78 research outputs found
Influence of the geology of coal deposits on their extraction and urbanistic development: a case study of Petrvald (Czech part of the Upper Silesian Basin)
Petrvald is a typical mining town in the Czech part of the Upper Silesian Basin. Since the Petrvald sub-basin is limited by significant tectonic structures, its development was to a great extent independent from other areas of the basin and can serve as an example of the influence of the geological structure on the development of mining and residential communities. In the first phase of mining development (ca 1830 to 1844) first claims begin to occur in the area. Thick coal seams were available in shallow depths. Due to missing railway connection, the demand for coal was not very large and the village economy was focused on agriculture. In the second phase (1844 to 1871), the first underground mines start to operate in the area. They were situated in favorable areas with thin overburden. Also, the connection to the railway improved the sale opportunities and a significant share of the local population worked in the mines. The third phase of mining (1871 to 1963) brought still increasing demand for coal, which resulted in establishing new coal mines in geologically less favorable areas (thicker overburden, water-bearing horizons). From the 1930s to the end of the 1950s the extraction peaked, which coincided with the urbanistic and cultural climax. New housing was provided for miners and their families by the companies. The final stage of mining development (1963 to 1998) is connected with the steady decline of production and phase-out of mining. The reason was a lack of economically recoverable coal reserves connected to unfavorable geological conditions. We conclude that the results of studies concerning specific geological parameters of coal deposits can be used for more detailed analyses regarding the development of urbanism, or to explain its causes.Web of Science362392
Analysis and Demonstration of Selected Network Attacks
Cílem bakalářské práce je popsat a v reálném prostředí provést vybrané síťové útoky, které se vyučují na FIT VUT v Brně. K útokům jsou vytvořeny demonstrační úlohy tak, aby je bylo možné využít při výuce bezpečnosti počítačových sítí. První část práce se zabývá teorií k jednotlivým útokům a možnými bezpečnostními řešeními. Ve druhé části jsou pak popsány praktické implementace každého útoku.The aim of this Bachelor thesis is to describe and realize selected network attacks which are taught at the FIT, Brno University of Technology. The thesis includes demonstration exercises that can be used for teaching computer network security. First part of this work discusses theory for each attack and possible security solutions. In the second part the practical realizations (for each network attack) are described.
Visualization of literary periodicum Perutě
Katedra žurnalistikyDepartment of JournalismFakulta sociálních vědFaculty of Social Science
Computer Identification Using Time Information
Tato práce se zabývá problematikou vzdálené identifikace počítače. Využívá k tomu časová razítka TCP získaná od sledovaného počítače. Z těchto razítek je možné určit posun vnitřních hodin sledovaného počítače. Tento posun je pro každý počítač jedinečný. Výsledek identifikace není ovlivněn lokací sledovaného počítače, síťovou adresou ani způsobem připojení. Díky využití pasivního odposlechu je tato identifikace pro sledovaný počítač neviditelná. Předpokladem úspěšného rozpoznání je možnost sledujícího počítače zachytit síťovou komunikaci od sledovaného počítače. Tato komunikace musí probíhat nad protokolem TCP a pakety musí ve svých hlavičkách obsahovat časová razítka.This work deals with the identification of a remote computer by monitoring TCP timestamps of the tracked device. It is possible to determine computer's clock skew from these timestamps as the clock skew is unique for every device. We are able to differentiate devices even though they have changed location, network address or connection type. Passive data capturing ensures that the identification process is invisible to the fingerprinted computer. It is necessary that the network communication of fingerprinted computer is visible to the observing device. We are able to utilise only TCP traffic with timestamps enabled.
The northernmost occurrence of the Lower Berriasian ammonite Pseudosubplanites grandis (Stramberk Limestone, Outer Western Carpathians, Czech Republic)
The first finding of the index ammonite Pseudosubplanites grandis (Mazenot, 1939) in the Lower Berriasian
Štramberk Limestone (Outer Western Carpathians, northeastern Czech Republic) is important from the point of view of
both the paleogeographical distribution of this species and of more precisely defining the upper boundary of the Štramberk
Limestone (Early Berriasian Berriasella jacobi Zone) formerly regarded as Late Tithonian in age. From the taxonomical
point of view, new data on a non-deformed cross-section of the adult whorl and above all on the shape of the adult
suture line of this species have been obtained.Web of Science64646646
Electricity generation in India: Present state, future outlook and policy implications
India is one of the fastest developing countries in the world. To sustain this growth, energy and electricity demands will increase. In 2015, of the 1337 TWh produced, 916 TWh were from fossil fuels. We prepared several models of electricity demand from 2015 to 2030, based on publicly available datasets and trends. Models were tested on data from previous years and adjusted accordingly. From several scenarios, we decided to introduce two possibilities, i.e., a scenario using high energy savings in all sectors, and a scenario counting on a high industrial growth not supported by an equal increase of electricity savings. For both cases we prepared models for extreme situations: (1) where coal- and lignite-based power plants are preferred after slow-down of a renewable energy boom, and (2) with high utilization of renewable energy supported by natural gas and nuclear energy. With GDP and population increasing at the same rate as in previous years, the unambiguous result in all scenarios is a 2 to 3-fold increase of the electricity demand by 2030. On the electricity production side, all scenarios stress the role of coal, renewables and nuclear sources. Both energy and climate policies should be prepared for such a development in advance.Web of Science127art. no. 136
High specific activity of radium isotopes in baryte from the Czech part of the Upper Silesian Basin- An example of spontaneous mine water treatment
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.Web of Science102art. no. 10
Coal-bearing capacity of the Petřkovice Member (Ostrava Formation, Serpukhovian, Mississippian) of the Upper Silesian Basin (Czech Republic and Poland)
The Petrkovice Member is the basal unit of the paralic succession of the Ostrava Formation of the Upper Silesian Basin. This member is a valuable source of information about the transition from a marine basin filled with siliciclastic sediments into a paralic basin with the beginning of coal-bearing sedimentation. Models of: (1) the number of coal seams, (2) their total thickness, and (3) the coal content with respect to the total thickness of the succession were created to describe and assess the coal-bearing capacity of the Petrkovice Member. The authors present models for coal seam thicknesses exceeding either 10 or 40 cm. The coal-bearing capacity of the Petfkovice Member is very low. The average share of coal seams thicker than 0.1 m is 3%. The share of coal seams with a thickness that exceeds 0.4 m is only 1.66%. Moreover, in large areas of the basin, in the N and NE parts, the coal-bearing capacity is close to zero, because coal seams of greater thickness were detected only locally there. Based on these models and on other geological data, it is obvious that the onset of coal sedimentation was gradual and limited to particular sites showing the greatest subsidence of the basin floor. In places where minor subsidence took place, there were likely unfavorable conditions for accumulation of organic matter.Web of Science60364963
Genetic aspects of barite mineralization related to rocks of the teschenite association in the Silesian Unit, Outer Western Carpathians, Czech Republic
Barite is a relatively uncommon phase in vein and amygdule mineralizations hosted by igneous rocks of the teschenite association in the Silesian Unit (Western Carpathians). In macroscopically observable sizes, it has been reported from 10 sites situated only in the Czech part of the Silesian Unit. Microscopic barite produced by the hydrothermal alteration of rock matrix and also by the supergene processes is more abundant. We examined four samples of barite by mineralogical and geochemical methods. Electron microprobe analyses proved pure barites with up to 0.038 apfu Sr and without remarkable internal zonation. Fluid inclusion and sulphur isotope data suggests that multiple sources of fluid components have been involved during barite crystallization. Barite contains primary and secondary aqueous all-liquid (L) or less frequent two-phase (L+V) aqueous fluid inclusions with variable salinity (0.4-2.9 wt. % NaCl eq.) and homogenization temperatures between 77 and 152 °C. The higher-salinity fluid endmember was probably Cretaceous seawater and the lower-salinity one was probably diagenetic water derived from surrounding flysch sediments during compaction and thermal alteration of clay minerals. The δ34S values of barite samples range between -1.0 ‰ and +16.4 ‰ CDT suggesting participation of two sources of sulphate, one with a near-zero δ34S values probably derived from wall rocks and another with high δ34S values being most probably sulphate from the Cretaceous seawater. All results underline the role of externally derived fluids during post-magmatic alteration of bodies of rock of the teschenite association.Web of Science68212911
Manganese-rich carbonate and phosphate concretions from the Subsilesian Unit of the Outer Western Carpathians (Czech Republic): Composition and unique selenium weathering products
This research focuses on two new occurrences of sedimentary concretions in the Subsilesian Unit of the Outer Western Carpathians (Czech Republic) from non-calcareous clays and claystones of the Paleocene to the Eocene age. Powder X-ray diffraction study proved heterogenous matrix, varying in content of siderite, Mn-rich siderite, Ca-rich rhodochrosite and fluorapatite. Electron microscopy revealed microsparitic carbonates with indistinct zoning. According to the geochemical and stable isotope clues the concretions originated in medium to highly reducting environment during early diagenesis. Stable isotope delta C-13 values (-11.3 and -4.8 parts per thousand PDB) and delta O-18 (1.8 and 1.0 parts per thousand PDB) correspond well to early diagenetic marine carbonates and part of the CO2 was derived from oxidation of biological material. Weathering of concretions has been on the surface and along fissures. While siderite-rich concretions produce goethite, rhodochmsite-rich concretions produce a cellular structure of todorokite, birnessite and buserite on rims of carbonate cores. Fissure mineralisation contains association of goethite accompanied by native selenium and clausthalite. The origin of the selenium minerals is interpreted as products on the redox barrier between Me2+/Mn4+ and/or Fe2+/Fe3+, where selenites and selenates are highly soluble but native selenium and selenides are extremely insoluble.Web of Science72216915
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