In this paper, starting from general tangent equation in arbitrary point of specified curve, using principles of differential geometry and given mathematical transformation tangent equation of polytrophic function in p – v diagram was obtained. This form is convenient for solving numerous practical and theoretical problems in engineering ther...

By B. Pejović, V. Mićić, M. Perušić, G. Tadić, S. Smiljanić

Mineral base oils are extracted from oil fractions of naphta that has boiling point of over 350 °C, and contain different kinds of carbohydrates and hetero-compunds. Removal of unwanted compunds from mineral base oils in domestic rafineries is made by rafination of imported commercial clays. For ther eventual replacement there has been conducte...

By Z. R. Petrović, P. T. Dugić, V. M. Aleksić, Lj. C. Vasiljević, T. T. Botić

Most commonly, all reforms of curriculum and study programmes in the educational system of Chemical Engineering are based on knowledge integration and developing tools which are designed to help students acquire a global picture of their professional calling. Therefore, this reform, which is the most comprehensive so far, and which was caused by th...

By M. Jotanović, G. Tadić

The effect different deposition regimes (constant and reversing currents), on the powdered copper electrodeposits morphology were investigated. The morphology of electrodeposited copper powder was investigated using a scanning electron microscope (SEM). The effect of the current amplitude, cathodic to anodic time ratio and period of the current wav...

By M. G. Pavlović, M. V. Tomić, Lj. Pavlović, V. Maksimović, N. D. Nikolić

Main objective of this paper is feasibility of alumina cement production on the Republic of Srpska resources basis. As is known calcium-alumina cement is type of mineral hydraulic binder. As basic resources of CAC production are used bauxite and calcite. There are two main production processes: the fusion, Al2O3 less than 50% and the sintering...

By M. Perušić, D. Lazić, Z. Obrenović, G. Ostojić

Methodological approach of identification and quantification of corrosion damages of the steel tubes which use for casing the well in petroleum industry are presented in the paper. A description and consequence of steel corrosion of casing steel tubes with examples from experience were also analyzed. Initiate steps with the aim to prevent these phe...

By V. Aleksić

This paper presents the results of authors' laboratory testing of the influence of steel fibers as fiber reinforcement on the change of properties of cement composite mortar and concrete type materials.Mixtures adopted - compositions of mortars had identical amounts of components: cement, sand and silica fume. The second type of mortar contained 60...

By D. Lj. Jevtić, D. M. Zakić, A. R. Savić

Starting from the Fourier's law for stationary heat transfer and Ohm's law for DC through the resistor, the paper presents the analogy between thermodynamic and electrical quantities. Based on this analogy, has been used knowledge of circuit theory for of the heat transfer through walls in the multilayer characteristic positions to derive the schem...

By B. Pejović, M. Perušić, D. Vujadinović, D. Đorđić

Increase of ecological awareness affected the realization of more strict laws concerning the environment, which are being imposed in many countries. It also affected lubricant area and tendency for decreased pollution that lubricants can induce if they are uncontrollably spread around. Earlier it was believed that biodegradability is the most impor...

By M. Dugić, P. Dugić, R. Macura

Synthetic sea water has been taken as a referential sample, in which Mg(OH)2 had been sedimented, in order to reduce biological effects and confirm reproducibility of results of the familiar composition sample. The synthetic sea water was prepared according to the scientifically developed procedure. Flotation experiments were performed in the ...

By M. Maksimović, Lj. Vukić, Đ. Vojinović, J. Mandić