Publikační činnost Institutu čistých technologií těžby a užití energetických surovin / of Institute of Clean Technologies for Mining and Utilization of Raw Materials for Energy Use (511)

Permanent URI for this collectionhttp://hdl.handle.net/10084/96236

Kolekce obsahuje bibliografické záznamy publikační činnosti (článků) akademických pracovníků Institutu čistých technologií těžby a užití energetických surovin (511) 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.

Browse

Now showing 1 - 20 out of 82 results

Reclamation and revitalization of post-mining sites - ups and downs
(Technická univerzita Košice, Fakulta baníctva, ekológie, riadenia a geotechnológií, 2023) Biegańska, Jolanta; Tora, Barbara; Sinka, Tomasz; Čablík, Vladimír; Hlavatá, Miluše
During the post-mining activities, all the forms of environment degradation are observed. This article refers to the projects of reclamation and revitalization of post-mining sites. The method of studying reclamation project documents was used to evaluate remedial actions. This allows for a comparative analysis of the obtained effects (the analyzed case) with the planned procedures. It has been shown what the main effects of degradation are caused by surface and underground mining, as well as what procedures are in force for the repair processes (recultivation and revitalization).
Wetting of refractory ceramics with high-manganese and structural steel and description of interfacial interaction
(MDPI, 2022) Novák, Vlastimil; Řeháčková, Lenka; Rosypalová, Silvie; Matýsek, Dalibor
This work aims to describe the interfacial interaction at the interface between refractory material and high-manganese (XT 720) and structural (11 523) steel using a wetting test up to 1600 degrees C. The contact angles were determined through the sessile drop method, and the results were put into context through degradation testing and the characterization of the interfacial interface by Energy Dispersive X-Ray (EDX), X-Ray Diffraction (XRD) analyses, and Scanning Electron Microscopy (SEM). The lowest resistance to molten steel was observed for chamotte materials, while the highest was observed for materials based on electrofused corundum. High-manganese steel was strongly erosive to the materials tested, with the wetting angle decreasing significantly from 10 to 103 degrees with decreasing Al2O3 content (an increase of 2.4 to 59.4% corundum) in the refractories. Structural steel showed wetting angles from 103 to 127 degrees for identical refractories. These results were consistent with the average erosion depth for Mn steel (0.2-7.8 mm) and structural steel (0-2.4 mm).
Notes on the abrasive water jet (AWJ) machining
(MDPI, 2021) Gembalová, Lucie; Hlaváč, Libor M.; Spadło, Sławomir; Geryk, Vladan; Oros, Luka
The aim of the research was to investigate changes of abrasive grains on metals observing the kerf walls produced by the Abrasive Water Jet (AWJ). The microscopy observations of the sidewalls of kerfs cut by the AWJ in several metal materials with an identical thickness of 10 mm are presented. The observed sizes of abrasive grains were compared with the results of research aimed at the disintegration of the abrasive grains during the mixing process in the cutting head during the injection AWJ creation. Some correlations were discovered and verified. The kerf walls observations show the size of material disintegration caused by the individual abrasive grains and also indicate the size of these grains. One part of this short communication is devoted to a critical look at some of the conclusions of the older published studies, namely regarding the correlation of the number of interacting particles with the acoustic emissions measured on cut materials. The discussion is aimed at the abrasive grain size after the mixing process and changes of this size in the interaction with the target material.
The effect of trace oxygen addition on the interface behavior of low-alloy steel
(MDPI, 2022) Novák, Vlastimil; Řeháčková, Lenka; Váňová, Petra; Sniegoň, Michal; Matýsek, Dalibor; Konečná, Kateřina; Smetana, Bedřich; Rosypalová, Silvie; Tkadlečková, Markéta; Drozdová, Ľubomíra; Klus, Petr
This work aims to assess the effect of an oxygen content graded in minimal quantities, on the order of hundreds of ppms, on the determination of surface tension of low-alloy FeCOCr and FeCONi steels in contact with a corundum substrate. Oxygen, as a surface-active element, was segregated at the surface where it interacted with the major components of the alloys, leading to a reduction in surface tension. The sessile drop method was used for wetting tests in the temperature range from steel liquidus temperatures to 1600 degrees C under nonoxidizing conditions. The effect of oxygen on surface tension and wetting angles was verified by statistical analysis using the Kruskal-Wallis test, which supported the results stating that the values of these quantities decreased with increasing oxygen content. Furthermore, liquidus temperatures, which are of practical importance, were determined by the optical and DTA methods and then compared with theoretically calculated temperature values. It turned out that the increased chromium content causes difficulties in determining surface tension up to 1550 degrees C due to the formation of a thin Cr2O3 layer. In addition, SEM and XRD analyses accompanied by calculations in the FactSage oxide database were performed to better understand the wetting mechanism.
Development of stimuli-responsive chitosan/ZnO NPs transdermal systems for controlled cannabidiol delivery
(MDPI, 2021) Radwan-Pragłowska, Julia; Janus, Łukasz; Piątkowski, Marek; Sierakowska, Aleksandra; Szajna, Ernest; Matýsek, Dalibor; Bogdał, Dariusz
One of the most common neurological diseases is epilepsy, which not only negatively affects the quality of people's life but also may lead to life-threatening situations when its symptoms such as seizures cannot be controlled medically. A very serious problem to be overcame is the untreatable form of this disease, which cannot be cured by any currently available medicines. Cannabidiol, which is a natural product obtained from Cannabis Sativa, brings a new hope to people suffering from drug-resistant epilepsy. However, the hydrophobic character of this compound significantly lowers its clinical efficiency. One of the promising methods of this substance bioactivity increase is delivery through the skin tissue. In this article, a new type of advanced transdermal systems based on chitosan and ZnO nanoparticles (NPs) has been developed according to Sustained Development principles. The chemical modification of the biopolymer confirmed by FT-IR method resulted in the preparation of the material with great swelling abilities and appropriate water vapor permeability. Obtained nanoparticles were investigated over their crystalline structure and morphology and their positive impact on drug loading capacity and cannabidiol controlled release was proved. The novel biomaterials were confirmed to have conductive properties and not be cytotoxic to L929 mouse fibroblasts.
High–temperature interaction of molten Fe–C–O–Cr alloys with corundum
(Elsevier, 2021) Řeháčková, Lenka; Novák, Vlastimil; Váňová, Petra; Matýsek, Dalibor; Konečná, Kateřina; Smetana, Bedřich; Dobrovská, Jana
The interaction of Fe-C-O-Cr alloys varying in chromium (0.924-4.760 wt%) and carbon (0.042-1.378 wt%) content with a ceramic substrate having a high content of Al2O3 was studied by experimental wettability tests up to 1600 degrees C. The degree of interaction was assessed based on changes in contact angles (wetting angles) between the above systems, and through Energy Dispersive X-Ray (EDX), X-Ray Diffraction (XRD) analyses and Scanning Electron Microscopy (SEM). The increasing trend of wetting angles with increasing content of chromium and carbon was found. The results of the analyzes confirmed the effect of carbon (>0.1 wt%) contained in the alloys on the structural changes in substrate surface within the area under the alloy. The original corundum phase was replaced by new ones (hibonite, grossite, larnite), of which hibonite was present to the highest degree. Furthermore, in the case of low carbon alloy (0.042 wt% C), hibonite was not detected on the substrate surface contrary to chromium-doped corundum.
3D reconstruction and visualization from 2D X-ray CT images in the study of ceramic membrane microstructure
(Ceramic Research Institute, 2020) Thomasová, Barbora; Thomas, Jan; Souček, Kamil; Michalek, Ondřej; Gembalová, Lucie
In the presented study, X-ray computed tomography (CT) technique was used to visualize the three-dimensional (3D) microstructure of ceramic membrane support made of alternative material - fly ash, kaolin and shale. Standard computed tomography output formats provide usually two-dimensional (2D) information about the object being studied in the form of image data set. However, to understand the material internal structure and its mechanical, physicochemical and hydraulic properties 3D visualization is needed. Our work shows that 3D image data reconstruction can be done with freely available DREAM.3D and ParaView software instead of costly commercial ones allowing wider community data sharing and greater freedom in processing. The resulting 3D model was suitable for quantitative pore space analysis and fluid dynamics modelling and provided important morphological information such as pore and mass shape, cracks, spatial distribution and the connectivity of the solid matrix.
Study of extraction of rare earth elements from hard coal fly ash
(Polskie Towarzystwo Przeróbki Kopalin, 2020) Znamenáčková, Ingrid; Dolinská, Silvia; Hredzák, Slavomír; Čablík, Vladimír; Lovás, Michal; Gesperová, Dana
Rare earth elements (REEs) extraction from wastes and/or by-products is alternative possibility of their winning. The occurrence of REEs, namely 50.1 ppm of La, 100.1 ppm of Ce and 44.3 ppm of Nd was confirmed in solid fly ash samples from the coal fired heating plant (TEKO, Inc. Kosice, eastern Slovakia). The submitted contribution presents laboratory results of REEs leaching from coal fly ash using 3M HCl, HNO3, H2SO4 and H3PO4 at 80 degrees C during 120 min. It was found, that recoveries 65.5% of La, 64.4% Ce and 64.3% of Nd into liquor may be attained after grain size reduction to below 5 mu m.
EU documents of major importance relevant to issues of mineral resource utilisation
(Polskie Towarzystwo Przeróbki Kopalin, 2020) Dvořáček, Jaroslav; Sousedíková, Radmila; Moravec, Ladislav
RAW MATERIALS INITIATIVE and REPORT ON CRITICAL RAW MATERIALS FOR THE EU are two documents of major importance as regards the issues of mineral resources of the European Union. The former document calls upon the EU Member States to maximize utilisation of domestic mineral resources, especially as regards those labelled as critical, the latter concerns occurrence of some such critical minerals in the Czech Republic. In actual fact, compliance with the implications of these documents means renewal of exploitation of residual mineral resources. Nonetheless, such activity anticipates positive economic results, and these are conditioned by investment means available for resumption of production. Both investment and operating expenses can be cut down if existing mining capacities are utilized. This paper investigates possibilities of mining resumption in the Czech Republic from the point of view of the methods employed for decommissioning and closure of mines. The so-called "wet" preservation of mines is recommended both for a future easy option of accessing decommissioned underground works and the possibilities of using pit water itself or employing its energy.
ZnO nanorods functionalized with chitosan hydrogels crosslinked with azelaic acid for transdermal drug delivery
(Elsevier, 2020) Radwan-Pragłowska, Julia; Janus, Łukasz; Piątkowski, Marek; Sierakowska, Aleksandra; Matýsek, Dalibor
The growing number of people suffering from civilization diseases increases the amount of medication taken. Thus, novel methods for drug delivery must be developed which will constitute an alternative to oral administration. A new hope for patients bring transdermal drug delivery systems. To overcome skin barrier function, they must be prepared from materials which increase cell membrane permeability for the medication. Therefore, there is an increasing need for novel, advanced transdermal systems capable of controlled active substance release under specific stimuli. The aim of this research was to obtain novel hydrogel-based transdermal delivery systems through crosslinking process of chitosan using azelaic acid followed by doping with ZnO nanorods to enhance its drug sorption properties. Ready materials were investigated over their structure, morphology and durability. Drug loading capacity, controlled drug release ability and its kinetics were determined on medication used in treatment of cardiovascular system diseases-acetylsalicylic acid. Finally, lack of cytotoxicity was confirmed by XTT assay and cell morphology study carried out on L929 mouse fibroblasts. Obtained results show a great potential of the developed transdermal delivery systems in active substances administration through skin tissue and may help to protect digestive tract of the patients in the future.
Macroscopic and Skyrme-Hartree-Fock test of E(5) symmetry in xenon isotopes
(IOP Publishing, 2020) Abolghasem, Mojgan; Cuxac, B.; Thiamova, G.; Alexa, Petr
Algebraic collective model calculations for even-even xenon isotopes Xe-128,Xe-130 have been performed to describe collective properties of these two isotopes, considered to be candidates for an E(5) transition from spherical to gamma-soft, O(6)-like nuclei. The shape transitional point and the E(5) symmetry are characterised by large fluctuations in the triaxiality parameter gamma reflected by a very flat potential in the gamma direction resulting in two symmetric prolate and oblate minima in the potential energy curves. This has been studied using the Skyrme-Hartree-Fock calculations with different parametrisations of the Skyrme interaction.
Be-7 atmospheric activity concentration and meteorological data: Statistical analysis and two-layer atmospheric model
(Elsevier, 2020) Uhlář, Radim; Haroková, Pavlína; Alexa, Petr; Kačmařík, Michal
Atmospheric activity concentration of Be-7 in the air was monitored during the period of one year from September 2015 to September 2016 at Ostrava, Czech Republic, with a two-day frequency that is shorter compared to a standard 7-day frequency of routine Be-7 measurements. Simultaneously, relevant meteorological data (temperature, rainfall amount, precipitation particle size and speed, tropopause height, and PM10 concentrations) and the sunspot number were accumulated. Weighted linear regression analysis applied to the Be-7 atmospheric activity concentration, the measured meteorological explanatory variables and the sunspot number revealed temperature as the most statistically significant explanatory variable. The tree model proved temperature as the most important explanatory variable and predicted the threshold value separating low and high temperature behavior of Be-7 at about 13 degrees C (2-day average). A simple local two-layer (stratosphere and troposphere) atmospheric model was then applied to the data analysis. The model is able to fit the data for a larger accumulation period (6 days).
3D hierarchical, nanostructured chitosan/PLA/HA scaffolds doped with TiO2/Au/Pt NPs with tunable properties for guided bone tissue engineering
(MDPI, 2020) Radwan-Pragłowska, Julia; Janus, Łukasz; Piątkowski, Marek; Bogdał, Dariusz; Matýsek, Dalibor
Bone tissue is the second tissue to be replaced. Annually, over four million surgical treatments are performed. Tissue engineering constitutes an alternative to autologous grafts. Its application requires three-dimensional scaffolds, which mimic human body environment. Bone tissue has a highly organized structure and contains mostly inorganic components. The scaffolds of the latest generation should not only be biocompatible but also promote osteoconduction. Poly (lactic acid) nanofibers are commonly used for this purpose; however, they lack bioactivity and do not provide good cell adhesion. Chitosan is a commonly used biopolymer which positively affects osteoblasts' behavior. The aim of this article was to prepare novel hybrid 3D scaffolds containing nanohydroxyapatite capable of cell-response stimulation. The matrixes were successfully obtained by PLA electrospinning and microwave-assisted chitosan crosslinking, followed by doping with three types of metallic nanoparticles (Au, Pt, and TiO2). The products and semi-components were characterized over their physicochemical properties, such as chemical structure, crystallinity, and swelling degree. Nanoparticles' and ready biomaterials' morphologies were investigated by SEM and TEM methods. Finally, the scaffolds were studied over bioactivity on MG-63 and effect on current-stimulated biomineralization. Obtained results confirmed preparation of tunable biomimicking matrixes which may be used as a promising tool for bone-tissue engineering.
Critical raw materials - what's the crux of the matter?
(Polskie Towarzystwo Przeróbki Kopalin, 2019) Dvořáček, Jaroslav; Sousedíková, Radmila; Jureková, Zdenka; Matyášová, Zuzana
The paper takes into account mineral commodities that have been listed as critical by the EU Commission. It concentrates attention on the issue of global demand/supply balances, and summarizes causes for critical listing of these commodities.
Overview of the activities of industrial parks and impacts on surface water quality in Ho Chi Minh City, Vietnam
(Polskie Towarzystwo Przeróbki Kopalin, 2019) Dao, Phan; Chi, Nguyen Thuy Lan; Lapčík, Vladimír; Nhung, Tran Cam
Ho Chi Minh City is an economic, commercial, financial and service center of Vietnam, concentrating many industrial and export processing zones with large scale and high growth rate. After nearly 30 years of construction and development (1991-2019), industrial parks and export processing zones have been formed, diversified and actively contributed to the socio-economic and industrial development. However, along with it, the level of environmental pollution caused by IPs and EPZs is increasing, becoming a threat to sustainable economic growth. This article provides an overview of the current status of operations as well as impacts on surface water from the operation of some industrial parks (IPs), export processing zones (EPZs) in Ho Chi Minh City, Vietnam.
Possibilities of obtaining metals from polymetallic ore from Zlate Hory
(Polskie Towarzystwo Przeróbki Kopalin, 2019) Vrlíková, Věra; Čablík, Vladimír; Janáková, Iva
The study deals with the use of flotation to obtain metals from the polymetallic ore from Zlate Hory, the Czech Republic. X-ray diffraction was performed, on the basis of which the mineralogical composition was determined in the sample. The most abundant was quartz with 87.03%. From ore minerals were detected pyrite 2.30%, sphalerite 3.64% and chalcopyrite 1.59%. Due to the high quartz content in the sample, heavy medium separation was selected to reduce its content. The treated polymetallic ore sample was subjected to flotation. In the flotation, the reagents xanthate was used as a collector, and pine oil as a frother. Different flotation conditions were observed, based on which the most suitable conditions for the flotation of metals were determined.
The issue of regional reserves for mineral extraction in the Czech Republic and its legal context
(Polskie Towarzystwo Przeróbki Kopalin, 2019) Vachtlová, Michaela; Urbanec, Vítězslav; Lapčík, Vladimír; Lapčík, Martin
The paper focuses on land – use planning (zoning) (hereinafter referred to as “planning”) as a part of Building Law, specifically on the issue of regional reserves and their definition in the land use plan (hereinafter referred to as “plan”). There are examples of determination of areas of regional reserves for mineral extraction. At the same time, attention is also paid to potential environmental conflicts that may present regional reserves and the possibilities of their solution. The paper also deals with some links between the institute of regional reserves and the mining claim.
High specific activity of radium isotopes in baryte from the Czech part of the Upper Silesian Basin- An example of spontaneous mine water treatment
(MDPI, 2020) Jirásek, Jakub; Matýsek, Dalibor; Alexa, Petr; Osovský, Michal; Uhlář, Radim; Sivek, Martin
Radium-bearing barytes (radiobarytes) have been known since the beginning of the 20th century. They are mainly found as precipitates of low-temperature hydrothermal solutions. In anthropogenic environments, they frequently occur as crusts on oil industry equipment used for borehole extraction, in leachates from uranium mill tailings, and as a by-product of phosphoric acid manufacturing. Recently, we recognized Ra-rich baryte as a precipitate in the water drainage system of a bituminous coal mine in the Czech part of the Upper Silesian Basin. The precipitate is a relatively pure baryte, with the empirical formula (Ba0.934Sr0.058Ca0.051Mg0.003)(Sigma 1.046)S0.985O4.000. The mean specific activity of Ra-226 was investigated by the two-sample method and it equals 39.62(22) Bq/g, a level that exceeds known natural occurrences. The values for Ra-228 and Ra-224 are 23.39(26) Bq/g and 11.03(25) Bq/g. The radium content in the baryte is 1.071 ng/g. It is clear that the Ra-rich baryte results from the mixing of two different mine waters-brines rich in Ba, Sr, and isotopes Ra-226 and Ra-228 and waters that are affected by sulfide weathering in mine works. When this mixing occurs in surface watercourses, it could present a serious problem due to the half-life of Ra-226, which is 1600 years. If such mixing spontaneously happens in a mine, then the environmental risks will be much lower and will be, to a great, extent eliminated after the closure of the mine.
Modified Texas Convention Method for fast neutron flux measurements
(IEEE, 2020) Uhlář, Radim; Alexa, Petr; Harkut, Ondřej; Haroková, Pavlína
The Texas Convention Method (TCM) is a standard method used for relatively fast calibration and check of the 14-MeV neutron flux from DT neutron generators in laboratory and field applications. It is shown that the homogeneous gamma source approximation used in the TCM overestimates the detection efficiency. To increase the accuracy of the method, a careful examination of sources of uncertainties is necessary. To be able to measure neutron fluxes lower than approximately 10(4) neutrons/cm(2)/s, a proper modification of the copper foil dimensions is beneficial. The article addresses both issues.
MCNP approaches for dose rates modeling in Laboratory for Neutron Activation Analysis and Gamma Spectrometry at Ostrava
(Oxford University Press, 2019) Uhlář, Radim; Alexa, Petr
Laboratory for Neutron Activation Analysis and Gamma Spectrometry at the VSB-Technical University of Ostrava was equipped with the neutron generator MP320 operating on the principle of the deuterium-tritium fusion and producing 10(8) neutrons/s at maximum. To ensure radiation protection of radiation workers and public outside the laboratory, the concrete shielding was designed and its protection efficiency was validated by MCNP simulations. Three approaches to calculate the dose rates were compared. The dose rates were estimated for the ORNL MIRD phantom located at the relevant positions (Tally F6 and *F8) and using the MCNPX mesh tally feature with the new ICRP Publication 116 flux-to-dose conversion factors. It was proven that the Approach II in which the absorbed dose rates due to neutrons for all organs are computed using the cell tally F6 and the photon dose calculation is performed by the *F8 energy deposition tally is the most valuable one.

Browse

Recent Submissions