Organic pollution in sediment-water systems on the Ratno Ostrvo location in Novi Sad, Serbia and Montenegro

ABSTRACT: Two-year (2001Two-year ( -2002 monitoring was conducted to determine residues of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides in sediment-water systems of three types of watercourses on the location of Ratno Ostrvo in Novi Sad (Serbia and Montenegro). Types of watercourses were established on the basis of the flow regime: drainage ditches with 1-2 m 3 /s (four sampling points), the DTD Canal with up to 10 m 3 /s (three sampling points) and the Danube River with 1500-3000 m 3 /s (five sampling points). Water quality was compared with the requirements given by the national and Dutch regulations, and the quality of sediment with the Dutch and Canadian quality guidelines, due to the lack of national legislaton. Based on the concentrations of organic pollutants in the samples of sediments and water from selected sampling points, average annual values were computed for the three types of watercourses. Great differences regarding the level of pollution between two years of monitoring were in smaller watercourses -drainage ditches and the DTD Canal, which might be a consequence of water flow, increased anthropogenic activity, decrease of self-purification potential. Concentrations of both PAHs and pesticides were below national maximum permissible levels in water and below Dutch intervention levels in sediment. Standard deviations of average annual concentrations were very high (up to 30-300%), probably because of the increased anthropogenic effect

The politics of performance: transnationalism and its limits in former Yugoslav popular music, 1999–2004

This paper examines transnational relations between the Yugoslav successor states from the point of view of popular music, and demonstrates how transnational musical figures (such as Djordje Balaševi?, Mom?ilo Bajagi?-Bajaga and Ceca Ražnatovi?) are interpreted as symbolic reference points in national ethnopolitical discourse in the process of identity construction. Another symbolic function is served by Serbian turbofolk artists, who in Croatia serve as a cultural resource to distance oneself from a musical genre associated by many urban Croats with the ruralization (and Herzegovinization) of Croatian city space. In addition, value judgements associated with both Serbian and Croatian newly composed folk music provide an insight into the transnational negotiation of conflicting identities in the ex-Yugoslav context. Ultimately the paper shows how the ethnonational boundaries established by nationalizing ideologies created separate cultural spaces which themselves have been transnationalized after Yugoslavia's disintegration

Microfacies and microfossils in Upper Jurassic limestones from Cheile Turenilor

In the Cheile Turenilor (Tureni Gorges) area, a carbonate succession about 150 m thick developed on top of island arc magmatites. It mainly consist of gravity - induced deposits (debris flows, mass flows and grain flows). Coral, sponges and stromatoporoid bioconstructions are associated. Microbolites play an important role, as binders of the intraclastic rudstones/ grainstones facies, as well as of the incorporated corals, sponges, stromatoporoids, bryozoans, molluscs

Microfacies and microfossils in upper Jurassic limestones from Cheile Turenilor

In the Cheile Turenilor (Tureni Gorges) area, a carbonate succession about 150 m thick developed on top of island arc magmatites. It mainly consist of gravity - induced deposits (debris flows, mass flows and grain flows). Coral, sponges and stromatoporoid bioconstructions are associated. Microbolites play an important role, as binders of the intraclastic rudstones/ grainstones facies, as well as of the incorporated corals, sponges, stromatoporoids, bryozoans, molluscs

Optimization of Surface Roughness Based on Turning Parameters and Insert Geometry

This study is focused on dry longitudinal turning of AISI steel using CVD coated cutting inserts. The machining was conducted at different levels of cutting speed, feed, depth of cut, corner radius, rake, inclination and approach angles. Surface roughness was measured after each experiment, and statistical analysis was used to derive an empirical, regression model for arithmetical mean surface roughness. The regression model was used to theoretically minimize surface roughness, followed by additional verification experiments. The 95 % confidence interval constructed using ten additional batteries of experiments, contained the theoretically predicted minimum roughness of Ra = 0.238 μm. The mean absolute prediction error of the optimal roughness equals 0.006 μm. The results reveal practical applicability of the developed model. (Received in March 2022, accepted in July 2022. This paper was with the authors 1 week for 1 revision.)

Modelling and prediction of surface roughness in cnc turning process using neural networks

© 2020, Strojarski Facultet. All rights reserved. The paper presents an approach to solving the problem of modelling and prediction of surface roughness in CNC turning process. In order to solve this problem an experiment was designed. Samples for experimental part of investigation were of dimensions Φ30 × 350 mm, and the sample material was GJS 500-7. Six cutting inserts were used for the designed experiment as well as variations of cutting speed, feed and depth of cut on CNC lathe DMG Moriseiki-CTX 310 Ecoline. After the conducted experiment, surface roughness of each sample was measured and a data set of 750 instances was formed. For data analysis, the Back-Propagation Neural Network (BPNN) algorithm was used. In modelling different BPNN architectures with characteristic features the results of RMS (Root Mean Square) error were controlled. Specially analysed were the RMS errors realised by different number of neurons in hidden layers. For the BPNN architecture with one hidden layer the architecture (4 – 8-1) was adopted with RMS error of 3,37%. In modelling the BPNN architecture with two hidden layers, a considerable amount of architectures was investigated. The adopted architecture with two hidden layers (4-2-10-1) generated the RMS error of 2,26%. The investigation was also directed at the size of the data set and controlling the level of RMS error

Optimization of Surface Roughness Based on turning parameters and insert geometry

This study is focused on dry longitudinal turning of AISI steel using CVD coated cutting inserts. The mashining was conducted at different levels of cutting speed, feed, depth of cut, corner radius, rake, inclination and approach angels