Publikační činnost Katedry požární ochrany / Publications of Department of Fire Protection (030)

Permanent URI for this collectionhttp://hdl.handle.net/10084/71277

Kolekce obsahuje bibliografické záznamy publikační činnosti (článků) akademických pracovníků Katedry požární ochrany(030) 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 59 results

Gas in scattering media absorption spectroscopy for time-resolved characterization of gas diffusion processes in porous materials
(Elsevier, 2024) Dostál, Michal; Suchánek, Jan; Bitala, Petr; Klečka, Vít; Nevrlý, Václav; Klímková, Lenka; Konečný, Petr; Vořechovská, Dita; Kubát, Pavel; Zelinger, Zdeněk
Signal denoising is a serious problem for in-situ laser diagnostics of gases dispersed in porous materials. An optical sensor system based on absorption spectroscopy of gases in a scattering environment was built using a 3D printed cell with reference samples of polystyrene foam. Selected A-band spectral lines of molecular oxygen were investigated using wavelength modulated spectroscopy with second harmonic detection. Quantitative information on the concentration of analyte dispersed in the porous medium was obtained at extremely low signal-to-noise ratio (SNR < 10). A spectral line shape fitting procedure based on the Gabor transform followed by a filtered inverse fast Fourier transform allowed to achieve a relatively high SNR with good linearity over a range of reduced oxygen concentrations in air. Finally, the applicability of the optical sensor system to monitor the diffusion of carbon dioxide into air dispersed in a Styrofoam sample and vice versa was successfully demonstrated.
Chemometrics approach to Cantilever enhanced photoacoustic spectroscopy with Quantum Cascade lasers
(Elsevier, 2024) Suchánek, Jan; Dostál, Michal; Nevrlý, Václav; Kubát, Pavel; Chaloupecká, Hana; Zelinger, Zdeněk
Cantilever-enhanced Photoacoustic Spectroscopy in combination with Wavelength Modulation Spectroscopy was used for the multicomponent analysis of gases. Distributed feedback Quantum Cascade Laser tunable in the region of similar to 1045 - 1048 cm(-1) was used as the excitation source. Principal component analysis (PCA) and Partial Least Squares (PLS) (the pls package in the statistical software R) methods were applied to a mixture of selected substances (methanol and ethanol) in the gas phase to both simulated (www.spectraplot.com) and experimentally acquired spectra, PCA predicting the number of substances and PLS its concentrations.
Operation of water supply systems in the Czech Republic - Risk analysis
(MDPI, 2024) Caithamlová, Martina; Kročová, Šárka; Mariňáková, Jitka
A reliable supply of quality drinking water is a fundamental prerequisite for a healthy society and its economic development. Public ownership of water infrastructure is prevalent in most European countries. In the Czech Republic, however, water infrastructure is highly fragmented, which entails multiple risks. The fragmentation of the sector leads to a low economic efficiency of operations, the unstable quality of service provision, and significant price differences. The aim of the paper is to use the IFE matrix to analyze the strengths and weaknesses of different ways of operating water supply systems in the Czech Republic. Furthermore, through the FMEA method (failure mode and effects analysis), this paper tries to identify the risks and threats to drinking water supplies for selected operators (representing the most frequently used operating models) and, subsequently, it proposes measures to mitigate the identified risks. The topic was addressed in the form of a case study of selected water system operators in the Czech Republic, and the findings indicate the compartmentalized model to be the most appropriate operating model.
Properties of fine graded perlite-based lightweight cement mortars subjected to elevated temperatures
(MDPI, 2023) Pizoń, Jan; Konečný, Petr; Mynarz, Miroslav; Bílek, Vlastimil
The present research compared the behaviours of lightweight mortars based on ordinary Portland cement (OPC), calcium sulphoaluminate cement (CSAC), and calcium aluminate cement (CAC) containing expanded perlite and subjected to elevated temperatures. The perlite substituted natural sand in amounts of 25, 50, 75, and 100% by volume. The mortars were subjected to heating at up to 300 ◦C, 650 ◦C, and 1000 ◦C at a rate of 20 ◦C/min. The consistency and density of fresh mortars, compressive strength and density of hardened mortars after heating and cooling, and absorbability were assessed. Such a holistic testing approach is the main novelty of this research, which is related to the aforementioned mixtures and elevated temperatures. The main contribution of this article is a comparison of various cement types coupled with variations in the level of sand replacement with expanded perlite. In previous studies, comparisons were made in pairs of OPC-CSAC and OPC-CAC for normal-weight concrete. There is a gap in our knowledge of triple comparisons and lightweight cement composites which is filled by the current study. The use of OPC at up to 650 ◦C is recommended because it is the most common solution, its performance is similar to that of CAC, and it is cheaper than other solutions. Above 650 ◦C and up to 1000 ◦C, CAC is the only solution because it performs better than other cements. CSAC is not suitable for use at elevated temperatures because of its poor strength performance, even if it is the best solution from an environmental point of view. Sand replacement with perlite does not increase the strength performance under elevated temperatures, but its efficiency is different for various types of cement.
Setup of a 3D printed wind tunnel: Application for calibrating bi-directional velocity probes used in fire engineering applications
(Elsevier, 2023) Smolka, Jan; Kempná, Kamila; Kučera, Petr; Kempný, Kamil; Asimakopoulou, Eleni; Danihelka, Pavel
The research presented here focuses on the development of a 3D printed wind tunnel and the relevant equipment to be used for calibrating bi-directional velocity probes (BDVP). BDVP are equipment to be used for measuring velocity flow by determining the pressure difference of hot gases generated during fires. The manufactured probes require calibration to determine the calibration factor. The calibration is usually performed in wind tunnels which can be difficult to access due to costs, complexity and the various pieces of equipment required. The aim of the current study is to develop and assemble an inexpensive and easy-to-build bench-scale wind tunnel, with a data-logging system and fan control functionalities for fast and effective calibration of BDVP. A 3D printer with a PET-G filament is used, able to produce parts for the wind tunnel system which are durable and easy to handle and assemble. The system additionally includes an Arduino-based measuring unit with a hot-wire anemometer and temperature correction: Rev. P. This takes precise measurements; continuously logging data on a computer through a USB interface and capable of saving data on an SD card. This design provides users with parameters of velocity flow up to 4 m/s with standard deviation of 1.2 % and turbulence intensity of 1 %. The main advantages of this wind tunnel are its simplicity to build and portability.
Sustainability and specifics of fire water sources in new climatic conditions using the example of the Czech Republic
(Springer Nature, 2023) Kavan, Štěpán; Kročová, Šárka
Sufficient fire water for fire protection of an area is of fundamental importance in the security of the state and its infrastructure. Fires cannot be completely prevented, but the consequent damages can be minimized provided that there are enough extinguishing agents to eliminate them. The main and most important current and future extinguishing agent is water. Due to the fact that climate change is ongoing, it can be assumed that many existing natural and multipurpose sources of fire water may not meet the capacity requirements for firefighting, or they will not be available at all. The aim of the scientific approach is to evaluate and specify the availability of fire water in the new climatic conditions using the example of the Czech Republic. Another aim of the article is to characterize the possible shortage of fire water and to propose means by which the maximum effect can be achieved with minimum investment costs, and to ensure the long-term sustainability of natural and multipurpose fire water sources. The analysis of strengths and weaknesses, opportunities and threats was used for the evaluation of the availability of fire water in new climatic conditions. It arises from the results of the article and its broader concept that, despite the current satisfactory situation in fire protection in the Czech Republic regarding fire water, the risks of its shortage are increasing when the climate changes significantly. The lack of fire water will not be nationwide, but most likely only regional.
1st international round robin test on safety characteristics of hybrid mixtures
(Elsevier, 2023) Spitzer, Stefan H.; Askar, Enis; Benke, Alexander; Cloney, Chris; D'Hyon, Sebastian; Dufaud, Olivier; Dyduch, Zdzislaw; Gabel, Dieter; Geoerg, Paul; Heilmann, Vanessa; Jankůj, Vojtěch; Jian, Wang; Krause, Ulrich; Krietsch, Arne; Mynarz, Miroslav; Norman, Frederik; Skřínský, Jan; Taveau, Jerome; Vignes, Alexis; Zakel, Sabine; Zhong, Shengjun
There is no applicable existing standard for the determination of safety characteristics for hybrid mixtures. While developing a new standard in a joint research project in Germany first results from parameter studies led to a standard procedure that can be adopted by laboratories that are already testing dusts in the so called 20L-sphere with as little additional effort as necessary. In fact, one of the main objectives of this research project was to keep modifications and adjustments from the generally accepted dust testing procedures as easy and minimal as possible so as to limit potential deviations from one laboratory to another.In this first round robin test on hybrid mixtures ever, with methane as gas component and a specific corn starch as dust sample, the practicality of the whole procedure, the scattering of the results and the deviation between the testing apparatuses is investigated. This paper summarizes the experimental procedure adopted and objectives of the first round-robin phase involving three of the four original German companies, plus volunteering laboratories from Australia, Belgium, Czech Republic, France, Poland and P.R. China. The results will have an impact on the new standard and may lead to robust data for later simulation purposes.
Experimental investigation of the consequences of acetylene pressure cylinder failure under fire conditions
(Elsevier, 2022) Jankůj, Vojtěch; Mynarz, Miroslav; Krietsch, Arne; Spitzer, Stefan H.; Lepík, Petr
Acetylene pressure cylinders are widely used in the industrial sector for welding, flame cutting, or heating. Sometimes during work, not only with acetylene cylinders, fires occur and in this case the risk of destruction increases and the behavior of such an exposed cylinder is unpredictable. The purpose of this study is to identify those critical conditions when acetylene cylinders burst and explode in fires. In the present study, acetylene cylinders were exposed to fire conditions. For this purpose, a woodpile as a source of fire was chosen, tested, and evaluated. In addition to the fire condition, this option guaranteed reproducibility and similar conditions for all tests. The individual cylinders were equipped with thermocouples measuring the shell temperature, and half of them were prepared in order to measure the temperatures inside the cylinder. An important factor was the measurement of the amount of pressure that was achieved during the destruction of the cylinder. For this purpose, a pressure transducer was attached to the outlet of the cylinder valve. Exposed to direct fire, they can explode in 10 min, which was confirmed. The critical pressure of 40 bar has been reached in 6 min, followed by destruction after 7 min in fire. Cylinders with internal thermocouples were destroyed when lower pressure was achieved. This confirms the fact that any change of the pressure cylinder affects the original properties. After the tests, the fragments of the selected cylinders were subjected to material tests. The results obtained in these tests are the main source of information for understanding the behavior of acetylene cylinders in fire and the possi-bility of increasing the safety of intervening rescue services in an emergency.
Uncontrolled and controlled destruction of acetylene pressure cylinders
(MDPI, 2022) Jankůj, Vojtěch; Mynarz, Miroslav; Lepík, Petr
The risk of physical destruction of a pressure cylinder increases with increasing temperature load. Acetylene is a significant hazardous gas in cylinders. If the destruction pressure is reached, the cylinder is torn into two or more pieces, followed by the gas release to the environment. The presence of ignition sources could lead to the formation of the fireball phenomenon. This phenomenon generally reaches approximately ten meters in diameter and can be accompanied by a blast wave and a spread of the cylinder's fragments or surrounding objects. The consequences of this type of fire could be fatal. Shooting through the cylinder shell may lead to the mitigation, if not elimination, of the effects of the uncontrolled destruction mentioned above. As a result of the review of relevant publications, several states commonly use this method as a standard procedure. Internal gas is released through the resulting hole, the pressure drops down and the gas creates a fire jet or disperses to surroundings. This study is based on a large-scale experiment where acetylene cylinders were placed inside a prepared woodpile and exposed to fire. In the fire condition, the cylinders exploded and created fireballs, or were penetrated via shooting and created fire jets. The results from these tests were compared, focusing on the shooting procedure, then analyzed and discussed.
Fire models as a tool for evaluation of energy balance in burning space relating to building structures
(MDPI, 2022) Tomašková, Marianna; Pokorný, Jiří; Kučera, Petr; Balážiková, Michaela; Marasová, Daniela Jr.
Fire is defined as an extremely hazardous event, causing a threat to life and health of persons, but also damage to the economic sphere. It has been shown many times that fire can occur anywhere and at any time. In order to minimize the risk of fire manifestations, it is necessary to understand its course. In technical practice, computational models are used to determine the partial manifestations of fire, such as fire spread rate, smoke generation rate in the burning area, formation of toxic burning products, flame height, and others. One of the important characteristics is also the energy balance in the burning area relating to the character of burning material, access of oxygen necessary for exothermic reaction of burning, and reaction of the installed safety devices. In this paper we will point out the fire safety of the building. The FDS (Fire Dynamics Simulator) model is recently used in practice, and its advantage is the possibility to model fire even in large and atypical spaces. The contribution of this paper is the practical application of fire safety of construction using the FDS Model, to reduce the cost of fire safety for the structure being constructed. Attention was paid to evaluating how the heat energy that is released during a fire can be influenced by the installed stable fire-extinguishing equipment, taking into consideration the fire resistance of the building structures.
Experimental and empirical study for prediction of blast loads
(MDPI, 2022) Filice, Anselmo; Mynarz, Miroslav; Zinno, Raffaele
This paper presents the issue of determining the blast load on an engineering structure. In cases of industrial accidents or terrorist attacks, in many cases it is necessary to determine the necessary explosion parameters to determine the response of the structure, preferably in a simple and time-saving manner. In such a way, the empirical relationships can be used to estimate the selected parameters of the explosion load. Many empirical relationships have been derived in the past, but not all are suitable for different types of explosions. This article compares and validates experimentally determined selected explosion parameters for the chosen explosive with empirical relationships. For comparison, three already verified and frequently used calculation procedures (Kingery, Kinney, Henrych) and one newly derived procedure (PECH) were used. As part of the experimental measurements, blast wave explosion parameters for small charges were determined for near-field explosions. The general-purpose plastic explosive Semtex 10-SE was used for the experiments. The results of the comparative study presented in this article demonstrate the importance of taking these procedures into account for a reliable determination of the effects of blast actions on buildings.
Air pollution associated with total suspended particulate and particulate matter in cement grinding plant in Vietnam
(MDPI, 2021) Thai, Tinh; Bernatík, Aleš; Kučera, Petr
Air pollution associated with suspended particles has become a significant concern in Vietnam recently. The study aimed to (1) investigate dust sources; (2) measure concentration levels of Total Suspended Particulate (TSP), Particulate Matter (PM) fractions; (3) identify silica levels and the correlation with respirable particles at a cement grinding plant in Vietnam. A total of 312 samples (52 TSP, 160 PMs) at 13 processes were measured using the direct-reading dust meter. The silica composition was analyzed in a certified laboratory using the X-ray fluorescence (XRF) technique. SPSS version 26 for Window was used to analyze the data. The operations of the cement grinding plant created multiple dust sources from the jetty to the cement dispatch process. The TSP levels ranged 0.06-38.24 mg m(-3), and 40.38% (n = 21) TSP samples exceeded the Permissible Exposure Limit (PEL) for an 8-h working shift. Besides that, there was a wide range and significant concentration levels of PMs in the cement processes. The levels of PMs were PM1 (0.00-0.06 mg m(-3)), PM2.5 (0.01-0.83 mg m(-3)), PM4 (0.02-4.59 mg m(-3)), PM7 (0.03-16.94 mg m(-3)), and PM10 (0.04-26.85 mg m(-3)). The highest mean levels of PMs factions were measured at the pre-grinding process. The inefficient operation of the dust collector contributed a significant factor to the dust dispersion in this process. The silica's mean (SD) composition in respirable dust was 20.4% (0.86) and was not significantly different amongst the processes. There was a significant correlation between the levels of respirable dust and silica exposure in the cement grinding plant (r = 0.99). The improvement of indoor air quality is needed to prevent health effects on cement workers.
Influence of the pyrotechnic igniter composition aging on explosion parameters of dispersed dusts
(MDPI, 2021) Szabová, Zuzana; Kuracina, Richard; Sahul, Martin; Mynarz, Miroslav; Lepík, Petr; Kosár, László
A commercially available pyrotechnic igniter was used according to the EN 14034 and ASTM E1226a Standards to study the explosiveness of dispersed dusts. Its pyrotechnic composition consists of 1.2 g of zirconium (40% wt.), barium peroxide (30% wt.) and barium nitrate (30% wt.). The energy released during the combustion of that amount of composition is 5 kJ. The article investigates the influence of aging of the pyrotechnic composition in the igniter on its initiation parameters. In the study, igniters of different years from date of manufacture were used: Igniter 1, manufactured in 2021 (less than 1 year from date of manufacture), and Igniter 2 (more than 2 years from date of manufacture). The study was performed in the KV 150M2 explosion chamber with a volume of 365 L and the 20 L sphere chamber with a volume of 20 L. A standard sample of Lycopodium clavatum was used in the KV 150M2 explosion chamber. Magnesium and benzoic acid were used as the samples in the 20 L sphere explosion chamber. The experiment showed that the explosion pressure P-max of the igniter with more than 2 years from date of manufacture decreased by up to 10%, while the value of the explosion constant K-st decreased by up to 40%. The attained results proved that aging of igniters affects their explosion parameters and measurement accuracy.
Occupational exposure to nanoparticles originating from welding – case studies from the Czech Republic
(Nofer Institute of Occupational Medicine, 2021) Berger, Filip; Bernatíková, Šárka; Kocůrková, Lucie; Přichystalová, Radka; Schreiberová, Lenka
Background: Nanomaterials are virtually ubiquitous as they are created by both natural processes and human activities. The amount of occupational exposure to unintentionally released nanoparticles can, therefore, be substantial. The aim of the study was to determine the concentrations of incidental nanoparticles that workers can be exposed to during welding operations and to assess related health risks. The specific focus on welding operations was determined based on the fact that other case studies on the manufacturing industry confirm significant exposure to incidental nanoparticles during welding. In the Czech Republic, 92% of all industrial workers are employed in the manufacturing industry, where welding operations are amply represented. Material and Methods: The particle number concentrations of particles in the size range of 20-1000 nm and particle mass concentrations of inhalable and PM1 fractions were determined via measurements carried out at 15-minute intervals for each welding operation by static sampling in close proximity to the worker. Measurements were obtained using the following instruments: NanoScan SMPS 3910, Optical Particle Sizer OPS 3330, P-TRAK 8525 and DustTrak DRX 8534. The assessed operations were manual arc welding and automatic welding. Results: The observed average particle number concentrations for electric arc welders ranged 84x10(3)-176x10(3) #/cm(3), for welding machine operators 96x10(3)-147x10(3) #/cm(3), and for a welding locksmith the obtained average concentration was 179x10(3) #/cm(3). The determined average mass concentration of PM1 particles ranged 0.45-1.4 mg/m(3). Conclusions: Based on the conducted measurements, it was confirmed that there is a significant number of incidental nanoparticles released during welding operations in the manufacturing industry as a part of production and processing of metal products. The recommended occupational exposure limits for nanoparticle number concentrations were exceeded approximately 4-8 times for all assessed welding operations. The use of local exhaust ventilation in conjunction with personal protective equipment, including FFP2 or FFP3 particle filters, for welding is, therefore, recommended.
A new 365-litre dust explosion chamber: Design and testing
(Elsevier, 2021) Kuracina, Richard; Szabová, Zuzana; Bachratý, Michal; Mynarz, Miroslav; Škvarka, Marián
The explosions of combustible dusts pose a hazard in many industries. Several serious accidents have resulted in material damage, impaired environment, and the losses of human lives. Specific equipment has been developed to determine the explosive properties of dispersed dusts; their requirements are specified in EN 14034 and ASTM 1226 standards. These standards specify the use of the equipment in the volume of 1 m(3) and 20 L. This paper deals with redesigning and testing a detonation chamber for the study of dispersed dust. It presents technical solutions to redesigning the detonation chamber of KV 150M2 type to a new 365 L dust explosion chamber. The article describes the technical solution to the dispersing, control and timing system. Finally, comparative measurements in the redesigned detonation chamber with the commercially available 20 L sphere are described. The samples of lycopodium, hard coal, beech wood, magnesium and urotropin powders were used to compare the results.
Noise pollution and its correlations with occupational noise-induced hearing loss in cement plants in Vietnam
(MDPI, 2021) Thai, Tinh; Kučera, Petr; Bernatík, Aleš
Noise-Induced Hearing Loss (NIHL) is a global issue that is caused by many factors. The purpose of this study was to survey noise level to identify NIHL and its relationship with other factors in cement plants in Vietnam. Noise level was measured at one cement plant and three cement grinding stations located in the South of Vietnam. The audiometric data of exposed workers were surveyed to determine NIHL. Finally, the relationship between NIHL and noise level in cement plants was determined. The results show that noise level in almost all processes exceeded the permissible exposure limit (PEL). In this study, 42 cases (10% of exposed workers) with occupational NIHL were found with mean age (SD) of 49 (9.0) years. All NIHL cases were found in the departments in which the noise level exceeded the PEL, which included quarry (n = 16), maintenance (n = 12), production (n = 10), co-waste processing (n = 3) and quality assurance (n = 1). There was a positive and significant correlation between the NIHL and the excessive noise exposure in the cement plants (r = 0.89, p = 0.04).
Assessment of the readiness and resilience of Czech society against water-related crises
(MDPI, 2021) Kavan, Štěpán; Kročová, Šárka; Pokorný, Jiří
This assessment of societal readiness and resilience to water-related situations in the Czech Republic focuses on an interdisciplinary approach in the Czech Republic for solving this problem. The goal of the article is to evaluate and characterize the preparedness for handling water-related crises. The analysis is carried out via a SWOT analysis, which is a universal analytical method used to understand and interpret strengths and weaknesses and to identify opportunities and threats. For the calculation of the weight factor of the SWOT analysis, an assessment was determined based on the multicriteria analysis. The pair comparison method was used to determine the relative importance of the parameters of the strengths and weaknesses, opportunities and threats. The Fuller Triangle method was chosen for the system used to make the comparisons of the individual criteria. The uniqueness of the study consists of the issue of water management, which is thus reflected from a non-traditional perspective, being a contemporary model-the paradigm of the view on the preparedness of the planning documentation as one of the characteristics of societal resilience for water-related crises. The result of the research is the fact that a positive approach prevails in the researched area from the perspective of preparedness for water-related crises. For the creation of the conditions, the factors arising from the internal environment currently prevail slightly over those arising from the external environment.
Characterization of ultrafine particles and VOCs emitted from a 3D printer
(MDPI, 2021) Bernatíková, Šárka; Dudáček, Aleš; Přichystalová, Radka; Klečka, Vít; Kocůrková, Lucie
Currently, widely available three-dimensional (3D) printers are very popular with the schema_dspacedb. Previous research has shown that these printers can emit ultrafine particles (UFPs) and volatile organic compounds (VOCs). Several studies have examined the emissivity of filaments from 3D printing, except glycol modified polyethylene terephthalate (PETG) and styrene free co-polyester (NGEN) filaments. The aim of this study was to evaluate UFP and VOC emissions when printing using a commonly available 3D printer (ORIGINAL PRUSA i3 MK2 printer) using PETG and NGEN. The concentrations of UFPs were determined via measurements of particle number concentration and size distribution. A thermal analysis was carried out to ascertain whether signs of fiber decomposition would occur at printing temperatures. The total amount of VOCs was determined using a photoionization detector, and qualitatively analyzed via gas chromatography-mass spectrometry. The total particle concentrations were 3.88 x 10(10) particles for PETG and 6.01 x 10(9) particles for NGEN. VOCs at very low concentrations were detected in both filaments, namely ethylbenzene, toluene, and xylene. In addition, styrene was identified in PETG. On the basis of our results, we recommend conducting additional measurements, to more accurately quantify personal exposure to both UFPs and VOCs, focusing on longer exposure as it can be a source of potential cancer risk.
Technical infrastructure increasing resistance in the natural environment
(Polskie Towarzystwo Przeróbki Kopalin, 2020) Kročová, Šárka
The natural environment has its specific patterns that a human must take into account during realisation of any technical infrastructure of the world countries. Underestimating the dangers that can arise from natural phenomena has often serious consequences. For some constructions of technical infrastructure, especially their line constructions, there will be a high number of operational accidents with extremely negative impact on the supplied regions with energy or drinking water. Other types of technical infrastructure for example in nuclear power have a potential to create a natural emergency threaten the environment not only in the country of their dislocation but also in the long term to change living conditions in entire regions. The following article deals with this issue in a suffcient basic range suggests chat ways and means to recognize the threat of danger and then based on risk analysis to eliminate the consequences to an acceptable level.
Ablation of single-crystalline cesium iodide by extreme ultraviolet capillary-discharge laser
(Instytut chemii i techniki jadrowej, 2020) Wild, Jan; Pira, Peter; Burian, Tomáš; Vyšín, Luděk; Juha, Libor; Zelinger, Zdeněk; Daniš, Stanislav; Nehasil, Václav; Rafaj, Zdeněk; Nevrlý, Václav; Dostál, Michal; Bitala, Petr; Kudrna, Pavel; Tichý, Milan; Rocca, Jorge J.
Extreme ultraviolet (XUV) capillary-discharge lasers (CDLs) are a suitable source for the efficient, clean ablation of ionic crystals, which are obviously difficult to ablate with conventional, long-wavelength lasers. In the present study, a single crystal of cesium iodide (CsI) was irradiated by multiple, focused 1.5-ns pulses of 46.9-nm radiation delivered from a compact XUV-CDL device operated at either 2-Hz or 3-Hz repetition rates. The ablation rates were determined from the depth of the craters produced by the accumulation of laser pulses. Langmuir probes were used to diagnose the plasma plume produced by the focused XUV-CDL beam. Both the electron density and electron temperature were sufficiently high to confirm that ablation was the key process in the observed CsI removal. Moreover, a CsI thin film on MgO substrate was prepared by XUV pulsed laser deposition; a fraction of the film was detected by X-ray photoelectron spectroscopy.

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