Selected parameters of quality and safety of herbal tea

The aim of this work was to assess the heavy metal presence and possible microbiological contamination in herbal teas. Evaluation of selected tea products was performed from Nitra locality during years 2009 - 2013. Microscopic filamentous fungi detection, bacteria such as Escherichia coli and Salmonella spp. were compared to requirements given in the Codex Alimentarius of Slovakia. The highest permissible limit for microscopic filamentous fungi was not exceeded (in 32 observed herbal tea samples). For incidence of Escherichia coli, 93 samples were investigated and for Salmonella spp., 91 herbal tea samples. No sample showed the presence of Salmonella spp., and at E. coli maximum permitted presence was detected below limit. Among chemical parameters, cadmium, lead and mercury content were monitored. The highest amount of lead and mercury was found in year 2012. In 2009, the highest cadmium content was found. The average content of lead in all 100 inspected herbal tea samples was 0.784 mg.kg-1 so all the samples met requirements defined in the legislation. The mean content of mercury (98 investigated herbal tea samples) was 0.0161 mg.kg-1 so all samples met the requirements as well. Average cadmium content was 0.1702 mg.kg-1 while the highest permitted limit for cadmium is 1.0 mg.kg-1. All herbal tea samples were in accordance with the legislation except one (white willow bark tea) with a very high content of cadmium (4.36 mg.kg-1)

The prevalence of Salmonella infections in laying hen flocks producing eggs and their impact on the public health

Since 2008, Slovakia has implemented the National control program of Salmonella infections in laying hen flocks. This program requires the farm operators to monitor and investigate the invasive types of Salmonella (S. Enteritidis and S. Typhimurium) according to STN ISO 6579. The aim of this study was to perform a microbiological examination of dust and chicken droppings samples of laying hens in the Trenčín region for the presence of Salmonella by Horizontal method according to STN ISO 6579: 2002, to compare results with the statistics across Slovakia and selected EU countries and to evaluate the impact of official controls of salmonellosis in animals and humans.  In the years 2009 - 2013 in the Trenčín region, 730 samples of dust from the conveyor belts and droppings of laying hens were taken to determine the prevalence of Salmonella in individual rearings. In these years, the incidence of positive samples was found from 0% to 29.17%. For the period from 2009 till 2013 was reported 22833 salmonellosis cases in human population of Slovakia, while in the Trenčín region it was 2636. Five-year EU-trend (2009 - 2013) showed a statistically significant decrease of salmonellosis occurence (with a mean reduction of 12% per year). The Wilcoxon signed-rank test was performed in order to provide in-depth epidemiological assessment of salmonellosis cases in Trenčin region in relation to selected characters: etiological agens, transmission mechanism, age, location as well as seasonality of infection

RENEWABLE ENERGY SOURCES IN THEIR SOCIOECONOMIC CONTEXT: PROSPECTS FOR THE TRANSFORMATION OF THE GLOBAL ENERGY LANDSCAPE, A BIBLIOMETRIC ANALYSIS

Focusing on renewable energy sources (RES), this article examines their comprehensive impact on society and the economy. This publication goes beyond traditional approaches by introducing bibliometric analysis using CiteSpace. By identifying key research trends in the scientific literature, it contributes to a better understanding of areas of research interest in the field of renewable energy. Bibliometric analysis serves to systematize knowledge and identify the main research trends – a valuable contribution to the development of this important field of science. As a research tool, it highlights the dynamics and evolution of the field of renewable energy research; this can support the further development of this important branch of science and serve as a platform for identifying potential areas for further research and practical activities. Through a detailed analysis of trends in the scientific literature, the article contributes to a deeper understanding of areas of interest in the field of renewable energy. The results are a valuable starting point for future scientific research and practical initiatives, supporting the development of this key field

Research And Practice: Quantification Of Raw And Heat-Treated Cow Milk in Sheep Milk, Cheese And Bryndza By ELISA Method

The aim of this study was to test the reliability of commercial ELISA tests (RC-bovino) within raw and heat treated cow milk detection in sheep milk and cheese in order to obtain a high-quality, reliable and economically beneficial method suitable for routine application in practice. These tests were subsequently used for quantification of cow milk in commercial "Bryndza". Raw sheep milk, cow milk and heat-treated cow milk (pasteurisation at 72 °C for 15 sec or at 85 °C for 3 sec) were mixed in precisely defined proportions (0 - 100% cow milk in sheep milk). The milk mixtures were sampled to detect adulteration and subsequently cheese was made. By ELISA tests was possible to determine these amounts of raw cow milk in sheep milk: 0.5% (0.2%), 5 % (4.81%), 50% (42.08%) and 75% (56.52%). The pasteurized samples in different combinations gave lower optical density responses than those prepared from raw milk (by approximately 60%). In context with the above mentioned, the relationship between the real and detected amount of cow milk (%) in different production stages (milk, cheese) using a regression analysis was examined. However, a lower reliability of the detection was indicated by R2 values, which ranged from 0.4058 (cheese) to 0.5175 (milk). In practice this means that although individual percentage (%) of cow milk in the sample can be detected, but in the unknown sample it can not be clearly confirm whether the cow milk was raw or heat-treated. In this context, the results can be inaccurate and may not correspond to the real situation. Within monitoring phase of this research, 9 samples of bryndza were analysed with the results of detected cow milk ranged from 11.56% to 14.3%. The obtained results confirm that the appropriate selection of ELISA tests can become an important factor in the setting of analytical capabilities for the detection of milk and cheese adulteration

Hydrological hazards assessment and management in Slovakia

One of the purpose of Water Framework Directive (WFD) (2000/60/EC) is to contribute to mitigating the effects of floods and droughts – hydrological hazards occurring nowdays more often in river basins. Effective water management, as required by the WFD, helps Member States prepare for extreme weather events which, due to climate change, are becoming more frequent and cause tremendous damages. The study of climatological data is performed with goal to reduce impacts of droughts and floods and thus to ensure sustainable and proper water resources management. Based on the precipitation time series obtained from Slovak Hydrometeorological Institute at a number of climatic stations over a considerable span of time a comprehensive analysis for the entire Slovakia is being carried out. Some of methods applied as well as some of the results achieved are briefly mentioned in this paper, namely (i) trend analysis applied to precipitation time series, (ii) the temporal and spatial evolution of climatological hazards in the area, and (iii) proposal of hazard mitigation measures. It is found increasing trends in precipitation time series in the most of stations in Slovakia, although it is also proved that the droughts are recurrent in Slovakia. The paper identifies climatological extremity in the country that significantly influences water resources management. It presents actual measures for proper water management in river basins aimed to mitigation of hydrological risks

Using fractal analysis in modeling the dynamics of forest areas and economic impact assessment:Maramureș County, Romania, as a case study

This study uses fractal analysis to quantify the spatial changes of forest resources caused by an increase of deforested areas. The method introduced contributes to the evaluation of forest resources being under significant pressure from anthropogenic activities. The pressure on the forest resources has been analyzed for Maramureș County, one of the most deforested counties in Romania. In order to evaluate this, the deforested areas were calculated for the period of 2001–2014, by using the Global Forest Change 2000–2014 database. The Fractal Fragmentation Index (FFI) and Fixed Grid 2D Lacunarity (FG2DL) were used to quantify the degree of fragmentation and dispersion of the forested areas, and thereby the extent to which a forest area is affected by deforestation. The process of quantifying the pressure on forested areas included the creation of a database for the period of 2000–2014 containing economic activities (turnover) related to woody recourses, important indicators of forest exploitation. Taken together, the results obtained indicate a dramatic increase in deforested areas (over 19,122 ha in total for the period of analysis), in Maramureș County

Modelling of Erosion and Transport Processes

Erosion phenomena are the result of complicated natural processes. The determination of their course, their mathematical expression, and predicting erosion phenomena of certain intensities is an important hydrological problem. To obtain a solution, it is necessary to evaluate the erosion factors in detail, which act by the origin and course of erosion processes, to analyse their influences, and to apply correct conclusions to their complex activity on this basis. Dimensional analysis is a conceptual tool often applied in engineering to understand physical situations involving a mix of different kinds of physical quantities. It is routinely used by physical scientists and engineers to check the plausibility of derived equations and computations. It is also used to form reasonable hypotheses about complex physical situations that can be tested by experiment or by more developed theories of the phenomena. In this paper, the dimensional analysis is used for the modelling of erosion and transport processes

Dynamic Analysis of Meteorological Parameters in Košice Climatic Station in Slovakia

Evaporation and precipitation are often considered the most important processes in the water cycle. Recent studies have turned to chaotic analysis and short-term prediction for analyzing and forecasting the time series of such phenomena. However, even with chaos theory, the accurate forecasting of pan evaporation is not a straightforward business, as it involves a number of variables whose changes directly and/or indirectly affect the scale and amount of pan evaporation. In this study, the use of the false nearest neighbour method for the chaotic analysis of pan evaporation and related metrological parameters is discussed. A literature review is presented on chaos theory and its applications in modelling physical systems. Also, a review of the literature on multivariate analysis and the presence of chaos in meteorology are presented. A detailed procedure for finding the presence of chaos in a time series using false nearest neighbour (FNN) is discussed. The possible lag time to be considered in the FNN analysis is estimated using the autocorrelation function (ACF) and average mutual information (AMI) apart from the time-step of the measurement. Thus, FNN is studied with three different lag times of the time series. Six meteorological parameters: average temperature, relative humidity, wind speed, sunshine hours, dew point temperature, and pan evaporation are measured at the observation station Kosice in Slovakia for a period of 20 years. Thus, the available time series are analysed using ACF, AMI, and FNN methods, and the results obtained are analysed in the study. Nonlinear behaviour is seen in all of the observed parameters. Pan evaporation, average temperature, and dew point temperature are found to exhibit clear chaotic behaviour, while relative humidity, sunshine hours, and wind speed show stochastic behaviour

An Analysis of the Effectiveness of Two Rainwater Harvesting Systems Located in Central Eastern Europe

Decentralized water systems are perceived as solutions that not only save water, but also as a way to partially or completely become independent from centralized suppliers. Taking this into account, an analysis of the effectiveness of rainwater harvesting systems (RWHS) for toilet flushing in existing academic facilities located in Poland and in Slovakia was carried out. The tests took into account the different volumes of storage tanks collecting rainwater. On the basis of two financial ratios, namely Net Present Value and Discounted Payback Period, the profitability of these systems was also assessed. The research was extended by the sensitivity analysis, which allowed determination of the impact of changes in individual cost components on the financial effectiveness of the investments considered. The results obtained clearly showed that the implementation of RWHS in the dormitory in Rzeszów was unprofitable for all tank capacities tested, and the payback period significantly exceeded the period of 30 years accepted for the analysis. Completely different results were obtained for RWHS in a dormitory located in the city of Košice, for which the financial ratios NPV (Net Present Value) and DPP (Discounted Payback Period) were very favorable. It was also confirmed by the results of the sensitivity analysis. The use of rainwater for toilet flushing caused that it was possible to achieve water savings of an average of 29% and 18%, respectively, for facilities located in Slovakia and Poland. The results of the research have a practical aspect and can provide an indication for potential investors and managers of academic facilities, similar to those analyzed in the article. Taking into account that in many countries water and sewage rates are significantly higher than in Poland and Slovakia, the cost-effectiveness of using the analyzed installation options in these countries could be even higher

The HEC RAS model of regulated stream for purposes of flood risk reduction

The work highlights the modeling of water flow in open channels using 1D mathematical model HEC-RAS in the area of interest Lopuchov village in eastern Slovakia. We created a digital model from a geodetic survey, which was used to show the area of inundation in ArcGIS software. We point out the modeling methodology with emphasis to collection of the data and their relevance for determination of boundary conditions in 3D model of the study area in GIS platform. The BIM objects can be exported to the defined model of the area. The obtained results were used for simulation of flooding. The results give to us clearly and distinctly defined areas of inundation, which we used in the processing of Cost benefit analysis. We used the developed model for stating the potential damages in flood vulnerable areas