Technical efficiency analysis of oil companies in the Republic of Serbia

The subject of this paper is the assessment of the efficiency of oil companies operating in the Republic of Serbia. This paper presents the possibilities of applying non-parametric methods in researching the efficiency of oil companies in the Serbian market. In addition to the standard variables for measuring technical efficiency, the market share should be taken into account, because the oil market is an example of an imperfect competition market. By applying the quantitative-analytical method (Data Envelopment Analysis), obtained results show the development of the efficiency of oil companies in the relevant market, and indicate that the efficiency of oil companies improved during the analysed period. However, the results also indicate that there is still a problem of misallocation of resources. The reasons for this outcome are interesting and debatable for this industrial area

The role and importance of logistics in diversifying the risk of import dependence of the Republic of Serbia on oil and petroleum products

After the outbreak of the conflict in Ukraine in early 2022, a series of events followed that influenced the change of the international order and the entire geopolitical scene. There has been an economic regrouping and redefinition of interstate relations, and in some countries there has been a deterioration or breakin of relations, and in others there has been a deepening and strengthening of cooperation. Bearing in mind that some are leaders in the export of oil and petroleum products, and some are the biggest importers of the same, the international market of these energy products has changed. This is also indicated by the prices of oil and petroleum products on the international market, as a clear indicator of the changed conditions on the supply and demand side. Securitization of the supply of oil and petroleum products, as well as the prevention of negative-inflationary consequences of price shocks of these energies to internal economic flows implies a strategic approach in supply chain management and logistics. Successfully coping with such challenges implies a multifaceted and synchronized approach by the state or competent entities. First of all, states or entities representing them may sign long-term arrangements on the supply of oil and petroleum products, which cannot be considered an absolute solution in the long term, given the general geopolitical circumstances, but also the practice in bilateral cooperation. Then, states can start the production of oil and petroleum products from conventional-commercial sources, if there are financial and objective-technical conditions for this. The third, and no less important approach, is to create conditions for the exploitation of renewable energy sources, which can help users meet their energy needs. This would reduce the demand for other energy sources, so if the country is imported dependent on fossil fuels, the need for imports would also reduce the import dependence of the country. All three approaches are in the function of diversifying the risk of fuel imports, and if this sphere is not given attention, all economic flows of any oil and petroleum products importing country can be drastically disrupted. There are many examples of mistakes made in the procurement strategy of oil and petroleum products, i.e. gas in the foreground. This paper covers the most interesting examples from practice in order to project the risks and damages that imported countries dependent on oil and petroleum products have faced due to the latest developments in Ukraine. In this paper, the authors also point out the economic aspects that reflect possible directions of diversification of risks from the import of oil and petroleum products, as well as the connection of diversification of import risk with supply and logistics in the Republic of Serbia

Significance of fiscal policy for economic development and agriculture

With the latest global economic crisis (2007-2009) the importance of fiscal policy as a part of economic policy is growing. Its significance extends from the experience of the Great Depression of the 1930s. In this paper, with the help of the ARIMA model, the influence of fiscal policy instruments on macroeconomic fiscal indicators and some selected indicators of economic development in the context of countries of Southeast Europe have been explored. Friedman's test has shown that the countries have not yet recovered from the global economic crisis. The results shows that fiscal policy can act on the individual's standard of living, but only responsible implementation will have the same effect on public finances and the overall sustainable development of a country. Also, fiscal policy is an important measure of agricultural policy and is increasingly being used as a directional development factor.Publishe

A triethanolamine:choline chloride deep eutectic solvent as a cosolvent in the ethanolysis of Brassica nigra L. seed oil

Black mustard (Brassica nigra L.) seeds oil (BMSO), characterized by a high content of erucic acid (C22:1), belongs to inedible oils. Since BMSO has a high percentage of monounsaturated and branched fatty acids, it is a suitable raw material for biodiesel production. Also, green cosolvents, like deep eutectic solvents (DESs), can improve the biodiesel production process. This study reports the influence of the triethanolamine:choline chloride DES (2:1 mol/mol) on the BMSO ethanolysis over calcined CaO as a catalyst, under the following reaction conditions: temperature of 50, 60, and 70 ºC, ethanol-to-oil molar ratio of 12:1, as well as TEOA:ChCl DES and calcined CaO content of 20% and 10%, respectively. At 70 ºC, the ChCl:TEOA DES provided a high content of fatty acid ethyl esters (FAEE) (98.46±0.7%) after 1.5 min, compared to the control reaction (without the presence of DES), where the maximum FAEE content (98.05±0.6%) was achieved within 4 h. BMSO ethanolysis was described by the kinetic model of the pseudo-first order and the model of variable reaction order concerning TAG and the autocatalytic behavior of the ethanolysis reaction. Both kinetic models, with great accuracy, fitted the experimental data. As a result, physicochemical properties of the obtained biodiesel were within the limit values prescribed by the quality standard EN 14214. Also, the reusability of calcined CaO was proven even in four cycles with the FAEE content of over 90%

REVERSE ENGINEERING OF THE MITKOVIC TYPE INTERNAL FIXATOR FOR LATERAL TIBIAL PLATEAU

In orthopaedic surgery it is very important to use proper fixation techniques in the treatment of various medical conditions, i.e. bone fractures or other traumas. If an internal fixation method, such as plating, is required, it is possible to use Dynamic Compression Plates (DCP) or Locking Compression Plates (LCP) and their variants. For DCP implants it is important to match the patient's bone shape with the most possible accuracy, so that the most frequent implant bending is applied in the surgery. For LCP implants it is not so important to match the patient’s bone shape, but additional locking screw holes are required. To improve the geometrical accuracy and anatomical correctness of the shape of DCP and to improve the LCP geometric definition, new geometrical modelling methods for the Mitkovic type internal fixator for Lateral Tibia Plateau are developed and presented in this research. The presented results are quite promising; it can be concluded that these methods can be applied to the creation of geometrical models of internal fixator customized for the given patient or optimized for a group of patients with required geometrical accuracy and morphological correctness

Noise at public event

Recent years the noise is one of the leading pollutants in working and living environment. Although in some cases the noise levels do not exceed proposed levels, people often have the opposite impression. While for the most activities noise regulation exists, for public events this is not the case. There are certain guidelines, however established levels differ from country to country. In order to determine the noise level during public events the equivalent level of noise was measured at one public event on which approximately 50,000 people was present. The results show significantly high levels of noise, especially during rock concert and firework, when certain protective measures should be implemented

Uranium contents from bomb craters

Depleted uranium (DU) is a by-product of uranium enrichment process and its use is very dangerous and harmful. We measured uranium concentration in the surface soil (0-5 cm depth) from bomb craters caused by cruise missiles in which DU might have been used as counterweights during NATO attack. Total uranium concentration and isotopic ratio were determined using y-spectrometry and inductively coupled plasma method. Obtained results were in the range 1.7 - 22 mg/kg dry soil that was comparable to the uranium values found in off-side locations of Serbian soils

Tržišna pozicija i efikasnost naftnih kompanija u uslovima oligopola

Oil industry is strategically important part of the energy system of each country. Therefore, each country must define a vision for development of oil industry. This is especially important because the interest for oil and oil products has become an immanent part of the economic and political relations in the world. During the time, the oil is becoming more valuable in the world and oil companies are aware of that, so there are seeking to maximize their profits by integrations between themselves on certain markets. The market conditions and competitiveness between companies in practice are determined by concetration on the observed market. Concetration of particular relevant market expresses via numerous of indicators of concetration and in this doctoral dissertation special attention is paid to measuring the concetration of supply. Therefore we point out that every market has a certain amount of competition between market participants, through competitive relations permeates and their market power. Today, the Serbian economy is on the way to the European Union. Towards this end, it seeks to strengthen its economy in order to better integrate into the global mainstream. Low standard of living, combined with the negative effects of the global economic crisis affecting further decline in economic growth dynamics. Given that the domestic market of oil and oil products since 2011 consists of several oil companies, it would be desirable that their business policies in the future contribute to economic growth. On the other hand, economic growth impacts on increase revenue of oil companies. Therefore, there is a need to investigate this correlation which is the subject of this dissertation. In this dissertation, special attention was given to the possibility of increasing the quality of competitive relations and the supply of oil companies in the domestic market. Based on quantitative and analytical approach, the results indicate the potential improvement of price/quality ratio on the market of oil and oil derivatives in the Republic of Serbia, and hence improvement the efficiency of performances of oil companies

MERENJE KONCENTRACIJE PONUDE NAFTE I NAFTNIH DERIVATA U REPUBLICI SRBIJI HERFINDAL-HIRŠMANOVIM INDEKSOM

One aspect of the intensity of competition analysis of the national oil market is the measurement of the concentration of supply, to which this paper is dedicated. That is why it is not surprising that there are different interpretations of these economic categories. The analysis of these phenomena dates back to the emergence of production relations and production forces. The relaxation of regulatory measures on the national oil market has opened the space for building quality competitive relationships between the participants. Market opportunities, conditions and competition in practice are determined by concentration in the certain observed market. Competitive relations between market participants change over time. Those changes impact on concentration level of certain and well defined market, in this case the oil market of the Republic of Serbia. As the competition changes, the concentration level changes as well. This is the reason why this paper is focused on concentration level measurement and analysis. In  measuring and expressing the concentration level of the certain market, many concentration indicators could be applied. Our choice was Herfindahl-Hirschman Index. Jedan od aspekata analize intenziteta konkurencije na određenom tržištu jeste merenje koncentracije ponude, čemu je ovaj rad i posvećen. Zato i ne čudi činjenica da postoje različita tumačenja ovih ekonomskih kategorija. Analiza ovih fenomena datira još od nastanka proizvodnih odnosa i proizvodnih snaga. Liberalizacija domaćeg tržišta nafte i naftnih derivata otvorila je prostor za izgradnju kvalitetnih konkurentskih odnosa. Tržišni uslovi i konkurencija u praksi su određeni nivoom koncentracije na posmatranom tržištu. Konkurentski odnosi između tržišnih učesnika se menjaju tokom vremena. Te promene utiču na nivo koncentracije određenih i jasno definisanih tržišta, u ovom slučaju tržište nafte Republike Srbije. Kako se nivo konkurencije menja, nivo koncentracije se takođe menja. Iz tog razloga je ovaj rad posvećen merenju i analizi nivoa koncentracije. Postoji niz pokazatelja koncentracije koji se mogu primeniti u cilju merenja i prikaza nivoa koncentracije na određenom tržištu. Naš izbor je Herfindal-Hiršmanov indek

Challenges of oil and gas procurement due to the oil crisis in Ukraine

It is generally known that without oil and gas, no economic system can function and that these energy sources are considered the "bloodstream" of any economy, whether it is a developed economy, a developing economy, or an underdeveloped economy. Oil reserves follow gas reserves, and the distribution of reserves of these energy sources in the world is not uniform. On the one hand, we have countries with surplus reserves of these energy sources, so they are also exporters of oil and gas, and on the other hand, countries that are in deficit or do not have them, and have to import them. Some countries, as well as some members of the European Union, have managed to develop more or less balanced energy consumption in the long run through their energy policies, while some have not. Due to the scarcity of fossil fuel reserves and the complexity of their economies, many countries have not been successful in this, and are still qualified as dependent on fossil fuel imports. In addition to improving energy efficiency and savings, in line with frequent geopolitical unrest and tensions caused by energy procurement, many import-dependent on energy countries sooner or later decide to diversify their supply, but also to replace fossil fuels with renewable energy sources