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Belgrade, Serbia

Mladenovic G.,University of Belgrade | Cirilovic J.,Institute IMS | Queiroz C.,University of Belgrade
Transportation Research Record | Year: 2011

This paper presents the application of the World Bank's Road Network Evaluation Tools (RONET) model to strategic network-level analysis of the Serbian state low-volume road (LVR) network. This network condition deteriorated considerably during the 1990s as a result of the under-financing of its operations and maintenance. In recent years, financing for the road sector has gradually increased and focuses on the most hazardous and highly trafficked parts of the network. However, the overall budget allocated to the sector remains inadequate to maintain the entire state road network in stable condition. The goals of the presented study are to obtain the optimum maintenance and rehabilitation (M&R) strategy and related budget, estimate the impact of different funding levels on future quality, and estimate the economic consequences of budget constraints for the M&R of the LVR network. Application of the RONET model to the prevailing conditions on the Serbian LVR network led to an optimal M&R strategy with a good balance between rehabilitation and periodic and recurrent maintenance. Implementation of the optimal M&R strategy would cause major improvement compared with the current condition of the LVR network. Implementation of higher M&R standards would lead to substantially higher road agency costs and, consequently, lower net benefits, whereas the implementation of lower M&R standards would lead to considerably worse network condition for approximately the same or slightly lower agency costs. This situation means that even minor budget constraints would result in considerably worse network condition and much higher total road transport costs.

Atanasovska I.,Serbian Institute Kirilo Savic | Mitrovic R.,University of Belgrade | Momcilovic D.,Institute IMS | Subic A.,RMIT University
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science | Year: 2010

This research investigates the effects of the nominal load value on load distribution of simultaneously meshing gear teeth pairs, and on the involute gear load capacity. The research results presented in this article confirm that the nominal load value has a significant influence on the gear load capacity calculations. However, this influence is generally neglected in standard gear calculations, which can result in oversized gear dimensions. This can lead to inadequate gear designs in practice due to increased demand for reduced gear size and weight in modern machinery. The article provides a detailed description of the iterative numerical method developed in this research to support the modelling and analysis of load distribution in meshed gears using the finite-element method. © Authors 2010.

Slovic Z.,Key to Metals D.o.o. | Nedeljkovic L.,University of Belgrade | Raic K.,University of Belgrade | Odanovic Z.,Institute IMS
Kovove Materialy | Year: 2012

The correlations between the sulphide capacity and the optical basicity models available in literature are reviewed. The relationship between sulphide capacity and the optical basicity was investigated on plant data collected from the BOF plant in the temperature range of 1565- 1650°C. The goal of this work was to compare results given by applying common acceptable Young's, Sosinsky-Sommerville's, Tsao-Katayama's and Taniguchi's optical basicity as well as the KTH model for calculating the sulphide capacities. The present paper is focused on the thermodynamic aspect of sulphur refining CaO-Al 22 3-SiO 2-MgO ladle slag during LF ladle treatment. Thirty one heats were employed in the present study in real production conditions of low carbon steels.

Dobric J.,University of Zagreb | Markovic Z.,University of Zagreb | Budevac D.,University of Zagreb | Flajs Z.,Institute IMS
Gradjevinar | Year: 2015

Stainless steel has a number of features that define different behaviour of structural elements made of this material, as related to equivalent carbon steel elements. These properties, especially prominent in case of compression elements, are manifested through the nonlinear stress and strain relationship, pronounced influences of material hardening due to cold forming. Basic principles for the analysis of coldformed stainless steel compression elements, either included in modern technical regulations, or resulting from current research, are presented in this paper.

The sensitization degree of austenitic stainless steel welded joints was investigated by electrochemical methods of the double loop electrochemical potentiokinetic reactivation (DL EPR) in H2;SO4; + KSCN solution, and by the measurement of corrosion potential of the steel in the drop of the solution of HNO3; + FeCl3; + HCl. The welded joints were tested by X-ray radiographic method in order to check the presence of the weld defects. The grain sizes of the base metal and the welded joints were determined by optical microscopy. Good agreement between the results obtained by different electrochemical methods was obtained. The heat-affected zone (HAZ) of the austenitic stainless steel welded joints has shown a significant degree of sensitization. The double loop electrochemical potentiokinetic method gave quantitative evidence about the susceptibility of stainless steel to intergranular corrosion.

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