshwater inflow. The data point at higher temperature in the Late Bartonian than in the Middle Bartonian and suggest differences in the depth habitats of the shark species studied.

13

Application of Nasicon and YSZ for the construction of CO2 and SOx potentiometric gas sensors

Pasierb P.

Materials Science Poland

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2006

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Vol. 24, No. 1

279--284

EN

Solid-state potentiometric CO2 and SOx sensors were fabricated using Nasicon (Na3Zr2Si2PO12) or YSZ (ZrO2 + 8 mole % of Y2O3) solid electrolytes, with fused carbonates or sulphates as sensing electrodes and Na2Ti6O13-Na2Ti3O7 two-phase systems or porous platinum as reference electrodes. A comparison of the performance and long-term stability of the prepared sensors was made. More stable behaviour of CO2 sensors was observed for cells prepared from Nasicon while SOx sensors with YSZ used as the solid electrolyte displayed a better performance. The sensing mechanism and long-term stability of the investigated cells was discussed in terms of the possible reactivity of solid electrolytes with the electrode materials and the formation and modification of "ionic-bridges" at the solid electrolyte-electrode interface.

14

Wettability of gold, nickel and NiO by molten alkali carbonate under oxidant and reducing atmospheres as relevant to molten carbonate fuel cell.

Godula-Jopek A., Suski L.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

880-883

EN

Wettability of gold by molten (Li+Na), (Li+K) carbonate eutectic systems has been measured by sessile-drop method, as relevant to the problem of adhesion at the molten electrolyte/solid interfaces in molten carbonate fuel cell. The determined parameters and the surface tension data for the respective systems, reported in the literature, have been used for calculation of the adhesion work parameters for the interfaces under study.

15

The carbonate aggressiveness of water in the karst areas of the basin of the Chochołowski and Kościeliski streams (Western Tatra Mts.)

Barczyk G.

Acta Geologica Polonica

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1998

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Vol. 48, no. 1

115-120

EN

Changes of the carbonate aggressiveness of water in the karst areas of the basin of the Chochołowski and Kościeliski streams (Western Tatra Mts.) are presented. The saturation index SI[c] is lowest for rainwater, higher for groundwater and highest for surface water. Most of the surface water flowing out of the West Tatra Mountains has the ability to dissolve carbonate rocks.