The aim of this study was the investigation of water, sediments and fi sh tissues contamination with heavy metals. All samples were taken from the Danube River in Belgrade region, a location upstream from Batajnica. Concentrations of Cd, Hg and Pb in water samples were not detected, while concentrations of Zn, Fe, Cu and As were in the range of 0.004 -0.330 mg L -1. Iron was the most deposited metal in sediment samples in contrast to water samples where all investigated metals were detected. For the purpose of heavy metals determination in fresh fi sh tissue, fi fteen samples of three different fi sh species, silver carp (Hypophthalmichthys molitrix), common carp (Cyprinus carpio) and wels catfi sh (Silurus glanis) were collected. Concentrations of Pb, Cd, As and Hg were determined in the digestive tract, liver and muscle by absorption spectroscopy. The highest concentration of Pb was in the digestive tract in all three fi sh species, ranging from 0.036 to 1.518 μg g -1 , while Cd was mostly deposited in the liver. Concentrations of As were in the range of 0.36 -0.73 μg g -1 in Hypophthalmichthys molitrix, 0.013 -0.18 μg g -1 in Cyprinus carpio and 0.003 -0.005 μg g -1 in Silurus glanis tissues, while the content of Hg was equal in all tested tissues of carp. Concentrations of all metals were found to be present in the fi sh samples at different levels, but these values are under the maximum residual levels prescribed by the European Union (EU) and the maximum allowed concentrations (MAC) for Serbia, so the fi sh meat is acceptable for the human consumption.
Peripheral pocket or contour milling in wood machining, using flat end milling tool, can be performed with different tool paths. Technology designers of multi axis CNC wood machining use their experience and intuition to choose some of the options offered by CAM systems that determine the final shape of tool path, thus the generated tool path largely depend on individual judgment. Minimum cutting force, maximum dynamic stability of the process and minimum tool wear are achieved, or some other technological requirements are met, by using optimal tool path. Tool path optimisation is based on analysis of possible tool paths and determination of cutting parameters which are dependable of chosen tool path and are affecting the main wood processing factors. Axial and radial depth of cut, engagement angle, feed and feed rate profile are identified as key parameters dependable of tool path, and their values and variations along the tool path influence the cutting speed, tool wear and cutting force. Knowledge of values and changes of those key machining parameters along the tool path is necessary for simulation and monitoring of the main cutting factors during the wood machining process. NC code transformation methodology and generation of tool path parameters necessary for calculating all elements needed for tool movement simulation from given NC programs are shown. Blank and tool mathematical description are used with tool movement information for simulation of wood machining process. Simulation of cutting parameters and their variation along the tool path, presented in this paper, can be used as bases for development of methodology for choosing the most adequate tool path for wood machining of given contour considering minimum cutting force and cutting force variation, minimum tool wear, maximum productivity or some other criteria.
Challenges to Sustainable Development in Island Tourism Every participant in the life of a local community, hence the local community of the island of Krk as well, must develop an awareness of how they can cooperate in the improvement of quality, environmental protection and safety. This awareness can be achieved through constant education, and the improvement and perfection of all the destination factors for the island of Krk. With the preventive measures of environmental protection and optimal resources usage in the construction projects and management of the island of Krk, as well as waste management practices (the system known as "The Eco Island of Krk"), the island of Krk has to become an example, aware of its responsibility for future generations and the need for sustainable development. Open communication and partner relations with the social community and all interested parties, primarily those related to environmental protection and tourist and visitor safety, must be main factors in the future sustainable development of the island. The adoption of an environmental management system as one of the strategic baselines of the sustainable development of the island provides it with a comparative advantage on the tourism market, thus defining it as an "eco island" with the fulfillment of all legal and other obligations, and satisfying the demands of tourists, the local community and the public, all with the goal of more successful environmental protection.
Purposethis paper presents the importance and necessity of measuring satisfaction of website users with the texts presenting the Croatian gastronomic offer, and their experienced sentiments during and after browsing. The goal is to determine the influence of these texts on successful decision-making process when choosing Croatia as a gastronomic holiday destination. Methodologythe empirical research was done in February 2019 using a structured questionnaire which was distributed online. The acquired data was analyzed using the SPSS 21 Statistical package. The authors used Cronbach Alpha Coefficient to test the questionnaire validity, as well as Pearson´s Coefficient of Correlation, and T-Test and Levene´s Test for Equality for variances. Findings -By using Pearson´s Coefficient of Correlation a positive correlation had been determined indicating that the growth of satisfaction of website users with the texts will result in experiencing positive sentiments towards Croatia as destination. No that no statistically significant difference has been determined for satisfaction in relation to their monthly income. By using Ttest and Levene´s Test for Equality of Variances a statistically significant difference for sentiments has been determing in relation to the respondent´s gender. A a statistically significant difference has been determined for positive sentiments in relation to the respondent´s gender, which was not the case for satisfaction and gender. Contribution -The results enable better understanding of where to focus in text improvements (its quality, diversity, etc.). The main goal has to be better success in tourist offer promotion, and positive decision when choosing Croatia as a holiday destination.
The purpose – It is important to emphasize that liquidity on Croatian stock market is low, the purpose of this paper is to test empirically and find out which variables make crucial role in decision making process of investing in stocks. Design – This paper explores the impact of various liquidity variables on liquidity ratio since it is still insufficiently researched topic. Methodology –This research uses secondary and primary data available from Croatian stock market. Considering primary data this paper use daily data from Zagreb stock exchange for 196 stocks traded in one year, with the purpose of finding the key variables that make up some stocks more attractive to investors. Liquidity is measured with Amihud's liquidity ratio, which shows the amount of capital sufficient to change price by 1%. Approach – With more than 61.035 input data, using the method of multiple regression, this paper examined the influence of different variables on the stock liquidity on Croatian capital market. Findings – Key findings of this paper indicate that size of firm measured by market capitalization, number of issued stocks and achieved volume affects liquidity ratio. This paper uses multiple regression, and correlation matrix to show dependence among liquidity variables. There is strong correlation coefficient among liquidity variables and liquidity ratio, results are statistically significant. The originality of this research – The originality of this work rises from the obtained research results and the fact that this is first paper that studies problem of stock liquidity on Croatian capital market.
Abstract:The demand for city tourism product is growing on a daily basis. The specificity and uniqueness of its tourism resources enable creation of a unique tourism offer, for a city to become recognizable, and compete on the international tourism market. In the Republic of Croatia, one of the cities with a significant predisposition to become recognizable on the European and world level is the city of Rijeka. The purpose of the paper is to indicate importance of city tourism as a selective tourism form for the purpose of achieving competitiveness of the city of Rijeka and the Republic of Croatia on the tourism market, while the goal of the paper is to present theoretical characteristics of the city tourism offer, current tourism offer of the city of Rijeka with the use of statistical indicators and results of empirical research, and to propose possible developmental guidelines for upgrading its future tourism offer.
Republic of Serbia) 2 High technical mechanical school Trstenik (Republic of Serbia)Peripheral pocket or contour milling using flat end milling tool can be performed using different tool paths. This paper presents analysis of possible tool paths and determination of cutting parameters which are dependable of chosen tool path and variable along the tool path. Engagement angle is identified as key parameter dependable of tool path which variations during the process causes the variations of cutting force. Knowledge of changes in engagement angle along the tool path is necessary for simulation and monitoring the cutting force during the machining process. Special characteristics of tool paths for high speed milling (HSM) and new demands in tool path construction arising with development of HSM machining are presented in this paper.Simulation of cutting parameters and cutting force variation along the tool path, presented in this paper, can be used as bases for development of methodology for choosing the most adequate tool path for machining of given contour considering minimum cutting force and minimum cutting force variation.
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