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

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

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

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

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

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

Nowadays, due to using many rare metals in the most advanced technologies, the demand for these metals is increasing. Rare metals, however, mostly don’t show the property of creating their own mineral deposits, making their production more complicated. Some rare metals, e.g. gallium, germanium, indium and thallium usually accompany zinc ore. ...

By D. D. STANOJEVIĆ, M. B. RAJKOVIĆ, D. V. TOŠKOVIĆ, M. V. TOMIĆ

Investigations, conducted in this study showed that waste phosphogypsum-dihydrate represents a burden which even must not be kept in deposits because of its large quantity in relation to the main product – phosphoric acid, as well as because of great impact of a phosphogypsum deposit on the environment. By the proposed procedure, calcium-sulp...

By M. B. RAJKOVIĆ, D. V. TOŠKOVIĆ, D. D. STANOJEVIĆ, Č. LAČNJEVAC

Today, rotary dryers are often use to dry sawdust prior to their further processing, palletizing and briquetting, into commercially voluble product. This paper present mathematical model for drying process of sawdust particles in a triple pass rotary dryer. As basis for this model, we used existing mathematical models for drying of sawdust and othe...

By S. PAPUGA, P. PETROVIĆ, M. MAKSIMOVIĆ