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This study aims to investigate the potential for biodiesel production from oilseed crops in Serbia, using a novel assessment method. The method involves calculating the arable land area that can be utilized for raw material production for the biodiesel industry. The available land for the production of biodiesel feedstocks is determined by subtracting the land required to meet the food needs of the domestic population and livestock from the maximum oilseed production area, which is defined as 20% of the total arable land area in Serbia. The findings reveal that approximately 353,000 hectares of land are available for producing raw materials for biodiesel production without compromising the domestic food supply. This land can provide enough raw materials to produce up to 324,000 tonnes of biodiesel annually, equivalent to 15.2% of the total domestic diesel fuel consumption for transportation in 2021.

This work examines pressurized accelerated oxidation by a RapidOxy tester as an alternative method for determination of biodiesel oxidation stability. Sunflower oil-based biodiesel was synthesized and treated with antioxidants: tert-butylhydroquinone (TBHQ) - a synthetic antioxidant known for its powerful protective effect, and a mixture of bio-based antioxidant compounds extracted from vinery waste, VWEeth. The antioxidant potency of TBHQ was evaluated at varying temperatures (110 - 140 °C) and concentrations (250 - 2,000 mg dm-3) by the RapidOxy method; assessment of selected results was performed by comparison with relevant data obtained by the standard Rancimat method. VWEeth was added in two high dosages to biodiesel (87,500 and 150,000 mg dm-3) and analyzed at 140°C by the RapidOxy method. Both antioxidants at all applied dosages showed beneficial effects on improving the oxidative stability of biodiesel, but not all of the achieved improvements reached the stability minimum identified by the EN14214 standard. The lowest addition of TBHQ seemed to have a similar effect as the tested dosages of VWEeth but these additions did not increase the induction period above the limit of 8 h; two-fold higher quantity of TBHQ was successful in this respect, increasing the initial oxidation stability by a factor of about 2, which was determined by both methods. The RapidOxy method proved to be a very fast method suitable for testing a large number of samples, which is particularly important for efficient testing of different types and doses of antioxidants.

This study evaluates six formulations in improving the oxidation stability of different fatty acid methyl esters (MEs). Two MEs differed in the unsaturation levels as they were synthesized from different feedstock: a blend of soybean and sunflower oils, and waste cooking oil; they did not fulfill the requirements of the EN 14214 standard concerning their oxidation stability (≈0.6 h) and some impurities. The third MEs (SoSuME-EN) were fully compliant with the standard. Five formulations were phenolic-based, containing single or mixed antioxidant compounds of different molecular structures; one was amine-based. Different dosages of the formulations were added to the ME samples (corresponding to the addition range 50–48300 ppm). The MEs stability expressed as induction periods, IP, determined by the Rancimat method, were used for the calculation of stabilization factors, SF, indicating the efficiency of the applied formulation. The formulation containing 2-(1,1-dimethylethyl)- 1,4-benzenediol was the most efficient concerning the lowest consumption rate and the highest SF achieved for the low quality ME. 2,2′-Methylene- -bis-(4-methyl-6-tert-butylphenol) was linked with higher antioxidant potency than the amine-based formulation and the phenolic compounds with two bulky tert-butyl groups. Among the 4 selected phenolic additives, butylated hydroxytoluene and 2,2′-methylene-bis-(4-methyl-6-tert-butylphenol) had similar efficiency in SoSuME-EN (at ≈500 ppm they produced SF ≈ 2), while it took twice of this amount for mixed butylphenols to achieve the same effect.

The critical role of energy in contemporary life and the environmental challenges associated with its production imply the need for research and exploration of its novel resources. The present review paper emphasizes the continuous exploitation of non-renewable energy sources, suggesting the transition toward renewable energy sources, termed 'green energy', as a crucial step for sustainable development. The research methodology involves a comprehensive review of articles, statistical data analysis, and examination of databases. The main focus is biomass, a valuable resource for bioenergy and biopesticide production, highlighting not only its traditional diverse sources, such as agricultural waste and industrial residues, but also non-edible invasive alien plant species. This study explores the utilization of invasive alien species in circular economy practices, considering their role in bioenergy and biopesticide production. The potential conflict between bioproduct acquisition and food sector competition is discussed, along with the need for a shift in approaching non-edible biomass sources. The paper emphasizes the untapped potential of under-explored biomass resources and the necessity for policy alignment and public awareness. Species with a significant potential for these sustainable strategies include Acer negundo L., Ailanthus altisima (Mill.) Swingle., Amorpha fruticosa L., Elaengus angustifolia L., Falopia japonica (Houtt.) Ronse Decr., Hibiscus syriacus L., Koelreuteria paniculata Laxm., Paulownia tomentosa Siebold and Zucc., Partenocissus quenquefolia (L.) Planch., Rhus typhina L., Robinia pseudoacacia L. and Thuja orientalis L. In conclusion, the paper highlights the intertwined relationship between energy, environmental sustainability, and circular economy principles, providing insights into Serbia's efforts and potential in adopting nature-based solutions for bioenergy and biopesticides acquisition. [ABSTRACT FROM AUTHOR]

Paper presented is focused on the operating measurements of a tractor wet disc brake system. Operating measurements were evaluated after tractor’s operation at 500 Mth on the 3rd, 4th and 5th gear. Reference fluid and ecological fluid were tested during operation. In addition, work results include the evaluation of the fluid samples taken during the operational tests to monitor the tractor braking performance with wet disc brakes. Fluid samples were also tested in order to determine the changes in their physico-chemical properties. Chemical analysis was performed for both oil samples by means of X-ray fluorescence analysis according to the DIN 51829 and DIN 51399-2. Observed physical properties of the tested oils – density, viscosity, acid number, water content – were within the appropriate ranges after the end of test. Further analysis was focused on an amount of abrasive metals, contaminants, additives, and other important elements. On the basis of analyses conducted, it can be concluded that majority of elements preserved their original level showed at the 0 reference hour sample. In terms of the abrasion metals, an increase in their presence was not found. Furthermore, analysis of the physical properties of tested fluids did not prove their negative impact on the tractor wet disc brake system. Results of the operating measurements suggest that neither the applied conference fluid nor the ecological fluid showed negative effect on the minimum braking value. The minimum braking deceleration was implemented in accordance with the Law no. 106/2018.

Dabigatran is a novel oral anticoagulant preferred due to its ease of use, favorable pharmacokinetics, decreased potential for drug-drug interactions, and the lack of monitoring requirements. With the growing use of dabigatran, it is important to highlight that dabigatran increases the risk of hemorrhage after some procedures. Therefore, when dabigatran is used before the elective or urgent procedures, it is necessary to compare the thromboembolic event risk with the relative risk of bleeding. Before the approval of a reversal agent, the lack of specific antidotes had been the major limitation against the widespread utilization of dabigatran. In October 2015, idarucizumab, a humanized monoclonal antigen-binding antibody fragment capable of reversing the anticoagulant activity of dabigatran, has been introduced into the market to be used in lifethreatening bleeding or urgent surgery. In this manuscript, the preoperative management of dabigatran and the initial experience of using idarucizumab in a patient with nonvalvular atrial fibrillation were described. We propose that the option of dabigatran reversal needs to be considered in patients with nonvalvular atrial fibrillation. However, additional research is needed to define optimal perioperative management of dabigatran and other novel oral anticoagulants, especially in high bleeding risk patients, and to determine whether pre-procedure coagulation testing should be performed.

Influence of the process parameters for the industrially relevant reaction of free fatty acid (FFA) with glycerol is investigated. Furthermore, several drying techniques are investigated and a novel method is suggested that can provide more realistic experimental conditions. Silica as an absorbent is found to be a more suitable method for water removal than distillation or carrier gas. Using response surface methodology, important parameters are identified and optimal conditions found. Empirical correlation is developed to account for the most important parameters. Both oil:glycerol ratio and temperature have optimal values for which the highest conversion can be achieved. Interestingly, the highest conversion can be obtained at 220°C; above this temperature the conversion decreases. It is found that the influence of oil:glycerol ratio also exhibits anomalous behavior, where conversion is constant and decreases above a certain value. At optimal conditions, the FFA is reduced to 1.6% from the initial 8.6%.

The influence of the physicochemical properties of a series of CaO catalysts activated at different temperatures on the biodiesel production was investigated. These catalysts show dissimilar yields in the transesterification of triglycerides with methanol. We have found significant relationships between structural properties (the type of the pore system, the typical CaO crystal phase and the sizes of crystallites (up to 25 nm), the minimal weight percentage of CaO phase, the total surface basicity and potential existence of two types of basic active sites) of CaO prepared and activated by means of thermal treatment at highest temperature and catalytic efficiency. Benefits of this catalyst are short contact time, standard operating temperature and atmospheric conditions, relatively low molar ratios and small catalyst loading. These all together resulted in a very high biodiesel yield of high purity. The properties of different biodiesel (obtained with the use of the prepared CaO catalyst) blends with different diesel and biodiesel ratios indicate that the higher the fraction of biodiesel fuel the better the achieved fuel properties according to the EU standards. A significant reduction of CO2 and CO emissions and only a negligible NOx increase occurred when blends with an increased biodiesel portion was used. The use of biodiesel derived blends, and the eventual complete replacement of fossil fuels with biodiesel as a renewable, alternative fuel for diesel engines, would greatly contribute to the reduction of greenhouse gases emissions. [Projekat Ministarstva nauke Republike Srbije, br. ON 172061 i TR 34008]

This paper presents a complete characterization of rapeseed oil, of Banaćanka variety, as well as the potential use of oil generated after filtering, in order to obtain biodiesel. Researches are based on the fact that Banaćanka is the oldest domestic rapeseed variety, the so-called double zero "00" (low in erucic acid, below 5%, and glucosinolates below than 30 mmol g-1), suitable for use in the region, since it is low temperatures tolerant, posseses high genetic potential for seed yield of about 5.2 t/ha, and high oil content of around 45%. Transesterification was carried out in batch reactor Parr 4520, with KOH as a catalyst. Cold pressed oil without prior treatment was used as feedstock for transesterificataion. The paper analyses the effects of temperature, reaction duration, catalyst amount and rate of agitation on the synthesis of biodiesel at constant pressure and molar methanol/oil ratio.[Projekat Ministarstva nauke Republike Srbije, br. TR-31046: Improvement of the quality of tractors and mobile systems with the aim of increasing competitiveness and preserving soil and environment]

The main purpose of this paper is to evaluate patterns among export diversification along with the economic development in the CEFTA 2006 region. The pattern, which is evaluated here, is a hump-shaped pattern, which states that diversification and re-concentration of export and has a „U“shape relationship with GDP per capita. Hump-shaped pattern suggests that countries add products to their export basket during the early stages of economic development, while high-income countries remove goods for which they have lost a comparative advantage. Consequently, countries are slower to specialize in exporting products in which they have a comparative advantage, which leads to a humpbacked appearance. It may be concluded that one of the driving forces for export diversification is certainly GDP per capita, where diversification and later re-concentration take place mainly through extensive margins. On the other hand, intensive margins do follow the same pattern as extensive margins. Furthermore, extensive margins represent export diversification to new markets, where intensive margins present export diversification of new products. Export diversification is closely related to commodity export dependence. The country is considered to be commodity export-dependent when more than 60 percent of its total merchandise exports are composed of commodities. In these terms, countries with lower export diversification usually suffer from slow development, non-diversified economic structures, macroeconomic instability, economic volatility, "Dutch disease", political instability, poor political and economic governance, etc. Empirical studies reveal that export diversification can promote economic growth and reduce economic volatility. Greater diversification of exports contributes to greater resilience to exogenous shocks as well as stronger long-term growth and development of the country. With greater export diversification of products and greater geographical diversification (extensive and intensive margins), the risk of exogenous negative impacts is reduced. To test the U-shaped hypothesis, we used Herfindahl–Hirschman index as a measurement for export diversification. In this paper, we used secondary data from the UNCTADstat database for export. Data for GDP per capita were gathered from the World Bank database. After calculating the mentioned index for export diversification/specialization for CEFTA 2006 region, we presented a link between mentioned indexes with GDP per capita. Our results reject the null hypothesis, which states that there is a U-shaped relationship between export diversification and GDP per capita in the CEFTA 2006 region. In the CEFTA 2006 region, countries do not follow the path of higher diversified export at lower GDP per capita, and later specialization in exporting products with an increase of GDP per capita, in a product that which they have comparative advantages. The examined period in this paper was from 2007 to 2020 (13 years). Future studies could examine what the main drivers for export diversification are in CEFTA 2006 region. Also, it would be interesting to examine which margins, extensive or intensive, are the main drivers for diversification and later re-concertation at an individual level of each country. [ABSTRACT FROM AUTHOR]