Vojnotehnicki glasnik / Military Technical Courier

38-50

Authors: Grečihin Ivanovič Leonid

This paper developed a mathematical model of gas dynamic fluid flow for a flat plate during its movement with positive and negative angles of attack. It is shown that at low velocities, the lifting force and the frontal resistance are determined by gasdynamic air flow in the fluid flow exit areawhile at velocities close to the speed of sound the decisive role is played by a mutualeffect of the pplate coliding with molecules of the surrounding environment in the fluid flow incidence field. The airflow behind the plate does not appear at low velocities. The conditions when the frontal resistance and the lifting force change the sign are determined.

56-73

Authors: Janković Bojan Ž.

The kinetic study of the crystallization process of the α-Fe phase from the amorphous Fe81B13Si4C2 alloy was investigated by DSC and XRD techniques. The kinetic parameters (lnA, Ea) of the investigated process were determined using the Kissinger and isoconversional (model-free) methods. It was established that the α-Fe crystallization process can be described by the JMA (Johnson-Mehl-Avrami) kinetic equation. In accordance with the XRD analysis and the calculated crystallization parameters (n = 4; m = 3), it was concluded that the crystallization stages of the considered process can be described by the bulk nucleation and the three-dimensional (3D) growth of nuclei.

72-88

Authors: Ryabtsev Anatoliy D., Troyanskyy Oleksandr A., Pashynskyi Volodymyr V., Snizhko Olga A.

The paper presents the results of alloying titanium by oxygen in the process of chamber electroslag remelting. As an oxygen-containing ligature, we used the electrodes-satellite from the reaction mass residues mixture from the retort lid for magnesium thermal reduction of a titanium sponge, a specially prepared gaseous argon oxygen mixture containing 30% oxygen applied directly to the melting space, microsize (10-15 mm) powder particles of titanium oxide and titanium oxide nanopowder with a particle size of 21 ± 5 nm. The structure and the properties of titanium alloyed by oxygen from the oxygen-containing ligature, gas phase and titanium oxide powder during chamber electroslag remelting of the titanium sponge are investigated. It was found that at the oxygen content of 0.053%mas. to 0.22%mas. in the metal formed a homogeneous single-phase structure typical for commercial titanium formed by polyhedral grains of the α-phase. The increase of the oxygen concentration in titanium for more than 0.22%mas. leads to the formation of the microstructure with a typical needle structure, which allows it to be classified as the α ׳-phase.

104-119

Authors: Petreski Drage T., Iliev Andrej P., Gjurov Lazar M., Petreska Aleksandra D.

Logistics is a set of activities for planning and implementing the relocation of materials. Since sources of raw materials, factories and outlets are not usually in the same location it is therefore necessary to conduct a series of logistics activities for supplying products or services to end users. Logistics manages the flow of data from suppliers, movement of materials through various operations within the organization as well as the flow of materials to final customers. Integrating these logistics activities is performed through supply chains which provide opportunities for cost saving and offering better services to customers. The supply chains in the Macedonian Army are an important factor in the planning and implementation of logistics support.

141-154

Authors: Lukovac Vesko M., Pejčić-Tarle Snežana A., Popović Milena J., Pamučar Dragan S.

It is difficult to achieve rational engagement, directing and developing, motivating, rewarding, and improving organizational efficiency, without the evaluation of the quality of job performance of employees. In management literature, this technique is known as 'employee performance evaluation'. Performance or productivity may be either a measurable result that has been achieved, or behaviour or personal characteristics necessary for performing certain activities in a defined period of time. Recently, a special management approach 'performance management' has been developed, in order to integrate the performance evaluation and the use of assessment results in management, aimed at improving performance. Since the employee performance evaluation is most often the result of subjective judgment of an evaluator about the quality of his/her work, one has to take into account possible errors that characterize such a way of judging. There are several types of errors that an evaluator can commit during the performance evaluation process, and in this paper, an approach to the identification and reduction of distribution errors of evaluators, most widely spread in organizations with a large number of employees, has been presented.

168-186

Authors: Arsić Slaviša N.

The process of professionalisation of the Serbian Army has caused qualitative and quantitative changes in the personnel structure and has led to the reduction in the numerical strength of its members. The restaurant at the Military Academy has faced infrastructural and organisational ballasts in its capacity for food preparation and distribution thus making the Military Academy food system uneconomic. The capacities of the restaurant are designed to allow for the preparation and distribution of 40% more meals than the actual needs, which, in the economic context, places unnecessary financial burden on the limited amount of funds allocated for this purpose. In terms of economic principles, it is possible to reduce or completely eliminate the negative effects through employing redundant workforce or finding alternative ways to organise the food system at the Military academy in a more rational way. The article represents a 'pro et contra' analysis that places an emphasis on some relevant facts in finding expedient solutions. The food system at the Military Academy was analyzed through the causeeffect relations of the factors within and outside the system and through the efforts to improve the system functioning from organizational, economic, technological and nutrition security aspects, based on current scientific knowledge and domestic and foreign experience.

201-215

Authors: Tešanović Branko M., Jović Saša B.

An oven for baking bread in field conditions is assigned to units that are by their nature relatively stationary and whose size does not require a movable bakery. It is intended for baking bread in our units located in international missions with supply difficulties, since our units have a habit od consuming bread instead of biscuits. The oven is of a prefabricated type, adapted for use in all types of terrains, simple design which makes it possible to be, dismantled and easily transported.