Publikační činnost Katedry geologického inženýrství / Publications of Department of Geological Engineering (541)

Permanent URI for this collectionhttp://hdl.handle.net/10084/64772

Kolekce obsahuje bibliografické záznamy publikační činnosti (článků) akademických pracovníků Katedry geologického inženýrství (541) v časopisech registrovaných ve Web of Science od roku 2003 po současnost.
Do kolekce jsou zařazeny:
a) publikace, u nichž je v originálních dokumentech jako působiště autora (adresa) uvedena Vysoká škola báňská-Technická univerzita Ostrava (VŠB-TUO),
b) publikace, u nichž v originálních dokumentech není v adrese VŠB-TUO uvedena, ale autoři prokazatelně v době jejich zpracování a uveřejnění působili na VŠB-TUO.

Bibliografické záznamy byly původně vytvořeny v kolekci Publikační činnost akademických pracovníků VŠB-TUO, která sleduje publikování akademických pracovníků od roku 1990.

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Now showing 1 - 20 out of 334 results

Evaluation of safe operating envelope for CO2 injection under uncertain rock mechanical parameters and earth stresses
(Elsevier, 2024) Nermoen, Anders; Shchipanov, Anton; Porzer, Michal Matloch; Šancer, Jindřich; Berenblyum, Roman
Carbon Capture and Storage (CCS) is a pre-requisite to decarbonize CO2 emissions from industrial sectors and as an industry capable of compensating for hard-to-abate emissions in a net zero scenario. A method was developed to evaluate the geomechanical constraints and safe operating envelope as function of pore pressure and temperature. The probability of failure was estimated from uncertain input stiffness and strength data, and as cooling and re-pressurization shifts the in-situ effective stresses, the safe operating envelope was determined, here given by pressure and temperature. Onshore storages nearby industrial clusters enable energy and cost-effective handling of CO2. In the SouthEastern European region, onshore depleted oil and gas fields located nearby high-emitting industries may developed into CO2 storages. This paper describes a method for determining maximum fluid pressure as function of temperature from geomechanical restrictions. The method was employed on a practical example used to evaluate the safe operation envelope for a pilot CO2 injection site into a depleted onshore naturally fractured carbonate oil and gas field. The tool uses Monte Carlo simulations to perform geomechanical stability analyses by sampling from the inherent uncertainty of the input parameters to probability of failure as function of pressure and temperature. The risk of re-opening natural fractures, induced fracturing and fault reactivation are evaluated so the safe operating envelope can be obtained. The uncertainty of the input parameters is thus directly reflected in the safe operating envelope - thus providing an effective communication of value information to external stake holders when maturing a CO2 storage pilot.
Laboratory experiments and geochemical modeling of gas–water–rock interactions for a CO2 storage pilot project in a carbonate reservoir in the Czech Republic
(MDPI, 2024) Ličbinská, Monika; Labus, Krzysztof; Klempa, Martin; Matýsek, Dalibor; Vašek, Milan
The aim of this study was to characterize the influence of CO2 in geological structures on mineralogical changes in rocks and assess the sequestration capacity in mineral form and solution of a potential pilot storage site in the Czech Republic. Rock samples from a dolomite reservoir and the overburden level, as well as the corresponding pore water, were used. The most important chemical process occurring in the reservoir rock is the dissolution of carbonate minerals and feldspars during the injection of CO2 into the structure, which increases the porosity of the structure by approximately 0.25 percentage points and affects the sequestration capacity of the reservoir rock. According to the results of geochemical modeling, the secondary carbonate minerals (dolomite, siderite, and ephemeral dawsonite) were present only during the first 50 years of storage, and the porosity at this stage decreased by 1.20 pp. In the caprocks, the decomposition of K-feldspar and calcite resulted in an increase in porosity by 0.15 percentage points at the injection stage only, while no changes in porosity were noted during storage. This suggests that their insulation efficiency can be maintained during the injection and post-injection periods. However, further experimental research is needed to support this observation. The results of this study indicate that the analyzed formation has a low potential for CO2 sequestration in mineral form and solution over 10,000 years of storage, amounting to 5.50 kg CO2/m(3) for reservoir rocks (4.37 kg CO2/m(3) in mineral form and 1.13 kg CO2/m(3) in dissolved form) and 3.22 kg CO2/m(3) for caprock rocks (3.01 kg CO2/m(3) in mineral form and 0.21 kg CO2/m(3) in dissolved form). These values are lower than in the case of the depleted Brodsk & eacute; oil field, which is a porous reservoir located in the Moravian part of the Vienna Basin.
Geochemistry and petrology of reservoir and cap rocks in Zar-3 pilot CO2 storage complex, SE Czechia
(MDPI, 2024) Franců, Juraj; Ocásková, Daniela; Pařízek, Petr; Vácha, Jakub; Pereszlényi, Miroslav; Jirman, Petr; Opletal, Vladimír; Ličbinská, Monika
The planned pilot CO2 storage Zar-3 is an oil field with a gas cap in the final production stage in the SE Czech Republic. It is composed of a dolomite Jurassic reservoir sealed by three different formations that differ significantly in lithology. Previous studies left open questions on the nature of pore space and connectivity and the quality of the seal in the future CO2 storage complex. Microscopic petrography of the reservoir suggests dolomitisation in shallow water followed by karstification and brecciation with fracture-correct-dominated porosity. The seal horizons have porosity limited to the micro- and nanoscales. The oil consists of significantly biodegraded black oil of Jurassic origin mixed with less biodegraded gasoline-range hydrocarbons. Biomarkers in the caprock bitumens trapped in nanopores show a genetic relationship to the reservoir oil. Gas in the not yet fully depleted gas cap of the field is of thermogenic origin with no contribution of microbial methane. The formation water has total dissolved solids typical of isolated brines not diluted by infiltrated fresh water. The geochemical characteristics of the storage system together with the fact that the initial oil column is about 105 m tall with another 150 m of gas cap suggest that the seals are efficient and the Zar-3 future storage complex is tight and safe.
The Jurassic-Cretaceous boundary on the northern Tethyan margin: Karpentná and Ropice sections (Outer Western Carpathians, Czech Republic)
(Elsevier, 2024) Skupien, Petr; Bubík, Miroslav; Reháková, Daniela; Švábenická, Lilian; Elbra, Tiiu; Košťák, Martin; Svobodová, Andrea; Rybová, Pavlína; Mikuláš, Radek; Pruner, Petr; Schnabl, Petr; Kdýr, Šimon; Vaňková, Lucie; Trubač, Jakub; Mazuch, Martin
Microfacies and high-resolution studies at the Silesian Unit (Outer Western Carpathians, Czech Republic) on calpionellids, calcareous and non-calcareous dinoflagellate cysts, foraminifers and calcareous nannofossils, aligned with paleomagnetism, delta C-13(carb) and delta C-18(carb), allow construction of a detailed stratigraphy and palaeoenvironmental interpretations across the Jurassic-Cretaceous (J/K) boundary. Two studied sections consist of allodapic and biomicritic limestones and marlstones. Ropice section spans the stratigraphic range from the upper Tithonian calpionellid Chitinoidella Zone, nannoplankton zone NJT16 to the lower Berriasian calpionellid Alpina Subzone of the Calpionella Zone, nannoplankton NC1 Zone. The J/K boundary is marked by the dominance of small forms of Calpionella alpina, rare occurrence of Nannoconus wintereri, and the first occurrence of organic-walled dinoflagellate cysts Dichadogonyaulax bensonii and Muderongia longicorna. A negative shift in the delta C-13(carb) values corresponds to the Tithonian/ Berriasian boundary, the base of the Calpionella Zone (Alpina Subzone). Karpentna section is represented by upper Tithonian calpionellid Chitinoidella to Crassicollaria zones. Remagnetization was documented in both sections.
Integrated stratigraphy across the Jurassic–Cretaceous boundary in the Rettenbacher section (Northern Calcareous Alps, Salzburg, Austria)
(Elsevier, 2024) Elbra, T.; Skupien, Petr; Bubík, M.; Košťák, M.; Molčan Matejová, M.; Pruner, P.; Rehaková, D.; Švábenická, L.; Vaňková, L.; Cígler, V.; Geist, J.; Kdýr, Š.; Lukeneder, A.; Rybová, P.; Mazuch, M.; Schnabl, P.; Svobodová, A.; Trubač, J.; Ucar, H.
Rettenbacher Quarry carbonate sequence in the Northern Calcareous Alps represents highly dynamic pelagic carbonate sedimentation in the lower slope environment. The section spans from upper Tithonian Crassicollaria colomi Subzone to middle Berriasian Calpionella elliptica Subzone. Radiolarian samples belong to Pseudodictyomitra carpatica Zone. Considerable redeposition of calpionellids, organic walled dinoflagellate cysts, calcareous nannofossils and foraminifera in the allodapic layers, as well as extensive normal polarity remagnetisation event with substantial clockwise rotation is documented. Quantitative predominance of genera Watznaueria and Cyclagelosphaera indicate strong nannofossil modification during diagenesis. The almost straight trend in the 313C with some slight carbon-isotope perturbations is recorded at Rettenbacher. Three significant and stratigraphically important negative excursions of the 313Ccarb values were identified - including tentative indication of a new "Negative peak 4" in the upper part of the Elliptica Subzone - and correlated with other sections confirming stability, respectively isochronity within carbon chemostratigraphy.
The integrated biostratigraphy and palaeoenvironments across the Jurassic–Cretaceous boundary in the Dedina section (eastern Serbian Carpathians)
(Elsevier, 2024) Bubík, Miroslav; Cígler, Vojtěch; Mikuláš, Radek; Rabrenović, Dragoman; Reháková, Daniela; Skupien, Petr; Švábenická, Lilian; Svobodová, Andrea; Svobodová, Marcela
Upper Tithonian to lower Berriasian carbonate sequence of the Getic Nappe System was studied near Golubac using an integrated biostratigraphy approach based on calpionellid, calcareous dinoflagellate, nannofossil, foraminifer, and palynomorph record. Calpionellids allowed subdivision of the section to standard calpionellid zones including the Colomi and Alpina subzones on the Tithonian–Berriasian transition. Nannofossil Nannoconus wintereri proves the presence of the NC0 Zone. Foraminifer fauna on the Tithonian–Berriasian transition contain zonal marker Globospirillina neocomiana and some other potential stratigraphic markers, whose range and taxonomy have to be fixed yet. Poor palynomorph spectra consist of long-ranging Lower-Cretaceous spores and pollen, and a few dinoflagellate cysts known from the Berriasian. Integrated biostratigraphy of the Tithonian–Berriasian oligotrophic open-marine carbonate facies of the Dedina section contributes to the stratigraphic framework necessary for the definition of the Berriasian Global Boundary Stratotype Section and Point.
Small-scale regional engineering geological study of the Czech Republic evaluating the relationship between slope gradients and engineering geological zones
(Springer Nature, 2024) Marschalko, Marian; Zięba, Zofia; Růžičková, Kateřina; Růžička, Jan; Kubáč, Jan; Dąbrowska, Jolanta; Sysala, David; Krčmář, David
The aim of the small-scale regional engineering geological study of the Czech Republic was to evaluate the relationship between slope gradient and engineering geological zones. The research motivation was to determine the average slope gradient, 25%, 50% (median) and 75% quantiles related to the different engineering geological zones. This scientific information is critical from the perspectives of engineering geology, geotechnical engineering, and foundation engineering because an increasing slope gradient evokes the need to create a cut respectively foundation excavation or another excavation in the geological structure, which increases the probability of occurrence of the problem in terms of differential settlement and bearing capacity of the structures. The research was carried out in the territory of the Czech Republic in 8 Quaternary zones with soil foundation ground and 10 pre-Quaternary zones with rocks and semi-rocks and their eluvia. A significant difference in the statistical characteristics of slope gradients was found in the group of Quaternary engineering geological zones (evaluated group I) compared to the group of pre-Quaternary zones (evaluated group II). The value range of the average slope gradient was 1.65 degrees (16.9%) to 5.89 degrees (60.3%) for the Quaternary engineering geological zones (soil foundation ground), representing 43.4% difference. Whereas for the over-quaternary engineering geological zones (rocks, semi-rocks and their eluvia), the difference was much higher, 3.59 degrees (36.8%) to 9.76 degrees (100%-value determined as a referential because it was the maximum), which is also reflected in a more significant percentage difference of 63.2%.
Interaction of seawater with (ultra)mafic alkaline rocks - Alternative process for the formation of aegirine
(Mineralogical Society of America, 2024) Rapprich, Vladislav; Matýsek, Dalibor; Pour, Ondřej; Jirásek, Jakub; Míková, Jitka; Magna, Tomáš
Submarine mafic and relatively Na-poor alkaline rocks in the Outer Carpathians often contain aegirine, a sodic pyroxene usually found in diferentiated alkaline rocks. Its presence in rocks that are too basic and Na-poor for its conventional magmatic appearance is linked to sodic alteration of submarine alkaline rocks. Aegirine crystals grow on altered rims of diopside, commonly with crystallographic unconformity, suggesting that their growth was related to alteration and that aegirine does not represent a late stage of continuous clinopyroxene crystallization. The U-shaped REE patterns in the studied aegirine lack Eu anomaly, characteristic for aegirine from differentiated alkaline rocks. Therefore, the involvement of chemically more evolved magma is unlikely to have played any role in the formation of aegirine in ijolites and essexites. Formation of aegirine in submarine alkaline rocks may thus represent an alternative process to spilitization. However, this process is strongly limited by the availability of Fe3+ oxidized and mobilized by hydrothermal alteration, which may explain a relative scarcity of aegirine observed in submarine alkaline rocks compared to near-complete albitization of spilites, and its absence in high-MgO rocks (>10 wt%). Due to the blocking effect related to Fe3+ unavailability, ijolites, and essexites do not display significant Na enrichment. We posit that Na incorporated in aegirine was mainly sourced from the zeolitized interstitial glass.
Recent reactivation of Variscan tectonic zones: A case of Rodl-Kaplice-Blanice fault system (Bohemian Massif, Austria/Czech Republic)
(Springer Nature, 2024) Roštínský, Pavel; Pospíšil, Lubomil; Švábenský, Otakar; Melnyk, Anastasiia; Nováková, Eva
The Rodl-Kaplice-Blanice fault system (RKB) of Variscan shear origin, repeatedly active since the Late Paleozoic to the Recent, is expressed by a number of lithological contacts, distinct geophysical gradients and many landforms. A general trend of the RKB as well as linear configuration of its internal architecture is fairly similar to those of topical near Rhine Graben and Alpine-Carpathian transition area as the two other consistent recently reactivated large-scale tectonic structures in the extended (thinned) crust of central Europe. In middle part of the RKB, the occurring linear topographic and geological features parallel to the main RKB sections point to the existence of a wide tectonic zone in the crust following the fault system. Our multidisciplinary study includes a summary of corresponding basic geological data, overview of seismic, regional geophysical and geomorphological conditions, primary model of recent kinematic activity in the RKB area derived from the space (Global Navigation Satellite System-GNSS) monitoring and terrestrial (repeated high precision levelling) geodetic data and comparison of these various information. The obtained knowledge indicates that the RKB is active up to similar to 1.0 mm horizontally and > 0.5 mm vertically. The fault system area in the Bohemian Massif can be subdivided into the three parts of diverse tectonic structure and block kinematics. Sinistral horizontal movements are highest near the southern surface sections (Rodl-Kaplice, Rudolfov and Drahotesice faults), whereas noticeable vertical differentiation is going on mainly along the Blanice and Kourim faults in the north where the RKB activity is gradually decreasing towards the extensive Elbe shear zone with transverse movements. The middle part of the RKB is dislocated by a large active transverse tectonic structure of the South Bohemian Basins (SBB) with variable horizontal velocity vectors of surface GNSS stations. Most of the weak regional earthquakes have been recorded west of the RKB. Besides faults of the SBB, these were mainly associated with the RKB-subparallel Lhenice fault. Based on the earthquake distribution and foci depths, the latter fault can have similar structural position as the RKB related to lower part of the Variscan level in the similar to 10-12 km depth.
Microwave-assisted hydrothermal synthesis of pure-phase sodalite (>99 wt.%) in suspension: Methodology design and verification
(MDPI, 2024) Rouchalová, Kamila; Rouchalová, Dana; Čablík, Vladimír; Matýsek, Dalibor
Despite numerous studies focused on the hydrothermal (HT) synthesis of fly ash zeolites (FAZs), this method still has many limitations, the main of which is the low yield of zeolites. Hydrothermally synthesized zeolites are typically multiphase and exhibit low purity, which limits their applicability. Pure-phase zeolites have been primarily prepared from filtrates after alkaline mineralization of fly ashes, not directly in suspension. In addition, the published methodologies have not been tested in a wider set of samples, and thus their reproducibility is not confirmed. The aim of the study is to propose a reproducible methodology that overcomes the mentioned limitations. The influence of the Si/Al ratio (1.3:1–1:2), the type and concentration of the activator (2/4 M NaOH/KOH/LiOH), the reagent (30% LiCl), the duration (24–168 h), and the temperature (50–180 °C) of the synthesis phases were studied. The sequence of the synthesis phases was also optimized, depending on the type of heat transfer. The fly ashes were analyzed by wavelength-dispersive X-ray fluorescence (WD XRF), flame atomic absorption spectrometry (F-AAS), and X-ray diffraction (XRD). The energy intensity of the synthesis was reduced through the application of unique microwave digestion technology. Both microwave and combined (microwave and convection) syntheses were conducted. FAZs were identified and quantified by XRD analysis. This study presents a three-stage (TS) hydrothermal synthesis of pure-phase sodalite in suspension. Sodalite (>99 wt.%) was prepared from nine fly ashes under the following conditions: I. microwave phase: 120 °C, 150 min, solid-to-liquid ratio (S/L) 1:5, Si/Al ratio 1:1.5, and 4 M NaOH; II. convection phase: 120 °C, 24 h, S/L 1:40, and the addition of 30 mL of 30% LiCl; and III. crystallization: 70 °C for 24 h. The formation of rhombododecahedral sodalite crystals was confirmed by scanning electron microscope (SEM) images.
Wetting of graphite and platinum substrate by oxide system with graded B2O3 content
(MDPI, 2023) Novák, Dalibor; Řeháčková, Lenka; Novák, Vlastimil; Matýsek, Dalibor; Peikertová, Pavlína
This work focuses on wetting two types of substrates (a platinum substrate and a polished graphite substrate) by molten polycomponent oxide system CaO–MgO–SiO2–Al2O3–B2O3 to test the level of interaction at high temperatures. The tested systems were subjected to high-temperature wetting tests in the temperature range from liquidus temperature to 1550 ◦C using the sessile drop method. A total of four oxide systems were tested with graded boron oxide contents ranging from 0 to 30 wt%. The experiments were conducted in a CLASIC high-temperature resistance observation furnace and an inert atmosphere of high-purity argon. Droplet silhouettes were obtained with a CANON EOS 550D high-resolution camera during heat treatment, with reactive and non-reactive wetting occurring depending on the substrate type. The dependence of the average wetting angles on temperature and time was evaluated, and it was found that boron oxide decreased the average wetting angles of molten oxide droplets. The analyses were accompanied by the SEM/EDX analysis of the substrate and FTIR analysis of the droplets after high-temperature experiments. The phase composition of the oxide systems was evaluated by XRD analysis.
Rare, slow but impressive: > 43 ka of rockslide in river canyon incising crystalline rocks of the eastern Bohemian Massif
(Springer Nature, 2023) Lenart, Jan; Kašing, Martin; Pánek, Tomáš; Braucher, Régis; Kuda, František
Despite significant progress in understanding the stability of rock slopes, little is known about the time scales of the evolution of slow-moving rockslides. The Ledové sluje rockslide in the Thaya River canyon is a unique and infrequent slope failure developed in crystalline rocks of the Variscan orogen in Central Europe. Fresh topography with trenches, rock walls, slided blocks, scree slopes and crevice-type caves has attracted generations of geologists for more than a century, but questions of mechanism and age of the rockslide have remained unresolved. To address this question, we combined geomorphological research with detailed analysis of the geological structure, electrical resistivity profiling and terrestrial cosmogenic nuclide dating (TCN). Our data show that failure developed above the river undercut bank along a planar sliding surface predisposed by NW-oriented gently dipping metamorphic foliation intersected by steep fractures and faults. Although TCN dating does not allow determination of the entire life span of the rockslide, its scarp predisposed by NE- to ENE-striking fault was largely exposed in the Last Glacial during marine isotope stages (MIS) 3 and 2 between ~ 43 and 23 ka, suggesting slow gradual or multievent movement of the rockslide slope rather than a single catastrophic event. We conclude that, although very rare in Central Europe, rockslides in the crystalline rocks of the Palaeozoic orogens may leave a much longer topographic footprint than in the adjacent Alpine mountain belts.
Corrensite and associated smectites in the Teschenite Association Rocks from the Podbeskydí Area (Czech Republic and Poland)
(Elsevier, 2023) Matýsek, Dalibor; Jirásek, Jakub
This study reports on the relatively common presence of the clay mineral corrensite in Teschenite Association Rocks of Early Cretaceous age. Significant quantities of corrensite were noted in monchiquite dikes and pillow lavas, pyroxene-rich rocks (teschenites), picrites, and also in the associated tuffs and tuffites including hyalo clastite breccias, and in strongly albitised calcareous shale enveloping small volcanic bodies. In addition to the transformation of primary mafic minerals such as forsteritic olivine, Ca-Fe-Mg clinopyroxenes, and amphiboles into clay associations, secondary zeolitisation (analcimisation), carbonatisation, silicification, and serpentinisa tion were also observed. The main clay mineral within the investigated rocks was smectite close to montmo rillonite and saponite, but chlorite and serpentinite subgroup minerals were also present. The corrensite-bearing rocks were macroscopically indistinguishable from their smectitised or chloritised equivalents. Corrensite itself formed extremely thin (<1 μm) wrinkled sheets, present both in the rock matrix and the amygdaloid cavities, where it was younger than albite but older than calcite. The presence of corrensite was proven through powder X-ray diffraction analyses; a sequence of basal reflections at 28–29 Å, 14.25 Å, 7.15 Å, etc., were recorded, which after the application of ethylene glycol slightly expanded to 31 Å, 15.5 Å, 7.83 Å, etc. According to the interlayer distances, behaviour of corrensite after ethylene glycolation, the chemical classification criteria, and geological setting the analysed mineral was a HC-type corrensite of hydrothermal origin. The results of wavelength dispersive spectroscopy (WDS) microanalyses yielded an empirical average formula (K0.12Na0.01Ca0.15)Σ0.28(Mg4.84Fe2+ 1.65Fe3+ 1.34Mn2+ 0.02Al0.82)Σ8.95(Si5.86Ti0.10Al2.03P0.01)Σ8.00O20(OH9.89,F0.11) Σ10.00 . nH2O. Elevated Ti content can be explained either by presentce of nanosize TiO2 particles or a substitution of Ti (up to 0.33 apfu) for tetravalent silicon. The abundance of clay minerals in the Teschenite Association Rocks revealed that they were overprinted by several metamorphic events. Corrensite occurrences narrowed the metamorphic conditions to a temperature interval of 60 to 300 ◦C, which overlaps both zeolite and prehnite pumpellyite metamorphic facies. The presence of smectites and corrensite in contact and hydrothermally altered sediments, as well as potassium metasomatites, proved that significant hydrothermal activity took place at the contact zones of magmatic/volcanic bodies.
Lower Berriasian ammonites from Dedina (Golubac Mountains, eastern Serbia) and their biostratigraphic implication
(Elsevier, 2023) Vašíček, Zdeněk; Rabrenović, Dragoman; Skupien, Petr; Radulović, Barbara
A rich ammonite fauna was collected from the Dedina section, which is part of the Getic nappe system of the Serbian Dacia Megaunit. More than three hundred ammonites were collected from the light grey to reddish bioclastic limestones of the lower part and light grey marlstones of the upper part. From this fauna, 10 genera with 17 species were described, and 4 aptychi species were recorded. The ammonites belong to the suborders Haploceratina, Perisphinctina, Olcostephanina, and Ancyloceratina. Perisphinctids belong to the genera Pseudosubplanites, Hegaratella, Delphinella, Substeueroceras, Malbosiceras, and Strambergella. Based on the occurrence of Pseudosubplanites grandis, the studied section can be considered to belong to the Grandis ammonite Subzone of the upper part of the lower Berriasian. The association described here appears to be close to the coeval ammonite association in Crimea.
Engineering-geological comparative analysis of four cases studies of waste landfills
(Springer Nature, 2023) Marschalko, Marian; Popielarczyk, Dariusz; Vicherek, Petr; Niemiec, Dominik; Kubáč, Jan
The aim of the paper is to carry out a comparative engineering-geological study of four diferent waste landflls using the evaluation criteria for the geological subsoil as a natural sealing barrier. The study evaluates 4 localities (Velké Pavlovice, Kvítkovice, Prakšice and Horní Suchá) using three variants (based on two standards) which approach the geological barrier requirements as a combination of impermeability requirements based on a fltration coefcient limit value. and the required geometry represented by investigation depths. The research was carried out in landflls in Moravia, in the east of the Czech Republic. The study’s motivation is to point at the diferences in engineering-geological investigations of waste landflls (as for the requirements for impermeable geological subsoil as a natural sealing barrier) when compared with other engineering structures (where the main goal is to evaluate load-bearing capacity and settlement). The purpose of the geological barrier is to prevent the spread of contamination, and the paper shows this can be approached diferently, as shown in two diferent methodologies investigated herein. The frst model (Model 1) assumes there is a 3-m-thick subsoil below the landfll’s footing bottom, which manifests impermeability characterized by the fltration coefcient Kf ≤ 1.0 * 10–9 m/s, or a 30-m-thick subsoil of Kf ≤ 1.0 * 10–8 m/s. The second model (Model 2) assumes a 1-m thick, impermeable subsoil massif of Kf ≤ 1.0 * 10–9 m/s. We found that none of the landflls in the four selected localities had an impermeable layer in the required depth (a fltration coefcient Kf from 1.8 * 10–9 to 3.9 * 10–9 m/s), and thus did not comply with the limiting conditions. As a result, an anthropogenic technical barrier had to be installed. An important goal of the study from an environmental point of view was to assess the existence of a suitable geological barrier under the proposed landflls. The most important criterion from this point of view is permeability. An additional technical objective of the project was also the assessment of the possible creation of a technical anthropogenic isolation barrier. In the event that the natural sealing barrier would not be sufcient. This was shown in all solved case studies of engineering geological investigations of waste landflls.
Chrysoberyl and associated beryllium minerals resulting from metamorphic overprinting of the Maršíkov–Schinderhübel III pegmatite, Czech Republic
(Cambridge University Press, 2023) Rybníková, Olena; Uher, Pavel; Novák, Milan; Chládek, Štěpán; Bačík, Peter; Kurylo, Sergii; Vaculovič, Tomáš
The Maršíkov–Schinderhübel III pegmatite in the Hrubý Jeseník Mountains, Silesian Domain, Czech Republic, is a classic example of chrysoberyl-bearing LCT granitic pegmatite of beryl–columbite subtype. This thin pegmatite dyke, (up to 1 m in thickness in biotite–amphibole gneiss is characterised by symmetrical internal zoning. Tabular and prismatic chrysoberyl crystals (≤3 cm) occur typically in the intermediate albite-rich unit and rarely in the quartz core. Chrysoberyl microtextures are quite complex; their crystals are irregularly patchy, concentric or fine oscillatory zoned with large variations in Fe content (1.1–5.3 wt.% Fe2O3; ≤0.09 apfu). Chrysoberyl compositions reveal dominant Fe3+ = Al3+ and minor Fe2+ + Ti4+ = 2(Al, Fe)3+ substitution mechanisms in the octahedral sites. Tin, Ga, and V (determined by LA-ICP-MS) are characteristic trace elements incorporated in the chrysoberyl structure, whereas anomalously high Ta and Nb concentrations (thousands ppm) in chrysoberyl are probably caused by nano- to micro-inclusions of Nb–Ta oxide minerals; especially columbite–tantalite. Textural relationships between associated minerals, distinct schistosity of the pegmatite parallel to the host gneiss foliation and fragmentation of the pegmatite body into blocks as a result of superimposed stress are clear evidence for deformation and metamorphic overprinting of the pegmatite. Primary magmatic beryl, albite and muscovite were transformed to chrysoberyl, fibrolitic sillimanite, secondary quartz and muscovite during a high-temperature (~600°C) and medium-pressure (~250–500 MPa) prograde metamorphic stage under amphibolite-facies conditions. A subsequent retrograde, low-temperature (~200–500°C) and pressure (≤250 MPa) metamorphic stage resulted in the local alteration of chrysoberyl to secondary Fe,Na-rich beryl, euclase, bertrandite and late muscovite.
Comparing the photocatalytic performance of GO/ZnO and g-C3N4/ZnO composites prepared using metallurgical waste as a source of zinc
(Elsevier, 2023) Škuta, Radim; Kostura, Bruno; Ritz, Michal; Foniok, Kryštof; Pavlovský, Jiří; Matýsek, Dalibor
Acid leachate from steel sludge was used as a source of zinc oxide (ZnO-L) for the preparation of photocatalytically active composites based on GO/ZnO-L and g-C3N4/ZnO-L (further denoted as gCN/ZnO-L). The prepared composites were characterized using UV–Vis spectrophotometry, SBET, XRD, FTIR and DRS. The photocatalytic efficiency was tested using the photodegradation of azo dye Acid Orange 7. The obtained results were confronted with model composites prepared from pure components. For GO/ZnO-L and gCN/ZnO-L samples, the degradation efficiency was found to be 60.2 % and 51.5 %, respectively. While in the case of gCN/ZnO-L composites, it was purely photochemical degradation, in the case of GO/ZnO-L composites adsorption was significantly co-applied. For both composites containing ZnO-L, a higher photo-degradation activity against azo dye was found compared to the model composites. The reason is the modification of the electronic structure and the emergence of new quantum levels between the valence band and the conduction band of ZnO and gCN due to the presence of other metal oxides in ZnO-L, which leads to a more efficient separation of photo-generated charge carriers.
Geophysical architecture of tectonized volcanic bodies near flysch thrust fronts (Outer Western Carpathians)
(Elsevier, 2023) Kašing, Martin; Jirásek, Jakub; Matýsek, Dalibor; Melnyk, Anastasiia; Jirman, Petr; Skupien, Petr; Pospíšil, Lubomil
Teschenite association rocks (TAR) represent a specific type of mostly alkaline igneous rocks which form an almost 100 km long belt of discontinuous rock bodies within the Outer Western Carpathians (OWC) in the territory of Czechia and Poland. At present, a detailed mineralogical, geochemical, and stratigraphic analysis or dating of the volcanic formations is available, but basic structural and spatial relations characterizing TAR bodies and their origin are missing due to the poor exposure of TAR and lack of borehole data. A drill-hole- and outcrop-data-calibrated geophysical survey has proven to be a powerful tool for the interpretation of spatial extent and subsurface structure of TAR. At two type localities of TAR in Czechia (sites Staré Město and Bruzovice), a geophysical investigation combining ground conductivity mapping (CM) with profile measurement of electrical resistivity tomography (ERT), gravity survey, and magnetic survey was performed. A joint interpretation of the geophysical data served to determine the spatial extent (up to 500 m long and 40 m deep), geometry, and structural features (often fault-bounded with highly anisotropic heterogeneous structure of mélange character) of the studied TAR bodies. The interpreted magmatism of the study area included a stage of intrusion and extrusion of magmatic bodies in the Early Cretaceous, followed by a phase of fold-thrust deformation during the tectonic shortening of the area from the Late Cretaceous to Oligocene times. The resulting highly anisotropic rock mass consisting of TAR and its country rocks structurally controls the subsequent post-tectonic gravity-driven deformation.
Analysis and modelling of single domain core-shell (αFeNi/chromite) nanoparticles emitted during selective laser melting, and their magnetic remanence
(Elsevier, 2023) Dvorský, Richard; Kukutschová, Jana; Pagáč, Marek; Svoboda, Ladislav; Šimonová, Zuzana; Peterek Dědková, Kateřina; Bednář, Jiří; Mendes, Rafael Gregorio; Matýsek, Dalibor; Malina, Ondřej; Tuček, Jiří; Vilamová, Zuzana; Kiselev, Sergei; Gemming, Thomas; Filip, Peter
Despite recent intense implementation of increasingly eco-friendly additive manufacturing, the properties of nanoparticulate pollutants emitted during Laser Powder Bed Fusion are still not fully understood, and have generally been overlooked. This study aims to fill this gap in current research by providing new insights into distinct metal/oxide core-shell nanoparticles (3–36 nm) that are produced during 3D printing using stainless steel. It also suggests possible ways for the removal of these potentially harmful by-products. Further, this research also provides a newly developed kinetic model that predicts a metal core growth time of below 200 μs and confirms the predicted theory for the formation of these by-products. In the current study it was found that the cores produced during this process are purely metallic and consist of meteoroid phase kamacite (αFeNi). Within this study there was found to be a complete dominance of single-domain cores of kamacite with prevailing particles below the superparamagnetic threshold showing strong magnetic response and remanence. This new knowledge can be used to minimize potential health risks and reduce contamination of raw materials by this nanoparticulate pollutant, which can adversely affect the quality of printed metal parts, the environment, and the health of the operator. These findings also provide a new possibility of targeted efficient production of superparamagnetic core-shell nanoparticles with a metallic kamacite core during laser powder bed fusion of austenitic steel 316L powder, which can be used in the production of sensors.
Quality assessment of the vitreous enamel coating applied to the weld joint
(MM Science, 2023) Sternadelová, Kristýna; Krupová, Hana; Matýsek, Dalibor; Mohyla, Petr
This work compares different thicknesses of vitreous enamel coating applied to welded joints. Low-carbon steel Kosmalt E300T was used as a base material. The MAG welding method was used for all samples. Metallography was performed to compare the thickness of the coating formed on the machined and unmachined surfaces of the weld. SEM analysis focused on the substrate/vitreous enamel coating interface. The results show that the high thickness of the vitreous enamel coating that occurs in unmachined weld joints significantly decreases the properties of the enamel coating. In comparison, the machining of the weld surface contributes to the quality improvement of the vitreous enamel coating.

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