Chlorination is one of the most commonly used procedures for drinking waterdisinfection. The research aimed to soptimise the subsequent disinfection ofdrinking water with chlorine in the water supply ...network in the city Velenje,taking into account the applicable legislation. The gradual reduction of chlorinedosage was implemented with simultaneous monitoring of selected physico-chemical and microbiological parameters of drinking water. During the two-month period, 418 samples were taken at 22 previously defined differentsampling spots. Free chlorine values were reduced from the initial 0,18 mg/L tothe final 0,08 mg/L at the outlet, while values at some remote sampling sitesreached only 0,01 mg/L of free chlorine. Microbiological analyses of samplesshowed that the drinking water met the limit values in the regulations, despitethe low values of free chlorine. Based on the results, a modified chlorination ofdrinking water was introduced in the tested supply area, and the introduction ofa similar regime in other supply areas is being actively considered. In this way,we reduce the consumption of disinfectants and ensure the supply of qualityand healthy drinking water to consumers.
Microseismicity has long been a precursor for underground mining hazards such as rockbursts and coal and gas outbursts. In this research, a methodology combining deterministic stress and failure ...analysis and stochastic fracture slip evaluation, based upon the widely accepted fracture slip seismicity-generation mechanism, has been developed to simulate microseismic events induced by longwall mining. Using the built-in DFN facility in FLAC3D, discrete fractures following a power law size distribution are distributed throughout a 3D continuum model in a probabilistic way to account for the stochastic nature of microseismicity. The DFN-based modelling approach developed was adopted to simulate the evolution of microseismicity induced by the progressive face advance in a longwall top coal caving (LTCC) panel at Coal Mine Velenje, Slovenia. At each excavation step, global stress and failure analysis with reference to the strain-softening post-failure behaviour characteristic of coal, and fracture slip evaluation for microseismicity are conducted sequentially. The model findings are compared to the microseismic event data recorded during a long-term field monitoring campaign conducted at the same LTCC panel. It was found that the released energy and frequency-magnitude distribution of microseismicity are associated with the slipped fracture sizes and fracture size distribution. These features for recorded microseismic events were fairly constant until a xylite rich heterogeneous zone ahead of the working face was approached, which indicates that fractures within the extracted coal seam follow the same size distribution. The features obtained from modelled microseismic events were consistent over the production period, and matched well the field observations. Furthermore, the model results indicate that the power law fracture size distribution can be used to model longwall-mining-induced microseismicity. This model provides a unique prospective to understand longwall coal mining-induced microseismicity and lays a foundation to predict microseismicity, or even rockburst potential in specific geological realisations.
•A modelling approach has been developed to simulate longwall top coal caving coal mining-induced microseismicity.•DFN has been considered as the hypocentre to generate synthetic microseismicity.•The b value of microseismicity is associated with fracture size distribution within the coal seam.•The histogram of released energy of microseismicity is related to slipped fracture sizes and fracture size distribution.•The power law fracture size distribution can be used in longwall coal mining environments to simulate microseismicity.
Kroz prikaz povijesti plemićke obitelji Adamović Čepinski tekst
pridonosi poznavanju kulturne, gospodarske i političke povijesti prostora
današnje Hrvatske, ali i Slovenije, Srbije, Austrije te Bosne ...i Hercegovine. Adamovići
su početkom 18. stoljeća upravljali Valpovačkim vlastelinstvom, a potom u
Slavoniji i Podunavlju posjedovali imanja Čepin, Tenje, Aljmaš, Erdut, Bačko
Novo Selo. S vremenom se obitelj podijelila na čepinsku i tenjsku granu. U
tekstu se donose manje poznati podatci iz povijesti tenjske grane obitelji Adamović, koja je od sredine 19. stoljeća
posjedovala imanje sa sjedištem u Velenju (Slovenija), a obiteljskim vezama
bila u bliskim odnosima s brojnim plemićkim obiteljima Austro-Ugarske
Monarhije. Uz sintezu dosadašnjih publiciranih istraživanja, rad se temelji na
informacijama i arhivskom gradivu nasljednika ove obitelji koji su i danas
povezani s Hrvatskom.
The noble family of Adamović Čepinski was from the 18th century in possession of the Čepin, Tenje, Aljmaš and Erdut estates in Slavonia and
Podunavlje as well as of some estates in Bačka; over the course of time, it split into the Čepin and Tenje factions. This text provides less known and yet unexplored data on the history of the Tenje family faction which from the 19th century owned an estate that had its seat in
Velenje (Slovenia). They left significant traces in economic, cultural and political life and constituted a connection between present-day eastern Croatia and Slovenia at the time when these areas belonged to the Austro-Hungarian Monarchy, i.e. to the same constitutional and cultural circle. Although they sold the Tenje estate in the late 19th century, they remained connected to the estates in Erdut, Bačko Novo Selo and Ostrožac; after they sold Velenje, they continued to live there
up until World War II. They strengthened their social position additionally through marital ties between notable families the relations
of which reached to the Viennese Court, the Russian Imperial Court and the Court of Victorian England. A significant family bond was created with the politician and landlord Ervin Cseh de Szent-Katolna, the grand prefect of the Syrmia County. His stepson Ivan Albrecht Baron Adamović of Čepin was also prefect of the Syrmia and subsequently the Virovitica County. After World War II the family was deprived of all its estates in
then Yugoslavia; however, after decades in exile the heirs were able to
reclaim their estates in Croatia in part.
Uncontrolled and excessive gas emissions pose a serious threat to safety in underground coal mining. In a recently completed research project, a suite of monitoring techniques were employed to assess ...the dynamic response of the coal seam being mined to longwall face advance at Coal Mine Velenje in Slovenia. Together with continuous monitoring of gas emissions, two seismic tomography measurement campaigns and a microseismic monitoring programme were implemented at one longwall top coal caving panel. Over 2000 microseismic events were recorded during a period of four months. Over the same period, there also was a recorded episode of relatively high gas emission in the same longwall district. In this paper, a detailed analysis of the processed microseismic data collected during the same monitoring period is presented. Specifically, the analysis includes the spatial distribution of the microseismic events with respect to the longwall face advance, the magnitude of the energy released per week and its temporal evolution. Examination of the spatial distribution of the recorded microseismic events has shown that most of the microseismic activity occurred ahead of the advancing face. Furthermore, the analysis of the gas emission and microseismic monitoring data has suggested that there is a direct correlation between microseismicity and gas emission rate, and that gas emission rate tends to reach a peak when seismic energy increases dramatically. It is believed that localised stress concentration over a relatively strong xylite-rich zone and its eventual failure, which was also identified by the seismic tomography measurements, may have triggered the heightened microseismic activity and the excessive gas emission episode experienced at the longwall panel monitored.
•Over 2000 micro-seismic events were recorded at a longwall top coal caving panel.•The spatial distribution of microseismic events was evaluated against face advance.•An episode of increased gas emission was correlated with mining induced microseismic activities.•A zone with heterogeneous coal structure was successfully detected by seismic monitoring.
The application of multi-level longwall top coal caving mining method in ultra-thick coal seams generally yields a much higher productivity and is more efficient in comparison to a mechanised ...single-slice longwall panel. However, the greater productivity achieved by this mining method may further exacerbate the gas emission problems often faced in longwall mining. In order to establish a thorough understanding of gas pressure regimes, and gas emission patterns around a producing multi-level longwall top coal caving face, a suite of in-situ measurements on seam gas pressure, gas composition, and ventilation environment was conducted at Coal Mine Velenje in Slovenia. This paper focuses on the analysis of these field observations which helped develop a conceptual gas emission model for multi-level longwall top coal caving mining of ultra-thick coal seams. It has been found that, at Coal Mine Velenje, the coal zone within 40m ahead of the face can significantly contribute to the overall district gas emission. In addition, floor coal and roof goaf may both play a major role towards the total gas emitted during mining.
•The in situ pressure regimes and gas composition at different mining levels of an ultra-thick coal seam were monitored.•Gas pressure and composition response to face advance of the coal seam around a LTCC extraction have been evaluated.•A conceptual gas emission model for a longwall top coal caving panel was developed.
Mining-induced microseismicity is widely considered as a result of slippage of pre-existing critically stressed fractures caused by stress perturbations around an advancing face. An in-depth analysis ...of the recorded microseismicity associated with longwall top coal caving mining at Coal Mine Velenje in Slovenia has been previously carried out and reported by the authors. It has been concluded that while microseismic event rate is affected by mining intensity (longwall face daily advance rate) as well as local abundance of pre-existing fractures, spatial and magnitude characteristics of microseismicity are predominantly influenced by the latter. Based upon this improved understanding of fracture-slip seismic-generation mechanism, the current work aimed at establishing a data-driven yet physics-based probabilistic forecasting methodology for hazardous microseismicity using microseismic monitoring data with concurrent face advance records. Through performing statistical analyses and probability distribution fitting for temporal, magnitude and spatial characteristics of microseismicity within a time window, a short-term forecasting model is developed to estimate the probability of potentially hazardous microseismicity over the next time interval in the form of a joint probability. The real time forecasting of hazardous microseismicity during longwall coal mining is realised through regularly updating the statistical model using the most recent microseismic sequence datasets and face advance records. This forecasting methodology is featured by the physical basis which provides a good explicability of forecasting results, and the probabilistic perspective which accounts for the stochastic nature of mining-induced microseismicity. This model has been employed to make time-varying forecasts of hazardous microseismicity around two longwall panels over a one-year coal production period at Coal Mine Velenje, and satisfactory results at both panels were achieved. In addition, the analysis suggested that the energy magnitude distribution of microseismicity is a dominant factor in contributing to the potential of hazardous microseismicity. This statistical model using microseismic monitoring data has important implications in the evaluation of mining-induced hazards and optimal control of longwall face advance in burst-prone deep-level mining sites.
•A probabilistic model was proposed for evaluation of seismic hazard potential.•Time-varying forecasting of hazardous microseismicity was verified.•Local fracture attributes are reflected in recorded microseismicity.•Segmental stationary of seismicity shows spatial continuity of fracture attributes.
According to the economic indicators, Velenje has a successful, export-oriented economy with high added value per employee. But like all industrial cities in Europe, Velenje is very vulnerable. This ...book seeks to shed light on the aspects of Velenje's transformation in the past, present and future. The purpose of the book is to provide an overview of Velenje's developmental factors. Emphasis is placed on social, cultural, spatial, environmental, economic and other aspects of the city, as well as a critical evaluation of future development resources and their actions. The second emphasis is on the originality and specificity of certain activities and phenomena that contribute to greater creativity and resilience of Velenje. We present 16 diverse contributions to the book that critically evaluate the current and future developmental resources of Velenje and its surroundings. Articles in the book ('Velenje, an industrial city in transformation') are written by locals and experts working on the BRIGHT FUTURE project dealing with small industrial towns across Europe. Two main messages emerge from all the contributions: the importance of using our own (endogenous) development resources and a participatory way of making decisions in the future.
The longwall top coal caving method, which enables the most productive exploitation of thick/ultra-thick coal seams, may result in a distinct geomechanical response of strata and associated gas ...emission patterns around longwall layouts. A two-way sequential coupling of a geomechanical and a reservoir simulator for the modelling of gas emissions around a longwall top coal caving (LTCC) panels was developed building on the understanding established from the analysis of in-situ gas pressure and concentration measurements carried out at Coal Mine Velenje in Slovenia. Model findings have shown that the modelling method implemented can reproduce the dynamic changes of stresses and gas pressure around a LTCC face and predict the total gas emissions and mixed gas concentrations accurately. It was found that, in LTCC panels, although the rate of gas emission from mined coal depends highly on the coal face advance, floor coal and roof goaf act as a constant and steady gas source accounting for a considerable part of the overall gas emission. Research has shown that, at first and/or second mining levels of multi-level LTCC mining, a notable stress relief and pore pressure drop induced by fracturing of the mined and roof coal can be experienced within 40m ahead of the face-line. In the floor coal, on the other hand, the pore pressure change was found to extend to 20m below the mining horizon. Model results have clearly shown the permeability enhancement and gas mobilisation zones around the LTCC panel, which can be the target zones for gas drainage boreholes.
•A two-way sequential coupling approach between a geomechanical and a reservoir simulator was developed.•The model was applied to simulate gas emissions around a longwall top coal caving panel.•Gas emission zones around LTCC panels were successfully identified.
Three different lithotypes (xylitic, gelified and matrix) of Pliocene lignite from the Velenje Basin, Slovenia, were investigated to establish the variations of biomarker compositions in solvent ...extracts and the stable isotope (carbon and nitrogen) compositions of bulk material. From the biomarker results, the xylitic lithotype almost exclusively originates from gymnosperms (conifers such as Taxodiaceae), as indicated by the very high contents of sesquiterpenoids and diterpenoids but very low abundances of n-alkanes and non-hopanoid triterpenoids. The relative proportion of gymnosperms to angiosperms in the paleomire is reflected by the ratio of diterpenoids to the sum of diterpenoids and non-hopanoid triterpenoids (Di-/(Di-+Tri-terpenoids)), which is close to 1 (av. 0.99) in the xylitic lithotype. The predominance of diterpenoids from conifers in the xylitic lithotype is associated with high C/N ratios and intermediate total sulfur (TS). The very low abundance of hop-17(21)-ene and the absence of further hopanoids in the xylitic lithotype indicate a restricted influence of bacterial degradation under relatively dry conditions in the paleomire. The matrix lithotype also originated preferentially from gymnosperms under dry depositional conditions, as indicated by the high Di-/(Di-+Tri-terpenoids) ratio (0.95), low amounts of hopanoids and low TS content. The gelified lithotype is characterized by a high content of n-alkanes and wide variation of the Di-/(Di-+Tri-terpenoids) ratio (0.13–0.88), indicating a fluctuating contribution of angiosperms to the plant community in the paleomire during formation of this lithotype. In addition, the high abundance of hop-17(21)-ene and TS in the gelified lithotype compared with the other two lithotypes suggests the effect of bacterial activity under relatively wet/humid conditions during formation of the gelified lithotype, which is also supported by the considerable content of mid-chain n-alkanes.
The high correlation between the δ13C and δ15N values (R2 = 0.68) indicates that the stable carbon and nitrogen isotope composition in the Velenje lignites were probably influenced by the same factors (e.g. precursor plants and/or microbial activity). The stable carbon isotopic values (av. −25.44‰) and nitrogen isotopic values (av. 2.15‰) of the xylitic lithotype are higher than those of the gelified lithotype (av. δ13C = −27.48‰, δ15N = 1.37‰) and the matrix lithotype (av. δ13C = −27.09‰, δ15N = 1.10‰). The relatively high correlation between the diterpenoid content and both δ13C and δ15N values suggests that the stable carbon and nitrogen isotopic composition of the three lithotypes might reflect the composition of the original plant material in the paleomire. The dominance of conifers as precursor plants in the xylitic lithotype might be the main reason for the higher δ13C values and probably also the higher δ15N values. The relatively higher δ15N values in the xylitic lithotype than in the other types could be explained by the high amount of decay-resistant xylem and low mineral (e.g. clay) content in the xylitic lithotype. The slightly lower δ13C but higher δ15N values in the gelified lithotype than in the matrix lithotype can be explained by variation of parent plant materials and the influence of bacterial activity.
•Different lithotypes (xylitic, gelified and matrix) of Pliocene lignite from the Velenje Basin, Slovenia, were analyzed for biomarkers and stable isotope (C and N) compositions.•The ratio of diterpenoids/(diterpenoids + triterpenoids) reflects the relative proportions of gymnosperms and angiosperms.•Xylitic and matrix lithotypes originate from gymnosperms, while gelified lithotypes are characterized by a fluctuating contribution of angiosperms.•The highest δ13C and δ15N values were measured in xylitic lithotype samples.•The δ13C and δ15N composition is preferentially influenced by the composition of the precursor plants community.
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