Analysis of the development of small and medium enterprises in the agro-food system of Serbia

The importance of agriculture to the national economy and economic stability of Serbia is great considering the fact that it makes a substantial part of the Gross domestic product. At the same time, the abundance of natural resources in Serbia, favorable geographic and climatic conditions and skilled labor force are resources which can make the local agriculture more competitive in the global market. The sector of small and medium enterprises (SMEs) stands out as an important factor in the economic growth and development of the countries in transition. Due to its numerous advantages over the large enterprises, such enterprises can accelerate the process of transition, increase the investment rate and reduce unemployment rate which is usually very high in the developing countries. Economic development of our country is based to a certain extent on the development of the SME sector which has a particularly important role in the agribusiness sector. This paper aims to provide an analysis of the SME sector in Serbia with the special focus on the agro-food system and its characteristics in the agriculture and food industry. Strengthening this sector will mean better business conditions in the Serbian economy, and the measures taken within economic and agricultural policies should be aimed at fostering innovation and competitiveness of small and medium enterprises

Trade and EU accession: the case of Serbia

This paper analyzes the export competitiveness of Serbia vis-a-vis European Union and the possible trade effects of Serbian EU accession scenario. We have observed several macroeconomic variables for determining the etternal position of Serbia. The trade effects of Serbia’s EU accession scenario are evaluated using the partial equilibrium Global Simulation Model

SME sector as a growth factor of employment in Serbia

Unemployment is the biggest economic and social problem facing the economy of Serbia. Its chronic presence causes a decrease in gross domestic product (GDP) and undermines social stability and quality of life. Given the fact that numerous social, economic, demographic and political problems emerge as the results of its effects, tackling of high unemployment requires a combination of different policies and strategies. One of the ways to lower unemployment in Serbia is creation of a business environment that stimulates entrepreneurship development encouraging in such a way formation of small and medium-sized enterprises. Taking into account that potential of SME sector in Serbia is not fully used, the goal of this paper is to identify the main barriers that hinder the development of entrepreneurship and due to its great presence prevent more significant contribution of SMEs to employment growth

WEAR AND FRICTION PROPERTIES OF SHOT PEENED SURFACES OF 36CRNIMO4 AND 36NICRMO16 ALLOYED STEELS UNDER DRY AND LUBRICATED CONTACT CONDITIONS

Method of Shot peening is often used to increase static and dynamic strength of the work piece. This method can change the characteristics of the surface layer, and thus the tribological properties of such treated surfaces. The quality of the contact surfaces in tribological terms, refers to the roughness parameters and surface microgeometry. Conclusions, presented in this paper, are the result of numerous investigations of tribological behavior of shot peening surfaces in dry and lubricated contact conditions. As materials for tribological tests 36CrNiMo4 and 36NiCrMo16 alloy steels were used. The paper presents a comparative view of tribological behavior of materials under conditions with and without lubrication, as well as in terms of different values of normal load and sliding velocity. Tribological investigations showed that total effects of final machining by shot peening have positive influence on tribological behaviour of machined parts and that they can contribute to the improvement of tribological level of tribomechanical elements.Publishe

Wear Behaviour of Cr Hard Coatings for Cold Forming Tools Under Dry Sliding Conditions

Cr hard coatings are largely used in industry in metal cutting and cold forming processes; This work on quantitative way represents improvement, in terms of wear resistance, which is obtained by depositing Cr hard coating on foundation material. Wear testing is done on tribometer with block –on – disc contact geometry at sliding contact of Cr hard coated sample with steel disc. Testing was performed in conditions without lubrication at variable value of contact parameters (normal load, sliding speed). Cr hard coatings in all contact conditions show smaller values of wear rate.Publishe

Application of multicriteria optimization methods in the design of road embankments

Tokom projektiranja saobraćajnica, izdvajaju se nasipi kao najosjetljiviji dio sa aspekta obezbjeđivanja ekonomičnosti, sigurnosti i udobnosti, a na to utiču mnogi faktori: temeljno tlo nasipa, materijal od kojega se gradi nasip, visina podzemne vode, blizina rasjeda pri zemljotresu i dr. Ekonomičnost s jedne strane, i sigurnost i udobnost s druge strane, uvijek su u koliziji. Zbog toga je potrebno tražiti rješenje koje će na neki način zadovoljiti sve zahtjeve koji se postavljaju tokom projektiranja. Predmet istraživanja ovog članka je iznalaženje najboljeg (optimalnog) rješenja tokom projektiranja nasipa. Analizirani su kriteriji projektiranja nasipa prometnica i izvršena je njihova optimizacija. Prikazani su rezultati optimizacije nasipa, uzimajući u obzir kriterije za određivanje optimalnog rješenja (ekonomski kriteriji, kriteriji sigurnosti, prometni kriteriji, geološki te hidrogeološki kriteriji). Rezultati istraživanja su prikazani analitički i grafički.In the design of roads, embankments stand out as the most sensitive elements of design in terms of cost-effectiveness, safety and comfort, and are influenced by numerous factors: subsoil fill, embankment material, groundwater level, proximity of earthquake faults, etc. Cost-effectiveness on the one hand, and safety and comfort on the other, are always in conflict. A solution should therefore be sought to somehow satisfy all the demands placed during the design stage. The subject of this paper is to find the best (optimal) solution in the design of embankments. Criteria for the design of road embankments have been analysed and optimized. The results of embankment design optimization are shown taking into account criteria for determining the optimal solution (economic criteria, safety criteria, traffic criteria, geological and hydro-geological criteria). Research results are presented analytically and graphically

THE SURFACE RECOMBINATION VELOCITY AND BULK LIFETIME INFLUENCES ON PHOTOGENERATED EXCESS CARRIER DENSITY AND TEMPERATURE DISTRIBUTIONS IN N-TYPE SILICON

The temperature distributions in the n-type silicon circular plate, excited by a frequency-modulated light source from one side, are investigated theoretically in the frequency domain. The influence of the photogenerated excess carrier density on the temperature distributions is considered with respect to the sample thickness, surface quality and carrier lifetime. The presence of the thermalization and non-radiative recombination processes are taken into account. The existence of the fast and slow heat sources in the sample is recognized. It is shown that the temperature distribution on sample surfaces is a sensitive function of an excess carrier density under a bulk and surface recombination. The most favorable values of surface velocities ratio and bulk lifetime are established, assigned for a simpler and more effective analysis of the carrier influence in semiconductors. The photothermal and photoacoustic transmission detection configuration is proposed as a most suitable experimental scheme for the investigation of the excess carrier influence on the silicon surface temperatures

AFM surface roughness and topography analysis of lithium disilicate glass ceramic

The aim of this study is presenting AFM analysis of surface roughness of Lithium disilicate glass ceramic (IPS e.max CAD) under different finishing procedure (techniques): polishing, glazing and grinding. Lithium disilicate glass ceramics is all-ceramic dental system which is characterized by high aesthetic quality and it can be freely said that properties of material provide all prosthetic requirements: function, biocompatibility and aesthetic. Experimental tests of surface roughness were investigated on 4 samples with dimensions: 18 mm length, 14 mm width and 12 mm height. Contact surfaces of three samples were treated with different finishing procedure (polishing, glazing and grinding), and the contact surface of the raw material is investigated as a fourth sample. Experimental measurements were done using the Atomic Force Microscopy (AFM) of NT-MDT manufacturers, in the contact mode. All obtained results of different prepared samples are presented in the form of specific roughness parameters (Rа, Rz, Rmax, Rq) and 3D surface topography.Publishe

MICRO SCRATCH TEST CHARACTERISATION OF ZA-27/SiC NANOCOMPOSITES

In this study tribological properties of obtained nanocomposites were investigated using micro scratch tester. Tested nanocomposites were developed on well-known tribological ZA-27 alloy using compocasting technique. SiC nanoparticles (average size 50nm) in different volume fraction were used as reinforcement. Main scratch test results were coefficient of friction, penetration and residual depth. Obtained results for nanocomposites were compared to the obtained results for base ZA-27 alloy. Scratch test results and SEM revealed existence of structural irregularities such as porosity (trapped gas bubbles in material structure) and agglomerated nanoparticles. Existence of structural irregularities mainly diminishes positive effects that are expected from addition of hard nanoparticles.Publishe